The present invention provides engineered clostridial toxins comprising at least one amino acid modification, wherein said at least one amino acid modification increases the isoelectric point (pI) of the engineered clostridial toxin to a value that is at least 0.2 pI units higher than the pI of an otherwise identical clostridial toxin lacking said at least one amino acid modification, and wherein said at least one amino acid modification is not located in the clostridial toxin binding domain (HCdomain). Also provided are medical uses of the engineered clostridial toxins.本發明提供包含至少一個胺基酸修飾之工程化的梭菌毒素，其中該至少一個胺基酸修飾增加工程化的梭菌毒素之等電點(pI)至高於缺少該至少一個胺基酸修飾之其他方面相同的梭菌毒素之pI至少0.2個pI單位的值，且其中該至少一個胺基酸修飾並未位於梭菌毒素結合域(HC域)。亦提供該工程化的梭菌毒素之醫藥用途。
