• 제목/요약/키워드: enzyme transport

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

  • 김현철;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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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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포도당 산화효소를 고정화한 Polypyrrole 효소전극의 배위자 변화에 따른 전기화학적 특성 (Electrochemical Properties of Polypyrrole Enzyme Electrode Immobilized Glucose Oxidase with Different Ligand)

  • 김현철;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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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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    • 제9권4호
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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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Polypyrrole-Glucose Oxidase 효소전극의 배위자 크기에 따른 전기화학적 특성 (Electrochemical Properties of Polypyrrole-Glucose Oxidase Enzyme Electrode with Different Dopants)

  • 김현철;구할본
    • 한국전기전자재료학회논문지
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    • 제15권2호
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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.

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

  • Kim, Moon-Kyoo;Kim, Sung-Rye;Cho, Wan-Kyoo
    • 한국동물학회지
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    • 제23권2호
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    • pp.61-68
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    • 1980
  • 발정주기에 EK라서 생쥐자궁의 alkaline phosphatase와 transport ATPases의 활성변화를 알아보기 위하여 정량적으로 분석하였다. 발정주기의 각 시기에 있어서 이 효소활성들의 비율은 대체로 그 양상이 서로 비슷하나, 발정기의 $K^+$-dependent와 $Na^+, K^+$-activated ATPases를 제외한 다른 효소들의 활성은 다른 어떤 시기보다도 유의하게 (p<0.025) 높았다. 즉, $K^+$-dependent와 $Na^+, K^+$-activated ATPases의 활성은 발정간기에서 발정기에 이르는 동안 무시할 정도이고, 다만 발정후기에 약간의 활성(0.04$\\sim$0.05 $\\mu$M/mg protein/hr), 총활성의 6$\\sim$7%)이 나타났다. 한편, 발정기에서 $Mg^++$-dependent phosphatase, transport ATPase와 alkaline phosphatase의 활성들은 급속히 현저하게 증가하였으며 각각 0.69(35%), 0.42(21%), 1.58(79%)였다. Alkaline phosphatase는 전 발정주기를 통해 0.60$\\sim$1.58(79$\\sim$90%)의 활성을 보여 그 주종을 이루었다. Alkaline phosphatase의 활성중에는 $Mg^++$-dependent의 것이 총활성의 12$\\sim$16%로 추정되었다. 그러므로 $K^+$-dependent와 $Na^+$-activated ATPases는 발정기 때에 자궁액의 누적을 조절하는 요인이 아니고 발정후기에는 자궁상피 속으로 내액을 재흡수하는 요인인 것으로 짐작되며, EH한 $Mg^++$-dependent phosphatase, transport ATPase 그리고 alkaline phosphatase는 생쥐의 자궁 상피세포에서부터 내액을 분지하는 데에 밀접히 관련되어 있는 것으로 사려된다.

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

  • 김현철;조영재;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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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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유기용매 첨가에 따른 Polypyrrole-Glucose Oxidase 효소전극의 효소고정화 향상 I. 자외선 분광분석 (Improvement on Enzyme Immobilization in Polypyrrole-Glucose Oxidase Enzyme Electrode using Organic Solvent Additive I. Ultraviolet Spectroscopic Analyses)

  • 김현철;구할본
    • 한국전기전자재료학회논문지
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    • 제15권7호
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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.

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

  • 최정우;민준홍;이원홍
    • 센서학회지
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    • 제3권2호
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    • pp.16-23
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    • 1994
  • 오염수에서 유기인 화합물을 측정하기 위해 개발된 광섬유 바이오센서의 신호의 분석과 최적설계를 위하여 센서에 사용되어진 AChE효소(acetylcholinesterase)의 반응, 반응기 내의 유체거동 및 물질전달현상의 해석이 필요하다. 사용되어진 센서의 반응기 부분을 해석하고 재설계하기 위하여 효소 반응을 연구하고, 이동현상학적으로 유체 및 물질확산 현상을 해석하여 반응기 모델을 성립하였다. 사용되어진 유기인 화합물에 의해 저해되는 AChE효소의 측정범위인 0-2 ppm 사이에서 저해반응을 실험하였으며, 비가역 저해 효소 반응식을 제안하였다. 반응기를 두상 즉 벌크상과 효소층으로 나누어 유체거동을 해석하였으며, 고정화겔 내의 확산의 영향을 조사하였다. 반응식, 유체거동식 및 확산식을 연계하여 세워진 반응기 전체모델을 제시하였고, 이를 이용하여 신호를 해석하였다. 제시된 모델을 이용하여 효소량, 효소층의 두께의 증가에 따른 센서 신호량의 민감도를 전산모사하였다.

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

  • 김현철;구할본
    • 한국전기전자재료학회논문지
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    • 제15권7호
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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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    • 제3권1호
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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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