• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.206-212
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• 1998

This study was undertaken to explore the applicability of glutathione S-transferase (GST) activity as a predictable indicator to monitor chemical pollution in shells and fishes utilized for food. There were some variations in the basal level of GST activity depending on species tested. Ark shells, Anadara satowi, showed the highest normal enzyme activity, followed by catfish and marine mussels, Mytilus coruscus. White clams, Meretrix lusoria, Israeli carp and catfish had lower activity. When A. satowi was exposed to 3-methyl-cholanthrene (3-MC), a prototypic polycyclic aromatic hydrocarbon for 1 week, GST activity decreased by about 30%. This reduction in GST activity induced by 3-MC did not recover until two weeks after the cessation of exposure. GST activity increased in response to 3-MC in most of the other species studied. The GST elevation in M. coruscus attained its maxinum of about 200% at the termination of 3-MC exposure maintaining this level up to 2 weeks, and declined gradually thereafter. 3-MC also induced GST activity in lsraeli carp in a similar fashion to M. coruscus. Phenobarbital induced GST activity both in M. coruscus and lsraeil carp. Other chemicals. such as clofibrate, butylated hydroxyanisole. hexachlorobenzene, and oxolinic acid did not change the enzyme activity significantly in most speciel. Phenol depressed GST activity only in lsraeli carp. These results suggest that the basal level of GST activity is somewhat variable and that the direction of change in response to chemicals seems to be related to its normal activity. The change in enzyme activity can be a preditable indicator of some environmental chemicals such as PAHs and phenol.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.329-337
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• 1995

The effect of N-(4-chlorophenyl) maleimide(CPMI), plant growth regulators, and alkylating agents on gluathione(GSH) content and glutathione S-transferase(GST) activity was examined with 3-day-old etiolated sorghum(Sorghum bicolor [L.] Moench) seedlings. The GSH content and GST activity of untreated seedlings were higher in shoots than that in roots. Response of GST activity in coleoptile was significantly greater than in other tissues of sorghum seedling. In CPMI-treated seedlings, GSH content was not significantly different from that in untreated seedlings. CPM treatment resulted in 2.3-fold increase in GST activity measured with metolachlor as substrate in the coleoptile region. In contrast, change in GST activity measured with metolachlor as substrate in the coleoptile region. In contrast, change in GST activity measured with 1-chloro-2, 4-dinitrobenzene did not occur. The increase of GST activity was caused by induction of a GST isozyme, which is substrate-specific to metolachlor. Subsequently, two hypotheses related to metolachlor detoxification were evaluated on the basis of regulation of plant growth regulators and substrate induction of GST activity. In coleoptile, GST activity measured with metolachior was increased to 2.1-and 3.4-fold by both 2, 4-dichlorophenoxyacetic acid(2,4-D) and metolachlor treated at the germination stage of sorghum, respectively. Treatments of 2.4-D and metolachlor also induced isozymes exhibiting the activity toward metolachlor. One of the isozymes was co-eluted with that induced by CPMI. These results indicated that increase in GST activity by CPMI may be partially related to auxin regulation and substrate induction.

• 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.

• 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.36 no.1
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• pp.64-69
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• 1993

This study was performed to investigate detoxifying enzyme activities of carboxylesterase(CE), glutathione S-transferase(GST) and lactate dehydrogenase(LDH) at variable toxicity levels in fresh water fish, carp(Cyprinus carpio L.). The carp was exposed to single and combined pesticides of IBP, isoprothiolane and cartap for 48 hr at sublethal doses, $LC_{10}$ and $LC_{26}$. The detoxifying enzyme activities were assayed for the liver, head and gut of the carp. The enzyme activities we discovered were as follows: Both activities of CE and GST were increased at the sublethal doses but were declined by increasing doses. In the gut, we found that the CE activity had high levels in the treatment groups of isoprothiolane+IBP and isoprothiolane+cartap. In the head, the CE activity had high levels in the treatment groups of cartap, IBP and isoprothiolane. However, the GST activities were inconsistent in the head and gut of the fish. Also, the GST activity was declined by increasing protein contents. The highest LDH activity was shown in the isoprothiolane treated fish, while the lowest activity was observed in the isoprothiolane+cartap treatment.

