• BMB Reports
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• 제29권4호
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• pp.335-342
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• 1996

Porcine liver cysteinesulfinic acid decarboxylase was purified approximately 460-fold by means of ammonium sulfate fractionation and sequential column chromatographic separation with Sephadex G-100, DEAE-cellulose and hydroxylapatite. The enzyme has a flat pH profile with maximum activity occurring between pH 6.0 and 7.6. Pyridoxal 5'-phosphate must be present in all buffers used for purification procedures in order to stabilize the enzyme. Addition of sulfhydryl reagents such as 2-mercaptoethanol are also necessary to maintain maximum enzyme activity throughout purification. The absorption spectrum shows that cysteinesulfinic acid decarboxylase is a pyridoxal 5' -phosphate-containing protein. The major absorption is at 280 nm with two smaller absorption regions, one at 425 nm which is ascribed to a Schiffs base between pyridoxal phosphate and protein, and another at 325 nm which is thought to be due to the interaction of 2-mercaptoethanol with the Schiffs base. A number of divalent cations tested did not affect enzyme activity with the exception of mercury, copper, and zinc which are inhibitory. The partially purified enzyme has an apparent $K_m$ of 0.94 mM for cysteinesulfinate. Cysteic acid is a competitive inhibitor of the enzyme with a $K_i$ of 1.32 mM. The molecular weight of the enzyme was estimated to be about 79,600 by using Sephadex G-200 column chromatography.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.261-261
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• 1994

Bovine milk xanthine oxidase (E.C.1.1.3.22, XO) purchased from Sigma Chemical Co. had the three protein fragments below 150 kDa on 7.5％ SDS-PAGE, which did not show enzyme activity. To remove these fragments, the enzyme preparation was further purified through Sephadex G-200 column chromatography. Two peaks exhibiting enzymatic activity were separated very closely to the void volume, which were revealed as two different enzyme forms, dimeric and monomeric, confirmed by activity staining on native PAGE. Anti sera-against each of the two enzyme forms were raised by subcutaneous injection at multiple sites on the back of rabbits during 4 weeks. On the immunodiffusion test, it was found that both of the antisera of the two forms could react with each other, which implied that their epitopes were identical In the Western blot analysis of mouse liver cytosol fraction, it was found that rabbit anti-XO antibody bound well with the protein band of monomeric mouse liver XO of about 150kDa. Based on this result, mouse liver cDNA 1 ibrary was screened by in situ hybridizat ion wi th rabbi t anti -XO antibody as probe. Through the immunological screening, recombinant phages giving positive signal by the production of XO were selected and further purified. To validate these clones, purified phages were lysogenized in E. coli Y1089 and their lysates were analysed for enzyme activity and immunoreactivity, It was verified that lysates of the purified recombinant phage lysogens exhibited the enzymatic activity as well as bound wi th XO antibody, when induced by IPTG. The above results assert that selected recombinant phage carries mouse liver XO gene.

• BMB Reports
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• 제28권1호
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• pp.12-16
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• 1995

The branched-chain ${\alpha}$-keto acid dehydrogenase (BCKAD) complex is a rate limiting enzyme which catalyzes the oxidative decarboxylation of branched-chain ${\alpha}$-keto acids. Numerous studies have suggested that BCKAD is subject to covalent modification in vitro via phosphorylation and dephosphorylation, which are catalyzed by a specific kinase and phosphatase, respectively. The biggest difficulty in the assay of BCKAD activity is to arrest the interconversion between the active and inactive forms. BCKAD activity was determined from fresh rat heart and liver tissues using homogenizing and assay buffers containing inhibitors of phosphatase and kinase. The results suggest that a radiochemical assay using ${\alpha}$-keto[1-$^{14}C$]-isovalerate as a substrate for the enzyme can be applied as a reliable method to determine in vitro enzyme activity with arrested interconversion between the active and inactive forms of the BCKAD complex.

• 대한의생명과학회지
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• 제12권4호
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• pp.427-433
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• 2006

We investigated the effect of propolis on the activity of antioxidant enzymes in rat liver exposed by X-ray irradiation. The dosage of propolis showed the effect of lowering the concentration of superoxide anion in irradiated rat liver, suggesting that propolis has a significant role to remove superoxide anion as an antioxidant and/or by activating the antioxidant enzyme. The activities of superoxide dismutase (SOD) and glutathione reductase (GR), disturbed by X-ray irradiation, were restored in 30 days to normal status in the group which dosed propolis before X-ray irradiation. Interestingly, catalase (CAT) and glutathione peroxidase (GPOX) activities were highly increased with feeding propolis to rat compared to untreated group, whereas glutathione s-transferase (GST) activity was little affected. Taken together, it suggests that the propolis has a protective role in the rat liver cells against X-ray irradiation by increasing and recovering the activities of antioxidant enzymes.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.134-138
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• 1999

The effects of dietary Coix(lacryma-jobi) water extract on the antioxidant enzyme activity in the liver and kidney of Sprague-Dawley rats were studied. Forty-five rats were fed for 3 weeks with either control diet or experimental diets that contain either Coix water extract or Coix water residue. Twenty percent of the carbohydrate was replaced with Coix water residue by dry weight in the water residue diet, while distilled water was replaced by Coix water extract to make a pellet-form diet in the Coix water extract diet. The levels of glutathione, glutathione-peroxidase, and glutathione-S-transferase activities in liver and kidney were measured . It has been found that glutathione, glutathione peroxidase, and glutathione-S-transferase enzyme activities from activities from liver and kidneyof the rats were enhanced in the group fed with Coix water extract.

