Patent ID: 7897158

Claim:
A single polypeptide fusion protein comprising first and second domains, wherein: (a) said first domain comprises a botulinum neurotoxin light chain that cleaves one or more vesicle or plasma membrane associated proteins essential to exocytosis, wherein said botulinum neurotoxin light chain is selected from a first botulinum neurotoxin serotype; (b) said second domain comprises a botulinum neurotoxin heavy chain H N that translocates said first domain into a cell, wherein said botulinum neurotoxin heavy chain is selected from a second botulinum neurotoxin serotype; (c) said polypeptide lacks a functional C-terminal part of a botulinum neurotoxin heavy chain designated H C ; and (d) said polypeptide comprises a site for cleavage by a proteolytic enzyme, said cleavage site being located between the first and second domains wherein said cleavage site allows proteolytic cleavage between said first and second domains, and when so cleaved said first domain exhibits greater enzyme activity in cleaving said one or more vesicle or plasma membrane associated proteins than does the polypeptide prior to said proteolytic cleavage; with the proviso that said protease cleavage site is not cleavable by trypsin.