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Vavrová K, Indra R, Pompach P, Heger Z, Hodek P. The impact of individual human cytochrome P450 enzymes on oxidative metabolism of anticancer drug lenvatinib. Biomed Pharmacother 2021; 145:112391. [PMID: 34847475 DOI: 10.1016/j.biopha.2021.112391] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/20/2021] [Accepted: 11/02/2021] [Indexed: 11/26/2022] Open
Abstract
Lenvatinib, a small molecule tyrosine kinase inhibitor (TKI), exhibits good inhibitory effect in several types of carcinomas. Specifically, it is the most effective TKI used for treatment of thyroid cancer. To extend pharmacokinetics data on this anticancer agent, we aimed to identify the metabolites of lenvatinib formed during in vitro incubation of lenvatinib with human hepatic microsomes or recombinant cytochromes P450 (CYPs) by using high performance liquid chromatography and mass spectrometry. The role of CYPs in the oxidation of lenvatinib was initially investigated in hepatic microsomes using specific CYP inhibitors. CYP-catalytic activities in each microsomal sample were correlated with the amounts of lenvatinib metabolites formed by these samples. Further, human recombinant CYPs were employed in the metabolic studies. Based on our data, lenvatinib is metabolized to O-desmethyl lenvatinib, N-descyclopropyl lenvatinib and lenvatinib N-oxide. In the presence of cytochrome b5, recombinant CYP3A4 was the most efficient to form these metabolites. In addition, CYP1A1 significantly contributes to the lenvatinib metabolism. It was even more efficient in forming of O-desmethyl lenvatinib than CYP3A4 in the absence of cytochrome b5. The present study indicates that further research focused on drug-drug interactions, in particular on CYP3A4 and CYP1A1 modulators, is needed. This will pave new avenues towards TKIs-mediated personalized therapy.
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Affiliation(s)
- Katarína Vavrová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 6, 128 00 Prague 2, Czech Republic
| | - Radek Indra
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 6, 128 00 Prague 2, Czech Republic.
| | - Petr Pompach
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 6, 128 00 Prague 2, Czech Republic
| | - Zbyněk Heger
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Purkynova 656/123, 612 00 Brno, Czech Republic
| | - Petr Hodek
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 6, 128 00 Prague 2, Czech Republic
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Stiborová M, Indra R, Moserová M, Bořek-Dohalská L, Hodek P, Frei E, Kopka K, Schmeiser HH, Arlt VM. Comparison of human cytochrome P450 1A1-catalysed oxidation of benzo[ a]pyrene in prokaryotic and eukaryotic expression systems. MONATSHEFTE FUR CHEMIE 2017; 148:1959-1969. [PMID: 29104317 PMCID: PMC5653725 DOI: 10.1007/s00706-017-2002-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/14/2017] [Indexed: 11/16/2022]
Abstract
ABSTRACT Cytochrome P450 (CYP) 1A1 is the most important enzyme activating and detoxifying the human carcinogen benzo[a]pyrene (BaP). In the previous studies, we had shown that not only the canonic NADPH:CYP oxidoreductase (POR) can act as electron donor but also cytochrome b5 and its reductase, NADH:cytochrome b5 reductase. Here, we studied the role of the expression system used on the metabolites generated and the levels of DNA adducts formed by activated BaP. We used an eukaryotic and a prokaryotic cellular system (Supersomes, microsomes isolated from insect cells, and Bactosomes, a membrane fraction of Escherichia coli, each transfected with cDNA of human CYP1A1 and POR). These were reconstituted with cytochrome b5 with and without NADH:cytochrome b5 reductase. We evaluated the effectiveness of each cofactor, NADPH and NADH, to mediate BaP metabolism. We found that both systems differ in catalysing the reactions