CONTINUUM ELECTROSTATIC ENERGIES OF MACROMOLECULES IN AQUEOUS-SOLUTIONS

The efficient evaluation of electrostatic energies of macromolecules i n aqueous solutions is useful for many problems in theoretical structu ral biology. A continuum method based on the generalized Born (GB) app roximation is implemented here. It is shown that the choice of the die lectric discontinuity surface is critical for obtaining correct electr ostatic energies of molecules in solution. In addition, it is demonstr ated that an electrostatic model validated on solvation energies (vacu um to water transfer) might not be appropriate for energies in solutio n and might not yield correct energy ranking of ligand/protein complex es. The agreement between the GB approach and the finite difference so lution of the Poisson equation is shown to be very good for both the m olecular and the solvent accessible surface. The discrepancies between the GB and the finite difference approach are much lower than the one s due to the use of different surfaces.