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Zeitschriftenartikel zum Thema „Tungsten enzymes“

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Autor: Grafiati

Veröffentlicht am 25. Juli 2024

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1

Sevcenco, Ana-Maria, Loes E. Bevers, Martijn W. H. Pinkse, Gerard C. Krijger, Hubert T. Wolterbeek, Peter D. E. M. Verhaert, Wilfred R. Hagen und Peter-Leon Hagedoorn. „Molybdenum Incorporation in Tungsten Aldehyde Oxidoreductase Enzymes from Pyrococcus furiosus“. Journal of Bacteriology 192, Nr. 16 (18.06.2010): 4143–52. http://dx.doi.org/10.1128/jb.00270-10.

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ABSTRACT The hyperthermophilic archaeon Pyrococcus furiosus expresses five aldehyde oxidoreductase (AOR) enzymes, all containing a tungsto-bispterin cofactor. The growth of this organism is fully dependent on the presence of tungsten in the growth medium. Previous studies have suggested that molybdenum is not incorporated in the active site of these enzymes. Application of the radioisotope 99Mo in metal isotope native radioautography in gel electrophoresis (MIRAGE) technology to P. furiosus shows that molybdenum can in fact be incorporated in all five AOR enzymes. Mo(V) signals characteristic for molybdopterin were observed in formaldehyde oxidoreductase (FOR) in electron paramagnetic resonance (EPR)-monitored redox titrations. Our finding that the aldehyde oxidation activity of FOR and WOR5 (W-containing oxidoreductase 5) correlates only with the residual tungsten content suggests that the Mo-containing AORs are most likely inactive. An observed W/Mo antagonism is indicative of tungstate-dependent negative feedback of the expression of the tungstate/molybdate ABC transporter. An intracellular selection mechanism for tungstate and molybdate processing has to be present, since tungsten was found to be preferentially incorporated into the AORs even under conditions with comparable intracellular concentrations of tungstate and molybdate. Under the employed growth conditions of starch as the main carbon source in a rich medium, no tungsten- and/or molybdenum-associated proteins are detected in P. furiosus other than the high-affinity transporter, the proteins of the metallopterin insertion machinery, and the five W-AORs.

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2

Boll, Matthias, Bernhard Schink, Albrecht Messerschmidt und Peter M. H. Kroneck. „Novel bacterial molybdenum and tungsten enzymes: three-dimensional structure, spectroscopy, and reaction mechanism“. Biological Chemistry 386, Nr. 10 (01.10.2005): 999–1006. http://dx.doi.org/10.1515/bc.2005.116.

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Abstract The molybdenum enzymes 4-hydroxybenzoyl-CoA reductase and pyrogallol-phloroglucinol transhydroxylase and the tungsten enzyme acetylene hydratase catalyze reductive dehydroxylation reactions, i.e., transhydroxylation between phenolic residues and the addition of water to a triple bond. Such activities are unusual for this class of enzymes, which carry either a mononuclear Mo or W center. Crystallization and subsequent structural analysis by high-resolution X-ray crystallography has helped to resolve the reaction centers of these enzymes to a degree that allows us to understand the interaction of the enzyme and the respective substrate(s) in detail, and to develop a concept for the respective reaction mechanism, at least in two cases.

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3

Seelmann, Carola S., Max Willistein, Johann Heider und Matthias Boll. „Tungstoenzymes: Occurrence, Catalytic Diversity and Cofactor Synthesis“. Inorganics 8, Nr. 8 (31.07.2020): 44. http://dx.doi.org/10.3390/inorganics8080044.

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Tungsten is the heaviest element used in biological systems. It occurs in the active sites of several bacterial or archaeal enzymes and is ligated to an organic cofactor (metallopterin or metal binding pterin; MPT) which is referred to as tungsten cofactor (Wco). Wco-containing enzymes are found in the dimethyl sulfoxide reductase (DMSOR) and the aldehyde:ferredoxin oxidoreductase (AOR) families of MPT-containing enzymes. Some depend on Wco, such as aldehyde oxidoreductases (AORs), class II benzoyl-CoA reductases (BCRs) and acetylene hydratases (AHs), whereas others may incorporate either Wco or molybdenum cofactor (Moco), such as formate dehydrogenases, formylmethanofuran dehydrogenases or nitrate reductases. The obligately tungsten-dependent enzymes catalyze rather unusual reactions such as ones with extremely low-potential electron transfers (AOR, BCR) or an unusual hydration reaction (AH). In recent years, insights into the structure and function of many tungstoenzymes have been obtained. Though specific and unspecific ABC transporter uptake systems have been described for tungstate and molybdate, only little is known about further discriminative steps in Moco and Wco biosynthesis. In bacteria producing Moco- and Wco-containing enzymes simultaneously, paralogous isoforms of the metal insertase MoeA may be specifically involved in the molybdenum- and tungsten-insertion into MPT, and in targeting Moco or Wco to their respective apo-enzymes. Wco-containing enzymes are of emerging biotechnological interest for a number of applications such as the biocatalytic reduction of CO2, carboxylic acids and aromatic compounds, or the conversion of acetylene to acetaldehyde.

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4

Davies, E. Stephen, Georgina M. Aston, Roy L. Beddoes, David Collison, Andrew Dinsmore, Arefa Docrat, John A. Joule, Clare R. Wilson und C. David Garner. „Oxo–tungsten bis-dithiolene complexes relevant to tungsten centres in enzymes“. Journal of the Chemical Society, Dalton Transactions, Nr. 21 (1998): 3647–56. http://dx.doi.org/10.1039/a805688i.

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5

Pushie, M. Jake, und Graham N. George. „Spectroscopic studies of molybdenum and tungsten enzymes“. Coordination Chemistry Reviews 255, Nr. 9-10 (Mai 2011): 1055–84. http://dx.doi.org/10.1016/j.ccr.2011.01.056.

