• Title/Summary/Keyword: Enzyme induction

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Antistress effect of red ginseng in brain cells is mediated by TACE repression via PADI4

  • Kim, Eun-Hye;Kim, In-Hye;Ha, Jung-Ah;Choi, Kwang-Tae;Pyo, Suhkneung;Rhee, Dong-Kwon
    • Journal of Ginseng Research
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    • v.37 no.3
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    • pp.315-323
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    • 2013
  • Ginseng is known to have antistress effects. Previously, red ginseng (RG) was shown to repress stress-induced peptidyl arginine deiminase type IV (PADI4) via estrogen receptor ${\beta}$ ($ER{\beta}$) in the brain, thus inhibiting brain cell apoptosis. Moreover, tumor necrosis factor (TNF)-${\alpha}$ plays a critical role in immobilization (IMO) stress. However, the signaling pathway of RG-mediated repressesion of inflammation is not completely understood. In this study, we determined how RG modulated gene expression in stressed brain cells. Since secretion of TNF-${\alpha}$ is modulated via TNF-${\alpha}$ converting enzyme (TACE) and nuclear factor (NF)-${\kappa}B$, we examined the inflammatory pathway in stressed brain cells. Immunohistochemistry revealed that TACE was induced by IMO stress, but RG repressed TACE induction. Moreover, PADI4 siRNA repressed TACE expression compared to the mock transfected control suggesting that PADI4 was required for TACE expression. A reporter assay also revealed that $H_2O_2$ oxidative stress induced NF-${\kappa}B$ in neuroblastoma SK-N-SH cells, however, RG pretreatment repressed NF-${\kappa}B$ induction. These findings were supported by significant induction of nitric oxide and reactive oxygen species (ROS) by oxidative stress, which could be repressed by RG administration. Taken together, RG appeared to repress stress-induced PADI4 via TACE and NF-${\kappa}B$ in brain cells thus preventing production of ROS and subsequently protecting brain cells from apoptosis.

Effect of Glucose-diethyldithiocarbamate on Drug Metabolizing Enzymes in Rats (Glucose-diethyldithiocarbamate가 흰쥐의 약물 대사 효소에 미치는 영향 연구)

  • 최병기;신혜주
    • 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.

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Optimization of \beta-mammanase Production from Bacillus subtilis JS-1. (\beta-Mannanase를 생산하는 Bacillus subtilis JS-1의 분리 및 효소 생산성)

  • 임지수;정진우;이종수;강대경;강하근
    • Microbiology and Biotechnology Letters
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    • v.31 no.1
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    • pp.57-62
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    • 2003
  • A bacteria strain producing extracellular $\beta$-mannanase was isolated from soil and was identified as Bacillus subtilis by 16S rRNA sequence comparison and biochemical determinations. The optimum pH and temperature for the $\beta$-mannanase activity were 5.0 and 5.5$^{\circ}C$, respectively. The zymogram technique revealed a single protein band exhibiting $\beta$-mannanase activity from the culture supernatant. The molecular mass of the enzyme was estimated at approximately 130 kDa. The addition of 0.5% lactose or 0.5% locust bean gum to the LB medium caused to Increase significantly the $\beta$-mannanase productivity from Bacillus subtilis JS-1. The cells grown on LB medium supplemented with lactose produced maximal enzyme activity at the stationary phase. In contrast to this, the $\beta$-mannanase was induced at the logarithmic phase from the cells grown on LB medium supplemented with locust bean gum. The discrepancy in induction times suggests that $\beta$-mannanase was induced by different induction mechanisms depending on the carbon sources in Bacillus subtilis JS-1 .

Screening of Quinone Reductase Inducers from Agricultural Byproducts Using Mouse Hepatoma Cell Line (Mouse hepatoma 세포를 이용한 농산부산물로부터 quinone reductase활성물질의 탐색)

  • Kim, Jong-Sang;Nam, Young-Jung;Kim, Joo-Won
    • Korean Journal of Food Science and Technology
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    • v.27 no.6
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    • pp.972-977
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    • 1995
  • The induction of phase II enzymes including quinone reductase [NAD(P)H dehydrogenase(quinone): NAD(P)H : (quinone acceptor) oxidoreductase, EC 1.6.99.2] is a major mechanism of whereby a large group of heterogeneous compounds prevent the toxic, mutagenic, and neoplastic effects of carcinogen. Using murine hepatoma cells(Hepalclc7 cells), quinone reductase(QR) inducers as the possible chemopreventive agents were screened from rice bran, wheat bran, soymilk residue, defatted soybean cake, defatted sesame and perilla residues. The 80% methanol extracts of defatted sesame and perilla residues induced quinone reductase significantly while the others did have little effect on the enzyme induction. Thin layer chromatography of the extracts showed that the fastest moving band(Rf=0.70) in the developing solvent of n-butanol : n-propanol : 2N ammonia(10 : 60 : 30) was responsible for the enzyme induction by the 80% methanol extracts of defatted sesame and perilla residues. Further identification of active component(s) is in progress.

