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Glucose-6-phosphate Dehydrogenase (glucose-6-phosphate + dehydrogenase)

Distribution by Scientific Domains
Medical Sciences42%
Life Sciences42%

Terms modified by Glucose-6-phosphate Dehydrogenase

  • glucose-6-phosphate dehydrogenase deficiency
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    Selected Abstracts

    Glucose-6-phosphate dehydrogenase from the hyperthermophilic bacterium Thermotoga maritima: expression of the g6pd gene and characterization of an extremely thermophilic enzyme

    FEMS MICROBIOLOGY LETTERS, Issue 2 2002
    Thomas Hansen
    Abstract The gene (open reading frame Tm1155, g6pd) encoding glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) of the hyperthermophilic bacterium Thermotoga maritima was cloned and functionally expressed in Escherichia coli. The purified recombinant enzyme is a homodimer with an apparent molecular mass of 95 kDa composed of 60-kDa subunits. Rate dependence (at 80°C) on glucose-6-phosphate and NADP+ followed Michaelis,Menten kinetics with apparent Km values of 0.15 mM and 0.03 mM, respectively; apparent Vmax values were about 20 U mg,1. The enzyme also reduced NAD+ (apparent Km 12 mM, Vmax 12 U mg,1). The 1000-fold higher catalytic activity (kcat/Km) with NADP+ over NAD+ defines the G6PD as NADP+ specific in vivo. G6PD activity was competitively inhibited by NADPH with a Ki value of 0.11 mM. With a temperature optimum of 92°C the enzyme is the most thermoactive G6PD described. [source]

    Prevalence of glucose-6-phosphate dehydrogenase deficiency in Northern Greece

    INTERNAL MEDICINE JOURNAL, Issue 3 2008
    G. Ntaios
    Abstract Glucose-6-phosphate dehydrogenase (G6PD) deficiency affects more than 400 million persons worldwide. Its distribution varies significantly among different geographic regions and different population groups. Purpose of our study was to estimate its prevalence in Northern Greece. The dataset comprised 5161 newborns and adults who were screened for G6PD deficiency between July 2001 and March 2007. G6PD deficiency was detected by the dye reduction method. In the screened group, 6.3% of subjects were G6PD deficient. Moderate enzyme deficiency was shown in 139 individuals (2.7%). Complete deficiency was identified in 3.7%. The prevalence of G6PD deficiency in Northern Greece is much higher compared with the general Greek population. Moreover, G6PD prevalence in the male sex is much higher , almost double , that in the female sex. [source]

    The 6-phosphogluconate Dehydrogenase Genes Are Responsive to Abiotic Stresses in Rice

    JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 5 2007
    Fu-Yun Hou
    Abstract Glucose-6-phosphate dehydrogenase (G6PDH, E.C. 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGDH, EC 1.1.1.44) are both key enzymes of the pentose phosphate pathway (PPP). The OsG6PDH1 and Os6PGDH1 genes encoding cytosolic G6PDH and cytosolic 6PGDH were isolated from rice (Oryza sativa L.). We have shown that Os6PGDH1 gene was up-regulated by salt stress. Here we reported the isolation and characterization of Os6PGDH2 from rice, which encode the plastidic counterpart of 6PGDH. Genomic organization analysis indicated that OsG6PDH1 and OsG6PDH2 genes contain multiple introns, whereas two Os6PGDH1 and Os6PGDH2 genes have no introns in their translated regions. In a step towards understanding the functions of the pentose phosphate pathway in plants in response to various abiotic stresses, the expressions of four genes in the rice seedlings treated by drought, cold, high salinity and abscisic acid (ABA) were investigated. The results show that OsG6PDH1 and OsG6PDH2 are not markedly regulated by the abiotic stresses detected. However, the transcript levels of both Os6PGDH1 and Os6PGDH2 are up-regulated in rice seedlings under drought, cold, high salinity and ABA treatments. Meanwhile, the enzyme activities of G6PDH and 6PGDH in the rice seedlings treated by various abiotic stresses were investigated. Like the mRNA expression patterns, G6PDH activity remains constant but the 6PGDH increases steadily during the treatments. Taken together, we suggest that the pentose phosphate pathway may play an important role in rice responses to abiotic stresses and the second key enzyme of PPP, 6PGDH, may function as a regulator controlling the efficiency of the pathway under abiotic stresses. (Handling editor: Kang Chong) [source]

    Screening for glucose-6-phosphate dehydrogenase deficiency using a modified formazan method: A pilot study on Filipino male newborns

    PEDIATRICS INTERNATIONAL, Issue 1 2003
    CARMENCITA PADILLA
    AbstractBackground: Glucose-6-phosphate dehydrogenase (G6PD) deficiency has increased prevalence rates in tropical Africa, tropical and subtropical Asia and some parts of the Mediterranean. Earlier studies on G6PD deficiency in the Philippines have shown prevalence rates of 4.5% to 25.7%. Methods: In the present study, 3278 male newborns were screened for G6PD deficiency using the modified formazan method, a simple screening procedure affordable in the setting of a developing country. Subjects with positive screening results were recalled for confirmatory testing using a commercial assay kit for quantitative enzyme determination. Results: Of the 3278 boys studied, 186 revealed positive screening results. Of the 186, 65 boys had confirmatory testing. Of these 65 boys, 45 were confirmed to have G6PD deficiency and 20 had normal results. This study reveals an incidence of G6PD deficiency of 3.9% among male Filipinos. Conclusion: This study recommends the inclusion of G6PD deficiency in the panel of disorders for newborn screening among Filipino newborns. [source]

