Conformational Sampling by Ab Initio Molecular Dynamics Simulations Improves NMR Chemical Shift Predictions

0396144 - ÚOCHB 2014 RIV US eng J - Journal Article
Dračínský, Martin - Möller, H. M. - Exner, T. E.
Conformational Sampling by Ab Initio Molecular Dynamics Simulations Improves NMR Chemical Shift Predictions.
Journal of Chemical Theory and Computation. Roč. 9, č. 8 (2013), s. 3806-3815. ISSN 1549-9618. E-ISSN 1549-9626
R&D Projects: GA ČR GA13-24880S
Institutional support: RVO:61388963
Keywords : ab initio molecular dynamics * NMR spectroscopy * DFT calculations * hydration
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 5.310, year: 2013

Car-Parrinello molecular dynamics simulations were performed for N-methyl acetamide as a small test system for amide groups in protein backbones, and NMR chemical shifts were calculated based on the generated ensemble. If conformational sampling and explicit solvent molecules are taken into account, excellent agreement between the calculated and experimental chemical shifts is obtained. These results represent a landmark improvement over calculations based on classical molecular dynamics (MD) simulations especially for amide protons, which are predicted too high-field shifted based on the latter ensembles. We were able to show that the better results are caused by the solute-solvents interactions forming shorter hydrogen bonds as well as by the internal degrees of freedom of the solute. Inspired by these results, we propose our approach as a new tool for the validation of force fields due to its power of identifying the structural reasons for discrepancies between the experimental and calculated data.
Permanent Link: http://hdl.handle.net/11104/0224058