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Mellor SB, Behrendorff JBYH, Ipsen JØ, Crocoll C, Laursen T, Gillam EMJ, Pribil M. Exploiting photosynthesis-driven P450 activity to produce indican in tobacco chloroplasts. FRONTIERS IN PLANT SCIENCE 2023; 13:1049177. [PMID: 36743583 PMCID: PMC9890960 DOI: 10.3389/fpls.2022.1049177] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 12/14/2022] [Indexed: 05/28/2023]
Abstract
Photosynthetic organelles offer attractive features for engineering small molecule bioproduction by their ability to convert solar energy into chemical energy required for metabolism. The possibility to couple biochemical production directly to photosynthetic assimilation as a source of energy and substrates has intrigued metabolic engineers. Specifically, the chemical diversity found in plants often relies on cytochrome P450-mediated hydroxylations that depend on reductant supply for catalysis and which often lead to metabolic bottlenecks for heterologous production of complex molecules. By directing P450 enzymes to plant chloroplasts one can elegantly deal with such redox prerequisites. In this study, we explore the capacity of the plant photosynthetic machinery to drive P450-dependent formation of the indigo precursor indoxyl-β-D-glucoside (indican) by targeting an engineered indican biosynthetic pathway to tobacco (Nicotiana benthamiana) chloroplasts. We show that both native and engineered variants belonging to the human CYP2 family are catalytically active in chloroplasts when driven by photosynthetic reducing power and optimize construct designs to improve productivity. However, while increasing supply of tryptophan leads to an increase in indole accumulation, it does not improve indican productivity, suggesting that P450 activity limits overall productivity. Co-expression of different redox partners also does not improve productivity, indicating that supply of reducing power is not a bottleneck. Finally, in vitro kinetic measurements showed that the different redox partners were efficiently reduced by photosystem I but plant ferredoxin provided the highest light-dependent P450 activity. This study demonstrates the inherent ability of photosynthesis to support P450-dependent metabolic pathways. Plants and photosynthetic microbes are therefore uniquely suited for engineering P450-dependent metabolic pathways regardless of enzyme origin. Our findings have implications for metabolic engineering in photosynthetic hosts for production of high-value chemicals or drug metabolites for pharmacological studies.
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Affiliation(s)
- Silas B. Mellor
- Section for Plant Biochemistry, Department of Plant and Environmental Science, University of Copenhagen, Frederiksberg, Denmark
| | - James B. Y. H. Behrendorff
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Research Council (ARC) Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, QLD, Australia
| | - Johan Ø. Ipsen
- Section for Forest, Nature and Biomass, Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg, Denmark
| | - Christoph Crocoll
- DynaMo Center, Section for Molecular Plant Biology, Department of Plant and Environmental Science, University of Copenhagen, Frederiksberg, Denmark
| | - Tomas Laursen
- Section for Plant Biochemistry, Department of Plant and Environmental Science, University of Copenhagen, Frederiksberg, Denmark
| | - Elizabeth M. J. Gillam
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
| | - Mathias Pribil
- Section for Molecular Plant Biology, Department of Plant and Environmental Science, University of Copenhagen, Frederiksberg, Denmark
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Thomson RES, D'Cunha SA, Hayes MA, Gillam EMJ. Use of engineered cytochromes P450 for accelerating drug discovery and development. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 95:195-252. [PMID: 35953156 DOI: 10.1016/bs.apha.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Numerous steps in drug development, including the generation of authentic metabolites and late-stage functionalization of candidates, necessitate the modification of often complex molecules, such as natural products. While it can be challenging to make the required regio- and stereoselective alterations to a molecule using purely chemical catalysis, enzymes can introduce changes to complex molecules with a high degree of stereo- and regioselectivity. Cytochrome P450 enzymes are biocatalysts of unequalled versatility, capable of regio- and stereoselective functionalization of unactivated CH bonds by monooxygenation. Collectively they catalyze over 60 different biotransformations on structurally and functionally diverse organic molecules, including natural products, drugs, steroids, organic acids and other lipophilic molecules. This catalytic versatility and substrate range makes them likely candidates for application as potential biocatalysts for industrial chemistry. However, several aspects of the P450 catalytic cycle and other characteristics have limited their implementation to date in industry, including: their lability at elevated temperature, in the presence of solvents, and over lengthy incubation times; the typically low efficiency with which they metabolize non-natural substrates; and their lack of specificity for a single metabolic pathway. Protein engineering by rational design or directed evolution provides a way to engineer P450s for industrial use. Here we review the progress made to date toward engineering the properties of P450s, especially eukaryotic forms, for industrial application, and including the recent expansion of their catalytic repertoire to include non-natural reactions.
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Affiliation(s)
- Raine E S Thomson
- School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Stephlina A D'Cunha
- School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Martin A Hayes
- Compound Synthesis and Management, Discovery Sciences, BioPharmaceuticals R&D AstraZeneca, Mölndal, Sweden
| | - Elizabeth M J Gillam
- School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.
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3
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He Z, Zeng Y, Li S, Lin L, Zhou R, Wang F, Yang W, Wu Y, Yang J, Chen A, Wang Z, Yang H, Zhao X, Xiao W, Li L, Gong S. Gut Commensal Fungi Protect Against Acetaminophen-Induced Hepatotoxicity by Reducing Cyp2a5 Expression in Mice. Front Microbiol 2022; 13:944416. [PMID: 35903481 PMCID: PMC9315200 DOI: 10.3389/fmicb.2022.944416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/09/2022] [Indexed: 11/16/2022] Open
Abstract
Background and Aims Drug-induced liver injury (DILI) is a common cause of acute liver failure and represents a significant global public health problem. When discussing the gut-liver axis, although a great deal of research has focused on the role of gut microbiota in regulating the progression of DILI, the gut commensal fungal component has not yet been functionally identified. Methods Mice were pretreated with fluconazole (FC) to deplete the gut commensal fungi and were then subject to acetaminophen (APAP) gavage. In addition, transcriptome sequencing was performed to identify differentially expressed genes (DEGs) between control and fluconazole-pretreated groups of the mice challenged with APAP. Results Gut commensal fungi ablation through fluconazole pretreatment predisposed mice to APAP-induced hepatotoxicity, characterized by elevated serum liver enzyme levels and more severe centrilobular necrosis, which appears to be caused by robust inflammation and oxidative stress. The 16S rDNA sequencing results indicated that Akkermansia muciniphila abundance had significantly decreased in gut fungi-depleted mice, whereas increased abundance of Helicobacter rodentium was observed. The gene interaction network between DEGs identified by the transcriptome sequencing highlighted a significant enrichment of Cyp2a5 in the liver of APAP-treated mice that were preadministrated with fluconazole. Pharmacological inhibition of Cyp2a5 by 8-methoxypsoralen (8-MOP) could significantly attenuate hepatic inflammation and oxidative stress in mice, thereby conferring resistance to acute liver injury caused by APAP administration. Conclusion Our data highlighted the significance of gut commensal fungi in hepatic inflammation and oxidative stress of APAP mice, shedding light on promising therapeutic strategies targeting Cyp2a5 for DILI treatment.
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Affiliation(s)
- Zhuoen He
- Department of Critical Care Medicine, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Yunong Zeng
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Shuyu Li
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Lizhen Lin
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Ruisi Zhou
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Fangzhao Wang
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Wenjiao Yang
- Department of Simulation Center, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Yuhao Wu
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Junhao Yang
- School of Life Science, South China Normal University, Guangzhou, China
| | - Ali Chen
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Guangzhou, China
| | - Zhang Wang
- School of Life Science, South China Normal University, Guangzhou, China
| | - Hong Yang
- Department of Critical Care Medicine, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Xiaoshan Zhao
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Wei Xiao
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
- Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education, Guangdong Pharmaceutical University, Guangzhou, China
- Wei Xiao,
| | - Lei Li
- Department of Respiratory and Critical Care Medicine, Affiliated Dongguan Hospital, Southern Medical University, Dongguan, China
- Lei Li,
| | - Shenhai Gong
- Department of Critical Care Medicine, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
- *Correspondence: Shenhai Gong,
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Lee R, Kim V, Chun Y, Kim D. Structure-Functional Analysis of Human Cytochrome P450 2C8 Using Directed Evolution. Pharmaceutics 2021; 13:pharmaceutics13091429. [PMID: 34575505 PMCID: PMC8469462 DOI: 10.3390/pharmaceutics13091429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/03/2021] [Accepted: 09/06/2021] [Indexed: 11/16/2022] Open
Abstract
The human genome includes four cytochrome P450 2C subfamily enzymes, and CYP2C8 has generated research interest because it is subject to drug-drug interactions and various polymorphic outcomes. To address the structure-functional complexity of CYP2C8, its catalytic activity was studied using a directed evolution analysis. Consecutive rounds of random mutagenesis and screening using 6-methoxy-luciferin produced two mutants, which displayed highly increased luciferase activity. Wild-type and selected mutants were expressed on a large scale and purified. The expression levels of the D349Y and D349Y/V237A mutants were ~310 and 460 nmol per liter of culture, respectively. The steady-state kinetic analysis of paclitaxel 6α-hydroxylation showed that the mutants exhibited a 5-7-fold increase in kcat values and a 3-5-fold increase in catalytic efficiencies (kcat/KM). In arachidonic acid epoxidation, two mutants exhibited a 30-150-fold increase in kcat values and a 40-110-fold increase in catalytic efficiencies. The binding titration analyses of paclitaxel and arachidonic acid showed that the V237A mutation had a lower Kd value, indicating a tighter substrate-binding affinity. The structural analysis of CYP2C8 indicated that the D349Y mutation was close enough to the putative binding domain of the redox partner; the increase in catalytic activity could be partially attributed to the enhancement of the P450 coupling efficiency or electron transfer.
