1
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Jobelius H, Bianchino GI, Borel F, Chaignon P, Seemann M. The Reductive Dehydroxylation Catalyzed by IspH, a Source of Inspiration for the Development of Novel Anti-Infectives. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030708. [PMID: 35163971 PMCID: PMC8837944 DOI: 10.3390/molecules27030708] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 11/16/2022]
Abstract
The non-mevalonate or also called MEP pathway is an essential route for the biosynthesis of isoprenoid precursors in most bacteria and in microorganisms belonging to the Apicomplexa phylum, such as the parasite responsible for malaria. The absence of this pathway in mammalians makes it an interesting target for the discovery of novel anti-infectives. As last enzyme of this pathway, IspH is an oxygen sensitive [4Fe-4S] metalloenzyme that catalyzes 2H+/2e− reductions and a water elimination by involving non-conventional bioinorganic and bioorganometallic intermediates. After a detailed description of the discovery of the [4Fe-4S] cluster of IspH, this review focuses on the IspH mechanism discussing the results that have been obtained in the last decades using an approach combining chemistry, enzymology, crystallography, spectroscopies, and docking calculations. Considering the interesting druggability of this enzyme, a section about the inhibitors of IspH discovered up to now is reported as well. The presented results constitute a useful and rational help to inaugurate the design and development of new potential chemotherapeutics against pathogenic organisms.
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Affiliation(s)
- Hannah Jobelius
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
| | - Gabriella Ines Bianchino
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
| | - Franck Borel
- Institut de Biologie Structurale, Université Grenoble Alpes/CEA/CNRS, 38000 Grenoble, France;
| | - Philippe Chaignon
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
| | - Myriam Seemann
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
- Correspondence:
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2
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Steverlynck J, Sitdikov R, Rueping M. The Deuterated "Magic Methyl" Group: A Guide to Site-Selective Trideuteromethyl Incorporation and Labeling by Using CD 3 Reagents. Chemistry 2021; 27:11751-11772. [PMID: 34076925 PMCID: PMC8457246 DOI: 10.1002/chem.202101179] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Indexed: 12/12/2022]
Abstract
In the field of medicinal chemistry, the precise installation of a trideuteromethyl group is gaining ever-increasing attention. Site-selective incorporation of the deuterated "magic methyl" group can provide profound pharmacological benefits and can be considered an important tool for drug optimization and development. This review provides a structured overview, according to trideuteromethylation reagent, of currently established methods for site-selective trideuteromethylation of carbon atoms. In addition to CD3 , the selective introduction of CD2 H and CDH2 groups is also considered. For all methods, the corresponding mechanism and scope are discussed whenever reported. As such, this review can be a starting point for synthetic chemists to further advance trideuteromethylation methodologies. At the same time, this review aims to be a guide for medicinal chemists, offering them the available C-CD3 formation strategies for the preparation of new or modified drugs.
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Affiliation(s)
- Joost Steverlynck
- Kaust Catalysis Center (KCC)King Abdullah University Science and Technology (KAUST)Thuwal23955-6900Saudi Arabia
| | - Ruzal Sitdikov
- Kaust Catalysis Center (KCC)King Abdullah University Science and Technology (KAUST)Thuwal23955-6900Saudi Arabia
| | - Magnus Rueping
- Kaust Catalysis Center (KCC)King Abdullah University Science and Technology (KAUST)Thuwal23955-6900Saudi Arabia
- Institute for Experimental Molecular ImagingRWTH Aachen UniversityForckenbeckstrasse 5552074Aachen
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3
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Chaignon P, Petit BE, Vincent B, Allouche L, Seemann M. Methylerythritol Phosphate Pathway: Enzymatic Evidence for a Rotation in the LytB/IspH-Catalyzed Reaction. Chemistry 2020; 26:1032-1036. [PMID: 31756006 DOI: 10.1002/chem.201904676] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Indexed: 11/10/2022]
Abstract
IspH/LytB, an oxygen-sensitive [4Fe-4S] enzyme, catalyzes the last step of the methylerythritol phosphate (MEP) pathway, a target for the development of new antimicrobial agents. This metalloenzyme converts (E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate (HMBPP) into the two isoprenoid precursors: isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Here, the synthesis of (S)-[4-2 H1 ]HMBPP and (R)-[4-2 H1 ]HMBPP is reported together with a detailed NMR analysis of the products formed after their respective incubation with E. coli IspH/LytB in the presence of the biological reduction system used by E. coli to reduce the [4Fe-4S] center. (S)-[4-2 H1 ]HMBPP was converted into [4-2 H1 ]DMAPP and (E)-[4-2 H1 ]IPP, whereas (R)-[4-2 H1 ]HMBPP yielded [4-2 H1 ]DMAPP and (Z)-[4-2 H1 ]IPP, hence providing the direct enzymatic evidence that the mechanism catalyzed by IspH/LytB involves a rotation of the CH2 OH group of the substrate to display it away from the [4Fe-4S].
