Expression of Recombinant Clostridial Neurotoxin by .

Tetanus neurotoxins (TeNT) and botulinum neurotoxins (BoNTs) are closely related ~150 kDa protein toxins that together comprise the group of clostridial neurotoxins (CNTs) expressed by various species of . While TeNT is expressed as a single polypeptide, BoNTs are always produced alongside multiple non-toxic proteins that form a stabilizing complex with BoNT and are encoded in a conserved toxin gene cluster. It is unknown how evolved without a similar gene cluster and why complex-free TeNT is secreted as a stable and soluble protein by , whereas complexing proteins appear to be essential for BoNT stability in culture supernatants of .

Potency Evaluations of Recombinant Botulinum Neurotoxin A1 Mutants Designed to Reduce Toxicity.

Recombinant mutant holotoxin BoNTs (rBoNTs) are being evaluated as possible vaccines against botulism. Previously, several rBoNTs containing 2-3 amino acid mutations in the light chain (LC) showed significant decreases in toxicity (2.5-million-fold-12.

Botulinum neurotoxin X lacks potency in mice and in human neurons.

Unlabelled: Botulinum neurotoxins (BoNTs) are a class of toxins produced by () and other species of . BoNT/X is a putative novel botulinum neurotoxin identified through genome sequencing and capable of SNARE cleavage, but its neurotoxic potential in humans and vertebrates remained unclear. The strain producing BoNT/X, Strain 111, encodes both a plasmid-borne as well as the chromosomal putative .

Recent Developments in Vaccine Design: From Live Vaccines to Recombinant Toxin Vaccines.

Vaccines are one of the most effective strategies to prevent pathogen-induced illness in humans. The earliest vaccines were based on live inoculations with low doses of live or related pathogens, which carried a relatively high risk of developing the disease they were meant to prevent. The introduction of attenuated and killed pathogens as vaccines dramatically reduced these risks; however, attenuated live vaccines still carry a risk of reversion to a pathogenic strain capable of causing disease.