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Affiliation(s)
- Rowoon Lee
- Department of Biological Sciences, Konkuk University, Seoul 05029, Korea; (R.L.); (V.K.)
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul 05029, Korea; (R.L.); (V.K.)
| | - Youngjin Chun
- College of Pharmacy, Chung-Ang University, Seoul 06974, Korea;
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 05029, Korea; (R.L.); (V.K.)
- Correspondence: ; Tel.: +82-2-450-3366; Fax: +82-2-3436-5432
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5
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Qian X, Westensee IN, Fernandes CC, Städler B. Enzyme Mimic Facilitated Artificial Cell to Mammalian Cell Signal Transfer. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Xiaomin Qian
- Interdisciplinary Nanoscience Center (iNANO) Aarhus University Gustav Wieds Vej 14 8000 Aarhus Denmark
| | - Isabella Nymann Westensee
- Interdisciplinary Nanoscience Center (iNANO) Aarhus University Gustav Wieds Vej 14 8000 Aarhus Denmark
| | | | - Brigitte Städler
- Interdisciplinary Nanoscience Center (iNANO) Aarhus University Gustav Wieds Vej 14 8000 Aarhus Denmark
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6
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Kim D, Kim V, Tateishi Y, Guengerich FP. Cytochrome b 5 Binds Tightly to Several Human Cytochrome P450 Enzymes. Drug Metab Dispos 2021; 49:902-909. [PMID: 34330716 DOI: 10.1124/dmd.121.000475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 07/13/2021] [Indexed: 01/18/2023] Open
Abstract
Numerous studies have been reported in the past 50-plus years regarding the stimulatory role of cytochrome b 5 (b 5) in some, but not all, microsomal cytochrome P450 (P450) reactions with drugs and steroids. A missing element in most of these studies has been a sensitive and accurate measure of binding affinities of b 5 with P450s. In the course of work with P450 17A1, we developed a fluorescent derivative of a human b 5 site-directed mutant, Alexa 488-T70C-b 5, that could be used in binding assays at sub-μM concentrations. Alexa 488-T70C-b 5 bound to human P450s 1A2, 2B6, 2C8, 2C9, 2E1, 2S1, 4A11, 3A4, and 17A1, with estimated K d values ranging from 2.5 to 61 nM. Only weak binding was detected with P450 2D6, and no fluorescence attenuation was observed with P450 2A6. All of the P450s that bound b 5 have some reported activity stimulation except for P450 2S1. The affinity of P450 3A4 for b 5 was decreased somewhat by the presence of a substrate or inhibitor. The fluorescence of a P450 3A4•Alexa 488-T70C-b 5 complex was partially restored by titration with NADPH-P450 reductase (POR) (K d,apparent 89 nM), suggesting the existence of a ternary P450 3A4-b 5-POR complex, as observed previously with P450 17A1. Gel filtration evidence was also obtained for this ternary complex with P450 3A4. Overall, the results indicated that the affinity of b 5 for many P450s is very high, and that ternary P450-b 5-POR complexes are relevant in P450 3A4 reactions as opposed to a shuttle mechanism. SIGNIFICANCE STATEMENT: High-affinity binding of cytochrome b 5 (b 5) (K d < 100 nM) was observed with many drug-metabolizing cytochrome P450 (P450) enzymes. There is some correlation of binding with reported stimulation, with several exceptions. Evidence is provided for a ternary P450 3A4-b 5-NADPH-P450 reductase complex.
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Affiliation(s)
- Donghak Kim
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 (D.K., Y.T., F.P.G.), and Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea (D.K., V.K.)
| | - Vitchan Kim
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 (D.K., Y.T., F.P.G.), and Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea (D.K., V.K.)
| | - Yasuhiro Tateishi
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 (D.K., Y.T., F.P.G.), and Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea (D.K., V.K.)
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 (D.K., Y.T., F.P.G.), and Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea (D.K., V.K.)
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7
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Qian X, Westensee IN, Fernandes CC, Städler B. Enzyme Mimic Facilitated Artificial Cell to Mammalian Cell Signal Transfer. Angew Chem Int Ed Engl 2021; 60:18704-18711. [PMID: 34096152 DOI: 10.1002/anie.202104904] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/25/2021] [Indexed: 11/10/2022]
Abstract
Catalyzing biochemical reactions with enzymes and communicating with neighboring cells via chemical signaling are two fundamental cellular features that play a critical role in maintaining the homeostasis of organisms. Herein, we present an artificial enzyme (AE) facilitated signal transfer between artificial cells (ACs) and mammalian HepG2 cells. We synthesize metalloporphyrins (MPs) based AEs that mimic cytochrome P450 enzymes (CYPs) to catalyze a dealkylation and a hydroxylation reaction, exemplified by the conversion of resorufin ethyl ether (REE) to resorufin and coumarin (COU) to 7-hydroxycoumarin (7-HC), respectively. The AEs are immobilized in hydrogels to produce ACs that generate the two diffusive fluorophores, which can diffuse into HepG2 cells and result in dual intracellular emissions. This work highlights the use of AEs to promote AC to mammalian signal transfer, which opens up new opportunities for integrating the synthetic and living world with a bottom-up strategy.
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Affiliation(s)
- Xiaomin Qian
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus, Denmark
| | - Isabella Nymann Westensee
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus, Denmark
| | | | - Brigitte Städler
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus, Denmark
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8
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Inhibition of cytochrome P450 2B6 by Astragalus extract mixture HT042. Toxicol Res 2020; 36:195-201. [PMID: 32685423 DOI: 10.1007/s43188-019-00027-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/17/2019] [Accepted: 10/29/2019] [Indexed: 10/24/2022] Open
Abstract
Astragalus extract mixture (AEM) HT042 is a functional food approved by the MFDS (Korean FDA) for increasing height. It comprises a mixture of three standardized extracts from Astragalus membranaceus root, Eleutherococcus senticosus stem, and Phlomis umbrosa root. In this study, drug-functional food interaction was analyzed using six major human cytochrome P450 enzymes. The inhibitory effect of AEM HT042 on P450 activities was studied using a P450-NADPH P450 reductase reconstitution system. Among the six P450 enzymes (1A2, 2A6, 2B6, 2D6, 2C9, and 3A4), only P450 2B6 activity was markedly decreased by AEM HT042 addition. The bupropion hydroxylation activity of P450 2B6 was analyzed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A calculated IC50 value of 10.62 µg/ml was obtained. To identify the inhibitory compounds in the mixture, four active compounds in AEM HT042 were analyzed. Shanzhiside methylester exhibited inhibitory effects on P450 2B6, whereas formononetin, eleutheroside E, and sesamoside did not affect P450 2B6 activity at all. Our results suggest that shanzhiside methylester in AEM HT042 is responsible for the inhibitory effect on P450 2B6 metabolism. Characterization of the inhibitory effect on P450 can help determine the safe administration of functional foods along with many clinical drugs that are metabolized by P450.
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9
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Park HG, Kim V, Kim H, Lee R, Cho MA, Park SW, Chun YJ, Kim D. CYP52A23 from Candida albicans and its Substrate Preference for Fatty Acid Hydroxylation. Arch Biochem Biophys 2019; 671:27-34. [PMID: 31181182 DOI: 10.1016/j.abb.2019.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 06/05/2019] [Accepted: 06/06/2019] [Indexed: 01/07/2023]
Abstract
The pathogenic fungus Candida albicans contains genes encoding five fatty acid hydroxylases belonging to the CYP52 family in its genome. Our previous study reported that CYP52A21 demonstrated typical omega-hydroxylation of lauric acid (Kim D, Cryle MJ, De Voss JJ, Ortiz de Montellano PR (2007) Arch Biochem Biophys 464, 213-220). Functional characterization of CYP52 fatty acid hydroxylases was studied, and their selectivity for hydroxylation was analyzed. Genes for four other CYP52 members (CYP52A22, CYP52A23, CYP52A24, and CYP52C3) from C. albicans were cloned, and their recombinant enzymes were expressed in Escherichia coli. CO-binding spectral analyses showed that the functional P450 holoenzyme was obtained only in CYP52A23, while no holoenzyme peak was observed in the other three CYP52 enzymes. Spectral change of the type II binding was observed in purified CYP52A23 when titrated with fatty acids but none was observed with alkanes. The gas chromatography-mass spectrometry (GC-MS) analysis revealed that CYP52A23 predominantly exhibited omega-hydroxylation activity during the oxidation reaction of fatty acids. Interestingly, it was found that CYP52A23 preferred longer-chain fatty acids (stearic acid and arachidic acid) for its catalytic activities while CYP52A21 preferred mid-chain fatty acids (lauric acid and mystic acid). To analyze the selectivity of fatty acids, hybrid mutagenesis of genes encoding CYP52A21 and CYP52A23 by overlap extension polymerase chain reaction was conducted. Two hybrid mutants containing the N-terminal fragments of CYP52A21 and C-terminal fragments of CYP52A23 displayed higher catalytic activity in palmitic acid and arachidic acid. These results suggested that the C-terminal part of CYP52A23 may be responsible for its preference to longer-chain fatty acids.
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Affiliation(s)
- Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Harim Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Rowoon Lee
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Myung-A Cho
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea
| | - Sung-Woo Park
- Division of Respiratory and Allergy, Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, 14584, South Korea
| | - Young-Jin Chun
- College of Pharmacy, Chung-Ang University, Seoul, 06974, South Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05029, South Korea.
