PURPOSE: To obtain a polypeptide such as short-chain peptide derivative of growth hormone-releasing factor useful as a remedy for dwarfism, etc., by condensing a plurality of specific different peptide fragments having protecting group successively with each other, and removing the protecting group from the product.
CONSTITUTION: The objective polypeptide can be produced by (1) condensing the peptide fragment of formula I having protecting group with the peptide fragment of formula II having protecting group, (2) condensing the condensation product with the peptide fragment of formula III having protecting group, (3) condensing the product with the peptide fragment of formula IV having protecting group, and (4) removing the protecting groups from the condensation product. The condensation of the peptide fragments is carried out preferably by using a carbodiimide condensation agent and an additive.
KAI HIROYUKI
TAKEBAYASHI YOSHIAKI
SUWA KAZUYUKI
ONO KEIICHI
