Homocysteine desulfhydrase

In enzymology, a homocysteine desulfhydrase is an enzyme that catalyzes the chemical reaction


 * L-homocysteine + H2O $$\rightleftharpoons$$ hydrogen sulfide + NH3 + 2-oxobutanoate

Thus, the two substrates of this enzyme are L-homocysteine and H2O, whereas its 3 products are hydrogen sulfide, NH3, and 2-oxobutanoate.

This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-homocysteine hydrogen-sulfide-lyase (deaminating 2-oxobutanoate-forming). Other names in common use include homocysteine desulfurase, L-homocysteine hydrogen-sulfide-lyase, and (deaminating). This enzyme participates in nitrogen metabolism and sulfur metabolism. It employs one cofactor, pyridoxal phosphate.