Mesoscopic simulation of cell membrane damage, morphology change and rupture by nonionic surfactants
Mesoscopic simulation of cell membrane damage, morphology change and rupture by nonionic surfactants
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DOI：
10.1016/s0006-3495(01)75737-2
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发表时间：
2001-08-01
影响因子：
3.4
通讯作者：
Rabone, KL
中科院分区：
文献类型：
--
作者：
Groot, RD;Rabone, KL
将一种新的模拟方法--耗散粒子动力学应用于生物膜的模拟。在这种方法中，几个原子被联合成一个模拟粒子。模拟模型再现了各液体组分的溶解度和可压缩性。当应用于磷脂酰乙醇胺的双层时，得到的膜结构与全原子模拟和文献报道的实验定量匹配。该方法被应用于研究细菌接触非离子表面活性剂时细胞死亡的原因。研究了脂类和非离子表面活性剂的混合双层膜，并监测了水在双层膜中的扩散。在摩尔分数为40%的C9E8处出现小的瞬变孔，在60%到70%的表面活性剂之间成为永久性的孔。当使用C12E6时，只有在摩尔分数为90%的表面活性剂时才会出现永久性孔洞。对磷脂酰乙醇胺和C12E6混合双层膜的破裂特性进行了模拟研究。这些模拟表明，纯脂双层膜的面积可以增加2倍。表面活性剂的加入大大降低了双层膜的延伸性和承受的最大应力。这可能解释了为什么分裂的细胞比静止的细胞更危险。
A new simulation method, dissipative particle dynamics, is applied to model biological membranes. In this method, several atoms are united into a single simulation particle. The solubility and compressibility of the various liquid components are reproduced by the simulation model. When applied to a bilayer of phosphatidylethanolamine, the membrane structure obtained matches quantitatively with full atomistic simulations and with experiments reported in the literature. The method is applied to investigate the cause of cell death when bacteria are exposed to nonionic surfactants. Mixed bilayers of lipid and nonionic surfactant were studied, and the diffusion of water through the bilayer was monitored. Small transient holes are seen to appear at 40% mole-fraction C9E8, which become permanent holes between 60 and 70% surfactant. When C12E6 is applied, permanent holes only arise at 90% mole-fraction surfactant. Some simulations have been carried out to determine the rupture properties of mixed bilayers of phosphatidylethanolamine and C12E6. These simulations indicate that the area of a pure lipid bilayer can be increased by a factor 2. The inclusion of surfactant considerably reduces both the extensibility and the maximum stress that the bilayer can withstand. This may explain why dividing cells are more at risk than static cells.