• Bulletin of the Korean Chemical Society
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• 제22권1호
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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.

• 한국식품영양과학회지
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• 제23권3호
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• pp.436-442
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• 1994

The effect of garlic on glutathione S-transferase activity and the level of glutathione in the mouse liver was studied. the intraperitoneal injection of the methanol extract of garlic and ally sulfide which is one of possible active compounds in garlic to ICR mouse before the injection of aflatoxin B1 (AFB1) increased the levels of glutathione and nonprotein-SH in microsomal fraction of the livers. The injection of the chloroform fraction 2 which revealed the highest antimutgenic activity in our previous research in the increase of the activity of glutathione S-transferase and the levels of glutathione and nonprotein -SH. The glutathione itself also had the antimutagenic effect on AFB1 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Salmonella typhimurium TA98 and TA100 in vitro.

• 한국식품영양학회지
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• 제23권2호
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• pp.276-284
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• 2010

The effects of different dietary fatty acids on the hepatic glutathione S-transferase(GST-P) positive foci and glutathione related enzyme system were investigated in carcinogen treated rats. Weaning male Sprague Dawley rats were divided into three groups and fed the diets of 15% corn(CO), perilla(PO), and sardine oil(SO), respectively. Hepatocellular carcinogenesis was initiated with diethylnitrosamine(DEN) and then fed the diet containing 0.02% 2-acetylaminofluorene(2-AAF) followed by 0.05% phenobarbital for 10 weeks. The hepatic tissues were homogenized and centrifugated to prepare microsomal and cytosolic fractions. The enzyme activities of hepatic glutathione S-transferase(GST), glutathione reductase(GR), and glutathione peroxidase(GPx) were determined from cytosolic fractions. The number of GST-P hyperplastic nodules was the highest in corn oil group at 6th week, the early stage of hyperplastic nodule formation. GST activities were increased significantly by carcinogens in all dietary groups after 6th wk. GR activities followed the same trend as GST activities. GPx activities were decreased by carcinogens in all dietary groups at 10th week. In this experiment, corn oil diet may have promotive effect on hyperplastic nodule formation during the early promotional stages of chemical carcinogenesis.

• 한국환경보건학회지
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• 제18권1호
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• pp.76-83
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• 1992

Effect of freeze drying leek against cadmium poisoning on glutathione peroxidase, on glutathione reductase and on glutathione-s-transferase in liver, kidney and testes of the male rats during the administered period. In this experiment, male rats of Sprague-Dawley strain were used. The rats which were fed for 15 weeks were divided into 4 groups basal diet 3% leek added diet basal diet and cadmium in water and 3% leek added diet and cadmium in water. Cadmium was administered ad libitum 100ppm CdCl$_{2}$ in distilled water. The followings are the result of this experiment. 1. Leek enhanced the glutathione peroxidase activities which were reduced by cadmium treatment in liver, kidney and testes but not significance. 2. Leek reduced glutathione reductase activities which were incresed by cadmium in liver, kidney and testes. 3. Leek incresed the activities of glutathfone-s-transferase in liver but not in kidney and but not in testes. 4. Leek incresed glutathione concentration which was decresed by cadmium treatment in liver and kidney but not testes. This experiment showed that leek-addition group had protective effect against cadmium poisoning and alleviated GR and glutathione-s-transferase activities in tissues. Leek incresed activities of glutathione peroxidase in liver, kidney and testes but not significance. Therefore, this experiment concluded that leek defensive power against long term cadmium poisoning.

• 농약과학회지
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• 제6권1호
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• pp.31-35
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• 2002

본 논문의 목적은 benfuracarb 원제(90.2%)에 함유된 불순물의 glutathione-S-transferase와 amidase에 대한 저해 특성과 해당 불순물의 구조를 밝히는데 있다. Benfuracarb 원제, 유효성분 및 불순물은 glutathione-S-transferase(GST)를 효과적으로 저해하였으나, 그 저해력은 GST 효소 저해제인 ethacrynic acid의 저해력보다는 낮았다. 즉, GST에 대한 benfuracarb 원제, 유효성분 및 불순물의 $I_{50}$은 각각 $9.7{\times}10^{-4}M,\;>1.0{\times}10^{-3}M,\;1.8{\times}10^{-4}M$이었으나, ethacrynic acid의 $I_{50}$은 $1.7{\times}10^{-5}M$이었다. Benfuracarb 원제, 유효성분 및 불순물은 amidase를 저해하였는데, 이들의 효소저해력은 iprobenfos의 저해력($I_{50},\;8.2{\times}10^{-7}M$)보다는 낮은 $6.0{\times}10^{-5}M,\;4.3{\times}10^{-4}M,\;7.6{\times}10^{-5}M$이었다. Benfuracarb 원제에는 4종의 불순물(IM $1{\sim}4$)이 검출되었는데, 이들 중 IM 2와 3은 GST와 amidase의 활성을 저해하였던 반면, IM 4는 효소활성을 저해하지 않았다. 이들 불순물 중 효소활성 저해특성을 갖는 IM 2와 3을 IR, $^1H$-NMR, $^{13}C$-NMR, LC-MS를 이용하여 구조를 분석한 결과, IM 2는 ethyl-N-isopropylamino propionate로, 그리고 IM 3은 ethyl-N-isopropyl-N-(chlorosulfenyl) aminopropionate로 확인되었다.

