• Title/Summary/Keyword: substrate inhibition

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Anti-Wrinkle Effect of Schizandra chinensis Baillon Fermented with Lactobacillus plantarum (오미자 유산균 발효물의 주름개선 효과)

  • Lee, Jung Hee;Kim, Jong Im;Choi, Hwa Jung;Lee, Jung Hyun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.40 no.4
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    • pp.365-371
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    • 2014
  • To identify new active anti-wrinkle ingredients, this study investigated the anti-wrinkle effects of Schizandra chinensis Baillon fermented with Lactobacillus plantarum (SCF) by assessment of cytotoxicity of human dermal fibroblast, collagen biosynthesis, matrix metalloproteinase-I (MMP-1) inhibition and elastase inhibition. S. chinensis was fermented with L. rhamnosus for 1 day at $37^{\circ}C$. The cytotoxicity of SCF was evaluated by a cytopathic effect reduction method. Effects on collagen biosynthesis and matrix metalloproteinase-I (MMP-1) of SCF were evaluated by previous reported method using procollagen type-IC peptide EIA kit and Matrix Metalloproteinase-1 Biotrack activity Assay Kit, respectively. Elastase inhibition assay was conducted by reaction of enzyme and substrate using N-Suc-$(Ala)_3$-nitroanilide as the substrate. As the results, SCF didn't show cytotoxicity against human dermal fibroblast at concentration of $100{\mu}g/mL$. Also, SCF was increased collagen synthesis and showed inhibitory effect of MMP-1 (p < 0.05). In the elastase inhibition assay, the $IC_{50}$ of SCF was $36.4{\mu}g/mL$. Therefore, our results indicated that SCF possesses anti-wrinkle effects and can be used practically for anti-wrinkle care of skin.

Standardization of Ecotoxicity Assay Method for Heavy Metals using Inhibition of Dehydrogenase Activity (탈수소효소 활성도 저해를 이용한 중금속 생태독성 평가법의 표준화)

  • Oh, Kyoung-Hee;Han, Ah-Won;Cho, Young-Cheol
    • Journal of Korean Society on Water Environment
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    • v.26 no.4
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    • pp.574-579
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    • 2010
  • In this study the enzyme inhibition method using dehydrogenase which has been popularly used to estimate ecotoxicity was optimized. When three bacterial strains, Escherichia coli HB101, Enterobacter asburiae KCAD-4, and Aeromonas media KCAD-13, were compared, KCAD-4 was considered as the adequate strain to estimate toxicity because of its sensitivity and reproducibility. The optimal bacterial density was estimated as $5.4{\times}10^9CFU/mL$, at which the maximum sensitivity was observed. The phosphate buffer was suitable for the reaction solution. When the reaction times required for inhibition of enzyme activity by contact of toxicants and for reaction of damaged bacteria and substrate were tested, the optimal value was estimated as 20 min and 2 hrs, respectively. It is expected that the optimized conditions can be used to develop the standardized kits to estimate ecotoxicity of heavy metals in effluent from the industrial wastewater treatment facilities.

Evaluation of Biological Kinetic Parameters in the Granular Sludge (입상슬러지의 동력학적 인자 산정)

  • 이재관;양병수
    • Journal of Environmental Science International
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    • v.4 no.2
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    • pp.201-214
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    • 1995
  • Design approach of upflow Anaerobic Sludge Blanket(UASB) process based on the biological kinetic parameters are known to be very difficult since the characteristics of the granular slut비e depends on the type of wastewater and size distribution of the granular sludge also depends on the upflow velocity in the UASB reactors. Furthermore, industrial wastewater containing toxic substances has been treated by UASB process without the clear knowledge of toxic effects on the granular slut형e. Hence, the present research was aimed on the intensive evaluation of biological kinetic parameters of the granular sludge in UASB reactor with and without toxic substance of 2, 4-dichlorophenol in order to present the basic design measures for UASB process design. The results could be summarized as follows. The biological kinetic parameters(k and Ks) considerably varied with the granular size of the sludge. Generally, 연e k and ks values of the granular sludge increased with the particle size of the granule. The biological kinetic parameters(k and Ks) of the granular sludge obtained from batch test were not applicable to design purpose of UASB process due to substrate diffusional limitation into the granular sludge in the completely mixed UASB reactors. The toxic effects on k and Ks greatly varied with the granular sixte. And as the toxicant concentration increased, the k value decreased while the Ks value increased. Inhibition constant(hi) for k with the toxicant of 2, 4-dichlorophenol varied from 0.5 to 2.3 depending on the granular sizes while the inhibition constant(Ki) for Ks varied from 20.7 to 80.1, showing the mixed inhibition.

