Isolation of two cytochrome P450 forms, CYP2A19 and CYP1A, from pig liver microsomes

• Published in: Journal of veterinary pharmacology and therapeutics Vol. 32; no. 5; pp. 470 - 476
• Main Authors: MATAL, J, TUNKOVÁ, A, ŠILLER, M, ANZENBACHEROVÁ, E, ANZENBACHER, P
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.10.2009; Blackwell Publishing Ltd
• Subjects: Animals; Aryl Hydrocarbon Hydroxylases - isolation & purification; biochemical pathways; biotransformation; Blotting, Western; chromatography; Chromatography, Agarose; cytochrome P-1A; cytochrome P-2A19; cytochrome P-450; Cytochrome P-450 CYP1A1 - isolation & purification; Cytochrome P-450 CYP2A6; drug evaluation; drug excretion; drug residues; enzyme activity; food safety; Humans; in vitro studies; liver; liver function; liver microsomes; Microsomes, Liver - enzymology; pharmacokinetics; pork; purification; risk assessment; separation; Swine; veterinary drugs
• ISSN: 0140-7783; 1365-2885
• DOI: 10.1111/j.1365-2885.2009.01076.x

Cytochromes P450 comprise a superfamily of proteins that play a crucial role in the biotransformation of numerous chemicals. Purified CYPs can be used e.g. in studies on structure or determining the drug metabolism pathways. In this work, purification of the porcine CYP1A and CYP2A19 to electrophoretic homogeneity from the pig hepatic microsomes using octylamino Sepharose and hydroxylapatite column chromatography is reported. The proteins have been clearly recognized by commercial antibodies against rat and human CYP1A2 (porcine CYP1A) and human CYP2A6 (CYP2A19) respectively, using Western blot. Activities of both enzymes were determined by specific substrates, 7-ethoxyresorufin, 7-methoxyresorufin (CYP1A) and coumarin (CYP2A19). The isolated enzymes show kinetic parameters similar to human counterparts. Taken together, pig cytochromes can be used for the testing of veterinary drug metabolism, useful for the determination of drug residues in meat of pigs. The results obtained show that the pigs may be a suitable model for biotransformation of xenobiotics in humans.