Vesicle deformations by clusters of transmembrane proteins

TL;DR

This study uses coarse-grained molecular dynamics to explore how transmembrane protein clusters influence vesicle shape and curvature, revealing how protein concentration affects clustering and vesicle morphology.

Contribution

It provides a quantitative analysis of protein cluster effects on vesicle shape and investigates the roles of depletion forces and vesiculation in clustering behavior.

Findings

Protein clusters alter vesicle shapes and curvatures.

Higher protein concentration leads to smaller, more symmetric clusters.

Large clusters and aspherical vesicles are limited at high protein fractions.

Abstract

We carry out a coarse-grained molecular dynamics simulation of phospholipid vesicles with transmembrane proteins. We measure the mean and Gaussian curvatures of our protein-embedded vesicles and quantitatively show how protein clusters change the shapes of their host vesicles. The effects of depletion force and vesiculation on protein clustering are also investigated. By increasing the protein concentration, clusters are fragmented to smaller bundles, which are then redistributed to form more symmetric structures corresponding to lower bending energies. Big clusters and highly aspherical vesicles cannot be formed when the fraction of protein to lipid molecules is large.