Freer J H, Arbuthnott J P, Bernheimer A W
J Bacteriol. 1968 Mar;95(3):1153-68. doi: 10.1128/jb.95.3.1153-1168.1968.
Comparison of hemolytic activity and chromate-releasing activity of partially purified preparations of staphylococcal alpha-toxin indicated the presence of a lytic factor other than alpha-toxin. This lytic release factor (RF) was isolated from the preparations and was shown to be active against both lipid spherules and erythrocytes. Heat-purified alpha-toxin (HP alpha-toxin) disrupted spherules, with the formation of fragments which always showed the presence of ring structures similar in dimensions (ca. 90 A) to pure alpha 12S-toxin. The interaction of HP alpha-toxin with spherules was accompanied by loss of hemolytic activity and adsorption of toxic protein. The alpha 12S-toxin, although only weakly hemolytic, was shown to be lytic for spherules. An alpha 12S-free toxin rapidly disrupted spherules, with formation of fragments with attached rings similar in dimensions to the alpha 12S molecule. Lipid monolayer experiments showed that HP alpha-toxin could penetrate lipid monolayers by virtue of a hydrophobic interaction. Effects of HP alpha-toxin on rabbit and human erythrocyte ghosts were similar to its effects on spherules, in that rings appeared on membrane fragments. Toxin-lysed rabbit erythrocytes showed similar rings on the resulting membrane fragments. However, rings were not seen on toxin-treated rabbit erythrocytes in the prelytic lag phase; this result and the fact that human erythrocytes are largely insensitive to alpha-toxin were interpreted as evidence against a lytic mechanism involving ring formation as the primary event. Rings were interpreted as toxin polymers similar to alpha 12S molecules, formed from specifically orientated active toxin molecules at the surface of lipid structures. Possible mechanisms for toxin lysis of spherules and erythrocytes are discussed.
对葡萄球菌α-毒素部分纯化制剂的溶血活性和铬释放活性进行比较，结果表明除α-毒素外还存在一种溶解因子。这种溶解释放因子（RF）从制剂中分离出来，并且显示出对脂质小球和红细胞均具有活性。热纯化的α-毒素（HP α-毒素）使小球破裂，形成的片段总是显示出存在尺寸（约90埃）与纯α 12S-毒素相似的环状结构。HP α-毒素与小球的相互作用伴随着溶血活性的丧失和有毒蛋白质的吸附。α 12S-毒素虽然溶血活性较弱，但对小球具有溶解性。一种不含α 12S的毒素能迅速使小球破裂，形成带有与α 12S分子尺寸相似的附着环的片段。脂质单层实验表明，HP α-毒素可通过疏水相互作用穿透脂质单层。HP α-毒素对兔和人红细胞血影的作用与其对小球的作用相似，即膜片段上出现环状结构。毒素裂解的兔红细胞在产生的膜片段上显示出类似的环状结构。然而，在裂解前的延迟期，毒素处理的兔红细胞上未见环状结构；这一结果以及人红细胞对α-毒素基本不敏感这一事实被解释为反对以环状结构形成为主要事件的溶解机制的证据。环状结构被解释为由脂质结构表面特定取向的活性毒素分子形成的类似于α 12S分子的毒素聚合物。文中讨论了毒素对小球和红细胞的溶解的可能机制。
