• 한국미생물·생명공학회지
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• 제25권1호
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• pp.37-43
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• 1997

Triphenylmethane was decolorized rapidly by enterbacter cloacae MG 82 at initial reaction time. The spheroplast showed higher activity of triphenylmentane decolorization than that of intact cell suspension. The outer part of the bacterial cell envelope and the peptidoglycan are important for the function of transport barrier of triphenylmethane. In intact cell, decolorization activity was higher at 37$\circ $C than at $\circ $C, indicating that triphenylmethane decolorization is due to the enzyme reaction. Culture filtrate showed no decolorization activity, while cell-free extract appeared high activity of 1.45 units, clearly showing that decolorization activity was due to the cell-free extract. Comparing decolorization activities of cell fractions, it was found that decolorization activity was located at the compartment of cytoplasmic membrane. The enzyme activity was also shown to be Mg$^{++}$-dependent. The optimum pH and temperature of enzyme activity were 7.0 and 50$\circ $C, respectively. The thermostability of this enzyme at 35$\circ $C was kept to 58% for 3 hours.

• Archives of Pharmacal Research
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• 제26권10호
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• pp.826-831
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• 2003

ADP-ribose pyrophosphatase (ADPRase) hydrolyzes ADP-ribose (ADPR) into AMP and ribose-5'-phosphate. It is classified into two groups, $Mg^{2+}$-dependent and $Mg^{2+}$-independent ADPRase, depending on its $Mg^{2+}$requirement. Here, we purified $Mg^{2+}$-dependent ADPRase from rabbit liver and examined what factors affect $Mg^{2+}$ requirement. The purified enzyme showed a single band with the molecular weight of 34 kDa on SDS-PAGE both in the presence and absence of 2-mercaptoethanol. The molecular weight of the native enzyme calculated by gel filtration was 68 kDa, indicating that ADPRase is a dimer made up of two identical subunits. $Mg^{2+}$-dependent ADPRase with the highest ADPR affinity had a $K_m$ of 160$\pm$10 $\mu$M and a pH optimum of around pH 9.5. Treatment of the purified ADPRase with heated cytosol fractions at 37$^{\circ}C$ for 3 h caused some changes in the chemical properties of the enzyme, including an increase in molecular weight, a decrease in solubility, and a loss of $Mg^{2+}$-dependency. The molecular weight of the cytosol-treated ADPRase measured by gel filtration was over 420 kDa, suggesting, for the first time, that ADPRase could be polymerized by undefined cytoplasmic factors, and that polymerization is accompanied by changes in the solubility and metal ion dependency of the enzyme.

• 한국동물학회지
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• 제23권2호
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• pp.61-68
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• 1980

발정주기에 EK라서 생쥐자궁의 alkaline phosphatase와 transport ATPases의 활성변화를 알아보기 위하여 정량적으로 분석하였다. 발정주기의 각 시기에 있어서 이 효소활성들의 비율은 대체로 그 양상이 서로 비슷하나, 발정기의 $K^+$-dependent와 $Na^+, K^+$-activated ATPases를 제외한 다른 효소들의 활성은 다른 어떤 시기보다도 유의하게 (p<0.025) 높았다. 즉, $K^+$-dependent와 $Na^+, K^+$-activated ATPases의 활성은 발정간기에서 발정기에 이르는 동안 무시할 정도이고, 다만 발정후기에 약간의 활성(0.04$\\sim$0.05 $\\mu$M/mg protein/hr), 총활성의 6$\\sim$7%)이 나타났다. 한편, 발정기에서 $Mg^++$-dependent phosphatase, transport ATPase와 alkaline phosphatase의 활성들은 급속히 현저하게 증가하였으며 각각 0.69(35%), 0.42(21%), 1.58(79%)였다. Alkaline phosphatase는 전 발정주기를 통해 0.60$\\sim$1.58(79$\\sim$90%)의 활성을 보여 그 주종을 이루었다. Alkaline phosphatase의 활성중에는 $Mg^++$-dependent의 것이 총활성의 12$\\sim$16%로 추정되었다. 그러므로 $K^+$-dependent와 $Na^+$-activated ATPases는 발정기 때에 자궁액의 누적을 조절하는 요인이 아니고 발정후기에는 자궁상피 속으로 내액을 재흡수하는 요인인 것으로 짐작되며, EH한 $Mg^++$-dependent phosphatase, transport ATPase 그리고 alkaline phosphatase는 생쥐의 자궁 상피세포에서부터 내액을 분지하는 데에 밀접히 관련되어 있는 것으로 사려된다.

