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Petrunak EM, Bart AG, Peng HM, Auchus RJ, Scott EE. Human cytochrome P450 17A1 structures with metabolites of prostate cancer drug abiraterone reveal substrate-binding plasticity and a second binding site. J Biol Chem 2023; 299:102999. [PMID: 36773804 PMCID: PMC10023946 DOI: 10.1016/j.jbc.2023.102999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
Abiraterone acetate is a first-line therapy for castration-resistant prostate cancer. This prodrug is deacetylated in vivo to abiraterone, which is a potent and specific inhibitor of cytochrome P450 17A1 (CYP17A1). CYP17A1 performs two sequential steps that are required for the biosynthesis of androgens that drive prostate cancer proliferation, analogous to estrogens in breast cancer. Abiraterone can be further metabolized in vivo on the steroid A ring to multiple metabolites that also inhibit CYP17A1. Despite its design as an active-site-directed substrate analog, abiraterone and its metabolites demonstrate mixed competitive/noncompetitive inhibition. To understand their binding, we solved the X-ray structures of CYP17A1 with three primary abiraterone metabolites. Despite different conformations of the steroid A ring and substituents, all three bound in the CYP17A1 active site with the steroid core packed against the I helix and the A ring C3 keto or hydroxyl oxygen forming a hydrogen bond with N202 similar to abiraterone itself. The structure of CYP17A1 with 3-keto, 5α-abiraterone was solved to 2.0 Å, the highest resolution to date for a CYP17A1 complex. This structure had additional electron density near the F/G loop, which is likely a second molecule of the inhibitor and which may explain the noncompetitive inhibition. Mutation of the adjacent Asn52 to Tyr positions its side chain in this space, maintains enzyme activity, and prevents binding of the peripheral ligand. Collectively, our findings provide further insight into abiraterone metabolite binding and CYP17A1 function.
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Affiliation(s)
- Elyse M Petrunak
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - Aaron G Bart
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | - Hwei-Ming Peng
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Richard J Auchus
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, USA; Endocrinology & Metabolism Section, Medicine Service, LTC Charles S. Kettles Veterans Affairs Medical Center, Ann Arbor, Michigan, USA
| | - Emily E Scott
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, USA; Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA; Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, USA.
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Bart AG, Morais G, Vangala VR, Loadman PM, Pors K, Scott EE. Cytochrome P450 Binding and Bioactivation of Tumor-Targeted Duocarmycin Agents. Drug Metab Dispos 2022; 50:49-57. [PMID: 34607808 PMCID: PMC8969195 DOI: 10.1124/dmd.121.000642] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 10/01/2021] [Indexed: 01/03/2023] Open
Abstract
Duocarmycin natural products are promising anticancer cytotoxins but too potent for systemic use. Re-engineering of the duocarmycin scaffold has enabled the discovery of prodrugs designed for bioactivation by tissue-specific cytochrome P450 (P450) enzymes. Lead prodrugs bioactivated by both P450 isoforms CYP1A1 and CYP2W1 have shown promising results in xenograft studies; however, to fully understand the potential of these agents it is desirable to compare dual-targeting compounds with isoform-selective analogs. Such redesign requires insight into the molecular interactions with these P450 enzymes. Herein binding and metabolism of the individual stereoisomers of the indole-based duocarmycin prodrug ICT2700 and a nontoxic benzofuran analog ICT2726 were evaluated with CYP1A1 and CYP2W1, revealing differences exploitable for drug design. Although enantiomers of both compounds bound to and were metabolized by CYP1A1, the stereochemistry of the chloromethyl fragment was critical for CYP2W1 interactions. CYP2W1 differentially binds the S enantiomer of ICT2726, and its metabolite profile could potentially be used as a biomarker to identify CYP2W1 functional activity. In contrast to benzofuran-based ICT2726, CYP2W1 differentially binds the R isomer of the indole-based ICT2700 over the S stereoisomer. Thus the ICT2700 R configuration warrants further investigation as a scaffold to favor CYP2W1-selective bioactivation. Furthermore, structures of both duocarmycin S enantiomers with CYP1A1 reveal orientations correlating with nontoxic metabolites, and further drug design optimization could lead to a decrease of CYP1A1 bioactivation. Overall, distinctive structural features present in the two P450 active sites can be useful for improving P450-and thus tissue-selective-bioactivation. SIGNIFICANCE STATEMENT: Prodrug versions of the natural product duocarmycin can be metabolized by human tissue-specific cytochrome P450 (P450) enzymes 1A1 and 2W1 to form an ultrapotent cytotoxin and/or high affinity 2W1 substrates to potentially probe functional activity in situ. The current work defines the binding and metabolism by both P450 enzymes to support the design of duocarmycins selectively activated by only one human P450 enzyme.
