Schroeder F, Nemecz G, Wood W G, Joiner C, Morrot G, Ayraut-Jarrier M, Devaux P F
Department of Pharmacology and Cell Biophysics, University of Cincinnati Medical Center, OH.
Biochim Biophys Acta. 1991 Jul 22;1066(2):183-92. doi: 10.1016/0005-2736(91)90185-b.
The transbilayer cholesterol distribution of human erythrocytes was examined by two independent techniques, quenching of dehydroergosterol fluorescence and fluorescence photobleaching of NBD-cholesterol. Dehydroergosterol in conjunction with leaflet selective quenching showed that, at equilibrium, 75% of the sterol was localized to the inner leaflet of resealed erythrocyte ghosts. NBD-cholesterol and fluorescence photobleaching displayed two diffusion values in both resealed ghosts and intact erythrocytes. The fractional contribution of the fast and slow diffusion constants of NBD-labelled cholesterol represent its inner and outer leaflet distribution. At room temperature the plasma membrane inner leaflet of erythrocyte ghosts as well as intact erythrocytes cells contained 78% of the plasma membrane sterol. The erythrocyte membrane transbilayer distribution of sterol was independent of temperature. In conclusion, dehydroergosterol and NBD-cholesterol data are consistent with an enrichment of cholesterol in the inner leaflet of the human erythrocyte.
采用两种独立技术检测了人红细胞的跨膜胆固醇分布，即脱氢麦角固醇荧光猝灭法和NBD-胆固醇荧光光漂白法。脱氢麦角固醇结合小叶选择性猝灭表明，在平衡状态下，75%的固醇定位于重封红细胞影的内膜小叶。NBD-胆固醇和荧光光漂白在重封影和完整红细胞中均显示出两个扩散值。NBD标记胆固醇的快速和慢速扩散常数的分数贡献代表其内膜小叶和外膜小叶分布。在室温下，红细胞影以及完整红细胞的质膜内膜小叶含有78%的质膜固醇。红细胞膜固醇的跨膜分布与温度无关。总之，脱氢麦角固醇和NBD-胆固醇数据与人类红细胞内膜小叶中胆固醇富集一致。
