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Yadav A, Kesharwani A, Chaurasia DK, Katara P. Mining of molecular insights of CYP2A6 and its variants complex with coumarin (CYP2A6*-coumarin) using molecular dynamics simulation. J Biomol Struct Dyn 2023; 41:4081-4092. [PMID: 35427216 DOI: 10.1080/07391102.2022.2062785] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/02/2022] [Indexed: 10/18/2022]
Abstract
CYP2A6 is a very important enzyme that plays a crucial role in nicotine compounds and is responsible for the metabolism of more than 3% drugs of total metabolized drugs by the CYP family and reported as one of very important pharmacogenes. CYP2A6 is highly polymorphic in nature and reported with more than 40 variants, most of these variants are SNPs originated and population specific. It has been well observed and reported that the presence of these population-specific non-synonymous SNPs in CYP2A6 alters the rate of drug metabolism and as a functional consequence, drugs produce an abnormal response. Though genomics and pharmacogenomics studies are there, very less is known about the structural effects of these SNPs on molecular-interaction and folding of CYP2A6. To fill the knowledge gap, SNPs based four variants, i.e., CYP2A6*2, CYP2A6*18, CYP2A6*21, and CYP2A6*35, which are frequently reported in the South Asian population, were considered for the study. Coumarin (DB04665), a well reported drug, is considered as a model substance, and the effect of all four variants on 'CYP2A6*-coumarin' complex was studied. MD simulation-based analysis (at 200 ns) was performed and comparative analysis with respect to wild type 'CYP2A6-coumarin' complex was done. Though observation didn't find any global effect on complete complex but found some crucial minor-local alteration in interaction and folding process. It is assumed that the change due to SNPs in the single amino acid did not bring global change in physiochemical properties of CYP2A6* but caused local-trivial changes which are very crucial for its metabolic activity.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Anamika Yadav
- Computational omics Lab, Centre of Bioinformatics, University of Allahabad, Prayagraj, India
| | - Akanksha Kesharwani
- Computational omics Lab, Centre of Bioinformatics, University of Allahabad, Prayagraj, India
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Dheeraj Kumar Chaurasia
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Pramod Katara
- Computational omics Lab, Centre of Bioinformatics, University of Allahabad, Prayagraj, India
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Lee YB, Kim V, Lee SG, Lee GH, Kim C, Jeong E, Kim D. Functional Characterization of Allelic Variations of Human Cytochrome P450 2C8 (V181I, I244V, I331T, and L361F). Int J Mol Sci 2023; 24:ijms24098032. [PMID: 37175734 PMCID: PMC10178350 DOI: 10.3390/ijms24098032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
The human cytochrome P450 2C8 is responsible for the metabolism of various clinical drugs as well as endogenous fatty acids. Allelic variations can significantly influence the metabolic outcomes. In this study, we characterize the functional effects of four nonsynonymous single nucleotide polymorphisms *15, *16, *17, and *18 alleles recently identified in cytochrome P450 2C8. The recombinant allelic variant enzymes V181I, I244V, I331T, and L361F were successfully expressed in Escherichia coli and purified. The steady-state kinetic analysis of paclitaxel 6-hydroxylation revealed a significant reduction in the catalytic activities of the V181I, I244V, and L361F variants. The calculated catalytic efficiency (kcat/Km) of these variants was 5-26% of that of the wild-type enzyme. The reduced activities were due to both decreased kcat values and increased Km values of the variants. The epoxidation of arachidonic acid by the variants was analyzed. The L361F variant only exhibited 4-6% of the wild-type catalytic efficiency in ω-9- and ω-6-epoxidation reactions to produce 11,12-epoxyeicosatrienoic acid (EET) and 14,15-EET, respectively. These reductions were mainly due to a decrease in the kcat value of the L361F variant. The binding titration analysis of paclitaxel and arachidonic acid showed that all variants had similar affinities to those of the wild-type (10-14 μM for paclitaxel and 20-49 μM for arachidonic acid). The constructed paclitaxel docking model of the variant enzyme suggests that the L361F substitution leads to the incorrect orientation of paclitaxel in the active site, with the 6'C of paclitaxel displaced from the productive catalytic location. This study suggests that individuals carrying the newly identified P450 2C8 allelic variations are likely to have an altered metabolism of clinical medicines and production of fatty acid-derived signal molecules.
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Affiliation(s)
- Yoo-Bin Lee
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Sung-Gyu Lee
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Gyu-Hyeong Lee
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Changmin Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Eunseo Jeong
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
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Shimada T, Nagayoshi H, Murayama N, Sawai A, Kim V, Kim D, Yamazaki H, Guengerich FP, Takenaka S. Oxidation of 3'-methoxyflavone, 4'-methoxyflavone, and 3',4'-dimethoxyflavone and their derivatives having 5,7-dihydroxyl moieties by human cytochromes P450 1B1 and 2A13. Xenobiotica 2022; 52:134-145. [PMID: 35387543 PMCID: PMC9896170 DOI: 10.1080/00498254.2022.2062486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Oxidation of 3'-methoxyflavone, 4'-methoxyflavone, and 3',4'-dimethoxyflavone and their derivatives containing 5,7-dihydroxyl groups by human cytochrome P450 (P450 or CYP) 1B1 and 2A13 was determined using LC-MS/MS systems.3'-Methoxyflavone and 4'-methoxyflavone were mainly O-demethylated to form 3'-hydroxyflavone and 4'-hydroxyflavone, respectively, and then 3',4'-dihydroxyflavone at higher rates with CYP1B1 than with CYP2A13. 4'-Methoxy-5,7-dihydroxyflavone (acacetin) was found to be demethylated by CYP1B1 and 2A13 to form 4',5,7-trihydroxyflavone (apigenin) at rates of 0.098-1 and 0.42 min-1, respectively. 3'-Methoxy-5,7-dihydroxyflavone was also demethylated by both P450s, with CYP2A13 being more active.3',4'-Dimethoxyflavone was a good substrate for CYP1B1 but not for CYP2A13 and was found to be mainly O-demethylated to form 3',4'-dihydroxyflavone (at a rate of 4.2 min-1) and also several ring-oxygenated products having m/z 299 fragments. Molecular docking analysis supported the proper orientation for formation of these products by CYP1B1.Our present results showed that 3'- and 4'-methoxyflavone can be oxidised to their O-demethylated products and, to a lesser extent, to ring oxidation products by both P450s 1B1 and 2A13 and that 3',4'-dimethoxyflavone is a good substrate for CYP1B1 in forming both O-demethylated and ring-oxidation products. Introduction of a 57diOHF moiety into these methoxylated flavonoids caused decreased in oxidation by CYP1B1 and 2A13.
