Efficient dynamic boundary solvation models for biomolecular simulations

COMP 380

Wusheng Zhu, zhuwu@bc.edu and Goran Krilov, goran.krilov@bc.edu. Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467
Two simple models are developed to accurately account for the solvation effects in molecular dynamics simulations of biomolecules. The methods reduce the amount of solvent that must be treated explicitly to one or two solvation shells, significantly reducing the computational complexity. In the dynamic boundary model, a confining potential is imposed on the solvent, that responds dynamically to the fluctuations in solvent distribution and biomolecular conformations. In pseudo-periodic boundary solvation model, surface solvent molecules are allowed to exchange via a translational shift to its ‘image' position akin to the periodic boundary condition simulation. In both models, long range solvation effects are treated via a Poisson-Boltzmann continuum dielectric method. The models are applied to simulations of a 9 residue polyalanine helix. Comparison of various structural properties with those computed from conventional periodic boundary condition simulations show excellent agreement.