Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.49 (glucose-6-phosphate dehydrogenase)
 7,794 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Co-immobilization methods have been developed for a bienzymatic system of luminescent Beneckea harveyi bacteria with formate dehydrogenase, glucose-6-phosphate dehydrogenase, and phosphoglucomutase. Bioluminescent assays have been devised for NADH, NAD, FMN, glucose 6-phosphate, and glucose 1-phosphate using the co-immobilized enzyme preparation. The lowest detection limits were in the picomole range with the bacterial extract and in the femtomole range with the partially purified enzymes, bacterial luciferase, and NADH:FMN oxidoreductase.
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PMID:Bioluminescent microassay of various metabolites using bacterial luciferase co-immobilized with multienzyme systems. 326 18

In the present study, fetuses were hypophysectomized (hypox) in utero on d 72 to 74 of gestation with an electrical cauterizing needle. One to six successfully hypox fetuses were removed on d 110 of gestation from each of five gilts. Subcutaneous adipose tissue samples and semitendinosus muscles were obtained from the hypox fetuses and an equal number of control fetuses. Body weights of control fetuses (n = 15; mean +/- SE, 1,195 +/- 33 g) were similar to weights of hypox fetuses (n = 15; 1,179 +/- 67 g). Fat cell size in the middle subcutaneous layer of adipose tissue was increased in hypox fetuses (P less than .01) compared with control fetuses. The number of obvious fat cell clusters (outer layer) in lipid stained sections was reduced (P less than .01) by 50% in hypox fetuses. Histochemical reactions for glucose-6-phosphate dehydrogenase, esterase and lipoprotein lipase (LPL) activities in middle layer cell clusters were considerably enhanced in sections from hypox fetuses compared with sections from controls. Quantitative analysis of percent light transmittance (Zeiss photometer) through LPL-stained cell clusters indicated an increase (P less than .001) in LPL staining in sections from hypox fetuses when compared with sections from control fetuses. Transverse muscle sections (cryostat) from hypox fetuses failed to show normal patterns (as seen in control muscles) of reactions for acid ATPase, malate dehydrogenase (NAD-dependent), NADH-TR and alpha-glycerol phosphate dehydrogenase (without NAD). The number of muscle fibers that were stained for these enzymes was greatly reduced in hypox fetuses compared with control fetuses. The number of lipid positive fibers was also reduced in hypox fetuses compared with control fetuses.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differentiation of adipose tissue and muscle in hypophysectomized pig fetuses. 357 Oct 30

Fifty-two strains of Bacteroides fragilis were examined for their enzyme electrophoretic patterns of glucose-6-phosphate dehydrogenase (G6PDH) and malate dehydrogenase (MDH). All strains tested possessed high levels of both enzymes but the G6PDH reduced NADP whereas MDH was NAD-dependent. Twenty-seven strains produced single bands of both G6PDH and MDH. In all cases G6PDH migrated faster than MDH. Strains clustered by a single linkage algorithm were recovered in eight clusters at the 77% similarity level. The remaining 25 strains produced multiple bands of one or both enzymes. These were recovered in six clusters at the 72% similarity level using the same algorithm. The results of this study revealed considerable heterogeneity of enzyme patterns within B. fragilis.
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PMID:Glucose-6-phosphate dehydrogenase and malate dehydrogenase enzyme electrophoretic patterns amongst strains of Bacteroides fragilis. 366 5

A method involving affinity chromatography on the yellow dye Remazol Brilliant Gelb GL to highly purify the cytoplasmic isoenzyme of glucose-6-phosphate dehydrogenase from pea shoots is described. Purification is at least 6000-fold. The specific activity of the purified enzyme is 185 mumol NADP reduced/min per mg protein. The preparation was free from any contamination of chloroplastic isoenzyme. The purified enzyme retains its activity in the presence of reducing agents which, in contrast, inactivate the chloroplast enzyme. The state of activity of the cytoplasmic and the chloroplastic isoenzyme in illuminated or darkened pea leaves was investigated using specific antibodies. While upon illumination the chloroplastic isoenzyme was inactivated by 80 to 90%, we could not find any change in activity of the cytoplasmic glucose-6-phosphate dehydrogenase. ATP, ADP, NAD, NADH, and various sugar phosphates do not inhibit the enzyme activity. Only NADPH is a strong competitive inhibitor with respect to NADP, suggesting that the enzyme is regulated by feedback inhibition by one of its products. Mg2+ ions have no influence on the activity of the enzyme. The molecular weight has found to be 240,000 for the native enzyme and 60,000 for the subunit. Throughout the purification procedure the enzyme was very unstable unless NADP was present in the buffer.
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PMID:Purification and properties of the cytoplasmic glucose-6-phosphate dehydrogenase from pea leaves. 371 51

