• Journal of Electrochemical Science and Technology
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• v.2 no.3
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• pp.163-167
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• 2011

Nicotinamide adenine dinucleotide, $NAD^+$, and its reduced form, NADH, play important roles as coenzymes in many enzymatic reactions. Electrochemical methods for $NAD^+$ or NADH detection or generation are drawn attention because it can provide the simple and low cost platform with fairly good sensitivity. In this study, the polysiloxane viologen polymer/diaphorase/hydrophilic polyurethane (PSV/DI/HPU) modified electrodes were simply prepared and demonstrated for bio-electrocatalytic $NAD^+$ sensors. The electrodes were co-immobilized with diaphorase and polysiloxane viologen polymer as an electron mediator followed by the overcoating with HPU membrane. The mixture of the enzyme and the electron mediator was well stabilized within HPU membrane and exhibited good reversibility and stability. The sensitivity was 0.2 $nA{\cdot}{\mu}M^{-1}$ and the detection limit was 28 ${\mu}M$ with a response time of 50 s ($t_{90%}$). The capability for NADH sensor was also observed on the PSV/DI/HPU electrode.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.1
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• pp.15-19
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• 2002

The role of vascular NAD(P)H oxidase in subarachnoid hemorrhage (SAH)-induced vasospasm in the basilar artery was examined in a rat model. Arterial vasospasm characterized by increased wall thickness and decreased lumen size was observed at 5 to 7 days after $2^{nd}$ injection of blood into cisterna magna, and these changes were significantly ameliorated by pretreatment of diphenyleneiodonium $(DPI,\;25\;{\mu}l\;of\;100\;{\mu}M),$ an inhibitor of NAD(P)H oxidase. To determine the time course of changes in the vascular NAD(P)H oxidase activity, cerebral vasculature was isolated at different time intervals from 12 hrs to 14 days after injection of autologous blood. At 24 hrs after the second injection of blood, the NAD(P)H oxidase activity was markedly increased with an enhanced membrane translocation of p47phox, but by 48 hours both the enzyme activity and p47phox translocation regained normal values, and were remained unchanged up to 14 days after SAH. However, no significant changes in the expression of p22phox mRNA was observed throughout the experiments. These findings suggest that the activation of NAD(P)H oxidase by which assembly of the oxidase components enhanced and subsequent production of superoxide in the early stages of SAH might contribute to the delayed cerebral vasospasm in SAH rats.

• Molecules and Cells
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• v.25 no.2
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• pp.158-162
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• 2008

Recent molecular genetics studies have revealed that cyclic electron transport around photosystem I is essential for normal photosynthesis and growth of plants. Chloroplastic NAD(P)H dehydorgenase (NDH) complex, a homologue of the complex I in respiratory electron transport, is involved in one of two cyclic pathways. Recent studies on the function and structure of the NDH complex are reviewed.

• The Korean Journal of Zoology
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• v.17 no.4
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• pp.163-166
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• 1974

Malate dehydrogenases of ten bivalved mollusks consist of one or two isozyme, which are species-spcific. It is concluded that the electrophoretic character of the enzyme is available for identification of these ten bivalves.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.2
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• pp.103-109
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• 2003

The cellular mechanisms that contribute to the acceleration of atherosclerosis in diabetes are poorly understood. Therefore, the potential mechanisms involved in the diabetes-dependent increase in vascular smooth muscle cell (VSMC) proliferation was investigated. Using primary culture of VSMC from streptozotocin-induced diabetic rat aorta, cell proliferation assay showed two-fold increase in cell number accompanied with enhanced superoxide generation compared to normal VSMC, 2 days after plating. Both the increased superoxide production and cell proliferation in diabetic VSMC were significantly attenuated by not only tiron (1 mM), a superoxide scavenger, but also by diphenyleneiodonium (DPI; $10{\mu}M$), an NAD(P)H oxidase inhibitor. NAD(P)H oxidase activity in diabetic VSMC was significantly higher than that in control cell, accompanied with increased mRNA expression of p22phox, a membrane subunit of oxidase. Furthermore, inhibition of p22phox expression by transfection of antisense p22phox oligonucleotides into diabetic VSMC resulted in a decrease in superoxide production, which was accompanied by a significant inhibition of cell proliferation. Based on these results, it is suggested that diabetes-associated increase in NAD(P)H oxidase activity via enhanced expression of p22phox contributes to augmented VSMC proliferation in diabetic rats.

• Korean Journal of Microbiology
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• v.12 no.2
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• pp.94-98
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• 1974

This study was conducted from April 1 to September 31, 1973. Ten strains of Fusarium spp. were isolated from the diseased ginseng in two local areas at Kangwha-Gun nad Kumsan-Gun in Korea. Among of them, 2 strains ($G_1$, $G_4$) did not have virulence to ginseng in reinoculation. Their cultural, morphological characteristic and hose virulence to pea seedling were examined. Taxonomical identification of 8 isolates followed by the method of Wollenweber, Snyder nad Toussoun, Booth, Matuo and Snyder. All of eight strains were identified as the Fusarium solani f.sp.pisi(Jones) Synd. et Hans.

