• 미생물학회지
• /
• 제34권4호
• /
• pp.207-211
• /
• 1998

메탄올을 이용하여 성장하는 Methylovorus sp. strain SS1은 formaldehyde의 산화를 위한 linear route의 주효소인 $NAD^+$-linked formaldehyde dehydrogenase 및 $NAD^+$-linked formate dehydrogenas와 cyclic route의 주효소인 hexulose-6-phosphate synthase, glucose-6-phosphate isomerae, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase 등의 활성을 나타내었는데, cyclic route에 관여하는 효소의 활성이 상대적으로 더 높았다. 이 세균은 formaldehyde의 동화와 관련된 ribulose monophosphate 경로의 주효소와 Entner-Doudoroff 경로의 주효소 및 transaldolase 활성과 함께 세포외 다당류 합성과 관련된 phosphoglucomutase, UDP-glucose pyrophyosphorylase, mannose-6-phosphate isomerase의 활성도 나타내었다. 2.3 mM의 ammonium sulfate가 포함된 배지에서 성장한 세균은 7.6 mM의 ammonium sulfate가 포함된 배지에서 성장한 세균보다 더 많은 세포외 다당류를 생산하였지만 균체 수율은 낮았고, 6-phosphogluconate dehydrogenase와 phosphoglucomutase 및 UDP-glucose pyrophoshorylase의 활성은 높게 나타내었으나 6-phosphogluconate dehydratase/2-keto-3-deoxy-6-phosphogluconate aldolase의 활성은 낮았다.

• Environmental Analysis Health and Toxicology
• /
• 제18권4호
• /
• pp.305-310
• /
• 2003

A rapid, inexpensive enzymatic method is proposed for indirect water quality testing in terms of heavy metal toxicity. The activity of glucose-6-phosphate dehydrogenase was applied for heavy metal toxicity test as an effective criterion in water quality. The toxicity of Pb (lead) and Cd (cadmium) for water flea, Moina macrocopa, were evaluated for 2-8 days with variables of mobilization ability. And the reproduction impairment of Moina macrocopa were investigated as the parameter of chronic toxicity test for Pb and Cd. As a result, the EC$_{50}$ for immobilization of Moina macrocopa were Pb and Cd were 1.6749 and 0.4683, respectively. The values of reproductive impairment to Moina macrocopa for Pb and Cd were 9.5938 and 8.3264 in EC$_{50}$ A significant alteration of G6PDH (Glucose-6-phosphate dehydrogenase) activity of Moina macrocopa was observed when Cd and Pb were treated in media. The results obtained indicate that G6PDH activity of Moina macrocopa can be used as an indicative parameter in aquatic toxicity tests for heavy metals.als.

• 대한화학회지
• /
• 제12권4호
• /
• pp.142-145
• /
• 1968

The relative activity of glucose-6-phosphate dehydrogenase in E. coli was measured at 340 $m\mu$ with a spectrophotometer. The synchronized E. coli cells in exponential phase were treated with Phage($T_2$) ghost, and used as a enzyme solution directly. This assay method supposed to be useful for the continuous determination of enzyme activity in E. coli.

• Journal of Plant Biology
• /
• 제27권2호
• /
• pp.73-80
• /
• 1984

Palmitoyl CoA was found to inhibit corn embryo axis glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, which were also inhibites by polyamines. However, reversal of inhibition of both enzymes by palmitoyl CoA was made by spermine. Activity of corn embryo axis protein kinase was found to increase steadily after germination. Activation and inhibition of protein kinase were made by MgCl$_2$and all polymines, respectively. Suc results suggest that fatty acid biosynthesis and lypolysis could be regulated to some extent by polyamines in corn embryo axis.