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Affiliation(s)
- Aaron G Bart
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology and Biological Chemistry (E.E.S.), University of Michigan, Ann Arbor, Michigan; Institute of Cancer Therapeutics (G.M., P.M.L., K.P.), Centre for Pharmaceutical Engineering Science (V.R.V.), Faculty of Life Sciences, University of Bradford, United Kingdom
| | - Goreti Morais
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology and Biological Chemistry (E.E.S.), University of Michigan, Ann Arbor, Michigan; Institute of Cancer Therapeutics (G.M., P.M.L., K.P.), Centre for Pharmaceutical Engineering Science (V.R.V.), Faculty of Life Sciences, University of Bradford, United Kingdom
| | - Venu R Vangala
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology and Biological Chemistry (E.E.S.), University of Michigan, Ann Arbor, Michigan; Institute of Cancer Therapeutics (G.M., P.M.L., K.P.), Centre for Pharmaceutical Engineering Science (V.R.V.), Faculty of Life Sciences, University of Bradford, United Kingdom
| | - Paul M Loadman
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology and Biological Chemistry (E.E.S.), University of Michigan, Ann Arbor, Michigan; Institute of Cancer Therapeutics (G.M., P.M.L., K.P.), Centre for Pharmaceutical Engineering Science (V.R.V.), Faculty of Life Sciences, University of Bradford, United Kingdom
| | - Klaus Pors
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology and Biological Chemistry (E.E.S.), University of Michigan, Ann Arbor, Michigan; Institute of Cancer Therapeutics (G.M., P.M.L., K.P.), Centre for Pharmaceutical Engineering Science (V.R.V.), Faculty of Life Sciences, University of Bradford, United Kingdom
| | - Emily E Scott
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology and Biological Chemistry (E.E.S.), University of Michigan, Ann Arbor, Michigan; Institute of Cancer Therapeutics (G.M., P.M.L., K.P.), Centre for Pharmaceutical Engineering Science (V.R.V.), Faculty of Life Sciences, University of Bradford, United Kingdom
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [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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Gillam EMJ, Thomson RES, D'Cunha SA, Harris KL, Foley G, Boden M, Bart AG, Scott EE. Using ancestral sequence reconstruction to create robust highly expressed proteins for crystallography. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321093478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lu J, Bart AG, Wu Q, Criscione KR, McLeish MJ, Scott EE, Grunewald GL. Structure-Based Drug Design of Bisubstrate Inhibitors of Phenylethanolamine N-Methyltransferase Possessing Low Nanomolar Affinity at Both Substrate Binding Domains 1. J Med Chem 2020; 63:13878-13898. [PMID: 33147410 DOI: 10.1021/acs.jmedchem.0c01475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The enzyme phenylethanolamine N-methyltransferase (PNMT, EC 2.1.1.28) catalyzes the final step in the biosynthesis of epinephrine and is a potential drug target, primarily for the control of hypertension. Unfortunately, many potent PNMT inhibitors also possess significant affinity for the a2-adrenoceptor, which complicates the interpretation of their pharmacology. A bisubstrate analogue approach offers the potential for development of highly selective inhibitors of PNMT. This paper documents the design, synthesis, and evaluation of such analogues, several of which were found to possess human PNMT (hPNMT) inhibitory potency <5 nM versus AdoMet. Site-directed mutagenesis studies were consistent with bisubstrate binding. Two of these compounds (19 and 29) were co-crystallized with hPNMT and the resulting structures revealed both compounds bound as predicted, simultaneously occupying both substrate binding domains. This bisubstrate inhibitor approach has resulted in one of the most potent (20) and selective (vs the a2-adrenoceptor) inhibitors of hPNMT yet reported.
