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Avila-Arias H, Casallas FC, Arbeli Z, García Gutiérrez A, Fajardo Gomez CA, Herrera Castillo DY, Carvajal Ramirez S, Tamayo-Figueroa DP, Benavides López de Mesa J, Roldan F. Bacteria isolated from explosive contaminated environments transform pentaerythritol tetranitrate (PETN) under aerobic and anaerobic conditions. Lett Appl Microbiol 2023; 76:ovad113. [PMID: 37740443 DOI: 10.1093/lambio/ovad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/01/2023] [Accepted: 09/20/2023] [Indexed: 09/24/2023]
Abstract
Pentaerythritol tetranitrate (PETN) is a nitrate ester explosive that may be persistent with scarce reports on its environmental fate and impacts. Our main objective was to isolate and characterize bacteria that transform PETN under aerobic and anaerobic conditions. Biotransformation of PETN (100 mg L-1) was evaluated using mineral medium with (M + C) and without (M - C) additional carbon sources under aerobic conditions and with additional carbon sources under anaerobic conditions. Here, we report on the isolation of 12 PETN-transforming cultures (4 pure and 8 co-cultures) from environmental samples collected at an explosive manufacturing plant. The highest transformation of PETN was observed for cultures in M + C under aerobic conditions, reaching up to 91% ± 2% in 2 d. Under this condition, PETN biotransformation was observed in conjunction with the release of nitrites and bacterial growth. No substantial transformation of PETN (<45%) was observed during 21 d in M - C under aerobic conditions. Under anaerobic conditions, five cultures could transform PETN (up to 52% ± 13%) as the sole nitrogen source, concurrent with the formation of two unidentified metabolites. PETN-transforming cultures belonged to Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Actinobacteria. In conclusion, we isolated 12 PETN-transforming cultures belonging to diverse taxa, suggesting that PETN transformation is phylogenetically widespread.
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Affiliation(s)
- Helena Avila-Arias
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia
| | - Francy-Carolina Casallas
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia
| | - Ziv Arbeli
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia
| | - Andrea García Gutiérrez
- Programa de ingeniería Ambiental y Sanitaria, Facultad de ingeniería, Universidad de la Salle, Bogotá 110231, Colombia
- Maestría en Diseño y gestión de Procesos, Facultad de Ingeniería, Universidad de la Sabana, Bogotá 110831, Colombia
| | - Carlos Andres Fajardo Gomez
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia
| | - Denis Yohana Herrera Castillo
- Programa de ingeniería Ambiental y Sanitaria, Facultad de ingeniería, Universidad de la Salle, Bogotá 110231, Colombia
| | - Sandra Carvajal Ramirez
- Programa de ingeniería Ambiental y Sanitaria, Facultad de ingeniería, Universidad de la Salle, Bogotá 110231, Colombia
| | - Diana Paola Tamayo-Figueroa
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia
| | | | - Fabio Roldan
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia
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Abstract
Flavoenzymes are broadly employed as biocatalysts for a large variety of reactions, owing to the chemical versatility of the flavin cofactor. Oxidases set aside, many flavoenzymes require a source of electrons in form of the biological reductant nicotinamide NAD(P)H in order to initiate catalysis via the reduced flavin. Chemists can take advantage of the reactivity of reduced flavins with oxygen to carry out monooxygenation reactions, while the reduced flavin can also be used for formal hydrogenation reactions. The main advantage of these reactions compared to chemical approaches is the frequent regio-, chemo- and stereo-selectivity of the biocatalysts, which allows the synthesis of chiral molecules in optically active form. This chapter provides an overview of the variety of biocatalytic processes that have been developed with flavoenzymes, with a particular focus on nicotinamide-dependent enzymes. The diversity of molecules obtained is highlighted and in several cases, strategies that allow control of the stereochemical outcome of the reactions are reviewed.
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Affiliation(s)
- Mélanie Hall
- Department of Chemistry, University of Graz, Graz, Austria.
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3
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Tsypik O, Makitrynskyy R, Frensch B, Zechel DL, Paululat T, Teufel R, Bechthold A. Oxidative Carbon Backbone Rearrangement in Rishirilide Biosynthesis. J Am Chem Soc 2020; 142:5913-5917. [PMID: 32182053 DOI: 10.1021/jacs.9b12736] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The structural diversity of type II polyketides is largely generated by tailoring enzymes. In rishirilide biosynthesis by Streptomyces bottropensis, 13C-labeling studies previously implied extraordinary carbon backbone and side-chain rearrangements. In this work, we employ gene deletion experiments and in vitro enzyme studies to identify key biosynthetic intermediates and expose intricate redox tailoring steps for the formation of rishirilides A, B, and D and lupinacidin A. First, the flavin-dependent RslO5 reductively ring-opens the epoxide moiety of an advanced polycyclic intermediate to form an alcohol. Flavin monooxygenase RslO9 then oxidatively rearranges the carbon backbone, presumably via lactone-forming Baeyer-Villiger oxidation and subsequent intramolecular aldol condensation. While RslO9 can further convert the rearranged intermediate to rishirilide D and lupinacidin A, an additional ketoreductase RslO8 is required for formation of the main products rishirilide A and rishirilide B. This work provides insight into the structural diversification of aromatic polyketide natural products via unusual redox tailoring reactions that appear to defy biosynthetic logic.
