Enzymes glucose dehydrogenase

In this biosensor a quartz radio crystal is functionalized with the enzyme glucose-6-phosphate dehydrogenase. As shown in Figure 3, a thin film of Pmssian blue [14038-43-8] C gN gFe, is then coated onto the crystal. 

Third, a poly[bis(phenoxy)phosphazene] has been coated on porous alumina particles, surface nitrated, reduced to the amino-derivative, and then coupled to the enzyme glucose-6-phosphate dehydrogenase or trypsin by means of glutaric dialdehyde. The immobilized enzymes were more stable than their counterparts in solution, and they could be used in continuous flow enzyme reactor equipment (25). 

Human CYPs are multicomponent enzyme systems, requiring at a minimum the CYP enzyme component and a reductase component to be functional. The reductase requires a reduced nicotinamide cofactor, typically NADPH, and this cofactor must be regenerated to provide a steady supply of reducing equivalents for the reductase. Regeneration is accomplished with a separate substrate and enzyme. Glucose-6-phosphate and glucose-6-phosphate dehydrogenase have been widely used for this purpose. The overall complexity of the reaction mixtures and their cost have been barriers to the widespread use of recombinant human CYPs for metabolite synthesis in the past. 

The importance of having adequate supplies of NADPH for the regeneration of these various enzymes cannot be over emphasized. In normal situations this cofactor can be adequately provided by the reductive pentose phosphate pathway. Monitoring the activity of the pentose phosphate pathway has been proposed as a unique way to study the metabolic response to oxidative stress, since the glutathione peroxidase activity is coupled via glutathione reductase to the enzyme glucose-6-phosphate dehydrogenase (Ben Yoseph et ah, 1994). 

D-Glucosone is not oxidized by the D-glucose dehydrogenase of liver and does not inhibit the oxidation of D-glucose by this enzyme.98... 

Another type of sensor was based on the utilization of glucose dehydrogenase enzyme coupling with /ra(2,2 -bipyridylruthenium(II) complex [31]. This sensor can be used in the 10-2500-pmol/L concentration range. Several interferences occur, like NADH, oxalate, proline, and tripropylamine. However, gluconic acid and NAD+ do not interfere. 

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