• BMB Reports
• /
• 제32권2호
• /
• pp.203-209
• /
• 1999

Three-week grown Arabidopsis thaliana leaves were wounded by cutting whole leaves with a razor blade into pieces (about$3\;mm\;{\times}\;3\;mm$) submerged in various solutions, and incubated in a growth chamber for 24 h. We measured and compared activities of several enzymes such as phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), thioredoxin, thioredoxin reductase, thioltransferase, glutathione reductase, and $NADP^+$ -malate dehydrogenase. PAL activity was decreased in $HgCl_2$-, $CdCl_2$-, and glyphosate-treated leaf slices, and could not be detected after treatment with $CdCl_2$. TAL activity was found to be maximal in the $CdCl_2$-treated leaf slices. Activity of thioredoxin, a small protein known as a cofactor of ribonucleotide reductase and a regulator of photosynthesis, was significantly increased in the $CdCl_2$-treated leaf slices, while thioredoxin reductase activity was maximal in the $HgCl_2$-treated leaf slices. Thioltransferase and glutathione reductase activities were significantly decreased in the $HgCl_2$-treated leaf slices. $NADP^+$ -malate dehydrogenase activity remained relatively constant after the chemical treatments. Our results strongly indicate that sulfhydryl-related and phenylpropanoid-synthesizing enzyme activities are affected by chemical treatments such as hydrogen peroxide, heavy metals, and glyphosate.

• BMB Reports
• /
• 제43권4호
• /
• pp.245-249
• /
• 2010

GDH has been known to be related with hyperinsulinism-hyperammonemia syndrome. We have screened new drugs with a view to developing effective drugs modulating GDH activity. In the present work, we investigated the effects of a new drug, KHG26377 on glutamate formation and GDH activity in cultured rat islets. When KHG26377 was added to the culture medium for 24 h prior to kinetic analysis, the $V_{max}$ of GDH was decreased by 59% whereas $K_m$ is not significantly changed. The concentration of glutamate decreased by 50% and perfusion of islets with KHG26377 reduced insulin release by up to 55%. Our results show that KHG26377 regulates insulin release by inhibiting GDH activity in primary cultured islets and support the previous studies for the connection between GDH activity and insulin release. Further studies are required to determine in vivo effects and pharmacokinetics of the drug.

• Applied Microscopy
• /
• 제28권4호
• /
• pp.563-575
• /
• 1998

To investigate the changes during the differentiation of the cerebral neurons of chick embryo of tne embryogenic day (ED) 7 and 8, the ultrastructural changes in the cerebral neurons, the activity of dehydronases (LDH, MDH and SDH), protein expression profile and adenosine triphosphate concentration were analyzed. In ED 7 chick embryos, relatively large nucleus, centrally located nucleolus, evenly spread chromatin over nucleoplasm, and prominent nuclear envelope were observed. Oval-shaped mitochondria with well-developed cristae were present over entire cytoplasm. In ED 8 chick embryos, evenly spread chromatin over nucleoplasm, and prominent nuclear envelope were observed. In the cytoplasm, well-developed rough endoplasmic reticulum and Golgi complex were observed. In ED 7 chick embryos and ED 8 chick embryos, 31 polypeptide bands and 34 polypeptide bands were observed, respectively. The activities of dehydrogenases were lower in ED 7 chick embryos than in ED 8 chick embryos. LDH activity was 8.16 (ED 7) and 9.28 (ED 8), MDH activity was 7.98 (ED 7) and 10.10 (ED 8), and SDH activity was 5.49 (ED 7) and 7.14 (ED 8) respectively. The ATP concentration remained unchanged over ED 7 and 8.