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Affiliation(s)
- Olga Tsypik
- Department of Pharmaceutical Biology and Biotechnology, Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Straße 19, 79104 Freiburg, Germany
| | - Roman Makitrynskyy
- Department of Pharmaceutical Biology and Biotechnology, Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Straße 19, 79104 Freiburg, Germany
| | - Britta Frensch
- Faculty of Biology, Schänzlestraße 1, 79104 Freiburg, Germany
| | - David L Zechel
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston K7L 3N6, Ontario, Canada
| | - Thomas Paululat
- Organic Chemistry, University of Siegen, Adolf-Reichwein-Straße 2, 57068 Siegen, Germany
| | - Robin Teufel
- Faculty of Biology, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Andreas Bechthold
- Department of Pharmaceutical Biology and Biotechnology, Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Straße 19, 79104 Freiburg, Germany
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4
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Pesic M, Fernández-Fueyo E, Hollmann F. Characterization of the Old Yellow Enzyme Homolog fromBacillus subtilis(YqjM). ChemistrySelect 2017. [DOI: 10.1002/slct.201700724] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Milja Pesic
- Department of Biotechnology; Delft University of Technology; Van der Maasewg 9 2629HZ Delft, The Netherlands
| | - Elena Fernández-Fueyo
- Department of Biotechnology; Delft University of Technology; Van der Maasewg 9 2629HZ Delft, The Netherlands
| | - Frank Hollmann
- Department of Biotechnology; Delft University of Technology; Van der Maasewg 9 2629HZ Delft, The Netherlands
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van Bergen B, Cyr N, Strasser R, Blanchette M, Sheppard JD, Jardim A. α,β-Dicarbonyl reduction is mediated by the Saccharomyces Old Yellow Enzyme. FEMS Yeast Res 2016; 16:fow059. [PMID: 27400981 DOI: 10.1093/femsyr/fow059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2016] [Indexed: 11/13/2022] Open
Abstract
The undesirable flavor compounds diacetyl and 2,3-pentanedione are vicinal diketones (VDKs) formed by extracellular oxidative decarboxylation of intermediate metabolites of the isoleucine, leucine and valine (ILV) biosynthetic pathway. These VDKs are taken up by Saccharomyces and enzymatically converted to acetoin and 3-hydroxy-2-pentanone, respectively. Purification of a highly enriched diacetyl reductase fraction from Saccharomyces cerevisiae in conjunction with mass spectrometry identified Old Yellow Enzyme (Oye) as an enzyme capable of catalyzing VDK reduction. Kinetic analysis of recombinant Oye1p, Oye2p and Oye3p isoforms confirmed that all three isoforms reduced diacetyl and 2,3-pentanedione in an NADPH-dependent reaction. Transcriptomic analysis of S. cerevisiae (ale) and S. pastorianus (lager) yeast during industrial fermentations showed that the transcripts for OYE1, OYE2, arabinose dehydrogenase (ARA1), α-acetolactate synthase (ILV2) and α-acetohydroxyacid reductoisomerase (ILV5) were differentially regulated in a manner that correlated with changes in extracellular levels of VDKs. These studies provide insights into the mechanism for reducing VDKs and decreasing maturation times of beer which are of commercial importance.
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Affiliation(s)
- Barry van Bergen
- Department of Bioresource Engineering, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Normand Cyr
- Institute of Parasitology, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27612, USA
| | - Rona Strasser
- Institute of Parasitology, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Maxime Blanchette
- Department of Bioresource Engineering, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - John D Sheppard
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27612, USA
| | - Armando Jardim
- Institute of Parasitology, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
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6
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Chilton AS, Ellis AL, Lamb AL. Structure of an Aspergillus fumigatus old yellow enzyme (EasA) involved in ergot alkaloid biosynthesis. Acta Crystallogr F Struct Biol Commun 2014; 70:1328-32. [PMID: 25286934 PMCID: PMC4188074 DOI: 10.1107/s2053230x14018962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 08/21/2014] [Indexed: 11/10/2022] Open
Abstract
The Aspergillus fumigatus old yellow enzyme (OYE) EasA reduces chanoclavine-I aldehyde to dihydrochanoclavine aldehyde and works in conjunction with festuclavine synthase at the branchpoint for ergot alkaloid pathways. The crystal structure of the FMN-loaded EasA was determined to 1.8 Å resolution. The active-site amino acids of OYE are conserved, supporting a similar mechanism for reduction of the α/β-unsaturated aldehyde. The C-terminal tail of one monomer packs into the active site of a monomer in the next asymmetric unit, which is most likely to be a crystallization artifact and not a mechanism of self-regulation.
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Affiliation(s)
- Annemarie S. Chilton
- Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
| | - Ashley L. Ellis
- Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
| | - Audrey L. Lamb
- Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
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Litthauer S, Gargiulo S, van Heerden E, Hollmann F, Opperman D. Heterologous expression and characterization of the ene-reductases from Deinococcus radiodurans and Ralstonia metallidurans. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcatb.2013.10.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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8
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Halecky M, Spackova R, Paca J, Stiborova M, Kozliak E. Biodegradation of nitroglycerin and ethylene glycol dinitrate by free and immobilized mixed cultures. WATER RESEARCH 2014; 48:529-537. [PMID: 24206758 DOI: 10.1016/j.watres.2013.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 10/01/2013] [Accepted: 10/02/2013] [Indexed: 06/02/2023]
Abstract
Aerobic biodegradation of nitroglycerin (NG) and ethylene glycol dinitrate (EGDN), both as individual substrates and in their mixture, was tested using batch or fed-batch cultivation with free suspended cells enriched from a soil sample subjected to a long-term contamination with explosives. EGDN was degraded only in the presence of glycerol as a co-substrate whereas NG could serve as a sole carbon, energy and nitrogen source for growth, its degradation being only slightly boosted by either glycerol or pyruvate. NG was not sufficient as a co-substrate for microbial growth on EGDN; furthermore, the presence of EGDN inhibited the NG degradation. The growth inhibition by both NG and EGDN was alleviated by the addition of glycerol. At an optimum nitroglycerin concentration of 30 mg/L, a maximum specific degradation rate of 60.9 ± 1.8 mg/gdw/h was observed. The biodegradation of both pollutants occurred with a release of nitrite. A method was developed for growing substantial amounts of NG-degrading biomass in the presence of glycerol for its immobilization on expanded slate in a pot-scale packed-bed reactor. Preliminary reactor tests were conducted in a continuous operation mode yielding a 70-90% NG biodegradation up to a load of 20 mg/L/h, with a removal rate up to 16 mg/L/h.
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Affiliation(s)
- Martin Halecky
- Institute of Chemical Technology, Department of Biotechnology, Prague 16628, Czech Republic.
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9
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Abstract
Explosives are synthesized globally mainly for military munitions. Nitrate esters, such as GTN and PETN, nitroaromatics like TNP and TNT and nitramines with RDX, HMX and CL20, are the main class of explosives used. Their use has resulted in severe contamination of environment and strategies are now being developed to clean these substances in an economical and eco-friendly manner. The incredible versatility inherited in microbes has rendered these explosives as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or nonspecific transformation of explosive waste either by aerobic or anaerobic processes. It is likely that ongoing genetic adaptation, with the recruitment of silent sequences into functional catabolic routes and evolution of substrate range by mutations in structural genes, will further enhance the catabolic potential of bacteria toward explosives and ultimately contribute to cleansing the environment of these toxic and recalcitrant chemicals. This review summarizes information on the biodegradation and biotransformation pathways of several important explosives. Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are also discussed. This may be useful in developing safer and economic microbiological methods for clean up of soil and water contaminated with such compounds. The necessity of further investigations concerning the microbial metabolism of these substances is also discussed.