Study of the activity of some myocardial enzymes in sudden death cases with alcoholic cardiomyopathy (ACMP) was made by quantitative histochemical methods. The decrease of dehydrogenase activity of succinate, lactate, beta-hydroxybutyrate, alpha-glycerophosphate and NAD-diaphorase was found in line with the increase of the activity of glucose-6-phosphate dehydrogenase, alcohol dehydrogenase and catalase versus control (myocardium of those who died of trauma). Disorders of major metabolic processes in the myocardium may occasionally lead to electrical instability resulting in ventricular fibrillation and sudden cardiac death. In almost 80% of sudden cardiac deaths in ACMP foci of acute myocardial ischemia are found, that can lead to ventricular fibrillation with lethal outcome.
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PMID:[Histoenzymologic characteristics of the myocardium in sudden death in patients with alcoholic cardiomyopathy]. 380 Jun 78

M. Kuwajima, C. B. Newgard, D. W. Foster, and J. D. McGarry (1986, J. Biol. Chem. 261, 8849-8853) have concluded that the reason postprandial hepatic glycogenesis occurs primarily from gluconeogenic precursors rather than glucose is because glucokinase activity is insufficient to support the observed rates of glycogen synthesis. F. L. Alvares and R. C. Nordlie (1977, J. Biol. Chem. 252, 8404-8414) have concluded that the combined activities of glucokinase and hexokinase are less than the apparent rates of hepatic glucose uptake. We have identified several factors in the assays used in these studies which lead to substantial underestimations of glucokinase activity. Glucokinase was assayed either by allowing glucose 6-phosphate to accumulate over 10 min (discontinuous assay) or by coupling the formation of glucose 6-phosphate with its oxidation by Leuconostoc mesenteroides glucose 6-phosphate dehydrogenase and NAD (continuous assay). Accurate determinations of glucokinase at 37 degrees C with subsaturating glucose require both 100 mM KCl and 2.5 mM dithioerythritol in the assay medium; 2-mercaptoethanol will not substitute for dithioerythritol. When both KCl and dithioerythritol are absent (Kuwajima et al.) glucokinase activity is underestimated by 3- to 5-fold. The discontinuous assay as used previously (Alvares and Nordlie) underestimates glucokinase activity in crude extracts by 2- to 2.5-fold, due in part to the hydrolysis of glucose 6-phosphate and its transformation to other hexose monophosphates. Under optimized conditions at 37 degrees C both assays yield similar results in extracts from fed rats, i.e., 2-3 and 4-5 units/g liver at 10 and 100 mM glucose, respectively. Some implications of the finding that total hepatic glucose phosphorylating capacity at physiological concentrations significantly exceeds the observed rates of postprandial glycogen synthesis are discussed.
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PMID:Factors underlying significant underestimations of glucokinase activity in crude liver extracts: physiological implications of higher cellular activity. 381 60

Reaction of NADP with 3-propiolactone at pH 6 gave new NADP derivatives carboxyethylated at the 2'-phosphate or 6-amino group, or both: 2'-O-(2-carboxyethyl)phosphono-NAD (I), N6-(2-carboxyethyl)-NADP (II), and 2'-O-(2-carboxyethyl)phosphono-N6-(2-carboxyethyl)-NAD (III). Their structures were assigned on the basis of ultraviolet, 1H-NMR and 31P-NMR spectra, and also treatment with nucleotide pyrophosphatase or alkaline phosphatase. Carbodiimide-promoted reaction of derivative I with 1,2-diaminoethane gave 2'-O-[N-(2-aminoethyl)carbamoylethyl]phosphono-NAD (IV); derivative III gave 2'-O-[N-(2-aminoethyl)carbamoylethyl]phosphono-N6-[N-(2-aminoethyl ) carbamoylethyl]-NAD (IV). The same reaction of derivative II, on the other hand, gave a mixture of N6-[N-(2-aminoethyl)carbamoylethyl]-NADP (Va) and its 3'-phosphate isomer (Vb). The mixture was converted to Va via the 2',3'-cyclic derivative (Vc). Their structures were assigned on the basis of ultraviolet and 1H-NMR spectra, and also treatment with alkaline phosphatase or 3'-nucleotidase. All the NADP derivatives obtained in this work could be reduced with yeast glucose-6-phosphate dehydrogenase.
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PMID:Preparation and characterization of NADP derivatives alkylated at 2'-phosphate and 6-amino groups. 383 79