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6

George, G. N., Y. Gea, R. C. Prince, S. Mukund und M. W. W. Adams. „Tungsten oxo-thiolate enzymes from hyperthermophilic bacteria.“ Journal of Inorganic Biochemistry 43, Nr. 2-3 (August 1991): 241. http://dx.doi.org/10.1016/0162-0134(91)84231-w.

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7

Scott, Israel M., Gabe M. Rubinstein, Gina L. Lipscomb, Mirko Basen, Gerrit J. Schut, Amanda M. Rhaesa, W. Andrew Lancaster, Farris L. Poole, Robert M. Kelly und Michael W. W. Adams. „A New Class of Tungsten-Containing Oxidoreductase in Caldicellulosiruptor, a Genus of Plant Biomass-Degrading Thermophilic Bacteria“. Applied and Environmental Microbiology 81, Nr. 20 (14.08.2015): 7339–47. http://dx.doi.org/10.1128/aem.01634-15.

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ABSTRACTCaldicellulosiruptor besciigrows optimally at 78°C and is able to decompose high concentrations of lignocellulosic plant biomass without the need for thermochemical pretreatment.C. besciiferments both C5and C6sugars primarily to hydrogen gas, lactate, acetate, and CO2and 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 theC. besciigenome sequence for oxidoreductase-type enzymes, evidence was uncovered to suggest that the primary redox metabolism ofC. besciihas a completely uncharacterized aspect involving tungsten, a rarely used element in biology. An active tungsten utilization pathway inC. besciiwas demonstrated by the heterologous production of a tungsten-requiring, aldehyde-oxidizing enzyme (AOR) from the hyperthermophilic archaeonPyrococcus furiosus. Furthermore,C. besciialso 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, inC. 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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8

Yang, Jing, John H. Enemark und Martin L. Kirk. „Metal–Dithiolene Bonding Contributions to Pyranopterin Molybdenum Enzyme Reactivity“. Inorganics 8, Nr. 3 (05.03.2020): 19. http://dx.doi.org/10.3390/inorganics8030019.

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Here we highlight past work on metal–dithiolene interactions and how the unique electronic structure of the metal–dithiolene unit contributes to both the oxidative and reductive half reactions in pyranopterin molybdenum and tungsten enzymes. The metallodithiolene electronic structures detailed here were interrogated using multiple ground and excited state spectroscopic probes on the enzymes and their small molecule analogs. The spectroscopic results have been interpreted in the context of bonding and spectroscopic calculations, and the pseudo-Jahn–Teller effect. The dithiolene is a unique ligand with respect to its redox active nature, electronic synergy with the pyranopterin component of the molybdenum cofactor, and the ability to undergo chelate ring distortions that control covalency, reduction potential, and reactivity in pyranopterin molybdenum and tungsten enzymes.

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9

Leimkühler, Silke. „Metal-Containing Formate Dehydrogenases, a Personal View“. Molecules 28, Nr. 14 (11.07.2023): 5338. http://dx.doi.org/10.3390/molecules28145338.

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Mo/W-containing formate dehydrogenases (FDH) catalyzes the reversible oxidation of formate to carbon dioxide at their molybdenum or tungsten active sites. The metal-containing FDHs are members of the dimethylsulfoxide reductase family of mononuclear molybdenum cofactor (Moco)- or tungsten cofactor (Wco)-containing enzymes. In these enzymes, the active site in the oxidized state comprises a Mo or W atom present in the bis-Moco, which is coordinated by the two dithiolene groups from the two MGD moieties, a protein-derived SeCys or Cys, and a sixth ligand that is now accepted as being a sulfido group. SeCys-containing enzymes have a generally higher turnover number than Cys-containing enzymes. The analogous chemical properties of W and Mo, the similar active sites of W- and Mo-containing enzymes, and the fact that W can replace Mo in some enzymes have led to the conclusion that Mo- and W-containing FDHs have the same reaction mechanism. Details of the catalytic mechanism of metal-containing formate dehydrogenases are still not completely understood and have been discussed here.

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10

Brondino, Carlos D., Maria João Romão, Isabel Moura und José JG Moura. „Molybdenum and tungsten enzymes: the xanthine oxidase family“. Current Opinion in Chemical Biology 10, Nr. 2 (April 2006): 109–14. http://dx.doi.org/10.1016/j.cbpa.2006.01.034.

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11

Hagen, Wilfred R. „The Development of Tungsten Biochemistry—A Personal Recollection“. Molecules 28, Nr. 10 (11.05.2023): 4017. http://dx.doi.org/10.3390/molecules28104017.

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The development of tungsten biochemistry is sketched from the viewpoint of personal participation. Following its identification as a bio-element, a catalogue of genes, enzymes, and reactions was built up. EPR spectroscopic monitoring of redox states was, and remains, a prominent tool in attempts to understand tungstopterin-based catalysis. A paucity of pre-steady-state data remains a hindrance to overcome to this day. Tungstate transport systems have been characterized and found to be very specific for W over Mo. Additional selectivity is presented by the biosynthetic machinery for tungstopterin enzymes. Metallomics analysis of hyperthermophilic archaeon Pyrococcus furiosus indicates a comprehensive inventory of tungsten proteins.

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12

Schulzke, Carola, und Christian Fischer. „Molybdenum and tungsten oxidoreductase model chemistry“. Acta Crystallographica Section A Foundations and Advances 70, a1 (05.08.2014): C1372. http://dx.doi.org/10.1107/s2053273314086276.

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After introducing the general topic of molybdenum and tungsten dependent oxidoreductases[1] our group's strategic approaches relating to issues posed by the structures and functions of these enzymes' cofactors will be presented. Cofactor related questions will be discussed in detail which, at least to some extent, could be answered by model synthesis and crystallographic plus spectroscopic and/or electrochemical evaluation. These are in particular the influence, the type of coordination to the peptide may have on the catalytic performance, the choice of metal (molybdeum versus tungsten) in these enzymes and the respective evolutionary change in preference.[2,3] Finally some exciting and entirly unanticipated crystallographic discoveries will be presented.These are for instance unusual binding motifs, coordination polymer structures, hydrogen bonding and additional non-covalent interactions between dithiolene sulfur ligand atoms and potassium and sodium counter ions.

