• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.2
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• pp.157-162
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• 2003

The glutathione S-transferase (GSTs) are enzymes responsible for the protection of cells from chemical toxicants and oxidative stress. We describe here the cDNA sequence and mRNA expression of a putative GST from the mole cricket, Gryllotalpa orientalis. The G. orientalis GST cDNA sequences comprised of 621 bp encoding 207 amino acid residues. The multiple sequence alignment of G. orientalis GST gene with other known insect GSTs showed several conserved residues that may be essential for the enzymatic activity of the protein. Phylogenetic analysis of the deduced amino acid sequences of G. orientalis GST gene with other insect GST sequences revealed that the G. orientalis GST gene belongs to class I GST, forming a strong monophyletic group (100% bootstrap value) exclusively for class I GSTs from a diverse insect species. Northern blot analysis confirmed midgut-specific expression at transcriptional level, evidencing the midgut as a site for GST synthesis.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.772-776
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• 2007

In order to study the role of residue in the active site of glutathione S-transferase (GST), Arg13 residue in human GST P1-1 was replaced with alanine, lysine and leucine by site-directed mutagenesis to obtain mutants R13A, R13K and R13L. These three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. Mutation of Arg13 into Ala caused a substantial reduction of the specific activity by 10-fold. Km GSH, Km DCNB and Km EPNP values of R13A were approximately 2-3 fold larger than those of the wild type. Mutation of Arg13 into Ala also significantly affected I50 values of S-methyl-GSH that compete with GSH and ethacrynic acid, an electrophilic substrate-like compound. These results appeared that the substitution of Arg13 with Ala resulted in significant structural change of the active site. Mutation of Arg13 into Leu reduced the catalytic activity by approximately 2-fold, whereas substitution by Lys scarcely affected the activity, indicating the significance of a positively charged residue at position 13. Therefore, arginine 13 participates in catalytic activity as mainly involved in the construction of the proper electrostatic field and conformation of the active site in human GST P1-1.

• Korean Journal of Crystallography
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• v.14 no.1
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• pp.32-34
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• 2003

A helminth glutathione S-transferase. 28 kDa isozyme from Clonorchis sinensis has been crystallized under several conditions. One of the crystals, grown from a 10% polyehtylene glycol MME 550 (PEG MME 5 K) solution in 0.05 M potassium phosphate buffer (pH 7.0), diffracts to $3.0{\AA}$ resolution, and belongs to monoclinic space group C2, with unit cell parameters $a=95.83{\AA}$, $b=63.82{\AA}$, $c=235.09{\AA}$, and ${\beta}=97.2^{\circ}$.

• Journal of Acupuncture Research
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• v.17 no.1
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• pp.129-142
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• 2000

Gamdutang aqua-acupuncture solution(GAS), Gamdutang water-extracted solution(GWS) and Degamdutang aqua-acupuncture solution(DGAS) were prepared and tested for potential antitumor activities. It was used three biomarkers (quinone reductase, omithine decarboxylase, glutathione) to test chemopreventive potentials of GAS, GWS, DGAS. GAS was potent inducer of quinone reductase activity in Hepalclc7 murine hepatoma cells in culture, whereas GWS is less potent. GAS, GWS and DGAS were significantly induced quinone reductase activity in cultured rat normal liver cell, Ac2F. Glutathione levels were increased about 1.8-fold with GAS, 1.0-1.1 fold with GWS, DGAS in cultured murine hepatoma hepaiclc7 cells. In addition glutathione s-transferase levels were increased with GAS, GWS and DGAS. The effects of GAS, GWS and DGAS were tested on the growth of Acanthamoeba castellanii. Proliferation of Acanthamoeba castellanii was inhibited by GAS, GWS and DGAS at concentradons of $1{\times}$ and $5{\times}$. These results suggest that GAS has chemopreventive potential by inducing quinone reductase and quinone reductase activities, inhibition of ornithine decarboxylase activity, and increasing glutathione levels.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1364-1368
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• 1999

