FLUOROPHORE-BASED KINASE SENSORS

RELATED APPLICATION

This application claims the benefit of prioirty to U.S. Provisional Patent Application serial number 62/331,903, filed May 4, 2016.

BACKGROUND OF THE INVENTION

Protein kinases are involved in all aspects of regulation within cells. A protein kinase catalyzes the transfer of a phosphoryl group from adenosine triphosphate (ATP) to a serine, threonine or tyrosine residue in a peptide or protein sequence. Each kinase is specific for the amino acids surrounding the residue to be phosphorylated. The traditional method for assaying kinase activity is discontinuous and requires ³ P-iabelled ATP, which requires special handling.

Many companies market specialized fluorescent kinase assay systems, ail of which are discontinuous, requiring sampling of the reaction mixture or additional handling steps or use of antibodies to identify the product of the reaction or create the fluorescent signal (e.g., Promega, Thermo Fisher, Calbiochem, Cell Signaling Technology, Molecular

Devices/Danaher, DiscoveRx, EMD-MiUipore, PerkinElraer). A continuous fluorescent assay that can be performed in real time is of great utility. Currently, few examples of sensors capable of such, assays exist. Approaches include: environment-sensitive fiuorophores near the phosphorylation site (Wright, D. E. et al. Proc. Natl. Acad. Sci. USA 1981 , 78, 6048- 6050, cllroy, B. K. et al. Anal. Biochem. 1991, 195, 148-152; Higashi, H. et al. FEBS Lett 1997, 414, 55-60; Post, P. L. et al. J. Biol. Che . 1994, 269, 12880-12887), FRET pairs flanking a sequence which undergoes a conformational change upon phosphorylation (Nagai, Y. et al. Nat. Biotech. 2000, 18, 313-316; Ohuchi, Y. et al. Analyst 2000, 125, 1905-1907; Zhang, J. et al. Proc. Nal Acad. Sci. USA 2001, 98, 14997-15002; Ting, A. Y. et al. Proc. Natl. Acad. Sci. USA 2001, 98, 15003-15008; Hofmann, R. M. et al. Bioorg. Med. Chem. Lett. 2001, 11, 3091-3094; Kurokawa, K. at el. J. Biol. Chem. 2001, 276, 31305-31310; Sato, M. et al. Nat. Biotech.2002, 20, 287-294, Violin, J. D et al. J. Ceil Biol. 2003, 161, 899-909), or Ca ²⁺ chelation between the phosphate and internal chelator causing disruption of PET- quenching (Chen, C.-A.; et al. J. Am. Chem. Soc. 2002, 124, 3840-3841). A majority of these sensors have very modest fluorescence increases or sometimes decreases, with the notable exception of 1.5-2.5-fold increases in the probes reported by Lawrence and coworkers (Chen 2002, supra, Yeh, R.-FI; et al. J. Biol. Chem. 2002, 277, 1 1527-1 1532; Wang, Q.; et al. J. Am. Chem. Soc.2006, 128, 1808-1809). However, these types of probes, with fiuorophores adjacent to the phosphorylated residue or using very large fluorophores, may interfere with their recognition by and reactivity with certain kinases.

SUMMARY OF THE INVENTION

The present invention provides metal-binding analytical reagents that exhibit chelation-enhanced fluorescence (CHEF) upon binding to Mg ²⁺ . The present invention further provides methods of using the reagents for detecting the presence of or quantifying the activity of individual kinases or groups of kinases in a sample. The corresponding phosphopeptides can also be used as substrates to monitor the activity of protein phosphatases, where removal of the phosphate group on the targeted serine, threonine or tyrosine residue will result in a reduction in fluorescence.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 2 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 3 is a graph of receptor tyrosine kinase activity dramatic improvement in selectivity after 1 round of optimization.

FIG. 4 is a graph of screen of kinase activity with Omnia Y12 substrate.

FIG. 5 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 6 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 7 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 8 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 9 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 10 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 11 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 12 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 13 is a graph of receptor tyrosine kinase (RTK) activity.

FIG. 14 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 15 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 16 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 17 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 18 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 19 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 20 is a graph of soluble tyrosine kinase (Soluble-TK) activity. FIG. 21 is a graph of soluble tyrosine kinase (Soluble-TK) activity.

FIG. 22 is a graph of tyrosine kinase activity for AQT0001 (Ac-EEEEYI-C(Sx)-IV-

NHz).

FIG. 23 is a chart of receptor tyrosine kinase (RTK) activity for AQT0001.

FIG. 24 is a chart of soluble tyrosine kinase (Soluble-TK) activity for AQT0001.

FIG. 25 is a graph of tyrosine kinase activity for AQT0032 (Ac-E-C(Sx)- I YAAPF AKKK- H2) .

FIG. 26 is a chart of receptor tyrosine kinase (RTK) activity for AQT0032.

FIG. 27 is a chart of soluble tyrosine kinase (Soluble-TK) activity for AQT0032.

FIG. 28 is a graph of AGC Serine/Threonine kinase activity.

FIG. 29 is a graph of CMGC Serine/Threonine kinase activity.

FIG. 30 is a graph of CMGC Serine/Threonine kinase activity.

FIG. 31 is a graph of CMGC Serine/Threonine kinase activity.

FIG. 32 is a chart of AGC Serine/Threonine kinase activity for AQT0074 (Ac- ARKRERAYSF-C(Sx)-HHA-amide).

FIG. 33 is a chart of AKTl, 2 & 3 Serine/Threonine Kinase Activity Measured Using AQT's Panel of Substrates.

FIG. 34 is a chart of EGFR Substrate Optimization (Mutant EGFRs).

FIG. 35 is a chart of Broad AGC Serine/Threonine Kinase Activity Measured Using PKA-S4 Including SGK1/2/3 and PRKACA/B.

FIG. 36 is a chart of Substrates for SGK1, SGK2, SGK3 Identified from AQT's CSx

Panel.

FIG. 37 is a chart FGFR Substrate Screening with Wild-type & Mutant FGFRs

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides metal-binding analytical reagents that are useful for detecting and quantifying kinase activities. The metal binding compounds of the invention are peptidyl sensors which include a metal-binding peptide of the present invention and at least one kinase recognition sequence comprising an amino acid (e.g., serine, threonine, or tyrosine) that can be phosphorylated in the presence of a kinase.

The present invention provides superior Sox-based substrates by allowing for flanking sequence recognition determinants on either side of the Sox moiety/phosphorylation site. This approach is used to generate both highly-generic substrates (for use with a range of purified kinases) or highly-selective substrates (for use with unfractionated cell or tissue iysates).

U.S. Patent No. 7,262,282 (incorporated by reference) discloses linear Sox peptide sensors that include a metal binding amino acid residue and a kinase recognition sequence with a hydroxy amino acid that can be phosphoiyiated in the presence of a kinase. The metal- binding amino acid residue is located on either side (N-terminally or C-terminally) of the hydroxyamino acid and is preferably separated from that recognition sequence by an amino acid or peptide that is capable of assuming a β-tum conformation ("a β-turn sequence"). In some cases, the β-turn sequence is separated from the hydroxyamino acid by one or more amino acids.

U.S. Patent No. 7,964,729 (incorporated by reference) discloses metal binding compounds that exhibit chelati on-enhanced fluorescence (CHEF) upon binding to Mg2+. This patent further provides peptidyl sensors which include a metal-binding component and at least one kinase recognition sequence with a hydroxyamino acid that can be

phosphoiyiated by the kinase. The peptide sensors may also be used to detect sulfation of hydroxyamino acids.

Definitions

The term "hydroxyl" or "hydroxy" means the— OH group.

The term "amino" means the— NR'R" group, where R' and R" are each

independently hydrogen or alkyl.

The term "halogen" means a chlorine, bromine, iodine, or fluorine atom.

The term "alkyl" means a hydrocarbon group that may be linear, cyclic, or branched or a combination thereof having the number of carbon atoms designated (i.e., Ci-s means one to eight carbon atoms). Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, cyc!ohexy!, cyciopentyl, (cyclohexyl)methyl, cyclopropylmethyl, bicyclo[2,2. i]heptane, bicyclo[2.2.2]octane, etc. Alkyl groups can be substituted or unsubstituted, unless otherwise indicated. Examples of substituted alkyl groups include haloaikyi, thioalkyl, aminoalkyl, and the like.

The term "substituent" means an atom or a group that replaces another atom or group in a molecule.

The term "N-terminal protecting group" refers to a group that prevents undesirable reaction of the amino functional group during subsequent transformations, and includes, but is not limited to, benzyl, substituted benzyl, benzyloxycarbonyl (Cbz), tert-butoxycarbonyl (Boc), 9-fluorenylmethoxycarbonyl (Fmoc), trityl, N-veratyloxycarbonyl (N-Voc), N- allyloxycarbonyl (N-Alloc) and N-pentenoyl (N-Pent).

The term "C-terminal protecting group" refers to a group that prevents undesirable reaction of the carboxyl functional group and includes, but is not limited to, Ci-12 alkyl (e.g., tert-butyi) and Ci-12 haloalkyl.

The term "chelation-enhanced fluorescence (CHEF)" means fluorescence

enhancement of a compound as a result of metal ion binding (chelation) to that compound.

The term "capping group" means a chemical group connected to the N- or C -terminus of a peptide to prevent the peptide from degrading or being otherwise inappropriately modified.

Sox

C(Sx) represents an amino acid of formula (I), ( II) or ( I f f ;· as described below. C-Sox is a species of C(Sx).

GENETIC CODE

Alanine (Ala, A) GCA, GCC, GCG, GCT

Arginine (Arg, R) AGA, ACG, CGA, CGC, CGG, CGT

Asparagine (Asn, N) AAC, AAT

Aspartic acid (Asp, D) GAC, GAT

Cysteine (Cys, C) TGC, TGT

Glutamic acid (Glu, E) GAA, GAG

Glutamine (Gin, Q) CAA, CAG

Glycine (Gly, G) GGA, GGC, GGG, GGT

Histidine (His, H) CAC, CAT

Isoleucine (He, I) ATA, ATC, ATT

Leucine (Leu, L) CTA, CTC, CTG, CTT, TTA, TTG Lysine (Lys, K) AAA, AAG

Methionine (Met, M) ATG

Phenylalanine (Phe, Έ) TTC, TTT

Proline (Pro, P) CCA, CCC, CCG, CCT

Serine (Ser, S) AGC, AGT, TCA, TCC, TCG, TCT

Threonine (Thr, T) ACA, ACC, ACG, ACT

Tryptophan (Trp, W) TGG

Tyrosine (Tyr, Y) TAC, TAT

Valine (Val, V) GTA, GTC, GTG, GTT

Termination signal (end) TAA, TAG, TGA

S* represents S or (phospho)S; and

T* represents T or (phospho)T; and

Y* represents Y or (phospho)Y.

Compounds

The compounds of the present invention contain a metal binding moiety, referred to as the metal binding peptide, which comprises a metal-binding amino acid residue. In some embodiments, the compounds of the invention are oligopeptide comprising a fluorophore; and a (phospho)S, a (phospho)T, or a (phospho)Y residue at the +2 or -2 position relative to the fluorophore. In some embodiments, the position may be the +3 or -3 position. In some embodiments, a (phospho)S, a (phospho)T, or a (phospho)Y residue may be used at a certain position to facilitate kinase recognition and phosphorylation of the target amino acid (i.e., ph opho-primed sub strates) .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEEEY*I-C(Sx)-IV-Z _; X-EEEY*I-C(Sx)-IV-Z, X- EEY*I-C(Sx)-IV-Z, X-EY*I-C(Sx)-IV-Z, X-Y*I-C(Sx)-IV-Z, X-EEEEY*I-C(Sx)-I-Z, X- EEEY*I-C(Sx)-I-Z, X-EEEEY*I-C(Sx)-Z, X-EEY*I-C(Sx)-I-Z, X-EY*I-C(Sx)-I-Z, X-Y*I- C(Sx)-I-Z, X-EEEY*I-C(Sx)-Z, X-EEY*I-C(Sx)-Z, X-EY*I-C(Sx)-Z, and X-Y*I-C(Sx)-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEEIY*F-C(Sx)-dP-(2-Nal)-G-Z, X-EEEIY*F- C(Sx)-Z, X-EEIY*F-C(Sx)-Z, X-EIY*F-C(Sx)-Z, X-IY*F-C(Sx)-Z, X-Y*F-C(Sx)-Z, X- EEEEY*I-C(Sx)-dP-(2-Nal)-G-Z, X-EEEEY*I-C(Sx)-VG-Z, X-DPQEY*I-C(Sx)-LP-Z, X- EDEDY*E-C(Sx)-VG-Z, X-EAEAIY*A-C(Sx)-dP-(2-Nal)-G-Z, X-EAEAIY*A-C(Sx)-PF- Z, X-EAEAIY*A-C(Sx)-P-Z, X-EAEAIY*A-C(Sx)-Z, X-EEPIY*I-C(Sx)-VP-Z, X- DEQIY*W-C(Sx)-IA-Z, X-KKGEAIY*A-C(Sx)-dP-(2-Nal)-G-Z, X-KKGEAIY*A-C(Sx)- PFAKKK-Z, X-KKGE-C(Sx)-IY*AAPFAKKK-Z, X-E-C(Sx)-IY*AAPF-Z, X-E-C(Sx)- IY*A-Z, X-E-C(Sx)-IY*-Z, X-C(Sx)-IY*-Z, X-KKGEAIY*A-C(Sx)-PF-Z, X-PE-C(Sx)- IY*ATPG-Z, and X-PEVIY*A-C(Sx)-PG-Z; X-GAEEPIY*I-C(Sx)-VPAKKKG-Z wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KKKKEEIY*F-C(Sx)- Z, X-AEE-C(Sx)- IY*GELEA-Z, X-EE-C(Sx)-IY*GIFG-Z, X-C(Sx)-IY*ETDYYRKG-Z, X-EEEEY*I-C(Sx)- DYYRKG-Z, X-ELEDDY*E-C(Sx)-Z, X-EE-C(Sx)-DY*VEFKKK-Z, X-EEEEY*I-C(Sx)- FKKK-Z, X-RRRRRRSETDDY*A-C(Sx)-IIDEEDT-Z, X-RAFIY*A-C(Sx)-IP-Z, X- DDEPIY*A-C(Sx)-LADIT-Z, X-C(Sx)-IY*GVIE-Z, X-EEE-C(Sx)-AY*GWLDF-Z, X- C(Sx)-EY*VNIEFG-Z, X-GEEPLY*W-C(Sx)-FPAKKK-Z, X-ESSDDY*V-C(Sx)-Z, and X- RAHEEIY*H-C(Sx)-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-VYS-C(Sx)-DY*[pY]RLF PS-Z, X-DE-C(Sx)- D Y* [p Y]EIP-Z, X-PD-C(Sx)-Q Y* [p Y] DF-Z, X-GAGEE-C(Sx)-D Y* [pY] [pYJIWAGKK- Z, and X-GEE-C(Sx)-DY*[pY][pY]IWA-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEEEY*F-C(Sx)-LV-Z, X-GADPQEY*I-C(Sx)- LPAKKKG-Z, X-GAEDEDY*E-C(Sx)-VGAKKKG-Z, X-GAEEPIY*I-C(Sx)-VPAKKKG- Z, X-GADEQIY*W-C(Sx)-IAAKKKG-Z, X-GAPE-C(Sx)-IY*ATPGAKKK-Z, and X- GAPEVIY* A-C(Sx)-PGAKKK-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-GAEE-C(Sx)-IY*GIFGAKKKG-Z, X-C(Sx)- DY*VEFKKK-Z, X-RRRRRRSETDDY*A-C(Sx)-IID-Z, X-RRRRRRSET-C(Sx)- DY*AEIID-Z, and X-GARAFIY*A-C(Sx)-IPAKKKG-Z; wherein X is H or acetyl; and Z is

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-VYS-C(Sx)-DY*YRLF PS-Z, X-A-C(Sx)- EY*LIPQQ-Z, X-DE-C(Sx)-DY*YEIP-Z, X-PD-C(Sx)-QY*YNDF-Z, X-EGDEDGIY*V- C(Sx)-FEPKT-Z, X-EGDED-C(Sx)-IY*VNFEPKT-Z, X-PAAENPEY*L-C(Sx)-QQDPV-Z, X-PAAEN-C(Sx)-EY*LWQQDPV-Z, X-IYS-C(Sx)-DY*YR-Z, X-KGGEE-C(Sx)- EY*FELVKK-Z, X-KGGEEEEY*F-C(Sx)-LVKK-Z, X-KVEKIGE-C(Sx)-TY*GVVYK-Z, X-RRLIED EY*T-C(Sx)-RG-Z, X-RRLIEDAEY*A-C(Sx)-RG-Z, X-EF-C(Sx)- IY*DFLPAKKK-Z, X-EFPIY*D-C(Sx)-LPAKKK-Z, X-GEE-C(Sx)-LY*WSFPAKKK-Z, X-GEEPLY*W-C(Sx)-FPAKKK-Z, X- E-C(Sx)-LY*WSFPA-Z, X-EPLY*W-C(Sx)-FPA-Z, and X-C(Sx)-IY*GSFK-Z, X-KKKKEEIY*F-C(Sx)-FG-Z, X-KKKKEEIY*F-C(Sx)-FG-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-ETSK-C(Sx)-IY*DFIEK-Z, and X-ETSKVIY*D- C(Sx)-IEK-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-ARKRERTY*SF-C(Sx)-HH-Z, X-VP-C(Sx)- LS*PGPF-Z, X-C(Sx)-LS*PGPF-Z, X-C(Sx)-RT*PGGRR-Z, and X-C(Sx)- GT * P S GE APNQ ALLR-Z ; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-VLTQMGSPSI-C(Sx)-SS*[pS]VS-Z, X- ESTSAPLS*P-C(Sx)-VTTSP-Z, X-GFLSRPLS*P-C(Sx)-FTTSP-Z, X-PSLLRPLS*P- C(Sx)-FFGAY-Z, X-STPSSPSS*P-C(Sx)-SSVAY-Z, X-SHGSAPLS*P-C(Sx)-APLTS-Z, X- SPFSVLSS*P-C(Sx)-SGHSN-Z, X-ALKLVRYPS*F-C(Sx)-IT-Z, X-ALKLSRYPS*F- C(Sx)-I-Z, X-RKKFGEREKT*K-C(Sx)-RIRL-Z, X-DYMR-C(Sx)-SS*RRRIRMAHQT-Z, X-DYMSAR-C(Sx)-SS*RRRIRHQT-Z, X-AHLQR-C(Sx)-LS*FRRR-Z, X-GRTGR-C(Sx)- NS*FRRR-Z, X-ALKLSR-C(Sx)-PS*FRRR-Z, X-RKRDR-C(Sx)-GT*FRRR-Z, and X- ARKRER-C(Sx)-YS*FRRR-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-HMRSAMS*V-C(Sx)-HLVK-Z, X- HMRSSMS*V-C(Sx)-HLVKRR-Z, X-HMRSSMS*V-C(Sx)-HLVK-Z, X-HMRSAMS*V- C(Sx)-HLV-Z, X-LRRAS*L-C(Sx)-Z, X-RRREEEEES*A-(cSx)-AA-Z, X- LS LYHQGKFLQT*F-C(Sx)-GSPLY-Z, X-QGKF-C(Sx)-QT*FSGSPLYRRR-Z, X- KKR RRLS*V-C(Sx)-Z, and X-AKRRRLAS*L-C(Sx)ASTSK-Z; wherein X is H or acetyl;

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-GRPRAAT*F-C(Sx)-EG-Z, X-GRP-MeArg- AFT*F-C(Sx)-EG-Z, X-GRP-MeArg-C(Sx)-FT*F-Sarc-EG-Z, X-RPRAAT*F-C(Sx)-Z, X- RPRAAT*F-C(Sx)-HHA-Z, X-FFKKIVTPRT*P-C(Sx)-P-Z, X-FFKNIVTPRT*P-C(Sx)- PSQGK-Z, and X-APRT*P-C(Sx)-GRR-Z; wherein X is H or acetyl; and Z is OH or H2. In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KKKVLTQMGSPSIR-C(Sx)-SS*VS-Z, X- KKKVLTQMGSPSI-C(Sx)-SS*[pS]VS-Z, X-SGRSRRKS*P-C(Sx)-PSPHP-Z, X-SGRSR- C(Sx)-KS*PRPSPHP-Z, X-SGRSR-C(Sx)-KS*VRRSPHP-Z, X-KKL RTLS*F-C(Sx)- EPG-Z, X-KKRPQRATS*N-C(Sx)-FAM-Z, X-RGRSRRDS*F-C(Sx)-VSPHY-Z, X- RKRSRRKS*F-C(Sx)-VLSSL-Z, X-AKRRRLSSLRASTSK-C(Sx)-ES*SQK-Z, X- AKRRRLSSLRASTSKSES*S-C(Sx)-K-Z, X-KMQPPR-C(Sx)-RS*SIMSIT-Z, X- KMQPPRSRS*S-C(Sx)-MSIT-Z, X-SGRSRPLS*P-C(Sx)-PSPHY-Z, X-LIDS*M-C(Sx)- NSFVG-Z, X-LIDSM-C(Sx)-NS*FVG-Z, X-PKRSR-C(Sx)-SS*YPNGHRD-Z, X- PKRSRSSS*V-C(Sx)-PSHSY-Z, X-SGLEDDDY*V-C(Sx)-PGGHW-Z, X- ALKLVRYPS*F-C(Sx)-ITAKKK-Z, X-AMRLERQDS*I-C(Sx)-YPKKK-Z, X- KKKVSRSGLYRSPS*M-C(Sx)-E L RPR-Z, X-KKVSRSGLYRSPS*M-C(Sx)-E-Z, X- KKVSRSGLYR-C(Sx)-PS*MPE-Z, X-GRPRTSS*F-C(Sx)-EPG-Z, X-LRREILS*R-C(Sx)- PSYRK-Z, X-LRREILSR-C(Sx)-PS*YRK-Z, X-LRRE-C(Sx)-LS*RRPSYRK-Z, X- LRREILSRRPS*Y-C(Sx)-K-Z, X-FQREGFGRQS*M-C(Sx)-EKR-Z, X-FQREGFG-C(Sx)- QS*MSEKR-Z, X-RS*R-C(Sx)-RSRSRSRSRSR-Z, X-RSR-C(Sx)-RS*RSRSRSRSR-Z, X- RSRSRS*R-C(Sx)-RSRSRSR-Z, X-RSRSRSR-C(Sx)-RS *RSRSR-Z, X-RSRSRSRSRS *R- C(Sx)-RSR-Z, X-RSRSRSRSRSR-C(Sx)-RS*R-Z, X-ILLSELS*R-C(Sx)-RIR-Z, X- ILLSESS*R-C(Sx)-RIR-Z, X-ILLR-C(Sx)-SS*RRIRR-Z, X-ILLS-C(Sx)- SS*RRRIRSG KLGRIGRN-Z, X-ILLS-C(Sx)-SS*RRRIRSG KLGRIGRN-Z, X- GKRGD-C(Sx)-KS*VSRSSSS-Z, X-SGRSR-C(Sx)-DS*PRPGTHK-Z, X-SKRSR-C(Sx)- KS*PRRSLSY-Z, X-R-C(Sx)-LS*FRRR-Z, X-PLSRT*L-C(Sx)-VAAKK-Z, X-KKKKK- C(Sx)-FS*FKKSFKLSGFSFKK KK-Z, X-KKKKKRF S*F-C(Sx)-K SFKL S GF SFKK KK- Z, X-KKKKKRFSF-C(Sx)-KS*FKLSGFSFKK KK-Z, X-KKKKKRF SFKKS*F-C(Sx)- LSGFSFKK KK-Z, X-KKKKKRF SFKK SF-C(Sx)-L S * GF SFKK KK-Z, X- KKKKKRFSFKKSFKLSGFS*F-C(Sx)-K KK-Z, X-KGTLVQTKGTGASGS*F-C(Sx)- L KK-Z, X-RRR-C(Sx)-SS*LRA-Z, X-RR-C(Sx)-SS*LRA-Z, X-RRLSS*L-C(Sx)-A-Z, X- RT-C(Sx)-RS*GSVYEPLKI-Z, X-RFAVRDMRQT*V-C(Sx)-VGVIKAVDKK-Z, X-AAKI- C(Sx)-AS*FRGHMARKK-Z, X-RR-C(Sx)-RT*GRGRRGIFR-Z, X-QK-C(Sx)- PS*QRSKYL-Z, X-STASQDVA RFARKGS*L-C(Sx)-QKNV-Z, X-MFAVRDRRQT*V- C(Sx)-KGVIKAVDAV-Z, X-RLGRDK-C(Sx)-KT*LRQIRQ-Z, X-RLGRDKYKT*L-C(Sx)- QIRQ-Z, X-ERMRPRKRQGS*V-C(Sx)RRV-Z, X-HAT*P-C(Sx)-KKKRK-Z, X-GGG- C(Sx)-AT*PKKAKKL-Z, X-C(Sx)-QS*PKKG-Z, X-RRRFRPAS*P-C(Sx)-RGPPK-Z, X- RRRFRPAS*P-C(Sx)-RGPPK-Z, X-IPTS*P-C(Sx)-TTTYFFF-Z, X-I-C(Sx)- TS*PITTTYFFF-Z, X-IPTS*P-C(Sx)-TTTYFFFKKK-Z, X-C(Sx)-KT*PKKAKKL-Z, and X-GGG-C(Sx)-AT*PKKAKKL-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-HMRSAMS*G-C(Sx)-HLVKRR-Z, X-HMRS- C(Sx)-MS*GLHLVKRR-Z, X-AMARAAS*A-C(Sx)-ALARRR-Z, X-KKK AL SRQF S * V- C(Sx)-Z, X-GRTGRRNS*I-C(Sx)-Z, X-FLAKRRRLSS*L-C(Sx)-A-Z, X-KKR RTLT * V- C(Sx)-Z, X-C(Sx)-FS*LRRKAK-Z, X-KEIYNT*I-C(Sx)-Z, X-RKIS*A-C(Sx)-EFDRPLR- Z, X-R-C(Sx)-IS*ASEFDRPLR-Z, X-RKIS*A-C(Sx)-EFDRPLR-Z, X-RKRS*R-C(Sx)-E-Z, X-RARTLS*F-C(Sx)-EPG-Z, X-KRRE-C(Sx)-LS*RRP[pS]YR-Z, X-RRAAEE-C(Sx)- DS*RAG[pS]PQL-Z, X-RYR-C(Sx)-PT*GMYY-Z, X-RYRHPT*R-C(Sx)-YY-Z, X- KPDRKKRY*TV-C(Sx)-G PY-Z, X-RRRLS*F-C(Sx)-EPG-Z, X-PL-C(Sx)- RT*LSVAGLPGKK-Z, X-KKLNRT*L-C(Sx)-VA-Z, X-KKALRRQET*V-C(Sx)-AL-Z, X- LS LYHQGKFLQT*F-C(Sx)-GSPLYRRR-Z, X-RISDELMDAT*F-C(Sx)-DQEAK-Z, X- DELMEFS*F-C(Sx)-DQEAKV-Z, X-SGEDT*L-C(Sx)-DSDDED-Z, X- GRHD[pS]GLDS*M-C(Sx)-Z, X-KRRRALS[pS]VAS*L-C(Sx)-Z, X- RRKDLHDDEEDEAMS*I-C(Sx)-A-Z, X-RRA-C(Sx)-DS*DDDDD-Z, X-LGKEF-C(Sx)- RS*YRLRYSRDGRR-Z, X-LGKEFSRS*Y-C(Sx)LRYSRDGRR-Z, X-GRPRTSS*F-C(Sx)- EG-Z, X-PRTSS*F-C(Sx)-E-Z, X-KRRRLAS*L-C(Sx)-A-Z, X-KKR RTLS*V-C(Sx)-Z, X-RKKFGES-C(Sx)-KT*KTKEFL-Z, and X-RKKFGESEKT*K-C(Sx)-KEFL-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EDPDY*F-C(Sx)-FG-Z, X-EDPDY*F-C(Sx)-FK- Z, X-EDPDY*F-C(Sx)-FP-Z, X-EDPDY*F-C(Sx)-IG-Z, X-EDPDY*F-C(Sx)-IK-Z, X- EDPDY*F-C(Sx)-IP-Z, X-EDPDY*F-C(Sx)-MG-Z, X-EDPDY*F-C(Sx)-MK-Z, X- EDPDY*F-C(Sx)-MP-Z, X-EDPDY*F-C(Sx)-VG-Z, X-EDPDY*F-C(Sx)-VK-Z, and X- EDPDY*F-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EDPDY*I-C(Sx)-FG-Z, X-EDPDY*I-C(Sx)-FK-Z, X-EDPDY*I-C(Sx)-FP-Z, X-EDPDY*I-C(Sx)-IG-Z, X-EDPDY*I-C(Sx)-IK-Z, X- EDPDY*I-C(Sx)-IP-Z, X-EDPDY*I-C(Sx)-MG-Z, X-EDPDY*I-C(Sx)-MK-Z, X- EDPDY*I-C(Sx)-MP-Z, X-EDPDY*I-C(Sx)-VG-Z, X-EDPDY*I-C(Sx)-VK-Z, and X- EDPDY*I-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EDPDY*V-C(Sx)-FG-Z, X-EDPDY*V-C(Sx)-FK- Z, X-EDPDY*V-C(Sx)-FP-Z, X-EDPDY*V-C(Sx)-IG-Z, X-EDPDY*V-C(Sx)-IK-Z, X- EDPDY*V-C(Sx)-IP-Z, X-EDPDY*V-C(Sx)-MG-Z, X-EDPDY*V-C(Sx)-MK-Z, X- EDPDY*V-C(Sx)-MP-Z, X-EDPDY*V-C(Sx)-VG-Z, X-EDPDY*V-C(Sx)-VK-Z, and X- EDPDY* V-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EDPEY*F-C(Sx)-FG-Z, X-EDPEY*F-C(Sx)-FK-Z, X-EDPEY*F-C(Sx)-FP-Z, X-EDPEY*F-C(Sx)-IG-Z, X-EDPEY*F-C(Sx)-IK-Z, X- EDPEY*F-C(Sx)-IP-Z, X-EDPEY*F-C(Sx)-MG-Z, X-EDPEY*F-C(Sx)-MK-Z, X- EDPEY*F-C(Sx)-MP-Z, X-EDPEY*F-C(Sx)-VG-Z, X-EDPEY*F-C(Sx)-VK-Z, and X- EDPEY*F-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EDPEY*I-C(Sx)-FG-Z, X-EDPEY*I-C(Sx)-FK-Z, X-EDPEY*I-C(Sx)-FP-Z, X-EDPEY*I-C(Sx)-IG-Z, X-EDPEY*I-C(Sx)-IK-Z, X-EDPEY*I- C(Sx)-IP-Z, X-EDPEY*I-C(Sx)-MG-Z, X-EDPEY*I-C(Sx)-MK-Z, X-EDPEY*I-C(Sx)-MP- Z, X-EDPEY*I-C(Sx)-VG-Z, X-EDPEY*I-C(Sx)-VK-Z, and X-EDPEY*I-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EDPEY*V-C(Sx)-FG-Z, X-EDPEY*V-C(Sx)-FK- Z, X-EDPEY*V-C(Sx)-FP-Z, X-EDPEY*V-C(Sx)-IG-Z, X-EDPEY*V-C(Sx)-IK-Z, X- EDPEY*V-C(Sx)-IP-Z, X-EDPEY*V-C(Sx)-MG-Z, X-EDPEY*V-C(Sx)-MK-Z, X- EDPEY*V-C(Sx)-MP-Z, X-EDPEY*V-C(Sx)-VG-Z, X-EDPEY*V-C(Sx)-VK-Z, and X- EDPEY*V-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EDPIY*F-C(Sx)-FG-Z, X-EDPIY*F-C(Sx)-FK-Z, X-EDPIY*F-C(Sx)-FP-Z, X-EDPIY*F-C(Sx)-IG-Z, X-EDPIY*F-C(Sx)-IK-Z, X-EDPIY*F- C(Sx)-IP-Z, X-EDPIY*F-C(Sx)-MG-Z, X-EDPIY*F-C(Sx)-MK-Z, X-EDPIY*F-C(Sx)-MP- Z, X-EDPIY*F-C(Sx)-VG-Z, X-EDPIY*F-C(Sx)-VK-Z, and X-EDPIY*F-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EDPIY*I-C(Sx)-FG-Z, X-EDPIY*I-C(Sx)-FK-Z, X-EDPIY*I-C(Sx)-FP-Z, X-EDPIY*I-C(Sx)-IG-Z, X-EDPIY*I-C(Sx)-IK-Z, X-EDPIY*I- C(Sx)-IP-Z, X-EDPIY*I-C(Sx)-MG-Z, X-EDPIY*I-C(Sx)-MK-Z, X-EDPIY*I-C(Sx)-MP-Z, X-EDPIY*I-C(Sx)-VG-Z, X-EDPIY*I-C(Sx)-VK-Z, and X-EDPIY*I-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ . In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EDPIY*V-C(Sx)-FG-Z, X-EDPIY*V-C(Sx)-FK-Z, X-EDPIY*V-C(Sx)-FP-Z, X-EDPIY*V-C(Sx)-IG-Z, X-EDPIY*V-C(Sx)-IK-Z, X- EDPIY*V-C(Sx)-IP-Z, X-EDPIY*V-C(Sx)-MG-Z, X-EDPIY*V-C(Sx)-MK-Z, X- EDPIY*V-C(Sx)-MP-Z, X-EDPIY*V-C(Sx)-VG-Z, X-EDPIY*V-C(Sx)-VK-Z, and X- EDPIY*V-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEPDY*F-C(Sx)-FG-Z, X-EEPDY*F-C(Sx)-FK-Z, X-EEPDY*F-C(Sx)-FP-Z, X-EEPDY*F-C(Sx)-IG-Z, X-EEPDY*F-C(Sx)-IK-Z, X- EEPDY*F-C(Sx)-IP-Z, X-EEPDY*F-C(Sx)-MG-Z, X-EEPDY*F-C(Sx)-MK-Z, X- EEPDY*F-C(Sx)-MP-Z, X-EEPDY*F-C(Sx)-VG-Z, X-EEPDY*F-C(Sx)-VK-Z, and X- EEPDY*F-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEPDY*I-C(Sx)-FG-Z, X-EEPDY*I-C(Sx)-FK-Z, X-EEPDY*I-C(Sx)-FP-Z, X-EEPDY*I-C(Sx)-IG-Z, X-EEPDY*I-C(Sx)-IK-Z, X-EEPDY*I- C(Sx)-IP-Z, X-EEPDY*I-C(Sx)-MG-Z, X-EEPDY*I-C(Sx)-MK-Z, X-EEPDY*I-C(Sx)-MP- Z, X-EEPDY*I-C(Sx)-VG-Z, X-EEPDY*I-C(Sx)-VK-Z, and X-EEPDY*I-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEPDY*V-C(Sx)-FG-Z, X-EEPDY*V-C(Sx)-FK- Z, X-EEPDY*V-C(Sx)-FP-Z, X-EEPDY*V-C(Sx)-IG-Z, X-EEPDY*V-C(Sx)-IK-Z, X- EEPDY*V-C(Sx)-IP-Z, X-EEPDY*V-C(Sx)-MG-Z, X-EEPDY*V-C(Sx)-MK-Z, X- EEPDY*V-C(Sx)-MP-Z, X-EEPDY*V-C(Sx)-VG-Z, X-EEPDY*V-C(Sx)-VK-Z, and X- EEPDY* V-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEPEY*F-C(Sx)-FG-Z, X-EEPEY*F-C(Sx)-FK-Z, X-EEPEY*F-C(Sx)-FP-Z, X-EEPEY*F-C(Sx)-IG-Z, X-EEPEY*F-C(Sx)-IK-Z, X- EEPEY*F-C(Sx)-IP-Z, X-EEPEY*F-C(Sx)-MG-Z, X-EEPEY*F-C(Sx)-MK-Z, X- EEPEY*F-C(Sx)-MP-Z, X-EEPEY*F-C(Sx)-VG-Z, X-EEPEY*F-C(Sx)-VK-Z, and X- EEPEY*F-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEPEY*I-C(Sx)-FG-Z, X-EEPEY*I-C(Sx)-FK-Z, X-EEPEY*I-C(Sx)-FP-Z, X-EEPEY*I-C(Sx)-IG-Z, X-EEPEY*I-C(Sx)-IK-Z, X-EEPEY*I- C(Sx)-IP-Z, X-EEPEY*I-C(Sx)-MG-Z, X-EEPEY*I-C(Sx)-MK-Z, X-EEPEY*I-C(Sx)-MP- Z, X-EEPEY*I-C(Sx)-VG-Z, X-EEPEY*I-C(Sx)-VK-Z, and X-EEPEY*I-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEPEY*V-C(Sx)-FG-Z, X-EEPEY*V-C(Sx)-FK- Z, X-EEPEY*V-C(Sx)-FP-Z, X-EEPEY*V-C(Sx)-IG-Z, X-EEPEY*V-C(Sx)-IK-Z, X- EEPEY*V-C(Sx)-IP-Z, X-EEPEY*V-C(Sx)-MG-Z, X-EEPEY*V-C(Sx)-MK-Z, X- EEPEY*V-C(Sx)-MP-Z, X-EEPEY*V-C(Sx)-VG-Z, X-EEPEY*V-C(Sx)-VK-Z, and X- EEPEY* V-C(Sx)-VP-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEPIY* A-C(Sx)-[Nle]-K-Z, X-EEPIY* A-C(Sx)- [Nle]-M-Z, X-EEPIY* A-C(Sx)-[Nle]-P-Z, X-EEPIY* A-C(Sx)-FK-Z, X-EEPIY* A-C(Sx)- FM-Z, X-EEPIY* A-C(Sx)-FP-Z, X-EEPIY* A-C(Sx)-IK-Z, X-EEPIY* A-C(Sx)-IM-Z, X- EEPIY*A-C(Sx)-IP-Z, X-EEPIY* A-C(Sx)-LK-Z, X-EEPIY* A-C(Sx)-LM-Z, X-EEPIY* A- C(Sx)-LP-Z, X-EEPIY* A-C(Sx)-MK-Z, X-EEPIY* A-C(Sx)-MM-Z, X-EEPIY*A-C(Sx)- MP-Z, X-EEPIY* A-C(Sx)-VK-Z, X-EEPIY* A-C(Sx)-VM-Z, X-EEPIY* A-C(Sx)-VP-Z, X- EEPIY*A-C(Sx)-WK-Z, X-EEPIY* A-C(Sx)-WM-Z, X-EEPIY*A-C(Sx)-WP-Z, X- EEPIY*A-C(Sx)-XK-Z, X-EEPIY* A-C(Sx)-XM-Z, and X-EEPIY* A-C(Sx)-XP-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEPIY*F-C(Sx)-[Nle]-K-Z, X-EEPIY*F-C(Sx)- [Nle]-M-Z, X-EEPIY*F-C(Sx)-[Nle]-P-Z, X-EEPIY*F-C(Sx)-FG-Z, X-EEPIY*F-C(Sx)-FK- Z, X-EEPIY*F-C(Sx)-FM-Z, X-EEPIY*F-C(Sx)-FP-Z, X-EEPIY*F-C(Sx)-IG-Z, X- EEPIY*F-C(Sx)-IK-Z, X-EEPIY*F-C(Sx)-IM-Z, X-EEPIY*F-C(Sx)-IP-Z, X-EEPIY*F- C(Sx)-LK-Z, X-EEPIY*F-C(Sx)-LM-Z, X-EEPIY*F-C(Sx)-LP-Z, X-EEPIY*F-C(Sx)-MG- Z, X-EEPIY*F-C(Sx)-MK-Z, X-EEPIY*F-C(Sx)-MM-Z, X-EEPIY*F-C(Sx)-MP-Z, X- EEPIY*F-C(Sx)-VG-Z, X-EEPIY*F-C(Sx)-VK-Z, X-EEPIY*F-C(Sx)-VM-Z, X-EEPIY*F- C(Sx)-VP-Z, X-EEPIY*F-C(Sx)-WK-Z, X-EEPIY*F-C(Sx)-WM-Z, and X-EEPIY*F-C(Sx)- WP-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEPIY*I-C(Sx)-[Nle]-K-Z, X-EEPIY*I-C(Sx)- [Nle]-M-Z, X-EEPIY*I-C(Sx)-[Nle]-P-Z, X-EEPIY*I-C(Sx)-FG-Z, X-EEPIY*I-C(Sx)-FK- Z, X-EEPIY*I-C(Sx)-FM-Z, X-EEPIY*I-C(Sx)-FP-Z, X-EEPIY*I-C(Sx)-IG-Z, X-EEPIY*I- C(Sx)-IK-Z, X-EEPIY*I-C(Sx)-FM-Z, X-EEPIY*I-C(Sx)-IP-Z, X-EEPIY*I-C(Sx)-LK-Z, X- EEPIY*I-C(Sx)-LM-Z, X-EEPIY*I-C(Sx)-LP-Z, X-EEPIY*I-C(Sx)-MG-Z, X-EEPIY*I- C(Sx)-MK-Z, X-EEPIY*I-C(Sx)-MK-Z, X-EEPIY*I-C(Sx)-MM-Z, X-EEPIY*I-C(Sx)-MP- Z, X-EEPIY*I-C(Sx)-VG-Z, X-EEPIY*I-C(Sx)-VK-Z, X-EEPIY*I-C(Sx)-VM-Z, X- EEPIY*I-C(Sx)-WK-Z, X-EEPIY*I-C(Sx)-WM-Z, X-EEPIY*I-C(Sx)-WP-Z, X-EEPIY*I- C(Sx)-XK-Z, X-EEPIY*I-C(Sx)-XM-Z, and X-EEPIY*I-C(Sx)-XP-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEPIY*M-C(Sx)-[Nle]-K-Z, X-EEPIY*M-C(Sx)- [Nle]-M-Z, X-EEPIY*M-C(Sx)-[Nle]-P-Z, X-EEPIY*M-C(Sx)-FK-Z, X-EEPIY*M-C(Sx)- FM-Z, X-EEPIY*M-C(Sx)-FP-Z, X-EEPIY*M-C(Sx)-IK-Z, X-EEPIY*M-C(Sx)-IM-Z, X- EEPIY*M-C(Sx)-IP-Z, X-EEPIY*M-C(Sx)-LK-Z, X-EEPIY*M-C(Sx)-LM-Z, X-EEPIY*M- C(Sx)-LP-Z, X-EEPIY*M-C(Sx)-MK-Z, X-EEPIY*M-C(Sx)-MM-Z, X-EEPIY*M-C(Sx)- MP-Z, X-EEPIY*M-C(Sx)-VK-Z, X-EEPIY*M-C(Sx)-VM-Z, X-EEPIY*M-C(Sx)-VP-Z, X- EEPIY*M-C(Sx)-WK-Z, X-EEPIY*M-C(Sx)-WM-Z, and X-EEPIY*M-C(Sx)-WP-Z;

wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEPIY*V-C(Sx)-[Nle]-K-Z, X-EEPIY*V-C(Sx)- [Nle]-M-Z, X-EEPIY*V-C(Sx)-[Nle]-P-Z, X-EEPIY*V-C(Sx)-FG-Z, X-EEPIY*V-C(Sx)- FK-Z, X-EEPIY*V-C(Sx)-FM-Z, X-EEPIY*V-C(Sx)-FP-Z, X-EEPIY*V-C(Sx)-IG-Z, X- EEPIY*V-C(Sx)-IK-Z, X-EEPIY*V-C(Sx)-FM-Z, X-EEPIY*V-C(Sx)-IP-Z, X-EEPIY*V- C(Sx)-LK-Z, X-EEPIY*V-C(Sx)-LM-Z, X-EEPIY*V-C(Sx)-LP-Z, X-EEPIY*V-C(Sx)-MG- Z, X-EEPIY*V-C(Sx)-MK-Z, X-EEPIY*V-C(Sx)-MM-Z, X-EEPIY*V-C(Sx)-MP-Z, X- EEPIY*V-C(Sx)-VG-Z, X-EEPIY*V-C(Sx)-VK-Z, X-EEPIY*V-C(Sx)-VM-Z, X- EEPIY*V-C(Sx)-VP-Z, X-EEPIY*V-C(Sx)-WK-Z, X-EEPIY*V-C(Sx)-WM-Z, X- EEPIY*V-C(Sx)-WP-Z, X-EEPIY*V-C(Sx)-XK-Z, X-EEPIY*V-C(Sx)-XM-Z, and X- EEPIY* V-C(Sx)-XP-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEPIY*W-C(Sx)-[Nle]-K-Z, X-EEPIY*W-C(Sx)- [Nle]-M-Z, X-EEPIY*W-C(Sx)-[Nle]-P-Z, X-EEPIY*W-C(Sx)-FK-Z, X-EEPIY*W-C(Sx)- FM-Z, X-EEPIY*W-C(Sx)-FP-Z, X-EEPIY*W-C(Sx)-IK-Z, X-EEPIY*W-C(Sx)-IM-Z, X- EEPIY*W-C(Sx)-IP-Z, X-EEPIY*W-C(Sx)-LK-Z, X-EEPIY*W-C(Sx)-LM-Z, X- EEPIY*W-C(Sx)-LP-Z, X-EEPIY*W-C(Sx)-MK-Z, X-EEPIY*W-C(Sx)-MM-Z, X- EEPIY*W-C(Sx)-MP-Z, X-EEPIY*W-C(Sx)-VK-Z, X-EEPIY*W-C(Sx)-VM-Z, X- EEPIY*W-C(Sx)-VP-Z, X-EEPIY*W-C(Sx)-WK-Z, X-EEPIY*W-C(Sx)-WM-Z, and X- EEPIY*W-C(Sx)-WP-Z; wherein X is H or acetyl; and Z is OH or H2. In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-RARRRLS*F-C(Sx)-GFGSR-Z, X- LKKLRRRLS*D-C(Sx)-VA-Z, X-SPS-C(Sx)-QS*SMVARTQTVR-Z, X-RKRDRLGT*L- C(Sx)-I-Z, X-KRRRLAS*L-C(Sx)-GHMAR-Z, X-ARARPRTYT*F-C(Sx)-HH-Z, X- KKR RTLS*V-C(Sx)-VG-Z, X-KKRPQRRYS*N-C(Sx)-FS-Z, X-ARKRERTYT*F-C(Sx)- HH-Z, X-ARKRERAYS*F-C(Sx)-HH-Z, X-KKKRFS*F-C(Sx)-KSFKLSGFSFKK-Z, X- KKKRFSF-C(Sx)-KS*FKLSGFSFKK-Z, X-MFAVRDRRQT*V-C(Sx)-KGVIKAVD-Z, X- KGTLVQTKGTGASGS*F-C(Sx)-L K-Z, X-KKKRFSFKKS*F-C(Sx)-LSGFSFKK-Z, X- KKKRFSFKKSF-C(Sx)-LS*GFSFKK-Z , X-RFAVRDMRQT*V-C(Sx)-VGVIKAVD-Z, X- KKK-C(Sx)-FS*FKKSFKLSGFSFKK-Z, X-KKRFSFKKSFKLSGFS*F-C(Sx)-KN-Z, X- TASQDVA RFARKGS*L-C(Sx)-QKN-Z, X-RFARKGS*L-C(Sx)-QKN-Z ; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KEVPR-C(Sx)-KS*LVGTPYWMAPE-Z, X- KEVPR-C(Sx)-KS*LVGTPYWMAPE-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KKALRRQET*V-C(Sx)-AL-Z, X-KL RVFS*V- C(Sx)-VA-Z, X-TRPRKRQGS*F-C(Sx)-RR-Z, X-KKRFSFKKT*F-C(Sx)-LSGFSFKK-Z, X-ARKRERAYS*F-C(Sx)-VG-Z, X-ARKKWKQS*V-C(Sx)-LIS-Z, X-D KLRRYT * T- C(Sx)-SKRKT-Z, X-EPPLSQET*F-C(Sx)-DLWKL-Z, X-IIMDSSIS*K-C(Sx)-ALSEI-Z, X- KTIERRYS*D-C(Sx)-TTLVA-Z, X-LSRRL-C(Sx)-VT*GDLFDFM-Z, X- KLRRQH S * Y- C(Sx)-TFVDL-Z, X-RREER-C(Sx)-LS*APGNLLT-Z, X-KRPQRATS*N-C(Sx)-FAMFD-Z, X-VRRRWKLS*F-C(Sx)-IVSL-Z, MSSKRTKT*K-C(Sx)-KKRPQ-Z, X-ARQSRRST*Q- C(Sx)-VTLTD-Z, X-DKKG FNY*I-C(Sx)-FTRIL-Z, X-EFKNIFGT*P-C(Sx)-FVAPE-Z, X-EYTIKSHS*S-C(Sx)-PPNNS-Z, X-KDPKRRMT*I-C(Sx)-QSLEH-Z, X-KKRPQRAT * S - C(Sx)-VFAMF-Z, X-KQTAR-C(Sx)-ST*GGKAPRK-Z, X-LGETKQET*L-C(Sx)-NISAV- Z, X-PERRRLKT*T-C(Sx)-LKEYT-Z, X-PYHFRAPS*R-C(Sx)-FWRTV-Z, X- QGRKRRQT* S-C(Sx)-TDF YH-Z, X-RPREKRRS*T-C(Sx)-VSFWT-Z, X- RQRKRHKS*D-C(Sx)-ISLSF-Z, X-SSRRR-C(Sx)-IS*ETEENSD-Z, X-TIGRSRST*R- C(Sx)-REQEN-Z, X-TTMGDRFT*D-C(Sx)-EVDEL-Z, X-TTRLK-C(Sx)-YT*IKSHSSL-Z, X-PLSQETFS*D-C(Sx)-WKLLP-Z, X-ENIPEDSS*M-C(Sx)-SKRFR-Z, X-PEDSSMVS*K- C(Sx)-FRFDD-Z, X-RFDCR-C(Sx)-IS*GLLTTTP-Z, X-RRRFD-C(Sx)-RS*ISGLLTT-Z, X-SEDKTSKS*S-C(Sx)-NGT-Z, X-SKSS-C(Sx)-NGT*CGDREDK-Z, X- KKRAARASTS*N-C(Sx)-RR-Z, X-ILSR-C(Sx)-PS*YRKILN-Z, X-PLRRTLS*V-C(Sx)- ASPS-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-HAAIGDDDDAYS*I-C(Sx)-A-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KK-C(Sx)-RLS*PGRRRK-Z, X-QGKFLQT*F- C(Sx)-GSPLYRRR-Z, X-GRDK-C(Sx)-KS*LRQIRQ-Z, X-LSR-C(Sx)- SS*PHQ[pS]EDEEE-Z, X-SR-C(Sx)-SS*PHQ[pS]EDEEEPRD-Z, X-GT*F-C(Sx)- A AIRRL A ARRR-Z , X-KTGPLS*P-C(Sx)-PFK-Z, X-GLYRS*P-C(Sx)-MPE L RPRL-Z, X-KRELVE-C(Sx)-LT*PSGEAPNQALLR-Z; wherein X is H or acetyl; and Z is OH or

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-GDQDYLS*L-C(Sx)-VG-Z, X-ILSRRPS*Y- C(Sx)-KILN-Z, X-QLIDSMANS*F-C(Sx)-GTRRR-Z, X-KKERLLDDRHD S * G-C(Sx)- DSMDEE-Z, X-KKERLLDDRHD SGLDS *M-C(Sx)-EE-Z; wherein X is H or acetyl; and Z

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-QDLDE-C(Sx)-VS*QEDVPLV-Z, X- ISAQIGAT*L-C(Sx)-RRLSF-Z, X-WHKTTQMS*A-C(Sx)-GTYA-Z, X-SGRPRTTS*F- C(Sx)-ESCKP-Z, X-RSGL-C(Sx)-RS*PSMPE L RPRLK-Z, X-

