Strength of (NHS)-S-... Hydrogen Bonds in Methionine Residues Revealed by Gas-Phase IR/UV Spectroscopy - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Physical Chemistry Letters Année : 2012

Strength of (NHS)-S-... Hydrogen Bonds in Methionine Residues Revealed by Gas-Phase IR/UV Spectroscopy

Résumé

Despite of being ubiquitous in proteins, (NHbackboneS)-S-... hydrogen bonds linking the sulfur atom of methionine or cysteine to backbone NH groups remain poorly documented. Here, we report vibrationally resolved IR NH stretch spectra of two methionine-containing dipeptides (Ac-Phe-Met-NH2 and Ac-Met-Phe-NH2). The conformations observed for both molecules, assigned with the help of DFT-D quantum chemistry, provide spectroscopic evidence for the formation of (NHbackboneS)-S-... H-bonds, surprisingly strong enough to challenge the classical intrabackbone (NHO)-O-...=C H-bonds. The methionine side chain is found to fold locally, forming a H-bond with the neighboring amide groups (NH(i) or NH(i+1)). Comparison with protein data bank structural information shows that such a local folding is also common in proteins where it concerns 24% of the methionine residues that have a sulfur atom linked to a backbone NH group. This convergence between the strength of these (NHS)-S-... H-bonds and protein structural data illustrates their contribution to the stability of protein chains.
Fichier non déposé

Dates et versions

hal-00724272 , version 1 (20-08-2012)

Identifiants

Citer

H.S. Biswal, Eric Gloaguen, Y. Loquais, B. Tardivel, M. Mons. Strength of (NHS)-S-... Hydrogen Bonds in Methionine Residues Revealed by Gas-Phase IR/UV Spectroscopy. Journal of Physical Chemistry Letters, 2012, 3 (6), pp.755-759. ⟨10.1021/jz300207k⟩. ⟨hal-00724272⟩
210 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More