Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.2.1.13 (glyceraldehyde-3-phosphate dehydrogenase)
6,511 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study was (a) to establish a red blood cell (RBC) protein map with immobilized pH gradient for the first dimension (b) to compare the pattern with previously published RBC protein map obtained with carrier-ampholyte pH gradients and (c) to localize four new enzymes on the map (i.e. 6-phosphogluconic dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutathione peroxidase and superoxide dismutase). This publication provides the most updated RBC polypeptide pattern with twelve proteins or enzymes localized on the map.
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PMID:Red blood cell protein map: a comparison between carrier-ampholyte pH gradient and immobilized pH gradient, and identification of four red blood cell enzymes. 147 17

Glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activities were assayed in superficial pectoral muscles of hereditary dystrophic chickens, 1 week, 2 weeks, 4 weeks and 4 months after hatching. In control chickens, activities of G6PDH and 6PGDH were very low at 4 months of age; however, at 1 week of age, they were much higher than those at 4 months of age. Activities of G6PDH and 6PGDH were significantly higher in dystrophic chickens compared with those in the controls at all the stages of development studied. These findings suggest that considerable activities of G6PDH and 6PGDH are present within the pectoral muscle cells at early stages of development, at least in dystrophic chickens. GAPDH activity was significantly lower in dystrophic chickens at 2 weeks, 4 weeks and 4 months of age compared with those in control chicken. These findings together with our previous studies (Mizuno 1984a,b) in which increased activities of superoxide dismutases, catalase, glutathione peroxidase and glutathione reductase were reported in dystrophic chickens, indicate the presence of an increased capacity for the turnover of oxygen-free radicals within muscle cells in dystrophic chickens, and that oxygen-free radicals and the related activated oxygen species may be playing a role in inducing cellular damage.
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PMID:Glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase activities in early stages of development in dystrophic chickens. 398 80

In order to evaluate properly red cell metabolic data obtained in newborns with congenital hemolytic disorders, the unique metabolic characteristics and normal developmental changes that occur prenatally and postnatally are presented. The age-dependent red cell glycolytic enzymes (hexokinase, aldolase, pyruvate kinase) and glucose-6-phosphate dehydrogenase and most glycolytic intermediates are elevated at birth and at 11 to 12 months of age, consistent with the presence of a young red cell population the entire first year of life. However, certain red cell enzymes are elevated out of proportion to the age of the red cell population [phosphoglucose isomerase. glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase (PGK), and enolase (ENO)] whereas others are decreased [phosphofructokinase (PFK), glutathione peroxidase, carbonic anhydrase, and others]. These metabolic characteristics are felt to be unique and representative of "fetal erythropoiesis." Activities of PGK and ENO decrease the PFK increases toward normal adult values beginning at eight to nine weeks of age. The concentration of glucose-6-phosphate steadily increases after birth and peaks at three to four weeks of age, at a time when PFK activity remains relatively unchanged, suggesting a relative block in glycolysis at the PFK step secondary to an enzyme with both decreased activity and altered kinetic properties (a "fetal" isozyme). Thus, evaluation of red cell enzyme and glycolytic intermediate data obtained in the first year of life should be related to the knowledge that a young red cell population is present and the characteristic unique metabolic red cell alterations described in cord blood persist beyond the immediate neonatal period.
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PMID:Red cell enzymopathies in the newborn. I. Evaluation of red cell metabolism. 628 May 78

