The condensing effect of cholesterol in lipid bilayers
The condensing effect of cholesterol in lipid bilayers
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DOI：
10.1529/biophysj.106.099234
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发表时间：
2007-06-01
影响因子：
3.4
通讯作者：
Huang, Huey W.
中科院分区：
文献类型：
--
作者：
Hung, Wei-Chin;Lee, Ming-Tao;Huang, Huey W.
系统地研究了胆固醇对磷脂双分子层饱和链和不饱和链的凝聚效应，并将其作为胆固醇浓度的函数。X-射线层状衍射用于测量跨双层的磷酸盐-磷酸盐距离PtP。测得的PtP随着胆固醇浓度非线性增加，直到达到最大值。随着胆固醇浓度的进一步增加，PtP保持在最大水平，直到胆固醇含量达到溶解度极限。在所有情况下的数据可以用一个简单的模型定量地解释，胆固醇形成复合物与磷脂的双层。与胆固醇复合的磷脂分子被延长，并且这种延长效应延伸到胆固醇复合物周围的未复合的磷脂中。这种长程增稠效应类似于短杆菌肽由于疏水匹配而对脂质双层厚度的效应。
The condensing effect of cholesterol on phospholipid bilayers was systematically investigated for saturated and unsaturated chains, as a function of cholesterol concentration. X-ray lamellar diffraction was used to measure the phosphate-to-phosphate distances, PtP, across the bilayers. The measured PtP increases nonlinearly with the cholesterol concentration until it reaches a maximum. With further increase of cholesterol concentration, the PtP remains at the maximum level until the cholesterol content reaches the solubility limit. The data in all cases can be quantitatively explained with a simple model that cholesterol forms complexes with phospholipids in the bilayers. The phospholipid molecules complexed with cholesterol are lengthened and this lengthening effect extends into the uncomplexed phospholipids surrounding the cholesterol complexes. This long-range thickening effect is similar to the effect of gramicidin on the thickness of lipid bilayers due to hydrophobic matching.