Coronavirus Infections

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application No. 63/106,689, filed October 28, 2020, which is hereby incorporated herein by reference in its entirety.

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an ongoing pandemic that has posed a serious threat to public health and global economy. The causative agent of COVID-19 is a coronavirus, severe acute respiratory coronavirus 2 (SARS-CoV-2), which first emerged towards the end of 2019 in Wuhan City, China. By March 2020, the World Health Organization declared COVID-19 a pandemic. The rapid spread of SARS-CoV-2 is attributable to its high reproductive number, community and asymptomatic spread through close contact, and airborne transmission of respiratory' droplets. CO VID-19 patients can become critically ill with severe hypoxemia, viral pneumonia, acute respiratory distress syndrome, and gastrointestinal and neurological symptoms. Unfortunately, to date, there are relatively few approved drugs specifically designed to treat SARS-CoV-2, with the most common treatments being supportive care and repurposed drugs. A wide array of diverse approaches are urgently needed to rapidly and effectively advance antiviral therapies.

SUMMARY

Therapeutics that target essential viral proteins are effective at controlling virus replication and spread. Presently, the key viral target for studies looking at possible treatments and vaccine candidates for SARS-CoV-2 is the viral Spike glycoprotein, which resides on the viral lipid bilayer of all coronaviruses. To invade the host cell, the viral Spike protein binds to the host cell’s angiotensin-converting enzyme 2 (ACE2) receptor, followed by cleavage events that allow the viral envelope to fuse with the host cell membrane.

