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 sequential use of GSH-affinity chromatography and chromatofocusing, the isoenzymes of glutathione transferase from tumor and non-tumor kidney tissues have been purified and their properties compared. On the basis of electrophoretic mobilities on SDS/polyacrylamide gel, substrate specificities toward the diagnostic substrates cumene hydroperoxide and ethacrynic acid and immunoreactivity with antisera raised against alpha, mu and pi class glutathione transferases, it was found that most of the isoenzymes purified from both tumor and non-tumor kidney can be identified as members of either alpha or pi classes. All the samples investigated lacked mu class glutathione transferase. In addition, we could identify in tumor samples two transferases GST-7.6 and GST-5.8/5.9 which on the basis of immunological properties cannot be related to any of the members of the three major classes of glutathione transferases. The latter do not appear to have corresponding forms in non-tumor tissues. It was suggested that specific transferases can be selectively expressed by tumor kidney carcinoma.
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PMID:Electrophoretic and immunological analysis of glutathione transferase isoenzymes of human kidney carcinoma. 249 96

Several electrophoretically distinct glutathione S-transferase isozymes from different tissues have been purified and characterized. The data confirm the suggestion that GST-1, GST-2 and GST-3 are the products of separate genetic loci. An apparently muscle-specific isozyme termed GST-4 has been identified and shown to differ structurally from GST-1, GST-2 and GST-3. It is likely that GST-4 is the product of an additional gene locus. Two isozymes termed GST-5 and GST-6 were purified from brain. GST-5 has a different isoelectric point, but shares many structural features with GST-1. GST-5 may be a brain-specific post-translationally modified product of the GST-1 gene. GST-6 is an acidic isozyme found in many tissues. The data indicate that GST-6 is composed of two dissimilar subunits that do not cross-react with antiserum directed against GST-1, GST-2 or GST-3. These observations therefore suggest that GST-6 may have an independent genetic origin.
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PMID:Electrophoretic and immunological analysis of human glutathione S-transferase isozymes. 311 57

Fourteen isoforms of glutathione S-transferase (GST) have been separated and purified from mullet (Mugil cephalus) liver by scaling up an automatic analytical method based on anionic exchange chromatography. The activity of each isoenzyme with several substrates was determined. Dimeric combinations of six subunits make up this heterogeneous isoenzyme population. Five of these were resolved by reverse phase chromatography; four of them, named a, b, c and d, were present in more than one isoform, had the same apparent molecular mass (25.2 kDa) by SDS-PAGE, and were immunochemically related to plaice GST-A and possibly to rat GST-5 but not to plaice GST-B or any other rat GST subunit; they would belong to the theta class. Subunit e was only present in isoenzyme I which was basic, had an apparent molecular mass of 23.4 kDa and would belong to the alpha class, since it was recognized by antibodies towards plaice GST-B and rat GST-1 and GST-8 and less intensely by anti-(rat)GST-2. Another subunit, named f, with 25.2 kDa apparent molecular mass that could not be distinguished by reverse phase chromatography, was detected immunochemically by positive reaction with antibodies to rat GST-1 and GST-2 in addition to reaction with anti-(plaice)GST-A. As suggested by these results we discuss the existence of genetic polymorphism, the differential expression and the evolutionary relationships of mullet GSTs.
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PMID:Purification and characterization of multiple glutathione transferase isoenzymes from grey mullet liver. 936 73

Previously we have purified and characterized a major glutathione S-transferase (GST) activity, GST-4a, from the Thai mosquito Anopheles dirus B, a model mosquito for study of anopheline malaria vectors [Prapanthadara, L. Koottathep, S., Promtet, N., Hemingway, J. and Ketterman, A.J. (1996) Insect Biochem. Mol. Biol. 26:3, 277-285]. In this report we have purified an isoenzyme, GST-4c, which has the greatest DDT-dehydrochlorinase activity. Three additional isoenzymes, GST-4b, GST-5 and GST-6, were also partially purified and characterized for comparison. All of the Anopheles GST isoenzymes preferred 1-chloro-2,4-dinitrobenzene (CDNB) as an electrophilic substrate. In kinetic studies with CDNB as an electrophilic substrate, the V(max) of GST-4c was 24.38 micromole/min/mg which was seven-fold less than GST-4a. The two isoenzymes also possessed different K(m)s for CDNB and glutathione. Despite being only partially pure GST-4b had nearly a four-fold greater V(max) for CDNB than GST-4c. In contrast, GST-4c possessed the greatest DDT-dehydrochlorinase specific activity among the purified insect GST isoenzymes and no activity was detected for GST-5. Seven putative GST substrates used in this study were not utilized by An. dirus GSTs, although they were capable of inhibiting CDNB conjugating activity to different extents for the different isoenzymes. Bromosulfophthalein and ethacrynic acid were the most potent inhibitors. The inhibition studies demonstrate different degrees of interaction of the An. dirus isoenzymes with various insecticides. The GSTs were inhibited more readily by organochlorines and pyrethroids than by the phosphorothioates and carbamate. In a comparison between An. dirus and previous data from An. gambiae the two anopheline species possess a similar pattern of GST isoenzymes although the individual enzymes differ significantly at the functional level. The available data suggests there may be a minimum of three GST classes in anopheline insects.
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PMID:Isoenzymes of glutathione S-transferase from the mosquito Anopheles dirus species B: the purification, partial characterization and interaction with various insecticides. 1074 63

microRNAs (miRNAs) post-transcriptionally regulate the expression of targeted genes. We here systematically identify miRNAs in response to simulated microgravity based on both expressions and functional analysis in Caenorhabditis elegans. After simulated microgravity treatment, we observed that 19 miRNAs (16 down-regulated and 3 up-regulated) were dysregulated. Among these dysregulated miRNAs, let-7, mir-54, mir-67, mir-85, mir-252, mir-354, mir-789, mir-2208, and mir-5592 were required for the toxicity induction of simulated microgravity in suppressing locomotion behavior. In nematodes, alteration in expressions of let-7, mir-67, mir-85, mir-252, mir-354, mir-789, mir-2208, and mir-5592 mediated a protective response to simulated microgravity, whereas alteration in mir-54 expression mediated the toxicity induction of simulated microgravity. Moreover, among these candidate miRNAs, let-7 regulated the toxicity of simulated microgravity by targeting and suppressing SKN-1/Nrf protein. In the intestine, a signaling cascade of SKN-1/Nrf-GST-4/GST-5/GST-7 required for the control of oxidative stress was identified to act downstream of let-7 to regulate the toxicity of simulated microgravity. Our data demonstrated the crucial function of miRNAs in regulating the toxicity of simulated microgravity stress in organisms. Moreover, our results further provided an important molecular basis for epigenetic control of toxicity of simulated microgravity.
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PMID:microRNAs involved in the control of toxicity on locomotion behavior induced by simulated microgravity stress in Caenorhabditis elegans. 3306 Jul 53