Thelestam M, Möllby R
Infect Immun. 1980 Sep;29(3):863-72. doi: 10.1128/iai.29.3.863-872.1980.
The membrane-damaging properties on human diploid embryonic lung fibroblasts of streptolysin O (from Streptococcus pyogenes) and theta-toxin (from Clostridium perfringens) were compared. The results are consistent with the suggested mechanism for hemolysis by streptolysin O involving one fixation site and one lytic site of this cytolysin. However, the membrane-damaging activity of the two toxins differed with respect to (i) relative cytolytic activity on human diploid lung fibroblasts compared with that on sheep erythrocytes, (ii) binding to the fibroblast membrane, (iii) activity at 0 degrees C, (iv) membrane repair after more than 30 min, and (v) effect on influx of amino acids. It is concluded that the mechanism of membrane damage caused by theta-toxin differs from that of cytoplasmic membrane. These results question the current concept that all thiol-activated, cholesterol-inactivated bacterial toxins are similar both structurally and functionally.
比较了链球菌溶血素O（来自化脓性链球菌）和θ毒素（来自产气荚膜梭菌）对人二倍体胚胎肺成纤维细胞的膜损伤特性。结果与链球菌溶血素O溶血的推测机制一致，该机制涉及这种细胞溶素的一个固定位点和一个裂解位点。然而，两种毒素的膜损伤活性在以下方面有所不同：（i）与人二倍体肺成纤维细胞相比，对绵羊红细胞的相对细胞溶解活性；（ii）与成纤维细胞膜的结合；（iii）0℃时的活性；（iv）30分钟以上后的膜修复；以及（v）对氨基酸流入的影响。得出的结论是，θ毒素引起的膜损伤机制与细胞质膜的不同。这些结果对当前认为所有硫醇激活、胆固醇失活的细菌毒素在结构和功能上都相似的概念提出了质疑。