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Affiliation(s)
- Tsutomu Shimada
- Department of Clinical Nutrition, Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan
| | - Haruna Nagayoshi
- Laboratory of Food Sanitation, Osaka Institute of Public Health, Osaka, Japan
| | - Norie Murayama
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | - Atsuki Sawai
- Department of Clinical Nutrition, Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | - F. Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Shigeo Takenaka
- Department of Clinical Nutrition, Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan
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Nagayoshi H, Murayama N, Takenaka S, Kim V, Kim D, Komori M, Yamazaki H, Guengerich FP, Shimada T. Roles of cytochrome P450 2A6 in the oxidation of flavone, 4'-hydroxyflavone, and 4'-, 3'-, and 2'-methoxyflavones by human liver microsomes. Xenobiotica 2021; 51:995-1009. [PMID: 34224301 DOI: 10.1080/00498254.2021.1950866] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nine forms of recombinant cytochrome P450 (P450 or CYP) enzymes were used to study roles of individual P450 enzymes in the oxidation of flavone and some other flavonoids, 4'-hydroxyflavone and 4'-, 3'-, and 2'-methoxyflavones, by human liver microsomes using LC-MS/MS analysis.As has been reported previously , 4'-, 3'-, and 2'-methoxyflavones were preferentially O-demethylated by human liver P450 enzymes to form 4'-, 3'-, and 2'-hydroxylated flavones and also 3',4'-dihydroxyflavone from the former two substrates.In comparisons of product formation by oxidation of these methoxylated flavones, CYP2A6 was found to be a major enzyme catalysing flavone 4'- and 3'-hydroxylations by human liver microsomes but did not play significant roles in 2'-hydroxylation of flavone, O-demethylations of three methoxylated flavones, and the oxidation of 4'-hydroxyflavone to 3',4'-dihydroxyflavone.The effects of anti-CYP2A6 IgG and chemical P450 inhibitors suggested that different P450 enzymes, as well as CYP2A6, catalysed oxidation of these flavonoids at different positions by liver microsomes.These studies suggest that CYP2A6 catalyses flavone 4'- and 3'-hydroxylations in human liver microsomes and that other P450 enzymes have different roles in oxidizing these flavonoids.
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Affiliation(s)
- Haruna Nagayoshi
- Laboratory of Food Sanitation, Osaka Institute of Public Health, Osaka, Japan
| | - Norie Murayama
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | - Shigeo Takenaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Masayuki Komori
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Tsutomu Shimada
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan.,Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
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Murphy SE. Biochemistry of nicotine metabolism and its relevance to lung cancer. J Biol Chem 2021; 296:100722. [PMID: 33932402 PMCID: PMC8167289 DOI: 10.1016/j.jbc.2021.100722] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/27/2022] Open
Abstract
Nicotine is the key addictive constituent of tobacco. It is not a carcinogen, but it drives smoking and the continued exposure to the many carcinogens present in tobacco. The investigation into nicotine biotransformation has been ongoing for more than 60 years. The dominant pathway of nicotine metabolism in humans is the formation of cotinine, which occurs in two steps. The first step is cytochrome P450 (P450, CYP) 2A6–catalyzed 5′-oxidation to an iminium ion, and the second step is oxidation of the iminium ion to cotinine. The half-life of nicotine is longer in individuals with low P450 2A6 activity, and smokers with low activity often decrease either the intensity of their smoking or the number of cigarettes they use compared with those with “normal” activity. The effect of P450 2A6 activity on smoking may influence one's tobacco-related disease risk. This review provides an overview of nicotine metabolism and a summary of the use of nicotine metabolite biomarkers to define smoking dose. Some more recent findings, for example, the identification of uridine 5′-diphosphoglucuronosyltransferase 2B10 as the catalyst of nicotine N-glucuronidation, are discussed. We also describe epidemiology studies that establish the contribution of nicotine metabolism and CYP2A6 genotype to lung cancer risk, particularly with respect to specific racial/ethnic groups, such as those with Japanese, African, or European ancestry. We conclude that a model of nicotine metabolism and smoking dose could be combined with other lung cancer risk variables to more accurately identify former smokers at the highest risk of lung cancer and to intervene accordingly.
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Affiliation(s)
- Sharon E Murphy
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA.
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Shimada T, Nagayoshi H, Murayama N, Takenaka S, Katahira J, Kim V, Kim D, Komori M, Yamazaki H, Guengerich FP. Liquid chromatography-tandem mass spectrometry analysis of oxidation of 2'-, 3'-, 4'- and 6-hydroxyflavanones by human cytochrome P450 enzymes. Xenobiotica 2020; 51:139-154. [PMID: 33047997 DOI: 10.1080/00498254.2020.1836433] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
2'-Hydroxyflavanone (2'OHFva), 3'OHFva, 4'OHFva, and 6OHFva, the major oxidative products of flavanone by human cytochrome P450 (P450, CYP) enzymes, were studied in regard to further oxidation by human CYP1A1, 1A2, 1B1.1, 1B1.3, and 2A6. The products formed were analyzed with LC-MS/MS and characterized by their positive ion fragmentations on mass spectrometry. Several di-hydroxylated flavanone (diOHFva) and di-hydroxylated flavone (diOHFvo) products, detected by analyzing parent ions at m/z 257 and 255, respectively, were found following incubation of these four hydroxylated flavanones with P450s. The m/z 257 products were produced at higher levels than the latter with four substrates examined. The structures of the m/z 257 products were characterized by LC-MS/MS product ion spectra, and the results suggest that 3'OHFva and 4'OHFva are further oxidized mainly at B-ring by P450s while 6OHFva oxidation was at A-ring. Different diOHFvo products (m/z 255) were also characterized by LC-MS/MS, and the results suggested that most of these diOHFvo products were formed through oxidation or desaturation of the diOHFva products (m/z 257) by P450s. Only when 4'OHFva (m/z 241) was used as a substrate, formation of 4'OHFvo (m/z 239) was detected, indicating that diOHFvo might also be formed through oxidation of 4'OHFvo by P450s. Finally, our results indicated that CYP1 family enzymes were more active than CYP2A6 in catalyzing the oxidation of these four hydroxylated flavanones, and these findings were supported by molecular docking studies of these chemicals with active sites of P450 enzymes.
