Reaction: heme + 3 AH2 + 3 O2 = biliverdin + Fe2+ + CO + 3 A + 3 H2O
For diagram, click here
Other name(s): ORP33 proteins; haem oxygenase; heme oxygenase (decyclizing); heme oxidase; haem oxidase
Systematic name: heme,hydrogen-donor:oxygen oxidoreductase (α-methene-oxidizing, hydroxylating)
Comments: Requires NAD(P)H and EC 1.6.2.4, NADPH—hemoprotein reductase. The terminal oxygen atoms that are incorporated into the carbonyl groups of pyrrole rings A and B of biliverdin are derived from two separate oxygen molecules [4]. The third oxygen molecule provides the oxygen atom that converts the α-carbon to CO. The central iron is kept in the reduced state by NAD(P)H.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9059-22-7
References:
1. Maines, M.D., Ibrahim, N.G. and Kappas, K. Solubilization and partial purification of heme oxygenase from rat liver. J. Biol. Chem. 252 (1977) 5900-5903. [PMID: 18477]
2. Sunderman, F.W., Jr., Downs, J.R., Reid, M.C. and Bibeau, L.M. Gas-chromatographic assay for heme oxygenase activity. Clin. Chem. 28 (1982) 2026-2032. [PMID: 6897023]
3. Yoshida, T., Takahashi, S. and Kikuchi, J. Partial purification and reconstitution of the heme oxygenase system from pig spleen microsomes. J. Biochem. (Tokyo) 75 (1974) 1187-1191. [PMID: 4370250]
4. Noguchi, M., Yoshida, T. and Kikuchi, G. Specific requirement of NADPH-cytochrome c reductase for the microsomal heme oxygenase reaction yielding biliverdin IX α. FEBS Lett. 98 (1979) 281-284. [PMID: 105935]
5. Lad, L., Schuller, D.J., Shimizu, H., Friedman, J., Li, H., Ortiz de Montellano, P.R. and Poulos, T.L. Comparison of the heme-free and -bound crystal structures of human heme oxygenase-1. J. Biol. Chem. 278 (2003) 7834-7843. [PMID: 12500973]