activating and detoxifying BaP. Two BaP-derived DNA adducts were generated by the CYP1A1-Supersomes, both in the presence of NADPH and NADH, whereas NADPH but not NADH was able to support this reaction in the CYP1A1-Bactosomes. Seven BaP metabolites were found in Supersomes with NADPH or NADH, whereas NADPH but not NADH was able to generate five BaP metabolites in Bactosomes. Our study demonstrates different catalytic efficiencies of CYP1A1 expressed in prokaryotic and eukaryotic cells in BaP bioactivation indicating some limitations in the use of E. coli cells for such studies. GRAPHICAL ABSTRACT
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Affiliation(s)
- Marie Stiborová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Radek Indra
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Michaela Moserová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Lucie Bořek-Dohalská
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Petr Hodek
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Eva Frei
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Klaus Kopka
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Heinz H. Schmeiser
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Volker M. Arlt
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King’s College London, London, SE1 9NH UK
- NIHR Health Protection Research Unit in Health Impact of Environmental Hazards at King’s College London in Partnership with Public Health England, London, SE1 9NH UK
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Stiborová M, Indra R, Moserová M, Frei E, Schmeiser HH, Kopka K, Philips DH, Arlt V. NADH:Cytochrome b5 Reductase and Cytochrome b5 Can Act as Sole Electron Donors to Human Cytochrome P450 1A1-Mediated Oxidation and DNA Adduct Formation by Benzo[a]pyrene. Chem Res Toxicol 2016; 29:1325-34. [PMID: 27404282 PMCID: PMC4987862 DOI: 10.1021/acs.chemrestox.6b00143] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Indexed: 11/29/2022]
Abstract
Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after activation by cytochrome P450 (P450). Here, we investigated whether NADH:cytochrome b5 reductase (CBR) in the presence of cytochrome b5 can act as sole electron donor to human P450 1A1 during BaP oxidation and replace the canonical NADPH:cytochrome P450 reductase (POR) system. We also studied the efficiencies of the coenzymes of these reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of CBR, to mediate BaP oxidation. Two systems containing human P450 1A1 were utilized: human recombinant P450 1A1 expressed with POR, CBR, epoxide hydrolase, and cytochrome b5 in Supersomes and human recombinant P450 1A1 reconstituted with POR and/or with CBR and cytochrome b5 in liposomes. BaP-9,10-dihydrodiol, BaP-7,8-dihydrodiol, BaP-1,6-dione, BaP-3,6-dione, BaP-9-ol, BaP-3-ol, a metabolite of unknown structure, and two BaP-DNA adducts were generated by the P450 1A1-Supersomes system, both in the presence of NADPH and in the presence of NADH. The major BaP-DNA adduct detected by (32)P-postlabeling was characterized as 10-(deoxyguanosin-N(2)-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-BaP (assigned adduct 1), while the minor adduct is probably a guanine adduct derived from 9-hydroxy-BaP-4,5-epoxide (assigned adduct 2). BaP-3-ol as the major metabolite, BaP-9-ol, BaP-1,6-dione, BaP-3,6-dione, an unknown metabolite, and adduct 2 were observed in the system using P450 1A1 reconstituted with POR plus NADPH. When P450 1A1 was reconstituted with CBR and cytochrome b5 plus NADH, BaP-3-ol was the predominant metabolite too, and an adduct 2 was also generated. Our results demonstrate that the NADH/cytochrome b5/CBR system can act as the sole electron donor both for the first and second reduction of P450 1A1 during the oxidation of BaP in vitro. They suggest that NADH-dependent CBR can replace NADPH-dependent POR in the P450 1A1-catalyzed metabolism of BaP.