• Biomedical Science Letters
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• v.7 no.4
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• pp.191-196
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• 2001

To evaluate an effect of cyclohexanone (CHO) treatment on the serum levels of glutathione S-transferase (GST) activity in acute liver damaged animals, acute liver damage was induced in rats with pretreatment of 50% $CCl_4$ in olive oil (0.1 ml/100 g body wt) intraperitoneally 14 times every other day. To liver damaged rats, CHO (1.56 g/kg body wt, i. p.) was injected once and then rats were sacrificed at 4 hours after injection of CHO. Increasing rate of GST activity to the control in serum was higher in CHO-treated rats pretreated with CCL$_4$ than the $CCl_4$-pretreated those. All the more, the injection of CHO to the liver damaged rats led to more enhanced liver damage on the basis of liver functional findings, i. e., serum levels of alanine aminotransferase (ALT) activity, liver weight per body weight, and malondialdehyde content. The changing pattern of serum ALT activity was similar with that of GST activity, whereas that of liver in both enzymes differed more or less from each other; the liver GST activity in CHO-treated rats pretreated with $CCl_4$ being more increased tendency than that of $CCl_4$-pretreated rats. Concomitantly the injection of CHO showed a increasing tendency of liver GST activity compared with the control. Furthermore, CHO injection to the liver damaged rats showed somewhat higher Vmax in the kinetics of liver GST enzymes. In conclusion, injection of CHO to the liver damaged animals led to more increased activity of serum GST, and it may be chiefly caused by the alteration of membrane permeability.

• BMB Reports
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• v.44 no.4
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• pp.279-284
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• 2011

The glutathione S-transferase (GST) system is useful for increasing protein solubility and purifying soluble GST fusion proteins. However, purifying half of the GST fusion proteins is still difficult, because they are virtually insoluble under non-denaturing conditions. To optimize a simple and rapid purification condition for GST-pyruvate kinase muscle 2 (GST-PKM2) protein, we used 1% sarkosyl for lysis and a 1 : 200 ratio of sarkosyl to Triton X-100 (S-T) for purification. We purified the GST-PKM2 protein with a high yield, approximately 5 mg/L culture, which was 33 times higher than that prepared using a conventional method. Notably, the GST-high-temperature requirement A2 (GST-HtrA2) protein, used as a model protein for functional activity, fully maintained its proteolytic activity, even when purified under our S-T condition. This method may be useful to apply to other biologically important proteins that become highly insoluble in the prokaryotic expression system.

• 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.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.327-336
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• 1996

This study was conducted to investigate the content of antioxidant and GST activity of the oxyfluorfen-tolerant and -susceptible rice cultivars with barnyardgrass, a typical susceptible weed in accordance by oxyfluorfen treatment. The content of vitamin C was higher in the tolerant rice cultivar than in the susceptible rice cultivar and barnyardgrass. The contents of vitamin E, carotenoid, glutathione(GSH, GSSG, total glutathione) were not different between the tolerant and susceptible plants. In the case of the content of vitamin C due to the treatment of oxyfluorfen, the tolerant rice cultivars, Hawon and Baru decreased less than the susceptible rice cultivars and barnyardgrass. After the treatment of oxyfluorfen the contents of vitamin E and GSH in the tolerant rice cultivars were higher than in the susceptible rice cultivars or barnyardgrass. But in the content of carotenoid was greater in the tolerant rice cultivars than in the susceptible rice cultivars but they didn`t have any difference in comparison with the susceptible barnyardgrass. And there was no difference in the content of GSSG between the tolerant and susceptible plants. When CDNB or oxyfluorfen were used as substrate, the GST activity, was higher in the tolerant rice cultivars than in the susceptible rice cultivars or batnyardgrass. After the treatment of oxyfluorfen the GST activity was not induced in the rice, but was induced in the barnyardgrass. Even after the treatment of acifluorfen, bifenox and oxadiazon the GST activity was not induced in the rice cultivars.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.299-304
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• 2000

The modulation of cytochrome P450(P450) activities and glutathione S-transferase (GST) was investigated after i.p. administration of glucose-diethyldithiocarbamate (Glu-DDTC) to rats. P450 1 A2 and 2El activities were inhibited by 60% 4 hr after the administration of 200 mg Glu-DDTC/kg and those activities were recovered to original levels 24 hr after dosing. In contrast, GST activities were enhanced up to 24 hr after dosing. These results seem to be due to the bifunctional activity of Glu-DDTC. Glu-DDTC acts as an inhibitor of P450 enzymes as well as inducer of GST enzyme. Glu-DDTC inhibited PNP hydroxylation (P450 2El) and ethoxycoumarin O-deethylation (P450 1A2) in a dose-dependent manner up to 200 mg/kg wherease it did not affect testosterone 6$\beta$-hydroxylation (P450 3A) and pentoxyresorufin O-dealkylation (P450 2B) activities. Induction of GST activity toward 1-chloro-2,4-dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzenen (DCNB) was dependent on the dose of Glu-DDTC and no species difference in the GST induction was seen between rat and mouse. Amoung GST subunits, Ya, Yb1 and partially Yb2 were induced by Glu-DDTC as conjugated by western blotting. The levels Yp, Yk and Yc subunits were not affected by Glu-DDTC treatment. Therefore the enhanced activity of GST toward CDNB and DCNB might be due to the induction of Ya, Ybl and partially Yb2 subunits. In conclusion, Glu-DDTC selectively inhibited P45O 1A2 and P450 2El activities whereas it enhanced Ya, Ybl subunits and partially Yb2 subunits of GST and the antimutagenic activity of this compound might be attributed from the modulation of these enzyme activities in animals.