• 제목/요약/키워드: Oxidoreductase

검색결과 203건 처리시간 0.023초

Catalytic Oxidoreduction of Pyruvate/Lactate and Acetaldehyde/Ethanol Coupled to Electrochemical Oxidoreduction of $NAD^+$/NADH

  • Shin, In-Ho;Jeon, Sung-Jin;Park, Hyung-Soo;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제14권3호
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    • pp.540-546
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    • 2004

  • We deviced a new graphite-Mn(II) electrode and found that the modified electrode with Mn(II) can catalyze NADH oxidation and $NAD^+$ reduction coupled to electricity production and consumption as oxidizing agent and reducing power, respectively. In fuel cell with graphite-Mn(II) anode and graphite-Fe(III) cathode, the electricity of 1.5 coulomb (A x s) was produced from NADH which was electrochemically reduced by the graphite-Mn(II) electrode. When the initial concentrations of pyruvate and acetaldehyde were adjusted to 40 mM and 200 mM, respectively, about 25 mM lactate and 35 mM ethanol were produced from 40 mM pyruvate and 200 mM acetaldehyde, respectively, by catalysis of ADH and LDH in the electrochemical reactor with $NAD^+$ as cofactor and electricity as reducing power. By using this new electrode with catalytic function, the bioelectrocatalysts are engineered; namely, oxidoreductase (e.g., lactate dehydrogenase) and $NAD^+$ can function for biotransformation without electron mediator and second oxidoreductase for $NAD^+$/NADH recycling.

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Induction of Anticarcinogenic Enzymes of Waxy Brown Rice Cultured with Phellinus igniarius 26005

  • Park, Ki-Bum;Ha, Hyo-Cheol;Kim, So-Yeun;Kim, Hyo-Jeong;Lee, Jae-Sung
    • Mycobiology
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    • 제30권4호
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    • pp.213-218
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    • 2002

  • The induction of NAD(P)H: quinone oxidoreductase(QR), glutathione S-transferase(GST), and glutathione(GSH) levels in hepa1c1c7 cells(murine hepatoma) by waxy brown rice cultured with Phellinus igniarius to induce anticarcinogenic enzymes were measured. In addition, the inhibition of polyamines metabolism was tested with the growth of Acanthamoeba castellanii. The result shows that QR, GST activities, and GSH levels of experimental animals were increased much more by feeding the methanol extract of waxy brown rice cultured with Phellinus igniarius than those of the rats received the ethanol of uncultured brown rice. The growth of A. castellanii was inhibited mostly at 40 mg/3 ml concentration of methanol extract of waxy brown rice cultured with P. gniarius. The results suggested that waxy brown rice cultured with P. igniarius possess chemopreventive activity by inducing anticarcinogenic enzymes and inhibiting polyamine metabolism.

  • https://doi.org/10.4489/MYCO.2002.30.4.213 인용 PDF KSCI

Electrochemical Reduction of Xylose to Xylitol by Whole Cells or Crude Enzyme of Candida peltata

  • Park Sun Mi;Sang Byung In;Park Dae Won;Park Doo Hyun
    • Journal of Microbiology
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    • 제43권5호
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    • pp.451-455
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    • 2005

  • In this study, whole cells and a crude enzyme of Candida peltata were applied to an electrochemical bioreactor, in order to induce an increment of the reduction of xylose to xylitol. Neutral red was utilized as an electron mediator in the whole cell reactor, and a graphite-Mn(IV) electrode was used as a catalyst in the enzyme reactor in order to induce the electrochemical reduction of $NAD^+$ to NADH. The efficiency with which xylose was converted to xylitol in the electrochemical bioreactor was five times higher than that in the conventional bioreactor, when whole cells were employed as a biocatalyst. Meanwhile, the xylose to xylitol reduction efficiency in the enzyme reactor using the graphite-Mn (IV) electrode and $NAD^+$ was twice as high as that observed in the conventional bioreactor which utilized NADH as a reducing power. In order to use the graphite-Mn(IV) electrode as a catalyst for the reduction of $NAD^+$ to NADH, a bioelectrocatalyst was engineered, namely, oxidoreductase (e.g. xylose reductase). $NAD^+$ can function in this biotransformation procedure without any electron mediator or a second oxidoreductase for $NAD^+/NADH$ recycling

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NQO1 (NAD(P)H:quinone oxidoreductase 1)에 의한 대식세포 활성화 억제 (Inhibitory Effect of NAD(P)H:Quinone Oxidoreductase 1 on the Activation of Macrophages)

  • 훙지;장펑;윤이나;김호
    • 생명과학회지
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    • 제27권8호
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    • pp.873-878
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    • 2017

  • 본 연구는 대식세포 활성화 과정에서 NQO1의 역할을 확인하는 것이다. 대식세포의 활성화 정도는 배양액으로 분비하는 IL-6와 $TNF-{\alpha}$ 양을 측정하여 평가하였다. 먼저 NQO1 WT 생쥐와 NQO1 KO 생쥐에서 각각 분리한 복강대식세포의 활성화 정도를 비교해 보았다. 특이하게도 NQO1 KO 복강대식세포가 NQO1 WT에 비해서 더 높게 활성화되어 있었다. 또한 일반 생쥐의 복강대식세포에 NQO1 억제제(dicumarol)을 처치한 경우에도 강한 활성이 유도됨을 확인하였다. Dicumarol을 처치한 RAW264.7 (대식세포주)에 서도 강한 활성화가 관찰되었다. 이는 NQO1이 대식세포의 활성화 과정을 억제하는 경로와 연관되어 있음을 보여준다. 더욱이 dicumarol을 처치하여 NQO1의 기능을 억제시킨 다양한 대식세포에서 $I{\kappa}B$ 단백질이 유의하게 감소한다는 사실을 확인하였다. 대식세포 활성화 과정을 매개하는 주요 신호분자가 $NF{\kappa}B$이며 이 분자에 대한 억제자가 $I{\kappa}B$라는 사실들을 감안할 때, NQO1의 기능이 $I{\kappa}B$ 단백질변성 억제와 연관되어 있으며 이를 통해 대식세포의 활성화를 차단했을 가능성이 있다. 본 연구는 향 후 대식세포 활성화 과정을 조절하는 NQO1의 역할을 규명하는데 있어서 중요한 기초 결과가 될 것이다.

  • https://doi.org/10.5352/JLS.2017.27.8.873 인용 PDF KSCI