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Richard AM, Estrada DF, Flynn L, Pochapsky SS, Scott EE, Pochapsky TC. Tracking protein-protein interactions by NMR: conformational selection in human steroidogenic cytochrome P450 CYP17A1 induced by cytochrome b5. Phys Chem Chem Phys 2024; 26:16980-16988. [PMID: 38842434 PMCID: PMC11186455 DOI: 10.1039/d4cp01268b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/26/2024] [Indexed: 06/07/2024]
Abstract
The human steroidogenic cytochrome P450 CYP17A1 catalyzes two types of reactions in the biosynthetic pathway leading from pregnenolone to testosterone and several other steroid hormones. The first is the hydroxylation of pregnenolone or progesterone to the corresponding 17α-hydroxy steroid, followed by a lyase reaction that converts these 17α-hydroxy intermediates to the androgens dehydroepiandrosterone and androstenedione, respectively. cytochrome b5 (cytb5) is known to act as both an effector and electron donor for the lyase oxidations, markedly stimulating the rate of the lyase reaction in its presence relative to the rate in its absence. Extensive sequential backbone 1H,15N and 13C nuclear magnetic resonance assignments have now been made for oxidized CYP17A1 bound to the prostate cancer drug and inhibitor abiraterone. This is the first eukaryotic P450 for which such assignments are now available. These assignments allow more complete interpretation of the structural perturbations observed upon cytb5 addition. Possible mechanism(s) for the effector activity of cytb5 are discussed in light of this new information.
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Affiliation(s)
- Alaina M Richard
- Chemical Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - D Fernando Estrada
- Department of Medicinal Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
| | - Liam Flynn
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA.
| | - Susan Sondej Pochapsky
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA.
| | - Emily E Scott
- Chemical Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Medicinal Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
- Departments of Medicinal Chemistry, Pharmacology, and Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas C Pochapsky
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA.
- Department of Biochemistry and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA
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2
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Tateishi Y, Webb SN, Li B, Liu L, Lindsey Rose K, Leser M, Patel P, Guengerich FP. Proteomics, modeling, and fluorescence assays delineate cytochrome b 5 residues involved in binding and stimulation of cytochrome P450 17A1 17,20-lyase. J Biol Chem 2024; 300:105688. [PMID: 38280431 PMCID: PMC10878793 DOI: 10.1016/j.jbc.2024.105688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/29/2024] Open
Abstract
Cytochrome b5 (b5) is known to stimulate some catalytic activities of cytochrome P450 (P450, CYP) enzymes, although mechanisms still need to be defined. The reactions most strongly enhanced by b5 are the 17,20-lyase reactions of P450 17A1 involved in steroid biosynthesis. We had previously used a fluorescently labeled human b5 variant (Alexa 488-T70C-b5) to characterize human P450 17A1-b5 interactions, but subsequent proteomic analyses indicated that lysines in b5 were also modified with Alexa 488 maleimide in addition to Cys-70, due to disulfide dimerization of the T70C mutant. A series of b5 variants were constructed with Cys replacements for the identified lysine residues and labeled with the dye. Fluorescence attenuation and the function of b5 in the steroid lyase reaction depended on the modified position. Apo-b5 (devoid of heme group) studies revealed the lack of involvement of the b5 heme in the fluorescence attenuation. A structural model of b5 with P450 17A1 was predicted using AlphaFold-Multimer algorithms/Rosetta docking, based upon the individual structures, which predicted several new contacts not previously reported, that is, interactions of b5 Glu-48:17A1 Arg-347, b5 Glu-49:17A1 Arg-449, b5 Asp-65:17A1 Arg-126, b5 Asp-65:17A1 Arg-125, and b5 Glu-61:17A1 Lys-91. Fluorescence polarization assays with two modified b5 variants yielded Kd values (for b5-P450 17A1) of 120 to 380 nM, the best estimate of binding affinity. We conclude that both monomeric and dimeric b5 can bind to P450 17A1 and stimulate activity. Results with the mutants indicate that several Lys residues in b5 are sensitive to the interaction with P450 17A1, including Lys-88 and Lys-91.
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Affiliation(s)
- Yasuhiro Tateishi
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Stephany N Webb
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Bian Li
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lu Liu
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Kristie Lindsey Rose
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Proteomics Laboratory, Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Micheal Leser
- Proteomics Laboratory, Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Purvi Patel
- Proteomics Laboratory, Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
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Wróbel TM, Jørgensen FS, Pandey AV, Grudzińska A, Sharma K, Yakubu J, Björkling F. Non-steroidal CYP17A1 Inhibitors: Discovery and Assessment. J Med Chem 2023; 66:6542-6566. [PMID: 37191389 DOI: 10.1021/acs.jmedchem.3c00442] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
CYP17A1 is an enzyme that plays a major role in steroidogenesis and is critically involved in the biosynthesis of steroid hormones. Therefore, it remains an attractive target in several serious hormone-dependent cancer diseases, such as prostate cancer and breast cancer. The medicinal chemistry community has been committed to the discovery and development of CYP17A1 inhibitors for many years, particularly for the treatment of castration-resistant prostate cancer. The current Perspective reflects upon the discovery and evaluation of non-steroidal CYP17A1 inhibitors from a medicinal chemistry angle. Emphasis is placed on the structural aspects of the target, key learnings from the presented chemotypes, and design guidelines for future inhibitors.
