Docking protein

Abstract

This chapter reviews the cleavage of several N-acylated amides and peptides of allyl-glycine and β-methallylglycine. The element of 2-amino-4-pentenoic acid in N-acylated tyrosine, tryptophan, and histidine is capable of 1, 5-interaction between the earboxyl group or the amide or peptide carbonyl group and the double bond under the influence of electrophilic reagents such as bromine, N-bromosuccinimide (NBS), and N-bromoaeetamide (NBA). The adjacent peptide bond is cleaved by the action of NBS. The principles and reactions of bonds reviewed are tryptophyl, tyrosyl, and histidyl bonds. The 2, 3 double bond of the pyrrole part of tryptophan that is γ,δ relative to the carboxamido group of tryptophan residues bound in peptides, participates in a displacement reaction with NBS. Oxidation of gramicidin A with NBS leads to several fragments that cleaves the peptide bond next to a tryptophan carboxyl group. Several N-acylated tyrosyl-S-alkyleysteine dipeptides, as well as simple tyrosyleystine peptides, undergo facile oxidative cleavage with NBS. The cleavage of a histidyl peptide requires about 3 moles of NBS. In the aliphatic γ,δ-unsaturated amino acid derivatives, cleavage yields are 60–80% when 1-2 equivalents of N-bromosuccinimide (NBS) are used.