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

By using affinity chromatography and isoelectric focusing techniques, several forms of glutathione transferase (GSTs) were resolved from human testis obtained from patients operated on for malignant diseases. Large interindividual variations in the expression of different isoenzymes resulted in the samples investigated. Five out of six samples analysed expressed GST-4.4 that resulted in being structurally and immunologically identical to GST-pi (class Pi). All the cationic GSTs of human testis, except for GST-8.36, GST-9.1 and GST-10.1, are homodimers of 24,500 Mr subunit and cross reacted with antisera raised against class Alpha GST. Some of the forms isolated (GST-3.8, GST-8.36, GST-9.1 and GST-10.1) can not apparently be related to any of GSTs so far characterized in other human tissues. Upon SDS/polyacrylamide gel electrophoresis, GST-8.36 and GST-9.1 appeared to be heterodimers of 24,500 and 26,500 Mr subunits and were found only in the testis seminoma suggesting that they might be tumour specific isoenzymes. GST-3.8 appeared to be formed by heterodimers of 23,000 and 26,500 Mr subunits whereas, GST-10.1 was found to be dimers of 22,000 and 24,500 Mr subunits. In addition, the results of immunohistochemical studies with antisera raised against both class Pi and Alpha GSTs are reported.
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PMID:Glutathione transferase isoenzymes from human testis. 268 47

Rats were injected intraperitoneally with phenobarbital (PB) and 3-methylcholanthrene (MC) which are microsomal enzyme inducers, and methyl iodide (MeI), cobalt chloride (CoCl2) and tri-o-cresyl phosphate (TOCP) which are inhibitors of the enzymes glutathione transferase, cytochrome (cyt) P-450 and carboxylesterase, respectively, and then challenged with soman (i.p.) to know its LD50. Pretreatment with PB and MC increased and TOCP decreased, whereas MeI as well as CoCl2 did not alter the LD50 value of soman in rats. The 1/2 LD50 dose of soman did not affect the liver microsomal cyt P-450 level, but significantly lowered carboxylesterase (CaE) and cholinesterase (ChE) activities in liver microsomes and in blood plasma. Induction of plasma CaE was more important than microsomal CaE in PB-mediated protection against soman toxicity. Gel filtration of plasma into four protein fractions for their relative soman binding capacity showed that a high-molecular-weight protein fraction (180,000 daltons on SDS-PAGE) which had no CaE activity could bind soman 6 times more than the low-molecular-weight CaE-containing protein fraction (60,000 daltons on SDS-PAGE).
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PMID:Role of carboxylesterase in protection against soman toxicity. 276 74

The effect of a single dose of lead nitrate (10 microM/100 g body wt), a hepatic mitogen, on rat liver glutathione transferase (GST) subunit expression was investigated. Using SDS-polyacrylamide gel electrophoresis and Western blot technique evidence for the induction of GST 7-7 is shown. This occurrence is identical to that observed in preneoplastic nodules generated in rat liver by different models of chemical carcinogenesis, suggesting that lead nitrate may be a very simple model for investigation of the mechanism of glutathione transferase 7-7 gene expression in chemical hepatocarcinogenesis.
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PMID:Induction of rat liver glutathione transferase subunit 7 by lead nitrate. 276 57

Glutathione S-transferase in the cytosol of rainbow trout liver was partially purified by affinity chromatography on a column with glutathione coupled to epoxy-activated Sepharose 6B, which retained 94% of the total activity. Chromatofocussing on a Polybuffer exchanger 118 column separated the glutathione S-transferase into six major cationic isoenzymes (K1-K6), and some minor fractions. SDS-polyacrylamide slab gel electrophoresis showed K1-K3 to be heterodimers with subunits of Mr 25,000 and 26,500, and K4-K6 to be homodimers with subunits of Mr 25,000. The glutathione S-transferase isoenzymes were partially characterized by different biochemical parameters. The hepatic rainbow trout glutathione S-transferases were inhibited by the organic water pollutants, 1,4-benzoquinone and 2,4-dichlorophenoxyacetic acid. The same kinetic inhibition patterns were observed with these inhibitors as for rat liver glutathione S-transferases. It is concluded that rainbow trout glutathione S-transferases can play a key role in the detoxication of organic micropollutants in the aquatic environment.
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PMID:Hepatic glutathione S-transferases in rainbow trout and their interaction with 2,4-dichlorophenoxyacetic acid and 1,4-benzoquinone. 286 27

