LATERAL DIFFUSION IN THE LIQUID-PHASES OF DIMYRISTOYLPHOSPHATIDYLCHOLINE CHOLESTEROL LIPID BILAYERS - A FREE-VOLUME ANALYSIS
LATERAL DIFFUSION IN THE LIQUID-PHASES OF DIMYRISTOYLPHOSPHATIDYLCHOLINE CHOLESTEROL LIPID BILAYERS - A FREE-VOLUME ANALYSIS
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DOI：
10.1021/bi00144a013
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发表时间：
1992-07-28
期刊：
影响因子：
2.9
通讯作者：
THOMPSON, TE
中科院分区：
文献类型：
--
作者：
ALMEIDA, PFF;VAZ, WLC;THOMPSON, TE
利用光漂白后的荧光恢复技术，在磷脂熔化温度以上，对磷脂探针在二肉豆蔻基磷脂酰胆碱/胆固醇二元混合物中的侧向扩散进行了广泛的研究。在单液相存在的相图区域，扩散可用修正的Macedo-Litovitz混合方程用自由体积理论来定量描述。在液-液不混相区，扩散系数的温度依赖性与目前复合两相介质中广义扩散系数的理论是一致的。对扩散数据的一致解释基本上可以基于胆固醇添加到双分子层的主要影响是占据自由体积的想法。在此基础上，给出了该混合物相行为的一般解释。
The technique of fluorescence recovery after photobleaching is used to perform an extensive study of the lateral diffusion of a phospholipid probe in the binary mixture dimyristoylphosphatidylcholine/cholesterol, above the melting temperature of the phospholipid. In the regions of the phase diagram where a single liquid phase exists, diffusion can be quantitatively described by free volume theory, using a modified Macedo-Litovitz hybrid equation. In the liquid-liquid immiscibility region, the temperature dependence of the diffusion coefficient is in excellent agreement with current theories of generalized diffusivities in composite two-phase media. A consistent interpretation of the diffusion data can be provided based essentially on the idea that the primary effect of cholesterol addition to the bilayer is to occupy free volume. On this basis, a general interpretation of the phase behavior of this mixture is also proposed.