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10
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Strohmaier SJ, Huang W, Baek JM, Hunter DJB, Gillam EMJ. Rational evolution of the cofactor-binding site of cytochrome P450 reductase yields variants with increased activity towards specific cytochrome P450 enzymes. FEBS J 2019; 286:4473-4493. [PMID: 31276316 DOI: 10.1111/febs.14982] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 04/30/2019] [Accepted: 07/02/2019] [Indexed: 12/22/2022]
Abstract
NADPH-cytochrome P450 reductase (CPR) is the natural redox partner of microsomal cytochrome P450 enzymes. CPR shows a stringent preference for NADPH over the less expensive cofactor, NADH, economically limiting its use as a biocatalyst. The complexity of cofactor-linked CPR protein dynamics and the incomplete understanding of the interaction of CPR with both cofactors and electron acceptors present challenges for the successful rational engineering of a CPR with enhanced activity with NADH. Here, we report a rational evolution approach to enhance the activity of CPR with NADH, in which mutations were introduced into the NADPH-binding flavin adenine dinucleotide (FAD) domain. Multiple CPR mutants that used NADH more effectively than the wild-type CPR in the reduction of the surrogate electron acceptor, cytochrome c were found. However, most were inactive in supporting P450 activity, arguing against the use of cytochrome c as a surrogate electron acceptor. Unexpectedly, several mutants showed significantly improved activity towards CYP2C9 (mutant 1-014) and/or CYP2A6 (mutants 1-014, 1-015, 1-053 and 1-077) using NADPH, even though the mutations were introduced at locations remote from the putative CPR-P450 interaction face. Therefore, mutations at sites in the FAD domain of CPR may be promising future engineering targets to enhance P450-mediated substrate turnover. ENZYMES: NADPH-cytochrome P450 reductase - EC 1.6.2.4; cytochrome P450 - EC 1.14.14.1.
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Affiliation(s)
- Silja J Strohmaier
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Weiliang Huang
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Jong-Min Baek
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Dominic J B Hunter
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Elizabeth M J Gillam
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
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11
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Jeong D, Park HG, Lim YR, Lee Y, Kim V, Cho MA, Kim D. Terfenadine metabolism of human cytochrome P450 2J2 containing genetic variations (G312R, P351L and P115L). Drug Metab Pharmacokinet 2017; 33:61-66. [PMID: 29223463 DOI: 10.1016/j.dmpk.2017.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/22/2017] [Accepted: 10/30/2017] [Indexed: 12/22/2022]
Abstract
The human cytochrome P450 2J2 is involved in several metabolic reactions, including the oxidation of important therapeutics and epoxidation of endogenous arachidonic acid. At least ten genetic variations of P450 2J2 have been identified, but their effects on enzymatic activity have not been clearly characterized. Here, we evaluated the functional effects of three genetic variations of P450 2J2 (G312R, P351L, and P115L). Recombinant enzymes of wild-type and three variant P450 2J2 were heterologously expressed in Escherichia coli and purified. P450 expression levels in the wild-type and two variants (P351L and P115L) were 142-231 nmol per liter culture, while the G312R variant showed no holoenzyme peak in the CO-binding spectra. Substrate binding titrations to terfenadine showed that the wild-type and two variants displayed Kd values of 0.90-2.2 μM, indicating tight substrate binding affinities. Steady-state kinetic analysis for t-butyl methyl hydroxylation of terfenadine indicated that two variant enzymes had similar kcat and Km values to wild-type P450 2J2. The locations of mutations in three-dimensional structural models indicated that the G312R is located in the I-helix region near the formal active site in P450 2J2 and its amino acid change affected the structural stability of the P450 heme environment.
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Affiliation(s)
- Dabin Jeong
- Department of Biological Sciences, Konkuk University, Seoul, 05025, South Korea
| | - Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul, 05025, South Korea
| | - Young-Ran Lim
- Department of Biological Sciences, Konkuk University, Seoul, 05025, South Korea
| | - Yejin Lee
- Department of Biological Sciences, Konkuk University, Seoul, 05025, South Korea
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05025, South Korea
| | - Myung-A Cho
- Department of Biological Sciences, Konkuk University, Seoul, 05025, South Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, 05025, South Korea.
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12
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Lim YR, Han S, Kim JH, Park HG, Lee GY, Le TK, Yun CH, Kim D. Characterization of a Biflaviolin Synthase CYP158A3 from Streptomyces avermitilis and Its Role in the Biosynthesis of Secondary Metabolites. Biomol Ther (Seoul) 2017; 25:171-176. [PMID: 27956713 PMCID: PMC5340542 DOI: 10.4062/biomolther.2016.182] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/22/2016] [Accepted: 09/22/2016] [Indexed: 11/16/2022] Open
Abstract
Streptomyces avermitilis produces clinically useful drugs such as avermectins and oligomycins. Its genome contains approximately 33 cytochrome P450 genes and they seem to play important roles in the biosynthesis of many secondary metabolites. The SAV_7130 gene from S. avermitilis encodes CYP158A3. The amino acid sequence of this enzyme has high similarity with that of CYP158A2, a biflaviolin synthase from S. coelicolor A3(2). Recombinant S. avermitilis CYP158A3 was heterologously expressed and purified. It exhibited the typical P450 Soret peak at 447 nm in the reduced CO-bound form. Type I binding spectral changes were observed when CYP158A3 was titrated with myristic acid; however, no oxidative product was formed. An analog of flaviolin, 2-hydroxynaphthoquinone (2-OH NQ) displayed similar type I binding upon titration with purified CYP158A3. It underwent an enzymatic reaction forming dimerized product. A homology model of CYP158A3 was superimposed with the structure of CYP158A2, and the majority of structural elements aligned. These results suggest that CYP158A3 might be an orthologue of biflaviolin synthase, catalyzing C-C coupling reactions during pigment biosynthesis in S. avermitilis.
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Affiliation(s)
- Young-Ran Lim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Songhee Han
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
| | - Joo-Hwan Kim
- 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
| | - Ga-Young Lee
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Thien-Kim Le
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Chul-Ho Yun
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 05025, Republic of Korea
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Amin HK, El-Araby AM, Eid S, Nasr T, Bondock S, Leheta O, Dawoud ME. A Thiazole Analogue Exhibits an Anti-Proliferative Effect in Different Human Carcinoma Cell Lines and Its Mechanism Based on Molecular Modeling. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/abc.2017.71005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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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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15
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Shimada T, Takenaka S, Murayama N, Yamazaki H, Kim JH, Kim D, Yoshimoto FK, Guengerich FP, Komori M. Oxidation of Acenaphthene and Acenaphthylene by Human Cytochrome P450 Enzymes. Chem Res Toxicol 2016; 28:268-78. [PMID: 25642975 DOI: 10.1021/tx500505y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Acenaphthene and acenaphthylene, two known environmental polycyclic aromatic hydrocarbon (PAH)pollutants, were incubated at 50 μM concentrations in a standard reaction mixture with human P450s 2A6, 2A13, 1B1,1A2, 2C9, and 3A4, and the oxidation products were determined using HPLC and LC-MS. HPLC analysis showed that P450 2A6 converted acenaphthene and acenaphthylene to several mono- and dioxygenated products. LC-MS analysis of acenaphthene oxidation by P450s indicated the formation of1-acenaphthenol as a major product, with turnover rates of 6.7,4.5, and 3.6 nmol product formed/min/nmol P450 for P4502A6, 2A13, and 1B1, respectively. Acenaphthylene oxidation by P450 2A6 showed the formation of 1,2-epoxyacenaphthene as a major product (4.4 nmol epoxide formed/min/nmol P450) and also several mono- and dioxygenated products.P450 2A13, 1B1, 1A2, 2C9, and 3A4 formed 1,2-epoxyacenaphthene at rates of 0.18, 5.3 2.4, 0.16, and 3.8 nmol/min/nmol P450, respectively. 1-Acenaphthenol, which induced Type I binding spectra with P450 2A13, was further oxidized by P450 2A13 but not P450 2A6. 1,2-Epoxyacenaphthene induced Type I binding spectra with P450 2A6 and 2A13 (K(s) 1.8 and 0.16 μM,respectively) and was also oxidized to several oxidation products by these P450s. Molecular docking analysis suggested different orientations of acenaphthene, acenaphthylene, 1-acenaphthenol, and 1,2-epoxyacenaphthene in their interactions with P450 2A6a nd 2A13. Neither of these four PAHs induced umu gene expression in a Salmonella typhimurium NM tester strain. These results suggest, for the first time, that acenaphthene and acenaphthylene are oxidized by human P450s 2A6 and 2A13 and other P450s to form several mono- and dioxygenated products. The results are of use in considering the biological and toxicological significance of these environmental PAHs in humans.
