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Singh H, Kumar R, Mazumder A, Salahuddin, Mazumder R, Abdullah MM. Insights into Interactions of Human Cytochrome P450 17A1: Review. Curr Drug Metab 2022; 23:172-187. [DOI: 10.2174/1389200223666220401093833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/15/2022] [Accepted: 02/04/2022] [Indexed: 11/22/2022]
Abstract
Abstract:
Cytochrome P450s are a widespread and vast superfamily of hemeprotein monooxygenases that metabolize physiologically essential chemicals necessary for most species' survival, from protists to plants to humans. They catalyze the synthesis of steroid hormones, cholesterol, bile acids, and arachidonate metabolites and the degradation of endogenous compounds such as steroids, fatty acids, and other catabolizing compounds as an energy source and detoxifying xenobiotics such as drugs, procarcinogens, and carcinogens. The human CYP17A1 is one of the cytochrome P450 genes located at the 10q chromosome. The gene expression occurs in the adrenals and gonads, with minor amounts in the brain, placenta, and heart. This P450c17 cytochrome gene is a critical steroidogenesis regulator which performs two distinct activities: 17 alpha-hydroxylase activity (converting pregnenolone to 17-hydroxypregnenolone and progesterone to 17-hydroxyprogesterone, these precursors are further processed to provide glucocorticoids and sex hormones) and 17, 20-lyase activity (which converts 17-hydroxypregnenolone to DHEA). Dozens of mutations within CYP17A1 are found to cause 17-alpha-hydroxylase and 17, 20-lyase deficiency. This condition affects the function of certain hormone-producing glands, resulting in high blood pressure levels (hypertension), abnormal sexual development, and other deficiency diseases. This review highlights the changes in CYP17A1 associated with gene-gene interaction, drug-gene interaction, chemical-gene interaction, and its biochemical reactions; they have some insights to correlate with the fascinating functional characteristics of this human steroidogenic gene. The findings of our theoretical results will be helpful to further the design of specific inhibitors of CYP17A1.
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Affiliation(s)
- Himanshu Singh
- Department of Pharmaceutical Chemistry, Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, India
| | - Rajnish Kumar
- Department of Pharmaceutical Chemistry, Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, India
| | - Avijit Mazumder
- Department of Pharmaceutical Chemistry, Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, India
| | - Salahuddin
- Department of Pharmaceutical Chemistry, Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, India
| | - Rupa Mazumder
- Department of Pharmaceutical Chemistry, Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, India
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2
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Claahsen - van der Grinten HL, Speiser PW, Ahmed SF, Arlt W, Auchus RJ, Falhammar H, Flück CE, Guasti L, Huebner A, Kortmann BBM, Krone N, Merke DP, Miller WL, Nordenström A, Reisch N, Sandberg DE, Stikkelbroeck NMML, Touraine P, Utari A, Wudy SA, White PC. Congenital Adrenal Hyperplasia-Current Insights in Pathophysiology, Diagnostics, and Management. Endocr Rev 2022; 43:91-159. [PMID: 33961029 PMCID: PMC8755999 DOI: 10.1210/endrev/bnab016] [Citation(s) in RCA: 176] [Impact Index Per Article: 88.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Indexed: 11/19/2022]
Abstract
Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders affecting cortisol biosynthesis. Reduced activity of an enzyme required for cortisol production leads to chronic overstimulation of the adrenal cortex and accumulation of precursors proximal to the blocked enzymatic step. The most common form of CAH is caused by steroid 21-hydroxylase deficiency due to mutations in CYP21A2. Since the last publication summarizing CAH in Endocrine Reviews in 2000, there have been numerous new developments. These include more detailed understanding of steroidogenic pathways, refinements in neonatal screening, improved diagnostic measurements utilizing chromatography and mass spectrometry coupled with steroid profiling, and improved genotyping methods. Clinical trials of alternative medications and modes of delivery have been recently completed or are under way. Genetic and cell-based treatments are being explored. A large body of data concerning long-term outcomes in patients affected by CAH, including psychosexual well-being, has been enhanced by the establishment of disease registries. This review provides the reader with current insights in CAH with special attention to these new developments.
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Affiliation(s)
| | - Phyllis W Speiser
- Cohen Children’s Medical Center of NY, Feinstein Institute, Northwell Health, Zucker School of Medicine, New Hyde Park, NY 11040, USA
| | - S Faisal Ahmed
- Developmental Endocrinology Research Group, School of Medicine Dentistry & Nursing, University of Glasgow, Glasgow, UK
| | - Wiebke Arlt
- Institute of Metabolism and Systems Research (IMSR), College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- Department of Endocrinology, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Richard J Auchus
- Division of Metabolism, Endocrinology, and Diabetes, Departments of Internal Medicine and Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Henrik Falhammar
- Department of Molecular Medicine and Surgery, Karolinska Intitutet, Stockholm, Sweden
- Department of Endocrinology, Karolinska University Hospital, Stockholm, Sweden
| | - Christa E Flück
- Pediatric Endocrinology, Diabetology and Metabolism, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland
| | - Leonardo Guasti
- Centre for Endocrinology, William Harvey Research Institute, Bart’s and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Angela Huebner
- Division of Paediatric Endocrinology and Diabetology, Department of Paediatrics, Universitätsklinikum Dresden, Technische Universität Dresden, Dresden, Germany
| | - Barbara B M Kortmann
- Radboud University Medical Centre, Amalia Childrens Hospital, Department of Pediatric Urology, Nijmegen, The Netherlands
| | - Nils Krone
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Deborah P Merke
- National Institutes of Health Clinical Center and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Walter L Miller
- Department of Pediatrics, Center for Reproductive Sciences, and Institute for Human Genetics, University of California, San Francisco, CA 94143, USA
| | - Anna Nordenström
- Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
- Pediatric Endocrinology, Karolinska University Hospital, Stockholm, Sweden
| | - Nicole Reisch
- Medizinische Klinik IV, Klinikum der Universität München, Munich, Germany
| | - David E Sandberg
- Department of Pediatrics, Susan B. Meister Child Health Evaluation and Research Center, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Philippe Touraine
- Department of Endocrinology and Reproductive Medicine, Center for Rare Endocrine Diseases of Growth and Development, Center for Rare Gynecological Diseases, Hôpital Pitié Salpêtrière, Sorbonne University Medicine, Paris, France
| | - Agustini Utari
- Division of Pediatric Endocrinology, Department of Pediatrics, Faculty of Medicine, Diponegoro University, Semarang, Indonesia
| | - Stefan A Wudy
- Steroid Research & Mass Spectrometry Unit, Laboratory of Translational Hormone Analytics, Division of Paediatric Endocrinology & Diabetology, Justus Liebig University, Giessen, Germany
| | - Perrin C White
- Division of Pediatric Endocrinology, UT Southwestern Medical Center, Dallas TX 75390, USA
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Pacheco-Garcia JL, Anoz-Carbonell E, Vankova P, Kannan A, Palomino-Morales R, Mesa-Torres N, Salido E, Man P, Medina M, Naganathan AN, Pey AL. Structural basis of the pleiotropic and specific phenotypic consequences of missense mutations in the multifunctional NAD(P)H:quinone oxidoreductase 1 and their pharmacological rescue. Redox Biol 2021; 46:102112. [PMID: 34537677 PMCID: PMC8455868 DOI: 10.1016/j.redox.2021.102112] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/21/2021] [Accepted: 08/17/2021] [Indexed: 10/31/2022] Open
Abstract
The multifunctional nature of human flavoproteins is critically linked to their ability to populate multiple conformational states. Ligand binding, post-translational modifications and disease-associated mutations can reshape this functional landscape, although the structure-function relationships of these effects are not well understood. Herein, we characterized the structural and functional consequences of two mutations (the cancer-associated P187S and the phosphomimetic S82D) on different ligation states which are relevant to flavin binding, intracellular stability and catalysis of the disease-associated NQO1 flavoprotein. We found that these mutations affected the stability locally and their effects propagated differently through the protein structure depending both on the nature of the mutation and the ligand bound, showing directional preference from the mutated site and leading to specific phenotypic manifestations in different functional traits (FAD binding, catalysis and inhibition, intracellular stability and pharmacological response to ligands). Our study thus supports that pleitropic effects of disease-causing mutations and phosphorylation events on human flavoproteins may be caused by long-range structural propagation of stability effects to different functional sites that depend on the ligation-state and site-specific perturbations. Our approach can be of general application to investigate these pleiotropic effects at the flavoproteome scale in the absence of high-resolution structural models.