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Affiliation(s)
- Marie Stiborová
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Radek Indra
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Michaela Moserová
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Eva Frei
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - Heinz H. Schmeiser
- Division
of Radiopharmaceutical Chemistry, German
Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Klaus Kopka
- Department
of Biochemistry, Faculty of Science, Charles
University, Albertov
2030, 128 40, Prague 2, Czech
Republic
| | - David H. Philips
- Analytical
and Environmental Sciences Division, MRC-PHE Centre for Environment
and Health, King’s College London, Franklin-Wilkins Building, 150 Stamford
Street, London SE1 9NH, United Kingdom
- NIHR
Health Protection Research Unit in Health Impact of Environmental
Hazards at King’s College London in Partnership with Public
Health England, Franklin-Wilkins
Building, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - Volker
M. Arlt
- Analytical
and Environmental Sciences Division, MRC-PHE Centre for Environment
and Health, King’s College London, Franklin-Wilkins Building, 150 Stamford
Street, London SE1 9NH, United Kingdom
- NIHR
Health Protection Research Unit in Health Impact of Environmental
Hazards at King’s College London in Partnership with Public
Health England, Franklin-Wilkins
Building, 150 Stamford Street, London SE1 9NH, United Kingdom
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Stiborová M, Indra R, Moserová M, Šulc M, Hodek P, Frei E, Schmeiser HH, Arlt VM. NADPH- and NADH-dependent metabolism of and DNA adduct formation by benzo[ a]pyrene catalyzed with rat hepatic microsomes and cytochrome P450 1A1. MONATSHEFTE FUR CHEMIE 2016; 147:847-855. [PMID: 27110038 PMCID: PMC4828493 DOI: 10.1007/s00706-016-1713-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/11/2016] [Indexed: 11/11/2022]
Abstract
ABSTRACT Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after metabolic activation by cytochrome P450 (CYP) enzymes. Here we investigated the efficiencies of rat hepatic microsomes and rat recombinant CYP1A1 expressed with its reductase, NADPH:CYP oxidoreductase (POR), NADH:cytochrome b5 reductase, epoxide hydrolase and/or cytochrome b5 in Supersomes™ to metabolize this carcinogen. We also studied the effectiveness of coenzymes of two of the microsomal reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of NADH:cytochrome b5 reductase, to mediate BaP metabolism in these systems. Up to eight BaP metabolites and two DNA adducts were generated by the systems, both in the presence of NADPH and NADH. Among BaP metabolites, BaP-9,10-dihydrodiol, BaP-4,5-dihydrodiol, BaP-7,8-dihydrodiol, BaP-1,6-dione, BaP-3,6-dione, BaP-9-ol, BaP-3-ol, and a metabolite of unknown structure were formed by hepatic microsomes and rat CYP1A1. One of two DNA adducts formed by examined enzymatic systems (rat hepatic microsomes and rat CYP1A1) was characterized to be 10-(deoxyguanosin-N2-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (dG-N2-BPDE), while another adduct has similar chromatographic properties on polyethylaneimine-cellulose thin layer chromatography to a guanine adduct derived from reaction with 9-hydroxy-BaP-4,5-oxide. In the presence of either of the reductase cofactors tested, NADPH or NADH, cytochrome b5 stimulated CYP1A1-mediated formation of both BaP-DNA adducts. The results demonstrate that NADH can act as a sole electron donor for both the first and the second reduction of CYP1A1 during its reaction cycle catalyzing oxidation of BaP, and suggest that the NADH:cytochrome b5 reductase as the NADH-dependent reductase might substitute POR in this enzymatic system. GRAPHICAL ABSTRACT
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Affiliation(s)
- Marie Stiborová
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Radek Indra
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Michaela Moserová
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Miroslav Šulc
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Petr Hodek
