ModA, the periplasmic-binding protein of the Escherichia coli mod transport system was overexpressed and purified. Binding of molybdate and tungstate to ModA was found to modify the UV absorption and fluorescence emission spectra of the protein. Titration of these changes showed that ModA binds molybdate and tungstate in a 1:1 molar ratio. ModA showed an intrinsic fluorescence emission spectrum...

The reagent is modified as follows: Serum chromogens are destroyed by trisodium phosphate. The use of phosphotungstic acid eliminates the tungstate and sulfate anions, a frequent cause of turbidity. Triethanolamine, added to the carbonate-urea mixture, provides unusual stability of the color through its buffering action. Only 0.2 ml of serum is required. The method is highly reproducible and ac...

Currently, the most popular automated method for the determination of serum uric acid is the automated method modified by Musser and Ortigoza (1966) for the TechniconS AutoAnalyzer system. While this method is considered reliable, it suffers from the following deficiencies: (a) it shows non-linearity with dilutions of aqueous uric acid standards and is thus dependent on costly reference sera as...

In this paper, a novel nanophosphor, Y10W2O21:Eu, was synthesized through co-precipitation which is a simple and low-costing method. The structure and morphology of the nanocrystal samples were characterized by using XRD and FE-SEM. The emission spectra, excitation spectra and fluorescence decay curves were measured. J-O parameters, quantum efficiencies of Eu3+ 5D0 energy level, color coordinat...

Transport across cellular membranes is an essential process that is catalyzed by diverse membrane transport proteins. The turnover rates of certain transporters are inhibited by their substrates in a process termed trans-inhibition, whose structural basis is poorly understood. We present the crystal structure of a molybdate/tungstate ABC transporter (ModBC) from Methanosarcina acetivorans in a ...

Bismuth complex oxides, in particular, bismuth tungstate, have recently attracted attention as promising photocatalytic materials for water treatment processes. In the present work, photocatalytic bismuth tungstate films were prepared by pulsed direct current (DC) reactive magnetron sputtering of Bi and W targets in an Ar/O2 atmosphere onto spherically-shaped glass beads. The uniform coverage o...