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Affiliation(s)
- Philippe Chaignon
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie UMR 7177, Université de Strasbourg, CNRS, 4, rue Blaise Pascal, 67070, Strasbourg, France
| | - Benoît Eric Petit
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie UMR 7177, Université de Strasbourg, CNRS, 4, rue Blaise Pascal, 67070, Strasbourg, France
| | - Bruno Vincent
- Service de R.M.N., Fédération de Chimie Le Bel FR2010, Université de Strasbourg, CNRS, 1, rue Blaise Pascal, 67008, Strasbourg, France
| | - Lionel Allouche
- Service de R.M.N., Fédération de Chimie Le Bel FR2010, Université de Strasbourg, CNRS, 1, rue Blaise Pascal, 67008, Strasbourg, France
| | - Myriam Seemann
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie UMR 7177, Université de Strasbourg, CNRS, 4, rue Blaise Pascal, 67070, Strasbourg, France
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4
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Borel F, Barbier E, Krasutsky S, Janthawornpong K, Chaignon P, Poulter CD, Ferrer JL, Seemann M. Further Insight into Crystal Structures of Escherichia coli IspH/LytB in Complex with Two Potent Inhibitors of the MEP Pathway: A Starting Point for Rational Design of New Antimicrobials. Chembiochem 2017; 18:2137-2144. [PMID: 28862365 DOI: 10.1002/cbic.201700363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Indexed: 01/12/2023]
Abstract
IspH, also called LytB, a protein involved in the biosynthesis of isoprenoids through the methylerythritol phosphate pathway, is an attractive target for the development of new antimicrobial drugs. Here, we report crystal structures of Escherichia coli IspH in complex with the two most potent inhibitors: (E)-4-mercapto-3-methylbut-2-en-1-yl diphosphate (TMBPP) and (E)-4-amino-3-methylbut-2-en-1-yl diphosphate (AMBPP) at 1.95 and 1.7 Å resolution, respectively. The structure of the E. coli IspH:TMBPP complex exhibited two conformers of the inhibitor. This unexpected feature was exploited to design and evolve new antimicrobial candidates in silico.
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Affiliation(s)
- Franck Borel
- Institut de Biologie Structurale IBS, Université Grenoble Alpes, CEA, CNRS, 38044, Grenoble, France
| | - Elodie Barbier
- Institut de Biologie Structurale IBS, Université Grenoble Alpes, CEA, CNRS, 38044, Grenoble, France
| | - Sergiy Krasutsky
- Department of Chemistry, University of Utah, 315 South 1400 East RM 2020, Salt Lake City, UT, 84112, USA
| | - Karnjapan Janthawornpong
- Université de Strasbourg, CNRS, Institut de Chimie UMR 7177, Chim Biol&Appl Therap, 4, rue Blaise Pascal, 67070, Strasbourg, France
| | - Philippe Chaignon
- Université de Strasbourg, CNRS, Institut de Chimie UMR 7177, Chim Biol&Appl Therap, 4, rue Blaise Pascal, 67070, Strasbourg, France
| | - C Dale Poulter
- Department of Chemistry, University of Utah, 315 South 1400 East RM 2020, Salt Lake City, UT, 84112, USA
| | - Jean-Luc Ferrer
- Institut de Biologie Structurale IBS, Université Grenoble Alpes, CEA, CNRS, 38044, Grenoble, France
| | - Myriam Seemann
- Université de Strasbourg, CNRS, Institut de Chimie UMR 7177, Chim Biol&Appl Therap, 4, rue Blaise Pascal, 67070, Strasbourg, France
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5
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Affiliation(s)
- Jeroen S. Dickschat
- Kekulé-Institute of Organic Chemistry and Biochemistry; Rheinische Friedrich Wilhelms University of Bonn; Gerhard-Domagk-Straße 1 53121 Bonn Germany
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6
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O'Dowd B, Williams S, Wang H, No JH, Rao G, Wang W, McCammon JA, Cramer SP, Oldfield E. Spectroscopic and Computational Investigations of Ligand Binding to IspH: Discovery of Non-diphosphate Inhibitors. Chembiochem 2017; 18:914-920. [PMID: 28253432 PMCID: PMC5445010 DOI: 10.1002/cbic.201700052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Indexed: 11/11/2022]
Abstract
Isoprenoid biosynthesis is an important area for anti-infective drug development. One isoprenoid target is (E)-1-hydroxy-2-methyl-but-2-enyl 4-diphosphate (HMBPP) reductase (IspH), which forms isopentenyl diphosphate and dimethylallyl diphosphate from HMBPP in a 2H+ /2e- reduction. IspH contains a 4 Fe-4 S cluster, and in this work, we first investigated how small molecules bound to the cluster by using HYSCORE and NRVS spectroscopies. The results of these, as well as other structural and spectroscopic investigations, led to the conclusion that, in most cases, ligands bound to IspH 4 Fe-4 S clusters by η1 coordination, forming tetrahedral geometries at the unique fourth Fe, ligand side chains preventing further ligand (e.g., H2 O, O2 ) binding. Based on these ideas, we used in silico methods to find drug-like inhibitors that might occupy the HMBPP substrate binding pocket and bind to Fe, leading to the discovery of a barbituric acid analogue with a Ki value of ≈500 nm against Pseudomonas aeruginosa IspH.
