Schellman Motif in Dehydrooligopeptides: Crystal and Molecular Structure of Boc-Val-triangle open Phe-Leu-Phe-Ala-triangle open Phe-Leu-OMe

摘要

In the last tew years it has become increasingly apparent that peptides containing alpha,beta-didehydrophenylaianine residues (triangle open Phe) exhibit preferential secondary structural features both in the solid stale and in solution. Introductionof triangle open Phe residues in peptide sequences results in beta-turns and helical structures." Recently we observed a novel beta-bend ribbon structure in a pentapeptide containing two APhe residues. In longer peptides containing several APhe residues3_(10)-helical structures dominate. In a recent example an alpha-helical conformation was observed in a pemapeptide containing a single triangle open Phe residue. Apparently the final conformation of any APhe peptide depends upon the number and positionof triangle open Phe residue- as well as the nature of the amino acids (Tanking them.