• Biomaterials and Biomechanics in Bioengineering
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• 제3권1호
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• pp.37-46
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• 2016

To maintain activity in a coenzyme/enzyme mixture system, such as ${\beta}$-nicotinamide adenine dinucleotide (NADH)/dehydrogenase, the water-soluble 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers as an additive were synthesized and investigated for their stabilizing function. The inhibitor for the NADH/dehydrogenase reaction was spontaneously formed when the NADH was stored in the dehydrogenase solution. Therefore, we hypothesized that if the additive polymer could interact with an inhibitor without any adverse effect on the dehydrogenase, the activity in the NADH/dehydrogenase mixture could be maintained. We selected lactose dehydrogenase (LDH) as the enzyme, and the NADH was dissolved and incubated at $37^{\circ}C$ in the LDH solution containing the polymers. The phospholipid polymers used in this study were poly(MPC) (PMPC), poly(MPC-co-3-trimethylammonium-2-hydroxypropyl methacrylate chloride) (PMQ) and poly[MPC-co-potassium 3-methacryloyloxypropyl sulfonate ($MSO_3$)] ($PMMSO_3$). The poly($MSO_3$) was used as a reference. For the PMQ and $PMSO_3$ aqueous solutions, the activity of the NADH/LDH mixture system decreased with incubation time as the same level or lower than that in the Tris buffered solution in the absence of the polymers. However, for the poly($MPC-co-MSO_3$) ($PMMSO_3$) aqueous solution, the activity of the NADH/LDH mixed system was six times higher than that in the buffered solution even after a 3-days incubation. The LDH activity was 1.5-1.8 times higher in the presence of the $PMMSO_3$ compared with that in the $PMSO_3$ solution. The mixture of two polymers, poly(MPC) and poly($MSO_3$), did not produce any stabilization. Thus, both the MPC and $MSO_3$ units in the polymer chain had important and cooperative effects for stabilizing the NADH/LDH mixture.

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.153-157
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• 1991

Intracellular enzymes of an extreme halophilic bacterium, Halobacterium sp. HE10, isolated from a saltern in Korea was investigated. The membrane-bound enzyme, NADH dehydrogenase, involved in electron transport system was stimulated by the addition of 2.0 M NaCl. The respiratory enzyme activities such as NADH oxidase and NADH dehydrogenase was decreased on removal of $Na^+$ ion and restored when replaced with cations like $K^+$, $Li^+$and $NH_{4}^{+}$ ions. Furthermore, their activities were affected by the anions such like carbonate, acetate, sulfate, chloride and nitrate at the presence of $Na^+$ion. Lactate dehydrogenase activity was highest at the asturated solution of NaCl and isocitrate dehydrogenase activity was a maximum level at 1.0 M NaCl. These results suggested that the enzyme activites of the respiratory chain in Halobacterium sp. EH10 was stimulated by the presence of $Na^+$ ion.

• 생명과학회지
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• 제8권1호
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• pp.8-13
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• 1998

옥수수의 미토콘드리아 변이체(NGS2)는 전자전달계 내의 NADH dehydrogenase를 구성하고 있는 subunit 4와 7 유전자의 재조합에 의해서 생성된 변이체이다. 이들의 변이체들은 식물의 성장과 발육에 절대적인 영양을 미치며, 또한 기내에서의 callus line들의 생성과 발달에도 상당한 영향을 미친다. 이들의 미토콘드리아 mutant 들은 3개의 primer를 사용하는 PCR 방법에 의해서 쉽게 선별이 가능하며, 세포 내의 키토콘드리아 변이 정도를 간접적으로 추측케 하며, 체시포 분열시 세포질 내의 기관들이 random으로 분리되는 현상을 간법적으로 알 수 있다. NGS2 mutant들에서 유기된callus line들은 식물체 재문화에도 영향을 미쳐 murant 미토콘드리아가 많은 call line들에슨 실질적인 부정 줄기의 유기를 방해하는 것으로 사료된다. 결론적으로 NADH-dehydrogenase는 식물체가 재분화 또는 성장하는데 있엇 필요한 요소라고 생각된다.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.160.3-161
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• 2003

Aldehyde and active form of free oxygen produced in alcohol metabolism in liver are the cause of liver cell damage. The main system of alcohol metabolism is composed of alcohol dehydrogenase(ADH), aldehyde dehydrogenase(ALDH) and cytochrome P4502E1. Alcohol dehydrogenase is reversible in alcohol metabolism. To block the backward reaction and enhance alcohol oxidation, acetaldehyde trapping agents were assayed. The assay was carried out by measuring decreasing NADH at 340nm, using acetaldcehyde and NADH as substrate and coenzyme respectively. (omitted)

• 한국균학회지
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• 제26권1호통권84호
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• pp.119-126
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• 1998

Mitochondria were isolated from Lentinus edodes and properties of the mitochondrial NADH dehydrogenase were studied. Optimal pH, temperature, and thermal stability of the enzyme were estimated to be 7.6, $33^{\circ}C$, and stable for one hour at $50^{\circ}C$. The apparent $K_m$ for the NADH was 0.33 mM. This enzyme catalyzed to transfer electrons from NADH to ferricyanide, decylubiquinone, and 2,6-dichloro-phenol-indophenol. 0.5 mM antimycin A and 0.01 mM dibromothymoquinone strongly inhibited 87.8% and 76.5% of the enzyme activities. 0.01 mM oligomycin known as an inhibitor of ATPase also strongly inhibited 79.2% of activities. 0.5 mM 5,5'-dithiobis-(2-nitrobenzoic acid) and 1.0 mM N-ethylmaleimide known as a modifier of SH group inhibited 50.4% and 36.7% of activities. 1 mM ethyl 2,4-dihydroxy-6-methyl benzoate and 10 mM orcinol, which had been known as an antibiotics isolated from Umbilicaria vellea according to our previous work, stimulated 68.4% and 48.1% of the enzyme activities.

