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)

Aggregation of thrombocytes, caused by ADP, affected the rate of anaerobic breakdown of carbohydrates due to inhibition of the glucose degradation, while the rate of lactate formation was not distinctly altered. Content of NAD was decreased simultaneously with an increase in content of NADP; the activity of glucose-6-phosphate dehydrogenase was distinctly increased but the unaltered activity of 6-phosphogluconate dehydrogenase was observed; content of reduced glutathione was increased 15-fold. The activity of NADP-dependent glutathione reductase was increased under effect of ADP; at the same time, the activity of NAD-dependent glutathione reductase did not depend on the diphosphate effect.
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PMID:[Relationship between glycolysis and pentose cycle intensity and thrombocyte aggregation induced by ADP in man]. 2 84

Sperm from normal human donors and a G6PD-A- individual were examined for x-linked glucose-6-phosphate dehydrogenase activity and autosomally linked 6-phosphogluconate dehydrogenase activity. With the use of fluorescence microscopy, we divised a procedure to visualise in individual sperm cells the fluorescence of reduced coenzyme NADPH formed by each of the two enzymes in the presence of appropriate substrates. We found significant differences in the population distribution of sperm expressing each of the two activities, and the ratio of the two activities in sperm homogenate is very different from the one found in erythrocyte lysates. The possibility of haploid gene expression has been considered in interpreting these results.
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PMID:Glucose-6-phosphate dehydrogenase (G6PD) activity of human sperm. 2 66

Plasma cholesterol was lower in spontaneously hypertensive rats (SHR), while plasma triglyceride and free fatty acid were increased in comparison with control normotensive Wistar-Kyoto (WK) rats. Correspondingly, [1-14C]-acetate incorporation into liver cholesterol was clearly decreased in SHR as compared with WK. As for lipogenic enzyme activities, glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase in SHR were respectively decreased, increased and not significantly different, in comparison with WK rats. Liver cholesterol was rather low and cardiac triglyceride was slightly increased in SHR. Aortic cholesterol and triglyceride levels were not significantly different between SHR AND WK rats. Thus, SHR have an abnormality in lipid metabolism, especially in cholesterol synthesis, but the pathological implication of this in hypertension and related vascular lesions is not yet clear.
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PMID:Lipid metabolism in spontaneously hypertensive rats (SHR). 2 30

The hexose monophosphate pathway of human glucose-6-phosphate dehydrogenase (EC 1.1.1.49) - deficient erythrocytes is under a severe and unexplained restraint (Gaetani, G.D., Parker, J.C. and Kirkman, H.N. (1974) Proc. Natl. Acad. Sci. U.S. 71, 3584-3587). In this study the hexose monophosphate pathway activity and the NADPH level of normal and glucose-6-phosphate dehydrogenase-deficient erythrocytes were measured soon after haemolysis. The results indicate a prompt increase in 14CO2 evolution and a rise in MADPH levels. Since, in this study, the concentration of the haemolysate is comparable to that of intact erythrocytes, the relief of the restraint on glucose-6-phosphate dehydrogenase through dilution-dependent dissociation from inactivator or inhibitor is excluded. The possibility that the intracellular restraint may result from compartmentalization of glucose-6-phosphate dehydrogenase and substrates or from properties of the intact membrane of the erythrocytes is suggested.
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PMID:Effect of haemolysis on the hexose monophosphate pathway in normal and in glucose-6-phosphate dehydrogenase-deficient erythrocytes. 2 53

Kinetic and electrophoretic properties of 230--300 fold purified preparations of glucose-6-phosphate dehydrogenase (G6PD) from red cells of donors and patients with acute drug hemolytic anemia due to G6PD deficiency were studied. A new abnormal variant of G6PD isolated from red cell of a patient with acute drug hemolytic anemia, which was not described in literature, has been discovered. The abnormal enzyme differs from the normal by decreased Michaelis constant for glucose-6-phosphate and nicotinamide adenine dinucleotide phosphate (NADP), by increased utilization of analogues of substrates--2-deoxy-glucose-6-phosphate and particularly deamino-NADP, by low thermal stability, by the character of pH-dependence, by the appearance of a single band of G6PD activity in polyacrylamide gel electrophoresis.
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PMID:[Detection of a new anomalous variant of glucose-6-phosphate dehydrogenase in human erythrocytes]. 2 88

Erythrocyte glucose-6-phosphate dehydrogenase from patients with acute viral hepatitis has been purified and characterized. The enzyme showed decreased activity (relative to protein), reduced affinity for glucose 6-phosphate and was inactivated at 45 degrees C or at low pH values. The activity and properties of normal erythrocyte enzyme, incubated in vitro with blood plasma of patients, showed a similar pattern of modifications. Incubation with bilirubin affected the enzyme stability, but not its activity or affinity for substrate.
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PMID:Acquired enzymopathy of erythrocyte glucose-6-phosphate dehydrogenase in acute viral hepatitis. 2 32