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Affiliation(s)
- Juan Luis Pacheco-Garcia
- Departamento de Química Física, Universidad de Granada, Av. Fuentenueva s/n, 18071, Granada, Spain
| | - Ernesto Anoz-Carbonell
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and Joint Unit), Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Pavla Vankova
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic; Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030/8, Prague 2, 128 43, Czech Republic
| | - Adithi Kannan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras (IITM), Chennai, 600036, India
| | - Rogelio Palomino-Morales
- Departmento de Bioquímica y Biología Molecular I, Facultad de Ciencias y Centro de Investigaciones Biomédicas (CIBM), Universidad de Granada, Granada, Spain
| | - Noel Mesa-Torres
- Departamento de Química Física, Universidad de Granada, Av. Fuentenueva s/n, 18071, Granada, Spain
| | - Eduardo Salido
- Center for Rare Diseases (CIBERER), Hospital Universitario de Canarias, Universidad de la Laguna, 38320, Tenerife, Spain
| | - Petr Man
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Milagros Medina
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and Joint Unit), Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras (IITM), Chennai, 600036, India
| | - Angel L Pey
- Departamento de Química Física, Unidad de Excelencia en Química Aplicada a Biomedicina y Medioambiente e Instituto de Biotecnología, Universidad de Granada, Av. Fuentenueva s/n, 18071, Granada, Spain.
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Vogt CD, Bart AG, Yadav R, Scott EE, Aubé J. Effects of fluorine substitution on substrate conversion by cytochromes P450 17A1 and 21A2. Org Biomol Chem 2021; 19:7664-7669. [PMID: 34524336 PMCID: PMC10042386 DOI: 10.1039/d1ob01178b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cytochromes P450 17A1 (CYP7A1) and 21A2 (CYP21A2) catalyze key reactions in the production of steroid hormones, including mineralocorticoids, glucocorticoids, and androgens. With the ultimate goal of designing probes that are selectively metabolized to each of these steroid types, fluorinated derivatives of the endogenous substrates, pregnenolone and progesterone, were prepared to study the effects on CYP17A1 and CYP21A2 activity. In the functional assays, the hydroxylase reactions catalysed by each of these enzymes were blocked when fluorine was introduced at the site of metabolism (positions 17 and 21 of the steroid core, respectively). CYP17A1, furthermore, performed the 17,20-lyase reaction on substrates with a fluorine installed at the 21-position. Importantly, none of the substitutions examined herein prevented compound entry into the active sites of either CYP17A1 or CYP21A2 as demonstrated by spectral binding assays. Taken together, the results suggest that fluorine might be used to redirect the metabolic pathways of pregnenolone and progesterone to specific types of steroids.
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Affiliation(s)
- Caleb D Vogt
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, North Carolina 27599, USA.
| | - Aaron G Bart
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | - Rahul Yadav
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | - Emily E Scott
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jeffrey Aubé
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, North Carolina 27599, USA.
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Burris-Hiday SD, Scott EE. Steroidogenic cytochrome P450 17A1 structure and function. Mol Cell Endocrinol 2021; 528:111261. [PMID: 33781841 PMCID: PMC8087655 DOI: 10.1016/j.mce.2021.111261] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 03/01/2021] [Accepted: 03/22/2021] [Indexed: 12/19/2022]
Abstract
Cytochrome P450 17A1 (CYP17A1) is a critical steroidogenic enzyme, essential for producing glucocorticoids and sex hormones. This review discusses the complex activity of CYP17A1, looking at its role in both the classical and backdoor steroidogenic pathways and the complex chemistry it carries out to perform both a hydroxylation reaction and a carbon-carbon cleavage, or lyase reaction. Functional and structural investigations have informed our knowledge of these two reactions. This review focuses on a few specific aspects of this discussion: the identities of reaction intermediates, the coordination of hydroxylation and lyase reactions, the effects of cytochrome b5, and conformational selection. These discussions improve understanding of CYP17A1 in a physiological setting, where CYP17A1 is implicated in a variety of steroidogenic diseases. This information can be used to improve ways in which CYP17A1 can be effectively modulated to treat diseases such as prostate and breast cancer, Cushing's syndrome, and glioblastoma.
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Affiliation(s)
| | - Emily E Scott
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA; Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
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6
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Ilany J, Liu J, Welsch C, Reznik-Wolf H, Levy-Lahad E, Auchus RJ. Salt-Losing 21-Hydroxylase Deficiency Caused by Double Homozygosity for Two "Mild" Mutations. J Clin Endocrinol Metab 2021; 106:e680-e686. [PMID: 33245778 DOI: 10.1210/clinem/dgaa875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Indexed: 02/13/2023]
Abstract
CONTEXT Congenital adrenal hyperplasia due to 21-hydroxylase deficiency presents with different severities that correlate with the genotype. The salt-losing phenotype requires 2 alleles with "severe" mutations. CASE DESCRIPTION We present a case of salt-losing 21-hydroxylase deficiency that was found to be homozygous for 2 "mild" pathogenic variants: V281L and S301Y. Both in silico and heterologous expression functional analysis demonstrated that co-occurrence of these 2 mutations in cis severely impairs the function of the 21-hydroxylase enzyme. CONCLUSIONS This case has important implications for genetic counseling. Regarding this combination of 2 "mild" variants as having mild phenotypic effects could lead to inappropriate counseling of heterozygote carriers.
