Monte-Carlo Simulation Taking Account of Solvent Effects for a Conformation Analysis of Peptides in Solution

Solvent effects were introduced into a Monte-Carlo simulation of peptide conformations by the use of a new potential function for evaluating the nonbonding interactions between solute and solvent molecules. The Monte-Carlo program, which included the electrostatic and nonbonding interactions of the solvent, was tested for a conformation analysis of the zwitterionic tetragastrin in DMSO. The theoretical coupling constants were in good agreement with the NMR data. The conformation of the zwitterion was a folded compact form at the lowest energy, which was different from those obtained from a simulation in vacuo and that without nonbonding solvent effects.