The Poisson-Boltzmann theory of continuum electrostatics with application to variational solvation of molecules

Professor Bo Li
Department of Mathematics and Center for Theoretical Biological Physics
UC San Diego

Abstract

Electrostatic interactions are crucial in determining biomoleular structures, dynamics, and functions. The Poisson-Boltzmann (PB) theory of continuum electrostatics has been widely used to describe such interactions. In this talk, I will begin with a review of the PB theory, in particular, the derivation of the PB equation by a variational approach. I will then present two classes of new results related to the PB theory. The first is on the calculation of effective electrostatic surface forces which is defined as negative the variation of the electrostatic free energy with respect to the location change of the dielectric boundary. This force is exactly the polar part of the normal velocity in the level-set variational implicit solvent model of biomolecular structures. The second is on the size-modified PB theory for multiple ionic species with different ionic sizes. Although explicit, generalized Boltzmann distributions can be hardly found, it is shown that a generalized PB equation is still available.