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

---

Query: EC:2.5.1.18 (glutathione S-transferase)
22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stress, catecholamines (CA), cAMP and protein-kinase A do not affect superoxide dismutase, catalase, thioredoxin reductase, thiol transferase and glutathione reductase (GR). However, they activate glutathione peroxidase and glutathione transferase (GT) in a number of organs and inhibit renal gamma-glutamyl transferase. Ca2+ ions activate GT through calmodulin. CA were found to stimulate GSH transport from liver to blood and GT phosphorylation by protein kinase C. This suggests a regulation of the GSH metabolism by hormones and a second messenger. This regulation favours metabolism of active O2 substances (including protection from peroxide stress and leukotriene C4 synthesis), supporting of SH-proteins in reduced state, xenobiotics detoxication. GT and GR induction can play an important role in the mechanism of anti-peroxide action of butylhydroxytoluene.
...
PMID:[The physiological significance of regulation by catecholamines, second messengers and enzyme inducers of glutathione metabolism]. 196 98

In vivo exo- and endogenous catecholamines have no influence on the activities of thioredoxin reductase, glutathione reductase, thiol transferase and nonselenium-dependent glutathione peroxidase. At the same time catecholamines activate via beta-adrenoceptors glutathione S-transferase and selenium-dependent glutathione peroxidase from many tissues and inhibit gamma-glutamyl transferase from kidney. In vitro cAMP has identical effects on the activities of the above enzymes. The possible significance of regulation of glutathione metabolism enzymes is discussed.
...
PMID:[Regulation by catecholamines and cAMP of enzymes of thiol and disulfide metabolism]. 288 35

The activities of glutathione-related enzymes in isolated rat small intestine were investigated under oxidative stress mediated by Fe(2+)-EDTA. The isoelectric points and approximate molecular weights of the enzymes investigated were first determined. The reduced and oxidized glutathione contents, and low molecular weight thiols in isolated rat small intestine were also studied under oxidative stress. Significant reducing activities of glutathione S-transferase and lactate dehydrogenase were observed accompanied by increases in oxidized glutathione content, whereas thioltransferase, glutathione reductase, glutathione peroxidase and thioredoxin reductase retained the same levels of activity as controls. First-order inactivation of purified rat small intestine glutathione S-transferase including class-alpha, mu and pi was observed and the isozyme class-pi was inactivated at several pH's under Fe(2+)-EDTA-mediated oxidative stress. Leakage of protein and both reduced and oxidized forms of glutathione was significantly increased during incubation with Fe(2+)-EDTA. In conclusion, enzymes which were not inactivated under Fe(2+)-EDTA-mediated oxidative stress may play an important role in cellular antioxidant defenses in the small intestine. Furthermore, enzymes such as glutathione S-transferase, mainly a class-pi isozyme, and lactate dehydrogenase which were inactivated may form part of the barrier against oxidative stress similar to reduced glutathione.
...
PMID:Responses of glutathione-related enzymes in isolated rat small intestine to Fe(2+)-EDTA-mediated oxidative stress. 792 Apr 17

Hydrogen peroxide was cytotoxic to the small intestine epithelial cell line, IEC-6, as judged from an MTT assay and the release of lactate dehydrogenase. The glutathione S-transferase and thioredoxin reductase activities and SH content decreased dose-dependently with H2O2, but thioredoxin activity increased at low H2O2 concentrations. In addition, the increase in thioredoxin activity was time-dependent during the initial stages of oxidative stress. A reverse transcription-polymerase chain reaction (RT-PCR) amplification also showed that the mRNA content in IEC-6 cells increased time-dependently at 0.25 mM H2O2. These results indicate that cellular oxidative shock causes an increase in the activity of thioredoxin, which is involved in the defense mechanism against oxidative stress.
...
PMID:Increase in thioredoxin activity of intestinal epithelial cells mediated by oxidative stress. 1051 9