S-nitro-N-acetyl-DL-penicillamine (SNAP), a nitric oxide (NO) donor, inactivated bovine glutathione peroxidase (GPx) in a dose- and time-dependent manner. The IC50 of SNAP for GPx was 2 microM at 1 h of incubation and was 20% of the IC50 for another thiol enzyme, glyceraldehyde-3-phosphate dehydrogenase, in which a specific cysteine residue is known to be nitrosylated. Incubation of the inactivated GPx with 5 mM dithiothreitol within 1 h restored about 50% of activity of the start of the SNAP incubation. A longer exposure to NO donors, however, irreversibly inactivated the enzyme. The similarity of the inactivation with SNAP and reactivation with dithiothreitol of GPx to that of glyceraldehyde-3-phosphate dehydrogenase, suggested that NO released from SNAP modified a cysteine-like essential residue on GPx. When U937 cells were incubated with 100 microM SNAP for 1 h, a significant decrease in GPx activity was observed although the change was less dramatic than that with the purified enzyme, and intracellular peroxide levels increased as judged by flow cytometric analysis using a peroxide-sensitive dye. Other major antioxidative enzymes, copper/zinc superoxide dismutase, manganese superoxide dismutase, and catalase, were not affected by SNAP, which suggested that the increased accumulation of peroxides in SNAP-treated cells was due to inhibition of GPx activity by NO. Moreover, stimulation with lipopolysaccharide significantly decreased intracellular GPx activity in RAW 264.7 cells, and this effect was blocked by NO synthase inhibitor N omega-methyl-L-arginine. This indicated that GPx was also inactivated by endogenous NO. This mechanism may at least in part explain the cytotoxic effects of NO on cells and NO-induced apoptotic cell death.
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PMID:Inactivation of glutathione peroxidase by nitric oxide. Implication for cytotoxicity. 767 30

We have developed a polymerase chain reaction (PCR)-based method to measure glutathione peroxidase (GSH-Px) mRNA levels. Expression was measured by multiplex competitive PCR amplification of (a) cDNA from GSH-Px and the "housekeeping" gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and (b) two internal standards consisting of single-base mutants of GSH-Px and GAPDH cDNA that cause either a loss (GSH-Px) or a gain (GAPDH) of an EcoRI restriction endonuclease recognition site. RNA extracted from a human papillomavirus-immortalized human bronchial epithelial cell line (BEP2D) was reverse transcribed. Serial dilutions of cDNA were PCR amplified in the presence of GSH-Px and GAPDH primers and quantified amounts of mutated internal standards. The amplified DNA was restriction digested with EcoRI and electrophoresed on an agarose gel stained with ethidium bromide, separating native from mutated products. Densitometry was performed to quantitate the bands. Our studies demonstrate that this technique measures the relative expression of GSH-Px to GAPDH precisely and reproducibly for studies done with the same master mixture and dilution of internal standards. Ratios of relative gene expression varied less than 25% from the mean. This technique will be useful to measure changes in gene expression, particularly when the amount of study sample is limited or the level of gene expression is low.
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PMID:Measurement of gene expression by multiplex competitive polymerase chain reaction. 823 2

Oxidative stress is known to cause cataracts in lens culture systems and is believed to be an important factor contributing to human cataracts. In this communication, it is demonstrated that cataract development of cultured rat lenses produced as a result of photochemically induced oxidation in a 4% oxygen atmosphere similar to the native environment of the lens can be blocked by the transition metal complex AL-3823A. In this system, riboflavin is added to the medium as a photosensitizer. AL-3823A acts primarily as a glutathione peroxidase mimic, which catalytically metabolizes H2O2 and also has low superoxide dismutase-like activity. Measurements of H2O2, O2.-, and OH. indicate that appreciable levels of the first two of these oxidants and low levels of OH. are produced by this photochemical stressing system. The H2O2 concentrations are similar to those found in some patients with cataracts. The development of cataracts was followed over a 96-hr period. Transparency, hydration, glyceraldehyde-3-phosphate dehydrogenase activity, and protein and nonprotein thiol were monitored. All parameters show marked changes during the 96-hr period. However, in the presence of 200 microM AL-3823A, no difference between control and light-exposed lenses was observed with respect to these parameters. The results suggest that in vivo human cataract development caused by oxidative stress may be prevented by compounds of this type.
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PMID:Photochemically induced cataracts in rat lenses can be prevented by AL-3823A, a glutathione peroxidase mimic. 835 43