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Characterization of Aspartate Aminotransferase Isoenzymes from Leaves of Lupinus albus L. cv Estoril

  • Martins, Maria Luisa Louro;De Freitas Barbosa, Miguel Pedro;De Varennes E Mendonca, Amarilis Paula Alberti
    • BMB Reports
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    • v.35 no.2
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    • pp.220-227
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    • 2002
  • Two aspartate aminoransferase (EC 2.6.1.1) isoenzymes (AAT-1 and AAT-2) from Lupinus albus L. cv Estoril were separated, purified, and characterized. The molecular weight, pI value, optimum pH, optimum temperature, and thermodynamic parameters for thermal inactivation of both isoenzymes were obtained. Studies of the kinetic mechanism, and the kinetics of product inhibition and high substrate concentration inhibition, were performed. The effect of some divalent ions and irreversible inhibitors on both AAT isoenzymes was also studied. Native PAGE showed a higher molecular weight for AAT-2 compared with AAT-1. AAT-1 appears to be more anionic than AAT-2, which was suggested by the anion exchange chromatography. SDS-PAGE showed a similar sub-unit molecular weight for both isoenzymes. The optimum pH (between 8,0 and 9.0) and temperature ($60-65^{\circ}C$) were similar for both isoenzymes. In the temperature range of $45-65^{\circ}C$, AAT-2 has higher thermostability than AAT-1. Both isoenzymes showed a high affinity for keto-acid substrates, as well as a higher affinity to aspartate than glutamate. Manganese ions induced an increase in both AAT isoenzymes activities, but no cooperative effect was detected. Among the inhibitors tested, hydroxylamine affected both isoenzymes activity by an irreversible inhibition mechanism.

The Interaction of Barley Acetolactate Synthase with 4,6-Dimethoxypyrimidine Inhibitors

  • Shim, Hee-Ok;Kim, Dae-Whang;Chang, Soo-Ik;Choi, Jung-Do
    • BMB Reports
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    • v.28 no.6
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    • pp.471-476
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    • 1995
  • Acetolactate synthase (ALS) catalyzes the first common step in the biosynthesis of valine, leucine, and isoleucine. ALS is the target enzyme for several classes of structually diverse herbicides. We have synthesized 4,6-dimethoxypyrimidine derivatives as ALS inhibitors, and their inhibitory activities on barley ALS were determined. $IC_{50}$ values for the derivatives are 0.2~200 ${\mu}m$. K11570, the most potent ALS inhibitor with $IC_{50}$ of 0.2 ${\mu}m$, showed mixed-type inhibition with respect to substrate pyruvate, and the progress curves for ALS inhibition by K11570 indicated that the amount of inhibition increased with time. Inhibition-competition experiments were carried out and indicated that three different classes of inhibitors, K11570, a sulfonylurea Ally, and leucine, bind to ALS in a mutually exclusive manner. Chemical modification of tryptophanyl and tyrosyl residues of ALS decreased the sensitivity of ALS to K11570, while cysteine modification did not affect the sensitivity. These results suggest that tryptophanyl and tyrosynyl residues are probably located at or near the inhibitor binding site.

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Effects of Ethanol on Na-K-ATPase Activity of Cat Kidney (Ethanol 이 고양이 신장 Na-K-ATPase 활성에 미치는 영향)

  • Kim, Joo-Heon;Kim, Yong-Keun
    • Korean Journal of Veterinary Research
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    • v.23 no.1
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    • pp.9-16
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    • 1983
  • The effects of ethanol on Na-K-ATPase activity were investigated with cat kidney homogenate. The results were summarized as follows: 1. Na-K-ATPase activity was inhibited with dose-dependent manner by ethanol of higher concentration than 1%, and showed an estimated $I_{50}$ (the inhibitor concentration to cause 50% inhibition) of 7.5%. 2. Hydrolysis of ATP was linear with the incubation time in the absence and presence of 8% ethanol, whereas it was different with preincubation time in the presence of 15% ethanol. 3. Inhibition of Na-K-ATPase activity by ethanol was not affected by increased enzyme concentration, and showed the reversibility of the inhibitory pattern. 4. Kinetic studies of cationic-substrate activation of Na-K-ATPase showed that ethanol had both properties of classical competitive inhibition for $Mg^{{+}{+}}$ or $K^+ and non-competitive inhibition for ATP or $Na^+$. 5. Arrhenius plot yield two break point at $21^{\circ}$ and $30^{\circ}C$ in the absence of ethanol, whereas showing only one break point at $18^{\circ}C$ in the presence of 8% ethanol. These results suggested that ethanol inhibited Na-K-ATPase activity reversible through a disturbance of microenvironment of lipids associated with the enzyme.

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Kinetic and Thermodynamic Analysis of AChE Inhibition of Solvent Extract Fractions from Inonotus obliquus (차가버섯 용매추출분획의 Acetylcholinesterase 저해활성에 대한 동역학 및 열역학적 해석)

  • Kim, Hak-Kyu;Hur, Won;Hong, Eok Kee;Lee, Shin-Young
    • Food Engineering Progress
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    • v.15 no.4
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    • pp.289-296
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    • 2011
  • Twenty four fractions by solvent extraction and/or acid precipitation from fruit body and culture broth of Inonotus obliquus were prepared, and their inhibitory effect against acetylcholinesterase (AChE) was investigated. Among these fractions, acid (1 M HCl) precipitates from cell-free culture broth and fruit body exhibited the highest inhibitory effect on AChE in vitro. Acid precipitates inhibited AChE activity in a concentration-dependant manner and $IC_{50}$ values of both acid precipitates were 0.53 mg/mL. The inhibition pattern was general non-competitive inhibition. The energetic parameters were also determined by dual substrate/temperature design. Both acid precipitates increased the values of Ea, ${\Delta}H,/;{\Delta}G$ and ${\Delta}H^{\ast}$ decreasing the value of ${\Delta}S$ for AChE. The results implied that the acid precipitates from I. obliquus increased the thermodynamic barrier, leading to the breakdown of ES complex and the formation of products as inhibitory mechanism.

