McEwen B F, Arion W J
J Cell Biol. 1985 Jun;100(6):1922-9. doi: 10.1083/jcb.100.6.1922.
Pathogenic staphylococci secrete a number of exotoxins, including alpha-toxin. alpha-Toxin induces lysis of erythrocytes and liposomes when its 3S protein monomers associate with the lipid bilayer and form a hexomeric transmembrane channel 3 nm in diameter. We have used alpha-toxin to render rat hepatocytes 93-100% permeable to trypan blue with a lactate dehydrogenase leakage less than or equal to 22%. Treatment conditions included incubation for 5-10 min at 37 degrees C and pH 7.0 with an alpha-toxin concentration of 4-35 human hemolytic U/ml and a cell concentration of 13-21 mg dry wt/ml. Scanning electron microscopy revealed signs of swelling in the treated hepatocytes, but there were no large lesions or gross damage to the cell surface. Transmission electron microscopy indicated that the nucleus, mitochondria, and cytoplasm were similar in control and treated cells and both had large regions of well-defined lamellar rough endoplasmic reticulum. Comparisons of the mannose-6-phosphatase and glucose-6-phosphatase activities demonstrated that 5-10 U/ml alpha-toxin rendered cells freely permeable to glucose-6-phosphate, while substantially preserving the selective permeability of the membranes of the endoplasmic reticulum and the functionality of the glucose-6-phosphatase system. Thus, alpha-toxin appears to have significant potential as a means to induce selective permeability to small ions. It should make possible the study of a variety of cellular functions in situ.
致病性葡萄球菌分泌多种外毒素，包括α毒素。当α毒素的3S蛋白单体与脂质双层结合并形成直径为3nm的六聚体跨膜通道时，它会诱导红细胞和脂质体裂解。我们使用α毒素使大鼠肝细胞对台盼蓝的通透性达到93%-100%，同时乳酸脱氢酶泄漏率小于或等于22%。处理条件包括在37℃和pH7.0下孵育5-10分钟，α毒素浓度为4-35人溶血单位/毫升，细胞浓度为13-21毫克干重/毫升。扫描电子显微镜显示处理后的肝细胞有肿胀迹象，但细胞表面没有大的损伤或明显破坏。透射电子显微镜表明，对照细胞和处理细胞中的细胞核、线粒体和细胞质相似，两者都有大片界限分明的板层状粗面内质网。对甘露糖-6-磷酸酶和葡萄糖-6-磷酸酶活性的比较表明，5-10单位/毫升的α毒素使细胞对葡萄糖-6-磷酸具有自由通透性，同时基本保留了内质网膜的选择性通透性和葡萄糖-6-磷酸酶系统的功能。因此，α毒素作为一种诱导对小离子选择性通透性的手段似乎具有巨大潜力。它应该能够原位研究多种细胞功能。