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Affiliation(s)
- Tomasz M Wróbel
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances, Faculty of Pharmacy, Medical University of Lublin, Chodźki 4a, 20093 Lublin, Poland
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Flemming Steen Jørgensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Amit V Pandey
- Pediatric Endocrinology, Department of Pediatrics, University Children's Hospital, Inselspital, Bern and Translational Hormone Research Program, Department of Biomedical Research, University of Bern, Freiburgstrasse 15, 3010 Bern, Switzerland
| | - Angelika Grudzińska
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances, Faculty of Pharmacy, Medical University of Lublin, Chodźki 4a, 20093 Lublin, Poland
| | - Katyayani Sharma
- Pediatric Endocrinology, Department of Pediatrics, University Children's Hospital, Inselspital, Bern and Translational Hormone Research Program, Department of Biomedical Research, University of Bern, Freiburgstrasse 15, 3010 Bern, Switzerland
| | - Jibira Yakubu
- Pediatric Endocrinology, Department of Pediatrics, University Children's Hospital, Inselspital, Bern and Translational Hormone Research Program, Department of Biomedical Research, University of Bern, Freiburgstrasse 15, 3010 Bern, Switzerland
| | - Fredrik Björkling
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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Yamagata S, Kageyama K, Usui T, Saito K, Takayasu S, Usutani M, Terui K, Daimon M. Identification of a homozygous c.1039C>T (p.R347C) variant in CYP17A1 in a 67-year-old female patient with partial 17α-hydroxylase/17,20-lyase deficiency. Endocr J 2022; 69:115-120. [PMID: 34483146 DOI: 10.1507/endocrj.ej21-0266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
17α-Hydroxylase/17,20-lyase deficiency (17OHD) is caused by pathogenic mutations in CYP17A1. Impaired 17α-hydroxylase and 17,20-lyase activities typically induce hypertension, hypokalemia, sexual infantilism, and amenorrhea. Most patients with 17OHD are diagnosed in adolescence. Here, we report a female (46, XX) patient with 17OHD who was diagnosed at the age of 67 years. Genetic analysis was performed using direct DNA sequencing of polymerase chain reaction (PCR) products and multiplex ligation-dependent probe amplification (MLPA) analysis. Direct DNA sequencing revealed a homozygous c.1039C>T in CYP17A1, corresponding to a p.R347C amino acid change. MLPA probe signals showed that the CYP17A1 mutation was present in the homozygous carrier state. The patient's dehydroepiandrosterone sulfate and androstenedione levels were extremely low, despite elevated adrenocorticotropic hormone (ACTH) and normal cortisol levels. A corticotropin-releasing hormone (CRH) test showed no response of cortisol, despite a normal response of ACTH. Rapid ACTH injection resulted in elevations in the deoxycorticosterone, corticosterone, aldosterone, and 17-hydroxypregnenolone levels, but not in the cortisol level. These results suggested that 17α-hydroxylase/17,20-lyase activities were partially impaired. Computed tomography revealed bilateral adrenal hyperplasia and a hypoplastic uterus. A high basal plasma ACTH level and a discrepancy between ACTH and cortisol responses in a CRH test may provide a definitive diagnostic clue for this disease.
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Affiliation(s)
- Satoshi Yamagata
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Kazunori Kageyama
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Takeshi Usui
- Department of Medical Genetics, Shizuoka General Hospital, Shizuoka 420-8527, Japan
- Shizuoka Graduate University of Public Health, Shizuoka 420-0881, Japan
| | - Kohei Saito
- Department of Medical Genetics, Shizuoka General Hospital, Shizuoka 420-8527, Japan
| | - Shinobu Takayasu
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Mari Usutani
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Ken Terui
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Makoto Daimon
- Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
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5
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Chen K, Liu C, Zhang X, Xu Z, Shao M, Yang T, Rao Z. Identification of a novel cytochrome P450 17A1 enzyme and its molecular engineering. Catal Sci Technol 2022. [DOI: 10.1039/d2cy01605b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Progesterone-17α-hydroxylase (CYP17A) could transform progesterone to 17α-hydroxyprogesterone (17-HP).
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Affiliation(s)
- Kexin Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, No. 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
- Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Chao Liu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, No. 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
- Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xian Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, No. 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
- Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhenghong Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, No. 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
| | - Minglong Shao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, No. 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
- Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Taowei Yang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, No. 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
- Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, No. 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
- Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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Kim D, Kim V, McCarty KD, Guengerich FP. Tight binding of cytochrome b 5 to cytochrome P450 17A1 is a critical feature of stimulation of C21 steroid lyase activity and androgen synthesis. J Biol Chem 2021; 296:100571. [PMID: 33753170 PMCID: PMC8080067 DOI: 10.1016/j.jbc.2021.100571] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 12/19/2022] Open
Abstract
It has been recognized for >50 years that cytochrome b5 (b5) stimulates some cytochrome P450 (P450)–catalyzed oxidations, but the basis of this function is still not understood well. The strongest stimulation of catalytic activity by b5 is in the P450 17A1 lyase reaction, an essential step in androgen synthesis from 21-carbon (C21) steroids, making this an excellent model system to interrogate b5 function. One of the issues in studying b5–P450 interactions has been the limited solution assay methods. We constructed a fluorescently labeled variant of human b5 that can be used in titrations. The labeled b5 bound to WT P450 17A1 with a Kd of 2.5 nM and rapid kinetics, on the order of 1 s−1. Only weak binding was observed with the clinical P450 17A1 variants E305G, R347H, and R358Q; these mutants are deficient in lyase activity, which has been hypothesized to be due to attenuated b5 binding. Kd values were not affected by the presence of P450 17A1 substrates. A peptide containing the P450 17A1 Arg-347/Arg-358 region attenuated Alexa 488-T70C-b5 fluorescence at higher concentrations. The addition of NADPH–P450 reductase (POR) to an Alexa 488-T70C-b5:P450 17A1 complex resulted in a concentration-dependent partial restoration of b5 fluorescence, indicative of a ternary P450:b5:POR complex, which was also supported by gel filtration experiments. Overall, these results are interpreted in the context of a dynamic and tight P450 17A1:b5 complex that also binds POR to form a catalytically competent ternary complex, and variants that disrupt this interaction have low catalytic activity.
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Affiliation(s)
- Donghak Kim
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea
| | - Vitchan Kim
- Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea
| | - Kevin D McCarty
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
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7
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Squires EJ, Gray MA, Lou Y. Effect of mutations in porcine CYB5A and CYP17A1 on the metabolism of pregnenolone. J Steroid Biochem Mol Biol 2019; 195:105469. [PMID: 31509771 DOI: 10.1016/j.jsbmb.2019.105469] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 11/28/2022]
Abstract
Cytochrome P450 17A1 (CYP17A1) catalyses the 17α-hydroxylation and 17,20 lyase reactions to convert pregnenolone to 17α-hydroxypregnenolone (17OHP) and subsequently the androgen dehydroepiandrosterone (DHEA). In pigs and humans, CYP17A1 also catalyses the delta-16-synthase reaction to produce the 16-androstene steroid 5,16-androstadien-3β-ol (16A), which is then further metabolised to the sex pheromone androstenone. Cytochrome b5A (CYB5A) stimulates the 17,20 lyase reaction and is required for the delta 16-synthase reaction. We have identified and mutated residues in porcine CYP17A1 and CYB5A that may alter the synthesis of DHEA and 16A. This included residues in the steroid binding pocket of CYP17A1 and residues on the surface of CYP17A1 and CYB5A that are involved in binding of CYP17A1 to CYB5A. We then expressed the various mutations of CYB5A and CYP17A1 along with porcine cytochrome P450 oxidoreductase (POR) and cytochrome b5 reductase (CYB5R3) in HEK293 cells and measured the formation of metabolites 16A, 17OHP and DHEA from radiolabelled pregnenolone by high performance liquid chromatography (HPLC). Mutations were identified in both CYP17A1 and CYB5A that affected the production of the different metabolites and also affected the overall production of metabolites. Several combinations of mutations decreased the production of both 16A and DHEA and increased production of 17OHP, while the N62S mutation of CYB5A with wild type CYP17A1 increased production of both 16A and DHEA. The best combination of mutations to reduce the production of 16A, while maintaining the production of DHEA and the overall conversion similar to wild type are the N21K, L28V, N21K/L28V and the R52 M/N62S mutations of CYB5A with the D103S mutation of CYP17A1.