KDQEAKVSRSGLYRS*P-C(Sx)-MPEN-Z, X-DE-C(Sx)-EGT*FRSSIRRLSSRRR-Z, X- DEE-C(Sx)-GT*FRSSIRRLSSRRR-Z, X-DEEEGT*F-C(Sx)-SSIRRLSSRRR-Z, X-DE- C(Sx)-EGT*FRAAIRRLAARRR-Z, X-DEE-C(Sx)-GT*FRAAIRRLAARRR-Z, X- DEEEGT*F-C(Sx)- AAIRRLAARRR-Z, X-QGKF-C(Sx)-QT*FCGSPLYRRR-Z, X- HVNATY*V-C(Sx)-VKCVAP-Z, X-CKRRRLAS*L-C(Sx)-Z, X-NTFIG-C(Sx)- PY*WMAPEVI-Z, X-RRNTFIGT*P-C(Sx)-WMAPE-Z, X-RTVGRRNT*F-C(Sx)- GTPYW-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-GRDK-C(Sx)-KT*LRQIRQ-Z, X-QLIDS*M- C(Sx)-NSFVGTRRR-Z, X-QLIDSM-C(Sx)-NS*FVGTRRR-Z, X-RAL-C(Sx)- DS*FRRRDTAQ-Z, X-KLRALTDS*F-C(Sx)-RR-Z; wherein X is H or acetyl; and Z is OH In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-SFLSRSKS*F-C(Sx)-PLLHY-Z, X-SFLSR-C(Sx)- KS*FSPLLHY-Z, X-SFLSRSKS*F-C(Sx)-PLLHL-Z, X-SFLSR-C(Sx)-KS*FRPLLHL-Z, X-SGLSRSKS*F-C(Sx)-RLSHQ-Z, X-SGLSR-C(Sx)-KS*FRRLSHQ-Z, X-QHLRLSTS*S- C(Sx)-RLLYA-Z, X-QHLRL-C(Sx)-TS*SGRLLYA-Z, X-PLSTWSGS*P-C(Sx)-YAAPE-Z, X-PLST-C(Sx)-SGS*PPYAAPE-Z, X-PLSTW-C(Sx)-GS*PPYAAPE-Z, X-PESFSSGS*Q- C(Sx)-VHQKR-Z, X-PESF-C(Sx)-SGS*QDVHQKR-Z, X-LLATWSGS*P-C(Sx)-YAAPE- Z, X-SAL RTSS*D-C(Sx)-ALHTS-Z, X-SAL R-C(Sx)-SS*DSALHTS-Z, X- AMARAAS*A-C(Sx)-ALARRR-Z, X-AMAR-C(Sx)-AS*AAALARRR-Z, X- AL RTSS*D-C(Sx)-ALHRRR-Z, X-ALNR-C(Sx)-SS*DSALHRRR-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-PKRSRSSS*F-C(Sx)-PGTRK-Z, X-PKRSR- C(Sx)-SS*FPPGTRK-Z, X-APNVH-C(Sx)-NT*IEPVNID-Z, X-PKALQRLS*R-C(Sx)- IVRSR-Z, X-ALQRLSRS*I-C(Sx)-RSRAH-Z, X-LSRSIVRS*R-C(Sx)-HSTAV-Z, X- IVRSRAHS*T-C(Sx)-VGIFS-Z, X-EIRSR-C(Sx)-SS*YPAGTED-Z, X-ARQSRRST*Q- C(Sx)-VTLTD-Z, X-SQRQRSTS*T-C(Sx)-NVH[Nle]V-Z, X-PKINRSAS*E-C(Sx)- SLHRA-Z, X-PKINR-C(Sx)-AS*EPSLHRA-Z, X-RKSGKRQT*E-C(Sx)-EKKKK-Z, X- RPRGQRDS*S-C(Sx)-YWEIE-Z, X-RPRGQ-C(Sx)-DS*SYYWEIE-Z, X- VSGQLIDS*[Nle]-C(Sx)-NSFVG-Z, X-VSGQL-C(Sx)-DS*[Nle]ANSFVG-Z, X- LIDS[Nle]ANS*F-C(Sx)-GTRSY-Z, X-LIDS[Nle]-C(Sx)-NS*FVGTRSY-Z, X- SPRSDRDS*F-C(Sx)-PLSSL-Z, X-SPRSD-C(Sx)-DS*FRPLSSL-Z, X-NVH[Nle]VSTT*L- C(Sx)-VDSR-Z, X-NVH[Nle]V-C(Sx)-TT*LPVDSR-Z, X-RRRSDDDS*P-C(Sx)-PSTHK- Z, X-RRRSD-C(Sx)-DS*PRPSTHK-Z, X-QNRSGAMS*P-C(Sx)-SWNSD-Z, X- AKELDQGS*L-C(Sx)-TSFVG-Z, X-AGTSF[Nle][Nle]T*P-C(Sx)-VVTRY-Z, X-AGTSF- C(Sx)-[Nle]T*PYVVTRY-Z, X-AGTSF-C(Sx)-[Nle]T*P[pY]VVTRY-Z, X- TSF[Nle][Nle]TPY*V-C(Sx)-TRYYR-Z, X-TSF[Nle][Nle][pT]PY*V-C(Sx)-TRYYR-Z, X- ETPPRPRT*P-C(Sx)-RPLSS-Z, X-ARLASKGT*GA-C(Sx)-EFQG-Z, X-FQGQLLGT*I- C(Sx)-F[Nle]APE-Z, X-NTIDLP[Nle]S*P-C(Sx)-TLDSL-Z, X-DPGSA-C(Sx)- PY*LKTKFI-Z, X-ISGQLVDS*I-C(Sx)-KTRDA-Z, X-ISGQL-C(Sx)-DS*IAKTRDA-Z, X- ISGRLVDS*K-C(Sx)-KTRSA-Z, X-ISGRL-C(Sx)-DS*KAKTRSA-Z, X-ISGYLVDS*V- C(Sx)-KTIDA-Z, X-ISGYL-C(Sx)-DS*VAKTIDA-Z, X-LVDSIAKT*R-C(Sx)-AGSRP-Z, X-LVDSI-C(Sx)-KT*RDAGSRP-Z, X-LVDSKAKT*R-C(Sx)-AGSAA-Z, X-LVDSK- C(Sx)-KT*RSAGSAA-Z, X-LVDSVAKT*I-C(Sx)-AGSKP-Z, X-LVDSV-C(Sx)- KT*IDAGSKP-Z, X-SQKLLDAS*K-C(Sx)-AK FV-Z, X-YEHQRVYT*Y-C(Sx)-QSRFY- Z, X-WHKTTKMS*A-C(Sx)-GTYAW-Z, X-LAREW-C(Sx)-KT*TK[Nle]SAAG-Z, X- TKQTARKS*T-C(Sx)-GKAPR-Z, X-KQTAR-C(Sx)-ST*GGKAPRK-Z, X- KRPQRATS*N-C(Sx)-FA[Nle]FD-Z, X-KKRPQRAT*S-C(Sx)-VFA[Nle]F-Z, X- TVG KLDT*F-C(Sx)-GSPPY-Z, X-TFGNKLDT*F-C(Sx)-GSPPY-Z, X-VSTQLVNS*I- C(Sx)-KTYVG-Z, X-LVNSIAKT*Y-C(Sx)-GTNAY-Z, X-S[Nle]DGLFGT*I-C(Sx)- YLPPE-Z, X-PDKQFLIS*P-C(Sx)-ASPPV-Z, X-FLISPPAS*P-C(Sx)-VGWKQ-Z, X- LVDSVAKT*[Nle]-C(Sx)-AGSKP-Z, X-KLKNN-C(Sx)-QT*[Nle]PGEVNS-Z, X-DE FE- C(Sx)-HS*APPSPEE-Z, X- EYLR-C(Sx)-IS*LPVPVLV-Z, X-GDNVLINT*Y-C(Sx)- GVLKI-Z, X-GINPSTET*F-C(Sx)-GTLQY-Z, X-TETFTGT*L-C(Sx)-Y[Nle]APE-Z, X- IPERDSRY*S-C(Sx)-PLHEE-Z, X-DNVLINTY*S-C(Sx)-VLKIS-Z, X-GGRRPGTS*P- C(Sx)-LLQGT-Z, X-LVQGI-C(Sx)-FS*QPTSPDH-Z, X-EDQPR-C(Sx)-QS*LDSALLE-Z, X-FPKDLRGT*E-C(Sx)-Y[Nle]SPE-Z, X-LELSRRRS*L-C(Sx)-ELHKR-Z, X- YDGERKKT*L-C(Sx)-GTPNY-Z, X-RTPGRPLS*S-C(Sx)-G[Nle]DSR-Z, X-PGRPL- C(Sx)-SY*G[Nle]DSRPP-Z, X-DGR[Nle]VQLS*P-C(Sx)-ALAAP-Z, X-SYTPTPRS*P- C(Sx)-FIGRR-Z, X-HDHTGFLT*E-C(Sx)-VATRW-Z, X-HDHTG-C(Sx)-LT*EYVATRW- Z, X-HDHTG-C(Sx)-LT*E[pY]VATRW-Z, X-HTGFLTEY*V-C(Sx)-TRWYR-Z, X- HTGFL[pT]EY*V-C(Sx)-TRWYR-Z, X-RGEPNVSY*I-C(Sx)-SRYYR-Z, X- TVNQSLLS*P-C(Sx)-VLEVD-Z, X-SPLNITST*P-C(Sx)-PDASS-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-AAFRLFKY*GV-C(Sx)-LYKN-Z, X-AAFRL- C(Sx)-KY*GVQLYKN-Z, X-SIESDIY*A-C(Sx)-IPDET-Z, X-DSQQT DY*[Nle]-C(Sx)- PEEDW-Z, X-DVYEEDSY*V-C(Sx)-RSQGR-Z, X-EELA[Nle]DVY*D-C(Sx)-VDRRE-Z, X-EGGW[Nle]EDY*D-C(Sx)-VHLQG-Z, X-EIYDRREY*S-C(Sx)-FEKEQ-Z, X- ELFDDPSY*V-C(Sx)-VQ LD-Z, X-ERSW[Nle]DDY*D-C(Sx)-VHLQG-Z, X-FGIED- C(Sx)-DY*VEPSGFT-Z, X-FGLGSRAY*P-C(Sx)-FAA-Z, X-FLSEETPY*S-C(Sx)- PTG H-Z, X-FLSEE-C(Sx)-PY*SYPTGNH-Z, X-FRK FAKY*E-C(Sx)-FKSSP-Z, X- GW[Nle]EDYDY*V-C(Sx)-LQGKE-Z, X-IIDEEDTY*T-C(Sx)-PSTRD-Z, X-IIDEE-C(Sx)- TY*T[Nle]PSTRD-Z, X-KDNDSHVY*A-C(Sx)-IEDT-Z, X-LDGEVTPY*A-C(Sx)- TNNNA-Z, X-LPQDKEYY*K-C(Sx)-KEPGE-Z, X-NSTPESDY*D-C(Sx)-TP D[Nle]-Z, X-PAPLTPAY*H-C(Sx)-LPHPS-Z, X-PSPATDLY*Q-C(Sx)-PPGPG-Z, X- QD DQPDY*D-C(Sx)-VASDE-Z, X-QPSSKAL*YD-C(Sx)-EPE D-Z, X- RDKQRLSY*GA-C(Sx)-TNQI-Z, X-RDKQR-C(Sx)-SY*GAFTNQI-Z, X-RETSKVIY*D- C(Sx)-IEKTG-Z, X-RLIED EY*T-C(Sx)-RQGAK-Z, X-RLIED-C(Sx)-EY*TARQGAK-Z, X-RY[Nle]ED-C(Sx)-TY*YKASKGK-Z, X-SGDKDHLY*S-C(Sx)-VAKPR-Z, X- SIREDDDY*D-C(Sx)-IIDHG-Z, X-SVSETDDY*A-C(Sx)-IIDEE-Z, X-VDPD EAY*E- C(Sx)-PSEEG-Z, X-VGEEEHVY* S-C(Sx)-P KQK-Z, X-VGEEE-C(Sx)-VY* SFP KQK- Z, X-VLPQD-C(Sx)-EY*YKVKEPG-Z, X-YMEDSTYY*K-C(Sx)-SKGKL-Z, X- YRLSVEIY*D-C(Sx)-REYSR-Z, [Nle]EAIAKY*D-C(Sx)-KATAD-Z, X-AEPLPPSY*V- C(Sx)-AS-Z, X-AEPLP-C(Sx)-SY*VASS-Z, X-AIETDKEY*Y-C(Sx)-VKDDR-Z, X- AIYNSISY*K-C(Sx)-FLPK-Z, X-AVPEG-C(Sx)-EY*YRVREDG-Z, X-DGFIPKNY*I- C(Sx)-[Nle]KPHP-Z, X-DGPKGTGY*I-C(Sx)-TELIS-Z, X-DGPK-C(Sx)-TGY*IKTELIS- Z, X-DPGSA-C(Sx)-PY*LKTKFI-Z, X-DQTPL-C(Sx)-IY*NSISYKT-Z, X- DRLSQGAY*GG-C(Sx)-SDRP-Z, X-DRLSQ-C(Sx)-AY*GGLSDRP-Z, X- EESDQNWY*K-C(Sx)-ELNGK-Z, X-EESEDPDY*Y-C(Sx)-YNIQG-Z, X-ESQEELHY*A- C(Sx)-L FPG-Z, X-EYLGTKRY*I-C(Sx)-RDLAT-Z, X-GSNQEEAY*V-C(Sx)-MSSFY- Z, X-GSVE[Nle]-C(Sx)-RY*DPLQDNT-Z, X-GVKKP-C(Sx)-RY*RPGTVAL-Z, X- HRIDGKIY*V-C(Sx)-KRVKY-Z, X-HTGFLTEY*V-C(Sx)-TRWYR-Z, X- HWKKYDIY*E-C(Sx)-QTKEE-Z, X-IDENSLLS*P-C(Sx)-AGEDD-Z, X-IETDKE YY* T- C(Sx)-KDDRD-Z, X-ILAIH-C(Sx)-SY*KPEFHSD-Z, X-ILLTIDRY*L-C(Sx)-IVHAV-Z, X-IPERDSRY*S-C(Sx)-PLHEE-Z, X-IRAKIQDY*H-C(Sx)-LTRKR-Z, X-IREFLDQY*D- C(Sx)-PL-Z, X-IREFL-C(Sx)-QY*DAPL-Z, X-KDISY-C(Sx)-RY*IPETL K-Z, X- KFGSLDTY*L-C(Sx)-K KN-Z, X-LAKAVDGY*V-C(Sx)-PQIKQ-Z, X-LAKA-C(Sx)- DGY*VKPQIKQ-Z, X-LILEDDDY*V-C(Sx)-VFFHQ-Z, X-LI[Nle]EY-C(Sx)- P Y* GSLRD YL-Z, X-LLPLDKDY*Y-C(Sx)-VREPG-Z, X-LPLDKDYY*V-C(Sx)-REPGQ- Z, X-LPQDKEYY*K-C(Sx)-KEPGE-Z, X-[Nle]APPSEET*P-C(Sx)-IPQRS-Z, X- HIGHTGY*L-C(Sx)-TVTVS-Z, X- HIG-C(Sx)-TGY*LNTVTVS-Z, X-NLKLI-C(Sx)- EY*LPYGSLR-Z, X- LQERRKY*L-C(Sx)-HRLI-Z, X- LQER-C(Sx)-KY*LKHRLI-Z, X-NSKPKKSY*I-C(Sx)-TQG-Z, X-NSLFTPDY*E-C(Sx)-LTE D-Z, X-NSLISSDY*E- C(Sx)-LSDPT-Z, X-PEHTKSVY*T-C(Sx)-SVIEP-Z, X-PKGTQADY*A-C(Sx)-VKFQ-Z, X-PKGTQ-C(Sx)-DY*AEVKFQ-Z, X-P EPVSDY*I-C(Sx)-ANI-Z, X-PPHLKYLY*L- C(Sx)-VSDSG-Z, X-PSSSIDEY*F-C(Sx)-EQPLK-Z, X-PTPPHLKY*L-C(Sx)-LVVSD-Z, X-PYGSLRDY*L-C(Sx)-KHKER-Z, X-QHDNIVKY*K-C(Sx)-VAYSA-Z, X- QISKG[Nle]EY*L-C(Sx)-SRRSV-Z, X-QISKG-C(Sx)-EY*LGTKRYI-Z, X-RHSTILDY*I- C(Sx)-VVPTA-Z, X-SFLSRSLY*F-C(Sx)-PLLHY-Z, X-SGGER-C(Sx)-DY*VAPSGSY-Z, X-SLRLV-C(Sx)-EY*LPSGSLR-Z, X-SPLTTGVY*V-C(Sx)-[Nle]PPTE-Z, X- T AKAVDGY* V-C(Sx)-PQIKQ-Z, X-TEQDL-C(Sx)-L Y* SDFPNII-Z, X-TGMFPRNY* V- C(Sx)-PV RN-Z, X-TPENN-C(Sx)-EY*AKVSGV[Nle]-Z, X-TSDEKVDY*V-C(Sx)- VDKEK-Z, X-VAKFIDDY*V-C(Sx)-VQIKQ-Z, X-VFLRSINY*V-C(Sx)-FPSLK-Z, X- VHPLSAPY*P-C(Sx)-LDTPE-Z, X-VHPLS-C(Sx)-PY*PPLDTPE-Z, X-VKYKGVAY*S- C(Sx)-GRRNL-Z, X-VLNQEEAY*V-C(Sx)-[Nle]ASFY-Z, X-VLPQD-C(Sx)- EY*YKVKEPG-Z, X-VLYRIRFY*F-C(Sx)-RWYSS-Z, X-VNGHLDSY*E-C(Sx)-VTQLP- Z, X-VPEGHEYY*R-C(Sx)-REDGD-Z, X-VRREVGDY*GQ-C(Sx)-HETE-Z, X-G[Nle]E- C(Sx)-IY*FEF[Nle]GGKKK-Z, X-G[Nle]EDIY*F-C(Sx)-F[Nle]GGKKK-Z, X-EAIY*A- C(Sx)-PFAKKK-Z, X-E-C(Sx)-IY*AAPFAKKK-Z; wherein X is H or acetyl; and Z is OH

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-RRAEEEEY*I-C(Sx)-LVA-Z, X-RAEEEEY*I- C(Sx)-LVA-Z, X-KKKAEEEEY*I-C(Sx)-L-Z, X-KKKAEEEEY*I-C(Sx)-Z, X-VYS-C(Sx)- DY*YRLF PSKKK-Z, X-VYS-C(Sx)-DY*[pY]RLF PSKKK-Z, X-GAGEE-C(Sx)- DY*[pY][pY]IWAGKKKK-Z, X-KKKK*E-C(Sx)-IYFFFG-Z, X-KKKRAHEEIY*F-C(Sx)- FWG-Z, X-KKKEEEIY*F-C(Sx)-FWG-Z, X-KKKKEEEIY*F-C(Sx)-FWG-Z, X-FTDRL- C(Sx)-QY*ISTRGLG-Z, X-FTDRLQQY*I-C(Sx)-TRGLG-Z, X-GC(Sx)- NY*RGYSLGNWV-Z, X-EEEIY*F-C(Sx)-FWG-Z, X-KKEEEIY*F-C(Sx)-FWG-Z, X- RAHEEIY*F-C(Sx)-FWG-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-IENEEQEY*V-C(Sx)-TVKSS-Z, X- AVLADVSY*L-C(Sx)-AMEKS-Z, X-ARPLVEFY*E-C(Sx)-IKKYE-Z, X-FYEEIKKY*E- C(Sx)-LETEE-Z, X-DGDGQVNY*E-C(Sx)-FVQMM-Z, X-FDKDGNGY*I-C(Sx)- AAELR-Z, X-TQEQYELY*S-C(Sx)-MGSTF-Z, X-MAEEKKAY*K-C(Sx)-AKERE-Z, X- TDGEDADY*T-C(Sx)-FTNQQ-Z, X-SSHKGFHY*K-C(Sx)-G-Z, X-SSHKG-C(Sx)- HY*KH-Z, X-GGPEPGPY*A-C(Sx)-PSVNT-Z, X-R EGVATY*A-C(Sx)-AVLFR-Z, X- DVVDADEY*L-C(Sx)-PQQGF-Z, X-DADEY*L-C(Sx)-PQQG-Z, X-EDSFLQRY*S- C(Sx)-DPTGA-Z, X-PVPEY*I-C(Sx)-QSV-Z, X-PVPEY*I-C(Sx)-QSV-Z, X- TFLPVPEY*I-C(Sx)-QSVPK-Z, X-TFLPV-C(Sx)-EY*INQSVPK-Z, X-ISLD PDY*Q- C(Sx)-DFFPK-Z, X-AENAEY*L-C(Sx)-VA-Z, X-AENAEY*L-C(Sx)-VA-Z, X- STAENAEY*L-C(Sx)-VAPQS-Z, X-STAEN-C(Sx)-EY*LRVAPQS-Z, X-RLDGE-C(Sx)- IY*IRHS LM-Z, X- FA FSAY*P-C(Sx)-EEDMI-Z, X-KEVHKSGY*L-C(Sx)-SERLI-Z, X-LMLRLQDY*E-C(Sx)-KTKKA-Z, X-TEADGELY*V-C(Sx)-NTPSG-Z, X- MRHVSISY*D-C(Sx)-PPTPG-Z, X-SEELDENY*V-C(Sx)-MNPNS-Z, X-EPIQEANY*V- C(Sx)-MTPGT-Z, X-SHDSEENY*V-C(Sx)-MNP L-Z, X-KGDKQVEY*L-C(Sx)-LDLDS- Z, X-VADERVDY*V-C(Sx)-VDQQK-Z, X-RNEEENIY*S-C(Sx)-PHDST-Z, X-SSTDR- C(Sx)-PY*EKVSAGN-Z, X-QLTFALRY*L-C(Sx)-FFTKA-Z, X-SSEPVGIY*Q-C(Sx)- FEKKT-Z, X-MQDNS-C(Sx)-TY*GKIWEGS-Z, X-TDVE-C(Sx)-TY*ADFIASG-Z, X- EGSFESRY*Q-C(Sx)-PFEDF-Z, X-IGTAE-C(Sx)-DY*GALYEGR-Z, X-EGR PGFY*V- C(Sx)-A PMP-Z, X-VTRRT-C(Sx)-DY*FL-Z, X-LHQED DY*I-C(Sx)-ASLIK-Z, X- LHQED DY*IN-C(Sx)-SLIK-Z, X-TVDGKEIY*N-C(Sx)-IRRKT-Z, X-TLMEKDSY*P- C(Sx)-FLKSP-Z, X-EEPPD-C(Sx)-QY*YNDFPGK-Z, X-EEPPD-C(Sx)- QY*[pY] DFPGK-Z, X-EPPDHQYY*N-C(Sx)-FPGKE-Z, X-ELFDDPSY*V-C(Sx)- VQ LD-Z, X-GDGSD-C(Sx)-PY*YNSIPSK-Z, X-GDGSD-C(Sx)-PY*[pY]NSIPSK-Z, X- DGSDHPYY*N-C(Sx)-IPSKM-Z, X-FAGKE-C(Sx)-TY*YQGRHLG-Z, X-FAGKE-C(Sx)- TY*[pY]QGRHLG-Z, X-AGKEQTYY*Q-C(Sx)-RHLGD-Z, X-RQGSSDIY*S-C(Sx)- PEGKL-Z, X-PTGEAPTY*V-C(Sx)-TQQIP-Z, X-TE DDDVY*R-C(Sx)-LEELA-Z, X- HDLGEDIY*D-C(Sx)-VP-Z, X-HDLGEDIY*D-C(Sx)-VP-Z, X-EDGGDDIY*E-C(Sx)- IIKVE-Z, X-EDGGDDIY*E-C(Sx)-IIKVE-Z, X-R EGVATY*A-C(Sx)-AVLFR-Z, X- SPQPEY*V-C(Sx)-QPDVR-Z, X-SPAFD-C(Sx)-LY*YWDQDPP-Z, X-SPAFD-C(Sx)- LY*[pY]WDQDPP-Z, X-PAFD LYY*W-C(Sx)-QDPPE-Z, X-PTAE PEY*L-C(Sx)- LDVPV-Z, X-QALD PEY*H-C(Sx)-ASNGP-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-RRRAEEEEY*I-C(Sx)-LVA-Z, X- KKKAEEEEY*I-C(Sx)-LVA-Z, X-KKAEEEEY*I-C(Sx)-LVA-Z, X-KAEEEEY*I-C(Sx)- LVA-Z, X-EEPIY*V-C(Sx)-VP-Z, X-EEPIY*V-C(Sx)-IK-Z, X-EEPIY*V-C(Sx)-[Nle]P-Z, X-EEPIY*I-C(Sx)-VK-Z, X-EEPIY*V-C(Sx)-VK-Z, X-EEPIY*I-C(Sx)-WP-Z, X- EEPIY*V-C(Sx)-WK-Z, X-EEPDY*I-C(Sx)-VP-Z, X-EEPEY*I-C(Sx)-VP-Z, X- EEPDY*V-C(Sx)-MK-Z, X-DEQIY*W-C(Sx)-IA-Z, X-KKKDEQIY*W-C(Sx)-IA-Z, X- S SKRAKAKTTKKRPQRAT S *N-C(Sx)-F S-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FS-Z, X-KTTKKRPQRATS*N-C(Sx)-FS-Z, X- KKRPQRATS*N-C(Sx)-FAM-Z, X-QETFS*D- C(Sx)-WKLLP-Z, X-QE-C(Sx)-FS*DLWKLLP-Z, X-VSGQL-C(Sx)- DS*MANSFVGTRSYKKK-Z, X-KKKVSGQLIDS*M-C(Sx)-NSFVGTRSY-Z, X- KKKVSGQLIDSM-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDSMANS*F-C(Sx)- GTRSY-Z, X-KKCVSGQLIDS*M-C(Sx)-NSFVGTRSYCKK-Z, X-KKCVSGQLIDSM- C(Sx)-NS*FVGTRSYCKK-Z , X-GYAKDV-C(Sx)-QGS*LCTSFVGTLQYLAKKK-Z, X- GYAKDVDQGS*L-C(Sx)-TSFVGTLQYLAKKK-Z, X-GYAKDVDQGSL-C(Sx)- TS*FVGTLQYLAKKK-Z, X-GYAKDVDQGSLCTS*F-C(Sx)-GTLQYLA-Z, X- DLGYAKDV-C(Sx)-QGS*LCTSFVGTLQYLAPEKKK-Z, X-DLGYAKD VDQGS *L- C(Sx)-TSFVGTLQYLAPE-Z, X-DLGYAKD VDQGSL-C(Sx)-TS*FVGTLQYLAPE-Z, X- DLGYAKDVDQGSLCTS*F-C(Sx)-GTLQYLAPE-Z, X-KKCDLGYAKD VDQGS *L- C(Sx)-TSFVGTLQYLAPECKK-Z, X-KKCDLGYAKD VDQGSL-C(Sx)- T S *F VGTLQ YL APECKK-Z, X-C(Sx)LS*FRRR-Z, X-GKKALRRQES*V-C(Sx)-ALGW- Z, X-G LLPMS*P-C(Sx)-EFD-Z; wherein X- is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-IPTS*P-C(Sx)-TTTYFFF-Z, X-I-C(Sx)- TS*PITTTYFFF-Z, X-IPTS*P-C(Sx)-TTTYFFFKKK-Z, X-VADQTPT*P-C(Sx)-RFLKN-Z, X-VA-C(Sx)-QT*P[pT]PTRFLKN-Z, X-IDQGDLMT*P-C(Sx)-FTPYY-Z, X-IDQGD- C(Sx)-MT*PQFTPYY-Z, X-TPPEELPS*P-C(Sx)-ASSLG-Z, X-TPPEE-C(Sx)- PS*PSASSLG-Z, X-NTIDLPMS*P-C(Sx)-TLDSL-Z, X-NTIDL-C(Sx)-MS*PRTLDSL-Z, X-KKKESTSAPLS*P-C(Sx)-VTTSP-Z, X-GFLSRPLS*P-C(Sx)-FTTSP-Z, X- PSLLRPLS*P-C(Sx)-FFGAY-Z, X-KKKSTPSSPSS*P-C(Sx)-SSVAY-Z, X- KKKSHGSAPLS*P-C(Sx)-APLTS-Z, X-KKKSPFSVLSS*P-C(Sx)-SGHSN-Z, X- TEERLPSS*P-C(Sx)-YEDAA-Z, X-TEERL-C(Sx)-SS*PVYEDAA-Z, X-SNGRRKRS*P- C(Sx)-QSFRF-Z, X-SNGRR-C(Sx)-RS*PTQSFRF-Z, X-EENVSDGS*P-C(Sx)-AGSVE-Z, X-EENV-C(Sx)-DGS*PNAGSVE-Z, X-APEKGLPT*P-C(Sx)-VLQRN-Z, X-APEKG- C(Sx)-PT*PQVLQRN-Z, X-LIDATGDT*P-C(Sx)-AEDDE-Z, X-LIDAT-C(Sx)- DT*PGAEDDE-Z, X-VEVDPMLT*P-C(Sx)-ERHLN-Z, X-VEVDP-C(Sx)-LT*PEERHLN- Z, X-EEYETPES*P-C(Sx)-PPARS-Z, X-EEYET-C(Sx)-ES*PVPPARS-Z, X- PAADAIMS*P-C(Sx)-EELDG-Z, X-PAADA-C(Sx)-MS*PEEELDG-Z, X-VLSRQITS*P- C(Sx)-SGING-Z, X-VLSRQ-C(Sx)-TS*PVSGING-Z, X-RSKSAPTS*P-C(Sx)-DQEIK-Z, X-TPPQEHIS*P-C(Sx)-IT EV-Z, X-TPPQE-C(Sx)-IS*PQIT EV-Z, X-LSTPVVLS*P- C(Sx)-PQKP-Z, X-LSTPV-C(Sx)-LS*PGPQKP-Z, X-QLSKWPGS*P-C(Sx)-SRSSD-Z, X- KNIVTPRT*P-C(Sx)-PSQGK-Z, X-KNIVT-C(Sx)-RT*PPPSQGK-Z, X-SGVEVRVT*P- C(Sx)-RTEII-Z, X-SGVEV-C(Sx)-VT*PTRTEII-Z, X-SRRSGLSS*P-C(Sx)-YVAVT-Z, X- SRRSG-C(Sx)-SS*PSYVAVT-Z, X-TFDSLPSS*P-C(Sx)-SATPH-Z, X-TFDSL-C(Sx)- SS*PSSATPH-Z, X-PVVSGDTS*P-C(Sx)-HLSNV-Z, X-PVVSG-C(Sx)-TS*PRHLSNV-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-PTIPGVTS*P-C(Sx)-SDEPP-Z, X-SRSHSAKT*P- C(Sx)-FSVQS-Z, X-GHVEEPAS*P-C(Sx)-AAYQK-Z, X-QGPAPVGT*P-C(Sx)-F RQH- Z, X-LLSNASAT*P-C(Sx)-GRRGR-Z, X-QARAKTQT*P-C(Sx)-VSPAP-Z, X-QARAK- C(Sx)-QT*PPVSPAP-Z, X-VSYEDPPT*A-C(Sx)-AAVEW-Z, X-QMAGTPIT*P-C(Sx)- KDGFT-Z, X-QMAGTPIT*P-C(Sx)-KDGFT-Z, X-DADRSILS*P-C(Sx)-GSCGP-Z, X- LVEKLPDS*P-C(Sx)-LAKKA-Z, X-FGESPPLS*P-C(Sx)-DMDTQ-Z, X-EVPDVTAT*P- C(Sx)-RLLFF-Z, X-SAVNGTSS*A-C(Sx)-T LEA-Z, X-LGGLRISS*D-C(Sx)-SSDIE-Z, X-LAGISRS*V-C(Sx)-VTVAY-Z, X- PQDSVGS*P-C(Sx)-SRVGE-Z, X-KDEILPTT*P- C(Sx)-SEQKG-Z, X-KDEIL-C(Sx)-TT*PISEQKG-Z, X-HQLFRGFS*F-C(Sx)-AITSD-Z, X-RGGPEPLS*P-C(Sx)-PVSPL-Z, X-SGDYMPMS*P-C(Sx)-SVSAP-Z, X- YMPMSPKS*V-C(Sx)-APQQI-Z, X-QAATGFGS*P-C(Sx)-QYSAD-Z, X-SFITPPTT*P- C(Sx)-LRRHT-Z, X-TKLKPPRT*P-C(Sx)-PPSRK-Z, X-ESPEKVS*P-C(Sx)-KICDF-Z, X- GLSGRKSS*T-C(Sx)-SPTSP-Z, X-PSV PSIS*P-C(Sx)-HGVAR-Z, X-YKRRYVET*P- C(Sx)-VHISS-Z, X-NVRVSNGS*P-C(Sx)-LERMD-Z, X-DDIEQWFT*E-C(Sx)-PGPDE-Z, X-EPPPRPKT*P-C(Sx)-IFRAL-Z, X-EPPPRPKT*P-C(Sx)-IFRAL-Z, X-ARVSPPES*P- C(Sx)-ARAAA-Z, X-ARVSPPES*P-C(Sx)-ARAAA-Z, X-KKKLAP PSFS*P-C(Sx)- PGFTP-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EIRSRHSS*Y-C(Sx)-AGTED-Z, X- SRDPVART*S-C(Sx)-LQTPA-Z, X-PSWHLADS*P-C(Sx)-VNGAT-Z, X-PTSPRRYS*P- C(Sx)-AKDLL-Z, X-IHFWSSLS*P-C(Sx)-APLSP-Z, X-LSPVAPLS*P-C(Sx)-RLQGP-Z, X-PQPLRS*P-C(Sx)-LD PT-Z, X-GSASASGS*P-C(Sx)-DPGFM-Z, X-RTD SLA AT *P- C(Sx)-AAK-Z, X-RRVSGNNS*P-C(Sx)-LSNGG-Z, X-RPASVNGS*P-C(Sx)-ATSES-Z, X- PSRPPPPT*P-C(Sx)-RPASV-Z, X-DRVSRSSS*P-C(Sx)-KTGEQ-Z, X-PLKTGEQT*P- C(Sx)-HEHI-Z, X-ATEEIYLT*P-C(Sx)-QRPPD-Z, X-SNGHITTT*P-C(Sx)-PTQFL-Z, X- GHITTTPT*P-C(Sx)-QFL-Z, X-KKKSNGLVTTT*P-C(Sx)-SSQFL-Z, X-PSAPALST*P- C(Sx)-IRDSA-Z, X-SF QQ-C(Sx)-DS*PHVVKYY-Z, X-EYSLPALT*P-C(Sx)-LDEVK-Z, X-RGSMAAPS*L-C(Sx)-PSLGP-Z, X-KRKLP-C(Sx)-DT*PGQGLT-Z, X-PRTSPIMS*P- C(Sx)-TSLAE-Z, X-GKKATQAS*Q-C(Sx)-Y-Z, X-NSKYNAES*T-C(Sx)-RESQD-Z, X- SKYNAES*T-C(Sx)-RESQDT-Z, X-SGYSSPGS*P-C(Sx)-TPGSR-Z, X-GQSSAAAT*P- C(Sx)-TTGTK-Z, X-TTGTKSNT*P-C(Sx)-SSVPS-Z, X-TTGTK-C(Sx)-NT*PTSSVPS-Z, X-SVPSAAVT*P-C(Sx)- ESLQ-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-SNTGQAIS*P-C(Sx)-MKRRI-Z, X-SNTGQ- C(Sx)-IS*PGMKRRI-Z, X-QSMVVPQT*P-C(Sx)-HTARV-Z, X-QSMVV-C(Sx)- QT*PLHTARV-Z, X-TTLHRNVS*P-C(Sx)-APQRP-Z, X-TTLHR-C(Sx)-VS*PGAPQRP- Z, X-SIKSEPIS*P-C(Sx)-RDRMT-Z, X-SIKSE-C(Sx)-IS*PPRDRMT-Z, X-DPRGDFHS*P- C(Sx)-VLGRP-Z, X-DPRGD-C(Sx)-HS*PIVLGRP-Z, X-PNTEDRES*P-C(Sx)-VKRMR-Z, X-PNTED-C(Sx)-ES*PSVKRMR-Z, X-KEHRG-C(Sx)-DS*PDPDTSY-Z, X- PDTSYVLT*P-C(Sx)-TEEKY-Z, X-PDTSY-C(Sx)-LT*PHTEEKY-Z, X-SAKSR-C(Sx)- QT*APVPMPD-Z, X-SAKSR-C(Sx)-QT*APVPMPD-Z, X-STSVT-C(Sx)-HS*PSSPVGS- Z, X-KMEVEELS*P-C(Sx)-ALGRF-Z, X-S*T-C(Sx)-SEPLSPTSSLGE-Z, X- GVRRRRLS*N-C(Sx)-SLTGV-Z, X-GVRRR-C(Sx)-LS*NVSLTGV-Z, X-RRRLSNVS*L- C(Sx)-GVSTI-Z, X-RRRLS-C(Sx)-VS*LTGVSTI-Z, X-GREKRSNS*Q-C(Sx)-YIGRP-Z, X-GREKR-C(Sx)-NS*QSYIGRP-Z, X-EDA RTIS*P-C(Sx)-TSNNI-Z, X-EDA RTISP- C(Sx)-TS*NNI-Z, X-RTISPSTS*N-C(Sx)-IPLMR-Z, X-RTISP-C(Sx)-TS*NNIPLMR-Z, X- GEKSFRRS*V-C(Sx)-GTPAY-Z, X-GEKSF-C(Sx)-RS*VVGTPAY-Z, X-EPGPVPSS*P- C(Sx)-QEPPT-Z, X-PLQRQPSS*P-C(Sx)-PTPRN-Z; wherein X- is H or acetyl; and Z is OH

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-YSHKGHLS*E-C(Sx)-LVTKW-Z, X- PPYNRAVS*L-C(Sx)-SPVSV-Z, X-PDVEMPS*P-C(Sx)-APSGD-Z, X-SRLRD-C(Sx)- PS*APLEAPE-Z, X-DPLPP-C(Sx)-FS*GTPKGSG-Z, X-VKAEPAHT*A-C(Sx)-SVAAK-Z, X-DSLSYYHS*P-C(Sx)-DSFSS-Z, X-SALQGFNS*P-C(Sx)-MLSLG-Z, X-LTDPRLLS*P- C(Sx)-QPALQ-Z, X-VNTRA-C(Sx)-PS*QHSSPAV-Z, X-QHSSPAVS*D-C(Sx)-LPSNS-Z, X-AVSDSLPS*N-C(Sx)-LKKSS-Z, X-SNSLKKSS*A-C(Sx)-LKKIL-Z, X-LPGPPS*P- C(Sx)-SDAES-Z, X-SPLSDPSS*P-C(Sx)-ASEDF-Z, X-A PSPPPS*P-C(Sx)-QQINL-Z, X- AHEGV-C(Sx)-LS*VPEYRSR-Z, X-EKGPEGVS*P-C(Sx)-QAHLH-Z, X-GPEDQAVT*E- C(Sx)-VATRW-Z, X-GGSSGT*S-C(Sx)-EKGPE-Z, X-DPQLPSRT*P-C(Sx)-QGPRP-Z, X- APEVL-C(Sx)-SS*HRYTLGV-Z, X-RADPQ-C(Sx)-PS*RTPVQGP-Z, X- S SKRAKAKTTKKRPQRAT S *N-C(Sx)-F S-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FS-Z, X-KTTKKRPQRATS*N-C(Sx)-FS-Z, X- KKRPQRATS*N-C(Sx)-FAM-Z, X-QETFS*D- C(Sx)-WKLLP-Z, X-QE-C(Sx)-FS*DLWKLLP-Z, X-GYAKDVDQGSL-C(Sx)- TS*FVGTLQYLAKKK-Z, X-GYAKDVDQGS*L-C(Sx)-TSFVGTLQYLAKKK-Z, X-R- C(Sx)-FS*LRRKAK-Z, X-A-C(Sx)-KTPKKAKKP-Z, X-I-C(Sx)-TS*PITTTYFFFKKK-Z, X-WD-C(Sx)-DS*DDDDDAAA-Z, X-WD-C(Sx)-DS*DDDDDAAAKKK-Z, X-VSGQL- C(Sx)-DS*MANSFVGTRSYKKK-Z, X-KKKVSGQLIDSM-C(Sx)-NS*FVGTRSY-Z, KKKVSGQLIDS*M-C(Sx)-NSFVGTRSY-Z, X-KKKVSGQLIDSMANSF-C(Sx)- GT*RSY-Z, X-KKKVSGQLIDSMANS*F-C(Sx)-GTRSY-Z, X-QYHFVASSST*I-C(Sx)- RDRQRPYS-Z, X-QYHFVAS-C(Sx)-ST*IERDRQRPYS-Z, X-DA PLMANGT*L-C(Sx)- RRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DANPLM-C(Sx)- NGT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LARRHQNGRF-Z, X-DANPLM- C(Sx)-NGT*LARRHQNGRF-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-[Nle]AKTTKKRPQRATS*N-C(Sx)-FS-Z, X- [Nle]AKTTKKRPQRATSN-C(Sx)-FS*-Z, X-[Nle]A PLMA-C(Sx)-GT*LTRRHQNGRF- Z, X-[Nle]-C(Sx)-DS*LRRKAK-Z, X-[Nle]-C(Sx)-LS*PGPF-Z, X-[Nle]KRPQRAT*S- C(Sx)-VFAMF-Z, X-[Nle]LLR-C(Sx)-SS*RRIRR-Z, X-[Nle]LPWWR-C(Sx)- YT * W VVERD VNTKQR-Z, X-[Nle]QREGFGRQS*M-C(Sx)-EKR-Z, X-[Nle]RR-C(Sx)- AS*FRRR-Z, X-AA-C(Sx)-IS*PLGALQHGFFR-Z, X-AANPLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-A-C(Sx)-DS*LRRKAK-Z, X-A-C(Sx)-IS*PLGALQHGFFR-Z, X-A-C(Sx)-KT*PKKAKKP-Z, X-A-C(Sx)-LS*PGPF-Z, X-ADPDHDHT*G-C(Sx)- LTEYVATRWRR-Z, X-ADPDHDHTG-C(Sx)-LT*EYVATRWRR-Z, X-AE-C(Sx)- Q S *LNAAD VE LHLPL-Z, X-AESQS*L-C(Sx)-AADVE LHLPL-Z, X-AFRLER-C(Sx)- DS*IFYPRR-Z, X-AGTS*F-C(Sx)-[Nle]TP[pY]VVTRKKK-Z, X-AGTS*F-C(Sx)- [Nl e] TP Y V VTRKKK-Z, X-AGTSF-C(Sx)-[Nle]T*P[pY]VVTRKKK-Z, X-AGTSF-C(Sx)- [Nle]T*PYVVTRKKK-Z, X-AHEGV-C(Sx)-LS*VPEYRSR-Z, X-AHLQRQLS*I-C(Sx)- EN-Z, X-AHLQRQLS*I-C(Sx)-EP-Z, X-AHLQRQLS*I-C(Sx)-FA-Z, X-AHLQRQLS*I- C(Sx)-FS-Z, X-AHLQRQLS*I-C(Sx)-HH-Z, X-AHLQRQLSI-C(Sx)-FS*-Z, X- AKRPQRAT*S-C(Sx)-VFA-Z, X-AKRPQRAT*S-C(Sx)-VF-Z, X-AKRPQRATS*N-C(Sx)- FA-Z, X-AKRPQRATS*N-C(Sx)-F-Z, X-AKRRRLAS*L-C(Sx)-ASTSK-Z, X- AKRRRLASL-C(Sx)-AS*TSK-Z, X-ALKLSRYS*F-C(Sx)-ITAK-Z, X-ALKLSRYSF- C(Sx)-IT*AK-Z, X-ALLR-C(Sx)-SS*RRIRR-Z, X-ALPWWR-C(Sx)- YT*WVVERD VNTKQR-Z, X-ALRRAS*L-C(Sx)-AA-Z, X-ALRRFS*L-C(Sx)-GA-Z, X- AP-C(Sx)-PS*QAMDDLMLSPDD-Z, and X-APEKG-C(Sx)-PT*PQVLQRN-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-APEKGLPT*P-C(Sx)-VLQRN-Z, X-APEVL- C(Sx)-SS*HRYTLGV-Z, X-APPSEET*P-C(Sx)-IPQRS-Z, X- AQ AEGF GRQ S * [Nl e] - C(Sx)-EKR[pT]K-Z, X-AQAEGFGRQS*[Nle]-C(Sx)-EKRTK-Z, X-AQAEGFGRQS*M- C(Sx)-EKR[pT]K-Z, X-AQAEGFGRQS*M-C(Sx)-EKRTK-Z, X-AQREGFGRQS*M- C(Sx)-EKR-Z, X-AR-C(Sx)-LS*FAEG-Z, X-AR-C(Sx)-LS*FAEPG-Z, X- ARKRERAYS*[Nle][dP]-C(Sx)-G-Z, X-ARKRERAYS*[Nle]-C(Sx)-G-Z, X- ARKRERAYS*A-C(Sx)-G-Z, X-ARKRERAYS*E[dP]-C(Sx)-G-Z, X- ARKRERAYS*F[dP]-C(Sx)-G-Z, X-ARKRERAYS*FA-C(Sx)-G-Z, X- ARKRERAYS *F- C(Sx)-G-Z, X-ARKRERAYS*FD-C(Sx)-G-Z, X-ARKRERAYS*FE-C(Sx)-G-Z, X- ARKRERAYS*FF-C(Sx)-G-Z, X-ARKRERAYS*FG-C(Sx)-G-Z, X- ARKRERAYS *FH- C(Sx)-G-Z, X- ARKRERAYS *FI-C(Sx)-G-Z, X- ARKRERAYS *FK-C(Sx)-G-Z, X- ARKRERAYS*FL-C(Sx)-G-Z, X- ARKRERAYS *FN-C(Sx)-G-Z, X- ARKRERAYS *FP- C(Sx)-G-Z, X- ARKRERAYS *FQ-C(Sx)-G-Z, X- ARKRERAYS *FR-C(Sx)-G-Z, X- ARKRERAYS*FV-C(Sx)-G-Z, X- ARKRERAYS *FW-C(Sx)-G-Z, X- ARKRERAYS*G[dP]-C(Sx)-G-Z, X-ARKRERAYS*G-C(Sx)-G-Z, X- ARKRERAYS *GG- C(Sx)-G-Z, X- ARKRERAYS *H[dP]-C(Sx)-G-Z, X- ARKRERAYS *H-C(Sx)-G-Z, X- ARKRERAYS*I[dP]-C(Sx)-G-Z, X- ARKRERAYS *I-C(Sx)-G-Z, X-ARKRERAYS*K[dP]- C(Sx)-G-Z, X- ARKRERAYS *K-C(Sx)-G-Z, X- ARKRERAYS *L[dP]-C(Sx)-G-Z, X- ARKRERAYS*L-C(Sx)-G-Z, X- ARKRERAYS *N-C(Sx)-G-Z, X- ARKRERAYS *P-C(Sx)- G-Z, X-ARKRERAYS*Q[dP]-C(Sx)-G-Z, X-ARKRERAYS*Q-C(Sx)-G-Z, X- ARKRERAYS*R[dP]-C(Sx)-G-Z, X- ARKRERAYS *R-C(Sx)-G-Z, X- ARKRERAYS*V[dP]-C(Sx)-G-Z, X- ARKRERAYS *V-C(Sx)-G-Z, X- ARKRERAYS*W[dP]-C(Sx)-G-Z, X- ARKRERAYS *W-C(Sx)-G-Z, X- ARKRERAYSN[dP]-C(Sx)-G-Z, X-ARKRERAYSP[dP]-C(Sx)-G-Z, X- ARKRRRHP S * G- C(Sx)-PTA-Z, and X-ARR-C(Sx)-AS*FRRR-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-ART*K-C(Sx)-TARKSTGGKAPRK-Z, X-ART*K- C(Sx)-TARKSTGGK-Z, X-ARTKQT*A-C(Sx)-KSTGGKAPRK-Z, X-ARTKQT*A-C(Sx)- KSTGGK-Z, X-ARTKQTARKS*T-C(Sx)-GKAPRK-Z, X-ARTKQTARKS*T-C(Sx)-GK-Z, X-ARVS*P-C(Sx)-ESPRARAAA-Z, X-ARVSP-C(Sx)-ES*PRARAAA-Z, X- ARVSPPES*P-C(Sx)-ARAAA-Z, X-ATEEIYLT*P-C(Sx)-QRPPD-Z, X-AVSDSLPS*N- C(Sx)-LKKSS-Z, X-C(Sx)-[Nle]S*LRRKAK-Z, X-C(Sx)-AS*LRRKAK-Z, X-C(Sx)- DS*LRRKAK-Z, X-C(Sx)-ES*LRRKAK-Z, X-C(Sx)-ES*QEAFADLWKK-Z, X-C(Sx)- E S * QETF SDL WKK-Z, X-C(Sx)-FS*[Nle]RRKAK-Z, X-C(Sx)-FS*ARRKAK-Z, X-C(Sx)- FS*DRRKAK-Z, X-C(Sx)-FS*ERRKAK-Z, X-C(Sx)-FS*FRRKAK-Z, X-C(Sx)- FS*GRRKAK-Z, X-C(Sx)-FS*HRRKAK-Z, X-C(Sx)-FS*IRRKAK-Z, X-C(Sx)- FS*KRRKAK-Z, X-C(Sx)-FS*L[Nle]RKAK-Z, X-C(Sx)-FS*LARKAK-Z, X-C(Sx)- FS*LDRKAK-Z, X-C(Sx)-FS*LERKAK-Z, X-C(Sx)-FS*LFRKAK-Z, X-C(Sx)- FS*LGRKAK-Z, X-C(Sx)-FS*LHRKAK-Z, X-C(Sx)-FS*LIRKAK-Z, X-C(Sx)- FS*LKRKAK-Z, X-C(Sx)-FS*LLRKAK-Z, X-C(Sx)-FS*L RKAK-Z, X-C(Sx)- FS*LPRGAK-Z, X-C(Sx)-FS*LPRKAK-Z, X-C(Sx)-FS*LQRKAK-Z, X-C(Sx)- FS*LR[Nle]KAK-Z, X-C(Sx)-FS*LRAKAK-Z, X-C(Sx)-FS*LRDKAK-Z, X-C(Sx)- FS*LREKAK-Z, X-C(Sx)-FS*LRFKAK-Z, X-C(Sx)-FS*LRGKAK-Z, X-C(Sx)- FS*LRHKAK-Z, X-C(Sx)-FS*LRIKAK-Z, X-C(Sx)-FS*LRKKAK-Z, X-C(Sx)- FS*LRLKAK-Z, X-C(Sx)-FS*LR KAK-Z, X-C(Sx)-FS*LRPKAK-Z, X-C(Sx)- FS*LRQKAK-Z, X-C(Sx)-FS*LRR[Nle]AK-Z, X-C(Sx)-FS*LRRAAK-Z, X-C(Sx)- FS*LRRDAK-Z, X-C(Sx)-FS*LRREAK-Z, X-C(Sx)-FS*LRRFAK-Z, X-C(Sx)- F S *LRRGAK-Z, X-C(Sx)-FS*LRRHAK-Z, X-C(Sx)-FS*LRRIAK-Z, X-C(Sx)- FS*LRRK[Nle]K-Z, and X-C(Sx)-FS*LRRKA[Nle]-Z; wherein X is H or acetyl; and Z is