Glutathione transferase (GST) was present in 71 of 72 animal species/stages representing nine phyla when measured with 1-chloro-2,4-dinitrobenzene (CDNB). Our hypothesis that all animals have GST was not falsified. Transferase activity towards ethacrynic acid (ETHA) was present in species from all phyla investigated, but some animals seem to be without this activity. Activity towards 1,2-dichloro-4-nitrobenzene (DCNB) was less developed in aquatic animals than in terrestrial ones. The amount of protein binding to GSH-affinity gel matrix was rather uniform, ranging between 0.3 and 0.7% of soluble protein in homogenates of widely diverse animal species, thus being less variable than the enzyme activity. Transferases active towards DCNB did not bind at all or were less firmly bound to the GSH-affinity gel than the activity towards CDNB or ETHA. Fractionation was obtained by using a gradient of GSH. With SDS-electrophoresis it was demonstrated that the proteins with affinity to GSH had monomers in the MW-range 21.500-29.000. Hydra attenuata had one band (MW = 25,000); all other sources gave a complex pattern with up to six bands. It is concluded that GSTs are characteristic major constituents of animal cells, probably with some common basic function. Mutant forms able to aid detoxication are retained in the phylogenesis when they increase the fitness of the animal.
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PMID:Glutathione transferases in aquatic and terrestrial animals from nine phyla. 288 31

A DNA-binding nonhistone protein, protein BA, was previously demonstrated to co-localize with U-snRNPs within discrete nuclear domains (Bennett, F. C., and L. C. Yeoman, 1985, Exp. Cell Res., 157:379-386). To further define the association of protein BA and U-snRNPs within these discrete nuclear domains, cells were fractionated in situ and the localization of the antigens determined by double-labeled immunofluorescence. Protein BA was extracted from the nucleus with the 2.0 M NaCl soluble chromatin fraction, while U-snRNPs were only partially extracted from the 2.0 M NaCl-resistant nuclear structures. U-snRNPs were extracted from the residual nuclear material by combined DNase I/RNase A digestions. Using an indirect immunoperoxidase technique and electron microscopy, protein BA was localized to interchromatinic regions of the cell nucleus. Protein BA was noted to share a number of chemical and physical properties with a family of cytoplasmic enzymes, the glutathione S-transferases. Comparison of the published amino acid composition of protein BA and glutathione S-transferases showed marked similarities. Nonhistone protein BA isolated from saline-EDTA nuclear extracts exhibited glutathione S-transferase activity with a variety of substrates. Substrate specificity and subunit analysis by SDS polyacrylamide gel electrophoresis revealed that it was a mixture of several glutathione S-transferase isoenzymes. Protein BA isolated from rat liver chromatin was shown by immunoblotting and peptide mapping techniques to be two glutathione S-transferase isoenzymes composed of the Yb and Yb' subunits. Glutathione S-transferase Yb subunits were demonstrated to be both nuclear and cytoplasmic proteins by indirect immunolocalization on rat liver cryosections. The identification of protein BA as glutathione S-transferase suggests that this family of multifunctional enzymes may play an important role in those nuclear domains containing U-snRNPs.
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PMID:Nonhistone protein BA is a glutathione S-transferase localized to interchromatinic regions of the cell nucleus. 293 45

