Brownian Dynamics study of the effects of dielectric constant on conductivity of porins

We report here the results of Brownian Dynamics simulation of ionic conduction in the OmpF membrane protein. The simulations of conductivity and selectivity were performed for a range of protein dielectric constant, and accounted for the ionization states of the Asp-127 and Glu-296 residues as recently computed by Varma and Jakobsson. In our calculations, we employed a non periodic Poisson-P3M force-field scheme, where the long-range components of the electrostatic interactions are computed in position space through the solution of Poisson's equation. Comparisons are performed with experimental measurements of conductivity.