Nernst equilibrium, rectification, and saturation: Insights into ion channel behavior
The dissipation of electrochemical gradients through ion channels plays a central role in biology. Herein we use voltage-responsive kinetic models of ion channels to explore how electrical and chemical potentials differentially influence ion transport properties. These models demonstrate how electrically driven flux is greater than the Nernstian equivalent chemically driven flux yet still perfectly cancels when the two gradients oppose each other. We find that the location and relative stability of ion-binding sites dictates rectification properties by shifting the location of the most voltage-sensitive transitions.
