Department of Physics and Astronomy, Dornsife College of Letters, Arts & Sciences, University of Southern California, Los Angeles, CA, USA.
J Membr Biol. 2012 Oct;245(10):599-610. doi: 10.1007/s00232-012-9471-1. Epub 2012 Jul 20.
Molecular dynamics simulations of electroporation of homogeneous phospholipid bilayers show that the pore creation time is strongly dependent on the magnitude of the applied electric field. Here, we investigated whether heterogeneous bilayers containing phospholipids with zwitterionic and anionic headgroups exhibit a similar dependence. To facilitate this analysis we divide the life cycle of an electropore into several stages, marking the sequence of steps for pore creation and pore annihilation (restoration of the bilayer after removal of the electric field). We also report simulations of calcium binding isotherms and the effects of calcium ions on the electroporation of heterogeneous lipid bilayers. Calcium binding simulations are consistent with experimental data using a 1:2 Langmuir binding isotherm. We find that calcium ions and phosphatidylserine increase pore creation time and decrease pore annihilation time. For all systems tested, pore creation time was inversely proportional to the bilayer internal electric field.
对均匀磷脂双层的电穿孔的分子动力学模拟表明，孔的形成时间强烈依赖于所施加电场的大小。在这里，我们研究了含有带两性离子和阴离子头基的磷脂的非均匀双层是否表现出类似的依赖性。为了便于分析，我们将电穿孔的生命周期分为几个阶段，标记出孔形成和孔消失（在电场移除后双层恢复）的步骤顺序。我们还报告了钙结合等温线的模拟以及钙离子对非均匀脂质双层电穿孔的影响。使用 1:2 的朗缪尔结合等温线，钙结合模拟与实验数据一致。我们发现钙离子和磷脂酰丝氨酸增加了孔的形成时间并减少了孔的消失时间。对于所有测试的系统，孔的形成时间与双层内部电场成反比。
