Sterols sense swelling in lipid bilayers
Sterols sense swelling in lipid bilayers
复制标题
甾醇感知脂质双层的肿胀
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
G. Rapp
中科院分区：
文献类型：
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作者：
F. Richter;L. Finegold;G. Rapp
在磷脂酰胆碱双分子层的模拟膜系统中，在主转变附近观察到双分子层的增厚（临界前行为，异常溶胀），这与温度呈非线性关系。甾醇、胆固醇和雄甾烯被用作时间分辨同时小角和广角X射线衍射研究中的传感器，以调查增厚的原因。我们观察到在纯脂质系统中的临界行为，以及与甾醇浓度小于15%。为了描述前临界行为，我们引入了前临界现象理论，数据的良好温度分辨率表明，涨落影响的理论需要修正。临界行为的主要原因似乎是双分子层的水合作用的变化。
In the mimetic membrane system of phosphatidylcholine bilayers, thickening (pre-critical behavior, anomalous swelling) of the bilayers is observed, in the vicinity of the main transition, which is non-linear with temperature. The sterols cholesterol and androsten are used as sensors in a time-resolved simultaneous small- and wide angle x-ray diffraction study to investigate the cause of the thickening. We observe precritical behavior in the pure lipid system, as well as with sterol concentrations less than 15%. To describe the precritical behavior we introduce a theory of precritical phenomena.The good temperature resolution of the data shows that a theory of the influence of fluctuations needs modification. The main cause of the critical behavior appears to be a changing hydration of the bilayer.