| abstract |
The present invention provides a clostridial toxin substrate useful for assaying the protease activity of any clostridial toxin, including all serotypes of botulinum toxin and tetanus toxin. The clostridial toxin substrate of the present invention comprises a donor fluorophore, an acceptor having an absorption spectrum overlapping the emission spectrum of the donor fluorophore, and a clostridial toxin recognition sequence comprising a cleavage site, wherein the cleavage site is a donor fluorophore. Resonant energy transfer is observed between the donor fluorophore and the acceptor, intervening between the fore and the acceptor, and under appropriate conditions. |