Electron microscopic observation of the aggregation of membrane proteins in human erythrocyte by melittin.
Electron microscopic observation of the aggregation of membrane proteins in human erythrocyte by melittin.
复制标题
蜂毒肽对人红细胞膜蛋白聚集的电镜观察。
DOI：
10.1016/0005-2736(90)90124-7
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Cherry,RJ
中科院分区：
文献类型：
--
作者：
Hui,SW;Stewart,CM;Cherry,RJ
用天然蜂毒素和经修饰的蜂毒素处理人红细胞和红细胞膜，膜蛋白含量高达250nmol/mg。天然蜂毒素诱导膜内颗粒(IMP)聚集(冷冻断裂电子显微镜观察)，并产生大的、光滑的双层区，没有IMP。随着蜂毒素浓度的增加，IMP的聚集程度增加，与溶血结果一致。膜上的幽灵对IMP的聚集比完整细胞上的膜更敏感。诱导IMP聚集的效价顺序为：天然蜂毒素>；乙酰化蜂毒素>；琥珀酸化蜂毒素=0。导致IMP聚集的蜂毒素的浓度范围与通过瞬时二向色性测量旋转迁移率检测到的引起带3蛋白固定的浓度范围一致(Dufton等人。(1984)欧元。J.生物物理学。11、17-24)。由于IMP聚集和带3蛋白固定化都随着蜂毒素正电荷的减少而减少，因此蜂毒素-蛋白质相互作用的性质很可能至少在人红细胞膜上是部分静电的。讨论了在蜂毒素的细胞毒性反应中IMP聚集的可能作用以及由此产生的“暴露的”双层区。
Human erythrocytes and erythrocyte ghost membranes were treated with native and modified melittins, up to 250 nmol/mg membrane protein. Native melittin induced aggregation of intramembranous particles (IMPs, observed by freeze-fracture electron microscopy), and created large, smooth bilayer areas devoid of IMP. The degree of IMP aggregation increased with increasing concentration of melittin, corresponding to hemolysis results. Membrane ghosts were slightly more susceptible to IMP aggregation than membranes on intact cells. The potency of inducing IMP aggregation was ranked in the order of: native melittin > acetylated melittin > succinylated melittin = 0. The concentration range of melittin which caused IMP aggregation corresponded to that which caused the immobilization of band 3 proteins as detected by measurement of rotational mobility by transient dichroism (Dufton et al. (1984) Eur. J. Biophys. 11, 17–24). Because both IMP aggregation and band 3 protein immobilization decreased with decreasing positive charge of the melittins used, the nature of melittin-protein interaction is likely to be at least in part electrostatic in the case of human erythrocyte membranes. Possible roles of IMP aggregation and the consequent creation of ‘exposed’ bilayer areas in the cytotoxic reaction of melittins are discussed.