• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.97-103
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• 1998

Effects of safener fluxofenim was investigated for crop injury of acetanilide's upland herbicides and for enzyme activity of glutathione S-transferase (GST) in grain sorghum. Bioassay with etiolated grain sorghum [Sorghum bicolor (L.) Moench. cv. 'G522DR'] seedlings grown in agar containing metolachlor or alachlor showed that they are strong inhibitors on root growth of grain sorghum ($GI_{50}=4.5{\mu}M$ for metolachlor and $6.2{\mu}M$ for alachlor). The safener fluxofenim applied by seed soaking protected growth of grain sorghum from crop injury of metolachlor or alachlor at the concentrations of 1 to 10 ${\mu}M$. There was a significant increase in glutathione-herbicide conjugates in root tissues of fluxofenim-treated seedlings. Activities of $GST_{-metolachlor}$ and $GST_{-CDNB}$ were increased by 82% and 70%, respectively, in the cytosolic fraction of roots with fluxofenim treatment.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.938-943
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• 2004

A gene responsible for the chlorothalonil-biotransformation was cloned from the chromosomal DNA of Ochrobactrum anthropi SH35B, an isolated bacterium strain from soil. We determined the nucleotide sequences and found an open reading frame for glutathione S-transferase (GST). The drug-hypersensitive Escherichia coli KAM3 cells transformed with a plasmid carrying the GST gene can grow in the presence of chlorothalonil. The GST of O. anthropi SH35B was expressed in E. coli and purified by affinity chromatography. The fungicide chlorothalonil was rapidly transformed by the purified GST in the presence of glutathione. No significant difference in the chlorothalonil-biotransformation effect was observed among the thiol compounds (cysteine, reduced glutathione, and $\beta$-mercaptoethanol). Thus, the result reported here is the first evidence on the chlorothalonil-biotransformation by conjugation with the cellular free thiol groups, especially glutathione, catalyzed by the bacterial GST.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.37-43
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• 1997

Tolerance mechanism to simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine) in Coix lacryma-jobi was investigated with respect to herbicide detoxification via glutathione conjugation. Simazine was initially absorbed by seedlings of C. lacryma-jobi and corn, but after 12 hours of treatment, no significant difference in simazine absorption was found in both species. Simazine absorbed was rapidly metabolized to glutathione-simazine conjugate. One to six hours after treatment, metabolism was approximately 2-fold faster in C. lacryma-jobi than in corn. Glutathione content was found 1.5- and 2.3-fold higher in coleoptile and root of C. lacryma-jobi, respectively, compared with corn. In both species, the highest concentration of glutathione was found in coleoptile tissue. Glutathione S-transferase that exhibits activity with 1-chloro-2,4-dinitrobenzene was not significantly different between two species. However, glutathione S-transferase activity with simazine was approximately 2-fold greater in C. lacryma-jobi than in corn. The glutathione S-transferase activity was 20 to 30% greater in shoot of either species than in root. Fast protein liquid chromatography-anion exchange column was used to separate glutathione S-transferase isozymes in coleoptiles of C. lacryma-jobi and corn. A peak of glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene and two peaks of glutathione S-transferase activity with simazine from C. lacryma-jobi were coeluted with those from corn, but showed greater activity than in the case of corn. Another glutathione S-transferase isozyme that exhibits activity with simazine was detected in the elution of C. lacryma-jobi extract, but not in corn. Electron transport in chloroplast thylakoids isolated from leaves of both species was equally sensitive to simazine applied at 1 to 100 nM. These results indicate that the simazine tolerance in C. lacryma-jobi is due to its capacity to detoxify the herbicide via glutathione conjugation, which is positively correlated with the level of glutathione content and glutathione S-transferase activity.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2949-2953
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• 2012

The glutathione S transferase (GST) family is a major part of cellular defense mechanisms against endogenous and exogenous substances, many of which have carcinogenic potential. Alteration in the expression level or structure of the glutathione-S-transferase (GST) enzymes may lead to inadequate detoxification of potential carcinogens and consequently contribute to cancer development. A member of the glutathione-S-transferase (GST) family, GSTP1, is an attractive candidate for involvement in susceptibility to carcinogen-associated colorectal cancer. An $Ag{\rightarrow}G$ transition in exon 5 resulting in an Ile105Val amino acid substitution has been identified which alters catalytic efficiency. The present study investigated the possible impact of Ile105Val GSTP1 polymorphism on susceptibility to colorectal cancer. in Jordan We examined 90 tissue samples previously diagnosed with colorectal carcinoma, and 56 non-cancerous colon tissues. DNA was extracted from paraffin embedded tissues and the status of the GSTP1 polymorphism was determined using a polymerase chain reaction restriction fragment length polymorphism (RFLP) method. No statistically significant differences were found between colorectal cancer cases and controls for the GSTP1 Ile/Ile, Ile/Val and Val/Val genotypes. The glutathione S-transferase polymorphism was not associated with risk in colorectal cancer cases in Jordan stratified by age, sex, site, grade or tumor stage. In conclusion, the GSTP1 Ile105Val polymorphism is unlikely to affect the risk of colorectal cancer.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3756-3759
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• 2011