• 생명과학회지
• /
• 제28권1호
• /
• pp.1-8
• /
• 2018

젖산탈수소효소(Lactate dehydrogenase, EC 1.1.1.27, LDH)의 기능을 확인하기 위해서 Ldh testis-specific C가 발현된 생쥐(Mus musculus)를 48 hr과 96 hr 기아상태로 유지시킨 후 조직들의 LDH 대사를 LDH 활성, 역학 및 동위효소를 분석하여 연구하였다. 골격근, 간 및 눈조직에서 LDH와 LDH $A_4$활성이 증가되어 혐기적 대사가 우세하였고, 심장과 신장조직의 LDH 활성은 감소되지만 LDH $B_4$ 활성이 증가되어 피루브산을 생성하는 호기적 대사가 우세하였다. 하지만 정소조직에서는 LDH $C_4$가 감소되었고, 뇌조직의 LDH 활성은 조직 중에서 가장 많이 증가되었지만 동위효소의 변화가 작고 피루브산의 양이 감소되었다. 신장조직을 제외한 조직들에서 $K{_m}^{PYR}$이 증가되어 피루브산에 대한 친화력이 감소된 것으로 확인되었다. 실험결과 Ldh-A, B가 발현된 조직에서는 상대 농도가 큰 동위효소의 활성이 증가되었으나 Ldh-A, B, C가 발현된 정소조직은 LDH $C_4$가 감소되어 기능이 저하되었으며 특히 뇌조직에서 LDH는 피루브산 환원효소로서 역할을 하는 것으로 확인되었다. 따라서 이 과정은 기아상태에서 에너지를 생성하는 기작이 될 수 있는 것으로 사료된다.

• 한국식품영양과학회지
• /
• 제30권4호
• /
• pp.679-683
• /
• 2001

본 실험은 알코올 투여한 흰쥐를 대상으로 콩나물, 솔잎, 표고버섯과 오가피 추출물의 알코올 탈수소효소 활성과 항산화 효과를 비교하기 위해 수행되었다. 약 200g 정도의 Sprague-Dawley계 쥐들을 정상군, 알코올 단독투여군, 4가지 식물추출물 투여군으로 나우어서, 각 식물추출물을 알코올을 주입하기 전 8일 동안 200mg/kg b.w. 을 하루에 한번 경구투여하였다. 모든 동물은 알코올을 주입하고 90분 후에 도살시켰다. 콩나물과 솔잎추출물 투여군의 혈중 알코올 농도는 알코올 단독투여군, 표고버섯, 오가피군 보다 유의적으로 낮게 나타났다. 또한 콩나물과 솔잎 추출물 투여군의 알코올 탈수소효소활성은 알코올 단독투여군과 표고버섯, 오가파군보다 유의적인 증가를 보여주었다. Catalase 활성은 식물추출물 투여군이 알코올 단독투여군보다 다소 높게 나타났지만, 유의성 있는 차이는 보이지 않았다. 이러한 결과는 흰쥐에게 일회성으로 알코올을 다량 투여했을 때 알코올 탈수소효소가 catalase보다 우선적으로 알코올 대사에 반응함을 보여준다. 모든 식물추출물 투여군들의 지질과산화와 glutathione peroxidase 활성은 알코올 단독투여군보다 유의적으로 낮게 나타났다. 이 결과는 본 실험에 사용된 식물추출물들이 알코올의 산화에 대한 항산화 효과를 가진다는 것을 보여주며, 특히 콩나물과 솔잎 추출물 투여군이 알코올 탈수소효소의 활성증가오 항산화에 대한 효과가 높음을 보여주었다.

