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Ramazan Demirdag - One of the best experts on this subject based on the ideXlab platform.

  • examination of changes in enzyme activities of erythrocyte glucose 6 phosphate Dehydrogenase and 6 Phosphogluconate Dehydrogenase in rats given naringenin and lead acetate
    Journal of Biochemical and Molecular Toxicology, 2015
    Co-Authors: Ramazan Demirdag, Veysel Comakli, Ahmet Ozkaya, Zafer Sahin, Uzeyir Dag, Emrah Yerlikaya, Muslum Kuzu
    Abstract:

    In our study, controlled experimental groups were performed by giving substances Lead acetate, Naringenin and Naringenin + Lead acetate to rats in vivo conditions Changes in the glucose 6-phosphate Dehydrogenase (G6PD) and 6-Phosphogluconate Dehydrogenase (6PGD) enzyme activities in erythrocytes of rats in these groups were compared to the Control group. An inhibition significant degree for G6PD enzyme activity was observed in all groups when compared to the Control group (p 0.05). In addition, lead levels in the groups of rats were determined using an inductively coupled plasma mass spectrometer (ICP-MS) device. As a result of measurements by the ICP-MS device, lead levels were found as an average of 42.9 ± 2.51, 36.71 ± 1.13, 172.16 ± 9.63, and 95.07 ± 5.87 ppm in the Control, Naringenin, Lead acetate and Naringenin + Lead acetate groups, respectively. Our results were shown that Naringenin has protective effects on the Lead acetate induced oxidative stress erythrocytes in rat.

  • investigation of the effects of some phenolic compounds on the activities of glucose 6 phosphate Dehydrogenase and 6 Phosphogluconate Dehydrogenase from human erythrocytes
    Journal of Biochemical and Molecular Toxicology, 2014
    Co-Authors: Sevki Adem, Veysel Comakli, Muslum Kuzu, Ramazan Demirdag
    Abstract:

    Polyphenols are the important compounds that have various bioactivities. They constitute vital active agents of not only daily diet but also natural medicines that are used traditionally. It is generally considered that they are safe because they are natural. In some conducted studies, different negative effects of these compounds were mentioned. Twelve phenolic compounds have been assayed to determine the effect of inhibition on glucose-6-phosphate Dehydrogenase (G6PD) and 6-Phosphogluconate Dehydrogenase (6PGD) enzymes activity. For in vitro studies, the enzymes were purified from human erythrocytes using 2',5'-ADP Sepharose 4B affinity chromatography. Naringenin, caffeic acid, ellagic acid, ferulic acid, and sinapic acid against two enzymes, hesperidin and polydatin, only on G6PD activity and chrysin solely against 6PGD showed inhibitory effect. Chlorogenic acid, p-coumaric acid, and syringic acid did not exhibit an effect on the activity of the two enzymes.

Stefania Hanau - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic characterization of substrate and inhibitor binding to trypanosoma brucei 6 Phosphogluconate Dehydrogenase
    FEBS Journal, 2007
    Co-Authors: Katy Montin, Franco Dallocchio, Carlo Cervellati, Stefania Hanau
    Abstract:

    6-Phosphogluconate Dehydrogenase is a potential target for new drugs against African trypanosomiasis. Phosphorylated aldonic acids are strong inhibitors of 6-Phosphogluconate Dehydrogenase, and 4-phospho-d-erythronate (4PE) and 4-phospho-d-erythronohydroxamate are two of the strongest inhibitors of the Trypanosoma brucei enzyme. Binding of the substrate 6-phospho-d-gluconate (6PG), the inhibitors 5-phospho-d-ribonate (5PR) and 4PE, and the coenzymes NADP, NADPH and NADP analogue 3-amino-pyridine adenine dinucleotide phosphate to 6-phospho-d-gluconate Dehydrogenase from T. brucei was studied using isothermal titration calorimetry. Binding of the substrate (K(d) = 5 microm) and its analogues (K(d) =1.3 microm and K(d) = 2.8 microm for 5PR and 4PE, respectively) is entropy driven, whereas binding of the coenzymes is enthalpy driven. Oxidized coenzyme and its analogue, but not reduced coenzyme, display a half-site reactivity in the ternary complex with the substrate or inhibitors. Binding of 6PG and 5PR poorly affects the dissociation constant of the coenzymes, whereas binding of 4PE decreases the dissociation constant of the coenzymes by two orders of magnitude. In a similar manner, the K(d) value of 4PE decreases by two orders of magnitude in the presence of the coenzymes. The results suggest that 5PR acts as a substrate analogue, whereas 4PE mimics the transition state of dehydrogenation. The stronger affinity of 4PE is interpreted on the basis of the mechanism of the enzyme, suggesting that the inhibitor forces the catalytic lysine 185 into the protonated state.