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Affiliation(s)
- Jacob Ilany
- Institute of Endocrinology, Sheba Medical Center, Tel-Hashomer, Israel
| | - Jiayan Liu
- Division of Metabolism, Endocrinology, and Diabetes, Departments of Internal Medicine and Pharmacology, University of Michigan, Ann Arbor, MI USA
| | - Christoph Welsch
- Department of Internal Medicine I, Goethe University Hospital-Frankfurt, Frankfurt am Main, Germany
| | - Haike Reznik-Wolf
- Genetics laboratory, Danek Gartner Institute, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ephrat Levy-Lahad
- Medical Genetics Institute, Shaare Zedek Medical Center, Jerusalem, Israel
- Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Richard J Auchus
- Division of Metabolism, Endocrinology, and Diabetes, Departments of Internal Medicine and Pharmacology, University of Michigan, Ann Arbor, MI USA
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Bracco P, Wijma HJ, Nicolai B, Buitrago JAR, Klünemann T, Vila A, Schrepfer P, Blankenfeldt W, Janssen DB, Schallmey A. CYP154C5 Regioselectivity in Steroid Hydroxylation Explored by Substrate Modifications and Protein Engineering*. Chembiochem 2020; 22:1099-1110. [PMID: 33145893 PMCID: PMC8048783 DOI: 10.1002/cbic.202000735] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/03/2020] [Indexed: 12/27/2022]
Abstract
CYP154C5 from Nocardia farcinica is a P450 monooxygenase able to hydroxylate a range of steroids with high regio- and stereoselectivity at the 16α-position. Using protein engineering and substrate modifications based on the crystal structure of CYP154C5, an altered regioselectivity of the enzyme in steroid hydroxylation had been achieved. Thus, conversion of progesterone by mutant CYP154C5 F92A resulted in formation of the corresponding 21-hydroxylated product 11-deoxycorticosterone in addition to 16α-hydroxylation. Using MD simulation, this altered regioselectivity appeared to result from an alternative binding mode of the steroid in the active site of mutant F92A. MD simulation further suggested that the entrance of water to the active site caused higher uncoupling in this mutant. Moreover, exclusive 15α-hydroxylation was observed for wild-type CYP154C5 in the conversion of 5α-androstan-3-one, lacking an oxy-functional group at C17. Overall, our data give valuable insight into the structure-function relationship of this cytochrome P450 monooxygenase for steroid hydroxylation.
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Affiliation(s)
- Paula Bracco
- Biocatalysis, Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Hein J Wijma
- Department of Biochemistry Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, Netherlands
| | - Bastian Nicolai
- Biocatalysis, Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Jhon Alexander Rodriguez Buitrago
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
| | - Thomas Klünemann
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Braunschweig, Germany
| | - Agustina Vila
- Biocatalysis, Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Patrick Schrepfer
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
| | - Wulf Blankenfeldt
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Braunschweig, Germany.,Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
| | - Dick B Janssen
- Department of Biochemistry Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, Netherlands
| | - Anett Schallmey
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
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Anoz-Carbonell E, Timson DJ, Pey AL, Medina M. The Catalytic Cycle of the Antioxidant and Cancer-Associated Human NQO1 Enzyme: Hydride Transfer, Conformational Dynamics and Functional Cooperativity. Antioxidants (Basel) 2020; 9:E772. [PMID: 32825392 PMCID: PMC7554937 DOI: 10.3390/antiox9090772] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 12/11/2022] Open
Abstract
Human NQO1 [NAD(H):quinone oxidoreductase 1] is a multi-functional and stress-inducible dimeric protein involved in the antioxidant defense, the activation of cancer prodrugs and the stabilization of oncosuppressors. Despite its roles in human diseases, such as cancer and neurological disorders, a detailed characterization of its enzymatic cycle is still lacking. In this work, we provide a comprehensive analysis of the NQO1 catalytic cycle using rapid mixing techniques, including multiwavelength and spectral deconvolution studies, kinetic modeling and temperature-dependent kinetic isotope effects (KIEs). Our results systematically support the existence of two pathways for hydride transfer throughout the NQO1 catalytic cycle, likely reflecting that the two active sites in the dimer catalyze two-electron reduction with different rates, consistent with the cooperative binding of inhibitors such as dicoumarol. This negative cooperativity in NQO1 redox activity represents a sort of half-of-sites activity. Analysis of KIEs and their temperature dependence also show significantly different contributions from quantum tunneling, structural dynamics and reorganizations to catalysis at the two active sites. Our work will improve our understanding of the effects of cancer-associated single amino acid variants and post-translational modifications in this protein of high relevance in cancer progression and treatment.
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Affiliation(s)
- Ernesto Anoz-Carbonell
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and BIFI-IQFR Joint Units), Universidad de Zaragoza, 50009 Zaragoza, Spain;
| | - David J. Timson
- School of Pharmacy and Biomolecular Sciences, The University of Brighton, Brighton BN2 4GJ, UK;
| | - Angel L. Pey
- Departamento de Química Física, Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Milagros Medina
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and BIFI-IQFR Joint Units), Universidad de Zaragoza, 50009 Zaragoza, Spain;
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Wright C, O’Day P, Alyamani M, Sharifi N, Auchus RJ. Abiraterone acetate treatment lowers 11-oxygenated androgens. Eur J Endocrinol 2020; 182:413-421. [PMID: 32045360 PMCID: PMC7096060 DOI: 10.1530/eje-19-0905] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/10/2020] [Indexed: 01/13/2023]
Abstract
CONTEXT The human adrenal is the dominant source of androgens in castration-resistant prostate cancer (CRPC) and classic 21-hydroxylase deficiency (21OHD). Abiraterone, derived from the prodrug abiraterone acetate (AA), inhibits the activity of cytochrome P450 17-hydroxylase/17,20-lyase (CYP17A1), the enzyme required for all androgen biosynthesis. AA treatment effectively lowers testosterone and androstenedione in 21OHD and CRPC patients. The 11-oxygenated androgens are major adrenal-derived androgens, yet little is known regarding the effects of AA administration on 11-oxygenated androgens. OBJECTIVE To test the hypothesis that AA therapy decreases 11-oxygenated androgens. DESIGN Samples were obtained from 21OHD or CRPC participants in AA or AA plus prednisone (AAP)-treatment studies, respectively. METHODS We employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure the 11-oxygenated androgens, 11β-hydroxyandrostenedione, 11-ketoandrostenedione, 11β-hydroxytestosterone, and 11-ketotestosterone, in plasma or serum samples from six 21OHD and six CRPC patients before and after treatment with AA or AAP, respectively. RESULTS In CRPC patients, administration of AAP (1000 mg/day AA with prednisone and medical castration) lowered all four 11-oxygenated androgens to below the lower limits of quantitation (<0.1-0.3 nmol/L), equivalent to 64-94% reductions from baseline. In 21OHD patients, administration of AA (100-250 mg/day for 6 days) reduced all 11-oxygenated androgens by on average 56-77% from baseline. CONCLUSIONS We conclude that AA and AAP therapies markedly reduce the production of the adrenal-derived 11-oxygenated androgens, both in patients with high (21OHD) or normal (CRPC) 11-oxygenated androgens at baseline, respectively. Reduction of 11-oxygenated androgens is an important aspect of AA and AAP pharmacology.