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13

Sohail, Muhammad, Muhammad Zeshan Ashraf, Raziya Nadeem, Shamsa Bibi, Rabia Rehman und Muhammad Adnan Iqbal. „Techniques in the synthesis of organometallic compounds of tungsten“. Reviews in Inorganic Chemistry 40, Nr. 1 (26.03.2020): 1–45. http://dx.doi.org/10.1515/revic-2019-0013.

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AbstractTungsten is an elegant substance, and its compounds have great significance because of their extensive range of applications in diverse fields such as in gas sensors, photocatalysis, lithium ion batteries, H2 production, electrochromic devices, dyed sensitized solar cells, microchip technology, and liquid crystal displays. Tungsten compounds exhibit a more efficient catalytic behavior, and tungsten-dependent enzymes generally catalyze the transfer of an oxygen atom to or from a physiological donor/acceptor with the metal center. Furthermore, tungsten has an n-type semiconductor band gap. Tungsten forms complexes by reacting with several elements such as H, C, N, O, and P as well as other numerous inorganic elements. Interestingly, all tungsten reactions occur at ambient temperature, usually with tetrahydrofuran and dichloromethane under vacuum. Tungsten has extraordinarily high-temperature properties, making it very useful for X-ray production and heating elements in furnaces. Tungsten coordinates with diverse nonmetallic elements and ligands and produces interesting compounds. This article describes an overview of the synthesis of various organometallic compounds of tungsten.

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Akbassova, A., M. Beisekova, A. Tassanbiyeva, D. Zhamshitova, A. Kurmanbayeva, S. Zhangazin, N. Moldakimova, A. Shalabayeva, Zh Masalimov und A. Akbassova. „COMBINED EFFECT OF TBSV P19 MUTANTS AND HEAVY METALS ON ANTIOXIDANT ENZYME ACTIVITY“. Eurasian Journal of Applied Biotechnology, Nr. 3 (16.10.2023): 48–59. http://dx.doi.org/10.11134/btp.3.2023.6.

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Crops of food value are often exposed to viral pathogens. Therefore, crops can noticeably decrease or die completely. For example, in 2021, the tomato brown wrinkle virus was detected in Kazakhstan, the main hosts of which are tomatoes and peppers. At the same time, in farms where the pathogen was detected, yield loss ranged from 30 to 70%. Therefore, it is important to develop methods aimed at increasing plant stress tolerance to viral infection. The scientific novelty of this manuscript is that previously the simultaneous effect of viral pathogens and heavy metals on plants has not been studied. Antioxidant enzymes play an important role in regulating the concentration of reactive oxygen species in plant cells. The enzyme catalase catalyzes the conversion of hydrogen peroxide into water and molecular oxygen, thereby neutralizing superoxide radicals. Thus, antioxidant enzymes prevent tissue damage and necrosis. Molybdenum enzymes can produce reactive oxygen species when exposed to adverse conditions, such as pathogen infestation or drought. Molybdenum is an integral part of the Moco cofactor within molybdoenzymes, but tungsten has the ability to substitute for molybdenum, resulting in a reversible loss of enzyme function. Consequently, tungsten acts as a stressor for plants. Inoculation of plants with tomato bush stunt virus of the wild type leads to their death. At the same time, when infected with TBSV 157, RMJ1 and RMJ2 mutants, the plants recovered after some time. Plants are expected to be more viable when the subject is exposed to heavy metal solutions and inoculated with viruses.

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15

Mukhamejanova, Akmaral, Zerekbay Alikulov, Bakyt Tuganova und Zhanna Adamzhanova. „The xanthine oxidase and its associated activities in the ovine milk and liver: distinctive in impact of in vivo molybdenum“. Potravinarstvo Slovak Journal of Food Sciences 15 (12.07.2021): 632–38. http://dx.doi.org/10.5219/1665.

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Xanthine oxidase is molybdenum and iron-containing flavoprotein, catalyzing the final oxidation stage of purines and oxidative transformation of pterins and some aliphatic and aromatic aldehydes. Despite the importance of this enzyme, the distribution of xanthine oxidase in traditional household animal’s milk and tissues is unknown. Formerly, we have found most of the xanthine oxidase molecules in animal milk are inactive because of a lack of molybdenum. Ovine milk was processed by inserting in vivo molybdenum (tungsten) into drinking water. We gave opposite dates in the presence of tungsten too. Heating the milk of animals at 80 °C for 5 minutes in the presence of molybdenum and cysteine led to a sharp increase of xanthine oxidase and its associated – nitrate reductase and nitrite reductase activities. The change of xanthine oxidase and its associated activities were examined by spectrophotometry after treatment. It was established that metal ions added in drinking water for animals have an impact on enzyme activities. The activity is formed in the ovine liver even in the absence of exogenous molybdenum in drinking water. The associated activities of liver enzymes in the presence of molybdenum in drinking water had slightly increased. Tungsten-containing water led to the loss of all activities of liver xanthine oxidase. It is proposed that the liver contains a special protein involving in the incorporation of molybdenum (or tungsten) into xanthine oxidase molecule, however, the milk or mammary gland compounds lack this protein.

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Romão, Maria João. „Molybdenum and tungsten enzymes: a crystallographic and mechanistic overview“. Dalton Transactions, Nr. 21 (2009): 4053. http://dx.doi.org/10.1039/b821108f.

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17

McMaster, J., und John H. Enemark. „The active sites of molybdenum- and tungsten-containing enzymes“. Current Opinion in Chemical Biology 2, Nr. 2 (April 1998): 201–7. http://dx.doi.org/10.1016/s1367-5931(98)80061-6.

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18

Cordas, Cristina M., und José J. G. Moura. „Molybdenum and tungsten enzymes redox properties – A brief overview“. Coordination Chemistry Reviews 394 (September 2019): 53–64. http://dx.doi.org/10.1016/j.ccr.2019.05.005.

