EVIDENCE FOR REGULAR DISTRIBUTION OF STEROLS IN LIQUID-CRYSTALLINE PHOSPHATIDYLCHOLINE BILAYERS

被引:131
作者
CHONG, PLG [1 ]
机构
[1] MEHARRY MED COLL,DEPT BIOCHEM,NASHVILLE,TN 37208
关键词
MEMBRANE ORGANIZATION; REGULAR LIPID DISTRIBUTION; FLUORESCENCE;
D O I
10.1073/pnas.91.21.10069
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
To investigate the lateral organization of sterols in membranes, the fluorescence intensity of dehydroergosterol at different mole fractions in liquid crystalline dimyristoyl phosphatidylcholine bilayers was examined. A number of intensity drops were observed at specific mole fractions, as predicted from a hexagonal super-lattice model. The fluorescence dips provide compelling evidence that a naturally occurring sterol is regularly distributed at fixed compositional fractions, consistent with the presence of hexagonal superlattices in the fluid membranes. Regularly distributed regions, however, coexist with irregularly distributed regions. The extent of regular distribution varies periodically with sterol mole fraction and, consequently, similar variations take place in the membrane volume and lipid packing. This level of modulation in local membrane structure by minute changes in sterol concentration should have profound implications for the functional role of cholesterol content in cell membranes.
引用
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页码:10069 / 10073
页数:5
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