11/9-Mixed Helices in the α<i>/</i>β-Peptides Derived from Alternating α<i>- </i>and β-Amino Acids with Proteinogenic Side Chains

Abstract

alpha/beta-Hybrid peptides are prepared from amino acids with proteinogenic side chains on the basis of the concept of "alternating chirality", involving D-Phe and a beta3-hVal. Through the extensive NMR, CD, and MD studies, robust left-handed 11/9-mixed helices were identified in these peptides in CDCl3 solutions, wherein the 11/9-mixed helix was observed even in a small peptide with three residues.