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Eva Frei
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Heinz H. Schmeiser
- />Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Volker M. Arlt
- />Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King’s College London, London, SE1 9NH UK
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Stiborová M, Moserová M, Černá V, Indra R, Dračínský M, Šulc M, Henderson CJ, Wolf CR, Schmeiser HH, Phillips DH, Frei E, Arlt VM. Cytochrome b5 and epoxide hydrolase contribute to benzo[a]pyrene-DNA adduct formation catalyzed by cytochrome P450 1A1 under low NADPH:P450 oxidoreductase conditions. Toxicology 2014; 318:1-12. [PMID: 24530354 DOI: 10.1016/j.tox.2014.02.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/31/2014] [Accepted: 02/04/2014] [Indexed: 10/25/2022]
Abstract
In previous studies we had administered benzo[a]pyrene (BaP) to genetically engineered mice (HRN) which do not express NADPH:cytochrome P450 oxidoreductase (POR) in hepatocytes and observed higher DNA adduct levels in livers of these mice than in wild-type mice. To elucidate the reason for this unexpected finding we have used two different settings for in vitro incubations; hepatic microsomes from control and BaP-pretreated HRN mice and reconstituted systems with cytochrome P450 1A1 (CYP1A1), POR, cytochrome b5, and epoxide hydrolase (mEH) in different ratios. In microsomes from BaP-pretreated mice, in which Cyp1a1 was induced, higher levels of BaP metabolites were formed, mainly of BaP-7,8-dihydrodiol. At a low POR:CYP1A1 ratio of 0.05:1 in the reconstituted system, the amounts of BaP diones and BaP-9-ol formed were essentially the same as at an equimolar ratio, but formation of BaP-3-ol was ∼ 1.6-fold higher. Only after addition of mEH were BaP dihydrodiols found. Two BaP-DNA adducts were formed in the presence of mEH, but only one when CYP1A1 and POR were present alone. At a ratio of POR:CYP1A1 of 0.05:1, addition of cytochrome b5 increased CYP1A1-mediated BaP oxidation to most of its metabolites indicating that cytochrome b5 participates in the electron transfer from NADPH to CYP1A1 required for enzyme activity of this CYP. BaP-9-ol was formed even by CYP1A1 reconstituted with cytochrome b5 without POR. Our results suggest that in livers of HRN mice Cyp1a1, cytochrome b5 and mEH can effectively activate BaP to DNA binding species, even in the presence of very low amounts of POR.
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Affiliation(s)
- Marie Stiborová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic.
| | - Michaela Moserová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Věra Černá
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Radek Indra
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry, v.v.i. Academy of Sciences, Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Miroslav Šulc
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Colin J Henderson
- Division of Cancer Research, Medical Research Institute, Jacqui Wood Cancer Centre, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - C Roland Wolf
- Division of Cancer Research, Medical Research Institute, Jacqui Wood Cancer Centre, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Heinz H Schmeiser
- Research Group Genetic Alterations in Carcinogenesis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - David H Phillips
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - Eva Frei
- Division of Preventive Oncology, National Center for Tumour Diseases, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Volker M Arlt
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, United Kingdom
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Waentig L, Techritz S, Jakubowski N, Roos PH. A multi-parametric microarray for protein profiling: simultaneous analysis of 8 different cytochromes via differentially element tagged antibodies and laser ablation ICP-MS. Analyst 2013; 138:6309-15. [DOI: 10.1039/c3an00468f] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Stiborová M, Indra R, Moserová M, Černá V, Rupertová M, Martínek V, Eckschlager T, Kizek R, Frei E. Cytochrome b5 Increases Cytochrome P450 3A4-Mediated Activation of Anticancer Drug Ellipticine to 13-Hydroxyellipticine Whose Covalent Binding to DNA Is Elevated by Sulfotransferases and N,O-Acetyltransferases. Chem Res Toxicol 2012; 25:1075-85. [DOI: 10.1021/tx3000335] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marie Stiborová
