Alkylglycerol monooxygenase

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.^[1] In 2010 finally, the gene coding for alkylglycerol monooxygenase was discovered as transmembrane protein 195 (TMEM195) on chromosome 7.^[2] 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[8H]-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.