Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.5.1.18 (glutathione S-transferase)
 22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study focuses on the GST composition of a tissue intrinsically resistant to chemotherapy, the human colon. GSTs were purified from matched pairs of colon tissue (normal and tumor) using glutathione affinity chromatography. The mean GST activity of colon tumors was 1.5-fold higher than that of normal tissue, with tumors of the sigmoid colon showing the greatest increase (2.3-fold). Two-dimensional gel electrophoresis and Western blot analysis of purified enzymes demonstrated the presence of all three GST classes (alpha, mu and pi) in colon, with GST pi being both the predominant isozyme in normal and malignant tissues. The level of alpha class subunits was the same in normal and tumor tissues, while the mu class subunits were decreased in tumors. A protein copurifying with GSTs from both normal and tumor tissue did not crossreact with GST antibodies, but instead reacted with a polyclonal antibody to glyoxylase I. This enzyme existed as a dimer in its native state. Upon boiling, monomeric subunits were produced with a molecular mass of 22.6 kDa and an isoelectric point more acidic than GST pi. Increased amounts of glyoxylase I were also found in tumor vs. normal colon. The apparent elevated levels of these glutathione-associated detoxifying enzymes in colon tumors may contribute to their intrinsic drug resistance.
 ...
PMID:Glutathione S-transferases in normal and malignant human colon tissue. 201 94

A seasonal variability of trace metal concentrations and antioxidant enzymes was observed in gills and digestive gland of the Mediterranean mussel Mytilus galloprovincialis from both a polluted and a nonpolluted population. Trace metals (As, Cu, Fe, Mn, Pb, and Zn) exhibited, in both organs, maximum values in later winter-early spring followed by a progressive decrease during the summer. While in the gills this behavior probably reflects a different bioavailability of metals, in the digestive gland it is influenced mainly by the progressive infiltration of the organ by gonadic tissues during gametogenesis. Metals, as other pollutants, are known to influence the oxidative status of these organisms and antioxidant enzymes have been often proposed as biomarkers of exposure to contaminants. In this respect, it was of interest to compare the variations of these biochemical parameters with those of metal levels in two mussel populations from a polluted and a nonpolluted site, respectively. The biochemical parameters examined included the level of glutathione and the activity of the following glutathione dependent and antioxidant enzymes: glyoxalase I, EC 4.4.1.5; glyoxalase II, EC3.1.2.6; glutathione S-transferases, EC 2.5.1.18; glutathione reductase, EC 1.6.4.2; Se-dependent, EC 1.11.1.9 and Se-independent, EC 2.5.1.18 glutathione peroxidases; catalase, EC 1. 11.1.6; superoxide dismutase, EC 1.15.1.1. Seasonal variations of trace metals did not appear to influence those of biochemical parameters, which generally showed an opposite trend with higher enzymatic activities in summer when trace metal concentrations were lower. The effects of metals on antioxidant enzymes were more evident when the two mussel populations were compared. In particular, organisms from the polluted site showed lower levels of glutathione and higher enzymatic activities of glyoxalase I even though the magnitude of these differences was not constant during the year. Moreover, native mussels from both the polluted and control populations exhibited limited differences in the activities of glutathione reductase, glutathione peroxidases, catalase, and superoxide dismutase, suggesting the possibility of some biochemical adaptation in organisms from chronically polluted environments.
 ...
PMID:Trace metals and antioxidant enzymes in gills and digestive gland of the Mediterranean mussel Mytilus galloprovincialis. 941 73

In the framework of an INTAS project, arctic populations of the clam Macoma balthica were collected from seven stations (Mezen, Khaypudyr, Pechora 3, Pechora 5, Dvina, Keret 1, and Keret 2) in the White Sea and Pechora Sea. The main objectives of this research were to define baseline concentrations of trace metals (As, Cd, Cr, Cu, Fe, Mn, Pb, Zn) in M. balthica and to evaluate antioxidant responses as biomarkers of anthropogenic stress in these organisms. The antioxidant parameters examined included the levels of glutathione and the activities of several glutathione-dependent and antioxidant enzymes: glyoxalase I and glyoxalase II (EC 4.4.1.5 and EC 3.1.2.6), glutathione S-transferases (EC 2.5.1.18), glutathione reductase (EC 1.6.4.2), glutathione peroxidases (EC1.11.1.9 and EC 2.5.1.18, respectively, for Se-dependent and Se-independent forms), superoxide dismutase (SOD, EC 1.15.1.1), and catalase (EC 1.11.1.6). Organisms revealed enhanced concentrations of lead in both Keret stations, Khaypudyr, and Mezen, and high levels of copper in Keret and cadmium in Khaypudyr. At the biochemical level, organisms from Pechora 3, Pechora 5, and Dvina were not statistically different, whereas those from Mezen and Khaypudyr exhibited higher activities of superoxide dismutase, glutathione peroxidase, and glyoxalase II. Catalase levels were lower in Mezen and Khaypudyr. More heterogeneous were the responses of glyoxalase I and glutathione S-transferases, while no significant differences among the stations were observed for glutathione reductase. Multiple regression analyses revealed significant positive relationships between the main antioxidant enzymes (glutathione peroxidases, superoxide dismutase, glyoxalase I, and glyoxalase II), and confirmed the exception of catalase, which, when significant, was negatively correlated with the other parameters. The results support the suitability of antioxidant responses as biomarkers of pollutant exposure and/or toxicity for arctic biomonitoring programs even though only moderately polluted sites were sampled.
 ...
PMID:Trace metals and variations of antioxidant enzymes in Arctic bivalve populations. 977 77