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Affiliation(s)
- Tsutomu Shimada
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Haruna Nagayoshi
- Division of Food Sanitation, Osaka Institute of Public Health, Osaka, Japan
| | - Norie Murayama
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | - Shigeo Takenaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan
| | - Jun Katahira
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Masayuki Komori
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
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Nagayoshi H, Murayama N, Tsujino M, Takenaka S, Katahira J, Kim V, Kim D, Komori M, Yamazaki H, Guengerich FP, Shimada T. Preference for O-demethylation reactions in the oxidation of 2'-, 3'-, and 4'-methoxyflavones by human cytochrome P450 enzymes. Xenobiotica 2020; 50:1158-1169. [PMID: 32312164 DOI: 10.1080/00498254.2020.1759157] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
2'-, 3'-, and 4'-Methoxyflavones (MeFs) were incubated with nine forms of recombinant human cytochrome P450 (P450 or CYP) enzymes in the presence of an NADPH-generating system and the products formed were analyzed with LC-MS/MS methods.CYP1B1.1 and 1B1.3 were highly active in demethylating 4'MeF to form 4'-hydroxyflavone (rate of 5.0 nmol/min/nmol P450) and further to 3',4'-dihydroxyflavone (rates of 2.1 and 0.66 nmol/min/nmol P450, respectively). 3'MeF was found to be oxidized by P450s to m/z 239 (M-14) products (presumably 3'-hydroxyflavone) and then to 3',4'-dihydroxyflavone. P450s also catalyzed oxidation of 2'MeF to m/z 239 (M-14) and m/z 255 (M-14, M-14 + 16) products, presumably mono- and di-hydroxylated products, respectively.At least two types of ring oxidation products having m/z 269 fragments were formed, although at slower rates than the formation of mono- and di-hydroxylated products, on incubation of these MeFs with P450s; one type was products oxidized at the C-ring, having m/z 121 fragments, and the other one was the products oxidized at the A-ring (having m/z 137 fragments).Molecular docking analysis indicated the preference of interaction of O-methoxy moiety of methoxyflavones in the active site of CYP1A2.These results suggest that 2'-, 3'-, and 4'-methoxyflavones are principally demethylated by human P450s to form mono- and di-hydroxyflavones and that direct oxidation occurs in these MeFs to form mono-hydroxylated products, oxidized at the A- or B-ring of MeF.
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Affiliation(s)
| | - Norie Murayama
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | | | - Shigeo Takenaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino, Osaka, Japan
| | - Jun Katahira
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea, and
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea, and
| | - Masayuki Komori
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Tsutomu Shimada
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
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Nagayoshi H, Murayama N, Kakimoto K, Tsujino M, Takenaka S, Katahira J, Lim YR, Kim D, Yamazaki H, Komori M, Guengerich FP, Shimada T. Oxidation of Flavone, 5-Hydroxyflavone, and 5,7-Dihydroxyflavone to Mono-, Di-, and Tri-Hydroxyflavones by Human Cytochrome P450 Enzymes. Chem Res Toxicol 2019; 32:1268-1280. [PMID: 30964977 DOI: 10.1021/acs.chemrestox.9b00078] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Biologically active plant flavonoids, including 5,7-dihydroxyflavone (57diOHF, chrysin), 4',5,7-trihydroxyflavone (4'57triOHF, apigenin), and 5,6,7-trihydroxyflavone (567triOHF, baicalein), have important pharmacological and toxicological significance, e.g., antiallergic, anti-inflammatory, antioxidative, antimicrobial, and antitumorgenic properties. In order to better understand the metabolism of these flavonoids in humans, we examined the oxidation of flavone, 5-hydroxyflavone (5OHF), and 57diOHF to various products by human cytochrome P450 (P450 or CYP) and liver microsomal enzymes. Individual human P450s and liver microsomes oxidized flavone to 6-hydroxyflavone, small amounts of 5OHF, and 11 other monohydroxylated products at different rates and also produced several dihydroxylated products (including 57diOHF and 7,8-dihydroxyflavone) from flavone. We also found that 5OHF was oxidized by several P450 enzymes and human liver microsomes to 57diOHF and further to 567triOHF, but the turnover rates in these reactions were low. Interestingly, both CYP1B1.1 and 1B1.3 converted 57diOHF to 567triOHF at turnover rates (on the basis of P450 contents) of >3.0 min-1, and CYP1A1 and 1A2 produced 567triOHF at rates of 0.51 and 0.72 min-1, respectively. CYP2A13 and 2A6 catalyzed the oxidation of 57diOHF to 4'57triOHF at rates of 0.7 and 0.1 min-1, respectively. Our present results show that different P450s have individual roles in oxidizing these phytochemical flavonoids and that these reactions may cause changes in their biological and toxicological properties in mammals.
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Affiliation(s)
- Haruna Nagayoshi
- Osaka Institute of Public Health , 1-3-69 Nakamichi , Higashinari-ku , Osaka 537-0025 , Japan
| | - Norie Murayama
- Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo 194-8543 , Japan
| | - Kensaku Kakimoto
- Osaka Institute of Public Health , 1-3-69 Nakamichi , Higashinari-ku , Osaka 537-0025 , Japan
| | - Masaki Tsujino
- Osaka Institute of Public Health , 1-3-69 Nakamichi , Higashinari-ku , Osaka 537-0025 , Japan
| | - Shigeo Takenaka
- Graduate School of Comprehensive Rehabilitation , Osaka Prefecture University , 3-7-30 , Habikino , Osaka 583-8555 , Japan
| | - Jun Katahira
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences , Osaka Prefecture University , 1-58 Rinku-Orai-Kita , Izumisano , Osaka 598-8531 , Japan
| | - Young-Ran Lim
- Department of Biological Sciences , Konkuk University , Seoul 05029 , Korea
| | - Donghak Kim
- Department of Biological Sciences , Konkuk University , Seoul 05029 , Korea
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo 194-8543 , Japan
| | - Masayuki Komori
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences , Osaka Prefecture University , 1-58 Rinku-Orai-Kita , Izumisano , Osaka 598-8531 , Japan
| | - F Peter Guengerich
- Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , Tennessee 37232-0146 , United States
| | - Tsutomu Shimada
- Laboratory of Cellular and Molecular Biology, Veterinary Sciences , Osaka Prefecture University , 1-58 Rinku-Orai-Kita , Izumisano , Osaka 598-8531 , Japan
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Nagayoshi H, Murayama N, Kakimoto K, Takenaka S, Katahira J, Lim YR, Kim V, Kim D, Yamazaki H, Komori M, Guengerich FP, Shimada T. Site-specific oxidation of flavanone and flavone by cytochrome P450 2A6 in human liver microsomes. Xenobiotica 2018; 49:791-802. [PMID: 30048196 DOI: 10.1080/00498254.2018.1505064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The roles of human cytochrome P450 (P450 or CYP) 2A6 in the oxidation of flavanone [(2R)- and (2S)-enantiomers] and flavone were studied in human liver microsomes and recombinant human P450 enzymes. CYP2A6 was highly active in oxidizing flavanone to form flavone, 2'-hydroxy-, 4'-, and 6-hydroxyflavanones and in oxidizing flavone to form mono- and di-hydroxylated products, such as mono-hydroxy flavones M6, M7, and M11 and di-hydroxy flavones M3, M4, and M5. Liver microsomes prepared from human sample HH2, defective in coumarin 7-hydroxylation activity, were very inefficient in forming 2'-hydroxyflavanone from flavanone and a mono-hydroxylated product, M6, from flavone. Coumarin and anti-CYP2A6 antibodies strongly inhibited the formation of these metabolites in microsomes prepared from liver samples HH47 and 54, which were active in coumarin oxidation activities. Molecular docking analysis showed that the C2'-position of (2R)-flavanone (3.8 Å) was closer to the iron center of CYP2A6 than the C6-position (10 Å), while distances from C2' and C6 of (2S)-flavanone to the CYP2A6 were 6.91 Å and 5.42 Å, respectively. These results suggest that CYP2A6 catalyzes site-specific oxidation of (racemic) flavanone and also flavone in human liver microsomes. CYP1A2 and CYP2B6 were also found to play significant roles in some of the oxidations of these flavonoids by human liver microsomes.
