The assimilatory nitrate reductase from Chlorella contains flavin, heme, and molybdenum as prosthetic groups. The molybdenum in assimilatory nitrate reductase is associated with a pterin moiety (molybdopterin) as evidenced by the ability of the enzyme to donate active molybdenum cofactor to the Neurospora nitrate reductase mutant nit-1 and by the oxidative conversion of the pterin to two well c...

Molybdenum (Mo), a bcc metal with a melting point of 2,610°C and a density of 10.22 g/cm, is an important refractory metal. The refractory properties of molybdenum reflect the high strength of interatomic bonding resulting from the overlap of the 4d-orbitals and the number of bonding electrons available (1). The melting point of molybdenum is exceeded only by those of tungsten and tantalum, amo...

The molybdenum nitrogenase, present in a diverse group of bacteria and archea, is the major contributor to biological nitrogen fixation. The nitrogenase active site contains an iron-molybdenum cofactor (FeMo-co) composed of 7Fe, 9S, 1Mo, one unidentified light atom, and homocitrate. The nifQ gene was known to be involved in the incorporation of molybdenum into nitrogenase. Here we show direct b...

Background: Molybden, as a vital and essential micronutrient is directly involved in the metabolism of other elements including carbon, sulfur, and nitrogen. Molybdenum alone is not biologically active unless it binds to specific cofactors. Except for the bacterial nitrogenase, which contains molybdenum-Iron complex, molybdenum cofactor (Moco) is considered as the bioactive component placed in ...

the reduction mechanism of molybdenum-methyl thymol blue (mtb)-chlorate system has been investigated in water on a mercury electrode. as this system is very sensitive for ultratrace determination of molybdenum, the actual mechanism involved was studied. electrochemical techniques, including dc tast polarography and cyclic voltammetry were employed. it is shown that, the cathodic wave of molybde...

Selenium and molybdenum are essential trace elements. Considering the characteristics of selenium and molybdenum, our research had the following purposes for both elements: Considering Se the uptake of selenium was investigatein maize and sunflower seedling, moreover the different effect of two selenium species (selenite and selenite) for the examined plants (a monocotyledon (maize, Zea mays L....

A molybdenum cofactor which is capable of reconstituting demolybdosulfite oxidase purified from livers of tungstentreated rats has been identified in rat liver and various organisms. Reconstitution with the rat liver cofactor is directly proportional to cofactor and demolybdoenzyme concentrations and proceeds most efficiently in 0.01 M potassium phosphate buffer, pH 7.4. The activation process ...

1. The effect ofdietary molybdenum on the growth rate and also on ascorbic acid metabolism in rats was studied. An excess of dietary molybdenum resulted in growth retardation and loss of weight. Tolerance to molybdenum was affected by the nature ofthe molybdenum salt administered. 2. Molybdenum ingestion altered certain aspects of ascorbic acid metabolism in rats. The conversion ofD-glucuronola...

Molybdenum, applied in vivo, restored the damage from low temperature with winter wheat (Triticum aestivum, var "Sadovo 1") grown on acid soil and, in addition, sharply increased productivity (G Salcheva, D Georgieva, 1982; G Salcheva et al., 1977, 1979). Two fractions with molybdenum-cofactor activity in seeds were detected. One of them has a molecular weight of about 230 kilodaltons correspon...