The Use of N-Bromosuccinimide and N-Bromoacetamide for the Selective Cleavage of C-Tryptophyl Peptide Bonds in Model Peptides and Glucagon

Abstract

Fifteen model peptides III-XVII (Table I) derived from indole-3-propionic acid or N-carbobenzyloxy- and N-benzoyl-tryptophan have been subjected to cleavage by N-bromosuccinimide and N-bromoacetamide in aqueous acetic-formic acid buffer systems as well as in 10.0 M lithium acetate solution of pH 4.0. Maximal yields of 60–90% of liberated amino acids have been obtained. Of the 28 peptide bonds present in the pancreas hormone glucagon, only the one following the single tryptophan present was cleaved with liberation of the known tetrapeptide Leu-Met-Asp-Thr. © 1960, American Chemical Society. All rights reserved.