L-3-cyanoalanine synthase

In enzymology, a L-3-cyanoalanine synthase (EC 4.4.1.9) is an enzyme that catalyzes the chemical reaction

L-cysteine + hydrogen cyanide L-3-cyanoalanine + hydrogen sulfide

Thus, the two substrates of this enzyme are L-cysteine and hydrogen cyanide, whereas its two products are L-3-cyanoalanine and hydrogen sulfide.

This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cysteine hydrogen-sulfide-lyase (adding hydrogen cyanide L-3-cyanoalanine-forming). Other names in common use include beta-cyanoalanine synthase, beta-cyanoalanine synthetase, beta-cyano-L-alanine synthase, and L-cysteine hydrogen-sulfide-lyase (adding HCN). This enzyme participates in cyanoamino acid metabolism.

References

IUBMB entry for 4.4.1.9
BRENDA references for 4.4.1.9 (Recommended.)
PubMed references for 4.4.1.9
PubMed Central references for 4.4.1.9
Google Scholar references for 4.4.1.9
Akopyan TN, Braunstein AE, Goryachenkova EV (1975). "Beta-cyanoalanine synthase: purification and characterization". Proc. Natl. Acad. Sci. U. S. A. 72: 1617–21. doi:10.1073/pnas.72.4.1617. PMID 1055433.
Castric PA, Conn EE (1971). "Formation of -cyanoalanine by O-acetylserine sulfhydrylase". J. Bacteriol. 108: 132–6. PMID 5001194.
Hendrickson HR (1968). "The beta-cyanoalanine synthase of blue lupine". Fed. Proc. 27: 593.
Hendrickson HR, Conn EE (1969). "Cyanide metabolism in higher plants. IV. Purification and properties of the beta-cyanolanine synthase of blue lupine". J. Biol. Chem. 244: 2632–40. PMID 5769995.