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Affiliation(s)
- Jian Lu
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Aaron G Bart
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Qian Wu
- Department of Chemistry and Chemical Biology, Purdue School of Science, IUPUI, Indianapolis, Indiana 46202, United States
| | - Kevin R Criscione
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Michael J McLeish
- Department of Chemistry and Chemical Biology, Purdue School of Science, IUPUI, Indianapolis, Indiana 46202, United States
| | - Emily E Scott
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Gary L Grunewald
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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Russell LE, Schleiff MA, Gonzalez E, Bart AG, Broccatelli F, Hartman JH, Humphreys WG, Lauschke VM, Martin I, Nwabufo C, Prasad B, Scott EE, Segall M, Takahashi R, Taub ME, Sodhi JK. Advances in the study of drug metabolism - symposium report of the 12th Meeting of the International Society for the Study of Xenobiotics (ISSX). Drug Metab Rev 2020; 52:395-407. [PMID: 32456484 DOI: 10.1080/03602532.2020.1765793] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The 12th International Society for the Study of Xenobiotics (ISSX) meeting, held in Portland, OR, USA from July 28 to 31, 2019, was attended by diverse members of the pharmaceutical sciences community. The ISSX New Investigators Group provides learning and professional growth opportunities for student and early career members of ISSX. To share meeting content with those who were unable to attend, the ISSX New Investigators herein elected to highlight the "Advances in the Study of Drug Metabolism" symposium, as it engaged attendees with diverse backgrounds. This session covered a wide range of current topics in drug metabolism research including predicting sites and routes of metabolism, metabolite identification, ligand docking, and medicinal and natural products chemistry, and highlighted approaches complemented by computational modeling. In silico tools have been increasingly applied in both academic and industrial settings, alongside traditional and evolving in vitro techniques, to strengthen and streamline pharmaceutical research. Approaches such as quantum mechanics simulations facilitate understanding of reaction energetics toward prediction of routes and sites of drug metabolism. Furthermore, in tandem with crystallographic and orthogonal wet lab techniques for structural validation of drug metabolizing enzymes, in silico models can aid understanding of substrate recognition by particular enzymes, identify metabolic soft spots and predict toxic metabolites for improved molecular design. Of note, integration of chemical synthesis and biosynthesis using natural products remains an important approach for identifying new chemical scaffolds in drug discovery. These subjects, compiled by the symposium organizers, presenters, and the ISSX New Investigators Group, are discussed in this review.
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Affiliation(s)
- Laura E Russell
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
| | - Mary Alexandra Schleiff
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Eric Gonzalez
- Division of Pre-Clinical Innovation, Therapeutic Development Branch, National Center for Advancing Translational Sciences, Bethesda, MD, USA.,Novartis Institutes for BioMedical Research, Cambridge, MA, USA
| | - Aaron G Bart
- Program in Biophysics, University of Michigan, Ann Arbor, MI, USA
| | - Fabio Broccatelli
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., South San Francisco, CA, USA
| | - Jessica H Hartman
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | | | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | | | - Bhagwat Prasad
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA
| | - Emily E Scott
- Program in Biophysics, University of Michigan, Ann Arbor, MI, USA.,Department of Medicinal Chemistry and Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | | | | | - Mitchell E Taub
- Department of Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, USA
| | - Jasleen K Sodhi
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California, San Francisco, CA, USA
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Bart AG, Harris KL, Gillam EMJ, Scott EE. Structure of an ancestral mammalian family 1B1 cytochrome P450 with increased thermostability. J Biol Chem 2020; 295:5640-5653. [PMID: 32156703 PMCID: PMC7186169 DOI: 10.1074/jbc.ra119.010727] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 03/09/2020] [Indexed: 01/07/2023] Open
Abstract
Mammalian cytochrome P450 enzymes often metabolize many pharmaceuticals and other xenobiotics, a feature that is valuable in a biotechnology setting. However, extant P450 enzymes are typically relatively unstable, with T50 values of ∼30-40 °C. Reconstructed ancestral cytochrome P450 enzymes tend to have variable substrate selectivity compared with related extant forms, but they also have higher thermostability and therefore may be excellent tools for commercial biosynthesis of important intermediates, final drug molecules, or drug metabolites. The mammalian ancestor of the cytochrome P450 1B subfamily was herein characterized structurally and functionally, revealing differences from the extant human CYP1B1 in ligand binding, metabolism, and potential molecular contributors to its thermostability. Whereas extant human CYP1B1 has one molecule of α-naphthoflavone in a closed active site, we observed that subtle amino acid substitutions outside the active site in the ancestor CYP1B enzyme yielded an open active site with four ligand copies. A structure of the ancestor with 17β-estradiol revealed only one molecule in the active site, which still had the same open conformation. Detailed comparisons between the extant and ancestor forms revealed increases in electrostatic and aromatic interactions between distinct secondary structure elements in the ancestral forms that may contribute to their thermostability. To the best of our knowledge, this represents the first structural evaluation of a reconstructed ancestral cytochrome P450, revealing key features that appear to contribute to its thermostability.
