• Title/Summary/Keyword: enzyme transport

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Electrochemical Properties of Polypyrrole Enzyme Electrode Immobilized Glucose Oxidase with Different Ligand (포도당 산화효소를 고정화한 Polypyrrole 효소전극의 배위자 변화에 다른 전기화학적 특성)

  • Kim, Hyun-Cheol;Gu, Han-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.529-532
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    • 2001
  • We synthesized polypyrrole (PPy) by electrolysis of the pyrrole monomer solution containing support electrolyte KCl and/or p-toluene sulfonic acid sodium salt (p-TS). The electrochemical behavior was investigated using cyclic voltammetry and AC impedance. In the case of using electrolyte p-TS, the redox potential was about -0.3 V vs. Ag/ AgCl reference electrode, while the potential was about 0 V for using electrolyte KCl. It is considered as the backbone forms a queue effectively by doping p-TS Therefore, it is possible to be arranged regularly. That leads to improvement in the electron hopping. The AC impedance plot gave a hint of betterment of mass transport. PPy doped with p-TS has improved in mass transport, or diffusion. That is because the PPy doped with p-TS has a good orientation, and is more porous than PPy with KCl.

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Electrochemical Properties of Polypyrrole Enzyme Electrode Immobilized Glucose Oxidase with Different Ligand (포도당 산화효소를 고정화한 Polypyrrole 효소전극의 배위자 변화에 따른 전기화학적 특성)

  • 김현철;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.529-532
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    • 2001
  • We synthesized polypyrrole (PPy) by electrolysis of the pyrrole monomer solution containing support electrolyte KCl and/or p-toluene sulfonic acid sodium salt (p-TS). The electrochemical behavior was investigated using cyclic voltammetry and AC impedance. In the case of using electrolyte p-75, the redox potential was about -0.3 V vs. Ag/AgCl reference electrode, while the potential was about 0 V for using electrolyte KCl. It is considered as the backbone forms a queue effectively by doping p-TS Therefore, it is possible to be arranged regularly. That leads to improvement in the electron hopping. The AC impedance plot gave a tent of betterment of mass transport. PPy doped with p-TS has improved in mass transport, or diffusion. That is because the PPy doped with p-TS has a good orientation, and is more porous than PPy with KCl.

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Synergistic Inhibition of Membrane ATPase and Cell Growth of Helicobacter pylori by ATPase Inhibitors

  • Ki, Mi-Ran;Yun, Soon-Kyu;Lim, Wang-Jin;Hong, Bum-Shik;Hwang, Se-Young
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.414-421
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    • 1999
  • Helicobacter pylori were found to be resistant to azide but sensitive to vanadate, suggesting that defect in the P-type ATPase activity rather than F-type ATPase would be lethal to cell survival or growth. To elucidate the relationship between this enzyme inhibition and H. pylori death, we determined the effect of omeprazole (OMP) plus vanadate on enzyme activity and cell growth. The minimum inhibitory concentration (MIC; ca. 0.8$\mu$mol/disk) of vanadate for H. pylori growth was lowered over l0-fold with the aid of OMP, whereby its inhibitory potential toward the P-type ATPase activity was diametrically increased. Alternatively, we found that this enzyme activity was essential for active transport in H. pylori. From these observations, we strongly suggest that the immediate cause of the growth inhibition of H. pylori cells with OMP and/or vanadate might be defective in the cell's active transport due to the lack of P-type ATPase activity. From the spectral data with circular dichroism (CD) spectroscopy, we found that activated OMP (OAS) at concentration below MIC did not disrupt helical structures of membrane proteins. Separately, we determined the cytopathic effect of OAS by SDS-PAGE, indicating the change in the production of cytoplasmic protein but not cell membrane.

