• Molecules and Cells
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• 제25권2호
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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.

• 한국동물학회지
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• 제17권4호
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• pp.163-166
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• 1974

Cellulose acetate 전기영동법으로 부족류의 MDH isozyme 은 1$\\sim$2개의 band로 구성되어 있음을 알았다. 이들 부족류의 MDH isozyme은 종에 따라 특징적이므로 생화학적인 다양성의 한가지 증거라 할 수 있다. 그러나 MDH isozyme pattern은 계통상의 유연 관계를 뚜렸하게 나타내고 있지는 않다. 몇 가지 실험하여본 종에 있어서 NAD-MDH 다형현상이 나타나지 않았다.

• Archives of Pharmacal Research
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• 제18권2호
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• pp.100-104
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• 1995

Lys-228 in horse liver alcohol dehydrogenase isoenzyme E(HLADH-E) was mutated to glycineby site-directed mutagenesis. The specific activity of the mutant enzyme was increased about 4-fold nad Michaelis constants for $NAD^+(K_a){\;}and{\;}NADH(K_q)$ increased by about 350-and 50-fold, respectively. The wild-type enzyme and K228TG mutant enzyme were treated with ethylacetimidate. Acetimidylation of the wild-type enzyme increased the activity about 10-fold, but the mutant enzyme ws little affected. These results confirm that Lys-228 residue plays an important role in the activity of the enzyme through forming the hydrogen bond with adenosine ribose of $NAD^+$.

• Molecules and Cells
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• 제24권3호
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• pp.351-357
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• 2007

Regions (about 3.7-3.8 kb) of the mitochondrial genomes (rrnL-cox1) of two tardigrades, a heterotardigrade, Batillipes pennaki, and a eutardigrade, Pseudobiotus spinifer, were sequenced and characterized. The gene order in Batillipes was $\underline{rrnL}-\underline{V}-\underline{rrnS}-\underline{Q}-\underline{I}$-M-nad2-W-$\underline{C}-\underline{Y}$-cox1, and in Pseudobiotus it was $\underline{rrnL}-\underline{V}-\underline{rrnS}-\underline{Q}$-M-nad2-W-$\underline{C}-\underline{Y}$-cox1. With the exception of the trnI gene, the two tardigrade regions have the same gene content and order. Their gene orders are strikingly similar to that of the chelicerate Limulus polyphemus (rrnL-V-rrnS-CR-I-Q-M-nad2-W-C-Y-cox1), which is considered to be ancestral for arthropods. Although the tardigrades do not have a distinct control region (CR) within this segment, the trnI gene in Pseudobiotus is located between rrnL-trnL1 and trnL2-nad1, and the trnI gene in Batillipes is located between trnQ and trnM. In addition, the 106-bp region between trnQ and trnM in Batillipes not only contains two plausible trnI genes with opposite orientations, but also exhibits some CR-like characteristics. The mitochondrial gene arrangements of 183 other protostomes were compared. 60 (52.2%) of the 115 arthropods examined have the M-nad2-W-C-Y-cox1 arrangement, and 88 (76.5%) the M-nad2-W arrangement, as found in the tardigrades. In contrast, no such arrangement was seen in the 70 non-arthropod protostomes studied. These are the first non-sequence molecular data that support the close relationship of tardigrades and arthropods.

• Molecules and Cells
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• 제41권4호
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• pp.331-341
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• 2018

L-pipecolic acid is a non-protein amino acid commonly found in plants, animals, and microorganisms. It is a well-known precursor to numerous microbial secondary metabolites and pharmaceuticals, including anticancer agents, immunosuppressants, and several antibiotics. Lysine cyclodeaminase (LCD) catalyzes ${\beta}$-deamination of L-lysine into L-pipecolic acid using ${\beta}$-nicotinamide adenine dinucleotide as a cofactor. Expression of a human homolog of LCD, ${\mu}$-crystallin, is elevated in prostate cancer patients. To understand the structural features and catalytic mechanisms of LCD, we determined the crystal structures of Streptomyces pristinaespiralis LCD (SpLCD) in (i) a binary complex with $NAD^+$, (ii) a ternary complex with $NAD^+$ and L-pipecolic acid, (iii) a ternary complex with $NAD^+$ and L-proline, and (iv) a ternary complex with $NAD^+$ and L-2,4-diamino butyric acid. The overall structure of SpLCD was similar to that of ornithine cyclodeaminase from Pseudomonas putida. In addition, SpLCD recognized L-lysine, L-ornithine, and L-2,4-diamino butyric acid despite differences in the active site, including differences in hydrogen bonding by Asp236, which corresponds with Asp228 from Pseudomonas putida ornithine cyclodeaminase. The substrate binding pocket of SpLCD allowed substrates smaller than lysine to bind, thus enabling binding to ornithine and L-2,4-diamino butyric acid. Our structural and biochemical data facilitate a detailed understanding of substrate and product recognition, thus providing evidence for a reaction mechanism for SpLCD. The proposed mechanism is unusual in that $NAD^+$ is initially converted into NADH and then reverted back into $NAD^+$ at a late stage of the reaction.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2863-2866
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• 2014