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Affiliation(s)
- E James Squires
- Dept. of Animal Biosciences, University of Guelph, Guelph, Ontario, N1G2W1, Canada.
| | - Matthew A Gray
- Dept. of Animal Biosciences, University of Guelph, Guelph, Ontario, N1G2W1, Canada
| | - Yanping Lou
- Dept. of Animal Biosciences, University of Guelph, Guelph, Ontario, N1G2W1, Canada
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Meng L, Yu H, Qu J, Niu J, Ni F, Han P, Yu H, Wang X. Two cyp17 genes perform different functions in the sex hormone biosynthesis and gonadal differentiation in Japanese flounder (Paralichthys olivaceus). Gene 2019; 702:17-26. [PMID: 30898704 DOI: 10.1016/j.gene.2019.02.104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 02/21/2019] [Accepted: 02/28/2019] [Indexed: 11/25/2022]
Abstract
P450c17, a key enzyme in the steroid generation pathway, plays an important role in the production of sex steroid and cortisol. In this study, two cyp17 gene isoforms, Pocyp17-I and Pocyp17-II were isolated from Paralichthys olivaceus gonads. Domain architecture analysis of Pocyp17-I and Pocyp17-II revealed that they had three regions important to enzymatic function. Structural analysis showed that Pocyp17-I and Pocyp17-II had 8 and 9 exons respectively, and the difference was caused by the insertion of an extra intron (intron1) in the latter. Quantitative real-time polymerase chain reaction results indicated that the expression of these two genes showed sexually dimorphism that Pocyp17-I and Pocyp17-II were highest expressed in testis and ovary, respectively. The in situ hybridization analysis of gonads indicated that Pocyp17-I and Pocyp17-II mRNA were both detected in oocytes, spermatocytes and Sertoli cells. After injection of androgen and estrogen (17α-methyltestosterone, 17β-estradiol) of different concentrations, the expression level of Pocyp17-I decreased significantly (P < 0.01), whereas estrogen had no influence on Pocyp17-II, but androgen upregulated the expression of Pocyp17-II (P < 0.05). Moreover, Pocyp17-I expression level was down-regulated significantly by NR0b1 but up-regulated by NR5a2 (P < 0.05), whereas Pocyp17-II expression level was down-regulated significantly by NR0b1 and NR5a2 (P < 0.05). All these results demonstrated that there were differences in expression patterns, feedback actions of sex hormones and transcriptional regulations between cyp17-I and cyp17-II, which revealed that cyp17-I and cyp17-II might perform different functions in sex hormones biosynthesis and gonadal differentiation in Japanese flounder.
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Affiliation(s)
- Lihui Meng
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China
| | - Haiyang Yu
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China
| | - Jiangbo Qu
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China
| | - Jingjing Niu
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China
| | - Feifei Ni
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China
| | - Ping Han
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China
| | - Haiyang Yu
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China.
| | - Xubo Wang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China.
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9
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Sarathi V, Reddy R, Atluri S, Shivaprasad C. A challenging case of primary amenorrhoea. BMJ Case Rep 2018; 2018:bcr-2018-225447. [PMID: 30002216 DOI: 10.1136/bcr-2018-225447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The differential diagnosis of a girl presenting with primary amenorrhoea includes numerous conditions. Often, patients of 46XY disorder of sex development (DSD) are reared as girl and present with primary amenorrhoea. Their further evaluation to reach the final diagnosis is often a great challenge. In this article, we report a challenging case of 46XY DSD presented with primary amenorrhoea. Patient had spontaneous breast development which initially confused the diagnosis to complete androgen insensitivity syndrome. However, low testosterone suggested against this possibility and further evaluation revealed hormonal findings consistent with 17α hydroxylase/17,20 lyase (CYP17A1) deficiency. Patient had 46XY karyotype and in consistence with hormonal findings patient was found to have a likely pathogenic homozygous c.1345C>T (p.Arg449Cys) variation in exon 8 of CYP17A1.
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Affiliation(s)
- Vijaya Sarathi
- Endocrinology, Vydehi Institute of Medical Sciences and Research Centre, Bangalore, Karnataka, India
| | - Ramesh Reddy
- General Surgery, Vydehi Institute of Medical Sciences and Research Centre, Bangalore, Karnataka, India
| | - Sridevi Atluri
- Endocrinology, Vydehi Institute of Medical Sciences and Research Centre, Bangalore, Karnataka, India
| | - Channabasappa Shivaprasad
- Endocrinology, Vydehi Institute of Medical Sciences and Research Centre, Bangalore, Karnataka, India
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10
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Gonzalez E, Guengerich FP. Kinetic processivity of the two-step oxidations of progesterone and pregnenolone to androgens by human cytochrome P450 17A1. J Biol Chem 2017; 292:13168-13185. [PMID: 28684414 DOI: 10.1074/jbc.m117.794917] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/24/2017] [Indexed: 11/06/2022] Open
Abstract
Cytochrome P450 (P450, CYP) 17A1 plays a critical role in steroid metabolism, catalyzing both the 17α-hydroxylation of pregnenolone and progesterone and the subsequent 17α,20-lyase reactions to form dehydroepiandrosterone (DHEA) and androstenedione (Andro), respectively, critical for generating glucocorticoids and androgens. Human P450 17A1 reaction rates examined are enhanced by the accessory protein cytochrome b5 (b5), but the exact role of b5 in P450 17A1-catalyzed reactions is unclear as are several details of these reactions. Here, we examined in detail the processivity of the 17α-hydroxylation and lyase steps. b5 did not enhance reaction rates by decreasing the koff rates of any of the steroids. Steroid binding to P450 17A1 was more complex than a simple two-state system. Pre-steady-state experiments indicated lag phases for Andro production from progesterone and for DHEA from pregnenolone, indicating a distributive character of the enzyme. However, we observed processivity in pregnenolone/DHEA pulse-chase experiments. (S)-Orteronel was three times more inhibitory toward the conversion of 17α-hydroxypregnenolone to DHEA than toward the 17α-hydroxylation of pregnenolone. IC50 values for (S)-orteronel were identical for blocking DHEA formation from pregnenolone and for 17α-hydroxylation, suggestive of processivity. Global kinetic modeling helped assign sets of rate constants for individual or groups of reactions, indicating that human P450 17A1 is an inherently distributive enzyme but that some processivity is present, i.e. some of the 17α-OH pregnenolone formed from pregnenolone did not dissociate from P450 17A1 before conversion to DHEA. Our results also suggest multiple conformations of P450 17A1, as previously proposed on the basis of NMR spectroscopy and X-ray crystallography.
