Thermal fluctuations and bending rigidity of bilayer membranes.
Thermal fluctuations and bending rigidity of bilayer membranes.
复制标题
DOI：
10.1063/1.4818421
复制
发表时间：
2013-09
期刊：
影响因子：
--
通讯作者：
P. Tarazona;E. Chacón;F. Bresme
中科院分区：
文献类型：
--
作者：
P. Tarazona;E. Chacón;F. Bresme
我们提出了一种在计算机模拟中估计生物膜弹性特性的新方案。该方法根据耦合波动模式分析热波动，从而消除介观波动和高 q 突起的混合。这种方法可以准确估计膜在应力和无张力条件下的弯曲模量；它还将波动分析的适用性扩展到原子模拟中通常使用的小膜区域。我们还阐明了通过压力耦合恒压器模拟时施加的表面张力与可以从耦合波状涨落谱的低波矢量依赖性分析中提取的表面张力之间的差异。通过分离体积和突起的贡献，蠕动模式的物理分析也得到了改进。我们通过分析 1-棕榈酰-2-油酰-sn-甘油-3-磷酸胆碱和 1,2-二棕榈酰-sn-甘油-3-磷酸胆碱双层来说明该过程。从我们的分析中获得的弯曲模量与现有实验显示出良好的一致性。
We present a new scheme to estimate the elastic properties of biological membranes in computer simulations. The method analyzes the thermal fluctuations in terms of a coupled undulatory mode, which disentangle the mixing of the mesoscopic undulations and the high-q protrusions. This approach makes possible the accurate estimation of the bending modulus both for membranes under stress and in tensionless conditions; it also extends the applicability of the fluctuation analysis to the small membrane areas normally used in atomistic simulations. Also we clarify the difference between the surface tension imposed in simulations through a pressure coupling barostat, and the surface tension that can be extracted from the analysis of the low wave vector dependence of the coupled undulatory fluctuation spectrum. The physical analysis of the peristaltic mode is also refined, by separating the bulk and protrusions contributions. We illustrate the procedure by analyzing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine bilayers. The bending moduli obtained from our analysis, shows good agreement with available experiments.