• Journal of Applied Biological Chemistry
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• 제59권4호
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• pp.373-377
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• 2016

An extracellular metalloprotease, Btmp, was partially purified from the culture supernatant of Bacillus thuringiensis 29-126, isolated from animal feces collected in a zoological garden in Japan, by ultrafiltration, ammonium sulfate precipitation, and a set of chromatography on Sephadex G-75 and High-Q. The molecular mass of the protease was estimated to be 60 kDa by SDS-PAGE. The enzyme showed optimum activity at $50^{\circ}C$ and pH 6.0, and had a half-life of 14 min at $50^{\circ}C$. The enzyme activity was not influenced by $Na^+$, $K^+$, $As^+$, $Mg^{+2}$, $Ca^{2+}$, $Ba^{2+}$, and phenylmethylsulfonyl fluoride, but it was moderately inhibited by $Zn^{+2}$ at a concentration of 1.0 mM, while the activity was significantly inhibited to less than 50 % by $Cu^{2+}$, $Co^{2+}$, $Cd^{2+}$, and ethylenediaminetetraacetic acid. Interestingly, the enzyme was activated to 178 % by 1.0 mM of $Mn^{2+}$. From these results, it may be suggested that the protease is a novel extracellular manganeseactivated metalloprotease.

• Journal of Applied Biological Chemistry
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• 제52권3호
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• pp.109-115
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• 2009

Xoo로 부터 aspartate aminotransferase로 추정되는 유전자를 분리한 다음 발현시켜 생화학 특성을 조사하였다. 분리된 유전자는 His6 pET-21(a) 운반체에 삽입시켰으며 E. coli BL21(DE3)에서 발현시켰다. 재조합된 Asp-AT는 affinity chromatography를 이용하여 분리하였으며 SDS-PAGE분석에서 43kDa의 단일 밴드를 나타내었다. 분리된 효소는 amino donor 로서 L-aspartate에 대하여 효소활성도가 가장 높았고, L-leucine 및 L-cysteine에 대하여서도 상당한 활성도를 나타내었다. 효소의 최적 pH는 약 7.5 근처에서 나타났고 효소의 안정성은 산성조건 보다는 알칼리 조건에서 훨씬 높았다. 최적 온도는 약 $35-40^{\circ}C$로 나타났고 $55^{\circ}C$에서 20분간 열처리한 이후의 잔여 활성도는 약 78%로 나타났다. 여러 중금속 중에서 망간 이온에 의해 효소활성이 촉진되었다.

• Journal of Ginseng Research
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• 제41권3호
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• pp.307-315
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• 2017

Background: Red-skin root disease has seriously decreased the quality and production of Panax ginseng (ginseng). Methods: To explore the disease's origin, comparative analysis was performed in different parts of the plant, particularly the epidermis, cortex, and/or fibrous roots of 5-yr-old healthy and diseased red-skin ginseng. The inorganic element composition, phenolic compound concentration, reactive oxidation system, antioxidant concentrations such as ascorbate and glutathione, activities of enzymes related to phenolic metabolism and oxidation, and antioxidative system particularly the ascorbate-glutathione cycle were examined using conventional methods. Results: Aluminum (Al), iron (Fe), magnesium, and phosphorus were increased, whereas manganese was unchanged and calcium was decreased in the epidermis and fibrous root of red-skin ginseng, which also contained higher levels of phenolic compounds, higher activities of the phenolic compound-synthesizing enzyme phenylalanine ammonia-lyase and the phenolic compound oxidation-related enzymes guaiacol peroxidase and polyphenoloxidase. As the substrate of guaiacol peroxidase, higher levels of $H_2O_2$ and correspondingly higher activities of superoxide dismutase and catalase were found in red-skin ginseng. Increased levels of ascorbate and glutathione; increased activities of $\text\tiny L$-galactose 1-dehydrogenase, ascorbate peroxidase, ascorbic acid oxidase, and glutathione reductase; and lower activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione peroxidase were found in red-skin ginseng. Glutathione-S-transferase activity remained constant. Conclusion: Hence, higher element accumulation, particularly Al and Fe, activated multiple enzymes related to accumulation of phenolic compounds and their oxidation. This might contribute to red-skin symptoms in ginseng. It is proposed that antioxidant and antioxidative enzymes, especially those involved in ascorbate-glutathione cycles, are activated to protect against phenolic compound oxidation.

• 한국식품과학회지
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• 제30권1호
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• pp.82-89
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• 1998

새우젓에서 protease를 추출, 정제하여 이의 효소학적 특성을 조사하였다. 새우젓 protease를 추출, 전기투석으로 탈염, ammonium sulfate로 단백질을 분획 시킨 후 Sephadex G-100 column chromatography와 DEAE-cellulose column chromatography를 행하여 정제하였으며 정제 효소는 전기영동상 단일 band로 나타났으며 분자량은 24 kDa, 수율은 14%, 비활성역가는 8.4 unit/mg, 정제배수는 9.8이었다. 정제효소의 최적 pH는 8.0이었고 $pH\;7.0{\sim}10.0$의 범위에서 안정하였다. 단백질 분해 효소 활성의 최적 온도는 $40^{\circ}C$이었고 $30{\sim}60^{\circ}C$의 온도 범위에서 안정성을 나타내었다. 기질에 대한 특이성으로 합성기질인 BAPNA, TAME에는 활성을 보였으며 hammersten casein을 기질로 사용하였을때의 Km값은 $5.1{\times}10^{-7}\;M$이었다. 금속 이온의 영향으로는 $M^{++}$만이 활성이 증가되었고 다른 금속 이온들에 의해서는 저해되었다. 저해제의 효과에서는 STI차 TLCK에 의해 현저하게 저해되었다. 이상의 성질에서 새우젓에서 분리된 protease는 serine계의 trypsin-like enzyme으로 추정되었다.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.581-588
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• 2016