• 한국식품영양과학회지
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• 제39권11호
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• pp.1654-1659
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• 2010

오징어 가공 부산물인 오징어 간의 효율적 이용을 위하여 오징어 간을 이용하여 액젓을 제조하고 이들 액젓의 ACE 저해효과를 살펴보았다. 액젓의 ACE 저해활성은 12개월까지는 점차적으로 증가하였으나 그 이후에는 저해활성이 둔화되어 거의 일정한 저해활성을 유지하였다. 숙성 액젓 중 15개월째 액젓($IC_{50}=29.66\;{\mu}g$)을 한외여과막으로 통과시켜 회수한 분자량 10,000 Da 이하의 저분자물질을 Bio-gel P-2 gel chromatography를 행하여 ACE 저해효과를 가지는 3개획분을 분취하였다. 이들 획분 중에서 ACE 저해효과가 가장 높은 B 획분을 SuperQ-Toyopearl 650S column을 이용한 음이온 교환크로마토그래피에 의해 B-1의 활성획분을 분리하였다. 획분 B-1의 아미노산 조성은 lysine, glycine 및 proline의 함량이 가장 많아 전체의 약 85%를 차지하였으며 $IC_{50}$은 $5.46\;{\mu}g$으로 나타났다.

• Advances in Traditional Medicine
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• 제8권2호
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• pp.164-170
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• 2008

The hepatoprotective activity of the alcoholic extract of Rosa damascena was studied against paracetamol induced acute hepatotoxicity in rats. Liver damage was assessed by estimating serum enzyme activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and histopathology of liver tissue. Pre- and post-treatment with ethanolic extracts showed a dose-dependent reduction of paracetamol induced elevated serum levels of enzyme activity. The mechanism underlying the protective effects was assayed in vitro and the R. damascena extracts displayed dosedependent free radical activity using DPPH ($IC_{50}=162.525\;{\mu}g/ml$) and TBA method. The hepatoprotective action was confirmed by histopathological observation. The ethanolic extracts reversed paracetamol induced liver injury. These results suggest that the hepatoprotective effects of R. damascena extracts are related to its antioxidative activity.

• BMB Reports
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• 제32권1호
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• pp.67-71
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• 1999

We have investigated the effect of cholestasis on the closely related acyl-CoA:amino acid N-acyltransferase, benzoyltransferase, and phenylacetyltransferase activities in rat liver. Benzoyltransferase and phenylacetyltransferase activities in the liver cytosol, mitochondria, and microsome were investigated for a period of 42 d after common bile duct ligation. Both the mitochondrial and microsomal benzoyltransferases showed significant increase in their activities between the 1st and 7th day after common bile duct ligation, although the cytosolic benzoyltransferase activity did not show a significant change compared to the activities from the sham-operated control. The cytosolic phenylacetyltransferase activity showed a significant increase between the 1st and 2nd day, the mitochondrial activity showed a significant increase between the 2nd and 7th day, and microsomal activity showed a significant increase between the 1st and 7th day, respectively. Enzyme kinetic parameters of hepatic benzoyltransferase were analyzed using benzoyl coenzyme A as a substrate with the preparations from the 1st day post-ligation. Enzyme parameters of hepatic phenylacetyltransferase were also analyzed using phenylacetyl coenzyme A as a substrate with the preparations from the 2nd day post-ligation. The results indicated that although the $K_m$ values of these enzymes were about the same as the sham-operated control, the $V_{max}$ values of both enzymes increased significantly. These results, therefore, suggest that the biosynthesis of benzoyltransferase and phenylacetyltransferase has been induced in response to cholestasis.

• 사상체질의학회지
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• 제17권2호
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• pp.64-73
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• 2005

1. Objectives The purpose of this study was to investigate the effects of the enzyme activity of Palmulgunja-tang with administered orally solution on cytochrome P450 isozyme 2. Methods This study was carried on through following methods. We treated the rat with the {3-naphthoflavone (${\beta}NF$) of 80mg/kg for 3 days i.p injection. Firstable, microsomal protein was separated and total intracellular protein test was done. Then GOT and GPT were measured and assay of cytochrome P450 IAI/2 enzyme activity was performed according to the method of EROD and MROD. (Ethoxyresorufin-O-deethylase(EROD) activity was used to measure cytochrome P450 lAI activity and methoxyresorufin O-demethylase(MROD) activity was used to measure cytochrome P450 lA2 activity. ) 3. Results and Conclusions 1) PGT recovered the liver damage on ${\beta}NF$ inducible CYP IAI/2 by pre-post and high-low condition. 2) At concentration of post-treated 50mg!kg of PGT, the inhibiting of $\betaNF$ metabolites to liver of rat cytochrome P450 lAl was inhibited by 53.0% respectively. 3) PGT showed 36.0% inhibition of ${\beta}NF$-induced lA2 activity at the concentration post-treated 50mg/kg.

• 한국임상수의학회지
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• 제14권2호
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• pp.273-278
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• 1997

Several serum enzyme activities were measured after intraBeritoneal administration of 0.01 ml $CCl_{4}$ per 100 g of body weight in Sprague Dawley rats. Senun AST activity increased significantly after administration of CCl$_{4}$ (P<0.05). The serum AST activity at 2 hours after $CCl_{4} administration (475 {\pm} 10^{6} IU/L)$ was significantly higher than that of control group $(65 {\pm} 14 IU/L)$. The high level of serum AST activity maintained up to 48 hours. Serum ALT activity in $CCl_{4}$-treated groups was also significantly higher from 4 hours after treatment companied to control group and the high level maintained up to 48 hours. Serum ALP and ${\gamma} GTP activities in CCl_{4}$-treated groups were significantly higher from 8 hours after treatment compared to control group and the level maintained up to 48 hours.