Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two enzymes have been partially purified from extracts of Escherchia coli B which together catalyze the conversion of the product of the action of GTP cyclohydrolase II, 2,5-diamino-6-oxy-4-(5'-phosphoribosylamine)pyrimidine, to 5-amino-2,6-dioxy-4-(5'-phosphoribitylamine)pyrimidine. These two compounds are currently thought to be intermediates in the biosynthesis of riboflavin. The enzymatic conversion occurs in two steps. The product of the action of GTP cyclohydrolase II first undergoes hydrolytic deamination at carbon 2 of the ring, followed by reduction of the ribosylamino group to a ribitylamino group. The enzyme which catalyzes the first step, herein called the "deaminase," has been purified 200-fold. The activity was assayed by detecting the conversion of the product of the reaction catalyzed by GTP cyclohydrolase II to a compound which reacts with butanedione to form 6,7-dimethyllumazine. The enzyme has a molecular weight of approximately 80,000 and a pH optimum of 9.1. The dephosphorylated form of the substrate is not deaminated in the presence of the enzyme. The assay for the enzyme which catalyzes the second step, referred to here as the "reductase," involves the detection of the conversion of the product of the deaminase-catalyzed reaction to a compound which, after treatment with alkaline phosphatase, reacts with butanedione to form 6,7-dimethyl-8-ribityllumazine. The reductase has a molecular weight of approximately 40,000 and a pH optimum of 7.5. Like the deaminase, the reductase does not act on the dephosphorylated form of its substrate. Reduced nicotinamide adenine dinucleotide phosphate is required as a cofactor; reduced nicotinamide adenine dinucleotide can be used about 30% as well as the phosphate form. The activity of neither enzyme is inhibited by riboflavin, FMN, or flavine adenine dinucleotide.
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PMID:Presence of Escherichia coli of a deaminase and a reductase involved in biosynthesis of riboflavin. 3 Jul 56

During the activation of the inactive dinitrogenase reductase from Rhodospirillum rubrum, an adenine-like molecules is lost and phosphate is found on both active and inactive forms of the protein. ATP and divalent metals are required for activation of the reduced protein, but ATP is not required for activation of phenazine methosulfate-oxidized dinitrogenase reductase. Snake venom diesterase and spleen diesterase have no effect on the inactive protein; alkaline phosphatase removes phosphate from the activated protein but not from the inactive protein. ATP binds to both active and inactive forms of the protein.
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PMID:Removal of an adenine-like molecule during activation of dinitrogenase reductase from Rhodospirillum rubrum. 11 62

Scolices and brood capsules of healthy hydatid cysts from lungs of human patients were studied with histochemical and histoenzymatic methods. The subtegumental and flame cells were sepcially rich in glycogen, RNA and some dehydrogenases such as SDH, MDH, NADH-reductase and G-6-PDH. The rostellar zone or invaginated pole, an area of marked contractile movements, showed intense activity in ATP'ase and simple esterase. The so-called excretory pole shows strong activity in simple esterases, lipase, beta-HBH, alpha-GDH and NADPH-reductase. Lipids are also abundant in this zone implying the important role of this metabolic path in the development of the parasite. Intense activity in alkaline phosphatase was observed in cells associated to the calcereous corpuscles. The largest corpuscles were devoid of enzymatic activity. The enzyme could play some role in the calcification of the corpuscles. Wide enzymatic variations are described according to morphology being orthoscolices the most rich in enzyme activity. Accumulations of small cells surrounded by specialized cells on the germinal membrane are interpreted as the origin or "embryo" of brood capsules. Some enzymes detected in the wall of mature brood capsules depicted alternating types of cells. Some of them are positive for ATP'ase that may be related to active transport of substances across the brood capsule wall. The intenst ATP'ase activity at the stalks of scolices may be similarly interpreted. However, a miosine-like activity is a more feasible explanation since this area showed striking contractile movements in vivo.
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PMID:Histochemistry and histoenzymology of the hydatid cyst (Echinococcus granulosus Batsch, 1786). II. Scolices and brood capsules. 13 Jul 50

