Sialic acid-dependent binding and transcytosis of serotype D botulinum neurotoxin and toxin complex in rat intestinal epithelial cells.

A large toxin complex (L-TC) produced by Clostridium botulinum is composed of neurotoxin (BoNT), non-toxic non-hemagglutinin (NTNHA) and hemagglutinin subcomponents (HA-70, -33 and -17). In animal botulism, BoNT or L-TC is internalized by intestinal epithelial cells. Previous studies showed that L-TC binds to intestinal cells via sugar chains on the cell surface, but the role of toxin binding to sugar chains in the toxin absorption from intestine is unclear.

Molecular characterization of the protease from Clostridium botulinum serotype C responsible for nicking in botulinum neurotoxin complex.

A protease was purified from the culture medium of Clostridium botulinum serotype C strain Stockholm (C-St). The purified protease belonged to the cysteine protease family based on assays for enzyme inhibitors, activators and kinetic parameters. The protease formed a binary complex consisting of 41- and 17-kDa proteins held together non-covalently.

Clostridium botulinum serotype D neurotoxin and toxin complex bind to bovine aortic endothelial cells via sialic acid.

Botulinum neurotoxin (BoNT) is produced as a large toxin complex (L-TC) associated with nontoxic nonhemagglutinin (NTNHA) and three hemagglutinin subcomponents (HA-70, -33 and -17). The binding properties of BoNT to neurons and L-TC to intestinal epithelial cells are well documented, while those to other tissues are largely unknown. Here, to obtain novel insights into the pathogenesis of foodborne botulism, we examine whether botulinum toxins bind to vascular endothelial cells.