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-C(Sx)-FS*LRRKAA-Z, X-C(Sx)-FS*LRRKAD-Z, X-C(Sx)-FS*LRRKAE-Z, X-C(Sx)-FS*LRRKAF-Z, X-C(Sx)-FS*LRRKAG-Z, X-C(Sx)- F S *LRRK AH-Z, X-C(Sx)-FS*LRRKAI-Z, X-C(Sx)-FS*LRRKAL-Z, X-C(Sx)- F S *LRRK AN-Z, X-C(Sx)-FS*LRRKAP-Z, X-C(Sx)-FS*LRRKAQ-Z, X-C(Sx)- FS*LRRKAR-Z, X-C(Sx)-FS*LRRKAV-Z, X-C(Sx)-FS*LRRKAW-Z, X-C(Sx)- FS*LRRKDK-Z, X-C(Sx)-FS*LRRKEK-Z, X-C(Sx)-FS*LRRKFK-Z, X-C(Sx)- F S *LRRKGK-Z, X-C(Sx)-FS*LRRKHK-Z, X-C(Sx)-FS*LRRKIK-Z, X-C(Sx)- F S *LRRKKK-Z, X-C(Sx)-FS*LRRKLK-Z, X-C(Sx)-FS*LRRK K-Z, X-C(Sx)- FS*LRRKPK-Z, X-C(Sx)-FS*LRRKQK-Z, X-C(Sx)-FS*LRRKRK-Z, X-C(Sx)- F S *LRRKVK-Z, X-C(Sx)-FS*LRRKWK-Z, X-C(Sx)-FS*LRRLAK-Z, X-C(Sx)- FS*LRRNAK-Z, X-C(Sx)-FS*LRRPAK-Z, X-C(Sx)-FS*LRRQAK-Z, X-C(Sx)- FS*LRRRAK-Z, X-C(Sx)-FS*LRRVAK-Z, X-C(Sx)-FS*LRRWAK-Z, X-C(Sx)- FS*LRVKAK-Z, X-C(Sx)-FS*LRWKAK-Z, X-C(Sx)-FS*LVRKAK-Z, X-C(Sx)- F S *LWRKAK-Z, X-C(Sx)-FS* RRKAK-Z, X-C(Sx)-FS*PRRKAK-Z, X-C(Sx)- FS*QRRKAK-Z, X-C(Sx)-FS*RRRKAK-Z, X-C(Sx)-FS*VRRKAK-Z, X-C(Sx)- FS*WRRKAK-Z, X-C(Sx)-GS*LRRKAK-Z, X-C(Sx)-HS*LKRGNR-Z, X-C(Sx)- HS*LKRK R-Z, X-C(Sx)-HS*LPRF R-Z, X-C(Sx)-HS*LPRK K-Z, X-C(Sx)- HS *LRRKAK-Z, X-C(Sx)-IS*LRRKAK-Z, X-C(Sx)-KS*LRRKAK-Z, X-C(Sx)- K S *P AKEK AK SPEK-Z , X-C(Sx)-LS*FAEG-Z, X-C(Sx)-LS*FAEPG-Z, X-C(Sx)- LS*FRRR-Z, X-C(Sx)-LS*LRRKAK-Z, X-C(Sx)-LS*QEAFADLWKK-Z, X-C(Sx)- NS*LRRKAK-Z, X-C(Sx)-PS*LRRKAK-Z, X-C(Sx)-QS*LRRKAK-Z, X-C(Sx)- Q S * QE AF ADLWKK-Z , X-C(Sx)-QS*QETFS*DLWKK-Z, and X-C(Sx)-RS*LRRKAK-Z; wherein X- is H or acetyl; and Z is OH or H2. In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-C(Sx)-RT*KQTARKSTGGKAPRK-Z, X-C(Sx)- RT*KQTARKSTGGK-Z, X-C(Sx)-VS*LRRKAK-Z, X-C(Sx)-WS*LRRKAK-Z, X- D[Nle] PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA[Nle]PLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DAAPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DADPLMA- C(Sx)-GT*LTRRHQNGRF-Z, X-DADRSILS*P-C(Sx)-GSSGP-Z, X-DADRSILSP-C(Sx)- GS*SGP-Z, X-DAEPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DAFPLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DAGPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DAHPLMA- C(Sx)-GT*LTRRHQNGRF-Z, X-DAIPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X- DAKPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DAKTTKKRPQRATS*N-C(Sx)-FS-Z, X- DAKTTKKRPQRATSN-C(Sx)-FS*-Z, X-DALPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X- DAN[Nle]LMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DANALMA-C(Sx)-GT*LTRRHQNGRF- Z, X-DA DLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA ELMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA FLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DANGLMA- C(Sx)-GT*LTRRHQNGRF-Z, X-DA HLMA-C(Sx)-GT*LTRRHQNGRF-Z, X- DANILMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA KLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA LLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DAN LMA-C(Sx)-GT*LTRRHQNGRF- Z, X-DANP[Nle]MA-C(Sx)-GT*LTRRHQNGRF-Z, X-DANPAMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PDMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PEMA- C(Sx)-GT*LTRRHQNGRF-Z, X-DA PFMA-C(Sx)-GT*LTRRHQNGRF-Z, X- DA PGMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PHMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PF A-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PKMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PL[Nle]A-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLAA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PLDA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLEA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PLFA-C(Sx)-GT*LTRRHQNGRF-Z, X-DANPLGA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PLHA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLIA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PLKA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLLA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PLM[Nle]-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMA- C(Sx)-[Nle]T*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-AT*LTRRHQNGRF-Z, X- DA PLMA-C(Sx)-DT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-ET*LTRRHQNGRF-Z, and X-DANPLMA-C(Sx)-FT*LTRRHQNGRF-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-DA PLMA-C(Sx)-GT*ATRRHQNGRF-Z, X- DA PLMA-C(Sx)-GT*DTRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*ETRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*FTRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*GT*RRHQNGRF- Z, X-DA PLMA-C(Sx)-GT*HTRRHQNGRF-Z, X-DA PLMA-C(Sx)- GT*ITRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*KTRRHQNGRF-Z, X-DA PLMA- C(Sx)-GT*L[Nle]RRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LARRHQNGRF-Z, X- DA PLMA-C(Sx)-GT*LDRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LERRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LFRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LGRRHQNGRF- Z, X-DA PLMA-C(Sx)-GT*LHRRHQNGRF-Z, X-DA PLMA-C(Sx)- GT*LIRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LKRRHQNGRF-Z, X-DANPLMA- C(Sx)-GT*LLRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*L RRHQNGRF-Z, X- DA PLMA-C(Sx)-GT*LPRRHQNGRF-Z, X-DANPLMA-C(Sx)-GT*LQRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LRRRHQNGRF-Z, X-DA PLMA-C(Sx)- GT*LT[Nle]RHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTARHQNGRF-Z, X-DA PLMA- C(Sx)-GT*LTDRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTERHQNGRF-Z, X- DA PLMA-C(Sx)-GT*LTFRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTGRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTHRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTIRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTKRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTLRHQNGRF- Z, X-DANPLMA-C(Sx)-GT*LT RHQNGRF-Z, X-DA PLMA-C(Sx)- GT*LTPRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTQRHQNGRF-Z, X-DA PLMA- C(Sx)-GT*LTR[Nle]HQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRAHQNGRF-Z, X- DA PLMA-C(Sx)-GT*LTRDHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTREHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRFHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRGHQNGRF- Z, X-DANPLMA-C(Sx)-GT*LTRHHQNGRF-Z, X-DA PLMA-C(Sx)- GT*LTRIHQNGRF-Z, X-DANPLMA-C(Sx)-GT*LTRKHQNGRF-Z, X-DA PLMA- C(Sx)-GT*LTRLHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRNHQNGRF-Z, X- DA PLMA-C(Sx)-GT*LTRPHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRQHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRR[Nle]QNGRF-Z, X-DA PLMA-C(Sx)- GT*LTRRAQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRDQNGRF-Z, X-DA PLMA- C(Sx)-GT*LTRREQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRFQNGRF-Z, X- DA PLMA-C(Sx)-GT*LTRRGQNGRF-Z, and X-DA PLMA-C(Sx)- GT*LTRRH[Nle]NGRF-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-DA PLMA-C(Sx)-GT*LTRRHANGRF-Z, X- DA PLMA-C(Sx)-GT*LTRRHDNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHENGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHFNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHGNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHHNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHINGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHKNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHLNGRF- Z, X-DANPLMA-C(Sx)-GT*LTRRHNNGRF-Z, X-DANPLMA-C(Sx)- GT*LTRRHPNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQ[Nle]GRF-Z, X-DA PLMA- C(Sx)-GT*LTRRHQAGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQDGRF-Z, X- DA PLMA-C(Sx)-GT*LTRRHQEGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQFGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQGGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQHGRF- Z, X-DANPLMA-C(Sx)-GT*LTRRHQIGRF-Z, X-DA PLMA-C(Sx)- GT*LTRRHQKGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQLGRF-Z, X-DA PLMA- C(Sx)-GT*LTRRHQN[Nle]RF-Z, X-DANPLMA-C(Sx)-GT*LTRRHQNARF-Z, X- DA PLMA-C(Sx)-GT*LTRRHQ DRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNERF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQ FRF-Z, X-DA PLMA-C(Sx)- GT*LTRRHQNG[Nle]F-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGAF-Z, X-DA PLMA- C(Sx)-GT*LTRRHQNGDF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGEF-Z, X- DA PLMA-C(Sx)-GT*LTRRHQNGFF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGGF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGHF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGIF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGKF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGLF- Z, X-DANPLMA-C(Sx)-GT*LTRRHQNG F-Z, X-DA PLMA-C(Sx)- GT*LTRRHQNGPF-Z, X-DANPLMA-C(Sx)-GT*LTRRHQNGQF-Z, X-DA PLMA- C(Sx)-GT*LTRRHQNGR[Nle]-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRA-Z, X- DA PLMA-C(Sx)-GT*LTRRHQNGRD-Z, X-DANPLMA-C(Sx)-GT*LTRRHQNGRE-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRG- Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRH-Z, X-DA PLMA-C(Sx)- GT*LTRRHQNGRI-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRK-Z, X-DA PLMA- C(Sx)-GT*LTRRHQNGRL-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRN-Z, and X- DA PLMA-C(Sx)-GT*LTRRHQNGRP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-DA PLMA-C(Sx)-GT*LTRRHQNGRQ-Z, X- DA PLMA-C(Sx)-GT*LTRRHQNGRR-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRV-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGRW-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNGVF- Z, X-DANPLMA-C(Sx)-GT*LTRRHQNGWF-Z, X-DA PLMA-C(Sx)- GT*LTRRHQ HRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNIRF-Z, X-DA PLMA- C(Sx)-GT*LTRRHQNKRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQ LRF-Z, X- DA PLMA-C(Sx)-GT*LTRRHQN RF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQ PRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQNQRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQ RRF- Z, X-DANPLMA-C(Sx)-GT*LTRRHQNVRF-Z, X-DANPLMA-C(Sx)- GT*LTRRHQNWRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQPGRF-Z, X-DANPLMA- C(Sx)-GT*LTRRHQQGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQRGRF-Z, X- DA PLMA-C(Sx)-GT*LTRRHQVGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHQWGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHRNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRHVNGRF- Z, X-DA PLMA-C(Sx)-GT*LTRRHWNGRF-Z, X-DA PLMA-C(Sx)- GT*LTRRIQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRKQNGRF-Z, X-DA PLMA- C(Sx)-GT*LTRRLQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRNQNGRF-Z, X- DA PLMA-C(Sx)-GT*LTRRPQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRQQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRRQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRRVQNGRF- Z, X-DA PLMA-C(Sx)-GT*LTRRWQNGRF-Z, X-DA PLMA-C(Sx)- GT*LTRVHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTRWHQNGRF-Z, X-DA PLMA- C(Sx)-GT*LTVRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LTWRHQNGRF-Z, X- DA PLMA-C(Sx)-GT*LVRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*LWRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*NTRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*PTRRHQNGRF- Z, X-DA PLMA-C(Sx)-GT*QTRRHQNGRF-Z, X-DA PLMA-C(Sx)- GT*RTRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT*VTRRHQNGRF-Z, X-DA PLMA- C(Sx)-GT*WTRRHQNGRF-Z, X-DA PLMA-C(Sx)-GT[Nle]TRRHQNGRF-Z, X- DA PLMA-C(Sx)-HT*LTRRHQNGRF-Z, and X-DA PLMA-C(Sx)-IT*LTRRHQNGRF- Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-DA PLMA-C(Sx)-KT*LTRRHQNGRF-Z, X- DA PLMA-C(Sx)-LT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-NT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-PT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-QT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-RT*LTRRHQNGRF-Z, X-DA PLMA-C(Sx)-VT*LTRRHQNGRF- Z, X-DA PLMA-C(Sx)-WT*LTRRHQNGRF-Z, X-DA PLMANGT*L-C(Sx)- RRHQNGRF-Z, X-DA PLM-C(Sx)-NGT*LARRHQNGRF-Z, X-DA PLM-C(Sx)- NGT*LTRRHQNGRF-Z, X-DA PLMD-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLME- C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMF-C(Sx)-GT*LTRRHQNGRF-Z, X- DA PLMG-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMH-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMI-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMK-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLML-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMN-C(Sx)-GT*LTRRHQNGRF- Z, X-DANPLMP-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMQ-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PLMR-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMV- C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLMW-C(Sx)-GT*LTRRHQNGRF-Z, X- DA PLNA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLPA-C(Sx)-GT*LTRRHQNGRF-Z, X- DA PLQA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLRA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLVA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PLWA-C(Sx)-GT*LTRRHQNGRF- Z, X-DANP MA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PPMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DA PQMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA PRMA- C(Sx)-GT*LTRRHQNGRF-Z, X-DA PVMA-C(Sx)-GT*LTRRHQNGRF-Z, X- DA PWMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DANQLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DA RLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DANVLMA-C(Sx)-GT*LTRRHQNGRF- Z, X-DANWLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DAPPLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DAQPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DARPLMA- C(Sx)-GT*LTRRHQNGRF-Z, X-DAVPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X- DAWPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-D-C(Sx)-DS*LRRKAK-Z, X-D-C(Sx)- LS*PGPF-Z, X-DDIEQWFTE-C(Sx)-PGPDE-Z, X-DD PLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DE-C(Sx)-EGT*FRAAIRRLAARRR-Z, X-DE-C(Sx)- EGT*FRSSIRRLSSRRR-Z, and X-DE PLMA-C(Sx)-GT*LTRRHQNGRF-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-DFGLSKWR[Nle][Nle]S*L-C(Sx)-QSRSSKS-Z, X-DFGLSKWR[Nle][Nle]SL-C(Sx)-QS*RSSKS-Z, X-DFGLSKWRMMS*L-C(Sx)- QSRSSKS-Z, X-DFGLSKWRMMS*L-C(Sx)-QSR-Z, X-DFGLSKWRMMS*L-C(Sx)-Q-Z, X-DFGLSKWRMMSL-C(Sx)-QS*RSSKS-Z, X-DFGLSKWRMMSL-C(Sx)-QS*R-Z, X- DF PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DG PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DHNPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DINPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DK PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DKRPQRAT*S-C(Sx)-VFAMF-Z, X- DLGYAKDV-C(Sx)-QGS*LCTSFVGTLQYLAPEKKK-Z, X-DLGYAKD VDQGS *L- C(Sx)-TSFVGTLQYLAPE-Z, X-DLGYAKD VDQGSL-C(Sx)-TS*FVGTLQYLAPE-Z, X- DLGYAKDVDQGSLCTS*F-C(Sx)-GTLQYLAPE-Z, X-DLGYAKD VDQGSLCTSF- C(Sx)-GT*LQYLAPE-Z, X-DLI[Nle]KEDYE-C(Sx)-VS*TKPTR-Z, X-DLIMKEDYE- C(Sx)-VS*TKPTR-Z, X-DLLR-C(Sx)-SS*RRIRR-Z, X-DL PLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DLPDM-C(Sx)-ET*KYTVDKRFGM-Z, X-DLPDMKET*K- C(Sx)-TVDKRFGM-Z, X-DLPDMKET-C(Sx)-YT*VDKRFGM-Z, X- DLPDMKETK YT * V-C( Sx)-KRF GM-Z , X-DLPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-DN PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DPLPP-C(Sx)-FS*GTPKGSGKKK-Z, X- DP PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-DPQLPSRT*P-C(Sx)-QGPRP-Z, X-DPRGD- C(Sx)-HS*PIVLGRP-Z, X-DPRGDFHS*P-C(Sx)-VLGRP-Z, X-DQ PLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DQREGFGRQS*M-C(Sx)-EKR-Z, X-DR PLMA-C(Sx)- GT*LTRRHQNGRF-Z, X-DRR-C(Sx)-AS*FRRR-Z, X-DRVS*R-C(Sx)-SSPLKTGEQ-Z, X-DRVSR-C(Sx)-SS*PLKTGEQ-Z, X-DSLSYYHS*P-C(Sx)-DSFSS-Z, X-DSLSYYHSP- C(Sx)-DS*FSS-Z, X-DV PLMA-C(Sx)-GT*LTRRHQNGRF-Z, and X-DW PLMA-C(Sx)- GT*LTRRHQNGRF-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EAKTTKKRPQRATS*N-C(Sx)-FS-Z, X- EAKTTKKRPQRATSN-C(Sx)-FS*-Z, X-EA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-E- C(Sx)-DS*LRRKAK-Z, X-E-C(Sx)-LS*PGPF-Z, X-EDFSS*I-C(Sx)-DMDFSALLSQISS-Z, X-EDPDYE-C(Sx)-PS*A-Z, X-EENV-C(Sx)-DGS*PNAGSVE-Z, X-EENVSDGS*P-C(Sx)- AGSVE-Z, X-EEYET-C(Sx)-ES*PVPPARS-Z, X-EEYETPES*P-C(Sx)-PPARS-Z, X- EGMI-C(Sx)-LS*ESSRRRIRSG KL-Z, X-EGMILLS*E-C(Sx)-SRRRIRSG KL-Z, X- EIRSRHSS*Y-C(Sx)-AGTED-Z, X-EKGPEGVS*P-C(Sx)-QAHLH-Z, X-EKRPQRAT* S- C(Sx)-VFAMF-Z, X-ELLR-C(Sx)-SS*RRIRR-Z, X-ELPWWR-C(Sx)- YT*WVVERDVNTKQR-Z, X-ELRKT-C(Sx)-TS*[Nle]SLGTTREKTD-Z, X- ELRKTQTS[Nle]S*L-C(Sx)-TTREKTD-Z, X-ELRKTQTS[Nle]SL-C(Sx)-TT*REKTD-Z, X-EPAA-C(Sx)-IS*PLGALQHGFFR-Z, X-EPAARIS*P-C(Sx)-GALQHGFFR-Z, X-EP- C(Sx)-LS*QEAFADLWKK-Z, X-EP-C(Sx)-LS*QETFSDLWKK-Z, X-EP-C(Sx)- Q S * QE AF ADLWKK-Z , X-EP-C(Sx)-QS*QETFSDLWK-Z, X-EPGPVPSS*P-C(Sx)- QEPPT-Z, X-EPIQEANYV-C(Sx)-MT*PGT-Z, X-EPPPR-C(Sx)-KT*PEIFRAL-Z, X- EPPPRPKT*P-C(Sx)-IFRAL-Z, X-EQREGFGRQS*M-C(Sx)-EKR-Z, X-ERR-C(Sx)- AS*FRRR-Z, and X-ESPEKVS*P-C(Sx)-KISDF-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-ET-C(Sx)-ST*QELYSIPEDQE-Z, X- EVPDVTAT*P-C(Sx)-RLLFF-Z, X-EYSLPALT*P-C(Sx)-LDEVK-Z, X-EYSLPALT*PG- C(Sx)-DEVK-Z, X-EYSLP-C(Sx)-LT*PGLDEVK-Z, X-F[Nle]REGFGRQS*M-C(Sx)- EKR-Z, X-FAKTTKKRPQRATS*N-C(Sx)-FS-Z, X-FAKTTKKRPQRATSN-C(Sx)-FS*-Z, X-FA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-FAREGFGRQS*M-C(Sx)-EKR-Z, X-F- C(Sx)-DS*LRRKAK-Z, X-F-C(Sx)-LS*PGPF-Z, X-FDREGFGRQS*M-C(Sx)-EKR-Z, X- FEREGFGRQS*M-C(Sx)-EKR-Z, X-FFKK-C(Sx)-VT*PRTP-Z, X-FFKKIVT*P-C(Sx)-TP- Z, X-FFKNIVT-C(Sx)-RT*PPPSQGK-Z, X-FFREGFGRQS*M-C(Sx)-EKR-Z, X- FGESPPLS*P-C(Sx)-DMDTQ-Z, X-FGREGFGRQS*M-C(Sx)-EKR-Z, X- FHREGFGRQS*M-C(Sx)-EKR-Z, X-FIREGFGRQS*M-C(Sx)-EKR-Z, X- FKREGFGRQS*M-C(Sx)-EKR-Z, X-FKRPQRAT*S-C(Sx)-VFAMF-Z, X-FKTEG-C(Sx)- DS*D-Z, X-FKTEGPDS*D-C(Sx)-Z, X-FLLR-C(Sx)-SS*RRIRR-Z, X-FLPWWR-C(Sx)- YT * W V VERD VNTKQR-Z , X-FLREGFGRQS*M-C(Sx)-EKR-Z, X-FNREGFGRQS*M- C(Sx)-EKR-Z, X-FP-C(Sx)-FS*YSASGTA-Z, X-FPREGFGRQS*M-C(Sx)-EKR-Z, X- FPRGSSSRST*F-C(Sx)-GEGLR-Z, X-FQ[Nle]EGFGRQS*M-C(Sx)-EKR-Z, X- FQAEGFGRQS*M-C(Sx)-EKR-Z, X-FQDEGFGRQS*M-C(Sx)-EKR-Z, X- FQEEGFGRQS*M-C(Sx)-EKR-Z, X-FQFEGFGRQS*M-C(Sx)-EKR-Z, X- FQGEGFGRQS*M-C(Sx)-EKR-Z, X-FQHEGFGRQS*M-C(Sx)-EKR-Z, X- FQIEGFGRQS*M-C(Sx)-EKR-Z, X-FQKEGFGRQS*M-C(Sx)-EKR-Z, X- FQLEGFGRQS*M-C(Sx)-EKR-Z, X-FQNEGFGRQS*M-C(Sx)-EKR-Z, X- FQPEGFGRQS*M-C(Sx)-EKR-Z, X-FQQEGFGRQS*M-C(Sx)-EKR-Z, X- FQR[Nle]GFGRQS*M-C(Sx)-EKR-Z, X-FQRAGFGRQS*M-C(Sx)-EKR-Z, X- FQRDGFGRQS*M-C(Sx)-EKR-Z, X-FQRE[Nle]FGRQS*M-C(Sx)-EKR-Z, X- FQREAFGRQS*M-C(Sx)-EKR-Z, X-FQREDFGRQS*M-C(Sx)-EKR-Z, X- FQREEFGRQS*M-C(Sx)-EKR-Z, X-FQREFFGRQS*M-C(Sx)-EKR-Z, X- FQREG[Nle]GRQS*M-C(Sx)-EKR-Z, X-FQREGAGRQS*M-C(Sx)-EKR-Z, X- FQREGDGRQS*M-C(Sx)-EKR-Z, X-FQREGEGRQS*M-C(Sx)-EKR-Z, X- FQREGF[Nle]RQS*M-C(Sx)-EKR-Z, X-FQREGFARQS*M-C(Sx)-EKR-Z, and X- FQREGFDRQS*M-C(Sx)-EKR-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-FQREGFERQS*M-C(Sx)-EKR-Z, X- FQREGFFRQS*M-C(Sx)-EKR-Z, X-FQREGFG[Nle]QS*M-C(Sx)-EKR-Z, X- FQREGFGAQS*M-C(Sx)-EKR-Z, X-FQREGFGDQS*M-C(Sx)-EKR-Z, X- FQREGFGEQS*M-C(Sx)-EKR-Z, X-FQREGFGFQS*M-C(Sx)-EKR-Z, X- FQREGFGGQS*M-C(Sx)-EKR-Z, X-FQREGFGHQS*M-C(Sx)-EKR-Z, X- FQREGFGIQS*M-C(Sx)-EKR-Z, X-FQREGFGKQS*M-C(Sx)-EKR-Z, X- FQREGFGLQS*M-C(Sx)-EKR-Z, X-FQREGFGNQS*M-C(Sx)-EKR-Z, X- FQREGFGPQS*M-C(Sx)-EKR-Z, X-FQREGFGQQS*M-C(Sx)-EKR-Z, X- FQREGFGR[Nle]S*M-C(Sx)-EKR-Z, X-FQREGFGRAS*M-C(Sx)-EKR-Z, X- FQREGFGRDS*M-C(Sx)-EKR-Z, X-FQREGFGRES*M-C(Sx)-EKR-Z, X- FQREGFGRFS*M-C(Sx)-EKR-Z, X-FQREGFGRGS*M-C(Sx)-EKR-Z, X- FQREGFGRHS*M-C(Sx)-EKR-Z, X-FQREGFGRIS*M-C(Sx)-EKR-Z, X- FQREGFGRKS*M-C(Sx)-EKR-Z, X-FQREGFGRLS*M-C(Sx)-EKR-Z, X- FQREGFGRNS*M-C(Sx)-EKR-Z, X-FQREGFGRPS*M-C(Sx)-EKR-Z, X- FQREGFGRQS*[Nle]-C(Sx)-EKR-Z, X-FQREGFGRQS*A-C(Sx)-EKR-Z, X- FQREGFGRQS*D-C(Sx)-EKR-Z, X-FQREGFGRQS*E-C(Sx)-EKR-Z, X- FQREGFGRQS*F-C(Sx)-EKR-Z, X-FQREGFGRQS*G-C(Sx)-EKR-Z, X- FQREGFGRQS*H-C(Sx)-EKR-Z, X-FQREGFGRQS*I-C(Sx)-EKR-Z, X- FQREGFGRQS*K-C(Sx)-EKR-Z, X-FQREGFGRQS*L-C(Sx)-EKR-Z, X- FQREGFGRQS*M-C(Sx)-[Nle]KR-Z, X-FQREGFGRQS*M-C(Sx)-AKR-Z, X- FQREGFGRQS*M-C(Sx)-DKR-Z, X-FQREGFGRQS*M-C(Sx)-E[Nle]R-Z, X- FQREGFGRQS*M-C(Sx)-EAATK-Z, X-FQREGFGRQS*M-C(Sx)-EAR-Z, X- FQREGFGRQS*M-C(Sx)-EDR-Z, X-FQREGFGRQS*M-C(Sx)-EER-Z, X- FQREGFGRQS*M-C(Sx)-EFR-Z, X-FQREGFGRQS*M-C(Sx)-EGR-Z, X- FQREGFGRQS*M-C(Sx)-EHR-Z, X-FQREGFGRQS*M-C(Sx)-EIR-Z, X- FQREGFGRQS*M-C(Sx)-EK[Nle]amide-Z, X-FQREGFGRQS*M-C(Sx)-EKA-Z, X- FQREGFGRQS*M-C(Sx)-EKD-Z, X-FQREGFGRQS*M-C(Sx)-EKE-Z, X- FQREGFGRQS*M-C(Sx)-EKF-Z, X-FQREGFGRQS*M-C(Sx)-EKG-Z, X- FQREGFGRQS*M-C(Sx)-EKH-Z, and X-FQREGFGRQS*M-C(Sx)-EKI-Z; wherein X is H or acetyl; and Z is OH or NH2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-FQREGFGRQS*M-C(Sx)-EKK-Z, X- FQREGFGRQS*M-C(Sx)-EKL-Z, X-FQREGFGRQS*M-C(Sx)-EKN-Z, X- FQREGFGRQS*M-C(Sx)-EKP-Z, X-FQREGFGRQS*M-C(Sx)-EKQ-Z, X- FQREGFGRQS*M-C(Sx)-EKR[pT]K-Z, X-FQREGFGRQS*M-C(Sx)-EKRTK-Z, X- FQREGFGRQS*M-C(Sx)-EKV-Z, X-FQREGFGRQS*M-C(Sx)-EKW-Z, X- FQREGFGRQS*M-C(Sx)-ELR-Z, X-FQREGFGRQS*M-C(Sx)-ENR-Z, X- FQREGFGRQS*M-C(Sx)-EPR-Z, X-FQREGFGRQS*M-C(Sx)-EQR-Z, X- FQREGFGRQS*M-C(Sx)-ERR-Z, X-FQREGFGRQS*M-C(Sx)-EVR-Z, X- FQREGFGRQS*M-C(Sx)-EWR-Z, X-FQREGFGRQS*M-C(Sx)-FKR-Z, X- FQREGFGRQS*M-C(Sx)-GKR-Z, X-FQREGFGRQS*M-C(Sx)-HKR-Z, X- FQREGFGRQS*M-C(Sx)-IKR-Z, X-FQREGFGRQS*M-C(Sx)-KKR-Z, X- FQREGFGRQS*M-C(Sx)-LKR-Z, X-FQREGFGRQS*M-C(Sx)-NKR-Z, X- FQREGFGRQS*M-C(Sx)-PKR-Z, X-FQREGFGRQS*M-C(Sx)-QKR-Z, X- FQREGFGRQS*M-C(Sx)-RKR-Z, X-FQREGFGRQS*M-C(Sx)-VKR-Z, X- FQREGFGRQS*M-C(Sx)-WKR-Z, X-FQREGFGRQS*N-C(Sx)-EKR-Z, X- FQREGFGRQS*P-C(Sx)-EKR-Z, X-FQREGFGRQS*Q-C(Sx)-EKR-Z, X- FQREGFGRQS*R-C(Sx)-EKR-Z, X-FQREGFGRQS*V-C(Sx)-EKR-Z, X- FQREGFGRQS*W-C(Sx)-EKR-Z, X-FQREGFGRRS*M-C(Sx)-EKR-Z, X- FQREGFGRVS*M-C(Sx)-EKR-Z, X-FQREGFGRWS*M-C(Sx)-EKR-Z, X- FQREGFGVQS*M-C(Sx)-EKR-Z, X-FQREGFGWQS*M-C(Sx)-EKR-Z, X- FQREGFHRQS*M-C(Sx)-EKR-Z, X-FQREGFIRQS*M-C(Sx)-EKR-Z, X- FQREGFKRQS*M-C(Sx)-EKR-Z, X-FQREGFLRQS*M-C(Sx)-EKR-Z, X- FQREGF RQS*M-C(Sx)-EKR-Z, X-FQREGFPRQS*M-C(Sx)-EKR-Z, X- FQREGFQRQS*M-C(Sx)-EKR-Z, X-FQREGFRRQS*M-C(Sx)-EKR-Z, X- FQREGFVRQS*M-C(Sx)-EKR-Z, X-FQREGFWRQS*M-C(Sx)-EKR-Z, X- FQREGGGRQS*M-C(Sx)-EKR-Z, X-FQREGHGRQS*M-C(Sx)-EKR-Z, X- FQREGIGRQS*M-C(Sx)-EKR-Z, X-FQREGKGRQS*M-C(Sx)-EKR-Z, X- FQREGLGRQS*M-C(Sx)-EKR-Z, X-FQREGNGRQS*M-C(Sx)-EKR-Z, X- FQREGPGRQS*M-C(Sx)-EKR-Z, X-FQREGQGRQS*M-C(Sx)-EKR-Z, X- FQREGRGRQS*M-C(Sx)-EKR-Z, X-FQREGVGRQS*M-C(Sx)-EKR-Z, X- FQREGWGRQS*M-C(Sx)-EKR-Z, X-FQREHFGRQS*M-C(Sx)-EKR-Z, X- FQREIFGRQS*M-C(Sx)-EKR-Z, X-FQREKFGRQS*M-C(Sx)-EKR-Z, X- FQRELFGRQS*M-C(Sx)-EKR-Z, X-FQRE FGRQS*M-C(Sx)-EKR-Z, X- FQREPFGRQS*M-C(Sx)-EKR-Z, X-FQREQFGRQS*M-C(Sx)-EKR-Z, X- FQRERFGRQS*M-C(Sx)-EKR-Z, X-FQREVFGRQS*M-C(Sx)-EKR-Z, X- FQREWFGRQS*M-C(Sx)-EKR-Z, X-FQRFGFGRQS*M-C(Sx)-EKR-Z, X- FQRGGFGRQS*M-C(Sx)-EKR-Z, X-FQRHGFGRQS*M-C(Sx)-EKR-Z, X- FQRIGFGRQS*M-C(Sx)-EKR-Z, X-FQRKGFGRQS*M-C(Sx)-EKR-Z, X- FQRLGFGRQS*M-C(Sx)-EKR-Z, X-FQRNGFGRQS*M-C(Sx)-EKR-Z, X- FQRPGFGRQS*M-C(Sx)-EKR-Z, X-FQRQGFGRQS*M-C(Sx)-EKR-Z, X- FQRRGFGRQS*M-C(Sx)-EKR-Z, X-FQRVGFGRQS*M-C(Sx)-EKR-Z, X- FQRWGFGRQS*M-C(Sx)-EKR-Z, X-FQVEGFGRQS*M-C(Sx)-EKR-Z, X- FQWEGFGRQS*M-C(Sx)-EKR-Z, X-FRR-C(Sx)-AS*FRRR-Z, X-FRREGFGRQS*M- C(Sx)-EKR-Z, X-FVREGFGRQS*M-C(Sx)-EKR-Z, and X-FWREGFGRQS*M-C(Sx)- EKR-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-GAKTTKKRPQRATS*N-C(Sx)-FS-Z, X- GAKTTKKRPQRAT SN-C(Sx)-F S * -Z, X-GA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-G- C(Sx)-DS*LRRKAK-Z, X-G-C(Sx)-LS*PGPF-Z, X-GDGS*D-C(Sx)-PY[pY]NSIPSK-Z, X- GDGS*D-C(Sx)-PYYNSIPSK-Z, X-GEKS*F-C(Sx)-RSVVGTPAY-Z, X-GEKSF-C(Sx)- RS*VVGTPAY-Z, X-GEKSFRRS*V-C(Sx)-GTPAY-Z, X-GEKSFRRSV-C(Sx)-GT*PAY- Z, X-GETSLMRT*L-C(Sx)-GTPTY-Z, X-GETSLMRTL-C(Sx)-GT*PTY-Z, X- GGPEPGPYA-C(Sx)-PS*VNT-Z, X-GGSSGT*S-C(Sx)-EKGPE-Z, X-GHVEEPAS*P- C(Sx)-AAYQK-Z, X-GKKALRRQES*V-C(Sx)-ALGW-Z, X-GKKAT-C(Sx)-AS*QEY-Z, X-GKKATQAS*Q-C(Sx)-Y-Z, X-GKRPQRAT*S-C(Sx)-VFAMF-Z, X-GLLR-C(Sx)- SS*RRIRR-Z, X-GLSGRKSS*T-C(Sx)-SPTSP-Z, X-G LLP[Nle]S*P-C(Sx)-EFD-Z, X- GQL-C(Sx)-DS*[Nle]ANSFVGTR-Z, X-GQLIDS*[Nle]-C(Sx)-NSFVGTR-Z, X- GQLIDS[Nle]ANS*F-C(Sx)-GTR-Z, X-GQLIDS[Nle]ANSF-C(Sx)-GT*R-Z, X- GQLIDS[Nle]-C(Sx)-NS*FVGTR-Z, X-GQREGFGRQS*M-C(Sx)-EKR-Z, X-GRDK- C(Sx)-KT*LRQIRQG-Z, X-GRDKYKT*L-C(Sx)-QIRQG-Z, X-GREKR-C(Sx)- NS*QSYIGRP-Z, X-GREKRSNS*Q-C(Sx)-YIGRP-Z, X-GRPR-C(Sx)-SS*FAEG-Z, X- GRR-C(Sx)-AS*FRRR-Z, X-GSASASGS*P-C(Sx)-DPGF-Z, X-GSNQEEAYV-C(Sx)- [Nle]S*SFY-Z, X-GVRRR-C(Sx)-LS*NVSLTGV-Z, X-GVRRRRLS*N-C(Sx)-SLTGV-Z, X-GYAKDV-C(Sx)-QGS*LCTSFVGTLQYLAKKK-Z, X-GYAKDVDQGS*L-C(Sx)- TSFVGTLQYLAKKK-Z, X-GYAKDVDQGSL-C(Sx)-TS*FVGTLQYLAKKK-Z, X- GYAKDVDQGSLCTS*F-C(Sx)-GTLQYLA-Z, X-GYAKDVDQGSLCTSF-C(Sx)- GT*LQYLA-Z, X-HAKTTKKRPQRATS*N-C(Sx)-FS-Z, X-HAKTTKKRPQRATSN- C(Sx)-FS*-Z, X-HA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-H-C(Sx)-DS*LRRKAK-Z, X-H-C(Sx)-LS*PGPF-Z, X-HKRPQRAT*S-C(Sx)-VFAMF-Z, X-HLLR-C(Sx)-SS*RRIRR- Z, X-HLPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-HQREGFGRQS*M-C(Sx)-EKR-Z, X-HRR-C(Sx)-AS*FRRR-Z, X-I[Nle]LR-C(Sx)-SS*RRIRR-Z, X-IADLG-C(Sx)- AS*FK[Nle]WSKL-Z, X-IADLG-C(Sx)-AS*FKMWSKL-Z, X-IADLGLAS*F-C(Sx)- [Nle]WSKL-Z, X-IAKTTKKRPQRATS*N-C(Sx)-FS-Z, X-IAKTTKKRPQRATSN-C(Sx)- FS*-Z, X-IALR-C(Sx)-SS*RRIRR-Z, X-IA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-I- C(Sx)-DS*LRRKAK-Z, X-I-C(Sx)-LS*PGPF-Z, X-I-C(Sx)-TS*PITTTYFFFKKK-Z, X-I- C(Sx)-TT*PITTTYFFFKKK-Z, X-IDLR-C(Sx)-SS*RRIRR-Z, X-IDQGD-C(Sx)- MT*PQFTPYY-Z, X-IDQGDLMT*P-C(Sx)-FTPYY-Z; wherein X- is H or acetyl; and Z is

In some embodiments, the nietal-hinding compound of the present invention is selected from the group consisting of: X-IELR-C(Sx)-SS*RRIRR-Z, X-IFLR-C(Sx)- SS*RRIRR-Z, X-IGLR-C(Sx)-SS*RRIRR-Z, X-IHLR-C(Sx)-SS*RRIRR-Z, X-IIHRD- C(Sx)-KS*NNIFLHE-Z, X-IIHRDLKS*N-C(Sx)-IFLHE-Z, X-IILR-C(Sx)-SS*RRIRR-Z, X-IKLR-C(Sx)-SS*RRIRR-Z, X-IKRPQRAT*S-C(Sx)-VFAMF-Z, X-IL[Nle]R-C(Sx)- SS*RRIRR-Z, X-ILAR-C(Sx)-SS*RRIRR-Z, X-ILDR-C(Sx)-SS*RRIRR-Z, X-ILER-C(Sx)- SS*RRIRR-Z, X-ILFR-C(Sx)-SS*RRIRR-Z, X-ILGR-C(Sx)-SS*RRIRR-Z, X-ILHR-C(Sx)- SS*RRIRR-Z, X-ILIR-C(Sx)-SS*RRIRR-Z, X-ILKR-C(Sx)-SS*RRIRR-Z, X-ILL[Nle]- C(Sx)-SS*RRIRR-Z, X-ILL[Nle]ESS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILL[pS]ESS*R- C(Sx)-RIRSG KLGR-Z, X-ILLA-C(Sx)-SS*RRIRR-Z, X-ILLAESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLD-C(Sx)-SS*RRIRR-Z, X-ILLDESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLE-C(Sx)-SS*RRIRR-Z, X-ILLEESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLF-C(Sx)-SS*RRIRR-Z, X-ILLFESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLG-C(Sx)-SS*RRIRR-Z, X-ILLGESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLH-C(Sx)-SS*RRIRR-Z, X-ILLHESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLI-C(Sx)-SS*RRIRR-Z, X-ILLIESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLK-C(Sx)-SS*RRIRR-Z, X-ILLKESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLL-C(Sx)-SS*RRIRR-Z, X-ILLLESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLN-C(Sx)-SS*RRIRR-Z, X-ILL ESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLP-C(Sx)-SS*RRIRR-Z, X-ILLPESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLQ-C(Sx)-SS*RRIRR-Z, X-ILLQESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLR-C(Sx)-[Nle]S*RRIRR-Z, X-ILLR-C(Sx)-AS*RRIRR-Z, X-ILLR-C(Sx)-DS*RRIRR-Z, X-ILLR-C(Sx)-ES*RRIRR-Z, X-ILLR-C(Sx)-FS*RRIRR-Z, X-ILLR-C(Sx)-GS*RRIRR-Z, X-ILLR-C(Sx)-HS*RRIRR-Z, X-ILLR-C(Sx)-IS*RRIRR-Z, X-ILLR-C(Sx)-KS*RRIRR-Z, X-ILLR-C(Sx)-LS**RRIRR-Z, X-ILLR-C(Sx)-NS*RRIRR- Z, X-ILLR-C(Sx)-PS*RRIRR-Z, X-ILLR-C(Sx)-QS*RRIRR-Z, X-ILLR-C(Sx)-RS*RRIRR- Z, X-ILLR-C(Sx)-SS*[Nle]RIRR-Z, X-ILLR-C(Sx)-SS*ARIRR-Z, X-ILLR-C(Sx)- SS*DRIRR-Z, X-ILLR-C(Sx)-SS*ERIRR-Z, X-ILLR-C(Sx)-SS*FRIRR-Z, X-ILLR-C(Sx)- SS*GRIRR-Z, X-ILLR-C(Sx)-SS*HRIRR-Z, X-ILLR-C(Sx)-SS*IRIRR-Z, X-ILLR-C(Sx)- SS*KRIRR-Z, X-ILLR-C(Sx)-SS*LRIRR-Z, X-ILLR-C(Sx)-SS* RIRR-Z, X-ILLR-C(Sx)- SS*PRIRR-Z, X-ILLR-C(Sx)-SS*QRIRR-Z, X-ILLR-C(Sx)-SS*R[Nle]IRR-Z, and X-ILLR- C(Sx)-SS*RAIRR-Z, X-ILLR-C(Sx)-SS*RDIRR-Z; wherein X is H or acetyl; and Z is OH

