Molybdenum and tungsten enzymes: a crystallographic and mechanistic overview.

Molybdenum and tungsten enzymes: a crystallographic and mechanistic overview.

Dalton transactions (Cambridge, England : 2003) (2009-05-20)

Maria João Romão

PMID19452052

ABSTRACT

Molybdenum and tungsten enzymes which contain the pyranopterin cofactor are ubiquitous in Nature and perform a wide variety of biological functions. They catalyze a diversity of mostly two-electron oxidation-reduction reactions crucial in the metabolism of nitrogen, sulfur and carbon. These enzymes share common structural features, but reveal different polypeptide folding topologies and different active site coordination geometries, which, in part, dictate their function and specificity. On the basis of structural, spectroscopic and biochemical characteristics, they have been classified into three broad families named according to well-studied enzymes of each family: xanthine oxidase, sulfite oxidase and DMSO reductase. An overview of the X-ray crystallography data for representative members of the three enzyme families is given here, focusing on the mechanistic implications drawn from the structural data.

MATERIALS

Product Number

Brand

Product Description

577987

Sigma-Aldrich

Molybdenum, nanopowder, <100 nm particle size (TEM), 99.8% trace metals basis

366986

Sigma-Aldrich

Molybdenum, powder, 10 μm, ≥99.95% trace metals basis

266892

Sigma-Aldrich

Molybdenum, powder, <150 μm, 99.9% trace metals basis

357227

Sigma-Aldrich

Molybdenum, foil, thickness 0.025 mm, ≥99.9% trace metals basis

266922

Sigma-Aldrich

Molybdenum, foil, thickness 0.1 mm, ≥99.9% trace metals basis

203823

Sigma-Aldrich

Molybdenum, powder, <150 μm, 99.99% trace metals basis

267546

Sigma-Aldrich

Tungsten, foil, thickness 0.25 mm, ≥99.9% trace metals basis

267511

Sigma-Aldrich

Tungsten, powder, 12 μm, 99.9% trace metals basis

357200

Sigma-Aldrich

Molybdenum, foil, thickness 1.0 mm, ≥99.9% trace metals basis

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Molybdenum, foil, light tested, 25x25mm, thickness 0.01mm, 99.9%

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Molybdenum, foil, light tested, 50x50mm, thickness 0.075mm, annealed, 99.9%

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Tungsten, foil, not light tested, 25x25mm, thickness 0.004mm, 99.95%

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Molybdenum, foil, not light tested, 100x100mm, thickness 0.004mm, 99.9%

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Molybdenum, foil, light tested, 25x25mm, thickness 0.005mm, 99.9%

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Tungsten, foil, 5m coil, thickness 0.035mm, coil width .5mm, as rolled, 99.95%

GF90717666

Tungsten, microfoil, disks, 10mm, thinness 0.05μm, specific density 96μg/cm², permanent mylar 3.5μm support, 99.95%

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Tungsten, insulated wire, 2m, conductor diameter 0.0125mm, insulation thickness 0.0035mm, polyimide insulation, 99.9%

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Molybdenum, foil, not light tested, 150x150mm, thickness 0.05mm, annealed, 99.9%

GF81654655

Tungsten, insulated wire, 5m, conductor diameter 0.05mm, insulation thickness 0.008mm, polyimide insulation, 99.9%

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Tungsten, mesh, 50x50mm, nominal aperture 0.2mm, wire diameter 0.05mm, 100 wires/inch, open area 64%, plain weave mesh, 99.95%

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Tungsten, microfoil, disks, 10mm, thinness 0.1μm, specific density 182μg/cm², permanent mylar 3.5μm support, 99.95%

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Molybdenum, foil, not light tested, 50x50mm, thickness 0.009mm, 99.9%

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Tungsten, insulated wire, 2m, conductor diameter 0.015mm, insulation thickness 0.002mm, polyimide insulation, 99.9%

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Tungsten, foil, not light tested, 50x50mm, thickness 0.005mm, 99.95%

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Tungsten, rod, 8.25mm, diameter 9.5mm, centerless ground, 99.95%

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Tungsten, foil, light tested, 50x50mm, thickness 0.075mm, as rolled, 99.95%

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Tungsten, insulated wire, 5m, conductor diameter 0.075mm, insulation thickness 0.02mm, PTFE (polytetrafluoroethylene) insulation, 99.9%

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