Ion pump activity generates fluctuating electrostatic forces in biomembranes

TL;DR

This study investigates how ion pumps in biomembranes create fluctuating electrostatic forces, affecting membrane tension and bending rigidity, with implications for understanding membrane dynamics.

Contribution

It introduces a model linking ion pump activity to electrostatic force fluctuations and their impact on membrane mechanical properties.

Findings

Ion pump activity causes fluctuating electrostatic forces.

These forces influence membrane tension and bending rigidity.

The model aligns with and extends previous force-multipole studies.

Abstract

We study the non-equilibrium dynamics of lipid membranes with proteins that actively pump ions across the membrane. We find that the activity leads to a fluctuating force distribution due to electrostatic interactions arising from variation in dielectric constant across the membrane. By applying a multipole expansion we find effects on both the tension and bending rigidity dominated parts of the membranes fluctuation spectrum. We discuss how our model compares with previous studies of force-multipole models.