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-ILLR-C(Sx)-SS*REIRR-Z, X-ILLR-C(Sx)- SS*RFIRR-Z, X-ILLR-C(Sx)-SS*RGIRR-Z, X-ILLR-C(Sx)-SS*RHIRR-Z, X-ILLR-C(Sx)- SS*RIIRR-Z, X-ILLR-C(Sx)-SS*RKIRR-Z, X-ILLR-C(Sx)-SS*RLIRR-Z, X-ILLR-C(Sx)- SS*RNIRR-Z, X-ILLR-C(Sx)-SS*RPIRR-Z, X-ILLR-C(Sx)-SS*RQIRR-Z, X-ILLR-C(Sx)- SS*RR[Nle]RR-Z, X-ILLR-C(Sx)-SS*RRARR-Z, X-ILLR-C(Sx)-SS*RRDRR-Z, X-ILLR- C(Sx)-SS*RRERR-Z, X-ILLR-C(Sx)-SS*RRFRR-Z, X-ILLR-C(Sx)-SS*RRGRR-Z, X- ILLR-C(Sx)-SS*RRHRR-Z, X-ILLR-C(Sx)-SS*RRI[Nle]R-Z, X-ILLR-C(Sx)-SS*RRIAR- Z, X-ILLR-C(Sx)-SS*RRIDR-Z, X-ILLR-C(Sx)-SS*RRIER-Z, X-ILLR-C(Sx)-SS*RRIFR- Z, X-ILLR-C(Sx)-SS*RRIGR-Z, X-ILLR-C(Sx)-SS*RRIHR-Z, X-ILLR-C(Sx)-SS*RRIIR- Z, X-ILLR-C(Sx)-SS*RRIKR-Z, X-ILLR-C(Sx)-SS*RRILR-Z, X-ILLR-C(Sx)-SS*RRINR- Z, X-ILLR-C(Sx)-SS*RRIPR-Z, X-ILLR-C(Sx)-SS*RRIQR-Z, X-ILLR-C(Sx)- SS*RRIR[Nle]-Z, X-ILLR-C(Sx)-SS*RRIRA-Z, X-ILLR-C(Sx)-SS*RRIRD-Z, X-ILLR- C(Sx)-SS*RRIRE-Z, X-ILLR-C(Sx)-SS*RRIRF-Z, X-ILLR-C(Sx)-SS*RRIRG-Z, X-ILLR- C(Sx)-SS*RRIRH-Z, X-ILLR-C(Sx)-SS*RRIRI-Z, X-ILLR-C(Sx)-SS*RRIRK-Z, X-ILLR- C(Sx)-SS*RRIRL-Z, X-ILLR-C(Sx)-SS*RRIRN-Z, X-ILLR-C(Sx)-SS*RRIRP-Z, X-ILLR- C(Sx)-SS*RRIRQ-Z, X-ILLR-C(Sx)-SS*RRIRV-Z, X-ILLR-C(Sx)-SS*RRIRW-Z, X-ILLR- C(Sx)-SS*RRIVR-Z, X-ILLR-C(Sx)-SS*RRIWR-Z, X-ILLR-C(Sx)-SS*RRKRR-Z, X- ILLR-C(Sx)-SS*RRLRR-Z, X-ILLR-C(Sx)-SS*RRNRR-Z, X-ILLR-C(Sx)-SS*RRPRR-Z, X-ILLR-C(Sx)-SS*RRQRR-Z, X-ILLR-C(Sx)-SS*RRRRR-Z, X-ILLR-C(Sx)-SS*RRVRR- Z, X-ILLR-C(Sx)-SS*RRWRR-Z, X-ILLR-C(Sx)-SS*RVIRR-Z, X-ILLR-C(Sx)- SS*RWIRR-Z, X-ILLR-C(Sx)-SS*VRIRR-Z, X-ILLR-C(Sx)-SS*WRIRR-Z, X-ILLR- C(Sx)-VS*RRIRR-Z, X-ILLR-C(Sx)-WS*RRIRR-Z, X-ILLRESS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLS[Nle]SS*R-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSASS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLS-C(Sx)-LS*RRR-Z, X-ILLSDSS*R- C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSE[Nle]S*R-C(Sx)-RIRSGNKLGRIGRN-Z, X- ILLSEAS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSEDS*R-C(Sx)-RIRSG KLGRIGRN- Z, X-ILLSEES*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSEFS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLSEGS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSEHS*R- C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSEIS*R-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSEKS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSELS*R-C(Sx)-RIRSG KLGRIGRN- Z, X-ILLSENS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSEPS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLSEQS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSERS*R- C(Sx)-RIRSG KLGRIGRN-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-ILLSESS*[Nle]-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSESS*A-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*D-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*E-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*F-C(Sx)-RIRSG KLGRIGRN- Z, X-ILLSESS*G-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*H-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLSESS*I-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*K- C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*L-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSESS*N-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*P-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*Q-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- [Nl e]IRS GNKLGRIGRN-Z , X-ILLSESS*R-C(Sx)-AIRSG KLGRIGRN-Z, X-ILLSESS*R- C(Sx)-DIRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-EIRSG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-FIRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-GIRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-HIRSGNKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-IIRSG KLGRIGRN- Z, X-ILLSESS*R-C(Sx)-KIRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- LIRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-NIRSG KLGRIGRN-Z, X-ILLSESS*R- C(Sx)-PIRSGNKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-QIRSG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-R[Nle]RSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RARSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RDRSG KLGRIGRN-Z, X-ILLSES S*R- C(Sx)-RERSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RFRSG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RGRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RHRSG KLGRIGRN- Z, X-ILLSESS*R-C(Sx)-RI[Nle]SG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIASG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIDSG KLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIESG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIFSG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIGSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIHSGNKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIISG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIKSG KLGRIGRN- Z, X-ILLSESS*R-C(Sx)-RILSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RINSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIPSG KLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIQSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIR[Nle]G KLGRIGRN-Z, X- ILLSES S *R-C(Sx)-RIRAG KLGRIGRN-Z, X-ILLSES S *R-C(Sx)-RIRDG KLGRIGRN- Z, X-ILLSESS*R-C(Sx)-RIREG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRFG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRGG KLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRHG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRIG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRKG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRLG KLGRIGRN- Z, X-ILLSES S *R-C(Sx)-R∑RNG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRPG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRQG KLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRRG KLGRIGRN-Z, and X-ILLSESS*R-C(Sx)-RIRS[Nle] KLGRIGRN-Z; wherein X is H or acetyl; and Z is OH or H2. In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-ILLSESS*R-C(Sx)-RIRSA KLGRIGRN-Z, X- ILLSES S *R-C(Sx)-RIRSD KLGRIGRN-Z, X-ILLSES S *R-C(Sx)-RIRSE KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSF KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG[Nle]KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGAKLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSGDKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGEKLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSGFKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGGKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGHKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGIKLGRIGRN- Z, X-ILLSESS*R-C(Sx)-RIRSGKKLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSGLKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGN[Nle]LGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSGNALGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG DLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG ELGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGNFLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGNGLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG HLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGNILGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG K[Nle]GRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KAGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KDGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KEGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KFGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG KGGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KHGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG KIGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KKGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KL[Nle]RIGRN-Z, X-ILLSESS*R-C(Sx)- RIRS G KL ARIGRN-Z , X-ILLSESS*R-C(Sx)-RIRSG KLDRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG KLERIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLFRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KLG[Nle]IGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG KLGAIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGDIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG KLGEIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGFIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KLGGIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGHIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGIIGRN-Z, X-ILLSES S*R-C(Sx)-RIRSG KLGKIGRN- Z, X-ILLSESS*R-C(Sx)-RIRSG KLGLIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG KLGNIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGPIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG KLGQIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGR[Nle]GRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KLGRAGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGRDGRN- Z, X-ILLSESS*R-C(Sx)-RIRSG KLGREGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG KLGRFGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGRGGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG KLGRHGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KLGRKGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGRLGRN- Z, X-ILLSESS*R-C(Sx)-RIRSG KLGRNGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG KLGRPGRN-Z, and X-ILLSESS*R-C(Sx)-RIRSG KLGRQGRN-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-ILLSESS*R-C(Sx)-RIRSG KLGRRGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KLGRVGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG KLGRWGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGR-Z, X-ILLSESS*R-C(Sx)- RIRSG KLGVIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLGWIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG KLHRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLIRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KLKRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLLRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KL RIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KLPRIGRN- Z, X-ILLSESS*R-C(Sx)-RIRSG KLQRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRS G KLRRIGRN-Z , X-ILLSESS*R-C(Sx)-RIRSG KLVRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG KLWRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KNGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG KPGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KQGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KRGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSG KVGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG KWGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSG LLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGN LGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSG PLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGNQLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSG RLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSGNVLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGNWLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSGPKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGQKLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSGRKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGVKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSGWKLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSHNKLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSINKLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSK KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSL KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRSN KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSP KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSQ KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RIRSR KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRSVNKLGRIGRN-Z, X-ILLSESS*R- C(Sx)-RIRSW KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIRVG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RIRWG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RIVSG KLGRIGRN- Z, X-ILLSESS*R-C(Sx)-RIWSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RKRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RLRSG KLGRIGRN-Z, and X- ILLSESS*R-C(Sx)-R RSG KLGRIGRN-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-ILLSESS*R-C(Sx)-RPRSG KLGRIGRN-Z, X- ILLSESS*R-C(Sx)-RQRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-RRRSG KLGRIGRN- Z, X-ILLSESS*R-C(Sx)-RVRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)- RWRSG KLGRIGRN-Z, X-ILLSESS*R-C(Sx)-VIRSG KLGRIGRN-Z, X-ILLSESS*R- C(Sx)-WIRSG KLGRIGRN-Z, X-ILLSESS*V-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSESS*W-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSEVS*R-C(Sx)-RIRSG KLGRIGRN- Z, X-ILLSEWS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSFSS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLSGSS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSHSS*R- C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSISS*R-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSKSS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSLSS*R-C(Sx)-RIRSGNKLGRIGRN-Z, X-ILLSNSS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSPSS*R-C(Sx)- RIRSG KLGRIGRN-Z, X-ILLSQSS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSRSS*R- C(Sx)-RIRSG KLGRIGRN-Z, X-ILLSVSS*R-C(Sx)-RIRSG KLGRIGRN-Z, X- ILLSWSS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLV-C(Sx)-SS*RRIRR-Z, X- ILLVESS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-ILLW-C(Sx)-SS*RRIRR-Z, X- ILLWESS*R-C(Sx)-RIRSG KLGRIGRN-Z, X-IL R-C(Sx)-SS*RRIRR-Z, X-ILPR-C(Sx)- SS*RRIRR-Z, X-ILPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-ILQR-C(Sx)-SS*RRIRR- Z, X-ILRR-C(Sx)-SS*RRIRR-Z, X-ILVR-C(Sx)-SS*RRIRR-Z, X-ILWR-C(Sx)- SS*RRIRR-Z, X-I LR-C(Sx)-SS*RRIRR-Z, X-IPLR-C(Sx)-SS*RRIRR-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-IPTT*P-C(Sx)-TTTYFFFKKK-Z, X-IPTTP-C(Sx)- TT*TYFFFKKK-Z, X-IQLR-C(Sx)-SS*RRIRR-Z, X-IQREGFGRQS*M-C(Sx)-EKR-Z, X- IRLR-C(Sx)-SS*RRIRR-Z, X-IRR-C(Sx)-AS*FRRR-Z, X-IS*G-C(Sx)-LSPI[Nle]TEQ-Z, X-ISG-C(Sx)-LS*PI[Nle]TEQ-Z, X-ISGRLS*P-C(Sx)-[Nle]TEQ-Z, X-ISGRLSP-C(Sx)- [Nle]T*EQ-Z, X-IVLR-C(Sx)-SS*RRIRR-Z, X-IWLR-C(Sx)-SS*RRIRR-Z, X- K[Nle]EVEELS*P-C(Sx)-ALGRF-Z, X-K[Nle]KTTKKRPQRATS*N-C(Sx)-FS-Z, X- K[Nle]KTTKKRPQRATSN-C(Sx)-FS*-Z, X-K[Nle]RPQRAT*S-C(Sx)-VFAMF-Z, X- KA[Nle]TTKKRPQRATS*N-C(Sx)-FS-Z, X-KA[Nle]TTKKRPQRATSN-C(Sx)-FS*-Z, X- K ADTTKKRPQRAT S *N-C(Sx)-F S-Z, X-KADTTKKRPQRATSN-C(Sx)-FS*-Z, X- KAETTKKRPQRATS*N-C(Sx)-FS-Z, X-KAETTKKRPQRATSN-C(Sx)-FS*-Z, X- KAFTTKKRPQRATS*N-C(Sx)-FS-Z, X-KAFTTKKRPQRATSN-C(Sx)-FS*-Z, X- K AGTTKKRPQRAT S *N-C(Sx)-F S-Z, X-KAGTTKKRPQRATSN-C(Sx)-FS*-Z, X- K AHTTKKRPQRAT S *N-C(Sx)-F S-Z, X-KAHTTKKRPQRATSN-C(Sx)-FS*-Z, X- KAITTKKRPQRATS*N-C(Sx)-FS-Z, X-KAITTKKRPQRATSN-C(Sx)-FS*-Z, X- KAK[Nle]TKKRPQRATS*N-C(Sx)-FS-Z, X-KAK[Nle]TKKRPQRATSN-C(Sx)-FS*-Z, X- KAKDTKKRPQRATS*N-C(Sx)-FS-Z, X-KAKDTKKRPQRATSN-C(Sx)-FS*-Z, X- KAKETKKRPQRATS*N-C(Sx)-FS-Z, X-KAKETKKRPQRATSN-C(Sx)-FS*-Z, X- KAKFTKKRPQRATS*N-C(Sx)-FS-Z, X-KAKFTKKRPQRATSN-C(Sx)-FS*-Z, X- KAKGTKKRPQRATS*N-C(Sx)-FS-Z, X-KAKGTKKRPQRATSN-C(Sx)-FS*-Z, X- KAKHTKKRPQRATS*N-C(Sx)-FS-Z, X-KAKHTKKRPQRATSN-C(Sx)-FS*-Z, X- KAKITKKRPQRATS*N-C(Sx)-FS-Z, X-KAKITKKRPQRATSN-C(Sx)-FS*-Z, X- KAKKKKKRPQRADS*D-C(Sx)-FA-Z, X-KAKKKKKRPQRADS*D-C(Sx)-FS-Z, X- KAKKKKKRPQRADS*N-C(Sx)-FA-Z, X-KAKKKKKRPQRADS*N-C(Sx)-FS-Z, X- KAKKKKKRPQRAD SD-C(Sx)-F S * -Z, X-KAKKKKKRPQRADSN-C(Sx)-FS*-Z, X- KAKKKKKRPQRAES*D-C(Sx)-FA-Z, X-KAKKKKKRPQRAES*D-C(Sx)-FS-Z, X- KAKKKKKRPQRAES*N-C(Sx)-FA-Z, X-KAKKKKKRPQRAES*N-C(Sx)-FS-Z, X- KAKKKKKRPQRAESD-C(Sx)-FS*-Z, X-KAKKKKKRPQRAESN-C(Sx)-FS*-Z, X- KAKKKKKRPQRAHS*D-C(Sx)-FA-Z, X-KAKKKKKRPQRAHS*D-C(Sx)-FS-Z, X- KAKKKKKRPQRAHS*N-C(Sx)-FA-Z, X-KAKKKKKRPQRAHS*N-C(Sx)-FS-Z, and X- KAKKKKKRPQRAHSD-C(Sx)-FS*-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KAKKKKKRPQRAHSN-C(Sx)-FS*-Z, X- KAKKKKKRPQRATS*D-C(Sx)-FA-Z, X-KAKKKKKRPQRATS*D-C(Sx)-FS-Z, X- KAKKKKKRPQRATS*N-C(Sx)-FA-Z, X-KAKKKKKRPQRATS*N-C(Sx)-FS-Z, X- KAKKKKKRPQRATSD-C(Sx)-FS*-Z, X-KAKKKKKRPQRATSN-C(Sx)-FS*-Z, X- KAKKRAGGANS*N-C(Sx)-FS[Nle]F-Z, X-KAKKRAGGANS*N-C(Sx)-FSMF-Z, X- KAKKRAGGANS*N-C(Sx)-FS-Z, X-KAKKRAGGANSN-C(Sx)-FS*[Nle]F-Z, X- KAKKRAGGANSN-C(Sx)-FS*MF-Z, X-KAKKRAGGANSN-C(Sx)-FS*-Z, X- KAKKRAGGANSNVF S * [Nle]-C(Sx)-EQ-Z, X-KAKKRAGGANSNVF S * [Nle]-C(Sx)-Z, X-KAKKRAGGANSNVF S*M-C(Sx)-EQ-Z, X-KAKKRAGGANSNVF S*M-C(Sx)-Z, X- KAKKRAGG-C(Sx)-NS*NVFS[Nle]F-Z, X-KAKKRAGG-C(Sx)-NS*NVFSMF-Z, X- KAKKRAGG-C(Sx)-NS*NVFS-Z, X-KAKKRKKRPQRADS*D-C(Sx)-FA-Z, X- KAKKRKKRPQRADS*D-C(Sx)-FS-Z, X-KAKKRKKRPQRADS*N-C(Sx)-FA-Z, X- KAKKRKKRPQRADS*N-C(Sx)-FS-Z, X-KAKKRKKRPQRADSD-C(Sx)-FS*-Z, X- KAKKRKKRPQRADSN-C(Sx)-FS*-Z, X-KAKKRKKRPQRAES*D-C(Sx)-FA-Z, X- KAKKRKKRPQRAES *D-C(Sx)-F S-Z, X-KAKKRKKRPQRAES*N-C(Sx)-FA-Z, X- KAKKRKKRPQRAES *N-C(Sx)-F S-Z, X-KAKKRKKRPQRAESD-C(Sx)-FS*-Z, X- KAKKRKKRPQRAESN-C(Sx)-FS*-Z, X-KAKKRKKRPQRAHS*D-C(Sx)-FA-Z, X- KAKKRKKRPQRAHS*D-C(Sx)-FS-Z, X-KAKKRKKRPQRAHS*N-C(Sx)-FA-Z, X- KAKKRKKRPQRAHS*N-C(Sx)-FS-Z, X-KAKKRKKRPQRAHSD-C(Sx)-FS*-Z, X- KAKKRKKRPQRAHSN-C(Sx)-F S *-Z, X-KAKKRKKRPQRATS*D-C(Sx)-FA-Z, X- KAKKRKKRPQRATS*D-C(Sx)-FS-Z, X-KAKKRKKRPQRATS*N-C(Sx)-FA-Z, X- KAKKRKKRPQRATS*N-C(Sx)-FS-Z, X-KAKKRKKRPQRATSD-C(Sx)-FS*-Z, X- KAKKRKKRPQRATSN-C(Sx)-FS*-Z, X-KAKKTKKRPQRADS*D-C(Sx)-FA-Z, X- KAKKTKKRPQRADS*D-C(Sx)-FS-Z, X-KAKKTKKRPQRADS*N-C(Sx)-FA-Z, X- KAKKTKKRPQRADS*N-C(Sx)-FS-Z, X-KAKKTKKRPQRADSD-C(Sx)-FS*-Z, X- KAKKTKKRPQRADSN-C(Sx)-FS*-Z, X-KAKKTKKRPQRAES*D-C(Sx)-FA-Z, X- KAKKTKKRPQRAES*D-C(Sx)-FS-Z, X-KAKKTKKRPQRAES*N-C(Sx)-FA-Z, X- KAKKTKKRPQRAES*N-C(Sx)-FS-Z, X-KAKKTKKRPQRAESD-C(Sx)-FS*-Z, X- KAKKTKKRPQRAESN-C(Sx)-FS*-Z, X-KAKKTKKRPQRAHS*D-C(Sx)-FA-Z, X- KAKKTKKRPQRAHS*D-C(Sx)-FS-Z, X-KAKKTKKRPQRAHS*N-C(Sx)-FA-Z, X- KAKKTKKRPQRAHS*N-C(Sx)-FS-Z, X-KAKKTKKRPQRAHSD-C(Sx)-FS*-Z, X- KAKKTKKRPQRAHSN-C(Sx)-F S * -Z, X-KAKKTKKRPQRATS*D-C(Sx)-FA-Z, X- KAKKTKKRPQRATS*D-C(Sx)-FS-Z, X-KAKKTKKRPQRATS*N-C(Sx)-FA-Z, X- KAKKTKKRPQRATS*N-C(Sx)-FS-Z, X-KAKKTKKRPQRATSD-C(Sx)-FS*-Z, X- KAKKTKKRPQRATSN-C(Sx)-FS*-Z, X-KAKKVKKRPQRADS*D-C(Sx)-FA-Z, X- KAKKVKKRPQRADS*D-C(Sx)-FS-Z, X-KAKKVKKRPQRADS*N-C(Sx)-FA-Z, X- KAKKVKKRPQRADS*N-C(Sx)-FS-Z, X-KAKKVKKRPQRADSD-C(Sx)-FS*-Z, X- KAKKVKKRPQRADSN-C(Sx)-FS*-Z, X-KAKKVKKRPQRAES*D-C(Sx)-FA-Z, X- KAKKVKKRPQRAES*D-C(Sx)-FS-Z, X-KAKKVKKRPQRAES*N-C(Sx)-FA-Z, X- KAKKVKKRPQRAES*N-C(Sx)-FS-Z, X-KAKKVKKRPQRAESD-C(Sx)-FS*-Z, X- KAKKVKKRPQRAESN-C(Sx)-FS*-Z, X-KAKKVKKRPQRAHS*D-C(Sx)-FA-Z, X- KAKKVKKRPQRAHS*D-C(Sx)-FS-Z, X-KAKKVKKRPQRAHS*N-C(Sx)-FA-Z, and X- KAKKVKKRPQRAHS*N-C(Sx)-FS-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KAKKVKKRPQRAHSD-C(Sx)-FS*-Z, X- KAKKVKKRPQRAHSN-C(Sx)-FS*-Z, X-KAKKVKKRPQRATS*D-C(Sx)-FA-Z, X- KAKKVKKRPQRATS*D-C(Sx)-FS-Z, X-KAKKVKKRPQRATS*N-C(Sx)-FA-Z, X- KAKKVKKRPQRATS*N-C(Sx)-FS-Z, X-KAKKVKKRPQRATSD-C(Sx)-FS*-Z, X- KAKKVKKRPQRATSN-C(Sx)-FS*-Z, X-KAKLTKKRPQRATS*N-C(Sx)-FS-Z, X- KAKLTKKRPQRATSN-C(Sx)-FS*-Z, X-KAKNTKKRPQRATS*N-C(Sx)-FS-Z, X- KAKNTKKRPQRATSN-C(Sx)-FS*-Z, X-KAKPTKKRPQRATS*N-C(Sx)-FS-Z, X- KAKPTKKRPQRATSN-C(Sx)-FS*-Z, X-KAKRTKKRPQRATS*N-C(Sx)-FS-Z, X- KAKRTKKRPQRATSN-C(Sx)-FS*-Z, X-KAKT[Nle]KKRPQRATS*N-C(Sx)-FS-Z, X- KAKT[Nle]KKRPQRATSN-C(Sx)-FS*-Z, X-KAKTDKKRPQRATS*N-C(Sx)-FS-Z, X- K AKTDKKRPQR AT SN-C( Sx)-F S * -Z , X-KAKTEKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTEKKRPQRAT SN-C(Sx)-F S * -Z, X-KAKTFKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTFKKRPQRATSN-C(Sx)-FS*-Z, X-KAKTGKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTGKKRPQRATSN-C(Sx)-FS*-Z, X-KAKTHKKRPQRATS*N-C(Sx)-FS-Z, X- K AKTHKKRPQR AT SN-C( Sx)-F S * -Z , X-KAKTIKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTIKKRPQRATSN-C(Sx)-FS*-Z, X-KAKTKKKRPQRADS*D-C(Sx)-FA-Z, X- KAKTKKKRPQRADS*D-C(Sx)-FS-Z, X-KAKTKKKRPQRADS*N-C(Sx)-FA-Z, X- KAKTKKKRPQRADS*N-C(Sx)-FS-Z, X-KAKTKKKRPQRADSD-C(Sx)-FS*-Z, X- KAKTKKKRPQRAD SN-C(Sx)-F S * -Z, X-KAKTKKKRPQRAES*D-C(Sx)-FA-Z, X- KAKTKKKRPQRAES*D-C(Sx)-FS-Z, X-KAKTKKKRPQRAES*N-C(Sx)-FA-Z, X- KAKTKKKRPQRAES*N-C(Sx)-FS-Z, X-KAKTKKKRPQRAESD-C(Sx)-FS*-Z, X- KAKTKKKRPQRAESN-C(Sx)-FS*-Z, X-KAKTKKKRPQRAHS*D-C(Sx)-FA-Z, X- KAKTKKKRPQRAHS *D-C(Sx)-F S-Z, X-KAKTKKKRPQRAHS*N-C(Sx)-FA-Z, X- KAKTKKKRPQRAHS*N-C(Sx)-FS-Z, X-KAKTKKKRPQRAHSD-C(Sx)-FS*-Z, and X- KAKTKKKRPQRAHSN-C(Sx)-FS*-Z, wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KAKTKKKRPQRATS*D-C(Sx)-FA-Z, X- KAKTKKKRPQRATS*D-C(Sx)-FS-Z, X-KAKTKKKRPQRATS*N-C(Sx)-FA-Z, X- KAKTKKKRPQRATS*N-C(Sx)-FS-Z, X-KAKTKKKRPQRATSD-C(Sx)-FS*-Z, X- KAKTKKKRPQRATSN-C(Sx)-FS*-Z, X-KAKTLKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTLKKRPQRAT SN-C(Sx)-F S * -Z, X-KAKTNKKRPQRATS*N-C(Sx)-FS-Z, X- K AKT KKRPQR AT SN-C( Sx)-F S * -Z , X-KAKTPKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTPKKRPQRATSN-C(Sx)-FS*-Z, X-KAKTRKKRPQRADS*D-C(Sx)-FA-Z, X- KAKTRKKRPQRADS*D-C(Sx)-FS-Z, X-KAKTRKKRPQRADS*N-C(Sx)-FA-Z, X- KAKTRKKRPQRADS*N-C(Sx)-FS-Z, X-KAKTRKKRPQRADSD-C(Sx)-FS*-Z, X- KAKTRKKRPQRAD SN-C(Sx)-F S * -Z, X-KAKTRKKRPQRAES*D-C(Sx)-FA-Z, X- KAKTRKKRPQRAES*D-C(Sx)-FS-Z, X-KAKTRKKRPQRAES*N-C(Sx)-FA-Z, X- KAKTRKKRPQRAES*N-C(Sx)-FS-Z, X-KAKTRKKRPQRAESD-C(Sx)-FS*-Z, X- KAKTRKKRPQRAESN-C(Sx)-FS*-Z, X-KAKTRKKRPQRAHS*D-C(Sx)-FA-Z, X- KAKTRKKRPQRAHS*D-C(Sx)-FS-Z, X-KAKTRKKRPQRAHS*N-C(Sx)-FA-Z, X- KAKTRKKRPQRAHS*N-C(Sx)-FS-Z, X-KAKTRKKRPQRAHSD-C(Sx)-FS*-Z, X- KAKTRKKRPQRAHSN-C(Sx)-FS*-Z, X-KAKTRKKRPQRATS*D-C(Sx)-FA-Z, X- KAKTRKKRPQRATS*D-C(Sx)-FS-Z, X-KAKTRKKRPQRATS*N-C(Sx)-FA-Z, X- KAKTRKKRPQRATS*N-C(Sx)-FS-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting o X-KAKTRKKRPQRATSD-C(Sx)-FS*-Z, X- KAKTRKKRPQRAT SN-C(Sx)-F S * -Z, X-KAKTT[Nle]KRPQRATS*N-C(Sx)-FS-Z, X- KAKTT[Nle]KRPQRATSN-C(Sx)-FS*-Z, X-KAKTTDKRPQRATS*N-C(Sx)-FS-Z, X- KAKTTDKRPQRAT SN-C(Sx)-F S * -Z, X-KAKTTEKRPQRATS*N-C(Sx)-FS-Z, X- KAKTTEKRPQRATSN-C(Sx)-FS*-Z, X-KAKTTFKRPQRATS*N-C(Sx)-FS-Z, X- KAKTTFKRPQRATSN-C(Sx)-FS*-Z, X-KAKTTGKRPQRATS*N-C(Sx)-FS-Z, X- KAKTTGKRPQRATSN-C(Sx)-FS*-Z, X-KAKTTHKRPQRATS*N-C(Sx)-FS-Z, X- KAKTTHKRPQRATSN-C(Sx)-FS*-Z, X-KAKTTIKRPQRATS*N-C(Sx)-FS-Z, X- KAKTTIKRPQRATSN-C(Sx)-FS*-Z, X-KAKTTK[Nle]RPQRATS*N-C(Sx)-FS-Z, X- KAKTTK[Nle]RPQRATSN-C(Sx)-FS*-Z, X-KAKTTKDRPQRATS*N-C(Sx)-FS-Z, X- KAKTTKDRPQRATSN-C(Sx)-FS*-Z, X-KAKTTKERPQRATS*N-C(Sx)-FS-Z, X- K AKTTKERPQR AT SN-C( Sx)-F S * -Z , X-KAKTTKFRPQRATS*N-C(Sx)-FS-Z, X- KAKTTKFRPQRATSN-C(Sx)-FS*-Z, X-KAKTTKGRPQRATS*N-C(Sx)-FS-Z, X- KAKTTKGRPQRAT SN-C(Sx)-F S * -Z, X-KAKTTKHRPQRATS*N-C(Sx)-FS-Z, X- KAKTTKHRPQRATSN-C(Sx)-FS*-Z, X-KAKTTKIRPQRATS*N-C(Sx)-FS-Z, X- KAKTTKIRPQRATSN-C(Sx)-FS*-Z, X-KAKTTKK[Nle]PQRATS*N-C(Sx)-FS-Z, X- KAKTTKK[Nle]PQRATSN-C(Sx)-FS*-Z, X-KAKTTKKDPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKDPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKEPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKEPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKFPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKFPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKGPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKGPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKHPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKHPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKIPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKIPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKKPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKKPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKLPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKLPQRATSN-C(Sx)-FS*-Z, X-KAKTTKK PQRATS*N-C(Sx)-FS-Z, X- KAKTTKK PQRATSN-C(Sx)-FS*-Z, X-KAKTTKKPPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKPPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKR[Nle]QRATS*N-C(Sx)-FS-Z, X- K AKTTKKR[N1 e] QR AT SN-C (Sx)-F S * -Z , X-KAKTTKKRDQRATS*N-C(Sx)-FS-Z, X- KAKTTKKRDQRATSN-C(Sx)-FS*-Z, X-KAKTTKKREQRAT S *N-C(Sx)-F S-Z, X- KAKTTKKREQRATSN-C(Sx)-FS*-Z, X-K AKTTKKRF QR AT S *N-C( Sx)-F S -Z , X- KAKTTKKRFQRAT SN-C(Sx)-F S * -Z, X-K AKTTKKRGQRAT S *N-C(Sx)-F S-Z, X- KAKTTKKRGQRATSN-C(Sx)-FS*-Z, X-K AKTTKKRHQR AT S *N-C( Sx)-F S -Z , X- KAKTTKKRHQRATSN-C(Sx)-FS*-Z, X-KAKTTKKRIQRATS*N-C(Sx)-FS-Z, X- KAKTTKKRIQRATSN-C(Sx)-FS*-Z, X-KAKTTKKRKQRATS*N-C(Sx)-FS-Z, X- KAKTTKKRKQRATSN-C(Sx)-FS*-Z, X-K AKTTKKRLQRAT S *N-C(Sx)-F S-Z, X- KAKTTKKRLQRATSN-C(Sx)-FS*-Z, X-KAKTTKKRNQRATS*N-C(Sx)-FS-Z, X- KAKTTKKRNQRATSN-C(Sx)-FS*-Z, X-KAKTTKKRP[Nle]RATS*N-C(Sx)-FS-Z, X- KAKTTKKRP[Nle]RATSN-C(Sx)-FS*-Z, and X-KAKTTKKRPDRATS*N-C(Sx)-FS-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the nietal-hinding compound of the present invention is selected from the group consisting of: X-KAKTTKKRPDRATSN-C(Sx)-FS*-Z, X- KAKTTKKRPERATS*N-C(Sx)-FS-Z, X-KAKTTKKRPERATSN-C(Sx)-FS*-Z, X- KAKTTKKRPFRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPFRATSN-C(Sx)-FS*-Z, X- K AKTTKKRPGRAT S *N-C(Sx)-F S-Z, X-KAKTTKKRPGRATSN-C(Sx)-FS*-Z, X- KAKTTKKRPHRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPHRATSN-C(Sx)-FS*-Z, X- KAKTTKKRPIRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPIRATSN-C(Sx)-FS*-Z, X- K AKTTKKRPKRAT S *N-C(Sx)-F S-Z, X-KAKTTKKRPKRATSN-C(Sx)-FS*-Z, X- KAKTTKKRPLRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPLRATSN-C(Sx)-FS*-Z, X- K AKTTKKRP RAT S *N-C(Sx)-F S-Z, X-KAKTTKKRP RATSN-C(Sx)-FS*-Z, X- KAKTTKKRPPRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPPRATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQ[Nle]ATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQ[Nle]ATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQDATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQDATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQEATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQEATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQFATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQFATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQGATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQGATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQHATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQHATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQIATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQIATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQKATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQKATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQLATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQLATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQNATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQNATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQPATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQPATSN-C(Sx)-FS*-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KAKTTKKRPQR[Nle]TS*N-C(Sx)-FS-Z, X- KAKTTKKRPQR[Nle]TSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRA[Nle]S*N-C(Sx)-FS-Z, X- KAKTTKKRPQRA[Nle]SN-C(Sx)-FS*-Z, X-KAKTTKKRPQRADS*D-C(Sx)-FA-Z, X- KAKTTKKRPQRADS*D-C(Sx)-FS-Z, X-KAKTTKKRPQRADS*N-C(Sx)-FA-Z, X- KAKTTKKRPQRADS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRADSD-C(Sx)-FS*-Z, X- KAKTTKKRPQRAD SN-C(Sx)-F S * -Z, X-KAKTTKKRPQRAES*D-C(Sx)-FA-Z, X- KAKTTKKRPQRAES*D-C(Sx)-FS-Z, X-KAKTTKKRPQRAES*N-C(Sx)-FA-Z, X- KAKTTKKRPQRAES*N-C(Sx)-FS-Z, X-KAKTTKKRPQRAESD-C(Sx)-FS*-Z, X- KAKTTKKRPQRAESN-C(Sx)-F S * -Z, X-KAKTTKKRPQRAFS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAF SN-C(Sx)-F S * -Z, X-KAKTTKKRPQRAGS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAGSN-C(Sx)-F S * -Z, X-KAKTTKKRPQRAHS*D-C(Sx)-FA-Z, X- KAKTTKKRPQRAHS*D-C(Sx)-FS-Z, X-KAKTTKKRPQRAHS*N-C(Sx)-FA-Z, X- KAKTTKKRPQRAHS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRAHSD-C(Sx)-FS*-Z, X- KAKTTKKRPQRAHSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRAIS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAISN-C(Sx)-FS*-Z, X-KAKTTKKRPQRAKS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAKSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRALS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAL SN-C(Sx)-F S * -Z, X-KAKTTKKRPQRANS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRANSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRAPS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAPSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRARS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRARSN-C(Sx)-FS*-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KAKTTKKRPQRAT*S-C(Sx)-VFAMF-Z, X- KAKTTKKRPQRAT*S-C(Sx)-VFS-Z, X-KAKTTKKRPQRATS*[Nle]-C(Sx)-FS-Z, X- KAKTTKKRPQRATS*D-C(Sx)-FA-Z, X-KAKTTKKRPQRATS*D-C(Sx)-FS-Z, X- KAKTTKKRPQRATS*E-C(Sx)-FS-Z, X-KAKTTKKRPQRATS*F-C(Sx)-FS-Z, X- KAKTTKKRPQRATS*G-C(Sx)-FS-Z, X-KAKTTKKRPQRATS*H-C(Sx)-FS-Z, X- KAKTTKKRPQRATS*I-C(Sx)-FS-Z, X-KAKTTKKRPQRATS*K-C(Sx)-FS-Z, X- KAKTTKKRPQRAT S *L-C(Sx)-F S-Z, X-KAKTTKKRPQRATS*N-C(Sx)-[Nle]S-Z, X- KAKTTKKRPQRAT S *N-C(Sx)-D S-Z, X-KAKTTKKRPQRATS*N-C(Sx)-ES-Z, X- KAKTTKKRPQRATS*N-C(Sx)-F[Nle]-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FA-Z, X- KAKTTKKRPQRATS*N-C(Sx)-FD-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FE-Z, X- KAKTTKKRPQRATS*N-C(Sx)-FF-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FG-Z, X- KAKTTKKRPQRATS*N-C(Sx)-FH-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FI-Z, X- KAKTTKKRPQRATS*N-C(Sx)-FK-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FL-Z, X- KAKTTKKRPQRATS*N-C(Sx)-FN-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FP-Z, X- KAKTTKKRPQRATS*N-C(Sx)-FR-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRATS*N-C(Sx)-FV-Z, X-KAKTTKKRPQRATS*N-C(Sx)-FW-Z, X- KAKTTKKRPQRATS*N-C(Sx)-F-Z, X-KAKTTKKRPQRATS*N-C(Sx)-GS-Z, X- KAKTTKKRPQRATS*N-C(Sx)-HS-Z, X-KAKTTKKRPQRATS*N-C(Sx)-IS-Z, X- KAKTTKKRPQRATS*N-C(Sx)-KS-Z, X-KAKTTKKRPQRATS*N-C(Sx)-LS-Z, X- KAKTTKKRPQRATS*N-C(Sx)-NS-Z, X-KAKTTKKRPQRATS*N-C(Sx)-PS-Z, X- KAKTTKKRPQRATS*N-C(Sx)-RS-Z, X-KAKTTKKRPQRATS*N-C(Sx)-VS-Z, X- KAKTTKKRPQRATS*N-C(Sx)-WS-Z, X-KAKTTKKRPQRATS*P-C(Sx)-FS-Z, X- KAKTTKKRPQRATS*R-C(Sx)-FS-Z, X-KAKTTKKRPQRATS*V-C(Sx)-FS-Z, X- KAKTTKKRPQRATS*W-C(Sx)-FS-Z, X-KAKTTKKRPQRATS[Nle]-C(Sx)-FS*-Z, X- KAKTTKKRPQRATSD-C(Sx)-FS*-Z, X-KAKTTKKRPQRATSE-C(Sx)-FS*-Z, X- KAKTTKKRPQRATSF-C(Sx)-FS*-Z, X-KAKTTKKRPQRATSG-C(Sx)-FS*-Z, X- KAKTTKKRPQRAT SH-C(Sx)-F S * -Z, X-KAKTTKKRPQRATSI-C(Sx)-FS*-Z, X- KAKTTKKRPQRATSK-C(Sx)-FS*-Z, X-KAKTTKKRPQRATSL-C(Sx)-FS*-Z, X- KAKTTKKRPQRAT SN-C(Sx)-D S * -Z, X-KAKTTKKRPQRATSN-C(Sx)-ES*-Z, X- KAKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRATSN-C(Sx)-GS*-Z, X- KAKTTKKRPQRATSN-C(Sx)-HS*-Z, X-KAKTTKKRPQRATSN-C(Sx)-IS*-Z, X- KAKTTKKRPQRATSN-C(Sx)-KS*-Z, X-KAKTTKKRPQRATSN-C(Sx)-LS*-Z, X- KAKTTKKRPQRAT SN-C(Sx)-NS * -Z, X-KAKTTKKRPQRATSN-C(Sx)-PS*-Z, X- KAKTTKKRPQRAT SN-C(Sx)-RS * -Z, X-KAKTTKKRPQRATSN-C(Sx)-VS*-Z, X- KAKTTKKRPQRATSN-C(Sx)-WS*-Z, X-KAKTTKKRPQRATSP-C(Sx)-FS*-Z, X- KAKTTKKRPQRATSR-C(Sx)-FS*-Z, X-KAKTTKKRPQRATSV-C(Sx)-FS*-Z, X- KAKTTKKRPQRATSW-C(Sx)-FS*-Z, X-KAKTTKKRPQRAVS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAVSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRAWS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRAWSN-C(Sx)-FS*-Z, X-KAKTTKKRPQRDTS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRDT SN-C(Sx)-F S * -Z, X-KAKTTKKRPQRETS*N-C(Sx)-FS-Z, X- KAKTTKKRPQRETSN-C(Sx)-FS*-Z, and X-KAKTTKKRPQRFTS*N-C(Sx)-FS-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KAKTTKKRPQRFTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRGT S *N-C(Sx)-F S-Z, X-KAKTTKKRPQRGTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRHT S *N-C(Sx)-F S-Z, X-KAKTTKKRPQRHTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRITS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRITSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRKT S *N-C(Sx)-F S-Z, X-KAKTTKKRPQRKTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRLTS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRLTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRNTS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRNTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRPTS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRPTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRRTS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRRTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRVTS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRVTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQRWTS*N-C(Sx)-FS-Z, X-KAKTTKKRPQRWTSN-C(Sx)-FS*-Z, X- KAKTTKKRPQVATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQVATSN-C(Sx)-FS*-Z, X- KAKTTKKRPQWATS*N-C(Sx)-FS-Z, X-KAKTTKKRPQWATSN-C(Sx)-FS*-Z, X- KAKTTKKRPRRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPRRATSN-C(Sx)-FS*-Z, X- KAKTTKKRPVRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPVRATSN-C(Sx)-FS*-Z, X- KAKTTKKRPWRATS*N-C(Sx)-FS-Z, X-KAKTTKKRPWRATSN-C(Sx)-FS*-Z, X- KAKTTKKRRQRATS*N-C(Sx)-FS-Z, X-KAKTTKKRRQRATSN-C(Sx)-FS*-Z, X- KAKTTKKRVQRATS*N-C(Sx)-FS-Z, X-KAKTTKKRVQRATSN-C(Sx)-FS*-Z, X- KAKTTKKRWQRATS*N-C(Sx)-FS-Z, X-KAKTTKKRWQRATSN-C(Sx)-FS*-Z, X- KAKTTKKVPQRATS*N-C(Sx)-FS-Z, X-KAKTTKKVPQRATSN-C(Sx)-FS*-Z, X- KAKTTKKWPQRATS*N-C(Sx)-FS-Z, X-KAKTTKKWPQRATSN-C(Sx)-FS*-Z, X- KAKTTKLRPQRATS*N-C(Sx)-FS-Z, X-KAKTTKLRPQRATSN-C(Sx)-FS*-Z, X- KAKTTK RPQRAT S *N-C(Sx)-F S-Z, X-KAKTTK RPQRATSN-C(Sx)-FS*-Z, X- KAKTTKPRPQRATS*N-C(Sx)-FS-Z, X-KAKTTKPRPQRATSN-C(Sx)-FS*-Z, X- KAKTTKRRPQRATS*N-C(Sx)-FS-Z, X-KAKTTKRRPQRATSN-C(Sx)-FS*-Z, X- KAKTTKVRPQRATS*N-C(Sx)-FS-Z, X-KAKTTKVRPQRATSN-C(Sx)-FS*-Z, X- KAKTTKWRPQRATS*N-C(Sx)-FS-Z, X-KAKTTKWRPQRATSN-C(Sx)-FS*-Z, X- KAKTTLKRPQRATS*N-C(Sx)-FS-Z, X-KAKTTLKRPQRATSN-C(Sx)-FS*-Z, X- KAKTT KRPQRAT S *N-C(Sx)-F S-Z, X-KAKTTNKRPQRATSN-C(Sx)-FS*-Z, X- KAKTTPKRPQRATS*N-C(Sx)-FS-Z, X-KAKTTPKRPQRATSN-C(Sx)-FS*-Z, X- KAKTTRKRPQRATS*N-C(Sx)-FS-Z, X-KAKTTRKRPQRATSN-C(Sx)-FS*-Z, X- KAKTTVKRPQRATS*N-C(Sx)-FS-Z, X-KAKTTVKRPQRATSN-C(Sx)-FS*-Z, X- KAKTTWKRPQRATS*N-C(Sx)-FS-Z, X-KAKTTWKRPQRATSN-C(Sx)-FS*-Z; wherein X- is H or acetyl; and Z is OH or H2. In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KAKTVKKRPQRADS*D-C(Sx)-FA-Z, X- KAKTVKKRPQRADS*D-C(Sx)-FS-Z, X-KAKTVKKRPQRADS*N-C(Sx)-FA-Z, X- KAKTVKKRPQRADS*N-C(Sx)-FS-Z, X-KAKTVKKRPQRADSD-C(Sx)-FS*-Z, X- KAKTVKKRPQRADSN-C(Sx)-FS*-Z, X-KAKTVKKRPQRAES*D-C(Sx)-FA-Z, X- KAKTVKKRPQRAES*D-C(Sx)-FS-Z, X-KAKTVKKRPQRAES*N-C(Sx)-FA-Z, X- KAKTVKKRPQRAES*N-C(Sx)-FS-Z, X-KAKTVKKRPQRAESD-C(Sx)-FS*-Z, X- KAKTVKKRPQRAESN-C(Sx)-FS*-Z, X-KAKTVKKRPQRAHS*D-C(Sx)-FA-Z, X- KAKTVKKRPQRAHS*D-C(Sx)-FS-Z, X-KAKTVKKRPQRAHS*N-C(Sx)-FA-Z, X- KAKTVKKRPQRAHS*N-C(Sx)-FS-Z, X-KAKTVKKRPQRAHSD-C(Sx)-FS*-Z, X- KAKTVKKRPQRAHSN-C(Sx)-FS*-Z, X-KAKTVKKRPQRATS*D-C(Sx)-FA-Z, X- KAKTVKKRPQRATS*D-C(Sx)-FS-Z, X-KAKTVKKRPQRATS*N-C(Sx)-FA-Z, X- KAKTVKKRPQRATS*N-C(Sx)-FS-Z, X-KAKTVKKRPQRATSD-C(Sx)-FS*-Z, X- KAKTVKKRPQRATSN-C(Sx)-FS*-Z, X-KAKTWKKRPQRATS*N-C(Sx)-FS-Z, X- KAKTWKKRPQRATSN-C(Sx)-FS*-Z, X-KAKVTKKRPQRATS*N-C(Sx)-FS-Z, X- KAKVTKKRPQRATSN-C(Sx)-FS*-Z, X-KAKWTKKRPQRATS*N-C(Sx)-FS-Z, X- KAKWTKKRPQRATSN-C(Sx)-FS*-Z, X-KALTTKKRPQRATS*N-C(Sx)-FS-Z, X- KALTTKKRPQRATSN-C(Sx)-FS*-Z, X-KA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X- K ANTTKKRPQRAT S *N-C(Sx)-F S-Z, X-KANTTKKRPQRATSN-C(Sx)-FS*-Z, X- KAPTTKKRPQRATS*N-C(Sx)-FS-Z, X-KAPTTKKRPQRATSN-C(Sx)-FS*-Z, X- KARTTKKRPQRATS*N-C(Sx)-FS-Z, X-KARTTKKRPQRATSN-C(Sx)-FS*-Z, X- KAVTTKKRPQRATS*N-C(Sx)-FS-Z, X-KAVTTKKRPQRATSN-C(Sx)-FS*-Z, X- KAWTTKKRPQRATS*N-C(Sx)-FS-Z, X-KAWTTKKRPQRATSN-C(Sx)-FS*-Z, X-K- C(Sx)-DS*LRRKAK-Z, X-K-C(Sx)-HS*LPRG K-Z, X-K-C(Sx)-LS*PGPF-Z, X-KDEIL- C(Sx)-TT*PISEQKG-Z, X-KDEILPTT*P-C(Sx)-SEQKG-Z, X-KDKTTKKRPQRATS *N- C(Sx)-FS-Z, X-KDKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KDRPQRAT*S-C(Sx)-VFAMF- Z, X-KEEQSQIT*S-C(Sx)-VTGQIGWR-Z, X-KEEQSQITS-C(Sx)-VT*GQIGWR-Z, X- KEEQSQITSQVT*G-C(Sx)-IGWR-Z, X-KEEQSQITSQVT*GQ-C(Sx)-GWR-Z, X- KEHRG-C(Sx)-DS*PDPDTSY-Z, X-KEKKAVSPL-C(Sx)-LT*TTNSSEG-Z, X- KEKKAVSPLL-C(Sx)-TT*TNSSEG-Z, X-KEKKAVSPLLL-C(Sx)-TT*NSSEG-Z, X- KEKKAVSPLLLT*T-C(Sx)-NSSEG-Z, X-KEKKAVSPLLLTT*T-C(Sx)-SSEG-Z, and X- KEKKAVSPLLLTT-C(Sx)-NS*SEG-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KEKKAVSPLLLTTT*N-C(Sx)-SEG-Z, X- KEKKAVSPLLLTTT-C(Sx)-SS*EG-Z, X-KEKTTKKRPQRATS*N-C(Sx)-FS-Z, X- KEKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KERPQRAT*S-C(Sx)-VFAMF-Z, X- KEVPRRKS*L-C(Sx)-GTPYW[Nle]APE-Z, X-KEVPRRKSL-C(Sx)-GT*PYW[Nle]APE-Z, X-KF-C(Sx)-KT*FKWM-Z, X-KFFKT*F-C(Sx)-WM-Z, X-KFKTTKKRPQRATS *N- C(Sx)-FS-Z, X-KFKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KFRPQRAT*S-C(Sx)-VFAMF-Z, X-KGKKKKKRPQRADS*D-C(Sx)-FA-Z, X-KGKKKKKRPQRADS*D-C(Sx)-FS-Z, X- KGKKKKKRPQRADS*N-C(Sx)-FA-Z, X-KGKKKKKRPQRADS*N-C(Sx)-FS-Z, X- KGKKKKKRPQRAD SD-C(Sx)-F S * -Z, X-KGKKKKKRPQRADSN-C(Sx)-FS*-Z, X- KGKKKKKRPQRAES*D-C(Sx)-FA-Z, X-KGKKKKKRPQRAES*D-C(Sx)-FS-Z, X- KGKKKKKRPQRAES*N-C(Sx)-FA-Z, X-KGKKKKKRPQRAES*N-C(Sx)-FS-Z, X- KGKKKKKRPQRAESD-C(Sx)-FS*-Z, X-KGKKKKKRPQRAESN-C(Sx)-FS*-Z, X- KGKKKKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKKKKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKKKKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKKKKKRPQRAHS*N-C(Sx)-FS-Z, X- KGKKKKKRPQRAHSD-C(Sx)-FS*-Z, X-KGKKKKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKKKKKRPQRATS*D-C(Sx)-FA-Z, X-KGKKKKKRPQRATS*D-C(Sx)-FS-Z, X- KGKKKKKRPQRATS*N-C(Sx)-FA-Z, X-KGKKKKKRPQRATS*N-C(Sx)-FS-Z, X- KGKKKKKRPQRATSD-C(Sx)-FS*-Z, X-KGKKKKKRPQRATSN-C(Sx)-FS*-Z, X- KGKKRKKRPQRADS*D-C(Sx)-FA-Z, X-KGKKRKKRPQRADS*D-C(Sx)-FS-Z, X- KGKKRKKRPQRADS*N-C(Sx)-FA-Z, X-KGKKRKKRPQRADS*N-C(Sx)-FS-Z, X- KGKKRKKRPQRADSD-C(Sx)-FS*-Z, X-KGKKRKKRPQRADSN-C(Sx)-FS*-Z, and X- KGKKRKKRPQRAES*D-C(Sx)-FA-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KGKKRKKRPQRAES*D-C(Sx)-FS-Z, X- KGKKRKKRPQRAES*N-C(Sx)-FA-Z, X-KGKKRKKRPQRAES*N-C(Sx)-FS-Z, X- KGKKRKKRPQRAESD-C(Sx)-FS*-Z, X-KGKKRKKRPQRAESN-C(Sx)-FS*-Z, X- KGKKRKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKKRKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKKRKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKKRKKRPQRAHS*N-C(Sx)-FS-Z, X- KGKKRKKRPQRAHSD-C(Sx)-FS*-Z, X-KGKKRKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKKRKKRPQRATS*D-C(Sx)-FA-Z, X-KGKKRKKRPQRATS*D-C(Sx)-FS-Z, X- KGKKRKKRPQRATS*N-C(Sx)-FA-Z, X-KGKKRKKRPQRATS*N-C(Sx)-FS-Z, X- KGKKRKKRPQRATSD-C(Sx)-FS*-Z, X-KGKKRKKRPQRATSN-C(Sx)-FS*-Z, X- KGKKTKKRPQRADS*D-C(Sx)-FA-Z, X-KGKKTKKRPQRADS*D-C(Sx)-FS-Z, X- KGKKTKKRPQRADS*N-C(Sx)-FA-Z, X-KGKKTKKRPQRADS*N-C(Sx)-FS-Z, X- KGKKTKKRPQRAD SD-C(Sx)-F S * -Z, X-KGKKTKKRPQRADSN-C(Sx)-FS*-Z, X- KGKKTKKRPQRAES*D-C(Sx)-FA-Z, X-KGKKTKKRPQRAES*D-C(Sx)-FS-Z, X- KGKKTKKRPQRAES*N-C(Sx)-FA-Z, X-KGKKTKKRPQRAES*N-C(Sx)-FS-Z, X- KGKKTKKRPQRAESD-C(Sx)-FS*-Z, X-KGKKTKKRPQRAESN-C(Sx)-FS*-Z, X- KGKKTKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKKTKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKKTKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKKTKKRPQRAHS*N-C(Sx)-FS-Z, X- KGKKTKKRPQRAHSD-C(Sx)-FS*-Z, X-KGKKTKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKKTKKRPQRATS*D-C(Sx)-FA-Z, X-KGKKTKKRPQRATS*D-C(Sx)-FS-Z, X- KGKKTKKRPQRATS*N-C(Sx)-FA-Z, X-KGKKTKKRPQRATS*N-C(Sx)-FS-Z, X- KGKKTKKRPQRATSD-C(Sx)-FS*-Z, X-KGKKTKKRPQRATSN-C(Sx)-FS*-Z, X- KGKKVKKRPQRADS*D-C(Sx)-FA-Z, X-KGKKVKKRPQRADS*D-C(Sx)-FS-Z, X- KGKKVKKRPQRADS*N-C(Sx)-FA-Z, X-KGKKVKKRPQRADS*N-C(Sx)-FS-Z, X- KGKKVKKRPQRADSD-C(Sx)-FS*-Z, X-KGKKVKKRPQRADSN-C(Sx)-FS*-Z, X- KGKKVKKRPQRAES*D-C(Sx)-FA-Z, X-KGKKVKKRPQRAES*D-C(Sx)-FS-Z, X- KGKKVKKRPQRAES*N-C(Sx)-FA-Z, X-KGKKVKKRPQRAES*N-C(Sx)-FS-Z, X- KGKKVKKRPQRAESD-C(Sx)-FS*-Z, X-KGKKVKKRPQRAESN-C(Sx)-FS*-Z, X- KGKKVKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKKVKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKKVKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKKVKKRPQRAHS*N-C(Sx)-FS-Z, and X- KGKKVKKRPQRAHSD-C(Sx)-FS*-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KGKKVKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKKVKKRPQRATS*D-C(Sx)-FA-Z, X-KGKKVKKRPQRATS*D-C(Sx)-FS-Z, X- KGKKVKKRPQRATS*N-C(Sx)-FA-Z, X-KGKKVKKRPQRATS*N-C(Sx)-FS-Z, X- KGKKVKKRPQRATSD-C(Sx)-FS*-Z, X-KGKKVKKRPQRATSN-C(Sx)-FS*-Z, X- KGKTKKKRPQRADS*D-C(Sx)-FA-Z, X-KGKTKKKRPQRADS*D-C(Sx)-FS-Z, X- KGKTKKKRPQRADS*N-C(Sx)-FA-Z, X-KGKTKKKRPQRADS*N-C(Sx)-FS-Z, X- KGKTKKKRPQRADSD-C(Sx)-FS*-Z, X-KGKTKKKRPQRADSN-C(Sx)-FS*-Z, X- KGKTKKKRPQRAES*D-C(Sx)-FA-Z, X-KGKTKKKRPQRAES*D-C(Sx)-FS-Z, X- KGKTKKKRPQRAES*N-C(Sx)-FA-Z, X-KGKTKKKRPQRAES*N-C(Sx)-FS-Z, X- KGKTKKKRPQRAESD-C(Sx)-FS*-Z, X-KGKTKKKRPQRAESN-C(Sx)-FS*-Z, X- KGKTKKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKTKKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKTKKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKTKKKRPQRAHS*N-C(Sx)-FS-Z, X- KGKTKKKRPQRAHSD-C(Sx)-FS*-Z, X-KGKTKKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKTKKKRPQRATS*D-C(Sx)-FA-Z, X-KGKTKKKRPQRATS*D-C(Sx)-FS-Z, X- KGKTKKKRPQRATS*N-C(Sx)-FA-Z, X-KGKTKKKRPQRATS*N-C(Sx)-FS-Z, X- KGKTKKKRPQRATSD-C(Sx)-FS*-Z, X-KGKTKKKRPQRATSN-C(Sx)-FS*-Z, X- KGKTRKKRPQRADS*D-C(Sx)-FA-Z, X-KGKTRKKRPQRADS*D-C(Sx)-FS-Z, X- KGKTRKKRPQRADS*N-C(Sx)-FA-Z, X-KGKTRKKRPQRADS*N-C(Sx)-FS-Z, X- KGKTRKKRPQRADSD-C(Sx)-FS*-Z, X-KGKTRKKRPQRADSN-C(Sx)-FS*-Z, X- KGKTRKKRPQRAES*D-C(Sx)-FA-Z, X-KGKTRKKRPQRAES*D-C(Sx)-FS-Z, X- KGKTRKKRPQRAES*N-C(Sx)-FA-Z, X-KGKTRKKRPQRAES*N-C(Sx)-FS-Z, X- KGKTRKKRPQRAESD-C(Sx)-FS*-Z, X-KGKTRKKRPQRAESN-C(Sx)-FS*-Z, X- KGKTRKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKTRKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKTRKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKTRKKRPQRAHS*N-C(Sx)-FS-Z, X- KGKTRKKRPQRAHSD-C(Sx)-FS*-Z, X-KGKTRKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKTRKKRPQRATS*D-C(Sx)-FA-Z, X-KGKTRKKRPQRATS*D-C(Sx)-FS-Z, X- KGKTRKKRPQRATS*N-C(Sx)-FA-Z, X-KGKTRKKRPQRATS*N-C(Sx)-FS-Z, X- KGKTRKKRPQRAT SD-C(Sx)-F S * -Z, X-KGKTRKKRPQRATSN-C(Sx)-FS*-Z, X- KGKTTKKRPQRADS*D-C(Sx)-FA-Z, X-KGKTTKKRPQRADS*D-C(Sx)-FS-Z, and X- KGKTTKKRPQRADS*N-C(Sx)-FA-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KGKTTKKRPQRADS*N-C(Sx)-FS-Z, X- KGKTTKKRPQRADSD-C(Sx)-FS*-Z, X-KGKTTKKRPQRADSN-C(Sx)-FS*-Z, X- KGKTTKKRPQRAES*D-C(Sx)-FA-Z, X-KGKTTKKRPQRAES*D-C(Sx)-FS-Z, X- KGKTTKKRPQRAES*N-C(Sx)-FA-Z, X-KGKTTKKRPQRAES*N-C(Sx)-FS-Z, X- KGKTTKKRPQRAESD-C(Sx)-FS*-Z, X-KGKTTKKRPQRAESN-C(Sx)-FS*-Z, X- KGKTTKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKTTKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKTTKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKTTKKRPQRAHS*N-C(Sx)-FS-Z, X- KGKTTKKRPQRAHSD-C(Sx)-FS*-Z, X-KGKTTKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKTTKKRPQRATS*D-C(Sx)-FA-Z, X-KGKTTKKRPQRATS*D-C(Sx)-FS-Z, X- KGKTTKKRPQRATS*N-C(Sx)-FA-Z, X-KGKTTKKRPQRATS*N-C(Sx)-FS-Z, X- KGKTTKKRPQRATSD-C(Sx)-FS*-Z, X-KGKTTKKRPQRATSN-C(Sx)-FS*-Z, X- KGKTVKKRPQRADS*D-C(Sx)-FA-Z, X-KGKTVKKRPQRADS*D-C(Sx)-FS-Z, X- KGKTVKKRPQRADS*N-C(Sx)-FA-Z, X-KGKTVKKRPQRADS*N-C(Sx)-FS-Z, X- KGKTVKKRPQRADSD-C(Sx)-FS*-Z, X-KGKTVKKRPQRADSN-C(Sx)-FS*-Z, X- KGKTVKKRPQRAES*D-C(Sx)-FA-Z, X-KGKTVKKRPQRAES*D-C(Sx)-FS-Z, X- KGKTVKKRPQRAES*N-C(Sx)-FA-Z, X-KGKTVKKRPQRAES*N-C(Sx)-FS-Z, X- KGKTVKKRPQRAESD-C(Sx)-FS*-Z, X-KGKTVKKRPQRAESN-C(Sx)-FS*-Z, X- KGKTVKKRPQRAHS*D-C(Sx)-FA-Z, X-KGKTVKKRPQRAHS*D-C(Sx)-FS-Z, X- KGKTVKKRPQRAHS*N-C(Sx)-FA-Z, X-KGKTVKKRPQRAHS*N-C(Sx)-FS-Z, X- KGKTVKKRPQRAHSD-C(Sx)-FS*-Z, X-KGKTVKKRPQRAHSN-C(Sx)-FS*-Z, X- KGKTVKKRPQRATS*D-C(Sx)-FA-Z, X-KGKTVKKRPQRATS*D-C(Sx)-FS-Z, X- KGKTVKKRPQRATS*N-C(Sx)-FA-Z, X-KGKTVKKRPQRATS*N-C(Sx)-FS-Z, X- KGKTVKKRPQRATSD-C(Sx)-FS*-Z, X-KGKTVKKRPQRATSN-C(Sx)-FS*-Z, X- KGRPQRAT*S-C(Sx)-VFAMF-Z, X-KGTLR-C(Sx)-MS*PEQISSQ-Z, X-KGTLRYMS*P- C(Sx)-QISSQ-Z, X-KHKKKKKRPQRADS*D-C(Sx)-FA-Z, X-KHKKKKKRPQRADS*D- C(Sx)-FS-Z, X-KHKKKKKRPQRADS*N-C(Sx)-FA-Z, X-KHKKKKKRPQRADS*N- C(Sx)-FS-Z, X-KHKKKKKRPQRADSD-C(Sx)-FS*-Z, X-KFD KKKKRPQRAD SN-C(Sx)- FS*-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KHKKKKKRPQRAES*D-C(Sx)-FA-Z, X- KHKKKKKRPQRAES*D-C(Sx)-FS-Z, X-KHKKKKKRPQRAES*N-C(Sx)-FA-Z, X- KHKKKKKRPQRAES*N-C(Sx)-FS-Z, X-KHKKKKKRPQRAESD-C(Sx)-FS*-Z, X- KHKKKKKRPQRAESN-C(Sx)-FS*-Z, X-KHKKKKKRPQRAHS*D-C(Sx)-FA-Z, X- KHKKKKKRPQRAHS*D-C(Sx)-FS-Z, X-KHKKKKKRPQRAHS*N-C(Sx)-FA-Z, X- KHKKKKKRPQRAHS*N-C(Sx)-FS-Z, X-KHKKKKKRPQRAHSD-C(Sx)-FS*-Z, X- KHKKKKKRPQRAHSN-C(Sx)-FS*-Z, X-KHKKKKKRPQRATS*D-C(Sx)-FA-Z, X- KHKKKKKRPQRATS*D-C(Sx)-FS-Z, X-KHKKKKKRPQRATS*N-C(Sx)-FA-Z, X- KHKKKKKRPQRATS*N-C(Sx)-FS-Z, X-KHKKKKKRPQRATSD-C(Sx)-FS*-Z, X- KHKKKKKRPQRATSN-C(Sx)-FS*-Z, X-KHKKRKKRPQRADS*D-C(Sx)-FA-Z, X- KHKKRKKRPQRADS*D-C(Sx)-FS-Z, X-KHKKRKKRPQRADS*N-C(Sx)-FA-Z, X- KHKKRKKRPQRADS*N-C(Sx)-FS-Z, X-KHKKRKKRPQRADSD-C(Sx)-FS*-Z, X- KHKKRKKRPQRADSN-C(Sx)-FS*-Z, X-KHKKRKKRPQRAES*D-C(Sx)-FA-Z, X- KFD KRKKRPQRAES *D-C(Sx)-F S-Z, X-KHKKRKKRPQRAES*N-C(Sx)-FA-Z, X- KFD KRKKRPQRAES *N-C(Sx)-F S-Z, X-KHKKRKKRPQRAESD-C(Sx)-FS*-Z, X- KHKKRKKRPQRAESN-C(Sx)-FS*-Z, X-KHKKRKKRPQRAHS*D-C(Sx)-FA-Z, X- KHKKRKKRPQRAHS*D-C(Sx)-FS-Z, X-KHKKRKKRPQRAHS*N-C(Sx)-FA-Z, X- KHKKRKKRPQRAHS*N-C(Sx)-FS-Z, X-KHKKRKKRPQRAHSD-C(Sx)-FS*-Z, X- KHKKRKKRPQRAHSN-C(Sx)-FS*-Z, X-KHKKRKKRPQRATS*D-C(Sx)-FA-Z, X- KHKKRKKRPQRATS*D-C(Sx)-FS-Z, X-KHKKRKKRPQRATS*N-C(Sx)-FA-Z, X- KHKKRKKRPQRATS*N-C(Sx)-FS-Z, X-KHKKRKKRPQRATSD-C(Sx)-FS*-Z, X- KHKKRKKRPQRATSN-C(Sx)-FS*-Z, X-KHKKTKKRPQRADS*D-C(Sx)-FA-Z, X- KHKKTKKRPQRADS*D-C(Sx)-FS-Z, X-KHKKTKKRPQRADS*N-C(Sx)-FA-Z, X- KHKKTKKRPQRADS*N-C(Sx)-FS-Z, X-KHKKTKKRPQRADSD-C(Sx)-FS*-Z, X- KHKKTKKRPQRADSN-C(Sx)-FS*-Z, X-KHKKTKKRPQRAES*D-C(Sx)-FA-Z, X- KHKKTKKRPQRAES*D-C(Sx)-FS-Z, X-KHKKTKKRPQRAES*N-C(Sx)-FA-Z, X- KHKKTKKRPQRAES*N-C(Sx)-FS-Z, X-KHKKTKKRPQRAESD-C(Sx)-FS*-Z, X- KHKKTKKRPQRAESN-C(Sx)-FS*-Z, and X-KHKKTKKRPQRAHS*D-C(Sx)-FA-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KHKKTKKRPQRAHS*D-C(Sx)-FS-Z, X- KHKKTKKRPQRAHS*N-C(Sx)-FA-Z, X-KHKKTKKRPQRAHS*N-C(Sx)-FS-Z, X- KHKKTKKRPQRAHSD-C(Sx)-FS*-Z, X-KHKKTKKRPQRAHSN-C(Sx)-FS*-Z, X- KHKKTKKRPQRATS*D-C(Sx)-FA-Z, X-KHKKTKKRPQRATS*D-C(Sx)-FS-Z, X- KHKKTKKRPQRATS*N-C(Sx)-FA-Z, X-KHKKTKKRPQRATS*N-C(Sx)-FS-Z, X- KHKKTKKRPQRATSD-C(Sx)-FS*-Z, X-KHKKTKKRPQRATSN-C(Sx)-FS*-Z, X- KHKKVKKRPQRADS*D-C(Sx)-FA-Z, X-KHKKVKKRPQRADS*D-C(Sx)-FS-Z, X- KHKKVKKRPQRADS*N-C(Sx)-FA-Z, X-KHKKVKKRPQRADS*N-C(Sx)-FS-Z, X- KHKKVKKRPQRADSD-C(Sx)-FS*-Z, X-KHKKVKKRPQRADSN-C(Sx)-FS*-Z, X- KHKKVKKRPQRAES*D-C(Sx)-FA-Z, X-KHKKVKKRPQRAES*D-C(Sx)-FS-Z, X- KHKKVKKRPQRAES*N-C(Sx)-FA-Z, X-KHKKVKKRPQRAES*N-C(Sx)-FS-Z, X- KHKKVKKRPQRAESD-C(Sx)-FS*-Z, X-KHKKVKKRPQRAESN-C(Sx)-FS*-Z, X- KHKKVKKRPQRAHS*D-C(Sx)-FA-Z, X-KHKKVKKRPQRAHS*D-C(Sx)-FS-Z, X- KHKKVKKRPQRAHS*N-C(Sx)-FA-Z, X-KHKKVKKRPQRAHS*N-C(Sx)-FS-Z, X- KHKKVKKRPQRAHSD-C(Sx)-FS*-Z, X-KHKKVKKRPQRAHSN-C(Sx)-FS*-Z, X- KHKKVKKRPQRATS*D-C(Sx)-FA-Z, X-KHKKVKKRPQRATS*D-C(Sx)-FS-Z, X- KHKKVKKRPQRATS*N-C(Sx)-FA-Z, X-KHKKVKKRPQRATS*N-C(Sx)-FS-Z, X- KHKKVKKRPQRATSD-C(Sx)-FS*-Z, X-KHKKVKKRPQRATSN-C(Sx)-FS*-Z, X- KHKTKKKRPQRADS*D-C(Sx)-FA-Z, X-KHKTKKKRPQRADS*D-C(Sx)-FS-Z, X- KHKTKKKRPQRADS*N-C(Sx)-FA-Z, X-KHKTKKKRPQRADS*N-C(Sx)-FS-Z, X- KHKTKKKRPQRADSD-C(Sx)-FS*-Z, X-KHKTKKKRPQRADSN-C(Sx)-FS*-Z, X- KHKTKKKRPQRAES*D-C(Sx)-FA-Z, X-KHKTKKKRPQRAES*D-C(Sx)-FS-Z, X- KHKTKKKRPQRAES*N-C(Sx)-FA-Z, X-KHKTKKKRPQRAES*N-C(Sx)-FS-Z, X- KHKTKKKRPQRAESD-C(Sx)-FS*-Z, X-KHKTKKKRPQRAESN-C(Sx)-FS*-Z, X- KHKTKKKRPQRAHS*D-C(Sx)-FA-Z, X-KHKTKKKRPQRAHS*D-C(Sx)-FS-Z, X- KHKTKKKRPQRAHS*N-C(Sx)-FA-Z, X-KHKTKKKRPQRAHS*N-C(Sx)-FS-Z, X- KHKTKKKRPQRAHSD-C(Sx)-FS*-Z, X-KHKTKKKRPQRAHSN-C(Sx)-FS*-Z, X- KHKTKKKRPQRATS*D-C(Sx)-FA-Z, X-KHKTKKKRPQRATS*D-C(Sx)-FS-Z, X- KHKTKKKRPQRATS*N-C(Sx)-FA-Z, X-KHKTKKKRPQRATS*N-C(Sx)-FS-Z, X- KHKTKKKRPQRATSD-C(Sx)-FS*-Z, X-KHKTKKKRPQRATSN-C(Sx)-FS*-Z, X- KHKTRKKRPQRADS*D-C(Sx)-FA-Z, X-KHKTRKKRPQRADS*D-C(Sx)-FS-Z, X- KHKTRKKRPQRADS*N-C(Sx)-FA-Z, X-KHKTRKKRPQRADS*N-C(Sx)-FS-Z, X- KHKTRKKRPQRADSD-C(Sx)-FS*-Z, X-KHKTRKKRPQRADSN-C(Sx)-FS*-Z, X- KHKTRKKRPQRAES*D-C(Sx)-FA-Z, X-KHKTRKKRPQRAES*D-C(Sx)-FS-Z, and X- KHKTRKKRPQRAES*N-C(Sx)-FA-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KHKTRKKRPQRAES*N-C(Sx)-FS-Z, X- KHKTRKKRPQRAESD-C(Sx)-FS*-Z, X-KHKTRKKRPQRAESN-C(Sx)-FS*-Z, X- KHKTRKKRPQRAHS*D-C(Sx)-FA-Z, X-KHKTRKKRPQRAHS*D-C(Sx)-FS-Z, X- KHKTRKKRPQRAHS*N-C(Sx)-FA-Z, X-KHKTRKKRPQRAHS*N-C(Sx)-FS-Z, X- KHKTRKKRPQRAHSD-C(Sx)-FS*-Z, X-KHKTRKKRPQRAHSN-C(Sx)-FS*-Z, X- KHKTRKKRPQRATS*D-C(Sx)-FA-Z, X-KHKTRKKRPQRATS*D-C(Sx)-FS-Z, X- KHKTRKKRPQRATS*N-C(Sx)-FA-Z, X-KHKTRKKRPQRATS*N-C(Sx)-FS-Z, X- KHKTRKKRPQRAT SD-C(Sx)-F S * -Z, X-KHKTRKKRPQRATSN-C(Sx)-FS*-Z, X- KHKTTKKRPQRADS*D-C(Sx)-FA-Z, X-KHKTTKKRPQRADS*D-C(Sx)-FS-Z, X- KHKTTKKRPQRADS*N-C(Sx)-FA-Z, X-KHKTTKKRPQRADS*N-C(Sx)-FS-Z, X- KHKTTKKRPQRADSD-C(Sx)-FS*-Z, X-KHKTTKKRPQRADSN-C(Sx)-FS*-Z, X- KHKTTKKRPQRAES*D-C(Sx)-FA-Z, X-KHKTTKKRPQRAES*D-C(Sx)-FS-Z, X- KHKTTKKRPQRAES*N-C(Sx)-FA-Z, X-KHKTTKKRPQRAES*N-C(Sx)-FS-Z, X- KHKTTKKRPQRAESD-C(Sx)-FS*-Z, X-KHKTTKKRPQRAESN-C(Sx)-FS*-Z, X- KHKTTKKRPQRAHS*D-C(Sx)-FA-Z, X-KHKTTKKRPQRAHS*D-C(Sx)-FS-Z, X- KHKTTKKRPQRAHS*N-C(Sx)-FA-Z, X-KHKTTKKRPQRAHS*N-C(Sx)-FS-Z, X- KHKTTKKRPQRAHSD-C(Sx)-FS*-Z, X-KHKTTKKRPQRAHSN-C(Sx)-FS*-Z, X- KHKTTKKRPQRATS*D-C(Sx)-FA-Z, X-KHKTTKKRPQRATS*D-C(Sx)-FS-Z, X- KHKTTKKRPQRATS*N-C(Sx)-FA-Z, X-KHKTTKKRPQRATS*N-C(Sx)-FS-Z, X- KHKTTKKRPQRATSD-C(Sx)-FS*-Z, X-KHKTTKKRPQRATSN-C(Sx)-FS*-Z, X- KHKTVKKRPQRADS*D-C(Sx)-FA-Z, X-KHKTVKKRPQRADS*D-C(Sx)-FS-Z, X- KHKTVKKRPQRADS*N-C(Sx)-FA-Z, X-KHKTVKKRPQRADS*N-C(Sx)-FS-Z, and X- KHKTVKKRPQRADSD-C(Sx)-FS*-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KHKTVKKRPQRADSN-C(Sx)-FS*-Z, X- KHKTVKKRPQRAES*D-C(Sx)-FA-Z, X-KHKTVKKRPQRAES*D-C(Sx)-FS-Z, X- KHKTVKKRPQRAES*N-C(Sx)-FA-Z, X-KHKTVKKRPQRAES*N-C(Sx)-FS-Z, X- KHKTVKKRPQRAESD-C(Sx)-FS*-Z, X-KHKTVKKRPQRAESN-C(Sx)-FS*-Z, X- KHKTVKKRPQRAHS*D-C(Sx)-FA-Z, X-KHKTVKKRPQRAHS*D-C(Sx)-FS-Z, X- KHKTVKKRPQRAHS*N-C(Sx)-FA-Z, X-KHKTVKKRPQRAHS*N-C(Sx)-FS-Z, X- KHKTVKKRPQRAHSD-C(Sx)-FS*-Z, X-KHKTVKKRPQRAHSN-C(Sx)-FS*-Z, X- KHKTVKKRPQRATS*D-C(Sx)-FA-Z, X-KHKTVKKRPQRATS*D-C(Sx)-FS-Z, X- KHKTVKKRPQRATS*N-C(Sx)-FA-Z, X-KHKTVKKRPQRATS*N-C(Sx)-FS-Z, X- KHKTVKKRPQRATSD-C(Sx)-FS*-Z, X-KHKTVKKRPQRATSN-C(Sx)-FS*-Z, X- KHRPQRAT*S-C(Sx)-VFAMF-Z, X-KIKTTKKRPQRATS*N-C(Sx)-FS-Z, X- KIKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KIRPQRAT*S-C(Sx)-VFAMF-Z, X- KK[Nle]PQRAT*S-C(Sx)-VFAMF-Z, X-KK-C(Sx)-AS*FKK-Z, X-KK-C(Sx)-AS*FRR-Z, X-KKCDLGYAKDVDQGS*L-C(Sx)-TSFVGTLQYLAPECKK-Z, X- KKCDLGYAKDVDQGSL-C(Sx)-TS*FVGTLQYLAPECKK-Z, X-KKCVSGQLIDS*M- C(Sx)-NSFVGTRSYCKK-Z, X-KKCVSGQLIDSM-C(Sx)-NS*FVGTRSYCKK-Z, X- KKDPQRAT*S-C(Sx)-VFAMF-Z, X-KKEPQRAT*S-C(Sx)-VFAMF-Z, X- KKERLLDDRHD S * G-C(Sx)-D SMKDEE-Z, X-KKERLLDDRHDSG-C(Sx)-DS*MKDEE- Z, X-KKERLLDDRHD SGLD S *M-C(Sx)-DEE-Z, X-KKFPQRAT*S-C(Sx)-VFAMF-Z, X- KKGPQRAT*S-C(Sx)-VFAMF-Z, X-KKHPQRAT*S-C(Sx)-VFAMF-Z, and X- KKIPQRAT*S-C(Sx)-VFAMF-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KKIS*G-C(Sx)-LSPI[Nle]TEQ-Z, X-KKISG- C(Sx)-LS*PI[Nle]TEQ-Z, X-KKISGRLS*P-C(Sx)-[Nle]TEQ-Z, X-KKISGRLSP-C(Sx)- [Nle]T*EQ-Z, X-KKKADKQFLIS*P-C(Sx)-ASP-Z, X-KKKADKQFLISP-C(Sx)-AS*P-Z, X-KKKAEPLPPSYV-C(Sx)-AS*-Z, X-KKKAGTSF[Nle][Nle]T*P-C(Sx)-VVTR-Z, X- KKKA PSPPPS*P-C(Sx)-QQI L-Z, X-KKKAPLSTWSGS*P-C(Sx)-YAAPE-Z, X- KKKDGR[Nle]VQLS*P-C(Sx)-ALAAP-Z, X-KKKFQGQLLGT*I-C(Sx)-F[Nle]APE-Z, X- KKKGDNVLINT*Y-C(Sx)-GVLKI-Z, X-KKKGHITTTPT*P-C(Sx)-QFL-Z, X- KKKGI PSTET*F-C(Sx)-GTLQY-Z, X-KKKGI PSTETF-C(Sx)-GT*LQY-Z, X- KKKG LLPMS*P-C(Sx)-EFD-Z, X-KKKGQSSAAAT*P-C(Sx)-TTGTK-Z, X- KKKGTQREGVSS*L-C(Sx)-SSSL-Z, X-KKKGTQREGVSSL-C(Sx)-SS*SL-Z, X- KKKGVITTTPT*P-C(Sx)-GQYFY-Z, X-KKKHQLFRGFS*F-C(Sx)-AITSD-Z, X- KKKIHFWSSLS*P-C(Sx)-APLSP-Z, X-KKKKKKKRPQRADS*D-C(Sx)-FA-Z, X- KKKKKKKRPQRADS*D-C(Sx)-FS-Z, X-KKKKKKKRPQRADS*N-C(Sx)-FA-Z, X- KKKKKKKRPQRADS *N-C(Sx)-F S-Z, X-KKKKKKKRPQRADSD-C(Sx)-FS*-Z, X- KKKKKKKRPQRAD SN-C(Sx)-F S *-Z, X-KKKKKKKRPQRAES*D-C(Sx)-FA-Z, X- KKKKKKKRPQRAES*D-C(Sx)-FS-Z, X-KKKKKKKRPQRAES*N-C(Sx)-FA-Z, X- KKKKKKKRPQRAES*N-C(Sx)-FS-Z, X-KKKKKKKRPQRAESD-C(Sx)-FS*-Z, X- KKKKKKKRPQRAESN-C(Sx)-FS*-Z, X-KKKKKKKRPQRAHS*D-C(Sx)-FA-Z, X- KKKKKKKRPQRAHS*D-C(Sx)-FS-Z, X-KKKKKKKRPQRAHS*N-C(Sx)-FA-Z, X- KKKKKKKRPQRAHS*N-C(Sx)-FS-Z, X-KKKKKKKRPQRAHSD-C(Sx)-FS*-Z, X- KKKKKKKRPQRAHSN-C(Sx)-F S *-Z, X-KKKKKKKRPQRATS*D-C(Sx)-FA-Z, X- KKKKKKKRPQRATS*D-C(Sx)-FS-Z, X-KKKKKKKRPQRATS*N-C(Sx)-FA-Z, X- KKKKKKKRPQRATS*N-C(Sx)-FS-Z, X-KKKKKKKRPQRATSD-C(Sx)-FS*-Z, X- KKKKKKKRPQRATSN-C(Sx)-FS*-Z, X-KKKKRKKRPQRADS*D-C(Sx)-FA-Z, X- KKKKRKKRPQRADS*D-C(Sx)-FS-Z, X-KKKKRKKRPQRADS*N-C(Sx)-FA-Z, X- KKKKRKKRPQRADS*N-C(Sx)-FS-Z, X-KKKKRKKRPQRADSD-C(Sx)-FS*-Z, X- KKKKRKKRPQRADSN-C(Sx)-FS*-Z, X-KKKKRKKRPQRAES*D-C(Sx)-FA-Z, X- KKKKRKKRPQRAES *D-C(Sx)-F S-Z, X-KKKKRKKRPQRAES*N-C(Sx)-FA-Z, X- KKKKRKKRPQRAES *N-C(Sx)-F S-Z, X-KKKKRKKRPQRAESD-C(Sx)-FS*-Z, X- KKKKRKKRPQRAESN-C(Sx)-FS*-Z, X-KKKKRKKRPQRAHS*D-C(Sx)-FA-Z, X- KKKKRKKRPQRAHS*D-C(Sx)-FS-Z, X-KKKKRKKRPQRAHS*N-C(Sx)-FA-Z, X- KKKKRKKRPQRAHS*N-C(Sx)-FS-Z, X-KKKKRKKRPQRAHSD-C(Sx)-FS*-Z, X- KKKKRKKRPQRAHSN-C(Sx)-F S *-Z, X-KKKKRKKRPQRATS*D-C(Sx)-FA-Z, X- KKKKRKKRPQRATS*D-C(Sx)-FS-Z, X-KKKKRKKRPQRATS*N-C(Sx)-FA-Z, and X- KKKKRKKRPQRATS*N-C(Sx)-FS-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KKKKRKKRPQRATSD-C(Sx)-FS*-Z, X- KKKKRKKRPQRATSN-C(Sx)-FS*-Z, X-KKKKTKKRPQRADS*D-C(Sx)-FA-Z, X- KKKKTKKRPQRADS*D-C(Sx)-FS-Z, X-KKKKTKKRPQRADS*N-C(Sx)-FA-Z, X- KKKKTKKRPQRADS*N-C(Sx)-FS-Z, X-KKKKTKKRPQRADSD-C(Sx)-FS*-Z, X- KKKKTKKRPQRADSN-C(Sx)-FS*-Z, X-KKKKTKKRPQRAES*D-C(Sx)-FA-Z, X- KKKKTKKRPQRAES*D-C(Sx)-FS-Z, X-KKKKTKKRPQRAES*N-C(Sx)-FA-Z, X- KKKKTKKRPQRAES*N-C(Sx)-FS-Z, X-KKKKTKKRPQRAESD-C(Sx)-FS*-Z, X- KKKKTKKRPQRAESN-C(Sx)-F S *-Z, X-KKKKTKKRPQRAHS*D-C(Sx)-FA-Z, X- KKKKTKKRPQRAHS*D-C(Sx)-FS-Z, X-KKKKTKKRPQRAHS*N-C(Sx)-FA-Z, X- KKKKTKKRPQRAHS*N-C(Sx)-FS-Z, X-KKKKTKKRPQRAHSD-C(Sx)-FS*-Z, X- KKKKTKKRPQRAHSN-C(Sx)-F S * -Z, X-KKKKTKKRPQRATS*D-C(Sx)-FA-Z, X- KKKKTKKRPQRATS*D-C(Sx)-FS-Z, X-KKKKTKKRPQRATS*N-C(Sx)-FA-Z, X- KKKKTKKRPQRATS*N-C(Sx)-FS-Z, X-KKKKTKKRPQRATSD-C(Sx)-FS*-Z, X- KKKKTKKRPQRATSN-C(Sx)-F S *-Z, X-KKKKVKKRPQRA[hE]S*D-C(Sx)-FS-Z, X- KKKKVKKRPQRA[hE]SD-C(Sx)-FS*-Z, X-KKKKVKKRPQRADS*D-C(Sx)-FA-Z, X- KKKKVKKRPQRADS*D-C(Sx)-FS-Z, X-KKKKVKKRPQRADS*N-C(Sx)-FA-Z, X- KKKKVKKRPQRADS*N-C(Sx)-FS-Z, X-KKKKVKKRPQRADSD-C(Sx)-FS*-Z, and X- KKKKVKKRPQRADSN-C(Sx)-FS*-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting o X-KKKKVKKRPQRAES*D-C(Sx)-FA-Z, X- KKKKVKKRPQRAES*D-C(Sx)-FS-Z, X-KKKKVKKRPQRAES*N-C(Sx)-FA-Z, X- KKKKVKKRPQRAES*N-C(Sx)-FS-Z, X-KKKKVKKRPQRAESD-C(Sx)-FS*-Z, X- KKKKVKKRPQRAESN-C(Sx)-FS*-Z, X-KKKKVKKRPQRAHS*D-C(Sx)-FA-Z, X- KKKKVKKRPQRAHS*D-C(Sx)-FS-Z, X-KKKKVKKRPQRAHS*N-C(Sx)-FA-Z, X- KKKKVKKRPQRAHS*N-C(Sx)-FS-Z, X-KKKKVKKRPQRAHSD-C(Sx)-FS*-Z, X- KKKKVKKRPQRAHSN-C(Sx)-FS*-Z, X-KKKKVKKRPQRATS*D-C(Sx)-FA-Z, X- KKKKVKKRPQRATS*D-C(Sx)-FS-Z, X-KKKKVKKRPQRATS*N-C(Sx)-FA-Z, X- KKKKVKKRPQRATS*N-C(Sx)-FS-Z, X-KKKKVKKRPQRATSD-C(Sx)-FS*-Z, X- KKKKVKKRPQRATSN-C(Sx)-FS*-Z, X-KKKLAP PSFS*P-C(Sx)-PGFTP-Z, X- KKKLIDS[Nle]ANS*F-C(Sx)-GTRSY-Z, X-KKKLIDS[Nle]ANSF-C(Sx)-GT*RSY-Z, X- KKKLPPVFSGT*P-C(Sx)-GSGAG-Z, X-KKKLPPVFSGTP-C(Sx)-GS*GAG-Z, X- KKKLSNSQGQS*P-C(Sx)-VPFPA-Z, X-KKKLTDPRLLS*P-C(Sx)-QPALQ-Z, X- KKKNVH[Nle]VSTT*L-C(Sx)-VDSR-Z, X-KKKPLSPFPVS*P-C(Sx)-AGPGS-Z, X- KKKPQPLRS*P-C(Sx)-LD PT-Z, X-KKKPQRAT*S-C(Sx)-VFAMF-Z, X-KKKPSAPA- C(Sx)-ST*PGIRDSA-Z, X-KKKPSAPALST*P-C(Sx)-IRDSA-Z, X-KKKPSAPALST*PG- C(Sx)-RDSA-Z, X-KKKQ[Nle]AGTPIT*P-C(Sx)-KDGFT-Z, X-KKKQAATGFGS*P- C(Sx)-QYSAD-Z, X-KKKQGPAPVGT*P-C(Sx)-F RQH-Z, X-KKKQLSKWPGS*P- C(Sx)-SRSSD-Z, X-KKKQ RSGAMS*P-C(Sx)-SWNSD-Z, X-KKKQS[Nle]VVPQT*P- C(Sx)-HTARV-Z, X-KKKQS[Nle]VVPQTP-C(Sx)-HT*ARV-Z, X-KKKQSAQS-C(Sx)- AT*PVVSVAT-Z, X-KKKQSAQSLAT*P-C(Sx)-VSVAT-Z, X-KKKQSAQSLATP-C(Sx)- VS*VAT-Z, X-KKKRPASVNGS*P-C(Sx)-ATSES-Z, X-KKKRPASVNGSP-C(Sx)- AT*SES-Z, X-KKKS[Nle]DGLFGT*I-C(Sx)-YLP-Z, X-KKKSALQG-C(Sx)- NS*PG[Nle]LSLG-Z, X-KKKSALQGFNS*P-C(Sx)-[Nle]LSLG-Z, X-KKKSASGSAFS*P- C(Sx)-PGSAA-Z, X-KKKSAVNGTSS*A-C(Sx)-T LEA-Z, and X-KKKSGYS*S-C(Sx)- GSPGTPGSR-Z; wherein X- is H or acetyl; and Z is OH or H ₂ . In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KKKSGYSS-C(Sx)-GS*PGTPGSR-Z, X- KKKSGYSSPGS*P-C(Sx)-TPGSR-Z, X-KKKSGYSSPGS*PG-C(Sx)-PGSR-Z, X- KKKSNGHITTT*P-C(Sx)-PTQFL-Z, X-KKKSNGHITTTP-C(Sx)-PT*QFL-Z, X- KKKSNGLVTTT*P-C(Sx)-SSQFL-Z, X-KKKSNGLVTTTP-C(Sx)-SS*QFL-Z, X- KKKSNGVITTT*P-C(Sx)-PPGQY-Z, X-KKKS PALLSS*P-C(Sx)-YYSAA-Z, X- KKKSPLNITST*P-C(Sx)-PDASS-Z, X-KKKSVPSAAVT*P-C(Sx)- ESLQ-Z, X- KKKSVSAATLT*P-C(Sx)-SQAVT-Z, X-KKKTETFTGT*L-C(Sx)-Y[Nle]APE-Z, X- KKKTKKKRPQRADS*D-C(Sx)-FA-Z, X-KKKTKKKRPQRADS*D-C(Sx)-FS-Z, X- KKKTKKKRPQRADS*N-C(Sx)-FA-Z, X-KKKTKKKRPQRADS*N-C(Sx)-FS-Z, X- KKKTKKKRPQRADSD-C(Sx)-FS*-Z, X-KKKTKKKRPQRADSN-C(Sx)-FS*-Z, X- KKKTKKKRPQRAES*D-C(Sx)-FA-Z, X-KKKTKKKRPQRAES*D-C(Sx)-FS-Z, X- KKKTKKKRPQRAES*N-C(Sx)-FA-Z, X-KKKTKKKRPQRAES*N-C(Sx)-FS-Z, X- KKKTKKKRPQRAESD-C(Sx)-FS*-Z, X-KKKTKKKRPQRAESN-C(Sx)-FS*-Z, X- KKKTKKKRPQRAHS*D-C(Sx)-FA-Z, X-KKKTKKKRPQRAHS*D-C(Sx)-FS-Z, X- KKKTKKKRPQRAHS*N-C(Sx)-FA-Z, X-KKKTKKKRPQRAHS*N-C(Sx)-FS-Z, X- KKKTKKKRPQRAHSD-C(Sx)-FS*-Z, X-KKKTKKKRPQRAHSN-C(Sx)-FS*-Z, X- KKKTKKKRPQRATS*D-C(Sx)-FA-Z, X-KKKTKKKRPQRATS*D-C(Sx)-FS-Z, X- KKKTKKKRPQRATS*N-C(Sx)-FA-Z, X-KKKTKKKRPQRATS*N-C(Sx)-FS-Z, X- KKKTKKKRPQRATSD-C(Sx)-FS*-Z, X-KKKTKKKRPQRATSN-C(Sx)-FS*-Z, X- KKKTPVVSVAT*P-C(Sx)-LPGQG-Z, X-KKKTRKKRPQRADS*D-C(Sx)-FA-Z, X- KKKTRKKRPQRADS*D-C(Sx)-FS-Z, X-KKKTRKKRPQRADS*N-C(Sx)-FA-Z, X- KKKTRKKRPQRADS*N-C(Sx)-FS-Z, X-KKKTRKKRPQRADSD-C(Sx)-FS*-Z, X- KKKTRKKRPQRADSN-C(Sx)-FS*-Z, X-KKKTRKKRPQRAES*D-C(Sx)-FA-Z, X- KKKTRKKRPQRAES*D-C(Sx)-FS-Z, X-KKKTRKKRPQRAES*N-C(Sx)-FA-Z, X- KKKTRKKRPQRAES*N-C(Sx)-FS-Z, X-KKKTRKKRPQRAESD-C(Sx)-FS*-Z, X- KKKTRKKRPQRAESN-C(Sx)-FS*-Z, X-KKKTRKKRPQRAHS*D-C(Sx)-FA-Z, X- KKKTRKKRPQRAHS*D-C(Sx)-FS-Z, X-KKKTRKKRPQRAHS*N-C(Sx)-FA-Z, X- KKKTRKKRPQRAHS*N-C(Sx)-FS-Z, X-KKKTRKKRPQRAHSD-C(Sx)-FS*-Z, X- KKKTRKKRPQRAHSN-C(Sx)-FS*-Z, and X-KKKTRKKRPQRATS*D-C(Sx)-FA-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KKKTRKKRPQRATS*D-C(Sx)-FS-Z, X- KKKTRKKRPQRATS*N-C(Sx)-FA-Z, X-KKKTRKKRPQRATS*N-C(Sx)-FS-Z, X- KKKTRKKRPQRATSD-C(Sx)-FS*-Z, X-KKKTRKKRPQRATSN-C(Sx)-FS*-Z, X- KKKTTGTKSNT*P-C(Sx)-SSVPS-Z, X-KKKTTGTKSNTP-C(Sx)-SS*VPS-Z, X- KKKTTKKRPQRADS*D-C(Sx)-FA-Z, X-KKKTTKKRPQRADS*D-C(Sx)-FS-Z, X- KKKTTKKRPQRADS*N-C(Sx)-FA-Z, X-KKKTTKKRPQRADS*N-C(Sx)-FS-Z, X- KKKTTKKRPQRADSD-C(Sx)-FS*-Z, X-KKKTTKKRPQRADSN-C(Sx)-FS*-Z, X- KKKTTKKRPQRAES*D-C(Sx)-FA-Z, X-KKKTTKKRPQRAES*D-C(Sx)-FS-Z, X- KKKTTKKRPQRAES*N-C(Sx)-FA-Z, X-KKKTTKKRPQRAES*N-C(Sx)-FS-Z, X- KKKTTKKRPQRAESD-C(Sx)-FS*-Z, X-KKKTTKKRPQRAESN-C(Sx)-FS*-Z, X- KKKTTKKRPQRAHS*D-C(Sx)-FA-Z, X-KKKTTKKRPQRAHS*D-C(Sx)-FS-Z, X- KKKTTKKRPQRAHS*N-C(Sx)-FA-Z, X-KKKTTKKRPQRAHS*N-C(Sx)-FS-Z, X- KKKTTKKRPQRAHSD-C(Sx)-FS*-Z, X-KKKTTKKRPQRAHSN-C(Sx)-FS*-Z, X- KKKTTKKRPQRATS*D-C(Sx)-FA-Z, X-KKKTTKKRPQRATS*D-C(Sx)-FS-Z, X- KKKTTKKRPQRATS*N-C(Sx)-FA-Z, X-KKKTTKKRPQRATS*N-C(Sx)-FS-Z, X- KKKTTKKRPQRATSD-C(Sx)-FS*-Z, X-KKKTTKKRPQRATSN-C(Sx)-FS*-Z, X- KKKTTQNALQT*P-C(Sx)-YTPYY-Z, X-KKKTTQNALQTP-C(Sx)-YT*PYY-Z, X- KKKTTSSTPSS*P-C(Sx)-PFPTS-Z, X-KKKTVKKRPQRADS*D-C(Sx)-FA-Z, X- KKKTVKKRPQRADS*D-C(Sx)-FS-Z, X-KKKTVKKRPQRADS*N-C(Sx)-FA-Z, X- KKKTVKKRPQRADS*N-C(Sx)-FS-Z, X-KKKTVKKRPQRADSD-C(Sx)-FS*-Z, X- KKKTVKKRPQRADSN-C(Sx)-FS*-Z, X-KKKTVKKRPQRAES*D-C(Sx)-FA-Z, X- KKKTVKKRPQRAES*D-C(Sx)-FS-Z, X-KKKTVKKRPQRAES*N-C(Sx)-FA-Z, X- KKKTVKKRPQRAES*N-C(Sx)-FS-Z, X-KKKTVKKRPQRAESD-C(Sx)-FS*-Z, X- KKKTVKKRPQRAESN-C(Sx)-FS*-Z, X-KKKTVKKRPQRAHS*D-C(Sx)-FA-Z, X- KKKTVKKRPQRAHS*D-C(Sx)-FS-Z, X-KKKTVKKRPQRAHS*N-C(Sx)-FA-Z, X- KKKTVKKRPQRAHS*N-C(Sx)-FS-Z, X-KKKTVKKRPQRAHSD-C(Sx)-FS*-Z, X- KKKTVKKRPQRAHSN-C(Sx)-FS*-Z, X-KKKTVKKRPQRATS*D-C(Sx)-FA-Z, X- KKKTVKKRPQRATS*D-C(Sx)-FS-Z, X-KKKTVKKRPQRATS*N-C(Sx)-FA-Z, X- KKKTVKKRPQRATS*N-C(Sx)-FS-Z, X-KKKTVKKRPQRATSD-C(Sx)-FS*-Z, X- KKKTVKKRPQRATSN-C(Sx)-FS*-Z, and X-KKKTVNQSLLS*P-C(Sx)-VLEVD-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KKKVLTQ[Nle]GSPS*I-C(Sx)-SS[pS]VS-Z, X- KKKVLTQ[Nle]GSPSI-C(Sx)-SS*[pS]VS-Z, X-KKKVPNGA-C(Sx)-SS*PVGNGFV-Z, X- KKKVPNGAGSS*P-C(Sx)-GNGFV-Z, X-KKKVSGQLID[Nle]M-C(Sx)-NS*FVGTRSY- Z, X-KKKVSGQLIDAM-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDDM-C(Sx)- NS*FVGTRSY-Z, X-KKKVSGQLIDEM-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDFM- C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDGM-C(Sx)-NS*FVGTRSY-Z, X- KKKVSGQLIDHM-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDF -C(Sx)-NS*FVGTRSY- Z, X-KKKVSGQLIDKM-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDLM-C(Sx)- NS*FVGTRSY-Z, X-KKKVSGQLIDMM-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLID M- C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDPM-C(Sx)-NS*FVGTRSY-Z, X- KKKVSGQLIDQM-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDRM-C(Sx)- NS*FVGTRSY-Z, X-KKKVSGQLIDS*[Nle]-C(Sx)-NSFVGTRSY-Z, X- KKKVSGQLIDS*[Nle]-C(Sx)-NSFVG-Z, X-KKKVSGQLIDS*M-C(Sx)-NAFVGTRSY-Z, X-KKKVSGQLIDS*M-C(Sx)- DFVGTRSY-Z, X-KKKVSGQLIDS*M-C(Sx)- EFVGTRSY-Z, X-KKKVSGQLIDS*M-C(Sx)- FFVGTRSY-Z, X-KKKVSGQLIDS*M- C(Sx)-NIFVGTRSY-Z, X-KKKVSGQLIDS*M-C(Sx)- PFVGTRSY-Z, X- KKKVSGQLIDS*M-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDS*M-C(Sx)-NSFVGTRS- Z, X-KKKVSGQLIDS[Nle]-C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDS[Nle]-C(Sx)- NS*FVG-Z, X-KKKVSGQLIDSMANS*F-C(Sx)-GTRSY-Z, X-KKK VSGQLID SMANSF - C(Sx)-GT*RSY-Z, X-KKKVSGQLIDSM-C(Sx)-NS*FVGTRS-Z, X-KKKVSGQLIDVM- C(Sx)-NS*FVGTRSY-Z, X-KKKVSGQLIDWM-C(Sx)-NS*FVGTRSY-Z, X- KKKVSRSGLYRSPS*[Nle]-C(Sx)-E L RPR-Z, X-KKKVSRSGLYRSPS*M-C(Sx)- E L RP-Z, X-KKKVSRSGLYRSPS*M-C(Sx)-E L R-Z, X-KKLGEDQAEEISDDLL- C(Sx)-DS*LSDEDE-Z, X-KKLGEDQAEEISDDLLEDS*L-C(Sx)-DEDE-Z, X-KKL R- C(Sx)-LS*FAEG-Z, X-KKL R-C(Sx)-LS*FAEPG-Z, X-KKLPQRAT*S-C(Sx)-VFAMF-Z, X-KKLSTPV-C(Sx)-LS*PGPQKP-Z, X-KKLSTPVVLS*P-C(Sx)-PQKP-Z, and X- KKLSTPVVLS*PG-C(Sx)-QKP-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KK PQRAT*S-C(Sx)-VFAMF-Z, X- KKNVH[Nle]V-C(Sx)-TT*LPVDSRKK-Z, X-KKPPQRAT*S-C(Sx)-VFAMF-Z, X- KKPSVNPSIS*P-C(Sx)-HGVAR-Z, X-KKQPQRAT*S-C(Sx)-VFAMF-Z, X- KKR[Nle]QRAT*S-C(Sx)-VFAMF-Z, X-KKRAA-C(Sx)-AT*SDVFA-Z, X- KKRAARAT*S-C(Sx)-VFA-Z, X-KKRAARATS*D-C(Sx)-FA-Z, X-KKRAAR-C(Sx)- TS*DVFA-Z, X-KKRDQRAT*S-C(Sx)-VFAMF-Z, X-KKREQRAT*S-C(Sx)-VFAMF-Z, X-KKRFQRAT*S-C(Sx)-VFAMF-Z, X-KKRGQRAT*S-C(Sx)-VFAMF-Z, X- KKRHQRAT*S-C(Sx)-VFAMF-Z, X-KKRIQRAT*S-C(Sx)-VFAMF-Z, X- KKRKQRAT*S-C(Sx)-VFAMF-Z, X-KKRLQRAT*S-C(Sx)-VFAMF-Z, X- KKRNQRAT*S-C(Sx)-VFAMF-Z, X-KKRP[Nle]RAT*S-C(Sx)-VFAMF-Z, X- KKRPDRAT*S-C(Sx)-VFAMF-Z, X-KKRPERAT*S-C(Sx)-VFAMF-Z, X-KKRPFRAT * S- C(Sx)-VFAMF-Z, X-KKRPGRAT*S-C(Sx)-VFAMF-Z, X-KKRPHRAT*S-C(Sx)-VFAMF- Z, X-KKRPIRAT*S-C(Sx)-VFAMF-Z, X-KKRPKRAT*S-C(Sx)-VFAMF-Z, X- KKRPLRAT*S-C(Sx)-VFAMF-Z, X-KKRP RAT*S-C(Sx)-VFAMF-Z, X-KKRPPRAT*S- C(Sx)-VFAMF-Z, X-KKRPQ[Nle]AT*S-C(Sx)-VFAMF-Z, X-KKRPQDAT*S-C(Sx)- VFAMF-Z, X-KKRPQEAT*S-C(Sx)-VFAMF-Z, X-KKRPQFAT*S-C(Sx)-VFAMF-Z, X- KKRPQGAT*S-C(Sx)-VFAMF-Z, X-KKRPQHAT*S-C(Sx)-VFAMF-Z, X-KKRPQIAT*S- C(Sx)-VFAMF-Z, X-KKRPQKAT*S-C(Sx)-VFAMF-Z, X-KKRPQLAT*S-C(Sx)-VFAMF- Z, X-KKRPQNAT*S-C(Sx)-VFAMF-Z, X-KKRPQPAT*S-C(Sx)-VFAMF-Z, X- KKRPQQAT*S-C(Sx)-VFAMF-Z, X-KKRPQR[Nle]T*S-C(Sx)-VFAMF-Z, X- KKRPQRAT*[Nle]-C(Sx)-VFAMF-Z, X-KKRPQRAT*D-C(Sx)-VFAMF-Z, X- KKRPQRAT*E-C(Sx)-VFAMF-Z, X-KKRPQRAT*F-C(Sx)-VFAMF-Z, X- KKRPQRAT*G-C(Sx)-VFAMF-Z, X-KKRPQRAT*H-C(Sx)-VFAMF-Z, X- KKRPQRAT*I-C(Sx)-VFAMF-Z, X-KKRPQRAT*K-C(Sx)-VFAMF-Z, X- KKRPQRAT*L-C(Sx)-VFAMF-Z, X-KKRPQRAT*N-C(Sx)-VFAMF-Z, X- KKRPQRAT*P-C(Sx)-VFAMF-Z, X-KKRPQRAT*Q-C(Sx)-VFAMF-Z, and X- KKRPQRAT*R-C(Sx)-VFAMF-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-KKRPQRAT*S-C(Sx)-[Nle]FAMF-Z, X- KKRPQRAT*S-C(Sx)-DFAMF-Z, X-KKRPQRAT*S-C(Sx)-EFAMF-Z, X-KKRPQRAT* S- C(Sx)-FFAMF-Z, X-KKRPQRAT* S-C(Sx)-GFAMF-Z, X-KKRPQRAT* S-C(Sx)-HFAMF- Z, X-KKRPQRAT* S-C(Sx)-IFAMF-Z, X-KKRPQRAT* S-C(Sx)-KFAMF-Z, X- KKRPQRAT*S-C(Sx)-LFAMF-Z, X-KKRPQRAT* S-C(Sx)- FAMF-Z, X-KKRPQRAT* S- C(Sx)-PFAMF-Z, X-KKRPQRAT* S-C(Sx)-QFAMF-Z, X-KKRPQRAT* S-C(Sx)-RFAMF- Z, X-KKRPQRAT* S-C(Sx)-V[Nle]AMF-Z, X-KKRPQRAT* S-C(Sx)-VDAMF-Z, X- KKRPQRAT*S-C(Sx)-VEAMF-Z, X-KKRPQRAT* S-C(Sx)-VF[Nle]MF-Z, X- KKRPQRAT*S-C(Sx)-VFADF-Z, X-KKRPQRAT* S-C(Sx)-VFAEF-Z, X-KKRPQRAT* S- C(Sx)-VFAFF-Z, X-KKRPQRAT* S-C(Sx)-VFAGF-Z, X-KKRPQRAT* S-C(Sx)-VFAHF-Z, X-KKRPQRAT* S-C(Sx)-VFAIF-Z, X-KKRPQRAT* S-C(Sx)-VFAKF-Z, X- KKRPQRAT*S-C(Sx)-VFALF-Z, X-KKRPQRAT* S-C(Sx)-VFAM[Nle]-Z, X- KKRPQRAT*S-C(Sx)-VFAMD-Z, X-KKRPQRAT* S-C(Sx)-VFAME-Z, X- KKRPQRAT*S-C(Sx)-VFAMG-Z, X-KKRPQRAT* S-C(Sx)-VFAMH-Z, X- KKRPQRAT*S-C(Sx)-VFAMI-Z, X-KKRPQRAT* S-C(Sx)-VFAMK-Z, X- KKRPQRAT*S-C(Sx)-VFAML-Z, X-KKRPQRAT* S-C(Sx)-VFAMN-Z, X- KKRPQRAT*S-C(Sx)-VFAMP-Z, X-KKRPQRAT*S-C(Sx)-VFAMQ-Z, X- KKRPQRAT*S-C(Sx)-VFAMR-Z, X-KKRPQRAT*S-C(Sx)-VFAMV-Z, X- KKRPQRAT*S-C(Sx)-VFAMW-Z, X-KKRPQRAT*S-C(Sx)-VFA F-Z, X- KKRPQRAT*S-C(Sx)-VFAPF-Z, X-KKRPQRAT*S-C(Sx)-VFAQF-Z, X-KKRPQRAT*S- C(Sx)-VFARF-Z, X-KKRPQRAT*S-C(Sx)-VFAVF-Z, X-KKRPQRAT* S-C(Sx)-VFAWF- Z, X-KKRPQRAT*S-C(Sx)-VFDMF-Z, X-KKRPQRAT*S-C(Sx)-VFEMF-Z, X- KKRPQRAT*S-C(Sx)-VFFMF-Z, X-KKRPQRAT*S-C(Sx)-VFGMF-Z, X-KKRPQRAT* S- C(Sx)-VFHMF-Z, X-KKRPQRAT* S-C(Sx)-VFIMF-Z, X-KKRPQRAT* S-C(Sx)-VFKMF- Z, X-KKRPQRAT* S-C(Sx)-VFLMF-Z, X-KKRPQRAT* S-C(Sx)-VF MF-Z, X- KKRPQRAT*S-C(Sx)-VFPMF-Z, X-KKRPQRAT* S-C(Sx)-VFQMF-Z, X-KKRPQRAT* S- C(Sx)-VFRMF-Z, X-KKRPQRAT* S-C(Sx)-VFVMF-Z, X-KKRPQRAT* S-C(Sx)-VFWMF- Z, X-KKRPQRAT* S-C(Sx)-VGAMF-Z, X-KKRPQRAT* S-C(Sx)-VHAMF-Z, X- KKRPQRAT*S-C(Sx)-VIAMF-Z, X-KKRPQRAT* S-C(Sx)-VKAMF-Z, X- KKRPQRAT*S-C(Sx)-VLAMF-Z, X-KKRPQRAT* S-C(Sx)-VNAMF-Z, X- KKRPQRAT*S-C(Sx)-VPAMF-Z, X-KKRPQRAT* S-C(Sx)-VQAMF-Z, X- KKRPQRAT*S-C(Sx)-VRAMF-Z, X-KKRPQRAT* S-C(Sx)-VVAMF-Z, X- KKRPQRAT*S-C(Sx)-VWAMF-Z, X-KKRPQRAT* S-C(Sx)-WFAMF-Z, X- KKRPQRAT*V-C(Sx)-VFAMF-Z, and X-KKRPQRAT*W-C(Sx)-VFAMF-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KKRPQR-C(Sx)-YS*NVF-Z, X-KKRPQRDT*S- C(Sx)-VFAMF-Z, X-KKRPQRET*S-C(Sx)-VFAMF-Z, X-KKRPQRFT*S-C(Sx)-VFAMF- Z, X-KKRPQRGT*S-C(Sx)-VFAMF-Z, X-KKRPQRHT*S-C(Sx)-VFAMF-Z, X- KKRPQRIT*S-C(Sx)-VFAMF-Z, X-KKRPQRKT*S-C(Sx)-VFAMF-Z, X-KKRPQRLT * S- C(Sx)-VFAMF-Z, X-KKRPQRNT*S-C(Sx)-VFAMF-Z, X-KKRPQRPT*S-C(Sx)-VFAMF- Z, X-KKRPQRQT*S-C(Sx)-VFAMF-Z, X-KKRPQRRT*S-C(Sx)-VFAMF-Z, X- KKRPQRRYS*N-C(Sx)-F-Z, X-KKRPQRVT*S-C(Sx)-VFAMF-Z, X-KKRPQRWT*S- C(Sx)-VFAMF-Z, X-KKRPQVAT*S-C(Sx)-VFAMF-Z, X-KKRPQWAT*S-C(Sx)- VFAMF-Z, X-KKRPRRAT*S-C(Sx)-VFAMF-Z, X-KKRPVRAT*S-C(Sx)-VFAMF-Z, X- KKRPWRAT*S-C(Sx)-VFAMF-Z, X-KKRQQRAT*S-C(Sx)-VFAMF-Z, X- KKRRQRAT*S-C(Sx)-VFAMF-Z, X-KKRVQRAT*S-C(Sx)-VFAMF-Z, X- KKRWQRAT*S-C(Sx)-VFAMF-Z, X-KKS*R-C(Sx)-DY[Nle]T[Nle]QIG-Z, X- KKVPQRAT*S-C(Sx)-VFAMF-Z, X-KKVSRSGLYRSPS*[Nle]-C(Sx)-E L RP-Z, X- KKVSRSGLYRSPS*[Nle]-C(Sx)-ENL R-Z, X-KKVSRSGLYRSPS*M-C(Sx)-E LNRPR- Z, X-KKVSRSGLYRSPS*M-C(Sx)-E L RP-Z, X-KKVSRSGLYRSPS*M-C(Sx)- E L R-Z, X-KKWPQRAT*S-C(Sx)-VFAMF-Z, X-KLKTTKKRPQRATS*N-C(Sx)-FS-Z, X-KLKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KLLR-C(Sx)-SS*RRIRR-Z, X-KLPWWR- C(Sx)-YT*WVVERDVNTKQR-Z, X-KLRPQRAT*S-C(Sx)-VFAMF-Z, X-K DG-C(Sx)- RT*RSKGTLRYMSPE-Z, X-K DGKRT*R-C(Sx)-KGTLRYMSPE-Z, X-K DGKRTRS- C(Sx)-GT*LRYMSPE-Z, X-K DGKRTRSKGT*L-C(Sx)-YMSPE-Z, X-KNIVT-C(Sx)- RT*PPPSQGK-Z, X-KNIVTPRT*P-C(Sx)-PSQGK-Z, X-KNIVTPRTP-C(Sx)-PS*QGK-Z, X-K KTTKKRPQRATS*N-C(Sx)-FS-Z, -K KTTKKRPQRATSN-C(Sx)-FS*-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-K RPQRAT*S-C(Sx)-VFAMF-Z, X- KPARKKRYT*V-C(Sx)-G PYWM-Z, X-KPKKKKKRPQRADS*D-C(Sx)-FA-Z, X- KPKKKKKRPQRADS*D-C(Sx)-FS-Z, X-KPKKKKKRPQRADS*N-C(Sx)-FA-Z, X- KPKKKKKRPQRADS*N-C(Sx)-FS-Z, X-KPKKKKKRPQRADSD-C(Sx)-FS*-Z, X- KPKKKKKRPQRADSN-C(Sx)-FS*-Z, X-KPKKKKKRPQRAES*D-C(Sx)-FA-Z, X- KPKKKKKRPQRAES*D-C(Sx)-FS-Z, X-KPKKKKKRPQRAES*N-C(Sx)-FA-Z, X- KPKKKKKRPQRAES*N-C(Sx)-FS-Z, X-KPKKKKKRPQRAESD-C(Sx)-FS*-Z, X- KPKKKKKRPQRAESN-C(Sx)-FS*-Z, X-KPKKKKKRPQRAHS*D-C(Sx)-FA-Z, X- KPKKKKKRPQRAHS*D-C(Sx)-FS-Z, X-KPKKKKKRPQRAHS*N-C(Sx)-FA-Z, X- KPKKKKKRPQRAHS*N-C(Sx)-FS-Z, X-KPKKKKKRPQRAHSD-C(Sx)-FS*-Z, X- KPKKKKKRPQRAHSN-C(Sx)-FS*-Z, X-KPKKKKKRPQRATS*D-C(Sx)-FA-Z, X- KPKKKKKRPQRATS*D-C(Sx)-FS-Z, X-KPKKKKKRPQRATS*N-C(Sx)-FA-Z, X- KPKKKKKRPQRATS*N-C(Sx)-FS-Z, X-KPKKKKKRPQRATSD-C(Sx)-FS*-Z, X- KPKKKKKRPQRATSN-C(Sx)-FS*-Z, X-KPKKRKKRPQRADS*D-C(Sx)-FA-Z, X- KPKKRKKRPQRADS*D-C(Sx)-FS-Z, X-KPKKRKKRPQRADS*N-C(Sx)-FA-Z, X- KPKKRKKRPQRADS*N-C(Sx)-FS-Z, X-KPKKRKKRPQRADSD-C(Sx)-FS*-Z, X- KPKKRKKRPQRADSN-C(Sx)-FS*-Z, X-KPKKRKKRPQRAES*D-C(Sx)-FA-Z, X- KPKKRKKRPQRAES*D-C(Sx)-FS-Z, X-KPKKRKKRPQRAES*N-C(Sx)-FA-Z, X- KPKKRKKRPQRAES*N-C(Sx)-FS-Z, X-KPKKRKKRPQRAESD-C(Sx)-FS*-Z, X- KPKKRKKRPQRAESN-C(Sx)-FS*-Z, X-KPKKRKKRPQRAHS*D-C(Sx)-FA-Z, X- KPKKRKKRPQRAHS*D-C(Sx)-FS-Z, X-KPKKRKKRPQRAHS*N-C(Sx)-FA-Z, X- KPKKRKKRPQRAHS*N-C(Sx)-FS-Z, X-KPKKRKKRPQRAHSD-C(Sx)-FS*-Z, X- KPKKRKKRPQRAHSN-C(Sx)-FS*-Z, X-KPKKRKKRPQRATS*D-C(Sx)-FA-Z, X- KPKKRKKRPQRATS*D-C(Sx)-FS-Z, and X-KPKKRKKRPQRATS*N-C(Sx)-FA-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KPKKRKKRPQRATS*N-C(Sx)-FS-Z, X- KPKKRKKRPQRATSD-C(Sx)-FS*-Z, X-KPKKRKKRPQRATSN-C(Sx)-FS*-Z, X- KPKKTKKRPQRADS*D-C(Sx)-FA-Z, X-KPKKTKKRPQRADS*D-C(Sx)-FS-Z, X- KPKKTKKRPQRADS*N-C(Sx)-FA-Z, X-KPKKTKKRPQRADS*N-C(Sx)-FS-Z, X- KPKKTKKRPQRADSD-C(Sx)-FS*-Z, X-KPKKTKKRPQRADSN-C(Sx)-FS*-Z, X- KPKKTKKRPQRAES*D-C(Sx)-FA-Z, X-KPKKTKKRPQRAES*D-C(Sx)-FS-Z, X- KPKKTKKRPQRAES*N-C(Sx)-FA-Z, X-KPKKTKKRPQRAES*N-C(Sx)-FS-Z, X- KPKKTKKRPQRAESD-C(Sx)-FS*-Z, X-KPKKTKKRPQRAESN-C(Sx)-FS*-Z, X- KPKKTKKRPQRAHS*D-C(Sx)-FA-Z, X-KPKKTKKRPQRAHS*D-C(Sx)-FS-Z, X- KPKKTKKRPQRAHS*N-C(Sx)-FA-Z, X-KPKKTKKRPQRAHS*N-C(Sx)-FS-Z, X- KPKKTKKRPQRAHSD-C(Sx)-FS*-Z, X-KPKKTKKRPQRAHSN-C(Sx)-FS*-Z, X- KPKKTKKRPQRATS*D-C(Sx)-FA-Z, X-KPKKTKKRPQRATS*D-C(Sx)-FS-Z, X- KPKKTKKRPQRATS*N-C(Sx)-FA-Z, X-KPKKTKKRPQRATS*N-C(Sx)-FS-Z, X- KPKKTKKRPQRATSD-C(Sx)-FS*-Z, X-KPKKTKKRPQRATSN-C(Sx)-FS*-Z, X- KPKKVKKRPQRADS*D-C(Sx)-FA-Z, X-KPKKVKKRPQRADS*D-C(Sx)-FS-Z, X- KPKKVKKRPQRADS*N-C(Sx)-FA-Z, X-KPKKVKKRPQRADS*N-C(Sx)-FS-Z, X- KPKKVKKRPQRADSD-C(Sx)-FS*-Z, X-KPKKVKKRPQRADSN-C(Sx)-FS*-Z, X- KPKKVKKRPQRAES*D-C(Sx)-FA-Z, X-KPKKVKKRPQRAES*D-C(Sx)-FS-Z, X- KPKKVKKRPQRAES*N-C(Sx)-FA-Z, X-KPKKVKKRPQRAES*N-C(Sx)-FS-Z, X- KPKKVKKRPQRAESD-C(Sx)-FS*-Z, X-KPKKVKKRPQRAESN-C(Sx)-FS*-Z, X- KPKKVKKRPQRAHS*D-C(Sx)-FA-Z, X-KPKKVKKRPQRAHS*D-C(Sx)-FS-Z, X- KPKKVKKRPQRAHS*N-C(Sx)-FA-Z, X-KPKKVKKRPQRAHS*N-C(Sx)-FS-Z, X- KPKKVKKRPQRAHSD-C(Sx)-FS*-Z, X-KPKKVKKRPQRAHSN-C(Sx)-FS*-Z, X- KPKKVKKRPQRATS*D-C(Sx)-FA-Z, X-KPKKVKKRPQRATS*D-C(Sx)-FS-Z, X- KPKKVKKRPQRATS*N-C(Sx)-FA-Z, X-KPKKVKKRPQRATS*N-C(Sx)-FS-Z, X- KPKKVKKRPQRATSD-C(Sx)-FS*-Z, X-KPKKVKKRPQRATSN-C(Sx)-FS*-Z, and X- KPKTKKKRPQRADS*D-C(Sx)-FA-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KPKTKKKRPQRADS*D-C(Sx)-FS-Z, X- KPKTKKKRPQRADS*N-C(Sx)-FA-Z, X-KPKTKKKRPQRADS*N-C(Sx)-FS-Z, X- KPKTKKKRPQRADSD-C(Sx)-FS*-Z, X-KPKTKKKRPQRADSN-C(Sx)-FS*-Z, X- KPKTKKKRPQRAES*D-C(Sx)-FA-Z, X-KPKTKKKRPQRAES*D-C(Sx)-FS-Z, X- KPKTKKKRPQRAES*N-C(Sx)-FA-Z, X-KPKTKKKRPQRAES*N-C(Sx)-FS-Z, X- KPKTKKKRPQRAESD-C(Sx)-FS*-Z, X-KPKTKKKRPQRAESN-C(Sx)-FS*-Z, X- KPKTKKKRPQRAHS*D-C(Sx)-FA-Z, X-KPKTKKKRPQRAHS*D-C(Sx)-FS-Z, X- KPKTKKKRPQRAHS*N-C(Sx)-FA-Z, X-KPKTKKKRPQRAHS*N-C(Sx)-FS-Z, X- KPKTKKKRPQRAHSD-C(Sx)-FS*-Z, X-KPKTKKKRPQRAHSN-C(Sx)-FS*-Z, X- KPKTKKKRPQRATS*D-C(Sx)-FA-Z, X-KPKTKKKRPQRATS*D-C(Sx)-FS-Z, X- KPKTKKKRPQRATS*N-C(Sx)-FA-Z, X-KPKTKKKRPQRATS*N-C(Sx)-FS-Z, X- KPKTKKKRPQRATSD-C(Sx)-FS*-Z, X-KPKTKKKRPQRATSN-C(Sx)-FS*-Z, X- KPKTRKKRPQRADS*D-C(Sx)-FA-Z, X-KPKTRKKRPQRADS*D-C(Sx)-FS-Z, X- KPKTRKKRPQRADS*N-C(Sx)-FA-Z, X-KPKTRKKRPQRADS*N-C(Sx)-FS-Z, X- KPKTRKKRPQRADSD-C(Sx)-FS*-Z, and X-KPKTRKKRPQRADSN-C(Sx)-FS*-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention i s selected from the group consisting of: X-KPKTRKKRPQRAES*D-C(Sx)-FA-Z, X- KPKTRKKRPQRAES*D-C(Sx)-FS-Z, X-KPKTRKKRPQRAES*N-C(Sx)-FA-Z, X- KPKTRKKRPQRAES*N-C(Sx)-FS-Z, X-KPKTRKKRPQRAESD-C(Sx)-FS*-Z, X- KPKTRKKRPQRAESN-C(Sx)-FS*-Z, X-KPKTRKKRPQRAHS*D-C(Sx)-FA-Z, X- KPKTRKKRPQRAHS*D-C(Sx)-FS-Z, X-KPKTRKKRPQRAHS*N-C(Sx)-FA-Z, X- KPKTRKKRPQRAHS*N-C(Sx)-FS-Z, X-KPKTRKKRPQRAHSD-C(Sx)-FS*-Z, X- KPKTRKKRPQRAHSN-C(Sx)-FS*-Z, X-KPKTRKKRPQRATS*D-C(Sx)-FA-Z, X- KPKTRKKRPQRATS*D-C(Sx)-FS-Z, X-KPKTRKKRPQRATS*N-C(Sx)-FA-Z, X- KPKTRKKRPQRATS*N-C(Sx)-FS-Z, X-KPKTRKKRPQRATSD-C(Sx)-FS*-Z, X- KPKTRKKRPQRATSN-C(Sx)-FS*-Z, X-KPKTTKKRPQRADS*D-C(Sx)-FA-Z, X- KPKTTKKRPQRADS*D-C(Sx)-FS-Z, X-KPKTTKKRPQRADS*N-C(Sx)-FA-Z, X- KPKTTKKRPQRADS*N-C(Sx)-FS-Z, X-KPKTTKKRPQRADSD-C(Sx)-FS*-Z, X- KPKTTKKRPQRADSN-C(Sx)-FS*-Z, X-KPKTTKKRPQRAES*D-C(Sx)-FA-Z, X- KPKTTKKRPQRAES*D-C(Sx)-FS-Z, X-KPKTTKKRPQRAES*N-C(Sx)-FA-Z, X- KPKTTKKRPQRAES*N-C(Sx)-FS-Z, X-KPKTTKKRPQRAESD-C(Sx)-FS*-Z, X- KPKTTKKRPQRAESN-C(Sx)-FS*-Z, X-KPKTTKKRPQRAHS*D-C(Sx)-FA-Z, X- KPKTTKKRPQRAHS*D-C(Sx)-FS-Z, X-KPKTTKKRPQRAHS*N-C(Sx)-FA-Z, X- KPKTTKKRPQRAHS*N-C(Sx)-FS-Z, X-KPKTTKKRPQRAHSD-C(Sx)-FS*-Z, X- KPKTTKKRPQRAHSN-C(Sx)-FS*-Z, X-KPKTTKKRPQRATS*D-C(Sx)-FA-Z, X- KPKTTKKRPQRATS*D-C(Sx)-FS-Z, X-KPKTTKKRPQRATS*N-C(Sx)-FA-Z, X- KPKTTKKRPQRATS*N-C(Sx)-FS-Z, X-KPKTTKKRPQRATSD-C(Sx)-FS*-Z, X- KPKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KPKTVKKRPQRADS*D-C(Sx)-FA-Z, X- KPKTVKKRPQRADS*D-C(Sx)-FS-Z, X-KPKTVKKRPQRADS*N-C(Sx)-FA-Z, X- KPKTVKKRPQRADS*N-C(Sx)-FS-Z, X-KPKTVKKRPQRADSD-C(Sx)-FS*-Z, X- KPKTVKKRPQRADSN-C(Sx)-FS*-Z, X-KPKTVKKRPQRAES*D-C(Sx)-FA-Z, X- KPKTVKKRPQRAES*D-C(Sx)-FS-Z, X-KPKTVKKRPQRAES*N-C(Sx)-FA-Z, X- KPKTVKKRPQRAES*N-C(Sx)-FS-Z, X-KPKTVKKRPQRAESD-C(Sx)-FS*-Z, X- KPKTVKKRPQRAESN-C(Sx)-FS*-Z, X-KPKTVKKRPQRAHS*D-C(Sx)-FA-Z, X- KPKTVKKRPQRAHS*D-C(Sx)-FS-Z, X-KPKTVKKRPQRAHS*N-C(Sx)-FA-Z, X- KPKTVKKRPQRAHS*N-C(Sx)-FS-Z, X-KPKTVKKRPQRAHSD-C(Sx)-FS*-Z, X- KPKTVKKRPQRAHSN-C(Sx)-FS*-Z, X-KPKTVKKRPQRATS*D-C(Sx)-FA-Z, X- KPKTVKKRPQRATS*D-C(Sx)-FS-Z, X-KPKTVKKRPQRATS*N-C(Sx)-FA-Z, X- KPKTVKKRPQRATS*N-C(Sx)-FS-Z, X-KPKTVKKRPQRATSD-C(Sx)-FS*-Z, X- KPKTVKKRPQRATSN-C(Sx)-FS*-Z, X-KPRPQRAT*S-C(Sx)-VFAMF-Z, X- KQREGFGRQS*M-C(Sx)-EKR-Z, and X-KQRPQRAT*S-C(Sx)-VFAMF-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-KRKLP-C(Sx)-DT*PGQGLT-Z, X- KRKTTKKRPQRATS*N-C(Sx)-FS-Z, X-KRKTTKKRPQRATSN-C(Sx)-FS*-Z, X-KRR- C(Sx)-AS*FRRR-Z, X-KRRPQRAT*S-C(Sx)-VFAMF-Z, X-KRRRLAS*L-C(Sx)-G-Z, X- KRS*R-C(Sx)-SSFPPGTRK-Z, X-KRSR-C(Sx)-SS*FPPGTRK-Z, X-KS*N-C(Sx)- ESGDSQQPSQPSQ-Z, X-KSN-C(Sx)-ES*GDSQQPSQPSQ-Z, X-KS EESGDS*Q-C(Sx)- PSQPSQQPSV-Z, X-KS EESGDSQ-C(Sx)-PS*QPSQQPSV-Z, X-