Human erythrocytes from healthy male donors were fractionated with respect to in vivo age by simple centrifugation in order to characterize changes in the functional integrity of the membrane during the life-span of the cell. The three enzymes, Na/K-ATPase, glyceraldehyde-3-phosphate dehydrogenase and NADH-ferricyanide reductase, were found not to change with age, but significant age-dependent decreases were observed in the cases of acetylcholinesterase, phosphoglycerate kinase, purine nucleoside phosphorylase, adenylate kinase, Mg-ATPase and alkaline phosphatase. The possibility that these changes were attributable to mechanisms other than age-related inactivation, such as reticulocyte contamination, differential resealing and crypticity, was investigated. Only the decrease in acetylcholinesterase could be explained wholly in terms of reticulocyte contamination. A decrease in membrane integrity on ageing was observed, which accounted for approximately half the change in alkaline phosphatase and may have contributed to the other enzyme activity changes. This membrane integrity effect masked a real decrease in the highly cryptic NADH-ferricyanide reductase, this decrease being apparent only after total disaggregation of the membrane with nonionic surfactant.
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PMID:Changes in the activities of some membrane-associated enzymes during in vivo ageing of the normal human erythrocyte. 14 40

Male guinea pigs were exposed to nitrogen dioxide (2 mg/m3) during 180 days (8 hours a day). Long-term exposure induced thickening of the corneal layer of the epidermis as well as inflammatory infiltrations in the proper skin. The following enzymes were estimated histochemically in skin samples of experimental and control animals: succinic dehydrogenase, NADH2-tetrazolium reductase, lactate dehydrogenase; alkaline phosphatase, acid phosphatase and adenosine triphosphatase. Chronic exposrue stimulated a decrease of NADH2-tetrazolium reductase in the epidermis and connective tissue components of proper skin and marked positive reaction of lactate dehydrogenase in epidermal cells and hair follicles. Increase of a diffuse reaction on adenosine triphosphatase in smooth muscles of the skin was found also in exposed animals.
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PMID:Histopathological and histochemical studies of the skin of guinea pigs after long-term exposure to nitrogen dioxide. 14 74

Growth characteristics, survival time, sex differences and hormonal effects, and various biochemical parameters were evaluated in a transplantable Furth/Wistar rat Wilms' tumor model. Survival time was dependent on site of tumor transplant and ranged from a mean of 28 days for intrarenal implantation to 44 days intramusculary. Maximum tumor weight (130 g) was obtained via subcutaneous implant. Lung metastasis was evident in the majority of animals with the exception of those receiving the tumor implant intraperitoneally. The levels of erythropoietin and serum calcium and phosphatase were comparable to control values whereas hematocrit levels declined. Tumor tissue arginase or total protein remained unchanged during tumor growth. In these same tissues DNA, content and 5-alpha-reductase activity significantly and progressively increased with concomitant tumor growths. Measurements of lactic dehydrogenase, alkaline phosphatase, and their isoenzymes indicated patterns of liver involvement which were not macroscopically evident. After 31 days of subcutaneous tumor transplant, male and female rats had tumors of comparable weights. Orchiectomy or estradiol treatment significantly reduced tumor weight in males. In female rats testosterone treatment significantly increased tumor weights. DNA concentration in tumor tissue was unaffected by treatment. Similiarly, although 5-alpha-reductase activity was higher in tumors from males, and arginase higher in females, these enzymes were not affected by surgical or hormonal treatment.
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PMID:Characterization of a Wilms' tumor model. 16 21

The organelle pathology of neutrophils in chronic granulocytic leukaemia (CGL) was investigated by analytical subcellular fractionation. There were minor reductions in activity of some granule enzymes with an abnormal distribution in sucrose density gradients of the specific granules. There was a marked reduction of 5'-nucleotidase activity but this is probably related to the relative reduction of the mononuclear cell contamination of the neutrophils isolated from leukaemic patients compared with controls. Another plasma membrane enzyme, NADH-nitroblue tetrazolium reductase, which has a microbicidal role, had increased activity. Neutrophils from patients with CGL had 13% the alkaline phosphatase activity of controls and were compared with neutrophils from women in the third trimester of pregnancy when the activity was increased to 8 times the control level. The latent activity, per cent inhibition by Levamisole, kinetic constants and subcellular distribution of alkaline phosphatase were similar in the three groups. It is suggested that the properties and intracellular localization of alkaline phosphatase are normal in CGL and that there is a quantitative lack of enzyme.
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PMID:Studies on the subcellular organelles of neutrophils in chronic granulocytic leukaemia with special reference to alkaline phosphatase. 28 20