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Affiliation(s)
- Bing O'Dowd
- Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, IL, 61801, USA
| | - Sarah Williams
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA, 92093, USA
| | - Hongxin Wang
- Department of Chemistry, University of California, 1 Shields Avenue, Davis, CA, 95616, USA
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Joo Hwan No
- Center for Biophysics and Computational Biology, 607 South Mathews Avenue, Urbana, IL, 61801, USA
| | - Guodong Rao
- Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, IL, 61801, USA
| | - Weixue Wang
- Center for Biophysics and Computational Biology, 607 South Mathews Avenue, Urbana, IL, 61801, USA
| | - J Andrew McCammon
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA, 92093, USA
- Howard Hughes Medical Institute, University of California at San Diego, La Jolla, CA, 92093, USA
- National Biomedical Computation Resource, University of California at San Diego, La Jolla, CA, 92093, USA
| | - Stephen P Cramer
- Department of Chemistry, University of California, 1 Shields Avenue, Davis, CA, 95616, USA
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Eric Oldfield
- Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, IL, 61801, USA
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7
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Lin CI, McCarty RM, Liu HW. The Enzymology of Organic Transformations: A Survey of Name Reactions in Biological Systems. Angew Chem Int Ed Engl 2017; 56:3446-3489. [PMID: 27505692 PMCID: PMC5477795 DOI: 10.1002/anie.201603291] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Indexed: 01/05/2023]
Abstract
Chemical reactions that are named in honor of their true, or at least perceived, discoverers are known as "name reactions". This Review is a collection of biological representatives of named chemical reactions. Emphasis is placed on reaction types and catalytic mechanisms that showcase both the chemical diversity in natural product biosynthesis as well as the parallels with synthetic organic chemistry. An attempt has been made, whenever possible, to describe the enzymatic mechanisms of catalysis within the context of their synthetic counterparts and to discuss the mechanistic hypotheses for those reactions that are currently active areas of investigation. This Review has been categorized by reaction type, for example condensation, nucleophilic addition, reduction and oxidation, substitution, carboxylation, radical-mediated, and rearrangements, which are subdivided by name reactions.
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Affiliation(s)
- Chia-I Lin
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin, Austin, TX, 78731, USA
| | - Reid M McCarty
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin, Austin, TX, 78731, USA
| | - Hung-Wen Liu
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, and Department of Chemistry, University of Texas at Austin, Austin, TX, 78731, USA
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8
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Lin C, McCarty RM, Liu H. Die Enzymologie organischer Umwandlungen: Namensreaktionen in biologischen Systemen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201603291] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Chia‐I. Lin
- Division of Chemical Biology and Medicinal Chemistry College of Pharmacy, and Department of Chemistry University of Texas at Austin Austin TX 78731 USA
| | - Reid M. McCarty
- Division of Chemical Biology and Medicinal Chemistry College of Pharmacy, and Department of Chemistry University of Texas at Austin Austin TX 78731 USA
| | - Hung‐wen Liu
- Division of Chemical Biology and Medicinal Chemistry College of Pharmacy, and Department of Chemistry University of Texas at Austin Austin TX 78731 USA
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9
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Affiliation(s)
- Annika Frank
- Center for Integrated Protein
Science Munich (CIPSM) at the Department Chemie, Technische Universität München, Lichtenbergstraße 4, 85748 Garching, Germany
| | - Michael Groll
- Center for Integrated Protein
Science Munich (CIPSM) at the Department Chemie, Technische Universität München, Lichtenbergstraße 4, 85748 Garching, Germany
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10
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Abstract
IspH, (E)-1-hydroxy-2-methyl-but-2-enyl 4-diphosphate reductase, is an essential enzyme in isoprenoid biosynthesis and an important drug/herbicide target. Using X-ray crystallographic, bioinformatics, mutagenesis/kinetics/stability, and electron paramagnetic resonance (EPR) results, we show that organisms from different environments ultilize one of four main IspH classes. The classes are based on the arrangement of the aromatic residues near the 4Fe-4S cluster and the presence or absence of N- and C-terminal extensions. Class A enzymes are found primarily in anaerobic and microaerophilic bacteria. Class B enzymes are found in aerobic bacteria. Class C enzymes are found in cyanobacteria and plants. Class D enzymes are found in apicomplexan parasites. Using mutagenesis, we show that the cluster-associated aromatic groups in class A and class B IspHs enhance cluster oxidative stability. Y198A, F302A, and a C-terminal truncation mutant of the class B (Escherichia coli) IspH have catalytic activity lower than that of the wild-type protein when using methyl viologen as the electron donor, but higher activity with dithionite as the electron donor, due to ready access of the small reductant to the cluster, consistent with their increased oxygen and H2O2 sensitivity. F302A has the largest effect on the reaction rates, and EPR studies indicate this residue affects Fe-S cluster structure. Similar effects on cluster stability are seen with class A (F14A and Y98A) mutants; however, effects on ET rates are smaller, and there are no differences between the EPR spectra of mutant and wild-type proteins. Overall, the results are of general interest because they show, for the first time, that there are multiple IspH classes that have evolved to allow organisms to survive in diverse oxidative-stress environments.
