• BMB Reports
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• 제32권2호
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• pp.154-160
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• 1999

A calcium-independent phospholipase $A_2$ ($iPLA_2$) was identified from the cytosolic fraction of rat liver cells. On gel filtration chromatography, the $iPLA_2$ activity was eluted as broad peaks of 150 to 500 kDa. The enzyme was maximally active at pH 7.5, retained 75% of its original activity after heating at $50^{\circ}C$ for 5 h, and was inhibited by $Ca^{2+}$, $Mg^{2+}$, and $Zn^{2+}$ ions, but was not affected by $Na^+$ and $K^+$ ions. The enzymatic activity was increased up to 150% by 1 to 4 mM DTT and was inhibited up to 25% by 0.1 to 1 mM PMSF. The $iPLA_2$ activity had preference for the head group of phospholipids, where phosphatidylethanolamine was preferred to phosphatidylcholine. The results suggest that the $iPLA_2$ may be a novel enzyme distinct from the previously reported $iPLA_2s$.

• BMB Reports
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• 제37권3호
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• pp.275-281
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• 2004

Rhodanese was isolated and purified from the cytosolic fraction of liver tissue homogenate of the fruit bat, Eidolon helvum, by using ammonium sulphate precipitation and CM-Sephadex C-50 ion exchange chromatography. The specific activity was increased 130-fold with a 53% recovery. The $K_m$ values for KCN and $Na_2S_2O_3$ as substrates were $13.5{\pm}2.2\;mM$ and $19.5{\pm}0.7\;mM$, respectively. The apparent molecular weight was estimated by gel filtration on a Sephadex G-100 column to be 36,000 Da. The optimal activity was found at a high pH (pH 9.0) and the temperature optimum was $35^{\circ}C$. An Arrhenius plot of the heat stability data consisted of two linear segments with a break occurring at $35^{\circ}C$. The apparent activation energy values from these slopes were 11.5 kcal/mol and 76.6 kcal/mol. Inhibition studies on the enzyme with a number of cations showed that $Mg^{2+}$, $Mn^{2+}$, $Ca^{2+}$, and $Co^{2+}$ did not affect the activity of the enzyme, but $Hg^{2+}$ and $Ba^{2+}$ inhibited the enzyme.

• BMB Reports
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• 제28권2호
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• pp.170-176
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• 1995

Rhodanese from mouse liver was purified to near homogeneity by ammonium sulfate precipitation, CM-Sephadex ion exchange, hydroxyapatite and Sephacryl S-200-HR gel filtration chromatographies with a purification of 776 folds. The molecular weight was determined by Sephadex G-150 gel filtration and found to be 34.8 KDa. SOS-PAGE showed molecular weight 34 KDa and two identical subunits splitting by aging for 3 weeks at $-70^{\circ}C$ the molecular weight of which was 17 KDa. The optimal pH of enzyme activity was 9.4 and the pI value of the enzyme was 6.6. Rhodanese showed the optimal reaction temperature of $25^{\circ}C$ and near linear increasing pattern until 10 min. incubation. $K_m$ values of rhodanese for KCN and $Na_{2}S_{2}O_{3}$ as substrates were 12.5 mM and 8.3 mM, respectively. Rhodanese activity was inhibited by more than 70% at a concentration of 100 ${\mu}M$ of $Ni^{2+}$, $Zn^{2+}$, $Cd^{2+}$, $Hg^{2+}$ and $Cu^{2+}$. Other metal ions, such as $Mn^{2+}$, $Mg^{2-}$, $Ca^{2+}$, and $Fe^{2+}$ showed no effect on rhodanese activity.

• 한국어병학회지
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• 제25권1호
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• pp.31-37
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• 2012

우리나라의 주요 해산양식어종인 돌돔, Oplegnathus fasciatus을 대상으로 30, 60, 120 및 240 mg/kg의 아연을 40일 동안 경구 투여에 따른 아가미와 간의 항산화효소 활성의 변화를 검토하였다. 돌돔 간의 superoxide dismutase(SOD) 활성은 30~240 mg/kg 아연농도, glutathione peroxidase (GPx) 활성은 30~120 mg/kg의 아연농도에서 유의적으로 증가하였다. 돌돔 아가미의 SOD 및 Glutathione(GSH) 활성은 120 및 240 mg/kg 아연농도, GPx활성은 60~240 mg/kg의 아연농도에서 유의한 증가가 관찰되었다.

