ABSTRACT
In solid-phase peptide synthesis, the addition of m-cresol to diluted methanesulfonic acid (MSA) in dichloromethane accelerated the deprotection rate of the acid-labile alpha-amino protecting group, the p-methoxybenzyloxycarbonyl (Z(OMe)) group. Further, 0.1 M MSA, 20% m-cresol/CH2Cl2 was found to be a practically useful N alpha-deprotecting reagent system, since the deprotection of the Z(OMe) group occurred selectively within 30 min at room temperature, leaving intact the other side chain protecting groups, such as benzyloxycarbonyl, benzyl ester, S-p-methoxybenzyl and NG-mesitylene-2-sulfonyl groups. This reagent system was applied to the Z(OMe)-based solid phase syntheses of human pancreastatin-29 and magainin 1.
Subject(s)
Antimicrobial Cationic Peptides , Cresols/chemistry , Mesylates/chemistry , Pancreatic Hormones/chemical synthesis , Peptide Fragments/chemical synthesis , Peptides/chemical synthesis , Xenopus Proteins , Amino Acid Sequence , Humans , Molecular Sequence DataABSTRACT
Model building studies and analogies drawn from peptides of similar biological activity have indicated that the C-terminus of avian pancreatic hormone III may possess significant biological information. To test this hypothesis, the C-terminal pentapeptide amide sequence has been synthesized by the Merrifield method. The synthesis, purification and characterization of this compound are reported here in detail. In vivo studies indicate that this synthetic segment possesses none of the secretogogic activity of the parent hormone; rather, it reduces "gastric" secretion levels even in the presence of the intact hormone.