KS EESGDSQQPSQPS*Q-C(Sx)-PSV-Z, X-KS EESGDSQQPSQPSQ-C(Sx)-PS*V-Z, X- KTTKKRPQRATS*N-C(Sx)-FS-Z, X-KTTKKRPQRATSN-C(Sx)-FS*-Z, X- KVKTTKKRPQRATS*N-C(Sx)-FS-Z, X-KVKTTKKRPQRATSN-C(Sx)-FS*-Z, X- KVRPQRAT*S-C(Sx)-VFAMF-Z, X-KVSRSGLYRSPS*[Nle]-C(Sx)-ENL RP-Z, X- KVSRSGLYRSPS*[Nle]-C(Sx)-E L R-Z, X-KVSRSGLYRSPS*M-C(Sx)-E L RPR-Z, X-KVSRSGLYRSPS*M-C(Sx)-E L RP-Z, X-KVSRSGLYRSPS*M-C(Sx)-E L R-Z, X- KWKTTKKRPQRATS*N-C(Sx)-FS-Z, X-KWKTTKKRPQRATSN-C(Sx)-FS*-Z, X- KWRfNle] [Nle] [Nle] S *L-C(Sx)-QSRSSKS-Z, X-KWR[Nle] [Nle] [Nle] SL-C(Sx)- QS*RSSKS-Z, X-KWR[Nle][Nle]S*L-C(Sx)-QSRSSKS-Z, X-KWR[Nle][Nle]SL-C(Sx)- QS*RSSKS-Z, X-KWR-C(Sx)-[Nle]S*LSQSRSSKS-Z, X-KWR-C(Sx)- MS*LSQSRSSKSAPE-Z, X-KWR-C(Sx)-MS*LSQSRSSKS-Z, X-KWRMMS*L-C(Sx)- QSRSSKS-Z, X-KWRMMSL-C(Sx)-QS*RSSKS-Z, X-KWRPQRAT*S-C(Sx)-VFAMF-Z, X-LAGISRS*V-C(Sx)-VTVAY-Z, X-LAKTTKKRPQRATS*N-C(Sx)-FS-Z, and X- L AKTTKKRPQRATSN-C(Sx)-F S * -Z ; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting o X-LA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X- LASFK[Nle]WS*K-C(Sx)-N EEH-Z, X-LASFK-C(Sx)-WS*KLN EEH-Z, X-L-C(Sx)- DS*LRRKAK-Z, X-L-C(Sx)-LS*PGPF-Z, X-LGGLRISS*D-C(Sx)-SSDIE-Z, X- LGGLRISSD-C(Sx)-SS*DIE-Z, X-LHQED DYI-C(Sx)-AS*LIK-Z, X-LIDAT-C(Sx)- DT*PGAEDDE-Z, X-LIDATGDT*P-C(Sx)-AEDDE-Z, X-LIDATGDT*PG-C(Sx)-EDDE- Z, X-LIDS*[Nle]-C(Sx)-NSFVGTRSYAKKK-Z, X-LIDS[Nle]-C(Sx)- NS *F VGTRS YAKKK-Z, X-LKKERLLDDRHD S * G-C( Sx)-D SMKDEE Y-Z , X- LKKERLLDDRHDSG-C(Sx)-DS*MKDEEY-Z, X-LKKERLLDDRHDSGLDS*M-C(Sx)- DEEY-Z, X-LKR-C(Sx)-AS*FKKFA-Z, X-LKRPQRAT*S-C(Sx)-VFAMF-Z, X-LLDDR- C(Sx)-DS*GLDSMKD-Z, X-LLDDRHDS*G-C(Sx)-DSMKD-Z, X-LLDDRHDSG-C(Sx)- DS*MKD-Z, X-LLLR-C(Sx)-SS*RRIRR-Z, X-LLPWWR-C(Sx)-YT*WVVERDVNTKQR- Z, X-LLSNASAT*P-C(Sx)-GRRGR-Z, X-LMLRLQDYE-C(Sx)-KT*KKA-Z, X- LPGPPS*P-C(Sx)-SDAES-Z, X-LQREGFGRQS*M-C(Sx)-EKR-Z, X-LRELGQGS*F- C(Sx)-MVYEG-Z, X-LRRAS*L-C(Sx)-AA-Z, X-LRR-C(Sx)-AS*FRRR-Z, X- LSPVAPLS*P-C(Sx)-RLQGP-Z, X-LSRDLIMKEDYE-C(Sx)-VS*TKPTR-Z, X- LSRDLIMKEDYE-C(Sx)-VS*TK-Z, X-LVEKLPDS*P-C(Sx)-LAKKA-Z, X-M-C(Sx)- LS*PGPF-Z, X-NAKTTKKRPQRATS*N-C(Sx)-FS-Z, X-NAKTTKKRPQRATSN-C(Sx)- FS*-Z, X-NANPLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-N-C(Sx)-DS*LRRKAK-Z, X-N- C(Sx)-LS*PGPF-Z, X- KEKKAVS*P-C(Sx)-LLTTT-Z, X- KEKK-C(Sx)-VS*PLLLTTT- Z, X- KRPQRAT*S-C(Sx)-VFAMF-Z, X- LLR-C(Sx)-SS*RRIRR-Z, X-NLPWWR- C(Sx)-YT*WVVERDVNTKQR-Z, X- PQDSVGS*P-C(Sx)-SRVGE-Z, X- NQREGFGRQS*M-C(Sx)-EKR-Z, X-NQRKA-C(Sx)-RS*LAPRFDL-Z, X- NQRKAKRS*L-C(Sx)-PRFDL-Z, X-NR-C(Sx)-LS*FAEG-Z, X- R-C(Sx)-LS*FAEPG-Z, X- RR-C(Sx)-AS*FRRR-Z, X-NSKYNAES*T-C(Sx)-RESQDT-Z, X-NTIDL-C(Sx)- MS*PRTLDSL-Z, X-NTIDLPMS*P-C(Sx)-TLDSL-Z, and X-NVLAP-C(Sx)- P S * Q AMDDLM-Z ; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of X-NVRVSNGS*P-C(Sx)-LER[Nle]D-Z, X-PAADA- C(Sx)-[Nle]S*PEEELDG-Z, X-PAADAI[Nle]S*P-C(Sx)-EELDG-Z, X- PAKTTKKRPQRATS*N-C(Sx)-FS-Z, X-PAKTTKKRPQRATSN-C(Sx)-FS*-Z, X- PA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-P-C(Sx)-DS*LRRKAK-Z, X-P-C(Sx)- ES*QEAFADLWKK-Z, X-P-C(Sx)-LS*PGPF-Z, X-PDTS*Y-C(Sx)-LTPHTEEKY-Z, X- PDTSY-C(Sx)-LT*PHTEEKY-Z, X-PDTSYVLT*P-C(Sx)-TEEKY-Z, X-PDVE[Nle]PS*P- C(Sx)-APSGD-Z, X-PKRPQRAT*S-C(Sx)-VFAMF-Z, X-PLKTGEQT*P-C(Sx)-HEHI-Z, X-PLLR-C(Sx)-SS*RRIRR-Z, X-PLPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X- PLQRQPSS*P-C(Sx)-PTPRN-Z, X-PLQRQPSSP-C(Sx)-PT*PRN-Z, X-PLST*W-C(Sx)- GSPP Y A APEAKKK-Z , X-PLSTW-C(Sx)-GS*PPYAAPEAKKK-Z, X-PNTED-C(Sx)- ES*PSVKR[Nle]RKKK-Z, X-PNTEDRES*P-C(Sx)-VKR[Nle]R-Z, X-PPYNRAVS*L- C(Sx)-SPVSV-Z, X-PQREGFGRQS*M-C(Sx)-EKR-Z, X-PR-C(Sx)- KS*LVGTPYW[Nle]APELISR-Z, X-PR-C(Sx)-KS*LVGTPYW[Nle]APE-Z, X-PR-C(Sx)- KS*LVGTPYWMAPE-Z, X-PR-C(Sx)-KS*LVGTPYWM-Z, X-PR-C(Sx)-KT*PEIFRAL- Z, X-PRPKT*P-C(Sx)-IFRAL-Z, X-PRR-C(Sx)-AS*FRRR-Z, X-PRTSPI[Nle]S*P-C(Sx)- TSLAE-Z, X-PRTSPI[Nle]SP-C(Sx)-TS*LAE-Z, X-PS*Y-C(Sx)-RSRSRSRSRSRSRSRSN- Z, X-PSRPP-C(Sx)-PT*PRRPASV-Z, X-PSVEP-C(Sx)-LS*QETFSDL-Z, X- PSWHLADS*P-C(Sx)-VNGAT-Z, X-PSY-C(Sx)-RS*RSRSRSRSRSRSRSN-Z, X-PSYGR- C(Sx)-RS*RSRSRSRSRSRSN-Z, X-PSYGRS*R-C(Sx)-RSRSRSRSRSRSN-Z, X- PSYGRSR-C(Sx)-RS*RSRSRSRSRSN-Z, X-PSYGRSRSRS*R-C(Sx)-RSRSRSRSN-Z, X- PSYGRSRSRSR-C(Sx)-RS*RSRSRSN-Z, X-PSYGRSRSRSRS*R-C(Sx)-RSRSRSN-Z, X- PSYGRSRSRSRSR-C(Sx)-RS*RSRSN-Z, X-PSYGRSRSRSRSRS*R-C(Sx)-RSRSN-Z, X- PSYGRSRSRSRSRSR-C(Sx)-RS*RSN-Z, X-PSYGRSRSRSRSRSRS*R-C(Sx)-RSN-Z, X- PSYGRSRSRSRSRSRSR-C(Sx)-RS*N-Z, X-PSYGRSRSRSRSRSRSRS*R-C(Sx)-N-Z, X- PSYGRSRSRSRSRSRSRSRS*N-C(Sx)-Z, X-PTIPGVTS*P-C(Sx)-SDEPP-Z, X- PTSPRRYS*P-C(Sx)-AKDLL-Z, X-PVPEYI-C(Sx)-QS*V-Z, X-PVVS*G-C(Sx)- TSPRHLSNV-Z, X-PVVSG-C(Sx)-TS*PRHLSNV-Z, X-PVVSGDTS*P-C(Sx)-HLSNV-Z, X-Q[Nle]AGT-C(Sx)-IT*PLKDGFTKKK-Z, X-QALD PEYH-C(Sx)-AS*NGP-Z, X- QA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-QARAK-C(Sx)-QT*PPVSPAP-Z, X- QARAKTQT*P-C(Sx)-VSPAP-Z, X-QARAKTQTP-C(Sx)-VS*PAP-Z, X-Q-C(Sx)- DS*LRRKAK-Z, X-Q-C(Sx)-LS*PGPF-Z, X-QE-C(Sx)-FS*DLWKLLP-Z, X-QETFS*D- C(Sx)-WKLLP-Z, X-QGV-C(Sx)-ES*PFTRTGEGLDIR-Z, X-QGVPES*P-C(Sx)- TRTGEGLDIR-Z , X-QGVPES-C(Sx)-FT*RTGEGLDIR-Z, X-QGVPESPF-C(Sx)- RT * GEGLDIR-Z, X-QGVPESPFT*R-C(Sx)-GEGLDIR-Z, X-QGVPESPFTRT*G-C(Sx)- GLDIR-Z, X-QHSSPAVS*D-C(Sx)-LPSNS-Z, X-QKRPQRAT*S-C(Sx)-VFAMF-Z, X- QLLR-C(Sx)-SS*RRIRR-Z, X-QLPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-QLS*K- C(Sx)-PGSPTSRSSD-Z, X-QMFHLDPS*L-C(Sx)-HTIFN-Z, X-QMFHLDPSL-C(Sx)- HT*IFN-Z, X-QP-C(Sx)-AS*PVV-Z, X-QQREGFGRQS*M-C(Sx)-EKR-Z, and X-QRE- C(Sx)-VS*SLDSSSLSLKKK-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-QRR-C(Sx)-AS*FRRR-Z, X-QS[Nle]VV-C(Sx)- QT*PLHTARV-Z, X-QYHFVAS-C(Sx)-ST*IERDRQRPYS-Z, X-QYHFVASSST*I-C(Sx)- RDRQRPYS-Z, X-R[Nle]PWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-R[Nle]R-C(Sx)- AS*FRRR-Z, X-RADPQ-C(Sx)-PS*RTPVQGP-Z, X-RAKTTKKRPQRATS*N-C(Sx)-FS- Z, X-RAKTTKKRPQRATSN-C(Sx)-FS*-Z, X-RA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-RAPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-RAR-C(Sx)-AS*FRRR-Z, X-RAR- C(Sx)-LS*FAEG-Z, X-RAR-C(Sx)-LS*FAEPG-Z, X-RARR-C(Sx)-LS*FSGFGSR-Z, X-R- C(Sx)-AS*FRRR-Z, X-R-C(Sx)-AS*FRR-Z, X-R-C(Sx)-AS*FR-Z, X-R-C(Sx)- DS*LRRKAK-Z, X-R-C(Sx)-FS*LRRKAK-Z, X-R-C(Sx)-LS*FAEG-Z, X-R-C(Sx)- LS*FAEPG-Z, X-R-C(Sx)-LS*PGPF-Z, X-RDPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-RDR-C(Sx)-AS*FRRR-Z, X-RE-C(Sx)-LS*RRP[pS]YR-Z, X-REPWWR-C(Sx)- YT*WVVERDVNTKQR-Z, X-RER-C(Sx)-AS*FRRR-Z, X-RFDS*R-C(Sx)- ISGLLTTAKKK-Z, X-RFDSR-C(Sx)-IS*GLLTTAKKK-Z, X-RFI-C(Sx)-PT*ALIRF-Z, X- RFI-C(Sx)-PT* RRRF-Z, X-RFILPT*A-C(Sx)-IRF-Z, X-RFILPT*N-C(Sx)-RRF-Z, X- RFPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-RFR-C(Sx)-AS*FRRR-Z, X- RGGPEPLS*P-C(Sx)-PVSPL-Z, X-RGPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-RGR- C(Sx)-AS*FRRR-Z, X-RGS[Nle]AAPS*L-C(Sx)-PSLGP-Z, X-RGS[Nle]AAPSL-C(Sx)- PS*LGP-Z, X-RHD[pS]GLDS*M-C(Sx)-DEEYE-Z, X-RHPWWR-C(Sx)- YT*WVVERDVNTKQR-Z, X-RHR-C(Sx)-AS*FRRR-Z, X-RIPWWR-C(Sx)- YT*WVVERDVNTKQR-Z, X-RIR-C(Sx)-AS*FRRR-Z, X-RKKYKFN-C(Sx)- DT*ERRRFL-Z, X-RKPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-RKR-C(Sx)- AS*FRRR-Z, X-RKRKGS*F-C(Sx)-YGG-Z, X-RKRPQRAT*S-C(Sx)-VFAMF-Z, and X- RLGWWR-C(Sx)-FT*LRRARQGNTKQR-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-RLGWWR-C(Sx)-YT*LQRARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LQRARDVNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LQRAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQRAREVNTKQR-Z, X-RLGWWR- C(Sx)-YT*LQRARQGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQRARQVNTKQR-Z, X- RLGWWR-C(Sx)-YT*LQRERDGNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LQRERDVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQREREGNTKQR-Z, X-RLGWWR- C(Sx)-YT*LQREREVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQRERQGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LQRERQVNTKQR-Z, X-RLGWWR-C(Sx)- YT*LQVARDGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQVARDVNTKQR-Z, X- RLGWWR-C(Sx)-YT*LQVAREGNTKQR-Z, X-RLGWWR-C(Sx)- YT *LQ VAREVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQVARQGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LQVARQVNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LQVERDGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQVERDVNTKQR-Z, X-RLGWWR- C(Sx)-YT*LQVEREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LQVEREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*LQVERQGNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LQVERQVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRRARDGNTKQR-Z, X-RLGWWR- C(Sx)-YT*LRRARDVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRRAREGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LRRAREVNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LRRARQGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRRARQVNTKQR-Z, X-RLGWWR- C(Sx)-YT*LRRERDGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRRERDVNTKQR-Z, X- RLGWWR-C(Sx)-YT*LRREREGNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LRREREVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRRERQGNTKQR-Z, X-RLGWWR- C(Sx)-YT*LRRERQVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRVARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LRVARDVNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LRVAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRVAREVNTKQR-Z, X-RLGWWR- C(Sx)-YT*LRVARQGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRVARQVNTKQR-Z, X- RLGWWR-C(Sx)-YT*LRVERDGNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LRVERDVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRVEREGNTKQR-Z, X-RLGWWR- C(Sx)-YT*LRVEREVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LRVERQGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LRVERQVNTKQR-Z, X-RLGWWR-C(Sx)- YT*LVRARDGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVRARDVNTKQR-Z, and X- RLGWWR-C(Sx)-YT*LVRAREGNTKQR-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-RLGWWR-C(Sx)-YT*LVRAREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*LVRARQGNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LVRARQVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVRERDGNTKQR-Z, X-RLGWWR- C(Sx)-YT*LVRERDVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVREREGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LVREREVNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LVRERQGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVRERQVNTKQR-Z, X-RLGWWR- C(Sx)-YT*LVVARDGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVVARD VNTKQR-Z, X- RLGWWR-C(Sx)-YT*LVVAREGNTKQR-Z, X-RLGWWR-C(Sx)- YT *L VVAREVNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVVARQGNTKQR-Z, X- RLGWWR-C(Sx)-YT*LVVARQVNTKQR-Z, X-RLGWWR-C(Sx)-