• Food Science and Biotechnology
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• 제14권2호
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• pp.290-296
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• 2005

Effects of water extract obtained from Chrysanthemum boreale M. (CE) on serum enzyme activities and Kupffer cells of carbon tetrachloride ($CCl_4$)-induced rats were investigated. Thirty-two healthy male Sprague-Dawley rats were divided into normal (N), $CCl_4$-induced (T), CE-supplemented (C), and $CCl_4$-induced and CE-supplemented (TC) groups. $CCl_4$ injection significantly increased aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and alkaline phosphatase activities in serum. Significant increases in total cholesterol and triglyceride concentrations were also observed in $CCl_4$-induced rats. Oral administration of CE at 300 mg/kg body weight significantly decreased serum enzyme levels and suppressed $CCl_4$ hepatotoxicity-induced lipid profile changes. Histological findings showed fatty change, fibrosis and increased number of Kupffer cells in T group. Electron microscopic examination showed increased lysosome content and dilation of rough endoplasmic reticulum within Kupffer cells in T group, whereas CE supplement attenuated liver injury in $CCl_4$-induced liver. These results indicated CE could significantly alleviate CC4-induced hepatotoxicity injury.

• 동아시아식생활학회지
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• 제5권1호
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• pp.21-27
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• 1995

The protective effect of omija methanol extract on benzo(a)pyrene induce liver injury was studied in rats in vitro and in vivo. In vitro experiment, primary cultured hepatocytes(5${\times}$105cells/$m\ell$) were cultured for 20∼24 hours after adding omija methanol extract(5.1$\mu\textrm{g}$/$m\ell$) and B(a)P(50$\mu\textrm{m}$) in culture medium. In vivo experiment, omija methanol extract(0.1g/kg/day, per os) was administered for 7days and B(a)P(0.1mg/kg body weight, intraperitoneally) was given to the rats after the last administration of extract. Omija methanol extract significantly recovered serum enzyme activities(AST, ALT and LDH) and lipid contents(total cholesterol, triglyceride and HDL-cholesterol) changed by benzo(a)pyrene (B(a)P) to normal levels in vivo. In vitro experiment, as a result of 3-(4, 5-dimethlythiazol-2-yl)-2, 5-diphenyl tetrazolium bromide(MTT) assay, omija methanol extract showed a little hepatotoxicity compared with group I (normal) but significantly recovered enzyme activities(AST, ALT and LDH) changed by B(a)P in comparison to group IIadministered B(a)P only. It was suggested that omija methanol extract has a protective effect on liver injury induced by B(a)P.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권3호
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• pp.179-182
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• 2001

Porcine liver esterase was immobilized in polyacrylamide gel for the enantioselective production of levofloxacin from ofloxacin butyl ester. The initial activity of immobilized esterase was found to be significantly affected by the polyacrylamide gel composition. The optimum concentrations of monomer and crosslinker were determined to be 20% and 8.3%, respectively. The activity of immobilized esterase was 55.4% compared to a free enzyme. Enantiomeric excess was maintained at 60%, almost the same level as that of free enzyme. In addition, the immobilized esterase could be used repeatedly up to 10 times without experiencing any severe loss of activity and enantioselectivity.

