Protein induced lipid demixing in homogeneous membranes

TL;DR

This paper introduces an exactly solvable continuum model demonstrating how proteins can induce local lipid demixing in membranes, forming domains even above critical temperatures, aligning with experimental observations.

Contribution

The study provides a novel theoretical framework explaining protein-induced lipid domain formation through local composition and thickness coupling in membranes.

Findings

Proteins can induce lipid demixing above critical temperatures.

The model explains experimentally observed actin-induced lipid domains.

Lipid domain formation is driven by local composition-thickness coupling.

Abstract

Specific lipid environments are necessary for the establishment of protein signalling platforms in membranes, yet their origin has been highly debated. We present a continuum, exactly solvable model of protein induced local demixing of lipid membranes. The coupling between a local composition and a local thickness of the membrane induces lipid domains around inclusions with hydrophobic mismatch, even for temperatures above the miscibility critical point of the membrane. The model qualitatively explains the experimentally observed formation of lipid domains induced by anchoring of reconstituted actin in flat supported lipid bilayers.