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Synergistic Effect of Substrates on the Biosynthesis of Cellulase and Xylanase Complexes from Aspergillus nidulans (Aspergillus nidulans 의 섬유질 분해효소계 생합성에 미치는 기질의 공조효과)

  • Lee, Jeong-Ae;Maeng, Jin-Soo;Maeng, Pil-Jae;Rhee, Young-Ha
    • The Korean Journal of Mycology
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    • v.17 no.2
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    • pp.57-65
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    • 1989
  • The effect of various cellulosic and hemicellulosic substrates on the induction of cellulase and xylanase complexes in Aapergillus nidulans was investigated. The most efficient substrates for the induction of cellulase and xylanase complexes were carboxymethylcellulose for endoglucanase, cellobiose for ${\beta}-glucosidase$, and xylan for endoxylanase and ${\beta}-xylosidase$, respectively. However, the mixtures of these substrates, especially CMC-xylan and CMC-xylan-laminarin mixture, were much more effective not only for the enhancement of the biosynthesis of all the cellulase and xylanase complexes but also for the balanced production of these enzyme components than individual substrate. The polyacrylamide gel electrophoresis followed by activity staining showed the variation in the patterns and relative intensity of ${\beta}-glucosidase$, endoglucanase and endoxylanase components in individual enzyme preparations from A. nidulans cultures grown on different substrates. These results suggest that the biosynthesis is of cellulase and xylanase systems in A. nidulans is regulated in coordination at the level of induction.

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Effects of Salicylic Acid on Oxidative Stress and UV-B Tolerance in Cucumber Leaves (살리실산이 오이 잎의 산화적 스트레스와 UV-B 내성에 미치는 영향)

  • Hong, Jung-Hee;Kim, Tae-Yun
    • Journal of Environmental Science International
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    • v.16 no.12
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    • pp.1345-1353
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    • 2007
  • The effect of salicylic acid(SA) on antioxidant system and protective mechanisms against UV-B induced oxidative stress was investigated in cucumber(Cucumis sativus L.) leaves. UV-B radiation and SA were applied separately or in combination to first leaves of cucumber seedlings, and dry matter accumulation, lipid peroxidation and activities of antioxidant enzymes were measured in both dose and time-dependant manner. UV-B exposure showed reduced levels of fresh weight and dry matter production, whereas SA treatment significantly increased them. SA noticeably recovered the UV-B induced inhibition of biomass production. UV-B stress also affected lipid peroxidation and antioxidant enzyme defense system. Malondialdehyde(MDA), a product of lipid peroxidation, was greatly increased under UV-B stress, showing a significant enhancement of a secondary metabolites, which may have antioxidative properties in cucumber leaves exposed to UV-B radiation. Combined application of UV-B and SA caused a moderate increase in lipid peroxidation. These results suggest that SA may mediate protection against oxidative stress. UV-B exposure significantly increased SOD, APX, and GR activity compared with untreated control plants. Those plants treated with 1.0 mM SA showed a similar pattern of changes in activities of antioxidant enzymes. SA-mediated induction of antioxidant enzyme activity may involve a protective accumulation of $H_2O_2$ against UV-B stress. Moreover, their activities were stimulated with a greater increase by UV-B+SA treatment. The UV-B+SA plants always presented higher values than UV-B and SA plants, considering the adverse effects of UV-B on the antioxidant cell system. ABA and JA, second messengers in signaling in response to stresses, showed similar mode of action in UV-B stress, supporting that they may be important in acquired stress tolerance. Based on these results, it can be suggested that SA may participates in the induction of protective mechanisms involved in tolerance to UV-B induced oxidative stress.

Effect of Environmental Factors on In Vivo Folding of Bacillus macerans Cyclodextrin Glycosyltransferase in Recombinant Escherichia coli

  • Jin, Hee-Hyun;Han, Nam-Soo;Kweon, Dae-Hyuk;Park, Yong-Cheol;Seo, Jin-Ho
    • Journal of Microbiology and Biotechnology
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    • v.11 no.1
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    • pp.92-96
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    • 2001
  • Effect of environmental factors on the expression of soluble forms of Bacillus macerans cyclodextrin glycosyltransferase in recombinant Escherichia coli BL21(DE3)pLysE:pTCGT1 were investigated. The amount of soluble CGTase produced in the cell was measured by determining its enzymatic activity. The soluble fractionof the enzyme was increased by lowering the culture temperature to $30{\circ}C$ and medium pH to 5.8 compared to the enzyme production in LB medium at $37^{\circ}C$ and pH7.0. Addition of 0.2 M NaCl enhanced enzyme expression levels at the expense of cell growth. Glycine betaine that was added after 3 h of induction protected not only the cell growth from hig osmotic pressue but also hepld in vivo folding of CGTase in recombinant E. coli. Addition of 1 mM $CaCl_2$ was also effective in the expression of soluble CGTase, resulting in 15 U/ml of the enzyme activity.

