Research Institute for Interdisciplinary Science and Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan.
Department of Computer Science and Engineering, Graduate School of Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580, Japan.
Phys Rev E. 2017 Oct;96(4-1):042410. doi: 10.1103/PhysRevE.96.042410. Epub 2017 Oct 19.
A two-step subdiffusion behavior of lateral movement of transmembrane proteins in plasma membranes has been observed by using single-molecule experiments. A nested double-compartment model where large compartments are divided into several smaller ones has been proposed in order to explain this observation. These compartments are considered to be delimited by membrane-skeleton "fences" and membrane-protein "pickets" bound to the fences. We perform numerical simulations of a master equation using a simple two-dimensional lattice model to investigate the heterogeneous diffusion dynamics behavior of transmembrane proteins within plasma membranes. We show that the experimentally observed two-step subdiffusion process can be described using fence and picket models combined with decreased local diffusivity of transmembrane proteins in the vicinity of the pickets. This allows us to explain the two-step subdiffusion behavior without explicitly introducing nested double compartments.
使用单分子实验观察到质膜中跨膜蛋白侧向运动的两步亚扩散行为。为了解释这一观察结果，提出了一种嵌套的双隔室模型，其中大隔室被分成几个较小的隔室。这些隔室被认为是由膜骨架“围栏”和与围栏结合的膜蛋白“尖桩”限定的。我们使用简单的二维格点模型对主方程进行数值模拟，以研究质膜内跨膜蛋白的非均匀扩散动力学行为。我们表明，实验观察到的两步亚扩散过程可以用围栏和尖桩模型来描述，同时结合尖桩附近跨膜蛋白局部扩散率的降低。这使得我们可以在不明确引入嵌套双隔室的情况下解释两步亚扩散行为。
