分子动力学模拟中两亲性双层膜的面积压缩性与屈曲

Area compressibility and buckling of amphiphilic bilayers in molecular dynamics simulations.

作者信息

den Otter W K

机构信息

Computational Dispersion Rheology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

出版信息

J Chem Phys. 2005 Dec 1;123(21):214906. doi: 10.1063/1.2132287.

DOI:10.1063/1.2132287

PMID:16356069

Abstract

The elastic modulus or area compressibility of a membrane is routinely calculated in molecular dynamics simulations as the proportionality constant relating surface tension and projected surface area. Recent studies, however, have revealed a marked system size dependence of these moduli, which we attribute to the neglect of thermal undulations in the area calculation. We discuss several methods, based on the Helfrich model and on numerical triangulation, to remedy this situation, and find a satisfying agreement between them. The Helfrich model also quantitatively describes a buckling transition observed for compressed bilayers.

摘要

在分子动力学模拟中，膜的弹性模量或面积压缩率通常作为与表面张力和投影表面积相关的比例常数来计算。然而，最近的研究表明，这些模量明显依赖于系统大小，我们将其归因于在面积计算中忽略了热涨落。我们讨论了几种基于赫尔弗里希模型和数值三角剖分的方法来纠正这种情况，并发现它们之间有令人满意的一致性。赫尔弗里希模型还定量描述了压缩双层膜中观察到的屈曲转变。