Binding and segregation of proteins in membrane adhesion: Theory, modelling, and simulations

TL;DR

This paper reviews models of biomembrane adhesion, highlighting how protein binding depends on membrane shape fluctuations and how length mismatches induce segregation through bending interactions.

Contribution

It provides a comprehensive review of theoretical and simulation models, revealing the role of nanoscale membrane fluctuations and length mismatch in protein binding and segregation.

Findings

Protein binding depends on membrane shape fluctuations.

Length mismatch causes repulsive interactions and segregation.

Membrane bending influences protein cooperativity.

Abstract

The adhesion of biomembranes is mediated by the binding of membrane-anchored receptor and ligand proteins. The proteins can only bind if the separation between apposing membranes is sufficiently close to the length of the protein complexes, which leads to an interplay between protein binding and membrane shape. In this article, we review current models of biomembrane adhesion and novel insights obtained from the models. Theory and simulations with elastic-membrane and coarse-grained molecular models of biomembrane adhesion indicate that the binding of proteins in membrane adhesion strongly depends on nanoscale shape fluctuations of the apposing membranes, which results in binding cooperativity. A length mismatch between protein complexes leads to repulsive interactions that are caused by membrane bending and act as a driving force for the length-based segregation of proteins during membrane adhesion.