- Oxygenase
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An oxygenase is any enzyme that oxidizes a substrate by transferring the oxygen from molecular oxygen O2 (as in air) to it. The oxygenases form a class of oxidoreductases; their EC number is EC 1.13 or EC 1.14.
Oxygenases were discovered in 1955 simultaneously by two groups, Osamu Hayaishi from Japan[1][2][3] and Howard S. Mason from the US.[4][5]
There are two types of oxygenases:
- Monooxygenases, or mixed function oxidase, transfer one oxygen atom to the substrate, and reduce the other oxygen atom to water.
- Dioxygenases, or oxygen transferases, incorporate both atoms of molecular oxygen (O2) into the product(s) of the reaction.[6]
Among the most important monooxygenases are the cytochrome P450 oxidases, responsible for breaking down numerous chemicals in the body.
References
- ^ Hayaishi et al. (1955) Mechanism of the pyrocatechase reaction, J. Am. Chem. Soc. 77 (1955) 5450-5451
- ^ Sligar SG, Makris TM, Denisov IG (2005). "Thirty years of microbial P450 monooxygenase research: peroxo-heme intermediates--the central bus station in heme oxygenase catalysis". Biochem. Biophys. Res. Commun. 338 (1): 346–54. doi:10.1016/j.bbrc.2005.08.094. PMID 16139790.
- ^ Hayaishi O (2005). "An odyssey with oxygen". Biochem. Biophys. Res. Commun. 338 (1): 2–6. doi:10.1016/j.bbrc.2005.09.019. PMID 16185652.
- ^ Mason HS, Fowlks WK, and Peterson E. (1955) Oxygen transfer and electron transport by the phenolase complex. J. Am. Chem. Soc.; 77(10) pp 2914 - 2915
- ^ Waterman MR (2005). "Professor Howard Mason and oxygen activation". Biochem. Biophys. Res. Commun. 338 (1): 7–11. doi:10.1016/j.bbrc.2005.08.120. PMID 16153596.
- ^ Bugg TDH (2003). "Dioxygenase enzymes: catalytic mechanisms and chemical models". Tetrahedron 59 (36): 7075–7101. doi:10.1016/S0040-4020(03)00944-X.
Oxidoreductases: monooxygenases (EC 1.13) 1.13.11: two atoms of oxygen lipoxygenase: Arachidonate 5-lipoxygenase · Arachidonate 12-lipoxygenase/ALOX12 · Arachidonate 8-lipoxygenase · Arachidonate 15-lipoxygenase/ALOX15 · Linoleate 11-lipoxygenase
other dioxygenase: Catechol dioxygenase · Homogentisate 1,2-dioxygenase · Cysteine dioxygenase · 4-Hydroxyphenylpyruvate dioxygenase · Indoleamine 2,3-dioxygenase1.13.12: one atom of oxygen 1.13.99: other Oxidoreductases: dioxygenases, including steroid hydroxylases (EC 1.14) 1.14.11: 2-oxoglutarate 1.14.13: NADH or NADPH Flavin-containing monooxygenase (FMO1, FMO2, FMO3, FMO4, FMO5) - Nitric oxide synthase (NOS1, NOS2, NOS3) - Cholesterol 7 alpha-hydroxylase - Methane monooxygenase - 3A4 - Lanosterol 14 alpha-demethylase1.14.14: reduced flavin or flavoprotein 1.14.15: reduced iron-sulfur protein 1.14.16: reduced pteridine (BH4 dependent) 1.14.17: reduced ascorbate 1.14.18-19: other 1.14.99 - miscellaneous Categories:- Enzyme stubs
- Enzymes
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