This study was carried out to investigate the inhibiton effects of Coprinus comatus ethanol extract of edible mushroom on liver damage in benzo(a)pyrene (B(a)P) treated mice. The activities of serum aminotransferase, cytochrome P 450 and hepatic content of lipid peroxide after B(a)P treatment were increased than those of control, but those levels were significantly decreased by the treatment of Coprinus comatus ethanol extract. Whereas, the hepatic glutathione content and glutathione S transferase activity were decreased by B(a)P treatment than those of control, but those were increased by the treatment of Coprinus comatus ethanol extract. Also the activities of superoxide dismutase, catalase and glutathione peroxidase after B(a)P treatment were markedly increased than those of control, but those levels were decreased by the treatment of Coprinus comatus ethanol extract. These results suggest that Coprinus comatus ethanol extract have a protective effect on liver damage by benzo(a)pyrene through the mechanisms of decreasing lipid peroxide and activities of free radical generating enzymes.

• YAKHAK HOEJI
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• v.36 no.5
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• pp.460-468
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• 1992

Several bichemical parameters related to free radicals were estimated in senile-prone (P) and resistant(R) strains of male senescence-accelerated mice(SAM) at 2, 5 and 11 months of age. The superoxide generation was increased with age in SAM-R/1 and SAM-P/2. Compared to SAM-R/1, more generation of superoxide was significantly noted in the SAM-P/2 liver. The activities of Cu/Zn-superoxide dismutase and catalase were decreased during aging and these activities in SAM-P/2 were significantly lower than in SAM-R/l liver. The activities of glutathione S-transferase were varied with aging, whereas SAM-P/2 showed lower levels compared to SAM-R/l. The gradual decreases of glutathione, protein bound-SH and nonprotein bound-SH contents were noted with increasing age. SAM-P/2 liver contained lesser amounts of glutathione and nonprotein bound-SH compared to SAM-R. In conclusion, superoxide generation was increased whereas the antioxidant enzyme activities were decreased during aging in SAM-R/1. In addition, SAM-P/2 strain showed more superoxide generation and less antioxidant enzyme activities than SAM-R/1 in the liver, thus we assume that these factors might accelerate the senescence of SAM-P/2 strain.

• YAKHAK HOEJI
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• v.40 no.5
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• pp.574-581
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• 1996

The study was initiated to elucidate the protective mechanism by examining in vivo effect of some marine natural products, Styela plicata, Ecklonia stolonifera and Pachymeniopsis elliptica on acetaminophen-induced lipid peroxidation. The methanol extract of S. plicata prevented acetaminophen (800mg/kg, i.p.)-induced hepatotoxicity in rats as evidenced by the decreased formation of lipid peroxide. But the methanol extracts of E. stolonifera and P. elliptica were not affected on the formation of lipid peroxidation. The activities of cytochrome P-450, animopyrine N-demethylase and aniline hydroxylase were not changed by the treatment with S. plicata in comparison with acetaminophen-teated group. In acetaminophen-treated control rats, the glutathione S-transferase activity was decreased markably. However. in S. plicata pretreated group, the effect caused by acetaminophen was markably reduced. A-cetaminophen decreased the level of hepatic, glutathione, which was restored to same degree by S. plicata pretreatment. And activity of ${\gamma}$-glutamylcystein synthetase was not changed by S. plicata pretreatment, but the activity of glutathione reductase was increased significantly.

• Preventive Nutrition and Food Science
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• v.5 no.1
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• pp.48-53
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• 2000

