Relative dielectric constants and selectivity ratios in open ionic channels

Abstract

We investigate the effects of the relative dielectric coefficient on ionic flows in open ion channels, using mathematical analysis of reasonably general Poisson-Nernst-Planck type models that can include the finite sizes of ions. The value of the relative dielectric coefficient is of course a crucial parameter for ionic behavior in general. Using the powerful theory of singularly perturbed problems in applied mathematics, we show that some properties of open channels are quite insensitive to variation in the relative dielectric coefficient, thereby explaining such effects seen unexpectedly in simulations. The ratio between the total number of one ion species and that of another ion species, and the ratio between the flux of one ion species and that of another ion species do not depend significantly on the relative dielectric coefficient.

arXiv commentMolecular Based Mathematical Biology 2017

References in corpus (6)

• Model Channel Ion Currents in NaCl - SPC/E Solution with Applied-Field Molecular Dynamics
• Poisson-Nernst-Planck Systems for Narrow Tubular-like Membrane Channels
• Interacting Ions in Biophysics: Real is not Ideal
• Energetics of discrete selectivity bands and mutation-induced transitions in the calcium-sodium ion channels family
• A Nonlocal Poisson-Fermi Model for Ionic Solvent
• Life's Solutions are Not Ideal