| Abstract: | Monte Carlo calculations for clusters consisting of 200 water molecules surrounding glycine in the neutral and zwitterionic forms were carried out at 300 K; all the relevant interaction potentials have been obtained by means of quantum–mechanical calculations. Water–water and amino acid–water energies were calculated, and the zwitterion was found to be strongly favored with respect to the neutral molecule, as expected. A detailed analysis of the energetic results yielded some information on the special extension of the solute-induced perturbation. The structural results were found to be in reasonable agreement with predictions that can be obtained by analyzing isoenergy contour maps, calculated for the two-body amino acid–water potential. |
