Computing the Field in Proteins and Channels

TL;DR

This paper reviews the PNP Poisson Nernst Planck theory for ion channels, explaining how it models ion movement and electrical potential using electrodiffusion principles similar to semiconductor physics.

Contribution

It provides a comprehensive overview of the PNP theory applied to ion channels, connecting biological electrodiffusion with concepts from solid state physics.

Findings

PNP theory effectively models ion flow in channels

Uses Poisson's equation for electrical potential

Employs Nernst-Planck equations for ion migration

Abstract

This is an early but comprehensive review of the PNP Poisson Nernst Planck theory of ion channels. Extensive reference is made to the earlier literature. The starting place for this theory of open channels is a theory of electrodiffusion rather like that used previously to describe membranes. The theory uses Poisson's equation to describe how charge on ions and the channel protein creates electrical potential; it uses the Nernst-Planck equations to describe migration and diffusion of ions in gradients of concentration and electrical potential. Combined, these are also the "drift-diffusion equations" of solid state physics, which are widely, if not universally used to describe the flow of current and the behavior of semiconductors.