EC 18.104.22.168 - Bontoxilysin
IntEnz Enzyme Nomenclature
- Limited hydrolysis of proteins of the neuroexocytosis apparatus, synaptobrevin (also known as neuronal vesicle-associated membrane protein, VAMP), synaptosome-associated protein of 25 kDa (SNAP25) or syntaxin. No detected action on small molecule substrates.
This zinc enzyme, produced by Clostridium botulinum, occurs as forms A-G that differ in specificity of action on the proteins of the neuroexocytosis apparatus [1-5]. The 150-kDa proenzymes of bontoxilysin are processed to disulfide-linked subunits of 100 and 50 kDa, the latter being responsible for the endopeptidase activities. Weakly inhibited by captopril, and phosphoramidon. Toxicity is due to action at the neuromuscular junctions that blocks release of acetylcholine, causing flaccid paralysis, in contrast to the spastic paralysis caused by tentoxilysin. In peptidase family M27 (tentoxilysin family).
Links to other databases
Identification of the nerve-terminal targets of botulinum neurotoxins serotypes A, D and E.J. Biol. Chem. 268: 23784-23787 (1993). [PMID: 8226912]
Botulinum neurotoxins serotypes A and E cleave SNAP-25 at distinct COOH-terminal peptide bonds.FEBS Lett. 335: 99-103 (1993). [PMID: 8243676]
Botulinum neurotoxin serotype F is a zinc endopeptidase specific for VAMP/synaptobrevin.J. Biol. Chem. 268: 11516-11519 (1993). [PMID: 8505288]
Botulinum G neurotoxin cleaves VAMP/synaptobrevin at a single Ala-Ala peptide bond.J. Biol. Chem. 269: 20213-20216 (1994). [PMID: 8051110]
Mechanism of action of tetanus and botulinum neurotoxins.Mol. Microbiol. 8: 1-13 (1994). [PMID: 7527117]
Tetanus and botulism neurotoxins.Methods Enzymol. 248: 643-652 (1995). [PMID: 7674951]
[EC 22.214.171.124 created 1995]