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Affiliation(s)
- Connor Wright
- Division of Metabolism, Diabetes, and Endocrinology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
| | - Patrick O’Day
- Division of Metabolism, Diabetes, and Endocrinology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
| | - Mohammed Alyamani
- Genitourinary Malignancies Research Center, Lerner Research Institute
| | - Nima Sharifi
- Genitourinary Malignancies Research Center, Lerner Research Institute
- Department of Urology, Glickman Urological and Kidney Institute
- Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Richard J. Auchus
- Division of Metabolism, Diabetes, and Endocrinology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109
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Maharaj A, Buonocore F, Meimaridou E, Ruiz-Babot G, Guasti L, Peng HM, Capper CP, Burgos-Tirado N, Prasad R, Hughes CR, Maudhoo A, Crowne E, Cheetham TD, Brain CE, Suntharalingham JP, Striglioni N, Yuksel B, Gurbuz F, Gupta S, Lindsay R, Couch R, Spoudeas HA, Guran T, Johnson S, Fowler DJ, Conwell LS, McInerney-Leo AM, Drui D, Cariou B, Lopez-Siguero JP, Harris M, Duncan EL, Hindmarsh PC, Auchus RJ, Donaldson MD, Achermann JC, Metherell LA. Predicted Benign and Synonymous Variants in CYP11A1 Cause Primary Adrenal Insufficiency Through Missplicing. J Endocr Soc 2018; 3:201-221. [PMID: 30620006 PMCID: PMC6316989 DOI: 10.1210/js.2018-00130] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 10/25/2018] [Indexed: 01/11/2023] Open
Abstract
Primary adrenal insufficiency (PAI) is a potentially life-threatening condition that can present with nonspecific features and can be difficult to diagnose. We undertook next generation sequencing in a cohort of children and young adults with PAI of unknown etiology from around the world and identified a heterozygous missense variant (rs6161, c.940G>A, p.Glu314Lys) in CYP11A1 in 19 individuals from 13 different families (allele frequency within undiagnosed PAI in our cohort, 0.102 vs 0.0026 in the Genome Aggregation Database; P < 0.0001). Seventeen individuals harbored a second heterozygous rare disruptive variant in CYP11A1 and two had very rare synonymous changes in trans (c.990G>A, Thr330 = ; c.1173C>T, Ser391 =). Although p.Glu314Lys is predicted to be benign and showed no loss-of-function in an Escherichia coli assay system, in silico and in vitro studies revealed that the rs6161/c.940G>A variant, plus the c.990G>A and c.1173C>T changes, affected splicing and that p.Glu314Lys produces a nonfunctional protein in mammalian cells. Taken together, these findings show that compound heterozygosity involving a relatively common and predicted "benign" variant in CYP11A1 is a major contributor to PAI of unknown etiology, especially in European populations. These observations have implications for personalized management and demonstrate how variants that might be overlooked in standard analyses can be pathogenic when combined with other very rare disruptive changes.
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Affiliation(s)
- Avinaash Maharaj
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Federica Buonocore
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Eirini Meimaridou
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Gerard Ruiz-Babot
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Leonardo Guasti
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Hwei-Ming Peng
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan,Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Cameron P Capper
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan,Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Neikelyn Burgos-Tirado
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan,Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Rathi Prasad
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Claire R Hughes
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Ashwini Maudhoo
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Elizabeth Crowne
- Department of Paediatric Endocrinology and Diabetes, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
| | - Timothy D Cheetham
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Caroline E Brain
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Jenifer P Suntharalingham
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Niccolò Striglioni
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Bilgin Yuksel
- Department of Pediatric Endocrinology and Diabetes, Cukurova University, Adana, Turkey
| | - Fatih Gurbuz
- Department of Pediatric Endocrinology and Diabetes, Cukurova University, Adana, Turkey
| | - Sangay Gupta
- Department of Pediatrics, Hull Royal Infirmary, Hull, United Kingdom
| | - Robert Lindsay
- Institute of Cardiovascular and Medical Sciences, British Heart Foundation Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Robert Couch
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Helen A Spoudeas
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Tulay Guran
- Department Pediatric Endocrinology and Diabetes, Marmara University, Istanbul, Turkey
| | - Stephanie Johnson
- Lady Cilento Children’s Hospital, Brisbane, Queensland, Australia,University of Queensland, Brisbane, Queensland, Australia
| | - Dallas J Fowler
- Lady Cilento Children’s Hospital, Brisbane, Queensland, Australia,University of Queensland, Brisbane, Queensland, Australia
| | - Louise S Conwell
- Lady Cilento Children’s Hospital, Brisbane, Queensland, Australia,University of Queensland, Brisbane, Queensland, Australia
| | - Aideen M McInerney-Leo
- Institute of Health and Biomedical Innovation, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Delphine Drui
- Department of Endocrinology, l’Institut du Thorax, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Bertrand Cariou
- INSERM UMR 1087, CNRS UMR 6291, l'Institut du Thorax, Université de Nantes, Nantes, France
| | - Juan P Lopez-Siguero
- Pediatric Endocrinology Unit, Children’s Hospital, Institute of Biomedical Research in Malaga, Málaga, Spain
| | - Mark Harris
- Lady Cilento Children’s Hospital, Brisbane, Queensland, Australia,University of Queensland, Brisbane, Queensland, Australia
| | - Emma L Duncan
- Institute of Health and Biomedical Innovation, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia,Department of Endocrinology and Diabetes, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Peter C Hindmarsh
- Department of Paediatrics, University College London Hospitals, London, United Kingdom
| | - Richard J Auchus
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan,Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Malcolm D Donaldson
- Section of Child Health, Glasgow University School of Medicine, Glasgow, United Kingdom
| | - John C Achermann
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Louise A Metherell
- Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom,Correspondence: Louise A. Metherell, PhD, Centre for Endocrinology, William Harvey Research Institute, John Vane Science Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom. E-mail:
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11
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Capper CP, Liu J, McIntosh LR, Larios JM, Johnson MD, Hollenberg PF, Osawa Y, Auchus RJ, Rae JM. Functional characterization of the G162R and D216H genetic variants of human CYP17A1. J Steroid Biochem Mol Biol 2018; 178:159-166. [PMID: 29229304 PMCID: PMC5835412 DOI: 10.1016/j.jsbmb.2017.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/30/2017] [Accepted: 12/08/2017] [Indexed: 10/18/2022]
Abstract
Cytochrome P450 17A1 (CYP17A1) is a dual-function enzyme catalyzing reactions necessary for cortisol and androgen biosynthesis. CYP17A1 is a validated drug target for prostate cancer as CYP17A1 inhibition significantly reduces circulating androgens and improves survival in castration-resistant prostate cancer. Germline CYP17A1 genetic variants with altered CYP17A1 activity manifesting as various endocrinopathies are extremely rare; however, characterizing these variants provides critical insights into CYP17A1 protein structure and function. By querying the dbSNP online database and publically available data from the 1000 genomes project (http://browser.1000genomes.org), we identified two CYP17A1 nonsynonymous genetic variants with unknown consequences for enzymatic activity and stability. We hypothesized that the resultant amino acid changes would alter CYP17A1 stability or activity. To test this hypothesis, we utilized a HEK-293T cell-based expression system to characterize the functional consequences of two CYP17A1 variants, D216H (rs200063521) and G162R (rs141821705). Cells transiently expressing the D216H variant demonstrate a selective impairment of 16α-hydroxyprogesterone synthesis by 2.1-fold compared to wild-type (WT) CYP17A1, while no effect on 17α-hydroxyprogesterone synthesis was observed. These data suggest that substrate orientations in the active site might be altered with this amino acid substitution. In contrast, the G162R substitution exhibits decreased CYP17A1 protein stability compared to WT with a near 70% reduction in protein levels as determined by immunoblot analysis. This variant is preferentially ubiquitinated and degraded prematurely, with an enzyme half-life calculated to be ∼2.5 h, and proteasome inhibitor treatment recovers G162R protein expression to WT levels. Together, these data provide new insights into CYP17A1 structure-function and stability mechanisms.