    Dietary protein/lipid level and protein source effects on growth, tissue composition and lipid metabolism of blackspot seabream (Pagellus bogaraveo)

    AQUACULTURE NUTRITION, Issue 2 2010
    A.C. FIGUEIREDO-SILVA
    Abstract A study was carried out to determine the effects of fish meal (FM) replacement by plant protein (PP) on growth, body composition and lipid metabolism of blackspot seabream fed different protein/lipid levels. Four experimental diets were formulated to contain two protein (P) and lipid (L) levels (60P/6L or 50P/10L), varying in their protein source (100% FM or 50% FM: 50% PP). Dietary inclusion of PP did not affect growth of fish fed 60P/6L, although fish fed 50P/10L exhibited lower final body weight and daily growth index. Fish fed 60P/6L presented the highest protein and the lowest lipid content. FM replacement by PP has decreased muscle n-3 whereas the n-6 fatty acids increased. Glucose-6-phosphate dehydrogenase and fatty acid synthetase (FAS) were depressed in fish fed 50P/10L. FAS was significantly increased with 60P/6L PP which was positively correlated with lipid retention data. Those results suggest the conversion of other nutrient than lipid (protein and/or carbohydrates) into corporal fat. Hepatic lipoprotein lipase activity was lowest in fish fed PP diets. Plasma glucose peaked 1,2 h postfeeding, in all groups and was generally higher with 60P/6L FM. This work shown that besides dietary P/L level, protein source has a strong effect on species lipogenesis and lipid retention. Hence, the 50P/10L FM diet was the most cost-effective for blackspot seabream juveniles. [source]

    Cell growth and cholesterol metabolism in human glucose- 6-phosphate dehydrogenase deficient lymphomononuclear cells

    CELL PROLIFERATION, Issue 3 2002
    Batetta B.
    Atherosclerosis is an inflammatory-fibroproliferative response of the arterial wall involving a complex set of interconnected events where cell proliferation (lymphomonocytes, and endothelial and smooth-muscle cells) and substantial perturbations of intracellular cholesterol metabolism are considered to be among the main features. Glucose-6-phosphate dehydrogenase (G6PD), the key enzyme of the hexose-monophosphate shunt pathway, is an essential enzyme involved in both cell growth and cholesterol metabolism, raising the question as to whether G6PD deficiency may have metabolic and growth implications in a deficient population. In the present study, we investigated cell growth and cholesterol metabolism in peripheral blood lymphomononuclear cells (PBMC) from G6PD-normal (n = 5) and -deficient (n = 5) subjects stimulated with lectins (phytohaemoagglutinin and Concanavalin A). G6PD activity, DNA ([3H]-thymidine incorporation) cholesterol synthesis and esterification ([14C]-acetate and [14C]-oleate incorporation), and G6PD, HMGCoA reductase and low density lipoprotein (LDL) receptor mRNA levels (RT-PCR) all increased following lectin stimulation in both normal and G6PD-deficient cells. However, these parameters were significantly lower in G6PD-deficient cells (P < 0.05). It is of interest that G6PD-deficient PBMC, which showed lower expression of G6PD and higher expression of the LDL receptor gene than normal PBMC under basal conditions, exhibited an opposite pattern after stimulation: G6PD and HMGCoA reductase being expressed at significantly higher levels in deficient than in normal cells (P < 0.05). We conclude that the reduced capability of G6PD-deficient cells to respond to mitogenic stimuli and to synthesize cholesterol esters may represent favourable conditions for reducing the risk of cardiovascular diseases. [source]

    Genetic polymorphisms in Thai neonates with hyperbilirubinemia

    ACTA PAEDIATRICA, Issue 7 2009
    Sariya Prachukthum
    Abstract Aim:, Polymorphisms of the UGT1A1 gene, SLCO1B1 gene and GST gene have been associated with significant hyperbilirubinemia. We would like to determine whether the variation of UGT1A1 gene, SLCO1B1 gene and GST gene may play a significant role in neonatal hyperbilirubinemia in Thai infants. Methods:, Ninety-one study subjects (hyperbilirubinemic group) and 86 control subjects were studied. Results:, The cause of neonatal hyperbilirubinemia could not be identified in 64 infants (70.3%), ABO blood group incompatibility in 14.3% and Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in 8.8%. In the hyperbilirubinemic group, 23 of 91 (25.3%) infants demonstrated variant of UGT1A1 at nucleotides (nt) 211 as compared to 6 of 86 (7%) in the control group (p = 0.001). There were no significant differences between groups in the variants UGT1A1 at nt 686, SLCO1B1 gene at nt 388, 463 and the GST gene. Male infants with G-6-PD deficiency were associated with hyperbilirubinemia (21.2% vs. 4.8% in the control group) with an odds ratio (OR) of 5.37 (p =0.02). The relationship between G-6-PD and variant in UGT1A1 gene at nt 211 could not be determined. Conclusion:, Thai infants with variant in the UGT1A1 at nt 211 or with G-6-PD deficiency are at higher risk for developing neonatal hyperbilirubinemia. [source]