32 results about "Serotype a" patented technology

Modified polypeptides based on the botulinum neurotoxin A heavy chain containing the double mutation Trp-Tyr->Leu-Ser in the ganglioside binding motif Ser-X-Trp-Tyr do not bind polysialogangliosides and nerve endings. The polypeptides are useful in the preparation of nontoxic vaccines against the effects of C. botulinum infection. The modified polypeptides are also useful as vehicles for the transepithelial delivery of diagnostic and therapeutic entities, through formation of conjugates between the polypeptides and the diagnostic or therapeutic entities.

Botulinum neurotoxins, the most potent of all toxins, induce lethal neuromuscular paralysis by inhibiting exocytosis at the neuromuscular junction. The light chains (LC) of these dichain neurotoxins are a new class of zinc-endopeptidases that specifically cleave the synaptosomal proteins, SNAP-25, VAMP, or syntaxin at discrete sites. The present invention relates to the construction, expression, purification, and use of synthetic or recombinant botulinum neutoroxin genes. For example, a synthetic gene for the LC of the botulinum neurotoxin serotype A (BoNT / A) was constructed and overexpressed in Escherichia coli. The gene product was purified from inclusion bodies. The methods of the invention can provide 1.1 g of the LC per liter of culture. The LC product was stable in solution at 4° C. for at least 6 months. This rBoNT / A LC was proteolytically active, specifically cleaving the Glu-Arg bond in a 17-residue synthetic peptide of SNAP-25, the reported cleavage site of BoNT / A. Its calculated catalytic efficiency kcat / Km was higher than that reported for the native BoNT / A dichain. Treating the rBoNT / A LC with mercuric compounds completely abolished its activity, most probably by modifying the cysteine-164 residue located in the vicinity of the active site. About 70% activity of the LC was restored by adding Zn2+ to a Zn2+-free, apo-LC preparation. The LC was nontoxic to mice and failed to elicit neutralizing epitope(s) when the animals were vaccinated with this protein. In addition, injecting rBoNT / A LC into sea urchin eggs inhibited exocytosis-dependent plasma membrane resealing.

The present invention provides clostridial toxin substrates useful in assaying for the protease activity of any clostridial toxin, including botulinum toxins of all serotypes as well as tetanus toxins. A clostridial toxin substrate of the invention contains a donor fluorophore; an acceptor having an absorbance spectrum overlapping the emission spectrum of the donor fluorophore; and a clostridial toxin recognition sequence that includes a cleavage site, where the cleavage site intervenes between the donor fluorophore and the acceptor and where, under the appropriate conditions, resonance energy transfer is exhibited between the donor fluorophore and the acceptor.

The present invention provides a novel isolated plasmid, wherein the plasmid is a native plasmid found in unique C. botulinum type A strains and encode either BoNT / A3 or BoNT / A4 and BoNT / B. The present invention also provides a method of obtaining a plasmid-encoded botulinum neurotoxin and botulinum neurotoxin complex comprising the step of isolating a plasmid encoding the cntA / A or cntA / B neurotoxin gene and genes encoding protein components of the toxin complex from a C. botulinum type A strain. The inventors performed comparative analyzes of representative BoNT / A subtype strains by pulsed-field gel electrophoresis (PFGE) and Southern hybridizations with probes specific for the BoNT / A and B genes, cntA / A and cntA / B. Unexpectedly, the inventors determined that the genes encoding BoNT / A3 in the A3 strain, and BoNT / A4 and BoNT / B in the A4 strain, are on plasmids.

This invention relates to novel recombinant botulinum neurotoxins serotype A exhibiting both (i) an increased duration of effect and (ii) a high specific biological activity. These novel recombinant botulinum neurotoxins comprise at least two additional domains consisting of proline, alanine and an additional amino acid residue and at least one amino acid modification which is located at the alpha-exosite or at the beta-exosite of the light chain of the neurotoxin. The invention further relates to novel recombinant single-chain precursor botulinum neurotoxins and compositions comprising the recombinant botulinum neurotoxin with an increased duration of effect and a high specific biological activity.

The application provides stable peptide-based Botulinum neurotoxin (BoNT) serotype A capture agents and methods of use as detection and diagnosis agents and in the treatment of diseases and disorders.The application further provides methods of manufacturing BoNT serotype A capture agents using iterative on-bead in situ click chemistry.