Prooxidant effect of chemotherapeutic agents is of significant interest in connection with activation of oxidative stress in cancer cells. Role of development of adaptive antioxidant response to the rise of resistance to cytotoxical effect of doxorubicin (DOX) has been studied in human erythroleukemia K562 cells. Growth of resistance to DOX caused enhancement of antioxidant enzymes (Cu, Zn-SOD, Mn-SOD, catalase) elevation of Mn-SOD activity being predominant. Additional increasing of antioxidant level was elevation of GSH maintenance and level of GST-related enzymes (glutathione peroxidase, glutathione S-transferase, glutathione reductase) in resistance K562/DOX cells. The enhancement of antioxidant system prevented activation of lipid peroxidation. Furthermore, the antioxidant growth caused decrease of level of proteintyrosine kinases, thioredoxin, thioredoxin reductase in contrary to elevation of glutaredoxin activity. Increasing of Bcl-2 and suppression of p53 levels was found to be caused by the change of redox state of K562DOX cells. The data support the suggestion that adaptive antioxidant response to prooxidant effect of DOX promotes the development of cellular drug resistance.
...
PMID:[Role of the antioxidant system and redox-dependent regulation of transcription factors bcl-2 and p53 in forming resistance of human K562 erythroleukemia cells to doxorubicin]. 1178 3

The cellular defense system (including glutathione, glutathione-related enzymes, antioxidant and redox enzymes) plays a crucial role in cell survival and growth in aerobic organisms. To understand its physiological role in tumor cells, the glutathione content and related enzyme activities in the human normal hepatic cell line, Chang and human hepatoma cell line, HepG2, were systematically measured and compared. Superoxide dismutase, catalase, and glutathione peroxidase activities are 2.8-, 4.3-, and 2.9-fold higher in HepG2 cells than in Chang cells. Total glutathione content is also about 1.4-fold higher in HepG2, which is supported by significant increases in gamma-glutamylcysteine synthetase and glutathione synthetase activities. Two other glutathione-related enzymes, glutathione reductase and gamma-glutamyltranspeptidase, are upregulated in HepG2 cells. However, thioredoxin reductase and glutathione S-transferase activities are significantly lower in HepG2 cells. These results propose that defense-related enzymes are largely modulated in tumor cells, which might be linked to their growth and maintenance.
...
PMID:Activities of antioxidant and redox enzymes in human normal hepatic and hepatoma cell lines. 1244 6

Cellular defense system, including glutathione, glutathione-related enzymes, and antioxidant and redox enzymes, may play crucial roles in the aging of aerobic organisms. To understand the physiological roles of these factors in the aging process, their levels were compared in the livers and brains of 5-week- and 9-month-old rats. GST activity was higher in livers and brains of 9-month-old rats than in those of 5-week-old rats, and brain catalase activity was about 2-fold higher. However, it was unchanged in the livers of the 9-month-old rats. gamma-Glutamylcysteine synthetase activity was about 2-fold higher in the brains of the older rats but again not in their livers. In contrast glutathione synthetase activity appeared to be lower in the livers of the older rats while GSH content did not change with age in livers and brains. Glutathione peroxidase activity was higher in 9-month-old rat brains, but lower in 9-month-old rat livers, while superoxide dismutase activity was higher in both tissues in the older rats. The activities of two redox enzymes, thiol-transferase and thioredoxin reductase, did not change with age, nor did that of glutathione reductase. These results indicate that levels of different cellular defense systems vary with age in an irregular manner.
...
PMID:Age-related changes in the activity of antioxidant and redox enzymes in rats. 1474 15