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Affiliation(s)
- Eric Gonzalez
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - F Peter Guengerich
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
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11
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Bhatt MR, Khatri Y, Rodgers RJ, Martin LL. Role of cytochrome b5 in the modulation of the enzymatic activities of cytochrome P450 17α-hydroxylase/17,20-lyase (P450 17A1). J Steroid Biochem Mol Biol 2017; 170:2-18. [PMID: 26976652 DOI: 10.1016/j.jsbmb.2016.02.033] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/25/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Abstract
Cytochrome b5 (cyt b5) is a small hemoprotein that plays a significant role in the modulation of activities of an important steroidogenic enzyme, cytochrome P450 17α-hydroxylase/17,20-lyase (P450 17A1, CYP17A1). Located in the zona fasciculata and zona reticularis of the adrenal cortex and in the gonads, P450 17A1 catalyzes two different reactions in the steroidogenic pathway; the 17α-hydroxylation and 17,20-lyase, in the endoplasmic reticulum of these respective tissues. The activities of P450 17A1 are regulated by cyt b5 that enhances the 17,20-lyase reaction by promoting the coupling of P450 17A1 and cytochrome P450 reductase (CPR), allosterically. Cyt b5 can also act as an electron donor to enhance the 16-ene-synthase activity of human P450 17A1. In this review, we discuss the many roles of cyt b5 and focus on the modulation of CYP17A1 activities by cyt b5 and the mechanisms involved.
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Affiliation(s)
- Megh Raj Bhatt
- Everest Biotech Pvt. Ltd., Khumaltar, Lalitpur, P.O. Box 21608, Kathmandu 44600, Nepal
| | - Yogan Khatri
- Institute of Biochemistry, Saarland University, 66123 Saarbrücken, Germany
| | - Raymond J Rodgers
- School of Medicine, Robinson Research Institute, University of Adelaide, Adelaide SA 5005, Australia
| | - Lisandra L Martin
- School of Chemistry, Monash University, Clayton, 3800, Victoria, Australia.
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12
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Peng HM, Auchus RJ. Molecular Recognition in Mitochondrial Cytochromes P450 That Catalyze the Terminal Steps of Corticosteroid Biosynthesis. Biochemistry 2017; 56:2282-2293. [DOI: 10.1021/acs.biochem.7b00034] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Hwei-Ming Peng
- Division of Metabolism, Endocrinology,
and Diabetes, Department of Internal Medicine, and Department of Pharmacology, University of Michigan Health System, Ann Arbor, Michigan 48109, United States
| | - Richard J. Auchus
- Division of Metabolism, Endocrinology,
and Diabetes, Department of Internal Medicine, and Department of Pharmacology, University of Michigan Health System, Ann Arbor, Michigan 48109, United States
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13
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Estrada DF, Laurence JS, Scott EE. Cytochrome P450 17A1 Interactions with the FMN Domain of Its Reductase as Characterized by NMR. J Biol Chem 2015; 291:3990-4003. [PMID: 26719338 DOI: 10.1074/jbc.m115.677294] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Indexed: 11/06/2022] Open
Abstract
To accomplish key physiological processes ranging from drug metabolism to steroidogenesis, human microsomal cytochrome P450 enzymes require the sequential input of two electrons delivered by the FMN domain of NADPH-cytochrome P450 reductase. Although some human microsomal P450 enzymes can instead accept the second electron from cytochrome b5, for human steroidogenic CYP17A1, the cytochrome P450 reductase FMN domain delivers both electrons, and b5 is an allosteric modulator. The structural basis of these key but poorly understood protein interactions was probed by solution NMR using the catalytically competent soluble domains of each protein. Formation of the CYP17A1·FMN domain complex induced differential line broadening of the NMR signal for each protein. Alterations in the exchange dynamics generally occurred for residues near the surface of the flavin mononucleotide, including 87-90 (loop 1), and for key CYP17A1 active site residues. These interactions were modulated by the identity of the substrate in the buried CYP17A1 active site and by b5. The FMN domain outcompetes b5 for binding to CYP17A1 in the three-component system. These results and comparison with previous NMR studies of the CYP17A1·b5 complex suggest a model of CYP17A1 enzyme regulation.
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Affiliation(s)
- D Fernando Estrada
- From the Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045 and
| | - Jennifer S Laurence
- the Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047
| | - Emily E Scott
- From the Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045 and
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14
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Simonov AN, Holien JK, Yeung JCI, Nguyen AD, Corbin CJ, Zheng J, Kuznetsov VL, Auchus RJ, Conley AJ, Bond AM, Parker MW, Rodgers RJ, Martin LL. Mechanistic Scrutiny Identifies a Kinetic Role for Cytochrome b5 Regulation of Human Cytochrome P450c17 (CYP17A1, P450 17A1). PLoS One 2015; 10:e0141252. [PMID: 26587646 PMCID: PMC4654539 DOI: 10.1371/journal.pone.0141252] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/06/2015] [Indexed: 01/12/2023] Open
Abstract
Cytochrome P450c17 (P450 17A1, CYP17A1) is a critical enzyme in the synthesis of androgens and is now a target enzyme for the treatment of prostate cancer. Cytochrome P450c17 can exhibit either one or two physiological enzymatic activities differentially regulated by cytochrome b5. How this is achieved remains unknown. Here, comprehensive in silico, in vivo and in vitro analyses were undertaken. Fluorescence Resonance Energy Transfer analysis showed close interactions within living cells between cytochrome P450c17 and cytochrome b5. In silico modeling identified the sites of interaction and confirmed that E48 and E49 residues in cytochrome b5 are essential for activity. Quartz crystal microbalance studies identified specific protein-protein interactions in a lipid membrane. Voltammetric analysis revealed that the wild type cytochrome b5, but not a mutated, E48G/E49G cyt b5, altered the kinetics of electron transfer between the electrode and the P450c17. We conclude that cytochrome b5 can influence the electronic conductivity of cytochrome P450c17 via allosteric, protein-protein interactions.