• BMB Reports
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• v.33 no.2
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• pp.179-183
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• 2000

The glutathione S-transferase (GST) activities of S-type and L-type thioltransferases (TTases), which are purified from the seeds and leaves of Arabidopsis thaliana, respectively, were identified and compared. The S-type and L-type TTases showed $K_m$ values of 9.72 mM and 3.18mM on 1-chloro-2,4-dinitrobenzene (CDNB), respectively, indicating the L-type TTase has higher affinity for CDNB. The GST activity of the L-type TTase was rapidly inactivated after being heated at $70^{\circ}C$ or higher. The GST activity of the S-type TTase remains active in a range of $30-90^{\circ}C$. $Hg^{2+}$ inhibited the GST activity of the S-type TTase, whereas $Ca^{2+}$ and $Cd^{2+}$ inhibited the GST activity of the L-type TTase. Our results suggest that the GST activities of two TTases of Arabidopsis thaliana may have different catalytic mechanisms. The importance of the co-existence of TTAse and GST activities in one protein remains to be elucidated.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.228-232
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• 2008

In the present study, we investigated the glutathione S-transferase (GST) induction of medicinal plants using a cultured PC12 cells. The methanol extracts of Dendrobium nobile Lindley, Schizonepeta tenuifolia Briquet, Glycyrrhiza uralensis Fischer, Paenoia lactiflora Pall were tested. As the result, exposure of PC12 cells to G. uralensis resulted in the significant induction of GST. On the continuous experiment, G. uralensis was extracted with methanol, ethanol, and acetone. Among these extracts, methanol extracts showed the highest GST induction. The methanol extracts were further fractionated with hexane, diethyl ether, ethyl acetate, and water layer according to the degree of polarity. The diethyl ether layer showed the highest exhibited GST induction on PC12 cells. Based on these results suggest that the extracts of G. uralensis can be applicable for the development of a new antioxidant agent.

• Parasites, Hosts and Diseases
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• v.40 no.4
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• pp.173-176
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• 2002

Glutathione S-transferase (28GST) with molecular mass of 28 kDa is an anti-oxidant enzyme abundant in Clonorchis sinensis. In adult C. sinensis, 28GST was localized in tegumental syncytium, cytons, parenchyma, and sperm tails examined by immunoelectron microscopy. C. sinensis 28GST was earlier found to neutralize bio-reactive compounds and to be rich in eggs. Accordingly. it is suggested that 28GST plays important roles in phase II defense system and physiological roles in worm fecundity of C. sinensis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.15-18
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• 1993

To evaluate an effect of dietary protein on the intoxication of methanethiol in rats, the methanethiol was intraperitoneally injected to the rats fed a low or high protein diet and then the liver weight per body weight and seurm levels of alanine aminotransferase (ALT) activities were determined to investigate the differences in liver damage between the animal groups fed low protein diet and that fed high protein diet. On the other hand, the hepatic glutathione content and its conjugating enzyme, glutathione S-transferase (GST) activity were determined to clarify the cause of difference in liver function between the two groups. The increasing rate of liver weigh/body wt., serum levels of ALT to its control group were higher in methanethiol-treated rats fed low protein diet than those fed high protein diet. The hepatic content of glutathione and GST activity were higher in rats fed high protein diet than those fed low protein diet and the decreasing rate of hepatic glu-tathione content to its control group was higher in rats fed low protein diet than those fed high protein diet. Furthermore, the hepatic GST activity in methanethiol-treated rats was higher in rats fed high protein diet than those fed low protein diet. In case of control group, the GST activity was also higher in rats fed high protein diet than those fed low protein diet.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.77-83
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• 2001

To gain further insight into the relationship between structure and function of glutathione S-transferase (GST), the four cysteine mutants, C14S, C47S, C101S and C169S, of human GST P1-1 were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized glutathione (GSH). The catalytic activities of the four mutant enzymes were characterized with five different substrates as well as by their binding to four different inhibitors. Cys14 seems to participate in the catalytic reaction of GST by stabilizing the conformation of the active-site loop, not in the GSH binding directly. The substitution of Cys47 with serine significantly reduces the affinity of GSH binding, although it does not prevent GSH binding. On the other hand, the substitution of Cys101 with serine appears to change the binding affinity of electrophilic substrate by inducing a conformational change of the $\alpha-helix$ D. Cys169 seems to be important for maintaining the stable conformation of the enzyme. In addition, all four cysteine residues are not needed for the steroid isomerase activity of human glutathione S-transferase P1-1.