Anaerobically induced NAD-linked glycerol dehydrogenase of Klebsiella pneumoniae for fermentative glycerol utilization was reported previously to be inactivated in the cell during oxidative metabolism. In vitro inactivation was observed in this study by incubating the purified enzyme in the presence of O2, Fe2+, and ascorbate or dihydroxyfumarate. It appears that O2 and the reducing agent formed H2O2 and that H2O2 reacted with Fe2+ to generate an activated species of oxygen which attacked the enzyme. The in vitro-oxidized enzyme, like the in vivo-inactivated enzyme, showed an increased Km for NAD (but not glycerol) and could no longer be activated by Mn2+ which increased the Vmax of the native enzyme but decreased its apparent affinity for NAD. Ethanol dehydrogenase and 1,3-propanediol oxidoreductase, two enzymes with anaerobic function, also lost activity when the cells were incubated aerobically with glucose. However, glucose 6-phosphate dehydrogenase (NADP-linked), isocitrate dehydrogenase, and malate dehydrogenase, expected to function both aerobically and anaerobically, were not inactivated. Thus, oxidative modification of proteins in vivo might provide a mechanism for regulating the activities of some anaerobic enzymes.
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PMID:Inactivation of glycerol dehydrogenase of Klebsiella pneumoniae and the role of divalent cations. 390 46

In porcine areolar placental epithelia, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, nonspecific esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that the enzyme activities remained almost unchanged during the period of investigation. Of the dehydrogenases, the diaphorases as well as succinate and lactate dehydrogenase demonstrated generally an intensive activity within the epithelia. The activity of the other dehydrogenases was only low. The activity of unspecific esterase was very intensive within the uterine epithelia but remarkably low within chorionic epithelia. Contrarily, the reaction of adenosine triphosphatase was more intensive within chorionic than uterine epithelia. All investigated glucosidases reacted distinctly positive within chorionic epithelia, but only beta-N-acetyl-hexosaminidase and beta-galactosidase in uterine epithelia. The high activity of acid phosphatase, especially within the chorionic epithelium, seems to be connected with uteroferrin, an iron-binding protein. The histochemical results are discussed in context with the function of the areolae in histiotrophic nutrition and iron transport.
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PMID:[Enzyme-histochemical studies of the pig placenta. II. Histotopics of enzymes in the areolar placenta epithelium]. 392 41

Implantation of cobalt-agar rods into the visual cortex of 16 adult rats induced in some of the animals epileptiform bioelectrical activity and provoked in all of them histological and histochemical changes in the region of the implantation (primary focus) as well as in some ipsilateral projection sites of the visual cortex (secondary foci). The changes within the secondary foci are demonstrated in the Corpus geniculatum laterale, pars dorsale (dLGN), by means of 18 histochemical and 5 histological methods. Together with the appearance of hyperactive and degenerating neurones combined with neuronophagy and diminution of the number of synapses a marked gliosis developed, especially an increase of microglia. The destruction of the tissue induced a depression of energy and transmitter metabolism and intensified lytic processes. This is confirmed by the decreased activities of LDH, SDH, GPDH, G6PDH, NAD(P)H-TR, GABA-T and GDH and the increased activity of acid phosphatase in the neuropil of the secondary foci. Single hyperactive nerve and glial cells were accented by high activities of those enzymes which had a reduced activity in the neuropil. Since in our experiments agar-rods without cobalt never induced histological or histochemical changes in subcortical grisea of the visual system, the secondary foci seem to result from the direct influence of the cobalt, migrating in the corticothalamic projection pathway and identifiable in the dLGN by the TIMM technique.
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PMID:[Morphologic and histochemical changes in the secondary focus following cobalt-induced epileptogenic bioelectrical activity of the visual cortex in the adult rat]. 393 55


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