A molecular dynamics investigation of the influence of hydration and temperature on structural and dynamical properties of a dimyristoylphosphatidylcholine bilayer
A molecular dynamics investigation of the influence of hydration and temperature on structural and dynamical properties of a dimyristoylphosphatidylcholine bilayer
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DOI：
10.1021/jp0614796
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发表时间：
2006-07-27
影响因子：
3.3
通讯作者：
Lyubartsev, Alexander P.
中科院分区：
文献类型：
--
作者：
Hogberg, Carl-Johan;Lyubartsev, Alexander P.
用分子动力学方法模拟了不同水化程度和不同温度的二肉豆蔻基磷脂酰胆碱双层膜，考察了水化作用对脂膜性质的影响。测定了结构和动力学性质，如每脂的面积、电子密度、所有CH键和水的有序参数、扩散和重定向自相关函数，并发现这些性质都受到水合水平的影响。模拟给出了当水合程度降低时，双层膜进入更有序状态的总体情况。当水分含量降低时，脂头基团的取向更多地平行于膜平面。动力学性质，如脂类扩散和重定向时间相关函数的松弛，被发现随着水分的去除而变慢。在有实验数据的情况下，我们的模拟结果与实验数据基本一致。得出的一个重要结论是，虽然结构性能只受到适度的影响，但水含量的下降对动力性能的影响非常大。
A series of molecular dynamics simulations of dimyristoylphosphatidylcholine bilayers, with different levels of hydration and temperature, were performed to examine the influence of hydration on properties of lipid membranes. Structural and dynamical properties such as area per lipid, electron densities, order parameters for all CH bonds and water, diffusion, and reorientation autocorrelation functions were determined and were all found to be affected by changes in the hydration level. The simulations give an overall picture of the bilayer going to a more ordered state when the hydration level is reduced. Lipid headgroups were found to adopt an orientation more parallel to the membrane plane when the water content was decreased. Dynamical properties such as lipid diffusion and relaxation of reorientation time correlation functions were found to become slower with the removal of water. Our simulation results generally agree with experimental data in cases where such data are available. One important conclusion drawn is that while structural properties are affected only moderately dynamical properties are affected very strongly by a decrease of water content.