Glyceryl-ether monooxygenase
Encyclopedia
Alkylglycerol monooxygenase (AGMO) is an enzyme that catalyzes the hydroxylation of alkylglycerols, a specific subclass of ether lipid
s. This enzyme was first described in 1964 as a pteridine-dependent etherlipid 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:
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 histidine
s, which can be found in all enzymes containing this motif.
Ether lipid
Ether lipids are lipids in which one or more of the carbon atoms on glycerol is bonded to an alkyl chain via an ether linkage, as opposed to the usual ester linkage.-Types:...
s. This enzyme was first described in 1964 as a pteridine-dependent etherlipid cleaving enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
. In 2010 finally, the gene coding for alkylglycerol monooxygenase was discovered as transmembrane protein 195 (TMEM195) on chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
7.
In analogy to the enzymes phenylalanine hydroxylase
Phenylalanine hydroxylase
Phenylalanine hydroxylase is an enzyme that catalyzes the hydroxylation of the aromatic side-chain of phenylalanine to generate tyrosine. PheOH is one of three members of the pterin-dependent amino acid hydroxylases, a class of monooxygenase that uses tetrahydrobiopterin and a non-heme iron for...
, tyrosine hydroxylase
Tyrosine hydroxylase
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L-tyrosine to dihydroxyphenylalanine . It does so using tetrahydrobiopterin as a coenzyme. DOPA is a precursor for dopamine, which, in turn, is a precursor for norepinephrine ...
, tryptophan hydroxylase
Tryptophan hydroxylase
Tryptophan hydroxylase is an enzyme involved in the synthesis of the neurotransmitter serotonin. TPH catalyzes the following chemical reactionIt employs one cofactor, iron.- Function :...
and nitric oxide synthase
Nitric oxide synthase
Nitric oxide synthases are a family of enzymes that catalyze the production of nitric oxide from L-arginine. NO is an important cellular signaling molecule, having a vital role in many biological processes...
, alkylglycerol monooxygenase critically depends on the cofactor
Cofactor (biochemistry)
A cofactor is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and cofactors can be considered "helper molecules" that assist in biochemical transformations....
tetrahydrobiopterin
Tetrahydrobiopterin
Tetrahydrobiopterin or sapropterin is a naturally occurring essential cofactor of the three aromatic amino acid hydroxylase enzymes, used in the degradation of amino acid phenylalanine and in the biosynthesis of the neurotransmitters serotonin , melatonin, dopamine, norepinephrine ,...
and iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
.
The reaction catalyzed
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
by alkylglycerol monooxygenase:
- 1-alkyl-sn-glycerol + tetrahydrobiopterin + O2
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 histidine
Histidine
Histidine Histidine, an essential amino acid, has a positively charged imidazole functional group. It is one of the 22 proteinogenic amino acids. Its codons are CAU and CAC. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans...
s, which can be found in all enzymes containing this motif.