In one aspect disclosed herein are isolated peptides comprising the sequence EDX1X2YQ (SEQ ID NO: 20); LX1X2MY (SEQ ID NO: 21), and/or TFX 1 DKX2X3I IE (SEQ ID NO: 22), In some aspects, peptide comprises the sequence EDX1X2YQ, wherein Xi is L, A, I, V, G, or P; and wherein X2 is F, Y, or W. For example, disclosed herein are peptides of any preceding aspect, wherein the peptide comprises the sequence EDX1X2YQ; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15. Also disclosed herein are peptides, wherein the peptide comprises the sequence LX1X2MY; wherein X1 is A, I, V, L, G, or P; and wherein X2 is Q, S, T, C, N, or M (such as, for example, peptides consisting of SEQ ID NO: 3, SEQ ID NO: 7, SEQ NO: 16, or SEQ ID NO: 17). In ID some aspects, disclosed herein are isolated peptides, wherein the peptide comprises the sequence TFX1DKX2X3HE; wherein X1 is L, A, I, V, G, or P, wherein X ₂ is F, Y, or W; and wherein X ₃ is N, Q, S, T, C, or M .For example, disclosed herein are isolated peptides, wherein the peptide comprises the sequence TFX1DKX2X3HE; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. In one aspect, the disclosed peptides do not include naturally occurring peptides. Therefore, disclosed herein are isolated peptides of any preceding aspect, wherein the peptide comprises the sequence EDX ₁ X ₂ YQ; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15; wherein the peptide comprises the sequence LX1X2MY; and wherein the peptide does not comprise SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17.; or wherein the peptide comprises the sequence TFX1DKX2X3HE; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. It is understood and herein contemplated that the disclosed peptides can be prepared in a composition with a pharmaceutically acceptable excipient. Thus, in one aspect disclosed herein are composition comprising one or more of the isolated peptides of any preceding aspect. It is understood and herein contemplated that the combination of multiple different peptides in a single composition can have synergistic or additive effects on the ability to inhibit viral entry by a spike protein, inhibit infection, treat an ongoing infection, and/or provide benefits for longer-term sequalae of infection. Thus, in one aspect, disclosed herein are compositions comprising any combination of two or more of the isolated peptides as set forth in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, and-SEQ ID NO: 19. The disclosed compositions are useful in the treatment and prevention of viral infections. Thus, in one aspect, disclosed herein are compositions of any preceding aspect further comprising one or more antiviral agents (such as, for example, Remdesivir and/or an anti-coronavirus monoclonal antibody, such as bamlanivimab, etesevimab, casirivimab, imdevimab, sotrovimab, or any combination thereof). In one aspect, disclosed herein are method of inhibiting, reducing, decreasing, and/or preventing viral entry (such as, for example, entry of a coronavirus including, but not limited to avian coronavirus (IBV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV), feline infectious peritonitis virus (FIPV), feline enteric coronavirus (FECV), canine coronavirus (CCoV), rabbit coronavirus (RaCoV), mouse hepatitis virus (MHV), rat coronavirus (RCoV), sialodacryadenitis virus of rats (SDAV), bovine coronavirus (BCoV), bovine enterovirus (BEV), porcine coronavirus HKU15 (PorCoV HKU15), Porcine epidemic diarrhea virus (PEDV), porcine hemagglutinating encephalomyelitis virus (HEV), turkey bluecomb coronavirus (TCoV), human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV) (SARS-CoV), Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV)-2 (SARS-CoV-2) (including, but not limited to the B1.351 variant, B.1.1.7 variant, USA-WA1/2020, or P.1 variant), or middle east respiratory syndrome (MERS) coronavirus (CoV) (MERS-CoV)) in a cell of a subject comprising administering to the subject a therapeutically effective amount of the isolated peptides of any preceding aspect or a therapeutically effective amount the composition of any preceding aspect; wherein the viral entry receptor comprises human angiotensin-converting enzyme 2 (ACE2). It is understood that the administration of the disclosed peptides and/or compositions can occur for therapeutic intervention or prophylactic uses. Thus, in one aspect, the disclosed compositions and/or peptides can be administered to the subject prior to or following exposure to or infection with the virus. Also disclosed herein are methods of inhibiting, reducing, decreasing, and/or preventing a viral infection (such as, for example, entry of a coronavirus including, but not limited to avian coronavirus (IBV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV), feline infectious peritonitis virus (FIPV), feline enteric coronavirus (FECV), canine coronavirus (CCoV), rabbit coronavirus (RaCoV), mouse hepatitis virus (MHV), rat coronavirus (RCoV), sialodacryadenitis virus of rats (SDAV), bovine coronavirus (BCoV), bovine enterovirus (BEV), porcine coronavirus HKU15 (PorCoV HKU15), Porcine epidemic diarrhea virus (PEDV), porcine hemagglutinating encephalomyelitis virus (HEV), turkey bluecomb coronavirus (TCoV), human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV) (SARS-CoV), Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV)-2 (SARS-CoV-2) (including, but not limited to the B1.351 variant, B.1.1.7 variant, USA-WA1/2020, or P.1 variant), or middle east respiratory syndrome (MERS) coronavirus (CoV) (MERS-CoV)) in a subject comprising administering to the subject a therapeutically effective amount of the isolated peptides of any preceding aspect or a therapeutically effective amount the composition of any preceding aspect. It is understood that the administration of the disclosed peptides and/or compositions can occur for therapeutic intervention or prophylactic uses. Thus, in one aspect, the disclosed compositions and/or peptides can be administered to the subject prior to or following exposure to or infection with the virus. In one aspect, disclosed herein are methods of treating, inhibiting, decreasing, reducing, ameliorating, and/or preventing a viral infection (such as, for example, entry of a coronavirus including, but not limited to avian coronavirus (IBV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV), feline infectious peritonitis virus (FIPV), feline enteric coronavirus (FECV), canine coronavirus (CCoV), rabbit coronavirus (RaCoV), mouse hepatitis virus (MHV), rat coronavirus (RCoV), sialodacryadenitis virus of rats (SDAV), bovine coronavirus (BCoV), bovine enterovirus (BEV), porcine coronavirus HKU15 (PorCoV HKU15), Porcine epidemic diarrhea virus (PEDV), porcine hemagglutinating encephalomyelitis virus (HEV), turkey bluecomb coronavirus (TCoV), human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV) (SARS-CoV), Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV)-2 (SARS-CoV-2) (including, but not limited to the B1.351 variant, B.1.1.7 variant, USA-WA1/2020, or P.1 variant), or middle east respiratory syndrome (MERS) coronavirus (CoV) (MERS-CoV)) in a subject comprising administering to the subject a therapeutically effective amount of the isolated peptides of any preceding aspect or a therapeutically effective amount the composition of any preceding aspect. It is understood that the administration of the disclosed peptides and/or compositions can occur for therapeutic intervention or prophylactic uses. Thus, in one aspect, the disclosed compositions and/or peptides can be administered to the subject prior to or following exposure to or infection with the virus. DESCRIPTION OF DRAWINGS Figure 1 is a plot illustrating the dose-dependent inhibition of SARS-CoV-2 Spike- pseudotyped lentivirus infection by SAPs. Dose response curves of the indicated SAPs generated by plotting the percent viral inhibition (y-axis) against the log transformation of SAP concentration (mM, x-axis). Each data point represents the average of three independent experiments, performed in duplicate. Error bars represent standard deviations. The dotted grey line indicates 50% viral inhibition used to determine the IC50 value. Computed IC ₅₀ values for the indicated SAPs from three independent experiments ± standard deviations are shown. Figures 2A-2C illustrate the inhibition of Spike- and VSV-G-pseudotyped lentivirus infection by SAPs. Luciferase-encoding lentiviruses pseudotyped with indicated viral glycoprotein were incubated with 3 mM of indicated SAP or diluent control for 1 h prior to infection of 293T-ACE2 cells. Infection was measured as relative luciferase expression 48 h post-infection. The luciferase signal obtained for the diluent control was set to 100%. Graphs indicate percentage of infected cells normalized to the diluent control for lentiviruses pseudotyped with SARS-CoV-2 Spike (Figure 2A), SARS-CoV Spike (Figure 2B), or VSV-G (Figure 2C). Bars represent averages from four independent experiments, performed in duplicate, with means from individual experiments shown as circles. Error bars represent standard deviations. Percent infections were compared to the diluent control using one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test. * p < 0.05, ns, not significant Figures 3A-3C show the binding of SAPs to SARS-CoV-2 Spike. Affinity precipitation of His-tagged SARS-CoV-2 Spike RBD (indicated ‘His-S RBD’) with FITC- SAPs. Figure 3A shows a representative SDS-PAGE gels of affinity precipitation of His-S RBD with increasing concentrations of indicated FITC-SAP (lanes 2–6: 0.125, 0.25, 0.5, 1, and 3 mM FITC-SAP). Lane 1 indicates control precipitation of 3 mM FITC-SAP without His-S RBD. FITC-labeled bands were detected at 488 nm fluorescence and His-S RBD was visualized with Coomassie staining. Figure 3B is a graphical representation of fluorescence intensities from (A) of indicated FITC-SAP bound to His-S RBD. Each data point represents the average of three independent experiments. Error bars represent standard deviations. Data were fit to the Hill equation to determine the apparent K _d of binding. Figure 3C shows the calculated binding K _d from three independent experiments ± standard deviations. Figures 4A-4B show the inhibition of SARS-CoV-2 infection by SAPs. SARS-CoV- 2 was incubated with 3 mM of indicated SAP or diluent control for 1 h prior to infection of 293T-ACE2-GFP cells. Infection was measured by flow cytometry as percentage of cells positive for SARS-CoV-2 nucleocapsid (N) protein 24 h post-infection. Figure 4A shows representative flow cytometry plots indicating percent infection. Figure 4B is a graph indicating the percentage of infected cells normalized to the diluent control, which was set to 100%. Bars represent averages from two independent experiments, performed in triplicate, with individual data points shown as circles. Error bars represent standard deviations. Percent infections were compared to the diluent control using one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test. * p < 0.05, ns, not significant Figures 5A-5B show the inhibition of HCoV-NL63 infection by SAPs. HCoV-NL63 was incubated with 3 mM of indicated SAP or diluent control for 1 h prior to infection of LLC-MK2 cells. Cytopathic effects and virus titers in the supernatants were analyzed at 72 h post-infection. Figure 5A shows representative bright field microscope images showing cytopathic effects. Figure 5B is a graph indicating virus titers in supernatants from LLC- MK2 cells. Bars represent averages from triplicate infections with individual data points shown as circles. Error bars represent standard deviations. Virus titers were compared to the diluent control using one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test. * p < 0.05, ns, not significant. Figure 6A-6C show gaphical illustration of SARS-CoV-2 Spike and SAP6 interaction interface. Figure 6A is an overall view of SARS-CoV-2 Spike RBD and human ACE2 interaction mode. N-terminal helix of human ACE2 is located at the central interface. Figure 6B shows the relative location of SAP6 (light blue) and SAP1 (green and light blue). Figure 6C shows the H-bonds interaction network between SAP6 and SARS-CoV-2 Spike RBD. The Y41, Q42, D38, and E37 of SAP6 peptide are involved in H-bond interactions with T500, Y449, N501, and Y505 of SARS-CoV-2 Spike RBD. Corresponding crystal structure: PDB Code: 6M0J (http://www.rcsb.org/structure/6M0J). Figure 7 is a plot illustrating the dose-dependent inhibition of SARS-CoV-2 Spike- pseudotyped lentivirus infection for SAP5 and SAP7. Dose response curves of the indicated SAPs generated by plotting the percent viral inhibition (y-axis) against the log transformation of SAP concentration (mM, x-axis). Each data point represents values from a single experimental run. The dotted line indicates 50% viral inhibition used to determine the IC ₅₀ value. Computed IC ₅₀ values for the indicated SAPs are also shown. Figures 8A-8C illustrate the inhibition of Spike- and VSV-G-pseudotyped lentivirus infection by SAP7. Luciferase-encoding lentiviruses pseudotyped with indicated viral glycoprotein were incubated with 3 mM of SAP7 or diluent control for 1 h prior to infection of 293T-ACE2 cells. Infection was measured as relative luciferase expression 48 h post- infection. The luciferase signal obtained for the diluent control was set to 100%. Graphs indicate percentage of infected cells normalized to the diluent control for lentiviruses pseudotyped with SARS-CoV-2 Spike (Figure 8A), SARS-CoV Spike (Figure 8B), or VSV-G (Figure 8C). Bars represent values obtained from a single experiment. Error bars represent standard deviations. DETAILED DESCRIPTION Definitions To facilitate understanding of the disclosure set forth herein, a number of terms are defined below. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference. The term “comprising” and variations thereof as used herein is used synonymously with the term “including” and variations thereof and are open, non-limiting terms. Although the terms “comprising” and “including” have been used herein to describe various embodiments, the terms “consisting essentially of” and “consisting of” can be used in place of “comprising” and “including” to provide for more specific embodiments of the invention and are also disclosed. Other than where noted, all numbers expressing quantities of ingredients, reaction conditions, geometries, dimensions, and so forth used in the specification and claims are to be understood at the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, to be construed in light of the number of significant digits and ordinary rounding approaches. As used in this specification and the following claims, the terms “comprise” (as well as forms, derivatives, or variations thereof, such as “comprising” and “comprises”) and “include” (as well as forms, derivatives, or variations thereof, such as “including” and “includes”) are inclusive (i.e., open-ended) and do not exclude additional elements or steps. For example, the terms "comprise" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Accordingly, these terms are intended to not only cover the recited element(s) or step(s), but may also include other elements or steps not expressly recited. Furthermore, as used herein, the use of the terms “a”, “an”, and “the” when used in conjunction with an element may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” Therefore, an element preceded by “a” or “an” does not, without more constraints, preclude the existence of additional identical elements. The use of the term “about” applies to all numeric values, whether or not explicitly indicated. This term generally refers to a range of numbers that one of ordinary skill in the art would consider as a reasonable amount of deviation to the recited numeric values (i.e., having the equivalent function or result). For example, this term can be construed as including a deviation of ±10 percent of the given numeric value provided such a deviation does not alter the end function or result of the value. Therefore, a value of about 1% can be construed to be a range from 0.9% to 1.1%. Furthermore, a range may be construed to include the start and the end of the range. For example, a range of 10% to 20% (i.e., range of 10%-20%) can includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwise herein. It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein. By way of example, if a composition is described herein as including a component of type A, a component of type B, a component of type C, or any combination thereof, it is understood that this phrase describes all of the various individual and collective combinations and permutations of these components. For example, in some embodiments, the composition described by this phrase could include only a component of type A. In some embodiments, the composition described by this phrase could include only a component of type B. In some embodiments, the composition described by this phrase could include only a component of type C. In some embodiments, the composition described by this phrase could include a component of type A and a component of type B. In some embodiments, the composition described by this phrase could include a component of type A and a component of type C. In some embodiments, the composition described by this phrase could include a component of type B and a component of type C. In some embodiments, the composition described by this phrase could include a component of type A, a component of type B, and a component of type C. In some embodiments, the composition described by this phrase could include two or more components of type A (e.g., A1 and A2). In some embodiments, the composition described by this phrase could include two or more components of type B (e.g., B1 and B2). In some embodiments, the composition described by this phrase could include two or more components of type C (e.g., C1 and C2). In some embodiments, the composition described by this phrase could include two or more of a first component (e.g., two or more components of type A (A1 and A2)), optionally one or more of a second component (e.g., optionally one or more components of type B), and optionally one or more of a third component (e.g., optionally one or more components of type C). In some embodiments, the composition described by this phrase could include two or more of a first component (e.g., two or more components of type B (B1 and B2)), optionally one or more of a second component (e.g., optionally one or more components of type A), and optionally one or more of a third component (e.g., optionally one or more components of type C). In some embodiments, the composition described by this phrase could include two or more of a first component (e.g., two or more components of type C (C1 and C2)), optionally one or more of a second component (e.g., optionally one or more components of type A), and optionally one or more of a third component (e.g., optionally one or more components of type B). Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. By “about” is meant within 5% of the value, e.g., within 4, 3, 2, or 1% of the value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. As used herein, the terms "may," "optionally," and "may optionally" are used interchangeably and are meant to include cases in which the condition occurs as well as cases in which the condition does not occur. Thus, for example, the statement that a formulation "may include an excipient" is meant to include cases in which the formulation includes an excipient as well as cases in which the formulation does not include an excipient. “Administration" to a subject includes any route of introducing or delivering to a subject an agent. Administration can be carried out by any suitable route, including oral, topical, intravenous, subcutaneous, transcutaneous, transdermal, intramuscular, intra-joint, parenteral, intra-arteriole, intradermal, intraventricular, intracranial, intraperitoneal, intralesional, intranasal, rectal, vaginal, by inhalation, via an implanted reservoir, parenteral (e.g., subcutaneous, intravenous, intramuscular, intra- articular, intra-synovial, intrasternal, intrathecal, intraperitoneal, intrahepatic, intralesional, and intracranial injections or infusion techniques), and the like. "Concurrent administration", "administration in combination", "simultaneous administration" or "administered simultaneously" as used herein, means that the compounds are administered at the same point in time or essentially immediately following one another. In the latter case, the two compounds are administered at times sufficiently close that the results observed are indistinguishable from those achieved when the compounds are administered at the same point in time. "Systemic administration" refers to the introducing or delivering to a subject an agent via a route which introduces or delivers the agent to extensive areas of the subject's body (e.g. greater than 50% of the body), for example through entrance into the circulatory or lymph systems. By contrast, "local administration" refers to the introducing or delivery to a subject an agent via a route which introduces or delivers the agent to the area or area immediately adjacent to the point of administration and does not introduce the agent systemically in a therapeutically significant amount. For example, locally administered agents are easily detectable in the local vicinity of the point of administration but are undetectable or detectable at negligible amounts in distal parts of the subject's body. Administration includes self-administration and the administration by another. As used here, the terms “beneficial agent” and “active agent” are used interchangeably herein to refer to a chemical compound or composition that has a beneficial biological effect. Beneficial biological effects include both therapeutic effects, i.e., treatment of a disorder or other undesirable physiological condition, and prophylactic effects, i.e., prevention of a disorder or other undesirable physiological condition. The terms also encompass pharmaceutically acceptable, pharmacologically active derivatives of beneficial agents specifically mentioned herein, including, but not limited to, salts, esters, amides, prodrugs, active metabolites, isomers, fragments, analogs, and the like. When the terms “beneficial agent” or “active agent” are used, then, or when a particular agent is specifically identified, it is to be understood that the term includes the agent per se as well as pharmaceutically acceptable, pharmacologically active salts, esters, amides, prodrugs, conjugates, active metabolites, isomers, fragments, analogs, etc. A "decrease" can refer to any change that results in a smaller amount of a symptom, disease, composition, condition, or activity. A substance is also understood to decrease the genetic output of a gene when the genetic output of the gene product with the substance is less relative to the output of the gene product without the substance. Also, for example, a decrease can be a change in the symptoms of a disorder such that the symptoms are less than previously observed. A decrease can be any individual, median, or average decrease in a condition, symptom, activity, composition in a statistically significant amount. Thus, the decrease can be a 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100% decrease so long as the decrease is statistically significant. "Inhibit," "inhibiting," and "inhibition" mean to decrease an activity, response, condition, disease, or other biological parameter. This can include but is not limited to the complete ablation of the activity, response, condition, or disease. This may also include, for example, a 10% reduction in the activity, response, condition, or disease as compared to the native or control level. Thus, the reduction can be a 10, 20, 30, 40, 50, 60, 70, 80, 90, 100%, or any amount of reduction in between as compared to native or control levels. “Inactivate”, “inactivating” and “inactivation” means to decrease or eliminate an activity, response, condition, disease, or other biological parameter due to a chemical (covalent bond formation) between the ligand and a its biological target. By “reduce” or other forms of the word, such as “reducing” or “reduction,” is meant lowering of an event or characteristic (e.g., viral replication and spread). It is understood that this is typically in relation to some standard or expected value, in other words it is relative, but that it is not always necessary for the standard or relative value to be referred to. For example, “reduces viral replication and spread” means reducing the rate of growth of a tumor relative to a standard or a control. As used herein, the terms “treating” or “treatment” of a subject includes the administration of a drug to a subject with the purpose of preventing, curing, healing, alleviating, relieving, altering, remedying, ameliorating, improving, stabilizing or affecting a disease or disorder, or a symptom of a disease or disorder. The terms “treating” and “treatment” can also refer to reduction in severity and/or frequency of symptoms, elimination of symptoms and/or underlying cause, prevention of the occurrence of symptoms and/or their underlying cause, and improvement or remediation of damage , and improvement or remediation of damage post-infection resolution. In particular, the term “treatment” includes the alleviation, in part or in whole, of the symptoms of coronavirus infection (e.g., sore throat, blocked and/or runny nose, cough and/or elevated temperature associated with a common cold). Such treatment may include eradication, or slowing of population growth, of a microbial agent associated with inflammation. By “prevent” or other forms of the word, such as “preventing” or “prevention,” is meant to stop a particular event or characteristic, to stabilize or delay the development or progression of a particular event or characteristic, or to minimize the chances that a particular event or characteristic will occur. Prevent does not require comparison to a control as it is typically more absolute than, for example, reduce. As used herein, something could be reduced but not prevented, but something that is reduced could also be prevented. Likewise, something could be prevented but not reduced, but something that is prevented could also be reduced. It is understood that where reduce or prevent are used, unless specifically indicated otherwise, the use of the other word is also expressly disclosed. For example, the terms “prevent” or “suppress” can refer to a treatment that forestalls or slows the onset of a disease or condition or reduced the severity of the disease or condition. Thus, if a treatment can treat a disease in a subject having symptoms of the disease, it can also prevent or suppress that disease in a subject who has yet to suffer some or all of the symptoms, including symptoms that present post-infection resolution. As used herein, the term “preventing” a disorder or unwanted physiological event in a subject refers specifically to the prevention of the occurrence of symptoms and/or their underlying cause, wherein the subject may or may not exhibit heightened susceptibility to the disorder or event. In particular embodiments, “prevention” includes reduction in risk of coronavirus infection in patients. However, it will be appreciated that such prevention may not be absolute, i.e., it may not prevent all such patients developing a coronavirus infection, or may only partially prevent an infection in a single individual. As such, the terms “prevention” and “prophylaxis” may be used interchangeably. By the term “effective amount” of a therapeutic agent is meant a nontoxic but sufficient amount of a beneficial agent to provide the desired effect. The amount of beneficial agent that is “effective” will vary from subject to subject, depending on the age and general condition of the subject, the particular beneficial agent or agents, and the like. Thus, it is not always possible to specify an exact “effective amount”. However, an appropriate “effective’ amount in any subject case may be determined by one of ordinary skill in the art using routine experimentation. Also, as used herein, and unless specifically stated otherwise, an “effective amount” of a beneficial can also refer to an amount covering both therapeutically effective amounts and prophylactically effective amounts. An “effective amount” of a drug necessary to achieve a therapeutic effect may vary according to factors such as the age, sex, and weight of the subject. Dosage regimens can be adjusted to provide the optimum therapeutic response. For example, several divided doses may be administered daily or the dose may be proportionally reduced as indicated by the exigencies of the therapeutic situation. As used herein, a “therapeutically effective amount” of a therapeutic agent refers to an amount that is effective to achieve a desired therapeutic result, and a “prophylactically effective amount” of a therapeutic agent refers to an amount that is effective to prevent an unwanted physiological condition. Therapeutically effective and prophylactically effective amounts of a given therapeutic agent will typically vary with respect to factors such as the type and severity of the disorder or disease being treated and the age, gender, and weight of the subject. The term “therapeutically effective amount” can also refer to an amount of a therapeutic agent, or a rate of delivery of a therapeutic agent (e.g., amount over time), effective to facilitate a desired therapeutic effect. The precise desired therapeutic effect will vary according to the condition to be treated, the tolerance of the subject, the drug and/or drug formulation to be administered (e.g., the potency of the therapeutic agent (drug), the concentration of drug in the formulation, and the like), and a variety of other factors that are appreciated by those of ordinary skill in the art. The terms “patient,” “subject,” and “individual” may be used interchangeably and refer to either a human or a non-human animal. These terms include mammals such as humans, primates, minks, livestock animals (e.g., bovines, porcines, sheep, deer), companion animals (e.g., equine, canines, felines), rodents (e.g., mice, hamsters, guinea pigs, and rats); and avian animals (e.g., chickens, ducks, and turkeys). The term “peptide,” as used herein, refers broadly to a sequence of two or more amino acids joined together by peptide bonds. It should be understood that this term does not connote a specific length of a polymer of amino acids, nor is it intended to imply or distinguish whether the polypeptide is produced using recombinant techniques, chemical or enzymatic synthesis, or is naturally occurring. The recitations “sequence identity”, “percent identity”, “percent homology”, or, for example, comprising a “sequence 50% identical to,” as used herein, refer to the extent that sequences are identical on a nucleotide-by-nucleotide basis or an amino acid-by-amino acid basis over a window of comparison. Thus, a “percentage of sequence identity” may be calculated by comparing two optimally aligned sequences over the window of comparison, determining the number of positions at which the identical nucleic acid base (e.g., A, T, C, G, I) or the identical amino acid residue (e.g., Ala, Pro, Ser, Thr, Gly, Val, Leu, Ile, Phe, Tyr, Trp, Lys, Arg, His, Asp, Glu, Asn, Gln, Cys and Met) occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison (i.e., the window size), and multiplying the result by 100 to yield the percentage of sequence identity. Calculations of sequence similarity or sequence identity between sequences (the terms are used interchangeably herein) can be performed as follows. To determine the percent identity of two amino acid sequences, or of two nucleic acid sequences, the sequences can be aligned for optimal comparison purposes (e.g., gaps can be introduced in one or both of a first and a second amino acid or nucleic acid sequence for optimal alignment and non-homologous sequences can be disregarded for comparison purposes). In certain embodiments, the length of a reference sequence aligned for comparison purposes is at least 30%, preferably at least 40%, more preferably at least 50%, 60%, and even more preferably at least 70%, 80%, 90%, 100% of the length of the reference sequence. The amino acid residues or nucleotides at corresponding amino acid positions or nucleotide positions are then compared. When a position in the first sequence is occupied by the same amino acid residue or nucleotide as the corresponding position in the second sequence, then the molecules are identical at that position. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences, taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences. The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm. In some embodiments, the percent identity between two amino acid sequences is determined using the Needleman and Wunsch, (1970, J. Mol. Biol. 48: 444-453) algorithm which has been incorporated into the GAP program in the GCG software package, using either a Blossum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6. In yet another preferred embodiment, the percent identity between two nucleotide sequences is determined using the GAP program in the GCG software package, using an NWSgapdna.CMP matrix and a gap weight of 40, 50, 60, 70, or 80 and a length weight of 1, 2, 3, 4, 5, or 6. Another exemplary set of parameters includes a Blossum 62 scoring matrix with a gap penalty of 12, a gap extend penalty of 4, and a frameshift gap penalty of 5. The percent identity between two amino acid or nucleotide sequences can also be determined using the algorithm of E. Meyers and W. Miller (1989, Cabios, 4: 11-17) which has been incorporated into the ALIGN program (version 2.0), using a PAM120 weight residue table, a gap length penalty of 12 and a gap penalty of 4. The peptide sequences described herein can be used as a “query sequence” to perform a search against public databases to, for example, identify other family members or related sequences. Such searches can be performed using the NBLAST and XBLAST programs (version 2.0) of Altschul, et al., (1990, J. Mol. Biol, 215: 403-10). BLAST nucleotide searches can be performed with the NBLAST program, score=100, wordlength=12 to obtain nucleotide sequences homologous to nucleic acid molecules of the invention. BLAST protein searches can be performed with the XBLAST program, score=50, wordlength=3 to obtain amino acid sequences homologous to protein molecules of the invention. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul et al. (Nucleic Acids Res. 25:3389-3402, 1997). When utilizing BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used. The term “conservative substitution” as used herein denotes that one or more amino acids are replaced by another, biologically similar residue. Examples include substitution of amino acid residues with similar characteristics, e.g., small amino acids, acidic amino acids, polar amino acids, basic amino acids, hydrophobic amino acids and aromatic amino acids. See, for example, the table below. In some embodiments of the invention, one or more Met residues are substituted with norleucine (Nle) which is a bioisostere for Met, but which, as opposed to Met, is not readily oxidized. Another example of a conservative substitution with a residue normally not found in endogenous, mammalian peptides and proteins is the conservative substitution of Arg or Lys with, for example, ornithine, canavanine, aminoethylcysteine or another basic amino acid. In some embodiments, one or more cysteines of a peptide analogue of the invention may be substituted with another residue, such as a serine. For further information concerning phenotypically silent substitutions in peptides and proteins, see, for example, Bowie et. al. Science 247, 1306-1310, 1990. In the scheme below, conservative substitutions of amino acids are grouped by physicochemical properties. I: neutral, hydrophilic, II: acids and amides, III: basic, IV: hydrophobic, V: aromatic, bulky amino acids. In the scheme below, conservative substitutions of amino acids are grouped by physicochemical properties. VI: neutral or hydrophobic, VII: acidic, VIII: basic, IX: polar, X: aromatic.

