Cytochrome P450 1A2

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Cytochrome P450 1A2
Cytochrome P450 1A2
Human microsomal cytochrome P4501A2 as a complex with alpha-naphthoflavone according to 2HI4
Properties of human protein
Mass / length primary structure 515 amino acids
Secondary to quaternary structure Heterotetramer
Cofactor 2-phenyl-4 H -benzo [H] chromen-4-one, heme
Identifier
Gene names CYP1A2 , CP12, P3-450, P450 (PA)
External IDs
Enzyme classification
EC, category 1.14.14.1 monooxygenase
Response type Hydroxylation
Substrate RH + FADH + O 2
Products ROH + FAD + + H 2 O
Occurrence
Homology family Cytochrome P450
Parent taxon Creature

Cytochrome P450 1A2 (CYP1A2) is a heme protein - enzyme of the cytochrome P450 group. The protein metabolizes estrogens and various xenobiotics , including caffeine , through oxidation and hydroxylation . In humans, the cytochrome P450 1A2 by the CYP1A2 - gene coded.

The gene expression of CYP1A2 is induced by various food components. Vegetables like cabbage , cauliflower, and broccoli increase cytochrome P450-1A2 levels. Lower levels in people in Southeast Asia appear to be related to the preparation of these vegetables in curries using cumin and turmeric ; these spices inhibit the enzyme.

Studies indicate that an increased function of the CYP1A2 could be linked to an increased risk of developing breast cancer .

function

Cytochrome P450 1A2 belongs to the cytochrome P450 superfamily of enzymes. All of these proteins are monooxygenases , which catalyze many reactions related to the metabolism of drugs and the synthesis of cholesterol and other steroids and lipids . Cytochrome P450 1A2 is located in the endoplasmic reticulum . Expression is stimulated by some polycyclic aromatic hydrocarbons ( PAHs ), some of which are found in tobacco smoke . The actual, endogenous substrate of the enzyme is unknown; however, it is able to convert some PAHs into carcinogenic metabolic intermediates. Xenobiotic substrates include caffeine , aflatoxin B1 and paracetamol . The transcription of the CYP1A2 gene contains four Alu sequences flanked by direct repeats in the 3 'untranslated region.

Individual evidence

  1. Jaiswal AK, Nebert DW, McBride OW, Gonzalez FJ: Human P (3) 450: cDNA and complete protein sequence, repetitive Alu sequences in the 3 'nontranslated region, and localization of gene to chromosome 15 . In: J. Exp. Pathol. . 3, No. 1, 1987, pp. 1-17. PMID 3681487 .
  2. Fontana R, Lown K, Paine M, Fortlage L, Santella R, Felton J, Knize M, Greenberg A, Watkins P: Effects of a chargrilled meat diet on expression of CYP3A, CYP1A, and P-glycoprotein levels in healthy volunteers . In: Gastroenterology . 117, No. 1, 1999, pp. 89-98. doi : 10.1016 / S0016-5085 (99) 70554-8 . PMID 10381914 .
  3. ^ Kate Sanday: South Asians and Europeans react differently to common drugs. University of Sydney Faculty of Pharmacy News , accessed October 17, 2011 .
  4. Chi-Chen Hong, Bing-Kou Tang, Venketeshwer Rao, Sanjiv Agarwal, Lisa Martin, David Tritchler, Martin Yaffe, Norman F Boyd: Cytochrome P450 1A2 (CYP1A2) activity, mammographic density, and oxidative stress: a cross-sectional study . (PDF; 310 kB) In: Breast Cancer Res . 6, May 7, 2004, pp. 338-351; doi: 10.1186 / bcr797 .
  5. Entrez Gene: cytochrome P450. National Center for Biotechnology Information , accessed March 28, 2013 .