Active transport of exogenous sulfate into log phase cells of Porphyridium aerueineum followed Michaelis-Menten kinetics, and the apparent Km for sulfate transport is approximately 2.5 x 10(-6)m. Molybdate, also a group VI anion, is a competitive inhibitor of sulfate transport, and the inhibition is freely reversible. Once in the cell, molybdate depresses the rate of sulfate pool utilization by...

A novel tungstate and molybdate binding protein has been discovered from the hyperthermophilic archaeon Pyrococcus furiosus. This tungstate transport protein A (WtpA) is part of a new ABC transporter system selective for tungstate and molybdate. WtpA has very low sequence similarity with the earlier-characterized transport proteins ModA for molybdate and TupA for tungstate. Its structural gene ...

We have recently purified the modulator of the glucocorticoid-receptor complex from rat liver. Purified modulator inhibits glucocorticoid-receptor complex activation and stabilizes the steroid-binding ability of the unoccupied glucocorticoid receptor. Since these activities are shared by exogenous sodium molybdate, modulator appears to be the endogenous factor that sodium molybdate mimics. In t...

Molybdenum (Mo) is an essential trace element for almost all living organisms including animals. Mo is used as a catalytic center of molybdo-enzymes for oxidation/reduction reactions of carbon, nitrogen, and sulfur metabolism. Whilst living cells are known to import inorganic molybdate oxyanion from the surrounding environment, the in vivo dynamics of cytosolic molybdate remain poorly understoo...

Almost all living organisms need to obtain molybdenum from the external medium to achieve essential processes for life. Activity of important enzymes such as sulfite oxidase, aldehyde oxidase, xanthine dehydrogenase, and nitrate reductase is strictly dependent on the presence of Mo in its active site. Cells take up Mo in the form of the oxianion molybdate, but the molecular nature of the transp...

Molybdenum is an essential element for almost all living beings, which, in the form of a molybdopterin-cofactor, participates in the active site of enzymes involved in key reactions of carbon, nitrogen, and sulfur metabolism. This metal is taken up by cells in form of the oxyanion molybdate. Bacteria acquire molybdate by an ATP-binding-cassette (ABC) transport system in a widely studied process...

For the molybdoenzymes synthesis as the nitrogenase, the molybdenum, in its most stable form, the molybdate, must be transported inside the cell. In Bradyrhizobium japonicum, the modABC genes code for a high-affinity ABC-type molybdate transporter. This work allowed to study the effect of inoculation of soybean plants with strains affected in the molybdate transport. modA and modB mutants, unab...

Weimberg, Ralph (Northern Regional Research Laboratory, Peoria, Ill.), and William L. Orton. Repressible acid phosphomonoesterase and constitutive pyrophosphatase of Saccharomyces mellis. J. Bacteriol. 86:805-813. 1963.-Saccharomyces mellis produces a nonspecific acid phosphomonoesterase (pH optimum of 5.5 to 6.0) when grown in a medium devoid of phosphate. Only minimal amounts of this enzyme a...

Contradictory findings on the effects of sodium molybdate on estrogen receptor activation have been recently reported. In a preliminary report (Mauck, L. A., and Notides, A. C. (1980) Proceedings of the 62nd Annual Meeting of the Endocrine Society, Abstr. 209) it was suggested that sodium molybdate prevents heat activation of the calf uterine estrogen receptor. This effect was reversible upon d...

Inhibition of 3':5'-cyclic-AMP-5'-nucleotidohydrolase (EC 3.1.4.17) type II (cAMP-phosphodiesterase) by sodium molybdate was studied: While determination of inorganic phosphate and 5'-ribonucleotide phosphohydrolase (5'-nucleotidase) (EC 3.1.3.5) activity was not disturbed by sodium molybdate in concentrations up to 10 mM, cAMP-phosphodiesterase was inhibited by millimolar concentrations of mol...