YT*LVVERDGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVVERD VNTKQR-Z, X-RLGWWR- C(Sx)-YT*LVVEREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*LVVEREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*LVVERQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*LVVERQVNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQRARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQRARDVNTKQR-Z, X-RLGWWR-C(Sx)- YT*WQRAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQRAREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQRARQGNTKQR-Z, X-RLGWWR-C(Sx)- YT * WQRARQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQRERDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQRERDVNTKQR-Z, X-RLGWWR-C(Sx)- YT*WQREREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQREREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQRERQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WQRERQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQVARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQVARD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WQVAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQVAREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQVARQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WQVARQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQVERDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQVERD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WQVEREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WQVEREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WQVERQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WQVERQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRRARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WRRARD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WRRAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRRAREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WRRARQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WRRARQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRRERDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WRRERD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WRREREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRREREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WRRERQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WRRERQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRVARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WRVARD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WRVAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRVAREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WRVARQGNTKQR-Z, X-RLGWWR-C(Sx)-

YT*WRVARQVNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRVERDGNTKQR-Z, X-

RLGWWR-C(Sx)-YT*WRVERD VNTKQR-Z, X-RLGWWR-C(Sx)-

YT * WRVEREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WRVEREVNTKQR-Z, X-

RLGWWR-C(Sx)-YT*WRVERQGNTKQR-Z, and X-RLGWWR-C(Sx)-

YT * WRVERQ VNTKQR-Z ; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-RLGWWR-C(Sx)-YT*WVRARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVRARD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WVRAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WVRAREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVRARQGNTKQR-Z, X-RLGWWR-C(Sx)- YT *WVRARQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WVRERDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVRERD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WVREREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WVREREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVRERQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WVRERQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WVVARDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVVARD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WVVAREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WVVAREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVVARQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WVVARQ VNTKQR-Z, X-RLGWWR-C(Sx)-YT*WVVERDGNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVVERD VNTKQR-Z, X-RLGWWR-C(Sx)- YT*WVVEREGNTKQR-Z, X-RLGWWR-C(Sx)-YT*WVVEREVNTKQR-Z, X- RLGWWR-C(Sx)-YT*WVVERQGNTKQR-Z, X-RLGWWR-C(Sx)- YT*WVVERQ VNTKQR-Z, X-RLLR-C(Sx)-SS*RRIRR-Z, X-RLPWWR-C(Sx)- FT*WVRERD VNTKQR-Z, X-RLPWWR-C(Sx)-FT*WVVERD VNTKQR-Z, X-RLPWWR- C(Sx)-YT*LQRARDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQRARD VNTKQR-Z, X- RLPWWR-C(Sx)-YT*LQRAREGNTKQR-Z, and X-RLPWWR-C(Sx)- YT*LQRARE VNTKQR-Z; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-RLPWWR-C(Sx)-YT*LQRARQGNTKQR-Z, X- RLPWWR-C(Sx)-YT*LQRARQ VNTKQR-Z, X-RLPWWR-C(Sx)-

YT*LQRERDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQRERD VNTKQR-Z, X-RLPWWR- C(Sx)-YT*LQREREGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQREREVNTKQR-Z, X- RLPWWR-C(Sx)-YT*LQRERQGNTKQR-Z, X-RLPWWR-C(Sx)- YT*LQRERQVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQVARDGNTKQR-Z, X-RLPWWR- C(Sx)-YT*LQVARDVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQVAREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*LQVAREVNTKQR-Z, X-RLPWWR-C(Sx)-

YT*LQVARQGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQVARQVNTKQR-Z, X-RLPWWR- C(Sx)-YT*LQVERDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQVERDVNTKQR-Z, X- RLPWWR-C(Sx)-YT*LQVEREGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LQVEREVNTKQR- Z, X-RLPWWR-C(Sx)-YT*LQVERQGNTKQR-Z, X-RLPWWR-C(Sx)- YT*LQVERQVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRRARDGNTKQR-Z, X-RLPWWR- C(Sx)-YT*LRRARDVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRRAREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*LRRAREVNTKQR-Z, X-RLPWWR-C(Sx)-

YT*LRRARQGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRRARQVNTKQR-Z, X-RLPWWR- C(Sx)-YT*LRRERDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRRERDVNTKQR-Z, X- RLPWWR-C(Sx)-YT*LRREREGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRREREVNTKQR- Z, X-RLPWWR-C(Sx)-YT*LRRERQGNTKQR-Z, X-RLPWWR-C(Sx)- YT*LRRERQVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRVARDGNTKQR-Z, X-RLPWWR- C(Sx)-YT*LRVARDVNTKQR-Z, and X-RLPWWR-C(Sx)-YT*LRVAREGNTKQR-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-RLPWWR-C(Sx)-YT*LRVAREVNTKQR-Z, X- RLPWWR-C(Sx)-YT*LRVARQGNTKQR-Z, X-RLPWWR-C(Sx)-

YT*LRVARQVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRVERDGNTKQR-Z, X-RLPWWR- C(Sx)-YT*LRVERDVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRVEREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*LRVEREVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LRVERQGNTKQR- Z, X-RLPWWR-C(Sx)-YT*LRVERQVNTKQR-Z, X-RLPWWR-C(Sx)- YT*LVRARDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVRARDVNTKQR-Z, X-RLPWWR- C(Sx)-YT*LVRAREGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVRAREVNTKQR-Z, X- RLPWWR-C(Sx)-YT*LVRARQGNTKQR-Z, X-RLPWWR-C(Sx)-

YT*LVRARQVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVRERDGNTKQR-Z, X-RLPWWR- C(Sx)-YT*LVRERDVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVREREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*LVREREVNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVRERQGNTKQR- Z, X-RLPWWR-C(Sx)-YT*LVRERQVNTKQR-Z, X-RLPWWR-C(Sx)- YT*LVVARDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVVARDVNTKQR-Z, X-RLPWWR- C(Sx)-YT*LVVAREGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVVAREVNTKQR-Z, X- RLPWWR-C(Sx)-YT*LVVARQGNTKQR-Z, X-RLPWWR-C(Sx)- YT *L VVARQ VNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVVERDGNTKQR-Z, X-RLPWWR- C(Sx)-YT*LVVERD VNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVVEREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*LVVEREVNTKQR-Z, X-RLPWWR-C(Sx)-

YT*LVVERQGNTKQR-Z, X-RLPWWR-C(Sx)-YT*LVVERQVNTKQR-Z, X-RLPWWR- C(Sx)-YT*WQRARDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WQRARD VNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQRAREGNTKQR-Z, X-RLPWWR-C(Sx)- YT*WQRARE VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WQRARQGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQRARQVNTKQR-Z, X-RLPWWR-C(Sx)- YT*WQRERDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WQRERD VNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQREREGNTKQR-Z, X-RLPWWR-C(Sx)- YT*WQRERE VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WQRERQGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQRERQVNTKQR-Z, X-RLPWWR-C(Sx)- YT * WQ VARD GNTKQR-Z , X-RLPWWR-C(Sx)-YT*WQVARD VNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQVAREGNTKQR-Z, X-RLPWWR-C(Sx)- YT *WQVARE VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WQVARQGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQVARQVNTKQR-Z, X-RLPWWR-C(Sx)- YT*WQVERDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WQVERD VNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQVEREGNTKQR-Z, and X-RLPWWR-C(Sx)- YT *WQVERE VNTKQR-Z ; wherein X is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-RLPWWR-C(Sx)-YT*WQVERQGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WQVERQVNTKQR-Z, X-RLPWWR-C(Sx)- YT*WRRARDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRRARD VNTKQR-Z, X- RLPWWR-C(Sx)-YT*WRRAREGNTKQR-Z, X-RLPWWR-C(Sx)- YT*WRRARE VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRRARQGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WRRARQVNTKQR-Z, X-RLPWWR-C(Sx)- YT*WRRERDGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRRERD VNTKQR-Z, X- RLPWWR-C(Sx)-YT*WRREREGNTKQR-Z, X-RLPWWR-C(Sx)-

YT*WRRERE VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRRERQGNTKQR-Z, X-RLPWWR- C(Sx)-YT*WRRERQ VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRVARDGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WRVARD VNTKQR-Z, X-RLPWWR-C(Sx)- YT*WRVAREGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRVAREVNTKQR-Z, X- RLPWWR-C(Sx)-YT*WRVARQGNTKQR-Z, X-RLPWWR-C(Sx)- YT*WRVARQ VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRVERDGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WRVERDVNTKQR-Z, X-RLPWWR-C(Sx)-

YT*WRVEREGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRVEREVNTKQR-Z, X-RLPWWR- C(Sx)-YT*WRVERQGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WRVERQVNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVRARDGNTKQR-Z, X-RLPWWR-C(Sx)- YT * WVRARD VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WVRAREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVRAREVNTKQR-Z, X-RLPWWR-C(Sx)- YT*WVRARQGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WVRARQVNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVRERDGNTKQR-Z, X-RLPWWR-C(Sx)- YT*WVRERD VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WVREREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVREREVNTKQR-Z, X-RLPWWR-C(Sx)- YT*WVRERQGNTKQR-Z, X-RLPWWR-C(Sx)-YT*WVRERQVNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVVARDGNTKQR-Z, X-RLPWWR-C(Sx)- YT*WVVARD VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WVVAREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVVAREVNTKQR-Z, X-RLPWWR-C(Sx)- YT * W V V ARQ GNTKQR-Z , X-RLPWWR-C(Sx)-YT*WVVARQVNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVVERDGNTKQR-Z, X-RLPWWR-C(Sx)- YT*WVVERD VNTKQR-Z, X-RLPWWR-C(Sx)-YT*WVVEREGNTKQR-Z, X- RLPWWR-C(Sx)-YT*WVVEREVNTKQR-Z, X-RLPWWR-C(Sx)-

YT*WVVERQGNTKQR-Z, and X-RLPWWR-C(Sx)-YT*WVVERQ VNTKQR-Z; wherein X- is H or acetyl; and Z is OH or NH2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-RLR-C(Sx)-AS*FRRR-Z, X-RNGKR-C(Sx)- PT*HTSRVGT-Z, X-RNGKRT*P-C(Sx)-HTSRVGT-Z, X-RNGKRTP-C(Sx)-HT*SRVGT- Z, X-RNGKRTPT*H-C(Sx)-SRVGT-Z, X-RNGKRTPTHT*S-C(Sx)-VGT-Z, X- RNPWWR-C(Sx)-YT*WVVERD VNTKQR-Z, X-RNR-C(Sx)-AS*FRRR-Z, X- RPASVPPS*P-C(Sx)-LSRHS[pS]HQRR-Z, X-RPASVPPS*P-C(Sx)-LSRHS[pS]HQR-Z, X- RPASVPPSP-C(Sx)-LS*RHS[pS]HQRR-Z, X-RPASVPPSP-C(Sx)-LS*RHS[pS]HQR-Z, X- RPHFP-C(Sx)-FS*YSASGTA-Z, X-RPPWWR-C(Sx)-YT*WVVERD VNTKQR-Z, X-RPR- C(Sx)-AS*FRRR-Z, X-RQPWWR-C(Sx)-YT*WVVERD VNTKQR-Z, X-RQR-C(Sx)- AS*FRRR-Z, X-RQREGFGRQS*M-C(Sx)-EKR-Z, X-RR[Nle]-C(Sx)-AS*FRRR-Z, X- RRA-C(Sx)-AS*FRRR-Z, X-RR-C(Sx)-AS*FRRR-Z, X-RR-C(Sx)-AS*FRR-Z, X-RR- C(Sx)-AS*FR-Z, X-RR-C(Sx)-LS*FAEG-Z, X-RR-C(Sx)-LS*FAEPG-Z, X-RRD-C(Sx)- AS*FRRR-Z, X-RRE-C(Sx)-AS*FRRR-Z, X-RRF-C(Sx)-AS*FRRR-Z, X-RRG-C(Sx)- AS*FRRR-Z, X-RRGGR-C(Sx)-RS*RSPDRRRR-Z, X-RRGGRRRS*R-C(Sx)-PDRRRR-Z, X-RRGGRRRSRS*P-C(Sx)-RRRR-Z, X-RRH-C(Sx)-AS*FRRR-Z, X-RRHYY-C(Sx)- DT*HTNTYYLRTFGHNTRR-Z, X-RRHYYYDT*H-C(Sx)-NTYYLRTFGHNTRR-Z, X- RRHYYYDTH-C(Sx)-NT*YYLRTFGHNTRR-Z, X-RRHYYYDTHTNT*Y-C(Sx)- LRTF GHNTRR-Z , X-RRH Y Y YD THTNT Y Y-C ( Sx)-RT *F GHNTRR-Z , X- RRHYYYDTHTNTYYLRT*F-C(Sx)-HNTRR-Z, X-RRI-C(Sx)-AS*FRRR-Z, X-RRK- C(Sx)-AS*FRRR-Z, X-RRK-C(Sx)-AT*RR[Nle]RF-Z, X-RRK-C(Sx)-AT*RRMRF-Z, X- RRK-C(Sx)-RT*[Nle]R[Nle]RF-Z, X-RRK-C(Sx)-RT*MRMRF-Z, X-RRKIAT*R-C(Sx)- [Nle]RF-Z, X-RRKIAT*R-C(Sx)-MRF-Z, X-RRKIRT*[Nle]-C(Sx)-[Nle]RF-Z, X- RRKIRT*M-C(Sx)-MRF-Z, X-RRL-C(Sx)-AS*FRRR-Z, X-RRN-C(Sx)-AS*FRRR-Z, X- RRPASVPPS*P-C(Sx)-LSRHS[pS]HQRR-Z, X-RRPASVPPS*P-C(Sx)-LSRHS[pS]HQR-Z, X-RRPASVPPSP-C(Sx)-LS*RHS[pS]HQRR-Z, X-RRPASVPPSP-C(Sx)- LS*RHS[pS]HQR-Z, X-RRP-C(Sx)-AS*FRRR-Z, and X-RRPWWR-C(Sx)- YT * W VVERD VNTKQR-Z ; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-RRQ-C(Sx)-AS*FRRR-Z, X-RRR-C(Sx)- [Nle]S*FRRR-Z, X-RRR-C(Sx)-A[Nle]FRRR-Z, X-RRR-C(Sx)-AS*[Nle]RRR-Z, X-RRR- C(Sx)-AS*ARRR-Z, X-RRR-C(Sx)-AS*DRRR-Z, X-RRR-C(Sx)-AS*ERRR-Z, X-RRR- C(Sx)-AS*F[Nle]RR-Z, X-RRR-C(Sx)-AS*FARR-Z, X-RRR-C(Sx)-AS*FDRR-Z, X-RRR- C(Sx)-AS*FERR-Z, X-RRR-C(Sx)-AS*FFRR-Z, X-RRR-C(Sx)-AS*FGRR-Z, X-RRR- C(Sx)-AS*FHRR-Z, X-RRR-C(Sx)-AS*FIRR-Z, X-RRR-C(Sx)-AS*FKRR-Z, X-RRR- C(Sx)-AS*FLRR-Z, X-RRR-C(Sx)-AS*F RR-Z, X-RRR-C(Sx)-AS*FPRR-Z, X-RRR- C(Sx)-AS*FQRR-Z, X-RRR-C(Sx)-AS*FR[Nle]R-Z, X-RRR-C(Sx)-AS*FRAR-Z, X-RRR- C(Sx)-AS*FRDR-Z, X-RRR-C(Sx)-AS*FRER-Z, X-RRR-C(Sx)-AS*FRFR-Z, X-RRR- C(Sx)-AS*FRGR-Z, X-RRR-C(Sx)-AS*FRHR-Z, X-RRR-C(Sx)-AS*FRIR-Z, X-RRR- C(Sx)-AS*FRKR-Z, X-RRR-C(Sx)-AS*FRLR-Z, X-RRR-C(Sx)-AS*FR R-Z, X-RRR- C(Sx)-AS*FRPR-Z, X-RRR-C(Sx)-AS*FRQR-Z, X-RRR-C(Sx)-AS*FRR[Nle]-Z, X-RRR- C(Sx)-AS*FRRA-Z, X-RRR-C(Sx)-AS*FRRD-Z, X-RRR-C(Sx)-AS*FRRE-Z, X-RRR- C(Sx)-AS*FRRF-Z, X-RRR-C(Sx)-AS*FRRG-Z, X-RRR-C(Sx)-AS*FRRH-Z, X-RRR- C(Sx)-AS*FRRI-Z, X-RRR-C(Sx)-AS*FRRK-Z, X-RRR-C(Sx)-AS*FRRL-Z, X-RRR- C(Sx)-AS*FRRN-Z, X-RRR-C(Sx)-AS*FRRP-Z, X-RRR-C(Sx)-AS*FRRQ-Z, X-RRR- C(Sx)-AS*FRRR-Z, X-RRR-C(Sx)-AS*FRRV-Z, X-RRR-C(Sx)-AS*FRRW-Z, X-RRR- C(Sx)-AS*FRR-Z, X-RRR-C(Sx)-AS*FRVR-Z, X-RRR-C(Sx)-AS*FRWR-Z, X-RRR- C(Sx)-AS*FR-Z, X-RRR-C(Sx)-AS*FVRR-Z, X-RRR-C(Sx)-AS*FWRR-Z, X-RRR-C(Sx)- AS*GRRR-Z, X-RRR-C(Sx)-AS*HRRR-Z, X-RRR-C(Sx)-AS*IRRR-Z, X-RRR-C(Sx)- AS*KRRR-Z, X-RRR-C(Sx)-AS*LRRR-Z, X-RRR-C(Sx)-AS* RRR-Z, X-RRR-C(Sx)- AS*PRRR-Z, X-RRR-C(Sx)-AS*QRRR-Z, X-RRR-C(Sx)-AS*RRRR-Z, X-RRR-C(Sx)- AS*VRRR-Z, X-RRR-C(Sx)-AS*WRRR-Z, X-RRR-C(Sx)-DS*FRRR-Z, X-RRR-C(Sx)- ES*FRRR-Z, X-RRR-C(Sx)-FS*FRRR-Z, X-RRR-C(Sx)-FS*LRRKA-Z, X-RRR-C(Sx)- GS*FRRR-Z, X-RRR-C(Sx)-HS*FRRR-Z, X-RRR-C(Sx)-IS*FRRR-Z, X-RRR-C(Sx)- KS*FRRR-Z, X-RRR-C(Sx)-LS*FRRR-Z, X-RRR-C(Sx)-NS*FRRR-Z, X-RRR-C(Sx)- PS*FRRR-Z, X-RRR-C(Sx)-QS*FRRR-Z, X-RRR-C(Sx)-RS*FRRR-Z, X-RRR-C(Sx)- VS*FRRR-Z, X-RRR-C(Sx)-WS*FRRR-Z, X-RRRLS-C(Sx)-VS*LTGVSTI-Z, X- RRRLSNVS*L-C(Sx)-GVSTI-Z, X-RRRPASVPPS*P-C(Sx)-LSRHS[pS]HQRR-Z, X- RRRPASVPPS*P-C(Sx)-LSRHS[pS]HQR-Z, X-RRRPASVPPSP-C(Sx)- LS*RHS[pS]HQRR-Z, X-RRRPASVPPSP-C(Sx)-LS*RHS[pS]HQR-Z, X-RRRQFS*L- C(Sx)-RKA-Z, X-RRV-C(Sx)-AS*FRRR-Z, X-RRVSGNNS*P-C(Sx)-LSNGG-Z, X- RRVSGNNSP-C(Sx)-LS*NGG-Z, X-RRW-C(Sx)-AS*FRRR-Z, X-RSKSAPTS*P-C(Sx)- DQEIK-Z, X-RSRSRS*R-C(Sx)-R-Z, X-RSRSRSRS*R-C(Sx)-R-Z, X-RSRSRSRSNS*R- C(Sx)-RS YSPRRS-Z, X-RSRSRSRSNSR-C(Sx)-RS * YSPRRS-Z, X-RSRSRSRSNSRS *R- C(Sx)-YSPRRS-Z, X-RSRSRSRSNSRSR-C(Sx)-YS*PRRS-Z, X-RSRSRSRSRS*R-C(Sx)- RAR-Z, X-RSRSRSRSRS*R-C(Sx)-RGR-Z, X-RSRSRSRSRS*R-C(Sx)-R-Z, X- RSRSRSRSRSNSRSRS*Y-C(Sx)-PR-Z, X-RSRSRSRSRSRS*R-C(Sx)-R-Z, X- RTDSLAAT*P-C(Sx)-AAK-Z, X-RVG-C(Sx)-AS*SLENTVDLHISNSHP-Z, X- RVGGASS*L-C(Sx)-NTVDLHISNSHP-Z, X-RVGGASSL-C(Sx)-NT*VDLHISNSHP-Z, X-RVPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-RVR-C(Sx)-AS*FRRR-Z, X- RWPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, and X-RWR-C(Sx)-AS*FRRR-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-S*R-C(Sx)-LSVSSLPGLED-Z, X-S*R-C(Sx)- SSPHQ[pS]EDEEE-Z, X-SAKS*R-C(Sx)-QTAPVP[Nle]PD-Z, X-SAKSR-C(Sx)- QT*APVP[Nle]PD-Z, X-SAKSRLQT*A-C(Sx)-VP[Nle]PD-Z, X-SA LLS*P-C(Sx)-PA-Z, X-SEGLS*M-C(Sx)-NYIGLINRIKK-Z, X-SFITPPTT*P-C(Sx)-LRRHT-Z, X-SGDED- C(Sx)-SS*IADMDFSAL-Z, X-SGDEDFSS*I-C(Sx)-DMDFSALLSQ-Z, X- SGDY[Nle]P[Nle]S*P-C(Sx)-SVSAP-Z, X-SGLS*R-C(Sx)-DSPEPFGHY-Z, X-SGLSR- C(Sx)-DS*PEPFGHY-Z, X-SGLSRRDS*P-C(Sx)-PFGHY-Z, X-SGQL-C(Sx)- DS*[Nle]ANSFV-Z, X-SGQLIDS*[Nle]-C(Sx)-NSFV-Z, X-SGQLIDS[Nle]ANS*F-C(Sx)- G-Z, X-SGQLIDS[Nle]-C(Sx)-NS*FV-Z, X-SGRPR-C(Sx)-TS*FAESSKP-Z, X- SGRPRTTS*F-C(Sx)-ESSKP-Z, X-SGVEV-C(Sx)-VT*PTRTEII-Z, X-SGVEVRVT*P- C(Sx)-RTEII-Z, X-SGVEVRVTP-C(Sx)-RT*EII-Z, X-SIKS*E-C(Sx)-ISPPRDR[Nle]T-Z, X-SIKSE-C(Sx)-IS*PPRDR[Nle]T-Z, X-SIKSEPIS*P-C(Sx)-RDR[Nle]T-Z, X-SIMQQ- C(Sx)-DS*PHVVKYYKKK-Z, X-SKS*S-C(Sx)-NGTSGDREDK-Z, X-SLD-C(Sx)- SS*LSLSLSSANSLYDD-Z, X-SLDSSSLS*L-C(Sx)-LSSANSLYDD-Z, X-SLDSSSLSL- C(Sx)-LS*SANSLYDD-Z, X-SNGRR-C(Sx)-RS*PTQSFRF-Z, X-SNGRRKRS*P-C(Sx)- QSFRF-Z, X-SNGRRKRSP-C(Sx)-QS*FRF-Z, X-SNSLKKSS*A-C(Sx)-LKKIL-Z, X- SNT*GQ-C(Sx)-ISPG[Nle]KRRI-Z, X-SNTGQAIS*P-C(Sx)-[Nle]KRRI-Z, X- SNTGQAIS*PG-C(Sx)-KRRI-Z, X-SNTGQ-C(Sx)-IS*PG[Nle]KRRI-Z, X-SPAR-C(Sx)- SS*YSEA EP-Z, X-SPLSDPSS*P-C(Sx)-ASEDF-Z, X-SPLSDPSSP-C(Sx)-AS*EDF-Z, X- SPS-C(Sx)-RS*RSRSRSRSPGRPSK-Z, X-SPSRRS*R-C(Sx)-RSRSRSPGRPSK-Z, X- SPSRRSR-C(Sx)-RS*RSRSPGRPSK-Z, X-SPSRRSRS*R-C(Sx)-RSRSPGRPSK-Z, X- SPSRRSRSR-C(Sx)-RS*RSPGRPSK-Z, X-SPSRRSRSRS*R-C(Sx)-RSPGRPSK-Z, X- SPSRRSRSRSR-C(Sx)-RS*PGRPSK-Z, X-SPSRRSRSRSRS*R-C(Sx)-PGRPSK-Z, X- SPSRRSRSRSRSRS*P-C(Sx)-RPSK-Z, X-SR-C(Sx)-LS*VSSLPGLED-Z, X-SR-C(Sx)- SS*PHQ[pS]EDEEE-Z, X-SRDPVART*S-C(Sx)-LQTPA-Z, X-SRLRD-C(Sx)- PS*APLEAPE-Z, X-SRRS*G-C(Sx)-SSPSYVAVT-Z, X-SRRSG-C(Sx)-SS*PSYVAVT-Z, X-SRRSGLSS*P-C(Sx)-YVAVT-Z, X-SRSHSAKT*P-C(Sx)-FSVQS-Z, X- SRSHSAKT*PG-C(Sx)-SVQS-Z, X-SRSHSAKTP-C(Sx)-FS*VQS-Z, X-SRSHS-C(Sx)- KT*PGFSVQS-Z, X-SRSRS*R-C(Sx)-RAPGRPSKG-Z, X-SRSRS*R-C(Sx)- RGPGRPSKG-Z, X-SRSRS*R-C(Sx)-RSPGRPSKG-Z, X-SRSRSNSRSRS*Y-C(Sx)- PRRSRGS-Z, X-SRSRSNSRSRSYS*P-C(Sx)-RSRGS-Z, X-SRSRSNSRSRSYSP-C(Sx)- RS*RGS-Z, X-SRSRSR-C(Sx)-RS*PGRPSKG-Z, X-SRSRSRSNSRSRSYS*P-C(Sx)-RSR- Z, X-SRSRSRSNSRSRSYSP-C(Sx)-RS*R-Z, X-SRSRSRSRS*P-C(Sx)-RPSKGR-Z, X- SRSRSRSRS*P-C(Sx)-RPSKG-Z, X-SRSRSRSRSNSRSRS*Y-C(Sx)-PRR-Z, X- SRSRSRSRSNSRSRSYS*P-C(Sx)-R-Z, X-SSKIRRLS*A-C(Sx)-KQQ-Z, X- SSKRAKAKTTKKRPQRAT*S-C(Sx)-VFS-Z, X-SSKRAKAKTTKKRPQRATS*N-C(Sx)- FS-Z, X-SSKRAKAKTTKKRPQRATSN-C(Sx)-FS*-Z, X-SSLET-C(Sx)-ST*QELYSIP-Z, X-SSPS-C(Sx)-RS*RSRSRSRS-Z, X-SSPSRR-C(Sx)-RS*RSRSRS-Z, X-SSPSRRS*R- C(Sx)-RSRSRS-Z, X-SSPSRRSR-C(Sx)-RS*RSRS-Z, X-SSPSRRSRSRS*R-C(Sx)-RA-Z, X-SSPSRRSRSRS*R-C(Sx)-RG-Z, X-SSPSRRSRSRS*R-C(Sx)-RS-Z, X- SSPSRRSRSRSR-C(Sx)-RS*-Z, and X-SSPSRRSRSRSRS*R-C(Sx)-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-SSPSRRSRSRSRSRS*P-C(Sx)-RPSKGR-Z, X- SSPSRRSRSRSRSRS*P-C(Sx)-RPSKG-Z, X-STPSEPLS*P-C(Sx)-SSLGE-Z, X- STPSEPLSP-C(Sx)-SS*LGE-Z, X-STSVT-C(Sx)-HS*PSSPVGSKKK-Z, X- SYYGRDRS*P-C(Sx)-RRATA-Z, X-TDGEDADYT-C(Sx)-FT*NQQ-Z, X-TEERL-C(Sx)- SS*PVYEDAA-Z, X-TFDS*L-C(Sx)-SSPSSATPH-Z, X-TFDSL-C(Sx)-SS*PSSATPH-Z, X-TFDSLPSS*P-C(Sx)-SATPH-Z, X-TFG KLDT*F-C(Sx)-GSP-Z, X-TFG KLDTF- C(Sx)-GS*P-Z, X-TFLPVPEYI-C(Sx)-QS*VPK-Z, X-TKLKPPRT*P-C(Sx)-PPSRK-Z, X- TPPEE-C(Sx)-PS*PSASSLG-Z, X-TPPEELPS*P-C(Sx)-ASSLG-Z, X-TPPEELPSP-C(Sx)- AS*SLG-Z, X-TPPQEHIS*P-C(Sx)-ITNEV-Z, X-TPPQEHISP-C(Sx)-IT* EV-Z, X- TPVVS-C(Sx)-AT*PTLPGQG-Z, X-TTGT*K-C(Sx)-NTPTSSVPSKKK-Z, X-TTGTK- C(Sx)-NT*PTSSVPSKKK-Z, X-TTLHR-C(Sx)-VS*PGAPQRP-Z, X-TTLHRNVS*P- C(Sx)-APQRP-Z, X-TTLHRNVS*PG-C(Sx)-PQRP-Z, X-TVG KLDT*F-C(Sx)-GSP-Z, X- TVG KLDTF-C(Sx)-GS*P-Z, X-VA-C(Sx)-QT*P[pT]PTRFLKN-Z, X-VADQTPT*P- C(Sx)-RFLKN-Z, X-VAKTTKKRPQRATS*N-C(Sx)-FS-Z, X- VAKTTKKRPQR AT SN- C(Sx)-FS*-Z, X-VA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-V-C(Sx)-DS*LRRKAK-Z, X-V-C(Sx)-LS*PGPF-Z, X-VDGFT-C(Sx)-KS*VRKAQRQ-Z, X-VDGFTRKS*V-C(Sx)- KAQRQ-Z, X-VDLHISNS*H-C(Sx)-LSLTSDQYK-Z, X-VDLHISNSH-C(Sx)- LS*LTSDQYK-Z, X-VDLHISNSHPL-C(Sx)-LT*SDQYK-Z, X-VEVDP[Nle]LT*P-C(Sx)- ERHLN-Z, X-VEVDP-C(Sx)-LT*PEERHLN-Z, X-VKAEPAHT*A-C(Sx)-SVAAK-Z, X- VKRPQRAT*S-C(Sx)-VFAMF-Z, X-VKS*P-C(Sx)-KEKAKSPEK-Z, X- VKSPAKEKAKS*P-C(Sx)-K-Z, X-VKSPAKEK-C(Sx)-KS*PEK-Z, X-VLLR-C(Sx)- SS*RRIRR-Z, X-VLPWWR-C(Sx)-YT*WVVERDVNTKQR-Z, X-VLSRQ-C(Sx)- TS*PVSGING-Z, X-VLSRQITS*P-C(Sx)-SGING-Z, X-VNTRA-C(Sx)-PS*QHSSPAV-Z, X-VP-C(Sx)-LT*PGGRR-Z, X-VQGI-C(Sx)-FS*QPTSPDHAKKK-Z, X- VQREGFGRQS*M-C(Sx)-EKR-Z, X-VRR-C(Sx)-AS*FRRR-Z, X-VSGQL-C(Sx)- DS*MANSFVGTRSYKKK-Z, X-VSYEDPPT*A-C(Sx)-AAVEW-Z, and X- WAKTTKKRPQRATS*N-C(Sx)-FS-Z; wherein X is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-WAKTTKKRPQRATSN-C(Sx)-FS*-Z, X- WA PLMA-C(Sx)-GT*LTRRHQNGRF-Z, X-W-C(Sx)-DS*LRRKAK-Z, X-W-C(Sx)- LS*PGPF-Z, X-WD-C(Sx)-DS*DDDDDAAAKKK-Z, X-WD-C(Sx)-DS*DDDDDAAA-Z, X-WKRPQRAT*S-C(Sx)-VFAMF-Z, X-WLLR-C(Sx)-SS*RRIRR-Z, X-WLPWWR-C(Sx)- YT*WVVERDVNTKQR-Z, X-WQREGFGRQS*M-C(Sx)-EKR-Z, X-WR-C(Sx)- YT*LRRARQGNTKQR-Z, X-WRR-C(Sx)-AS*FRRR-Z, X-Y[Nle]P[Nle]SPKS*V-C(Sx)- APQQI-Z, X-YANWMAAS*I-C(Sx)-LDGKKK-Z, X-YANWM-C(Sx)-AS*IYLDGKKK-Z, X-YKRRYVET*P-C(Sx)-VHISS-Z, X-YRRAAVPPSPSLS*R-C(Sx)-SSPHQ[pS]EDEEE-Z, X-YRRAAVPPSPSLSR-C(Sx)-SS*PHQ[pS]EDEEE-Z, X-YSHKGHLS*E-C(Sx)-LVTKW- Z, X-[Nle]EEEEY*I-C(Sx)-Z, X-[Nle]EEEY*I-C(Sx)-IV-Z, X-[Nle]EPIY*I-C(Sx)-VP-Z, X- [Nle]VSETDDY*A-C(Sx)-IIDEE-Z, X-ADEY*L-C(Sx)-PQQ-Z, X- ADPDHDHTGFLTEY*V-C(Sx)-TRWRR-Z, X-AEE-C(Sx)-IY*GEFEAKKKK-Z, X- AEEEEY*I-C(Sx)-Z, X-AEEEY*I-C(Sx)-IV-Z, X-AENAEY*L-C(Sx)-VA-Z, X- AGKEQTYY*Q-C(Sx)-RHLGD-Z, X-AKAA-C(Sx)-GY*VKPQIKQVV-Z, X- AKAADGY*V-C(Sx)-PQIKQVV-Z, X-AKA-C(Sx)-DGY*VKPQIKQVV-Z, X- ARKRERAY*SA[dP]-C(Sx)-G-Z, X-ARKRERAY*SD[dP]-C(Sx)-G-Z, X- ARKRERAY*SE-C(Sx)-G-Z, X-ARKRERAY*SF[Nle]-C(Sx)-G-Z, X-ARPLVEFY*E- C(Sx)-IKKYE-Z, X-AVLADVSY*L-C(Sx)-AMEKS-Z, X-AVSETDDY*A-C(Sx)-IIDEE-Z, X-C(Sx)-FY*TLRRARQGNTKQR-Z, X-DADEY*L-C(Sx)-PQQG-Z, X-DE-C(Sx)- DY*EEPDEP-Z, X-DEEDY*E-C(Sx)-PDEP-Z, X-DEEEEY*I-C(Sx)-Z, X-DEEEY*I- C(Sx)-IV-Z, X-DEPE-C(Sx)-DY*EEVLEPED-Z, X-DEPE-C(Sx)-DY*FEWLEPED-Z, X- DEPEGDY*E-C(Sx)-VLEPED-Z, X-DEPEGDY*F-C(Sx)-WLEPED-Z, X- DGDGQVNY*E-C(Sx)-FVQMM-Z, X-DGSDHPYY*N-C(Sx)-IPSKM-Z, X-DLI[Nle]K- C(Sx)-DY*ELVSTKPTR-Z, X-DLI[Nle]KEDY*E-C(Sx)-VSTKPTR-Z, X-DLIMK-C(Sx)- DY*ELVSTKPTR-Z, X-DLIMKEDY*E-C(Sx)-VSTKPTR-Z, X-D DP-C(Sx)- EY*ITLDED-Z, X-D DP-C(Sx)-RY*IRTEDE-Z, X-D DPDEY*I-C(Sx)-LDED-Z, X- D DPDRY*I-C(Sx)-TEDE-Z, X-DRHEQEDEPE-C(Sx)-DY*EEVLEPE-Z, X- DRHEQEDEPE-C(Sx)-DY*FEWLEPE-Z, X-DRHEQEDEPEGDY*E-C(Sx)-VLEPE-Z, X- DRHEQEDEPEGDY*F-C(Sx)-WLEPE-Z, and X-DVSETDDY*A-C(Sx)-IIDEE-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-DVVDADEY*L-C(Sx)-PQQGF-Z, X-ED-C(Sx)- DY*EWPSA-Z, X-EDE-C(Sx)-IY*EELDEP-Z, X-EDEDIY*E-C(Sx)-LDEP-Z, X-EDEG- C(Sx)-RY*LKLEED-Z, X-EDEGDRY*L-C(Sx)-LEED-Z, X-EDGGDDIY*E-C(Sx)-IIKVE- Z, X-EDPDY*E-C(Sx)-PSA-Z, X-EDPDY*F-C(Sx)-FG-Z, X-EDPDY*F-C(Sx)-FK-Z, X- EDPDY*F-C(Sx)-FP-Z, X-EDPDY*F-C(Sx)-IG-Z, X-EDPDY*F-C(Sx)-IK-Z, X- EDPDY*F-C(Sx)-IP-Z, X-EDPDY*F-C(Sx)-MG-Z, X-EDPDY*F-C(Sx)-MK-Z, X- EDPDY*F-C(Sx)-MP-Z, X-EDPDY*F-C(Sx)-VG-Z, X-EDPDY*F-C(Sx)-VK-Z, X- EDPDY*F-C(Sx)-VP-Z, X-EDPDY*I-C(Sx)-FG-Z, X-EDPDY*I-C(Sx)-FK-Z, X- EDPDY*I-C(Sx)-FP-Z, X-EDPDY*I-C(Sx)-IG-Z, X-EDPDY*I-C(Sx)-IK-Z, X-EDPDY*I- C(Sx)-IP-Z, X-EDPDY*I-C(Sx)-MG-Z, X-EDPDY*I-C(Sx)-MK-Z, X-EDPDY*I-C(Sx)- MP-Z, X-EDPDY*I-C(Sx)-VG-Z, X-EDPDY*I-C(Sx)-VK-Z, X-EDPDY*I-C(Sx)-VP-Z, X- EDPDY*V-C(Sx)-FG-Z, X-EDPDY*V-C(Sx)-FK-Z, X-EDPDY*V-C(Sx)-FP-Z, X- EDPDY*V-C(Sx)-IG-Z, X-EDPDY*V-C(Sx)-IK-Z, X-EDPDY*V-C(Sx)-IP-Z, X- EDPDY*V-C(Sx)-MG-Z, X-EDPDY*V-C(Sx)-MK-Z, X-EDPDY*V-C(Sx)-MP-Z, X- EDPDY*V-C(Sx)-VG-Z, X-EDPDY*V-C(Sx)-VK-Z, X-EDPDY*V-C(Sx)-VP-Z, X- EDPEY*F-C(Sx)-FG-Z, X-EDPEY*F-C(Sx)-FK-Z, X-EDPEY*F-C(Sx)-FP-Z, X- EDPEY*F-C(Sx)-IG-Z, X-EDPEY*F-C(Sx)-IK-Z, X-EDPEY*F-C(Sx)-IP-Z, X-EDPEY*F- C(Sx)-MG-Z, X-EDPEY*F-C(Sx)-MK-Z, X-EDPEY*F-C(Sx)-MP-Z, X-EDPEY*F-C(Sx)- VG-Z, X-EDPEY*F-C(Sx)-VK-Z, X-EDPEY*F-C(Sx)-VP-Z, X-EDPEY*I-C(Sx)-FG-Z, X- EDPEY*I-C(Sx)-FK-Z, X-EDPEY*I-C(Sx)-FP-Z, X-EDPEY*I-C(Sx)-IG-Z, X-EDPEY*I- C(Sx)-IK-Z, X-EDPEY*I-C(Sx)-IP-Z, X-EDPEY*I-C(Sx)-MG-Z, X-EDPEY*I-C(Sx)-MK- Z, X-EDPEY*I-C(Sx)-MP-Z, X-EDPEY*I-C(Sx)-VG-Z, X-EDPEY*I-C(Sx)-VK-Z, X- EDPEY*I-C(Sx)-VP-Z, X-EDPEY*V-C(Sx)-FG-Z, X-EDPEY*V-C(Sx)-FK-Z, X- EDPEY*V-C(Sx)-FP-Z, X-EDPEY*V-C(Sx)-IG-Z, X-EDPEY*V-C(Sx)-IK-Z, X- EDPEY*V-C(Sx)-IP-Z, X-EDPEY*V-C(Sx)-MG-Z, X-EDPEY*V-C(Sx)-MK-Z, X- EDPEY*V-C(Sx)-MP-Z, X-EDPEY*V-C(Sx)-VG-Z, X-EDPEY*V-C(Sx)-VK-Z, and X- EDPEY* V-C(Sx)-VP-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EDPIY*F-C(Sx)-FG-Z, X-EDPIY*F-C(Sx)-FK-Z, X-EDPIY*F-C(Sx)-FP-Z, X-EDPIY*F-C(Sx)-IG-Z, X-EDPIY*F-C(Sx)-IK-Z, X-EDPIY*F- C(Sx)-IP-Z, X-EDPIY*F-C(Sx)-MG-Z, X-EDPIY*F-C(Sx)-MK-Z, X-EDPIY*F-C(Sx)-MP- Z, X-EDPIY*F-C(Sx)-VG-Z, X-EDPIY*F-C(Sx)-VK-Z, X-EDPIY*F-C(Sx)-VP-Z, X- EDPIY*I-C(Sx)-FG-Z, X-EDPIY*I-C(Sx)-FK-Z, X-EDPIY*I-C(Sx)-FP-Z, X-EDPIY*I- C(Sx)-IG-Z, X-EDPIY*I-C(Sx)-IK-Z, X-EDPIY*I-C(Sx)-IP-Z, X-EDPIY*I-C(Sx)-MG-Z, X-EDPIY*I-C(Sx)-MK-Z, X-EDPIY*I-C(Sx)-MP-Z, X-EDPIY*I-C(Sx)-VG-Z, X- EDPIY*I-C(Sx)-VK-Z, X-EDPIY*V-C(Sx)-FG-Z, X-EDPIY*V-C(Sx)-FK-Z, X-EDPIY*V- C(Sx)-FP-Z, X-EDPIY*V-C(Sx)-IG-Z, X-EDPIY*V-C(Sx)-IK-Z, X-EDPIY*V-C(Sx)-IP-Z, X-EDPIY*V-C(Sx)-MG-Z, X-EDPIY*V-C(Sx)-MK-Z, X-EDPIY*V-C(Sx)-MP-Z, X- EDPIY*V-C(Sx)-VG-Z, X-EDPIY*V-C(Sx)-VK-Z, X-EDPIY*V-C(Sx)-VP-Z, X- EDSFLQRY*S-C(Sx)-DPTGA-Z, X-EEEEEY*I-C(Sx)-Z, X-EEEEY*[Nle]-C(Sx)-VG-Z, X-EEEEY*[Nle]Q[dP]-C(Sx)-G-Z, X-EEEEY*[Nle]Q-C(Sx)-VG-Z, X-EEEEY*A-C(Sx)- VG-Z, X-EEEEY*AQ[dP]-C(Sx)-G-Z, X-EEEEY*AQ-C(Sx)-VG-Z, X-EEEEY*D-C(Sx)- VG-Z, X-EEEEY*DQ[dP]-C(Sx)-G-Z, X-EEEEY*DQ-C(Sx)-VG-Z, X-EEEEY*E-C(Sx)- VG-Z, X-EEEEY*EQ[dP]-C(Sx)-G-Z, X-EEEEY*EQ-C(Sx)-VG-Z, X-EEEEY*F-C(Sx)- VG-Z, X-EEEEY*FQ[dP]-C(Sx)-G-Z, X-EEEEY*FQ-C(Sx)-VG-Z, X-EEEEY*G-C(Sx)- VG-Z, X-EEEEY*GG[dP]-C(Sx)-G-Z, X-EEEEY*GG-C(Sx)-VG-Z, X-EEEE Y* GGG- C(Sx)-G-Z, X-EEEEY*GQ[dP]-C(Sx)-G-Z, X-EEEEY*GQ-C(Sx)-VG-Z, X-EEEEY*H- C(Sx)-VG-Z, X-EEEEY*HQ[dP]-C(Sx)-G-Z, X-EEEEY*HQ-C(Sx)-VG-Z, X- EEEEY*I[Nle][dP]-C(Sx)-G-Z, X-EEEEY*I[Nle]-C(Sx)-VG-Z, X-EEEEY*IA[dP]-C(Sx)- G-Z, X-EEEEY*IA-C(Sx)-VG-Z, X-EEEEY*I-C(Sx)-EV-Z, X-EEEEY*I-C(Sx)-IV-Z, X- EEEEY*ID[dP]-C(Sx)-G-Z, X-EEEEY*ID-C(Sx)-VG-Z, X-EEEEY*IE[dP]-C(Sx)-G-Z, X- EEEEY*IE-C(Sx)-VG-Z, X-EEEEY*IF[dP]-C(Sx)-G-Z, X-EEEEY*IF-C(Sx)-VG-Z, X- EEEEY*IG[dP]-C(Sx)-G-Z, X-EEEEY*IG-C(Sx)-VG-Z, X-EEEEY*IH[dP]-C(Sx)-G-Z, X- EEEEY*IH-C(Sx)-VG-Z, X-EEEEY*II[dP]-C(Sx)-G-Z, X-EEEEY*II-C(Sx)-VG-Z, X- EEEEY*IK[dP]-C(Sx)-G-Z, X-EEEEY*IK-C(Sx)-VG-Z, X-EEEEY*IL[dP]-C(Sx)-G-Z, X- EEEEY*IL-C(Sx)-VG-Z, X-EEEEY*IN[dP]-C(Sx)-G-Z, X-EEEEY*IN-C(Sx)-VG-Z, X- EEEEY*IP[dP]-C(Sx)-G-Z, X-EEEEY*IP-C(Sx)-VG-Z, X-EEEEY*IQ[dP]-C(Sx)-G-Z, X- EEEEY*IQ[Nle]-C(Sx)-G-Z, X-EEEEY*IQA-C(Sx)-G-Z, X-EEEEY*IQ-C(Sx)-VG-Z, X- EEEEY*IQD-C(Sx)-G-Z, X-EEEEY*IQE-C(Sx)-G-Z, X-EEEEY*IQF-C(Sx)-G-Z, X- EEEEY*IQG-C(Sx)-G-Z, X-EEEEY*IQH-C(Sx)-G-Z, X-EEEEY*IQI-C(Sx)-G-Z, X- EEEEY*IQK-C(Sx)-G-Z, X-EEEEY*IQL-C(Sx)-G-Z, X-EEEEY*IQN-C(Sx)-G-Z, X- EEEEY*IQP-C(Sx)-G-Z, X-EEEEY*IQQ-C(Sx)-G-Z, X-EEEEY*IQR-C(Sx)-G-Z, X- EEEEY*IQV-C(Sx)-G-Z; and X-EEEEY*IQW-C(Sx)-G-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EEEEY*IR[dP]-C(Sx)-G-Z, X-EEEEY*IR-C(Sx)- VG-Z, X-EEEEY*IV[dP]-C(Sx)-G-Z, X-EEEEY*IV-C(Sx)-VG-Z, X-EEEEY*IW[dP]- C(Sx)-G-Z, X-EEEEY*IW-C(Sx)-VG-Z, X-EEEEY*K-C(Sx)-VG-Z, X-EEEE Y*KQ[dP]- C(Sx)-G-Z, X-EEEEY*KQ-C(Sx)-VG-Z, X-EEEEY*L-C(Sx)-VG-Z, X-EEEEY*LQ[dP]- C(Sx)-G-Z, X-EEEEY*LQ-C(Sx)-VG-Z, X-EEEEY*N-C(Sx)-VG-Z, X-EEEEY*NQ[dP]- C(Sx)-G-Z, X-EEEEY*NQ-C(Sx)-VG-Z, X-EEEEY*P-C(Sx)-VG-Z, X-EEEE Y*PQ[dP]- C(Sx)-G-Z, X-EEEEY*PQ-C(Sx)-VG-Z, X-EEEEY*Q-C(Sx)-VG-Z, X-EEEE Y* QQ[dP]- C(Sx)-G-Z, X-EEEEY*QQ-C(Sx)-VG-Z, X-EEEEY*R-C(Sx)-VG-Z, X-EEEEY*RQ[dP]- C(Sx)-G-Z, X-EEEEY*RQ-C(Sx)-VG-Z, X-EEEEY*V-C(Sx)-VG-Z, X-EEEEY*VQ[dP]- C(Sx)-G-Z, X-EEEEY*VQ-C(Sx)-VG-Z, X-EEEEY*W-C(Sx)-VG-Z, X-EEEEY*WQ[dP]- C(Sx)-G-Z, X-EEEEY*WQ-C(Sx)-VG-Z, X-EEEIY*F-C(Sx)-FWG-Z, X-EEEY*I-C(Sx)- [Nle]V-Z, X-EEEY*I-C(Sx)-AV-Z, X-EEEY*I-C(Sx)-DV-Z, X-EEEY*I-C(Sx)-FV-Z, X- EEEY*I-C(Sx)-GV-Z, X-EEEY*I-C(Sx)-HV-Z, X-EEEY*I-C(Sx)-I[Nle]-Z, X-EEEY*I- C(Sx)-IA-Z, X-EEEY*I-C(Sx)-ID-Z, X-EEEY*I-C(Sx)-IE-Z, X-EEEY*I-C(Sx)-IF-Z, X- EEEY*I-C(Sx)-IG-Z, X-EEEY*I-C(Sx)-IH-Z, X-EEEY*I-C(Sx)-II-Z, X-EEEY*I-C(Sx)-IK- Z, X-EEEY*I-C(Sx)-IL-Z, X-EEEY*I-C(Sx)-IM-Z, X-EEEY*I-C(Sx)-IN-Z, X-EEEY*I- C(Sx)-IP-Z, X-EEEY*I-C(Sx)-IQ-Z, X-EEEY*I-C(Sx)-IR-Z, X-EEEY*I-C(Sx)-IW-Z, X- EEEY*I-C(Sx)-KV-Z, X-EEEY*I-C(Sx)-LV-Z, X-EEEY*I-C(Sx)-MV-Z, X-EEEY*I- C(Sx)-NV-Z, X-EEEY*I-C(Sx)-PV-Z, X-EEEY*I-C(Sx)-QV-Z, X-EEEY*I-C(Sx)-RV-Z, X- EEEY*I-C(Sx)-VV-Z, X-EEEY*I-C(Sx)-WV-Z, X-EEPDY*E-C(Sx)-QP-Z, X-EEPDY*F- C(Sx)-FG-Z, X-EEPDY*F-C(Sx)-FK-Z, X-EEPDY*F-C(Sx)-FP-Z, X-EEPDY*F-C(Sx)-IG- Z, X-EEPDY*F-C(Sx)-IK-Z, X-EEPDY*F-C(Sx)-IP-Z, X-EEPDY*F-C(Sx)-MG-Z, X- EEPDY*F-C(Sx)-MK-Z, X-EEPDY*F-C(Sx)-MP-Z, X-EEPDY*F-C(Sx)-VG-Z, X- EEPDY*F-C(Sx)-VK-Z, X-EEPDY*F-C(Sx)-VP-Z, X-EEPDY*I-C(Sx)-FG-Z, X- EEPDY*I-C(Sx)-FK-Z, X-EEPDY*I-C(Sx)-FP-Z, X-EEPDY*I-C(Sx)-IG-Z, X-EEPDY*I- C(Sx)-IK-Z, X-EEPDY*I-C(Sx)-IP-Z, X-EEPDY*I-C(Sx)-MG-Z, X-EEPDY*I-C(Sx)-MK- Z, X-EEPDY*I-C(Sx)-MP-Z, X-EEPDY*I-C(Sx)-VG-Z, X-EEPDY*I-C(Sx)-VK-Z, X- EEPDY*V-C(Sx)-FG-Z, X-EEPDY*V-C(Sx)-FK-Z, X-EEPDY*V-C(Sx)-FP-Z, X- EEPDY*V-C(Sx)-IG-Z, X-EEPDY*V-C(Sx)-IK-Z, X-EEPDY*V-C(Sx)-IP-Z, X- EEPDY*V-C(Sx)-MG-Z, X-EEPDY*V-C(Sx)-MK-Z, X-EEPDY*V-C(Sx)-MP-Z, X- EEPDY*V-C(Sx)-VG-Z, X-EEPDY*V-C(Sx)-VK-Z, X-EEPDY*V-C(Sx)-VP-Z, X- EEPEY*F-C(Sx)-FG-Z, X-EEPEY*F-C(Sx)-FK-Z, X-EEPEY*F-C(Sx)-FP-Z, X-EEPEY*F- C(Sx)-IG-Z, X-EEPEY*F-C(Sx)-IK-Z, X-EEPEY*F-C(Sx)-IP-Z, X-EEPEY*F-C(Sx)-MG- Z, X-EEPEY*F-C(Sx)-MK-Z, X-EEPEY*F-C(Sx)-MP-Z, X-EEPEY*F-C(Sx)-VG-Z, X- EEPEY*F-C(Sx)-VK-Z, and X-EEPEY*F-C(Sx)-VP-Z; wherein X- is H or acetyl; and Z is