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19

Boll, Matthias, Oliver Einsle, Ulrich Ermler, Peter M. H. Kroneck und G. Matthias Ullmann. „Structure and Function of the Unusual Tungsten Enzymes Acetylene Hydratase and Class II Benzoyl-Coenzyme A Reductase“. Journal of Molecular Microbiology and Biotechnology 26, Nr. 1-3 (2016): 119–37. http://dx.doi.org/10.1159/000440805.

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In biology, tungsten (W) is exclusively found in microbial enzymes bound to a bis<i>-</i>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 Hg<sup>2+</sup> (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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Roy, Roopali, Swarnalatha Mukund, Gerrit J. Schut, Dianne M. Dunn, Robert Weiss und Michael W. W. Adams. „Purification and Molecular Characterization of the Tungsten-Containing Formaldehyde Ferredoxin Oxidoreductase from the Hyperthermophilic Archaeon Pyrococcus furiosus: the Third of a Putative Five-Member Tungstoenzyme Family“. Journal of Bacteriology 181, Nr. 4 (15.02.1999): 1171–80. http://dx.doi.org/10.1128/jb.181.4.1171-1180.1999.

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ABSTRACT Pyrococcus furiosus is a hyperthermophilic archaeon which grows optimally near 100°C by fermenting peptides and sugars to produce organic acids, CO2, and H2. Its growth requires tungsten, and two different tungsten-containing enzymes, aldehyde ferredoxin oxidoreductase (AOR) and glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR), have been previously purified from P. furiosus. These two enzymes are thought to function in the metabolism of peptides and carbohydrates, respectively. A third type of tungsten-containing enzyme, formaldehyde ferredoxin oxidoreductase (FOR), has now been characterized. FOR is a homotetramer with a mass of 280 kDa and contains approximately 1 W atom, 4 Fe atoms, and 1 Ca atom per subunit, together with a pterin cofactor. The low recovery of FOR activity during purification was attributed to loss of sulfide, since the purified enzyme was activated up to fivefold by treatment with sulfide (HS−) under reducing conditions. FOR usesP. furiosus ferredoxin as an electron acceptor (Km = 100 μM) and oxidizes a range of aldehydes. Formaldehyde (Km = 15 mM for the sulfide-activated enzyme) was used in routine assays, but the physiological substrate is thought to be an aliphatic C5semi- or dialdehyde, e.g., glutaric dialdehyde (Km = 1 mM). Based on its amino-terminal sequence, the gene encoding FOR (for) was identified in the genomic database, together with those encoding AOR and GAPOR. The amino acid sequence of FOR corresponded to a mass of 68.7 kDa and is highly similar to those of the subunits of AOR (61% similarity and 40% identity) and GAPOR (50% similarity and 23% identity). The three genes are not linked on the P. furiosuschromosome. Two additional (and nonlinked) genes (termedwor4 and wor5) that encode putative tungstoenzymes with 57% (WOR4) and 56% (WOR5) sequence similarity to FOR were also identified. Based on sequence motif similarities with FOR, both WOR4 and WOR5 are also proposed to contain a tungstobispterin site and one [4Fe-4S] cluster per subunit.

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Yergaliev, T. „Molybdenum and plant resistance to viral infection“. BULLETIN of the L.N. Gumilyov Eurasian National University. BIOSCIENCE Series 135, Nr. 2 (2021): 63–70. http://dx.doi.org/10.32523/2616-7034-2021-135-2-63-70.

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Molybdenum takes an active part in several physiological processes necessary for the growth and development of plants and other domains of life. Molybdenum participates in numerous biochemical reactions and lack of this metal may affect the total amount of proteins in plants. More than fifty Mo-containing enzymes are currently known, although most of them were found in bacteria. Plants contain Mo-containing enzymes such as nitrate reductase, sulfite oxidase, aldehyde oxidase, xanthine dehydrogenase, and mitochondrial amidoxime reductase. Tungsten is another heavy metal, which due to highly similar physico-chemical properties with Molybdenum may be incorporated instead of the latest as enzyme cofactor, leading to its inactivation. In this article, preliminary results from a pilot experiment are shown, demonstrating the effect of Molybdenum and Tungsten treatment on Nicotiana benthamiana plants infected with Tomato Bushy Stunt Virus, which refers to viruses parasitizing economically important crops. This virus infects more than 100 species of monocotyledonous and dicotyledonous plants from more than 20 different families. Infection of plants with a viral infection occurs through mechanical damage to the root system; virions in this case can be transmitted through soil or water. It was found that Molybdenum treatment may lead to mitigation of otherwise fatal for the host viral infection.

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Moura, José J. G., Paul V. Bernhardt, Luísa B. Maia und Pablo J. Gonzalez. „Molybdenum and tungsten enzymes: from biology to chemistry and back“. JBIC Journal of Biological Inorganic Chemistry 20, Nr. 2 (11.02.2015): 181–82. http://dx.doi.org/10.1007/s00775-015-1243-9.

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23

Rothery, R. A., B. Stein, M. Solomonson, M. L. Kirk und J. H. Weiner. „Pyranopterin conformation defines the function of molybdenum and tungsten enzymes“. Proceedings of the National Academy of Sciences 109, Nr. 37 (27.08.2012): 14773–78. http://dx.doi.org/10.1073/pnas.1200671109.

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24

Roy, Roopali, und Michael W. W. Adams. „Characterization of a Fourth Tungsten-Containing Enzyme from the Hyperthermophilic Archaeon Pyrococcus furiosus“. Journal of Bacteriology 184, Nr. 24 (15.12.2002): 6952–56. http://dx.doi.org/10.1128/jb.184.24.6952-6956.2002.