• 대한화학회지
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• 제23권4호
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• pp.248-258
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• 1979

저자들은 Cibacron Blue F3G-A Separose 컬럼 어피니티크로마토그래피에 의하여 GIn-cose-6-phosphate dehydrogenase를 Leuconostoc mesenteroides로부터 순수 분리한 바 있다. 이 효소를 사용하여 효소특성을 조사한 결과 분자량은 Sephadex G-200 컬럼에 의해 112,000이었으며 최적온도는 50$^{\circ}$, 활성화에너 지는 8.36kcal/mole 불활성화에너지는 -58.2kcal/mole로 나타났다. $NADP^+$를 조효소로 사용하였을때 최적 pH7.8에서 K_{G6p}:76.9${\mu}$M, ${\alpha}K_{NADP}:\;7.46{\mu}M,\;{\alpha}KNNADP:\;7.l4{\mu}M$이었으며 같은 조건에서 $NAD^+$를 조효소로 사용하였을때 $K_{G6P}:\;53.65{\mu}M,\;K_{NAD}:\;115.2{\mu}M\;{\alpha}K_{NAD}:\;707.2{\mu}M$이었다. 따라서 $NADP^+$ 및 $NAD^+$를 조효소로 사용한 경우에 있어서 ${\alpha}$ 값은 각각 1과 6으로 나타났다. pH변화에 따른 반응속도상수의 변화에 의하면 $NAD^+$를 조효소로 하였을때 최적 pH는 7.8 이었고 pKa가 7.2인 활성기와 ${\mu}Kb$가 9.0∼9.6인 활성기가 효소와 기질의 상호작용에 관여함을 알았다. 이중 pKa 7.2인 활성기를 밝히기 위하여 효소를 광산화와 carboxymethylation을 시킨결과 histidine의 imidazole기임을 알수 있있다.

• 미생물학회지
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• 제46권2호
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• pp.213-218
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• 2010

Lactate dehydrogenases (LDHs)는 세포 내의 생화학적 대사경로에서 중요한 역할을 담당하는 효소로서 오랜 동안 많은 관심을 받았다. 본 연구에서는 다양한 미생물 genome database의 탐색을 통해 Bacillus cereus ATCC 14579 genome으로부터 LDH로 추정되는 3종의 유전자를 발견하고, 대장균에서 클로닝 및 대량 발현하였다. 모든 BcLDH 동질효소들의 상동부위 아미노산 잔기 대부분이 기존의 $NAD^+$-의존형 LDH와 높은 상동성을 보였다. 한편 314개의 아미노산으로 이루어진 BcLDH1과 2는 86%의 서열 상동성을 보였으나, BcLDH3와는 49%의 상동성을 나타냈다. 흥미롭게도 BcLDH1만이 $NAD^+$ 조효소 존재 하에서 L-lactate와 pyruvate 간의 상호전환 활성을 나타냈으며, 그 외의 동질효소들은 거의 활성을 보이지 않았다. 결론적으로 BcLDH1은 전형적인 $NAD^+$-의존형이며, L-lactate에 특이적인 dehydrogenase 효소임을 확인하였다.

• Journal of Preventive Medicine and Public Health
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• 제3권1호
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• pp.111-119
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• 1970

Alterations of H-and M-isozymes of Lactic Dehydrogenase(LDH) were observed in the various tissues after exposing the rats to 50ppm and 250ppm of sulfur dioxide. These isozymes of the respective tissue were separated by Diethlaminoethyl (DTAE)-cellulose from the tissue homogenates of brain, lung and muscle, presenting the activities by rate of reduction of nicotinamide-adenine-dinucleotide ($NAD^+$). Pure LDH and the coenzyme ($NAD^+$) were directly treated with sulfur dioxide in vitro in order to find out the direct to sulfur dioxide on LDH and $NAD^+$ and the results were as follows. 1. In the normal tissues, the H-isozyme activity was dominant in the brain and heart, and the M-isozyme in the muscle. 2. In the lung tissue of normal rats, there was no difference between the activity of H-and M-type of LDH. 3. When rats inhale sulfur dioxide gas in concentration of 50ppm and 250ppm, it appeared that the H-type tend to be suppressed in aerobic tissues and the M-type in anaerobic tissues. 4. In the lung tissue exposed to sulfur dioxide, both the LDH activities were suppressed. 5. It seems that LDH and the coenzyme ($NAD^+$) are not directly affected by exposing in sulfur dioxide gas.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2010년도 정기총회 및 춘계학술발표회
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• pp.15-15
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• 2010

Koran ginseng(Pnax ginseng) is one of the most important medicinal plants in Orient. Among the nine cultivars of Korea ginseng, Chunpoong commands a much greater market value and has been planted widely. A rapid and reliable method for discriminating the Chunpoong cultivar was developed by exploiting a single nucleotide polymorphism (SNP) in the mitochondrial nad7 intron 4 region of nine Korea ginseng cultivars using universal primers. A SNP was detected between Chunpoong and other cultivars and modified allele-specific primers were designed from this SNP site to effective method for the geneic identification of the Chunpoong cultivar of ginseng.