• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.180-180
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• 1994

Farnesyl protein transferase는 Ras precursor의 C-terminal에 있는 cystein residue에 farnesyl group을 결합시키는 효소다. 이 효소를 bovine testis에서 30-50% ammonium sulfate fractionation, DEAE-sephacel ion exchange, Sephacryl s-300 gel filtration, hexapeptide(KKCVIM) affinity chromatography를 통해 30000배로 분리하였다. 분리된 효소는 gel filtration시 약 100kDa으로, SDS-polyacrylamide 전기영동시 50kDa의 인접한 두 bands로 나타났고 이것은 $\alpha$, $\beta$ subunits으로 생각되었다. $\alpha$ subunit을 encoding하는 RAM2 유전자를 site directed mutagenesis로 145번의 histidine을 aspartate로, 140번의 aspartate를 asparagine 으로 바꾸었더니 optimal pH와 $K_{m}$ 값이 변했다. Diethyl pyrocarbonate로 histidine residues를 chemical modification시켰을때 효소의 활성이 저하되었다. 145번 histidine이 aspartate로 바뀐 돌연변이효소에서 비교적 느리게 활성이 저하되므로 145번 histidine이 이 효소의 active site에 있을것으로 추측된다.

• BMB Reports
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• 제30권4호
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• pp.280-284
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• 1997

Phenylglyoxal diethyl pyrocarbonate (DEPC), and 1-cyclohexyl-3-[2-morpholinoethyl]-carbodiimide metho-p-toluenesulfonate (CMC) are modifying reagents specific for arginine, histidine, and aspartate or glutamate, respectively. They were found to inactivate S. cerevisiae farnesyl protein transferase (FPTase). The peptide substrate protected the enzyme against inactivation by CMC and the other substrate farnesyl pyrophosphate showed protection against inactivation by phenylglyoxal. while neither of the two substrates protected the enzyme against DEPC inactivation. These results suggest the presence of aspartate/glutamate, arginine and histidine residues at the active site of this enzyme.

• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.529-534
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• 2006

Chemical modification of the S. cerevisiae farnesyl protein transferase (FPT) with CMC, phenylglyoxal and DEPC resulted in enzyme inactivation, depending upon the reagent concentration. The peptide substrate GST-PEP-I, a GST-fused undecapeptide mimicking the C-terminus of $p21^{Ki-ras}$, protected the enzyme against inactivation by CMC which is specific to either aspartate or glutamate, while the other substrate farnesyl pyrophosphate (FPP) showed protection against phenylglyoxal which is the specific modifier of arginine residues, dependent on the substrate concentrations. Neither of the two substrates protected the enzyme against histidine inactivation by DEPC. It is suggested that there is at least one aspartate or glutamate residue at the peptide substrate binding site, and that at least one arginine residue is located at the binding site of FPP. There also seems to be at least one histidine residue which is critical for enzymic activity and is exposed toward the bulk solution, excluded from the substrate binding sites.

• 환경위생공학
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• 제19권1호
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• pp.50-56
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• 2004

Dibutyl phthalate (DBP) is used extensively in the plastic industry and has been known as an endocrine disruptor. Present study was undertaken to examine whether DBP can induce oxidative stress in mice. In this study, oxidative stress was measured in terms of the modification of lipid peroxidation and gamma-glutamyl transferase (GGT) activity. The serum toxicity index, level of lipid peroxidation and triglyceride (TG), and activity of GGT were measured in male ICR mice after a single administration of DBP (5 g/kg, po). DBP did not alter serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, glucose and cholesterol level. However, the treatment with DBP was found to significantly increase the level of lipid peroxidation in liver and lung. The TG content and activity of GGT in the liver of DBP-exposed animals was also increased. These results indicate that DBP can induce mild oxidative stress in mice. The GGT activity is considered to be increased as one of the adaptive defense mechanisms to oxidative stress induced by DBP.