Inhibition of Acetolactate Synthase from Pea by Pyrimidine Derivatives (Pyrimidine 유도체에 의한 완두 Acetolactate Synthase의 저해에 관한 연구)

  • Joo, Young A;Kim, Dae Whang;Chang, Soo Ik;Choi, Jung Do
    • Journal of the Korean Chemical Society
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    • v.41 no.6
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    • pp.304-312
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    • 1997
  • Acetolactate synthase(ALS) is the common enzyme in the biosynthetic of valine, leucine, and isoleucine, and is the target of several classes of structually unrelated herbicides, including sulfonylureas, imidazolinones, and triazolopyrimidines. In an effort to develop new and desirable herbicides, we have synthesized 4,6-dimethoxypyrimidine derivatives, and examined their inhibitory activities on pea ALS. The most active compound was found to be K11570 and $IC_{50}$ value for K11570 was 0.2 ${\mu}M.$ The inhibition of pea ALS by K11570 was biphasic, showing increased inhibition with incubation time. The K11570 showed mixed-type inhibition with respect to substrate pyruvate. Dual inhibition analysis of K11570 versus sufonylurea herbicide Ally and feedback inhibitor leucine revealed that three inhibitors were competitive for binding to ALS. The arginine modified enzyme showed decreased inhibition by K11570, sufonylurea Ally, and leucine, in constrast to, tryptophan modification did not affect on the sensitivity of ALS to the inhibitors.

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In vitro Methanogenesis, Microbial Profile and Fermentation of Green Forages with Buffalo Rumen Liquor as Influenced by 2-Bromoethanesulphonic Acid

  • Agarwal, Neeta;Kamra, D.N.;Chatterjee, P.N.;Kumar, Ravindra;Chaudhary, L.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.6
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    • pp.818-823
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    • 2008
  • The interaction of fibre degrading microbes and methanogens was studied using two forages, lucerne (Medicago sativa) hay and maize (Zea mays) hay, as substrate and 2-bromoethanesulphonic acid (BES) as an additive in an in vitro gas production test. Gas and methane production (ml/g dry matter) were significantly higher (p<0.05) on lucerne as compared to maize hay. Inclusion of BES in the incubation medium significantly suppressed methane emission irrespective of substrate. The population density of total bacteria, fungi, Ruminococcus flavefaciens and Fibrobacter succinogenes was higher, whereas that of methanogens was lower with maize hay as compared to lucerne as substrate. BES suppressed methanogen population by 7 fold on lucerene and by 8.5 fold on maize at 24 h incubation as estimated by real time-PCR. This suppression was accompanied by almost complete (>98% of control) inhibition of methanogenesis. The proportion of acetate decreased, whereas that of propionate increased significantly by inclusion of BES, resulting in narrowing of acetate to propionate ratio. In vitro true digestibility (IVTD) of lucerne was significantly higher as compared to maize but BES inclusion did not affect IVTD.

Optimization and kinetic modeling for bioconversion of cheese whey to Ganoderma lucidum in batch fermentations

  • Song, Min-Gyeong;Lee, Hwan-Yeong;Hwang, Seok-Hwan
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.381-384
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    • 2002
  • Response surface methodology (RSM) was successfully applied to optimize for the production of Ganoderma lucidum in batch fermentations using the whey (40,000 mg latose/L) as substrate. This study was performed according to the central composite design (CCD) with respect to pH and temperature, where the designed intervals were 3.3$22.9^{\circ}C$$37.1^{\circ}C$, respectively. A second-order factorial design of the experiments was used to build empirical models providing a quantitative interpretation of the relationships between the two variables. The optimum conditions to maximize the production of G. lucidum were pH 4.2 and $28.3^{\circ}C$. At optimum conditions, the mycelial dry weight (MDW) and residual soluble COD (SCOD) were simultaneously used to evaluate the biokinetic coefficients assocoated with substrate inhibition model by nonlinear least squares method with 95% confidence interval. The. maximum microbial growth rates (${\mu}m$), half saturation coefficient ($K_s$), and the inhibition substrate concentration ($K_{is}$) were determined to be 0.095 l/hr, 128,000 mg SCOD/L and 49,000 mg SCOD/L, respectively. And the microbial yield coefficient (Y), biomass decay rate coefficient ($K_d$), and the maintenance energy coefficient ($m_s$) were determined to be 0.37 mg MDW/mg SCOD, 0.001 1/hr, and 0.0015 1/hr, respectively.

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