Sung W, Park P J
Department of Physics, Pohang University of Science and Technology, Korea.
Biophys J. 1997 Oct;73(4):1797-804. doi: 10.1016/S0006-3495(97)78210-9.
Pores can form and grow in biomembranes because of factors such as thermal fluctuation, transmembrane electrical potential, and cellular environment. We propose a new statistical physics model of the pore growth treated as a non-Markovian stochastic process, with a free energy barrier and memory friction from the membrane matrix treated as a quasi-two-dimensional viscoelastic and dielectric fluid continuum. On the basis of the modern theory of activated barrier crossing, an analytical expression for membrane lifetime and the phase diagram for membrane stability are obtained. The memory effect due to membrane viscoelasticity and the elasticity due to cytoskeletal network are found to induce sharp transitions to membrane stability against pore growth and compete with other factors to manifest rich dynamic transitions over the membrane lifetime.
由于热涨落、跨膜电势和细胞环境等因素，生物膜中会形成并生长孔道。我们提出了一种新的统计物理模型来描述孔道生长，将其视为一个非马尔可夫随机过程，把来自膜基质的自由能垒和记忆摩擦当作准二维粘弹性和介电流体连续介质来处理。基于现代活化势垒穿越理论，得到了膜寿命的解析表达式以及膜稳定性的相图。发现膜粘弹性引起的记忆效应和细胞骨架网络产生的弹性会导致膜对孔道生长的稳定性发生急剧转变，并与其他因素相互竞争，从而在膜的寿命期间表现出丰富的动态转变。