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10
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Sinha V, Wijewickrama GT, Chandrasena REP, Xu H, Edirisinghe PD, Schiefer IT, Thatcher GRJ. Proteomic and mass spectroscopic quantitation of protein S-nitrosation differentiates NO-donors. ACS Chem Biol 2010; 5:667-80. [PMID: 20524644 DOI: 10.1021/cb100054m] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protein S-nitrosation has been argued to be the most important signaling pathway mediating the bioactivity of NO. This post-translational modification of protein thiols is the result of chemical nitrosation of cysteine residues. The term NO-donors covers very different chemical classes, from clinical therapeutics to probes of routine use in chemical biology; their different chemistry is predicted to result in distinctive biology regulated by protein S-nitrosation. To measure the extent of protein S-nitrosation by NO-donors, a proteomic mass spectrometry method was developed, which quantitates free thiol versus nitrosothiol for each modified cysteine residue, coined d-Switch. This method is adapted from the biotin switch (BST) method, used extensively to identify S-nitrosated proteins in complex biological mixtures; however, BST does not quantitate free thiol. Since glutathione-S-transferase P1-1 (GST-P1) has been proposed to be a biological "NO-carrier", GST-P1 was used as a reporter protein. The 5 different chemical classes of NO-donors compared by d-Switch demonstrated very different profiles of protein S-nitrosation and response to O(2) and cysteine, although all NO-donors were oxidants toward GST-P1. The low limits of detection and the ability to use established MS database searching allowed facile generalization of the d-Switch method. Therefore after incubation of neuronal cell cultures with nitrosothiol, it was possible to quantitate not only S-nitrosation of GST-P1 but also many other proteins, including novel targets such as ubiquitin carboxyl-terminal esterase L1 (UCHL1). Moreover, d-Switch also allowed identification of non-nitrosated proteins and quantitation of degree of nitrosation for individual protein thiols.
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Affiliation(s)
- Vaishali Sinha
- Department of Medicinal Chemistry and Pharmacognosy (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231
| | - Gihani T. Wijewickrama
- Department of Medicinal Chemistry and Pharmacognosy (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231
| | - R. Esala P. Chandrasena
- Department of Medicinal Chemistry and Pharmacognosy (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231
| | - Hua Xu
- Department of Medicinal Chemistry and Pharmacognosy (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231
| | - Praneeth D. Edirisinghe
- Department of Medicinal Chemistry and Pharmacognosy (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231
| | - Isaac T. Schiefer
- Department of Medicinal Chemistry and Pharmacognosy (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231
| | - Gregory R. J. Thatcher
- Department of Medicinal Chemistry and Pharmacognosy (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231
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11
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Toogood H, Gardiner J, Scrutton N. Biocatalytic Reductions and Chemical Versatility of the Old Yellow Enzyme Family of Flavoprotein Oxidoreductases. ChemCatChem 2010. [DOI: 10.1002/cctc.201000094] [Citation(s) in RCA: 250] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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12
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Cheng JZ, Coyle CM, Panaccione DG, O'Connor SE. A role for Old Yellow Enzyme in ergot alkaloid biosynthesis. J Am Chem Soc 2010; 132:1776-7. [PMID: 20102147 DOI: 10.1021/ja910193p] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ergot alkaloids, secondary metabolites produced by filamentous fungi, elicit a diverse array of pharmacological effects. The biosynthesis of this class of natural products has not been fully elucidated. Here we demonstrate that a homologue of Old Yellow Enzyme encoded in the Aspergillus fumigatus ergot gene cluster catalyzes reduction of the alpha,beta unsaturated alkene of chanoclavine-I aldehyde 3. This reduction, which yields dihydrochanoclavine aldehyde, facilitates an intramolecular reaction between a secondary amine and aldehyde to form the D ring of the ergot alkaloid structural framework.
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Affiliation(s)
- Johnathan Z Cheng
- Massachusetts Institute of Technology, Department of Chemistry, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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13
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Crystal structure of a thermostable Old Yellow Enzyme from Thermus scotoductus SA-01. Biochem Biophys Res Commun 2010; 393:426-31. [DOI: 10.1016/j.bbrc.2010.02.011] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 02/03/2010] [Indexed: 11/20/2022]
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14
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Grau MM, van der Toorn J, Otten L, Macheroux P, Taglieber A, Zilly F, Arends IW, Hollmann F. Photoenzymatic Reduction of CC Double Bonds. Adv Synth Catal 2009. [DOI: 10.1002/adsc.200900560] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Nyanhongo GS, Schroeder M, Steiner W, Gübitz GM. Biodegradation of 2,4,6-trinitrotoluene (TNT): An enzymatic perspective. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420500090169] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Ji Y, Anderson DJ, Bennett BM. Role of microsomal glutathione transferase 1 in the mechanism-based biotransformation of glyceryl trinitrate in LLC-PK1 cells. Biochem Pharmacol 2009; 77:1702-8. [PMID: 19428324 DOI: 10.1016/j.bcp.2009.02.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 02/22/2009] [Accepted: 02/24/2009] [Indexed: 11/24/2022]
Abstract
Although glyceryl trinitrate (GTN) has been used in the treatment of angina for many years, details of its conversion to the proximal activator (presumed to be NO or an NO congener) of soluble guanylyl cyclase (sGC) are still unclear. We reported previously that purified microsomal glutathione transferase 1 (MGST1) mediates the denitration of GTN. In the current study, we investigated in intact cells whether this enzyme also converts GTN to species that activate sGC (mechanism-based biotransformation). We utilized LLC-PK1 cells, a cell line with an intact NO/sGC/cGMP system, and generated a stable cell line that overexpressed MGST1. MGST1 in the stably transfected cells was localized to the endoplasmic reticulum, and microsomes from these cells exhibited markedly increased GST activity. Although incubation of these cells with GTN resulted in a 3-4-fold increase in GTN biotransformation, attributed primarily to an increase in formation of the 1,3-glyceryl dinitrate metabolite, GTN-induced cGMP accumulation in cells overexpressing MGST1 was not different than that observed in wild type cells or in cells stably transfected with empty vector. To determine whether overexpression of NADPH cytochrome P450 reductase might act in concert with MGST1 to generate activators of sGC, we assessed GTN-induced cGMP accumulation in MGST1-overexpressing cells that had been transiently transfected with CPR. In this case, GTN-induced cGMP accumulation was also not different than that observed in wild type cells. We conclude that although MGST1 mediates the biotransformation of GTN in intact cells, this biotransformation does not contribute to the formation of activators of sGC.
