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.
Discoverers
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] Hayaishi was awarded the 1986 Wolf Prize in Medicine "for the discovery of the oxygenase enzymes and elucidation of their structure and biological importance."[6]
Chemical Makeup
Oxygenases consist of both constitutive and inducible isozymes (HO-1, HO-2). These constitute a major intracellular source of iron and carbon monoxide[7]
Types
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.[8]
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, 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.
- ^ SW, Ryter; J, Alam (April 2006). "Heme oxygenase-1/carbon monoxide: from basic science to therapeutic applications". Physiol Rev. 86. 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.
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