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Affiliation(s)
| | - Jessica K. Holien
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
| | | | - Ann D. Nguyen
- School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - C. Jo Corbin
- School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Jie Zheng
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, California, United States of America
| | | | - Richard J. Auchus
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alan J. Conley
- School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Alan M. Bond
- School of Chemistry, Monash University, Clayton, Victoria, Australia
| | - Michael W. Parker
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Raymond J. Rodgers
- Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
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15
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Xiao F, Yang M, Xu Y, Vongsangnak W. Comparisons of Prostate Cancer Inhibitors Abiraterone and TOK-001 Binding with CYP17A1 through Molecular Dynamics. Comput Struct Biotechnol J 2015; 13:520-7. [PMID: 26682016 PMCID: PMC4652021 DOI: 10.1016/j.csbj.2015.10.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 10/25/2015] [Accepted: 10/26/2015] [Indexed: 12/19/2022] Open
Abstract
Cytochrome P450 17A1 (CYP17A1) is associated in the steroid hormone biosynthesis in human. As cell proliferation of prostate cancer in response to androgen steroid, an inhibition of CYP17A1 becomes an alternative approach to inhibit biosynthesis of androgen and support treatment of prostate cancer. However, biology-driven inhibitor development of prostate cancer is poorly elucidated. The aims of this study are to address structural differences at atomic-level between CYP17A1 and inhibitors i.e., abiraterone and TOK-001, and further investigate the effect of point mutation of CYP17A1 on the active site stability and the local interactions that are hydrophobic interaction and hydrogen bonding throughout molecular dynamics (MD) simulation. After performing multiple comparisons among four different complexes across CYP17A1 and inhibitors, interestingly TOK-001 oriented toward the active pocket and formed larger volume with I-helix of CYP17A1 than abiraterone, whereas abiraterone showed tighter binding and more active site stability. Considering on the effect of hydrophobic interaction and hydrogen bonding between abiraterone and CYP17A1, the key residues of Phe114, Ile371, Val482, and Asn202 were identified. This contributes into tight binding interactions; however abiraterone is effectively weakened along with the global conformation mobility increased in A105L mutation. Surprisingly, overall conformation of the CYP17A1 remained stable when bound to TOK-001. This basic knowledge can guide future experiments on design of efficient inhibitors for CYP17A1, which provides theoretical basis of androgen-dependent disease therapy.
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Affiliation(s)
- Fei Xiao
- School of Biology and Basic Medical Sciences, Medical College of Soochow University, 199 Ren ai Road, China-Singapore Industrial Park, Suzhou, JiangSu 215123, China
- Corresponding authors.
| | - Maohua Yang
- School of Biology and Basic Medical Sciences, Medical College of Soochow University, 199 Ren ai Road, China-Singapore Industrial Park, Suzhou, JiangSu 215123, China
| | - Youjun Xu
- School of Biology and Basic Medical Sciences, Medical College of Soochow University, 199 Ren ai Road, China-Singapore Industrial Park, Suzhou, JiangSu 215123, China
| | - Wanwipa Vongsangnak
- Department of Zoology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Corresponding authors.
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16
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Takayama SIJ, Loutet SA, Mauk AG, Murphy MEP. A Ferric-Peroxo Intermediate in the Oxidation of Heme by IsdI. Biochemistry 2015; 54:2613-21. [PMID: 25853501 DOI: 10.1021/acs.biochem.5b00239] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The canonical heme oxygenases (HOs) catalyze heme oxidation via a heme-bound hydroperoxo intermediate that is stabilized by a water cluster at the active site of the enzyme. In contrast, the hydrophobic active site of IsdI, a heme-degrading enzyme from Staphylococcus aureus, lacks a water cluster and is expected to oxidize heme by an alternative mechanism. Reaction of the IsdI-heme complex with either H2O2 or m-chloroperoxybenzoic acid fails to produce a specific oxidized heme iron intermediate, suggesting that ferric-hydroperoxo or ferryl derivatives of IsdI are not involved in the catalytic mechanism of this enzyme. IsdI lacks a proton-donating group in the distal heme pocket, so the possible involvement of a ferric-peroxo intermediate has been evaluated. Density functional theory (DFT) calculations indicate that heme oxidation involving a ferric-peroxo intermediate is energetically accessible, whereas the energy barrier for a reaction involving a ferric-hydroperoxo intermediate is too great in the absence of a proton donor. We propose that IsdI catalyzes heme oxidation through nucleophilic attack by the heme-bound peroxo species. This proposal is consistent with our previous demonstration by nuclear magnetic resonance spectroscopy that heme ruffling increases the susceptibility of the meso-carbon of heme to nucleophilic attack.
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Affiliation(s)
- Shin-Ichi J Takayama
- †Department of Microbiology and Immunology, ‡Department of Biochemistry and Molecular Biology, and §UBC Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Slade A Loutet
- †Department of Microbiology and Immunology, ‡Department of Biochemistry and Molecular Biology, and §UBC Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - A Grant Mauk
- †Department of Microbiology and Immunology, ‡Department of Biochemistry and Molecular Biology, and §UBC Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael E P Murphy
- †Department of Microbiology and Immunology, ‡Department of Biochemistry and Molecular Biology, and §UBC Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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17
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Peng HM, Liu J, Forsberg SE, Tran HT, Anderson SM, Auchus RJ. Catalytically relevant electrostatic interactions of cytochrome P450c17 (CYP17A1) and cytochrome b5. J Biol Chem 2014; 289:33838-49. [PMID: 25315771 DOI: 10.1074/jbc.m114.608919] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Two acidic residues, Glu-48 and Glu-49, of cytochrome b5 (b5) are essential for stimulating the 17,20-lyase activity of cytochrome P450c17 (CYP17A1). Substitution of Ala, Gly, Cys, or Gln for these two glutamic acid residues abrogated all capacity to stimulate 17,20-lyase activity. Mutations E49D and E48D/E49D retained 23 and 38% of wild-type activity, respectively. Using the zero-length cross-linker ethyl-3-(3-dimethylaminopropyl)carbodiimide, we obtained cross-linked heterodimers of b5 and CYP17A1, wild-type, or mutations R347K and R358K. In sharp contrast, the b5 double mutation E48G/E49G did not form cross-linked complexes with wild-type CYP17A1. Mass spectrometric analysis of the CYP17A1-b5 complexes identified two cross-linked peptide pairs as follows: CYP17A1-WT: (84)EVLIKK(89)-b5: (53)EQAGGDATENFEDVGHSTDAR(73) and CYP17A1-R347K: (341)TPTISDKNR(349)-b5: (40)FLEEHPGGEEVLR(52). Using these two sites of interaction and Glu-48/Glu-49 in b5 as constraints, protein docking calculations based on the crystal structures of the two proteins yielded a structural model of the CYP17A1-b5 complex. The appositional surfaces include Lys-88, Arg-347, and Arg-358/Arg-449 of CYP17A1, which interact with Glu-61, Glu-42, and Glu-48/Glu-49 of b5, respectively. Our data reveal the structural basis of the electrostatic interactions between these two proteins, which is critical for 17,20-lyase activity and androgen biosynthesis.
