Perelle S, Scalzo S, Kochi S, Mock M, Popoff M R
Unité des Toxines Microbiennes, CNRS URA1858, Institut Pasteur, Paris, France.
FEMS Microbiol Lett. 1997 Jan 1;146(1):117-21. doi: 10.1111/j.1574-6968.1997.tb10180.x.
Clostridium perfringens iota and C. spiroforme toxins consist of two separate proteins. One is the binding component and the other the enzymatic component. The two toxins secreted by Bacillus anthracis are composed of binary combinations of three proteins: protective antigen, lethal factor, and edema factor. As shown by Western blotting and ELISA, the binding component of anthrax toxin shares common epitopes with that of iota toxin and C. spiroforme toxin which are closely related immunologically. However, no functional complementation was observed between iota toxin and anthrax toxin components. The binding components can form toxins active on macrophages only in combination with their respective enzymatic components. Agents which prevent acidification of endosomes do not have the same effects on anthrax toxin activity as they do on iota and C. spiroforme toxins. Therefore, the mechanisms of entry into the cells are presumably different. Since the binding components of anthrax toxins and iota toxin share a conserved putative translocation domain, these binding components could have a common mode of insertion into the cell membranes.
产气荚膜梭菌iota毒素和螺旋体梭菌毒素由两种不同的蛋白质组成。一种是结合成分，另一种是酶成分。炭疽芽孢杆菌分泌的两种毒素由三种蛋白质的二元组合构成：保护性抗原、致死因子和水肿因子。如蛋白质免疫印迹法和酶联免疫吸附测定所示，炭疽毒素的结合成分与iota毒素和螺旋体梭菌毒素的结合成分具有共同的表位，它们在免疫学上密切相关。然而，未观察到iota毒素与炭疽毒素成分之间的功能互补。结合成分只有与各自的酶成分结合才能形成对巨噬细胞有活性的毒素。阻止内体酸化的试剂对炭疽毒素活性的影响与对iota毒素和螺旋体梭菌毒素的影响不同。因此，进入细胞的机制可能不同。由于炭疽毒素和iota毒素的结合成分共享一个保守的假定易位结构域，这些结合成分可能具有共同的插入细胞膜的模式。
