EC 188.8.131.52 - S-alkylcysteine lyase
IntEnz Enzyme Nomenclature
S-alkyl-L-cysteine sulfoxide lyase
alkyl cysteine lyase
S-alkyl-L-cysteine alkylthiol-lyase (deaminating)
- (1) An S-alkyl-L-cysteine + H2O = an alkyl thiol + NH3 + pyruvate
- (1a) An S-alkyl-L-cysteine + H2O = an alkyl thiol + 2-aminoprop-2-enoate
- (1b) 2-aminoprop-2-enoate = 2-iminopropanoate (spontaneous)
- (1c) 2-iminopropanoate + H2O = pyruvate + NH3 (spontaneous)
A pyridoxal-phosphate protein. The enzyme cleaves a carbon-sulfur bond, releasing an alkyl thiol 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 184.108.40.206, 2-iminobutanoate/2-iminopropanoate deaminase. Possibly identical, in yeast, with EC 220.127.116.11 cystathionine β-lyase.
Links to other databases
S-Alkylcysteinase: enzymatic cleavage of S-methyl-L-cysteine and its sulfoxide.J. Biol. Chem. 238: 1441-1446 (1963).
[EC 18.104.22.168 created 1965, deleted 1972, reinstated 1976]