This document discusses the strength of hydrogen bonds involving sulfur in methionine residues, highlighting its role as a strong hydrogen bond acceptor comparable to oxygen. The study employs gas phase IR/UV spectroscopy to examine intramolecular and intermolecular hydrogen bonds and their implications on peptide structure. The findings suggest that sulfur-hydrogen bonds should be considered in force field simulations for protein structures due to their significant influence on protein chain folding.

1. The Strength of NH---S Hydrogen Bonds
in Methionine Residues Revealed by Gas
Phase IR/UV Spectroscopy
Himansu S. Biswal*#†, Eric Gloaguen#, Yohan
Loquais#, Benjamin Tardivel# and Michel Mons*#
# CEA, Laboratoire Francis
Perrin, DSM/IRAMIS/SPAM, Bât 522, 91191 Gif-sur-
Yvette, France
# CNRS, Laboratoire Francis Perrin, URA 2453, 91191
Gif-sur-Yvette, France.
† National Institute of Science Education and Research,
Sachivalaya Marg, Bhubaneswar - 751 005, India.
J. Phys. Chem. Lett. 2012, 3, 755 -759 1