Cytoplasmic inclusion bodies corresponding in their tinctorial properties to Negri bodies were detected in TEp-2/2 and BHK-21/13S cell cultures chronically infected with fixed rabies virus. The number of cells containing the inclusions was always than that of the cells producing virus-specific antigen. Histological examinations of chronically infected cultures revealed considerable inhibition of the acid phosphatase activity, some weakening of the reaction to alkaline phosphatase, and a marked decline in the activity of succinate dehydrogenase. The intensity of reaction to RNA in chronically infected cultures was increased, particularly in those zones of the cells where RNA-containing inclusions were detected. The activity of the respiratory enzyme HAD-H2 tetrasolium reductase in HEp-2/2 cells was reduced and in BHK-21/13S cells increased as compared to the control.
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PMID:[Cytologic and histochemical study of cell cultures chronically infected with fixed rabies virus]. 35 98

From the original Dunning R-3327 rat prostatic adenocarcinoma, several distinct sublines have been obtained. These sublines include a well-differentiated, slow-growing, androgen-sensitive tumor (R-3327-H); a well-differentiated, slow-growing, androgen-insensitive tumor (R-3327-HI); and a fast-growing, androgen-insensitive, anaplastic tumor (R-3327-AT). These three sublines were compared in order to develop new model methods for the prediction of the androgen sensitivity and the degree of differentiation of prostatic adenocarcinomas. The R-3327-AT was very distinct in all parameters examined except the tissue protein electrophoretic patterns which contained a uniform pattern in all tumors. The significant differences between R-3327-H and -HI sublines were (a) the inability of testosterone to stimulate DNA synthesis in the R-3327-HI tumor and (b) the difference in the enzymatic profiles of these sublines. The specific activity of three enzymes (3 alpha-hydroxysteroid dehydrogenase, leucine aminopeptidase, lactic dehydrogenase) increased while the activity of another three enzymes (6 alpha,7 alpha-hydroxylase, 5 alpha-reductase, alkaline phosphatase) decreased in the sublines which are androgen insensitive and less differentiated. An arbitrary index was constructed, based upon these enzyme differences, which clearly discriminates the degree of androgen sensitivity and differentiation of these R-3327 rat prostatic adenocarcinomas.
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PMID:Models for development of nonreceptor methods for distinguishing androgen-sensitive and -insensitive prostatic tumors. 44 68

Mycotoxic porcine nephropathy was induced by p.o. administration of crystalline ochratoxin A for periods of 5 days, 3 months and 2 years. Enzyme activities of the renal tissue were studied histochemically. These were NADH-tetrazolium reductase, NADPH-tetrazolium reductase, lactate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase, glucose-6-phosphate dehydrogenase, alpha-glycerophosphate dehydrogenase, unspecific acid phosphatase and unspecific alkaline phosphatase. The activity of NADH-tetrazolium reductase and succinate dehydrogenase was reduced in the proximal tubule of all nephrons after 5 days ochratoxin A exposure and remained reduced after 3 months and 2 years exposure. The effect of ochratoxin A on these enzymes would appear to cause the impairment of proximal tubular function and the morphological changes observed in the proximal tubule in ochratoxin A-induced mycotoxic porcine nephropathy. The localization of alterations in enzyme activity corresponds to the localization of ochratoxin A previously demonstrated in the kidney. The activities of NADPH-tetrazolium reductase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase and unspecific alkaline phosphatase were reduced focally corresponding to the areas with focal tubular atrophy and the degree of reduction was roughly parallel to the degree of atrophy.
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PMID:Ochratoxin A-induced mycotoxic porcine nephropathy: alterations in enzyme activity in tubular cells. 47 26


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