cis-2-Aminocyclopentanecarboxylic Acid Oligomers Adopt a Sheetlike Structure: Switch from Helix to Nonpolar Strand

Abstract

Rational control over helix and strand secondary structures is possible when conformationally restricted cyclic β-amino acid residues are incorporated in the β-peptides. Inversion of the relative configuration of these residues enables the preferred periodic structure to be switched from a helix to a single nonpolar strand (see picture).