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ABSTRACT Pyrococcus furiosus grows optimally near 100°C using peptides and carbohydrates as carbon sources, and it reduces elemental sulfur (S0), if present, to H2S. Tungsten (W), an element rarely used in biology, is required for optimal growth, and three different tungsten-containing enzymes have been previously purified from this organism. They all oxidize aldehydes of various types and are thought to play primary roles in the catabolism of sugars or amino acids. Here, the purification of a fourth tungsten-containing enzyme, termed WOR 4, from cell extracts of P. furiosus grown with S0 is described. This was achieved by monitoring through multiple chromatography steps the W that is not associated with the three characterized tungstoenzymes. The N-terminal sequence of WOR 4 and the approximate molecular weight of its subunit determined electrophoretically (69,000) correspond to the product of an ORF (PF1961, wor4) present in the complete genome sequence of P. furiosus. WOR 4 is a homodimer and contains approximately one W, three Fe, three or four acid-labile sulfide, and one Ca atom per subunit. The visible and electron paramagnetic resonance spectra of the oxidized and reduced enzyme indicate the presence of an unusual iron-sulfur chromophore. WOR 4 does not oxidize aliphatic or aromatic aldehydes or hydroxy acids, nor does it reduce keto acids. Consistent with prior microarray data, the protein could not be purified from P. furiosus cells grown in the absence of S0, suggesting that it may have a role in S0 metabolism.

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Grant, MP, CR VanderSchee, H. Chou, A. Bolt, LM Epure, D. Kuter, J. Antoniou, S. Bohle, KK Mann und F. Mwale. „Tungsten accumulates in the intervertebral disc and vertebrae stimulating disc degeneration and upregulating markers of inflammation and pain“. European Cells and Materials 41 (17.05.2021): 517–30. http://dx.doi.org/10.22203/ecm.v041a33.

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Tungsten is incorporated in many industrial goods, military applications and medical devices due to its ability to impart flexibility, strength and conductance to materials. Emerging evidence has questioned the safety of tungsten exposure as studies have demonstrated it can promote tumour formation, induce pulmonary disease and alter immune function. Although tungsten is excreted from the body it can accumulate in certain organs such as the brain, colon, liver, kidneys, spleen and bones, where most of the bioaccumulation occurs. Whether prolonged tungsten exposure leads to accumulation in other tissues is unknown. The present study demonstrated that mice exposed to 15 ppm sodium tungstate for 4 weeks in their drinking water showed comparable accumulation in both the bony vertebrae and intervertebral discs (IVDs). Lumbar IVD height was significantly reduced in tungsten-exposed mice and accompanied by decreased proteoglycan content and increased fibrosis. In addition to catabolic enzymes, tungsten also increased the expression of the inflammatory cytokines IL-1β and tumour necrosis factor (TNF)-α as well as the neurotrophic factors nerve growth factor (NGF) and brain-derived nerve factor (BDNF) in IVD cells. Tungsten significantly increased the presence of nociceptive neurons at the endplates of IVDs as observed by the expression of calcitonin gene-related peptide (CGRP) and anti-protein gene product 9.5 (PGP9.5) in endplate vessels. The present study provided evidence that tungsten may enhance disc degeneration and fibrosis as well as increase the expression of markers for pain. Therefore, tungsten toxicity may play a role in disc degeneration disease.

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Burgmayer, Sharon J. Nieter, und Martin L. Kirk. „Advancing Our Understanding of Pyranopterin-Dithiolene Contributions to Moco Enzyme Catalysis“. Molecules 28, Nr. 22 (07.11.2023): 7456. http://dx.doi.org/10.3390/molecules28227456.

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The pyranopterin dithiolene ligand is remarkable in terms of its geometric and electronic structure and is uniquely found in mononuclear molybdenum and tungsten enzymes. The pyranopterin dithiolene is found coordinated to the metal ion, deeply buried within the protein, and non-covalently attached to the protein via an extensive hydrogen bonding network that is enzyme-specific. However, the function of pyranopterin dithiolene in enzymatic catalysis has been difficult to determine. This focused account aims to provide an overview of what has been learned from the study of pyranopterin dithiolene model complexes of molybdenum and how these results relate to the enzyme systems. This work begins with a summary of what is known about the pyranopterin dithiolene ligand in the enzymes. We then introduce the development of inorganic small molecule complexes that model aspects of a coordinated pyranopterin dithiolene and discuss the results of detailed physical studies of the models by electronic absorption, resonance Raman, X-ray absorption and NMR spectroscopies, cyclic voltammetry, X-ray crystallography, and chemical reactivity.

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Young, Charles G., und Anthony G. Wedd. „Metal chemistry relevant to the mononuclear molybdenum and tungsten pterin enzymes“. Chemical Communications, Nr. 14 (1997): 1251–57. http://dx.doi.org/10.1039/a606660g.

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28

ENEMARK, J. H., und C. G. YOUNG. „ChemInform Abstract: Bioinorganic Chemistry of Pterin-Containing Molybdenum and Tungsten Enzymes.“ ChemInform 25, Nr. 43 (18.08.2010): no. http://dx.doi.org/10.1002/chin.199443309.

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29

Sihombing, Victor H., und Abd Hakim S. „The Use of Tungsten in Potentiometry to Detect Pospat Baffer and Urease Enzyme“. Jurnal Penelitian Pendidikan IPA 7, Nr. 3 (26.05.2021): 325. http://dx.doi.org/10.29303/jppipa.v7i3.699.

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This study aims to characterize phosphate buffer and urease enzymes through the absorbance spectrum of UV-Vis and FTIR using tungsten as the indicator electrode. The method used in this research is the biosensor potentiometric method carried out in the Laboratory of the Faculty of Mathematics and Natural Sciences, State University of Medan and the Beacukai Belawan Medan laboratory. The absorbance characterization of electrolyte solutions in various compositions using UV-Vis showed that phosphate buffer solution 0.001 M pH 7.5+KCl 0.001 M + urea 0.001 M+3 drops urease enzyme had the highest absorbance compared to electrolyte solutions with phosphate buffer and urea content. Likewise, the FTIR results showed the same thing where phosphate buffer solution was 0.001 M pH 7.5 + KCl 0.001 M + urea 0.001 M + 3 drops urease enzyme had the highest% T (transmission) pattern of phosphate buffer solution and urea. The urease enzyme in this study functions as a catalyst. Based on UV-Vis and FTIR characterization, it was concluded that the phosphate buffer solution of 0.001 M pH 7.5+KCl 0.001 M + urea 0.001 M + 3 drops of urease enzyme was the best.

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Sugimoto, Hideki, und Kunihisa Sugimoto. „New bis(pyranodithiolene) tungsten(IV) and (VI) complexes as chemical analogues of the active sites of tungsten enzymes“. Inorganic Chemistry Communications 11, Nr. 1 (Januar 2008): 77–80. http://dx.doi.org/10.1016/j.inoche.2007.10.020.

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31

S, Abd Hakim. „Characterization of PVA-Enzyme Coated Indicator Electrodes GA coated again with PVC-KTpClPB-o-NPOE UV-Vis analysis, variable signal analysis, sensor sensitivity and SEM-EDS“. Jurnal Penelitian Pendidikan IPA 7, SpecialIssue (26.12.2021): 370–76. http://dx.doi.org/10.29303/jppipa.v7ispecialissue.1248.

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This study aims to characterize the phosphate buffer and urease enzymes through UV-Vis and SEM-EDS absorbance spectra using tungsten as an indicator electrode. The method used is a potentiometric biosensor with urease enzyme immobilization technique for urea analyte. A small detection range of 10-5-10-4M has been studied with PVA-enzyme coated indicator electrodes coated with PVC-KTpClPB. On this basis, the researchers increased the detection range by analyzing glutaraldehyde (GA) mixed with PVA-enzyme and o-NPOE mixed with PVC-KTpClPB. The best results of GA mixed PVA-enzyme at GA2.9% UV-Visible analysis. The best results were PVA-enzyme coated indicator electrodes coated with GA coated again with PVC-KTpClPB-o-NPOE SEM-EDS analysis on PVA-enzyme samples 3x coated with GA 1x and PVC-KTpClPB-o-NPOE 1x with o-NPOE variation of 61% and 66%.

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Fogeron, Thibault, Yun Li und Marc Fontecave. „Formate Dehydrogenase Mimics as Catalysts for Carbon Dioxide Reduction“. Molecules 27, Nr. 18 (14.09.2022): 5989. http://dx.doi.org/10.3390/molecules27185989.

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Formate dehydrogenases (FDH) reversibly catalyze the interconversion of CO2 to formate. They belong to the family of molybdenum and tungsten-dependent oxidoreductases. For several decades, scientists have been synthesizing structural and functional model complexes inspired by these enzymes. These studies not only allow for finding certain efficient catalysts but also in some cases to better understand the functioning of the enzymes. However, FDH models for catalytic CO2 reduction are less studied compared to the oxygen atom transfer (OAT) reaction. Herein, we present recent results of structural and functional models of FDH.

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Sosorova, S. B., I. N. Lavrent’eva, L. N. Boloneva, V. L. Ubugunov und E. G. Tsyrempilov. „Enzymative Activity of Soils in the Activity Territory of the Dzhida Tungsten-Molybdenum Combine (Western Zabaikalie)“. Ecology and Industry of Russia 25, Nr. 7 (20.07.2021): 48–53. http://dx.doi.org/10.18412/1816-0395-2021-7-48-53.

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The enzymatic activity (catalase, cellulase) of soils and technogenic sand on the territory of the former Dzhida tungsten-molybdenum combine (Western Transbaikalia) was studied. The objects of the study were the surface 0-10 cm layers of alluvial dark humus soil (Fluvisols) as a background, man-made sand (waste after mining and processing of tungsten and molybdenum ores) and soils of recultivated contours № 1, 3, 4. At the same depth, linen cloths were laid to assess the activity of cellulase. Differences in the activity of soil enzymes of the background soil and soils on the studied contours were established, depending on the level of heavy metals content in them and the technologies used for reclamation.

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Stiefel, E. I. „Transition metal sulfur chemistry and its relvance to molybdenum and tungsten enzymes“. Journal of Inorganic Biochemistry 67, Nr. 1-4 (Juli 1997): 8. http://dx.doi.org/10.1016/s0162-0134(97)89891-1.

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35

Majumdar, Amit, und Sabyasachi Sarkar. „Bioinorganic chemistry of molybdenum and tungsten enzymes: A structural–functional modeling approach“. Coordination Chemistry Reviews 255, Nr. 9-10 (Mai 2011): 1039–54. http://dx.doi.org/10.1016/j.ccr.2010.11.027.

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36

Stiefel, E. I. „Transition metal sulfur chemistry and its relevance to molybdenum and tungsten enzymes“. Pure and Applied Chemistry 70, Nr. 4 (01.01.1998): 889–96. http://dx.doi.org/10.1351/pac199870040889.

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37

Serikovna, Tokasheva Dana, Akbassova Alya Zholdasbayevna und Omarov Rustem Tukenovich. „Molybdenum and tungsten stimulate immune responses under biotic stress in Nicotiana abenthamiana infected with tomato bushy stunt virus“. International Journal of Innovative Research and Scientific Studies 7, Nr. 1 (23.01.2024): 261–70. http://dx.doi.org/10.53894/ijirss.v7i1.2616.

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The present research examines how molybdenum and tungsten stimulate immune responses under biotic stress in Nicotiana abenthamiana. Plants are subjected to a wide range of environmental stressors that reduce and limit crop productivity. The primary response to any stress type is the production of reactive oxygen species (ROS) that cause oxidative stress, whose elimination by molybdoenzymes plays an active role. However, in the case of a molybdenum shortage in the soil or substrate, tungsten replaces molybdenum in the active centre of enzymes. Our study demonstrates the potential use of tungsten (W) and molybdenum (Mo) to stimulate the immune response of Nicotiana abenthamiana plants when interacting with Tomato bushy stunt virus (TBSV). The results indicate that the use of Mo and W metal salts activates the antioxidant system, particularly aldehyde oxidase (AO). Seed priming in metal solutions resulted in the appearance of the additional AO isoform. Furthermore, root length was high in the 1 mM Mo+W solution (4.05 cm, compared to 2.03 cm in the control). And seedling biomasses were significantly higher in infected plants in molybdenum and tungsten solutions at concentrations of 1 mM, 8.5 and 8.8 g, and about 7.6 g in control. The incubation of infected N. benthamiana plants in a solution of tungsten increased their resistance to TBSV. This is shown by a low level of accumulation of hydrogen peroxide (0.014), which is 23% less than the control infected plant. These results suggest the involvement of Mo and W in the mechanisms of resistance against viral infection and stimulation of the immune response of plants to biotic stress.

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38

Park, Myong-Ok, Taeko Mizutani und Patrik R. Jones. „Glyceraldehyde-3-Phosphate Ferredoxin Oxidoreductase from Methanococcus maripaludis“. Journal of Bacteriology 189, Nr. 20 (17.08.2007): 7281–89. http://dx.doi.org/10.1128/jb.00828-07.

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ABSTRACT The genome sequence of the non-sugar-assimilating mesophile Methanococcus maripaludis contains three genes encoding enzymes: a nonphosphorylating NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPN), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR); all these enzymes are potentially capable of catalyzing glyceraldehyde-3-phosphate (G3P) metabolism. GAPOR, whose homologs have been found mainly in archaea, catalyzes the reduction of ferredoxin coupled with oxidation of G3P. GAPOR has previously been isolated and characterized only from a sugar-assimilating hyperthermophile, Pyrococcus furiosus (GAPORPf), and contains the rare metal tungsten as an irreplaceable cofactor. Active recombinant M. maripaludis GAPOR (GAPORMm) was purified from Escherichia coli grown in minimal medium containing 100 μM sodium molybdate. In contrast, GAPORMm obtained from cells grown in medium containing tungsten (W) and W and molybdenum (Mo) or in medium without added W and Mo did not display any activity. Activity and transcript analysis of putative G3P-metabolizing enzymes and corresponding genes were performed with M. maripaludis cultured under autotrophic conditions in chemically defined medium. The activity of GAPORMm was constitutive throughout the culture period and exceeded that of GAPDH at all time points. As GAPDH activity was detected in only the gluconeogenic direction and GAPN activity was completely absent, only GAPORMm catalyzes oxidation of G3P in M. maripaludis. Recombinant GAPORMm is posttranscriptionally regulated as it exhibits pronounced and irreversible substrate inhibition and is completely inhibited by 1 μM ATP. With support from flux balance analysis, it is concluded that the major physiological role of GAPORMm in M. maripaludis most likely involves only nonoptimal growth conditions.

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Joshi, H. K., J. J. A. Cooney, F. E. Inscore, N. E. Gruhn, D. L. Lichtenberger und J. H. Enemark. „Investigation of metal-dithiolate fold angle effects: Implications for molybdenum and tungsten enzymes“. Proceedings of the National Academy of Sciences 100, Nr. 7 (24.03.2003): 3719–24. http://dx.doi.org/10.1073/pnas.0636832100.

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40

YOUNG, C. G., und A. G. WEDD. „ChemInform Abstract: Metal Chemistry Relevant to the Mononuclear Molybdenum and Tungsten Pterin Enzymes“. ChemInform 28, Nr. 42 (03.08.2010): no. http://dx.doi.org/10.1002/chin.199742321.

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41

Tokasheva, D. S., M. K. Beisekova, K. E. Zhanassova, Zh B. Tleukulova, A. Zh Akbasova und R. T. Omarov. „Influence of various molybdenum, tungsten, and molybdenum with tungsten concentrations to the growth of Nicotiana Benthamiana“. BULLETIN of the L.N. Gumilyov Eurasian National University. BIOSCIENCE Series 137, Nr. 4 (2021): 84–91. http://dx.doi.org/10.32523/2616-7034-2021-137-4-84-91.

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Molybdenum is a key microelement in plant functioning, as it takes part in oxidation-reduction reaction of nitrogen and sulphuric exchange, plant hormone biosynthesis, and xenobiotic detoxication. Molybdenum deficiency is widely spread among pulses and some vegetable crops, which are intensively irrigated, or which grow in acid or sandy soils. Plant cells can absorb molybdenum in the form of molybdate oxyanion. Even though molybdenum is available for a cell, it is biologically inactive element until there is a formed complex of molybdenum co-factor (Moco). Moco is situated in the active center of molybdenum ferments, which are used as short bonds of electron passage and take part in nitrogen and sulfur metabolism, hormone biosynthesis, and plant harmful bond detoxification. There are known four molybdenum ferments of higher plants such as nitrate reductase (NR), xanthine dehydrogenase (XDH), aldehyde oxidase (AO), and sulfite oxidase (SO). Tungsten (T) is molybdenum antagonist. It pushes molybdenum out of mobdoenzymes, as a result molybdenum-containing enzymes become inactive. Molybdenum is a vital element which is in minimal qualities required for plant growth and development. On the other hand, huge amount of Molybdenum is toxic, and its complete absence is lethal for the plant organism. As a result, the search for the perfect molybdenum concentration for the growth and development plays an important role in agriculture. Nicotiana Benthamiana, or Australian tobacco was used as a model plant, it is nightshade family (Solanaceae). The article presents sodium molybdate (Na2MoO4•2H2O), sodium wolframate (Na2WO4•2H2O), and molybdate with wolframate influence to germinating capacity and length of Nicotiana Benthamiana plantlets.

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42

Sugimoto, Hideki, Hiroyuki Tano, Reiko Tajima, Hiroyuki Miyake, Hiroshi Tsukube, Hiromi Ohi und Shinobu Itoh. „In Situ Generation of Oxo−sulfidobis(dithiolene)tungsten(VI) Complexes: Active-Site Models for the Aldehyde Ferredoxin Oxidoreductase Family of Tungsten Enzymes“. Inorganic Chemistry 46, Nr. 21 (Oktober 2007): 8460–62. http://dx.doi.org/10.1021/ic7012733.