The term “amino acid” or “any amino acid” as used here refers to any and all amino acids, including naturally occurring amino acids (e.g., a-amino acids), unnatural amino acids, modified amino acids, and non-natural amino acids. It includes both D- and L-amino acids. Natural amino acids include those found in nature, such as, e.g., the 23 amino acids that, combine into peptide chains to form the building-blocks of a vast array of proteins. These are primarily L stereoisomers, although a few D-amino acids occur in bacterial envelopes and some antibiotics. The 20 “standard,” natural amino acids are listed in the above tables. The “non-standard,” natural amino acids are pyrrolysine (found in methanogenic organisms and other eukaryotes), selenocysteine (present in many noneukaryotes as well as most eukaryotes), and N-formylmethionine (encoded by the start codon AUG in bacteria, mitochondria and chloroplasts). “Unnatural” or “non-natural” amino acids are non-proteinogenic amino acids (i.e., those not naturally encoded or found in the genetic code) that either occur naturally or are chemically synthesized. Over 140 unnatural amino acids are known and thousands of more combinations are possible. Examples of “unnatural” amino acids include P-amino acids (P ³ and p ² ), homo-amino acids, proline and pyruvic acid derivatives, 3-substituted alanine derivatives, glycine derivatives, ring-substituted phenylalanine and tyrosine derivatives, linear core amino acids, diamino acids, D-amino acids, alpha-methyl amino acids and N-methyl amino acids. Unnatural or non-natural amino acids also include modified amino acids. “Modified” amino acids include amino acids (e.g., natural amino acids) that have been chemically modified to include a group, groups, or chemical moiety not naturally present on the amino acid.

For the most part, the names of naturally occurring and non-naturally occurring aminoacyl residues used herein follow the naming conventions suggested by the IUPAC Commission on the Nomenclature of Organic Chemistry and the IUPAC-IUB Commission on Biochemical Nomenclature as set out in “Nomenclature of a-Amino Acids (Recommendations, 1974)” Biochemistry', 14(2), (1975). To the extent that the names and abbreviations of amino acids and aminoacyl residues employed in this specification and appended claims differ from those suggestions, they will be made clear to the reader. Some abbreviations useful in describing the invention are defined below. Abbreviations of Non-Natural Amino Acids and Chemical Moieties (for amino acid derivatives, all L unless stated) Abbreviation Definition Ac- Acetyl Hy Hydrogen (Free N-terminal) Dap L-Diaminopropionic acid Dab L-Diaminobutyric acid Orn L-Ornathine Pen L-Penicillamine Sarc Sarcosine Cit L-Citrulline Cav L-Cavanine Phe-(4-Guanidino) 4-Guanidine-L-Phenylalanine N-MeArg N-Methyl-L-Arginine N-MeTrp N-Methyl-L-Tryptophan N-MeGln N-Methyl-L-Glutamine N-MeAla N-Methyl-L-Alanine N-MeLys N-Methyl-Lysine N-MeAsn N-Methyl-L-Asparagine 6-ChloroTrp 6-Chloro-L-Tryptophan 5-HydroxyTrp 5-Hydroxy-L-Tryptophan 1,2,3,4-tetrahydro-norharman L-1,2,3,4-tetrahydro-norharman 2-Nal L-2-Napthylalanine (also referred to as 2-Nap) 1-Nal L-1-Napthylalanine (also referred to as 1-Nap) Phe(4-OMe) 4-Methoxy-L-phenylalanine Abu 2-Aminobutyric acid Bip L-^^^ƍ-Biphenylalanine ȕ$OD beta-Alanine ȕK7\U beta homo-L-Tyrosine ȕK7US beta homo-L-Trptophan ȕK$OD beta homo-L-Alanine ȕK/HX^ beta homo-L-Leucine ȕK9DO beta homo-L-Valine Aib 2-aminoisobutyric acid Azt L-azetidine-2-carboxylic acid Tic (3S)-1,2,3,4- Tetrahydroisoquinoline-7-hydroxy- 3-carboxylic Acid Phe(4-OMe) 4-methoxy-L-phenylalanine N-Me-Lys N-Methyl-L-Lysine N-Me-Lys(Ac) N-İ-Acetyl-D-lysine CONH ₂ Carboxamide COOH Acid 3-Pal L-3-Pyridylalanine Phe(4-F) 4-Fluoro-L-Phenylalanine DMT 2,6-DimethylTyrosine Phe(4-OMe) 4-Methoxyphenylalanine hLeu L-homoLeucine hArg L-homoArginine Į-MeLys alpha-methyl-L-Lysine Į-MeOrn alpha-methyl-L-Ornathine Į-MeLeu alpha-methyl-L-Leucine Į-MeTrp alpha-methyl-L-Tryptophan Į-MePhe alpha-methyl-L-Phenylalanine Į-MeTyr alpha-methyl-L-Tyrosine Į-DiethylGly Į-DiethylGlycine Lys(Ac) N-İ-acetyl-L-Lysine DTT Dithiothreotol Nle L-Norleucine ȕK7US L-ȕ-homoTrypophan ȕK3KH L-ȕ-homophenylalanine ȕK3UR L-ȕ-homoproline Phe(4-CF ₃ ) 4-Trifluoromethyl-L-Phenylalanine ȕ-Glu L-ȕ-Glutamic acid ȕK*OX L-ȕ-homog1utamic acid 2-2-Indane 2-Aminoindane-2-carboxylic acid 1-1-Indane 1-Aminoindane-1-carboxylic acid hCha L-homocyclohexylalanine Cyclobutyl L-cyclobutylalanine ȕK3KH L-ȕ-homo-phenylalanine Gla Gama-Carboxy-L-Glutamic acid Cpa Cyclopentyl-L-alanine Cha Cyclohexyl-L-alanine Octgly L-Octylglycine t-butyl-Ala 3-(tert-butyl)-L-Ala-OH t-butyl-Gly tert-butyl-glycine AEP 3-(2-aminoethoxy)propanoic acid AEA (2-aminoethoxy)acetic acid Phe(4-Phenoxy)] 4-Phenoxy-L-phenylalanine Phe(4-OBzl) O-Benzyl-L-tyrosine Phe(4-CONH ₂ ) 4-Carbamoyl-L-phenylalanine Phe(4-CO ₂ H) 4-Carboxy-L-phenylalanine Phe(3,4-Cl2) 3,4 dichloro-L-phenylalanine Tyr(3-t-Bu) 3-t-butyl-L-tyrosine Phe(t-Bu) t-butyl-L-phenylalanine Phe[4-(2-aminoethoxy)] Phe(4-CN) 4-cyano-L-phenylalanine Phe(4-Br) 4-bromo-L-phenylalanine Phe(4-NH ₂ ) 4-amino-L-phenylalanine Phe(4-Me) 4-methyl-L-phenylalanine 4-Pyridylalanine 4-L-Pyridylalanine 4-amino-4-carboxy- piperidine hPhe(3,4-dimethoxy) 3,4-dimethoxy-L-homophenylalanine Phe(2,4-Me ₂ ) 2,4-dimethyl-L-phenylalanine Phe(3,5-F2) 3,5-difluoro-L-phenylalanine Phe(penta-F) pentafluoro-L-phenylalanine 2,5,7-tert butyl Trp 2,5,7-Tris-tert-butyl-L-tryptophan Tic Phe(4-OAlly1) Phe(4-N ₃ ) Achc Acvc Acbc Acpc

1- aminocyclopropylcarboxylic acid

4-amino-4-carboxy- tetrahydropyran (also referred as THP)

4-amino-4- carboxy- tetrahydropyran

Throughout the present specification, unless naturally occurring amino acids are referred to by their full name (e.g. alanine, arginine, etc.), they are designated by their conventional three-letter or single-letter abbreviations (e.g. Ala or A for alanine, Arg or R for arginine, etc.). Unless otherwise indicated, three-letter and single-letter abbreviations of amino acids refer to the L-isomeric form of the amino acid in question . The term “L-amino acid,” as used herein, refers to the ‘17’ isomeric form of a peptide, and conversely the term “D-aniino acid” refers to the “D” isomeric form of a peptide (e.g., Dasp, (D)Asp or D-Asp;

Dphe, (D)Phe or D-Phe). Amino acid residues in the D isomeric form can be substituted for any L-amino acid residue, as long as the desired function is retained by the peptide. D- amino acids may be indicated as customary in lower case when referred to using singleletter abbreviations.