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Development of Apoptosis Model and Bioimmune Responses and Morphological Characterization in Experimental Animal II. Activities of Serum Hepatic Enzyme and Histological Findings between Apoptosis and Hepatic Tumorigenesis (실험동물에서 apoptosis의 모델개발과 생체면역반응 및 형태학적 특징 II. Apoptosis 및 hepatic tumorigenesis 과정에서의 혈청 간 효소활성치 및 조직소견)

  • 강정부;하우송;곽수동;김지경
    • Journal of Veterinary Clinics
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    • v.16 no.1
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    • pp.108-117
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    • 1999
  • Hepatic tumorigenesis was induced by ad libitum feeding of diethylnitrosamine (DEN) only. We could also observe hepatic tumor induction in 100% of DEN treated rats without any other cocarcinogen. The liver specific enzyme activities (AST, ALT, ALP, ${\gamma}$-GTP) were significantly increased (P<0.05) in all treated groups compared to control and induced apoptosis groups. In histopathological analysis, the altered foci, hyperplastic nodules, neoplastic nodules, adenomas and carcinomas were observed in liver tumors induced by administration of DEN in rats. Lipopolysaccharide-induced apoptosis in D-galactosamine sensitized mice was investigated in hepatocytes in vivo. Typical morphological changes of apoptosis were detectable in liver 12 hr and 24 hr after the injection of Lipopolysaccharide (5 $\mu\textrm{g}$) and D-galactosamine (20 mg) to mice. It was suggested that organ specific enzyme activities and morphological findings might be very useful for understanding the role of hepatic tumorigenesis including the apoptotic cell death.

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Improvement of Aspergillus niger 55, a Raw Corn Meal Saccharifying Enzyme Hyperproducer, through Mutation and Selective Screening Techniques (옥수수 生 전분 당화 효소 高 생산성 변이주 개발)

  • Oh, Sung-Hoon;O, Pyong-Su
    • Microbiology and Biotechnology Letters
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    • v.19 no.2
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    • pp.140-146
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    • 1991
  • Mutation experiments were performed to select the mutant of Aspergillus niger 55, which had lost almost all the ability to produce transglucosidases but retained that of high productivity of raw meal saccharifying enzyme, by means of successive induction with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), ultraviolet(UV) light, and ${\gamma}$-rays. Also, we used the mutant enrichment techniques, such as liquid culture-filtration procedure and differential heat sensitivity of conidia, in order to increase the possibility of obtaining a mutant. The glucoamylase productivity of mutant PFST-38 was 11 times higher than that of the parent strain. The mutant PFST-38 was morphologically identical to the parent strain, except for the size of conidia, the tendency to form conidia and the lenght of conidiophore. Asp. niger mutant PFST-38 apeared to be useful for the submerged production of the raw corn meal saccharifying enzyme.

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Sulforaphane is Superior to Glucoraphanin in Modulating Carcinogen-Metabolising Enzymes in Hep G2 Cells

  • Abdull Razis, Ahmad Faizal;Noor, Noramaliza Mohd
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.7
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    • pp.4235-4238
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    • 2013
  • Glucoraphanin is the main glucosinolate found in broccoli and other cruciferous vegetables (Brassicaceae). The objective of the study was to evaluate whether glucoraphanin and its breakdown product sulforaphane, are potent modulators of various phase I and phase II enzymes involved in carcinogen-metabolising enzyme systems in vitro. The glucosinolate glucoraphanin was isolated from cruciferous vegetables and exposed to human hepatoma cell line HepG2 at various concentrations (0-25 ${\mu}M$) for 24 hours. Glucoraphanin at higher concentration (25 ${\mu}M$) decreased dealkylation of methoxyresorufin, a marker for cytochrome P4501 activity; supplementation of the incubation medium with myrosinase (0.018 U), the enzyme that converts glucosinolate to its corresponding isothiocyanate, showed minimal induction in this enzyme activity at concentration 10 ${\mu}M$. Quinone reductase and glutathione S-transferase activities were unaffected by this glucosinolate; however, supplementation of the incubation medium with myrosinase elevated quinone reductase activity. It may be inferred that the breakdown product of glucoraphanin, in this case sulforaphane, is superior than its precursor in modulating carcinogen-metabolising enzyme systems in vitro and this is likely to impact on the chemopreventive activity linked to cruciferous vegetable consumption.