An Enhanced β Turn in Water

Abstract

Aiming to design short linear peptides featuring strong intramolecular hydrogen bonds in water, a series of tetrapeptides based on the sequence Ac-Ala-Pro-Ala-Ala-NH₂ containing all possible combinations of l- and d-amino acids was synthesized. A regiospecific combination of heterochiral residues (ddll or its mirror image lldd) can be used to increase turn formation and stability within short peptides in water.