Pairwise Coupling in an Arg-Phe-Met Triplet Stabilizes alpha-Helical Peptide via Shared Rotamer Preferences

摘要

alpha-Helices are stabilized by the helix-forming tendencies of constituent amino acids,capping interactions at the amino and carboxyl termini,solvent environment,and side chain interactions.Interaction energies,in particular,have been measured for salt bridge,aromatic-basic,hydrogen bond,and hydrophobic interactions.In proteins,side chains interact within a complex network of multiple noncovalent bonds,which may reinforce or weaken each other.The simplest system to investigate these effects is to study triplets of side chains.This has previously been studied as salt bridae interactions in d-helical nentides.