Structure and Orientation of Water at Charged Lipid Monolayer/Water Interfaces Probed by Heterodyne-Detected Vibrational Sum Frequency Generation Spectroscopy
Structure and Orientation of Water at Charged Lipid Monolayer/Water Interfaces Probed by Heterodyne-Detected Vibrational Sum Frequency Generation Spectroscopy
复制标题
DOI：
10.1021/ja104327t
复制
发表时间：
2010-08-11
影响因子：
15
通讯作者：
Tahara, Tahei
中科院分区：
文献类型：
--
作者：
Mondal, Jahur A.;Nihonyanagi, Satoshi;Tahara, Tahei
细胞膜/水界面为许多生化反应提供了独特的环境，相关的界面水是此类反应的组成部分。要实现生物界面上的复杂化学，需要在分子水平上了解脂质/水界面上水的结构和方向。在这里，我们报告了脂质单层/水界面的外差检测振动和频率产生（HD-VSFG）研究。在带电的脂质/水界面，界面水的方向由脂质头基上的净电荷控制；在阴离子脂质/水界面，水处于氢向上的方向，而在阳离子脂质/水界面，水处于氢向下的方向。在阳离子和阴离子脂质/水界面，界面水具有相当的氢键强度，并且与本体水类似。
Cell membrane/water interfaces provide a unique environment for many biochemical reactions, and associated interfacial water is an integral part of such reactions. A molecular level understanding of the structure and orientation of water at lipid/water interfaces is required to realize the complex chemistry at biointerfaces. Here we report the heterodyne-detected vibrational sum frequency generation (HD-VSFG) studies of lipid monolayer/water interfaces. At charged lipid/water interfaces, the orientation of interfacial water is governed by the net charge on the lipid head-group; at an anionic lipid/water interface, water is in the hydrogen-up orientation, and at the cationic lipid/water interface, water is in the hydrogen-down orientation. At the cationic and anionic lipid/water interfaces, interfacial water has comparable hydrogen bond strength, and it is analogous to the bulk water.