EC 4.4.1.13 - Cysteine-S-conjugate β-lyase

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IntEnz Enzyme Nomenclature
EC 4.4.1.13

Names

Accepted name:
cysteine-S-conjugate β-lyase
Other names:
cysteine conjugate β-lyase
glutamine transaminase K/cysteine conjugate β-lyase
L-cysteine-S-conjugate thiol-lyase (deaminating)
Systematic name:
L-cysteine-S-conjugate thiol-lyase (deaminating; pyruvate-forming)

Reactions

Cofactor

Comments:

A pyridoxal 5′-phosphate protein. This mammalian enzyme has been shown to act on many substrates, including aromatic compounds such as S-(4-bromophenyl)-L-cysteine and S-(2,4-dinitrophenyl)-L-cysteine. The enzyme cleaves a carbon-sulfur bond, releasing a thiol and an unstable enamine product that tautomerizes to an imine form, which undergoes a hydrolytic deamination to form pyruvate and ammonia. All of the cysteine-S-conjugate β-lyases discovered thus far are bifunctional enzymes, most of which also act as aminotransferases. Despite some overlap in their activity, this enzyme is not identical to the bacterial EC 4.4.1.8, cystathionine β-lyase.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0047804
CAS Registry Number: 68652-57-3
UniProtKB/Swiss-Prot:

References

  1. Tateishi, M., Suzuki, S. and Shimizu, H.
    Cysteine conjugate β-lyase in rat liver. A novel enzyme catalyzing formation of thiol-containing metabolites of drugs.
    J. Biol. Chem. 253: 8854-8859 (1978). [PMID: 721818]
  2. Stevens, J. L.
    Isolation and characterization of a rat liver enzyme with both cysteine conjugate beta-lyase and kynureninase activity.
    J. Biol. Chem. 260: 7945-7950 (1985). [PMID: 4008484]
  3. Stevens, J. L., Robbins, J. D., Byrd, R. A.
    A purified cysteine conjugate beta-lyase from rat kidney cytosol. Requirement for an alpha-keto acid or an amino acid oxidase for activity and identity with soluble glutamine transaminase K.
    J. Biol. Chem. 261: 15529-15537 (1986). [PMID: 3782077]
  4. Gaskin, P. J., Adcock, H. J., Buckberry, L. D., Teesdale-Spittle, P. H., Shaw, P. N.
    The C-S lysis of L-cysteine conjugates by aspartate and alanine aminotransferase enzymes.
    Hum Exp Toxicol 14: 422-427 (1995). [PMID: 7612304]
  5. Cooper, A. J., Bruschi, S. A., Iriarte, A., Martinez-Carrion, M.
    Mitochondrial aspartate aminotransferase catalyses cysteine S-conjugate beta-lyase reactions.
    Biochem. J. 368: 253-261 (2002). [PMID: 12137566]
  6. Cooper, A. J., Bruschi, S. A., Conway, M., Hutson, S. M.
    Human mitochondrial and cytosolic branched-chain aminotransferases are cysteine S-conjugate beta-lyases, but turnover leads to inactivation.
    Biochem. Pharmacol. 65: 181-192 (2003). [PMID: 12504794]
  7. Cooper, A. J., Pinto, J. T.
    Cysteine S-conjugate beta-lyases.
    Amino Acids 30: 1-15 (2006). [PMID: 16463021]

[EC 4.4.1.13 created 1981]