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Affiliation(s)
| | - Norie Murayama
- b Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo , Japan
| | | | - Shigeo Takenaka
- c Graduate School of Comprehensive Rehabilitation , Osaka Prefecture University , Habikino Osaka , Japan
| | - Jun Katahira
- d Laboratory of Cellular and Molecular Biology , Veterinary Sciences, Osaka Prefecture University , Izumisano , Osaka , Japan
| | - Young-Ran Lim
- e Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Vitchan Kim
- e Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Donghak Kim
- e Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Hiroshi Yamazaki
- b Laboratory of Drug Metabolism and Pharmacokinetics , Showa Pharmaceutical University , Machida , Tokyo , Japan
| | - Masayuki Komori
- d Laboratory of Cellular and Molecular Biology , Veterinary Sciences, Osaka Prefecture University , Izumisano , Osaka , Japan
| | - F Peter Guengerich
- f Department of Biochemistry Vanderbilt University School of Medicine , Nashville , Tennessee , USA
| | - Tsutomu Shimada
- d Laboratory of Cellular and Molecular Biology , Veterinary Sciences, Osaka Prefecture University , Izumisano , Osaka , Japan
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10
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Lee Y, Park HG, Kim V, Cho MA, Kim H, Ho TH, Cho KS, Lee IS, Kim D. Inhibitory effect of α-terpinyl acetate on cytochrome P450 2B6 enzymatic activity. Chem Biol Interact 2018; 289:90-97. [PMID: 29723517 DOI: 10.1016/j.cbi.2018.04.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/16/2018] [Accepted: 04/25/2018] [Indexed: 10/17/2022]
Abstract
Human cytochrome P450 2B6 is an important hepatic enzyme for the metabolism of xenobiotics and clinical drugs. Recently, more attention has been paid to P450 2B6 because of the increasing number of drugs it metabolizes. It has been known to interact with terpenes, the major constituents of the essential oils used for various medicinal purposes. In this study, the effect of monoterpenes on P450 2B6 catalytic activity was investigated. Recombinant P450 2B6 was expressed in Escherichia coli and purified using Ni-affinity chromatography. The purified P450 2B6 enzyme displayed bupropion hydroxylation activity in gas-mass spectrometry (GC-MS) analysis with a kcat of 0.5 min-1 and a Km of 47 μM. Many terpenes displayed the type I binding spectra to purified P450 2B6 enzyme and α-terpinyl acetate showed strong binding affinity with a Kd value of 5.4 μM. In GC-MS analysis, P450 2B6 converted α-terpinyl acetate to a putative oxidative product. The bupropion hydroxylation activity of P450 2B6 was inhibited by α-terpinyl acetate and its IC50 value was 10.4 μM α-Terpinyl acetate was determined to be a competitive inhibitor of P450 2B6 with a Ki value of 7.6 μM. The molecular docking model of the binding site of the P450 2B6 complex with α-terpinyl acetate was constructed. It showed the tight binding of α-terpinyl acetate in the active site of P450 2B6, which suggests that it could be a competitive substrate for P450 2B6.
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Affiliation(s)
- Yejin Lee
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Myung-A Cho
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Harim Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Thien-Hoang Ho
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Kyoung Sang Cho
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Im-Soon Lee
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025 Republic of Korea.
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11
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Kim V, Yeom S, Lee Y, Park HG, Cho MA, Kim H, Kim D. In vitro functional analysis of human cytochrome P450 2A13 genetic variants: P450 2A13*2, *3, *4, and *10. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2018; 81:493-501. [PMID: 29652224 DOI: 10.1080/15287394.2018.1460784] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Humans possess three cytochrome P450 enzymes in the 2A subfamily (2A6, 2A7, and 2A13). P450 2A13 is mainly expressed in the human trachea and lung, whereas P450 2A6 is found in human liver. The P450 2A13 enzyme may be considered as the primary enzyme responsible for metabolic activation of many tobacco-specific carcinogens. Genetic variations significantly influence the toxicological consequences attributed to tobacco smoking. The aim of this study was to examine the in vitro functional activities of five P450 2A13 genetic variations (R257C, 133_134insT, R101Q, I331T, and R257C/I331T) in P450 2A13*2, *3, *4, and *10 alleles. Mutant clones were constructed and their recombinant enzymes were expressed in Escherichia coli. P450 2A13 mutants containing R257C, 133_134insT, I331T, and R257C/I331T displayed P450 holoenzyme spectra. The R101Q mutant was not apparently expressed. P450 2A13 enzymes displayed the typical type I binding spectra to coumarin and the calculated binding affinities of R257C, R257C/I331T, and 133_134insT mutants were decreased approximately three- to sevenfold. In catalytic analyses of purified mutant enzymes for coumarin and nicotine, the R257C and I331T mutants exhibited lower kcat values with catalytic efficiencies reduced up to approximately 20%. The double mutation of R257C/I331T induced increased Km values and diminished kcat values that resulted in >50% decrease in catalytic efficiencies. For 133_134insT mutant, catalytic activities were not markedly saturated but the measured rates at the highest concentrations were significantly lower than those of the wild-type or other mutant enzymes. Functional analysis of these variations in P450 2A13 allelic variants may help to understand the consequences of P450 2A13 polymorphism in bioactivation of many tobacco-derived carcinogens.
