Pinisetty D, Moldovan D, Devireddy R
Department of Mechanical Engineering, Louisiana State University, 2508 CEBA Bldg., Baton Rouge, LA 70803, USA.
Ann Biomed Eng. 2006 Sep;34(9):1442-51. doi: 10.1007/s10439-006-9148-y. Epub 2006 Aug 8.
The interactions of methanol with lipid bilayers were studied by means of molecular dynamics (MD) simulations. Our MD simulations focus on the effect of approximately 11.3 mol% methanol on two fully hydrated dipalmitoylphosphatidylcholine (DPPC) and palmitoyloleoylphosphatidylcholine (POPC) lipid bilayers both in the fluid phase and under equilibrium conditions at 323 and 298 K, respectively. The effects of methanol on bilayers structural characteristics were investigated. In both systems the simulations show that the presence of relatively high concentration of methanol leads to a significant increase in the area per lipid. The increase in the area per lipid is accompanied by a corresponding decrease of the bilayer thickness such that the volume occupied per lipid does not change significantly in the presence of methanol. Other properties such as ordering of phospholipid tails and lateral diffusion of the lipids are also affected significantly by the presence of methanol. Consistent with other previously reported MD simulation studies of bilayers in the presence of methanol (albeit at a significantly smaller concentration of 1 mol%) our study shows very few hydrogen bonding formation between lipids and methanol.
通过分子动力学(MD)模拟研究了甲醇与脂质双层的相互作用。我们的MD模拟聚焦于约11.3摩尔%的甲醇分别在323 K和298 K的平衡条件下对处于流体相的两种完全水合的二棕榈酰磷脂酰胆碱(DPPC)和棕榈酰油酰磷脂酰胆碱(POPC)脂质双层的影响。研究了甲醇对双层结构特征的影响。在这两个系统中,模拟结果表明,相对高浓度甲醇的存在导致每个脂质的面积显著增加。每个脂质面积的增加伴随着双层厚度的相应减小,使得在甲醇存在下每个脂质占据的体积没有显著变化。其他性质,如磷脂尾部的有序性和脂质的横向扩散,也受到甲醇存在的显著影响。与之前其他关于甲醇存在下脂质双层的MD模拟研究一致(尽管甲醇浓度显著较低,为1摩尔%),我们的研究表明脂质与甲醇之间形成的氢键非常少。