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Affiliation(s)
- C P Capper
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA; Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - J Liu
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - L R McIntosh
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - J M Larios
- Division of Hematology and Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - M D Johnson
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, Washington, D.C., USA
| | - P F Hollenberg
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Y Osawa
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - R J Auchus
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA; Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
| | - J M Rae
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA; Division of Hematology and Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
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12
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Gonzalez E, Johnson KM, Pallan PS, Phan TTN, Zhang W, Lei L, Wawrzak Z, Yoshimoto FK, Egli M, Guengerich FP. Inherent steroid 17α,20-lyase activity in defunct cytochrome P450 17A enzymes. J Biol Chem 2017; 293:541-556. [PMID: 29212707 DOI: 10.1074/jbc.ra117.000504] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/11/2017] [Indexed: 01/08/2023] Open
Abstract
Cytochrome P450 (P450) 17A1 catalyzes the oxidations of progesterone and pregnenolone and is the major source of androgens. The enzyme catalyzes both 17α-hydroxylation and a subsequent 17α,20-lyase reaction, and several mechanisms have been proposed for the latter step. Zebrafish P450 17A2 catalyzes only the 17α-hydroxylations. We previously reported high similarity of the crystal structures of zebrafish P450 17A1 and 17A2 and human P450 17A1. Five residues near the heme, which differed, were changed. We also crystallized this five-residue zebrafish P450 17A1 mutant, and the active site still resembled the structure in the other proteins, with some important differences. These P450 17A1 and 17A2 mutants had catalytic profiles more similar to each other than did the wildtype proteins. Docking with these structures can explain several minor products, which require multiple enzyme conformations. The 17α-hydroperoxy (OOH) derivatives of the steroids were used as oxygen surrogates. Human P450 17A1 and zebrafish P450s 17A1 and P450 17A2 readily converted these to the lyase products in the absence of other proteins or cofactors (with catalytically competent kinetics) plus hydroxylated 17α-hydroxysteroids. The 17α-OOH results indicate that a "Compound I" (FeO3+) intermediate is capable of formation and can be used to rationalize the products. We conclude that zebrafish P450 17A2 is capable of lyase activity with the 17α-OOH steroids because it can achieve an appropriate conformation for lyase catalysis in this system that is precluded in the conventional reaction.
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Affiliation(s)
- Eric Gonzalez
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Kevin M Johnson
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Pradeep S Pallan
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Thanh T N Phan
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Wei Zhang
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Li Lei
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Zdzislaw Wawrzak
- the Life Sciences Collaborative Access Team, Sector 21, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, and
| | | | - Martin Egli
- 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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13
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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: 37] [Impact Index Per Article: 5.3] [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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14
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Wang C, Pallan PS, Zhang W, Lei L, Yoshimoto FK, Waterman MR, Egli M, Guengerich FP. Functional analysis of human cytochrome P450 21A2 variants involved in congenital adrenal hyperplasia. J Biol Chem 2017; 292:10767-10778. [PMID: 28539365 DOI: 10.1074/jbc.m117.792465] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 05/12/2017] [Indexed: 11/06/2022] Open
Abstract
Cytochrome P450 (P450, CYP) 21A2 is the major steroid 21-hydroxylase, converting progesterone to 11-deoxycorticosterone and 17α-hydroxyprogesterone (17α-OH-progesterone) to 11-deoxycortisol. More than 100 CYP21A2 variants give rise to congenital adrenal hyperplasia (CAH). We previously reported a structure of WT human P450 21A2 with bound progesterone and now present a structure bound to the other substrate (17α-OH-progesterone). We found that the 17α-OH-progesterone- and progesterone-bound complex structures are highly similar, with only some minor differences in surface loop regions. Twelve P450 21A2 variants associated with either salt-wasting or nonclassical forms of CAH were expressed, purified, and analyzed. The catalytic activities of these 12 variants ranged from 0.00009% to 30% of WT P450 21A2 and the extent of heme incorporation from 10% to 95% of the WT. Substrate dissociation constants (Ks) for four variants were 37-13,000-fold higher than for WT P450 21A2. Cytochrome b5, which augments several P450 activities, inhibited P450 21A2 activity. Similar to the WT enzyme, high noncompetitive intermolecular kinetic deuterium isotope effects (≥ 5.5) were observed for all six P450 21A2 variants examined for 21-hydroxylation of 21-d3-progesterone, indicating that C-H bond breaking is a rate-limiting step over a 104-fold range of catalytic efficiency. Using UV-visible and CD spectroscopy, we found that P450 21A2 thermal stability assessed in bacterial cells and with purified enzymes differed among salt-wasting- and nonclassical-associated variants, but these differences did not correlate with catalytic activity. Our in-depth investigation of CAH-associated P450 21A2 variants reveals critical insight into the effects of disease-causing mutations on this important enzyme.
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Affiliation(s)
- Chunxue Wang
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Pradeep S Pallan
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Wei Zhang
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Li Lei
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Francis K Yoshimoto
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Michael R Waterman
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Martin Egli
- 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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15
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Bonomo S, Jørgensen FS, Olsen L. Mechanism of Cytochrome P450 17A1-Catalyzed Hydroxylase and Lyase Reactions. J Chem Inf Model 2017; 57:1123-1133. [DOI: 10.1021/acs.jcim.6b00759] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Silvia Bonomo
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen Ø, Denmark
| | - Flemming Steen Jørgensen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen Ø, Denmark
| | - Lars Olsen
- Department
of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen Ø, Denmark
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16
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Auchus RJ. Steroid 17-hydroxylase and 17,20-lyase deficiencies, genetic and pharmacologic. J Steroid Biochem Mol Biol 2017; 165:71-78. [PMID: 26862015 PMCID: PMC4976049 DOI: 10.1016/j.jsbmb.2016.02.002] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 01/22/2016] [Accepted: 02/03/2016] [Indexed: 12/12/2022]
Abstract
Steroid 17-hydroxylase 17,20-lyase (cytochrome P450c17, P450 17A1, CYP17A1) catalyzes two major reactions: steroid 17-hydroxylation followed by the 17,20-lyase reactions. The most severe mutations in the cognate CYP17A1 gene abrogate all activities and cause combined 17-hydroxylase/17,20-lyase deficiency (17OHD), a biochemical phenotype that is replicated by treatment with the potent CYP17A1 inhibitor abiraterone acetate. The adrenals of patients with 17OHD synthesize 11-deoxycorticosterone (DOC) and corticosterone but no 19-carbon steroids, similar to the rodent adrenal, and DOC causes hypertension and hypokalemia. Loss of 17,20-lyase activity precludes sex steroid synthesis and leads to sexual infantilism. Rare missense CYP17A1 mutations minimally disrupt 17-hydroxylase activity but cause isolated 17,20-lyase deficiency (ILD), Mutations in the POR gene encoding the required cofactor protein cytochrome P450-oxidoreductase causes a spectrum of disease from ILD to 17OHD combined with 21-hydroxylase and aromatase deficiencies, sometimes including skeletal malformations. Mutations in the CYB5A gene encoding a second cofactor protein cytochrome b5 also selectively disrupt 17,20-lyase activity and cause the purest form of ILD. The clinical manifestations of these conditions are best understood in the context of the biochemistry of CYP17A1.
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Affiliation(s)
- Richard J Auchus
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine and Department of Pharmacology, University of Michigan, Rm. 5560A MSRBII, 1150 W Medical Center Drive, Ann Arbor, MI 48109, United States.