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Affiliation(s)
- Vitchan Kim
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Sora Yeom
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Yejin Lee
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Hyoung-Goo Park
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Myung-A Cho
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Harim Kim
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Donghak Kim
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
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12
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Kakimoto K, Murayama N, Takenaka S, Nagayoshi H, Lim YR, Kim V, Kim D, Yamazaki H, Komori M, Guengerich FP, Shimada T. Cytochrome P450 2A6 and other human P450 enzymes in the oxidation of flavone and flavanone. Xenobiotica 2018; 49:131-142. [PMID: 29310511 DOI: 10.1080/00498254.2018.1426133] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
1. We previously reported that flavone and flavanone interact spectrally with cytochrome P450 (P450 or CYP) 2A6 and 2A13 and other human P450s and inhibit catalytic activities of these P450 enzymes. In this study, we studied abilities of CYP1A1, 1A2, 1B1, 2A6, 2A13, 2C9 and 3A4 to oxidize flavone and flavanone. 2. Human P450s oxidized flavone to 6- and 5-hydroxylated flavones, seven uncharacterized mono-hydroxylated flavones, and five di-hydroxylated flavones. CYP2A6 was most active in forming 6-hydroxy- and 5-hydroxyflavones and several mono- and di-hydroxylated products. 3. CYP2A6 was also very active in catalyzing flavanone to form 2'- and 6-hydroxyflavanones, the major products, at turnover rates of 4.8 min-1 and 1.3 min-1, respectively. Other flavanone metabolites were 4'-, 3'- and 7-hydroxyflavanone, three uncharacterized mono-hydroxylated flavanones and five mono-hydroxylated flavones, including 6-hydroxyflavone. CYP2A6 catalyzed flavanone to produce flavone at a turnover rate of 0.72 min-1 that was ∼3-fold higher than that catalyzed by CYP2A13 (0.29 min-1). 4. These results indicate that CYP2A6 and other human P450s have important roles in metabolizing flavone and flavanone, two unsubstituted flavonoids, present in dietary foods. Chemical mechanisms of P450-catalyzed desaturation of flavanone to form flavone are discussed.
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Affiliation(s)
- Kensaku Kakimoto
- a Osaka Institute of Public Health , Higashinari-ku , Osaka , Japan
| | - Norie Murayama
- b Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University , Machida , Tokyo , Japan
| | - Shigeo Takenaka
- c Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University , Habikino , Osaka , Japan
| | - Haruna Nagayoshi
- a Osaka Institute of Public Health , Higashinari-ku , Osaka , Japan
| | - Young-Ran Lim
- d Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Vitchan Kim
- d Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Donghak Kim
- d Department of Biological Sciences , Konkuk University , Seoul , Korea
| | - Hiroshi Yamazaki
- b Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University , Machida , Tokyo , Japan
| | - Masayuki Komori
- e Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University , Izumisano , Osaka , Japan , and
| | - F Peter Guengerich
- f Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , TN , USA
| | - Tsutomu Shimada
- e Laboratory of Cellular and Molecular Biology, Veterinary Sciences, Osaka Prefecture University , Izumisano , Osaka , Japan , and
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13
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Shimada T, Murayama N, Kakimoto K, Takenaka S, Lim YR, Yeom S, Kim D, Yamazaki H, Guengerich FP, Komori M. Oxidation of 1-chloropyrene by human CYP1 family and CYP2A subfamily cytochrome P450 enzymes: catalytic roles of two CYP1B1 and five CYP2A13 allelic variants. Xenobiotica 2017. [PMID: 28648140 DOI: 10.1080/00498254.2017.1347306] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
1. 1-Chloropyrene, one of the major chlorinated polycyclic aromatic hydrocarbon contaminants, was incubated with human cytochrome P450 (P450 or CYP) enzymes including CYP1A1, 1A2, 1B1, 2A6, 2A13, 2B6, 2C9, 2D6, 2E1, 3A4 and 3A5. Catalytic differences in 1-chloropyrene oxidation by polymorphic two CYP1B1 and five CYP2A13 allelic variants were also examined. 2. CYP1A1 oxidized 1-chloropyrene at the 6- and 8-positions more actively than at the 3-position, while both CYP1B1.1 and 1B1.3 preferentially catalyzed 6-hydroxylation. 3. Five CYP2A13 allelic variants oxidized 8-hydroxylation much more than 6- and 3-hydroxylation, and the variant CYP2A13.3 was found to slowly catalyze these reactions with a lower kcat value than other CYP2A13.1 variants. 4. CYP2A6 catalyzed 1-chloropyrene 6-hydroxylation at a higher rate than the CYP2A13 enzymes, but the rate was lower than the CYP1A1 and 1B1 variants. Other human P450 enzymes had low activities towards 1-chloropyrene. 5. Molecular docking analysis suggested differences in the interaction of 1-chloropyrene with active sites of CYP1 and 2 A enzymes. In addition, a naturally occurring Thr134 insertion in CYP2A13.3 was found to affect the orientation of Asn297 in the I-helix in interacting with 1-chloropyrene (and also 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, NNK) and caused changes in the active site of CYP2A13.3 as compared with CYP2A13.1.
