Multi-ion conduction bands in a simple model of calcium ion channels

TL;DR

This study uses self-consistent Brownian dynamics simulations to reveal structured conduction bands and selectivity in calcium ion channels, identifying specific bands with high calcium selectivity and linking them to known channel types.

Contribution

It introduces a simple electrostatic model that uncovers regular conduction and selectivity patterns, including distinct conduction bands, in calcium ion channels.

Findings

Identification of conduction bands M0, M1, M2 with high conductance

M1 and M2 bands show high calcium selectivity

M1 and M2 correspond to L-type and RyR calcium channels

Abstract

We report self-consistent Brownian dynamics simulations of a simple electrostatic model of the selectivity filters (SF) of calcium ion channels. They reveal regular structure in the conductance and selectivity as functions of the fixed negative charge Qf at the SF. This structure consists of distinct regions of high conductance (conduction bands) M0, M1, M2 separated by regions of zero-conductance (stop-bands). Two of these conduction bands, M1 and M2, demonstrate high calcium selectivity and prominent anomalous mole fraction effects and can be identified with the L-type and RyR calcium channels.