Molybdenum and tungsten in biology.

Trends in biochemical sciences (2002-07-13)
Russ Hille
ABSTRACT

Molybdenum is the only second-row transition metal that is required by most living organisms, and the few species that do not require molybdenum use tungsten, which lies immediately below molybdenum in the periodic table. Because of their unique chemical versatility and unusually high bioavailability these two transition metals have been incorporated into the active sites of enzymes over the course of evolution. Enzymes that contain molybdenum or tungsten continue to be discovered and several crystal structures have become available recently. This new structural information has been complemented by spectroscopic and kinetic methods, as well as computational approaches. Together, these studies provide an increasingly detailed view of the reaction mechanisms and the correlation between the electronic structure of the active site and catalytic function, one of the fundamental goals in metallobiochemistry.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Molybdenum, powder, <150 μm, 99.9% trace metals basis
Sigma-Aldrich
Tungsten, powder, 10 μm, ≥99.99% trace metals basis
Sigma-Aldrich
Molybdenum, powder, 1-5 μm, ≥99.9% trace metals basis
Sigma-Aldrich
Molybdenum, foil, thickness 0.1 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Tungsten, powder, 12 μm, 99.9% trace metals basis
Sigma-Aldrich
Tungsten, wire, diam. 0.25 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Molybdenum, powder, <150 μm, 99.99% trace metals basis
Sigma-Aldrich
Molybdenum, foil, thickness 0.025 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Tungsten, foil, thickness 0.05 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Molybdenum, nanopowder, <100 nm particle size (TEM), 99.8% trace metals basis
Sigma-Aldrich
Tungsten, foil, thickness 0.127 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Molybdenum, wire, diam. 1.0 mm, 99.95% trace metals basis
Sigma-Aldrich
Tungsten, foil, thickness 0.25 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Molybdenum, foil, thickness 1.0 mm, ≥99.9% trace metals basis
Sigma-Aldrich
Tungsten, foil, thickness 0.5 mm, ≥99.9% trace metals basis
Tungsten, wire reel, 5m, diameter 0.005mm, gold plated, 99.95%
Tungsten, wire reel, 25m, diameter 0.05mm, clean, 99.95%
Tungsten, foil, light tested, 100x100mm, thickness 0.05mm, as rolled, 99.95%
Tungsten, wire, straight, 300mm, diameter 0.10mm, 99.9+%
Tungsten, wire reel, 5m, diameter 0.125mm, clean, 99.95%
Tungsten, wire reel, 20m, diameter 1.0mm, clean, 99.95%
Tungsten, wire reel, 25m, diameter 0.1mm, clean, 99.95%
Tungsten, rod, 100mm, diameter 1.6mm, centerless ground, 99.95%
Tungsten, wire reel, 5m, diameter 0.25mm, clean, 99.95%
Tungsten, foil, 100x100mm, thickness 0.125mm, as rolled, 99.95%
Tungsten, foil, 100x100mm, thickness 0.15mm, as rolled, 99.95%
Tungsten, foil, 100x100mm, thickness 0.1mm, as rolled, 99.95%
Tungsten, foil, 100x100mm, thickness 0.2mm, as rolled, 99.95%
Tungsten, foil, 100x100mm, thickness 0.3mm, as rolled, 99.95%
Tungsten, foil, 100x100mm, thickness 0.5mm, as rolled, 99.95%