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Affiliation(s)
- Tsutomu Shimada
- a Laboratory of Cellular and Molecular Biology, Osaka Prefecture University , Osaka , Japan
| | - Norie Murayama
- b Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University , Machida , Tokyo
| | | | - Shigeo Takenaka
- d Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University , Osaka , Japan
| | - Young-Ran Lim
- e Department of Biological Sciences , Konkuk University , Seoul , Korea , and
| | - Sora Yeom
- e Department of Biological Sciences , Konkuk University , Seoul , Korea , and
| | - Donghak Kim
- e Department of Biological Sciences , Konkuk University , Seoul , Korea , and
| | - Hiroshi Yamazaki
- b Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University , Machida , Tokyo
| | - F Peter Guengerich
- f Department of Biochemistry , Vanderbilt University School of Medicine , Nashville, TN , USA
| | - Masayuki Komori
- a Laboratory of Cellular and Molecular Biology, Osaka Prefecture University , Osaka , Japan
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14
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Hosono H, Kumondai M, Maekawa M, Yamaguchi H, Mano N, Oda A, Hirasawa N, Hiratsuka M. Functional Characterization of 34 CYP2A6 Allelic Variants by Assessment of Nicotine C-Oxidation and Coumarin 7-Hydroxylation Activities. Drug Metab Dispos 2016; 45:279-285. [PMID: 27974382 DOI: 10.1124/dmd.116.073494] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 12/13/2016] [Indexed: 11/22/2022] Open
Abstract
CYP2A6, a member of the cytochrome P450 (P450) family, is one of the enzymes responsible for the metabolism of therapeutic drugs and such tobacco components as nicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and N-nitrosodiethylamine. Genetic polymorphisms in CYP2A6 are associated with individual variation in smoking behavior, drug toxicities, and the risk of developing several cancers. In this study, we conducted an in vitro analysis of 34 allelic variants of CYP2A6 using nicotine and coumarin as representative CYP2A6 substrates. These variant CYP2A6 proteins were heterologously expressed in 293FT cells, and their enzymatic activities were assessed on the basis of nicotine C-oxidation and coumarin 7-hydroxylation activities. Among the 34 CYP2A6 variants, CYP2A6.2, CYP2A6.5, CYP2A6.6, CYP2A6.10, CYP2A6.26, CYP2A6.36, and CYP2A6.37 exhibited no enzymatic activity, whereas 14 other variants exhibited markedly reduced activity toward both nicotine and coumarin. These comprehensive in vitro findings may provide useful insight into individual differences in smoking behavior, drug efficacy, and cancer susceptibility.
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Affiliation(s)
- Hiroki Hosono
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
| | - Masaki Kumondai
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
| | - Masamitsu Maekawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
| | - Hiroaki Yamaguchi
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
| | - Nariyasu Mano
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
| | - Akifumi Oda
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
| | - Noriyasu Hirasawa
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (H.H., M.K., N.H., M.H.), Department of Pharmaceutical Sciences, Tohoku University Hospital, Sendai, Japan (M.M., H.Y., N.M.), Department of Biophysical Chemistry, Faculty of Pharmacy, Meijo University, Nagoya, Japan (A.O.)
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15
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Biochemical analysis of recombinant CYP4A11 allelic variant enzymes: W126R, K276T and S353G. Drug Metab Pharmacokinet 2016; 31:445-450. [DOI: 10.1016/j.dmpk.2016.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 08/09/2016] [Accepted: 09/12/2016] [Indexed: 11/19/2022]
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16
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Condoluci A, Mazzara C, Zoccoli A, Pezzuto A, Tonini G. Impact of smoking on lung cancer treatment effectiveness: a review. Future Oncol 2016; 12:2149-61. [PMID: 27424719 DOI: 10.2217/fon-2015-0055] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tobacco smoke contains more than 4000 detectable substances, such as polycyclic aromatic hydrocarbons, nicotine, carbon monoxide and heavy metals, which are considered powerful enzymatic inducers that have notable influence on the efficacy and tolerability of many medications through complex pharmacokinetic and pharmacodynamic interactions. As a result, adjustments of drug dosages are required in smokers, both if they continue to smoke or if they quit after smoking cessation treatment. The purpose of this review is to examine the main drug interactions with tobacco smoke clinically relevant, with a closer look on patients developing oncologic diseases.
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Affiliation(s)
| | - Calogero Mazzara
- Department of Oncology, University Campus Bio-Medico of Rome, Rome, Italy
| | - Alice Zoccoli
- Department of Oncology, University Campus Bio-Medico of Rome, Rome, Italy
| | - Aldo Pezzuto
- Cardiovascular & Pulmonary Department, Sant'Andrea Hospital, Sapienza University, Rome, Italy
| | - Giuseppe Tonini
- Department of Oncology, University Campus Bio-Medico of Rome, Rome, Italy
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17
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Wassenaar CA, Zhou Q, Tyndale RF. CYP2A6 genotyping methods and strategies using real-time and end point PCR platforms. Pharmacogenomics 2015; 17:147-62. [PMID: 26670214 DOI: 10.2217/pgs.15.156] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CYP2A6 genotyping is of clinical importance--CYP2A6 gene variants influence nicotine metabolism and are associated with nicotine dependence, cigarettes per day, smoking cessation and the risk for tobacco-associated cancers. CYP2A6 gene variants also influence the metabolism of therapeutic drugs, such as the anticancer agents, tegafur and letrozole. Over the years, CYP2A6 genotyping methods have evolved to incorporate novel gene variants and to circumvent genotyping errors resulting from the high degree of homology between CYP2A6 and neighboring CYP2A genes. Herein, CYP2A6 genotyping strategies are described for commonly genotyped functionally significant alleles including SNPs, small insertions/deletions and more complex structural variants. The methods presented utilize higher throughput SYBR green real-time PCR technology in addition to standard thermocycling.
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Affiliation(s)
- Catherine A Wassenaar
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
| | - Qian Zhou
- Department of Pharmacology & Toxicology, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
| | - Rachel F Tyndale
- Campbell Family Mental Health Research Institute, Centre for Addiction & Mental Health (CAMH), Departments of Pharmacology & Toxicology & Psychiatry, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
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18
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Potential Role of Honey in Learning and Memory. Med Sci (Basel) 2015; 3:3-15. [PMID: 29083387 PMCID: PMC5635760 DOI: 10.3390/medsci3020003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 03/30/2015] [Accepted: 04/01/2015] [Indexed: 01/12/2023] Open
Abstract
The composition and physicochemical properties of honey are variable depending on its floral source and often named according to the geographical location. The potential medicinal benefits of Tualang honey, a multifloral jungle honey found in Malaysia, have recently been attracting attention because of its reported beneficial effects in various diseases. This paper reviews the effects of honey, particularly Tualang honey, on learning and memory. Information regarding the effects of Tualang honey on learning and memory in human as well as animal models is gleaned to hypothesize its underlying mechanisms. These studies show that Tualang honey improves morphology of memory-related brain areas, reduces brain oxidative stress, increases brain-derived neurotrophic factor (BDNF) and acetylcholine (ACh) concentrations, and reduces acetylcholinesterase (AChE) in the brain homogenates. Its anti-inflammatory roles in reducing inflammatory trigger and microglial activation have yet to be investigated. It is hypothesized that the improvement in learning and memory following Tualang honey supplementation is due to the significant improvement in brain morphology and enhancement of brain cholinergic system secondary to reduction in brain oxidative damage and/or upregulation of BDNF concentration. Further studies are imperative to elucidate the molecular mechanism of actions.