• BMB Reports
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• 제28권3호
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• pp.197-203
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• 1995

Famesyl protein transferase involved in the first step of post-translational modification of $p21^{ras}$ proteins transfers the famesyl moiety from famesyl pyrophosphate to a cysteine residue in $p21^{ras}$ proteins. The enzyme was first purified 30,000-fold from bovine testis by use of 30~50% ammonium sulfate fractionation, DEAE-Sephacel ion exchange chromatography, Sephacryl S-300 gel filtration chromatography, Sephacryl S-200 gel filtration chromatography, and hexapeptide (Lys-Lys-Cys-Val-Ile-Met) affinity chromatography. The molecular weight of the purified enzyme was estimated to be ~100 kDa by gel filtration and SDS-polyacrylamide gels showed two closely spaced bands of ~50 kDa protein. These indicate that the enzyme consists of two nonidentical subunits, a and 13, which have slightly different molecular weights. The enzyme was inhibited by hexapeptide (Lys-Lys-Cys-Val-Ile-Met), which acted as an alternative substrate that competed for famesylation. Kinetic analysis by measuring initial velocities showed that famesyl protein transferase is a very slow enzyme. EDTA-treated famesyl protein transferase showed little activity with $Mg^{2+}$ or $Zn^{2+}$ alone, but required both $Mg^{2+}$ and $Zn^{2+}$ for the catalytic activity.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3756-3759
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• 2011

• 대한약리학회지
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• 제26권2호
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• pp.185-192
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• 1990

Diallyl disulfide의 간손상 예방효과를 검토할 목적으로 mouse에 bromobenzene을 투여해 간 손상의 model을 만든 다음 실험을 행하였을 때, diallyl disulfide를 전처치한 실험군이 대조군에 비하여 간손상의 정도가 경미하게 나타났다. 한편 diallyl disulfide의 간손상예방 효과 기전을 구명할 목적으로 bromobenzene의 활성화 및 해독 관련 효소들의 활성을 검토하였을때 활성화 효소인 aniline hydroxylase와 해독 효소의 일종인 epoxide hydrolase의 활성은 diallyl disulfide 전처치에 의해 변동이 없었으나, 나머지 해독 효소인 glutathione S-transferase의 활성은 유의 하게 증가되었고 이의 포합인자인 glutathione의 함량도 증가하였다. 또한 diallyl disulflde에 의한 glutathione S-transferase 활성 증가현상이 어떠한 기전으로 나타나는지 검토 하였을때, diallyl disulfide를 전처치 함으로서 Km치는 별다른 차이가 없었으나 Vmax치는 대단히 증가하였다. 그러나 시험관내에서 diallyl disulfide의 첨가농도를 증가시켰을 때에는 효소활성은 변하지 않았다. 이러한 실험결과들을 종합해 볼 때, diallyl disulfide 전처치에 의한 bromobenzene이 유도한 간손상의 예방효과는 diallyl disulfide가 bromobenzene의 독성 중간 대사산물인 bromobenzene 3,4-oxide를 해독하는 glutathione S-transferase 단백의 합성을 유도함으로서 나타난 결과로 사료되어지나 이점에 대해서는 추후 계속적인 연구 검토가 행해져야 할것이다.

• 한국응용과학기술학회지
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• 제36권1호
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• pp.341-347
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• 2019

본 연구에서는 한약재의 활용도를 높이기 위한 연구로 추출물 농도에 따른 생리활성물질의 용출량을 측정하기 위해 한방약술의 품질 특성과 Glutathione S-transferase의 활성 저해능을 측정한 결과는 다음과 같다. 한방약술의 pH결과는 4.4로 발효 전의 대조구 3.9보다 증가하였다. 이러한 변화는 알코올 발효과정 중 발효부산물 및 유기산 때문으로 사료된다. 한방약술의 산도는 0.55%로 발효 전의 대조구 0.09%보다 약 6배 증가하였다. 이런 결과는 유기산이 알코올 등과 결합하여 ester와 같은 향미 형성 등에 이용되는 것을 알 수 있다. 한방약술 15%의 glutathione S-transferase의 활성 저해능 $5.1{\pm}0.3$, 한방약술 20%는 저해능 $6.5{\pm}0.5$, 한방약술 25%는 $7.6{\pm}0.6$, 한방약술 30%는 $8.4{\pm}0.2$, 최대 농도인 35%에서의 저해능은 $9.7{\pm}0.7$로 나타내었다. 추출 농도별로 glutathione S-transferase의 활성 저해능은 통계학적으로 유의한 차이가 있음을 보였다 (p<0.05).

• 한국식품영양과학회지
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• 제23권4호
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• pp.581-586
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• 1994

The study was initiated elucidate the mechanism by examining the effect of GE-132 on hepatic glutathione S-transferase (GST) activity. Activity of GST increased with dose-dependent manner in hepatic cytosolic fraction of GE-132 treatment rats. Double reciprocal plotting gave Vmax value 1.4 fold increase by the treatment of GE-132(100mg/kg, p.o.for 6 weeks) compared with control group, but did not change Km value. Ethacryinc acid (85mg/kg, once a day, i.p) was injected to control rat, the GST activity decreased remarkably . However, GE-132 pretreated group, the effect caused by ethacrynic acid was markedly reduced. And activity of ${\gamma}$-glutamylcys- teine synthetase was not changed either by GE-132 treatment , but the activity of glutathione reudctase increased significantly. Decreasing properties of ethacrynic acid decreased level of hepatic glutathione , which was restored to same degree by GE -132 pretreatment . GE-132 protective effect on ethacrynic acid-induced mortality. It is concluded that the efect of GE-132 is partly mediated by increase in hepatic GST activity.