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16
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Uno T, Ogura C, Izumi C, Nakamura M, Yanase T, Yamazaki H, Ashida H, Kanamaru K, Yamagata H, Imaishi H. Point mutation of cytochrome P450 2A6 (a polymorphic variant CYP2A6.25) confers new substrate specificity towards flavonoids. Biopharm Drug Dispos 2015. [DOI: 10.1002/bdd.1966] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tomohide Uno
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
| | - Chika Ogura
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
| | - Chiho Izumi
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
| | - Masahiko Nakamura
- Department of Bioscience and Biotechnology, Faculty of Bioenvironmental Science; Kyoto Gakuen University; 1-1 Nanjo, Sogabe Kameoka Kyoto 621-8555 Japan
| | - Takeshi Yanase
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics; Showa Pharmaceutical University; Machida Tokyo 194-8543 Japan
| | - Hitoshi Ashida
- Laboratory of Biochemistry Frontiers, Graduate School of Agricultural Science; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
| | - Kengo Kanamaru
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
| | - Hiroshi Yamagata
- Laboratory of Biological Chemistry, Department of Biofunctional Chemistry, Faculty of Agriculture; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
| | - Hiromasa Imaishi
- Functional Analysis of Environmental Genes, Research Center for Environmental Genomics; Kobe University; Nada-ku Kobe Hyogo 657-8501 Japan
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17
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Shimada T, Takenaka S, Murayama N, Kramlinger VM, Kim JH, Kim D, Liu J, Foroozesh MK, Yamazaki H, Guengerich FP, Komori M. Oxidation of pyrene, 1-hydroxypyrene, 1-nitropyrene and 1-acetylpyrene by human cytochrome P450 2A13. Xenobiotica 2015; 46:211-24. [PMID: 26247835 PMCID: PMC5270756 DOI: 10.3109/00498254.2015.1069419] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
1. The polycyclic hydrocarbons (PAHs), pyrene, 1-hydroxypyrene, 1-nitropyrene and 1-acetylpyrene, were found to induce Type I binding spectra with human cytochrome P450 (P450) 2A13 and were converted to various mono- and di-oxygenated products by this enzyme. 2. Pyrene was first oxidized by P450 2A13 to 1-hydroxypyrene which was further oxidized to di-oxygenated products, i.e. 1,8- and 1,6-dihydroxypyrene. Of five other human P450s examined, P450 1B1 catalyzed pyrene oxidation to 1-hydroxypyrene at a similar rate to P450 2A13 but was less efficient in forming dihydroxypyrenes. P450 2A6, a related human P450 enzyme, which did not show any spectral changes with these four PAHs, showed lower activities in oxidation of these compounds than P450 2A13. 3. 1-Nitropyrene and 1-acetylpyrene were also found to be efficiently oxidized by P450 2A13 to several oxygenated products, based on mass spectrometry analysis. 4. Molecular docking analysis supported preferred orientations of pyrene and its derivatives in the active site of P450 2A13, with lower interaction energies (U values) than observed for P450 2A6 and that several amino acid residues (including Ala-301, Asn-297 and Ala-117) play important roles in directing the orientation of these PAHs in the P450 2A13 active site. In addition, Phe-231 and Gly-329 were found to interact with pyrene to orient this compound in the active site of P450 1B1. 5. These results suggest that P450 2A13 is one of the important enzymes that oxidizes these PAH compounds and may determine how these chemicals are detoxicated and bioactivated in humans.
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Affiliation(s)
- Tsutomu Shimada
- Laboratory of Cellular and Molecular Biology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Orai-Kita, Izumisano, Osaka 598-8531, Japan
| | - Shigeo Takenaka
- Laboratory of Cellular and Molecular Biology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Orai-Kita, Izumisano, Osaka 598-8531, Japan
| | - Norie Murayama
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
| | - Valerie M. Kramlinger
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, United States
| | - Joo-Hwan Kim
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Jiawang Liu
- Department of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Maryam K. Foroozesh
- Department of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125, United States
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
| | - F. Peter Guengerich
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, United States
| | - Masayuki Komori
- Laboratory of Cellular and Molecular Biology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Orai-Kita, Izumisano, Osaka 598-8531, Japan
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18
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Ohk SO, Park HG, Lee H, Kwon YJ, Kim BJ, Kim D, Chun YJ. Heterologous expression and characterization of CYP61A1 from dandruff-causing Malassezia globosa. Protein Expr Purif 2015; 114:89-94. [PMID: 26160660 DOI: 10.1016/j.pep.2015.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 07/04/2015] [Accepted: 07/04/2015] [Indexed: 11/17/2022]
Abstract
Malassezia globosa is pathogenic fungus that causes skin disorders including dandruff in humans. Many yeast cytochrome CYP enzymes are involved in the biosynthesis of sterols and are considered major targets of azole antifungal agents. Here, we report on the expression and characterization of the MGL_0310 gene product (CYP61A1), a sterol C-22 desaturase in M. globosa. The open reading frame of the CYP61A1 gene was amplified by PCR from M. globosa CBS 7966 genomic DNA and cloned into a pCW vector. The CYP61A1 gene was heterologously expressed in Escherichia coli and purified using a Ni(2+)-NTA affinity column. The purified CYP61A1 protein exhibited a CO-difference spectrum typical of CYPs with a maximum absorption at 452nm. Binding spectral titration with β-sitosterol and campesterol demonstrated the type I binding mode with an increase at 411nm and a decrease at 432nm. The calculated Kd values are 5.4±0.6μM and 6.1±1.0μM for β-sitosterol and campesterol, respectively. No metabolic product, however, was observed in the CYP61A1-supported enzyme reaction with these sterols. The purified CYP61A1 protein exhibited tight binding to azole agents, suggesting that this enzyme may be a target for the pathogenic M. globosa fungus. Moreover, several fatty acids were found to bind to CYP61A1, indicating that the architecture of the enzyme includes a relatively large active site space. This study provides new insight into the biosynthesis of fungal sterols in M. globosa and a basis for the development of antifungal as potential therapeutic agents to treat dandruff.
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Affiliation(s)
- Seul-Ong Ohk
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Hwayoun Lee
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
| | - Yeo-Jung Kwon
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Beom Joon Kim
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul 156-755, Republic of Korea
| | - Donghak Kim
- 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.
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19
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Directed evolution of cytochrome P450 enzymes for biocatalysis: exploiting the catalytic versatility of enzymes with relaxed substrate specificity. Biochem J 2015; 467:1-15. [DOI: 10.1042/bj20141493] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cytochrome P450 enzymes are renowned for their ability to insert oxygen into an enormous variety of compounds with a high degree of chemo- and regio-selectivity under mild conditions. This property has been exploited in Nature for an enormous variety of physiological functions, and representatives of this ancient enzyme family have been identified in all kingdoms of life. The catalytic versatility of P450s makes them well suited for repurposing for the synthesis of fine chemicals such as drugs. Although these enzymes have not evolved in Nature to perform the reactions required for modern chemical industries, many P450s show relaxed substrate specificity and exhibit some degree of activity towards non-natural substrates of relevance to applications such as drug development. Directed evolution and other protein engineering methods can be used to improve upon this low level of activity and convert these promiscuous generalist enzymes into specialists capable of mediating reactions of interest with exquisite regio- and stereo-selectivity. Although there are some notable successes in exploiting P450s from natural sources in metabolic engineering, and P450s have been proven repeatedly to be excellent material for engineering, there are few examples to date of practical application of engineered P450s. The purpose of the present review is to illustrate the progress that has been made in altering properties of P450s such as substrate range, cofactor preference and stability, and outline some of the remaining challenges that must be overcome for industrial application of these powerful biocatalysts.
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20
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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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21
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Kim D, Cha GS, Nagy LD, Yun CH, Guengerich FP. Kinetic analysis of lauric acid hydroxylation by human cytochrome P450 4A11. Biochemistry 2014; 53:6161-72. [PMID: 25203493 PMCID: PMC4188250 DOI: 10.1021/bi500710e] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Cytochrome P450 (P450) 4A11 is the
only functionally active subfamily
4A P450 in humans. P450 4A11 catalyzes mainly ω-hydroxylation
of fatty acids in liver and kidney; this process is not a major degradative
pathway, but at least one product, 20-hydroxyeicosatetraenoic acid,
has important signaling properties. We studied catalysis by P450 4A11
and the issue of rate-limiting steps using lauric acid ω-hydroxylation,
a prototypic substrate for this enzyme. Some individual reaction steps
were studied using pre-steady-state kinetic approaches. Substrate
and product binding and release were much faster than overall rates
of catalysis. Reduction of ferric P450 4A11 (to ferrous) was rapid
and not rate-limiting. Deuterium kinetic isotope effect (KIE) experiments
yielded low but reproducible values (1.2–2) for 12-hydroxylation
with 12-2H-substituted lauric acid. However, considerable
“metabolic switching” to 11-hydroxylation was observed
with [12-2H3]lauric acid. Analysis of switching
results [Jones, J. P., et al. (1986) J. Am. Chem. Soc.108, 7074–7078] and the use of tritium KIE
analysis with [12-3H]lauric acid [Northrop, D. B. (1987) Methods Enzymol.87, 607–625] both
indicated a high intrinsic KIE (>10). Cytochrome b5 (b5) stimulated steady-state
lauric acid ω-hydroxylation ∼2-fold; the apoprotein was
ineffective, indicating that electron transfer is involved in the b5 enhancement. The rate of b5 reoxidation was increased in the presence of ferrous
P450 mixed with O2. Collectively, the results indicate
that both the transfer of an electron to the ferrous·O2 complex and C–H bond-breaking limit the rate of P450 4A11
ω-oxidation.
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Affiliation(s)
- Donghak Kim
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
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Castrignanò S, Ortolani A, Sadeghi SJ, Di Nardo G, Allegra P, Gilardi G. Electrochemical detection of human cytochrome P450 2A6 inhibition: a step toward reducing dependence on smoking. Anal Chem 2014; 86:2760-6. [PMID: 24527722 DOI: 10.1021/ac4041839] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Inhibition of human cytochrome P450 2A6 has been demonstrated to play an important role in nicotine metabolism and consequent smoking habits. Here, the "molecular Lego" approach was used to achieve the first reported electrochemical signal of human CYP2A6 and to improve its catalytic efficiency on electrode surfaces. The enzyme was fused at the genetic level to flavodoxin from Desulfovibrio vulgaris (FLD) to create the chimeric CYP2A6-FLD. Electrochemical characterization by cyclic voltammetry shows clearly defined redox transitions of the haem domain in both CYP2A6 and CYP2A6-FLD. Electrocatalysis experiments using coumarin as substrate followed by fluorimetric quantification of the product were performed with immobilized CYP2A6 and CYP2A6-FLD. Comparison of the kinetic parameters showed that coumarin catalysis was carried out with a higher efficiency by the immobilized CYP2A6-FLD, with a calculated kcat value significantly higher (P < 0.005) than that of CYP2A6, whereas the affinity for the substrate (KM) remained unaltered. The chimeric system was also successfully used to demonstrate the inhibition of the electrochemical activity of the immobilized CYP2A6-FLD, toward both coumarin and nicotine substrates, by tranylcypromine, a potent and selective CYP2A6 inhibitor. This work shows that CYP2A6 turnover efficiency is improved when the protein is linked to the FLD redox module, and this strategy can be utilized for the development of new clinically relevant biotechnological approaches suitable for deciphering the metabolic implications of CYP2A6 polymorphism and for the screening of CYP2A6 substrates and inhibitors.