• Biomolecules & Therapeutics
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• 제4권3호
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• pp.280-284
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• 1996

Licorice has been widely used in combination with other herbs or synthetic drugs for various disorders. In an effort to study the effect of licorice roots (Glycyrrhizae Radix, GR) and glycyrrhizin on the hepatic glucuronidation, we have previously found that the pretreatment of GR or glycyrrhizin for 6 days resulted in a marked increase in the enzymatic activity of 3-methylcholanthrene (3-MC)-inducible hepatic UDP-glucuronosyltransferase (UGT) isozyme that has high affinity toward phenolic substrates (p-nitrophenol form, UGTIA) in Sprague-Dawley rats. As an approach to elucidate the mechanism for the enzyme activation by licorice in rat liver, we examined the levels of hepatocellular mRNAs for UGTIA upon the treatment of GR or glycyrrhizin. The hepatic mRNAs were extracted from Sprague-Dawley rats and Wistar rats after the treatment of the methanol extract of GR (1 g/kg, p.o.), glycyrrhizin (23 mg/kg, p.o.) for 6 days, or 3-MC (40 mg/kg, i.p.) for 3 days. Using the UGT1A1 CDNA as a probe, we found that the mRNAs for the enzyme were induced by 3-MC treatment while those were influenced neither by GR nor by glycyrrhizin in both strains of rats. These results indicate that the activation of rat liver UGTI A by licorice and glycyrrhizin was not due to the induction of mRNAs for the enzyme.

• Journal of Preventive Medicine and Public Health
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• 제48권3호
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• pp.151-169
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• 2015

Objectives: The deleterious effects of air pollution on various health outcomes have been demonstrated. However, few studies have examined the effects of air pollution on liver enzyme levels. Methods: Blood samples were drawn up to three times between 2008 and 2010 from 545 elderly individuals who regularly visited a community welfare center in Seoul, Korea. Data regarding ambient air pollutants (particulate matter ${\leq}2.5{\mu}m$ [$PM_{2.5}$], nitrogen dioxide [$NO_2$], ozone [$O_3$], carbon monoxide, and sulfur dioxide) from monitoring stations were used to estimate air pollution exposure. The effects of the air pollutants on the concentrations of three liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and ${\gamma}$-glutamyltranspeptidase [${\gamma}$-GTP)]) were evaluated using generalized additive and linear mixed models. Results: Interquartile range increases in the concentrations of the pollutants showed significant associations of $PM_{2.5}$ with AST (3.0% increase, p=0.0052), ALT (3.2% increase, p=0.0313), and ${\gamma}$-GTP (5.0% increase, p=0.0051) levels; $NO_2$ with AST (3.5% increase, p=0.0060) and ALT (3.8% increase, p=0.0179) levels; and $O_3$ with ${\gamma}$-GTP (5.3% increase, p=0.0324) levels. Significant modification of these effects by exercise and alcohol consumption was found (p for interaction <0.05). The effects of air pollutants were greater in non-exercisers and heavy drinkers. Conclusions: Short-term exposure to air pollutants such as $PM_{2.5}$, $NO_2$, and $O_3$ is associated with increased liver enzyme levels in the elderly. These adverse effects can be reduced by exercising regularly and abstinence from alcohol.

• 대한핵의학회지
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• 제28권1호
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• pp.112-123
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• 1994

${\gamma}$-Glutamyltransferase (GGT: E.C. 2.3.2.2.) is a glycoprotein enzyme which is involved in glutathione metabolism and amino acid transport through the plasma membrane. It is distributed widely in several organs including liver and kidney. Several isozymes of GGT have been reported and some of the isozymes may be associated with hepatocarcinogenesis. We have produced six monoclnal antibodies (mAbs) against GGT purified from the liver of 2-acetamidofluorene (AAF) treated rats. All of the six mAbs were obtained by immunizing mice with liver GGT Six hybridomas which produced anti-GGT Abs were extensively subcloned and injected into the peritoneal cavity of BALB/c mice to obtain large quantities of Abs. These mAbs were purified from ascites by ammonium sulfate precipitation and protein A sepharose CL-4B column chromatography. Using these mAbs we preformed enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), immunohistochemistry (IHC), and autoradiography (ARG) to study the distribution of GGT isozyme in tissue. The results indicate that GGT-mAb 1 is specific for the AAF treated liver GGT, GGT-mAb 5 for the normal liver GGT, and GGT-mAb 6 for the normal kindey GGT. These mAbs may be used to evaluate the distribution of GGT isozymes in different tissues.