Geometry-based simulation of the hydration of small molecules

The behaviour of water structure-makers and breakers is of practical importance in protein folding in aqueous solution (G. Nemethy, Angew. Chem., Intl. Ed. Engl., 1967, 6, 195), but the mechanism for this process is not fully understood (K. A. T. Silverstein, A. D. J. Haymet and K. A. Dill, J. Am. Chem. Soc., 1998, 120, 3166). A computer simulation has been developed, of water structure around solutes, using only hydrogen bond geometry data rather than traditional forcefield methods. The simulation builds networks of hydrogen bonded water around structure-makers such as sulfate and phosphate, but not around structure-breakers such as urea and guanidinium. We have tested the software with a preliminary set of 17 varying solutes and our results are generally consistent with existing practical data