Reaction: 4 Fe(II) + 4 H+ + O2 = 4 Fe(III) + 2 H2O
Other name(s): ceruloplasmin; caeruloplasmin; ferroxidase I; iron oxidase, iron(II):oxygen oxidoreductase; ferro:O2 oxidoreductase; iron II:oxygen oxidoreductase; hephaestin; HEPH
Systematic name: Fe(II):oxygen oxidoreductase
Comments: The enzyme in blood plasma (ceruloplasmin) belongs to the family of multicopper oxidases. In humans it accounts for 95% of plasma copper. It oxidizes Fe(II) to Fe(III), which allows the subsequent incorporation of the latter into proteins such as apotransferrin and lactoferrin. An enzyme from iron oxidizing bacterium strain TI-1 contains heme a.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9031-37-2, 104404-69-5
References:
1. Osaki, S. Kinetic studies of ferrous ion oxidation with crystalline human ferroxidase (ceruloplasmin). J. Biol. Chem. 241 (1966) 5053-5059. [PMID: 5925868]
2. Osaki, S. and Walaas, O. Kinetic studies of ferrous ion oxidation with crystalline human ferroxidase. II. Rate constants at various steps and formation of a possible enzyme-substrate complex. J. Biol. Chem. 242 (1967) 2653-2657. [PMID: 6027241]
3. Lindley, P.F. Card, G. Zaitseva, I. Zaitsev, V. Reinhammar, B. SelinLindgren, E. and Yoshida, K. An X-ray structural study of human ceruloplasmin in relation to ferroxidase activity. J. Biol. Inorg. Chem. 2 (1997) 454-463.
4. Takai, M., Kamimura, K. and Sugio, T. A new iron oxidase from a moderately thermophilic iron oxidizing bacterium strain TI-1. Eur. J. Biochem. 268 (2001) 1653-1658. [PMID: 11248684]
5. Chen, H., Attieh, Z.K., Su, T., Syed, B.A., Gao, H., Alaeddine, R.M., Fox, T.C., Usta, J., Naylor, C.E., Evans, R.W., McKie, A.T., Anderson, G.J. and Vulpe, C.D. Hephaestin is a ferroxidase that maintains partial activity in sex-linked anemia mice. Blood 103 (2004) 3933-3939. [PMID: 14751926]