Cytochrome P450 2C18 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''CYP2C18''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

Function

This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum but its specific substrate has not yet been determined. The gene is located within a cluster of cytochrome P450 genes on chromosome 10q24. An additional gene, CYP2C17, was once thought to exist; however, CYP4217 is now considered an artefact based on a chimera of CYP2C18 and CYP2C19. CYP2C18 also possesses

epoxygenase Epoxygenases are a set of membrane-bound, heme-containing cytochrome P450 (CYP450 or just CYP) enzymes that metabolize polyunsaturated fatty acids (PUFAs) to epoxide products that have a range of biological activities. The most thoroughly-studi ...

activity: it can attack various long-chain polyunsaturated fatty acids at their double (i.e.

alkene In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The Internationa ...

) bonds to form

epoxide In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ...

products that act as signaling agents. It metabolizes: 1)

arachidonic acid Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega−6 fatty acid 20:4(ω−6), or 20:4(5,8,11,14). It is a precursor in the formation of leukotrienes, prostaglandins, and thromboxanes. Together with omega−3 fatty acids an ...

to various

epoxyeicosatrienoic acid The epoxyeicosatrienoic acids or EETs are signaling molecules formed within various types of cells by the metabolism of arachidonic acid by a specific subset of cytochrome P450 enzymes, termed cytochrome P450 epoxygenases. They are nonclassic e ...

s (also termed EETs); 2)

linoleic acid Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsat ...

to 9,10-epoxy octadecenoic acids (also termed

vernolic acid Vernolic acid (leukotoxin B or isoleukotoxin) is a long chain fatty acid that is monounsaturated and contains an epoxide. It is a ''cis'' epoxide derived from the C12–C13 alkene of linoleic acid. Vernolic acid was first definitively character ...

, linoleic acid 9:10-oxide, or leukotoxin) and 12,13-epoxy-octadecenoic (also termed coronaric acid, linoleic acid 12,13-oxide, or isoleukotoxin); 3)

docosahexaenoic acid Docosahexaenoic acid (DHA) is an omega−3 fatty acid that is an important component of the human brain, cerebral cortex, skin, and retina. It is given the fatty acid notation 22:6(''n''−3). It can be synthesized from alpha-linolenic acid or ...

to various

epoxydocosapentaenoic acid Epoxide docosapentaenoic acids (epoxydocosapentaenoic acids, EDPs, or EpDPEs) are metabolites of the 22-carbon straight-chain omega-3 fatty acid, docosahexaenoic acid (DHA). Cell types that express certain cytochrome P450 (CYP) epoxygenases meta ...

s (also termed EDPs); and 4)

eicosapentaenoic acid Eicosapentaenoic acid (EPA; also icosapentaenoic acid) is an omega−3 fatty acid. In physiological literature, it is given the name 20:5(''n''−3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid wi ...

to various epoxyeicosatetraenoic acids (also termed EEQs). While CYP2C19, CYP2C8,

CYP2C9 Cytochrome P450 family 2 subfamily C member 9 (abbreviated CYP2C9) is an enzyme protein. The enzyme is involved in the metabolism, by oxidation, of both xenobiotics, including drugs, and endogenous compounds, including fatty acids. In humans, t ...

, CYP2J2, and possibly

CYP2S1 Cytochrome P450 2S1 is a protein that in humans is encoded by the ''CYP2S1'' gene. The gene is located in chromosome 19q13.2 within a cluster including other CYP2 family members such as CYP2A6, CYP2A13, CYP2B6, and CYP2F1. Expression CYP2S1 is h ...

are the main producers of EETs and, very likely EEQs, EDPs, and the epoxides of linoleic acid, CYP2C18 may contribute to the production of these metabolites in certain tissues.

Function

References

External links

Further reading