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Affiliation(s)
- Guodong Rao
- Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
| | - Eric Oldfield
- Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
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11
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Jeroen S. Dickschat. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/anie.201511670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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12
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Jeroen S. Dickschat. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201511670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Rao G, O'Dowd B, Li J, Wang K, Oldfield E. IspH-RPS1 and IspH-UbiA: "Rosetta Stone" Proteins. Chem Sci 2015; 6:6813-6822. [PMID: 26865948 PMCID: PMC4746011 DOI: 10.1039/c5sc02600h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
IspH forms fusion hybrids with RPS1 as well as UbiA, examples of Rosetta stone proteins.
The protein IspH, (E)-1-hydroxy-2-methyl-but-2-enyl 4-diphosphate (HMPPP) reductase, is an essential 4Fe–4S cluster-containing protein in the methylerythritol phosphate pathway for isoprenoid biosynthesis. Using a sequence similarity network we found that there are >400 IspH proteins that are about twice as large as most of the IspHs studied to date since their IspH domains are fused to either the ribosomal protein S1 (RPS1), or to a UbiA (4-hydroxybenzoate octaprenyltransferase)-like protein. Many of the IspH–RPS1 proteins are present in anaerobes found in the human gut and some, such as Clostridium botulinum, C. tetani and Fusobacterium nucleatum, are pathogens. The IspH–UbiAs are all found in sulfate-reducing anaerobes. The IspH domains in IspH–RPS1 are fused to 4 and in a few cases 6 tandem repeats in RPS1 that, in most organisms, bind to mRNA or form part of the bacterial ribosome. Mutants in which the four RPS1 domains were sequentially eliminated had similar IspH activity as wild-type protein, indicating they are not essential for IspH catalysis. Overall, the results are of interest since they represent the first isolation of a catalytically active IspH–RPS1, as well as the identification of IspH–UbiA hybrids, two “Rosetta stone” proteins that are likely to be functionally related—IspH producing the isoprenoids required for a UbiA-like prenyltransferase; the IspH–RPS1 hybrids, perhaps, being involved in the stringent response or as Fe/O2 sensors.
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Affiliation(s)
- Guodong Rao
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
| | - Bing O'Dowd
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
| | - Jikun Li
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
| | - Ke Wang
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
| | - Eric Oldfield
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801
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14
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Blachly PG, Sandala GM, Giammona DA, Bashford D, McCammon JA, Noodleman L. Broken-Symmetry DFT Computations for the Reaction Pathway of IspH, an Iron-Sulfur Enzyme in Pathogenic Bacteria. Inorg Chem 2015; 54:6439-61. [PMID: 26098647 PMCID: PMC4568833 DOI: 10.1021/acs.inorgchem.5b00751] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The recently discovered methylerythritol phosphate (MEP) pathway provides new targets for the development of antibacterial and antimalarial drugs. In the final step of the MEP pathway, the [4Fe-4S] IspH protein catalyzes the 2e(-)/2H(+) reductive dehydroxylation of (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP) to afford the isoprenoid precursors isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). Recent experiments have attempted to elucidate the IspH catalytic mechanism to drive inhibitor development. Two competing mechanisms have recently emerged, differentiated by their proposed HMBPP binding modes upon 1e(-) reduction of the [4Fe-4S] cluster: (1) a Birch reduction mechanism, in which HMBPP remains bound to the [4Fe-4S] cluster through its terminal C4-OH group (ROH-bound) until the -OH is cleaved as water; and (2) an organometallic mechanism, in which the C4-OH group rotates away from the [4Fe-4S] cluster, allowing the HMBPP olefin group to form a metallacycle complex with the apical iron (η(2)-bound). We perform broken-symmetry density functional theory computations to assess the energies and reduction potentials associated with the ROH- and η(2)-bound states implicated by these competing mechanisms. Reduction potentials obtained for ROH-bound states are more negative (-1.4 to -1.0 V) than what is typically expected of [4Fe-4S] ferredoxin proteins. Instead, we find that η(2)-bound states are lower in energy than ROH-bound states when the [4Fe-4S] cluster is 1e(-) reduced. Furthermore, η(2)-bound states can already be generated in the oxidized state, yielding reduction potentials of ca. -700 mV when electron addition occurs after rotation of the HMBPP C4-OH group. We demonstrate that such η(2)-bound states are kinetically accessible both when the IspH [4Fe-4S] cluster is oxidized and 1e(-) reduced. The energetically preferred pathway gives 1e(-) reduction of the cluster after substrate conformational change, generating the 1e(-) reduced intermediate proposed in the organometallic mechanism.