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Affiliation(s)
- Yanbin Ji
- Department of Pharmacology and Toxicology, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
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17
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Nivinskas H, Sarlauskas J, Anusevicius Z, Toogood HS, Scrutton NS, Cenas N. Reduction of aliphatic nitroesters and N-nitramines by Enterobacter cloacae PB2 pentaerythritol tetranitrate reductase: quantitative structure-activity relationships. FEBS J 2008; 275:6192-203. [PMID: 19016851 DOI: 10.1111/j.1742-4658.2008.06744.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enterobacter cloacae PB2 NADPH:pentaerythritol tetranitrate reductase (PETNR) performs the biodegradation of explosive organic nitrate esters via their reductive denitration. In order to understand the enzyme substrate specificity, we have examined the reactions of PETNR with organic nitrates (n = 15) and their nitrogen analogues, N-nitramines (n = 4). The reactions of these compounds with PETNR were accompanied by the release of 1-2 mol of nitrite per mole of compound, but were not accompanied by their redox cycling and superoxide formation. The reduction rate constants (k(cat)/K(m)) of inositol hexanitrate, diglycerol tetranitrate, erythritol tetranitrate, mannitol hexanitrate and xylitol pentanitrate were similar to those of the established PETNR substrates, PETN and glycerol trinitrate, whereas the reactivities of hexahydro-1,3,5-trinitro-1,3,5-triazine and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine were three orders of magnitude lower. The log k(cat)/K(m) value of the compounds increased with a decrease in the enthalpy of formation of the hydride adducts [DeltaH(f)(R-O-N(OH)O(-)) or DeltaH(f)(R(1),R(2) > N-N(OH)O(-))], and with an increase in their lipophilicity (octanol/water partition coefficient, log P(ow)), and did not depend on their van der Waals' volumes. Hydrophobic organic nitroesters and hydrophilic N-nitramines compete for the same binding site in the reduced enzyme form. The role of the hydrophobic interaction of PETNR with glycerol trinitrate was supported by the positive dependence of glycerol trinitrate reactivity on the solution ionic strength. The discrimination of nitroesters and N-nitramines according to their log P(ow) values seems to be a specific feature of the Old Yellow Enzyme family of flavoenzymes.
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Petersson M, Rundqvist B, Bennett BM, Adams MA, Friberg P. Impaired nitroglycerin biotransformation in patients with chronic heart failure. Clin Physiol Funct Imaging 2008; 28:229-34. [PMID: 18384624 DOI: 10.1111/j.1475-097x.2008.00793.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Patients with chronic heart failure (CHF) often require higher doses of nitroglycerin (glyceryl trinitrate, GTN) than patients with normal cardiac function to achieve a given haemodynamic goal. Two pathways leading to biotransformation of GTN have been characterized; a high-affinity pathway operative in nanomolar concentration ranges yielding predominantly 1,2-glyceryl dinitrate (1,2-GDN), and a low-affinity pathway operative at higher, micromolar concentrations of GTN associated with a greater proportion of 1,3-GDN formation. We tested the hypothesis that, at a given GTN-induced blood pressure reduction, the CHF group would present with: (i) higher concentrations of GTN; and (ii) decreased ratios of 1,2-GDN/GTN and 1,2-GDN/1,3-GDN compared with healthy subjects (HS). METHODS Twelve patients with CHF (left ventricular ejection fraction 20 +/- 5%, NYHA III) and nine HS were investigated during a right cardiac catheterization. GTN was titrated intravenously until mean arterial blood pressure (MAP) was reduced by 15%. RESULTS At arterial GTN concentrations of 27.2 [10.0-57.8] nmol l(-1) in CHF and 2.8 [2.5-3.5] nmol l(-1) in HS [median (quartile range), P<0.05 between groups], MAP and mean capillary wedge pressures were reduced similarly in both groups (approx. 15% and 65%, respectively, P = NS between groups). The ratios of 1,2-GDN/GTN and 1,2-GDN/1,3-GDN were lower in CHF (0.86 [0.28-1.58] and 5.8 [5.6-6.3]) compared with HS [1.91 (1.54-2.23) and 7.6 (7.2-10.2), P<0.05], with a negative correlation between the 1,2-GDN/1,3-GDN ratio and the arterial GTN concentrations in the CHF patients (R = -0.8, P<0.05). CONCLUSION Patients with CHF have attenuated GTN responsiveness and decreased relative formation of 1,2-GDN in comparison with HS, indicating an altered biotransformation of GTN.
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Affiliation(s)
- Magnus Petersson
- Department of Cardiology, Sahlgrenska University Hospital, Göteborg, Sweden
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Dudek M, Bednarski M, Bilska A, Iciek M, Sokołowska-Jezewicz M, Filipek B, Włodek L. The role of lipoic acid in prevention of nitroglycerin tolerance. Eur J Pharmacol 2008; 591:203-10. [PMID: 18616939 DOI: 10.1016/j.ejphar.2008.06.073] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 06/18/2008] [Accepted: 06/22/2008] [Indexed: 11/28/2022]
Abstract
Besides other organic nitrates, nitroglycerin (glyceryl trinitrate; GTN) has been used to treat acute heart failure particularly due to ischemic heart disease. However, one of serious clinical problems of the GTN therapy, particularly a long-standing medication, is hemodynamic tolerance to GTN, manifested by the decreased therapeutic efficacy of the drug. The most recent studies have suggested that mitochondrial lipoate/dihydrolipoate system-dependent aldehyde dehydrogenase-2 plays a key role in nitric oxide release from GTN. The aldehyde dehydrogenase-2 performs three enzymatic activities of dehydrogenase, esterase and reductase. The reductase activity is responsible for bioactivation of organic nitrates, such as GTN yielding nitrite and dinitrate (1,2-GDN/1,3-GDN, approximately 8:1). In view of a large contribution of dihydrolipoic acid to stabilization and regeneration of thiol groups, necessary for the reductase activity of aldehyde dehydrogenase-2, we conducted studies aimed to determine whether lipoic acid administration to rats is able to prevent GTN tolerance. The studies were conducted on 4 groups of animals: control saline-treated, model GTN-tolerant, GTN + lipoic acid-treated, lipoic acid alone-administered groups. On the 9th day of experiment animals were given i.v. therapeutic dose of GTN. We measured in all animals systolic and diastolic blood pressure before injection of therapeutic dose of GTN into the cadual vein and during 20 min thereafter. Levels of nitric oxide and reactive oxygen species and activities of glutathione peroxidase and superoxide dismutase were assayed in the aorta, plasma and heart of all animals. In addition, levels of malondialdehyde, and non-protein thiols, and activities of glutathione S-transferase and gamma-glutamyl transpeptidase were evaluated in the heart and plasma. The obtained results indicate that treatment of rats with a combination of lipoic acid and GTN can efficiently counteract GTN tolerance.
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Affiliation(s)
- Magdalena Dudek
- Laboratory of Pharmacological Screening, Jagiellonian University, Collegium Medicum, 9, Medyczna Street, PL 30-688 Kraków, Poland
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20
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Smets BF, Yin H, Esteve-Nuñez A. TNT biotransformation: when chemistry confronts mineralization. Appl Microbiol Biotechnol 2007; 76:267-77. [PMID: 17534614 DOI: 10.1007/s00253-007-1008-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 04/19/2007] [Accepted: 04/19/2007] [Indexed: 10/23/2022]
Abstract
Our understanding of the genetics and biochemistry of microbial 2,4,6-trinitrotoluene (TNT) biotransformation has advanced significantly during the past 10 years, and biotreatment technologies have developed. In this review, we summarize this new knowledge. A number of enzyme classes involved in TNT biotransformation include the type I nitroreductases, the old yellow enzyme family, a respiration-associated nitroreductase, and possibly ring hydroxylating dioxygenases. Several strains harbor dual pathways: nitroreduction (reduction of the nitro group in TNT to a hydroxylamino and/or amino group) and denitration (reduction of the aromatic ring of TNT to Meisenheimer complexes with nitrite release). TNT can serve as a nitrogen source for some strains, and the postulated mechanism involves ammonia release from hydroxylamino intermediates. Field biotreatment technologies indicate that both stimulation of microbial nitroreduction and phytoremediation result in significant and permanent immobilization of TNT via its metabolites. While the possibility for TNT mineralization was rekindled with the discovery of TNT denitration and oxygenolytic and respiration-associated pathways, further characterization of responsible enzymes and their reaction mechanisms are required.
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Affiliation(s)
- Barth F Smets
- Institute of Environment and Resources, Technical University of Denmark, Bygningstorvet, Bldg 115, 2800 Kgs. Lyngby, Denmark.
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21
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van den Hemel D, Brigé A, Savvides SN, Van Beeumen J. Ligand-induced conformational changes in the capping subdomain of a bacterial old yellow enzyme homologue and conserved sequence fingerprints provide new insights into substrate binding. J Biol Chem 2006; 281:28152-61. [PMID: 16857682 DOI: 10.1074/jbc.m603946200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have recently reported that Shewanella oneidensis, a Gram-negative gamma-proteobacterium with a rich arsenal of redox proteins, possesses four old yellow enzyme (OYE) homologues. Here, we report a series of high resolution crystal structures for one of these OYEs, Shewanella yellow enzyme 1 (SYE1), in its oxidized form at 1.4A resolution, which binds a molecule of PEG 400 in the active site, and in its NADH-reduced and p-hydroxybenzaldehyde- and p-hydroxyacetophenone-bound forms at 1.7A resolution. Although the overall structure of SYE1 reveals a monomeric enzyme based on the alpha(8)beta(8) barrel scaffold observed for other OYEs, the active site exhibits a unique combination of features: a strongly butterfly-bent FMN cofactor both in the oxidized and NADH-reduced forms, a collapsed and narrow active site tunnel, and a novel combination of conserved residues involved in the binding of phenolic ligands. Furthermore, we identify a second p-hydroxybenzaldehyde-binding site in a hydrophobic cleft next to the entry of the active site tunnel in the capping subdomain, formed by a restructuring of Loop 3 to an "open" conformation. This constitutes the first evidence to date for the entire family of OYEs that Loop 3 may indeed play a dynamic role in ligand binding and thus provides insights into the elusive NADH complex and into substrate binding in general. Structure-based sequence alignments indicate that the novelties we observe in SYE1 are supported by conserved residues in a number of structurally uncharacterized OYEs from the beta- and gamma-proteobacteria, suggesting that SYE1 represents a new subfamily of bacterial OYEs.
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Affiliation(s)
- Debbie van den Hemel
- Department of Biochemistry, Physiology and Microbiology, Laboratory for Protein Biochemistry and Protein Engineering, K.L. Ledeganckstraat 35, Ghent University, 9000 Ghent, Belgium
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Ji Y, Bennett BM. Biotransformation of Glyceryl Trinitrate by Rat Hepatic Microsomal GlutathioneS-Transferase 1. J Pharmacol Exp Ther 2006; 318:1050-6. [PMID: 16720755 DOI: 10.1124/jpet.106.103713] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although the biotransformation of organic nitrates by the cytosolic glutathione S-transferases (GSTs) is well known, the relative contribution of the microsomal GST (MGST1) to nitrate biotransformation has not been described. We therefore compared the denitration of glyceryl trinitrate (GTN) by purified rat liver MGST1 and cytosolic GSTs. Both MGST1 and cytosolic GSTs catalyzed the denitration of GTN, but the activity of MGST1 toward GTN was 2- to 3-fold higher. To mimic oxidative/nitrosative stress in vitro, we treated enzyme preparations with hydrogen peroxide, S-nitrosoglutathione, and peroxynitrite. Both oxidants and nitrating reagents increased the activity of MGST1 toward the GST substrate, 1-chloro-2,4-dinitrobenzene (CDNB) whereas these treatments inhibited GTN denitration by MGST1. Alkylation of the sole cysteine residue of MGST1 by N-ethylmaleimide markedly increased enzyme activity with CDNB as substrate but decreased the rate of GTN denitration. In aortic microsomes from GTN-tolerant animals, there was a decreased abundance of MGST1 dimers and trimers. In hepatic microsomes from GTN-tolerant animals, GTN biotransformation was unaltered whereas the rate of CDNB conjugation was doubled, suggesting that chronic GTN exposure causes structural modifications to the enzyme, resulting in increased activity to certain substrates. Collectively, these data indicate that MGST1 contributes significantly to the biotransformation of GTN and that chemical modification of the microsomal enzyme has differential effects on the catalytic activity toward different substrates.
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Affiliation(s)
- Yanbin Ji
- Department of Pharmacology and Toxicology, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6
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Li H, Liu X, Cui H, Chen YR, Cardounel AJ, Zweier JL. Characterization of the Mechanism of Cytochrome P450 Reductase-Cytochrome P450-mediated Nitric Oxide and Nitrosothiol Generation from Organic Nitrates. J Biol Chem 2006; 281:12546-54. [PMID: 16527817 DOI: 10.1074/jbc.m511803200] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian cytochrome P450 reductase (CPR) and cytochrome P450 (CP) play important roles in organic nitrate bioactivation; however, the mechanism by which they convert organic nitrate to NO remains unknown. Questions remain regarding the initial precursor of NO that serves to link organic nitrate to the activation of soluble guanylyl cyclase (sGC). To characterize the mechanism of CPR-CP-mediated organic nitrate bioactivation, EPR, chemiluminescence NO analyzer, NO electrode, and immunoassay studies were performed. With rat hepatic microsomes or purified CPR, the presence of NADPH triggered organic nitrate reduction to NO2(-). The CPR flavin site inhibitor diphenyleneiodonium inhibited this NO2(-) generation, whereas the CP inhibitor clotrimazole did not. However, clotrimazole greatly inhibited NO2(-)-dependent NO generation. Therefore, CPR catalyzes organic nitrate reduction, producing nitrite, whereas CP can mediate further nitrite reduction to NO. Nitrite-dependent NO generation contributed <10% of the CPR-CP-mediated NO generation from organic nitrates; thus, NO2(-) is not the main precursor of NO. CPR-CP-mediated NO generation was largely thiol-dependent. Studies suggested that organic nitrite (R-O-NO) was produced from organic nitrate reduction by CPR. Further reaction of organic nitrite with free or microsome-associated thiols led to NO or nitrosothiol generation and thus stimulated the activation of sGC. Thus, organic nitrite is the initial product in the process of CRP-CP-mediated organic nitrate activation and is the precursor of NO and nitrosothiols, serving as the link between organic nitrate and sGC activation.
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Affiliation(s)
- Haitao Li
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Columbus, Ohio 43210-1252, USA.
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Clarke JL, Kastrati I, Johnston LJ, Thatcher GRJ. Photochemical reactions of thiols with organic nitrates Oxygen atom transfer via a thionitrate. CAN J CHEM 2006. [DOI: 10.1139/v06-056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitroglycerin is an organic nitrate that has been used in the clinical treatment of angina for 130 years, yet important details of its mechanism of action remain unanswered. The biological activity of nitrates suggests that they are bioactivated to NO via a three-electron reduction. The involvement of free or bound protein thiols in this reduction has often been proposed. To examine the involvement of thiyl radicals in such a process, the photochemical generation of benzenethiyl radical from thiol and disulfide precursors was studied in the presence of isopropyl nitrate. Analysis of reaction products and kinetics led to the conclusion that photolysis of the nitrate to NO2dominated the observed photochemistry. Formation of sulfonothioate and NO as products, and trapping of NO2by 4-chlorophenol, indicated a mechanism involving oxygen atom transfer from N to S via a thionitrate intermediate. The results of the study did not indicate a rapid reaction between thiyl radical and organic nitrate. Despite weak nitrate absorption of light >300 nm and a relatively high BDE for homolysis to give NO2, the photochemistry under thiyl-generating conditions was driven by nitrate photolysis to NO2. A novel nitrate, containing a phenyl disulfanyl group linked to nitrate groups, did not undergo photolysis to NO2or generate sulfonothioate, but did yield NO. These observations suggest that reaction between thiyl radicals and nitrates leading to NO release is a viable pathway, but it is subservient to other competing reactions, such as photolysis, in the case of IPN, and reaction with thiolate, in the case of the novel nitrate.Key words: nitrate, photolysis, thiyl radical, nitrogen dioxide, nitric oxide.
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Mackenzie IS, Maki-Petaja KM, McEniery CM, Bao YP, Wallace SM, Cheriyan J, Monteith S, Brown MJ, Wilkinson IB. Aldehyde dehydrogenase 2 plays a role in the bioactivation of nitroglycerin in humans. Arterioscler Thromb Vasc Biol 2005; 25:1891-5. [PMID: 16051882 DOI: 10.1161/01.atv.0000179599.71086.89] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Nitrates are used widely in clinical practice. However, the mechanism underlying the bioactivation of nitrates to release NO remains unclear. Recent animal data suggest that mitochondrial aldehyde dehydrogenase (ALDH2) plays a central role in nitrate bioactivation, but its role in humans is not known. We investigated the role of ALDH2 in the vascular effects of nitroglycerin (NTG) in humans in vivo. METHODS AND RESULTS Forearm blood flow (FBF) responses to intra-arterial infusions of NTG, sodium nitroprusside (SNP), and verapamil were measured in 12 healthy volunteers before and after ALDH2 inhibition by disulfiram. All drugs caused a dose-dependent vasodilatation. However, only the response to NTG was significantly reduced after disulfiram therapy (33% reduction in area under the curve [AUC]; P=0.002). Separately, 11 subjects of East Asian origin, with the loss-of-function glu504lys mutation in the ALDH2 gene, received intra-arterial NTG, SNP, and verapamil. Only the FBF response to NTG was lower in the volunteers with the glu504lys mutation compared with East Asian and non-Asian wild-type control subjects (40% reduction in AUC; P=0.02). CONCLUSIONS The findings suggest that ALDH2 is involved in the bioactivation of NTG in humans in vivo but accounts for less than half of the total bioactivation. This may be of clinical importance in patients with mutations in the ALDH2 gene and in those taking drugs that inhibit ALDH2.
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Affiliation(s)
- Isla S Mackenzie
- Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
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26
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Li H, Cui H, Liu X, Zweier JL. Xanthine oxidase catalyzes anaerobic transformation of organic nitrates to nitric oxide and nitrosothiols: characterization of this mechanism and the link between organic nitrate and guanylyl cyclase activation. J Biol Chem 2005; 280:16594-600. [PMID: 15695823 DOI: 10.1074/jbc.m411905200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Organic nitrates have been used clinically in the treatment of ischemic heart disease for more than a century. Recently, xanthine oxidase (XO) has been reported to catalyze organic nitrate reduction under anaerobic conditions, but questions remain regarding the initial precursor of nitric oxide (NO) and the link of organic nitrate to the activation of soluble guanylyl cyclase (sGC). To characterize the mechanism of XO-mediated biotransformation of organic nitrate, studies using electron paramagnetic resonance spectroscopy, chemiluminescence NO analyzer, NO electrode, and immunoassay were performed. The XO reducing substrates xanthine, NADH, and 2,3-dihydroxybenz-aldehyde triggered the reduction of organic nitrate to nitrite anion (NO2-). Studies of the pH dependence of nitrite formation indicated that XO-mediated organic nitrate reduction occurred via an acid-catalyzed mechanism. In the absence of thiols or ascorbate, no NO generation was detected from XO-mediated organic nitrate reduction; however, addition of L-cysteine or ascorbate triggered prominent NO generation. Studies suggested that organic nitrite (R-O-NO) is produced from XO-mediated organic nitrate reduction. Further reaction of organic nitrite with thiols or ascorbate leads to the generation of NO or nitrosothiols and thus stimulates the activation of sGC. Only flavin site XO inhibitors such as diphenyleneiodonium inhibited XO-mediated organic nitrate reduction and sGC activation, indicating that organic nitrate reduction occurs at the flavin site. Thus, organic nitrite is the initial product in the process of XO-mediated organic nitrate biotransformation and is the precursor of NO and nitrosothiols, serving as the link between organic nitrate and sGC activation.
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Affiliation(s)
- Haitao Li
- Center for Biomedical Electron Paramagnetic Resonance Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH 43210, USA.
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Hemmi H, Ikeda Y, Yamashita S, Nakayama T, Nishino T. Catalytic mechanism of type 2 isopentenyl diphosphate:dimethylallyl diphosphate isomerase: verification of a redox role of the flavin cofactor in a reaction with no net redox change. Biochem Biophys Res Commun 2004; 322:905-10. [PMID: 15336549 DOI: 10.1016/j.bbrc.2004.08.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2004] [Indexed: 11/21/2022]
Abstract
Type 2 isopentenyl diphosphate:dimethylallyl diphosphate isomerase requires redox co-enzymes, i.e., flavin mononucleotide (FMN) and NAD(P)H, for activity, although it catalyzes a non-redox reaction. Spectrometric studies and enzyme assays under anaerobic conditions indicate that FMN is reduced through the reaction and is sufficient for activity. The sole function of NAD(P)H appears to be the reduction of FMN since it could be replaced by an alternate reducing agent. When the enzyme was reconstructed with a flavin analogue, no activity was detected, suggesting that the isomerase reaction proceeds via a radical transfer mechanism.
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Affiliation(s)
- Hisashi Hemmi
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba-yama 07, Sendai, Miyagi 980-8579, Japan.
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Thatcher GRJ, Nicolescu AC, Bennett BM, Toader V. Nitrates and NO release: contemporary aspects in biological and medicinal chemistry. Free Radic Biol Med 2004; 37:1122-43. [PMID: 15451053 DOI: 10.1016/j.freeradbiomed.2004.06.013] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Accepted: 06/03/2004] [Indexed: 11/28/2022]
Abstract
Nitroglycerine has been used clinically in the treatment of angina for 130 years, yet important details on the mechanism of action, biotransformation, and the associated phenomenon of nitrate tolerance remain unanswered. The biological activity of organic nitrates can be said to be nitric oxide mimetic, leading to recent, exciting progress in realizing the therapeutic potential of nitrates. Unequivocally, nitroglycerine and most other organic nitrates, including NO-NSAIDs, do not behave as NO donors in the most fundamental action: in vitro activation of sGC to produce cGMP. The question as to whether the biological activity of nitrates results primarily or exclusively from NO donation will not be satisfactorily answered until the location, the apparatus, and the mechanism of reduction of nitrates to NO are defined. Similarly, the therapeutic potential of nitrates will not be unlocked until this knowledge is attained. Aspects of the therapeutic and biological activity of nitrates are reviewed in the context of the chemistry of nitrates and the elusive efficient 3e- reduction required to generate NO.
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Affiliation(s)
- Gregory R J Thatcher
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, IL 60612-7231, USA.
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Nagpal A, Valley MP, Fitzpatrick PF, Orville AM. Crystallization and preliminary analysis of active nitroalkane oxidase in three crystal forms. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2004; 60:1456-60. [PMID: 15272176 PMCID: PMC1680162 DOI: 10.1107/s0907444904013289] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Accepted: 06/02/2004] [Indexed: 11/10/2022]
Abstract
Nitroalkane oxidase (NAO), a flavoprotein cloned and purified from Fusarium oxysporum, catalyzes the oxidation of neutral nitroalkanes to the corresponding aldehydes or ketones, with the production of H2O2 and nitrite. In this paper, the crystallization and preliminary X-ray data analysis of three crystal forms of active nitroalkane oxidase are described. The first crystal form belongs to a trigonal space group (either P3(1)21 or P3(2)21, with unit-cell parameters a = b = 103.8, c = 487.0 A) and diffracts to at least 1.6 A resolution. Several data sets were collected using 2theta and kappa geometry in order to obtain a complete data set to 2.07 A resolution. Solvent-content and Matthews coefficient analysis suggests that crystal form 1 contains two homotetramers per asymmetric unit. Crystal form 2 (P2(1)2(1)2(1); a = 147.3, b = 153.5, c = 169.5 A) and crystal form 3 (P3(1) or P3(2); a = b = 108.9, c = 342.5 A) are obtained from slightly different conditions and also contain two homotetramers per asymmetric unit, but have different solvent contents. A three-wavelength MAD data set was collected from selenomethionine-enriched NAO (SeMet-NAO) in crystal form 3 and will be used for phasing.
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Affiliation(s)
- Akanksha Nagpal
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta 30332-0400, USA
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Marshall SJ, Krause D, Blencowe DK, White GF. Characterization of glycerol trinitrate reductase (NerA) and the catalytic role of active-site residues. J Bacteriol 2004; 186:1802-10. [PMID: 14996811 PMCID: PMC355970 DOI: 10.1128/jb.186.6.1802-1810.2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glycerol trinitrate reductase (NerA) from Agrobacterium radiobacter, a member of the old yellow enzyme (OYE) family of oxidoreductases, was expressed in and purified from Escherichia coli. Denaturation of pure enzyme liberated flavin mononucleotide (FMN), and spectra of NerA during reduction and reoxidation confirmed its catalytic involvement. Binding of FMN to apoenzyme to form the holoenzyme occurred with a dissociation constant of ca. 10(-7) M and with restoration of activity. The NerA-dependent reduction of glycerol trinitrate (GTN; nitroglycerin) by NADH followed ping-pong kinetics. A structural model of NerA based on the known coordinates of OYE showed that His-178, Asn-181, and Tyr-183 were close to FMN in the active site. The NerA mutation H178A produced mutant protein with bound FMN but no activity toward GTN. The N181A mutation produced protein that did not bind FMN and was isolated in partly degraded form. The mutation Y183F produced active protein with the same k(cat) as that of wild-type enzyme but with altered K(m) values for GTN and NADH, indicating a role for this residue in substrate binding. Correlation of the ratio of K(m)(GTN) to K(m)(NAD(P)H), with sequence differences for NerA and several other members of the OYE family of oxidoreductases that reduce GTN, indicated that Asn-181 and a second Asn-238 that lies close to Tyr-183 in the NerA model structure may influence substrate specificity.
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DiFabio J, Ji Y, Vasiliou V, Thatcher GRJ, Bennett BM. Role of mitochondrial aldehyde dehydrogenase in nitrate tolerance. Mol Pharmacol 2003; 64:1109-16. [PMID: 14573760 DOI: 10.1124/mol.64.5.1109] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glyceryl trinitrate (GTN) is used in the treatment of angina pectoris and cardiac failure, but the rapid onset of GTN tolerance limits its clinical utility. Research suggests that a principal cause of tolerance is inhibition of an enzyme responsible for the production of physiologically active concentrations of NO from GTN. This enzyme has not conclusively been identified. However, the mitochondrial aldehyde dehydrogenase (ALDH2) is inhibited in GTN-tolerant tissues and produces NO2- from GTN, which is proposed to be converted to NO within mitochondria. To investigate the role of this enzyme in GTN tolerance, cumulative GTN concentration-response curves were obtained for both GTN-tolerant and -nontolerant rat aortic rings treated with the ALDH inhibitor cyanamide or the ALDH substrate propionaldehyde. Tolerance to GTN was induced using both in vivo and in vitro protocols. The in vivo protocol resulted in almost complete inhibition of ALDH2 activity and GTN biotransformation in hepatic mitochondria, indicating that long-term GTN exposure results in inactivation of the enzyme. Treatment with cyanamide or propionaldehyde caused a dose-dependent increase in the EC50 value for GTN-induced relaxation of similar magnitude in both tolerant and nontolerant aorta, suggesting that although cyanamide and propionaldehyde inhibit GTN-induced vasodilation, these inhibitors do not affect the enzyme or system involved in tolerance development to GTN. Treatment with cyanamide or propionaldehyde did not significantly inhibit 1,1-diethyl-2-hydroxy-2-nitrosohydrazine-mediated vasodilation in tolerant or nontolerant aorta, indicating that these ALDH inhibitors do not affect the downstream effectors of NO-induced vasodilation. Immunoblot analysis indicated that the majority of vascular ALDH2 is present in the cytoplasm, suggesting that mitochondrial biotransformation of GTN by ALDH2 plays a minor role in the overall vascular biotransformation of GTN by this enzyme.
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Affiliation(s)
- Jon DiFabio
- Department of Pharmacology and Toxicology, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada K7L 3N6
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Fitzpatrick TB, Amrhein N, Macheroux P. Characterization of YqjM, an Old Yellow Enzyme homolog from Bacillus subtilis involved in the oxidative stress response. J Biol Chem 2003; 278:19891-7. [PMID: 12660247 DOI: 10.1074/jbc.m211778200] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this paper, we demonstrate that a protein from Bacillus subtilis (YqjM) shares many characteristic biochemical properties with the homologous yeast Old Yellow Enzyme (OYE); the enzyme binds FMN tightly but noncovalently, preferentially uses NADPH as a source of reducing equivalents, and forms charge transfer complexes with phenolic compounds such as p-hydroxybenzaldehyde. Like yeast OYE and other members of the family, YqjM catalyzes the reduction of the double bond of an array of alpha,beta-unsaturated aldehydes and ketones including nitroester and nitroaromatic compounds. Although yeast OYE was the first member of this family to be discovered in 1933 and was the first flavoenzyme ever to be isolated, the physiological role of the family still remains obscure. The finding that alpha,beta-unsaturated compounds are substrates provoked speculation that the OYE family might be involved in reductive degradation of xenobiotics or lipid peroxidation products. Here, for the first time, we demonstrate on the protein level that whereas YqjM shows a basal level of expression in B. subtilis, the addition of the toxic xenobiotic, trinitrotoluene, leads to a rapid induction of the protein in vivo denoting a role in detoxification. Moreover, we show that YqjM is rapidly induced in response to oxidative stress as exerted by hydrogen peroxide, demonstrating a potential physiological role for this enigmatic class of proteins.
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Affiliation(s)
- Teresa B Fitzpatrick
- ETH-Zürich, Institut für Pflanzenwissenschaften, Universitätstrasse 2, Switzerland.
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Kubata BK, Kabututu Z, Nozaki T, Munday CJ, Fukuzumi S, Ohkubo K, Lazarus M, Maruyama T, Martin SK, Duszenko M, Urade Y. A key role for old yellow enzyme in the metabolism of drugs by Trypanosoma cruzi. J Exp Med 2002; 196:1241-51. [PMID: 12417633 PMCID: PMC2194105 DOI: 10.1084/jem.20020885] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Trypanosoma cruzi is the etiological agent of Chagas' disease. So far, first choice anti-chagasic drugs in use have been shown to have undesirable side effects in addition to the emergence of parasite resistance and the lack of prospect for vaccine against T. cruzi infection. Thus, the isolation and characterization of molecules essential in parasite metabolism of the anti-chagasic drugs are fundamental for the development of new strategies for rational drug design and/or the improvement of the current chemotherapy. While searching for a prostaglandin (PG) F(2alpha) synthase homologue, we have identified a novel "old yellow enzyme" from T. cruzi (TcOYE), cloned its cDNA, and overexpressed the recombinant enzyme. Here, we show that TcOYE reduced 9,11-endoperoxide PGH(2) to PGF(2alpha) as well as a variety of trypanocidal drugs. By electron spin resonance experiments, we found that TcOYE specifically catalyzed one-electron reduction of menadione and beta-lapachone to semiquinone-free radicals with concomitant generation of superoxide radical anions, while catalyzing solely the two-electron reduction of nifurtimox and 4-nitroquinoline-N-oxide drugs without free radical production. Interestingly, immunoprecipitation experiments revealed that anti-TcOYE polyclonal antibody abolished major reductase activities of the lysates toward these drugs, identifying TcOYE as a key drug-metabolizing enzyme by which quinone drugs have their mechanism of action.
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Affiliation(s)
- Bruno Kilunga Kubata
- Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874, Japan.
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Khan H, Harris RJ, Barna T, Craig DH, Bruce NC, Munro AW, Moody PCE, Scrutton NS. Kinetic and structural basis of reactivity of pentaerythritol tetranitrate reductase with NADPH, 2-cyclohexenone, nitroesters, and nitroaromatic explosives. J Biol Chem 2002; 277:21906-12. [PMID: 11923299 DOI: 10.1074/jbc.m200637200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The reaction of pentaerythritol tetranitrate reductase with reducing and oxidizing substrates has been studied by stopped-flow spectrophotometry, redox potentiometry, and X-ray crystallography. We show in the reductive half-reaction of pentaerythritol tetranitrate (PETN) reductase that NADPH binds to form an enzyme-NADPH charge transfer intermediate prior to hydride transfer from the nicotinamide coenzyme to FMN. In the oxidative half-reaction, the two-electron-reduced enzyme reacts with several substrates including nitroester explosives (glycerol trinitrate and PETN), nitroaromatic explosives (trinitrotoluene (TNT) and picric acid), and alpha,beta-unsaturated carbonyl compounds (2-cyclohexenone). Oxidation of the flavin by the nitroaromatic substrate TNT is kinetically indistinguishable from formation of its hydride-Meisenheimer complex, consistent with a mechanism involving direct nucleophilic attack by hydride from the flavin N5 atom at the electron-deficient aromatic nucleus of the substrate. The crystal structures of complexes of the oxidized enzyme bound to picric acid and TNT are consistent with direct hydride transfer from the reduced flavin to nitroaromatic substrates. The mode of binding the inhibitor 2,4-dinitrophenol (2,4-DNP) is similar to that observed with picric acid and TNT. In this position, however, the aromatic nucleus is not activated for hydride transfer from the flavin N5 atom, thus accounting for the lack of reactivity with 2,4-DNP. Our work with PETN reductase establishes further a close relationship to the Old Yellow Enzyme family of proteins but at the same time highlights important differences compared with the reactivity of Old Yellow Enzyme. Our studies provide a structural and mechanistic rationale for the ability of PETN reductase to react with the nitroaromatic explosive compounds TNT and picric acid and for the inhibition of enzyme activity with 2,4-DNP.
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Affiliation(s)
- Huma Khan
- Department of Biochemistry and Centre for Chemical Biology, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
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Williams RE, Bruce NC. 'New uses for an Old Enzyme'--the Old Yellow Enzyme family of flavoenzymes. MICROBIOLOGY (READING, ENGLAND) 2002; 148:1607-1614. [PMID: 12055282 DOI: 10.1099/00221287-148-6-1607] [Citation(s) in RCA: 200] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Richard E Williams
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK1
| | - Neil C Bruce
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK1
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