Novel periplasmic and membrane-bound nitrate reductases lacking molybdenum and molybdenum cofactor were isolated from the vanadate-reducing bacterium Pseudomonas isachenkovii, and their properties were studied. Both enzymes have some unusual features, i. e., the individual subunits (130-kD subunit of the membrane-bound enzyme and monomeric 55-kD subunit of the periplasmic enzyme) possess their ...

Vanadate is the hallmark inhibitor of the P-type ATPase family; however, structural details of its inhibitory mechanism have remained unresolved. We have determined the crystal structure of sarcoplasmic reticulum Ca(2+)-ATPase with bound vanadate in the absence of Ca(2+). Vanadate is bound at the catalytic site as a planar VO3(-) in complex with water and Mg(2+) in a dephosphorylation transitio...

Vanadate induces the formation of two-dimensional crystalline arrays of Ca2+-ATPase molecules in sarcoplasmic reticulum. The Ca2+-ATPase membrane crystals are evenly distributed among the terminal cisternae and longitudinal tubules of sarcoplasmic reticulum, but very few crystals were observed in the T tubules. Tryptic cleavage of the Ca2+ transport ATPase into two major fragments (A and B) did...

The binding of vanadate and fluorescein isothiocyanate to the Ca2+-transport ATPase of sarcoplasmic reticulum (EC 3.6.1.3) was analyzed. Monovanadate binds to the Ca2+-transport ATPase at a single high affinity site (site 1), that is presumably related to the binding site for inorganic orthophosphate, and to one of the two sites for decavanadate. Binding of vanadate to this site stabilizes the ...

The biological and chemical basis of vanadium action in fungi is relatively poorly understood. In the present study, we investigate the influence of vanadate (V5+) on phosphate metabolism of Phycomyces blakesleeanus. Addition of V5+ caused increase of sugar phosphates signal intensities in 31P NMR spectra in vivo. HPLC analysis of mycelial phosphate extracts demonstrated increased concentration...

Single crystals of lithium zinc vanadate, LiZnVO(4), were grown by the flux method. The structural type of this vanadate is characterized by a three-dimensional arrangement of tetra-hedra sharing apices in an LiZnVO(4) network. This arrangement contains three different tetra-hedra, namely one [VO(4)] and two disordered mixed-site [Li/ZnO(4)] tetra-hedra. The resulting lattice gives rise to hexa...

The presence of (Na(+)+K+)ATPase activity in CL14 clone and NIH NTY strain of Trypanosoma cruzi epimastigotes is demonstrated. A Na+ plus K+ stimulated ATPase activity is found in both strains. The optimal Na+/K+ ratio is 5:1 and 9:1 in CL14 clone and NIH NTY strain, respectively. In both strains, vanadate completely inhibits the ouabain-sensitive ATPase activity indicating that it belongs to t...

The mechanisms of a one-pot colloidal conversion hydroxycarbonate templates into vanadate nanoparticles were investigated, with further correlation Eu3+ spectroscopic properties to particle size, texture, nanocrystallinity, and defect density.

The luminescence of complex ions like vanadate, niobate and tungstate is well known and has been studied intensively [1]. We have shown that edgeor face-sharing octahedra of this type are luminescent species with high quenching temperatures [2,3]. Examples are Mg4Nb20g and BasSrNb209 with Nb20g8_ anions and Ba3W20g with W2O96anions. These anions consist of face-sharing niobate and tungstate oct...

n-Type bismuth vanadate has been identified as one of the most promising photoanodes for use in a water-splitting photoelectrochemical cell. The major limitation of BiVO4 is its relatively wide bandgap (∼2.5 eV), which fundamentally limits its solar-to-hydrogen conversion efficiency. Here we show that annealing nanoporous bismuth vanadate electrodes at 350 °C under nitrogen flow can result in n...