Oxygenase
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.
Structure
[edit]Most oxygenases contain either a metal, usually iron, or an organic cofactor, usually flavin. These cofactors interact with O2, leading to its transfer to substrate.[1]
Oxygenases constitute a major intracellular source of iron and carbon monoxide[2]
Mechanism
[edit]Two types of oxygenases are recognized:
- 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.[3]
Among the most common monooxygenases are the cytochrome P450 oxidases, responsible for breaking down numerous chemicals in the body.
History
[edit]Oxygenases were discovered in 1955 simultaneously by two groups, Osamu Hayaishi from Japan[4][5][6] and Howard S. Mason from the US.[7][8] Hayaishi was awarded the 1986 Wolf Prize in Medicine "for the discovery of the oxygenase enzymes and elucidation of their structure and biological importance."[9]
References
[edit]- ^ Fetzner, Susanne; Steiner, Roberto A. (2010). "Cofactor-independent oxidases and oxygenases". Applied Microbiology and Biotechnology. 86 (3): 791–804. doi:10.1007/s00253-010-2455-0. PMID 20157809. S2CID 25377247.
- ^ SW, Ryter; J, Alam (April 2006). "Heme oxygenase-1/carbon monoxide: from basic science to therapeutic applications". Physiol Rev. 86 (2). Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, The University of Pittsburgh School of Medicine: 583–650. doi:10.1152/physrev.00011.2005. PMID 16601269.
- ^ Bugg TDH (2003). "Dioxygenase enzymes: catalytic mechanisms and chemical models". Tetrahedron. 59 (36): 7075–7101. doi:10.1016/S0040-4020(03)00944-X.
- ^ 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, Peterson E (1955). "Oxygen transfer and electron transport by the phenolase complex". J. Am. Chem. Soc. 77 (10): 2914–2915. doi:10.1021/ja01615a088.
- ^ 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.
- ^ "The Medicine Prize Committee unanimously decided that the Wolf Prize in Medicine for 1986 be awarded to Osamu Hayaishi". Wolf Foundation. Retrieved May 12, 2014.[dead link]
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