A Reactive Force Field for Molecular Dynamics Simulations of Glucose in Aqueous Solution.

To expand the capabilities of reactive force field (ReaxFF) in simulations of biological processes involving glucose, in this work, using Metropolis Monte Carlo algorithm, new ReaxFF parameters for glucose have been developed to better describe the properties of glucose in water during molecular dynamics (MD) simulations. With the newly trained ReaxFF, the mutarotation of glucose in water can be better described, as suggested by our metadynamics simulations. In addition, the newly trained ReaxFF can better describe the distributions of the three stable conformers along the key dihedral angle of α-anomer and β-anomer. With better descriptions of hydration around glucose, the Raman and Raman optical activity spectra can be more accurately calculated. In addition, the infrared spectra obtained from simulations with the new glucose ReaxFF are more accurate than those obtained with the original ReaxFF. We note that although our trained ReaxFF performs better than the original ReaxFF, it is not generally applicable to all carbohydrates, which require further parametrization. We also find that the absence of explicit water molecules in the training sets may lead to inaccurate descriptions of water-water interactions around the glucose, implicating that it is necessary to optimize the water ReaxFF parameters together with the target molecule. The improved ReaxFF makes it possible to explore interesting biological processes involving glucose more accurately and efficiently.