Fractional Poisson–Nernst–Planck Model for Ion Channels
Host
Department of Applied Mathematics
Speaker
Duan Chen
Department of Mathematics and Statistics, University of North Carolina at Charlotte
https://clas-math.uncc.edu/duan-chen/
Description
In this work, we propose a fractional Poisson-Nernst-Planck model to describe ion permeation in gated ion channels. Due to the intrinsic conformational changes, crowdedness in narrow channel pores, binding and trapping introduced by functioning units of channel proteins, ionic transport in the channel exhibits a power-law-like anomalous diffusion dynamics. We start from continuous time random walk model for a single ion, and use a long-tailed density distribution function for the particle jump waiting time, to derive the fractional Fokker-Planck equation. Then it is generalized to the macroscopic fractional Poisson-Nernst-Planck model for ionic concentrations. Necessary computational algorithms are designed to implement numerical simulations for the proposed model and the dynamics of gating current is investigated. Numerical simulations show that the fractional PNP model provides a more qualitatively reasonable match to the profile of gating currents from experimental observations. Meanwhile, the proposed model motivates new challenges in terms of mathematical modeling and computations.
Event Topic
Stochastic & Multiscale Modeling and Computation