- Department of Biochemistry,
Faculty of Science, Charles University,
Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Radek Indra
- Department of Biochemistry,
Faculty of Science, Charles University,
Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Michaela Moserová
- Department of Biochemistry,
Faculty of Science, Charles University,
Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Věra Černá
- Department of Biochemistry,
Faculty of Science, Charles University,
Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Martina Rupertová
- Department of Biochemistry,
Faculty of Science, Charles University,
Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Václav Martínek
- Department of Biochemistry,
Faculty of Science, Charles University,
Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Tomáš Eckschlager
- Department of Pediatric Hematology
and Oncology, Charles University and University Hospital Motol, Prague, Czech Republic
| | - René Kizek
- Department of Chemistry and Biochemistry,
Faculty of Agronomy, Mendel University,
Brno, Czech Republic
| | - Eva Frei
- Division
of Preventive Oncology,
National Center for Tumor Diseases, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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Cytochrome b5 shifts oxidation of the anticancer drug ellipticine by cytochromes P450 1A1 and 1A2 from its detoxication to activation, thereby modulating its pharmacological efficacy. Biochem Pharmacol 2011; 82:669-80. [DOI: 10.1016/j.bcp.2011.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 06/03/2011] [Accepted: 06/03/2011] [Indexed: 01/19/2023]
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Bořek-Dohalská L, Stiborová M. Cytochrome P450 3A activities and their modulation by α-naphthoflavone in vitro are dictated by the efficiencies of model experimental systems. ACTA ACUST UNITED AC 2010. [DOI: 10.1135/cccc2009525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The knowledge on efficiencies of different in vitro systems containing cytochromes P450 (CYP) of a 3A subfamily is crucial to screen potential substrates of these CYPs. We evaluated and compared efficiencies of several in vitro CYP3A enzymatic systems to oxidize the model substrates, α-NF and testosterone, under the standardized experimental conditions. Five CYP3A systems were tested: (i) human hepatic microsomes rich in CYP3A4, (ii) hepatic microsomes of rabbits treated with a CYP3A6 inducer, rifampicine, (iii) microsomes of Baculovirus transfected insect cells containing recombinant human CYP3A4 and NADPH:CYP reductase with or without cytochrome b5 (SupersomesTM), (iv) membranes isolated from Escherichia coli, containing recombinant human CYP3A4, NADPH:CYP reductase and cytochrome b5, and (v) human CYP3A4 or rabbit CYP3A6 reconstituted with NADPH:CYP reductase with or without cytochrome b5 in liposomes. All systems oxidize testosterone to its 6β-hydroxylated metabolite and α-NF to trans-7,8-dihydrodiol and 5,6-epoxide. The most efficient systems oxidizing both compounds were CYP3A4-SupersomesTM containing cytochrome b5, followed by human hepatic microsomes. This finding suggests these systems to be suitable for general evaluating a variety of compounds as potential substrates of CYP3A4. The lowest efficiencies to oxidize α-NF and testosterone were found for CYP3A4 expressed in membranes of E. coli, and for reconstituted CYP3A4 or CYP3A6. Utilizing the tested enzymatic systems, we also explain here the discrepancies, which showed previously the controversial effects of α-NF on CYP3A-mediated reactions. We demonstrate that inhibition or stimulation of the CYP3A-mediated testosterone hydroxylation by α-NF is dictated by efficiencies of individual enzymatic systems to oxidize the CYP3A substrates.