Glutathione (GSH) and glutathione-related enzyme systems in astrocytes play an important role in cellular defense against oxidative stress in the nervous system. The present study was designed to characterize the cellular responses of cultured astrocytes to chemically-induced perturbations of mitochondrial and cytosolic GSH homeostasis. Treatment of astrocytes in culture with ethacrynic acid (EA), a mitochondrion-penetrating thiol reagent, induced rapid and extensive depletion of both cytosolic and mitochondrial pools of GSH. Concomitant with the effects of EA on cellular GSH were significant and concentration-dependent increases in intracellular generation of reactive oxygen species (ROS) as indicated by the oxidation of preloaded 2',7'-dichlorofluorescein diacetate. Significant elevation of intracellular ROS occurred by 15 min following exposure to 100 microM EA and reached peak levels by 30 min which were approximately 7-fold higher than corresponding control levels. Ethacrynic acid-induced GSH depletion and intracellular ROS elevation was followed by marked decreases in glutathione reductase (GR) activity in mitochondria, and to a lesser extent, in cytosolic fractions of cultured astrocytes. This inhibitory effect was time- and concentration-dependent, and other GSH-related enzymes, glutathione peroxidase and glutathione S-transferase, were not or only slightly affected. Kinetic studies showed that EA markedly diminished V(max) values of both mitochondrial and cytosolic GR without affecting K(m), suggesting noncompetitive inhibition of this thiol-dependent enzyme. Another thiol-dependent enzyme glyceraldehyde-3-phosphate dehydrogenase was also markedly inhibited by EA in a time-dependent fashion. Subsequent decline of mitochondrial transmembrane potential (rhodamine 123 uptake) and cellular ATP production following EA treatment occurred prior to the onset of loss of cell viability as indicated by lactate dehydrogenase leakage. These results suggest that the loss of mitochondrial GSH may render the astrocytes unable to combat the pathological sequelae of endogenous oxidative stress, leading to perturbations of thiol-dependent enzyme activities, mitochondrial function and energy metabolism.
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PMID:Cellular responses of cultured cerebellar astrocytes to ethacrynic acid-induced perturbation of subcellular glutathione homeostasis. 868 Aug 62

Antioxidant enzymes, Cu/Zn- and Mn-superoxide dismutase, catalase, and glutathione peroxidase, constitute an important defense mechanism against cytotoxicity of reactive oxygen species. Copper is essential for the activity of Cu/Zn-superoxide dismutase. Oxidative stress, therefore, is expected in organs of rats fed copper-deficient diet due to reduced Cu/Zn-superoxide dismutase activity. Our previous studies have shown that the expression of antioxidant enzymes was altered in copper-deficient rat liver. The present report was undertaken to study further the transcription of these enzymes in liver nuclei of rats made copper-deficient for 4 weeks. While copper deficiency decreased the copper in liver by about 80%, it did not alter the copper content in liver nuclei. In spite of a 100% elevation in nuclear iron concentration, liver nuclei from copper-deficient rats showed normal appearance. The transcriptional rates for Cu/Zn-superoxide dismutase, glutathione peroxidase, and glyceraldehyde-3-phosphate dehydrogenase were not altered by dietary copper deprivation. In contrast, transcriptional rates for Mn-superoxide dismutase and beta-actin were increased but that for catalase was reduced in the nuclei isolated from the copper-deficient rat liver. These results suggest that oxidative stress, resulting from copper deficiency, differentially modulates the gene transcription for the antioxidant enzymes in rat liver.
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PMID:Antioxidant enzyme gene transcription in copper-deficient rat liver. 881 39