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Affiliation(s)
| | - Gregory M Sandala
- ‡Department of Chemistry and Biochemistry, Mount Allison University, 63C York Street, Sackville, New Brunswick E4L 1G8, Canada
| | - Debra Ann Giammona
- §Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105, United States
| | - Donald Bashford
- §Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105, United States
| | | | - Louis Noodleman
- #Department of Integrative Structural and Computational Biology, CB213, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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15
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Citron CA, Rabe P, Barra L, Nakano C, Hoshino T, Dickschat JS. Synthesis of Isotopically Labelled Oligoprenyl Diphosphates and Their Application in Mechanistic Investigations of Terpene Cyclases. European J Org Chem 2014. [DOI: 10.1002/ejoc.201403002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Blachly PG, Sandala GM, Giammona D, Liu T, Bashford D, McCammon JA, Noodleman L. Use of Broken-Symmetry Density Functional Theory To Characterize the IspH Oxidized State: Implications for IspH Mechanism and Inhibition. J Chem Theory Comput 2014; 10:3871-3884. [PMID: 25221444 PMCID: PMC4159220 DOI: 10.1021/ct5005214] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Indexed: 12/31/2022]
Abstract
With current therapies becoming less efficacious due to increased drug resistance, new inhibitors of both bacterial and malarial targets are desperately needed. The recently discovered methylerythritol phosphate (MEP) pathway for isoprenoid synthesis provides novel targets for the development of such drugs. Particular attention has focused on the IspH protein, the final enzyme in the MEP pathway, which uses its [4Fe-4S] cluster to catalyze the formation of the isoprenoid precursors IPP and DMAPP from HMBPP. IspH catalysis is achieved via a 2e-/2H+ reductive dehydroxylation of HMBPP; the mechanism by which catalysis is achieved, however, is highly controversial. The work presented herein provides the first step in assessing different routes to catalysis by using computational methods. By performing broken-symmetry density functional theory (BS-DFT) calculations that employ both the conductor-like screening solvation model (DFT/COSMO) and a finite-difference Poisson-Boltzmann self-consistent reaction field methodology (DFT/SCRF), we evaluate geometries, energies, and Mössbauer signatures of the different protonation states that may exist in the oxidized state of the IspH catalytic cycle. From DFT/SCRF computations performed on the oxidized state, we find a state where the substrate, HMBPP, coordinates the apical iron in the [4Fe-4S] cluster as an alcohol group (ROH) to be one of two, isoenergetic, lowest-energy states. In this state, the HMBPP pyrophosphate moiety and an adjacent glutamate residue (E126) are both fully deprotonated, making the active site highly anionic. Our findings that this low-energy state also matches the experimental geometry of the active site and that its computed isomer shifts agree with experiment validate the use of the DFT/SCRF method to assess relative energies along the IspH reaction pathway. Additional studies of IspH catalytic intermediates are currently being pursued.
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Affiliation(s)
- Patrick G. Blachly
- Department
of Chemistry and Biochemistry, University
of California San Diego, 9500 Gilman Drive, Mail Code 0365, La Jolla, California 92093-0365, United States
| | - Gregory M. Sandala
- Department
of Chemistry and Biochemistry, Mount Allison
University, 63C York
Street, Sackville, New Brunswick E4L 1G8, Canada
| | - Debra
Ann Giammona
- Department
of Structural Biology, St. Jude Children’s
Research Hospital, 262
Danny Thomas Place, Memphis, Tennessee 38105, United States
| | - Tiqing Liu
- Skaggs School of Pharmacy and Pharmaceutical
Sciences, Howard Hughes Medical
Institute, and Department of Pharmacology, University
of California San Diego, La Jolla, California 92093-0365, United States
| | - Donald Bashford
- Department
of Structural Biology, St. Jude Children’s
Research Hospital, 262
Danny Thomas Place, Memphis, Tennessee 38105, United States
| | - J. Andrew McCammon
- Department
of Chemistry and Biochemistry, University
of California San Diego, 9500 Gilman Drive, Mail Code 0365, La Jolla, California 92093-0365, United States
- Skaggs School of Pharmacy and Pharmaceutical
Sciences, Howard Hughes Medical
Institute, and Department of Pharmacology, University
of California San Diego, La Jolla, California 92093-0365, United States
| | - Louis Noodleman
- Department
of Integrative Structural and Computational Biology, The Scripps Research Institute, TPC15, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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17
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Span I, Wang K, Eisenreich W, Bacher A, Zhang Y, Oldfield E, Groll M. Insights into the binding of pyridines to the iron-sulfur enzyme IspH. J Am Chem Soc 2014; 136:7926-32. [PMID: 24813236 PMCID: PMC4063180 DOI: 10.1021/ja501127j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Indexed: 11/29/2022]
Abstract
(E)-1-Hydroxy-2-methylbut-2-enyl 4-diphosphate reductase (IspH) is a [Fe4S4] cluster-containing enzyme involved in isoprenoid biosynthesis in many bacteria as well as in malaria parasites and is an important drug target. Several inhibitors including amino and thiol substrate analogues, as well as acetylene and pyridine diphosphates, have been reported. Here, we investigate the mode of binding of four pyridine diphosphates to Escherichia coli IspH by using X-ray crystallography. In three cases, one of the iron atoms in the cluster is absent, but in the structure with (pyridin-3-yl)methyl diphosphate, the most potent pyridine-analogue inhibitor reported previously, the fourth iron of the [Fe4S4] cluster is present and interacts with the pyridine ring of the ligand. Based on the results of quantum chemical calculations together with the crystallographic results we propose a side-on η(2) coordination of the nitrogen and the carbon in the 2-position of the pyridine ring to the unique fourth iron in the cluster, which is in the reduced state. The X-ray structure enables excellent predictions using density functional theory of the (14)N hyperfine coupling and quadrupole coupling constants reported previously using HYSCORE spectroscopy, as well as providing a further example of the ability of such [Fe4S4]-containing proteins to form organometallic complexes.
