Expression and stability of the nontoxic component of the botulinum toxin complex |
| |
Authors: | Keita Miyata Tomonori Suzuki Ken Inui Toshihiro Watanabe |
| |
Institution: | a Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri 099-2493, Japan b Department of Medicinal and Life Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2614 Yamazaki, Noda 278-8510, Japan c Hokkaido Institute of Public Health, N19, W12, Kita-Ku, Sapporo 060-0819, Japan |
| |
Abstract: | Clostridium botulinum produces botulinum neurotoxin (BoNT) as a large toxin complex associated with nontoxic-nonhemagglutinin (NTNHA) and/or hemagglutinin components. In the present study, high-level expression of full-length (1197 amino acids) rNTNHA from C. botulinum serotype D strain 4947 (D-4947) was achieved in an Escherichia coli system. Spontaneous nicking of the rNTNHA at a specific site was observed during long-term incubation in the presence of protease inhibitors; this was also observed in natural NTNHA. The rNTNHA assembled with isolated D-4947 BoNT with molar ratio 1:1 to form a toxin complex. The reconstituted toxin complex exhibited dramatic resistance to proteolysis by pepsin or trypsin at high concentrations, despite the fact that the isolated BoNT and rNTNHA proteins were both easily degraded. We provide definitive evidence that NTNHA plays a crucial role in protecting BoNT, which is an oral toxin, from digestion by proteases common in the stomach and intestine. |
| |
Keywords: | Clostridium botulinum Nontoxic-nonhemagglutinin Botulinum toxin complex Spontaneous nicking |
本文献已被 ScienceDirect 等数据库收录! |
|