In the case of less common or non-naturally occurring amino acids, unless they are referred to by their full name (e.g. sarcosine, ornithine, etc.), frequently employed three- or four-character codes are employed for residues thereof, including, Sar or Sarc (sarcosine, i.e. N-methylglycine), Alb (a-aminoisobutyric acid), Dab (2,4-diaminobutanoic acid), Dapa (2,3-diaminopropanoic acid), y-Glu (y-glutamic acid), Gaba (y-aminobutanoic acid), P-Pro (pyrrolidine-3-carboxylic acid), and 8Ado (8-amino-3,6-dioxaoctanoic acid), .Abu (2-amino butyric acid), phPro (p-homoproline), piiPhe (p-homophenylalanine) and Bip (P,p di phenyl alanine), and Ida (Iminodiacetic acid). As is clear to the skilled artisan, the peptide sequences disclosed herein are shown proceeding from left to right, with the left end of the sequence being the N-terminus of the peptide and the right end of the sequence being the C-terminus of the peptide. Among sequences disclosed herein are sequences incorporating a “Hy-” moiety at the amino terminus (N-terminus) of the sequence, and either an “—OH” moiety or an “—NH ₂ ” moiety at the carboxy terminus (C-terminus) of the sequence. In such cases, and unless otherwise indicated, a “Hy-” moiety at the N-terminus of the sequence in question indicates a hydrogen atom, corresponding to the presence of a free primary or secondary amino group at the N-terminus, while an “—OH” or an “—NH ₂ ” moiety at the C-terminus of the sequence indicates a hydroxy group or an amino group, corresponding to the presence of an amido (CONH ₂ ) group at the C-terminus, respectively. In each sequence of the invention, a C-terminal “—OH” moiety may be substituted for a C-terminal “—NH ₂ ” moiety, and vice- versa. The term “NH ₂ ,” as used herein, refers to a free amino group present at the amino terminus of a polypeptide. The term “OH,” as used herein, refers to a free carboxy group present at the carboxy terminus of a peptide. Further, the term “Ac,” as used herein, refers to Acetyl protection through acylation of the C- or N-terminus of a polypeptide. The term “carboxy,” as used herein, refers to —CO2H. The term “isostere replacement,” as used herein, refers to any amino acid or other analog moiety having chemical and/or structural properties similar to a specified amino acid. The term “pharmaceutically acceptable salt,” as used herein, represents salts or zwitterionic forms of the peptides or compounds of the present invention which are water or oil-soluble or dispersible, which are suitable for treatment of diseases without undue toxicity, irritation, and allergic response; which are commensurate with a reasonable benefit/risk ratio, and which are effective for their intended use. The salts can be prepared during the final isolation and purification of the compounds or separately by reacting an amino group with a suitable acid. Representative acid addition salts include acetate, adipate, alginate, citrate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate, digluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate, formate, fumarate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethansulfonate (isethionate), lactate, maleate, mesitylenesulfonate, methanesulfonate, naphthylenesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, pamoate, pectinate, persulfate, 3-phenylproprionate, picrate, pivalate, propionate, succinate, tartrate, trichloroacetate, trifluoroacetate, phosphate, glutamate, bicarbonate, para-toluenesulfonate, and undecanoate. Also, amino groups in the compounds of the present invention can be quaternized with methyl, ethyl, propyl, and butyl chlorides, bromides, and iodides; dimethyl, diethyl, dibutyl, and diamyl sulfates; decyl, lauryl, myristyl, and steryl chlorides, bromides, and iodides; and benzyl and phenethyl bromides. Examples of acids which can be employed to form therapeutically acceptable addition salts include inorganic acids such as hydrochloric, hydrobromic, sulfuric, and phosphoric, and organic acids such as oxalic, maleic, succinic, and citric. A pharmaceutically acceptable salt may suitably be a salt chosen, e.g., among acid addition salts and basic salts. Examples of acid addition salts include chloride salts, citrate salts and acetate salts. Examples of basic salts include salts where the cation is selected among alkali metal cations, such as sodium or potassium ions, alkaline earth metal cations, such as calcium or magnesium ions, as well as substituted ammonium ions, such as ions of the type N(R1)(R2)(R3)(R4)+, where R1, R2, R3 and R4 independently will typically designate hydrogen, optionally substituted C1-6-alkyl or optionally substituted C2-6-alkenyl. Examples of relevant C1-6-alkyl groups include methyl, ethyl, 1-propyl and 2-propyl groups. Examples of C2-6-alkenyl groups of possible relevance include ethenyl, 1-propenyl and 2-propenyl. Other examples of pharmaceutically acceptable salts are described in “Remington's Pharmaceutical Sciences”, 17th edition, Alfonso R. Gennaro (Ed.), Mark Publishing Company, Easton, Pa., USA, 1985 (and more recent editions thereof), in the “Encyclopaedia of Pharmaceutical Technology”, 3rd edition, James Swarbrick (Ed.), Informa Healthcare USA (Inc.), NY, USA, 2007, and in J. Pharm. Sci. 66: 2 (1977). Also, for a review on suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley-VCH, 2002). Other suitable base salts are formed from bases which form non-toxic salts. Representative examples include the aluminum, arginine, benzathine, calcium, choline, diethylamine, diolamine, glycine, lysine, magnesium, meglumine, olamine, potassium, sodium, tromethamine, and zinc salts. Hemisalts of acids and bases may also be formed, e.g., hemisulphate and hemicalcium salts. The term “alkyl” includes a straight chain or branched, noncyclic or cyclic, saturated aliphatic hydrocarbon containing from 1 to 24 carbon atoms. Representative saturated straight chain alkyls include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n- pentyl, n-hexyl, and the like, while saturated branched alkyls include, without limitation, isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, and the like. Representative saturated, cyclic alkyls include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like, while unsaturated cyclic alkyls include, without limitation, cyclopentenyl, cyclohexenyl, and the like.

The term “mammal” refers to any mammalian species such as a human, mouse, rat, dog, cat, hamster, guinea pig, rabbit, livestock, and the like.

As used herein, a “therapeutically effective amount” of the peptide inhibitor of the invention is meant to describe a sufficient amount of the peptide inhibitor to treat a. coronavirus infection (e.g., Covid- 19). In particular embodiments, the therapeutically effective amount will achieve a desired benefit/risk ratio applicable to any medical treatment.

An “analog” of an amino acid, e.g., a “Phe analog” or a “Tyr analog” means an analog of the referenced amino acid. A variety of amino acid analogs are known and available in the art, including Phe and Tyr analogs. In certain embodiments, an amino acid analog, e.g., a. Phe analog or a Tyr analog comprises one, two, three, four or five substitutions as compared to Phe or Tyr, respectively. In certain embodiments, the substi tutions are present in the side chai ns of the amino acids. In certain embodiments, a Phe analog has the structure Phe(R ² ), wherein R ² is a Hy, OH, CEE, CO2H, CONH2, CONH2OCH2CH2NH2, t-Bu, OCH2CH2NH2, phenoxy, OCH3, OAHyl, Br, Cl, F, Ni l :, N3, or guanadino. In certain embodiments, R ² is CONH2OCH2CH2NH2, OCH3, CONH2, OCH3 or CO2H. Examples of Phe analogs include, but are not limited to: hPhe, Phe(4- OMe), a-Me-Phe, hPhe(3,4-dimethoxy), Phetd-CONth), Phe(4-phenoxy), Phe(4- guanadino), Phe(4-tBu), Phe(4-CN), Phe(4-Br), Phe(4-OBzl), Phe(4-NH ₂ ), BhPhe(4-F), Phe(4-F), Phe(3,5 DiF), Phe(Cl b.CO -H).. Phe(penta-F), Phe(3,4-Ch), Phe (3,4-F ₂ ), Phe(4- CF3), pP-diPheAla, Phe(4-N?), Phe[4-(2-aminoethoxy)J, 4-Phenylbenzylalanine, Phe(4- CONH2), Phe(3,4-Di methoxy), Phe(4-CF3), Phe(2,3-Ch), and Phe(2,3-F2). Examples of Tyr analogs include, but are not limited to: hTyr, N-Me-Tyr, Tyr(3-tBu), Tyr(4-Nj) and phTyr.