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Affiliation(s)
- Silvia Castrignanò
- Department of Life Sciences and Systems Biology, University of Torino , 10123 Torino, Italy
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23
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Tiong KH, Mohammed Yunus NA, Yiap BC, Tan EL, Ismail R, Ong CE. Inhibitory potency of 8-methoxypsoralen on cytochrome P450 2A6 (CYP2A6) allelic variants CYP2A6 15, CYP2A6 16, CYP2A6 21 and CYP2A6 22: differential susceptibility due to different sequence locations of the mutations. PLoS One 2014; 9:e86230. [PMID: 24475091 PMCID: PMC3903516 DOI: 10.1371/journal.pone.0086230] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 12/06/2013] [Indexed: 11/19/2022] Open
Abstract
Human cytochrome P450 2A6 (CYP2A6) is a highly polymorphic isoform of CYP2A subfamily. Our previous kinetic study on four CYP2A6 allelic variants (CYP2A6 15, CYP2A6 16, CYP2A6 21 and CYP2A6 22) have unveiled the functional significance of sequence mutations in these variants on coumarin 7-hydroxylation activity. In the present study, we further explored the ability of a typical CYP2A6 inhibitor, 8-methoxypsoralen (8-MOP), in inhibition of these alleles and we hypothesized that translational mutations in these variants are likely to give impact on 8-MOP inhibitory potency. The CYP2A6 variant and the wild type proteins were subjected to 8-MOP inhibition to yield IC50 values. In general, a similar trend of change in the IC50 and Km values was noted among the four mutants towards coumarin oxidation. With the exception of CYP2A6 16, differences in IC50 values were highly significant which implied compromised interaction of the mutants with 8-MOP. Molecular models of CYP2A6 were subsequently constructed and ligand-docking experiments were performed to rationalize experimental data. Our docking study has shown that mutations have induced enlargement of the active site volume in all mutants with the exception of CYP2A6 16. Furthermore, loss of hydrogen bond between 8-MOP and active site residue Asn297 was evidenced in all mutants. Our data indicate that the structural changes elicited by the sequence mutations could affect 8-MOP binding to yield differential enzymatic activities in the mutant CYP2A6 proteins.
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Affiliation(s)
- Kai Hung Tiong
- School of Pharmacy and Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Nafees Ahemad Mohammed Yunus
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Beow Chin Yiap
- School of Pharmacy and Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Eng Lai Tan
- School of Pharmacy and Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Rusli Ismail
- Centre of Excellence for Research in AIDS (CERiA), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Chin Eng Ong
- Discipline of Pharmacy, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
- * E-mail:
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24
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Choi S, Han S, Lee H, Chun YJ, Kim D. Evaluation of Luminescent P450 Analysis for Directed Evolution of Human CYP4A11. Biomol Ther (Seoul) 2014; 21:487-92. [PMID: 24404341 PMCID: PMC3879922 DOI: 10.4062/biomolther.2013.086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 11/08/2013] [Accepted: 11/13/2013] [Indexed: 11/29/2022] Open
Abstract
Cytochrome P450 4A11 (CYP4A11) is a fatty acid hydroxylase enzyme expressed in human liver. It catalyzes not only the hydroxylation of saturated and unsaturated fatty acids, but the conversion of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a regulator of blood pressure. In this study, we performed a directed evolution analysis of CYP4A11 using the luminogenic assay system. A random mutant library of CYP4A11, in which mutations were made throughout the entire coding region, was screened with luciferase activity to detect the demethylation of luciferin-4A (2-[6-methoxyquinolin-2-yl]-4,5-dihydrothiazole-4-carboxylic acid) of CYP4A11 mutants in Escherichia coli. Consecutive rounds of random mutagenesis and screening yielded three improved CYP4A11 mutants, CP2600 (A24T/T263A), CP2601 (T263A), and CP2616 (A24T/T263A/V430E) with ~3-fold increase in whole cells and >10-fold increase in purified proteins on the luminescence assay. However, the steady state kinetic analysis for lauric acid hydroxylation showed the significant reductions in enzymatic activities in all three mutants. A mutant, CP2600, showed a 51% decrease in catalytic efficiency (kcat/Km) for lauric acid hydroxylation mainly due to an increase in Km. CP2601 and CP2616 showed much greater reductions (>75%) in the catalytic efficiency due to both a decrease in kcat and an increase in Km. These decreased catalytic activities of CP2601 and CP2616 can be partially attributed to the changes in substrate affinities. These results suggest that the enzymatic activities of CYP4A11 mutants selected from directed evolution using a luminogenic P450 substrate may not demonstrate a direct correlation with the hydroxylation activities of lauric acid.
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Affiliation(s)
- Seunghye Choi
- Department of Biological Sciences, Konkuk University, Seoul 143-701
| | - Songhee Han
- Department of Biological Sciences, Konkuk University, Seoul 143-701
| | - Hwayoun Lee
- Department of Biological Sciences, Konkuk University, Seoul 143-701
| | - Young-Jin Chun
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul 143-701
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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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Pouyfung P, Prasopthum A, Sarapusit S, Srisook E, Rongnoparut P. Mechanism-based Inactivation of Cytochrome P450 2A6 and 2A13 by Rhinacanthus nasutus Constituents. Drug Metab Pharmacokinet 2014; 29:75-82. [DOI: 10.2133/dmpk.dmpk-13-rg-048] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Eun CY, Han S, Lim YR, Park HG, Han JS, Cho KS, Chun YJ, Kim D. Bioactivation of Aromatic Amines by Human CYP2W1, An Orphan Cytochrome P450 Enzyme. Toxicol Res 2013; 26:171-5. [PMID: 24278521 PMCID: PMC3834484 DOI: 10.5487/tr.2010.26.3.171] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 08/02/2010] [Accepted: 08/14/2010] [Indexed: 11/30/2022] Open
Abstract
The human genome contains approximately 13 orphan cytochrome P450 (P450, CYP) genes, of which the apparent function or substrate has not been identified. However, they seem to possess their own biological relevance in some tissues or developmental stages. Here, we characterized the heterologously expressed CYP2W1, an orphan P450 enzyme. The recombinant CYP2W1 protein containing a 6 × (His) -tag at Nterminus has been expressed in Escherichia coli and purified. Expression level of CYP2W1 holoenzyme was around 500 nmol P450 holoenzyme per liter culture medium. The reduced CO difference spectrum of CYP2W1 showed a maximum absorption at 449 nm. CYP2W1 indicated the significant induction to bioactivate Trp-P-1, MeIQ, and IQ in E. coli DJ701 tester strain. However, the bioactivation of B[α]P, and NNK by CYP2W1 was relatively low. The model structure of CYP2W1 suggested the characteristic P450 folds with the lengths and orientations of the individual secondary elements. The F-G loop is situated on the distal side of heme to accommodate the flexibility of active site of CYP2W1. These studies can provide useful information for the finding of its biological roles and structure-function relationships of an orphan CYP2W1 enzyme.
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Affiliation(s)
- Chang-Yong Eun
- Department of Biological Sciences, Konkuk University, Seoul 143-701
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28
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Synthesis of novel psoralen analogues and their in vitro antitumor activity. Bioorg Med Chem 2013; 21:5047-53. [DOI: 10.1016/j.bmc.2013.06.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/19/2013] [Accepted: 06/20/2013] [Indexed: 11/21/2022]
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29
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Analysis of Substrate Recognition Site 2 (SRS2) in human cytochrome P450 1A2 using whole-plasmid random mutagenesis. Mol Cell Toxicol 2013. [DOI: 10.1007/s13273-013-0002-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Shimada T, Murayama N, Yamazaki H, Tanaka K, Takenaka S, Komori M, Kim D, Guengerich FP. Metabolic activation of polycyclic aromatic hydrocarbons and aryl and heterocyclic amines by human cytochromes P450 2A13 and 2A6. Chem Res Toxicol 2013; 26:529-37. [PMID: 23432465 DOI: 10.1021/tx3004906] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Human cytochrome P450 (P450) 2A13 was found to interact with several polycyclic aromatic hydrocarbons (PAHs) to produce Type I binding spectra, including acenaphthene, acenaphthylene, benzo[c]phenanthrene, fluoranthene, fluoranthene-2,3-diol, and 1-nitropyrene. P450 2A6 also interacted with acenaphthene and acenaphthylene, but not with fluoranthene, fluoranthene-2,3-diol, or 1-nitropyrene. P450 1B1 is well-known to oxidize many carcinogenic PAHs, and we found that several PAHs (i.e., 7,12-dimethylbenz[a]anthracene, 7,12-dimethylbenz[a]anthracene-5,6-diol, benzo[c]phenanthrene, fluoranthene, fluoranthene-2,3-diol, 5-methylchrysene, benz[a]pyrene-4,5-diol, benzo[a]pyrene-7,8-diol, 1-nitropyrene, 2-aminoanthracene, 2-aminofluorene, and 2-acetylaminofluorene) interacted with P450 1B1, producing Reverse Type I binding spectra. Metabolic activation of PAHs and aryl- and heterocyclic amines to genotoxic products was examined in Salmonella typhimurium NM2009, and we found that P450 2A13 and 2A6 (as well as P450 1B1) were able to activate several of these procarcinogens. The former two enzymes were particularly active in catalyzing 2-aminofluorene and 2-aminoanthracene activation, and molecular docking simulations supported the results with these procarcinogens, in terms of binding in the active sites of P450 2A13 and 2A6. These results suggest that P450 2A enzymes, as well as P450 Family 1 enzymes including P450 1B1, are major enzymes involved in activating PAHs and aryl- and heterocyclic amines, as well as tobacco-related nitrosamines.
