Shiryayev Andrey, Pagan Daniel L, Gunton James D, Rhen D S, Saxena Avadh, Lookman Turab
Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
J Chem Phys. 2005 Jun 15;122(23):234911. doi: 10.1063/1.1931655.
The properties of the solvent affect the behavior of the solution. We propose a model that accounts for the contribution of the solvent free energy to the free energy of globular proteins in solution. For the case of an attractive square-well potential, we obtain an exact mapping of the phase diagram of this model without solvent to the model that includes the solute-solvent contribution. In particular we find for appropriate choices of parameters upper critical points, lower critical points, and even closed loops with both upper and lower critical points similar to those found before [Macromolecules 36, 5843 (2003)]. In the general case of systems whose interactions are not attractive square wells, this mapping procedure can be a first approximation to understand the phase diagram in the presence of solvent. We also present simulation results for both the square-well model and a modified Lennard-Jones model.