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Affiliation(s)
- Ingrid Span
- Center
for Integrated Protein Science Munich, Chemistry Department, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Ke Wang
- Department
of Chemistry, 600 South
Mathews Avenue, University
of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Wolfgang Eisenreich
- Center
for Integrated Protein Science Munich, Chemistry Department, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Adelbert Bacher
- Center
for Integrated Protein Science Munich, Chemistry Department, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Yong Zhang
- Department
of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, New Jersey 07030, United States
| | - Eric Oldfield
- Department
of Chemistry, 600 South
Mathews Avenue, University
of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Michael Groll
- Center
for Integrated Protein Science Munich, Chemistry Department, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
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18
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Wang W, Oldfield E. Biometallorganische Chemie mit IspG und IspH: Struktur, Funktion und Hemmung der an der Isoprenoid-Biosynthese beteiligten [Fe 4S 4]-Proteine. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201306712] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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19
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Kegler C, Nollmann FI, Ahrendt T, Fleischhacker F, Bode E, Bode HB. Rapid determination of the amino acid configuration of xenotetrapeptide. Chembiochem 2014; 15:826-8. [PMID: 24616055 DOI: 10.1002/cbic.201300602] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 01/15/2014] [Indexed: 02/01/2023]
Abstract
An E. coli strain with deletions in five transaminases (ΔaspC ΔilvE ΔtyrB ΔavtA ΔybfQ) was constructed to be unable to degrade several amino acids. This strain was used as an expression host for the analysis of the amino acid configuration of nonribosomally synthesized peptides, including the novel peptide "xenotetrapeptide" from Xenorhabdus nematophila, by using a combination of labeling experiments and mass spectrometry. Additionally, the number of D-amino acids in the produced peptide was assigned following simple cultivation of the expression strain in D2 O.
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Affiliation(s)
- Carsten Kegler
- Merck Stiftungsprofessur für Molekulare Biotechnologie, Fachbereich Biowissenschaften, Goethe Universität Frankfurt, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main (Germany)
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20
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Wang W, Oldfield E. Bioorganometallic chemistry with IspG and IspH: structure, function, and inhibition of the [Fe(4)S(4)] proteins involved in isoprenoid biosynthesis. Angew Chem Int Ed Engl 2014; 53:4294-310. [PMID: 24481599 DOI: 10.1002/anie.201306712] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Indexed: 11/12/2022]
Abstract
Enzymes of the methylerythritol phosphate pathway of isoprenoid biosynthesis are attractive anti-infective drug targets. The last two enzymes of this pathway, IspG and IspH, are [Fe4 S4 ] proteins that are not produced by humans and catalyze 2 H(+) / 2 e(-) reductions with novel mechanisms. In this Review, we summarize recent advances in structural, mechanistic, and inhibitory studies of these two enzymes. In particular, mechanistic proposals involving bioorganometallic intermediates are presented, and compared with other mechanistic possibilities. In addition, inhibitors based on substrate analogues as well as developed by rational design and compound-library screening, are discussed. The results presented support bioorganometallic catalytic mechanisms for IspG and IspH, and open up new routes to anti-infective drug design targeting [Fe4 S4 ] clusters in proteins.
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Affiliation(s)
- Weixue Wang
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
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21
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Citron CA, Dickschat JS. [(2)H26]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus. Beilstein J Org Chem 2013; 9:2841-5. [PMID: 24367448 PMCID: PMC3869315 DOI: 10.3762/bjoc.9.319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 11/05/2013] [Indexed: 11/23/2022] Open
Abstract
During growth on fully deuterated medium the volatile terpene [2H26]-1-epi-cubenol was released by the actinomycete Streptomyces griseus. This compound represents the first completely deuterated terpene obtained by fermentation. Despite a few previous reports in the literature the operability of this approach to fully deuterated compounds is still surprising, because the strong kinetic isotope effect of deuterium is known to slow down all metabolic processes in living organisms. Potential applications of completely labelled compounds from natural sources in structure elucidation, biosynthetic or pharmacokinetic investigations are discussed.