Cashew nut shell oil has been reported to possess tumour promoting property. Therefore an attempt has been made to study the modulatory effect of cashew nut (Anlacardium occidentale) kernel oil on antioxidant potential in liver of Swiss albino mice and also to see whether it has tumour promoting ability like the shell oil. The animals were treated orally with two doses (50 and 100 microl/animal/day) of kernel oil of cashew nut for 10 days. The kernel oil was found to enhance the specific activities of SOD, catalase, GST, methylglyoxalase I and levels of GSH. These results suggested that cashew nut kernel oil had an ability to increase the antioxidant status of animals. The decreased level of lipid peroxidation supported this possibility. The tumour promoting property of the kernel oil was also examined and found that cashew nut kernel oil did not exhibit any solitary carcinogenic activity.
 ...
PMID:Modulation of antioxidant potential in liver of mice by kernel oil of cashew nut (Anacardium occidentale) and its lack of tumour promoting ability in DMBA induced skin papillomagenesis. 1508 87

Abundant evidence indicates that potential scaffold proteins and adaptor or linker molecules organize and specify various MAP kinase cascades. In the present study, proteomic methodologies were applied to screen these potential molecules in combination with cell morphology and cell cycle analysis. MEK1E, MKK3b, MKK5D and MKK7D were selected as representative MKKs of four main MAPK pathways. Our results showed that similar morphological transformation and G(2)/M cell cycle arrest were promoted by the over-expressed four kinases. Furthermore, global change in response to the over-expressed four kinases was characterized by differential proteomics. Eleven distinctly changed proteins were detected, in which four proteins (serine/threonine kinase 4, glutathione S-transferase p1-1, glycoprotein IX and soluble inorganic pyrophosphatase) were reported to be relative to MAPK pathways, while the other seven proteins may be new elements of substrates of the kinases. In our experiment, the expression of platelet glycoprotein IX precursor, glutathione S-transferase p1-1, peroxiredoxin 6, Ras-related protein Rab-34 and arginase II, mitochondrial precursor was up-regulated, while the expression of serine/threonine kinase 4 (MST1) was down-regulated by the four kinases. These results suggest that these six proteins may be common targets of all the MAPK pathways in 293T cell line. Interestingly, the expression of splicing factor 3B subunit 4 and soluble inorganic pyrophosphatase (Ppase) was specifically up-regulated by MEK1E and MKK5D, and by MEK1E, MKK3b and MKK5D, respectively. The expression of methylglyoxalase was down-regulated by MEK1E and MKK7D. Furthermore, the expression of ADP-ribosylation factor-like protein 1 was up-regulated by MKK5D but down-regulated by MKK3b and MKK7D. These findings revealed the characteristic molecular responses to four MKKs. In conclusion, our study not only confirms that MST1, glutathione S-transferase p1-1, glycoprotein IX and soluble PPase belong to MAPK pathways, but also provides seven novel molecules for the further study of the pathways.
 ...
PMID:Proteomic approach to substrates related to MAPK pathway in 293T cells. 1704 91

Wild halophytic tomato has long been considered as an ideal gene donor for improving salt tolerance in tomato cultivars. Extensive research has been focused on physiological and quantitative trait locus (QTL) characterization of wild tomato species in comparison with cultivated tomato. However, the global gene expression modification of wild tomato in response to salt stress is not well known. A wild tomato genotype, Solanum pimpinellifolium 'PI365967' is significantly more salt tolerant than the cultivar, Solanum lycopersicum 'Moneymaker', as evidenced by its higher survival rate and lower growth inhibition at the vegetative stage. The Affymetrix Tomato Genome Array containing 9,200 probe sets was used to compare the transcriptome of PI365967 and Moneymaker. After treatment with 200 mM NaCl for 5 h, PI365967 showed relatively fewer responsive genes compared with Moneymaker. The salt overly sensitive (SOS) pathway was found to be more active in PI365967 than in Moneymaker, coinciding with relatively less accumulation of Na(+) in shoots of PI365967. A gene encoding salicylic acid-binding protein 2 (SABP2) was induced by salinity only in PI365967, suggesting a possible role for salicylic acid signaling in the salt response of PI365967. The fact that two genes encoding lactoylglutathione lyase were salt inducible only in PI365967, together with much higher basal expression of several glutathione S-transferase genes, suggested a more effective detoxification system in PI365967. The specific down-regulation in PI365967 of a putative high-affinity nitrate transporter, known as a repressor of lateral root initiation, may explain the better root growth of this genotype during salt stress.
 ...
PMID:Comparative transcriptomic profiling of a salt-tolerant wild tomato species and a salt-sensitive tomato cultivar. 2041 49