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17
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Bird IM, Abbott DH. The hunt for a selective 17,20 lyase inhibitor; learning lessons from nature. J Steroid Biochem Mol Biol 2016; 163:136-46. [PMID: 27154414 PMCID: PMC5046225 DOI: 10.1016/j.jsbmb.2016.04.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/26/2016] [Accepted: 04/28/2016] [Indexed: 01/10/2023]
Abstract
Given prostate cancer is driven, in part, by its responsiveness to androgens, treatments historically employ methods for their removal from circulation. Approaches as crude as castration, and more recently blockade of androgen synthesis or receptor binding, are still of limited use long term, since other steroids of adrenal origin or tumor origin can supersede that role as the 'castration resistant' tumor re-emerges. Broader inhibition of steroidogenesis using relatively nonselective P450 inhibitors such as ketoconazole is not an alternative since a general disruption of steroid biosynthesis is neither safe nor effective. The recent emergence of drugs more selectively targeting CYP17 have been more effective, and yet extension of life has been on the scale of months rather than years. It is now becoming clear this shortcoming arises from the adaptive capabilities of many tumors to initiate local steroid synthesis and/or become responsive to novel early pathway adrenal steroids that are synthesized when lyase activity is not selectively blocked, and ACTH rises in the face of declining cortisol feedback. Abiraterone has been described as a lyase selective inhibitor, yet its use still requires co-administration of prednisone to suppress such a rise of ACTH and fall in cortisol. So is creation of a selective lyase inhibitor even possible? Can C19 steroid production be achieved without a prominent decline in cortisol and corresponding rise in ACTH? Decades of scientific study of CYP17 in humans and nonhuman primates, as well as nature's own experiments of gene mutations in humans, reveal 'true' or 'isolated' 17,20 lyase deficiency does quite selectively prevent C19 steroid biosynthesis whereas simple 17 hydroxylase deficiency also suppresses cortisol. We propose these known outcomes of natural mutations should be used to guide analysis of clinical trials and long term outcomes of CYP17 targeted drugs. In this review, we use that framework to re-evaluate the basic and clinical outcomes of many compounds being used or in development for treatment of castration resistant prostate cancer. Specifically, we include the nonselective drug ketoconazole, and then the CYP17 targeted drugs abiraterone, orteronel (TAK-700), galaterone (TOK-001), and seviteronel (VT-464). Using this framework, we can fully discriminate the clinical outcomes for ketoconazole, a drug with broad specificity, yet clinically ineffective, from that of abiraterone, the first CYP17 targeted therapy that is limited by its need for prednisone co-therapy. We also can identify potential next generation CYP17 targeted drugs now emerging that show signs of being far more 17,20 lyase selective. We conclude that a future for improved therapy without substantial cortisol decline, thus avoiding prednisone co-administration, seems possible at long last.
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Affiliation(s)
- Ian M Bird
- Department Ob/Gyn, University of Wisconsin-Madison SMPH, Madison, WI, USA.
| | - David H Abbott
- Department Ob/Gyn, University of Wisconsin-Madison SMPH, Madison, WI, USA; Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI, USA
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18
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McCammon KM, Panda SP, Xia C, Kim JJP, Moutinho D, Kranendonk M, Auchus RJ, Lafer EM, Ghosh D, Martasek P, Kar R, Masters BS, Roman LJ. Instability of the Human Cytochrome P450 Reductase A287P Variant Is the Major Contributor to Its Antley-Bixler Syndrome-like Phenotype. J Biol Chem 2016; 291:20487-502. [PMID: 27496950 PMCID: PMC5034044 DOI: 10.1074/jbc.m116.716019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/18/2016] [Indexed: 11/06/2022] Open
Abstract
Human NADPH-cytochrome P450 oxidoreductase (POR) gene mutations are associated with severe skeletal deformities and disordered steroidogenesis. The human POR mutation A287P presents with disordered sexual development and skeletal malformations. Difficult recombinant expression and purification of this POR mutant suggested that the protein was less stable than WT. The activities of cytochrome P450 17A1, 19A1, and 21A2, critical in steroidogenesis, were similar using our purified, full-length, unmodified A287P or WT POR, as were those of several xenobiotic-metabolizing cytochromes P450, indicating that the A287P protein is functionally competent in vitro, despite its functionally deficient phenotypic behavior in vivo Differential scanning calorimetry and limited trypsinolysis studies revealed a relatively unstable A287P compared with WT protein, leading to the hypothesis that the syndrome observed in vivo results from altered POR protein stability. The crystal structures of the soluble domains of WT and A287P reveal only subtle differences between them, but these differences are consistent with the differential scanning calorimetry results as well as the differential susceptibility of A287P and WT observed with trypsinolysis. The relative in vivo stabilities of WT and A287P proteins were also examined in an osteoblast cell line by treatment with cycloheximide, a protein synthesis inhibitor, showing that the level of A287P protein post-inhibition is lower than WT and suggesting that A287P may be degraded at a higher rate. Current studies demonstrate that, unlike previously described mutations, A287P causes POR deficiency disorder due to conformational instability leading to proteolytic susceptibility in vivo, rather than through an inherent flavin-binding defect.
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Affiliation(s)
- Karen M McCammon
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Satya P Panda
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Chuanwu Xia
- the Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Jung-Ja P Kim
- the Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Daniela Moutinho
- the Centre for Toxicogenomics and Human Health (ToxOmics), Genetics, Oncology and Human Toxicology, NOVA Medical School/FCM, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130, 1169-056 Lisboa, Portugal
| | - Michel Kranendonk
- the Centre for Toxicogenomics and Human Health (ToxOmics), Genetics, Oncology and Human Toxicology, NOVA Medical School/FCM, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130, 1169-056 Lisboa, Portugal
| | - Richard J Auchus
- the Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
| | - Eileen M Lafer
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Debashis Ghosh
- the Department of Pharmacology, State University of New York Upstate Medical University, Syracuse, New York 13210, and
| | - Pavel Martasek
- the Department of Pediatrics, First Faculty of Medicine, Charles University in Prague and General University Hospital, 116 36 Prague 1, Czech Republic
| | - Rekha Kar
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Bettie Sue Masters
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229,
| | - Linda J Roman
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229,
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19
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Yoshimoto FK, Auchus RJ. Rapid kinetic methods to dissect steroidogenic cytochrome P450 reaction mechanisms. J Steroid Biochem Mol Biol 2016; 161:13-23. [PMID: 26472553 PMCID: PMC4841756 DOI: 10.1016/j.jsbmb.2015.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/12/2015] [Accepted: 10/07/2015] [Indexed: 01/03/2023]
Abstract
All cytochrome P450 enzyme reactions involve a catalytic cycle with several discreet physical or chemical steps. This cycle ends with the formation of the reactive heme iron-oxygen complex, which oxygenates substrate. While the steps might be very similar for each P450 enzyme, the rates of each step varies tremendously for each enzyme and sometimes even for different reactions catalyzed by the same enzyme. For example, the rate-limiting step for most bacterial P450 enzymes, with turnover numbers over 1000s(-1), is the second electron transfer. In contrast, steroidogenic P450s from eukaryotes catalyze much slower reactions, with turnover numbers of ∼5-250min(-1); therefore, assumptions about kinetic properties for the mammalian P450 enzymes based on the bacterial enzymes are tenuous. In order to dissect the rates for individual steps, special techniques that isolate individual steps and/or single turnovers are required. This article will review the theoretical principles and practical considerations for several of these techniques, with illustrative published examples. The reader should gain an appreciation for the appropriate methods used to interrogate particular steps in the P450 reaction cycle.
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Affiliation(s)
- Francis K Yoshimoto
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Richard J Auchus
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, Ann Arbor, MI 48019, USA; Department of Pharmacology, University of Michigan, Ann Arbor, MI 48019, USA.