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Affiliation(s)
- Hwei-Ming Peng
- From the Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine
| | - Jiayan Liu
- From the Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine
| | - Sarah E Forsberg
- From the Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine
| | | | - Sean M Anderson
- From the Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine
| | - Richard J Auchus
- From the Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, the Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109
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18
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Kandel SE, Lampe JN. Role of protein-protein interactions in cytochrome P450-mediated drug metabolism and toxicity. Chem Res Toxicol 2014; 27:1474-86. [PMID: 25133307 PMCID: PMC4164225 DOI: 10.1021/tx500203s] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
![]()
Through their unique oxidative chemistry,
cytochrome P450 monooxygenases
(CYPs) catalyze the elimination of most drugs and toxins from the
human body. Protein–protein interactions play a critical role
in this process. Historically, the study of CYP–protein interactions
has focused on their electron transfer partners and allosteric mediators,
cytochrome P450 reductase and cytochrome b5. However, CYPs can bind
other proteins that also affect CYP function. Some examples include
the progesterone receptor membrane component 1, damage resistance
protein 1, human and bovine serum albumin, and intestinal fatty acid
binding protein, in addition to other CYP isoforms. Furthermore, disruption
of these interactions can lead to altered paths of metabolism and
the production of toxic metabolites. In this review, we summarize
the available evidence for CYP protein–protein interactions
from the literature and offer a discussion of the potential impact
of future studies aimed at characterizing noncanonical protein–protein
interactions with CYP enzymes.
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Affiliation(s)
- Sylvie E Kandel
- XenoTech, LLC , 16825 West 116th Street, Lenexa, Kansas 66219, United States
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19
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Johnson EF, Connick JP, Reed JR, Backes WL, Desai MC, Xu L, Estrada DF, Laurence JS, Scott EE. Correlating structure and function of drug-metabolizing enzymes: progress and ongoing challenges. Drug Metab Dispos 2013; 42:9-22. [PMID: 24130370 DOI: 10.1124/dmd.113.054627] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
This report summarizes a symposium sponsored by the American Society for Pharmacology and Experimental Therapeutics at Experimental Biology held April 20-24 in Boston, MA. Presentations discussed the status of cytochrome P450 (P450) knowledge, emphasizing advances and challenges in relating structure with function and in applying this information to drug design. First, at least one structure of most major human drug-metabolizing P450 enzymes is known. However, the flexibility of these active sites can limit the predictive value of one structure for other ligands. A second limitation is our coarse-grain understanding of P450 interactions with membranes, other P450 enzymes, NADPH-cytochrome P450 reductase, and cytochrome b5. Recent work has examined differential P450 interactions with reductase in mixed P450 systems and P450:P450 complexes in reconstituted systems and cells, suggesting another level of functional control. In addition, protein nuclear magnetic resonance is a new approach to probe these protein/protein interactions, identifying interacting b5 and P450 surfaces, showing that b5 and reductase binding are mutually exclusive, and demonstrating ligand modulation of CYP17A1/b5 interactions. One desired outcome is the application of such information to control drug metabolism and/or design selective P450 inhibitors. A final presentation highlighted development of a CYP3A4 inhibitor that slows clearance of human immunodeficiency virus drugs otherwise rapidly metabolized by CYP3A4. Although understanding P450 structure/function relationships is an ongoing challenge, translational advances will benefit from continued integration of existing and new biophysical approaches.
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Affiliation(s)
- Eric F Johnson
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California (E.F.J.); Department of Pharmacology and Experimental Therapeutics and the Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, Louisiana (J.P.C., J.R.R., W.L.B.); Department of Medicinal Chemistry, Gilead Sciences, Inc., Foster City, California (M.C.D., L.X.); Department of Pharmaceutical Chemistry (J.S.L.) and Department of Medicinal Chemistry (D.F.E., E.E.S.), University of Kansas, Lawrence, Kansas
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20
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Storbeck KH, Swart AC, Goosen P, Swart P. Cytochrome b5: novel roles in steroidogenesis. Mol Cell Endocrinol 2013; 371:87-99. [PMID: 23228600 DOI: 10.1016/j.mce.2012.11.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 11/20/2012] [Accepted: 11/20/2012] [Indexed: 11/25/2022]
Abstract
Cytochrome b(5) (cyt-b(5)) is essential for the regulation of steroidogenesis and as such has been implicated in a number of clinical conditions. It is well documented that this small hemoprotein augments the 17,20-lyase activity of cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1). Studies have revealed that this augmentation is accomplished by cyt-b(5) enhancing the interaction between cytochrome P450 reductase (POR) and CYP17A1. In this paper we present evidence that cyt-b(5) induces a conformational change in CYP17A1, in addition to facilitating the interaction between CYP17A1 and POR. We also review the recently published finding that cyt-b(5) allosterically augments the activity of 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4) isomerase (3βHSD), a non cytochrome P450 enzyme, by increasing the enzymes affinity for its cofactor, NAD(+). The physiological importance of this finding, in terms of understanding adrenal androstenedione production, is examined. Finally, evidence that cyt-b(5) is able to form homomeric complexes in living cells is presented and discussed.
