Computational Protocols for Prediction of Solute NMR Relative Chemical Shifts. A Case Study of L-Tryptophan in Aqueous Solution

TY - JOUR

T1 - Computational Protocols for Prediction of Solute NMR Relative Chemical Shifts. A Case Study of L-Tryptophan in Aqueous Solution

AU - Eriksen, Janus J.

AU - Olsen, Jógvan Magnus H.

AU - Aidas, Kestutis

AU - Ågren, Hans

AU - Mikkelsen, Kurt Valentin

AU - Kongsted, Jacob

PY - 2011/10

Y1 - 2011/10

N2 - In this study, we have applied two different spanning protocols for obtaining the molecular conformations of L-tryptophan in aqueous solution, namely a molecular dynamics simulation and a molecular mechanics conformational search with subsequent geometry re-optimization of the stable conformers using a quantum mechanically based method. These spanning protocols represent standard ways of obtaining a set of conformations on which NMR calculations may be performed. The results stemming from the solute-solvent configurations extracted from the MD simulation at 300 K are found to be inferior to the results stemming from the conformations extracted from the MM conformational search in terms of replicating an experimental reference as well as in achieving the correct sequence of the NMR relative chemical shifts of L-tryptophan in aqueous solution. We find this to be due to missing conformations visited during the molecular dynamics run as well as inaccuracies in geometrical parameters generated from the classical molecular dynamics simulations.

AB - In this study, we have applied two different spanning protocols for obtaining the molecular conformations of L-tryptophan in aqueous solution, namely a molecular dynamics simulation and a molecular mechanics conformational search with subsequent geometry re-optimization of the stable conformers using a quantum mechanically based method. These spanning protocols represent standard ways of obtaining a set of conformations on which NMR calculations may be performed. The results stemming from the solute-solvent configurations extracted from the MD simulation at 300 K are found to be inferior to the results stemming from the conformations extracted from the MM conformational search in terms of replicating an experimental reference as well as in achieving the correct sequence of the NMR relative chemical shifts of L-tryptophan in aqueous solution. We find this to be due to missing conformations visited during the molecular dynamics run as well as inaccuracies in geometrical parameters generated from the classical molecular dynamics simulations.

M3 - Journal article

SN - 0192-8651

VL - 32

SP - 2853

EP - 2864

JO - Journal of Computational Chemistry

JF - Journal of Computational Chemistry

ER -