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Affiliation(s)
- Aaron G Bart
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan 48109
| | - Kurt L Harris
- School of Chemistry and Molecular Biosciences, University of Queensland St. Lucia, Brisbane 4072, Australia
| | - Elizabeth M J Gillam
- School of Chemistry and Molecular Biosciences, University of Queensland St. Lucia, Brisbane 4072, Australia
| | - Emily E Scott
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan 48109; Departments of Medicinal Chemistry and Pharmacology, University of Michigan, Ann Arbor, Michigan 48109.
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Scott EE, Bart AG. S6.2 - Substrate recognition by cytochrome P450s. Drug Metab Pharmacokinet 2020. [DOI: 10.1016/j.dmpk.2020.04.310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Bart AG, Takahashi RH, Wang X, Scott EE. Human Cytochrome P450 1A1 Adapts Active Site for Atypical Nonplanar Substrate. Drug Metab Dispos 2019; 48:86-92. [PMID: 31757797 DOI: 10.1124/dmd.119.089607] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 11/12/2019] [Indexed: 01/13/2023] Open
Abstract
The human cytochrome P450 1A1 (CYP1A1) is well known for chemical activation of procarcinogens and often has a substrate scope of small and highly planar compounds. Substrates deviating from these characteristics are certainly known, but how these larger and nonplanar substrates are accommodated and oriented within the CYP1A1 active site is not understood. Herein a new X-ray structure of CYP1A1 bound to the pan-Pim kinase inhibitor GDC-0339 reveals how the CYP1A1 active site cavity is reconfigured to bind larger and nonplanar compounds. The shape and size of the cavity are controlled by structural elements in the active site roof, with major changes in the conformation of the F helix break and relocation of Phe224 from the active site to the protein surface. This altered CYP1A1 active site architecture is consistent with the proposed mechanism for CYP1A1 generation of an unusual aminoazepane-rearranged metabolite for this substrate. SIGNIFICANCE STATEMENT: Cytochrome P450 1A1 metabolizes drugs, procarcinogens, and toxins and although previous structures have revealed how its stereotypical planar, aromatic compounds are accommodated in the CYP1A1 active site, this is not the case for flexible and nonplanar compounds. The current work determines the X-ray structure of CYP1A1 with such a flexible, nonplanar Pim kinase inhibitor, revealing significant modification of the CYP1A1 roof that accommodate this preclinical candidate and support an unusual intramolecular rearrangement reaction.
