Effects of sulfoxide and sulfone sidechain-backbone hydrogen bonding on local conformations in peptide models

Abstract

We examine peptide model systems designed to probe short-range N-H⋯O 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 S sidechain-backbone hydrogen bonding involving amino acid residues with sidechain sulfoxide or sulfone functional groups and its effects on local conformations. A strong 7-membered ring hydrogen bond of this type accompanies an intra-residue N-H⋯O C interaction and stabilizes an extended backbone conformation in preference to classical folded structures.