• Asian-Australasian Journal of Animal Sciences
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• 제19권9호
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• pp.1354-1360
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• 2006

Maize-soybean meal diets with 0, 100, 200 and 300 g/kg double zero rapeseed meal ('00' RSM) with and without an enzyme mixture (xylanase, pectinase, cellulase) at a level of 1.6 g/kg were evaluated with 624 day-old broiler chicks for 5 weeks. The birds were randomly allocated to eight dietary treatments with three replicates of 26 birds each. Average daily gain (ADG) and feed intake (FI) were recorded weekly and ileal viscosity, organ weights, serum enzyme activity, hormonal profile and hematological parameters were measured at the end of week 5. Average daily gain during the weekly periods was significantly influenced by the dietary level of '00'RSM (p<0.01). Inclusion of '00' RSM improved the ADG up to day 28 with the increased level; beyond that time no improvement was recorded when compared to control groups. However, ADG from 1-35 days was significantly different between 300 g/kg inclusion level of '00' RSM and the control diet. Inconsistent decline in feed intake and feed conversion ratio was observed up to day 21 and the trend was reversed thereafter. The proportion of '00' RSM in the diet had a significant ($p{\leq}0.05$) influence on thyroid weight but had no effect on the relative weights of liver and heart, serum enzyme activities (${\gamma}$-glutamyl transferase, alanine amino transferase and aspartate amino transferase), thyroid hormones ($T_3$ and $T_4$), hemoglobin level and hematocrit. Significant improvement in ADG was recorded during the 2nd week of age with the addition of enzyme, whereas for all other periods, including the whole period of the trial, higher but non-significant ADG was observed. FI and FCR were not affected by the addition of enzyme but there was a numerical reduction in FCR during the whole period. The addition of enzyme reduced the ileal viscosity at all levels of '00' RSM inclusion. The results suggest that '00' RSM can be included up to 300 g/kg in broiler diets without any adverse effects on health and performance. The addition of commercial enzyme mixture containing xylanase, pectinase, cellulase to broiler diets containing '00'RSM has some effect on growth rate and feed conversion efficiency.

• 한국임상수의학회지
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• 제21권1호
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• pp.45-48
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• 2004

5년령의 암컷 히말라얀 고양이가 복막심낭횡격막 허니아가 의심되어서 건국대학교 수의과대학 부속 동물병원에 내원하였다. 일련의 검사를 실시한 후 환자는 복막심낭횡격막 허니아와 간기능 부전이 확진되었다. 그 후 한 달간의 약물치료에도 불구하고, 혈청화학검사에서 간효소 (aspartate transferase, alanine transferase, gamma-glutamyl transferase) 수치는 정상범위로 내려 가지 않았다. 이 환자는 수술 중에 간 일부가 횡격막에 유착되어서 괴사가 일어난 것이 발견되었고, 유착되고 괴사된 간 조직은 횡격막에서 조심스럽게 분리하여 절제하였다. 횡격막은 괴사된 부분을 잘 정리하고 난 뒤에 손상된 횡격막 부분을 simple continuous suture pattern으로 봉합하였다. 수술 후 한 달 뒤 환축은 정상적인 상태를 보였고 다른 복합증 없이 회복되었다. 그리고 혈청화학 수치 중 간효소 수치도 정상 범위로 떨어졌다.