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Affiliation(s)
- Aaron G Bart
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology (E.E.S.), University of Michigan, Ann Arbor, Michigan; and Department of Drug Metabolism and Pharmacokinetics (R.H.T.) and Department of Discovery Chemistry (X.W.), Genentech Inc., South San Francisco, California
| | - Ryan H Takahashi
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology (E.E.S.), University of Michigan, Ann Arbor, Michigan; and Department of Drug Metabolism and Pharmacokinetics (R.H.T.) and Department of Discovery Chemistry (X.W.), Genentech Inc., South San Francisco, California
| | - Xiaojing Wang
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology (E.E.S.), University of Michigan, Ann Arbor, Michigan; and Department of Drug Metabolism and Pharmacokinetics (R.H.T.) and Department of Discovery Chemistry (X.W.), Genentech Inc., South San Francisco, California
| | - Emily E Scott
- Program in Biophysics (A.G.B., E.E.S.) and Departments of Medicinal Chemistry and Pharmacology (E.E.S.), University of Michigan, Ann Arbor, Michigan; and Department of Drug Metabolism and Pharmacokinetics (R.H.T.) and Department of Discovery Chemistry (X.W.), Genentech Inc., South San Francisco, California
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Bart AG, Pors K, Scott EE. Structural Investigations of Prodrug Activation by Human Cytochrome P450 Enzymes. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.673.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Klaus Pors
- Institute of Cancer TherapeuticsUniversity of BradfordBradfordUnited Kingdom
| | - Emily E. Scott
- Biophysics ProgramUniversity of MichiganAnn ArborMI
- Departments of Medicinal Chemistry and PharmacologyUniversity of MichiganAnn ArborMI
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Bart AG, Scott EE. Structures of human cytochrome P450 1A1 with bergamottin and erlotinib reveal active-site modifications for binding of diverse ligands. J Biol Chem 2018; 293:19201-19210. [PMID: 30254074 DOI: 10.1074/jbc.ra118.005588] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 09/19/2018] [Indexed: 11/06/2022] Open
Abstract
Human cytochrome P450 1A1 (CYP1A1) is an extrahepatic enzyme involved in the monooxygenation of structurally diverse compounds ranging from natural products to drugs and protoxins. Because CYP1A1 has a role in human carcinogenesis, inhibiting its activity may potentially aid in cancer chemoprevention, whereas utilizing CYP1A1's oxidative activity could help selectively activate anticancer prodrugs. Such potential therapeutic purposes require detailed knowledge of CYP1A1's interactions with potential ligands. Known CYP1A1 ligands also vary substantially in size, and it has not been apparent from a single existing CYP1A1 structure how larger, structurally diverse ligands are accommodated within the enclosed active site. Here, two new X-ray structures with the natural product furanocoumarin bergamottin (at 2.85 Å resolution) and the lung cancer drug erlotinib (3.0 Å) revealed binding orientations consistent with the formation of innocuous metabolites and of toxic metabolites, respectively. They also disclosed local changes in the roof of the active site that enlarge the active site and ultimately form a channel to the protein exterior. Although further structural modifications would be required to accommodate the largest CYP1A1 ligands, knowing which components of the active site are malleable provides powerful information for those attempting to use computational approaches to predict compound binding and substrate metabolism by this clinically relevant monooxygenase.
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Affiliation(s)
| | - Emily E Scott
- From the Program in Biophysics and .,Departments of Medicinal Chemistry and.,Pharmacology, University of Michigan, Ann Arbor, Michigan 48109
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12
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Bart AG, Scott EE. Exploring Structural Conformations of Human P450 1A1 with Diverse Ligands. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.564.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Emily E. Scott
- Departments of Medicinal Chemistry and Pharmacology, Biophysics ProgramUniversity of MichiganAnn ArborMI
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Bart AG, Scott EE. Structural and functional effects of cytochrome b5 interactions with human cytochrome P450 enzymes. J Biol Chem 2017; 292:20818-20833. [PMID: 29079577 DOI: 10.1074/jbc.ra117.000220] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 10/22/2017] [Indexed: 02/04/2023] Open
Abstract
The small heme-containing protein cytochrome b5 can facilitate, inhibit, or have no effect on cytochrome P450 catalysis, often in a P450-dependent and substrate-dependent manner that is not well understood. Herein, solution NMR was used to identify b5 residues interacting with different human drug-metabolizing P450 enzymes. NMR results revealed that P450 enzymes bound to either b5 α4-5 (CYP2A6 and CYP2E1) or this region and α2-3 (CYP2D6 and CYP3A4) and suggested variation in the affinity for b5 Mutations of key b5 residues suggest not only that different b5 surfaces are responsible for binding different P450 enzymes, but that these different complexes are relevant to the observed effects on P450 catalysis.
