Heat-labile 150 kDa exotoxin of Clostridium botulinum (anaerobic, gram-positive bacterium). First used as a drug for the treatment of strabismus in 1979. Approved as a drug since 1993. The light chain of the botulinum toxin is a zinc endopeptidase. This enzyme is absorbed into nerve cells through endocytosis. There it leads to enzymatic destruction of the exocytosis proetin SNAP-25 anchored to the axolemma, thus blocking the endocytotic release of acetylcholine.
S.a.Botulism