Inhibitory effects of the methanol extract, hexane extract, methanol soluble fraction (MSF) and juice from 3 weeks fermented Kimchi on the tumor formation in sarcoma-180 cell transplanted mice were studied. Effects of the solvent extracts and juice of the Kimchi on the levels of lipid peroxide, glutathione, and the enzyme activities of the liver were also investigated in normal and sarcoma-180 cell transplanted mice. At 32 days following trans-plantation, MSF reduced the tumor formation by 54% compared with the control group, resulting in the smallest tumor weight. Lipid peroxided content in liver increased by the transplantation of sarcoma-180 cells. However, it decreased when MSF of Kimchi was treated to the mice. MSF also suppressed xanthine oxidase activity in cytosol of the liver cells in mice transplanted by sarcoma-180 cells. Kimchi extracts had no inhibitory effect on hepatic aminopyrine-N-demethylase activity in sarcoma-180 cell transplanted or normal mice. Methanol extract and hexane extract of Kimchi slightly increased hepatic glutathione contents in sarcoma-180 treated mice. The injection of MSF from Kimchi markedly increased glutathione levels in the liver of sarcoma-180 treated mice. The injection of MSF from Kimchi markedly increased glutathione levels in the liver of sarcoma-180 treated mice compared to the controls. The MSF recovered the activities of hepatic glutathione reductase and glutathione S-transferase that decreased by the injection of sarcoma-180 cells. These results showed that MSF of Kimchi could suppress the growth of tumors, inhibiting lipid peroxide production and xanthine oxidase activity, in mice. We also suggested that Kimchi extract might play an important role in the prevention of cancer by enhancement of the glutathione level itself as well as via glutathione reductase and glutathione S-transferase.

• BMB Reports
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• v.40 no.4
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• pp.511-516
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• 2007

A glutathione S-transferase (GST) related to the phi (F) class of enzymes only found in plants has been cloned from the Oryza sativa. The GST cDNA was cloned by PCR using oligonucleotide primers based on the OsGSTF5 (GenBank Accession No. $\underline{AF309382}$) sequences. The cDNA was composed of a 669-bp open reading frame encoding for 223 amino acids. The deduced peptide of this gene shared on overall identity of 75% with other known phi class GST sequences. On the other hands, the OsGSTF5 sequence showed only 34% identity with the sequence of the OsGSTF3 cloned by our previous study (Cho et al., 2005). This gene was expressed in Escherichia coli with the pET vector system and the gene product was purified to homogeneity by GSH-Sepharose affinity column chromatography. The expressed OsGSTF5 formed a homo-dimer composed of 28 kDa subunit and its pI value was approximately 7.8. The expressed OsGSTF5 displayed glutathione conjugation activity toward 1-chloro-2,4-dinitrobenzene and 1,2-epoxy-3-(p-nitrophenoxy)propane and glutathione peroxidase activity toward cumene hydroperoxide. The OsGSTF5 also had high activities towards the herbicides alachlor, atrazine and metolachlor. The OsGSTF5 was highly sensitive to inhibition by S-hexylGSH, benastatin A and hematin. We propose from these results that the expressed OsGSTF5 is a phi class GST and appears to play a role in the conjugation of herbicide and GPOX activity.

• BMB Reports
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• v.33 no.6
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• pp.469-475
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• 2000

The purpose of this study was to examine the chemopreventive potential of taurine at various levels on the diethylnitrosamine (DEN)·induced hepatocarcinogenesis. Male Sprague-Dawley rats were fed on diets containing 0, 1, 2, 3% taurine or 5% ${\beta}-alanine$ for taurine depletion. Then they were treated with DEN and 2/3 partial hepatectomy. The number of placental glutathione S-transferase positive ($GST-P^+$) foci, as a preneoplastic marker in the 1 % taurine group was lower than the control diet group. However the difference was insignificant. Although taurine diets reduced the thiobarbituric acid reactive substance (TBARS) level, the number of $GST-P^+$ foci was increased in 3% taurine diet group. The 1 % taurine diet increased the glutathione (GSH) level and GST activity, however they unfortunately did not suppress the foci formation. In the 3% taurine group, the GSH level and GSH peroxidase (GPx) activity were significantly decreased. Excess taurine supplementation of the pharmaceutical dose worked against hepatic chemoprevention, which might result from modulation of GPx activity and GSH utility. On the contrary, taurine might work as an antioxidant against TBARS production as the 1 % taurine diet increased GSH level. The potency of the cancer preventive effect of taurine still remains and further studies should investigate the effect of taurine with less than 1 % levels on the prevention of hepatic cancer.