STEROL DOMAINS IN PHOSPHOLIPID-MEMBRANES - DEHYDROERGOSTEROL POLARIZATION MEASURES MOLECULAR STEROL TRANSFER
STEROL DOMAINS IN PHOSPHOLIPID-MEMBRANES - DEHYDROERGOSTEROL POLARIZATION MEASURES MOLECULAR STEROL TRANSFER
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DOI：
10.1016/0165-022x(92)90043-a
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发表时间：
1992-03-01
影响因子：
--
通讯作者：
SCHROEDER, F
中科院分区：
文献类型：
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作者：
BUTKO, P;HAPALA, I;SCHROEDER, F
膜内胆固醇的结构域及其影响因素尚不清楚。采用DELTA(5,7,9,(11),22)-麦角甾醇-3- β -醇（脱氢麦角甾醇）荧光偏振变化动力学，无需分离供体膜和受体膜的方法，对脱氢麦角甾醇-磷脂小单层囊泡（SUV）三组分胆固醇中的甾醇结构域进行了检测。建立了一种新的数学数据处理方法，以提供分子甾醇交换与稳态脱氢麦角甾醇荧光偏振测量之间的直接关联。该方法确定了SUV中甾醇的多个动力学池：一个小但快速交换池，一个主要的慢交换池和一个非常慢交换（不可交换）池。池的相对大小和交换的半倍高度依赖于酸性磷脂和参与固醇转移的胞质蛋白的存在。因此，该方法提供了一种直接测量分子甾醇在膜之间转移的方法，而无需分离供体和受体膜。
The domain structure of cholesterol in membranes and factors affecting it are not well understood. A method, based on kinetics of DELTA(5,7,9,(11),22)-ergostatetraen-3-beta-ol (dehydroergosterol) fluorescence polarization change and not requiring separation of donor and acceptor membranes, was used to examine sterol domains in three-component cholesterol:dehydroergosterol:phospholipid small unilamellar vesicles (SUV). A new mathematical data treatment was developed to provide a direct correlation between molecular sterol exchange and steady-state dehydroergosterol fluorescence polarization measurements. The method identified multiple kinetic pools of sterol in SUV: a small but rapidly exchanging pool, a predominant slowly exchanging pool, and a very slowly exchangeable (nonexchangeable) pool. The relative sizes of the pools and half-times of exchange were highly dependent on the presence of acidic phospholipids and on cytosolic proteins involved in sterol transfer. Thus, the method provides a direct measure of molecular sterol transfer between membranes without separating donor and acceptor membranes.