The malaria parasite Plasmodium falciparum is highly adapted to cope with the oxidative stress to which it is exposed during the erythrocytic stages of its life cycle. This includes the defence against oxidative insults arising from the parasite's metabolism of haemoglobin which results in the formation of reactive oxygen species and the release of toxic ferriprotoporphyrin IX. Central to the parasite's defences are superoxide dismutases and thioredoxin-dependent peroxidases; however, they lack catalase and glutathione peroxidases. The vital importance of the thioredoxin redox cycle (comprising NADPH, thioredoxin reductase and thioredoxin) is emphasized by the confirmation that thioredoxin reductase is essential for the survival of intraerythrocytic P. falciparum. The parasites also contain a fully functional glutathione redox system and the low-molecular-weight thiol glutathione is not only an important intracellular thiol redox buffer but also a cofactor for several redox active enzymes such as glutathione S-transferase and glutaredoxin. Recent findings have shown that in addition to these cytosolic redox systems the parasite also has an important mitochondrial antioxidant defence system and it is suggested that lipoic acid plays a pivotal part in defending the organelle from oxidative damage.
...
PMID:Redox and antioxidant systems of the malaria parasite Plasmodium falciparum. 1538 10

Thiol proteins are important in cellular antioxidant defenses and redox signalling. It is postulated that reactive oxidants cause selective thiol oxidation, but relative sensitivities of different cell proteins and critical targets are not well characterized. We exposed Jurkat cells to H2O2 for 10 min and measured changes in reversibly oxidized proteins by labelling with iodoacetamidofluorescein and two-dimensional electrophoresis. At 200 microM H2O2, which caused activation of the MAP (mitogen-activated protein) kinase ERK (extracellular-signal-regulated kinase), growth arrest and apoptosis, relatively few changes were seen. A total of 28 spots were reversibly oxidized (increased labelling intensity) and 24 decreased. The latter included isoforms of peroxiredoxins 1 and 2, which were irreversibly oxidized. Oxidation of GAPDH (glyceraldehyde-3-phosphate dehydrogenase) was striking, and other affected proteins included glutathione S-transferase P1-1, enolase, a regulatory subunit of protein kinase A, annexin VI, the mitotic checkpoint serine/threonine-protein kinase BUB1beta, HSP90beta (heat-shock protein 90beta) and proteosome components. At 20 microM H2O2, changes were fewer, but GAPDH and peroxiredoxin 2 were still modified. Dinitrochlorobenzene treatment, which inhibited cellular thioredoxin reductase and partially depleted GSH, caused reversible oxidation of several proteins, including thioredoxin 1 and peroxiredoxins 1 and 2. Most changes were distinct from those with H2O2, and changes with H2O2 were scarcely enhanced by dinitrochlorobenzene. Relatively few proteins, including deoxycytidine kinase, nucleoside diphosphate kinase and a proteosome activator subunit, responded only to the combined treatment. Thus most of the effects of H2O2 were not linked to thioredoxin oxidation. Our study has identified peroxiredoxin 2 and GAPDH as two of the most oxidant-sensitive cell proteins and has highlighted how readily peroxiredoxins undergo irreversible oxidation.
...
PMID:Proteomic detection of hydrogen peroxide-sensitive thiol proteins in Jurkat cells. 1580 6

Reactive oxygen species (ROS) are involved in a diversity of important phenomena in the process of tumor development. To investigate the alterations of oxidative stress and their related systems in tumor progression, a variety of components in the antioxidative stress defense system were examined in prostate cancer cell lines, PC3 and LNCaP. Cell surface molecules involved in metastasis were expressed highly in PC3 cells compared with LNCaP cells, and strong invasion ability was shown in PC3 cells only. ROS level in LNCaP cells was twice higher than that in PC3 cells, although nitric oxide (NO) level was similar between the two cell lines. The content of GSH increased up to about 2-fold in PC3 compared with LNCaP. Activities of glutathione reductase, thioredoxin reductase, and glutathione S-transferase except catalase are significantly higher in PC3 cells than in LNCaP cells. Furthermore, oxidative stress-inducing agents caused down-regulation of GSH and glutathione S-transferase much more significantly in LNCaP cells than in PC3 cells. These results imply that malignant tumor cells may maintain low ROS content by preserving relatively high anti-oxidative capacity, even in the presence of stressful agents.
...
PMID:Up-regulation of defense enzymes is responsible for low reactive oxygen species in malignant prostate cancer cells. 1626 76


1 2 3 4 5 6 7 Next >>

---