Peptides

Disclosed herein are isolated peptides derived, from an examination of the interaction of a coronavirus spike protein and the angiotensin-converting enzyme 2 protein (ACE2), which is the viral entry receptor for coronaviral infections. As disclosed herein, certain residues of ACE2 served as contact residues for the spike protein and followed the sequence motif EDX1X2YQ (SEQ ID NO: 20); LX1X2MY (SEQ ID NO: 21), and/or TFX ₁ DKX ₂ X ₃ HE (SEQ ID NO: 22). Accordingly, disclosed herein are peptides comprising the sequence EDX ₁ X ₂ YQ; wherein X ₁ is L, A, I, V, G, or P; and wherein X ₂ is F, Y, or W (for example, EDAFYQ EDLFYQ, EDLYYQ, EDAFYQ, EDAYYQ, EDAWYQ, EDIFYQ, EDIYYQ, EDIWYQ, EDLVFYQ, EDVYYQ, EDVWYQ, EDGFYQ, EDGYYQ, EDGWYQ, EDPFYQ, EDPYYQ, OR EDPWYQ), . For example, disclosed herein are peptides, wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15. Also disclosed herein are isolated peptides, wherein the peptide comprises the sequence LX1X2MY; wherein X1 is A, I, V, L, G, or P; and wherein X2 is Q, S, T, C, N, or M (such as, for example, peptides consisting of SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17 as well as, peptides comprising or consisting of LAQMY, LASMY, LATMY, LACMY, LANMY, LAMMY, LIQMY, LISMY, LITMY, LICMY, LINMY, LIMMY, LVQMY, LVSMY, LVTMY, LVCMY, LVNMY, LVMMY, LLQMY, LLSMY, LLTMY, LLCMY, LLNMY, LLMMY, LGQMY, LGSMY, LGTMY, LGCMY, LGNMY, LGMMY). In some aspects, disclosed herein are isolated peptides, wherein the peptide comprises the sequence TFX1DKX2X3HE; wherein X1 is L, A, I, V, G, or P, wherein X2 is F, Y, or W; and wherein X3 is N, Q, S, T, C, or M .For example, disclosed herein are isolated peptides, wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. The disclosed peptides can be between 6 and 30 amino acids in length, between 10 and 30 amino acids in length. For example, is some aspects the isolated peptides are 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,or 30 amino acids long. In one aspect, the disclosed peptides do not include naturally occurring peptides. Therefore, disclosed herein are isolated peptides of any preceding aspect, wherein the peptide comprises the sequence EDX1X2YQ; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15; wherein the peptide comprises the sequence LX ₁ X ₂ MY; and wherein the peptide does not comprise SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17.; or wherein the peptide comprises the sequence TFX ₁ DKX ₂ X ₃ HE; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14 It is understood and herein contemplated that the disclosed peptides can be prepared in a composition with a pharmaceutically acceptable excipient. Thus, in one aspect disclosed herein are composition comprising one or more of the isolated peptides disclosed herein. For example, the composition can comprise any 6-30 amino acid long peptides comprising the sequence motif as set forth in EDX1X2YQ (SEQ ID NO: 20); LX1X2MY (SEQ ID NO: 21), and/or TFX ₁ DKX ₂ X ₃ HE (SEQ ID NO: 22). In one aspect, the peptide of the composition can consist of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, or-SEQ ID NO: 19. It is understood and herein contemplated that the combination of multiple differnt peptides in a single composition can have synergistic effect on the ability to inhibit viral entry by a spike protein, inhibit infection, treat an ongoing infection, and/or provide benefits for longer term sequalae of infection. Thus, in one aspect, disclosed herein are compositions comprising any combination of two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, ninetheen or more of the isolated peptides as set forth in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, and-SEQ ID NO: 19. It is understood and herein contemplated that the disclosed compositions are useful in the treatment and prevention of coronaviral infections. Thus, in one aspect, disclosed herein are any composition disclosed herein further comprising one or more antiviral agents (such as, for example, Remdesivir and/or an anti-coronavirus monoclonal antibody, such as bamlanivimab, etesevimab, casirivimab, imdevimab, sotrovimab, or any combination thereof). It is further understood and herein contemplated that the dislosed peptides and compositions can be useful in the generation of antibody responses to the spike protein. In particular, the peptides (such as, for example SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, and-SEQ ID NO: 19) and compositions disclosed herein comprising said peptides can cause the virus to agglutinate at the viral entry receptor. This leads to the generation of IgA and IgM antibodies and can also provide a vehicle for enhanced endogenous T cell responses (including, but not limited to TH1 and TH2 CD4 T cells responses, the generation and/or activation of CD8 effector T cells, and/or the activation of CD8 memory T cells). Thus, in one aspect, disclosed herein are methods of stimulating and/or enhancing an endogenous immune response in a subject to a coronavirus comprising administereing to the subject one or more of the peptides and/or compositions disclosed herein. In one aspect the stimulated and/or enhanced endogenous immune response is an IgA or IgM response. In one aspect, the stimulated and/or enhanced endogenous immune response is a CD4 and/or CD8 T cell response. The disclosed peptides and compositions can be useful in pharmaceutical uses, but also propylitic use such as disinfectant, surface cleaner or in livestock building ventilation systems etc. Thus, disclosed herein are disinfectant, surface cleaners, airfilters, and detergents for cleaning humans, livestock, and/or companion animals comprising any of the peptides or compositions disclosed herein. Pharmaceutical Compositions When employed as pharmaceuticals, the peptides and compositions provided herein can be administered in the form of pharmaceutical compositions. These compositions can be prepared as described herein or elsewhere, and can be administered by a variety of routes, depending upon whether local or systemic treatment is desired and upon the area to be treated. Administration may be topical (including transdermal, epidermal, ophthalmic and to mucous membranes including intranasal, vaginal and rectal delivery), pulmonary (e.g., by inhalation or insufflation of powders or aerosols, including by nebulizer; intratracheal or intranasal administration), oral, or parenteral. In some embodiments, the composition can be formulated and administered a nasal spray or mist. In some embodiments, the composition can be formulated to deliver the peptides and compositions described herein to the nasal passageways of a subject. In some embodiments, the composition can be formulated to deliver the peptides and compositions described herein to the upper respiratory tract of a subject. In some embodiments, the composition can be formulated to deliver the peptides and compositions described herein to the lower respiratory tract of a subject. Parenteral administration includes intravenous, intraarterial, subcutaneous, intraperitoneal intramuscular or injection or infusion; or intracranial, (e.g., intrathecal or intraventricular, administration). Parenteral administration can be in the form of a single bolus dose, or may be, for example, by a continuous perfusion pump. In some embodiments, the compounds provided herein, or a pharmaceutically acceptable salt thereof, are suitable for parenteral administration. In some embodiments, the compounds provided herein are suitable for intravenous administration. In some embodiments, the compounds provided herein are suitable for oral administration. In some embodiments, the compounds provided herein are suitable for topical administration. Pharmaceutical compositions and formulations for topical administration may include, but are not limited to, transdermal patches, ointments, lotions, creams, gels, drops, suppositories, sprays, liquids and powders. Conventional pharmaceutical carriers, aqueous, powder or oily bases, thickeners and the like may be necessary or desirable. In some embodiments, the pharmaceutical compositions provided herein are suitable for parenteral administration. In some embodiments, the pharmaceutical compositions provided herein are suitable for intravenous administration. In some embodiments, the pharmaceutical compositions provided herein are suitable for oral administration. In some embodiments, the pharmaceutical compositions provided herein are suitable for topical administration. In some embodiments, the composition can comprise a nasal spray or mist. In some embodiments, the composition can be a formulation for use in irrigation of nasal passageways. Also provided are pharmaceutical compositions which contain, as the active ingredient, a compound provided herein in combination with one or more pharmaceutically acceptable carriers (e.g. excipients). In making the pharmaceutical compositions provided herein, the active ingredient is typically mixed with an excipient, diluted by an excipient or enclosed within such a carrier in the form of, for example, a capsule, sachet, paper, or other container. When the excipient serves as a diluent, it can be a solid, semi-solid, or liquid material, which acts as a vehicle, carrier or medium for the active ingredient. Thus, the compositions can be, for example, in the form of tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols (as a solid or in a liquid medium), ointments, soft and hard gelatin capsules, suppositories, sterile injectable solutions, and sterile packaged powders. Some examples of suitable excipients include, without limitation, lactose, dextrose, xylitol, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, and methyl cellulose. The formulations can additionally include, without limitation, lubricating agents such as talc, magnesium stearate, and mineral oil; wetting agents; emulsifying and suspending agents; preserving agents such as methyl- and propylhydroxy-benzoates; sweetening agents; flavoring agents, or combinations thereof. The active compound can be effective over a wide dosage range and is generally administered in an effective amount. It will be understood, however, that the amount of the compound actually administered will usually be determined by a physician, according to the relevant circumstances, including the condition to be treated, the chosen route of administration, the actual compound administered, the age, weight, and response of the individual subject, the severity of the subject’s symptoms, and the like. The compositions provided herein can be administered one from one or more times per day to one or more times per week; including once every other day. The skilled artisan will appreciate that certain factors can influence the dosage and timing required to effectively treat a subject, including, but not limited to, the severity of the disease or disorder, previous treatments, the general health and/or age of the subject, and other diseases present. Moreover, treatment of a subject with a therapeutically effective amount of a compound described herein can include a single treatment or a series of treatments. Dosage, toxicity and therapeutic efficacy of the compounds provided herein can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD ₅₀ /ED ₅₀ . Compounds exhibiting high therapeutic indices are preferred. While compounds that exhibit toxic side effects can be used, care should be taken to design a delivery system that targets such compounds to the site of affected tissue in order to minimize potential damage to uninfected cells and, thereby, reduce side effects. In some embodiments, the compositions described herein may further contain (or be administered in combination or alternation with) one or more additional active agents. Representative examples additional active agents include agents for the treatment and/or prevention of coronavirus infections such as SARS-CoV-2 infections (e.g., an anti- coronavirus monoclonal antibody, such as bamlanivimab, etesevimab, casirivimab, imdevimab, sotrovimab, or any combination thereof), other antimicrobial agents (including antibiotics, antiviral agents and anti-fungal agents), anti-inflammatory agents (including steroids and non-steroidal anti-inflammatory agents), anti-coagulant agents, immunomodulatory agents, anticytokine, antiplatelet agents, and antiseptic agents. Representative examples of antibiotics include amikacin, amoxicillin, ampicillin, atovaquone, azithromycin, aztreonam, bacitracin, carbenicillin, cefadroxil, cefazolin, cefdinir, cefditoren, cefepime, cefiderocol, cefoperazone, cefotetan, cefoxitin, cefotaxime, cefpodoxime, cefprozil, ceftaroline, ceftazidime, ceftibuten, ceftizoxime, ceftriaxone, chloramphenicol, colistimethate, cefuroxime, cephalexin, cephradine, cilastatin, cinoxacin, ciprofloxacin, clarithromycin, clindamycin, dalbavancin, dalfopristin, daptomycin, demeclocycline, dicloxacillin, doripenem, doxycycline, eravacycline, ertapenem, erythromycin, fidaxomicin, fosfomycin, gatifloxacin, gemifloxacin, gentamicin, imipenem, lefamulin, lincomycin, linezolid, lomefloxacin, loracarbef, meropenem, metronidazole, minocycline, moxifloxacin, nafcillin, nalidixic acid, neomycin, norfloxacin, ofloxacin, omadacycline, oritavancin, oxacillin, oxytetracycline, paromomycin, penicillin, pentamidine, piperacillin, plazomicin, quinupristin, rifaximin, sarecycline, secnidazole, sparfloxacin, spectinomycin, sulfamethoxazole, sulfisoxazole, tedizolid, telavancin, telithromycin, ticarcillin, tigecycline, tobramycin, trimethoprim, trovafloxacin, and vancomycin. Representative examples of antiviral agents include, but are not limited to, abacavir, acyclovir, adefovir, amantadine, amprenavir, atazanavir, balavir, baloxavir marboxil, boceprevir, cidofovir, cobicistat, daclatasvir, darunavir, delavirdine, didanosine, docasanol, dolutegravir, doravirine, ecoliever, edoxudine, efavirenz, elvitegravir, emtricitabine, enfuvirtide, entecavir, etravirine, famciclovir, fomivirsen, fosamprenavir, forscarnet, fosnonet, famciclovir, favipravir, fomivirsen, foscavir, ganciclovir, ibacitabine, idoxuridine, indinavir, inosine, inosine pranobex, interferon type I, interferon type II, interferon type III, lamivudine, letermovir, letermovir, lopinavir, loviride, maraviroc, methisazone, moroxydine, nelfinavir, nevirapine, nitazoxanide, oseltamivir, peginterferon alfa-2a, peginterferon alfa-2b, penciclovir, peramivir, pleconaril, podophyllotoxin, pyramidine, raltegravir, remdesevir, ribavirin, rilpivirine, rimantadine, rintatolimod, ritonavir, saquinavir, simeprevir, sofosbuvir, stavudine, tarabivirin, telaprevir, telbivudine, tenofovir alafenamide, tenofovir disoproxil, tenofovir, tipranavir, trifluridine, trizivir, tromantadine, umifenovir, valaciclovir, valganciclovir, vidarabine, zalcitabine, zanamivir, and zidovudine. Representative examples of anticoagulant agents include, but are not limited to, heparin, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin, and fondaparinux. Representative examples of antiplatelet agents include, but are not limited to, clopidogrel, ticagrelor, prasugrel, dipyridamole, dipyridamole/aspirin, ticlopidine, and eptifibatide. Representative examples of antifungal agents include, but are not limited to, voriconazole, itraconazole, posaconazole, fluconazole, ketoconazole, clotrimazole, isavuconazonium, miconazole, caspofungin, anidulafungin, micafungin, griseofulvin, terbinafine, flucytosine, terbinafine, nystatin, and amphotericin b. Representative examples of steroidal anti-inflammatory agents include, but are not limited to, hydrocortisone, dexamethasone, prednisolone, prednisone, triamcinolone, methylprednisolone, budesonide, betamethasone, cortisone, and deflazacort. Representative examples of non-steroidal anti-inflammatory drugs include ibuprofen, naproxen, ketoprofen, tolmetin, etodolac, fenoprofen, flurbiprofen, diclofenac, piroxicam, indomethacin, sulindax, meloxicam, nabumetone, oxaprozin, mefenamic acid, and diflunisal. Other examples of additional active agents include chloroquine, hydrochloroquine, Vitamin D, and Vitamin C. Methods of Use As noted above, the disclosed compositions and peptides are useful in the treatment and prevention of coronaviral infections. Specifically, the disclosed peptides can disrupt and otherwise inhibit viral entry into a cell via ACE2. Thus, in one aspect, disclosed herein are method of inhibiting, reducing, decreasing, and/or preventing viral entry (such as, for example, entry of a coronavirus including, but not limited to avian coronavirus (IBV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV), feline infectious peritonitis virus (FIPV), feline enteric coronavirus (FECV), canine coronavirus (CCoV), rabbit coronavirus (RaCoV), mouse hepatitis virus (MHV), rat coronavirus (RCoV), sialodacryadenitis virus of rats (SDAV), bovine coronavirus (BCoV), bovine enterovirus (BEV), porcine coronavirus HKU15 (PorCoV HKU15), Porcine epidemic diarrhea virus (PEDV), porcine hemagglutinating encephalomyelitis virus (HEV), turkey bluecomb coronavirus (TCoV), human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV) (SARS- CoV), Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV)-2 (SARS-CoV-2) (including, but not limited to the B1.351 variant, B.1.1.7 variant, USA-WA1/2020, or P.1 variant), or middle east respiratory syndrome (MERS) coronavirus (CoV) (MERS-CoV)) in a cell of a subject comprising administering to the subject a therapeutically effective amount of the isolated peptides disclosed herein or a therapeutically effective amount of any of the compositions disclosed herein; wherein the viral entry receptor comprises human angiotensin-converting enzyme 2 (ACE2). For example, for the inhibition, reduction, and/or prevetntion of viral entry of a coronavirus, the subject can be administered a therapeutically effective amount of peptides comprising the sequence EDX1X2YQ (SEQ ID NO: 20); LX ₁ X ₂ MY (SEQ ID NO: 21), and/or TFX ₁ DKX ₂ X ₃ HE (SEQ ID NO: 22). In some aspects, peptide for use in the disclosed methods of inhibiting viral entry comprise the sequence EDX1X2YQ; wherein X1 is L, A, I, V, G, or P; and wherein X2 is F, Y, or W. For example, disclosed herein are methods of inhibiting viral entry, wherein the peptide comprises the sequence EDX ₁ X ₂ YQ; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15. Also disclosed herein are methods of inhibiting viral entry, wherein the peptide comprises the sequence LX ₁ X ₂ MY; wherein X ₁ is A, I, V, L, G, or P; and wherein X2 is Q, S, T, C, N, or M (such as, for example, peptides consisting of SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17). Also disclosed herein are methods of inhibiting viral entry, wherein the peptide comprises the sequence TFX1DKX2X3HE; wherein X1 is L, A, I, V, G, or P, wherein X2 is F, Y, or W; and wherein X3 is N, Q, S, T, C, or M .For example, the peptide can comprise the sequence TFX ₁ DKX ₂ X ₃ HE; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. In some aspects, the methods of inhibiting viral entry do not use a naturally occurring peptide alone, but can comprise the use of multiple naturally occurring peptides in a composition or one or more naturally occurring peptides in combination with an antiviral agent. Thus, disclosed herein are methods of inhibiting viral entry wherein the peptide comprises the sequence EDX1X2YQ; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15; wherein the peptide comprises the sequence LX1X2MY; and wherein the peptide does not comprise SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17.; or wherein the peptide comprises the sequence TFX ₁ DKX ₂ X ₃ HE; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. It is understood that the administration of the disclosed peptides and/or compositions can occur for therapeutic intervention or prophylactic uses. Thus, in one aspect, the disclosed compositions and/or peptides can be administered to the subject prior to or following exposure to or infection with the virus. Also disclosed herein are methods of treating, inhibiting, reducing, decreasing, and/or preventing a viral infection (such as, for example, entry of a coronavirus including, but not limited to avian coronavirus (IBV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV), feline infectious peritonitis virus (FIPV), feline enteric coronavirus (FECV), canine coronavirus (CCoV), rabbit coronavirus (RaCoV), mouse hepatitis virus (MHV), rat coronavirus (RCoV), sialodacryadenitis virus of rats (SDAV), bovine coronavirus (BCoV), bovine enterovirus (BEV), porcine coronavirus HKU15 (PorCoV HKU15), Porcine epidemic diarrhea virus (PEDV), porcine hemagglutinating encephalomyelitis virus (HEV), turkey bluecomb coronavirus (TCoV), human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV) (SARS-CoV), Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV)-2 (SARS-CoV-2) (including, but not limited to the B1.351 variant, B.1.1.7 variant, USA-WA1/2020, or P.1 variant), or middle east respiratory syndrome (MERS) coronavirus (CoV) (MERS-CoV)) in a subject comprising administering to the subject a therapeutically effective amount of the isolated peptides of any peptide disclosed herein or a therapeutically effective any composition disclosed herein. For example, disclosed herein are methods of treating, inhibiting, reducing, decreasing, and/or preventing a coronaviral infection comprising administering to the subject a therapeutically effective amount of peptides comprising the sequence EDX1X2YQ (SEQ ID NO: 20); LX ₁ X ₂ MY (SEQ ID NO: 21), and/or TFX ₁ DKX ₂ X ₃ HE (SEQ ID NO: 22). In some aspects, peptide for use in the disclosed methods of treating, inhibiting, reducing, decreasing, and/or preventing a coronaviral infection comprise the sequence EDX1X2YQ; wherein X1 is L, A, I, V, G, or P; and wherein X ₂ is F, Y, or W. For example, disclosed herein are methods of treating, inhibiting, reducing, decreasing, and/or preventing a coronaviral infection, wherein the peptide comprises the sequence EDX1X2YQ; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15. Also disclosed herein are methods of treating, inhibiting, reducing, decreasing, and/or preventing a coronaviral infection, wherein the peptide comprises the sequence LX1X2MY; wherein X1 is A, I, V, L, G, or P; and wherein X2 is Q, S, T, C, N, or M (such as, for example, peptides consisting of SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17). Also disclosed herein are methods of treating, inhibiting, reducing, decreasing, and/or preventing a coronaviral infection, wherein the peptide comprises the sequence TFX1DKX2X3HE; wherein X1 is L, A, I, V, G, or P, wherein X ₂ is F, Y, or W; and wherein X ₃ is N, Q, S, T, C, or M. For example, the peptide used in the disvlosed methods can comprise the sequence TFX1DKX2X3HE; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. In some aspects, the methods of inhibiting, reducing, decreasing, and/or preventing a coronaviral infection do not use a naturally occurring peptide alone, but can comprise the use of multiple naturally occurring peptides in a composition or one or more naturally occurring peptides in combination with an antiviral agent. Thus, isclosed herein are methods of inhibiting, reducing, decreasing, and/or preventing a coronaviral infection wherein the peptide comprises the sequence EDX1X2YQ; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15; wherein the peptide comprises the sequence LX1X2MY; and wherein the peptide does not comprise SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17.; or wherein the peptide comprises the sequence TFX ₁ DKX ₂ X ₃ HE; and wherein the peptide does not comprise SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. It is understood that the administration of the disclosed peptides and/or compositions can occur for therapeutic intervention or prophylactic uses. Thus, in one aspect, the disclosed compositions and/or peptides can be administered to the subject prior to or following exposure to or infection with the virus. In one aspect, the treatment of the coronaviral infection is not limited to inhibition, reduction, and/or amelioration of the actual infection, but also includes a inhibition, reduction, and/or amelioration of symptoms and long term residual complications and effects resulting from the infection (e.g., post-COVID-syndrome), such symptoms and/or complications including, but not limited to reduced sense of smell and/or taste, memory loss, fatigue, shortness of breath, cough, joint pain, difficulty concentrating, depression, muscle pain, headache, rapid heartbeat, Postural orthostatic tachycardia syndrome, diabetes, and intermittent fever. The administration of any of the peptides and/or compositions disclosed herein can be used to prevent, inhibit, reduce, ameliorate, and/or alleviate any one or combination of these symptoms in a subject with an active coronaviral infection as well as after clearance of said infection. Thus, in one aspect, disclosed herein are methods of treating, inhibiting, reducing, ameliorating, alleviating, and/or preventing one or more symptoms or post-infection complications (such as, for example, reduced sense of smell and/or taste, memory loss, fatigue, shortness of breath, cough, joint pain, difficulty concentrating, depression, muscle pain, headache, rapid heartbeat, Postural orthostatic tachycardia syndrome, diabetes, and intermittent fever) of a coronalviral infection such as, for example, entry of a coronavirus including, but not limited to avian coronavirus (IBV), porcine epidemic diarrhea virus (PEDV), porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus (TGEV), feline coronavirus (FCoV), feline infectious peritonitis virus (FIPV), feline enteric coronavirus (FECV), canine coronavirus (CCoV), rabbit coronavirus (RaCoV), mouse hepatitis virus (MHV), rat coronavirus (RCoV), sialodacryadenitis virus of rats (SDAV), bovine coronavirus (BCoV), bovine enterovirus (BEV), porcine coronavirus HKU15 (PorCoV HKU15), Porcine epidemic diarrhea virus (PEDV), porcine hemagglutinating encephalomyelitis virus (HEV), turkey bluecomb coronavirus (TCoV), human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV) (SARS- CoV), Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV)-2 (SARS-CoV-2) (including, but not limited to the B1.351 variant, B.1.1.7 variant, USA-WA1/2020, or P.1 variant), or middle east respiratory syndrome (MERS) coronavirus (CoV) (MERS-CoV)) comprising administering to the subject a therapeutically effective amount of peptides comprising the sequence EDX ₁ X ₂ YQ (SEQ ID NO: 20); LX ₁ X ₂ MY (SEQ ID NO: 21), and/or TFX1DKX2X3HE (SEQ ID NO: 22) and/or compositions disclosed herein comprising said peptides. In some aspects, peptide for use in the disclosed methods of treating, inhibiting, reducing, ameliorating, alleviating, and/or preventing one or more symptoms or post-infection complications of a coronaviral infection comprise the sequence EDX1X2YQ; wherein X1 is L, A, I, V, G, or P; and wherein X2 is F, Y, or W. For example, disclosed herein are methods of treating, inhibiting, reducing, ameliorating, alleviating, and/or preventing one or more symptoms or post-infection complications of a coronaviral infection, wherein the peptide comprises the sequence EDX1X2YQ; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 11, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15. Also disclosed herein are methods of treating, inhibiting, reducing, ameliorating, alleviating, and/or preventing one or more symptoms or post-infection complications of a coronaviral infection, wherein the peptide comprises the sequence LX1X2MY; wherein X1 is A, I, V, L, G, or P; and wherein X ₂ is Q, S, T, C, N, or M (such as, for example, peptides consisting of SEQ ID NO: 3, SEQ ID NO: 7, SEQ ID NO: 16, or SEQ ID NO: 17). Also disclosed herein are methods of treating, inhibiting, reducing, ameliorating, alleviating, and/or preventing one or more symptoms or post-infection complications of a coronaviral infection, wherein the peptide comprises the sequence TFX1DKX2X3HE; wherein X1 is L, A, I, V, G, or P, wherein X2 is F, Y, or W; and wherein X3 is N, Q, S, T, C, or M. For example, the peptide used in the disvlosed methods can comprise the sequence TFX ₁ DKX ₂ X ₃ HE; and wherein the peptide consists of SEQ ID NO: 1, SEQ ID NO: 5, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 14. EXAMPLES The invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes, and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of non- critical parameters which can be changed or modified to yield essentially the same results. Example 1: Rationally designed ACE2-derived peptides inhibit SARS-CoV-2. Overview Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 is a novel and highly pathogenic coronavirus and is the causative agent of the coronavirus disease 2019 (COVID- 19). The high morbidity and mortality associated with COVID-19 and the limited SARS- CoV-2 underscores the urgent need for developing effective antiviral therapies. Therapeutics that target essential viral proteins are effective at controlling virus replication and spread. Coronavirus Spike glycoproteins mediate viral entry and fusion with the host cell, and thus, are essential for viral replication. To enter host cells, the Spike proteins of SARS-CoV-2 and related coronavirus, SARS-CoV, bind the host angiotensin-converting enzyme 2 (ACE2) receptor through their receptor binding domains (RBDs). In this example, a panel of ACE2-derived peptides were designed based on the RBD-ACE2 binding interfaces of SARS-CoV-2 and SARS-CoV. Using SARS-CoV-2 and SARS-CoV Spike- pseudotyped viruses, subset of peptides were found to inhibit Spike-mediated infection with IC ₅₀ values in the low millimolar range. Two peptides were found that bound Spike RBD in affinity precipitation assays and inhibited infection with genuine SARS-CoV-2. Moreover, these peptides inhibited the replication of a common cold causing coronavirus, which also uses ACE2 as its entry receptor. Results from the infection experiments and modeling of the peptides with Spike RBD identified a six amino acid (Glu37-Gln42) ACE2 motif that is important for SARS-CoV-2 inhibition. These studies demonstrate the feasibility of inhibiting SARS-CoV-2 with peptide-based inhibitors. These findings allow for the successful development of engineered peptides and peptidomimetic-based compounds for the treatment of COVID-19. Background Of the seven coronaviruses known to infect humans, SARS-CoV-2 and two other highly pathogenic coronaviruses, SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), are the result of zoonotic transmission. Sequence analyses of coronaviruses have revealed that the SARS-CoV-2 genome shares ~80% identity with SARS-CoV and ~96% identity with bat coronavirus RaTG13. Similar to all coronaviruses, SARS-CoV-2 virions display the characteristic club-shaped projections formed by trimers of viral Spike glycoprotein on their surface. Spike proteins are essential for viral replication as they mediate viral entry into the host cell. During virion morphogenesis, the trimeric Spike protein is cleaved into the S1 and S2 subunits. The cleavage event positions the receptor-binding domain (RBD) in the S1 subunits in a receptor-accessible conformation and induces structural changes in the S2 subunits to stabilize its prefusion state. SARS-CoV and SARS-CoV-2 RBDs bind to the peptidase domain of human angiotensin-converting enzyme 2 (ACE2), which serves as the viral entry receptor. Binding of the RBD to ACE2 triggers another cleavage event of the S2 subunit, which results in formation of the six-helix bundle fusion core necessary for viral-host membrane fusion. The essential role of Spike protein in receptor binding and viral fusion makes it a target for vaccine candidate development and therapeutic interventions. Seminal SARS-CoV and SARS-CoV-2 structural studies have revealed the overall structures of Spike trimers, detailed atomic level structures of RBD bound to ACE2, and structural intermediates of the Spike-ACE2 interaction events. These structural studies have identified that SARS-CoV and SARS-CoV-2 Spikes bind ACE2 with a nearly identical binding mode – the N-terminal lobe of the ACE2 peptidase domain binds a concave groove on the Spike RBD. Moreover, these studies highlighted that SARS-CoV and SARS-CoV-2 have conserved interactions at the RBD-ACE2 binding interface. For example, 17/20 contacting amino acid residues in ACE2 have conserved interactions with the two RBDs. Likewise, 13/14 contacting residues in the two RBDs are either conserved or have conservatively substituted side chains. Given the significance of the RBD-ACE2 interaction interface for SARS-CoV-2 infection, computational approaches have identified potential inhibitory peptides that could interfere with the interaction of Spike protein with ACE2. These theoretical studies have suggested that regions in Spike and select residues in ACE2 could be exploited for competitive inhibition. While potentially promising, the antiviral potential of such peptides have not been experimentally evaluated. In this example, we performed comparative analyses of the SARS-CoV and SARS- CoV-2 RBD-ACE2 interaction interfaces to rationally design a panel of Spike-targeting ACE2-derived peptides (SAPs). A combination of approaches were used to evaluate the inhibitory potential, selective inhibition, and binding affinity of SAPs. Antiviral potential of selected SAPs was validated against two pathogenic human coronaviruses, SARS-CoV-2 and HCoV-NL63, both of which use ACE2 as entry receptors. Importantly, these findings provide a proof-of-principle and demonstrate feasibility of inhibiting SARS-CoV-2 infection by disrupting the Spike-ACE2 interaction interface with peptide-based inhibitors Materials and Methods Peptide design and recombinant proteins. SAPs were designed using the following published structures: SARS-CoV-2 Spike S1 subunit bound to ACE2 (PDB codes: 7A91-98), SARS-CoV-2 RBD bound to ACE2 (PDB codes: 6M0J and 6VW1), SARS-CoV RBD bound to ACE2 (PDB code: 2AJF), and SARS-CoV S1-S2 subunits bound to ACE2 (PDB codes: 6ACK, 6ACJ, 6ACC, 6ACD, and 6ACG). Sequence and structural comparisons of the SARS-CoV and SARS-CoV-2 binding interfaces with ACE2 were performed using Clustal Omega (EMBL-EBI, England), SWISS-MODEL (Biozentrum, Switzerland), and MUSTER (University of Michigan, USA). Once designed, synthetic SAPs were purchased from Biomatik (95% purity, with TFA removed) either unmodified or with an N-terminal FITC label (FITC-SAP). 1X Phosphate Buffered Saline (PBS) was used as a diluent to reconstitute SAPs. To improve the solubility of SAP1 and SAP2, 1X PBS was supplemented with 10% and 5% aqueous NH ₃ , respectively. Recombinant His-tagged SARS-CoV-2 Spike RBD (His-S RBD, amino acids Arg319- Phe541) was purchased from RayBiotech. Affinity precipitation assay. Affinity precipitation assays using Ni-NTA beads (GE Healthcare) were performed with His-S RBD and FITC-SAPs using known methods. Briefly, Ni-NTA beads were equilibrated in binding buffer (50 mM Tris pH 7.5, 250 mM NaCl, 50 mM LPLGD]ROH^^DQG^^^P0^ȕ-mercaptoethanol). Binding reactions were setup by incubating equilibrated Ni-NTA beads with His-S RBD (1 μM) and increasing concentrations (3, 1, 0.5, 0.25, and 0.125 mM) of indicated FITC-SAP in the binding buffer and incubated for 1 h at 4ºC. In parallel, control reactions with 3 mM of indicated FITC- SAP without His-S RBD were preformed to rule out non-specific FITC-SAP binding to the Ni-NTA beads. Reactions were spun and washed three times in the binding buffer to remove unbound proteins/peptides. The resulting protein-peptide complexes bound to the beads were extracted using NuPAGE lithium dodecyl sulfate sample buffer (Invitrogen), subjected to SDS-PAGE analysis, and visualized by Coomassie staining or fluorescence detection at 488 nm. Resulting FITC-labeled bands were quantified using ImageJ software. To estimate K _d values for FITC-SAP binding to His-S RBD, the data were fit to the Hill equation using Origin 8 software (OriginLab). Cells, plasmids, viruses. HEK293T (ATCC CRL-3216), HEK293T-ACE2 (BEI Resources), Vero E6 (ATCC CRL-1586), and LLC-MK2 (ATCC CCL-7) cells were cultured in Dulbecco's modified Eagle’s medium (DMEM, Gibco) supplemented with 10% fetal bovine serum (FBS, Gibco). HEK293T cells stably expressing GFP-tagged human ACE2 (HEK293T-ACE2-GFP) were generated using known methods, and were maintained in DMEM supplemented with 10% FBS and 1 μg/mL puromycin (Sigma). Plasmid encoding SARS-CoV-2 Spike (pCAGGS-SARS-CoV-2 Spike) was obtained from BEI Resources. Generation of plasmid encoding SARS-CoV Spike (pCAGGS-SARS-CoV Spike) has been described previously. Vesicular stomatitis virus-G (VSV-G) expression plasmid (pMD2.G) was purchased from Addgene. HIV-1-derived luciferase reporter vector (pNL4-3.Luc.R-E-) was obtained from NIH AIDS Reagent Program. SARS-CoV-2 USA-WA1/2020 stock virus was obtained from BEI Resources. Human coronavirus NL63 (HCoV-NL63) stock was obtained from Dr. Susan Baker (Loyola University, Chicago, IL). Pseudovirus production. Zz/d/mrs-e-encoding lentiviruses pseudotyped with viral glycoprotein of interest were generated using known methods. Briefly, HEK293T cells were transfected with pNL4-3.Luc.Rl? and pCAGGS-SARS-CoV-2 Spike, pCAGGS-SARS- CoV Spike, or pMD2.G using Fugene 6 transfection reagent (Roche) following manufacturer’s protocol. Forty-eight hours post-transfection, virus-containing supernatants were harvested, filtered through 0.45 pm sterile filter, and concentrated using Ami con Ultra-15 centrifugal filters (Millipore). Aliquots of pseudoviruses were stored at -80°C. The titers of SARS-CoV-2 Spike-, SARS-CoV Spike-, and VSV-G-pseudotyped viruses were in the range of 2 x 10 ⁵ , ~1 x 10 ³ , and ~3 x IO ⁷ relative luciferase units (RLUs)/ml, respectively.