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19
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Lim YR, Kim IH, Han S, Park HG, Ko MJ, Chun YJ, Yun CH, Kim D. Functional Significance of Cytochrome P450 1A2 Allelic Variants, P450 1A2*8, *15, and *16 (R456H, P42R, and R377Q). Biomol Ther (Seoul) 2015; 23:189-94. [PMID: 25767688 PMCID: PMC4354321 DOI: 10.4062/biomolther.2015.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 11/18/2022] Open
Abstract
P450 1A2 is responsible for the metabolism of clinically important drugs and the metabolic activation of environmental chemicals. Genetic variations of P450 1A2 can influence its ability to perform these functions, and thus, this study aimed to characterize the functional significance of three P450 1A2 allelic variants containing nonsynonymous single nucleotide polymorphisms (P450 1A2*8, R456H; *15, P42R; *16, R377Q). Variants containing these SNPs were constructed and the recombinant enzymes were expressed and purified in Escherichia coli. Only the P42R variant displayed the typical CO-binding spectrum indicating a P450 holoenzyme with an expression level of ∼ 170 nmol per liter culture, but no P450 spectra were observed for the two other variants. Western blot analysis revealed that the level of expression for the P42R variant was lower than that of the wild type, however the expression of variants R456H and R377Q was not detected. Enzyme kinetic analyses indicated that the P42R mutation in P450 1A2 resulted in significant changes in catalytic activities. The P42R variant displayed an increased catalytic turnover numbers (kcat) in both of methoxyresorufin O-demethylation and phenacetin O-deethylation. In the case of phenacetin O-deethylation analysis, the overall catalytic efficiency (kcat/Km) increased up to 2.5 fold with a slight increase of its Km value. This study indicated that the substitution P42R in the N-terminal proline-rich region of P450 contributed to the improvement of catalytic activity albeit the reduction of P450 structural stability or the decrease of substrate affinity. Characterization of these polymorphisms should be carefully examined in terms of the metabolism of many clinical drugs and environmental chemicals.
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Affiliation(s)
- Young-Ran Lim
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - In-Hyeok Kim
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Songhee Han
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Mi-Jung Ko
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Young-Jin Chun
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Chul-Ho Yun
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
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20
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Okamatsu G, Komatsu T, Kubota A, Onaga T, Uchide T, Endo D, Kirisawa R, Yin G, Inoue H, Kitazawa T, Uno Y, Teraoka H. Identification and functional characterization of novel feline cytochrome P450 2A. Xenobiotica 2014; 45:503-10. [PMID: 25547627 DOI: 10.3109/00498254.2014.998322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
1. Cytochrome P450s are the major metabolizing enzymes for xenobiotics in humans and other mammals. Although the domestic cat Felis catus, an obligate carnivore, is the most common companion animal, the properties of cytochrome P450 subfamilies are largely unknown. 2. We newly identified the feline CYP2A13, which consists of 494 deduced amino acids, showing the highest identity to CYP2As of dogs, followed by those of pigs, cattle and humans. 3. The feline CYP2A13 transcript and protein were expressed almost exclusively in the liver without particular sex-dependent differences. 4. The feline CYP2A13 protein heterogeneously expressed in Escherichia coli showed metabolic activity similar to those of human and canine CYP2As for coumarin, 7-ethoxycoumarin and nicotine. 5. The results indicate the importance of CYP2A13 in systemic metabolism of xenobiotics in cats.
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Affiliation(s)
- Gaku Okamatsu
- School of Veterinary Medicine, Rakuno Gakuen University , Ebetsu, Hokkaido , Japan
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21
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Zhang T, Wei D. Recent progress on structural bioinformatics research of cytochrome P450 and its impact on drug discovery. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 827:327-39. [PMID: 25387973 DOI: 10.1007/978-94-017-9245-5_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Cytochrome P450 is predominantly responsible for human drug metabolism, which is of critical importance for drug discovery and development. Structural bioinformatics focuses on analysis and prediction of three-dimentional structure of biological macromolecules and elucidation of structure-function relationship as well as identification of important binding interactions. Rapid advancement of structural bioinformatics has been made over the last decade. With more information available for CYP structures, the methods of structural bioinformatics may be used in the CYP field. In this review, we demonstrate three previous studies on CYP using the methods of structural bioinformatics, including the investigation of reasons for decrease of enzymatic activity of CYP1A2 caused by a peripheral mutation, the construction of a pharmacophore model specific to active site of CYP1A2 and the prediction of the functional consequences of single residue mutation in CYP. By illustrating these studies we attempt to show the potential role of structural bioinformatics in CYP research and help better understanding the importance of structural bioinformatics in drug designing.
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Affiliation(s)
- Tao Zhang
- State Key Laboratory of Microbial Metabolism, College of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China,
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22
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Yamamiya I, Yoshisue K, Ishii Y, Yamada H, Chiba M. Effect of CYP2A6 genetic polymorphism on the metabolic conversion of tegafur to 5-fluorouracil and its enantioselectivity. Drug Metab Dispos 2014; 42:1485-92. [PMID: 25002745 DOI: 10.1124/dmd.114.058008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tegafur (FT), a prodrug of 5-fluorouracil, is a chiral molecule, a racemate of R- and S-isomers, and CYP2A6 plays an important role in the enantioselective metabolism of FT in human liver microsomes (R-FT >> S-FT). This study examined the enantioselective metabolism of FT by microsomes prepared from Sf9 cells expressing wild-type CYP2A6 and its variants (CYP2A6*7, *8, *10, and *11) that are highly prevalent in the Asian population. We also investigated the metabolism of coumarin and nicotine, both CYP2A6 probe drugs, in these variants. Enzyme kinetic analyses showed that CYP2A6.7 (I471T) and CYP2A6.10 (I471T and R485L) had markedly lower Vmax values for both enantiomers than wild-type enzyme (CYP2A6.1) and other variant enzymes, whereas Km values were higher in most of the variant enzymes for both enantiomers than CYP2A6.1. The ratios of Vmax and Km values for R-FT to corresponding values for S-FT (R/S ratio) were similar among enzymes, indicating little difference in enantioselectivity among the wild-type and variant enzymes. Similarly, both CYP2A6.7 and CYP2A6.10 had markedly lower Vmax values for coumarin 7-hydroxylase and nicotine C-oxidase activities than CYP2A6.1 and other variant enzymes, whereas Km values were higher in most of the variant enzymes for both activities than CYP2A6.1. In conclusion, the amino acid substitutions in CYP2A6 variants generally resulted in lower affinity for substrates, while Vmax values were selectively reduced in CYP2A6.7 and CYP2A6.10. Consistent R/S ratios among CYP2A6.1 and variant enzymes indicated that the amino acid substitutions had little effect on enantioselectivity in the metabolism of FT.