Dog liver cytosolic glutathione S-transferases (GSTs) were investigated to characterize their properties in comparison with rat liver transferases. Dog liver GSTs after the glutathione affinity column chromatography showed three subunit bands on SDS-polyacrylamide gel electrophoresis. These three subunits, designated as Yd1 (mol.wt 26,000), Yd2 (mol.wt 27,000) and Yd3 (mol.wt 28,000), were distinctly different from rat liver GST subunits, i.e. Ya(1) (mol.wt 26,500), Yb1(3)/Yb2(4) (mol.wt 27,500) and Yc(2) (mol.wt 28,500). Western blot analysis revealed that Yd1, Yd2 and Yd3 were immunoreacted with anti-rat GST 7-7, 1-1 and 3-3 antibodies, respectively. Four transferase activity fractions, I (pH greater than 7.63), II (pH 6.92), III (pH 5.80) and IV (pH 5.65), were obtained from affinity purified GSTs by chromatofocusing. Each fraction exhibited a characteristic substrate specificity. GST-II, III and IV were all strongly immunoreacted with anti-rat GST 7-7 antibody by immunoblotting, thus suggesting the occurrence of the heterogeneity of transferases immunologically related to rat GST subunit 7 in dog liver. Immunohistochemical examination showed that transferases immunoreacted with anti-GST 7-7 antibody have diffusely distributed throughout the lobule, while enzymes related to subunit 3 have been localized in a narrow range of cells around the central vein. These data suggest that GSTs immunologically associated with rat transferase subunit 7 may be major forms in dog liver.
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PMID:Dog liver glutathione S-transferase and its strong immunoreactivity with rat transferase-P(7-7). 306 Jan 25

Four glutathione S-transferase (GST, EC 2.5.1.18) forms were purified from human kidney by S-hexylglutathione affinity chromatography followed by chromatofocusing using a fast protein liquid chromatography system. These forms were demonstrated to be identical with GSTs I, II, IV, V(pi) in human liver previously characterized by us, by SDS-polyacrylamide slab gel electrophoresis, two-dimensional gel electrophoresis and double immunodiffusion. GST III (mu) was not detected in any of 5 specimens examined. GST-pi was a major form in the kidney. The activity was 30-40% of the total activity in kidney cytosol and the protein amount was approximately 140 micrograms/g of tissue; 0.27% of the total cytosol protein amount. In many organs including the placenta, GST-pi is present at levels similar to that in the kidney but low in the liver (34 micrograms/g).
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PMID:Purification and characterization of glutathione S-transferases in human kidney. 311 72

The developmental expression of the basic, near-neutral and acidic isoenzymes of glutathione S-transferase (RX:glutathione R-transferase, EC 2.5.1.18) has been studied in heart and diaphragm. Neither these enzymes nor the putative muscle-specific GST4 isoenzyme demonstrated any developmental trends in expression. In vitro hybridisation and SDS-discontinuous polyacrylamide gel electrophoresis were used to show that the GST4 isoenzyme is a homodimer composed of monomers that have a slightly larger molecular weight than the near-neutral isoenzyme. The sensitivity of GST4 to inhibitors also appeared similar to that of the GST1 2 isoenzyme. Immunodiffusion and immunoblotting techniques were used to show that the acidic enzyme in muscle is immunologically identical to that in other tissues.
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PMID:Studies on the developmental expression of glutathione S-transferase isoenzymes in human heart and diaphragm. 311 98

The occurrence of glutathione transferase in human malignant melanoma cell lines and solid tumor material has been analyzed and compared with the enzyme composition in fibroblasts and naevus samples. All cells and tissues investigated contained essentially only the acidic class Pi glutathione transferase as demonstrated by SDS-PAGE and immunoblotting. The enzyme was purified from tumor material and characterized. Its intracellular concentration was significantly higher in all the melanoma cell preparations analyzed than in the non-malignant cells, supporting the view that the class Pi glutathione transferase may contribute to the drug resistance that is characteristic of malignant melanoma.
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PMID:Expression of class Pi glutathione transferase in human malignant melanoma cells. 311 48


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