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Detection of electrophoretically separated cytochromes P450 by element-labelled monoclonal antibodies via laser ablation inductively coupled plasma mass spectrometry. Anal Bioanal Chem 2008; 392:1135-47. [DOI: 10.1007/s00216-008-2242-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 06/06/2008] [Accepted: 06/10/2008] [Indexed: 10/21/2022]
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Rodríguez-Cea A, de la Campa MRF, Sanz-Medel A. Preparation of trout liver microsomes for iron speciation in P-450 enzymes by AE?FPLC with ICP?(ORS)MS detection. Anal Bioanal Chem 2004; 381:388-93. [PMID: 15578166 DOI: 10.1007/s00216-004-2766-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Revised: 07/08/2004] [Accepted: 07/12/2004] [Indexed: 11/26/2022]
Abstract
Cytochromes P-450 are members of a superfamily of hemoproteins involved in the oxidative metabolism of various physiological and xenobiotic compounds in eukaryotes and prokaryotes. The multiplicity of this group of enzymes has been widely studied by chromatographic techniques, mainly high-performance liquid chromatography (HPLC). Because these enzymes are membrane-bound proteins, sample preparation for chromatographic separation of P-450 enzymes requires a solubilization step. The sample-preparation procedures are critical, because detergents affect not only the efficiency of protein solubilization but also their further chromatographic resolution. Trout liver microsomes have been taken here as a model sample to investigate iron speciation in cytochrome P-450. Trouts were treated intraperitoneally with beta-naphthoflavone, a potent inducer of some P-450 enzymes, and a microsomal suspension containing 7.4+/-0.1 nmol mL(-1) P-450 enzymes was obtained by ultracentrifugation. Lubrol PX was selected as detergent for solubilization, resulting in about 90% solubilization recovery. The solubilized cytochromes P-450 were further separated by AE-FPLC, with UV detection, or coupled to ICP-MS with an octapole reaction system, ICP-(ORS)MS (monitoring Fe signals at masses 54, 56, and 57). A sampling procedure and chromatographic conditions are developed and were successfully applied to iron speciation in trout liver P-450 enzymes. ICP-(ORS)MS detection of P-450 enzymes is Fe-specific and so will give accurate information on the prosthetic group of the protein, which can constitute an advantageous alternative to classical methods for detection of these hemoproteins.
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Affiliation(s)
- Andrés Rodríguez-Cea
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain
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Da Silva MEF, Silva JA, Marangoni S, Novello JC, Meirelles NC. A new method to purify hepatic CYP1A of Prochilodus scrofa, a Brazilian freshwater fish. Comp Biochem Physiol C Toxicol Pharmacol 2004; 138:67-74. [PMID: 15313448 DOI: 10.1016/j.cca.2004.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Revised: 05/03/2004] [Accepted: 05/06/2004] [Indexed: 11/21/2022]
Abstract
Cytochromes P450 constitute a superfamily of the phase I enzymes whose primary task is the detoxification of both endogenous and xenobiotic compounds. Fish, among non-mammalian species, have received great interest because they are a direct food source for humans as well as conveyors of toxic chemicals to human beings. The aim of the present study was the purification of the hepatic isoform of CYP1A in Prochilodus scrofa (Prochilodontidae), a Brazilian fish, using only one chromatographic step. The purification of CYP1A was done by Reverse Phase HPLC on a C18 column. Purified CYP1A was characterized with respect to electrophoretic, immunochemical and biocatalyst properties. CYP1A fractions produced a single uniform band on SDS-PAGE with an apparent molecular mass of 58 kDa. Purified CYP1A of P. scrofa showed strong cross-reactivity with antibodies directed against CYP1A from trout. The fraction was also encapsulated in two different reconstituted systems; one composed of neutral lipids and another of negatively charged lipids. In both of them, we could detect EROD activity but not PROD activity, which confirms that the CYP1A was purified with all its enzyme activity. There was an increase of activity when CYP1A and NADPH cytochrome P450 (CYP) reductase were encapsulated in negatively charged lipids, which confirms that the charge of lipid is essential to CYP1A activity. All these characteristics strongly suggest that this new procedure is efficient for purifying hepatic CYP1A from P. scrofa, showing that the CYP1A isoform of this fish has a highly conserved protein region.
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Affiliation(s)
- M E F Da Silva
- Laboratory of Biomembranes, Department of Biochemistry, Institute of Biology, State University of Campinas, CP 6109, Cidade Universitária Zeferino Vaz, Barão Geraldo, 13083-970 Campinas, SP, Brazil
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Hydroxyapatite Chromatography. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0301-4770(08)60533-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Ion Exchange Chromatography. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0301-4770(08)60529-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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