• Journal of Ginseng Research
• /
• 제22권1호
• /
• pp.51-59
• /
• 1998

In this study, rat hepatocytes known to have active glucose metabolism were obtained to investigate the hypoglycemic action of fat soluble fraction of red ginseng by using the liver perfusion technique and incubated in two different media-one containing insulin and glucagon (control group), and the other containing glucagon only The activities of main regulating enzymes, such as glucokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenate, and glucose 6-phosphatase, related to metabolic pathways of glucose in these two kinds of hepatocytes were compared between these two groups and the effects of addition of fat soluble fraction ($10^1$~$10^4$%) from red ginseng to these two groups on these enzymes were also detected. The results were as follows. The specific activity of enzymes such as glucokinase, flucorse 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase related to glucose-consuming pathways of insulin-deficient group was much less than control one. However, their decreased activity was recovered after the addition of fat-soluble fraction at all range of concentrations. The specific activity of these enzymes after the addition of ginseng components to the control group was also increased. On the other hand, the specific activity of glucose 6-phosphatase related to glucose-producing pathway of insulin-deficient group was much higher than control one, but their increased activity was decreased obviously after the addition of fat soluble fraction at all range of concentrations. The same results were observed after the addition of fat-soluble fraction to the control group. These results suggest that the red ginseng saponin components might be effective on diabetic hyperglycemia by regulating the activity of enzymes related to glucose metabolism directly and/or indirectly. The effects of fat-soluble fraction ($10^2$%) and ginsenosides (mixture, $Rb_1$ and $Rg_1$, $10^4$%) on hypoglycemic action were compared. As a result, they showed considerable effect on hyperglycemia, but the best eff ect on the activities of glucokinase and glucose 6-phosphate dehydrogenase was appeared by ginsenoside $Rb_1$ and that of 6-phosphogluconate dehydrogenase and glucose 6-phosphatase was by ginsenoside mixture.

• 미생물학회지
• /
• 제21권4호
• /
• pp.221-228
• /
• 1983

Saccharomyces cerevisiae로 부터 glucose-6-phosphate dehydrogenase을 신속하고 간편하게 정제하는 과정을 affinity chromatography를 이용하여 개발하였다. 이 효소를 정제하는데 적절한 affinity medium을 조사해 본 결과, $NADP^+ -agarose$와 Affi-gel Blue(Cibacron Blue F3GA)가 Affi-gel Red(Procion Red HE-3B), AMP-agarose, ATP-agarose, 그리고 $NADP^+ -agarose$보다 유용함이 밝혀졌다. 이 두가지 affinity media에 흡착된 효소를 분리 하는데 가장 적합한 elution 조건을 조사하였는데 KCI gradient( (0-1.OM)가 효소의 순도 및 수회율을 가장 높일 수 있는 적합한 방법이었다. 특히 Affi-gel Blue를 사용할 경우, KCI gradient로 효소를 용출시키기 전에 NAD-(15mM)로NAD+에 친화역을 갖는 효소들을 제거하는 것이 enzyme의 순도를 높이는데 매우 효과적이었다. 그 결과 glucose-6-phosphate dehydrogenase를 baker's yeast로 부터 기존의 간단한 정제 과정과 affinity chromatography를 병행한 방식을 샤용하여 분리 하였는데, affinity medium으로 Affi-gel Blue를 사용했을 때는 180배 정도, NADP+-agarose를 사용했을 때는 2,000배 정도로 정제 되었다. 대량으로 glucose-6-phosphate dehydrogenase를 정제하는 경우, Affi-gel Blue를 사용하던 효소의 순도는 NADP+-agarose보다 낮으나, 효소의 회수율은 훨씬 더 높았다. 또한 G-6-P dehydrogenase에 대한 affinity medium의 capacity도 Affi-gel Blue가 NADP+-agarose보다 5배정도 높았으며 더우기 Affi-gel Blue는 여러번 반복적으로 사용될 수 있고, 그 제조 과정도 NADP+-agarose보다 간단하며 경비도 적게 들었다.

