• Title/Summary/Keyword: Oxidoreductase

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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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    • v.14 no.3
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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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    • v.30 no.4
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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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    • v.43 no.5
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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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Inhibitory Effect of NAD(P)H:Quinone Oxidoreductase 1 on the Activation of Macrophages (NQO1 (NAD(P)H:quinone oxidoreductase 1)에 의한 대식세포 활성화 억제)

  • Hong, Ji;Zhang, Peng;Yoon, I Na;Kim, Ho
    • Journal of Life Science
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    • v.27 no.8
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    • pp.873-878
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    • 2017

  • We previously reported that NAD(P)H:quinone oxidoreductase 1 (NQO1)-knockout (KO) mice exhibited spontaneous inflammation in the gut. We also found that NQO1-KO mice showed highly increased inflammatory responses compared with NQO1-WT control mice when subjected to DSS-induced experimental colitis. In a Clostridium difficile toxin-induced mouse enteritis model, NQO1-KO mice were also sensitive compared with NQO1-WT mice. Moreover, numerous studies have shown that NQO1 is functionally associated with immune regulation. Here, we assessed whether NQO1 defects can alter macrophage activation. We found that peritoneal macrophages isolated from NQO1-KO mice produced more IL-6 and $TNF-{\alpha}$ than those isolated from NQO1-WT mice. Moreover, the dicumarol-induced inhibition of NQO1 significantly increased IL-6 and $TNF-{\alpha}$ production in peritoneal macrophages isolated from NQO1-WT mice, as well as in the cultured mouse macrophage cell line, RAW264.7. These results indicate that NQO1 may negatively regulate the activation of macrophages. Knockout or chemical inhibition of NQO1 markedly reduced the expression of $I{\kappa}B$ (inhibitor of $NF{\kappa}B$) in both mouse peritoneal macrophages and RAW264.7 cells. Finally, RAW264.7 cells treated with dicumarol exhibited morphological changes reflecting macrophage activation. Our results suggest that NQO1 may suppress the $NF{\kappa}B$ pathways in macrophages, thereby suppressing the activation of these cells. Thus, immunosuppressive activity may be among the many possible functions of NQO1.

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