Protein Crowding in Lipid Bilayers Gives Rise to Non-Gaussian Anomalous Lateral Diffusion of Phospholipids and Proteins

Jae-Hyung Jeon,Hector Martinez-Seara,Ilpo Vattulainen,Ralf Metzler,Matti Javanainen

doi:10.1103/physrevx.6.021006

Abstract

An investigation into how lipids diffuse in the presence of varying protein:lipid number ratios reveals that protein crowding results in drastically different lipid and protein diffusion due to the strengthened impact of correlated motion.

Highlights

The dynamics of biomembranes plays a crucial role in the regulation of numerous cellular processes
Our focus here is to pin down the stochastic character and physical origins of the anomalous lateral diffusion induced by protein crowding
(2) The protein crowding effects a non-Gaussian character in the anomalous diffusion, which is incompatible with the known models describing lateral diffusion

Summary

INTRODUCTION

The dynamics of biomembranes plays a crucial role in the regulation of numerous cellular processes. Most notably, crowding shapes the reaction kinetics [11,17,18,19] by modifying the mobility [20] as well as association rates [21,22,23,24,25] This multitude of examples together with the shift in dimensionality from three to two hints that, besides the cytoplasm, crowding plays a substantial role in cellular membranes. Our findings are central to resolving the mechanisms governing how molecules move along crowded membranes and, to understanding how the multitude of processes occurring in cellular membranes are controlled by anomalous diffusion-reaction dynamics. Additional results to support those presented in the main text are given in Supplemental Material [80]

MODELS AND SIMULATION

RESULTS

Protein crowding induces non-Gaussian anomalous diffusion

Protein crowding induces spatiotemporal heterogeneity in lateral diffusion

DISCUSSION AND CONCLUSIONS