Electrostatic screening and energy barriers of ions in low-dielectric membranes.
We present exact solutions of the linear Poisson-Boltzmann equation for several problems relevant for ion translocation across low-dielectric membranes. Our results are obtained for a finite Debye screening length, and they generalize the classical results for pure Coulombic electrostatics (Parsegian, A. Nature (London) 1969, 221, 844). We calculate the electrostatic self-energy of an ion in the middle of a low-dielectric slab, its energy inside a cylindrical high-dielectric pore, and its energy inside a high-dielectric spherical jacket. We consider also the influence of negative charges distributed on the walls of the cylindrical pore. We show that ion self-energy barriers are considerably reduced due to screening of electrolyte. We compare our results with some numerical results for screened electrostatics of ion channels and wide pores.
Cherstvy
A G
AG
Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzerstrasse 38, D-01187 Dresden, Germany. cherstvy@pks.mpg.de
D003198:Computer Simulation; D007477:Ions / Q000737:chemistry*; D007700:Kinetics; D008567:Membranes, Artificial; D008956:Models, Chemical; D055672:Static Electricity
D007477:Ions; D008567:Membranes, Artificial