Patent ID: 8017134

Claim:
A single-chain polypeptide comprising: (a) a clostridial neurotoxin light chain peptide that cleaves a vesicle- or plasma membrane-associated protein essential to exocytosis; and (b) a clostridial neurotoxin heavy chain peptide that comprises a clostridial neurotoxin heavy chain H N peptide and a clostridial neurotoxin heavy chain C-terminal extension of said heavy chain H N peptide; wherein (i) the clostridial neurotoxin heavy chain peptide translocates the clostridial neurotoxin light chain peptide into a cell, and (ii) the clostridial neurotoxin heavy chain peptide lacks a functional heavy chain H C peptide thereby rendering the polypeptide incapable of binding to cell surface receptors to which a native clostridial neurotoxin binds.