Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
Phys Rev Lett. 2010 Jul 2;105(1):018105. doi: 10.1103/PhysRevLett.105.018105.
We demonstrate the self-organization process of a stable pore structure in a phospholipid bilayer by unsteady and nonequilibrium molecular dynamics simulations. The simulation is started from an initial state including some amount of water molecules in its hydrophobic region, which is a model of a cell membrane stimulated by ultrasound radiation for the membrane permeabilization (sonoporation). We show that, in several nanoseconds, the bilayer-water system can spontaneously develop into a water-filled pore structure without any mechanical and electrical forcing from outside, when the initial number of water molecules in the hydrophobic region exceeds a critical value. The increase in the initial number of water molecules enhances the probability of pore formation, and sometimes induces the formation of transient micellelike structures of phospholipid molecules.
我们通过非稳态和非平衡分子动力学模拟展示了磷脂双层中稳定孔结构的自组织过程。模拟从包括一些水分子的初始状态开始，这些水分子位于疏水区，这是超声辐射刺激细胞膜用于膜通透性（声孔）的模型。我们表明，在几纳秒内，当疏水区域中的初始水分子数量超过临界值时，双层-水体系可以在没有任何外部机械和电作用力的情况下自发地发展成充满水的孔结构。初始水分子数量的增加提高了形成孔的概率，有时还会诱导磷脂分子形成短暂的胶束样结构。
