Modified neurotoxin comprising neurotoxin including structural modification, wherein the structural modification alters the biological persistence, such as the biological half-life and/or a biological activity of the modified neurotoxin relative to an identical neurotoxin without the structural modification. In one embodiment, methods of making the modified neurotoxin include using recombinant techniques. In another embodiment, methods of using the modified neurotoxin to treat conditions include treating various disorders, neuromuscular aliments and pain.