Structure of water molecules in aqueous maltose and cellobiose solutions using molecular dynamics simulation. I. Statics

A molecular dynamics (MD) simulation, which includes all degrees of freedom of atomic motion, has been carried out for aqueous maltose and cellobiose solutions in order to investigate whether the solvent as a background of solutes changed its static characteristics or not. The partial radial and the angular distribution function have been calculated for the whole solvent from which the first hydration shell of the solute was omitted. In the solutions, the relative configuration of two water molecules positioned at the primary hydrogen bond (1413) was distorted and the secondary HB was more formed compared with the bulk water system. Less half-hydrogen bonded water molecules were included in the solutions than in the bulk water, and the secondary HB network (O-W...O-W...O-W) was slightly distorted in the solutions compared with the bulk water. No remarkable difference could be observed between maltose and cellobiose solutions, but a s light divergence of a configuration between-two solutions could be observed in the second hydration shell of the solute. (C) 2003 Elsevier Science B.V. All rights reserved.