Pseudovirus inhibition assay. HEK293T-ACE2 cells were seeded in pCIear Black 96-well plates (Greiner Bio-One) in 100 pl of DMEM supplemented with 10% FBS at a density of 1.25 x 10 ⁴ cells per well. Sixteen hours after plating, equal amounts (RLUs/ml) of a given pseudovirus were incubated with indicated concentrations of the test peptide or diluent control (IX PBS) in 50 pl of DMEM supplemented with 10% FBS for 1 h at 37°C in a V-bottom 96-well plate. The virus-peptide mixture was then added to the HEK293T- ACE2 cells. Polybrene (Sigma) at the final concentration of 5 pg/ml was added to the cells. After 48 h, 100 pl of supernatant was removed from each well and luciferase activity was measured using Bright-Glo Luciferase Assay System (Promega) following the manufacturer’s protocol. Luminescence was detected using an Infinite M PLEX multimode plate reader (Tecan).

Dose response curves. For dose response curves, the pseudovirus inhibition assays were performed with increasing concentrations of SAP (0.001, 0.01, 0.1, 1.0, 2.5, 5.0, and 7.5 mM). Percent viral inhibition was calculated as the percent reduction in luciferase activity of pseudovirus incubated with a given concentration of SAP compared to the pseudovirus incubated with the diluent control. The concentration of SAP that resulted in 50% inhibition of viral replication (ICso) was interpolated from a non-linear, best-fit curve using GraphPad Prism 8.0.2 software.

Biosafety procedures for live SARS-CoV-2 experiments. All experiments involving live SARS-CoV-2 were performed at Biosafety Level 3 (BSL3) according to the standard operating procedures approved by The Ohio State University BSL3 Operations Group (BOG) and Institutional Biosafety Committee. Infected cells were removed from the BSL3 facility for subsequent analyses after fixation with 4% paraformaldehyde for a minimum of 1 h in accordance with a validated decontamination protocol approved by the BOG and Institutional Biosafety Officer.

SARS-CoV-2 propagation. SARS-CoV-2 USA-WA1/2020 stock was diluted 1 : 10,000 in DMEM and added to confluent Veto E6 cells. After infection for 1 h at 37°C, media was replaced with DMEM supplemented with 4% FBS. Following incubation at 37°C for 72 h, virus-containing supernatant was clarified at 1,000 x g for 10 min to remove cell debris, aliquoted, flash frozen in liquid nitrogen, and stored at -80°C. The viral stock titer was determined by plaque assay on Vero E6 cells in 12-well plates with 0.3% low- melting agarose (Sigma) overlay and visualization with 0.25% crystal violet (Sigma).

SARS-CoV-2 infections. 10 ⁶ plaque-forming units of SARS-CoV -2 were incubated with 3 mM final concentration of the test peptide or diluent control (I X PBS) in 400 pl of DMEM for 1 h at 37°C. The virus-peptide mixture was then added to near-confluent HEK293T-ACE2-GFP cells in a 12-well plate. Infection was allowed to proceed for 1 h at 37°C at which point media was removed and replaced with 500 pl of DMEM supplemented with 10% FBS, After 24 h, the cells were harvested using 0.25% trypsin-EDTA (Gibco), fixed with 4% paraformaldehyde (Thermo Scientific) for 1 h at room temperature, permeabilized with IX PBS containing 0.1% Triton X-100, and blocked with IX PBS containing 2% FBS. The cells were then stained with anti -SARS-CoV-2 N mouse monoclonal antibody (1 : 1000, Sino Biological) followed by staining with anti-mouse AlexaFluor-647 secondary antibody (1 : 1000, Life Technologies). The stained cells were analyzed using a FACSCanto II flow cytometer (BD Biosciences). Flow cytometry data was analyzed using FlowJo software.

HCoV-NL63 propagation. HCoV-NL63 stock was expanded and titered on LLC- MK2 cells using previously described methods. The virus was aliquoted and stored at - 80°C.

HCoV-NL63 infections. HCoV~NL63 equivalent to MOI of 0.5 was incubated with 3 mM final concentration of the test peptide or diluent control (IX PBS) in 300 pl of DMEM for 1 h at 37°C. Confluent LLC-MK2 cells in 6-well plates were washed once with DMEM. The virus-peptide mixture was then added to LLC-MK2 cells in triplicate. Infection was allowed to proceed for 1 h at 37°C at which point media was removed and replaced with 1 ml of DMEM: supplemented with 2% FBS. After 72 h, the cytopathic effects (CPE) in each well were imaged under a light microscope. The cell culture supernatants were collected for virus titration by plaque assay. HCoV~NL63 plaque assay. Confluent LLC-MK2 cells in 6-well plates were infected with serial dilutions (ranging from 10' ¹ to IO" ⁷ ) of HCoV-NL63 in DMEM. After infection for 1 h at 37°C, cells were washed three times with DMEM and overlaid with 1% low-melting agarose in 2 ml of DMEM supplemented with 2% FBS. After incubation at 37°C for 5 days, cells \vere fixed with 4% paraformaldehyde for 2 h and plaques were visualized after staining with 0.05% crystal violet.

Results and Discussion

Rational design of ACE2-derived peptides. In order to design a panel of small peptide-based inhibitors that can block the interaction of SARS-CoV-2 Spike with the ACE2 receptor, a combination of structural and biochemical data, and known amino acid interactions necessary for binding of SARS-CoV and SARS-CoV-2 Spike proteins to ACE2 were utilized. This included: 1) crystal structures of ACE2 bound to SARS-CoV and SARS- CoV-2 Spike receptor binding domains (RBDs); 2) cryoEM structures of ACE2 in complex with trimeric SARS-CoV Spike and RBD or SI subunit of SARS-CoV-2 Spike; and 3) biochemical binding data of the ACE 2 -interacting motif with the SARS-CoV and SARS- CoV-2 Spikes. In particular, wre focused on the Spike-ACE2 interaction interface as it offers a prime target for competitive inhibition of viral entry. Structural and biochemical analyses suggest that SARS-CoV and SARS-CoV-2 RBDs bind ACE2 with nearly identical binding modes and with similar low nanomolar binding affinities. The al helix of ACE2, which is cradled in a concave groove formed by the p5 and p6 sheets of the RBD, provides the most contacts with the two RBDs (ACE2 residues Gln24, Thr27, Phe28, Lys31, His34, Glu37, Asp38, Tyr41, and Gln42). Additional contacts from ACE2 are provided by a.3 helix (ACE2 residues Leu79, Met82, Tyr83 for the two RBDs), a short loop between alO and al 1 helices (ACE2 residues Gln325 and Glu329 for SARS-CoV RBD and Asn330 for both RBDs), p~ hairpin flanking al 1 helix (ACE2 residue Lys353 for both RBDs), and al 1 helix (ACE2 residues Gly354, Asp355, and Arg357 for both RBDs). Conversely, 14 residues (402, 426, 436, 440, 442, 472, 473, 475, 479, 484, 486, 487, 488, and 491) in the two RBDs provide contacts with ACE2. These RBD residues form a network of hydrogen bonds, salt bridges, and van der Waals contacts with ACE2 residues. Based on these insights, six Spiketargeting ACE2-derived peptides (SAPs) — four derived from al, one derived from a3, and one derived from al l helix of ACE2-— were designed (Table 1). The SAPs were designed using the following criteria: 1) they contain at least three residues predicted to interact with RBDs based on structural data (Table 1, highlighted in bold); 2) they are not highly disordered or unresolved in the crystal structures (such as ACE2 residues 1-18); and 3) the length is more than six and less than 30 amino acids, making them amenable for synthesis. Table 1. Spike-targeting ACE2-derived peptides (SAPs) used in Example 1. Amino acid sequence with the residue number of the first and last amino acid in the sequence is indicated. The EDLFYQ motif is underlined. The SARS-CoV and SARS-CoV-2 contacting residues are indicated with bold font. SAPs inhibit SARS-CoV-2 Spike-pseudotyped lentivirus infection. We evaluated the antiviral potencies of SAPs against lentiviral vectors pseudotyped with SARS- CoV-2 Spike glycoprotein. Lentiviral cores pseudotyped with viral surface glycoproteins offer an alternative to highly pathogenic viruses that require biosafety level 3 (BSL3) or BSL4 facilities. Importantly, pseudotyped viruses can be utilized at BSL2 and are ideal for studies pertaining to viral entry and screening of therapeutic agents that target viral entry, such as the peptides in this study. Luciferase-encoding lentiviruses pseudotyped with SARS-CoV-2 Spike were incubated with test peptides to allow binding to the vector particle-associated Spike prior to infection of HEK293T-ACE2 cells. Luciferase production was measured 48 hours post-infection. A titration curve for each peptide was generated for determining its inhibitory concentration (IC50). Of the six SAPs tested, SAP1, SAP2, and SAP6 inhibited SARS-CoV-2 Spike-mediated virus infection with an IC ₅₀ value of 2.39 ± 0.20, 3.72 ± 0.37, and 1.90 ± 0.14 mM, respectively (Figure 1). In contrast, 50% inhibition of Spike-mediated virus infection was not achieved with SAP3, SAP4 or SAP5 even at 7.5 mM, the highest concentration tested. Thus, three of the six SAPs inhibit SARS-CoV-2 Spike-mediated virus infection with IC ₅₀ values in the low millimolar range. Despite the fact that the genomes of SARS-CoV and SARS-CoV-2 share ~80% sequence identity and most of the sequence variation is within the Spike open reading frame, the overall structure and ACE2-binding mode of their Spike RBDs are nearly identical. Moreover, the majority of amino acid residues in the SARS-CoV and SARS-CoV- 2 RBDs that are essential for binding ACE2 are either identical or have conserved side chains. Thus, we sought to determine whether SAPs that inhibit SARS-CoV-2 Spike- mediated virus infection are also able to inhibit infection mediated by SARS-CoV Spike. For this, SAPs with positive inhibitory profiles from Figure 1 were evaluated for their ability to inhibit infection of SARS-CoV Spike- and SARS-CoV-2 Spike-pseudotyped viruses at 3 mM dose, which is within the IC50 range for the test peptides (Figure 1). As specificity control, antiviral activity of SAPs was also measured against lentiviruses pseudotyped with vesicular stomatitis virus Glycoprotein (VSV-G), which utilizes low- density lipoprotein receptor, LDL-R for viral entry. In comparison to the diluent control, SAP1, SAP2, and SAP6 treatment resulted in ~1.6–3.5-fold reduction in SARS-CoV-2 Spike-mediated infection (Figure 2A) and ~1.9–7.5-fold reduction in SARS-CoV Spike- mediated infection (Figure 2B). Consistent with the results in Figure 1, SAP5 treatment had no significant effect on SARS-CoV-2 Spike-mediated infection, but resulted in ~1.5-fold reduction in SARS-CoV Spike-mediated infection. None of the SAPs affected VSV-G- mediated virus infection demonstrating their specificity for inhibiting Spike-mediated viral entry (Figure 2C). The slightly higher potency of SAP1, SAP5, and SAP6 against SARS- CoV Spike-mediated infection compared to SARS-CoV-2 Spike-mediated infection could be attributable to subtle differences in the SARS-CoV and SARS-CoV-2 RBD-ACE2 interaction interfaces. Importantly, these results highlight the fact that minor differences in the number of contact residues and their interactions at the RBD-ACE2 interface could be exploitable for structure-based rational design of viral-specific inhibitors. Binding affinities of SAPs to SARS-CoV-2 Spike RBD. Recent studies using biochemical and biophysical methods have demonstrated that the RBD within the S1 subunit of SARS-CoV-2 Spike is responsible for binding ACE2 with high affinity. Thus, we employed affinity precipitation assays to determine the binding affinities of SAPs with positive inhibitory profiles to recombinantly expressed and purified Spike RBD. A titration curve for each FITC-labeled peptide was generated for determining its binding affinity to His-tagged Spike RBD (Figure 3 A and B). Of the four SAPs tested, SAP1 displayed the highest binding affinity (K _d = 0.53 ± 0.01 mM) whereas SAP5 did not display any detectable binding in vitro (Figure 3B). SAP6, which contains the overlapping region in SAP1 and SAP2 (Table 1), displayed binding affinity similar to SAP1 (Figure 3C, SAP6 K _d of 1.36 ± 0.14 mM vs SAP1 K _d = 0.53 ± 0.01 mM). SAP2 displayed lower binding (K _d = 10.7 ± 4.2 mM) possibly attributable to the presence of two consecutive serine residues in the peptide, which could affect its flexibility. Thus, our results suggest that SAP6 contains the minimal residues needed for binding RBD and additional residues in SAP1 can slightly improve the binding affinity. Moreover, we found that the in vitro binding affinities of SAPs track closely with their antiviral IC50 values (Figures 1 and 3). SAP1 and SAP6 inhibit SARS-CoV-2 infection. We next sought to determine whether SAPs that bind RBD with high affinity and display positive inhibitory profiles against pseudotyped viruses are also able to inhibit the infection of genuine SARS-CoV-2. To this end, SAP1, SAP5, and SAP6 were evaluated for their ability to inhibit infection of SARS-CoV-2. Viruses was incubated with 3 mM of test peptide or diluent control to allow binding to the virion-associated Spike prior to infection of HEK293T-ACE2-GFP cells. Percent infection was measured by intracellular staining of SARS-CoV-2 N protein and flow cytometry 24 hours post-infection. In comparison to the diluent control, SAP1 and SAP6 treatment resulted in ~2-fold reduction in SARS-CoV-2 infection (Figure 4 A and B). In contrast, SAP5, which does not bind RBD and does not inhibit SARS-CoV-2 Spike- pseudotyped lentiviruses, had no significant effect on virus infection. Based on the findings that SAP1 and SAP6 have comparable IC ₅₀ values (Figure 1), bind RBD with similar affinity (Figure 3C), and inhibit SARS-CoV-2 infection to similar levels (Figure 4B), we conclude that SAP6 contains the minimal necessary residues for inhibition of SARS-CoV-2. SAP1 and SAP6 inhibit HCoV-NL63 infection. In addition to the three highly pathogenic coronaviruses known to infect humans, four low pathogenicity coronaviruses (HCoV-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63) are endemic in humans and cause common cold and upper and lower respiratory tract infections. Of the four endemic human coronaviruses, only HCoV-NL63 uses ACE2 as entry receptor. Similar to SARS- CoV and SARS-CoV-2, the S1 subunit of HCoV-NL63 Spike binds ACE2 to mediate viral entry. Thus, we sought to determine whether SAP1 and SAP6, which inhibit SARS-CoV-2 infection, could also inhibit HCoV-NL63 infection. Viruses were incubated with 3 mM of test peptide or diluent control to allow binding to the virion-associated Spike prior to infection of LLC-MK2 cells. Virus-induced cytopathic effects (CPEs) and virus titers in the supernatants were measured 72 hours post-infection. Severe CPEs were observed in cells that were infected with viruses treated with diluent control or SAP5 indicating robust viral infection (Figure 5A). In contrast, reduced CPEs were observed in cells infected with SAP1- or SAP6-treated viruses indicating reduced viral infection. Moreover, in comparison to the diluent control, SAP1 and SAP6 treatment resulted in ~3-fold reduced HCoV-NL63 titers (Figure 5B). In contrast, SAP5 treatment did not result in significant reduction of viral titers. Taken together, our results demonstrate that SAP1 and SAP6 inhibit infection of SARS-CoV-2 and HCoV-NL63, both of which utilize ACE2 as entry receptor. Structural modeling of SAP1 and SAP6 with SARS-CoV-2 Spike. The findings from our infectivity assays suggest that SAP1 and SAP6, and to a lesser degree SAP2, block the interaction of SARS-CoV-2 Spike with ACE2. We found that both SAP1 and SAP6 inhibit SARS-CoV-2 infection to similar levels. Since SAP6 contains the minimal conserved short EDLFYQ motif present in SAP1 and SAP2, we conclude that it is the minimal essential motif important for inhibition of SARS-CoV-2. The co-crystal structure of SARS-CoV-2 Spike RBD and human ACE2 has been recently solved and available through the Protein Data Bank (PDB). As shown in Figure 6A, magenta surface and ribbon represent the Spike RBD and yellow ribbon corresponds to ACE2. The RBD-ACE2 interaction interface is contacted mainly by the N-terminal helix (residues Ile21-Asn51) of ACE2. Our results suggest that SAP6 (Glu37-Gln42, blue ribbon in Figure 6B) and SAP1 (Thr27-Gln42, blue and green ribbon in Figure 6B) are able to disrupt the RBD-ACE2 interaction in low millimolar range, indicating the importance of these residues at the N- terminal helix of ACE2 for RBD-ACE2 interaction. Based on the crystal structure solved by Lan et al. and highlighted in the modeling studies, polar residues (Glu37, Asp38, Tyr41 and Gln42) of SAP6 are able to form a network of hydrogen bonds with Thr500, Tyr449, Asn501, and Tyr505 of SARS-CoV-2 Spike RBD (Figure 6C). In particular, the carboxy groups of Glu37, Asp38, and Gln42 and hydroxyl group of Tyr41 of SAP6 interface with Spike cavity surrounded by Gln498, Thr500, Tyr449, Asn501, and Tyr505. Taken together, these structural insights lend support to our identification of SAP1 and SAP6 as peptide disruptors of the Spike RBD-ACE2 interaction. Evaluation of SAP7. We also evaluated the antiviral potency of SAP7 against lentiviral vectors pseudotyped with SARS-CoV-2 Spike glycoprotein. As described above, luciferase-encoding lentiviruses pseudotyped with SARS-CoV-2 Spike were incubated with increasing concentrations of SAP7 to allow binding to the vector particle-associated Spike prior to infection of HEK293T-ACE2 cells. Luciferase production was then measured 48 hours post-infection. A titration curve for SAP7 was then generated to determining its inhibitory concentration (IC50). The results are shown Figure 7. As shown in Figure 7, SAP7 inhibited SARS-CoV-2 Spike-mediated virus infection with an IC ₅₀ value of 0.5 mM. As described above, luciferase-encoding lentiviruses pseudotyped with indicated viral glycoprotein were incubated with 3 mM of SAP7 or diluent control for 1 h prior to infection of 293T-ACE2 cells. Infection was measured as relative luciferase expression 48 h post-infection. The luciferase signal obtained for the diluent control was set to 100%. Graphs indicate percentage of infected cells normalized to the diluent control for lentiviruses pseudotyped with SARS-CoV-2 Spike (Figure 8A), SARS-CoV Spike (Figure 8B), or VSV-G (Figure 8C). In comparison to the diluent control, SAP7 treatment resulted in ~2-fold reduction in SARS-CoV-2 Spike-mediated infection (Figure 8A) and ~4-fold reduction in SARS-CoV Spike-mediated infection (Figure 8B). SAP7 had little (if any) impact on VSV-G-mediated virus infection, consistent with its expected specificity for inhibiting Spike-mediated viral entry (Figure 8C). Conclusion In summary, we have developed and screened a panel of rationally designed, small peptide inhibitors and identified peptides that block the interaction of coronavirus Spike proteins with ACE2. Importantly, we have identified two peptides, SAP! and SAP6, which inhibit SARS-CoV-2 infection - demonstrating the feasibility of targeting Spike-ACE2 interaction interface with peptide-based inhibitors to inhibit virus infection. SAP6, which contains the minimal conserved EDLFYQ sequence, highlights the importance of the N- terminal al helix of ACE2 for interaction with Spike protein. Future structure-based rational design studies focused on improved conformational matching between SAPs and SARS-CoV-2 Spike protein will allow ⁷ for increased binding affinity and potent viral inhibition. Such approaches could include increased noncovalent interactions between aromatic amino acid residues and the enhancement of peptide a-helicity to increase the stability of the SAPs. Lending support to such approaches, a recent study employed computer-generated scaffolds built around the al helix of ACE2 to design de novo miniprotein inhibitors of SARS-CoV-2. In summary, our proof-of-principle study that SARS-CoV-2 can be inhibited by small peptides will further allow for the successful development of engineered peptides and peptidomimetic-based compounds for the treatment of COVID-19.

