Patent ID: 8012479

Claim:
A method for producing an antibody or antibody fragment that binds to a single-chain polypeptide comprising first and second domains, wherein the first domain is a clostridial neurotoxin light chain; and the second domain is a clostridial neurotoxin heavy chain H N portion; and wherein said second domain is capable of (i) translocating the polypeptide into a cell or (ii) increasing the solubility of the polypeptide compared to the solubility of the first domain on its own or (iii) both translocating the polypeptide into a cell and increasing the solubility of the polypeptide compared to the solubility of the first domain on its own; and wherein the second domain lacks a functional C-terminal part of a clostridial neurotoxin heavy chain designated H C thereby rendering the polypeptide incapable of binding to cell surface receptors that are the natural cell surface receptors to which native clostridial neurotoxin binds; said method comprising the steps of: (a) administering to a host animal a single-chain polypeptide comprising first and second domains, wherein: the first domain is a clostridial neurotoxin light chain; and the second domain is a clostridial neurotoxin heavy chain H N portion; and wherein said second domain is capable of (i) translocating the polypeptide into a cell or (ii) increasing the solubility of the polypeptide compared to the solubility of the first domain on its own or (iii) both translocating the polypeptide into a cell and increasing the solubility of the polypeptide compared to the solubility of the first domain on its own; and wherein the second domain lacks a functional C-terminal part of a clostridial neurotoxin heavy chain designated H C thereby rendering the polypeptide incapable of binding to cell surface receptors that are the natural cell surface receptors to which native clostridial neurotoxin binds; and (b) isolating said antibody or antibody fragment.