• 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.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.242-249
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• 2019

Biosynthesis of indole-3-acetate (IAA) from L-tryptophan via indole-3-pyruvate pathway requires three enzymes including aminotransferase, indole-3-pyruvate decarboxylase, and indole-3-acetate dehydrogenase. To establish a bio-based production of IAA, the aspC, ipdC, and iad1 from Escherichia coli, Enterobacter cloacae, and Ustilago maydis, respectively, were expressed under control of the tac, ilvC, and sod promoters in C. glutamicum. Cells harboring ipdC produced tryptophol, indicating that the ipdC product is functional in this host. Analyses of SDS-PAGE and enzyme activity revealed that genes encoding AspC and Iad1 were efficiently expressed from the sod promoter, and their enzyme activities were 5.8 and 168.5 nmol/min/mg-protein, respectively. The final resulting strain expressing aspC, ipdC, and iad1 produced 2.3 g/l and 7.3 g/l of IAA from 10 g/l L-tryptophan, respectively, in flask cultures and a 5-L bioreactor.

• Applied Biological Chemistry
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• 제38권3호
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• pp.278-282
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• 1995

오미자 추출물이 Saccharomyces cerevisiae의 생리에 미치는 영향을 조사하기 위하여 포도당 기본배지에 오미자 추출물을 0, 0.01, 0.1, 0.5, 1%(w/v)씩 첨가하고 S. cerevisiae KTCC 1199를 접종하여 96시간 진탕배양하면서 균의 증식, 알콜생성, 발효율 등의 변화와 alcohol dehydrogenase, pyruvate decarboxylase활성을 조사하였다. S. cerevisiae의 증식은 전 발효기간중 추출물 0.01%및 0.1%첨가구에서 대조구보다 증가하였으며, 각 시험구의 알콜생성은 추출물 0.1%, 0.01%, 0%, 0.5%, 1% 첨가순으로 0.1%첨가구에서 가장 높았다. alcohol dehydrogenase 효소활성은 0.1%구와 0.01%구에서 대조구보다 각각 1.25배, 1.18배 높은 활성을 보였다. pyruvate decarboxylase 활성의 경우도 ADH 활성과 유사하여 각각 대조구보다 1.31배, 1.26배 높은 활성을 보였으며, 0.5%구와 1%구는 대조구보다 각각 1.3배및 1.4배 낮은 활성을 보였다.

• 생명과학회지
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• 제14권4호
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• pp.702-707
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• 2004

Pangasius polyuranodon 조직의 젖산탈수소효소(EC 1.1.1.27, lactate dehydrogenase, LDH)는$A_4$, $A_3$B, $A_2$$B_2$, $AB_3$ 및 $B_4$동위효소들이 모두 발현되었다. Hypostomus Plecostomus LDH의 경우 $A_4$와 liver-specific $C_4$동위효소가 발현되었다. 골격 근, 심장 및 눈조직에서는 동위효소의 band가 나타나지 않았고, 신장 및 간조직에서 각각 하나의 band가 나타났으며, 뇌조직에서는 4개의 동위효소 band들이 나타났다. 간조직의 band는 alcohol dehydrogenase로 확인되었고, 골격근에서 양극쪽 band는 nothing dehydrogenase로 확인되었다. 따라서 골격근, 심장 및 눈조직에서 LDH는 pyruvate reductase 로서 기능을 하는 것으로 생각된다. P. polyuranodon 조직별 피루브산에 의한 저해정도는 10 mM 피루브산에서 골격근은 57.6%, 심장은 73.8%로 측정되었으나 H. plecostomus의 조직들은 52.7-61.8%로 측정되어 조직특이성이 나타나지 않았다. 따라서 H. plecostomus가 P. polyuranodon 보다 더욱 저산소 환경에서 혐기적 대사에 의해 순응되어졌다고 사료된다.

• Nutritional Sciences
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• 제6권4호
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• pp.189-194
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• 2003

Most of the ethyl alcohol consumed by humans is oxidized to acetaldehyde in the liver by the cytoplasmic alcohol dehydrogenase (ADH) system. For this ADH-catalyzed oxidation of alcohol, $NAD^+$ is required as the coenzyme and $NAD^+$becomes reduced to NADH. As the $NAD^+$becomes depleted and NADH accumulates, alcohol oxidation is reduced. For continued alcohol oxidation, the accumulated NADH must be quickly reoxidized to $NAD^+$, and it is this reoxidation of NADH to $NAD^+$that is known to be the rate-limiting step in the overall oxidation rate of alcohol The reoxidation of NADH to $NAD^+$is catalyzed by lactate dehydrogenase in the cytoplasm of hepatocytes, with pyruvate being utilized as the substrate. The pyruvate may be supplied from alanine as a result of amino acid metabolism via the urea cycle. Also, glutamine is thought to help with the supply of pyruvate indirectly, and to activate the urea cycle by producing $NH_3$. Thus, in the present study, we have examined the effects of alanine and glutamine on the alcohol oxidation rate. We utilized isolated perfused liver tissue in a system where media containing alanine and glutamine was circulated. Our results showed that when alanine (5.0mM) was added to the glucose-free infusion media, the alcohol oxidation rate was increased by 130%. Furthermore, when both glutamine and alanine were added together to the infusion media, the alcohol oxidation rate increased by as much as 190%, and the rate of urea nitrogen production increased by up to 200%. The addition of glutamine (5.0mM) alone to the infusion media did not accelerate the alcohol oxidation rate. The increases in the rates of alcohol oxidation and urea nitrogen production through the addition of alanine and glutamine indicate that these amino acids have contributed to the enhanced supply of pyruvate through the urea cycle. Based on these results, it is concluded that the dietary supplementation of alanine and glutamine could contribute to increased alcohol detoxification through the urea cycle, by enhancing the supply of pyruvate and $NAD^+$to ensure accelerated rates of alcohol oxidation.