Further Investigations and Strategies

Peptide solubility. A major hindrance in commercial application of peptide-based inhibitors is insolubility, poor or low solubility, and/or aggregation of peptides due to long sequences, presence of hydrophobic amino acids, and presence of cysteines. The solubility and aggregation issues are impediments for application of peptide-based inhibitors for therapeutic, prophylactic, and surface virus-inactivation purposes. SAP1-SAP7 were all soluble in IX Phosphate Buffered Saline (PBS). Further, our most active peptide, SAP6 was readily soluble in IX PBS. To improve the solubility of SAP! and SAP2, IX PBS was supplemented with 10% and 5% aqueous NEb, respectively. For SAP! and SAP2, supplementation of IX PBS with 5-10% of aqueous NF Is did not result in any spurious effects when these peptides were tested in various assays at a concentration of 3 mM, which is above the IC50 range for both these peptides. Thus, since solubility of synthetic peptides is often an issue and challenge when working with peptide-based inhibitors, our SAPs are particularly attractive for targeting of SARS-CoV-2 due to their solubility.

Peptide improvement. Even though we are targeting a surface-exposed protein, unmodified peptides can be plagued by poor stability and short plasma half-life when administered by injection to patients. Once positive lead peptides are identified, w ^z e propose to employ a number of structure-based rational design approaches focused on improved conformational matching between SAPs and SARS-CoV-2 Spike protein, which will allow for increased binding affinity and potent viral inhibition. Such approaches could include increased noncovalent interactions between aromatic amino acid residues and the enhancement of peptide a-helicity to increase the stability of the SAPs. Our proof-of- principle findings that SARS-CoV-2 can be inhibited by small peptides will allow for the successful development of engineered peptides and peptidomimetic-based compounds for the treatment of COVID-19. Further potential directions are briefly outlined below.

1. Substitutions of amino acid residues in peptides with positive inhibitory profiles, A network of hydrogen bonds with the Spike RBD anchors the most active peptides, SAP1 and SAP6. Because SAP6 contains the minimal conserved short EDLFYQ motif present in SAP1 and SAP2, we conclude that it is useful motif for inhibition of SARS-CoV-2. The polar residues (Glu37, Asp38, Tyrd l and Gln42) of SAP6 are able to form a network of hydrogen bonds with ThrSOO, Tyr449, AsnSOl , and Tyr505 of SARS-CoV-2 Spike RBD. In particular, the carboxy groups of Glu37, Asp38, and Gln42 and hydroxyl group of Tyr41 of SA.P6 interface with Spike cavity surrounded by Gln498, Thr500, Tyr449, Asn501, and Tyr505.

Additionally, Tyr41 of SAP6 provides limited hydrophobic interactions. Thus, we seek to improve the binding affinities and antiviral potencies of our peptides by employing the following approaches: a) In SAP6 there are two surface exposed residues Leu39 and Phe4, which would be normally shielded by other residues in ACE2. Therefore, we will substitute these nonpolar residues with hydrophilic residues such as Lys, Arg, Glu, Asp, Gin, or Asn to increase interactions with solvent water. This should increase its predicated solubility and decrease its overall hydrophobicity. b) Strengthen hydrogen bonding of Glu37, Asp38, and Gln42 with residues that form stronger hydrogen bonds such as His, Tyr or Trp. c) Increase the number of available hydrogen bonds through substitutions of Glu37, Asp38, Tyr41, and Gln42, which can form two hydrogen bonds. Substitutions with Arg, which can form three, and His, which can from four, hydrogen bonds, could pick up additional interactions with the Spike RBD. d) Increase hydrophobicity of SAP6 through substitutions of Glu37, Asp38, Tyr41, and Gln42 with Trp, which could maintain hydrogen bonding while increasing the hydrophobic nature of the interface residues. e) Extend peptides by three to ten amino acids at the N-terminal and/or C- terminal to determine if the extended peptides improve binding affinity.

2. Generation of a helical hydrocarbon stapled peptides. Our shortest and most active peptide, SAP6, is likely too short to form a stable a helix, which may limit its stability in vivo. Moreover, a formed a helix is more likely to mimic the observed interactions seen in the context of full-length ACE2 protein. As each turn in an a helix contains -3.6 amino acid residues, SAP6 can form approximately a turn and a half. Several different conformations can be achieved for stapling a short six amino acid peptide with a conformation of i, i + 4/, which could stabilize one full helical turn. As an example, S-pentenylalanine can be incorporated into SAP6 to from the peptide staple and help stabilize the a helix. Alternatively, the length of SAP6 can be extended by two to three amino acids in conjunction with incorporation of R- octenylalanine/S-pentenylalanine --- this will allow a conformation of /, i + 7, which could stabilize a double helical turn.

3. Molecular dynamics simulations of peptides. We will use the peptides with positive inhibitory profiles and perform equilibrium molecular dynamics simulation to study the dynamics of Spike RBD-SAP complexes. Such an in silico approach will allow us to measure the end state binding energy calculations, which wall be used to understand the RBD-SAP binding complex at single-residue resolution - amino acid changes that are predicted to increase binding form will then be substituted in the peptides and their binding affinities and antiviral potencies will be evaluated. For promising leads, we will also employ computational alanine scanning to identify amino acid residues that are important for binding of Spike RBD - the identified critical residues will be substituted with other amino acids to enhance binding and antiviral potency.

4. Determination of synergistic and additive effects of peptides. We have developed a panel of peptides and evaluated the antiviral potency against genuine SARS-CoV-2 and HCoV-NL63. The peptides are derived from al , a3, al O, and al l helices of ACE2. Peptides with positive inhibitory profiles would be examined in combination(s) to test for increased potency and/or synergy using our pseudovirus inhibition assay and SARS-CoV-2 infectivity assays. If synergy or additive effects are observed for given peptides, linkers (such as introduction of giycine(s) or serine(s) resides between peptides) can be engineered to further increase the antiviral potency of Jinked peptides. For example, separate Spike RBD-ACE2 interaction interfaces are targeted by SAPS, SAP4, and SAP6 - SAP3 is derived from a3, SAP4 is derived from al 1 , and SAP6 is derived from al helices of ACE2 and thus predicted to target three distinct interaction of Spike RBD with these regions of ACE2. Thus, evaluating the potencies in combination or through linked peptides would offer two advantages: 1) higher barrier to the evolution of antiviral resistance, and 2) potential increased potency due to synergy and additive effects.

5. Determination of delivery in tissue culture and small animal models of SARS-CoV-2 infection. The short nature of the peptides described herein makes them attractive for use in therapeutic, prophylactic, and surface disinfectant purposes for the following reasons: they likely display enhanced stability in comparison to longer proteins/peptides and the smaller size of these peptides could increase their local molar density with the Spike proteins on virion surface. We would seek to evaluate the prophylactic and therapeutic effectiveness of our most active peptides and derivatives in the rodent/small animal models of SAR.S-CoV-2 infection. We would employ approaches to determine whether delivery of peptides/ derivatives directly in the upper and lower respiratory tracts through intranasal administration, aerosolization, or nebulization would offer protection. We would also evaluate the effectiveness of our most active peptides and derivatives as surface disinfectant by performing virus-inactivation assay, which will be performed by incubation of vims and test peptides/derivate on air-liquid interfaces for increasing amounts of time followed by infection of cells in tissue culture models of SARS-CoV-2 infection.

The compounds, compositions, and methods of the appended claims are not limited in scope by the specific compounds, compositions, and methods described herein, which are intended as illustrations of a few aspects of the claims. Any compounds, compositions, and methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications of the compounds, compositions, and methods in addition to those shown and described herein are intended to fall within the scope of the appended claims. Further, while only certain representative compounds, components, compositions, and method steps disclosed herein are specifically described, other combinations of the compounds, components, compositions, and method steps also are intended to fall within the scope of the appended claims, even if not specifically recited. Thus, a combination of steps, elements, components, or constituents may be explicitly mentioned herein or less, however, other combinations of steps, elements, components, and constituents are included, even though not explicitly stated. The term “comprising” and variations thereof as used herein is used synonymously with the term “including” and variations thereof and are open, non-limiting terms. Although the terms “comprising” and “including” have been used herein to describe various embodiments, the terms “consisting essentially of” and “consisting of” can be used in place of “comprising” and “including” to provide for more specific embodiments of the invention and are also disclosed. Other than where noted, all numbers expressing geometries, dimensions, and so forth used in the specification and claims are to be understood at the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, to be construed in light of the number of significant digits and ordinary rounding approaches. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference.