The xylose-fermenting recombinant Saccharomyces cerevisiae and its improvement have been studied extensively. The redox balance between xylose reductase (XR) and xylitol dehydrogenase (XDH) is thought to be an important factor in effective xylose fermentation. Using protein engineering, we previously successfully reduced xylitol accumulation and improved ethanol production by reversing the depe...

The peroxisome proliferator, WY 14,643 exhibits a pure non-competitive inhibition pattern in the aldehyde reduction and in alcohol oxidation activities of human Aldose reductase (hAR). Fluorescence emission measurements of the equilibrium dissociation constants, Kd, of oxidized (hAR•NADP+) and reduced (hAR•NADPH) holoenzyme complexes display a 2-fold difference between them. Kd values for the d...

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common hereditary enzyme defect in humans, caused by a mutation X-linked gene encoding G6PD. The G6PD plays an important role to produced reducing agents which maintain reduced glutathione through pentose phosphate pathway. On ingestion of Faba Bean (Vicia faba L.), vicine and convicine are hydrolyzed β -glucosidase divicine isoura...

The cytosolic NADP+-dependent isocitrate dehydrogenase from germinating blackgram shows an absolute requirement of a divalent metal ion such as Mn2+ or Mg2+ for expression of its full activity. Other metal ions like Co2+, Zn2+ and Cu2+ could also activate the enzyme, though the degree of activation was lower than that of either Mn2+ or Mg2+ at the same concentration. In contrast, three metal io...

Degradation products of nicotinamide adenine dinucleotide phosphate, formed under the hot mild alkaline conditions that are used in the determination of NADPH in the presence of NADP+, were found to inhibit the enzyme used for NADPH estimation. The agent primarily responsible for inhibition was isolated and identified as phosphoadenosine diphosphate ribose. Phosphoadenosine diphosphate ribose w...

As a result of studies of guinea-pig liver testosterone 17/J-dehydrogenase (NADP+) (EC 1.1.1.64), anew testosterone 17f8-dehydrogenase was discovered. The new enzyme was purified to a single homogeneous protein from the 105000g-supernatant fraction of guinea-pig liver by (NH4)2SO4 fractional precipitation and two gel-filtration stages, DEAE-cellulose column chromatography and hydroxyapatite col...

The behaviours of the principal NADPH-producing enzymes (glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, cytoplasmic and mitochondrial 'malic' enzyme and NAPD+-dependent isocitrate dehydrogenase) were studied during the development of rat heart and compared with those in brain and liver. 1. The enzymes belonging to the pentose phosphate pathway exhibit lower activities in h...

Oxidative stress in plants causes ferredoxin down-regulation and NADP(+) shortage, over-reduction of the photosynthetic electron transport chain, electron leakage to oxygen and generation of reactive oxygen species (ROS). Expression of cyanobacterial flavodoxin in tobacco chloroplasts compensates for ferredoxin decline and restores electron delivery to productive routes, resulting in enhanced s...

Escherichia coli cells from strain fpr, deficient in the soxRS-induced ferredoxin (flavodoxin)-NADP(H) reductase (FPR), display abnormal sensitivity to the bactericidal effects of the superoxide-generating reagent methyl viologen (MV). Neither bacteriostatic effects nor inactivation of oxidant-sensitive hydrolyases could be detected in fpr cells exposed to MV. FPR inactivation did not affect th...

Data from the U.S. Geological Survey (USGS) collocated-sampler program for the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) are used to estimate the overall error of NADP/NTN measurements. Absolute errors are estimated by comparison of paired measurements from collocated instruments. Spatial and temporal differences in absolute error were identified and are consist...