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)

Two glutathione S-transferase (GST) isozymes, A1/A1 and B1/B2, were purified from etiolated, O-1,3-dioxolan-2-yl-methyl-2,2,2, -trifluoro-4'-chloroacetophenone-oxime-treated sorghum (Sorghum bicolor L. Moench) shoots. GST A1/A1, a constitutively expressed homodimer, had a subunit molecular mass of 26 kD and an isoelectric point of 4.9. GST A1/A1 exhibited high activity with 1-chloro-2, 4, dinitrobenzene (CDNB) but low activity with the chloroacetanilide herbicide metolachlor. For GST A1/A1, the random, rapid-equilibrium bireactant kinetic model provided a good description of the kinetic data for the substrates CDNB and glutathione (GSH). GST B1/B2 was a heterodimer with subunit molecular masses of 26 kD (designated the B1 subunit) and 28 kD (designated the B2 subunit) and a native isoelectric point of 4.8. GST B1/B2 exhibited low activity with CDNB and high activity with metolachlor as the substrate. The kinetics of GST B1/B2 activity with GSH and metolachlor fit a model describing a multisite enzyme having two binding sites with different affinities for these substrates. Both GST A1/A1 and GST B1/B2 exhibited GSH-conjugating activity with ethacrynic acid and GSH peroxidase activity with cumene hydroperoxide, 9-hydroperoxy-trans-10, cis-12-octadecadienoic acid and 13-hydroperoxy-cis-9, trans-11-octadecadienoic acid. Both GST A1/A1 and GST B1/B2 are glycoproteins, as indicated by their binding of concanavalin A. Polyclonal antibodies raised against GST A1/A1 exhibited cross-reactivity with the B1 subunit of GST B1/B2. Comparisons of the N-terminal amino acid sequences of the GST A1, B1, and B2 subunits with other type I theta-GSTs indicated a high degree of homology with the maize GST I subunit and a sugarcane GST.
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PMID:Isolation and characterization of glutathione S-transferase isozymes from sorghum. 966 30

Increasing evidence indicates that reactive oxygen species and other physiologically existing oxidative stimuli upregulate the antioxidant system, thereby triggering the adaptive response. In this study, we focused on adaptive cytoprotection induced by lipopolysaccharide (LPS), which induces oxidative stress and inflammatory cytokines, in PC12 cells, a model of the neuronal cell. After treating PC12 cells with LPS at sublethal concentrations, we found that they developed resistance to subsequent oxidative stress induced by 13S-hydroperoxy-9Z,11E-octadecadienoic acid and 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium. To determine the underlying molecular mechanisms responsible for an adaptive response induced by LPS, we studied the changes in the antioxidant system. LPS treatment resulted in an increase in the gene expression of glutathione S-transferase A3 (GST-A3) by up to 60-fold as well as in GST enzyme activity. A GST inhibitor and GST A3 small interfering RNA effectively attenuated the adaptive response. The nuclear factor erythroid 2 p45-related factor 2 (Nrf2) was transcriptionally activated by LPS. Nrf2 small interfering RNA effectively attenuated the increase in GST A3 mRNA level as well as the adaptive response induced by LPS. In addition, peripheral injection of LPS at sublethal concentrations increased GST enzyme activity in mouse brain. These findings, taken together, indicate that stimulation with LPS at sublethal concentrations induces an adaptive response and enhances PC12 cell tolerance, primarily through the induction of GST A3 via the transcriptional activation of the Nrf2 signaling pathway.
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PMID:Induction of adaptive response and enhancement of PC12 cell tolerance by lipopolysaccharide primarily through the upregulation of glutathione S-transferase A3 via Nrf2 activation. 1879 14