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-EEPEY*I-C(Sx)-FG-Z, X-EEPEY*I-C(Sx)-FK-Z, X-EEPEY*I-C(Sx)-FP-Z, X-EEPEY*I-C(Sx)-IG-Z, X-EEPEY*I-C(Sx)-IK-Z, X-EEPEY*I- C(Sx)-IP-Z, X-EEPEY*I-C(Sx)-MG-Z, X-EEPEY*I-C(Sx)-MK-Z, X-EEPEY*I-C(Sx)-MP- Z, X-EEPEY*I-C(Sx)-VG-Z, X-EEPEY*I-C(Sx)-VK-Z, X-EEPEY*V-C(Sx)-FG-Z, X- EEPEY*V-C(Sx)-FK-Z, X-EEPEY*V-C(Sx)-FP-Z, X-EEPEY*V-C(Sx)-IG-Z, X- EEPEY*V-C(Sx)-IK-Z, X-EEPEY*V-C(Sx)-IP-Z, X-EEPEY*V-C(Sx)-MG-Z, X- EEPEY*V-C(Sx)-MK-Z, X-EEPEY*V-C(Sx)-MP-Z, X-EEPEY*V-C(Sx)-VG-Z, X- EEPEY*V-C(Sx)-VK-Z, and X-EEPEY*V-C(Sx)-VP-Z, X-EEPIY*F-C(Sx)-FG-Z, X- EEPIY*F-C(Sx)-FK-Z, X-EEPIY*F-C(Sx)-FP-Z, X-EEPIY*F-C(Sx)-IG-Z, X-EEPIY*F- C(Sx)-IK-Z, X-EEPIY*F-C(Sx)-IP-Z, X-EEPIY*F-C(Sx)-MG-Z, X-EEPIY*F-C(Sx)-MK-Z, X-EEPIY*F-C(Sx)-MP-Z, X-EEPIY*F-C(Sx)-VG-Z, X-EEPIY*F-C(Sx)-VK-Z, X- EEPIY*I-C(Sx)-FG-Z, X-EEPIY*I-C(Sx)-FK-Z, X-EEPIY*I-C(Sx)-IG-Z, X-EEPIY*I- C(Sx)-IK-Z, X-EEPIY*I-C(Sx)-MG-Z, X-EEPIY*I-C(Sx)-MK-Z, X-EEPIY*V-C(Sx)-FG-Z, X-EEPIY*V-C(Sx)-FK-Z, X-EEPIY*V-C(Sx)-FP-Z, X-EEPIY*V-C(Sx)-IG-Z, X- EEPIY*V-C(Sx)-IK-Z, X-EEPIY*V-C(Sx)-IP-Z, X-EEPIY*V-C(Sx)-MG-Z, X-EEPIY*V- C(Sx)-MK-Z, X-EEPIY*V-C(Sx)-MP-Z, X-EEPIY*V-C(Sx)-VG-Z, X-EEPIY*V-C(Sx)- VK-Z, X-EEPPD-C(Sx)-QY*[pY] DFPGK-Z, X-EEPPD-C(Sx)-QY*YNDFPGK-Z, X- EGRNPGFY*V-C(Sx)-A PMP-Z, X-EGSFESRY*Q-C(Sx)-PFEDF-Z, X-EPIQEANY*V- C(Sx)-MTPGT-Z, X-EPPDHQYY*N-C(Sx)-FPGKE-Z, X-EQEDEPE-C(Sx)-DY*EEVLE- Z, X-EQEDEPE-C(Sx)-DY*FEWLE-Z, X-EQEDEPEGDY*E-C(Sx)-VLE-Z, X- EQEDEPEGDY*F-C(Sx)-WLE-Z, X-EVSETDDY*A-C(Sx)-IIDEE-Z, X-FAGKE-C(Sx)- TY*[pY]QGRHLG-Z, X-FAGKE-C(Sx)-TY*YQGRHLG-Z, X-FD[Nle]DR-C(Sx)- IY*RMSFFRK-Z, X-FD[Nle]DRDIY*R-C(Sx)-SFFRK-Z, X-FDKDGNGY*I-C(Sx)- AAELR-Z, X-FDMDR-C(Sx)-IY*RMSFFRK-Z, X-FDMDRDIY*R-C(Sx)-SFFRK-Z, X- FEEEEY*I-C(Sx)-Z, X-FEEEY*I-C(Sx)-IV-Z, X-FTDRL-C(Sx)-QY*ISTRGLG-Z, X- FTDRLQQY*I-C(Sx)-TRGLG-Z, and X-FVSETDDY*A-C(Sx)-IIDEE-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal -binding compound of the present invention is selected from the group consisting of: X-FYEEIKKY*E-C(Sx)-LETEE-Z, X-GAEDPEY*I- C(Sx)-IPAKKKG-Z, X-GAEEPDY*I-C(Sx)-FGAKKKG-Z, X-GAEEPEY*I-C(Sx)- FGAKKKG-Z, X-GAEEPEY*I-C(Sx)-VKAKKKG-Z, X-GAEEPIY*I-C(Sx)- [Nl e]P AKKKG-Z , X-GAEEPIY*I-C(Sx)-FGAKKKG-Z, X-GAEEPIY*V-C(Sx)- FGAKKKG-Z, X-GAEEPIY*V-C(Sx)-VKAKKKG-Z, X-GAEEPIY*V-C(Sx)-VPAKKKG- Z, X-GAGEE-C(Sx)-DY*[pY][pY]IWAGKKKK-Z, X-GC(XX)-NY*RGYSLGNWV-Z, X- GDGSD-C(Sx)-PY*[pY]NSIPSK-Z, X-GDGSD-C(Sx)-PY*YNSIPSK-Z, X-GEEEEY*I- C(Sx)-Z, X-GEEEY*I-C(Sx)-IV-Z, X-GGPEPGPY*A-C(Sx)-PSVNT-Z, X-GLPWWR- C(Sx)-YT*WVVERDVNTKQR-Z, X-GSNQEEAY*V-C(Sx)-[Nle]SSFY-Z, X- GVSETDDY*A-C(Sx)-IIDEE-Z, X-HDLGEDIY*D-C(Sx)-VP-Z, X-HEEEEY*I-C(Sx)-Z, X-HEEEY*I-C(Sx)-IV-Z, X-HRIDG-C(Sx)-TY*VIKRVKY*-Z, X-HRIDGKTY*V-C(Sx)- KRVKY-Z, X-HVNATY*V-C(Sx)-VKSVAP-Z, X-HVSETDDY*A-C(Sx)-IIDEE-Z, X- IEEEEY*I-C(Sx)-Z, X-IEEEY*I-C(Sx)-IV-Z, X-IE EEQEY*V-C(Sx)-TVKSS-Z, X- IGTAE-C(Sx)-DY*GALYEGR-Z, X-ISLD PDY*Q-C(Sx)-DFFPK-Z, X-IVSETDDY*A- C(Sx)-IIDEE-Z, X-KAEEEEY*I-C(Sx)-LVA-Z, X-KEEEEY*I-C(Sx)-Z, X-KEEEY*I- C(Sx)-IV-Z, X-KEVHKSGY*L-C(Sx)-SERLI-Z, X-KGDKQVEY*L-C(Sx)-LDLDS-Z, X- KKAEEEEY*I-C(Sx)-LVA-Z, X-KKEEEIY*F-C(Sx)-FWG-Z, X-KKGE-C(Sx)- IY*AAPFA-Z, X-KKKAEEEEY*I-C(Sx)-LVA-Z, X-KKKAEEEEY*I-C(Sx)-LV-Z, X- KKKAEEEEY*I-C(Sx)-L-Z, X-KKKAEEEEY*I-C(Sx)-Z, X-KKKAEPLPPSY*V-C(Sx)- AS-Z, X-KKKDEQIY*W-C(Sx)-IA-Z, X-KKKDNVLINTY*S-C(Sx)-VLKIS-Z, X- KKKEEEIY*F-C(Sx)-FWG-Z, X-KKKKE-C(Sx)-IY*FFFG-Z, X-KKKKEEEIY*F-C(Sx)- FWG-Z, X-KKKLSRSLY*F-C(Sx)-PLLH-Z, X-KKKLTIDRY*L-C(Sx)-IVHAV-Z, and X- KKK HIGHTGY*L-C(Sx)-TVTVS-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting o X-KKKQAATGFGSP-C(Sx)-QY*SAD-Z, X- KKKRAHEEIY*F-C(Sx)-FWG-Z, X-KKKS PALLSSP-C(Sx)-YY*SAA-Z, X- KKKTSF[Nle][Nle][pT]PY*V-C(Sx)-TRY-Z, X-KKSR-C(Sx)-DY*[Nle]T[Nle]QIG-Z, X- KKTNSSEGLSMGNY*I-C(Sx)-LI R-Z, X-KVSETDDY*A-C(Sx)-IIDEE-Z, X- LEEEEY*I-C(Sx)-Z, X-LEEEY*I-C(Sx)-IV-Z, X-LHQED DY*I-C(Sx)-ASLIK-Z, X- LHQED DY*IN-C(Sx)-SLIK-Z, X-LMLRLQDY*E-C(Sx)-KTKKA-Z, X-LSRDLIMK- C(Sx)-DY*ELVSTKPTR-Z, X-LSRDLIMKEDY*E-C(Sx)-VSTKPTR-Z, X- LSRDLIMKEDY*E-C(Sx)-VSTK-Z, X-LVSETDDY*A-C(Sx)-IIDEE-Z, X- MAEEKKAY*K-C(Sx)-AKERE-Z, X-MEEEEY*I-C(Sx)-Z, X-MEEEY*I-C(Sx)-IV-Z, X- MK-C(Sx)-DY*ELVSTKPTRTSKVR-Z, X-MQDNS-C(Sx)-TY*GKIWEGS-Z, X- MRHVSISY*D-C(Sx)-PPTPG-Z, X- EEEEY*I-C(Sx)-Z, X- EEEY*I-C(Sx)-IV-Z, X- FA FSAY*P-C(Sx)-EEDMI-Z, X-NHIG-C(Sx)-TGY*LNTVTVSAKKK-Z, X- KVDD- C(Sx)-NY*AIKRIRL-Z, X- KVDDCNY*A-C(Sx)-KRIRL-Z, X-NVSETDDY*A-C(Sx)- IIDEE-Z, X-PAFD LYY*W-C(Sx)-QDPPE-Z, X-PEEEEY*I-C(Sx)-Z, X-PEEEY*I-C(Sx)- IV-Z, X-PTAE PEY*L-C(Sx)-LDVPV-Z, X-PTGEAPTY*V-C(Sx)-TQQIP-Z, X- PVPEY*I-C(Sx)-QSV-Z, X-PVSETDDY*A-C(Sx)-IIDEE-Z, X-QALD PEY*H-C(Sx)- ASNGP-Z, X-QEEEEY*I-C(Sx)-Z, X-QEEEY*I-C(Sx)-IV-Z, X-QLAAK-C(Sx)- AY*LQILSEE-Z, X-QLAAKLAY*L-C(Sx)-ILSEE-Z, X-QLTFALRY*L-C(Sx)-FFTKA-Z, X-QVSETDDY*A-C(Sx)-IIDEE-Z, X-RAEEEEY*I-C(Sx)-LVA-Z, X-RAHEEIY*F-C(Sx)- FWG-Z, X-R-C(Sx)-DY*[Nle]TMQIGKK-Z, X-REEEEY*I-C(Sx)-Z, X-REEEY*I-C(Sx)- IV-Z, X-RLDGE-C(Sx)-IY*IRHS LM-Z, X-R EEENIY*S-C(Sx)-PHDST-Z, X- R EGVATY*A-C(Sx)-AVLFR-Z, X-RQGSSDIY*S-C(Sx)-PEGKL-Z, X-RRAEEEEY*I- C(Sx)-LVA-Z, X-RRHY*Y-C(Sx)-DTHTNTYYLRTFGHNTRR-Z, X- RRHYYYDTHTNTY*Y-C(Sx)-RTFGHNTRR-Z, X-RRRAEEEEY*I-C(Sx)-LVA-Z, X- RVSETDDY*A-C(Sx)-IIDEE-Z, X-S[Nle]SETDDY*A-C(Sx)-IIDEE-Z, X-SASETDDY*A- C(Sx)-IIDEE-Z, X-SDSETDDY*A-C(Sx)-IIDEE-Z, X-SEELDENY*V-C(Sx)-MNPNS-Z, X-SEGLSM-C(Sx)-NY*IGLINRIKK-Z, X-SESETDDY*A-C(Sx)-IIDEE-Z, X- SFSETDDY*A-C(Sx)-IIDEE-Z, X-SGSETDDY*A-C(Sx)-IIDEE-Z, X-SHDSEENY*V- C(Sx)-MNPNL-Z, X-SHSETDDY*A-C(Sx)-IIDEE-Z, X-SISETDDY*A-C(Sx)-IIDEE-Z, X- SKSETDDY*A-C(Sx)-IIDEE-Z, X-SLSETDDY*A-C(Sx)-IIDEE-Z, X-SNSETDDY*A- C(Sx)-IIDEE-Z, X-SPAFD-C(Sx)-LY*[pY]WDQDPP-Z, X-SPAFD-C(Sx)- LY*YWDQDPP-Z, and X-SPATDLY*Q-C(Sx)-PPG-Z; wherein X is H or acetyl; and Z is

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting o X-SPQPEY*V-C(Sx)-QPDVR-Z, X-SPSETDDY*A- C(Sx)-IIDEE-Z, X-SQSETDDY*A-C(Sx)-IIDEE-Z, X-SRSETDDY*A-C(Sx)-IIDEE-Z, X- SSEPVGIY*Q-C(Sx)-FEKKT-Z, X-SSHKG-C(Sx)-HY*KH-Z, X-SSHKGFHY*K-C(Sx)- G-Z, X-SSTDR-C(Sx)-PY*EKVSAGN-Z, X-STAENAEY*L-C(Sx)-VAPQS-Z, X-STAEN- C(Sx)-EY*LRVAPQS-Z, X-SV[Nle]ETDDY*A-C(Sx)-IIDEE-Z, X-SVAETDDY*A-C(Sx)- IIDEE-Z, X-SVDETDDY*A-C(Sx)-IIDEE-Z, X-SVEETDDY*A-C(Sx)-IIDEE-Z, X- SVFETDDY*A-C(Sx)-IIDEE-Z, X-SVGETDDY*A-C(Sx)-IIDEE-Z, X-SVHETDDY*A- C(Sx)-IIDEE-Z, X-SVIETDDY*A-C(Sx)-IIDEE-Z, X-SVKETDDY*A-C(Sx)-IIDEE-Z, X- SVLETDDY*A-C(Sx)-IIDEE-Z, X-SV ETDDY*A-C(Sx)-IIDEE-Z, X-SVPETDDY*A- C(Sx)-IIDEE-Z, X-SVQETDDY*A-C(Sx)-IIDEE-Z, X-SVRETDDY*A-C(Sx)-IIDEE-Z, X- SVS[Nle]TDDY*A-C(Sx)-IIDEE-Z, X-SVSATDDY*A-C(Sx)-IIDEE-Z, X- SVSDTDDY*A-C(Sx)-IIDEE-Z, X-SVSE[Nle]DDY*A-C(Sx)-IIDEE-Z, X- SVSEADDY*A-C(Sx)-IIDEE-Z, X-SVSEDDDY*A-C(Sx)-IIDEE-Z, X-SVSEEDDY*A- C(Sx)-IIDEE-Z, X-SVSEFDDY*A-C(Sx)-IIDEE-Z, X-SVSEGDDY*A-C(Sx)-IIDEE-Z, X- SVSEHDDY*A-C(Sx)-IIDEE-Z, X-SVSEIDDY*A-C(Sx)-IIDEE-Z, X-SVSEKDDY*A- C(Sx)-IIDEE-Z, X-SVSELDDY*A-C(Sx)-IIDEE-Z, X-SVSE DDY*A-C(Sx)-IIDEE-Z, X- SVSEPDDY*A-C(Sx)-IIDEE-Z, X-SVSEQDDY*A-C(Sx)-IIDEE-Z, and X- SVSERDDY* A-C(Sx)-IIDEE-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-SVSET[Nle]DY*A-C(Sx)-IIDEE-Z, X- SVSETADY*A-C(Sx)-IIDEE-Z, X-SVSETD[Nle]Y*A-C(Sx)-IIDEE-Z, X-SVSETDAY*A- C(Sx)-IIDEE-Z, X-S VSETDD Y* [Nle]-C(Sx)-IIDEE-Z, X-S VSETDD Y* A-C(Sx)- [Nle]IDEE-Z, X-SVSETDDY*A-C(Sx)-AIDEE-Z, X-SVSETDDY*A-C(Sx)-DIDEE-Z, X- SVSETDDY*A-C(Sx)-EIDEE-Z, X-SVSETDDY*A-C(Sx)-FIDEE-Z, X-SVSETDDY*A- C(Sx)-GIDEE-Z, X-SVSETDDY*A-C(Sx)-HIDEE-Z, X-SVSETDDY*A-C(Sx)-I[Nle]DEE- Z, X-SVSETDDY*A-C(Sx)-IADEE-Z, X-SVSETDDY*A-C(Sx)-IDDEE-Z, X- SVSETDDY*A-C(Sx)-IEDEE-Z, X-SVSETDDY*A-C(Sx)-IFDEE-Z, X-SVSETDDY*A- C(Sx)-IGDEE-Z, X-SVSETDDY*A-C(Sx)-IHDEE-Z, X-SVSETDDY*A-C(Sx)-II[Nle]EE- Z, X-SVSETDDY*A-C(Sx)-IIAEE-Z, X-SVSETDDY*A-C(Sx)-IID[Nle]E-Z, X- SVSETDDY*A-C(Sx)-IIDAE-Z, X-SVSETDDY*A-C(Sx)-IIDDE-Z, X-SVSETDDY*A- C(Sx)-IIDE[Nle]-Z, X-SVSETDDY*A-C(Sx)-IIDEA-Z, X-SVSETDDY*A-C(Sx)-IIDED-Z, X-SVSETDDY*A-C(Sx)-IIDEF-Z, X-SVSETDDY*A-C(Sx)-IIDEG-Z, X-SVSETDDY*A- C(Sx)-IIDEH-Z, X-SVSETDDY*A-C(Sx)-IIDEI-Z, X-SVSETDDY*A-C(Sx)-IIDEK-Z, X- SVSETDDY*A-C(Sx)-IIDEL-Z, X-SVSETDDY*A-C(Sx)-IIDEN-Z, X-SVSETDDY*A- C(Sx)-IIDEP-Z, X-SVSETDDY*A-C(Sx)-IIDEQ-Z, X-SVSETDDY*A-C(Sx)-IIDER-Z, X- SVSETDDY*A-C(Sx)-IIDEV-Z, X-SVSETDDY*A-C(Sx)-IIDEW-Z, X-SVSETDDY*A- C(Sx)-IIDFE-Z, X-SVSETDDY*A-C(Sx)-IIDGE-Z, and X-SVSETDDY*A-C(Sx)-IIDHE- Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting o X-SVSETDDY*A-C(Sx)-IIDIE-Z, X-SVSETDDY*A- C(Sx)-IIDKE-Z, X-SVSETDDY*A-C(Sx)-IIDLE-Z, X-SVSETDDY*A-C(Sx)-IID E-Z, X- SVSETDDY*A-C(Sx)-IIDPE-Z, X-SVSETDDY*A-C(Sx)-IIDQE-Z, X-SVSETDDY*A- C(Sx)-IIDRE-Z, X-SVSETDDY*A-C(Sx)-IIDVE-Z, X-SVSETDDY*A-C(Sx)-IIDWE-Z, X- SVSETDDY*A-C(Sx)-IIEEE-Z, X-SVSETDDY*A-C(Sx)-IIFEE-Z, X-SVSETDDY*A- C(Sx)-IIGEE-Z, X-SVSETDDY*A-C(Sx)-IIHEE-Z, X-SVSETDDY*A-C(Sx)-IIIEE-Z, X- SVSETDDY*A-C(Sx)-IIKEE-Z, X-SVSETDDY*A-C(Sx)-IILEE-Z, X-SVSETDDY*A- C(Sx)-IINEE-Z, X-SVSETDDY*A-C(Sx)-IIPEE-Z, X-SVSETDDY*A-C(Sx)-IIQEE-Z, X- SVSETDDY*A-C(Sx)-IIREE-Z, X-SVSETDDY*A-C(Sx)-IIVEE-Z, X-SVSETDDY*A- C(Sx)-IIWEE-Z, X-SVSETDDY*A-C(Sx)-IKDEE-Z, X-SVSETDDY*A-C(Sx)-ILDEE-Z, X-SVSETDDY*A-C(Sx)-I DEE-Z, X-SVSETDDY*A-C(Sx)-IPDEE-Z, X- SVSETDDY*A-C(Sx)-IQDEE-Z, X-SVSETDDY*A-C(Sx)-IRDEE-Z, X-SVSETDDY*A- C(Sx)-IVDEE-Z, X-SVSETDDY*A-C(Sx)-IWDEE-Z, X-SVSETDDY*A-C(Sx)-KIDEE-Z, X-SVSETDDY*A-C(Sx)-LIDEE-Z, X-SVSETDDY*A-C(Sx)-NIDEE-Z, X- SVSETDDY*A-C(Sx)-PIDEE-Z, X-SVSETDDY*A-C(Sx)-QIDEE-Z, X-SVSETDDY*A- C(Sx)-RIDEE-Z, X-SVSETDDY*A-C(Sx)-VIDEE-Z, X-SVSETDDY*A-C(Sx)-WIDEE-Z, X-SVSETDDY*D-C(Sx)-IIDEE-Z, X-SVSETDDY*E-C(Sx)-IIDEE-Z, X-SVSETDDY*F- C(Sx)-IIDEE-Z, X-SVSETDDY*G-C(Sx)-IIDEE-Z, X-SVSETDDY*H-C(Sx)-IIDEE-Z, X- SVSETDDY*I-C(Sx)-IIDEE-Z, X-SVSETDDY*K-C(Sx)-IIDEE-Z, X-SVSETDDY*L- C(Sx)-IIDEE-Z, X-SVSETDDY*N-C(Sx)-IIDEE-Z, X-SVSETDDY*P-C(Sx)-IIDEE-Z, X- SVSETDDY*Q-C(Sx)-IIDEE-Z, X-SVSETDDY*R-C(Sx)-IIDEE-Z, X-SVSETDDY*V- C(Sx)-IIDEE-Z, X-SVSETDDY*W-C(Sx)-IIDEE-Z, X-SVSETDEY*A-C(Sx)-IIDEE-Z, X- SVSETDFY*A-C(Sx)-IIDEE-Z, X-SVSETDGY*A-C(Sx)-IIDEE-Z, X-SVSETDHY*A- C(Sx)-IIDEE-Z, X-SVSETDIY*A-C(Sx)-IIDEE-Z, X-SVSETDKY*A-C(Sx)-IIDEE-Z, X- SVSETDLY*A-C(Sx)-IIDEE-Z, X-SVSETDNY*A-C(Sx)-IIDEE-Z, X-SVSETDPY*A- C(Sx)-IIDEE-Z, X-SVSETDQY*A-C(Sx)-IIDEE-Z, X-SVSETDRY*A-C(Sx)-IIDEE-Z, X- SVSETDVY*A-C(Sx)-IIDEE-Z, and X-SVSETDWY*A-C(Sx)-IIDEE-Z; wherein X is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting o X-SVSETEDY*A-C(Sx)-IIDEE-Z, X-SVSETFDY*A- C(Sx)-IIDEE-Z, X-SVSETGDY*A-C(Sx)-IIDEE-Z, X-SVSETHDY*A-C(Sx)-IIDEE-Z, X- SVSETIDY*A-C(Sx)-IIDEE-Z, X-SVSETKDY*A-C(Sx)-IIDEE-Z, X-SVSETLDY*A- C(Sx)-IIDEE-Z, X-SVSETNDY*A-C(Sx)-IIDEE-Z, X-SVSETPDY*A-C(Sx)-IIDEE-Z, X- SVSETQDY*A-C(Sx)-IIDEE-Z, X-SVSETRDY*A-C(Sx)-IIDEE-Z, X-SVSETVDY*A- C(Sx)-IIDEE-Z, X-SVSETWDY*A-C(Sx)-IIDEE-Z, X-SVSEVDDY*A-C(Sx)-IIDEE-Z, X- SVSEWDDY*A-C(Sx)-IIDEE-Z, X-SVSFTDDY*A-C(Sx)-IIDEE-Z, X-SVSGTDDY*A- C(Sx)-IIDEE-Z, X-SVSHTDDY*A-C(Sx)-IIDEE-Z, X-SVSITDDY*A-C(Sx)-IIDEE-Z, X- SVSKTDDY*A-C(Sx)-IIDEE-Z, X-SVSLTDDY*A-C(Sx)-IIDEE-Z, X-SVSNTDDY*A- C(Sx)-IIDEE-Z, X-SVSPTDDY*A-C(Sx)-IIDEE-Z, X-SVSQTDDY*A-C(Sx)-IIDEE-Z, X- SVSRTDDY*A-C(Sx)-IIDEE-Z, X-SVSVTDDY*A-C(Sx)-IIDEE-Z, X-SVSWTDDY*A- C(Sx)-IIDEE-Z, X-SVVETDDY*A-C(Sx)-IIDEE-Z, X-SVWETDDY*A-C(Sx)-IIDEE-Z, X- SWSETDDY*A-C(Sx)-IIDEE-Z, X-TDGEDADY*T-C(Sx)-FTNQQ-Z, X-TDVE-C(Sx)- TY*ADFIASG-Z, X-TEADGELY*V-C(Sx)-NTPSG-Z, X-TEERLPSS*P-C(Sx)-YEDAA-Z, X-TE DDDVY*R-C(Sx)-LEELA-Z, X-TFLPV-C(Sx)-EY*INQSVPK-Z, X-TFLPVPEY*I- C(Sx)-QSVPK-Z, X-TG[Nle]FPRNY*V-C(Sx)-PV RN-Z, X-TLMEKDSY*P-C(Sx)- FLKSP-Z, X-TPENN-C(Sx)-EY*AKVSGV-Z, X-TQEQYELY*S-C(Sx)-MGSTF-Z, X- TVDGKEIY*N-C(Sx)-IRRKT-Z, X-VADERVDY*V-C(Sx)-VDQQK-Z, X-VEEEEY*I- C(Sx)-Z, X-VEEEY*I-C(Sx)-IV-Z, X-VQPSPARSSS*Y-C(Sx)-EANE-Z, X-VSETDDY*A- C(Sx)-IIDEEDT-Z, X-VTRRT-C(Sx)-DY*FL-Z, X-VVSETDDY*A-C(Sx)-IIDEE-Z, X- VY*S-C(Sx)-DY[pY]RLF PSKKK-Z, X-VY*S-C(Sx)-DYYRLFNPSKKK-Z, X-VYS- C(Sx)-DY*[pY]RLF PSKKK-Z, X-VYS-C(Sx)-DY*YRLF PSKKK-Z, X-WEEEEY*I- C(Sx)-Z, X-WEEEY*I-C(Sx)-IV-Z, and X-WVSETDDY*A-C(Sx)-IIDEE-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-EPDY*I-C(Sx)-FG-Z; X-PDY*I-C(Sx)-FG-Z; X- KKHTDDGY*M-C(Sx)-MSPGVA-Z; X-KKHTD-C(Sx)-GY*MPMSPGVA-Z; X-KKHT- C(Sx)-DGY*MPMSPGVA-Z; X-KKHTDDGY* [Nle]-C(Sx)-[Nle] SPGVA-Z; X-KKHTD- C(Sx)-GY* [Nle]P[Nle] SPGVA-Z; X-KKHT-C(Sx)-DGY* [Nle]P[Nle] SPGVA-Z; X- KKAEEEEY*I-C(Sx)-LV-Z; X-RRRAEEEEY*I-C(Sx)-LV-Z; X-RRAEEEEY*I-C(Sx)-LV- Z; X-[Nle]-C(Sx)-DY*[Nle]TMQIGKK-Z; X-A-C(Sx)-DY*[Nle]TMQIGKK-Z; X-D-C(Sx)- D Y* [Nl e] TMQIGKK-Z ; X-E-C(Sx)-DY*[Nle]TMQIGKK-Z; X-F-C(Sx)- D Y* [Nl e] TMQIGKK-Z ; X-G-C(Sx)-DY*[Nle]TMQIGKK-Z; X-H-C(Sx)- D Y* [Nl e] TMQIGKK-Z ; X-I-C(Sx)-DY*[Nle]TMQIGKK-Z; X-K-C(Sx)- D Y* [Nl e] TMQIGKK-Z ; X-L-C(Sx)-DY*[Nle]TMQIGKK-Z; X-N-C(Sx)- D Y* [Nl e] TMQIGKK-Z ; X-P-C(Sx)-DY*[Nle]TMQIGKK-Z; X-Q-C(Sx)- DY*[Nle]TMQIGKK-Z; X-R-C(Sx)-[Nle]Y*[Nle]TMQIGKK-Z; X-R-C(Sx)- AY*[Nle]TMQIGKK-Z; X-R-C(Sx)-DY*[Nle][Nle]MQIGKK-Z; X-R-C(Sx)- D Y* [Nle] AMQIGKK-Z; X-R-C(Sx)-DY*[Nle]DMQIGKK-Z; X-R-C(Sx)- DY*[Nle]EMQIGKK-Z; X-R-C(Sx)-DY*[Nle]FMQIGKK-Z; X-R-C(Sx)- DY*[Nle]GMQIGKK-Z; X-R-C(Sx)-DY*[Nle]HMQIGKK-Z; X-R-C(Sx)- DY*[Nle]FMQIGKK-Z; X-R-C(Sx)-DY*[Nle]KMQIGKK-Z; X-R-C(Sx)- DY*[Nle]LMQIGKK-Z; X-R-C(Sx)-DY*[Nle]NMQIGKK-Z; X-R-C(Sx)- DY* [Nle]PMQIGKK-Z; X-R-C(Sx)-DY*[Nle]QMQIGKK-Z; X-R-C(Sx)- DY*[Nle]RMQIGKK-Z; wherein X- is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-R-C(Sx)-DY*[Nle]T[Nle]QIGKK-Z; X-R-C(Sx)- D Y* [Nl e] T AQIGKK-Z ; X-R-C(Sx)-DY*[Nle]TDQIGKK-Z; X-R-C(Sx)- D Y* [Nl e] TEQIGKK-Z ; X-R-C(Sx)-DY*[Nle]TFQIGKK-Z; X-R-C(Sx)- D Y* [Nl e] TGQIGKK-Z ; X-R-C(Sx)-DY*[Nle]THQIGKK-Z; X-R-C(Sx)- D Y* [Nl e] TIQIGKK-Z ; X-R-C(Sx)-DY*[Nle]TKQIGKK-Z; X-R-C(Sx)- DY*[Nle]TLQIGKK-Z; X-R-C(Sx)-DY*[Nle]TM[Nle]IGKK-Z; X-R-C(Sx)- DY* [Nle]TMAIGKK-Z; X-R-C(Sx)-DY*[Nle]TMDIGKK-Z; X-R-C(Sx)- DY*[Nle]TMEIGKK-Z; X-R-C(Sx)-DY*[Nle]TMFIGKK-Z; X-R-C(Sx)- DY*[Nle]TMGIGKK-Z; X-R-C(Sx)-DY*[Nle]TMHIGKK-Z; X-R-C(Sx)- DY*[Nle]TMIIGKK-Z; X-R-C(Sx)-DY*[Nle]TMKIGKK-Z; X-R-C(Sx)- DY*[Nle]TMLIGKK-Z; X-R-C(Sx)-DY*[Nle]TMNIGKK-Z; X-R-C(Sx)- DY* [Nle]TMPIGKK-Z; X-R-C(Sx)-DY*[Nle]TMQ[Nle]GKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQ AGKK-Z ; X-R-C(Sx)-DY*[Nle]TMQDGKK-Z; X-R-C(Sx)- DY*[Nle]TMQEGKK-Z; X-R-C(Sx)-DY*[Nle]TMQFGKK-Z; X-R-C(Sx)- DY*[Nle]TMQGGKK-Z; X-R-C(Sx)-DY*[Nle]TMQHGKK-Z; X-R-C(Sx)- DY*[Nle]TMQI[Nle]KK-Z; X-R-C(Sx)-DY*[Nle]TMQIAKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIDKK-Z ; X-R-C(Sx)-DY*[Nle]TMQIEKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIFKK-Z ; X-R-C(Sx)-DY*[Nle]TMQIG[Nle]K-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGAK-Z ; wherein X- is H or acetyl; and Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-R-C(Sx)-DY*[Nle]TMQIGDK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGEK-Z ; X-R-C(Sx)-DY*[Nle]TMQIGFK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGGK-Z ; X-R-C(Sx)-DY*[Nle]TMQIGHK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGIK-Z ; X-R-C(Sx)-DY*[Nle]TMQIGK[Nle]-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGK A-Z ; X-R-C(Sx)-DY*[Nle]TMQIGKD-Z; X-R-C(Sx)- DY*[Nle]TMQIGKE-Z; X-R-C(Sx)-DY*[Nle]TMQIGKF-Z; X-R-C(Sx)- DY*[Nle]TMQIGKG-Z; X-R-C(Sx)-DY*[Nle]TMQIGKH-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGKI-Z ; X-R-C(Sx)-DY*[Nle]TMQIGKL-Z; X-R-C(Sx)- DY*[Nle]TMQIGKN-Z; X-R-C(Sx)-DY*[Nle]TMQIGKP-Z; X-R-C(Sx)- DY*[Nle]TMQIGKQ-Z; X-R-C(Sx)-DY*[Nle]TMQIGKR-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGK V-Z ; X-R-C(Sx)-DY*[Nle]TMQIGKW-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGLK-Z ; X-R-C(Sx)-DY*[Nle]TMQIGNK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGPK-Z ; X-R-C(Sx)-DY*[Nle]TMQIGQK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGRK-Z ; X-R-C(Sx)-DY*[Nle]TMQIGVK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIGWK-Z ; X-R-C(Sx)-DY*[Nle]TMQIHKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIIKK-Z ; X-R-C(Sx)-DY*[Nle]TMQIKKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQILKK-Z ; X-R-C(Sx)-DY*[Nle]TMQINKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIPKK-Z ; X-R-C(Sx)-DY*[Nle]TMQIQKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQIRKK-Z ; X-R-C(Sx)-DY*[Nle]TMQIVKK-Z; wherein X- is H or acetyl; Z is OH or NH ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-R-C(Sx)-DY*[Nle]TMQIWKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQKGKK-Z ; X-R-C(Sx)-DY*[Nle]TMQLGKK-Z; X-R-C(Sx)- DY*[Nle]TMQNGKK-Z; X-R-C(Sx)-DY*[Nle]TMQPGKK-Z; X-R-C(Sx)- DY*[Nle]TMQQGKK-Z; X-R-C(Sx)-DY*[Nle]TMQRGKK-Z; X-R-C(Sx)- D Y* [Nl e] TMQ VGKK-Z ; X-R-C(Sx)-DY*[Nle]TMQWGKK-Z; X-R-C(Sx)- DY*[Nle]TMRIGKK-Z; X-R-C(Sx)-DY*[Nle]TMVIGKK-Z; X-R-C(Sx)- DY*[Nle]TMWIGKK-Z; X-R-C(Sx)-DY*[Nle]TNQIGKK-Z; X-R-C(Sx)- DY*[Nle]TPQIGKK-Z; X-R-C(Sx)-DY*[Nle]TQQIGKK-Z; X-R-C(Sx)- D Y* [Nl e] TRQIGKK-Z ; X-R-C(Sx)-DY*[Nle]TVQIGKK-Z; X-R-C(Sx)- DY*[Nle]TWQIGKK-Z; X-R-C(Sx)-DY*[Nle]VMQIGKK-Z; X-R-C(Sx)- D Y* [Nle] WMQIGKK-Z; X-R-C(Sx)-DY* ATMQIGKK-Z; X-R-C(Sx)-DY*DTMQIGKK-Z; X-R-C(Sx)-DY*ETMQIGKK-Z; X-R-C(Sx)-DY*FTMQIGKK-Z; X-R-C(Sx)- DY*GTMQIGKK-Z; X-R-C(Sx)-DY*HTMQIGKK-Z; X-R-C(Sx)-DY*ITMQIGKK-Z; X- R-C(Sx)-DY*KTMQIGKK-Z; X-R-C(Sx)-DY*LTMQIGKK-Z; X-R-C(Sx)- DY*NTMQIGKK-Z; X-R-C(Sx)-DY*PTMQIGKK-Z; X-R-C(Sx)-DY*QTMQIGKK-Z; X- R-C(Sx)-DY*RTMQIGKK-Z; X-R-C(Sx)-DY*VTMQIGKK-Z; X-R-C(Sx)- DY*WTMQIGKK-Z; X-R-C(Sx)-EY*[Nle]TMQIGKK-Z; X-R-C(Sx)- FY*[Nle]TMQIGKK-Z; X-R-C(Sx)-GY*[Nle]TMQIGKK-Z; wherein X- is H or acetyl; and

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-R-C(Sx)-HY*[Nle]TMQIGKK-Z; X-R-C(Sx)- I Y* [Nl e] TMQIGKK-Z ; X-R-C(Sx)-KY*[Nle]TMQIGKK-Z; X-R-C(Sx)- L Y* [Nl e] TMQIGKK-Z ; X-R-C(Sx)-NY*[Nle]TMQIGKK-Z; X-R-C(Sx)- PY*[Nle]TMQIGKK-Z; X-R-C(Sx)-QY*[Nle]TMQIGKK-Z; X-R-C(Sx)- RY* [Nle] TMQIGKK-Z; X-R-C(Sx)-VY*[Nle]TMQIGKK-Z; X-V-C(Sx)- DY*[Nle]TMQIGKK-Z; X-KKHTDDGYM-C(Sx)-MS*PGVA-Z; X-KKHT*D-C(Sx)- GYMPMSPGVA-Z; X-KKHTDDGY[Nle]-C(Sx)-[Nle]S*PGVA-Z; X-KKHT*D-C(Sx)- GY[Nle]P[Nle]SPGVA-Z; X-KKKKVKKRPQRAHSD-C(Sx)-FS*-Z; X-EDFSS*I-C(Sx)- DMDFSALLSQISS; X-GDQDYLS*L-C(Sx)-VG-Z; X-KKRAARATS*-C(Sx)-VFA-Z; X- ARKRRRHPS*G-C(Sx)-PTA-Z; X-ARKRRRHPS*G-C(Sx)-PT-Z; X- ARKRRRHP S * G- C(Sx)-P-Z; X-ARKRRRHPS*G[dP]-C(Sx)-Z; X-ARKRRRHPS*GP-C(Sx)-Z; X- ARKRRRHPS*G-C(Sx)-Z; X-RRRQFS*L-C(Sx)-Z; X-KKERLLDDRHDS*G-C(Sx)- DDMKDEE-Z; X-KKERLLDDRHD S * G-C (Sx)-DEMKDEE-Z ; X-KKERLLDDRHD S * G- C(Sx)-DAMKDEE-Z; X-KKERLLDDRHDDG-C(Sx)-DS*MKDEE-Z; X- KKERLLDDRHDEG-C(Sx)-DS*MKDEE-Z; X-KKERLLDDRHDAG-C(Sx)-DS*MKDEE- Z; wherein X- is H or acetyl; and Z is OH or NH2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-[Nle]KR-C(Sx)-AS*FKKFA-Z; X-AKR-C(Sx)- AS*FKKFA-Z; X-DKR-C(Sx)-AS*FKKFA-Z; X-EKR-C(Sx)-AS*FKKFA-Z; X-FKR- C(Sx)-AS*FKKFA-Z; X-GKR-C(Sx)-AS*FKKFA-Z; X-HKR-C(Sx)-AS*FKKFA-Z; X- IKR-C(Sx)-AS*FKKFA-Z; X-KKR-C(Sx)-AS*FKKFA-Z; X-L[Nle]R-C(Sx)-AS*FKKFA- Z; X-LAR-C(Sx)-AS*FKKFA-Z; X-LDR-C(Sx)-AS*FKKFA-Z; X-LER-C(Sx)- AS*FKKFA-Z; X-LFR-C(Sx)-AS*FKKFA-Z; X-LGR-C(Sx)-AS*FKKFA-Z; X-LHR- C(Sx)-AS*FKKFA-Z; X-LIR-C(Sx)-AS*FKKFA-Z; X-LK[Nle]-C(Sx)-AS*FKKFA-Z; X- LKA-C(Sx)-AS*FKKFA-Z; X-LKD-C(Sx)-AS*FKKFA-Z; X-LKE-C(Sx)-AS*FKKFA-Z; X-LKF-C(Sx)-AS*FKKFA-Z; X-LKG-C(Sx)-AS*FKKFA-Z; X-LKH-C(Sx)-AS*FKKFA- Z; X-LKI-C(Sx)-AS*FKKFA-Z; X-LKK-C(Sx)-AS*FKKFA-Z; X-LKL-C(Sx)-AS*FKKFA- Z; X-LKN-C(Sx)-AS*FKKFA-Z; X-LKP-C(Sx)-AS*FKKFA-Z; X-LKQ-C(Sx)- AS*FKKFA-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-LKR-C(Sx)-[Nle]S*FKKFA-Z; X-LKR-C(Sx)- AS*[Nle]KKFA-Z; X-LKR-C(Sx)-AS*AKKFA-Z; X-LKR-C(Sx)-AS*DKKFA-Z; X-LKR- C(Sx)-AS*EKKFA-Z; X-LKR-C(Sx)-AS*F[Nle]KFA-Z; X-LKR-C(Sx)-AS*FAKFA-Z; X- LKR-C(Sx)-AS*FDKFA-Z; X-LKR-C(Sx)-AS*FEKFA-Z; X-LKR-C(Sx)-AS*FFKFA-Z; X-LKR-C(Sx)-AS*FGKFA-Z; X-LKR-C(Sx)-AS*FHKFA-Z; X-LKR-C(Sx)-AS*FIKFA-Z; X-LKR-C(Sx)-AS*FK[Nle]FA-Z; X-LKR-C(Sx)-AS*FKAFA-Z; X-LKR-C(Sx)- AS*FKDFA-Z; X-LKR-C(Sx)-AS*FKEFA-Z; X-LKR-C(Sx)-AS*FKFFA-Z; X-LKR- C(Sx)-AS*FKGFA-Z; X-LKR-C(Sx)-AS*FKHFA-Z; X-LKR-C(Sx)-AS*FKIFA-Z; X-LKR- C(Sx)-AS*FKK[Nle]A-Z; X-LKR-C(Sx)-AS*FKKAA-Z; X-LKR-C(Sx)-AS*FKKDA-Z; X- LKR-C(Sx)-AS*FKKEA-Z; X-LKR-C(Sx)-AS*FKKF[Nle]-Z; X-LKR-C(Sx)-AS*FKKFD- Z; X-LKR-C(Sx)-AS*FKKFE-Z; X-LKR-C(Sx)-AS*FKKFF-Z; X-LKR-C(Sx)- AS*FKKFG-Z; X-LKR-C(Sx)-AS*FKKFH-Z; X-LKR-C(Sx)-AS*FKKFI-Z; X-LKR-C(Sx)- AS*FKKFK-Z; X-LKR-C(Sx)-AS*FKKFL-Z; X-LKR-C(Sx)-AS*FKKFN-Z; X-LKR- C(Sx)-AS*FKKFP-Z; X-LKR-C(Sx)-AS*FKKFQ-Z; X-LKR-C(Sx)-AS*FKKFR-Z; X- LKR-C(Sx)-AS*FKKFV-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-LKR-C(Sx)-AS*FKKFW-Z; X-LKR-C(Sx)- AS*FKKGA-Z; X-LKR-C(Sx)-AS*FKKHA-Z; X-LKR-C(Sx)-AS*FKKIA-Z; X-LKR- C(Sx)-AS*FKKKA-Z; X-LKR-C(Sx)-AS*FKKLA-Z; X-LKR-C(Sx)-AS*FKKNA-Z; X- LKR-C(Sx)-AS*FKKPA-Z; X-LKR-C(Sx)-AS*FKKQA-Z; X-LKR-C(Sx)-AS*FKKRA-Z; X-LKR-C(Sx)-AS*FKKVA-Z; X-LKR-C(Sx)-AS*FKKWA-Z; X-LKR-C(Sx)-AS*FKLFA- Z; X-LKR-C(Sx)-AS*FK FA-Z; X-LKR-C(Sx)-AS*FKPFA-Z; X-LKR-C(Sx)- AS*FKQFA-Z; X-LKR-C(Sx)-AS*FKRFA-Z; X-LKR-C(Sx)-AS*FKVFA-Z; X-LKR- C(Sx)-AS*FKWFA-Z; X-LKR-C(Sx)-AS*FLKFA-Z; X-LKR-C(Sx)-AS*F KFA-Z; X- LKR-C(Sx)-AS*FPKFA-Z; X-LKR-C(Sx)-AS*FQKFA-Z; X-LKR-C(Sx)-AS*FRKFA-Z; X-LKR-C(Sx)-AS*FVKFA-Z; X-LKR-C(Sx)-AS*FWKFA-Z; X-LKR-C(Sx)-AS*GKKFA- Z; X-LKR-C(Sx)-AS*HKKFA-Z; X-LKR-C(Sx)-AS*IKKFA-Z; X-LKR-C(Sx)- AS*KKKFA-Z; X-LKR-C(Sx)-AS*LKKFA-Z; X-LKR-C(Sx)-AS* KKFA-Z; X-LKR- C(Sx)-AS*PKKFA-Z; X-LKR-C(Sx)-AS*QKKFA-Z; X-LKR-C(Sx)-AS*RKKFA-Z; X- LKR-C(Sx)-AS*VKKFA-Z; X-LKR-C(Sx)-AS*WKKFA-Z; X-LKR-C(Sx)-DS*FKKFA-Z; X-LKR-C(Sx)-ES*FKKFA-Z; X-LKR-C(Sx)-FS*FKKFA-Z; X-LKR-C(Sx)-GS*FKKFA-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-LKR-C(Sx)-HS*FKKFA-Z; X-LKR-C(Sx)- IS*FKKFA-Z; X-LKR-C(Sx)-KS*FKKFA-Z; X-LKR-C(Sx)-LS*FKKFA-Z; X-LKR-C(Sx)- NS*FKKFA-Z; X-LKR-C(Sx)-PS*FKKFA-Z; X-LKR-C(Sx)-QS*FKKFA-Z; X-LKR- C(Sx)-RS*FKKFA-Z; X-LKR-C(Sx)-VS*FKKFA-Z; X-LKR-C(Sx)-WS*FKKFA-Z; X- LKV-C(Sx)-AS*FKKFA-Z; X-LKW-C(Sx)-AS*FKKFA-Z; X-LLR-C(Sx)-AS*FKKFA-Z; X-L R-C(Sx)-AS*FKKFA-Z; X-LPR-C(Sx)-AS*FKKFA-Z; X-LQR-C(Sx)-AS*FKKFA-Z; X-LRR-C(Sx)-AS*FKKFA-Z; X-LVR-C(Sx)-AS*FKKFA-Z; X-LWR-C(Sx)-AS*FKKFA- Z; X- KR-C(Sx)-AS*FKKFA-Z; X-PKR-C(Sx)-AS*FKKFA-Z; X-QKR-C(Sx)- AS*FKKFA-Z; X-RKR-C(Sx)-AS*FKKFA-Z; X-VKR-C(Sx)-AS*FKKFA-Z; X-WKR- C(Sx)-AS*FKKFA-Z; X-C(Sx)-PGS*FRR-Z; X-C(Sx)-AS*FRR-Z; X-C(Sx)- [Nle]GS*FRRR-Z; X-C(Sx)-AGS*FRRR-Z; X-C(Sx)-DGS*FRRR-Z; X-C(Sx)-EGS*FRRR- Z; X-C(Sx)-FGS*FRRR-Z; X-C(Sx)-GGS*FRRR-Z; X-C(Sx)-HGS*FRRR-Z; wherein X- is H or acetyl; and Z is OH or H2.