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43

Huwiler, Simona G., Claudia Löffler, Sebastian E. L. Anselmann, Hans-Joachim Stärk, Martin von Bergen, Jennifer Flechsler, Reinhard Rachel und Matthias Boll. „One-megadalton metalloenzyme complex inGeobacter metallireducensinvolved in benzene ring reduction beyond the biological redox window“. Proceedings of the National Academy of Sciences 116, Nr. 6 (23.01.2019): 2259–64. http://dx.doi.org/10.1073/pnas.1819636116.

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Reversible biological electron transfer usually occurs between redox couples at standard redox potentials ranging from +0.8 to −0.5 V. Dearomatizing benzoyl-CoA reductases (BCRs), key enzymes of the globally relevant microbial degradation of aromatic compounds at anoxic sites, catalyze a biological Birch reduction beyond the negative limit of this redox window. The structurally characterized BamBC subunits of class II BCRs accomplish benzene ring reduction at an active-site tungsten cofactor; however, the mechanism and components involved in the energetic coupling of endergonic benzene ring reduction have remained hypothetical. We present a 1-MDa, membrane-associated, Bam[(BC)2DEFGHI]2complex from the anaerobic bacteriumGeobacter metallireducensharboring 4 tungsten, 4 zinc, 2 selenocysteines, 6 FAD, and >50 FeS cofactors. The results suggest that class II BCRs catalyze electron transfer to the aromatic ring, yielding a cyclic 1,5-dienoyl-CoA via two flavin-based electron bifurcation events. This work expands our knowledge of energetic couplings in biology by high-molecular-mass electron bifurcating machineries.

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44

Burgmayer, Sharon. „Making Moco: A Personal History“. Molecules 28, Nr. 21 (27.10.2023): 7296. http://dx.doi.org/10.3390/molecules28217296.

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This contribution describes the path of my nearly forty-year quest to understand the special ligand coordinated to molybdenum and tungsten ions in their respective enzymes. Through this quest, I aimed to discover why nature did not simply use a methyl group on the dithiolene that chelates Mo and W but instead chose a complicated pyranopterin. My journey sought answers through the synthesis of model Mo compounds that allowed systematic investigations of the interactions between molybdenum and pterin and molybdenum and pterin-dithiolene and revealed special features of the pyranopterin dithiolene chelate bound to molybdenum.

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Maia, Luisa B. „Bringing Nitric Oxide to the Molybdenum World—A Personal Perspective“. Molecules 28, Nr. 15 (02.08.2023): 5819. http://dx.doi.org/10.3390/molecules28155819.

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Molybdenum-containing enzymes of the xanthine oxidase (XO) family are well known to catalyse oxygen atom transfer reactions, with the great majority of the characterised enzymes catalysing the insertion of an oxygen atom into the substrate. Although some family members are known to catalyse the “reverse” reaction, the capability to abstract an oxygen atom from the substrate molecule is not generally recognised for these enzymes. Hence, it was with surprise and scepticism that the “molybdenum community” noticed the reports on the mammalian XO capability to catalyse the oxygen atom abstraction of nitrite to form nitric oxide (NO). The lack of precedent for a molybdenum- (or tungsten) containing nitrite reductase on the nitrogen biogeochemical cycle contributed also to the scepticism. It took several kinetic, spectroscopic and mechanistic studies on enzymes of the XO family and also of sulfite oxidase and DMSO reductase families to finally have wide recognition of the molybdoenzymes’ ability to form NO from nitrite. Herein, integrated in a collection of “personal views” edited by Professor Ralf Mendel, is an overview of my personal journey on the XO and aldehyde oxidase-catalysed nitrite reduction to NO. The main research findings and the path followed to establish XO and AO as competent nitrite reductases are reviewed. The evidence suggesting that these enzymes are probable players of the mammalian NO metabolism is also discussed.

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Holm, Richard H., Edward I. Solomon, Amit Majumdar und Adam Tenderholt. „Comparative molecular chemistry of molybdenum and tungsten and its relation to hydroxylase and oxotransferase enzymes“. Coordination Chemistry Reviews 255, Nr. 9-10 (Mai 2011): 993–1015. http://dx.doi.org/10.1016/j.ccr.2010.10.017.

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47

Sugimoto, Hideki. „Chemistry of Synthetic Models Relevant to the Active Sites of Molybdenum and Tungsten Containing Enzymes“. Bulletin of Japan Society of Coordination Chemistry 50 (2007): 26–39. http://dx.doi.org/10.4019/bjscc.50.26.

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48

Permyakov, Eugene A. „Metal Binding Proteins“. Encyclopedia 1, Nr. 1 (15.03.2021): 261–92. http://dx.doi.org/10.3390/encyclopedia1010024.

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Metal ions play several major roles in proteins: structural, regulatory, and enzymatic. The binding of some metal ions increase stability of proteins or protein domains. Some metal ions can regulate various cell processes being first, second, or third messengers. Some metal ions, especially transition metal ions, take part in catalysis in many enzymes. From ten to twelve metals are vitally important for activity of living organisms: sodium, potassium, magnesium, calcium, manganese, iron, cobalt, zinc, nickel, vanadium, molybdenum, and tungsten. This short review is devoted to structural, physical, chemical, and physiological properties of proteins, which specifically bind these metal cations.

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Hochheimer, Andreas, Ruth A. Schmitz, Rudolf K. Thauer und Reiner Hedderich. „The Tungsten Formylmethanofuran Dehydrogenase from Methanobacterium Thermoautotrophicum Contains Sequence Motifs Characteristic for Enzymes Containing Molybdopterin Dinucleotide“. European Journal of Biochemistry 234, Nr. 3 (Dezember 1995): 910–20. http://dx.doi.org/10.1111/j.1432-1033.1995.910_a.x.

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Sugimoto, Hideki, Kohei Hatakeda, Kazuo Toyota, Susumu Tatemoto, Minoru Kubo, Takashi Ogura und Shinobu Itoh. „A new series of bis(ene-1,2-dithiolato)tungsten(iv), -(v), -(vi) complexes as reaction centre models of tungsten enzymes: Preparation, crystal structures and spectroscopic properties“. Dalton Trans. 42, Nr. 9 (2013): 3059–70. http://dx.doi.org/10.1039/c2dt32179c.

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