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Affiliation(s)
- Christian A Citron
- Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Jeroen S Dickschat
- Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
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22
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Zhao L, Chang WC, Xiao Y, Liu HW, Liu P. Methylerythritol phosphate pathway of isoprenoid biosynthesis. Annu Rev Biochem 2013; 82:497-530. [PMID: 23746261 DOI: 10.1146/annurev-biochem-052010-100934] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Isoprenoids are a class of natural products with more than 55,000 members. All isoprenoids are constructed from two precursors, isopentenyl diphosphate and its isomer dimethylallyl diphosphate. Two of the most important discoveries in isoprenoid biosynthetic studies in recent years are the elucidation of a second isoprenoid biosynthetic pathway [the methylerythritol phosphate (MEP) pathway] and a modified mevalonic acid (MVA) pathway. In this review, we summarize mechanistic insights on the MEP pathway enzymes. Because many isoprenoids have important biological activities, the need to produce them in sufficient quantities for downstream research efforts or commercial application is apparent. Recent advances in both MVA and MEP pathway-based synthetic biology are also illustrated by reviewing the landmark work of artemisinic acid and taxadien-5α-ol production through microbial fermentations.
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Affiliation(s)
- Lishan Zhao
- Amyris, Inc., Emeryville, California 94608, USA.
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23
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Chang WC, Song H, Liu HW, Liu P. Current development in isoprenoid precursor biosynthesis and regulation. Curr Opin Chem Biol 2013; 17:571-9. [PMID: 23891475 PMCID: PMC4068245 DOI: 10.1016/j.cbpa.2013.06.020] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 06/12/2013] [Accepted: 06/17/2013] [Indexed: 11/20/2022]
Abstract
Isoprenoids are one of the largest classes of natural products and all of them are constructed from two precursors, isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP). For decades, the mevalonic acid (MVA) pathway was proposed to be the only IPP and DMAPP biosynthetic pathway. This review summarizes the newly discovered IPP and DMAPP production pathways since late 1990s, their distribution among different kingdoms, and their roles in secondary metabolite production. These new IPP and DMAPP production pathways include the methylerythritol phosphate (MEP) pathway, a modified MVA pathway, and the 5-methylthioadenosine shunt pathway. Relative to the studies on the MVA pathway, information on the MEP pathway regulation is limited and the mechanistic details of several of its novel transformations remain to be addressed. Current status on both MEP pathway regulation and mechanistic issues is also presented.
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Affiliation(s)
- Wei-chen Chang
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Heng Song
- Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Pinghua Liu
- Department of Chemistry, Boston University, Boston, Massachusetts 02215
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24
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Li J, Wang K, Smirnova TI, Khade RL, Zhang Y, Oldfield E. Isoprenoid Biosynthesis: Ferraoxetane or Allyl Anion Mechanism for IspH Catalysis? Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201302343] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Li J, Wang K, Smirnova TI, Khade RL, Zhang Y, Oldfield E. Isoprenoid biosynthesis: ferraoxetane or allyl anion mechanism for IspH catalysis? Angew Chem Int Ed Engl 2013; 52:6522-5. [PMID: 23649534 PMCID: PMC3821072 DOI: 10.1002/anie.201302343] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Jikun Li
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 607 South Mathews Avenue, Urbana, IL 61801 (USA)
| | - Ke Wang
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (USA), Fax: (+1)217-244-0997
| | - Tatyana I. Smirnova
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695 (USA)
| | - Rahul L. Khade
- Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken NJ 07030 (USA)
| | - Yong Zhang
- Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken NJ 07030 (USA)
| | - Eric Oldfield
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (USA), Fax: (+1)217-244-0997
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26
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Span I, Wang K, Wang W, Jauch J, Eisenreich W, Bacher A, Oldfield E, Groll M. Structures of fluoro, amino, and thiol inhibitors bound to the [Fe4S4] protein IspH. Angew Chem Int Ed Engl 2013; 52:2118-21. [PMID: 23307751 PMCID: PMC3734547 DOI: 10.1002/anie.201208469] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Ingrid Span
- Center for Integrated Protein Science Munich, Chemie Department, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany.
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27
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Span I, Wang K, Wang W, Zhang Y, Bacher A, Eisenreich W, Li K, Schulz C, Oldfield E, Groll M. Discovery of acetylene hydratase activity of the iron-sulphur protein IspH. Nat Commun 2013; 3:1042. [PMID: 22948824 DOI: 10.1038/ncomms2052] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 08/03/2012] [Indexed: 11/09/2022] Open
Abstract
The final step of the methylerythritol phosphate isoprenoid biosynthesis pathway is catalysed by the iron-sulphur enzyme IspH, producing the universal precursors of terpenes: isopentenyl diphosphate and dimethylallyl diphosphate. Here we report an unforeseen reaction discovered during the investigation of the interaction of IspH with acetylene inhibitors by X-ray crystallography, Mößbauer, and nuclear magnetic resonance spectroscopy. In addition to its role as a 2H(+)/2e(-) reductase, IspH can hydrate acetylenes to aldehydes and ketones via anti-Markovnikov/Markovnikov addition. The reactions only occur with the oxidised protein and proceed via η(1)-O-enolate intermediates. One of these is characterized crystallographically and contains a C4 ligand oxygen bound to the unique, fourth iron in the 4Fe-4S cluster: this intermediate subsequently hydrolyzes to produce an aldehyde product. This unexpected side to IspH reactivity is of interest in the context of the mechanism of action of other acetylene hydratases, as well as in the design of antiinfectives targeting IspH.
