title: Synthesis of an open-chain asymmmetrical cystine peptide corresponding to the sequence A18-21--B19-26 of bovine insulin by solid phase fragment condensation.
abstract: An insulin fragment containing residues A 18-21 and B 19-26 linked by the disulfide bond between residues A 20 and B 19 was synthesized. The sequence B 21-26 was assembled on a solid support by the Merrifield technique. The protected fragments A 18-21 and B 19-20 were prepared by conventional methods. After forming the disulfide bridge through cleavage of the S-thiocarbonate derivative of A 18-21 by the thiol peptide B 19-20, the resulting assymmetrical cystine peptide A 18-21--B 19-20 was coupled via the carboxyl group of residue B 20 to the free NH 2-terminal amino group of the protected B 21-26 resin. The product was deprotected, cleaved from the resin, and purified to give the homogenous dodecapeptide A 18-21--B 19-26.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003553:Cystine; D007328:Insulin / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D008722:Methods; D010446:Peptide Fragments / Q000138:chemical synthesis; D010455:Peptides / Q000138:chemical synthesis*
chemical_list: D007328:Insulin; D010446:Peptide Fragments; D010455:Peptides; D003553:Cystine