Kinetic and electrophoretic properties were studied in 230--300 fold purified preparations of glucose-6-phosphate dehydrogenase (G-6-PD) from red cells of donors and patients with hemolytic anemia induced by G-6-PD deficiency. In abnormal variant of G-6-PD isolated from red cells of a patient with hemolytic anemia which had not before been described in the literature was found. The abnormal variant differs from the normal enzyme by a decreased Michaelis constant for G-6-P and NADP, by increased utilization of substrate-analogues (2-deoxy-G-6-P and deamino NADP in particular), by low heat stability, the character of pH dependence, and by the appearance of one band of G-6-PD activity during electrophoresis in polyacrylamide gel. The isolated abnormal variant of G-6-PD has been called "Kremenchug" according to the origin of the patient.
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PMID:Characteristics of a new abnormal variant of G-6-PD in human red cells. 2 34

The kinetic and molecular properties of cyanobacterial glucose-6-phosphate dehydrogenase, partly purified from Anabaena sp. ATCC 27893, show that it undergoes relatively slow, reversible transitions between different aggregation states which differ in catalytic activity. Sucrose gradient centrifugation and polyacrylamide gel electrophoresis reveal three pincipal forms, with approximate molecular weights of 120 000 (M1), 240 000 (M2) and 345 000 (M3). The relative catalytic activities are: M1 less than M2 less than M3. In concentrated solutions of the enzyme, the equilibrium favors the more active, oligomeric forms. Dilution in the absence of effectors shifts the equilibrium in favor of the M1 form, with a marked diminution of catalytic activity. This transition is prevented by a substrate, glucose-6-phosphate, and also by glutamine. The other substrate, nicotinamide adenine dinucleotide phosphate (NADP+), and (in crude cell-free extracts) ribulose-1,5-diphosphate are negative effectors, which tend to maintain the enzyme in the M1 form. The equilibrium state between different forms of the enzyme is also strongly dependent on hydrogen ion concentration. Although the optimal pH for catalytic activity is 7.4, dissociation to the hypoactive M1 form is favored at pH values above 7; a pH of 6.5 is optimal for maintenance of the enzyme in the active state. Reduced nicotamide adenine dinucleotide phosphate (NADPH) and adenosine 5'-triphosphate (ATP), inhibit catalytic activity, but do not significantly affect the equilibrium state. The relevance of these findings to the regulation of enzyme activity in vivo is discussed.
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PMID:Glucose-6-phosphate dehydrogenase of Anabaena sp. Kinetic and molecular properties. 2 37

High activity alkaline protease was obtained when the enzyme was immobilized on Dowex MWA-1 (mesh 20-50) with 10% glutaraldehyde in chilled phosphate buffer (M/15, PH 6.5). Activity yields of the protease and rennet were 27 and 29, respectively. The highest activities appeared at 60 degrees C, pH 10 for alkaline protease and 50 degrees C, pH 4.0 for rennet. The properties of both proteases were not essentially changed by the immobilization except that the Km values of both enzymes were increased about tenfold as a result of immobilization. Both proteases in the immobilized state were more stable than those in the free state at 60 degrees C. Other peptide hydrolases, beta-galactosidase, invertase, and glucoamylase, were successfully immobilized with high activities, but lipase, hexokinase, glucose-6-phosphate dehydrogenase, and xanthine oxidase became inactive.
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PMID:Preparation and properties of proteases immobilized on anion exchange resin with glutaraldehyde. 2 75

This study examines the effects of MPA (medroxyprogesterone acetate) on some of the hepatic enzymes of carbohydrate and lipid metabolism in the rat, and compares these with the effects of cortisol and saline. Levels of reduced nicotinamide adenine dinucleotide phosphate (NADPH) were also measured. Intact mature female Wistar rats with average initial weight of 200 gms were injected with MPA (mO mg/kg IM) once a week for 4 weeks and were sacrificed 3 to 5 days after the last injection. Hydrocortisone (Solu-Cortef [R]) 40 mg/kg IM were given to cortisol-treated animals twice daily for 7 days. The animals were sacrificed 2-4 hours after the last dose was given. Normal saline (0.2 mg. IM) was injected in control animals twice a day. The method of Jellinek, Amako, and Willman was used to analyze NADPH. Liver samples were assayed for various enzymatic activities such as phophofructokinase (PFK); pyruvate kinase (PK), glycerol-3-phosphate dehydrogenase (G3PD), "malic" enzyme (ME), and glucose-6-phosphate dehydrogenase (G6PD). The methods of Colowick and Kaplan were used in enzymatic analyses. Lipogenic stimulation by MPA is indicated by increased levels of G3PD and ME, both of which are implicated in lipogenesis, as well as by NADPH. PFK, PK, and G6PD were all unaffected by the MPA regimen, suggesting that elevation of ME and NADPH activities may reflect increased amino acid conservation. The enzymatic pattern of MPA treatment shows lipogenesis and protein conservation, while that of cortisol regimen shows significantly lower levels of ME, G3PD, and PRK.
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PMID:Some effects of medroxyprogesterone acetate on intermediary metabolism in rat liver. 2 59


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