• KSBB Journal
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• 제28권6호
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• pp.349-355
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• 2013

SC092 strain, producing a polysaccharide degrading enzyme, was isolated from the seawater. This strain was identified as Microbulbifer sp. using the comparative sequence analysis against known 16S rRNA sequence. A polysaccharide degrading enzyme from this strain was used to acquire the enzymatic extracts of Sargassum fulvellum. DPPH radical scavenging and SOD activity of the enzyme extracts of S. fulvellum were about 61.9% and 82.9% at 2 mg/mL, respectively. Nitrite scavenging activities was 52.5% at 2 mg/mL on pH 1.2. In addition, ${\alpha}$-glucosidase inhibitory activity was also increased in a dose-dependent manner and was about 52.7% at 2 mg/mL. To determine the influence of enzyme extracts of S. fulvellum on alcohol metabolism, the generating activity of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were measured. ADH and ALDH activities were 118.0% and 177% at 2 mg/mL, respectively. ${\alpha}$-glucosidase inhibitory activity of enzyme extracts of S. fulvellum was remarkably increased in a dose-dependent manner and was about 52.7% at 2 mg/mL. These results indicate alcoholizing and ${\alpha}$-glucosidase inhibitory activities can be enhanced by the enzymatic extracts of S. fulvellum.

• 한국식품영양과학회지
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• 제19권4호
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• pp.349-355
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• 1990

Actomyosine prepared from Yellowtail fish(seriola quinqueradiata) were stored at $0^{\circ}C$(ice-cooling) -3.5$^{\circ}C$(partial freeaing) and -2$0^{\circ}C$(freezing) Another actomyosin samples were prepared from the fish previously stored at the temperatures for a week as the maximum .Remaining activity of {{{{ {Ca }^{2+ } }}}}-and {{{{ {Mg }^{2+ } }}}}- dependent adenosine triphosphatase(ATPase) activity was measured fronm the actomyosin preparations. Specific activity of {{{{ {Mg }^{2+ } }}}}-ATPase of actomy-osin before storagew was 0.253$\mu$ mole pi/min/mg of protein and it was 1.5 times higher than that of {{{{ {Ca }^{2+ } }}}} -ATPase. The enzyme activities were markedly decreased during early period of storage. However no significant differences in the enzyme activity were revealed among the samples stored at different temperature. The enzyme of actomyosin prepared from the fish previously stored at the temperatures for a week revealed an acitivity of 2-3 times higher than that of freezing. Apparent denaturation constant of {{{{ {Mg }^{2+ } }}}} -ATPase of actomyosin was between 0.810-1.139 per day and it was about 1.5 times hgiher than that of {{{{ {Ca }^{2+ } }}}} -ATPase. But the constant of {{{{ {Mg }^{2+ } }}}} ATPase of actomyosin extracted from the fist stored for a week at each temperature was between 0.176-0.356 per day. This constant was 4 times higher than that of {{{{ {Ca }^{2+ } }}}}- ATPase in frozen stored fish. It was presumed from these results that denaturation of ATPase is largely accorded to the structural changes of actomyosin.

• 약학회지
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• 제36권2호
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• pp.129-136
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• 1992

The effects of ginseng saponins, gypsophila saponin, sodium dodecyl sulfate(SDS), and Triton X-100 on membrane $K^+-dependent$ phosphatase activity which is lipid dependent and represents dephosphorylation step of the complete Na+, $K^+-ATPase$ reaction were investigated in this study to elucidate whether the effects of ginseng saponins are due to the detergent action, using sarcolemma enriched preparation isolated from dog ventricle. $Na^+$, $K^+-ATPase$ and $K^+-dependent$ phosphatase activities of cardiac sarcolemma were about $143\;{\mu}mol$ Pi/mg protein/hr and $34\;{\mu}mol$ p-nitrophenol/mg protein/hr, respectively. While ginseng saponins (triol>total>diol) inhibited $K^+-dependent$ phosphatase activity, gypsophila saponin, and low dose of SDS($0.4\;{\mu}g/{\mu}g$ protein), and Triton X-100 ($0.6\;{\mu}g/{\mu}g$ protein) increased the enzyme activity, indicating disruptive effect of detergents on membrane barriers. The activating effect of low doses of Triton X-100 on membrane $K^+-dependent$ phosphatase appeared at concentration decreasing light scattering. However, the inhibitory effect of ginseng saponin appeared before a decrease in light scattering. These results suggest that low concentrations of ginseng saponins inhibit the membrane $K^+-dependent$ phosphatase by interacting directly with enzyme before membrane disruption.