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Affiliation(s)
- Karl-Heinz Storbeck
- Department of Biochemistry, University of Stellenbosch, Stellenbosch 7602, South Africa
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21
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Estrada DF, Laurence JS, Scott EE. Substrate-modulated cytochrome P450 17A1 and cytochrome b5 interactions revealed by NMR. J Biol Chem 2013; 288:17008-17018. [PMID: 23620596 DOI: 10.1074/jbc.m113.468926] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The membrane heme protein cytochrome b5 (b5) can enhance, inhibit, or have no effect on cytochrome P450 (P450) catalysis, depending on the specific P450, substrate, and reaction conditions, but the structural basis remains unclear. Here the interactions between the soluble domain of microsomal b5 and the catalytic domain of the bifunctional steroidogenic cytochrome P450 17A1 (CYP17A1) were investigated. CYP17A1 performs both steroid hydroxylation, which is unaffected by b5, and an androgen-forming lyase reaction that is facilitated 10-fold by b5. NMR chemical shift mapping of b5 titrations with CYP17A1 indicates that the interaction occurs in an intermediate exchange regime and identifies charged surface residues involved in the protein/protein interface. The role of these residues is confirmed by disruption of the complex upon mutagenesis of either the anionic b5 residues (Glu-48 or Glu-49) or the corresponding cationic CYP17A1 residues (Arg-347, Arg-358, or Arg-449). Cytochrome b5 binding to CYP17A1 is also mutually exclusive with binding of NADPH-cytochrome P450 reductase. To probe the differential effects of b5 on the two CYP17A1-mediated reactions and, thus, communication between the superficial b5 binding site and the buried CYP17A1 active site, CYP17A1/b5 complex formation was characterized with either hydroxylase or lyase substrates bound to CYP17A1. Significantly, the CYP17A1/b5 interaction is stronger when the hydroxylase substrate pregnenolone is present in the CYP17A1 active site than when the lyase substrate 17α-hydroxypregnenolone is in the active site. These findings form the basis for a clearer understanding of this important interaction by directly measuring the reversible binding of the two proteins, providing evidence of communication between the CYP17A1 active site and the superficial proximal b5 binding site.
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Affiliation(s)
| | | | - Emily E Scott
- Departments of Medicinal Chemistry, Lawrence, Kansas 66045.
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22
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Storbeck KH, Swart AC, Lombard N, Adriaanse CV, Swart P. Cytochrome b(5) forms homomeric complexes in living cells. J Steroid Biochem Mol Biol 2012; 132:311-21. [PMID: 22878120 DOI: 10.1016/j.jsbmb.2012.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 07/23/2012] [Accepted: 07/25/2012] [Indexed: 11/24/2022]
Abstract
Cytochrome b(5) (cyt-b(5)) is a ubiquitous hemoprotein also associated with microsomal cytochrome P450 17α-hydroxylase/17,20 lyase (CYP17A1). In the steroidogenic pathway CYP17A1 catalyses the metabolism of pregnenolone, yielding both glucocorticoid and androgen precursors. While not affecting the 17α-hydroxylation of pregnenolone, cyt-b(5) augments the 17,20 lyase reaction of 17-hydroxypregnenolone, catalyzing the formation of DHEA, through direct protein-protein interactions. In this study, multimeric complex formation of cyt-b(5) and the possible regulatory role of these complexes were investigated. Cyt-b(5) was isolated from ovine liver and used to raise anti-sheep cyt-b(5) immunoglobulins. Immunochemical studies revealed that, in vivo, cyt-b(5) is primarily found in the tetrameric form. Subsequent fluorescent resonance energy transfer (FRET) studies in COS-1 cells confirmed the formation of homomeric complexes by cyt-b(5) in live cells. Site-directed mutagenesis revealed that the C-terminal linker domain of cyt-b(5) is vital for complex formation. The 17,20-lyase activity of CYP17 was augmented by truncated cyt-b(5), which is unable to form complexes when co-expressed in COS-1 cells, thereby implicating the monomeric form of cyt-b(5) as the active species. This study has shown for the first time that cyt-b(5) forms homomeric complexes in vivo, implicating complex formation as a possible regulatory mechanism in steroidogenesis.
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Affiliation(s)
- Karl-Heinz Storbeck
- Department of Biochemistry, University of Stellenbosch, Stellenbosch 7600, South Africa
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23
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Jin GX, Wen HS, He F, Li JF, Chen CF, Zhang JR, Chen XY, Shi B, Shi D, Yang YP, Qi BX, Li N. Molecular cloning, characterization expression of P450c17-I and P450c17-II and their functions analysis during the reproductive cycle in males of barfin flounder (Verasper moseri). FISH PHYSIOLOGY AND BIOCHEMISTRY 2012; 38:807-817. [PMID: 22057547 DOI: 10.1007/s10695-011-9564-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 10/03/2011] [Indexed: 05/31/2023]
Abstract
P450c17, a key steroidogenic enzyme, plays important roles in the production of sex steroid and cortisol. In teleost, there are two types of P450c17, P450c17-I possessing 17α-hydroxylase and 17, 20-lyase activities, and P450c17-II only possessing 17α-hydroxylase activity. This work describes the molecular cloning of the cDNA encoding the barfin flounder (Verasper moseri) P450c17-I and P450c17-II by means of RT-PCR and 5' and 3' rapid amplification of cDNA ends (RACE) analyses and mRNA expression profiles analyzing by semiquantitative RT-PCR. Respectively, P450c17-I and P450c17-II mRNA levels in the testes correlated with serum testosterone (T) level, as well as gonadosomatic index (GSI) of males during specific stages of spermatogenesis. P450c17-I and P450c17-II mRNA were expressed in the testis and ovary, suggesting that both of them participate in the production of sex steroid in barfin flounder gonads. P450c17-I mRNA was undetectable; in contrast, P450c17-II mRNA was detected at the highest level in the head kidney, meaning that only P450c17-II is involved in the production of cortisol in barfin flounder. The results demonstrated that both of P450c17-I and P450c17-II participate in the production of sex steroid in male barfin flounder gonads.
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Affiliation(s)
- Guo X Jin
- Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao, China
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24
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Structures of cytochrome P450 17A1 with prostate cancer drugs abiraterone and TOK-001. Nature 2012; 482:116-9. [PMID: 22266943 PMCID: PMC3271139 DOI: 10.1038/nature10743] [Citation(s) in RCA: 248] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 11/30/2011] [Indexed: 12/03/2022]
Abstract
Cytochrome P450 17A1 (P450c17) catalyzes the biosynthesis of androgens in humans1. Since prostate cancer cells proliferate in response to androgen steroids2,3, CYP17A1 inhibition is a new strategy to prevent androgen synthesis and treat lethal metastatic castration-resistant prostate cancer4, but drug development has been hampered by the lack of a CYP17A1 structure. Here we report the only known structures of CYP17A1, which contain either abiraterone, a first-in-class steroidal inhibitor recently approved by the FDA for late-stage prostate cancer5, or TOK-001, another inhibitor in clinical trials4,6. Both bind the heme iron forming a 60° angle above the heme plane, packing against the central I helix with the 3β-OH interacting with N202 in the F helix. Importantly, this binding mode differs substantially from those predicted by homology models or from steroids in other cytochrome P450 enzymes with known structures, with some features more similar to steroid receptors. While the overall CYP17A1 structure provides a rationale for understanding many mutations found in patients with steroidogenic diseases, the active site reveals multiple steric and hydrogen bonding features that will facilitate better understanding of the enzyme’s dual hydroxylase and lyase catalytic capabilities and assist in rational drug design. Specifically, structure-based design is expected to aid development of inhibitors that bind only CYP17A1 and solely inhibit its androgen-generating lyase activity to improve treatment of prostate and other hormone-responsive cancers.