Lonchocarpine is a phenylpropanoid compound isolated from Abrus precatorius that has anti-bacterial, anti-inflammatory, antiproliferative, and antiepileptic activities. In the present study, we investigated the antioxidant effects of lonchocarpine in brain glial cells and analyzed its molecular mechanisms. We found that lonchocarpine suppressed reactive oxygen species (ROS) production and cell death in hydrogen peroxide-treated primary astrocytes. In addition, lonchocarpine increased the expression of anti-oxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), and manganese superoxide dismutase (MnSOD), which are all under the control of Nrf2/antioxidant response element (ARE) signaling. Further, mechanistic studies showed that lonchocarpine increases the nuclear translocation and DNA binding of Nrf2 to ARE as well as ARE-mediated transcriptional activities. Moreover, lonchocarpine increased the phosphorylation of AMP-activated protein kinase (AMPK) and three types of mitogen-activated protein kinases (MAPKs). By treating astrocytes with each signaling pathway-specific inhibitor, AMPK, c-jun N-terminal protein kinase (JNK), and p38 MAPK were identified to be involved in lonchocarpine-induced HO-1 expression and ARE-mediated transcriptional activities. Therefore, lonchocarpine may be a potential therapeutic agent for neurode-generative diseases that are associated with oxidative stress.

• 펄프종이기술
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• 제31권5호
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• pp.1-11
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• 1999

Wood components, cellulose and lignin, are degraded simultaneously and the general outline for the complementary character of carbohydrates and lignin decomposition as well as the existence of enzymatic systems combining these processes is still valid. The degradatiion of free cellulose or hemicellulose into monosaccharides has long been known to be relatively simple, but the mechanism of lignin degradatiion wasn ot solved very clearly yet. Anyway the biodegradation of woold constituents is understood at present as an enzymatic process. Kigninolytic activity has been correlated with lignin and manganese peroxidases. At present the attention is paid to laccase. Laccase oxidizes lignin molecule to phenoxy radicals and quinones . This oxidation can lead to the cleavageo f C-C or C-O bonds in the lignin phenyl-propane subunits, resulting either in degradation of both side chains and aromatic rings, or in demethylation processes. The role of laccase lies in the "activation" of some low molecular weight mediators and radicals produced by fungal cultures. Such activated factors produced also in cooperation with other enzymes are probably exported to the wood environment where they work in degradation processes as the ' enzyme messengers." It is worth mentioning that only fungi possessing laccase show demethylating activity. Thus demethylation, the process important for ligninolysis, is probably caused exclusively by laccase. Under natural conditions laccase seems to work with other fungal enzymes , mediators and mediating radicals. It has shown the possibility of direct Bjrkman lignin depolymerization by cooperative activity of laccase and glucose oxidase.

• 한국식품저장유통학회지
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• 제19권3호
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• pp.443-450
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• 2012

최근 연구에 의하면, NOX4에 의해 생성된 세포내 ROS는 지방세포의 분화를 촉진하는 것으로 알려져 있다. 본 연구진의 보고에 의하면 천년초 추출물은 $PPAR{\gamma}$의 발현 및 지방세포의 분화를 억제하는 것으로 밝혀진 바 있다. 따라서 본 연구에서는 천년초 선인장의 건강기능식품 소재화시 기초자료를 제공하고자 지방세포내 생성되는 ROS에 대한 천년초 열수 및 에탄올 추출물의 억제효과 및 주요 유전자(NOX4, G6PDH 및 항산화효소)의 발현 양상을 조사하였다. 천년초 열수 및 에탄올 추출물을 처리한 지방세포에서는 대조군에 비해 ROS 생성량이 유의적으로 감소하는 것으로 나타내었고, 추출용매별 천년초 추출물의 ROS 저감효능은 열수 추출물에 비해 에탄올 추출물에서 높게 나타났다. 천년초 추출물을 처리한 지방세포에서는 ROS 생성과 연관된 주요 유전자 NOX4 및 G6PDH의 발현이 대조군에 비해 감소하는 경향을 나타낸 반면, Cu/Zn-SOD, Mn-SOD, catalase, GPx 등과 같은 항산화효소의 발현은 대조군에 비해 증가한 것으로 나타났다. 이상의 결과들로 볼 때, 천년초 추출물은 지방세포의 분화과정에서 ROS의 생성을 억제하고 항산화효소의 발현을 증가시켜 ROS에 의한 산화적 스트레스를 효과적으로 저감화하는 것으로 밝혀졌다.