Entropy-driven aggregation in multilamellar membranes

TL;DR

This paper investigates how entropy-driven forces influence the aggregation of ligand-receptor sites in multilamellar membranes, revealing conditions that promote large domain formation through simulations and theoretical models.

Contribution

It introduces a combined simulation and theoretical approach to understand entropy-driven aggregation in multilamellar membranes, highlighting the effects of multiple membrane binding and membrane hardening.

Findings

Entropic attraction alone is insufficient for large domain formation in two-membrane systems.

Binding three or more membranes enhances aggregation significantly.

Membrane hardening around anchors further promotes large domain formation.

Abstract

Membrane-fluctuation-induced attraction between ligand--receptor sites binding neighboring membranes is studied using meshless membrane simulations and the Weil--Farago two-dimensional lattice model. For the adhesion sites binding two membranes, this entropic interaction is too weak by itself for the adhesion sites to form a large stable domain. However, it is found that this attraction is enhanced sufficiently to induce large domains either when the sites bind three or more neighboring membranes together or have anchors that harden surrounding membranes. The latter effect is understood by the Asakura--Oosawa type of effective potential in the depletion theory.