• 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.

• 분석과학
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• 제8권3호
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• pp.359-364
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• 1995

Urinary dipeptidase와 alanine dehydrogenase의 연쇄반응을 이용한 형광분석법을 개발하였다. 반응계는 기질로서 L-ala-ala, ${\beta}-NAD^+$, L-alanine dehydrogenase와 pH 9의 12.5mM sodium carbonate buffer를 포함하며 urinary dipeptidase를 가함으로써 반응을 시작했다. 생성된 NADH는 여기파장 340nm, 형광파장 460nm에서 측정했다. 기존의 glycyldehydrophenylalanine(Gdp)의 가수분해 방법과 형광분석법을 비교한 결과 0.996의 높은 상관계수를 나타냈으며 10배 이상의 감도 증가를 보였다.

• 한국미생물·생명공학회지
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• 제41권2호
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• pp.153-159
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• 2013

Sinorhizobium meliloti 1021 (KCTC 2353) 유전체로부터 mannitol dehydrogenase (SmMDH)로 추정되는 유전자를 클로닝하고, 대장균에서 대량 발현하였다. 이 유전자는 494개의 아미노산(약 54 kDa)을 암호화하는 1,485 bp의 염기로 구성되며, 기존에 보고된 long-chain dehydrogenase/reductase 계열 MDH 효소들과 약 35-55%의 아미노산 서열상동성을 나타내었다. 재조합 SmMDH의 최적 반응온도는 $40^{\circ}C$이며, pH 7.0의 조건에서 최대의 D-fructose 환원활성, 그리고 pH 9.0에서 최대의 D-mannitol 산화활성을 보였다. 특히, 이 효소는 $NAD^+/NADH$ 조효소의 존재 하에서 산화 환원 활성을 나타내며, $NAD^+/NADPH$는 조효소로 이용하지 못하였다. 결론적으로 SmMDH는 전형적인 $NAD^+/NADH$-의존형 mannitol dehydrogenase (EC 1.1.1.67)임을 확인하였다.

• 미생물학회지
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• 제48권2호
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• pp.156-162
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• 2012

Salmonella typhimurium LT2 (KCTC 2421)로부터 mannitol dehydrogenase (StMDH)로 추정되는 유전자를 클로닝하고, 대장균에서 대량 발현하였다. 이 유전자는 488개의 아미노산 서열(약 54 kDa)을 암호화하는 1,467 bp의 염기로 구성되며, 이미 보고된 long-chain dehydrogenase/ reductase (LDR) 계열 효소들과 약 36%의 아미노산 서열 상동성을 나타내었다. 재조합 StMDH의 최적 반응온도는 $30^{\circ}C$이며, pH 5.0의 조건에서 최대의 D-fructose 환원활성, 그리고 pH 10.0에서 최대의 D-mannitol 산화활성을 보인다. 반면에 glucose, galactose, xylose, arabinose 등의 기질에 대해서는 활성을 보이지 않았다. 이 효소는 $NAD^+$/NADH 존재 하에서만 산화 환원 활성을 가지며, $NADP^+$/NADPH는 조효소로 이용하지 못하였다. 결론적으로 StMDH는 전형적인 $NAD^+$/NADH 의존형의 mannitol dehydrogenase (EC 1.1.1.67)임을 확인하였다.

• 대한약리학회지
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• 제23권2호
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• pp.113-121
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• 1987

국소마취제가 mitochondria에서의 전자이동 및 superoxide라디칼의 생성 그리고 지질의 과산화에 따른 malondialdehyde생성에 미치는 영향을 관찰하였다. 국소마취제는 전자이동계 의 효소활성도에 영향을 나타내었다. NADH dehydrogenase, NADH oxidase와 NADH-ubiquinone oxidoreductase의 활성도는 lidocaine, procaine과 dibucaine에 의하여 효과적으로 억제되었고 cocaine에 의하여 약간 억제되었다. Succinate dehydrogenase, succinate cytochrome c oxidoreductase와 succinate-ubiquinone oxidoreductase 활성도는 lidocaine 과 dibucaine에 의하여 억제되었으나 succinate oxidase는 국소마취제에 의하여 활성화되었다. 국소마취제는 dihydroubiquinone-cytochrome c oxidoreducatse와 cytochrome c oxidase의 활성도를 억제하였다. 이와 같은 반응에서 국소마취제에 대한 complex I segment의 반응이 다른 complex segment보다 크게 나타났다. 국소마취제는 succinate 또는 NADH에 의한 superoxide 생성과 이에 대한 antimycin의 자극효과를 억제하였다. 또한 국소마취제는 산소라디칼에 의한 지질의 과산화를 억제하였다. 이상의 결과로부터 국소마취제는 mitochondria의 전자전달 과정 중 Complex I segment때 또는 인접한 부위에 작용하여 전자이동을 억제함으로써 superoxide 생성과 지질의 과산화를 억제할 것으로 시사되었다.