Since the study of Al ion on the enzyme activity by using of electrochemical techniques was rarely found in available literatures, the differential-pulse polarography (DPP) technique was applied to study the effects of Al ion on the glutamate dehydrogenase (GDH) activity in the catalytical reaction of α-KG +NADH+NH4 ⇔ L-Glu+NAD+H2O by monitoring the DPP reduction current of NAD. At the plant an...

A method was developed for extracting enzymes from micro-organisms closely associated with ammonia-treated straw (NH3-S) that had been incubated in nylon bags in the rumen. Incubation of washed straw with 125 ml carbon tetrachloride/l and 20 micrograms lysozyme/ml for 3 h at 37 degrees gave carboxymethylcellulase (EC 3.2.1.4; CMCase) and NAD-linked glutamate dehydrogenase (EC 1.4.1.2; GDH) acti...

Several mutants of quinoprotein glucose dehydrogenase (GDH) in Escherichia coli were obtained and characterized. Of these, significant mutants were further characterized by kinetic analysis after purification or by site-directed mutagenesis to introduce different amino acid substitutions. H775R and H775A showed a pronounced reduction of affinity for a prosthetic group, pyrroloquinoline quinone ...

Serratia sp. T241, a newly isolated xylose-utilizing strain, produced three 2,3-butanediol (2,3-BD) stereoisomers. In this study, three 2,3-butanediol dehydrogenases (BDH1-3) and one glycerol dehydrogenase (GDH) involved in 2,3-BD isomers formation by Serratia sp. T241 were identified. In vitro conversion showed BDH1 and BDH2 could catalyzed (3S)-acetoin and (3R)-acetoin into (2S,3S)-2,3-BD and...

In this paper, we study a bybridizable discontinuous Galerkin (HDG) method for the numerical solution of 2D time-harmonic Maxwell’s equations. The formulations are given, and the relationship between the HDG scheme and the upwind flux DG method is also examined. The presented numerical results show the effectiveness of the proposed HDG method especially in comparison to the upwind flux DG metho...

Land snails, Otala lactea, survive in seasonally hot and dry environments by entering a state of aerobic torpor called estivation. During estivation, snails must prevent excessive dehydration and reorganize metabolic fuel use so as to endure prolonged periods without food. Glutamate dehydrogenase (GDH) was hypothesized to play a key role during estivation as it shuttles amino acid carbon skelet...

The structure of human glutamate dehydrogenase (GDH) has been determined in the absence of active site and regulatory ligands. Compared to the structures of bovine GDH that were complexed with coenzyme and substrate, the NAD binding domain is rotated away from the glutamate-binding domain. The electron density of this domain is more disordered the further it is from the pivot helix. Mass spectr...

Infection with the white spot syndrome virus (WSSV) induces a metabolic shift in shrimp that resembles the "Warburg effect" in mammalian cells. This effect is triggered via activation of the PI3K-Akt-mTOR pathway, and it is usually accompanied by the activation of other metabolic pathways that provide energy and direct the flow of carbon and nitrogen. Here we show that unlike the glutamine meta...

The ability to solubilize insoluble inorganic phosphate compounds by Gluconacetobacter diazotrophicus was studied using different culture approaches. Qualitative plate assays using tricalcium phosphate as the sole P-source showed that G. diazotrophicus produced solubilization only when aldoses were used as the C-source. Extracellular aldose oxidation via a pyrroloquinoline quinone-linked glucos...