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Affiliation(s)
- Ingrid Span
- Department of Chemistry, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Ke Wang
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois, Urbana, Illinois 61801, USA
| | - Weixue Wang
- Center for Biophysics and Computational Biology, 607 South Mathews Avenue, University of Illinois, Urbana, Illinois 61801, USA
| | - Yonghui Zhang
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois, Urbana, Illinois 61801, USA
| | - Adelbert Bacher
- Department of Chemistry, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Wolfgang Eisenreich
- Department of Chemistry, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Kai Li
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois, Urbana, Illinois 61801, USA
| | - Charles Schulz
- Department of Physics, Knox College, 2 East South Street, Galesburg, Illinois 61401, USA
| | - Eric Oldfield
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois, Urbana, Illinois 61801, USA.,Center for Biophysics and Computational Biology, 607 South Mathews Avenue, University of Illinois, Urbana, Illinois 61801, USA
| | - Michael Groll
- Department of Chemistry, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
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28
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Janthawornpong K, Krasutsky S, Chaignon P, Rohmer M, Poulter CD, Seemann M. Inhibition of IspH, a [4Fe-4S]2+ enzyme involved in the biosynthesis of isoprenoids via the methylerythritol phosphate pathway. J Am Chem Soc 2013; 135:1816-22. [PMID: 23316732 DOI: 10.1021/ja309557s] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The MEP pathway, which is absent in animals but present in most pathogenic bacteria, in the parasite responsible for malaria and in plant plastids, is a target for the development of antimicrobial drugs. IspH, an oxygen-sensitive [4Fe-4S] enzyme, catalyzes the last step of this pathway and converts (E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate (HMBPP) into the two isoprenoid precursors: isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). A crucial step in the mechanism of this enzyme is the binding of the C4 hydroxyl of HMBPP to the unique fourth iron site in the [4Fe-4S](2+) moiety. Here, we report the synthesis and the kinetic investigations of two new extremely potent inhibitors of E. coli IspH where the OH group of HMBPP is replaced by an amino and a thiol group. (E)-4-Mercapto-3-methylbut-2-en-1-yl diphosphate is a reversible tight-binding inhibitor of IspH with K(i) = 20 ± 2 nM. A detailed kinetic analysis revealed that (E)-4-amino-3-methylbut-2-en-1-yl diphosphate is a reversible slow-binding inhibitor of IspH with K(i) = 54 ± 19 nM. The slow binding behavior of this inhibitor is best described by a one-step mechanism with the slow step consisting of the formation of the enzyme-inhibitor (EI) complex.
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Affiliation(s)
- Karnjapan Janthawornpong
- Université de Strasbourg, CNRS UMR 7177, Institut Le Bel, 4 rue Blaise Pascal, CS 90032, 67081 Strasbourg Cedex, France
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29
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Brock NL, Ravella SR, Schulz S, Dickschat JS. A Detailed View of 2-Methylisoborneol Biosynthesis. Angew Chem Int Ed Engl 2013; 52:2100-4. [DOI: 10.1002/anie.201209173] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Indexed: 11/09/2022]
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30
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Brock NL, Ravella SR, Schulz S, Dickschat JS. Eine Nahaufnahme der 2-Methylisoborneol-Biosynthese. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201209173] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Span I, Wang K, Wang W, Jauch J, Eisenreich W, Bacher A, Oldfield E, Groll M. Fluor-, Amino- und Thiolinhibitoren im Komplex mit dem [Fe4
S4
]-Protein IspH. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201208469] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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32
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Wang W, Wang K, Span I, Jauch J, Bacher A, Groll M, Oldfield E. Are free radicals involved in IspH catalysis? An EPR and crystallographic investigation. J Am Chem Soc 2012; 134:11225-34. [PMID: 22687151 DOI: 10.1021/ja303445z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The [4Fe-4S] protein IspH in the methylerythritol phosphate isoprenoid biosynthesis pathway is an important anti-infective drug target, but its mechanism of action is still the subject of debate. Here, by using electron paramagnetic resonance (EPR) spectroscopy and (2)H, (17)O, and (57)Fe isotopic labeling, we have characterized and assigned two key reaction intermediates in IspH catalysis. The results are consistent with the bioorganometallic mechanism proposed earlier, and the mechanism is proposed to have similarities to that of ferredoxin, thioredoxin reductase, in that one electron is transferred to the [4Fe-4S](2+) cluster, which then performs a formal two-electron reduction of its substrate, generating an oxidized high potential iron-sulfur protein (HiPIP)-like intermediate. The two paramagnetic reaction intermediates observed correspond to the two intermediates proposed in the bioorganometallic mechanism: the early π-complex in which the substrate's 3-CH(2)OH group has rotated away from the reduced iron-sulfur cluster, and the next, η(3)-allyl complex formed after dehydroxylation. No free radical intermediates are observed, and the two paramagnetic intermediates observed do not fit in a Birch reduction-like or ferraoxetane mechanism. Additionally, we show by using EPR spectroscopy and X-ray crystallography that two substrate analogues (4 and 5) follow the same reaction mechanism.
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Affiliation(s)
- Weixue Wang
- Center for Biophysics and Computational Biology, 607 South Mathews Avenue, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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33
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