| 摘要 |
The invention relates to a modified botulinum toxin comprising a natural heavy chain and a modified light chain, characterized in that the modification of the light chain resides in that it comprises (i) an extension of the chain on its N-terminus which has the structure—(C)n-(tag)m-(X)l—in the direction from the N- to the C-terminal end, wherein C represents a cysteine residue, tag represents any tag and X represents the residue of any naturally occurring amino acid, n represents an integer from 1 to 50, m represents 0 or 1, and l represents 0 or an integer from 1 to 50, and in that (ii) at least one of the cysteine residues in the extension of the chain is coupled to at least one chain of PEG. |