• 농약과학회지
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• 제9권4호
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• pp.338-346
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• 2005

Carbendazim의 랫드 간 해독체계에 대한 영향을 검색하기 위하여 간장독성의 지표 효소인 혈장 ALT(alanine aminotransferase) 및 AST(aspartate aminotransferase) 활성, 간에 대한 독성, 해독 및 대사에 대한 영향을 구명하기 위하여 간 GSH(glutathione), GST(glutathione-S-transferase), cytochrome P450 및 cytochrome P450 reductase 활성을 375, 750, 1,500 mg/kg 약량에서 측정한 결과 혈장 ALT 및 AST 활성이 120분 후에 약간의 증가가 있었으나 특이한 독성증상은 관찰되지 않았다. GSH는 고농도와 중농도 120분에서 20%의 함량증가가 있었고, GST는 120분까지 $36{\sim}50%$ 정도의 활성저해가 있었으나 240분에는 활성이 회복되었다. Cytochrome P450함량은 60분까지 $25{\sim}50%$까지 함량이 저하되었으나 120분에 70%이상 회복되었고, 240분 저농도에서는 거의 회복되었으며, cytochrome P450 reductase도 120분까지 $25{\sim}50%$ 활성저해가 있었으나, 240분에는 무처리 군의 활성과 유사하게 회복되어 대사관련 효소에 대한 손상은 크지 않을 것으로 판단되었다. 이상의 결과에서 benzimidazole 계 살균제인 carbendazim은 생체내 해독 및 대사관련 체계에 영향이 적은 농약으로 급성적인 중독은 일으키지 않을 것으로 판단되었다.

• 한국식품위생안전성학회지
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• 제14권2호
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• pp.172-178
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• 1999

Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl4-induced hepatotoxicity. The hepatoprotective effect of subfractions has been evaluated by analyzing blood and hepatocyte biochemical analyses and biotransformation enzyme analyses. Treatment of BS-5, subfraction has significantly decreased the activities of alanine aminotransferase and aspartate aminotransferase. In addition, the levels of cholesterol and triglyceride in liver have been decreased as compared with that of CCl4 treated rats. The hepatoprotective effect of BS-5, subfraction on the CCl4-induced hepatotoxicity would be mediated of the attenuation of the level of cytochrome P450 and the enhancement of the activity of glutathion S-transferase.

• Preventive Nutrition and Food Science
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• 제3권1호
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• pp.62-66
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• 1998

The effect of dietary capsaicin (8-methyl-N-vanillyl-6-nonenamide, CAP) on drug-metabolizing enzyme activities was investigated in mice. Male ICR mice were divided into 4 groups and fed diets containing 0, 5, 20, 100 ppm CAP for 4 seeks. Hepatic drug-metabolizing enzyme activities and serum alanine aminotransferase and aspartate transaminease activities were measured. There was no difference in hepatic alanine aminotransferse and aspartate transaminase activities among the groups. Hepatic microsomal cytochrome P450 in CAP fed groups, but p-nitrophenol hydroxylase and the cytosolic acitivity of glutathione S-transferase activities were decreased in the dietary CAP supplemetned groups compared to the control. These results suggest that the dietary CAP at a low dose differentially modulates drug-metabolizing enzyme acitvities without causing hepatic toxicity.

• Biomolecules & Therapeutics
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• 제10권4호
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• pp.211-217
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• 2002

Hepatoprotective activity of methanol extract of Angelica tenuissima Nakai on the $CCl_4$-induced hepatotoxicity was investigated. To elucidate the hepatoprotective activity and free radical scavenging effect, we examined alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, total protein, cholesterol, malondialdehyde (MDA) levels in serum and activities of superoxide dismutase (SOD), catalase (CAT) in hepatic tissue as compared with those of carbon tetrachloride-induced rats. The action mechanism also has been estimated by quantative analysis of cytochrome P450 (CYP), NADPH-CYP reductase for phase I metabolism and glutathion (GSH), glutathion S-transferase (GST) level for phase II metabolsim. Treatment of Angelica tenuissima methanol extract significantly lowered the levels of alanine aminotransferase and aspartate aminotransferase. In addition, the levels of cholesterol, triglyceride, MDA, CAT were decreased, and SOD was activated. This result indicates that the hepatoprotective effect of Angelica tenuissima methanol extract on the CCl4-induced hepatotoxicity would be originated from reduction of the NADPH-CYP reductase, GSH and the enhancement of the activities of GST, CYP.