Spectroscopic Evidences for Strong Hydrogen Bonds with Selenomethionine in Proteins
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- 作者：V. Rao Mundlapati ; Dipak Kumar Sahoo ; Sanat Ghosh ; Umesh Kumar Purame ; Shubhant Pandey ; Rudresh Acharya ; Nitish Pal ; Prince Tiwari ; Himansu S. Biswal
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2017
- 出版时间：February 16, 2017
- 年：2017
- 卷：8
- 期：4
- 页码：794-800
- 全文大小：476K
- ISSN：1948-7185
文摘
Careful protein structure analysis unravels many unknown and unappreciated noncovalent interactions that control protein structure; one such unrecognized interaction in protein is selenium centered hydrogen bonds (SeCHBs). We report, for the first time, SeCHBs involving the amide proton and selenium of selenomethionine (Mse), i.e., amide–N–H···Se H-bonds discerned in proteins. Using mass selective and conformer specific high resolution vibrational spectroscopy, gold standard quantum chemical calculations at CCSD(T), and in-depth protein structure analysis, we establish that amide–N–H···Se and amide–N–H···Te H-bonds are as strong as conventional amide–NH···O and amide–NH···O═C H-bonds despite smaller electronegativity of selenium and tellurium than oxygen. It is in fact, electronegativity, atomic charge, and polarizability of the H-bond acceptor atoms are at play in deciding the strength of H-bonds. The amide–N–H···Se and amide–N–H···Te H-bonds presented here are not only new additions to the ever expanding world of noncovalent interactions, but also are of central importance to design new force-fields for better biomolecular structure simulations.