A Structural Ensemble of Hen Egg-White Lysozyme in Aqueous Solution Based on 2043 NMR NOE, ³ <i>J</i> -Coupling and <i>S</i> ² Order-Parameter Data

A set of 1630 NOE atom-atom distance upper bounds, 213 ³<i>J</i>-coupling constant values and 200 <i>S</i>² order-parameter values derived from experimental NMR data is used in molecular dynamics simulations of Hen Egg-White Lysozyme (HEWL) in aqueous solution in order to generate a Boltzmann-weighted structural ensemble for the protein in aqueous solution that is compatible with the 2043 NMR data. The two protein force fields used, the GROMOS 54A7 and 54A8 force fields, which only differ in the partial charges of the charged side chains and the chain termini of the protein, show comparable behavior. Analysis of the generated structural ensembles shows that the protein in aqueous solution adopts a greater variety of hydrogen-bond patterns than is suggested by the various X-ray crystal structures of the protein.