Water interaction with α,α-trehalose:: molecular dynamics simulation

This paper reports on simulations of a rather large water-trehalose system, based on the AMBER compatible GLYCAM force-field (R. J. Woods, R. A. Dwek, C. J. Edge and B. Fraser-Reid, J. Phys. Chem., 1995, 99, 3832), whose applicability to trehalose has been carefully examined using ab initio quantum mechanical calculations to optimize the molecular geometry and to evaluate the net atomic charges. Statistical analyses of the simulation trajectories show that the structure and dynamics of the solvent are remarkably affected by the presence of trehalose. In particular, ca. 36 water molecules are found to reside in the first hydration shell, 19 of which are hydrogen bonded to trehalose. The water mobility within the first hydration shell is ca. 25% smaller than that of pure water.