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-C(Sx)-IGS*FRRR-Z; X-C(Sx)-KGS*FRRR-Z; X- C(Sx)-LGS*FRRR-Z; X-C(Sx)-NGS*FRRR-Z; X-C(Sx)-P[Nle]S*FRRR-Z; X-C(Sx)- PAS*FRRR-Z; X-C(Sx)-PDS*FRRR-Z; X-C(Sx)-PES*FRRR-Z; X-C(Sx)-PFS*FRRR-Z; X- C(Sx)-PGS*[Nle]RRR-Z; X-C(Sx)-PGS*ARRR-Z; X-C(Sx)-PGS*DRRR-Z; X-C(Sx)- PGS*ERRR-Z; X-C(Sx)-PGS*F[Nle]RR-Z; X-C(Sx)-PGS*FARR-Z; X-C(Sx)-PGS*FDRR- Z; X-C(Sx)-PGS*FERR-Z; X-C(Sx)-PGS*FFRR-Z; X-C(Sx)-PGS*FGRR-Z; X-C(Sx)- PGS*FHRR-Z; X-C(Sx)-PGS*FIRR-Z; X-C(Sx)-PGS*FKRR-Z; X-C(Sx)-PGS*FLRR-Z; X- C(Sx)-PGS*FNRR-Z; X-C(Sx)-PGS*FPRR-Z; X-C(Sx)-PGS*FQRR-Z; X-C(Sx)- PGS*FR[Nle]R-Z; X-C(Sx)-PGS*FRAR-Z; X-C(Sx)-PGS*FRDR-Z; X-C(Sx)-PGS*FRER- Z; X-C(Sx)-PGS*FRFR-Z; X-C(Sx)-PGS*FRGR-Z; X-C(Sx)-PGS*FRHR-Z; X-C(Sx)- PGS*FRIR-Z; X-C(Sx)-PGS*FRKR-Z; X-C(Sx)-PGS*FRLR-Z; wherein X- is H or acetyl; and Z is OH or H2. In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-C(Sx)-PGS*FRNR-Z; X-C(Sx)-PGS*FRPR-Z; X- C(Sx)-PGS*FRQR-Z; X-C(Sx)-PGS*FRR[Nle]-Z; X-C(Sx)-PGS*FRRA-Z; X-C(Sx)- PGS*FRRD-Z; X-C(Sx)-PGS*FRRE-Z; X-C(Sx)-PGS*FRRF-Z; X-C(Sx)-PGS*FRRG-Z; X-C(Sx)-PGS*FRRH-Z; X-C(Sx)-PGS*FRRI-Z; X-C(Sx)-PGS*FRRK-Z; X-C(Sx)- PGS*FRRL-Z; X-C(Sx)-PGS*FRRN-Z; X-C(Sx)-PGS*FRRP-Z; X-C(Sx)-PGS*FRRQ-Z; X-C(Sx)-PGS*FRRR-Z; X-C(Sx)-PGS*FRRV-Z; X-C(Sx)-PGS*FRRW-Z; X-C(Sx)- PGS*FRVR-Z; X-C(Sx)-PGS*FRWR-Z; X-C(Sx)-PGS*FVRR-Z; X-C(Sx)-PGS*FWRR-Z; X-C(Sx)-PGS*GRRR-Z; X-C(Sx)-PGS*HRRR-Z; X-C(Sx)-PGS*IRRR-Z; X-C(Sx)- PGS*KRRR-Z; X-C(Sx)-PGS*LRRR-Z; X-C(Sx)-PGS*NRRR-Z; X-C(Sx)-PGS*PRRR-Z; X-C(Sx)-PGS*QRRR-Z; X-C(Sx)-PGS*RRRR-Z; X-C(Sx)-PGS*VRRR-Z; X-C(Sx)- PGS*WRRR-Z; X-C(Sx)-PHS*FRRR-Z; X-C(Sx)-PIS*FRRR-Z; X-C(Sx)-PKS*FRRR-Z; X-C(Sx)-PLS*FRRR-Z; X-C(Sx)-PNS*FRRR-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-C(Sx)-PPS*FRRR-Z; X-C(Sx)-PQS*FRRR-Z; X- C(Sx)-PRS*FRRR-Z; X-C(Sx)-PVS*FRRR-Z; X-C(Sx)-QGS*FRRR-Z; X-C(Sx)- RGS*FRRR-Z; X-C(Sx)-VGS*FRRR-Z; X-C(Sx)-[Nle]S*FRRR-Z; X-C(Sx)-AS*FRRR-Z; X-C(Sx)-DS*FRRR-Z; X-C(Sx)-ES*FRRR-Z; X-C(Sx)-FS*FRRR-Z; X-C(Sx)- GS*[Nle]RRR-Z; X-C(Sx)-GS*ARRR-Z; X-C(Sx)-GS*DRRR-Z; X-C(Sx)-GS*ERRR-Z; X- C(Sx)-GS*F[Nle]RR-Z; X-C(Sx)-GS*FARR-Z; X-C(Sx)-GS*FDRR-Z; X-C(Sx)- GS*FERR-Z; X-C(Sx)-GS*FFRR-Z; X-C(Sx)-GS*FGRR-Z; X-C(Sx)-GS*FHRR-Z; X- C(Sx)-GS*FIRR-Z; X-C(Sx)-GS*FKRR-Z; X-C(Sx)-GS*FLRR-Z; X-C(Sx)-GS*FNRR-Z; X-C(Sx)-GS*FPRR-Z; X-C(Sx)-GS*FQRR-Z; X-C(Sx)-GS*FR[Nle]R-Z; X-C(Sx)- GS*FRAR-Z; X-C(Sx)-GS*FRDR-Z; X-C(Sx)-GS*FRER-Z; X-C(Sx)-GS*FRFR-Z;

wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-C(Sx)-GS*FRGR-Z; X-C(Sx)-GS*FRHR-Z; X- C(Sx)-GS*FRIR-Z; X-C(Sx)-GS*FRKR-Z; X-C(Sx)-GS*FRLR-Z; X-C(Sx)-GS*FR R-Z; X-C(Sx)-GS*FRPR-Z; X-C(Sx)-GS*FRQR-Z; X-C(Sx)-GS*FRR[Nle]-Z; X-C(Sx)- GS*FRRA-Z; X-C(Sx)-GS*FRRD-Z; X-C(Sx)-GS*FRRE-Z; X-C(Sx)-GS*FRRF-Z; X- C(Sx)-GS*FRRG-Z; X-C(Sx)-GS*FRRH-Z; X-C(Sx)-GS*FRRI-Z; X-C(Sx)-GS*FRRK-Z; X-C(Sx)-GS*FRRL-Z; X-C(Sx)-GS*FRRN-Z; X-C(Sx)-GS*FRRP-Z; X-C(Sx)-GS*FRRQ- Z; X-C(Sx)-GS*FRRR-Z; X-C(Sx)-GS*FRRV-Z; X-C(Sx)-GS*FRRW-Z; X-C(Sx)- GS*FRVR-Z; X-C(Sx)-GS*FRWR-Z; X-C(Sx)-GS*FVRR-Z; X-C(Sx)-GS*FWRR-Z; X- C(Sx)-GS*GRRR-Z; X-C(Sx)-GS*HRRR-Z; X-C(Sx)-GS*IRRR-Z; X-C(Sx)-GS*KRRR-Z; X-C(Sx)-GS*LRRR-Z; X-C(Sx)-GS* RRR-Z; X-C(Sx)-GS*PRRR-Z; X-C(Sx)-GS*QRRR- Z; X-C(Sx)-GS*RRRR-Z; X-C(Sx)-GS*VRRR-Z; X-C(Sx)-GS*WRRR-Z; X-C(Sx)- HS*FRRR-Z; X-C(Sx)-IS*FRRR-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, the metal-binding compound of the present invention is selected from the group consisting of: X-C(Sx)-KS*FRRR-Z; X-C(Sx)-NS*FRRR-Z; X- C(Sx)-PS*FRRR-Z; X-C(Sx)-QS*FRRR-Z; X-C(Sx)-RS*FRRR-Z; X-C(Sx)-VS*FRRR-Z; X-[Nle]-C(Sx)-GS*FRRR-Z; X-A-C(Sx)-GS*FRRR-Z; X-D-C(Sx)-GS*FRRR-Z; X-E- C(Sx)-GS*FRRR-Z; X-F-C(Sx)-GS*FRRR-Z; X-G-C(Sx)-GS*FRRR-Z; X-H-C(Sx)- GS*FRRR-Z; X-I-C(Sx)-GS*FRRR-Z; X-K-C(Sx)-GS*FRRR-Z; X-L-C(Sx)-GS*FRRR-Z; X-N-C(Sx)-GS*FRRR-Z; X-Q-C(Sx)-GS*FRRR-Z; X-R-C(Sx)-GS*FRRR-Z; X-V-C(Sx)- GS*FRRR-Z; X-P-C(Sx)-GS*FRRR-Z; X-LD-C(Sx)-AS*LSLSLSSANSLYDD-Z; X- SGDED-C(Sx)-AS*IADMDFSAL-Z; X-SGDEDFAS*I-C(Sx)-DMDFSALLSQ-Z; X- EDFAS*I-C(Sx)-DMDFSALLSQISS; X-SLDSSSLAL-C(Sx)-LS*AANSLYDD-Z; X- SLDSSSLS*L-C(Sx)-LASANSLYDD-Z; X-DLGYAKDVDQGS*L-C(Sx)-TSFVGTLQY- Z; X-RRKDLHDDEEDEA[Nle]S*I-C(Sx)-A-Z; X-KKKVSGQLIDS*[Nle]-C(Sx)- NSFVGTRSY-Z; X-KKKVSGQLIDS[Nle]-C(Sx)-NS*FVGTRSY-Z; wherein X- is H or acetyl; and Z is OH or H ₂ .

In some embodiments, C(Sx) represents an amino acid of forrnul

each R is independently hydrogen, or -SO2X', wherein at least one R group is -SO2X';

X' is -OR" or -XR ^" R ^'" :

R' is hydroxyl, amino, or thiol;

R"' is hydrogen or aikyi; and

n is \, 2 or 3.

In some embodiments, R' is hydroxyl.

In some embodiments, at least one R is hydrogen. In some embodiments, all instances of R represent hydrogen. In some embodiments, one and only one R is -8O2X' .

In some embodiments, n is 1 ,

In some embodiments, R' is hydroxyl and one and only one R is -SO2X' .

In some embodiments, C(Sx) represents an amino acid of formula (II):

, wherein

X' is -OR" or -X ^' R ^" :

R" is Ci-6 alkyl; and

R.'" is hydrogen or Ci-6 alky] .

odiments, C(Sx) represents an amino acid of formula (III):

The metal-binding compounds of the present invention undergo chelation-enhanced fluorescence (CHEF) upon binding to Mg ^1÷ . The fluorescence of the amino acid residues in accordance with the present invention increases by at least about 100%, when bound to Mg ²⁺ . In some embodiments, fluorescence of the amino acid residues increases by at least about 200%, when bound to Mg ^2"*" . In some embodiments, fluorescence of the amino acid residues increases by at least about 400%, when bound to Mg ²⁺ .

The compounds of the invention can be synthesized using peptide synthesis (solid phase or solution phase). Standard peptide synthesis is well-known in the art. See, for example, Fmoc Solid Phase Peptide Synthesis— A Practical Approach, Oxford University Press, 2003, Eds W. C. Chan and P. D. White (ISBN 0 19 963 724 5); and The Chemical Synthesis of Peptides, Clarendon Press, Oxford, 1994, Jones, J. (ISBN 0 19 855839 2).

In some embodiments, the metal binding amino acid residue (e.g., -C(Sx)-) of the chemosensors is -2 or +2 residues from the amino acid (e.g., tyrosine, serine or threonine) that is phosphorylated by the kinase. In some embodiments, the metal binding amino acid residue of the chemosensors is -3 or +3 residues from the amino acid that is phosphorylated by the kinase. Negative (-) positions indicate the compound is located on the N-terminal side of the amino acid that is phosphorylated by the kinase, while positive (+) positions indicate the compound is located on the C-terminal side of the amino acid that is

phosphorylated by the kinase.

The metal binding amino acid residue comprises a fluorophore that can be used as readout when positioned appropriately within the optimized peptide substrate to create fluorescence-based kinase assays. Examples of fluorophores include, but are not limited to, 5-FAM (5-Carboxyfluorescein; Caliper EZ Reader, Perkin Elmer and IMAP from Molecular Devices), Coumarin and Fluorescein (Z-Lyte, Thermo Fisher), pyrene, perylene, borodiazaindacene (BODIP Y™), cyanine dye 2, cyanine dye 3, cyanine dye 5 and Alexa dyes.

In some embodiments, the metal binding amino acid residue is an amino acid of formula I, II, or III.

In some embodiments, the metal binding amino acid residue is Sox, C-Sox, or C-Clk. In some embodiments, the metal binding amino acid residue is C-Sox.

Phosphorylation sites in accordance with the present invention include hydroxyl- containing amino acids within kinase recognition motifs. Examples include naturally occurring hydroxyl-containing amino acid residues, such as serine, threonine, tyrosine and histidine and non-naturaily occurring hydroxyl-containing amino acid residues.

The peptide sensors according to the present invention have at least one kinase recognition sequence. In some cases, the residues on one side of the side chain to be phosphorylated are more important, however, it is clear that more residues might confer additional specificity. This specificity could play an important role in any assays that assess kinases in complex media, in particular in live cells or cell lysates where all cellular enzymes have the potential to interact with the substrate peptide. Added recognition elements can target the sensor more specifically to the desired kinase in competitive assays where several different kinases or isozymes of one kinase are present. Including additional amino acid sequence or altering the order of residues in the sequence can also improve the kinetic properties of the substrate, for example resulting in lower Km, higher Vmax or kcat etc. values.

Exemplary Synthetic Procedures

The chemosensor peptides were constructed in a variety of ways.

In the one approach, Fmoc-based solid-phase peptide synthesis (SPPS) was utilized to assemble the intact peptide that includes an appropriately placed cysteine protected with an acid-labile group. After selective on-resin suifhydryl group deprotection with acid, the free thiol is alkylated with Sox -Br. Standard TFA cleavage from the resin and concomitant removal of all side chain protecting groups reveal the desired chemosensor with excellent conversion to the alkylated product (>95%). The solid support-based alkylation is particularly valuable when utilizing automated SPPS or SPOT34 synthesis to generate libraries of peptides in a rapid manner.

In some instances, peptides were synthesized on Fmoc-PAL-PEG-PS resin (Applied Biosystems, 0.19 mmol/g) using on-resin alkylation. The resin was swelled in CH2CI2 (DCM) (5 min) and then DMF (5 min) prior to synthesis. The amino acids were coupled according to the following procedure: Fmoc deprotection (20% 4-methylpiperidine in DMF, 3-5 min), rinsing step (DMF), coupling step (amino aci d/PyB OP/HOB t/DIE A, 6:6:6:6, 0.15 M in DMF, 30-45 min), rinsing step (DMF, then DCM). The coupling was repeated if necessary as determined by the T BS test. At the end of the synthesis, the Fmoc group was removed with 20%) 4-methylpiperidine in DMF, and the resin was rinsed with DMF. The resin-attached free amines were capped by exposure to Ac ₂ 0 (20 equiv.) and pyridine (20 equiv.) in DMF for 30 min. The resin was rinsed with DMF and then DCM, and subjected to 20% 4- methylpiperidine in DMF. The resin was finally washed with DMF, DCM, and MeOH, and dried under vacuum.

Resin-attached peptides (50 mg, 0.0095 mmol, 1 equiv) incorporating Cys-(Mmt) (Mmt = 4-methoxytrityl) were swelled in DCM and then DMF. The Mmt protecting group was removed from the resin-bound peptide by bubbling N2 through a solution of 1%> TFA and 5% TIS in DCM. The resin was washed with DCM and DMF. Anhydrous DMF was added to the resin followed by freshly distilled tetramethylguanidine (0.0475 mmol, 5 equiv.). The mixture was incubated for 2-3 min. Sox-Br (3 equiv.) was dissolved in anhydrous DMF and added to the resin. After ca. 12 h of reaction time, the excess reagents were drained and the resin was washed with DMF, DCM, MeOH, and DCM.

Alternatively, a building block approach may be used to prepare a chemosensor peptide. In this case, the synthesis of the building block, Fmoc-C(Sox[TBDPS])-OH, may commence with the aliylation of commercially available amino acid, followed by removal of the p-methoxytrityl (Mmt) masking group. The sulfhydryl is then alkylated with Sox-Br in excellent yield (95%). Lastly, Pd(II)-assisted deallylation produces the desired amino acid that was subsequently used in standard Fmoc-based SPPS (described above) to produce sensors in excellent yields. Peptide identities and purities were confirmed via matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) or electrospray ionization mass spectrometry together with high performance liquid chromatography analysis. The synthesis of C-Sox, and therefore of chemosensor peptides, is facile since a chiral starting material is used.

Peptides were purified by preparative reversed-phase HPLC using dual wavelength detection (228 nm: amide; 360 nm: C-Sox). Peptide concentrations were then determined using UV-vis spectrophotometry based on the C-Sox-cbromophore extinction coefficient of 8247M-1 cm-1 at 355 nM in 0.1 M NaOH and 1 mM EDTA.

Assays

Fluorescence of the peptides was measured in the presence and absence of Mg ^{2 f} . The reporter functionality is the unnatural chromophore (e.g., C-Sox) that undergoes ch elation - enhanced fluorescence (CHEF) upon metal binding. The Mg ² ~ affinity of the chemosensors is low (KD ^:::: 100-300 mM) when the phosphate group is not present, while phosphorylation, significantly increases Mg ^1÷ affinity ( Kv> 0. 1 - 20 mM). Thus, at a selected

Mg ²⁺ concentration, a large portion of phosphopeptide exists in the bound, fluorescent state. In the presence of saturated MgCl ₂ , the Sox peptides exhibit a maximum emission at 485 nm with a maximum excitation at 360 nm. In addition, these peptides maintain striking luminescence properties of the fluorophore. The extinction coefficient and quantum yield values for representative chemosensor-Mg ^{2 "} complexes are determined following quantitative amino acid analysis.

To solve for enzyme kinetic parameters for this reaction, determination of the initial rate of product formation from the increase in fluorescence intensity is necessary. With this sensor, a correction for the decrease in fluorescence intensity due to the starting material being consumed is needed to determine the rate of product formation from the initial slope. The fluorescence intensity at any given point can be determined from the following equation:

/(/) / s .Yi/} · / />(/) (1)

where I(t) is the fluorescence intensity, S(t) is the amount of substrate in μΜ, P(t) is the amount of product in μΜ, fs is the fluorescence intensity per μΜ of substrate, and fp is fluorescence intensity per μΜ of product. The amount of substrate and product at any given point are related by:

S(l) ^■ !'{() .S o (2)

where So is the initial amount of substrate. Substitution of (2) into (1) followed by

rearrangement, yields:

(3)

The initial velocity of the reaction is the change in the amount of product over time, so taking the derivative of (3) with respect to time gives: dli i)

_ d P(i) _ ~ f

______ ₌

(4)

The initial slope of the reaction, dl(t)/dl, was measured within the first 5% of substrate turnover. The constants fp and fs were calculated from the slope of a line of fluorescence intensity versus concentration of P and S, respectively. A linear fit of a Hanes plot ([S]/V vs. V) was used to find Km and Vma .

The sensors of the present invention can be used in a method for detecting kinase activity.

In some embodiments, the method for detecting kinase activity, comprising the steps of:

a) providing a compound of the invention;

b) contacting the compound wit a sample comprising Mg ² *, a phosphate source, and a kinase; and

c) analyzing for the presence of a phosphorylated peptide product;

In some embodiments, the method for detecting kinase activity, compri sing the step of:

determining phosphorylation of a compound of the invention using fluorescence of the compound.

Serine/threonine and tyrosine kinases can be used in the present invention. Exemplary Ser/Thr kinases include cAMP dependent protein kinase, protein kinase C, Ca/calmodulin- dependent kinases, AMP activated kinase, s6 kinases, eIF-2 kinases, p34 ^cdc2 protein kinase, mitogen-activated protein kinases, casein kinase-2, casein kinase- 1, glycogen synthase kinase-3, AURORA, Akt, Erk, ink, CDK2, and exemplar}- Tyr-specific protein kinases include Src Abi, insulin receptor kinase and EGFR among others.

For in vitro applications, the concentration of kinase can range from about 0.5 nM to about 100 nM, typically not more than about 500 nM, and preferably not more than about 250 nM. The concentrations of sensor can vary, but usually ranges between about 0.01 μΜ to 0.1 mM. Adenosine 5 ' ^' -triphosphate (ATP) is the preferred source of phosphate, in stock solutions of about. 10-100 mM. Because most, kinases have Km values for ATP in the range of about 10- 150 μΜ, saturating concentrations of ATP are used to arrive at values of Km and Vmax for the substrates. Since this assay format can be used with any ATP concentration, 1 mM or -physiological concentrations are used unless being titrated. For in vivo applications, when the sensor is internalized into a cell, sufficient kinases, Mg ²⁺ and phosphate sources exist in the cytosoi. For in vivo sensing, a cellular internalization sequence can be included in the sensor design. Suitable cellular internalization sequences include Penetratins, HIV-Tat domains and poly-arginine sequences (Lindgren, M. et al. Trends Pharmacol. Sci. 2000, 21 , 99-103; Wadia, J. S. et ai. Ctirr Opm. Biotech. 2002, 13, 52-56; Carrigan, C. N. Atialyl.

Biochem. 2005, 341 , 290-298).

For applications in which the kinase is dependent on cofactors, a source of cofactor is also included in the sample. For example, for certain PKC family enzymes, sources of Ca ²⁺ , phospholipid and diacylglycerol are needed.

The sensors of the present invention can be used to measure a kinase reaction continuously, as the metal-binding amino acid residues do not experience photobleaching.

EXAMPLES

General Experimental

A fluorescence-based assay may be performed to determine the activity of a given protein

kinase. This involves incubating the protein kinase with a suitable fluorescent peptide substrate and the co-substrates in an appropriate buffer and monitoring the change in fluorescence over time. Generally, a reaction mixture is prepared in the absence of a substrate peptide, which is then added to initiate the assay. The assay may be performed in a fluorimeter, where usually a single reaction is monitored at a time, or in a plate reader where multiple reactions may be monitored simultaneously.

This experimental may be modified based on various optimized reaction conditions as detailed in Examples 1-22, Microliter plates can be 96-, 384- or 1536-well formats. The final reaction volume is based on the manufacturers recommendations for each plate product, which may also vary based on the type of experiment, for example, 25-125uL for Corning 96-well Half Area Fiat Bottom Polystyrene NBSTM Microplates (Cat #3642) or 5-50uL for Corning 384-well Low Volume Flat Bottom Polystyrene NBSTM Microplates (Cat #3824).

The reactions in each plate are incubated at the specified temperature and the fluorescence signal is monitored in kinetic mode using an appropriate microplate reader with an excitation wavelength of 365 nm and an emission wavelength of 485 nm. Somewhat lower or higher wavelengths can also be used as long as the resulting signal is sufficient. Readings are made at preset intervals (e.g., every 5-30 seconds) over the desired time period (typically 30 min to 2 hours). Although the assay is most commonly monitored kinelically, it is also possible to stop the reactions using 5M Guanidine Hydrochloride to read the reactions in end point mode.

Setting up a reaction initiated with the peptide substrate:

1. Prepare Solution A (Assay reaction mixture comprises all reagents but the Sox-based Peptide Substrate) and incubate on ice:

2. Assay Reaction mixture:

i. Add 40 μΐ, of the reaction mixture to each well of the 96-well plate, pre- warmed at 30 °C.

ii. Incubate reactions at 30 °C in the plate reader for 5 minutes,

iii. Initiate the reactions with 10 uL of the 5x peptide solution, pre- warmed to 30 °C.

iv. Monitor the change in fluorescence emission continuously at 485 nm during the

linear phase of the reaction (conversion of the first 5-10% of the substrate to product) where readings are taken every 5-30 seconds (most plate readers have a setting that

allows measurements to be determined at set time intervals).

Alternatively, solution B (Assay reaction mixture comprises all reagents but the protein kinase enzyme) or solution C (Assay reaction mixture comprises all reagents but the ATP) could be used and the reactions would be initiated in step 4 by addition of the enzyme or ATP respectively.

Example 1: Receptor Tyrosine Kinase Activity

Reaction Conditions: 50 raM HEPES, pH 7.4

lO mM MgCh

0.5 mM EGTA

10 μΜ So -based Peptide Substrate

1 raM ATP

1 niM DTT

0.01% Brij-35

5 nM Carna Bioscience kinase (or alternative enzyme sources) 30 minute reaction at 30 °C

* + 3 to 300 μΜ nCh

* Used for kinases that require MsnCb

Receptor-type Tyrosine Kinases:

ALK (cat# 08-518, lot# 09CBS-0698F)

EML4-ALK (cat# 08-516, lot# 09CBS-0483D

NPM1-ALK (cat# 08-517, iot# 08CBS-1302D)

ALK (G1269A) (cat# 08-537, lot# 12CBS-0530B)

ALK (Tl 151 _L1 152 ins T)(cat# 08-539, lot# 12CBS-0810B)

AXL (cat# 08-107, lot# 09CBS-0686J)

EGFR (cat# 08-1 15, lot# 13CBS-0005P)*

EGFR (d746-750) (cat# 08-527, lot# 11CBS-0259E)*

EGFR (d746-750/T790M) (cat# 08-528, lot# 11CBS-0285H)*

EGFR (L858R) (cat# 08-502, iot# 09CBS-0597E)*

EGFR (T790M/L858R) (cat# 08-510, \ot# 11CBS-0004B)*

EPHA1 (cat# 08-119, lot# 10CBS-0048B)

EPHA2 (cat# 08-121, lot# 08CBS-0480L)

EPHA4 (cat# 08-123, lot# 08CBS-1014B)

EPHA7 (cat# 08-126, lot# 07CBS-2615J)

EPFIA8 (cat# 08-127, lot# 07CBS-1584G)

EPFIB l (cat# 08-128, lot# 09CBS-1 144B)

EPHB2 (cat# 08-129, \ot# 07CBS-2306G)

EPHB3 (cat# 08-130, iot# 06CBS-3285L)

EPHB4 (cat# 08-131, lot# 07CBS-3269F)

FGFR1 (cat# 08-133, lot# 12CBS-0123J) FGFR2 (cat# 08-134, lot# 07CBS-2468F)

FGFR3 (cai# 08-135, k>†.# 12CBS-0744 )

FGFR3 (K650E) (cat# 08-501, lot# 07CBS-1740H)

FGFR3 (G697C) (cat# 10-1-0000-1, lot# 001)*

FGFR4 (cat# 08-136, lot# 12CBS-0076F)

FLT1 (cat# 08-189, lot# 09CBS-0092E)

FLT4 (cat# 08-190, lot# 13CBS-0858B)

HER2 (cat# 08-016, lot# 10CBS-0748T)*

HER4 (cat# 08-1 18, lot# 08CBS-0652P)

IGF1R (cat# 08-141 , lot# 07CBS-0753B)

INSR (cat# 08-142, lot# 07CBS-0620K)

KDR (cat# 08-191, lot# 13CBS-0442G)

KIT (cat# 08-156, lot# 11CBS-1067L)

LT (cat.# 08-106, !ot# 06CBS-2044L)

MET (cat# 08-151, lot# 10CBS-1118N)

MUSK (cat# 08-153, lot# 07CBS-0004J)*

PDGFRa (cat# 08-157, lot# 009BS-1.164B)

PDGFRp (cat# 08-158, lot# 08CBS-0282H)

RET (cat# 08-1 59, lot# 13CBS-0134B)

RON (cat# 08-152, lot# 08CBS-0903B)

T1E2 (cat# 08-185, lot# 07CBS-2698H)

TRKA (cat# 08-186, lot# 13CBS-0565M)

TRKB (cat# 08-187, lot# 09CBS-0265G)

TRKC (cat# 08-197, !ot# 08CBS-0549F)

* Indicated enzyme obtained from ProQinase (other sources of kinases have also been validated)

Example 2: Reeepior Tyrosine Kinase Activity

Reaction Conditions:

20 niM HEPES, pH 7.4

5 niM MgCLi

0.1 mM EGTA

10 μΜ Sox-based Peptide Substrate

1 mM ATP 0.2 niM DTT

0.01% Brij-35

5 nM Caraa Bioscience kinase

Example 3: CMGC Serine/Threonine Ki ase Activity

Reaction Conditions:

50 niM HEPES, pH 7.4

lO mM MgCh

0,5 mM EGTA

10 μ.Μ So -based Peptide Substrate

1 mM ATP

1 mM DTT

0.01% Brij-35

5 nM Carna Bioscience kinase

CM GC Seri tie Threonine Ki nases :

DYRKIA (cat# 04-130, lot# 10CBS-0742H)

DYRK1 B (cat# 04-131, lot# 13CBS-0831D)

ERK1 (cat# 04-142, lot# 11CBS-0072E)

ERK2 (cat# 04-143, lot# 10CBS-0740E)

ERK5 (cat# 04-146, lot# 13CBS-0805B)

ERK7 (cat# 04-147, lot# 09CBS-0079E)

JNK1 (cat# 04-163, lot# 09CBS-0154B)

JNK2 (cat# 04-164, lot# 07CBS-1214G)

.IN (cat# 04-150, iot# 09CBS-0155G)

p38a (cat# 04-152, lot# 07CBS-0319H)

ρ38β (cat# 04-153, lot# 07CBS-0172D)

ρ38γ (cat# 04-155, lot# 07CBS-2630B)

ρ38δ (cat# 04-154, lot# 07CBS-2631B)

MK2 (cat# 07-142, lot# 10CBS-0101B)

Example 4: AGC Serine/Threonine Kinase Activity AQT0074 (Ac-A K ERAYSF- C(Sx)-HHA-amide)

Reaction Conditions: 50 raM HEPES, pH 7.4

lO mM MgCh

0.5 mM EGTA

10 μΜ So -based Peptide Substrate 1 raM ATP

1 niM DTT

0.01% Brij-35

5 iiM Carna Bioscience kinase

*20 raM HEPES, pH 7.4

lO mM MgCh

0.1 raM EGTA

10 μΜ Peptide

0.1 mM ATP

1 mM DTT

0.01% Brij-35

0.3 mM CaCh

0.5 .Lig/ml phosphatidylserine

0.1 ,ug/m] diacylglycerol

5 nM Carna Bioscience kinase

AGC Serine/Threonine Kinases:

AKT1 (cat# 01-101, lot# 08CBS-0149J) A T2 (cat# 01 -102, lot# 07CBS-3271B) AKT3 (cat# 01-103, lot# 09CBS-0605G) CRIK (cat# 01-104, lot# 11CBS-1034B) p70S6K (cat# 01-176, lot# 14CBS-0617B) PASK (cat# 02-128, lot# 07CBS-1805E) PHKG2 (cat# 02-153, lot# 10CBS-0646B) PKACa (cat# 01-127, lot# 10CBS-0315N) PKACy (cat# 01 -129, lot# 12CBS-0329B) PKCa (cat# 01-133, lot# 09CBS-0233H)* PKC5 (cat# 01-135, iot# 07CBS-2223B)* PKCy (cat# 01-137, lot# 07CBS-2676F)* SGK (cat# 01 -158, iot# 09CBS-0646F) SGK2 (cat# 01-159, lot# 08CBS-0830B)

SGK3 (cat# 01-160, lot# 08CBS-0586B)

RSK1 (cat# 01-149, lot# 08CBS-0354K)

Example 5: ABL Substrate Time Course

Reaction Conditions:

20 niM HEPES, pH 7.4

5 mM MgCh

I mM ATP

1 mM DTT

0.01% Brij-35

3.3 nM Protein Kinase:

ABL, amino acids 2-1 130 Cama Bioscience (cat# 08-001, lot# 14CBS-0812 E)

ARG, amino acids 2-52, 74-1182 Carna Bioscience (cat# 08-102, lot# 07CBS-1313 B)

ABL(T315I), amino acids 2-1 130 Carna Bioscience (cat# 08-093, lot# 08CBS-1142 B)

ABL,(E255K), amino acids 2-1 130 Carna Bioscience (cat# 08-094, lot# 08CBS-0324 B)

PDGFRp, amino acids 557-1106 Carna Bioscience (cat# 08-158, lot# 08CBS-0282 H)

KIT, amino acids 544-976 Carna Bioscience (cat# 08-156, lot# 1 lCBS-1067 L)

10 μΜ So -based Peptide Substrate:

AQT0030 ( Ac-KKGEAIYA~C(Sx)~PF AKKK-NH2)

AQT0031 (Ac-KKGE-C(Sx)-IYAAPFAKKK- H ₂ )

AQT0032 (Ac-E-C(Sx)-IYAAPFAKKK- H ₂ )

AQT0033 (Ac-GAPE-C(Sx)-IYATPGAKKK-NH ₂ )

AQT0034 (Ac-GAPE TYA-C(Sx)-PGAKKK- H ₂ )

AQT0035 ( Ac-E-C(Sx)-! Y A APF-NH2

AQT0036 ( Ac-E-C(Sx)-IYA- H ₂

AQT0037 (Ac-E-C(Sx)-IY~NH2)

AQT0038 (Ac-C(Sx)-I Y- H2)

AQT0039 ( Ac-KKGEATYA-C(Sx)-PF-NH ₂ )

Reaction was run at 30°C.

Example 6: Soluble Tyrosine mase Activity

Reaction Conditions:

20 mM HEPES, pH 7.4

- Ill - 5 ffiM MgCh

0. 1 mM EGTA

10 μΜ Sox-based Peptide Substrate

I I M ATP

0.2 mM DTT

0.01% Brij-35

5 ηΜ Carna Bioscience kinase

30 minute reaction at 30 °C

* + 3-300 μ.Μ MnCi ₂

Soluble Tyrosine Kinases:

ABL (cat# 08-001, lot# 14CBS-0812E)

ABL (E255K) (cat# 08-094, lot# 08CBS-0324B)

ABL (T315I) (cat# 08-093, lot# 1 1 CBS-0498J)

ACK (cat# 08-196, lot# 13CBS-0886B)

ARG (cat# 08-102, lot# 07CBS-1313B)

BLK (cat# 08-164, lot# 08CBS-1084B)

BMX (cat# 08-179, lot# 08CBS-0426G)

BI K (cat# 08-165, lot# 07CBS-2947D)

BTK (cat# 08-180, lot# 14CBS-0619F)

CSK (cat# 08-1 1 1, lot# 12CBS-0040E) *

FAK (cat# 08- 137, iot# 12CBS-0121E)

FER (cat# 08-139, lot# 10CBS-0584B)

FGR (cat# 08- 166, lot# 10CBS-0459B)

FRK (cat# 08-167, lot# 08CBS-1 1 52G)

FYN (cat# 08-168, iot# 1 1CBS-1043E)

PICK (cat# 08-169, lot# 1 1CBS-0575B)

ITK (cat# 08-181 , lot# 13CBS-0356L)

JAKl (cat# 08-144, lot# 1 1CBS-0144T)

JAK2 (cat# 08-514, iot.# 08CBS-1002D)

JAK3 (cat# 08-046, iot# 1 1CBS-0891E)

LCK (cat# 08- 170, lot# 10CBS-0924P)

SRC (cat# 08-173, lot# 10CBS-1 134F)

SYK (cat# 08-176, lot# 13CBS-0926E) YES (cat# 08-175, lot# 09CBS-0412E)

Example 7: EGFR Assay Optimization

Reaction Conditions (except where titrated):

20 mM HEPES, pH 7.4

1 mM ATP

1 mM DTT

0.01% Brij-35

0, 1 mM EGTA

lO mM MgCh

3 μΜ \ 1Γ:(Ί :

30 μΜ AQTOOOl (Ac-EEEEYI-C(Sx)-IV-NH2) Sox-based Peptide Substrate

2 nM EGFR, amino acids 669-1210

Carna Bioscience (cat. & iot #: 08-1 15, 13CBS-0005P)

Reaction was run at 0 ( for 2 hours

Example 8: Screen of Tyr Kinase Substrates with Tee

Reaction Con di ions.

50 mM HEPES, pH 7.5

1 mM ATP

1 mM DTT

0.01% Brij-35

0.5 mM EGTA

lO mM MgCh

10 μΜ Sox-based Peptide Substrate

5 nM BTK, amino acids 2-659, Carna Bioscience (cat. & lot #: 08-080, 14CBS-0619F) Reaction was run at 30°C for 60 minutes.

Example 9: Serine/Threonine Kinase Activity Measured Using AQT's Panel of

Substrates

Reaction Conditions:

50 mM HEPES, pH 7.5

1 mM ATP

I mM DTT 0.01% Brij-35

0.5 ttiM EGTA

lO mM MgCh

10 μΜ So -based Peptide Substrate

5 nM Λ ^' Π , amino acids 104-480, Carna Bioscience (cat. & lot #: 01 - 101 , 08CBS-0149J) 5 nM AKT2, amino acids 120-481, Carna Bioscience (cat. & lot #: 01 · 102, 07CBS-3271B) 5 nM AKT3, amino acids 108-479, Carna Bioscience (cat. & lot #: 01- 103, 09CBS-0605G) Reaction run at 30°C for 60 min.

Example 10: CHE I (CAMK Group) Serine/Threonine Kinase Activity

Reaction Conditions:

50 fflM HEPES, pH 7.5

1 mM ATP

I mM DTT

0.01 % Brij-35

0.5 mM EGTA

l O mM MgCk

10 uM CHK Sox-based peptide substrate

5nM CHK1 , amino acids 1-476, CARNA BS (cat. & lot #: 02-1 17, 08CBS-8008H)

Reaction was run at 30°C for 120 minutes.

Example 11: CHE 2 (CAMK Group) Serine/Threonine Kinase Activity

Reaction Conditions:

50 mM HEPES, pH 7.5

1 mM ATP

1 mM DTT

0.01% Brij-35

0,5 mM EGTA

lO mM MgCh

10 μΜ CHK Sox-based Peptide Substrate

5nM CH 2, amino acids 1-543, CARNA BS (cat. & lot #: 02-162, 10CBS-0386B)

Reaction was run at 30°C for 120 minutes.

Example 12: Comparison of a Panel of CSx and Sox-Pro (Y4) RTK Substrates for TrkA Reaction Conditions:

50 mM HEPES, pH 7.5

1 mM ATP

I mM DTT

0.01 % Brij-35

0.5 mM EGTA

l O mM MgCh

10 μΜ Sox-based Peptide Substrate

5 nM* TRKA, amino acids 436-790

Carna Bioscience (cat. & lot #: 08-186, 13CBS-0585M)

Reaction was run at 30 ( for 180 minutes.

Example 13: EGFR Substrate Optimization (Mutant EGFRs)

Reacti on Condi ti ons :

50 mM HEPES, pH 7.5 5% glycerol 1 mM ATP 1 mM DTT 0.01% Brij-35 0.1% CHAPS 0.5 mM EGTA 10 mM MgC12 250 μΜ MnC12 10 μΜ Sox-based Peptide Substrate 5nM EGFR.:

• Wild-type, amino acids 668-1210, BPS BS (cat. & lot #: 40187, 120321 -GC)

• Mutant. (L858R/T790M), amino acids 668-1210, BPS BS (cat. & lot . #: 40350, 150804-G2)

• Mutant (L858R/T790M), amino acids 669-1210, ( \ \. \ BS (cat. & lot #: 08-510, 1 1CBS- 0004B)

• Mutant (L861 Q), amino acids 669-1210, CARNA BS (cat. & lot #: 08-513, 10CBS-0896B)

• Mutant (T790M), amino acids 669-1210, CARNA BS (cat. & lot #: 08-522, 07CBS-0923B)

• Mutant (L858R), amino acids 669-1210, CARNA BS (cat. & lot #: 08-502, 09CBS-0597E)

• Mutant (d746-750), amino acids 669-745, 751-1210, CARNA BS (cat. & lot #: 08-527, 11CBS-0259E)

• Mutant (d746-750/T790M), amino acids 669-745, 751-1210, CARNA BS (cat. & lot #: 08- 528, 11CBS-0285H) Reaction was run at 30°C for 120 minutes.

Example 14: Broad AGC Serine/Threonine Kinase Activity Measured Using PKA-S4 Including SG l/2/3 and PRKACA/B

Reaction Conditions:

50 mM HEPES, pH 7.5

1 mM ATP

1 mM DTT 0.01% Brij-35

0.5 ttiM EGTA

lO mM MgCh

10 μΜ ΡΚΑ-84 Sox-based Peptide Substrate

5 nM kinase

Reaction was run at 0 ( for 120 minutes.

Example 15: Substrates for SGK I, SGK2, SGK3 Identified from AQT's CSx Panel

Reaction Conditions:

50 mM HEPES, pH 7.5

1 mM ATP

1 mM DTT

0.01% Brij-35

0,5 mM EGTA

10 mM MgC12

10 μΜ Sox-based Peptide Substrate

5 nM SGK, amino acids 61-431, Carna Bioscience (cat. & lot #: 01 -158, 09CBS-0646F) 5 nM SGK2, amino acids 1-367, Carna Bioscience (cat. & lot #: 01-159, 08CBS-0830B) 5 nM SGK.3, amino acids 119-496, Cama Bioscience (cat & lot #: 01-160, 08CBS-0586B) Reaction was run at 0 ( for 120 minutes.

Example 16: AQT's Panel of CSx and Sox-Pro (Y4) RTK Substrates for TrkA

Reaction Conditions:

50 mM HEPES, pH 7.5

1 mM ATP

1 mM DTT

0,01 % Brij-35

0.5 mM EGTA

lO mM MgCh

10 isM Sox-based Peptide Substrate

5 nM* TRKA, amino acids 436-790, Cama Bioscience (cat. & lot #: 08-186, 13CBS-0585M) Reaction was run at 30°C for 180 minutes.

Example 17: Substrates for TRK RTKs Reaction Conditions:

50 fflM HEPES, pH 7.5

1 mM ATP

I mM DTT

0.01 % Brij-35

0.5 mM EGTA

l O mM MgCh

10 μΜ Sox-based Peptide Substrate

5 nM TRKA, amino acids 442-796, BPS BS (cat. & lot #: 40280, 151 1 13-G)

5 nM TRKB, amino acids 456-822, BPS BS (cat. & lot #: 40281, 130826)

5 nM TRKC, amino acids 456-825, BPS BS (cat. & lot #: 40282, 140205-G1)

Reaction was nan at 30°C for 150 minutes.

Example 18: FGFR Substrate Optimization (Mutant FGFRs)

Reacti on Condi Si on s ;

50 mM HEPES, pH 7.5

I mM ATP

1 mM DTT

0.01% Brij-35

0.5 mM EGTA

10 mM MgC12

10 μΜ So -based Peptide Substrate

5 nM FGFRl, amino acids 396-820, CARN A BS (cat. & lot #: 08-133, 12CBS-0123J) 5 nM FGFR2, amino acids 399-821 , CARNA BS (cat. & lot #: 08-134, 07CBS-2468F) 5 nM FGFR3, amino acids 436-806, CARNA BS (cat. & lot #: 08-135, 12CBS-0744K) 5 nM FGFR4, amino acids 460-802, CARNA BS (cat. & lot #: 08-136, 12CBS-0076F) 5 nM FGFR (K650E), amino acids 436-806, CARNA BS (cat. & lot #: 08-501, 07CBS- 1740H)

5 nM FGFR (G697C), amino acids 397-806 Proqinase (cat. & lot #: 1071 -0000-1 , 001) 5 nM FGFR (K650M), amino acids 436-806, CARNA BS (cat. & lot #: 08-199, 08CBS- 0670B)

5 nM FGFR (V555L), amino acids 436-806, ( \R\. \ BS (cat. & lot #: 08-548, 15CBS- 0370B) 5 nM FGFR (V555M), amino acids 436-806, CARNA BS (cat. & lot #: 08-543, 12CBS- 0565E)

Reaction was nan at 30°C for 90 minutes.

Example 19: Fmoc-C(Sox[TBDPS])-OH synthesis

a ~Cys-OA / iyl

To an oven-dried, one-necked, 500 mL round-bottomed flask equipped with a stir bar and under positive N2 pressure was added Fmoc-Cys(Mmt)-OH (8.92 mmol, 5.49 g, 1 equiv. dissolved in 50 mL CH2C12) followed by MeOH (50 mL). The colorless solution then was allowed to stir for 3 mm at room temperature. To this solution was added CS2CO3 (4.46 mmol, 1 .45 g, 0.5 equiv.) and mixture was allowed to stir at room temperature under ₂ for 45 min at which time the solvent was removed in vacuo. The resulting white, fluffy solid was dissolved in DMF (100 mL, anhydrous) and immediately following this, ally I bromide (26.75 mmol, 3.24 g, 3 equiv.) was added. The reaction mixture was stirred at room temperature under positive N ₂ pressure for 5 hours. During this time, the reaction was monitored by TLC (Rf = 0.23, 20% EtOAc in hexanes). Upon completion, the reaction mixture was diluted with EtOAc (1 L), washed with 2% NaHCO.3 (200 mL), H2O (250 mL x 3), brine (250 mL x 3), dried (Na ₂ S0 ₄ ), and concentrated in vacuo.

The crude product from the previous step was dissolved in degassed, anhydrous CH2C12 (90 mL). To the slightly yellow solution were added TIS (5 mL) and TFA (5 mL). The resulting red solution was allowed to react at room temperature under N ² for 2.5 hrs and was monitored by TLC (Rf = 0.28, 20% EtOAc in hexanes). The reaction mixture turns a clear yellow color upon completion. The reaction then was diluted in CH2C12 (300 mL), washed with 5% \a! i( ()3 (250 mL x 2), H2O (250 mL), brine (300 mL), dried (Na2S04) and concentrated in vacuo. Flash column chromatography (Si0 ₂ ; diameter: 70 mm; length: 23 cm; packing: 20% EtOAc in hexanes; load crude product in CH2CI2; ehient 20% EtOAc in hexanes) was used to purify the product, which was isolated as a fluffy white solid. Yield: 69% (2.36 g). 1H NMR (400 MHz, CDCh, 20 °C) δ ppm: 1.38 (t, J - 8.90 Hz, i f ! ). 3.10- 2.94 (m, 2H), 4.24 (t, J - 6.83 Hz, 1 1 1 ), 4.49-4.38 (m, 2H), 4.78-4.62 (m, 3H), 5.29 (d, J 1 0 38 Hz, 1H), 5.37 (d, J - 17.15 Hz, 1H), 5.72 (d, J - 6.97 Hz, 1 H), 5.98-5.88 (m, 1H), 7.33 (t, J - 7.45 Hz, 2H), 7.41 (t, J = 7.47 Hz, 2H), 7.61 (d, J - 7.25 Hz, 2H), 7.77 (d, J - 7.48 Hz, 2H). 13C NMR (100 MHz, CDC13, 20 °C) δ ppm: 27.1, 47.1, 55.2, 66.5, 67. 1, 1 19.4, 120.0, 125.0, 127.1 , 127.7, 13 1 .2, 141 .3, 143.7, 1 55.6, 169.6. HRMS (ESI): calcd for

C21H21NNa04S [M + Na]+: 406.1089, found : 406. 1098.

-Cys(Sox[TBDPS])-OAllyl

To an oven-dried, one-necked, 500 ml, round-bottomed flask equipped with a stir bar and under positive N?. pressure was added Fmoc-Cys-OAllyl (4.98 mmol, 1.91 g, 1 equiv.) dissolved in anhydrous CH2C12 (70 niL). To thi s colorless solution was added Sox-Br ₂ (4.98 mmol, 2.9 g, 1 equiv.) followed by freshly di sti lled DIEA (7.46 mmol, 1.3 niL, 1.5 equiv.). The reaction (pale yellow in color) was stirred at room temperature under the positive N2 pressure overnight and was monitored by TLC (Rf = 0.36, 1 :2 EtOAc in hexanes) until completion. The crude reaction was diluted with CH2CI2 (400 mL), washed with sat'd. NH4CI (2 x 100 mL), H2O (100 mL), brine (100 ml,), dried (Na2S()4) and concentrated in vacuo. Flash column chromatography (Si02; diameter: 70 mm; length: 26 cm; packing: 10% EtOAc in hexanes; load crude product in CH2C12; elueni: 10, 20, 30% EtOAc in hexanes) was used to isolate the product as a white solid. Yield: 95% (3.43 g).

1H NMR. (400 MHz, CDC13, 20 °C) δ ppm: 1. 18 (s, 9H), 2.82-2.67 (m, 2FI), 2.72 (s, 6FI), 3.57 ( in, 2H), 4.24 (t, J - 7.04 Hz, 1H), 4.45-4.34 (m, 2H), 4.68-4.48 (m, 3 ! I ). 5.22 (dd, J 10.42, 1.09 Hz, 1H), 5.28 (dd, J = 17. 19, 1.23 Hz, 1H), 5.51 (d, J = 8.13 Hz, IH), 5.89-5.78 (m, I H), 7.1 1 (d, J = 8.32 Hz, i l l ). 7.34-7.29 (m, 6H), 7.45-7.35 (m, 4H), 7.53 (d, ./ 8.97 Hz, IH), 7.61 (dd, J = 7.21, 2.86 Hz, 2H), 7.78-7.75 (m, 6H), 7.99 (d, J - 8.32 Hz, IH), 8.95 (d, J - 8.96 ! !/, IH), 13C NMR (100 MHz, CDC33, 20 °C) δ ppm: 20.0, 26.4, 34. 1 , 37.2, 38.2, 46.9, 53.3, 66.2, 67.1, 1 15.3, 1 18.9, 1 19.9, 122.3, 123.7, 125.0, 125.1, 127.0, 127.6, 127.6, 129.6, 131.1, 131.6, 133.3, 133.3, 134.2, 134.8, 140.3, 141.1 , 143.6, 143.6, 155.5, 156.8, 157. 1 , 170.1 .

HUMS (ESI): calcd for C49H51N3Na07S2Si [M + Na]+: 908.2835, found: 908.2827.

-Cys(Sox[TBDPS])-OH

To an oven-dried, one-necked, 250 niL round-bottomed flask equipped with a stir bar and under positive N2 pressure was added Fmoc-Cys(Sox[TBPDS])-OAlIyl (3.62 mmol, 3.21 g, 1 equiv.) dissolved in anhydrous and degassed CH2CI2 (100 mL). To the pale red solution was added PhSiH3 (90.47 mmol, 11.2 mL, 25 equiv.) followed by Pd(PPh3)4 (0.145 mmol, 167.26 mg, 0.04 equiv.). After 10 min the reaction turned a deep red color. The resulting mixture was stirred at room temperature under the positive N2 pressure for 3 hours and was monitored by TLC (Rf = 0.36, 10 % MeOH in CH2CI2). Upon completion of the reaction, the solvent was removed in vacuo. The cmde mixture was passed through a short flash column (Si 02; diameter: 70 mm; length: 7 cm; packing: CFI2CI2; load crude product in CH2CI2; eluent: 1, 2, 3, 4, 5, 10, 15% MeOH in CH2CI2) to obtain 77% recovery of product. Analytical HPLC revealed one peak (tR = 32.1 min, loading: dissolve 3 mg in DMSO; injection: 12 \iL, method: 5% B (5 min)→ 20% B (1 min)→95% B (30 min), Abs: 280 run and 316 run) that was determined by ESI-MS to be Fmoc-C(Sox)-OH (calcd for C30H30N3O7S2 [M + H]+: 608.15, found: 608.1) since the acidic conditions of HPLC solvents remove the TBDPS protecting group. I I NMR, prior to HPLC analysis, shows that the TBDPS protecting group is still present in the crude material. The amino acid was used in SPPS without further purification. 1 1 RMS (ESI) of Fmoc-C(Sox[TBDPS])-OH: calcd for C46H47N3Na07S2Si [M + Na]+:

868.2522, found: 868.2540.

Example 20: Peptide synthesis

a. Coupling chemistry and conditions

All peptides were synthesized using the standard Fmoc-based amino acid protection chemistry using a variety of methods. For example, in some cases, peptides were synthesized on Fmoc-PAL-PEG-PS resin (Applied Biosystems, 0.19 mmol/g) using either the on-resin alkylation (vide infra) or the Fmoc-C(Sox[TBDPS])-OH building block. In other cases, peptides were synthesized on Fmoc-G!y-NovaSyn TGT resin (Novabiochem, 0.20 mmol/g) using the C-Sox building block. The resin was swelled in CH2O2 (5 min.) and then DMF (5 min) prior to synthesis. All the amino acids except for Fmoc-C(Sox[TBDPS])-OH were coupled according to the following procedure: Fmoc deprotection (20% 4-methylpiperidine in DMF, 3 5 min), rinsing step (DMF, 5 x), coupling step (amino acid/PyBOP/HOBt DIEA, 6:6:6:6, 0.15 M in DMF, 30-45 min), rinsing step (DMF, 5 x; Ci WL 5 x). Fmoc- C(Sox[TBDPS])-OH was coupled in the following manner: amino acid/PyAOP/FIOAt/DiEA, 2:2:2:5, 0.15 M in DMF, 2-12 hr. The coupling was repeated if necessary (amino

aci d Py A OP/HO At/D lEA, 1 : 1 : 1 :3, 0. 15 M in DMF, 2-12 hr) as determined by the TNBS test for free amines. It is important to wash the resin rigorously (DMF followed by CH2C12) to remove excess amino acid before performing any tests for f ee amines. This is particularly necessary after coupling of Fmoc-C(Sox[TBDPS])-OH due to its deep red color, which does not affect its coupling efficiency. At the end of the synthesis, the Fmoc group was removed with 20% 4-methylpiperidine in DMF (3 x 5 min.) and the resin was rinsed with DMF (5 x). The resin-attached free amines were capped by exposure to Ac20 (20 equiv.) and pyridine (20 equiv.) in DMF for 30 min. The resin was rinsed with DMF (5 x), CFI2CI2 (5 x) and subjected to 20% 4-methylpiperidine in DMF (3 5 min.) to remove any Sox aryl esters that might have formed during acetylation. The resin was finally washed with DMF, CH2CI2, MeOH (5 x each) and dried under vacuum. Different variations on the above methods may be required to improve yield and purity of the desired chemosensor.

/;. On-resin alkylation of peptides with Sox-Br

Resin-bound peptides (50 mg, 0.0095 mmol, I equiv.) incorporating Cys(Mmt) were swelled in CH2CI2, then DMF (5 min each). The Mmt protecting group was removed from the resin-bound peptide by bubbling N2 through a solution of 1% TFA, 5% TIS in CH2CI2 (4 x 20 min or until most of the yellow color due to the Mmt cation has disappeared). The resin then was subjected to rigorous washing with CH2CI2 (5 x) and DMF (5 x). Anhydrous DMF (200 μΐ,) was added to the resin followed by freshly distilled tetrametbylguamdine (5.96 μΕ, 0.0475 mmol, 5 equiv.). The mixture was incubated for 2-3 min. Sox-Br (17 mg, 0.0285 mmol, 3 equiv.) was dissolved in anhydrous DMF (150 μΕ) and added to the resin. After ca. 12 hours of reaction time, the excess reagents were drained and the resin washed with DMF, CH2CI2, MeOH, CH2CI2 (5 x each). Different variations on the above methods may be required to improve yield and purity of the desired chemosensor.

c. Side chain deprotection and cleavage from resin

The resin cleavage and protecting group removal was achieved by exposing the resin- bound peptides to TFA EDT H20/TIS (94:2.5:2.5: 1% v/v) for sequences containing easily oxidized residues (e.g. Cys, Met, Trp) or TFA/H ₂ 0/TIS (95:2.5:2.5% v/v) for sequences without such residues (C-Sox does not require EOT in the cleavage cocktail). The resulting solution was concentrated under a stream of N2 and precipitated by addition of cold Et20. The pellet was triturated with cold Et ₂ 0 (3 x), redissolved in water, filtered and lyophilized. The peptides were purified by preparative reverse-phase HPLC using UV detection at either 228 fiffl (amide bond absorption) and 280 nra (Fmoc, Trp, and/or Tyr absorption) or 228 nra and 316 urn (Sox absorption). Only fractions showing a single peak of correct mass by analytical HPLC were used in further experiments.

Characterization of purified peptides.

The purity of the synthetic peptides was assessed by reversed-phase HPLC and identity was confirmed by ESI-MS, prior to characterizing specificity (testing with a panel of protein kinases) and enzyme kinetic properties with the target kinase.

Example 21: Representative peptides

The following peptides were synthesized as previous described, and characterized as followed:

Ac-EEPITl-C(Sx)-VP-amide (AQT0026~Sx): MW: calc (mono MW): 1366.6 Da; exp (avg): 1367.6 Da; HPLC-purity: expected 95+%; measured: 99.85%; Mass Spec, TOF: 684.3; Tandem Mass Spec: 1 14.0, 171 .0, 227.9; 510.2; 580.2; 673,3; 682.5; 786.4, 952.4; 1066.5; 1 195.6; 1252.5.

Ac~EDPEYI-C(Sx)~lP~amide (AQT0099-BBCSx): MW: calc. (mono MW): 1382.5 Da; exp (avg): 1383.5 Da; HPLC-purity: expected 95+%; measured: 95.51%; Mass Spec. TOF: 892.2; Tandem Mass Spec : 114.1, 69.1, 286.2, 548.9, 694.4, 805.9. Ac-GRPRiATF-C(8x)~EG-amide (AQTQQ76-Sx): MW: calc. ( mono M ): 1468.6 Da; exp (avg): 1469,5 Da, HPLC-purity: expected 95+%; measured: 96.35%; Mass Spec. TOF: 735.3; Tandem Mass Spec : 1 19.0, 227.1, 268.9, 285.1, 296.0, 633.3, 733.8, 870.4, 967.4, 1375.5.

Ac-C(Sx)-LSPGPF-amide (AQT0082-Sx): MW: calc, (mono MW): 1024.4 Da; exp (avg): 1025.2 Da; HPLC-purity: expected 95+%; measured: 99.28%; Mass Spec, TOF:

1025.41 ; Tandem Mass Spec : 399.2, 415.2, 502.2, 615.3, 1007.4, 1024.4.

While the invention has been described with reference to certain embodiments, other features may be included without departing from the spirit and scope of the invention. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention