351
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352
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Hasenaka Y, Okamura TA, Onitsuka K. Modeling of the hydrophobic microenvironment of water-soluble molybdoenzymes in an aqueous micellar solution. Dalton Trans 2016; 44:12618-22. [PMID: 26076318 DOI: 10.1039/c5dt01112d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A toluene-soluble molybdenum(vi) complex containing a bulky hydrophobic substituent, (Et4N)2[Mo(VI)O2{1,2-S2-3,6-(RCONH)2C6H2}2] (R = (4-(t)BuC6H4)3C), was dissolved in the hydrophobic core of a micelle in an aqueous medium and catalyzed the biomimetic reduction of an amine N-oxide by an NADH analog. The kinetic isotope effect of solvent water clearly indicates that water molecules are essential for catalysis and are involved in the rate-determining step.
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Affiliation(s)
- Yuki Hasenaka
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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353
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Schwarz G. Molybdenum cofactor and human disease. Curr Opin Chem Biol 2016; 31:179-87. [DOI: 10.1016/j.cbpa.2016.03.016] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/22/2016] [Accepted: 03/22/2016] [Indexed: 11/27/2022]
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354
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Affiliation(s)
- Charles G. Young
- Department of Chemistry and PhysicsLa Trobe Institute for Molecular ScienceLa Trobe University3086MelbourneVictoriaAustralia
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355
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Paul T, Rodehutskors PM, Schmidt J, Burzlaff N. Oxygen Atom Transfer Catalysis with Homogenous and Polymer-Supported N,N- and N,N,O-Heteroscorpionate Dioxidomolybdenum(VI) Complexes. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tobias Paul
- Inorganic Chemistry; Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM); University of Erlangen-Nürnberg; Egerlandstr. 1 91058 Erlangen Germany
| | - Philipp M. Rodehutskors
- Inorganic Chemistry; Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM); University of Erlangen-Nürnberg; Egerlandstr. 1 91058 Erlangen Germany
| | - Jochen Schmidt
- Inorganic Chemistry; Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM); University of Erlangen-Nürnberg; Egerlandstr. 1 91058 Erlangen Germany
| | - Nicolai Burzlaff
- Inorganic Chemistry; Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM); University of Erlangen-Nürnberg; Egerlandstr. 1 91058 Erlangen Germany
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356
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Heider J, Szaleniec M, Sünwoldt K, Boll M. Ethylbenzene Dehydrogenase and Related Molybdenum Enzymes Involved in Oxygen-Independent Alkyl Chain Hydroxylation. J Mol Microbiol Biotechnol 2016; 26:45-62. [PMID: 26960184 DOI: 10.1159/000441357] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Ethylbenzene dehydrogenase initiates the anaerobic bacterial degradation of ethylbenzene and propylbenzene. Although the enzyme is currently only known from a few closely related denitrifying bacterial strains affiliated to the Rhodocyclaceae, it clearly marks a universally occurring mechanism used for attacking recalcitrant substrates in the absence of oxygen. Ethylbenzene dehydrogenase belongs to subfamily 2 of the DMSO reductase-type molybdenum enzymes together with paralogous enzymes involved in the oxygen-independent hydroxylation of p-cymene, the isoprenoid side chains of sterols and even possibly n-alkanes; the subfamily also extends to dimethylsulfide dehydrogenases, selenite, chlorate and perchlorate reductases and, most significantly, dissimilatory nitrate reductases. The biochemical, spectroscopic and structural properties of the oxygen-independent hydroxylases among these enzymes are summarized and compared. All of them consist of three subunits, contain a molybdenum-bis-molybdopterin guanine dinucleotide cofactor, five Fe-S clusters and a heme b cofactor of unusual ligation, and are localized in the periplasmic space as soluble enzymes. In the case of ethylbenzene dehydrogenase, it has been determined that the heme b cofactor has a rather high redox potential, which may also be inferred for the paralogous hydroxylases. The known structure of ethylbenzene dehydrogenase allowed the calculation of detailed models of the reaction mechanism based on the density function theory as well as QM-MM (quantum mechanics - molecular mechanics) methods, which yield predictions of mechanistic properties such as kinetic isotope effects that appeared consistent with experimental data.
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Affiliation(s)
- Johann Heider
- Laboratory of Microbial Biochemistry, LOEWE Center for Synthetic Microbiology, Philipps University of Marburg, Marburg, Germany
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357
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Boll M, Einsle O, Ermler U, Kroneck PMH, Ullmann GM. Structure and Function of the Unusual Tungsten Enzymes Acetylene Hydratase and Class II Benzoyl-Coenzyme A Reductase. J Mol Microbiol Biotechnol 2016; 26:119-37. [PMID: 26959374 DOI: 10.1159/000440805] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In biology, tungsten (W) is exclusively found in microbial enzymes bound to a bis-pyranopterin cofactor (bis-WPT). Previously known W enzymes catalyze redox oxo/hydroxyl transfer reactions by directly coordinating their substrates or products to the metal. They comprise the W-containing formate/formylmethanofuran dehydrogenases belonging to the dimethyl sulfoxide reductase (DMSOR) family and the aldehyde:ferredoxin oxidoreductase (AOR) families, which form a separate enzyme family within the Mo/W enzymes. In the last decade, initial insights into the structure and function of two unprecedented W enzymes were obtained: the acetaldehyde forming acetylene hydratase (ACH) belongs to the DMSOR and the class II benzoyl-coenzyme A (CoA) reductase (BCR) to the AOR family. The latter catalyzes the reductive dearomatization of benzoyl-CoA to a cyclic diene. Both are key enzymes in the degradation of acetylene (ACH) or aromatic compounds (BCR) in strictly anaerobic bacteria. They are unusual in either catalyzing a nonredox reaction (ACH) or a redox reaction without coordinating the substrate or product to the metal (BCR). In organic chemical synthesis, analogous reactions require totally nonphysiological conditions depending on Hg2+ (acetylene hydration) or alkali metals (benzene ring reduction). The structural insights obtained pave the way for biological or biomimetic approaches to basic reactions in organic chemistry.
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Affiliation(s)
- Matthias Boll
- Fakultx00E4;t fx00FC;r Biologie/Mikrobiologie, Institut fx00FC;r Biochemie, Albert-Ludwigs-Universitx00E4;t Freiburg, Freiburg, Germany
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358
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Carrano CJ. A Family of Homo- and Heteroscorpionate Ligands: Applications to Bioinorganic Chemistry. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501476] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Carl J. Carrano
- Department of Chemistry and Biochemistry; San Diego State University; 92182-1030 San Diego CA USA
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359
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360
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Youngblut MD, Tsai CL, Clark IC, Carlson HK, Maglaqui AP, Gau-Pan PS, Redford SA, Wong A, Tainer JA, Coates JD. Perchlorate Reductase Is Distinguished by Active Site Aromatic Gate Residues. J Biol Chem 2016; 291:9190-202. [PMID: 26940877 DOI: 10.1074/jbc.m116.714618] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Indexed: 11/06/2022] Open
Abstract
Perchlorate is an important ion on both Earth and Mars. Perchlorate reductase (PcrAB), a specialized member of the dimethylsulfoxide reductase superfamily, catalyzes the first step of microbial perchlorate respiration, but little is known about the biochemistry, specificity, structure, and mechanism of PcrAB. Here we characterize the biophysics and phylogeny of this enzyme and report the 1.86-Å resolution PcrAB complex crystal structure. Biochemical analysis revealed a relatively high perchlorate affinity (Km = 6 μm) and a characteristic substrate inhibition compared with the highly similar respiratory nitrate reductase NarGHI, which has a relatively much lower affinity for perchlorate (Km = 1.1 mm) and no substrate inhibition. Structural analysis of oxidized and reduced PcrAB with and without the substrate analog SeO3 (2-) bound to the active site identified key residues in the positively charged and funnel-shaped substrate access tunnel that gated substrate entrance and product release while trapping transiently produced chlorate. The structures suggest gating was associated with shifts of a Phe residue between open and closed conformations plus an Asp residue carboxylate shift between monodentate and bidentate coordination to the active site molybdenum atom. Taken together, structural and mutational analyses of gate residues suggest key roles of these gate residues for substrate entrance and product release. Our combined results provide the first detailed structural insight into the mechanism of biological perchlorate reduction, a critical component of the chlorine redox cycle on Earth.
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Affiliation(s)
| | - Chi-Lin Tsai
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and
| | | | | | | | | | | | - Alan Wong
- From the Energy Biosciences Institute and
| | - John A Tainer
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - John D Coates
- From the Energy Biosciences Institute and Department of Plant and Microbial Biology, University of California, Berkeley, California 94720,
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361
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Porcher JP, Fogeron T, Gomez-Mingot M, Chamoreau LM, Li Y, Fontecave M. Synthesis and Reactivity of a Bio-inspired Dithiolene Ligand and its Mo Oxo Complex. Chemistry 2016; 22:4447-53. [PMID: 26880579 DOI: 10.1002/chem.201504373] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Indexed: 12/15/2022]
Abstract
An original synthesis of the fused pyranoquinoxaline dithiolene ligand qpdt(2-) is discussed in detail. The most intriguing step is the introduction of the dithiolene moiety by Pd-catalyzed carbon-sulfur coupling. The corresponding Mo(IV)O complex (Bu4N)2 [MoO(qpdt)2] (2) underwent reversible protonation in a strongly acidic medium and remained stable under anaerobic conditions. Besides, 2 was found to be very sensitive towards oxygen, as upon oxidation it formed a planar dithiin derivative. Moreover, the qpdt(2-) ligand in the presence of [MoCl4 (tBuNC)2] formed a tetracyclic structure. The products resulting from the unique reactivity of qpdt(2-) were characterized by X-ray diffraction, mass spectrometry, NMR spectroscopy, UV/Vis spectroscopy, and electrochemistry. Plausible mechanisms for the formation of these products are also proposed.
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Affiliation(s)
- Jean-Philippe Porcher
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France
| | - Thibault Fogeron
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France
| | - Maria Gomez-Mingot
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France
| | - Lise-Marie Chamoreau
- Sorbonne Universités, UPMC Université Paris 6, Institut Parisien de Chimie Moléculaire, UMR 8232 CNRS, 4 Place Jussieu, 75252, Paris CEDEX 05, France
| | - Yun Li
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France.
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231, Paris CEDEX 05, France.
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362
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Sugimoto H, Sato M, Asano K, Suzuki T, Mieda K, Ogura T, Matsumoto T, Giles LJ, Pokhrel A, Kirk ML, Itoh S. A Model for the Active-Site Formation Process in DMSO Reductase Family Molybdenum Enzymes Involving Oxido-Alcoholato and Oxido-Thiolato Molybdenum(VI) Core Structures. Inorg Chem 2016; 55:1542-50. [PMID: 26816115 PMCID: PMC4912129 DOI: 10.1021/acs.inorgchem.5b02395] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
New bis(ene-1,2-dithiolato)-oxido-alcoholato molybdenum(VI) and -oxido-thiolato molybdenum(VI) anionic complexes, denoted as [Mo(VI)O(ER)L2](-) (E = O, S; L = dimethoxycarboxylate-1,2-ethylenedithiolate), were obtained from the reaction of the corresponding dioxido-molybdenum(VI) precursor complex with either an alcohol or a thiol in the presence of an organic acid (e.g., 10-camphorsulfonic acid) at low temperature. The [Mo(VI)O(ER)L2](-) complexes were isolated and characterized, and the structure of [Mo(VI)O(OEt)L2](-) was determined by X-ray crystallography. The Mo(VI) center in [Mo(VI)O(OEt)L2](-) exhibits a distorted octahedral geometry with the two ene-1,2-dithiolate ligands being symmetry inequivalent. The computed structure of [Mo(VI)O(SR)L2](-) is essentially identical to that of [Mo(VI)O(OR)L2](-). The electronic structures of the resulting molybdenum(VI) complexes were evaluated using electronic absorption spectroscopy and bonding calculations. The nature of the distorted O(h) geometry in these [Mo(VI)O(EEt)L2](-) complexes results in a lowest unoccupied molecular orbital wave function that possesses strong π* interactions between the Mo(d(xy)) orbital and the cis S(p(z)) orbital localized on one sulfur donor from a single ene-1,2-dithiolate ligand. The presence of a covalent Mo-S(dithiolene) bonding interaction in these monooxido Mo(VI) compounds contributes to their low-energy ligand-to-metal charge transfer transitions. A second important d-p π bonding interaction derives from the ∼180° O(oxo)-Mo-E-C dihedral angle involving the alcoholate and thiolate donors, and this contributes to ancillary ligand contributions to the electronic structure of these species. The formation of [Mo(VI)O(OEt)L2](-) and [Mo(VI)O(SEt)L2](-) from the dioxidomolybdenum(VI) precursor may be regarded as a model for the active-site formation process that occurs in the dimethyl sulfoxide reductase family of pyranopterin molybdenum enzymes.
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Affiliation(s)
- Hideki Sugimoto
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masanori Sato
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kaori Asano
- Comprehensive Analysis Center, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0057, Japan
| | - Takeyuki Suzuki
- Comprehensive Analysis Center, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0057, Japan
| | - Kaoru Mieda
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 678-0057, Japan
| | - Takashi Ogura
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, RSC-UH Leading Program Center, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 678-0057, Japan
| | | | - Logan J. Giles
- Department of Chemistry and Chemical Biology, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA
| | - Amrit Pokhrel
- Department of Chemistry and Chemical Biology, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA
| | - Martin L. Kirk
- Department of Chemistry and Chemical Biology, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA
| | - Shinobu Itoh
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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363
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Lee CC, Sickerman NS, Hu Y, Ribbe MW. YedY: A Mononuclear Molybdenum Enzyme with a Redox-Active Ligand? Chembiochem 2016; 17:453-5. [PMID: 26751730 DOI: 10.1002/cbic.201600004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Indexed: 11/07/2022]
Abstract
A recent electrochemical investigation suggests that the mononuclear molybdenum enzyme YdeY utilizes redox-active ligands during catalysis.
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Affiliation(s)
- Chi Chung Lee
- Department of Molecular Biology and Biochemistry, University of California in Irvine, 2230/2236 McGaugh Hall, Irvine, CA, 92697-3900, USA
| | - Nathaniel S Sickerman
- Department of Molecular Biology and Biochemistry, University of California in Irvine, 2230/2236 McGaugh Hall, Irvine, CA, 92697-3900, USA
| | - Yilin Hu
- Department of Molecular Biology and Biochemistry, University of California in Irvine, 2230/2236 McGaugh Hall, Irvine, CA, 92697-3900, USA.
| | - Markus W Ribbe
- Department of Molecular Biology and Biochemistry, University of California in Irvine, 2230/2236 McGaugh Hall, Irvine, CA, 92697-3900, USA. .,Department of Chemistry, University of California in Irvine, 2236 McGaugh Hall, Irvine, CA, 92697-2025, USA.
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364
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Foti A, Hartmann T, Coelho C, Santos-Silva T, Romao MJ, Leimkuhler S. Optimization of the Expression of Human Aldehyde Oxidase for Investigations of Single-Nucleotide Polymorphisms. Drug Metab Dispos 2016; 44:1277-85. [DOI: 10.1124/dmd.115.068395] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/01/2016] [Indexed: 01/02/2023] Open
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365
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Archaeal Mo-Containing Glyceraldehyde Oxidoreductase Isozymes Exhibit Diverse Substrate Specificities through Unique Subunit Assemblies. PLoS One 2016; 11:e0147333. [PMID: 26808202 PMCID: PMC4726530 DOI: 10.1371/journal.pone.0147333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 01/01/2016] [Indexed: 11/19/2022] Open
Abstract
Archaea use glycolytic pathways distinct from those found in bacteria and eukaryotes, where unique enzymes catalyze each reaction step. In this study, we isolated three isozymes of glyceraldehyde oxidoreductase (GAOR1, GAOR2 and GAOR3) from the thermoacidophilic archaeon Sulfolobus tokodaii. GAOR1-3 belong to the xanthine oxidoreductase superfamily, and are composed of a molybdo-pyranopterin subunit (L), a flavin subunit (M), and an iron-sulfur subunit (S), forming an LMS hetero-trimer unit. We found that GAOR1 is a tetramer of the STK17810/STK17830/STK17820 hetero-trimer, GAOR2 is a dimer of the STK23390/STK05620/STK05610 hetero-trimer, and GAOR3 is the STK24840/STK05620/STK05610 hetero-trimer. GAOR1-3 exhibited diverse substrate specificities for their electron donors and acceptors, due to their different L-subunits, and probably participate in the non-phosphorylative Entner-Doudoroff glycolytic pathway. We determined the crystal structure of GAOR2, as the first three-dimensional structure of an archaeal molybdenum-containing hydroxylase, to obtain structural insights into their substrate specificities and subunit assemblies. The gene arrangement and the crystal structure suggested that the M/S-complex serves as a structural scaffold for the binding of the L-subunit, to construct the three enzymes with different specificities. Collectively, our findings illustrate a novel principle of a prokaryotic multicomponent isozyme system.
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366
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Schut GJ, Zadvornyy O, Wu CH, Peters JW, Boyd ES, Adams MWW. The role of geochemistry and energetics in the evolution of modern respiratory complexes from a proton-reducing ancestor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:958-70. [PMID: 26808919 DOI: 10.1016/j.bbabio.2016.01.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/26/2015] [Accepted: 01/18/2016] [Indexed: 11/29/2022]
Abstract
Complex I or NADH quinone oxidoreductase (NUO) is an integral component of modern day respiratory chains and has a close evolutionary relationship with energy-conserving [NiFe]-hydrogenases of anaerobic microorganisms. Specifically, in all of biology, the quinone-binding subunit of Complex I, NuoD, is most closely related to the proton-reducing, H2-evolving [NiFe]-containing catalytic subunit, MbhL, of membrane-bound hydrogenase (MBH), to the methanophenzine-reducing subunit of a methanogenic respiratory complex (FPO) and to the catalytic subunit of an archaeal respiratory complex (MBX) involved in reducing elemental sulfur (S°). These complexes also pump ions and have at least 10 homologous subunits in common. As electron donors, MBH and MBX use ferredoxin (Fd), FPO uses either Fd or cofactor F420, and NUO uses either Fd or NADH. In this review, we examine the evolutionary trajectory of these oxidoreductases from a proton-reducing ancestral respiratory complex (ARC). We hypothesize that the diversification of ARC to MBH, MBX, FPO and eventually NUO was driven by the larger energy yields associated with coupling Fd oxidation to the reduction of oxidants with increasing electrochemical potential, including protons, S° and membrane soluble organic compounds such as phenazines and quinone derivatives. Importantly, throughout Earth's history, the availability of these oxidants increased as the redox state of the atmosphere and oceans became progressively more oxidized as a result of the origin and ecological expansion of oxygenic photosynthesis. ARC-derived complexes are therefore remarkably stable respiratory systems with little diversity in core structure but whose general function appears to have co-evolved with the redox state of the biosphere. This article is part of a Special Issue entitled Respiratory Complex I, edited by Volker Zickermann and Ulrich Brandt.
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Affiliation(s)
- Gerrit J Schut
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, United States
| | - Oleg Zadvornyy
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States
| | - Chang-Hao Wu
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, United States
| | - John W Peters
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, United States
| | - Eric S Boyd
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, United States
| | - Michael W W Adams
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, United States.
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367
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Acetylene hydratase: a non-redox enzyme with tungsten and iron-sulfur centers at the active site. J Biol Inorg Chem 2016; 21:29-38. [PMID: 26790879 DOI: 10.1007/s00775-015-1330-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/30/2015] [Indexed: 01/05/2023]
Abstract
In living systems, tungsten is exclusively found in microbial enzymes coordinated by the pyranopterin cofactor, with additional metal coordination provided by oxygen and/or sulfur, and/or selenium atoms in diverse arrangements. Prominent examples are formate dehydrogenase, formylmethanofuran dehydrogenase, and aldehyde oxidoreductase all of which catalyze redox reactions. The bacterial enzyme acetylene hydratase (AH) stands out of its class as it catalyzes the conversion of acetylene to acetaldehyde, clearly a non-redox reaction and a reaction distinct from the reduction of acetylene to ethylene by nitrogenase. AH harbors two pyranopterins bound to W, and a [4Fe-4S] cluster. W is coordinated by four dithiolene sulfur atoms, one cysteine sulfur, and one oxygen ligand. AH activity requires a strong reductant suggesting W(IV) as the active oxidation state. Two different types of reaction pathways have been proposed. The 1.26 Å structure reveals a water molecule coordinated to W which could gain a partially positive net charge by the adjacent protonated Asp-13, enabling a direct attack of C2H2. To access the W-Asp site, a substrate channel was evolved distant from where it is found in other members of the DMSOR family. Computational studies of this second shell mechanism led to unrealistically high energy barriers, and alternative pathways were proposed where C2H2 binds directly to W. The architecture of the catalytic cavity, the specificity for C2H2 and the results from site-directed mutagenesis do not support this first shell mechanism. More investigations including structural information on the binding of C2H2 are needed to present a conclusive answer.
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368
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Fogeron T, Porcher JP, Gomez-Mingot M, Todorova TK, Chamoreau LM, Mellot-Draznieks C, Li Y, Fontecave M. A cobalt complex with a bioinspired molybdopterin-like ligand: a catalyst for hydrogen evolution. Dalton Trans 2016; 45:14754-63. [DOI: 10.1039/c6dt01824f] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A cobalt complex using a bioinspired ligand, that mimics the molybdopterin cofactor, displays very good activity for electrochemical proton reduction in terms of turnover frequency, faradic yields and stability.
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Affiliation(s)
- Thibault Fogeron
- Laboratoire de Chimie des Processus Biologiques
- UMR 8229 CNRS
- Collège de France
- Université Paris 6
- 75231 Paris Cedex 05
| | - Jean-Philippe Porcher
- Laboratoire de Chimie des Processus Biologiques
- UMR 8229 CNRS
- Collège de France
- Université Paris 6
- 75231 Paris Cedex 05
| | - Maria Gomez-Mingot
- Laboratoire de Chimie des Processus Biologiques
- UMR 8229 CNRS
- Collège de France
- Université Paris 6
- 75231 Paris Cedex 05
| | - Tanya K. Todorova
- Laboratoire de Chimie des Processus Biologiques
- UMR 8229 CNRS
- Collège de France
- Université Paris 6
- 75231 Paris Cedex 05
| | - Lise-Marie Chamoreau
- Sorbonne Universités
- UPMC Université Paris 6
- Institut Parisien de Chimie Moléculaire
- UMR 8232 CNRS
- 75252 Paris Cedex 5
| | - Caroline Mellot-Draznieks
- Laboratoire de Chimie des Processus Biologiques
- UMR 8229 CNRS
- Collège de France
- Université Paris 6
- 75231 Paris Cedex 05
| | - Yun Li
- Laboratoire de Chimie des Processus Biologiques
- UMR 8229 CNRS
- Collège de France
- Université Paris 6
- 75231 Paris Cedex 05
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques
- UMR 8229 CNRS
- Collège de France
- Université Paris 6
- 75231 Paris Cedex 05
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369
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370
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Abstract
In Escherichia coli, hydrogen metabolism plays a prominent role in anaerobic physiology. The genome contains the capability to produce and assemble up to four [NiFe]-hydrogenases, each of which are known, or predicted, to contribute to different aspects of cellular metabolism. In recent years, there have been major advances in the understanding of the structure, function, and roles of the E. coli [NiFe]-hydrogenases. The membrane-bound, periplasmically oriented, respiratory Hyd-1 isoenzyme has become one of the most important paradigm systems for understanding an important class of oxygen-tolerant enzymes, as well as providing key information on the mechanism of hydrogen activation per se. The membrane-bound, periplasmically oriented, Hyd-2 isoenzyme has emerged as an unusual, bidirectional redox valve able to link hydrogen oxidation to quinone reduction during anaerobic respiration, or to allow disposal of excess reducing equivalents as hydrogen gas. The membrane-bound, cytoplasmically oriented, Hyd-3 isoenzyme is part of the formate hydrogenlyase complex, which acts to detoxify excess formic acid under anaerobic fermentative conditions and is geared towards hydrogen production under those conditions. Sequence identity between some Hyd-3 subunits and those of the respiratory NADH dehydrogenases has led to hypotheses that the activity of this isoenzyme may be tightly coupled to the formation of transmembrane ion gradients. Finally, the E. coli genome encodes a homologue of Hyd-3, termed Hyd-4, however strong evidence for a physiological role for E. coli Hyd-4 remains elusive. In this review, the versatile hydrogen metabolism of E. coli will be discussed and the roles and potential applications of the spectrum of different types of [NiFe]-hydrogenases available will be explored.
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371
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Hasenaka Y, Okamura TA, Onitsuka K. Efficient uptake of dimethyl sulfoxide by the desoxomolybdenum(IV) dithiolate complex containing bulky hydrophobic groups. Dalton Trans 2015; 44:6260-7. [PMID: 25739371 DOI: 10.1039/c5dt00075k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A desoxomolybdenum(IV) complex containing bulky hydrophobic groups and NH···S hydrogen bonds, (Et4N)[Mo(IV)(OSi(t)BuPh2)(1,2-S2-3,6-{(4-(t)BuC6H4)3CCONH}2C6H2)2], was synthesized. This complex promotes the oxygen-atom-transfer (OAT) reaction of DMSO by efficient uptake of the substrate into the active center. The clean OAT reaction of Me3NO is also achieved.
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Affiliation(s)
- Yuki Hasenaka
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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372
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Warnke M, Jung T, Dermer J, Hipp K, Jehmlich N, von Bergen M, Ferlaino S, Fries A, Müller M, Boll M. 25-Hydroxyvitamin D3 Synthesis by Enzymatic Steroid Side-Chain Hydroxylation with Water. Angew Chem Int Ed Engl 2015; 55:1881-4. [PMID: 26695374 DOI: 10.1002/anie.201510331] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Indexed: 12/14/2022]
Abstract
The hydroxylation of vitamin D3 (VD3, cholecalciferol) side chains to give 25-hydroxyvitamin D3 (25OHVD3) is a crucial reaction in the formation of the circulating and biologically active forms of VD3 . It is usually catalyzed by cytochrome P450 monooxygenases that depend on complex electron donor systems. Cell-free extracts and a purified Mo enzyme from a bacterium anaerobically grown with cholesterol were employed for the regioselective, ferricyanide-dependent hydroxylation of VD3 and proVD3 (7-dehydrocholesterol) into the corresponding tertiary alcohols with greater than 99 % yield. Hydroxylation of VD3 strictly depends on a cyclodextrin-assisted isomerization of VD3 into preVD3 , the actual enzymatic substrate. This facile and robust method developed for 25OHVD3 synthesis is a novel example for the concept of substrate-engineered catalysis and offers an attractive alternative to chemical or O2 /electron-donor-dependent enzymatic procedures.
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Affiliation(s)
- Markus Warnke
- Faculty of Biology - Microbiology, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Tobias Jung
- Faculty of Biology - Microbiology, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Juri Dermer
- Faculty of Biology - Microbiology, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Karin Hipp
- Faculty of Biology - Microbiology, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Nico Jehmlich
- Department of Proteomics, Helmholtz Centre of Environmental Sciences, Permoserstr. 15, 04318, Leipzig, Germany
| | - Martin von Bergen
- Department of Proteomics, Helmholtz Centre of Environmental Sciences, Permoserstr. 15, 04318, Leipzig, Germany
| | - Sascha Ferlaino
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, 79104, Freiburg, Germany
| | - Alexander Fries
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, 79104, Freiburg, Germany
| | - Michael Müller
- Institute of Pharmaceutical Sciences, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, 79104, Freiburg, Germany
| | - Matthias Boll
- Faculty of Biology - Microbiology, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
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373
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Warnke M, Jung T, Dermer J, Hipp K, Jehmlich N, von Bergen M, Ferlaino S, Fries A, Müller M, Boll M. 25-Hydroxyvitamin D3
Synthesis by Enzymatic Steroid Side-Chain Hydroxylation with Water. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201510331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Markus Warnke
- Faculty of Biology - Microbiology; Albert-Ludwigs-Universität Freiburg; Schänzlestrasse 1 79104 Freiburg Germany
| | - Tobias Jung
- Faculty of Biology - Microbiology; Albert-Ludwigs-Universität Freiburg; Schänzlestrasse 1 79104 Freiburg Germany
| | - Juri Dermer
- Faculty of Biology - Microbiology; Albert-Ludwigs-Universität Freiburg; Schänzlestrasse 1 79104 Freiburg Germany
| | - Karin Hipp
- Faculty of Biology - Microbiology; Albert-Ludwigs-Universität Freiburg; Schänzlestrasse 1 79104 Freiburg Germany
| | - Nico Jehmlich
- Department of Proteomics; Helmholtz Centre of Environmental Sciences; Permoserstr. 15 04318 Leipzig Germany
| | - Martin von Bergen
- Department of Proteomics; Helmholtz Centre of Environmental Sciences; Permoserstr. 15 04318 Leipzig Germany
| | - Sascha Ferlaino
- Institute of Pharmaceutical Sciences; Albert-Ludwigs-Universität Freiburg; Albertstrasse 25 79104 Freiburg Germany
| | - Alexander Fries
- Institute of Pharmaceutical Sciences; Albert-Ludwigs-Universität Freiburg; Albertstrasse 25 79104 Freiburg Germany
| | - Michael Müller
- Institute of Pharmaceutical Sciences; Albert-Ludwigs-Universität Freiburg; Albertstrasse 25 79104 Freiburg Germany
| | - Matthias Boll
- Faculty of Biology - Microbiology; Albert-Ludwigs-Universität Freiburg; Schänzlestrasse 1 79104 Freiburg Germany
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374
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Yang J, Mogesa B, Basu P, Kirk ML. Large Ligand Folding Distortion in an Oxomolybdenum Donor-Acceptor Complex. Inorg Chem 2015; 55:785-93. [PMID: 26692422 DOI: 10.1021/acs.inorgchem.5b02252] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Interligand charge transfer is examined in the novel metallo-dithiolene complex MoO(SPh)2((i)Pr2Dt(0)) (where (i)Pr2Dt(0) = N,N'-isopropyl-piperazine-2,3-dithione). The title complex displays a remarkable 70° "envelope"-type fold of the five-membered dithiolene ring, which is bent upward toward the terminal oxo ligand. A combination of electronic absorption and resonance Raman spectroscopies have been used to probe the basic electronic structure responsible for the large fold-angle distortion. The intense charge transfer transition observed at ∼18 000 cm(-1) is assigned as a thiolate → dithione ligand-to-ligand charge transfer (LL'CT) transition that also possesses Mo(IV) → dithione charge transfer character. Strong orbital mixing between occupied and virtual orbitals with Mo(x(2)-y(2)) orbital character is derived from a strong pseudo Jahn-Teller effect, which drives the large fold-angle distortion to yield a double-well potential in the electronic ground state.
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Affiliation(s)
- Jing Yang
- Department of Chemistry and Chemical Biology, The University of New Mexico , MSC03 2060, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, United States
| | - Benjamin Mogesa
- Department of Chemistry and Biochemistry, Duquesne University , Pittsburgh, Pennsylvania 15282, United States
| | - Partha Basu
- Department of Chemistry and Biochemistry, Duquesne University , Pittsburgh, Pennsylvania 15282, United States
| | - Martin L Kirk
- Department of Chemistry and Chemical Biology, The University of New Mexico , MSC03 2060, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, United States
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375
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Ghosh AC, Weisz K, Schulzke C. Selective Capture of Ni2+Ions by Naphthalene- and Coumarin-Substituted Dithiolenes. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500847] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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376
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Terry LR, Kulp TR, Wiatrowski H, Miller LG, Oremland RS. Microbiological oxidation of antimony(III) with oxygen or nitrate by bacteria isolated from contaminated mine sediments. Appl Environ Microbiol 2015; 81:8478-88. [PMID: 26431974 PMCID: PMC4644646 DOI: 10.1128/aem.01970-15] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/29/2015] [Indexed: 11/20/2022] Open
Abstract
Bacterial oxidation of arsenite [As(III)] is a well-studied and important biogeochemical pathway that directly influences the mobility and toxicity of arsenic in the environment. In contrast, little is known about microbiological oxidation of the chemically similar anion antimonite [Sb(III)]. In this study, two bacterial strains, designated IDSBO-1 and IDSBO-4, which grow on tartrate compounds and oxidize Sb(III) using either oxygen or nitrate, respectively, as a terminal electron acceptor, were isolated from contaminated mine sediments. Both isolates belonged to the Comamonadaceae family and were 99% similar to previously described species. We identify these novel strains as Hydrogenophaga taeniospiralis strain IDSBO-1 and Variovorax paradoxus strain IDSBO-4. Both strains possess a gene with homology to the aioA gene, which encodes an As(III)-oxidase, and both oxidize As(III) aerobically, but only IDSBO-4 oxidized Sb(III) in the presence of air, while strain IDSBO-1 could achieve this via nitrate respiration. Our results suggest that expression of aioA is not induced by Sb(III) but may be involved in Sb(III) oxidation along with an Sb(III)-specific pathway. Phylogenetic analysis of proteins encoded by the aioA genes revealed a close sequence similarity (90%) among the two isolates and other known As(III)-oxidizing bacteria, particularly Acidovorax sp. strain NO1. Both isolates were capable of chemolithoautotrophic growth using As(III) as a primary electron donor, and strain IDSBO-4 exhibited incorporation of radiolabeled [(14)C]bicarbonate while oxidizing Sb(III) from Sb(III)-tartrate, suggesting possible Sb(III)-dependent autotrophy. Enrichment cultures produced the Sb(V) oxide mineral mopungite and lesser amounts of Sb(III)-bearing senarmontite as precipitates.
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Affiliation(s)
- Lee R Terry
- Department of Geological Sciences and Environmental Studies, Binghamton University, SUNY, Binghamton, New York, USA
| | - Thomas R Kulp
- Department of Geological Sciences and Environmental Studies, Binghamton University, SUNY, Binghamton, New York, USA
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377
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Cerqueira NMFSA, Gonzalez PJ, Fernandes PA, Moura JJG, Ramos MJ. Periplasmic nitrate reductase and formate dehydrogenase: similar molecular architectures with very different enzymatic activities. Acc Chem Res 2015; 48:2875-84. [PMID: 26509703 DOI: 10.1021/acs.accounts.5b00333] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It is remarkable how nature has been able to construct enzymes that, despite sharing many similarities, have simple but key differences that tune them for completely different functions in living cells. Periplasmic nitrate reductase (Nap) and formate dehydrogenase (Fdh) from the DMSOr family are representative examples of this. Both enzymes share almost identical three-dimensional protein foldings and active sites, in terms of coordination number, geometry and nature of the ligands. The substrates of both enzymes (nitrate and formate) are polyatomic anions that also share similar charge and stereochemistry. In terms of the catalytic mechanism, both enzymes have a common activation mechanism (the sulfur-shift mechanism) that ensures a constant coordination number around the metal ion during the catalytic cycle. In spite of these similarities, they catalyze very different reactions: Nap abstracts an oxygen atom from nitrate releasing nitrite, whereas FdH catalyzes a hydrogen atom transfer from formate and releases carbon dioxide. In this Account, a critical analysis of structure, function, and catalytic mechanism of the molybdenum enzymes periplasmic nitrate reductase (Nap) and formate dehydrogenase (Fdh) is presented. We conclude that the main structural driving force that dictates the type of reaction, catalyzed by each enzyme, is a key difference on one active site residue that is located in the top region of the active sites of both enzymes. In both enzymes, the active site is centered on the metal ion of the cofactor (Mo in Nap and Mo or W in Fdh) that is coordinated by four sulfur atoms from two pyranopterin guanosine dinucleotide (PGD) molecules and by a sulfido. However, while in Nap there is a Cys directly coordinated to the Mo ion, in FdH there is a SeCys instead. In Fdh there is also an important His that interacts very closely with the SeCys, whereas in Nap the same position is occupied by a Met. The role of Cys in Nap and SeCys in FdH is similar in both enzymes; however, Met and His have different roles. His participates directly on catalysis, and it is therefore detrimental for the catalytic cycle of FdH. Met only participates in substrate binding. We concluded that this small but key difference dictates the type of reaction that is catalyzed by each enzyme. In addition, it allows explaining why formate can bind in the Nap active site in the same way as the natural substrate (nitrate), but the reaction becomes stalled afterward.
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Affiliation(s)
- Nuno M. F. S. A. Cerqueira
- REQUIMTE/UCIBIO,
Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Pablo J. Gonzalez
- REQUIMTE/UCIBIO,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
| | - Pedro A. Fernandes
- REQUIMTE/UCIBIO,
Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - José J. G. Moura
- REQUIMTE/UCIBIO,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
| | - Maria João Ramos
- REQUIMTE/UCIBIO,
Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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378
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Electrochemical evidence that pyranopterin redox chemistry controls the catalysis of YedY, a mononuclear Mo enzyme. Proc Natl Acad Sci U S A 2015; 112:14506-11. [PMID: 26561582 DOI: 10.1073/pnas.1516869112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A long-standing contradiction in the field of mononuclear Mo enzyme research is that small-molecule chemistry on active-site mimic compounds predicts ligand participation in the electron transfer reactions, but biochemical measurements only suggest metal-centered catalytic electron transfer. With the simultaneous measurement of substrate turnover and reversible electron transfer that is provided by Fourier-transformed alternating-current voltammetry, we show that Escherichia coli YedY is a mononuclear Mo enzyme that reconciles this conflict. In YedY, addition of three protons and three electrons to the well-characterized "as-isolated" Mo(V) oxidation state is needed to initiate the catalytic reduction of either dimethyl sulfoxide or trimethylamine N-oxide. Based on comparison with earlier studies and our UV-vis redox titration data, we assign the reversible one-proton and one-electron reduction process centered around +174 mV vs. standard hydrogen electrode at pH 7 to a Mo(V)-to-Mo(IV) conversion but ascribe the two-proton and two-electron transition occurring at negative potential to the organic pyranopterin ligand system. We predict that a dihydro-to-tetrahydro transition is needed to generate the catalytically active state of the enzyme. This is a previously unidentified mechanism, suggested by the structural simplicity of YedY, a protein in which Mo is the only metal site.
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379
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Dupé A, Judmaier ME, Belaj F, Zangger K, Mösch-Zanetti NC. Activation of molecular oxygen by a molybdenum complex for catalytic oxidation. Dalton Trans 2015; 44:20514-22. [PMID: 26548583 DOI: 10.1039/c5dt02931g] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A sterically demanding molybdenum(VI) dioxo complex was found to catalytically activate molecular oxygen and to transfer its oxygen atoms to phosphines. Intermediate peroxo as well as reduced mono-oxo complexes were isolated and fully characterized. Monomeric Mo(IV) monooxo species proved to be of an unusual nature with the coordinated phosphine trans to the oxo group. The reduced molybdenum centers can activate O2 to form a stable Mo(VI) oxo-peroxo complex unambiguously characterized by single crystal X-ray diffraction analysis. NMR experiments demonstrate that both oxygen atoms of the peroxo unit are transferred to an accepting substrate, generating the Mo(IV) intermediate and restarting the catalytic cycle.
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Affiliation(s)
- Antoine Dupé
- Institute of Chemistry, University of Graz, Schubertstrasse 1, 8010 Graz, Austria.
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380
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Niks D, Duvvuru J, Escalona M, Hille R. Spectroscopic and Kinetic Properties of the Molybdenum-containing, NAD+-dependent Formate Dehydrogenase from Ralstonia eutropha. J Biol Chem 2015; 291:1162-74. [PMID: 26553877 DOI: 10.1074/jbc.m115.688457] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Indexed: 11/06/2022] Open
Abstract
We have examined the rapid reaction kinetics and spectroscopic properties of the molybdenum-containing, NAD(+)-dependent FdsABG formate dehydrogenase from Ralstonia eutropha. We confirm previous steady-state studies of the enzyme and extend its characterization to a rapid kinetic study of the reductive half-reaction (the reaction of formate with oxidized enzyme). We have also characterized the electron paramagnetic resonance signal of the molybdenum center in its Mo(V) state and demonstrated the direct transfer of the substrate Cα hydrogen to the molybdenum center in the course of the reaction. Varying temperature, microwave power, and level of enzyme reduction, we are able to clearly identify the electron paramagnetic resonance signals for four of the iron/sulfur clusters of the enzyme and find suggestive evidence for two others; we observe a magnetic interaction between the molybdenum center and one of the iron/sulfur centers, permitting assignment of this signal to a specific iron/sulfur cluster in the enzyme. In light of recent advances in our understanding of the structure of the molybdenum center, we propose a reaction mechanism involving direct hydride transfer from formate to a molybdenum-sulfur group of the molybdenum center.
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Affiliation(s)
- Dimitri Niks
- From the Department of Biochemistry, University of California, Riverside, Riverside, California 92521
| | - Jayant Duvvuru
- From the Department of Biochemistry, University of California, Riverside, Riverside, California 92521
| | - Miguel Escalona
- From the Department of Biochemistry, University of California, Riverside, Riverside, California 92521
| | - Russ Hille
- From the Department of Biochemistry, University of California, Riverside, Riverside, California 92521
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381
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Kwan P, McIntosh CL, Jennings DP, Hopkins RC, Chandrayan SK, Wu CH, Adams MWW, Jones AK. The [NiFe]-Hydrogenase of Pyrococcus furiosus Exhibits a New Type of Oxygen Tolerance. J Am Chem Soc 2015; 137:13556-65. [PMID: 26436715 DOI: 10.1021/jacs.5b07680] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We report the first direct electrochemical characterization of the impact of oxygen on the hydrogen oxidation activity of an oxygen-tolerant, group 3, soluble [NiFe]-hydrogenase: hydrogenase I from Pyrococcus furiosus (PfSHI), which grows optimally near 100 °C. Chronoamperometric experiments were used to probe the sensitivity of PfSHI hydrogen oxidation activity to both brief and prolonged exposure to oxygen. For experiments between 15 and 80 °C, following short (<200 s) exposure to 14 μM O2 under oxidizing conditions, PfSHI always maintains some fraction of its initial hydrogen oxidation activity; i.e., it is oxygen-tolerant. Reactivation experiments show that two inactive states are formed by interaction with oxygen and both can be quickly (<150 s) reactivated. Analogous experiments, in which the interval of oxygen exposure is extended to 900 s, reveal that the response is highly temperature-dependent. At 25 °C, under sustained 1% O2/ 99% H2 exposure, the H2oxidation activity drops nearly to zero. However, at 80 °C, up to 32% of the enzyme's oxidation activity is retained. Reactivation of PfSHI following sustained exposure to oxygen occurs on a much longer time scale (tens of minutes), suggesting that a third inactive species predominates under these conditions. These results stand in contrast to the properties of oxygen-tolerant, group 1 [NiFe]-hydrogenases, which form a single state upon reaction with oxygen, and we propose that this new type of hydrogenase should be referred to as oxygen-resilient. Furthermore, PfSHI, like other group 3 [NiFe]-hydrogenases, does not possess the proximal [4Fe3S] cluster associated with the oxygen tolerance of some group 1 enzymes. Thus, a new mechanism is necessary to explain the observed oxygen tolerance in soluble, group 3 [NiFe]-hydrogenases, and we present a model integrating both electrochemical and spectroscopic results to define the relationships of these inactive states.
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Affiliation(s)
- Patrick Kwan
- Department of Chemistry and Biochemistry, Arizona State University , Tempe, Arizona 85287, United States
| | - Chelsea L McIntosh
- Department of Chemistry and Biochemistry, Arizona State University , Tempe, Arizona 85287, United States
| | - David P Jennings
- Department of Chemistry and Biochemistry, Arizona State University , Tempe, Arizona 85287, United States
| | - R Chris Hopkins
- Department of Biochemistry and Molecular Biology, The University of Georgia , Athens, Georgia 30602, United States
| | - Sanjeev K Chandrayan
- Department of Biochemistry and Molecular Biology, The University of Georgia , Athens, Georgia 30602, United States
| | - Chang-Hao Wu
- Department of Biochemistry and Molecular Biology, The University of Georgia , Athens, Georgia 30602, United States
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, The University of Georgia , Athens, Georgia 30602, United States
| | - Anne K Jones
- Department of Chemistry and Biochemistry, Arizona State University , Tempe, Arizona 85287, United States
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382
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Leimkühler S, Iobbi-Nivol C. Bacterial molybdoenzymes: old enzymes for new purposes. FEMS Microbiol Rev 2015; 40:1-18. [PMID: 26468212 DOI: 10.1093/femsre/fuv043] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2015] [Indexed: 02/06/2023] Open
Abstract
Molybdoenzymes are widespread in eukaryotic and prokaryotic organisms where they play crucial functions in detoxification reactions in the metabolism of humans and bacteria, in nitrate assimilation in plants and in anaerobic respiration in bacteria. To be fully active, these enzymes require complex molybdenum-containing cofactors, which are inserted into the apoenzymes after folding. For almost all the bacterial molybdoenzymes, molybdenum cofactor insertion requires the involvement of specific chaperones. In this review, an overview on the molybdenum cofactor biosynthetic pathway is given together with the role of specific chaperones dedicated for molybdenum cofactor insertion and maturation. Many bacteria are involved in geochemical cycles on earth and therefore have an environmental impact. The roles of molybdoenzymes in bioremediation and for environmental applications are presented.
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Affiliation(s)
- Silke Leimkühler
- Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, 14476 Potsdam, Germany
| | - Chantal Iobbi-Nivol
- The Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, CNRS, Aix Marseille Université, 13402 Marseille cedex 20, France
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383
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Pimkov IV, Serli-Mitasev B, Peterson AA, Ratvasky SC, Hammann B, Basu P. Designing the Molybdopterin Core through Regioselective Coupling of Building Blocks. Chemistry 2015; 21:17057-72. [DOI: 10.1002/chem.201502845] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Indexed: 01/08/2023]
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384
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Chen QL, Zhou ZH. Interaction between molybdate and histidine and its reduction to molybdenum(V) dimer. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.06.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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385
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Okamura TA, Okamura ATA, Omi Y, Fujii M, Tatsumi M, Onitsuka K. Significant differences of monooxotungsten(IV) and dioxotungsten(VI) benzenedithiolates containing two intramolecular NHS hydrogen bonds from molybdenum analogues. Dalton Trans 2015; 44:18090-100. [PMID: 26417921 DOI: 10.1039/c5dt03278d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A monooxotungsten(iv) benzenedithiolate complex containing two intramolecular NHS hydrogen bonds, (NEt4)2[W(IV)O(1,2-S2-3-t-BuNHCOC6H3)2] (1-W), was synthesized via a ligand-exchange reaction between a new starting complex, (NEt4)2[W(IV)O(SC6F5)4], and a partially deprotonated dithiol. When dithiol was used in solution, the oxo ligand was protonated and removed to afford (NEt4)2[W(IV)(1,2-S2-3-t-BuNHCOC6H3)3]. The trans isomer, trans-1-W, was crystallized, and the molecular structure was determined via X-ray analysis. Trans-1-W was gradually isomerized by heating it in solution and it eventually achieved an approximately 1 : 1 mixture of trans/cis isomers after 48 days. However, a slightly excess amount of trans isomer remained, so the isomerization rate was considerably slower than that of the molybdenum analogue. In the presence of NEt4BH4, deuteration of the NH protons was observed in acetonitrile-d3. The oxidation of both trans- and cis-1-W by Me3NO afforded the corresponding dioxotungsten(vi) complex, (NEt4)2[W(VI)O2(1,2-S2-3-t-BuNHCOC6H3)2] (2-W), as a single isomer. The contributions of the NHS hydrogen bonds to the bond distances, vibrational data, and electrochemical properties are described via comparisons with their molybdenum analogues. The results of this comparative study yielded insights into both tungsten and molybdenum enzymes.
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Affiliation(s)
| | - A Taka-Aki Okamura
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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386
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Porcher JP, Fogeron T, Gomez-Mingot M, Derat E, Chamoreau LM, Li Y, Fontecave M. A Bioinspired Molybdenum Complex as a Catalyst for the Photo- and Electroreduction of Protons. Angew Chem Int Ed Engl 2015; 54:14090-3. [PMID: 26404460 DOI: 10.1002/anie.201505607] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 07/18/2015] [Indexed: 12/25/2022]
Abstract
A molybdenum-dithiolene-oxo complex was prepared as a model of some active sites of Mo/W-dependent enzymes. The ligand, a quinoxaline-pyran-fused dithiolene, mimics molybdopterin present in these active sites. For the first time, this type of complex was shown to be active as a catalyst for the photoreduction of protons with excellent turnover numbers (500) and good stability in aqueous/organic media and for the electroreduction of protons in acetonitrile with remarkable rate constants (1030 s(-1) at -1.3 V versus Ag/AgCl). DFT calculations provided insight into the catalytic cycle of the reaction, suggesting that the oxo ligand plays a key role in proton exchange. These results provide a basis to optimize this new class of H2 -evolving catalysts.
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Affiliation(s)
- Jean-Philippe Porcher
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
| | - Thibault Fogeron
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
| | - Maria Gomez-Mingot
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
| | - Etienne Derat
- Sorbonne Universités, UPMC Université Paris 6, Institut Parisien de Chimie Moléculaire, UMR 8232 CNRS, 4 place Jussieu, 75252 Paris Cedex 5 (France)
| | - Lise-Marie Chamoreau
- Sorbonne Universités, UPMC Université Paris 6, Institut Parisien de Chimie Moléculaire, UMR 8232 CNRS, 4 place Jussieu, 75252 Paris Cedex 5 (France)
| | - Yun Li
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France).
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France).
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387
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Oxygen reactivity of mammalian sulfite oxidase provides a concept for the treatment of sulfite oxidase deficiency. Biochem J 2015; 469:211-21. [PMID: 26171830 DOI: 10.1042/bj20140768] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mammalian sulfite oxidase (SO) is a dimeric enzyme consisting of a molybdenum cofactor- (Moco) and haem-containing domain and catalyses the oxidation of toxic sulfite to sulfate. Following sulfite oxidation, electrons are passed from Moco via the haem cofactor to cytochrome c, the terminal electron acceptor. In contrast, plant SO (PSO) lacks the haem domain and electrons shuttle from Moco to molecular oxygen. Given the high similarity between plant and mammalian SO Moco domains, factors that determine the reactivity of PSO towards oxygen, remained unknown. In the present study, we generated mammalian haem-deficient and truncated SO variants and demonstrated their oxygen reactivity by hydrogen peroxide formation and oxygen-consumption studies. We found that intramolecular electron transfer between Moco and haem showed an inverse correlation to SO oxygen reactivity. Haem-deficient SO variants exhibited oxygen-dependent sulfite oxidation similar to PSO, which was confirmed further using haem-deficient human SO in a cell-based assay. This finding suggests the possibility to use oxygen-reactive SO variants in sulfite detoxification, as the loss of SO activity is causing severe neurodegeneration. Therefore we evaluated the potential use of PEG attachment (PEGylation) as a modification method for future enzyme substitution therapies using oxygen-reactive SO variants, which might use blood-dissolved oxygen as the electron acceptor. PEGylation has been shown to increase the half-life of other therapeutic proteins. PEGylation resulted in the modification of up to eight surface-exposed lysine residues of SO, an increased conformational stability and similar kinetic properties compared with wild-type SO.
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388
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Porcher J, Fogeron T, Gomez‐Mingot M, Derat E, Chamoreau L, Li Y, Fontecave M. A Bioinspired Molybdenum Complex as a Catalyst for the Photo‐ and Electroreduction of Protons. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505607] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Jean‐Philippe Porcher
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
| | - Thibault Fogeron
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
| | - Maria Gomez‐Mingot
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
| | - Etienne Derat
- Sorbonne Universités, UPMC Université Paris 6, Institut Parisien de Chimie Moléculaire, UMR 8232 CNRS, 4 place Jussieu, 75252 Paris Cedex 5 (France)
| | - Lise‐Marie Chamoreau
- Sorbonne Universités, UPMC Université Paris 6, Institut Parisien de Chimie Moléculaire, UMR 8232 CNRS, 4 place Jussieu, 75252 Paris Cedex 5 (France)
| | - Yun Li
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05 (France)
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389
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Hu L, Chen H. Assessment of DFT Methods for Computing Activation Energies of Mo/W-Mediated Reactions. J Chem Theory Comput 2015; 11:4601-14. [DOI: 10.1021/acs.jctc.5b00373] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Lianrui Hu
- Beijing National Laboratory
for Molecular Sciences (BNLMS), CAS Key Laboratory of Photochemistry,
Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hui Chen
- Beijing National Laboratory
for Molecular Sciences (BNLMS), CAS Key Laboratory of Photochemistry,
Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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390
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Heinze K. Bioinspired functional analogs of the active site of molybdenum enzymes: Intermediates and mechanisms. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2015.04.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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391
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Structural insights into xenobiotic and inhibitor binding to human aldehyde oxidase. Nat Chem Biol 2015; 11:779-83. [DOI: 10.1038/nchembio.1895] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/13/2015] [Indexed: 12/20/2022]
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392
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Wu SY, Rothery RA, Weiner JH. Pyranopterin Coordination Controls Molybdenum Electrochemistry in Escherichia coli Nitrate Reductase. J Biol Chem 2015; 290:25164-73. [PMID: 26297003 DOI: 10.1074/jbc.m115.665422] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Indexed: 11/06/2022] Open
Abstract
We test the hypothesis that pyranopterin (PPT) coordination plays a critical role in defining molybdenum active site redox chemistry and reactivity in the mononuclear molybdoenzymes. The molybdenum atom of Escherichia coli nitrate reductase A (NarGHI) is coordinated by two PPT-dithiolene chelates that are defined as proximal and distal based on their proximity to a [4Fe-4S] cluster known as FS0. We examined variants of two sets of residues involved in PPT coordination: (i) those interacting directly or indirectly with the pyran oxygen of the bicyclic distal PPT (NarG-Ser(719), NarG-His(1163), and NarG-His(1184)); and (ii) those involved in bridging the two PPTs and stabilizing the oxidation state of the proximal PPT (NarG-His(1092) and NarG-His(1098)). A S719A variant has essentially no effect on the overall Mo(VI/IV) reduction potential, whereas the H1163A and H1184A variants elicit large effects (ΔEm values of -88 and -36 mV, respectively). Ala variants of His(1092) and His(1098) also elicit large ΔEm values of -143 and -101 mV, respectively. An Arg variant of His(1092) elicits a small ΔEm of +18 mV on the Mo(VI/IV) reduction potential. There is a linear correlation between the molybdenum Em value and both enzyme activity and the ability to support anaerobic respiratory growth on nitrate. These data support a non-innocent role for the PPT moieties in controlling active site metal redox chemistry and catalysis.
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Affiliation(s)
- Sheng-Yi Wu
- From the Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Richard A Rothery
- From the Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Joel H Weiner
- From the Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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393
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Hahn A, Engelhard C, Reschke S, Teutloff C, Bittl R, Leimkühler S, Risse T. Strukturelle Einblicke in den Mo-Cofaktor-Einbau in Sulfitoxidase durch ortsspezifische Spinmarkierung. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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394
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Hahn A, Engelhard C, Reschke S, Teutloff C, Bittl R, Leimkühler S, Risse T. Structural Insights into the Incorporation of the Mo Cofactor into Sulfite Oxidase from Site‐Directed Spin Labeling. Angew Chem Int Ed Engl 2015; 54:11865-9. [DOI: 10.1002/anie.201504772] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 06/29/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Aaron Hahn
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany)
| | | | - Stefan Reschke
- Institut für Biochemie und Biologie, Universität Potsdam, Karl‐Liebknecht‐Str. 24‐25, 14476 Golm (Germany)
| | - Christian Teutloff
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany)
- Berlin Joint EPR Laboratory Freie Universität Berlin (Germany)
| | - Robert Bittl
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany)
- Berlin Joint EPR Laboratory Freie Universität Berlin (Germany)
| | - Silke Leimkühler
- Institut für Biochemie und Biologie, Universität Potsdam, Karl‐Liebknecht‐Str. 24‐25, 14476 Golm (Germany)
| | - Thomas Risse
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany)
- Berlin Joint EPR Laboratory Freie Universität Berlin (Germany)
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395
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A New Class of Tungsten-Containing Oxidoreductase in Caldicellulosiruptor, a Genus of Plant Biomass-Degrading Thermophilic Bacteria. Appl Environ Microbiol 2015; 81:7339-47. [PMID: 26276113 DOI: 10.1128/aem.01634-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 07/30/2015] [Indexed: 12/18/2022] Open
Abstract
Caldicellulosiruptor bescii grows optimally at 78°C and is able to decompose high concentrations of lignocellulosic plant biomass without the need for thermochemical pretreatment. C. bescii ferments both C5 and C6 sugars primarily to hydrogen gas, lactate, acetate, and CO2 and is of particular interest for metabolic engineering applications given the recent availability of a genetic system. Developing optimal strains for technological use requires a detailed understanding of primary metabolism, particularly when the goal is to divert all available reductant (electrons) toward highly reduced products such as biofuels. During an analysis of the C. bescii genome sequence for oxidoreductase-type enzymes, evidence was uncovered to suggest that the primary redox metabolism of C. bescii has a completely uncharacterized aspect involving tungsten, a rarely used element in biology. An active tungsten utilization pathway in C. bescii was demonstrated by the heterologous production of a tungsten-requiring, aldehyde-oxidizing enzyme (AOR) from the hyperthermophilic archaeon Pyrococcus furiosus. Furthermore, C. bescii also contains a tungsten-based AOR-type enzyme, here termed XOR, which is phylogenetically unique, representing a completely new member of the AOR tungstoenzyme family. Moreover, in C. bescii, XOR represents ca. 2% of the cytoplasmic protein. XOR is proposed to play a key, but as yet undetermined, role in the primary redox metabolism of this cellulolytic microorganism.
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396
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Hasenaka Y, Okamura TA, Tatsumi M, Inazumi N, Onitsuka K. Behavior of anionic molybdenum(IV, VI) and tungsten(IV, VI) complexes containing bulky hydrophobic dithiolate ligands and intramolecular NH···S hydrogen bonds in nonpolar solvents. Dalton Trans 2015; 43:15491-502. [PMID: 25190301 DOI: 10.1039/c4dt01646g] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molybdenum(IV, VI) and tungsten(IV, VI) complexes, (Et4N)2[M(IV)O{1,2-S2-3,6-(RCONH)2C6H2}2] and (Et4N)2[M(VI)O2{1,2-S2-3,6-(RCONH)2C6H2}2] (M = Mo, W; R = (4-(t)BuC6H4)3C), with bulky hydrophobic dithiolate ligands containing NH···S hydrogen bonds were synthesized. These complexes are soluble in nonpolar solvents like toluene, which allows the detection of unsymmetrical coordination structures and elusive intermolecular interactions in solution. The (1)H NMR spectra of the complexes in toluene-d8 revealed an unsymmetrical coordination structure, and proximity of the counterions to the anion moiety was suggested at low temperatures. The oxygen-atom-transfer reaction between the molybdenum(IV) complex and Me3NO in toluene was considerably accelerated in nonpolar solvents, and this increase was attributed to the favorable access of the substrate to the active center in the hydrophobic environment.
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Affiliation(s)
- Yuki Hasenaka
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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397
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Doonan CJ, Gourlay C, Nielsen DJ, Ng VWL, Smith PD, Evans DJ, George GN, White JM, Young CG. d(1) Oxosulfido-Mo(V) Compounds: First Isolation and Unambiguous Characterization of an Extended Series. Inorg Chem 2015; 54:6386-96. [PMID: 26046577 DOI: 10.1021/acs.inorgchem.5b00708] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reaction of Tp(iPr)Mo(VI)OS(OAr) with cobaltocene in toluene results in the precipitation of brown, microcrystalline oxosulfido-Mo(V) compounds, [CoCp2][Tp(iPr)Mo(V)OS(OAr)] (Cp(-) = η(5)-C5H5(-), Tp(iPr)(-) = hydrotris(3-isopropylpyrazol-1-yl)borate, OAr(-) = phenolate or 2-(s)Bu, 2-(t)Bu, 3-(t)Bu, 4-(s)Bu, 4-Ph, 3,5-(s)Bu2, 2-CO2Me, 2-CO2Et or 2-CO2Ph derivative thereof). The compounds are air- and water-sensitive and display ν(Mo═O) and ν(Mo[Formula: see text]S) IR absorption bands at ca. 890 and 435 cm(-1), respectively, 20-40 cm(-1) lower in energy than the corresponding bands in Tp(iPr)MoOS(OAr). They are electrochemically active and exhibit three reversible cyclovoltammetric waves (E(Mo(VI)/Mo(V)) = -0.40 to -0.66 V, E([CoCp2](+)/CoCp2) = -0.94 V and E(CoCp2/[CoCp2](-)) = -1.88 V vs SCE). Structural characterization of [CoCp2][Tp(iPr)MoOS(OC6H4CO2Et-2)]·2CH2Cl2 revealed a distorted octahedral Mo(V) anion with Mo═O and Mo[Formula: see text]S distances of 1.761(5) and 2.215(2) Å, respectively, longer than corresponding distances in related Tp(iPr)MoOS(OAr) compounds. The observation of strong S(1s) → (S(3p) + Mo(4d)) S K-preedge transitions indicative of a d(1) sulfido-Mo(V) moiety and the presence of short Mo═O (ca. 1.72 Å) and Mo[Formula: see text]S (ca. 2.25 Å) backscattering contributions in the Mo K-edge EXAFS further support the oxosulfido-Mo(V) formulation. The compounds are EPR-active, exhibiting highly anisotropic (Δg 0.124-0.150), rhombic, frozen-glass spectra with g1 close to the value observed for the free electron (ge = 2.0023). Spectroscopic studies are consistent with the presence of a highly covalent Mo[Formula: see text]S π* singly occupied molecular orbital. The compounds are highly reactive, with reactions localized at the terminal sulfido ligand. For example, the compounds react with cyanide and PPh3 to produce thiocyanate and SPPh3, respectively, and various (depending on solvent) oxo-Mo(V) species. Reactions with copper reagents also generally lead to desulfurization and the formation of oxo-Mo(V) or -Mo(IV) complexes.
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Affiliation(s)
| | | | | | | | | | | | - Graham N George
- §Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | | | - Charles G Young
- ¶Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
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398
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Duca M, Weeks JR, Fedor JG, Weiner JH, Vincent KA. Combining Noble Metals and Enzymes for Relay Cascade Electrocatalysis of Nitrate Reduction to Ammonia at Neutral pH. ChemElectroChem 2015. [DOI: 10.1002/celc.201500166] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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399
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Majumdar A. Structural and functional models in molybdenum and tungsten bioinorganic chemistry: description of selected model complexes, present scenario and possible future scopes. Dalton Trans 2015; 43:8990-9003. [PMID: 24798698 DOI: 10.1039/c4dt00631c] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A brief description about some selected model complexes in molybdenum and tungsten bioinorganic chemistry is provided. The synthetic strategies involved and their limitations are discussed. Current status of molybdenum and tungsten bioinorganic modeling chemistry is presented briefly and synthetic problems associated therein are analyzed. Possible future directions which may expand the scope of modeling chemistry are suggested.
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Affiliation(s)
- Amit Majumdar
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
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400
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Maiti BK, Maia LB, Silveira CM, Todorovic S, Carreira C, Carepo MSP, Grazina R, Moura I, Pauleta SR, Moura JJG. Incorporation of molybdenum in rubredoxin: models for mononuclear molybdenum enzymes. J Biol Inorg Chem 2015; 20:821-9. [PMID: 25948393 DOI: 10.1007/s00775-015-1268-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/29/2015] [Indexed: 12/21/2022]
Abstract
Molybdenum is found in the active site of enzymes usually coordinated by one or two pyranopterin molecules. Here, we mimic an enzyme with a mononuclear molybdenum-bis pyranopterin center by incorporating molybdenum in rubredoxin. In the molybdenum-substituted rubredoxin, the metal ion is coordinated by four sulfurs from conserved cysteine residues of the apo-rubredoxin and two other exogenous ligands, oxygen and thiol, forming a Mo((VI))-(S-Cys)4(O)(X) complex, where X represents -OH or -SR. The rubredoxin molybdenum center is stabilized in a Mo(VI) oxidation state, but can be reduced to Mo(IV) via Mo(V) by dithionite, being a suitable model for the spectroscopic properties of resting and reduced forms of molybdenum-bis pyranopterin-containing enzymes. Preliminary experiments indicate that the molybdenum site built in rubredoxin can promote oxo transfer reactions, as exemplified with the oxidation of arsenite to arsenate.
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Affiliation(s)
- Biplab K Maiti
- UCIBIO, REQUIMTE, Departamento Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
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