To understand the molecular mechanisms that upregulate the activities of pulmonary antioxidant enzymes in adult rats during exposure to 85% oxygen, the relative contents of corresponding mRNA in normal and hyperoxic lungs were determined. Hyperoxic exposure drastically induced the expression of lung manganese-containing superoxide dismutase (MnSOD) mRNA. Maximal induction of MnSOD mRNA occurred at days 3 and 5 of exposure to hyperoxia, reaching a 600 and a 340% increase over the levels of air-exposed rats, respectively. In addition, hyperoxia induced lung mRNA for glucose-6-phosphate dehydrogenase, glutathione peroxidase, glyceraldehyde-3-phosphate dehydrogenase, alpha-tubulin, and gamma-actin to different extends at various days of exposure. Hyperoxia had little or no effect on the levels of mRNA for copper/zinc-containing superoxide dismutase (CuZnSOD), catalase, heat shock protein (HSP70), and creatine kinase. Nuclear run-on experiments showed that the transcriptional rate of the MnSOD gene is enhanced in hyperoxic rat lungs by approximately 400% at day 3 of exposure compared with that of controls. The specific activities of CuZnSOD and MnSOD in these lung samples per unit of lung protein or DNA were also determined. The activity of CuZnSOD in hyperoxic lungs was found to be unchanged compared with controls, except a 20% decrease at day 7 of exposure when standardized against protein content of lung homogenate. Changes of CuZnSOD activity were more dramatic in hyperoxic lungs (a 40% increase at days 3, 5, 7, and 14 of exposure) when enzyme activity was normalized using lung DNA content. Surprisingly, no proportional increase of lung MnSOD enzyme activity was observed at days 3 and 5 of oxygen exposure. The increase of MnSOD activity per unit of lung protein also did not parallel the increase in MnSOD protein content at days 5, 7, and 14 of exposure. These data suggest that, in addition to transcriptional activation, translational and/or posttranslational regulation of the MnSOD gene expression may play a critical role in controlling lung MnSOD activity on hyperoxic exposure.
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PMID:Antioxidant enzyme expression in rat lungs during hyperoxia. 896 16

The redox homeostasis is controlled by several enzyme systems. Sulfhydryl groups in lens proteins are very sensitive to oxidative stress and can easily conjugate with nonprotein thiols (S-thiolation) to form protein-thiol mixed disulfides. We have observed an elevation of protein S-S-glutathione (PSSG) and protein-S-S-cysteine (PSSC) in cataractous lenses from humans and from animal models subjected to oxidative stress. We also observed that these protein-thiol mixed disulfides could be spontaneously dissociated and lowered to basal levels if the lens which was pre-exposed to H2O2 was subsequently cultured in H2O2-free medium. This suggests that the lens has a system to repair oxidative damage through dethiolation thereby restoring its redox homeostasis. In other tissues, an enzyme, thioltransferase (TTase), has been shown to be responsible for thiol/disulfide regulation. We recently demonstrated the presence of this enzyme in the lens and in cultured lens epithelial cells. Here, we investigated the response of TTase to H2O2 stress and its possible repair function in cultured lens epithelial cells. Rabbit lens epithelial cell line N/N 1003A was raised to confluence, trypsinized and plated at 0.8 million cells per 60 mm culture dish. The cells were incubated overnight in Eagle's minimum essential medium (MEM) with 1% rabbit serum and then in serum-free MEM for 30 min before a bolus of 0.5 mm H2O2 was added. At intervals of 5, 15, 30 min and up to 3 hr, the cells were harvested and used for enzyme assays for TTase, glutathione reductase (GR), glutathione peroxidase (GPx) and glyceraldehyde-3-phosphate dehydrogenase (G-3PD). Free GSH, total SH and PSSG and PSSC were also determined. Hydrogen peroxide in the medium was measured at each time point. Cells incubated without H2O2 were used as controls. The results showed that the H2O2 concentration was reduced to 50% within 30 min and was undetectable at 2 hr. Cellular GSH dropped to 40% within 5 min and stayed at this level before it began to increase at 90 min and completely recovered by 2 hr. The total SH groups were similar to free GSH. PSSG and PSSC increased 6.5 and 2 times respectively before 30 min and then decreased when GSH started to recover. G-3PD was most sensitive to H2O2 and lost 95% activity within 5 min. The activity was regained quickly when H2O2 diminished in the medium. A similar but less severe pattern was observed in both GPx (60% loss at 60 min) and GR (30% loss at 90 min). In contrast, TTase activity remained constant during the entire 3 hr. Only when a higher dose of H2O2 (0.8-1.0 mM) was used, did TTase activity show a brief loss (<30% at 60 min) and a swift recovery. Cells exposed to H2O2 exhibited a normal morphology with no evidence of DNA fragmentation. The lens epithelial cells showed a remarkable ability to repair the early damages induced by H2O2. The unusual oxidative stress-resistant property displayed by TTase, coupled with its known function suggest that it plays an important role in the repair of oxidative damage.
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PMID:Thioltransferase is present in the lens epithelial cells as a highly oxidative stress-resistant enzyme. 959 40


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