• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.667-671
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• 2003

The total phenolic and flavonoid contents of Lentinus edodes extracts were determinated by spectrophotometrical .method, and antihepatotoxic activity was detected on glutathione S-Transferases(GST). The total phenolic contents was highest water extract than solvent(ethanol, methanol) extracts, but flavonoid content was appear on opposite. GST activity was the highest appears in water extract. This fact verified of anticancer effect indirectly of Lentinus edodes.

• Toxicological Research
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• v.23 no.2
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• pp.127-133
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• 2007

Metformin is a drug used to lower blood sugar levels in patients with type 2 diabetes via activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK). The primary objective of this study was to investigate whether metformin at the pharmacologically effective concentrations affects the expressions of ${\gamma}$-glutamylcysteine synthetase and phase II antioxidant genes in the H4IIE cell. Treatment of the cells with either metformin or 5-aminoimidazole-4-carboxamide riboside (AICAR) abrogated tert-butylhydroxyquinone (t-BHQ) induction of ${\gamma}$-glutamylcysteine synthetase, a rate limiting enzyme of GSH synthesis. The ability of t-BHQ to induce glutathione S-transferases (GSTs), a major class of phase II detoxifying enzymes that playa critical role in protecting cells from oxidative stress or electrophiles, was also inhibited by the agents. Transcriptional gene repression by metformin was verified by the GSTA2 promoter luciferase assay. Moreover, either metformin or AICAR treatment significantly decreased t-BHQ-dependent induction of other GSTs (i.e., $GST{\mu}$ and $GST{\pi}$ forms). Taken together, our data indicate that metformin treatment may result in the repression of ${\gamma}$-glutamylcysteine synthetase and glutathione S-transferase genes possibly via AMPK activation.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.294-297
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• 2002

A gene coding for the GST of cotton (Gh-5) was cloned into Escherichia coli and experssed. The enzyme remained within the cytoplasm of E. coli. An 696 bp open reading frame was in the 988 base pair fragment of the recombinant plasmid pET-30b(+). The deduced protein sequence consists of 232 amino acids and has a molecular mass of 30235.58 Da. The cloned enzyme conjugated reduced glutathione and 1-chloro-2,4-dinitrobenzene (CDNB). Plant GST cDNA was expressed in microbe and produced polypeptide had function as an enzyme.

• Environmental Analysis Health and Toxicology
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• v.13 no.3_4
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• pp.55-61
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• 1998

Glutathione-S-transferases (GSTs) detoxify electrophilic xenobiotics and reactive metabolites. Recently benzene-fused heterocycles have been shown to increase the total amount of hepatic GSTs in rats. Primarily this study aimed to determine the induction of GSTs by benzoazoles (BAs) including benzoxazole (BX), 2-methylbenzoxazole (M-BX), 2,5-dimethyl benzoxazole (D-BX), benzothiazole (BT), aminobenzothiazole (A-BT) and 2-mercaptobenzothiazole (M-BT) in rats. Hepatic cytosol and poly(A)$^+$ mRNA were prepared from rats after oral administration of BX, BT, M-BX, D-BX, A-BT and M-BT for 5 consecutive days at doses of 1 mmol/kg. Western immunoblot and northern blot analysis were conducted with rabbit anti-GST Ya, Yb$_1$, Yb$_2$, Yc antibodies and cDNA probes containing = 500 bps in the specific coding regions of Ya, Yb$_1$, Yb$_2$, Yc$_1$, and Yc$_2$, respectively. All BAs increased the amount of enzymes and mRNA levels of GSTs. BT was the most effective inducer of GSTs among the compounds examined in this study. Although A-BT and M-BT, the derivatives of BT, induced GSTs, these chemicals had lesser effect on induction of GSTs than BT. The derivatives of BX also induced less GSTs than the parent compound and the addition of methyl group to the benzene ring of BX reduced the induction of GSTs. BAs had better inductive effects on the class $\alpha$(Ya, Yc) than class $\mu$ GSTs (Yb$_1$, Yb$_2$). BAs enhanced mRNA levels of GSTs in parallel with the protein levels. These results indicate that 1) most of BAs induced various isozymes of GSTs, 2) the induction of GSTs appears to be correlated with the chemical structure of the derivatives, and 3) the expression of GST by BAs is presumably under the transcriptional regulation.

• Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.314-328
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• 2024

The mechanism for the elimination of xenobiotics undergoes three different phases of reactions in organisms. Among these, glutathione S-transferases (GSTs) are classified as phase II detoxification enzymes, catalyzing the conjugation of electrophilic substrates to glutathione or reduced hydroperoxides. This study aimed to investigate the molecular characteristics, detoxification functions, and immune responses of GST omega (LhGSTO1) and kappa (LhGSTK1) in redlip mullet. The open reading frames of LhGSTO1 (720 bp) and LhGSTK1 (687 bp) encoded proteins of 239 and 228 amino acids, respectively. Sequence analysis revealed that LhGSTO1 and LhGSTK1 possessed GSH-binding sites in their N-terminal domains. Substrate-binding sites in the C-terminal domain were exclusively identified in LhGSTO1. In the tissue-specific transcription profile analysis, both LhGSTO1 and LhGSTK1 were ubiquitously expressed in all tissues of healthy mullets. Temporal expression analysis of LhGSTO1 and LhGSTK1 in the blood showed that their expression was significantly modulated by polyinosinic:polycytidylic (poly I:C), lipopolysaccharide (LPS), and Lactococcus garvieae. Different chemical and cellular assays were performed to assess the detoxification and cellular protective abilities of the two proteins. A substrate specificity test using the recombinant proteins revealed that both proteins possessed specific activity toward 1-chloro-2,4-dinitrobenzene (CDNB). In the disk diffusion assay, the smallest clearance zones were observed for LhGSTO1 and LGSTK1 against CdCl₂. In the cell protection assay, both LhGSTO1 and LhGSTK1 showed significant Cd detoxification ability compared to the control. Collectively, these results demonstrate that GST omega and kappa are involved in host defense against immune stimulants and xenobiotics in redlip mullet.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.187-192
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• 2008

The effects of some coumarins(coumarin, 7-hydroxycoumarin, scopoletin and esculetin) were investigated on pumpkin(Cucurbita maxima Duch.) seedlings and on pumpkin glutathione S-transferases(GSTs). Coumarin and esculetin suppressed the growth of seedlings, especially the elongation of roots as well as hypocotyls. Among the compounds tested, only esculetin inhibited the activity of a particular pumpkin GST by 50%, CmGSTU3 toward 1-chloro-2, 4- dinitrobenzene(CDNB) and at a concentration of 22 ${\mu}M$. Both ethylacetae(EtOAc) and water fractions in pumpkin seedlings and different organs of one-month-old pumpkin plants contained esculetin or similar hydrophobic fluorescent substances as well as hydrophilic substances, which showed different degrees of inhibitory effects on CmGSTU3 activity.

• Journal of Yeungnam Medical Science
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• v.12 no.1
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• pp.32-47
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• 1995

Glutathione(GSH) has a very important role in detoxification of cells and is closely related to antitumor drug-resistance of cancer cells. In order to evaluate the importance of glutathione metabolism in the drug-resistant cancer cells, the concentration of celluar GSH and activities of ${\gamma}$-glutamylcysteine synthetase(GCS), ${\gamma}$-glutamyl transpeptidase (GGT) and glutathione S-transferases(GST) in the adriamycin, vincristine, or cisplatin resistant L1210 (L1210AdR, L1210VcR, or L1210Cis) sublines were measured. Expression and amplification of GCS, GGT, and GST-${\pi}$ genes were also observed in the parent Ll210 and the drug-resistant Ll210 sublines. The concentration of GSH was increased 5.34 fold in L1210Cis, 2.83 fold in L1210VcR, and 1.78 fold in L1210AdR, compared to L1210. The activities of GCS and GGT were increased in drug-resistant L1210 sublines. The GST activity was increased in L1210VcR and L1210Cis but decreased in L1210AdR compared to Ll210. Expression of GCS, GGT, and GST-${\pi}$ genes were increased in the resistant L1210 sublines compare to the parent L1210 in northern blot analyses. Overexpression of GCS, GGT, and GST-${\pi}$ were observed in the resistant sublines, and the increases of the concentration of glutathione and the activities of GCS and GGT in the resistant sublines may be involved in a part of the drug-resistance in the resistant sublines.

• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.19-26
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• 2007

Glutathione S-transferases(GSTs, EC 2.5.1.18), glyoxalase-I(EC 4.4.1.5) and alliin lyase(alliinase, EC 4.4.1.4) are important enzyme systems in plant bodies. The first two are mainly detoxifying enzymes that utilize glutathione(GSH) in the defense mechanism, and the last one is mainly involved in secondary metabolism and relevant to sulfur compounds derived from GSH. The activities of the three enzymes have been investigated in soluble extracts of vegetable crops, including pumpkin, cabbage, broccoli, radish, carrot, potato, sweet potato, mungbean, and onion. GST activities were detected in all of the vegetables, and the extract of onion bulb exhibited the highest specific activity(648 nmol/min/mgP). The putative GSTs of most of the vegetables were found to be induced by ethanol. The activities of GSTs in onion bulb were found to be markedly inhibited by S-hexyl glutathione and were also inhibited by S-butyl glutathione and S-propyl glutathione. The anti-CmGSTF1 antiserum recognized a thick band for putative onion GST. The estimated glyoxalase-I activity level was also high in onion bulb(4540 nmol/min/mgP), indicating that the thick band detected by Western blot analysis might result from partial recognition of glyoxalase-I by the antiserum. The specific activities for glyoxalase-I were moderate in radish and carrot, and the extracts of other vegetables had rather low levels of activities. The extract of onion also showed the highest specific activity level for alliinase(2069nmol pyruvate/mgP). The extracts of other vegetables also had alliinase activities, although the estimated values were much lower than that of onion.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.73-81
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• 2016

Heat shock proteins (HSPs), one of the most highly conserved groups of proteins characterized to date, play crucial roles in protecting cells against environmental stresses, such as heat shock, salinity and oxidative stress. The glutathione S-transferases (GST) have important role in detoxification of oxidative stress, environmental chemicals and environmental stress. GST mRNA expression have been used as biomarkers on environmental stress. The purpose of this study was to investigate the death rate and the gene expression of Hsp70 and GST during air exposure and starvation. Results showed that, the expression of Hsp70 mRNA was significantly changed in the experiment groups, such as air exposure and starvation. GST mRNA expression was significantly increased in the experimental group of starvation. These results suggest that Hsp70 and GST were played roles in biomarker gene on the air exposure and starvation.

• Parasites, Hosts and Diseases
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• v.62 no.2
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• pp.205-216
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• 2024

Sigma-class glutathione transferase (GST) proteins with dual GST and prostaglandin synthase (PGS) activities play a crucial role in the establishment of Clonorchis sinensis infection. Herein, we analyzed the structural and enzymatic properties of sigma-class GST (CsGST-σ) proteins to obtain insight into their antioxidant and immunomodulatory functions in comparison with mu-class GST (CsGST-µ) proteins. CsGST-σ proteins conserved characteristic structures, which had been described in mammalian hematopoietic prostaglandin D₂ synthases. Recombinant forms of these CsGST-σ and CsGST-µ proteins expressed in Escherichia coli exhibited considerable degrees of GST and PGS activities with substantially different specific activities. All recombinant proteins displayed higher affinities toward prostaglandin H₂ (PGS substrate; average K_m of 30.7 and 3.0 ㎛ for prostaglandin D₂ [PGDS] and E₂ synthase [PGES], respectively) than those toward CDNB (GST substrate; average K_m of 1,205.1 ㎛). Furthermore, the catalytic efficiency (K_cat/K_m) of the PGDS/PGES activity was higher than that of GST activity (average K_cat/K_m of 3.1, 0.7, and 7.0×10^-3 s^-1㎛^-1 for PGDS, PGES, and GST, respectively). Our data strongly suggest that the C. sinensis sigma- and mu-class GST proteins are deeply involved in regulating host immune responses by generating PGD₂ and PGE₂ in addition to their roles in general detoxification.