AN EXPLORATION OF A CONTINUUM METHOD FOR THE SOLVATION OF BIOMOLECULES THAT INCLUDES SOLUTE POLARIZATION

A method based on the continuum solvation model of Miertus and Tomasi (S. Miertus and J. Tomasi, Chem., Phys., 65 (1982) 239), which can be used to calculate the free energy change in transferring a molecule fr om the gas phase to a solvent, is presented. The solute is represented as a set of interlocking spheres with a polarisable point charge at e ach center. In order to reduce the number of atom types in the method, the atoms are assigned to classes based on the concept of molecular o rbital valency state as proposed by Clementi. Solute polarisation by t he solvent field and the effects of cavitation are included. The param eterisation, based on the Frage potential, and the results of the calc ulations for a series of molecules ranging from H2O to small peptides are presented. Other applications include ionic solvation and the form ation of ''salt-bridges'', which are essential for the stabilisation o f amino acid residues with charged side chains. Initial results from t he incorporation of this algorithm in a conformational study on Met-en kaphlin (met is methionine) are also presented.