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20
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Yoshimoto FK, Gonzalez E, Auchus RJ, Guengerich FP. Mechanism of 17α,20-Lyase and New Hydroxylation Reactions of Human Cytochrome P450 17A1: 18O LABELING AND OXYGEN SURROGATE EVIDENCE FOR A ROLE OF A PERFERRYL OXYGEN. J Biol Chem 2016; 291:17143-64. [PMID: 27339894 DOI: 10.1074/jbc.m116.732966] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Indexed: 11/06/2022] Open
Abstract
Cytochrome P450 (P450) reactions can involve C-C bond cleavage, and several of these are critical in steroid and sterol biosynthesis. The mechanisms of P450s 11A1, 17A1, 19A1, and 51A1 have been controversial, in the context of the role of ferric peroxide (FeO2 (-)) versus perferryl (FeO(3+), compound I) chemistry. We reinvestigated the 17α-hydroxyprogesterone and 17α-hydroxypregnenolone 17α,20-lyase reactions of human P450 17A1 and found incorporation of one (18)O atom (from (18)O2) into acetic acid, consonant with proposals for a ferric peroxide mechanism (Akhtar, M., Lee-Robichaud, P., Akhtar, M. E., and Wright, J. N. (1997) J. Steroid Biochem. Mol. Biol. 61, 127-132; Akhtar, M., Wright, J. N., and Lee-Robichaud, P. (2011) J. Steroid Biochem. Mol. Biol. 125, 2-12). However, the reactions were supported by iodosylbenzene (a precursor of the FeO(3+) species) but not by H2O2 We propose three mechanisms that can involve the FeO(3+) entity and that explain the (18)O label in the acetic acid, two involving the intermediacy of an acetyl radical and one a steroid 17,20-dioxetane. P450 17A1 was found to perform 16-hydroxylation reactions on its 17α-hydroxylated products to yield 16,17α-dihydroxypregnenolone and progesterone, suggesting the presence of an active perferryloxo active species of P450 17A1 when its lyase substrate is bound. The 6β-hydroxylation of 16α,17α-dihydroxyprogesterone and the oxidation of both 16α,17α-dihydroxyprogesterone and 16α,17α-dihydroxypregnenolone to 16-hydroxy lyase products were also observed. We provide evidence for the contribution of a compound I mechanism, although contribution of a ferric peroxide pathway in the 17α,20-lyase reaction cannot be excluded.
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Affiliation(s)
- Francis K Yoshimoto
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and the Division of Metabolism, Diabetes and Endocrinology, Departments of Internal Medicine and Pharmacology, University of Michigan, Ann Arbor, Michigan 48019
| | - Eric Gonzalez
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
| | - Richard J Auchus
- the Division of Metabolism, Diabetes and Endocrinology, Departments of Internal Medicine and Pharmacology, University of Michigan, Ann Arbor, Michigan 48019
| | - F Peter Guengerich
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
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21
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Yoshimoto FK, Auchus RJ. The diverse chemistry of cytochrome P450 17A1 (P450c17, CYP17A1). J Steroid Biochem Mol Biol 2015; 151:52-65. [PMID: 25482340 PMCID: PMC4456341 DOI: 10.1016/j.jsbmb.2014.11.026] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/25/2014] [Accepted: 11/30/2014] [Indexed: 11/28/2022]
Abstract
The steroid hydroxylation and carbon-carbon bond cleavage activities of cytochrome P450 17A1 (CYP17A1) are responsible for the production of glucocorticoids and androgens, respectively. The inhibition of androgen synthesis is an important strategy to treat androgen-dependent prostate cancer. We discuss the different enzymatic activities towards the various substrates of CYP17A1, demonstrating its promiscuity. Additionally, a novel interhelical interaction is proposed between the F-G loop and the B'-helix to explain the 16α-hydroxylase activity of human CYP17A1 with progesterone as the substrate. The techniques used by biochemists to study this important enzyme are also summarized. This article is part of a Special Issue entitled 'Steroid/Sterol signaling'.
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Affiliation(s)
- Francis K Yoshimoto
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, United States
| | - Richard J Auchus
- Division of Metabolism, Diabetes, and Endocrinology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48019, United States.
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22
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Miller WL, Tee MK. The post-translational regulation of 17,20 lyase activity. Mol Cell Endocrinol 2015; 408:99-106. [PMID: 25224484 DOI: 10.1016/j.mce.2014.09.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/06/2014] [Accepted: 09/08/2014] [Indexed: 01/20/2023]
Abstract
A single enzyme, microsomal P450c17, catalyzes the 17α-hydroxylase activity needed to make cortisol and the subsequent 17,20 lyase activity needed to produce the 19-carbon precursors of sex steroids. The biochemical decision concerning whether P450c17 stops after 17α-hydroxylation or proceeds to 17,20 lyase activity is largely dependent on three post-translational factors. First, 17,20 lyase activity is especially sensitive to the molar abundance of the electron-transfer protein P450 oxidoreductase (POR). Second, cytochrome b5 strongly promotes 17,20 lyase activity, principally by acting as an allosteric factor promoting the interaction of P450c17 with POR, although a minor role as an alternative electron-transfer protein has not been wholly excluded. Third, the serine/threonine phosphorylation of P450c17 itself promotes 17,20 lyase activity, again apparently by promoting the interaction of P450c17 with POR. The principal kinase that phosphorylates P450c17 to confer 17,20 lyase activity appears to be p38α (MAPK14), which increases the maximum velocity of the 17,20 lyase reaction, while having no effect on the Michaelis constant for 17,20 lyase or any detectable effect on the 17α-hydroxylase reaction. Other kinases can also phosphorylate P450c17, but only p38α has been shown to affect its enzymology. Understanding the mechanisms regulating 17,20 lyase activity is essential for the understanding of hyperandrogenic disorders such as premature, exaggerated adrenarche and the polycystic ovary syndrome, and also for the design of selective 17,20 lyase inhibitors for use in hyperandrogenic states and in sex-steroid dependent cancers.
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Affiliation(s)
- Walter L Miller
- Department of Pediatrics, University of California, San Francisco, CA 94143-0978, USA.
| | - Meng Kian Tee
- Department of Pediatrics, University of California, San Francisco, CA 94143-0978, USA
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23
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Pallan PS, Wang C, Lei L, Yoshimoto FK, Auchus RJ, Waterman MR, Guengerich FP, Egli M. Human Cytochrome P450 21A2, the Major Steroid 21-Hydroxylase: STRUCTURE OF THE ENZYME·PROGESTERONE SUBSTRATE COMPLEX AND RATE-LIMITING C-H BOND CLEAVAGE. J Biol Chem 2015; 290:13128-43. [PMID: 25855791 DOI: 10.1074/jbc.m115.646307] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Indexed: 11/06/2022] Open
Abstract
Cytochrome P450 (P450) 21A2 is the major steroid 21-hydroxylase, and deficiency of this enzyme is involved in ∼95% of cases of human congenital adrenal hyperplasia, a disorder of adrenal steroidogenesis. A structure of the bovine enzyme that we published previously (Zhao, B., Lei, L., Kagawa, N., Sundaramoorthy, M., Banerjee, S., Nagy, L. D., Guengerich, F. P., and Waterman, M. R. (2012) Three-dimensional structure of steroid 21-hydroxylase (cytochrome P450 21A2) with two substrates reveals locations of disease-associated variants. J. Biol. Chem. 287, 10613-10622), containing two molecules of the substrate 17α-hydroxyprogesterone, has been used as a template for understanding genetic deficiencies. We have now obtained a crystal structure of human P450 21A2 in complex with progesterone, a substrate in adrenal 21-hydroxylation. Substrate binding and release were fast for human P450 21A2 with both substrates, and pre-steady-state kinetics showed a partial burst but only with progesterone as substrate and not 17α-hydroxyprogesterone. High intermolecular non-competitive kinetic deuterium isotope effects on both kcat and kcat/Km, from 5 to 11, were observed with both substrates, indicative of rate-limiting C-H bond cleavage and suggesting that the juxtaposition of the C21 carbon in the active site is critical for efficient oxidation. The estimated rate of binding of the substrate progesterone (kon 2.4 × 10(7) M(-1) s(-1)) is only ∼2-fold greater than the catalytic efficiency (kcat/Km = 1.3 × 10(7) M(-1) s(-1)) with this substrate, suggesting that the rate of substrate binding may also be partially rate-limiting. The structure of the human P450 21A2-substrate complex provides direct insight into mechanistic effects of genetic variants.
