Patent ID: 7815917

Claim:
A recombinantly modified Botulinum neurotoxin toxin serotype B (BoNT/B) comprising an enzymatic domain having a zinc-dependent endopeptidase activity which targets a vesicle associated membrane protein (VAMP), 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/B substrate cleavage site from a VAMP 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/B; and wherein expression of the recombinantly modified BoNT/B within a cell results in single chain to di-chain conversion of the recombinantly modified BoNT/B due to proteolytic cleavage of the BoNT/B substrate cleavage site.