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Electrochemical Properties of Polypyrrole-Glucose Oxidase Enzyme Electrode with Different Dopants (Polypyrrole-Glucose Oxidase 효소전극의 배위자 크기에 따른 전기화학적 특성)

  • 김현철;구할본
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.2
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    • pp.141-146
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    • 2002
  • We synthesized polypyrrole (PPy) by electrolysis of the pyrrole monomer solution containing support electrolyte, KCl and/or p-toluene sulfonic acid sodium salt (p-TS). The electrochemical behavior, was investigated using cyclic voltammetry and AC impedance. In the case of using electrolyte p-TS, the oxidation potential of the PPy was about -02 V vs Ag/AgCl reference electrode, while the potential was about 0 V for using electrolyte KCl. The falloff of the oxidation potential gave a sign of an improvement in the electron hopoing mechanism on the backbone. The AC impedance plot gave a hint of betterment of mass transport. PPy doped with p-TS improved in mass transport or diffusion. That was because the PPy doped with p-TS was more porous than PPy with KCl. We attained an effect of good kinetic parameters, in the case of PP-GOx enzyme electrodes doped with p-TS, which were determined by 58 mmol dm$\^$-3/ for apparent Michaelis constant and by 581 ㎂ for maximum current respectively.

Changes in Phosphatase Activity of the Mouse Uterus during the Estrous Cycle (發情週期에 EK른 생쥐子宮의 Phosphatase 活性의 變化에 관하여)

  • Kim, Moon-Kyoo;Kim, Sung-Rye;Cho, Wan-Kyoo
    • The Korean Journal of Zoology
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    • v.23 no.2
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    • pp.61-68
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    • 1980
  • Quantitative analysis of the activities of transport ATPases as well as alkaline phosphatase of the mouse uterus was carried out during the estrous cycle. Even though the proportional patterns of the enzyme activities were similar each another between the stages of estrous cycle, the absolute activities of the enzymes except $K^+$-dependent and $Na^+$, $K^+$-activated ATPases at the time of estrus were significantly (p<0.025) higher than that at any other time of the estrous cycle. That is, the activities of $K^+$-dependent and $Na^+$, $K^+$-activated ATPases were negligible during the period of time from diestrus to estrus while the little activities (0.04 $\\sim$ 0.05$\\mu$M/mg protein/hr in average, $6\\sim7$% of the total enzyme activity) of these enzymes appeared at the time of metaestrus. On the other hand, at the time of estrus, the activities of $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase were rapidly and tremendously increased to be 0.69 (35%), 0.42 (21%) and 1.58 (79%), respectively. The activity of alkaline phosphatase was in the range of 0.60 $\\sim$ 1.58 (79 $\\sim$ 90%) and predominant throughout the estrous cycle. The activity of $Mg^++$-dependent alkaline phosphatase was estimated as 12 $\\sim$ 16% of the total enzyme activity. Therefore, it is assumed likely that $K^+$-dependent and $Na^+$, $K^+$-activated ATPases are not the main factors to control the fluid accumulation at the time of estrus, but may be the factors to reabsorb the luminal fluid into the uterine epithelium at the time of metaestrus, and that $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase must be closely involved in the secretion of luminal fluid from the epithelial cells of the mouse uterus.

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Improvement in Enzyme Immobilization of Polypyrrole Enzyme Electrode using Radical Transfer (Radical Transfer 반응을 이용한 Polypyrrole 효소전극의 효소고정화 향상)

  • Kim, Hyun-Cheol;Cho, Young-Jai;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04b
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    • pp.100-103
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    • 2000
  • In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidase (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized the enzyme electrode by electropolymerization added some organic solvent. A formative seeds of film growth is delayed by adding ethanol. The delay is induced by radical transfer between ethanol and pyrrole monomer. The radical transfer shares the contribution of dopant between electrolyte anion and GOx polyanion. This may lead to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased. We established qualitatively that amount of immobilization can be improved by adding a little ethanol in the synthetic solution. It is due to radical transfer reaction. The radical transfer shares the contribution of dopant between small and fast electrolyte anion and big and slow GOx polyanion.

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Improvement on Enzyme Immobilization in Polypyrrole-Glucose Oxidase Enzyme Electrode using Organic Solvent Additive I. Ultraviolet Spectroscopic Analyses (유기용매 첨가에 따른 Polypyrrole-Glucose Oxidase 효소전극의 효소고정화 향상 I. 자외선 분광분석)

  • 김현철;구할본
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.7
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    • pp.615-620
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    • 2002
  • In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidise (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized enzyme electrodes by electropolymerization added some organic solvent, such as ethanol and tetrahydrofuran (THF). The formative seeds of film growth was delayed by adding ethanol. The delay was induced by radical transfer between ethanol and pyrrole monomer. The radical transfer reactions shared the contribution of dopants between electrolyte anion and GOx polyanion. This led to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased.

