US Patent 7820411 None

A method of producing botulinum toxin C-terminal receptor binding domain (HCR) is disclosed. The one embodiment, the method comprises the steps of (a) preparing E. coli transformed with an expression vector comprising DNA encoding HCR protein, (b) inducing expression of the HCR protein at a reduced temperature in a culture media, and (c) purifying the HCR protein via extraction, wherein the extraction comprises a clarification by centrifugation and a filtration, wherein the purified HCR protein is at least 10 mg/L of culture medium.