• Journal of Applied Biological Chemistry
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• 제42권4호
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• pp.169-174
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• 1999

Arabidopsis AHL gene contains 4 exons encoding a putative protein highly homologous to the yeast salt-sensitive enzyme HAL2, a 3'(2'),5'-bisphosphate nucleotidase involving in reductive sulfate assimilation. AHL cDNA complemented yeast met22 (hal2) mutant. AHL fusion protein expressed in E. coli exhibited $Mg^{2+}$-dependent, 3'-phosphoadenosine 5'-phosphate (PAP)-specific phosphatase activity. $Li^+,\;Na^+,\;K^+$ and $Ca^{2+}$ ions inhibit the enzyme activity by competing with $Mg^{2+}$ for the active site of the enzyme. The enzyme activity was also sensitive to ${\mu}M$ concentrations of toxic heavy metal ions such as $Cd^{2+},\;Cu^{2+}$ and $Zn^{2+}$, but was not recovered by addition of more $Mg^{2+}$ ions, suggesting that these ions inactivate the enzyme with a mechanism other than competition with $Mg^{2+}$ ions. Inhibition of the AHL enzyme activity may result in accumulation of PAP, which is highly toxic to the cell. Thus, the AHL enzyme could be one of the intial targets of heavy metal toxicity in plants.

• 생명과학회지
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• 제20권5호
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• pp.768-774
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• 2010

전통발효주 막걸리의 기능성을 증명하기 위하여 S사막걸리로부터 구입한 막걸리 침전물의 여러 가지 생리활성에 대하여 조사하였다. 우선 막걸리 침전물 열수 추출물의 항산화 효과를 측정하기 위해 DPPH radical 소거능과 SOD 유사활성을 측정하였다. 그 결과 DPPH법을 통해 측정한 막걸리 침전물 열수 추출물의 radical 소거능은 10 mg/ml에서 48.0%으로 나타났으며, 농도가 증가함에 따라 유의적으로 증가하는 경향을 나타내었다. 또한 SOD 유사활성은 10 mg/ml 농도에서 98.7%로 비교적 높은 SOD 유사활성을 보였다. 항고혈압 활성 측정 실험에서는 현재 시판되고 있는 항고혈압제인 captopril은 0.1 mg/ml에서 93.4%의 ACE 억제효과가 나타났고, 막걸리 침전물 열수 추출물 10 mg/ml에서는 74.0%의 높은 저해 활성을 나타내었다. 따라서, 막걸리 침전물 열수 추출물은 인체에 부작용이 적은 천연 항고혈압소재로서 이용가능성이 높은 것으로 사료된다. 아질산염 소거능 측정 실험에서는 positive control인 Vit. C1 mg/ml의 경우 pH 1.2와 3.0에서는 74~64%, pH 6.0에서는 45%의 소거능을 보인반면, 막걸리 침전물 열수 추출물의 경우 pH 1.2와 3.0에서는 51~42%, pH 6.0에서는 28%의 소거능을 나타내었다. 막걸리 침전물 열수 추출물의 숙취해소 효능은 ADH와 ALDH 활성증진에 막걸리 침전물 열수 추출물이 미치는 영향을 조사함으로써 증명하고자 하였다. 그 결과, 알콜과 acetaldehyde 분해능은 높게 나타났다. 이상의 결과들은 막걸리 침전물의 우수한 기능성으로서의 이용 가능성에 대한 기초자료로 그 가치가 기대된다.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.738-744
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• 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 Microbiology and Biotechnology
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• 제26권8호
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• pp.1348-1357
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• 2016

An enzymatic reaction system was developed and optimized for bioconversion of resveratrol from glucose. Liquid enzyme extracts were prepared from Alternaria sp. MG1, an endophytic fungus from grape, and used directly or after immobilization with sodium alginate. When the enzyme solution was used, efficient production of resveratrol was found within 120 min in a manner that was pH-, reaction time-, enzyme amount-, substrate type-, and substrate concentration-dependent. After the optimization experiments using the response surface methodology, the highest value of resveratrol production (224.40 μg/l) was found under the conditions of pH 6.84, 0.35 g/l glucose, 0.02 mg/l coenzyme A, and 0.02 mg/l ATP. Immobilized enzyme extracts could keep high production of resveratrol during recycling use for two to five times. The developed system indicated a potential approach to resveratrol biosynthesis independent of plants and fungal cell growth, and provided a possible way to produce resveratrol within 2 h, the shortest period needed for biosynthesis of resveratrol so far.