Fiber-optic biosensor for the detection of organophosphorus compounds in a contaminated water (Part II : The signal analysis and simulation) (오염수 내의 유기인 화합물의 측정을 위한 광섬유 바이오센서 (제 2 부 : 신호분석 및 수치모사))

  • Choi, Jeong-Woo;Min, Jun-Hong;Lee, Won-Hong
    • Journal of Sensor Science and Technology
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    • v.3 no.2
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    • pp.16-23
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    • 1994
  • Developed fiber-optic biosensor for the detection of organophosphorus compounds in a contaminated water needs the analysis of an enzyme kinetics and the transport phenomena in the reaction part to analyze the sensor signal and to design the sensor. The enzyme inhibition kinetics was investigated and the reactor model was proposed to design the reaction part in the proposed sensor. Since the acetylcholinesterase was inhibited by the organophosphorus compounds, experiments for enzyme inhibition reaction were performed from 0 to 2 ppm to be detected by the developed sensor, and irreversible enzyme inhibition kinetics was proposed. The reactor parts were divided into the two phases, i.e. bulk phase and immobilized enzyme layer, to analyze the flow and diffusion. Sensor signal was able to be analyzed based on the total reactor model established by linking the enzyme reaction kinetics. Based on the proposed model, the effects of loading enzyme amount and enzyme layer thickness on the magnitude of readout signal were simulated.

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Improvement on Enzyme Immobilization in Polypyrrole-Glucose Oxidase Enzyme Electrode using Organic Solvent Additive II. Electrochemical Analyses and Glucose Sensing (유기용매 첨가에 따른 Polypyrrole-Glucose Oxidase 효소전극의 효소고정화 향상 II. 전기화학적 분석 및 포도당 감지)

  • 김현철;구할본
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.7
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    • pp.621-626
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    • 2002
  • In the case of immobilizing of glucose oxidase (GOx) in polypyrrole (PPy) conducting polymer using electrosynthesis, the GOx obstructs charge transfer and mass transport during the film growth. This may lead to short chained polymer and/or make charge-coupling weak between the GOx and the backbone of the PPy. That is mainly due to insulating property and net chain of the GOx. Since being the case, it is useless to increase in amount of GOx mere than reasonable in the synthetic solution. We improved the amount of immobilized GOx into the PPy by adding a little ethanol in the synthetic solution without any more amount of GOx in the solution. We electrochemically analyzed an improvement in the immobilizing event. For the glucose sensing, when ethanol was added by 0.1 mol $dm^{-3}$ in the synthetic solution, the Michaelis constant of the resulting enzyme electrode was about 32 mmol $dm^{-3}$ and maximum current was about $146\mu A$.

Cloning and Expression of the Gene Encoding Mannose Enzyme II of the Corynebacterium glutamicum Phosphoenolpyruvate-Dependent Phosphotransferase System in Escherichia coli

  • Lee, Jung-Kee;Sung, Moon-Hee;Yoon, Ki-Hong;Pan, Jae-Gu;Yu, Ju-Hyun;Oh, Tae-Kwang
    • Journal of Microbiology and Biotechnology
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    • v.3 no.1
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    • pp.1-5
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    • 1993
  • The gene for mannose enzyme II of phosphoenolpyruvate-dependent phosphotransferase system from Corynebacterium glutamicum KCTC 1445 was cloned into Escherichia coli ZSC113 using plasmid pBR 322. The recombinant plasmid, designated pCTS3, contained 2.2 kb DNA fragment, and the physical map of the cloned DNA fragment was determined. The E. coli ptsM ptsG mutant transformed with pCTS3 restored glucose and mannose fermentation ability, and grew well on these sugars as the sole carbon source in the minimal medium. The transform ant harboring pCTS3 showed a PTS-mediated repression of growth on maltose by mannose analogue, 2-deoxyglucose. The specificity of the response to 2DG therefore indicates that the cloned DNA fragment carries mannose enzyme II gene.

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