Sakurai J, Nagahama M
Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Japan.
Microb Pathog. 1987 Dec;3(6):469-74. doi: 10.1016/0882-4010(87)90017-9.
The maximal number of norleucine methyl ester (NME) incorporated into carboxyl groups in epsilon toxin of Clostridium perfringens by the carbodiimide-nucleophile procedure was 7 and 17 in the absence and presence of 8 M urea, respectively. The introduction of 3-4 nucleophilic modifying agents such as NME, glycine methyl ester or taurine into carboxyl groups of the toxin reduced the lethality to approximately 10% of the original activity. The incorporation of 6-7 of these agents resulted in complete loss of the activity. On the other hand, circular dichroism spectra and the reaction between the toxin or the NME-incorporated toxin and antiepsilon toxin reaction showed no difference between the intact toxin and the NME-incorporated toxin. The data suggested that at least 4 out of 7 carboxyl groups on the surface of the toxin are important in maintaining the lethal activity of toxin.
通过碳二亚胺-亲核试剂法，在无8 M尿素和有8 M尿素的情况下，产气荚膜梭菌ε毒素羧基中掺入的正亮氨酸甲酯（NME）的最大数量分别为7和17。向毒素的羧基中引入3 - 4种亲核修饰剂，如NME、甘氨酸甲酯或牛磺酸，可使致死率降低至原始活性的约10%。掺入6 - 7种这些试剂会导致活性完全丧失。另一方面，圆二色光谱以及毒素或掺入NME的毒素与抗ε毒素反应之间的反应表明，完整毒素与掺入NME的毒素之间没有差异。数据表明，毒素表面7个羧基中至少有4个对维持毒素的致死活性很重要。