• 대한의생명과학회지
• /
• 제3권2호
• /
• pp.169-175
• /
• 1997

닭의장풀 추출액을 쥐의 체중 1 kg 당 40 mg의 alloxan을 미정맥 주사한 당뇨쥐를 실험군으로 하여 혈당강하효과를 보았다. 정상대조군에게는 0.9% saline용액을 투여하고 당뇨쥐에게는 쥐의 체중 1 kg당 100 mg의 식물단백추출액을 경구투여하여 683.6$\pm$115.61 (mg/dl)에서 85.6$\pm$43.34 (mg/dl)의 혈당치의 정상수준으로 회복하는 경향을 확인하였다. 정상군과 당뇨대조군, 약물투여군으로 나눈 실험쥐를 대상으로 간조직에서의 glucose-6-phosphate dehydrogenase (G6PD) 효소의 활성도를 측정한 결과 당뇨대조군에서는 정상군의 34.2%로 G6PD 효소 활성도가 감소되었으며 식물추출액을 투여함으로써 정상치의 61%로 회복되었다. 실험쥐 간조직내에 G6PD효소활성도의 감소 또는 회복과 G6PD isozyme분자의 구조변화와의 연관성을 알아보기 위하여 native gel 전기영동을 실시하였다. 정상쥐의 간조직에서의 G6PD isozyme형태는 band I, II, III(전기영동상의 분자이동 차이에 따른 형태)로 나타났고 alloxan을 투여한 당뇨쥐의 간조직내에서는 band I, III만이 나타났다. 닭의장풀 추출액을 투여 한 실험 군에서는 G6PD의 isozyme 형태가 정상쥐의 경우에서와 같이 band I, II와 III가 모두 나타났다. 이러한 결과는 G6PD isozyme의 구조변화가 G6PD의 효소활성도와 매우 큰 연관성이 있는 것으로 보여진다.

• Nutrition Research and Practice
• /
• 제2권2호
• /
• pp.80-84
• /
• 2008

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ${\sim}5$ fold and glucose 6-phosphate dehydrogenase activities were decreased by ${\sim}25%$ compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased siguificantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to fimction in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.

• 한국동물학회지
• /
• 제17권1호
• /
• pp.17-22
• /
• 1974

Pentose phosphate shunt의 첫 작용때 나타나는 효소 glucose-6-phosphate dehydorgenase의 활성을 출생전 및 출생후 연령에 따라서 쥐(white rat)의 간세포를 암수 성별로 spectrophotometer를 써서 측정하였다. 이 활성이 16일 된 배에서 가장 높았고 (54 I.U.), 그때부터 출생후 13일 까지 조금씩 저하되지만 (17 I.U.), 다시 서서히 증가해서 19일에는 53 I.U.까지 높아졌다. 성별로 본 결과는 일반적으로 수컷보다 암컷에서 G-6-PD의 활성이 약간 높게 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제29권4호
• /
• pp.577-586
• /
• 2019

The engineered Aspergillus oryzae has a high NADPH demand for xylose utilization and overproduction of target metabolites. Glucose-6-phosphate dehydrogenase (G6PDH, E.C. 1.1.1.49) is one of two key enzymes in the oxidative part of the pentose phosphate pathway, and is also the main enzyme involved in NADPH regeneration. The open reading frame and cDNA of the putative A. oryzae G6PDH (AoG6PDH) were obtained, followed by heterogeneous expression in Escherichia coli and purification as a his6-tagged protein. The purified protein was characterized to be in possession of G6PDH activity with a molecular mass of 118.0 kDa. The enzyme displayed maximal activity at pH 7.5 and the optimal temperature was $50^{\circ}C$. This enzyme also had a half-life of 33.3 min at $40^{\circ}C$. Kinetics assay showed that AoG6PDH was strictly dependent on $NADP^+$ ($K_m=6.3{\mu}M$, $k_{cat}=1000.0s^{-1}$, $k_{cat}/K_m=158.7s^{-1}{\cdot}{\mu}M^{-1}$) as cofactor. The $K_m$ and $k_{cat}/K_m$ values of glucose-6-phosphate were $109.7s^{-1}{\cdot}{\mu}M^{-1}$ and $9.1s^{-1}{\cdot}{\mu}M^{-1}$ respectively. Initial velocity and product inhibition analyses indicated the catalytic reaction followed a two-substrate, steady-state, ordered BiBi mechanism, where $NADP^+$ was the first substrate bound to the enzyme and NADPH was the second product released from the catalytic complex. The established kinetic model could be applied in further regulation of the pentose phosphate pathway and NADPH regeneration of A. oryzae to improve its xylose utilization and yields of valued metabolites.