Botulinum Neurotoxin Serotype B Activatable Botulinum Neurotoxin Serotype Bs

Abstract

The specification discloses modified Clostridial toxins comprising a Clostridial toxin substrate cleavage site located within the di-chain loop region; polynucleotide molecules encoding such modified Clostridial toxins comprising a Clostridial toxin substrate cleavage site located in the di-chain loop region; and method of producing modified Clostridial toxins comprising Clostridial toxin substrate cleavage site located within the di-chain loop region.

1 . A recombinantly modified BoNT/A comprising an enzymatic domain having a zinc-dependent endopeptidase activity which targets a synaptosomal-associated protein of 25 kDa (SNAP-25), a translocation domain, a binding domain and a modified di-chain loop region, the modified di-chain loop region intervening between the enzymatic domain and the translocation domain;
 wherein the di-chain loop region modification comprises a BoNT/A substrate cleavage site from a SNAP-25 of at least six amino acids in length located within the di-chain loop region that is proteolytically cleaved by the enzymatic domain of the recombinantly modified BoNT/A; and   wherein expression of the recombinantly modified BoNT/A within a cell results in single chain to di-chain conversion of the recombinantly modified BoNT/A due to proteolytic cleavage of the BoNT/A substrate cleavage site.   
     
     
         2 .- 9 . (canceled)