• Journal of the Korean Chemical Society
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• v.23 no.4
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• pp.248-258
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• 1979

Glucose 6-phosphate dehydrogenase of Leuconostoc mesenteroides which was purifid by an affinity chromatography was studied on the characterization, kinetics and chemical modification. The apparent molecular weight of the enzyme was 112,000 by the gel filtration method of Sephadex G-200 column. The optimum temperature of $NAD^+$-linked reation was 50$^{circ}C$ and the activation energy and the heat of inactivation were 8.36 kcal/mole and -58.2kcal/mole, respectively. The steady state kinetic study showed KG6P, Kemp, and CX KNADP to be 76.9 PM, 7.46${\mu}M$ and 7.14 ${\mu}M$, respectively, and KGGP, KNAD,and aKNm to be 53.7${\mu}M$, 115.2${\mu}M$ and 702.2${\mu}M$ for the $NAD^+$-linked reaction at pH 7.8, optimum pH. The pH dependent kinetic constants suggested that the two ionizing groups whose pKa is 7.2 .and pKb is 9.0-9.6 were involved in the enzyme-substrate interaction. Evidence by photooxidation and carboxymethylation of the enzyme suggested that the imidazole group of histidine with pKa group may participate in the catalytic site.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.213-218
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• 2010

Lactate dehydrogenases (LDHs) have been highly focused for long time, due to their important roles in biochemical and metabolic pathways of cells. On the basis of genome-wide searching results, three putative LDH genes from Bacillus cereus ATCC 14579 genome have been PCR-amplified, cloned, and well-expressed in E. coli. All three BcLDH isozymes are supposed to share highly conserved catalytic amino acid residues in common $NAD^+$-dependent LDHs. Meanwhile, BcLDH1 consisting of 314 amino acids shares 86 and 49% of identities with BcLDH2 and 3, respectively. Interestingly, only BcLDH1 showed the converting activities between L-lactate and pyruvate in the presence of $NAD^+$ coenzyme, while the other isozymes are likely to have almost no activity. As a result, it was revealed that BcLDH1 can be a typical $NAD^+$-dependent L-lactate-specific dehydrogenase.

• Korean Journal of Medicinal Crop Science
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• v.21 no.2
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• pp.91-96
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• 2013

This study describes the identification of Panax species using mitochondrial consensus primers. Initially, a total of thirty primers were tested in ten Korean ginseng cultivars and two foreign Panax species, P. quinquefolius and P. notoginseng. In the polymerase chain reaction (PCR) amplification results, three primers (cox1, nad1/2-3 and nad2/1-2) generated co-dominant polymorphic banding patterns discriminating Korean ginseng cultivars from P. quinquefolius and P. notoginseng. However, these primers could not generated polymorphisms among the Korean ginseng cultivars, and simply represented species-specific polymorphisms for P. quinquefolius and P. notoginseng. Primers PQ91 and PN418 were designed from the consensus sequence of nad1/2-3 region. Two banding patterns (A or B) were detected in PQ91. Korean ginseng cultivars and P. notoginseng shared the same banding pattern (A type) and P. quinquefolius was identified another banding pattern (B type). In the case of PN418, two banding patterns (A or B) were detected in the Korean ginseng cultivars and two foreign Panax species. Korean ginseng cultivars and P. quinquefolius shared the same banding pattern (A type) and P. notoginseng was identified another banding pattern (B type). The combination banding patterns of three Panax species, Korean ginseng cultivars (Panax ginseng C. A. Mey.), P. quinquefolius and P. notoginseng, was identified as 'AA', 'BA' and 'AB', respectively. Consequently, PQ91 and PN418 primer sets can be used to distinguish among Panax species.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.304-310
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• 1986

A. calcoaceticus C10 grown on cyclohexanol as sole source of carbon and energy produced cyclohexanol dehydrogenase(CDH) and glucose dehydrogenase (GDH) concomitantly. CDH and GDH were different in coenzyme, induction and electrophoretic patterns. CDH depended for activity on $NAD^+$ only, while GDH required $NAD^+$ or $NADP^+$ alternatively. CDH was produced in the medium added cyclohexanol, but GDH was produced in various media such as LB, LB added 0.2% glucose or cyclohexanol and cyclohexanol medium. Productivity of CDH in A. calcoaceticus C10 was enhanced about 8 times by the addition of 0.2% cyclohexanol to LB medium after 4 hours as much as LB medium only. Production of CDH was induced by cyclohexanol, cyclohexanone, cyclohexan-1,2-diol and cyclohexene oxide, but not induced by ${\varepsilon}-caprolactone$ and adipate.