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Affiliation(s)
- Tsutomu Shimada
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
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Shimada T, Kim D, Murayama N, Tanaka K, Takenaka S, Nagy LD, Folkman LM, Foroozesh MK, Komori M, Yamazaki H, Guengerich FP. Binding of diverse environmental chemicals with human cytochromes P450 2A13, 2A6, and 1B1 and enzyme inhibition. Chem Res Toxicol 2013; 26:517-28. [PMID: 23432429 DOI: 10.1021/tx300492j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A total of 68 chemicals including derivatives of naphthalene, phenanthrene, fluoranthene, pyrene, biphenyl, and flavone were examined for their abilities to interact with human P450s 2A13 and 2A6. Fifty-one of these 68 chemicals induced stronger Type I binding spectra (iron low- to high-spin state shift) with P450 2A13 than those seen with P450 2A6, i.e., the spectral binding intensities (ΔAmax/Ks ratio) determined with these chemicals were always higher for P450 2A13. In addition, benzo[c]phenanthrene, fluoranthene, 2,3-dihydroxy-2,3-dihydrofluoranthene, pyrene, 1-hydroxypyrene, 1-nitropyrene, 1-acetylpyrene, 2-acetylpyrene, 2,5,2',5'-tetrachlorobiphenyl, 7-hydroxyflavone, chrysin, and galangin were found to induce a Type I spectral change only with P450 2A13. Coumarin 7-hydroxylation, catalyzed by P450 2A13, was strongly inhibited by 2'-methoxy-5,7-dihydroxyflavone, 2-ethynylnaphthalene, 2'-methoxyflavone, 2-naphththalene propargyl ether, acenaphthene, acenaphthylene, naphthalene, 1-acetylpyrene, flavanone, chrysin, 3-ethynylphenanthrene, flavone, and 7-hydroxyflavone; these chemicals induced Type I spectral changes with low Ks values. On the basis of the intensities of the spectral changes and inhibition of P450 2A13, we classified the 68 chemicals into eight groups based on the order of affinities for these chemicals and inhibition of P450 2A13. The metabolism of chemicals by P450 2A13 during the assays explained why some of the chemicals that bound well were poor inhibitors of P450 2A13. Finally, we compared the 68 chemicals for their abilities to induce Type I spectral changes of P450 2A13 with the Reverse Type I binding spectra observed with P450 1B1: 45 chemicals interacted with both P450s 2A13 and 1B1, indicating that the two enzymes have some similarty of structural features regarding these chemicals. Molecular docking analyses suggest similarities at the active sites of these P450 enzymes. These results indicate that P450 2A13, as well as Family 1 P450 enzymes, is able to catalyze many detoxication and activation reactions with chemicals of environmental interest.
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Affiliation(s)
- Tsutomu Shimada
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
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Zheng ZZ, Sun YY, Zhao M, Huang H, Zhang J, Xia NS, Miao J, Zhao Q. Specific interaction between hnRNP H and HPV16 L1 proteins: implications for late gene auto-regulation enabling rapid viral capsid protein production. Biochem Biophys Res Commun 2012; 430:1047-53. [PMID: 23261416 DOI: 10.1016/j.bbrc.2012.12.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 12/08/2012] [Indexed: 01/05/2023]
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs), including hnRNP H, are RNA-binding proteins that function as splicing factors and are involved in downstream gene regulation. hnRNP H, which binds to G triplet regions in RNA, has been shown to play an important role in regulating the staged expression of late proteins in viral systems. Here, we report that the specific association between hnRNP H and a late viral capsid protein, human papillomavirus (HPV) L1 protein, leads to the suppressed function of hnRNP H in the presence of the L1 protein. The direct interaction between the L1 protein and hnRNP H was demonstrated by complex formation in solution and intracellularly using a variety of biochemical and immunochemical methods, including peptide mapping, specific co-immunoprecipitation and confocal fluorescence microscopy. These results support a working hypothesis that a late viral protein HPV16 L1, which is down regulated by hnRNP H early in the viral life cycle may provide an auto-regulatory positive feedback loop that allows the rapid production of HPV capsid proteins through suppression of the function of hnRNP H at the late stage of the viral life cycle. In this positive feedback loop, the late viral gene products that were down regulated earlier themselves disable their suppressors, and this feedback mechanism could facilitate the rapid production of capsid proteins, allowing staged and efficient viral capsid assembly.
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Affiliation(s)
- Zi-Zheng Zheng
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, Fujian 361005, PR China
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Qu Y, Shi S, Zhou H, Ma Q, Li X, Zhang X, Zhou J. Characterization of a novel phenol hydroxylase in indoles biotransformation from a strain Arthrobacter sp. W1 [corrected]. PLoS One 2012; 7:e44313. [PMID: 23028517 PMCID: PMC3441600 DOI: 10.1371/journal.pone.0044313] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 08/01/2012] [Indexed: 11/30/2022] Open
Abstract
Background Indigoids, as popular dyes, can be produced by microbial strains or enzymes catalysis. However, the new valuable products with their transformation mechanisms, especially inter-conversion among the intermediates and products have not been clearly identified yet. Therefore, it is necessary to investigate novel microbial catalytic processes for indigoids production systematically. Findings A phenol hydroxylase gene cluster (4,606 bp) from Arthrobacter sp. W1 (PHw1) was obtained. This cluster contains six components in the order of KLMNOP, which exhibit relatively low sequence identities (37–72%) with known genes. It was suggested that indole and all the tested indole derivatives except for 3-methylindole were transformed to various substituted indigoid pigments, and the predominant color products derived from indoles were identified by spectrum analysis. One new purple product from indole, 2-(7-oxo-1H-indol-6(7H)-ylidene) indolin-3-one, should be proposed as the dimerization of isatin and 7-hydroxylindole at the C-2 and C-6 positions. Tunnel entrance and docking studies were used to predict the important amino acids for indoles biotransformation, which were further proved by site-directed mutagenesis. Conclusions/Significance We showed that the phenol hydroxylase from genus Arthrobacter could transform indoles to indigoids with new chemical compounds being produced. Our work should show high insights into understanding the mechanism of indigoids bio-production.
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Affiliation(s)
- Yuanyuan Qu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China.
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Han S, Choi S, Chun YJ, Yun CH, Lee CH, Shin HJ, Na HS, Chung MW, Kim D. Functional characterization of allelic variants of polymorphic human cytochrome P450 2A6 (CYP2A6*5, *7, *8, *18, *19, and *35). Biol Pharm Bull 2012; 35:394-9. [PMID: 22382327 DOI: 10.1248/bpb.35.394] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytochrome P450 2A6 (CYP2A6) catalyzes important metabolic reactions of many xenobiotic compounds, including coumarin, nicotine, cotinine, and clinical drugs. Genetic polymorphisms of CYP2A6 can influence its metabolic activities. This study analyzed the functional activities of six CYP2A6 allelic variants (CYP2A6*5, *7, *8, *18, *19, and *35) containing nonsynonymous single-nucleotide polymorphisms. Recombinant variant enzymes of CYP2A6*7, *8, *18, *19, and *35 were successfully expressed in Escherichia coli and purified. However, a P450 holoenzyme spectrum was not detected for the CYP2A6*5 allelic variant (G479V). Structural analysis shows that the G479V mutation may alter the interaction between the A helix and the F-G helices. Enzyme kinetic analyses indicated that the effects of mutations in CYP2A6 allelic variants on drug metabolism are dependent on the substrates. In the case of coumarin 7-hydroxylation, CYP2A6*8 and *35 displayed increased K(m) values whereas CYP2A6*18 and *19 showed decreased k(cat) values, which resulted in lower catalytic efficiencies (k(cat)/K(m)). In the case of nicotine 5-oxidation, the CYP2A6*19 variant exhibited an increased K(m) value, whereas CYP2A6*18 and *35 showed much greater decreases in k(cat) values. These results suggest that individuals carrying these allelic variants are likely to have different metabolisms for different CYP2A6 substrates. Functional characterization of these allelic variants of CYP2A6 can help determine the importance of CYP2A6 polymorphisms in the metabolism of many clinical drugs.
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Affiliation(s)
- Songhee Han
- Department of Biological Sciences, Konkuk University, Seoul, Korea
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Kumar S, Jin M, Weemhoff JL. Cytochrome P450-Mediated Phytoremediation using Transgenic Plants: A Need for Engineered Cytochrome P450 Enzymes. ACTA ACUST UNITED AC 2012; 3. [PMID: 25298920 PMCID: PMC4186655 DOI: 10.4172/2157-7463.1000127] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
There is an increasing demand for versatile and ubiquitous Cytochrome P450 (CYP) biocatalysts for biotechnology, medicine, and bioremediation. In the last decade there has been an increase in realization of the power of CYP biocatalysts for detoxification of soil and water contaminants using transgenic plants. However, the major limitations of mammalian CYP enzymes are that they require CYP reductase (CPR) for their activity, and they show relatively low activity, stability, and expression. On the other hand, bacterial CYP enzymes show limited substrate diversity and usually do not metabolize herbicides and industrial contaminants. Therefore, there has been a considerable interest for biotechnological industries and the scientific community to design CYP enzymes to improve their catalytic efficiency, stability, expression, substrate diversity, and the suitability of P450-CPR fusion enzymes. Engineered CYP enzymes have potential for transgenic plants-mediated phytoremediation of herbicides and environmental contaminants. In this review we discuss: 1) the role of CYP enzymes in phytoremediation using transgenic plants, 2) problems associated with wild-type CYP enzymes in phytoremediation, and 3) examples of engineered CYP enzymes and their potential role in transgenic plant-mediated phytoremediation.
