Canadian Medical Guide > Chemicals and Drugs > Enzymes and Coenzymes > Cytochromes > Cytochrome P-450 Enzyme System > Aryl Hydrocarbon Hydroxylases Terms and Definitions




Aryl Hydrocarbon Hydroxylases

Medical Definition: A large group of cytochrome P-450 (heme-thiolate) monooxygenases that complex with NAD(P)H-FLAVIN OXIDOREDUCTASE in numerous mixed-function oxidations of aromatic compounds. They catalyze hydroxylation of a broad spectrum of substrates and are important in the metabolism of steroids, drugs, and toxins such as PHENOBARBITAL, carcinogens, and insecticides.
Also Called: Xenobiotic Monooxygenases
CAS Number: EC 1.14.14.1
Previously Indexed: Hydroxylases (1971-1974),Polycyclic Hydrocarbons (1974)
Aryl Hydrocarbon Hydroxylases Categories.
Canadian Medical Guide Definition Aniline Hydroxylase - A drug-metabolizing, cytochrome P-450 enzyme which catalyzes the hydroxylation of aniline to hydroxyaniline in the presence of reduced flavoprotein and molecular oxygen. EC 1.14.14.-.
Canadian Medical Guide Definition Benzopyrene Hydroxylase - A drug-metabolizing, cytochrome P-448 (P-450) enzyme which catalyzes the hydroxylation of benzopyrene to 3-hydroxybenzopyrene in the presence of reduced flavoprotein and molecular oxygen. Also acts on certain anthracene derivatives. An aspect of EC 1.14.14.1.
Canadian Medical Guide Definition Cytochrome P-450 CYP1A1 - A liver microsomal cytochrome P-450 monooxygenase capable of biotransforming xenobiotics such as polycyclic hydrocarbons and halogenated aromatic hydrocarbons into carcinogenic or mutagenic compounds. They have been found in mammals and fish. This enzyme, encoded by CYP1A1 gene, can be measured by using ethoxyresorufin as a substrate for the ethoxyresorufin O-deethylase activity.
Canadian Medical Guide Definition Cytochrome P-450 CYP1A2 - A cytochrome P-450 monooxygenase that can be induced by polycyclic aromatic xenobiotics in the liver of human and several animal species. This enzyme is of significant clinical interest due to the large number of drug interactions associated with its induction and its metabolism of THEOPHYLLINE. Caffeine is considered to be a model substrate for this enzyme. CYP1A2 activity can also be increased by environmental factors such as cigarette smoking, charbroiled meat, cruciferous vegetables, and a number of drugs including phenytoin, phenobarbital, and omeprazole.
Canadian Medical Guide Definition Cytochrome P-450 CYP2B1 - A major cytochrome P-450 enzyme which is inducible by PHENOBARBITAL in both the LIVER and SMALL INTESTINE. It is active in the metabolism of compounds like pentoxyresorufin, TESTOSTERONE, and ANDROSTENEDIONE. This enzyme, encoded by CYP2B1 gene, also mediates the activation of CYCLOPHOSPHAMIDE and IFOSFAMIDE to MUTAGENS.
Canadian Medical Guide Definition Cytochrome P-450 CYP2D6 - A cytochrome P450 enzyme that catalyzes the hydroxylation of many drugs and environmental chemicals, such as DEBRISOQUINE, ADRENERGIC RECEPTOR ANTAGONISTS, and TRICYCLIC ANTIDEPRESSANTS. This enzyme is deficient in up to 10 percent of the Caucasian population.
Canadian Medical Guide Definition Cytochrome P-450 CYP2E1 - An ethanol-inducible cytochrome P450 enzyme that metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. Substrates include alcohol; NITROSAMINES; BENZENE; URETHANE; and other low molecular weight compounds. CYP2E1 has been used as an enzyme marker in the study of alcohol abuse.

Aryl Hydrocarbon Hydroxylases Medical Definitions and Terms

CANADIAN MEDICAL GUIDE

Thank you for visiting Canadian Medical Guide .com





Wildlife On Video »

Canadian Medical Guide Canada's Great Outdoors
Tour Canadian Rockies »
Book Banff »
Book Jasper »
Maligne Lake Boat Cruise »
Gondola Banff »
Hike Jasper »
Jasper Columbia Icefield »