A Multifrequency ESR Study of the Complex Dynamics of Membranes
A Multifrequency ESR Study of the Complex Dynamics of Membranes
复制标题
膜复杂动力学的多频 ESR 研究
DOI：
10.1021/jp013226c
复制
发表时间：
2001
影响因子：
3.3
通讯作者：
J. Freed
中科院分区：
文献类型：
--
作者：
Yan;Andersen Ge;J. Freed
使用末端链标记的脂质 16-PC，对由纯脂质 (DPPC) 和摩尔比为 1:1 的 DPPC: 胆固醇组成的膜囊泡进行了 250 和 9 GHz ESR 联合研究。结果表明，250 GHz 光谱代表“快速时间尺度”，使得膜中脂质的整体受限运动被冻结，但它对末端链的内部动力学敏感。然而，9 GHz 频谱对整体运动也很敏感。因此，这项联合研究允许将两种类型的运动分开。结果表明，胆固醇的添加通过限制末端链的运动同时增加运动速率，对末端链动力学产生很大影响，而其对整体脂质运动的影响则不大。与液晶相相比，这使得富含胆固醇的液体有序相的动态结构得到更清晰的表征。因此，这项研究表明了多频 ESR 方法在解决复杂动态问题方面的巨大潜力……
A combined 250 and 9 GHz ESR study was performed on membrane vesicles composed of pure lipid (DPPC) and of DPPC:cholesterol in a 1:1 molar ratio using the end chain labeled lipid, 16-PC. It is shown that the 250 GHz spectra represent a “fast time-scale” such that the overall restricted motion of the lipid in the membrane is frozen out, but it is sensitive to the internal dynamics of the end chain. The 9 GHz spectra are, however, sensitive to the overall motion as well. This combined study thus permitted the separation of both types of motion. It is shown that the addition of cholesterol has a large effect on the end chain dynamics by restricting its motion while increasing motional rates, whereas its effects on the overall lipid motion are modest. This leads to a clearer characterization of the dynamic structure of the cholesterol-rich liquid-ordered phase as compared to the liquid crystalline phase. This study thus shows the significant potential of a multifrequency ESR approach to the complex dynamics o...