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Affiliation(s)
- Ikuo Yamamiya
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Kunihiro Yoshisue
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Yuji Ishii
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Hideyuki Yamada
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
| | - Masato Chiba
- Pharmacokinetics Research Laboratories, Taiho Pharmaceutical Co., Ltd., Tsukuba, Japan (I.Y., K.Y., M.C.); and Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan (I.Y., Y.I., H.Y.)
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Lee H, Kim JH, Han S, Lim YR, Park HG, Chun YJ, Park SW, Kim D. Directed-evolution analysis of human cytochrome P450 2A6 for enhanced enzymatic catalysis. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2014; 77:1409-1418. [PMID: 25343290 DOI: 10.1080/15287394.2014.951757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cytochrome P450 2A6 (P450 2A6) is the major enzyme responsible for the oxidation of coumarin, nicotine, and tobacco-specific nitrosamines in human liver. In this study, the catalytic turnover of coumarin oxidation was improved by directed-evolution analysis of P450 2A6 enzyme. A random mutant library was constructed using error-prone polymerase chain reaction (PCR) of the open reading frame of the P450 2A6 gene and individual mutant clones were screened for improved catalytic activity in analysis of fluorescent coumarin 7-hydroxylation. Four consecutive rounds of random mutagenesis and screening were performed and catalytically enhanced mutants were selected in each round of screening. The selected mutants showed the sequentially accumulated mutations of amino acid residues of P450 2A6: B1 (F209S), C1 (F209S, S369G), D1 (F209S, S369G, E277K), and E1 (F209S, S369G, E277K, A10V). E1 mutants displayed approximately 13-fold increased activity based on fluorescent coumarin hydroxylation assays at bacterial whole cell level. Steady-state kinetic parameters for coumarin 7-hydroxylation and nicotine oxidation were measured in purified mutant enzymes and indicated catalytic turnover numbers (kcat) of selected mutants were enhanced up to sevenfold greater than wild-type P450 2A6. However, all mutants displayed elevated Km values and therefore catalytic efficiencies (kcat/Km) were not improved. The increase in Km values was partially attributed to reduction in substrate binding affinities measured in the analysis of substrate binding titration. The structural analysis of P450 2A6 indicates that F209S mutation is sufficient to affect direct interaction of substrate at the active site.
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Affiliation(s)
- Hwayoun Lee
- a Department of Biological Sciences , Konkuk University , Seoul , Korea
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Yasutake Y, Kitagawa W, Hata M, Nishioka T, Ozaki T, Nishiyama M, Kuzuyama T, Tamura T. Structure of the quinoline N-hydroxylating cytochrome P450 RauA, an essential enzyme that confers antibiotic activity on aurachin alkaloids. FEBS Lett 2013; 588:105-10. [PMID: 24269679 DOI: 10.1016/j.febslet.2013.11.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/06/2013] [Accepted: 11/06/2013] [Indexed: 01/08/2023]
Abstract
The cytochrome P450 RauA from Rhodococcus erythropolis JCM 6824 catalyzes the hydroxylation of a nitrogen atom in the quinolone ring of aurachin, thereby conferring strong antibiotic activity on the aurachin alkaloid. Here, we report the crystal structure of RauA in complex with its substrate, a biosynthetic intermediate of aurachin RE. Clear electron density showed that the quinolone ring is oriented parallel to the porphyrin plane of the heme cofactor, while the farnesyl chain curls into a U-shape topology and is buried inside the solvent-inaccessible hydrophobic interior of RauA. The nearest atom from the heme iron is the quinolone nitrogen (4.3Å), which is consistent with RauA catalyzing the N-hydroxylation of the quinolone ring to produce mature aurachin RE.
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Affiliation(s)
- Yoshiaki Yasutake
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
| | - Wataru Kitagawa
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan; Graduate School of Agriculture, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan
| | - Miyako Hata
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan
| | - Taiki Nishioka
- Graduate School of Agriculture, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan
| | - Taro Ozaki
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Makoto Nishiyama
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tomohisa Kuzuyama
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tomohiro Tamura
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan; Graduate School of Agriculture, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan
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Kim J, Lim YR, Han S, Han JS, Chun YJ, Yun CH, Lee CH, Kim D. Functional influence of human CYP2D6 allelic variations: P34S, E418K, S486T, and R296C. Arch Pharm Res 2013; 36:1500-6. [PMID: 23897164 DOI: 10.1007/s12272-013-0212-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 07/09/2013] [Indexed: 11/29/2022]
Abstract
CYP2D6 is responsible for the oxidative metabolism of 20-25 % of clinical drugs and its genetic polymorphisms can significantly influence the drug metabolism. In this study, we analyzed the functional activities of four nonsynonymous single nucleotide polymorphisms from CYP2D6*52 allele, which were recently found, and one found frequently in CYP2D6 alleles. Recombinant variant enzymes of E418K, S486T, and R296C were successfully expressed in Escherichia coli and purified. However, a CYP holoenzyme spectrum of P34S variant was not detected in E. coli whole cell level. Structural analysis indicated that P34S mutation seemed to perturb a highly conserved proline-rich N-terminus of CYP2D6. Steady state kinetic analyses showed the significant reductions of enzymatic activities in E418K and R296C variants. In the case of bufuralol 1'-hydroxylation, a novel mutant, E418K, showed 32 % decrease in catalytic efficiency (k cat/K m) mainly due to the decrease of k cat value. R296C showed much greater reduction in the catalytic efficiency (9 % of wild-type) due to both of a decrease of k cat value and an increase of K m value. In the case of dextromethorphan O-demethylation, E418K showed both of a decrease of k cat value and an increase K m value to result in ~43 % reduction of catalytic efficiency. A highly decreased catalytic efficiency (~6 % of wild-type) in the mutant of R296C also was observed mainly due to the dramatic change of k cat value of dextromethorphan O-demethylation. These results suggested that individuals carrying these allelic variants are likely to have the altered metabolic abilities of many clinical drugs therefore, these polymorphisms of CYP2D6 should be much concerned for reliable drug treatment.
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Affiliation(s)
- Joohwan Kim
- Department of Biological Sciences, Konkuk University, 120 Neungdong-ro, Gwangjjn-gu, Seoul, 143-701, Korea
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Tian J, Chen H, Chen S, Xing L, Wang Y, Wang J. Comparative studies on the constituents, antioxidant and anticancer activities of extracts from different varieties of corn silk. Food Funct 2013; 4:1526-34. [DOI: 10.1039/c3fo60171d] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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