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Akhtar M, Wright JN, Lee-Robichaud P. A review of mechanistic studies on aromatase (CYP19) and 17α-hydroxylase-17,20-lyase (CYP17). J Steroid Biochem Mol Biol 2011; 125:2-12. [PMID: 21094255 DOI: 10.1016/j.jsbmb.2010.11.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 10/25/2010] [Accepted: 11/03/2010] [Indexed: 11/26/2022]
Abstract
In the conventional P-450 dependent hydroxylation reaction, the Fe(III) resting state of the enzyme, by a single electron transfer, is reduced to Fe(II), which reacts with O(2) to produce a Fe(III)-O-O intermediate. The latter following the transfer of another electron furnishes a ferric-peroxyanion, Fe(III)-O-O(-), which after protonation leads to the fission of the O-O bond resulting in the formation of Fe(V)O, the key player in the hydroxylation process. Certain members of the P-450 family, including CYP17 and CYP19, catalyze, at the same active site, not only the hydroxylation process but also an acyl-carbon bond cleavage reaction which has been interpreted to involve the nucleophilic attack of the ferric-peroxyanion, Fe(III)-O-O(-), on the acyl carbon to furnish a tetrahedral intermediate which fragments, leading to acyl-carbon cleavage. Evidence is presented to show that in the case of CYP17 the attack of Fe(III)-O-O(-) on the target carbon is promoted by cytochrome b(5), which acts as a conformational regulator of CYP17. It is this regulation of CYP17 that provides a safety mechanism which ensures that during corticoid biosynthesis, which involves 17α-hydroxylation by CYP17, androgen formation is avoided. Finally, a brief account is presented of the inhibitors, of the two enzymes, which have been designed on the basis of their mechanism of action. Article from the Special issue on 'Targeted Inhibitors'.
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Affiliation(s)
- Muhammad Akhtar
- School of Biological Sciences, University of the Punjab, New Campus, Lahore, 54590, Pakistan.
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Nikfarjam L, Izumi S, Yamazaki T, Kominami S. The interaction of cytochrome P450 17α with NADPH-cytochrome P450 reductase, investigated using chemical modification and MALDI-TOF mass spectrometry. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:1126-31. [PMID: 16713412 DOI: 10.1016/j.bbapap.2006.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Revised: 03/22/2006] [Accepted: 04/01/2006] [Indexed: 11/28/2022]
Abstract
The lysine residues of guinea pig P450 17alpha were acetylated by acetic anhydride in the absence and presence of NADPH cytochrome P450 reductase (CPR). Eight acetylated peptides were identified in the MALDI-TOF mass spectra of the tryptic fragments from the P450 acetylated without CPR in the limited reaction time of 15 min at ice temperature. The presence of CPR during the acetylation of P450 17alpha prevented double acetylations at K326 and K327 in the J-helix. The activity of P450 17alpha was decreased to 35% by the acetylation, but almost no inactivation was detected in the P450 after acetylation in the presence of CPR. This protection from inactivation shows the importance of K326 and/or K327 in the J-helix of P450 17alpha in the interaction between the two enzymes. Our results provided the first experimental evidence for the importance of the J-helix of P450 in the interaction with CPR. The interaction of P450 17alpha with CPR on the membrane is discussed based on the results of this study, which used molecular modeling.
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Affiliation(s)
- Laleh Nikfarjam
- Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashihiroshima 739-8528, Japan
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Prosser DE, Guo Y, Jia Z, Jones G. Structural motif-based homology modeling of CYP27A1 and site-directed mutational analyses affecting vitamin D hydroxylation. Biophys J 2006; 90:3389-409. [PMID: 16500955 PMCID: PMC1440725 DOI: 10.1529/biophysj.105.069369] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Human CYP27A1 is a mitochondrial cytochrome P450, which is principally found in the liver and plays important roles in the biological activation of vitamin D(3) and in the biosynthesis of bile acids. We have applied a systematic analysis of hydrogen bonding patterns in 11 prokaryotic and mammalian CYP crystal structures to construct a homology-based model of CYP27A1. Docking of vitamin D(3) structures into the active site of this model identified potential substrate contact residues in the F-helix, the beta-3 sheet, and the beta-5 sheet. Site-directed mutagenesis and expression in COS-1 cells confirmed that these positions affect enzymatic activity, in some cases shifting metabolism of 1alpha-hydroxyvitamin D(3) to favor 25- or 27-hydroxylation. The results suggest that conserved hydrophobic residues in the beta-5 hairpin help define the shape of the substrate binding cavity and that this structure interacts with Phe-248 in the F-helix. Mutations directed toward the beta-3a strand suggested a possible heme-binding interaction centered on Asn-403 and a structural role for substrate contact residues Thr-402 and Ser-404.
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Affiliation(s)
- David E Prosser
- Department of Biochemistry, Queen's University, Kingston, Ontario, Canada
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Jushchyshyn MI, Hutzler JM, Schrag ML, Wienkers LC. Catalytic turnover of pyrene by CYP3A4: Evidence that cytochrome b5 directly induces positive cooperativity. Arch Biochem Biophys 2005; 438:21-8. [PMID: 15910734 DOI: 10.1016/j.abb.2005.02.027] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2004] [Revised: 02/15/2005] [Accepted: 02/17/2005] [Indexed: 11/23/2022]
Abstract
The metabolism of pyrene to hydroxypyrene by CYP3A4 was investigated to determine the effect of cytochrome b5 (b5) on turnover kinetics. In the absence of b5, formation of hydroxypyrene in in vitro incubations showed a biphasic substrate-velocity curve where K(m1) and V(max1) were 1.3 microM and 0.5 pmol/min/pmol P450, respectively. The addition of testosterone to the incubation mixture completely abolished the second phase to yield a typical, hyperbolic curve, presumably through the disruption in the formation of a pi-pi stacked pyrene complex within the CYP3A4 active site. Finally, the addition of b5 yielded an increase hydroxypyrene formation that resulted in a sigmoidal substrate velocity curve. The V(max) was 15.7 pmol/min/pmol P450, the K(m) was 7.5 microM, and the Hill coefficient was greater than two. This demonstrated that b5 could directly induce positive cooperativity on CYP3A4 and that this biological factor needs to be carefully considered when included in in vitro P450 reactions.
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