Binding Properties of Clostridium botulinum Type C Progenitor Toxin
Clostridium botulinum has been classified into seven types, A to G, which are differentiated by the immunological specificity of the neurotoxin (NT) produced. NT is a high-potent inhibitor of the neurotransmitter release from the peripheral nerve terminus. Once localized in the cytoplasm of nerve cells, the NT functions by specifically cleaving one of the three different SNARE proteins essential for synaptic vesicle fusion (Lalli et al. 2003). The molecular masses of all types of these NTs are approximately 150 kDa. In the type C strain, two different sized progenitor toxins with molecular masses of 500 kDa (C16S) and 300 kDa (C12S) are produced. The C12S toxin consists of an NT and a non-toxic component having no hemagglutinin (HA) activity that is designated as non-toxic non-HA. The C16S toxin consists of C12S toxin and four kinds of different subcomponents (HAs) (Fig. 1). The previous data suggest that the HA subcomponents and non-toxic component assume to have the role of protecting the NT against acidity and proteases in the digestive tract. Furthermore, HAs seem to play an important role in transferring the toxin from digestive tract to circulating system. The HAs function as an adhesion in the attachment of 16S toxin to the microvilli of the intestine of a guinea pig (Fujinaga et al. 1997). Here, we introduce our assay methods of toxin binding ability to glycoprotein, and show the binding specificity of the C16S toxin to mucin.
KeywordsClostridium Botulinum Toxin Binding Bovine Submaxillary Mucin Synaptic Vesicle Fusion Porcine Gastric Mucin
Unable to display preview. Download preview PDF.
- Fujinaga Y, Inoue K, Watanabe S, Yokota K, Hirai Y, Nagamachi E, Oguma K (1997) The haemagglutinin of Clostridium botulinum type C progenitor toxin plays an essential role in binding of toxin to the epithelial cells of guinea pig small intestine, leading to the efficient absorption of the toxin. Microbiology 143:3841–3847PubMedCrossRefGoogle Scholar
- Nishikawa A, Uotsu N, Arimitsu H, Lee J-C, Miura Y, Fujinaga Y, Nakada H, Watanabe T, Ohyama T, Sakano Y, Oguma K (2004) The receptor and transporter for internalization of Clostridium botulinum type C progenitor toxin into HT-29 cells. Biochem Biophys Res Commun 319:327–333PubMedCrossRefGoogle Scholar