Formation of a pseudo-β-hairpin motif utilizing the Ant–Pro reverse turn: consequences of stereochemical reordering

Abstract

Herein, we report a special case of pseudo-β-hairpin formation by tetrapetide sequences featuring a two-membered Ant-Pro dipeptide motif (Ant = anthranilic acid and Pro = proline) at the loop region. These folded structures uniquely feature the presence of C9- and C17-H-bonding patterns at reverse turn and interstrand regions, respectively. Their hairpin nucleation and folding propensities have been expounded using solution and solid state studies of distinct stereochemically altered sequences.