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Alkylglycerol monooxygenase (AGMO) (EC 1.14.16.5) is an enzyme that catalyzes the hydroxylation of alkylglycerols, a specific subclass of ether lipids. This enzyme was first described in 1964 as a pteridine-dependent ether lipid cleaving enzyme. In 2010 finally, the gene coding for alkylglycerol monooxygenase was discovered as transmembrane protein 195 (TMEM195) on chromosome 7. In analogy to the enzymes phenylalanine hydroxylase, tyrosine hydroxylase, tryptophan hydroxylase and nitric oxide synthase, alkylglycerol monooxygenase critically depends on the cofactor tetrahydrobiopterin and iron.

The reaction catalyzed by alkylglycerol monooxygenase:

• 1-alkyl-sn-glycerol + tetrahydrobiopterin + O₂ ${\displaystyle \rightleftharpoons }$ 1-hydroxyalkyl-sn-glycerol + 6,7-dihydrobiopterin + H₂O

The unstable intermediate product 1-hydroxyalkyl-sn-glycerol rearranges into the fatty aldehyde and the free glycerol derivative. The fatty aldehyde is then further oxidized to the corresponding acid by fatty aldehyde dehydrogenase.

Alkylglycerol monooxygenase is a membrane-bound mixed-function oxidase and harbours a fatty acid hydroxylase motif. The iron is believed to be coordinated by a diiron center composed of eight histidines, which can be found in all enzymes containing this motif.

Nomenclature

The systematic name for this enzyme is 1-alkyl-sn-glycerol,tetrahydrobiopterin:oxygen oxidoreductase. Other names in use are glyceryl-ether monooxygenase, glyceryl-ether cleaving enzyme, glyceryl ether oxygenase, glyceryl etherase, and O-alkylglycerol monooxygenase.

References

1. Tietz, AA; Lindberg, M; Kennedy, EP (December 1964). "A New Pteridine-Requiring Enzyme System For The Oxidation Of Glyceryl Ethers". The Journal of Biological Chemistry. 239 (12): 4081–90. doi:10.1016/S0021-9258(18)91137-3. PMID 14247652.
2. Watschinger, K (2010). "Identification of the gene encoding alkylglycerol monooxygenase defines a third class of tetrahydrobiopterin-dependent enzymes". Proc. Natl. Acad. Sci. U.S.A. 107 (31): 13672–13677. Bibcode:2010PNAS..10713672W. doi:10.1073/pnas.1002404107. PMC 2922233. PMID 20643956.

Further reading

• Watschinger K, Keller MA, Hermetter A, Golderer G, Werner-Felmayer G, Werner ER (2009). "Glyceryl ether monooxygenase resembles aromatic amino acid hydroxylases in metal ion and tetrahydrobiopterin dependence". Biol. Chem. 390 (1): 3–10. doi:10.1515/BC.2009.010. PMC 2847825. PMID 19007315.
• Werner ER, Hermetter A, Prast H, Golderer G, Werner-Felmayer G (2007). "Widespread occurrence of glyceryl ether monooxygenase activity in rat tissues detected by a novel assay". J. Lipid Res. 48 (6): 1422–1427. doi:10.1194/jlr.D600042-JLR200. PMC 2851153. PMID 17303893.
• Ishibashi T, Imai Y (1983). "Solubilization and partial characterization of alkylglycerol monooxygenase from rat liver microsomes". Eur. J. Biochem. 132 (1): 23–7. doi:10.1111/j.1432-1033.1983.tb07320.x. PMID 6840084.
• Pfleger RC, Piantadosi C, Snyder F (1967). "The biocleavage of isomeric glyceryl ethers by soluble liver enzymes in a variety of species". Biochim. Biophys. Acta. 144 (3): 633–48. doi:10.1016/0005-2760(67)90052-5. PMID 4383918.
• Snyder F, Malone B, Piantadosi C (1973). "Tetrahydropteridine-dependent cleavage enzyme for O-alkyl lipids: substrate specificity". Biochim. Biophys. Acta. 316 (2): 259–65. doi:10.1016/0005-2760(73)90018-0. PMID 4355017.
• Soodsma JF, Piantadosi C, Snyder F (1972). "Partial characterization of the alkylglycerol cleavage enzyme system of rat liver". J. Biol. Chem. 247 (12): 3923–9. doi:10.1016/S0021-9258(19)45123-5. PMID 4402391.

• Biology

• EC 1.14.16
• Phospholipids
• Enzymes of unknown structure