• 한국동물학회지
• /
• 제12권2호
• /
• pp.50-56
• /
• 1969

붕어, 비둘기, 흰쥐의 肝組織內의 蛋白質含量과 蛋白質代謝에 관하여는 GDH, GOT 및 GPT의 活性과 比較活性, 그리고 GDH 同位酵素를 測定하였다. 1. 蛋白質含量은 흰쥐, 비둘기가 各各 22.0$\pm$0.01mg/ml 및 22.0$\pm$0.16으로서 거의 같은 量의 蛋白質含量으로 組成되었으나 붕어의 肝臟組織內 蛋白質含量은 約 60%에 該當하는 13.0$\pm$0.09이었다(p < 0.01). 2. Glutamic transaminase는 흰쥐, 비둘기, 붕어의 순위로 그 活性度가 낮았다. 卽 GPT의 比較活性은 各各 3.77$\pm$0.18 unit/mg, 1.93$\pm$0.01 및 0.71$\pm$0.07 이었으며 GOT는 8.23$\pm$0.06 unit/mg, 3.95$\pm$0.09 및 0.92$\pm$0.01이었다(p < 0.01). 3. GOT/GDT 比는 흰쥐, 비둘기, 붕어에서 各各 0.20$\pm$0.004, 0.22$\pm$0.005 및 0.20$\pm$0.002로서 별 차이 없었다. 4. GDH 比較活性은 비둘기가 가장 높은 35.7$\pm$0.81 unit/mg이고 붕어는 9.6$\pm$0.16, 흰쥐는 20.5$\pm$0.81이었다. 5. Glutamic transaminase 와 GDH 比較活性이 動物의 種類에 따라 병행하였으며 特히 進化過程과 一致되는 것으로 思料된다. 6. GDH 同位酵素의 樣相은 種特異性이 뚜렷하였다. 흰쥐에서는 음극이 遲延性易動度區劃의 活性이 가장 높았으나, 비둘기에서는 兩極性區劃의 活性이 가장 높았다. 特히 魚類에서는 陰極性區劃이 全然 發見되지 않았으나 兩極性에 4個의 區劃을 볼수 있었다.

• 한국물환경학회지
• /
• 제26권4호
• /
• pp.574-579
• /
• 2010

In this study the enzyme inhibition method using dehydrogenase which has been popularly used to estimate ecotoxicity was optimized. When three bacterial strains, Escherichia coli HB101, Enterobacter asburiae KCAD-4, and Aeromonas media KCAD-13, were compared, KCAD-4 was considered as the adequate strain to estimate toxicity because of its sensitivity and reproducibility. The optimal bacterial density was estimated as $5.4{\times}10^9CFU/mL$, at which the maximum sensitivity was observed. The phosphate buffer was suitable for the reaction solution. When the reaction times required for inhibition of enzyme activity by contact of toxicants and for reaction of damaged bacteria and substrate were tested, the optimal value was estimated as 20 min and 2 hrs, respectively. It is expected that the optimized conditions can be used to develop the standardized kits to estimate ecotoxicity of heavy metals in effluent from the industrial wastewater treatment facilities.

• Journal of Microbiology and Biotechnology
• /
• 제13권4호
• /
• pp.628-631
• /
• 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 $NAD^+$.

• Journal of Microbiology and Biotechnology
• /
• 제13권5호
• /
• pp.738-744
• /
• 2003

The gene ADH encoding NAD-dependent alcohol dehydrogenase from Bacillus stearothennophilus was cloned and overexpressed as a GST fusion protein at a high level in Escherichia coli. The expressed fusion protein was purified simply by glutathione affinity chromatography. GST fusion protein was then cleaved by thrombin, while soluble enzyme was further purified by glutathione affinity chromatography. The recombinant enzyme had the same elctrophoretic mobility as the native enzyme from Bacillus stearothennophilus. The recombinant enzyme catalyzed the oxidation of a number of alcohols and exhibited high activities towards secondary alcohols. The $K_m\;and\;V_{max}$ values of the recombinant enzyme for ethanol were 5.11 mM and 61.35 U/mg, respectively. Pyridine and imidazole notably inhibited the enzymatic activity. The activity of the recombinant enzyme optimally proceeded at pH 9.0 and $70^{\circ}C$. The midpoint of the temperature-stability curve for the recombinant enzyme was approximately $68^{\circ}C$, and the enzyme was not completely inactivated even at $85^{\circ}C$. The recombinant enzyme showed a high resistance towards denaturing agents (0.05% SDS, 0.1 M urea). Therefore, due to its stability and relatively broad substrate specificity, the recombinant enzyme could be utilized in bio-industrial processes and biosensors.

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