Non-Brownian diffusion in lipid membranes: Experiments and simulations

作者：Ralf Metzler, Jae‐Hyung Jeon, Andrey G. Cherstvy · 发表于：Biochimica et Biophysica Acta (BBA) - Biomembranes · 年份：2016 · DOI：10.1016/j.bbamem.2016.01.022 · 被引用次数：250 · 研究领域：Lipid Membrane Structure and Behavior、Spectroscopy and Quantum Chemical Studies、Protein Structure and Dynamics

The dynamics of constituents and the surface response of cellular membranes-also in connection to the binding of various particles and macromolecules to the membrane-are still a matter of controversy in the membrane biophysics community, particularly with respect to crowded membranes of living biological cells. We here put into perspective recent single particle tracking experiments in the plasma membranes of living cells and supercomputing studies of lipid bilayer model membranes with and without protein crowding. Special emphasis is put on the observation of anomalous, non-Brownian diffusion of both lipid molecules and proteins embedded in the lipid bilayer. While single component, pure lipid bilayers in simulations exhibit only transient anomalous diffusion of lipid molecules on nanosecond time scales, the persistence of anomalous diffusion becomes significantly longer ranged on the addition of disorder-through the addition of cholesterol or proteins-and on passing of the membrane lipids to the gel phase. Concurrently, experiments demonstrate the anomalous diffusion of membrane embedded proteins up to macroscopic time scales in the minute time range. Particular emphasis will be put on the physical character of the anomalous diffusion, in particular, the occurrence of ageing observed in the experiments-the effective diffusivity of the measured particles is a decreasing function of time. Moreover, we present results for the time dependent local scaling exponent of the mean s...