Surface Recognition and Helix Stabilization of a Tetraaspartate Peptide by Shape and Electrostatic Complementarity of an Artificial Receptor

Abstract

The recognition of tetraaspartate peptide (2) by tetra-guanidinium (1) in (a) water and (b) aqueous methanol (10% H2O/90% CH3OH) has been investigated. The conformations of the free peptide and its complex with 1 have been characterized in both solvent systems by CD and 2D NMR spectroscopies. Increased α-helicity as a result of solvent composition and receptor binding are discussed. Control experiments show that the recognition stems from complementary electrostatic interactions, hydrogen bonding, and matching of surface topologies.