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Affiliation(s)
| | - Emily E Scott
- From the Biophysics Program and .,the Departments of Medicinal Chemistry and Pharmacology, University of Michigan, Ann Arbor, Michigan 48109
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Abstract
Human xenobiotic-metabolizing cytochrome P450 (CYP) enzymes can each bind and monooxygenate a diverse set of substrates, including drugs, often producing a variety of metabolites. Additionally, a single ligand can interact with multiple CYP enzymes, but often the protein structural similarities and differences that mediate such overlapping selectivity are not well understood. Even though the CYP superfamily has a highly canonical global protein fold, there are large variations in the active site size, topology, and conformational flexibility. We have determined how a related set of three human CYP enzymes bind and interact with a common inhibitor, the muscarinic receptor agonist drug pilocarpine. Pilocarpine binds and inhibits the hepatic CYP2A6 and respiratory CYP2A13 enzymes much more efficiently than the hepatic CYP2E1 enzyme. To elucidate key residues involved in pilocarpine binding, crystal structures of CYP2A6 (2.4 Å), CYP2A13 (3.0 Å), CYP2E1 (2.35 Å), and the CYP2A6 mutant enzyme, CYP2A6 I208S/I300F/G301A/S369G (2.1 Å) have been determined with pilocarpine in the active site. In all four structures, pilocarpine coordinates to the heme iron, but comparisons reveal how individual residues lining the active sites of these three distinct human enzymes interact differently with the inhibitor pilocarpine.
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Affiliation(s)
- Natasha M DeVore
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, KS 66045, USA
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Bart AG, Klochkova NP, Kozhanov VM, Chmykhova NM. [Study of mechanisms of the interneuronal interaction based on the reflection principal]. Zh Evol Biokhim Fiziol 1997; 33:462-74. [PMID: 9542044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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16
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Sokolova LA, Bondarenko BB, Bart AG, Dzhafarova OA, Klochkova NP. [Clinico-hemodynamic characteristics of patients with initial signs of hypertension]. Kardiologiia 1991; 31:11-3. [PMID: 1921119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Multifactor analysis was used to make clinical and hemodynamic comparisons in 42 patients with borderline arterial hypertension, 27 with Stage I hypertension, 40 with Stage II hypertension, and 40 healthy persons. Central hemodynamic parameters at rest and during graded bicycle ergometer exercise were measured by the Defares carbon dioxide return respiration method modified by V. L. Karpman. As compared with patients with hyperkinetic circulation, those with hypokinetic one were older, had a longer history of arterial hypertension, obesity, more common left ventricular hypertrophy, higher baseline diastolic pressures and total peripheral vascular resistance, less increase in cardiac index and greater enhancement of total peripheral vascular resistance during submaximal exercise. There was a clear-cut correlation between the progression of arterial hypertension and increase in values of factors I (clinical and hemodynamic) and III (cardiotonic).
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Fedoseev GB, Zhikharev SS, Subbotina TF, Kotenko TV, Bart AG, Yaffarova OA. The study of pathogenetic basis of asthma using biostatistic models. Allergol Immunopathol (Madr) 1988; 16:37-41. [PMID: 2837892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In 50 patients with asthma we have determined skin tests on dust and pollen allergens, forced expiratory volume for one second (FEV1) before and after subcutaneous injections of epinephrine standard dose, adrenoreactivity by adrenodependent cyclic AMP levels and glycogenolysis, cyclic AMP phosphodiesterase activity, levels of eosinophils in blood (in all 28 characteristic features). Factor and correlation analysis were carried out by electronic computer. In addition, in 121 patients we have determined adrenodependent glycogenolysis in leucocyte suspension incubated with various allergens the content of diene conjugates and total antioxidative activity of plasma. It is concluded that atopic and nonatopic forms of asthma are diseases of different nature in their constitutional origin, pathogenic agents of environment and cellular and subcellular mechanisms of their development. Moreover, the pathogenetic role of allergen-induced lipid peroxidation that correlates with lymphocyte adrenoreactivity is shown.
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Affiliation(s)
- G B Fedoseev
- Department of Internal Medicine, University of Leningrad, U.S.S.R
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