• 약학회지
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• 제33권1호
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• pp.39-45
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• 1989

Effects of dammarane glycosides of Panax ginseng on primary cultured chicken embryonic brain cells were studied by microscopic observation and determination of the activity of pyruvate dehydrogenase complex (PDHC). Brain cells were prepared from the brain of 10-day-old chicken embryo and cultured with either a standard medium consisted of 85% Dulbecco's Modified Eagle Medium (DMEM), 10% horse serum and 5% chicken embryonic extracts or a deficient medium consisted of 90% DMEM and 10% horse serum. It was observed that dammarane glycosides of Panax ginseng seemed to show the tendency to stimulate the neurite outgrowth of brain cells which were cultured with a deficient medium under microscopic observation. The activity of PDHC in brain cells cultured with a deficient medium was increased by dammarane glycosides of Panax ginseng.

• 생약학회지
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• 제20권1호
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• pp.32-36
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• 1989

Effects of Lycium chinensis, Epimedium koreanum and tuguaconitine which is isolated from Aconitum sibiricum on primary culture chicken embryonic brain cells were studied by microscopic observation and determined of the activity of pyruvate dehydrogenase complex(PDHC). Brain cells were prepared from the brain of 10-day-old chicken embryo and cultured with a medicine consisted of 90% Dulbecco's Modified Eagle Medium(DMEM) and 10% horse serum. It was observed that all substances studied seemed to show the tendency to stimulate the neurite outgrowth of brain cells which were cultured with a deficient medium under microscopic observation. The activity of PDHC in brain cells cultured with a deficient medium was increased by Lysium chinensis and Epimedium koreanum. However, tuguaconitine had not influence on the activity of PDHC.

• Biomolecules & Therapeutics
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• 제4권3호
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• pp.271-274
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• 1996

The antihepatotoxic activity of Bezoar Bovis and Moschus was investigated by in vitro assay method using galactosamine and carbon tetrachloride-induced cytotoxicity in primary-cultured rat hepatocytes. The antihepatotoxic activity was evaluated by measuring the level of glutamate pyruvate transaminase and sorbitol dehydrogenase which were released from the necrotic hepatocytes to the culture medium. In galactosamine-intoxicated hepatocytes, the chloroform fraction of Bezoar Bovis reduced the level of glutamate pyruvate transaminase and sorbitol dehydrogenase resulting in 65% and 59% protection, respectively. The n-Hexane fraction of Moschus resulted in 45% and 40% protection, respectively in this system. In the case of carbon tetrachloride-intoxicated rat hepatocytes, Bezoar Bovis did not have significant effect and only the aqueous fraction of Moschus showed 42% and 40% protection, respectively.

• 한국식품영양과학회지
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• 제29권2호
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• pp.193-197
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• 2000

The effects of black soybena extracts on enzymes activies of rat were evaluated in present study. Eighty-four male Sprague-Dawley rats weighing 100$\pm$10g were divided into twelve groups which consisted of black soybean extract, Pb and Cd solution, and black soybean extract plus Pb or Cd soln groups. The weight gain was increased in black soybean extracts and Pb soln solution group but decreased in Cd soln solution group. The results obtained form the experiment were as follows: Glutamate pyruvate trasaminase (GPT) and glutamate oxaloacetate oxaloacetate transaminase (GOT) activities were not significantly different among experimental groups. The lactate dehydrogenase (LDH) activities of black soybean extract administered groups were decreased than those of Pb and Cd solution group. Black soybean group increased cholinesterase (ChEase) activity as compared to administration of Pb and Cd soln group.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.628-631
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• 2003

The recombinant alanine dehydrogenase (ADH) from E. coli containing Thermus caldophilus ADH was purified to homogeneity from a cell-free extract. The enzyme was purified 38-fold with a yield of 68% from the starting cell-free extract. The purified enzyme gave a single band in polyacrylamide gel electrophoresis, and its molecular weight was estimated to be 45 kDa. The pH optimum was 8.0 for reductive amination of pyruvate and 12.0 for oxidative deamination of L-alanine. The enzyme was stable up to $70^{\circ}C$. The activity of the enzyme was inhibited by 1 mM $Zn^{2+}$, 20% hexane, and 20% $CHCl_3$. However, 10 mM $Mg^{2+}$ and 40% propanol had no effect on the enzyme activity. The Michaelis constants ($K_m$) for the substrates were $50\;\mu\textrm{M}$ for NADH, 0.2 mM for pyruvate, 39.4 mM for $NH_4+$, 2.6 mM for L-alanine, and 1.8 mM for $NAD^+$.