  • use of trinitrobenzensulfonate for affinity labeling of lysine residues at phosphate binding sites of some enzymes
    Archives of Biochemistry and Biophysics, 1993
    Co-Authors: Stefania Hanau, Franco Dallocchio, Mario Rippa
    Abstract:

    Abstract Trinitrobenzensulfonate, a reagent for lysine residues, inactivates lamb liver 6-Phosphogluconate Dehydrogenase through affinity labeling. Complete inactivation is due to the binding of only one residue of reagent per enzyme subunit. Other enzymes with a phosphate binding site are also inactivated by affinity labeling. It appears that trinitrobenzensulfonate, when used at low concentrations, first binds to a phosphate binding site, then reacts with a nearby lysine residue. This reagent presents some advantages over pyridoxal phosphate, which has similar characteristics.

Sunghoon Park - One of the best experts on this subject based on the ideXlab platform.

  • co production of hydrogen and ethanol from glucose in escherichia coli by activation of pentose phosphate pathway through deletion of phosphoglucose isomerase pgi and overexpression of glucose 6 phosphate Dehydrogenase zwf and 6 Phosphogluconate Dehydrogenase gnd
    Biotechnology for Biofuels, 2017
    Co-Authors: Balaji Sundara Sekar, Eunhee Seol, Sunghoon Park
    Abstract:

    Biologically, hydrogen (H2) can be produced through dark fermentation and photofermentation. Dark fermentation is fast in rate and simple in reactor design, but H2 production yield is unsatisfactorily low as <4 mol H2/mol glucose. To address this challenge, simultaneous production of H2 and ethanol has been suggested. Co-production of ethanol and H2 requires enhanced formation of NAD(P)H during catabolism of glucose, which can be accomplished by diversion of glycolytic flux from the Embden–Meyerhof–Parnas (EMP) pathway to the pentose-phosphate (PP) pathway in Escherichia coli. However, the disruption of pgi (phosphoglucose isomerase) for complete diversion of carbon flux to the PP pathway made E. coli unable to grow on glucose under anaerobic condition. Here, we demonstrate that, when glucose-6-phosphate Dehydrogenase (Zwf) and 6-Phosphogluconate Dehydrogenase (Gnd), two major enzymes of the PP pathway, are homologously overexpressed, E. coli Δpgi can recover its anaerobic growth capability on glucose. Further, with additional deletions of ΔhycA, ΔhyaAB, ΔhybBC, ΔldhA, and ΔfrdAB, the recombinant Δpgi mutant could produce 1.69 mol H2 and 1.50 mol ethanol from 1 mol glucose. However, acetate was produced at 0.18 mol mol−1 glucose, indicating that some carbon is metabolized through the Entner–Doudoroff (ED) pathway. To further improve the flux via the PP pathway, heterologous zwf and gnd from Leuconostoc mesenteroides and Gluconobacter oxydans, respectively, which are less inhibited by NADPH, were overexpressed. The new recombinant produced more ethanol at 1.62 mol mol−1 glucose along with 1.74 mol H2 mol−1 glucose, which are close to the theoretically maximal yields, 1.67 mol mol−1 each for ethanol and H2. However, the attempt to delete the ED pathway in the Δpgi mutant to operate the PP pathway as the sole glycolytic route, was unsuccessful. By deletion of pgi and overexpression of heterologous zwf and gnd in E. coli ΔhycA ΔhyaAB ΔhybBC ΔldhA ΔfrdAB, two important biofuels, ethanol and H2, could be successfully co-produced at high yields close to their theoretical maximums. The strains developed in this study should be applicable for the production of other biofuels and biochemicals, which requires supply of excessive reducing power under anaerobic conditions.

Muslum Kuzu - One of the best experts on this subject based on the ideXlab platform.

  • examination of changes in enzyme activities of erythrocyte glucose 6 phosphate Dehydrogenase and 6 Phosphogluconate Dehydrogenase in rats given naringenin and lead acetate
    Journal of Biochemical and Molecular Toxicology, 2015
    Co-Authors: Ramazan Demirdag, Veysel Comakli, Ahmet Ozkaya, Zafer Sahin, Uzeyir Dag, Emrah Yerlikaya, Muslum Kuzu
    Abstract:

    In our study, controlled experimental groups were performed by giving substances Lead acetate, Naringenin and Naringenin + Lead acetate to rats in vivo conditions Changes in the glucose 6-phosphate Dehydrogenase (G6PD) and 6-Phosphogluconate Dehydrogenase (6PGD) enzyme activities in erythrocytes of rats in these groups were compared to the Control group. An inhibition significant degree for G6PD enzyme activity was observed in all groups when compared to the Control group (p 0.05). In addition, lead levels in the groups of rats were determined using an inductively coupled plasma mass spectrometer (ICP-MS) device. As a result of measurements by the ICP-MS device, lead levels were found as an average of 42.9 ± 2.51, 36.71 ± 1.13, 172.16 ± 9.63, and 95.07 ± 5.87 ppm in the Control, Naringenin, Lead acetate and Naringenin + Lead acetate groups, respectively. Our results were shown that Naringenin has protective effects on the Lead acetate induced oxidative stress erythrocytes in rat.

  • investigation of the effects of some phenolic compounds on the activities of glucose 6 phosphate Dehydrogenase and 6 Phosphogluconate Dehydrogenase from human erythrocytes
    Journal of Biochemical and Molecular Toxicology, 2014
    Co-Authors: Sevki Adem, Veysel Comakli, Muslum Kuzu, Ramazan Demirdag
    Abstract:

    Polyphenols are the important compounds that have various bioactivities. They constitute vital active agents of not only daily diet but also natural medicines that are used traditionally. It is generally considered that they are safe because they are natural. In some conducted studies, different negative effects of these compounds were mentioned. Twelve phenolic compounds have been assayed to determine the effect of inhibition on glucose-6-phosphate Dehydrogenase (G6PD) and 6-Phosphogluconate Dehydrogenase (6PGD) enzymes activity. For in vitro studies, the enzymes were purified from human erythrocytes using 2',5'-ADP Sepharose 4B affinity chromatography. Naringenin, caffeic acid, ellagic acid, ferulic acid, and sinapic acid against two enzymes, hesperidin and polydatin, only on G6PD activity and chrysin solely against 6PGD showed inhibitory effect. Chlorogenic acid, p-coumaric acid, and syringic acid did not exhibit an effect on the activity of the two enzymes.

Stuart L Schreiber - One of the best experts on this subject based on the ideXlab platform.

  • 6 Phosphogluconate Dehydrogenase links cytosolic carbohydrate metabolism to protein secretion via modulation of glutathione levels
    Chemistry & Biology, 2019
    Co-Authors: Maria Ericsson, Bokang Rabasha, Bogdan Budnik, Bridget K Wagner, Levi A Garraway, Sze Ham Chan, Elizaveta Freinkman, Caroline A Lewis, John G Doench, Stuart L Schreiber
    Abstract:

    Summary The proteinaceous extracellular matrix (ECM) is vital for the survival, proliferation, migration, and differentiation of many types of cancer. However, little is known regarding metabolic pathways required for ECM secretion. By using an unbiased computational approach, we searched for enzymes whose suppression may lead to disruptions in protein secretion. Here, we show that 6-Phosphogluconate Dehydrogenase (PGD), a cytosolic enzyme involved in carbohydrate metabolism, is required for ER structural integrity and protein secretion. Chemical inhibition or genetic suppression of PGD activity led to cell stress accompanied by significantly expanded ER volume and was rescued by compensating endogenous glutathione supplies. Our results also suggest that this characteristic ER-dilation phenotype may be a general marker indicating increased ECM protein congestion inside cells and decreased secretion. Thus, PGD serves as a link between cytosolic carbohydrate metabolism and protein secretion.

  • 6 Phosphogluconate Dehydrogenase links cytosolic carbohydrate metabolism to protein secretion
    bioRxiv, 2018
    Co-Authors: Maria Ericsson, Bokang Rabasha, Bogdan Budnik, Bridget K Wagner, Levi A Garraway, Stuart L Schreiber
    Abstract:

    SUMMARY The proteinaceous extracellular matrix (ECM) is vital for cancer cell survival, proliferation, migration, and differentiation. However, little is known regarding metabolic pathways required in the ECM secretion process. By using an unbiased computational approach, we searched for enzymes whose suppression may lead to disruptions in protein secretion. Here, we show that 6-Phosphogluconate Dehydrogenase (PGD), a cytosolic enzyme involved in carbohydrate metabolism, is required for endoplasmic reticulum (ER) structural integrity and protein secretion. Chemical inhibition or genetic suppression of its activity led to cell stress accompanied by significantly expanded ER volume and can be rescued by compensating glutathione supplies. Our results also suggest that this characteristic ER-dilation phenotype may be a general marker indicating increased ECM protein congestion inside cells and decreased secretion. Thus, PGD exemplifies a nexus of cytosolic carbohydrate metabolism and protein secretion.