Ohishi I, Hama Y
University of Osaka Prefecture, College of Agriculture, Japan.
Microbiol Immunol. 1992;36(3):221-9. doi: 10.1111/j.1348-0421.1992.tb01660.x.
Botulinum C2 toxin (C2T) elaborated by certain strains of Clostridium botulinum types C and D is composed of separate and dissimilar two proteins, components I and II. Previous studies have shown that these two components of C2T produced by type C and D strains were immunologically heterologous and that C2T-producers were classified into three groups depending on the difference in molecular characteristics of the components I and II. In the present study, the heterologous component IIs of C2T were purified from three representative strains of the groups and the molecular characteristics of the components were compared. Immunological analyses by agar gel double immunodiffusion test showed that the component IIs purified from the three strains have the specific epitope(s) in addition to the common one(s). The biological activity of C2Ts reconstituted with component I purified from a fixed strain and component II each from the three strains differed depending on the source of the component II. These results indicate that the component II of C2T produced by C. botulinum types C and D differs in molecular structure, which reflects on the difference in the biological activity of the toxin. The present study suggests that the pathophysiological activity of C2T, which possibly causes a necrotic enteritis, is dependent on the C2T-producing bacteria infected.
由某些C型和D型肉毒梭菌菌株产生的肉毒杆菌C2毒素（C2T）由两种不同的蛋白质成分I和成分II组成。先前的研究表明，C型和D型菌株产生的C2T的这两种成分在免疫上是异源的，并且根据成分I和成分II分子特征的差异，C2T产生菌被分为三组。在本研究中，从这三组的三个代表性菌株中纯化出C2T的异源成分II，并比较了这些成分的分子特征。琼脂凝胶双向免疫扩散试验的免疫分析表明，从这三个菌株中纯化出的成分II除了具有共同的表位外，还具有特异性表位。用从一个固定菌株纯化的成分I和分别从这三个菌株纯化的成分II重构的C2T的生物活性因成分II的来源而异。这些结果表明，C型和D型肉毒梭菌产生的C2T的成分II在分子结构上存在差异，这反映在毒素生物活性的差异上。本研究表明，可能导致坏死性肠炎的C2T的病理生理活性取决于所感染的产生C2T的细菌。