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Affiliation(s)
- Pradeep S Pallan
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
| | - Chunxue Wang
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
| | - Li Lei
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
| | - Francis K Yoshimoto
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
| | - Richard J Auchus
- the Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Michael R Waterman
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
| | - F Peter Guengerich
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
| | - Martin Egli
- From the Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146 and
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24
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Yoshimoto FK, Peng HM, Zhang H, Anderson SM, Auchus RJ. Epoxidation activities of human cytochromes P450c17 and P450c21. Biochemistry 2014; 53:7531-40. [PMID: 25386927 PMCID: PMC4263428 DOI: 10.1021/bi5011865] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
![]()
Some cytochrome P450 enzymes epoxidize
unsaturated substrates,
but this activity has not been described for the steroid hydroxylases.
Physiologic steroid substrates, however, lack carbon–carbon
double bonds in the parts of the pregnane molecules where steroidogenic
hydroxylations occur. Limited data on the reactivity of steroidogenic
P450s toward olefinic substrates exist, and the study of occult activities
toward alternative substrates is a fundamental aspect of the growing
field of combinatorial biosynthesis. We reasoned that human P450c17
(steroid 17-hydroxylase/17,20-lyase, CYP17A1), which 17- and 16α-hydroxylates
progesterone, might catalyze the formation of the 16α,17-epoxide
from 16,17-dehydroprogesterone (pregna-4,16-diene-3,20-dione). CYP17A1
catalyzed the novel 16α,17-epoxidation and the ordinarily minor
21-hydroxylation of 16,17-dehydroprogesterone in a 1:1 ratio. CYP17A1
mutation A105L, which has reduced progesterone 16α-hydroxylase
activity, gave a 1:5 ratio of epoxide:21-hydroxylated products. In
contrast, human P450c21 (steroid 21-hydroxylase, CYP21A2) converted
16,17-dehydroprogesterone to the 21-hydroxylated product and only
a trace of epoxide. CYP21A2 mutation V359A, which has significant
16α-hydroxylase activity, likewise afforded the 21-hydroxylated
product and slightly more epoxide. CYP17A1 wild-type and mutation
A105L do not 21- or 16α-hydroxylate pregnenolone, but the enzymes
21-hydroxylated and 16α,17-epoxidized 16,17-dehydropregnenolone
(pregna-5,16-diene-3β-ol-20-one) in 4:1 or 12:1 ratios, respectively.
Catalase and superoxide dismutase did not prevent epoxide formation.
The progesterone epoxide was not a time-dependent, irreversible CYP17A1
inhibitor. Our substrate modification studies have revealed occult
epoxidase and 21-hydroxylase activities of CYP17A1, and the fraction
of epoxide formed correlated with the 16α-hydroxylase activity
of the enzymes.
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Affiliation(s)
- Francis K Yoshimoto
- Division of Metabolism, Endocrinology, & Diabetes, Department of Internal Medicine and ‡Department of Pharmacology, University of Michigan , Ann Arbor, Michigan 48109, United States
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25
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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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26
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Yoshimoto FK, Guengerich FP. Mechanism of the third oxidative step in the conversion of androgens to estrogens by cytochrome P450 19A1 steroid aromatase. J Am Chem Soc 2014; 136:15016-25. [PMID: 25252141 PMCID: PMC4210144 DOI: 10.1021/ja508185d] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
Aromatase
is the cytochrome P450 enzyme that cleaves the C10–C19
carbon–carbon bond of androgens to form estrogens, in a three-step
process. Compound I (FeO3+) and ferric peroxide (FeO2–) have both been proposed in the literature
as the active iron species in the third step, yielding an estrogen
and formic acid. Incubation of purified aromatase with its 19-deutero-19-oxo
androgen substrate was performed in the presence of 18O2, and the products were derivatized using a novel diazo reagent.
Analysis of the products by high-resolution mass spectrometry showed
a lack of 18O incorporation in the product formic acid,
supporting only the Compound I pathway. Furthermore, a new androgen
19-carboxylic acid product was identified. The rates of nonenzymatic
hydration of the 19-oxo androgen and dehydration of the 19,19-gem-diol were shown to be catalytically competent. Thus,
the evidence supports Compound I and not ferric peroxide as the active
iron species in the third step of the steroid aromatase reaction.
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Affiliation(s)
- Francis K Yoshimoto
- Department of Biochemistry, Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
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27
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Petrunak EM, DeVore NM, Porubsky PR, Scott EE. Structures of human steroidogenic cytochrome P450 17A1 with substrates. J Biol Chem 2014; 289:32952-64. [PMID: 25301938 DOI: 10.1074/jbc.m114.610998] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The human cytochrome P450 17A1 (CYP17A1) enzyme operates at a key juncture of human steroidogenesis, controlling the levels of mineralocorticoids influencing blood pressure, glucocorticoids involved in immune and stress responses, and androgens and estrogens involved in development and homeostasis of reproductive tissues. Understanding CYP17A1 multifunctional biochemistry is thus integral to treating prostate and breast cancer, subfertility, blood pressure, and other diseases. CYP17A1 structures with all four physiologically relevant steroid substrates suggest answers to four fundamental aspects of CYP17A1 function. First, all substrates bind in a similar overall orientation, rising ∼60° with respect to the heme. Second, both hydroxylase substrates pregnenolone and progesterone hydrogen bond to Asn(202) in orientations consistent with production of 17α-hydroxy major metabolites, but functional and structural evidence for an A105L mutation suggests that a minor conformation may yield the minor 16α-hydroxyprogesterone metabolite. Third, substrate specificity of the subsequent 17,20-lyase reaction may be explained by variation in substrate height above the heme. Although 17α-hydroxyprogesterone is only observed farther from the catalytic iron, 17α-hydroxypregnenolone is also observed closer to the heme. In conjunction with spectroscopic evidence, this suggests that only 17α-hydroxypregnenolone approaches and interacts with the proximal oxygen of the catalytic iron-peroxy intermediate, yielding efficient production of dehydroepiandrosterone as the key intermediate in human testosterone and estrogen synthesis. Fourth, differential positioning of 17α-hydroxypregnenolone offers a mechanism whereby allosteric binding of cytochrome b5 might selectively enhance the lyase reaction. In aggregate, these structures provide a structural basis for understanding multiple key reactions at the heart of human steroidogenesis.
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Affiliation(s)
- Elyse M Petrunak
- From the Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045 and
| | - Natasha M DeVore
- From the Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045 and
| | - Patrick R Porubsky
- the Specialized Chemistry Center, 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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