Cytochrome P450 2A6 (abbreviated CYP2A6) is a member of the
cytochrome P450
Cytochromes P450 (P450s or CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that mostly, but not exclusively, function as monooxygenases. However, they are not omnipresent; for examp ...
mixed-function oxidase system, which is involved in the metabolism of
xenobiotics in the body. CYP2A6 is the primary enzyme responsible for the oxidation of
nicotine
Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As ...
and
cotinine. It is also involved in the metabolism of several pharmaceuticals, carcinogens, and a number of coumarin-type alkaloids. CYP2A6 is the only enzyme in the human body that appreciably catalyzes the 7-hydroxylation of
coumarin, such that the formation of the product of this reaction, 7-hydroxycoumarin, is used as a probe for CYP2A6 activity.
The CYP2A6 gene is part of a large cluster of cytochrome P450 genes from the CYP2A, CYP2B and CYP2F subfamilies on chromosome 19q. The gene was formerly referred to as CYP2A3; however, it has been renamed CYP2A6.
Interactive pathway map
Distribution
CYP2A6 localizes to the
endoplasmic reticulum
The endoplasmic reticulum (ER) is a part of a transportation system of the eukaryote, eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for ...
and is found predominantly in the liver.
Variability
Significant interindividual variability in CYP2A6 apoprotein and mRNA levels has been observed.
Induction
CYP2A6 is known to be
inducible by
phenobarbital
Phenobarbital, also known as phenobarbitone or phenobarb, sold under the brand name Luminal among others, is a medication of the barbiturate type. It is recommended by the World Health Organization (WHO) for the treatment of certain types of ...
and
rifampicin, and it is suspected that other antiepileptic drugs may also have this effect.
CYP2A6 Ligands
See also
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List of cytochrome P450 modulators
References
Further reading
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External links
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