Free energy calculation for DNA bases in various solvents using Flory-Huggins theory

The solvation of various DNA bases in water, ethanol and chloroform has bee n explored using the modified Flory-Huggins theory employing Monte Carlo si mulation techniques. The extent of solvation has been obtained by computing , free energy and entropy of mixing. The calculated thermodynamic propertie s, free energies, enthalpy and entropy of the bases in the solvent environm ent reveals that, bases are not generally soluble in water but are soluble in chloroform. These results are in accordance with the previous finding th at the bases tend to aggregate in water medium. The Flory-Huggins theory qu alitatively describes DNA-solvent interaction. In addition, the results fro m the present theory depend on the quality of the force field employed in t he calculation. (C) 2001 Elsevier Science B.V. All rights reserved.