Cytochromes P450 and metabolism of xenobiotics.
Cytochromes P450 (henceforth P450s) are involved in a variety of metabolic and biosynthetic processes. The number of known P450 enzymes exceeds 1000, while the endogenous substrates of most of them remain unknown. All P450 enzymes exhibit similarity in their structure and general mechanism of action; however, there are significant differences in the detailed function of individual enzymes as well as in the structures and properties of their active sites. This review discusses the properties of the most important P450 enzymes taking part in drug metabolism in humans. P450 3A4 is of paramount importance, because it is the most abundant P450 in the human liver and is known to metabolize the majority of drugs whose biotransformation is known. Genetically dependent variabilities of individual P450 activities and levels are described, documenting the importance of pharmacogenetics aimed at explaining differences in the response of the organism to various drugs.
Anzenbacher
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Institute of Pharmacology, Faculty of Medicine, Palacký University, Olomouc, Czech Republic. anzen@tunw.upol.cz
Anzenbacherová
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E
D001711:Biotransformation; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism; D019389:Cytochrome P-450 CYP2D6 / Q000378:metabolism; D019392:Cytochrome P-450 CYP2E1 / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D006801:Humans; D008658:Inactivation, Metabolic; D008862:Microsomes, Liver / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000378:metabolism; D013379:Substrate Specificity; D015262:Xenobiotics / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics
D015262:Xenobiotics; C400322:cytochrome P-450 CYP2C subfamily; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D019392:Cytochrome P-450 CYP2E1; C104464:CYP3A protein, human; D019388:Cytochrome P-450 CYP1A2; D019389:Cytochrome P-450 CYP2D6; D051544:Cytochrome P-450 CYP3A