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Affiliation(s)
| | - Mengyao Jin
- School of Pharmacy, University of Missouri, USA
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Francisco CS, Rodrigues LR, Cerqueira NMFSA, Oliveira-Campos AMF, Rodrigues LM. Synthesis of novel benzofurocoumarin analogues and their anti-proliferative effect on human cancer cell lines. Eur J Med Chem 2011; 47:370-6. [PMID: 22119152 DOI: 10.1016/j.ejmech.2011.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 10/28/2011] [Accepted: 11/02/2011] [Indexed: 02/04/2023]
Abstract
The synthesis of five new tetracyclic benzofurocoumarin (benzopsoralen) analogues is described. Their inhibitory effects on the growth of three human tumor cell lines (MDA MB 231 (breast adenocarcinoma), HeLa (cervix adenocarcinoma) and TCC-SUP (bladder transitional cell carcinoma) were evaluated, and discussed in terms of structure-activity relationship.
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Affiliation(s)
- Carla S Francisco
- Chemistry Centre, School of Sciences, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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Xu Y, Shen Z, Shen J, Liu G, Li W, Tang Y. Computational insights into the different catalytic activities of CYP2A13 and CYP2A6 on NNK. J Mol Graph Model 2011; 30:1-9. [PMID: 21680215 DOI: 10.1016/j.jmgm.2011.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 02/06/2023]
Abstract
The human cytochrome P450 2A13 (CYP2A13) and P450 2A6 (CYP2A6) are 94% identical in amino acid sequence, but they metabolize many substrates with different efficiencies. Previous experimental results have shown that CYP2A13 exhibited catalytic activity that was more than 300-fold higher than CYP2A6 toward 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a carcinogen present in tobacco products. At present, however, the structural determinants accounting for the differential catalytic activities of these two isozymes toward NNK remain unclear. In the present study, molecular docking combined with molecular dynamics simulation and binding free energy calculation was performed to investigate the above issue. The results demonstrate that NNK was able to form a hydrogen bond with Asn297 in either CYP2A13 or CYP2A6. The hydrogen-bond acceptor was the pyridine nitrogen of NNK in the CYP2A13 complex, but it changed to the carbonyl oxygen in the CYP2A6 complex. NNK interacted with the residues in helix I and the K-β2 loop in CYP2A13, whereas it preferred to contact with the phenylalanine cluster in CYP2A6. The residues in helix I and the K-β2 loop of CYP2A13 played a vital role in keeping NNK in a more stable binding state. The binding free energies calculated by MM-GBSA were in agreement with the experimental results.
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Affiliation(s)
- You Xu
- Department of Pharmaceutical Sciences, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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Park HG, Lee IS, Chun YJ, Yun CH, Johnston JB, Montellano PROD, Kim D. Heterologous expression and characterization of the sterol 14α-demethylase CYP51F1 from Candida albicans. Arch Biochem Biophys 2011; 509:9-15. [PMID: 21315684 DOI: 10.1016/j.abb.2011.02.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 01/31/2011] [Accepted: 02/03/2011] [Indexed: 11/18/2022]
Abstract
Lanosterol 14α-demethylase (CYP51F1) from Candida albicans is known to be an essential enzyme in fungal sterol biosynthesis. Wild-type CYP51F1 and several of its mutants were heterologously expressed in Escherichia coli, purified, and characterized. It exhibited a typical reduced CO-difference spectrum with a maximum at 446 nm. Reconstitution of CYP51F1 with NADPH-P450 reductase gave a system that successfully converted lanosterol to its demethylated product. Titration of the purified enzyme with lanosterol produced a typical type I spectral change with K(d)=6.7 μM. The azole antifungal agents econazole, fluconazole, ketoconazole, and itraconazole bound tightly to CYP51F1 with K(d) values between 0.06 and 0.42 μM. The CYP51F1 mutations F105L, D116E, Y132H, and R467K frequently identified in clinical isolates were examined to determine their effect on azole drug binding affinity. The azole K(d) values of the purified F105L, D116E, and R467K mutants were little altered. A homology model of C. albicans CYP51F1 suggested that Tyr132 in the BC loop is located close to the heme in the active site, providing a rationale for the modified heme environment caused by the Y132H substitution. Taken together, functional expression and characterization of CYP51F1 provide a starting basis for the design of agents effective against C. albicans infections.
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Affiliation(s)
- Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
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Huang WC, Cullis PM, Raven EL, Roberts GCK. Control of the stereo-selectivity of styrene epoxidation by cytochrome P450 BM3 using structure-based mutagenesis. Metallomics 2011; 3:410-6. [DOI: 10.1039/c0mt00082e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Oezguen N, Kumar S. Analysis of Cytochrome P450 Conserved Sequence Motifs between Helices E and H: Prediction of Critical Motifs and Residues in Enzyme Functions. ACTA ACUST UNITED AC 2011; 2:1000110. [PMID: 25426333 PMCID: PMC4241269 DOI: 10.4172/2157-7609.1000110] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rational approaches have been extensively used to investigate the role of active site residues in cytochrome P450 (CYP) functions. However, recent studies using random mutagenesis suggest an important role for non-active site residues in CYP functions. Meta-analysis of the random mutants showed that 75% of the functionally important non-active site residues are present in 20% of the entire protein between helices E and H (E-H) and conserved sequence motif (CSM) between 7 and 11. The CSM approach was developed recently to investigate the functional role of non-active site residues in CYP2B4. Furthermore, we identified and analyzed the CSM in multiple CYP families and subfamilies in the E-H region. Results from CSM analysis showed that CSM 7, 8, 10, and 11 are conserved in CYP1, CYP2, and CYP3 families, while CSM 9 is conserved only in CYP2 family. Analysis of different CYP2 subfamilies showed that CYP2B and CYP2C have similar characteristics in the CSM, while the characteristics of CYP2A and CYP2D subfamilies are different. Finally, we analyzed CSM 7, 8, 10, and 11, which are common in all the CYP families/subfamilies analyzed, in fifteen important drug-metabolizing CYPs. The results showed that while CSM 8 is most conserved among these CYPs, CSM 7, 9, and 10 have significant variations. We suggest that CSM8 has a common role in all the CYPs that have been analyzed, while CSM 7, 10, and 11 may have relatively specific role within the subfamily. We further suggest that these CSM play important role in opening and closing of the substrate access/egress channel by modulating the flexible/plastic region of the protein. Thus, site-directed mutagenesis of these CSM can be used to study structure-function and dynamic/plasticity-function relationships and to design CYP biocatalysts.
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Affiliation(s)
- Numan Oezguen
- Internal Medicine-Endocrinology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-1060, USA
| | - Santosh Kumar
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte St., Kansas City, MO, USA
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Kim D, Lim YR, Ohk SO, Kim BJ, Chun YJ. Functional expression and characterization of CYP51 from dandruff-causing Malassezia globosa. FEMS Yeast Res 2010; 11:80-7. [PMID: 21114623 DOI: 10.1111/j.1567-1364.2010.00692.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Malassezia globosa is one of the most common yeasts to cause various human skin diseases including dandruff and seborrheic dermatitis. Genomic analysis of M. globosa revealed four putative cytochrome P450 (CYP) enzymes. Here, we report the purification and characterization of recombinant CYP51, a putative lanosterol 14α-demethylase, from M. globosa. The M. globosa CYP51 was expressed heterologously in Escherichia coli, followed by purification. Purified CYP51 showed a typical reduced CO-difference spectrum of P450, with a maximum absorption at 447 nm. Purified CYP51 exhibited tight binding to azole antifungal agents such as ketoconazole, econazole, fluconazole, or itraconazole, with K(d) values around 0.26-0.84 μM, which suggests that CYP51 is an orthologous target for antifungal agents in the M. globosa. In addition, three mutations (Y127F, A169S, and K176N) in the amino acid sequence of M. globosa CYP51 were identified in one of the azole-resistant strains. Homology modeling of M. globosa CYP51 suggested that the Y127F mutation may influence the resistance to azoles by blocking substrate access channels. Taken together, functional expression and characterization of the CYP51 enzyme can provide a fundamental basis for a specific antifungal drug design for dandruff caused by M. globosa.
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Affiliation(s)
- Donghak Kim
- Department of Biological Sciences, Konkuk University, Seoul, Korea College of Pharmacy, Chung-Ang University, Seoul, Korea
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42
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Zhang H, Lountos GT, Ching CB, Jiang R. Engineering of glycerol dehydrogenase for improved activity towards 1, 3-butanediol. Appl Microbiol Biotechnol 2010; 88:117-24. [PMID: 20585771 DOI: 10.1007/s00253-010-2735-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/12/2010] [Accepted: 06/12/2010] [Indexed: 10/19/2022]
Abstract
The objective of this study was to use protein engineering techniques to enhance the catalytic activity of glycerol dehydrogenase (GlyDH) on racemic 1, 3-butanediol (1, 3-BDO) for the bioproduction of the important pharmaceutical intermediate 4-hydroxy-2-butanone. Three GlyDH genes (gldA) from Escherichia coli K-12, Salmonella enterica, and Klebsiella pneumoniae MGH78578 were shuffled to generate a random mutagenesis library. The nitroblue tetrazolium/phenazine methosulfate high throughput screening protocol was used to select four chimeric enzymes with up to a 2.6-fold improved activity towards 1, 3-BDO. A rational design method was also employed to further improve the enzyme activity after DNA shuffling. Based on the homology model of GlyDH (Escherichia coli), Asp121 was predicted to influence 1, 3-BDO binding and replaced with Ala by site-directed mutagenesis. Combination of the mutations from both DNA shuffling and rational design produced the best mutant with a V (max) value of 126.6 U/mg, a 26-fold activity increase compared with that of the wild type GlyDH from E. coli.
