EC 18.104.22.168 - Tryptophanase
IntEnz Enzyme Nomenclature
L-tryptophan indole-lyase (deaminating)
- (1) L-tryptophan + H2O = indole + pyruvate + NH3
- (1a) L-tryptophan = indole + 2-aminoprop-2-enoate
- (1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
- (1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)
A pyridoxal-phosphate protein, requiring K+. The enzyme cleaves a carbon-carbon bond, releasing indole and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. The latter reaction, which can occur spontaneously, can also be catalysed by EC 22.214.171.124, 2-iminobutanoate/2-iminopropanoate deaminase. Also catalyses 2,3-elimination and β-replacement reactions of some indole-substituted tryptophan analogues of L-cysteine, L-serine and other 3-substituted amino acids.
Links to other databases
Properties of tryptophanase from Escherichia coli.Biochim. Biophys. Acta 65: 233-244 (1962). [PMID: 14017164]
Tryptophanase from Aeromonas liquifaciens. Purification, molecular weight and some chemical, catalytic and immunological properties.Biochim. Biophys. Acta 315: 449-463 (1973).
Properties of crystalline tryptophanase.J. Biol. Chem. 240: 1211-1218 (1965). [PMID: 14284727]
Tryptophanase: structure, catalytic activities, and mechanism of action.Adv. Enzymol. Relat. Areas Mol. Biol. 42: 287-333 (1975). [PMID: 236639]
[EC 126.96.36.199 created 1972]