The Coordination and Bioinorganic Chemistry of Molybdenum
09 Mar 2007-pp 1-223
About: The article was published on 2007-03-09. It has received 78 citations till now. The article focuses on the topics: Bioorganometallic chemistry & Bioinorganic chemistry.
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TL;DR: The 2011 WHO Guidelines for Drinking-Water Quality (fourth edition) advised a health-based value of 70μg/L for Mo but this is no longer promulgated as a formal guideline value as WHO consider such concentrations to be rarely found in drinking water as discussed by the authors.
196 citations
TL;DR: An overview of the current state of our understanding of the molybdenum-containing enzyme xanthine oxidoreductase is presented, with an emphasis on work done in the past five years.
Abstract: An overview of the current state of our understanding of the reaction mechanism of the molybdenum-containing enzyme xanthine oxidoreductase is presented, with an emphasis on work done in the past five years Recent studies of the biosynthesis of the pterin cofactor bound to the metal in the active site are also reviewed, as is crystallographic work that has clarified the coordination geometry of the molybdenum center This structural work provides the context in which to understand recent mechanistic studies of the enzyme, in particular those aimed at elucidating the role of specific amino acid residues in the active site of the enzyme(© Wiley-VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2006)
119 citations
TL;DR: In this article, synthetic aspects of molybdenum sulfide-based materials were reviewed, with emphasis on the catalytic materials, and a number of preparation methods were critically compared, including molecular precursor decomposition, hydrothermal, soft chemistry aqueous, surfactant-aided, intercalation-exfoliation, and solid gas reactions.
114 citations
TL;DR: The ability of Desulfovibrio desulfuricans formate dehydrogenase (DdFDH) to reduce carbon dioxide was kinetically and mechanistically characterized and a kinetic model of a hysteretic enzyme is proposed to interpret and predict the progress curves of the Dd FDH-catalyzed reactions.
Abstract: Carbon dioxide accumulation is a major concern for the ecosystems, but its abundance and low cost make it an interesting source for the production of chemical feedstocks and fuels. However, the thermodynamic and kinetic stability of the carbon dioxide molecule makes its activation a challenging task. Studying the chemistry used by nature to functionalize carbon dioxide should be helpful for the development of new efficient (bio)catalysts for atmospheric carbon dioxide utilization. In this work, the ability of Desulfovibrio desulfuricans formate dehydrogenase (Dd FDH) to reduce carbon dioxide was kinetically and mechanistically characterized. The Dd FDH is suggested to be purified in an inactive form that has to be activated through a reduction-dependent mechanism. A kinetic model of a hysteretic enzyme is proposed to interpret and predict the progress curves of the Dd FDH-catalyzed reactions (initial lag phase and subsequent faster phase). Once activated, Dd FDH is able to efficiently catalyze, not only t...
103 citations
TL;DR: The mesoporous molecular sieve MCM-41 was covalently grafted with 3-aminopropyl trimethoxysilane (AmpMCM41) in this article.
Abstract: The mesoporous molecular sieve MCM-41 was covalently grafted with 3-aminopropyl trimethoxysilane to give aminopropyl modified MCM-41 (AmpMCM-41). Reaction of this material with furfural, pyrrolcarbaldehyde, 2-acetylpyrrol, 2-aminoacetophenone, salicylaldehyde and acetylacetone afforded the corresponding supported Schiff base ligands. Subsequent reaction with bis(acetylacetonato)dioxomolybdenum(VI) leads to various molybdenum complexes supported on MCM-41 through propyl chain spacer. Characterization of these materials was carried out with FT-IR, atomic absorption spectroscopy, powder X-ray diffraction (XRD) and BET nitrogen adsorption–desorption methods. The XRD and BET analyses revealed that textural properties of support were preserved during the grafting experiments. The resultant materials successfully catalyzed the epoxidation of cyclooctene, cyclohexene, 1-hexene and 1-octene with tert -butyl hydroperoxide (TBHP) to the corresponding epoxides with 98–100% selectivities.
92 citations
References
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TL;DR: A systematic analysis of the influence of a series of inhibitors on the reduction of various electron acceptors by the enzyme in the presence of its substrates permits an estimate of the minimal number of sites of electron egress from xanthine oxidase.
186 citations
TL;DR: An active Neurospora-like assimilatory NADPH-nitrate reductase (EC 1.6.2) and several molybdenum-amino-acid complexes, as possible catalytic models of nitrogenase, were inactive (as were some previously tested 20 nonmolyb denum enzymes) in place of the acid-treated molyB denum-containing enzymes.
Abstract: An active Neurospora-like assimilatory NADPH-nitrate reductase (EC 1.6.6.2), which can be formed in vitro by incubation of extracts of nitrate-induced Neurospora crassa mutant nit-1 with extracts of (a) certain other nonallelic nitrate reductase mutants, (b) uninduced wild type, or (c) xanthine oxidizing and liver aldehyde-oxidase systems was also formed by combination of the nit-1 extract with other acid-treated enzymes known to contain molybdenum. These molybdenum enzymes included (a) nitrogenase, or its molybdenum-iron protein, from Clostridium, Azotobacter, and soybeannodule bacteroids, (b) bovine liver sulfite oxidase, (c) respiratory formate-nitrate reductase from Escherichia coli, (d) NADH-nitrate reductase from foxtail grass (Setaria faberii), and (e) FADH2- and reduced methyl viologennitrate reductase preparations from certain Neurospora mutants. Several molybdenum-amino-acid complexes, as possible catalytic models of nitrogenase, were inactive (as were some previously tested 20 nonmolybdenum enzymes) in place of the acid-treated molybdenum-containing enzymes. The results imply the existence of a molybdenum-containing component shared by the known molybdenum-enzymes.
184 citations
TL;DR: Nitrogen fixation, measured by the reduction of acetylene to ethylene, was found in workers of the dry-wood termite Kalotermes minor, and the soldiers and reproductive castes fixed little or no nitrogen.
Abstract: Nitrogen fixation, measured by the reduction of acetylene to ethylene, was found in workers of the dry-wood termite Kalotermes minor. The soldiers and reproductive castes fixed little or no nitrogen. The fixation rates ranged between 24 and 566 micrograms of nitrogen fixed per month per gram (wet weight) of termite. Nitrogen fixation can be a significant source of nitrogen for these termites.
183 citations
TL;DR: This review of the present situation of glutathione ends with some suggestions for the future.
Abstract: Glutathione plays many parts in living organisms, and new methods for the oxidation of this tripeptide reveal some of them This review of the present situation ends with some suggestions for the future
183 citations
TL;DR: Deficiency of sulfite oxidase, which has not apparently been described in man, provides a reasonable explanation for the abnormalities in this infant.
Abstract: An infant who died with neurological abnormalities, mental retardation, and dislocated ocular lenses excreted in his urine abnormally large amounts of S-sulfo-L-cysteine, sulfite, and thiosulfate and virtulally no inorganic sutlfate. The present report establishes the occurrence of an ezymatic defect in this infant. His liver, brain, and kidney specifically lacked sulfite oxidase activity. Deficiency of sulfite oxidase, which has not apparently been described in man, provides a reasonable explanation for the abnormalities in this infant.
179 citations