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Affiliation(s)
- Hongfang Zhang
- School of Chemical & Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore
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43
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Park HG, Lim YR, Eun CY, Han S, Han JS, Cho KS, Chun YJ, Kim D. Candida albicans NADPH-P450 reductase: expression, purification, and characterization of recombinant protein. Biochem Biophys Res Commun 2010; 396:534-8. [PMID: 20435019 DOI: 10.1016/j.bbrc.2010.04.138] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 04/27/2010] [Indexed: 10/19/2022]
Abstract
Candida albicans is responsible for serious fungal infections in humans. Analysis of its genome identified NCP1 gene coding for a putative NADPH-P450 reductase (NPR) enzyme. This enzyme appears to supply reducing equivalents to cytochrome P450 or heme oxygenase enzymes for fungal survival and virulence. In this study, we report the characterization of the functional features of NADPH-P450 reductase from C. albicans. The recombinant C. albicans NPR protein harboring a 6x(His)-tag was expressed heterologously in Escherichia coli, and was purified. Purified C. albicans NPR has an absorption maximum at 453 nm, indicating the feature of an oxidized flavin cofactor, which was decreased by the addition of NADPH. It also evidenced NADPH-dependent cytochrome c or nitroblue tetrazolium reducing activity. This purified reductase protein was successfully able to substitute for purified mammalian NPR in the reconstitution of the human P450 1A2-catalyzed O-deethylation of 7-ethoxyresorufin. These results indicate that purified C. albicans NPR is an orthologous reductase protein that supports cytochrome P450 or heme oxygenase enzymes in C. albicans.
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Affiliation(s)
- Hyoung-Goo Park
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Republic of Korea
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Kumar S. Engineering cytochrome P450 biocatalysts for biotechnology, medicine and bioremediation. Expert Opin Drug Metab Toxicol 2010; 6:115-31. [PMID: 20064075 DOI: 10.1517/17425250903431040] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
IMPORTANCE OF THE FIELD Cytochrome P450 enzymes comprise a superfamily of heme monooxygenases that are of considerable interest for the: i) synthesis of novel drugs and drug metabolites; ii) targeted cancer gene therapy; iii) biosensor design; and iv) bioremediation. However, their applications are limited because cytochrome P450, especially mammalian P450 enzymes, show a low turnover rate and stability, and require a complex source of electrons through cytochrome P450 reductase and NADPH. AREAS COVERED IN THIS REVIEW In this review, we discuss the recent progress towards the use of P450 enzymes in a variety of the above-mentioned applications. We also present alternate and cost-effective ways to perform P450-mediated reaction, especially using peroxides. Furthermore, we expand upon the current progress in P450 engineering approaches describing several recent examples that are utilized to enhance heterologous expression, stability, catalytic efficiency and utilization of alternate oxidants. WHAT THE READER WILL GAIN The review provides a comprehensive knowledge in the design of P450 biocatalysts for potentially practical purposes. Finally, we provide a prospective on the future aspects of P450 engineering and its applications in biotechnology, medicine and bioremediation. TAKE HOME MESSAGE Because of its wide applications, academic and pharmaceutical researchers, environmental scientists and healthcare providers are expected to gain current knowledge and future prospects of the practical use of P450 biocatalysts.
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Affiliation(s)
- Santosh Kumar
- University of Missouri-Kansas City, School of Pharmacy, Division of Pharmacology and Toxicology, 2464 Charlotte St., Kansas City, MO 64108, USA.
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Tiong KH, Yiap BC, Tan EL, Ismail R, Ong CE. Functional Characterization of Cytochrome P450 2A6 Allelic VariantsCYP2A6*15,CYP2A6*16,CYP2A6*21, andCYP2A6*22. Drug Metab Dispos 2010; 38:745-51. [DOI: 10.1124/dmd.109.031054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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46
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Park SH, Kim DH, Kim D, Kim DH, Jung HC, Pan JG, Ahn T, Kim D, Yun CH. Engineering Bacterial Cytochrome P450 (P450) BM3 into a Prototype with Human P450 Enzyme Activity Using Indigo Formation. Drug Metab Dispos 2010; 38:732-9. [DOI: 10.1124/dmd.109.030759] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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47
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Zhou SF, Liu JP, Chowbay B. Polymorphism of human cytochrome P450 enzymes and its clinical impact. Drug Metab Rev 2009; 41:89-295. [PMID: 19514967 DOI: 10.1080/03602530902843483] [Citation(s) in RCA: 502] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pharmacogenetics is the study of how interindividual variations in the DNA sequence of specific genes affect drug response. This article highlights current pharmacogenetic knowledge on important human drug-metabolizing cytochrome P450s (CYPs) to understand the large interindividual variability in drug clearance and responses in clinical practice. The human CYP superfamily contains 57 functional genes and 58 pseudogenes, with members of the 1, 2, and 3 families playing an important role in the metabolism of therapeutic drugs, other xenobiotics, and some endogenous compounds. Polymorphisms in the CYP family may have had the most impact on the fate of therapeutic drugs. CYP2D6, 2C19, and 2C9 polymorphisms account for the most frequent variations in phase I metabolism of drugs, since almost 80% of drugs in use today are metabolized by these enzymes. Approximately 5-14% of Caucasians, 0-5% Africans, and 0-1% of Asians lack CYP2D6 activity, and these individuals are known as poor metabolizers. CYP2C9 is another clinically significant enzyme that demonstrates multiple genetic variants with a potentially functional impact on the efficacy and adverse effects of drugs that are mainly eliminated by this enzyme. Studies into the CYP2C9 polymorphism have highlighted the importance of the CYP2C9*2 and *3 alleles. Extensive polymorphism also occurs in other CYP genes, such as CYP1A1, 2A6, 2A13, 2C8, 3A4, and 3A5. Since several of these CYPs (e.g., CYP1A1 and 1A2) play a role in the bioactivation of many procarcinogens, polymorphisms of these enzymes may contribute to the variable susceptibility to carcinogenesis. The distribution of the common variant alleles of CYP genes varies among different ethnic populations. Pharmacogenetics has the potential to achieve optimal quality use of medicines, and to improve the efficacy and safety of both prospective and currently available drugs. Further studies are warranted to explore the gene-dose, gene-concentration, and gene-response relationships for these important drug-metabolizing CYPs.
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Affiliation(s)
- Shu-Feng Zhou
- School of Health Sciences, RMIT University, Bundoora, Victoria, Australia.
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Cheng Q, Sohl CD, Guengerich FP. High-throughput fluorescence assay of cytochrome P450 3A4. Nat Protoc 2009; 4:1258-61. [PMID: 19661996 DOI: 10.1038/nprot.2009.123] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cytochrome P450 mono-oxygenases (P450s) are the principal enzymes involved in the oxidative metabolism of drugs and other xenobiotics. In this protocol, we describe a fluorescence-based, high-throughput assay for measuring the activity of P450 3A4, one of the key enzymes involved in drug metabolism. The assay involves the oxidative debenzylation of a substituted coumarin, yielding an increase in fluorescence on reaction. The entire procedure can be accomplished in 1 h or less.
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Affiliation(s)
- Qian Cheng
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee USA
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DeVore NM, Smith BD, Wang JL, Lushington GH, Scott EE. Key residues controlling binding of diverse ligands to human cytochrome P450 2A enzymes. Drug Metab Dispos 2009; 37:1319-27. [PMID: 19251817 PMCID: PMC2683692 DOI: 10.1124/dmd.109.026765] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 02/26/2009] [Indexed: 11/22/2022] Open
Abstract
Although the human lung cytochrome P450 2A13 (CYP2A13) and its liver counterpart cytochrome P450 2A6 (CYP2A6) are 94% identical in amino acid sequence, they metabolize a number of substrates with substantially different efficiencies. To determine differences in binding for a diverse set of cytochrome P450 2A ligands, we have measured the spectral binding affinities (K(D)) for nicotine, phenethyl isothiocyanate (PEITC), coumarin, 2'-methoxyacetophenone (MAP), and 8-methoxypsoralen. The differences in the K(D) values for CYP2A6 versus CYP2A13 ranged from 74-fold for 2'-methoxyacetophenone to 1.1-fold for coumarin, with CYP2A13 demonstrating the higher affinity. To identify active site amino acids responsible for the differences in binding of MAP, PEITC, and coumarin, 10 CYP2A13 mutant proteins were generated in which individual amino acids from the CYP2A6 active site were substituted into CYP2A13 at the corresponding position. Titrations revealed that substitutions at positions 208, 300, and 301 individually had the largest effects on ligand binding. The collective relevance of these amino acids to differential ligand selectivity was verified by evaluating binding to CYP2A6 mutant enzymes that incorporate several of the CYP2A13 amino acids at these positions. Inclusion of four CYP2A13 amino acids resulted in a CYP2A6 mutant protein (I208S/I300F/G301A/S369G) with binding affinities for MAP and PEITC much more similar to those observed for CYP2A13 than to those for CYP2A6 without altering coumarin binding. The structure-based quantitative structure-activity relationship analysis using COMBINE successfully modeled the observed mutant-ligand trends and emphasized steric roles for active site residues including four substituted amino acids and an adjacent conserved Leu(370).
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Affiliation(s)
- N M DeVore
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045, USA
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50
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Li W, Ode H, Hoshino T, Liu H, Tang Y, Jiang H. Reduced Catalytic Activity of P450 2A6 Mutants with Coumarin: A Computational Investigation. J Chem Theory Comput 2009; 5:1411-20. [DOI: 10.1021/ct900018t] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Weihua Li
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China, and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Hirotaka Ode
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China, and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Tyuji Hoshino
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China, and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Hong Liu
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China, and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yun Tang
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China, and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Hualiang Jiang
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China, and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
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