Reaction: L-homocysteine + H2O = hydrogen sulfide + NH3 + 2-oxobutanoate (overall reaction)
(1a) L-homocysteine = hydrogen sulfide + 2-ammoniobut-2-enoate
(1b) 2-ammoniobut-2-enoate + H2O = 2-oxobutanoate + NH3 (spontaneous)
For diagram click here.
Other name(s): homocysteine desulfurase, L-homocysteine hydrogen-sulfide-lyase (deaminating)
Systematic name: L-homocysteine hydrogen-sulfide-lyase (deaminating; 2-oxobutanoate-forming)
Comments: A pyridoxal-phosphate protein.
Links to other databases: BRENDA, EXPASY, KEGG, CAS registry number: 9024-41-3
References:
1. Kallio, R.E. Function of pyridoxal phosphate in desulfhydrase systems of Proteus morganii. J. Biol. Chem. 192 (1951) 371-377. [PMID: 14917685]