• 한국식품과학회지
• /
• 제22권1호
• /
• pp.13-18
• /
• 1990

피망고추 중에 함유되어 있는 L. Activator 를 0.85M NaCl 용액으로 추출하고 ammonium sulfate 0.2포화시켜 분리한 후 그의 성질을 검토하였다. 분리된 조 L.Activator (농도 $OD_{280}=1.0$)는 1.0ml 이내의 범위에서 첨가량에 비례하여 효소활성을 증가시켰으며 $35^{\circ}C$에서 작용력이 가장 높았다. 이 L.Activator는 $50^{\circ}C$ 이하의 온도에서 가장 큰 안정성을 나타내었으며 $100^{\circ}C$에서 30분간 가열하였을 때에도 약 60%의 활성이 잔존되어 높은 안전성을 나타내었다. 또 pH안정성의 경우는 pH7-9의 약알카리성 쪽에서 가장 큰 안정성을 나타내었고 pH3에서 72%, pH 10에서 85%의 활성이 잔존되는 등의 대단히 큰 안정성을 나타내었다. 한편 이 L. Activator는 $Na^+,\;Mg^{++},\;and\;Ca^{++}$등을 제외한 대부분의 금속이온에 의해서 활성이 감소되는 경향을 나타내었으나 $Ag^+\;,\;Hg^{++}$등 중금속의 L. Activator 활성저하 영향은 일반적인 효소활성에 미치는 영향에 비해서는 그리 현저하지 못하였다. 또한 이 L. Activator 는 cellulofine column chromatography에 의해서 4개의 peak로 분리되었으며 그중 주 활성 peak는 L. Inhibitor 에서 분리된 activatory peak와 일치되었다. 이 L. Activator 의 활성 peak에는 단백질 이외에 RNA, lipid 등이 함유되어 있었으며 당분은 함유되어 있지 않았다.

• Corrosion Science and Technology
• /
• 제9권3호
• /
• pp.137-141
• /
• 2010

Sodium nitrite is widely used as one of the popular corrosion inhibitors for the protection of ferrous metal in closed cooling water system, such as a diesel engine and a chiller. The optimum treatment conditions are studied through laboratory tests using linear polarization resistance (LPR) technique. Corrosion rate of the carbon steel electrode could be maintained less than $2.5{\times}10^{-3}$ mmpy in the test condition of 500 ppm as ${NO_2}^-$, 200 ppm as $Cl^-$, $70^{\circ}C$ and pH 6.8. The pH control is confirmed not to be an important factor in the protection of carbon steel by sodium nitrite inhibitor. The addition of tolyltriazole was needed for the protection of the copper alloy in the sodium nitrite treatment system.

• KSBB Journal
• /
• 제28권5호
• /
• pp.310-314
• /
• 2013

Antifreeze peptide from Myoxocephalus octodecemspinosus was overexpressed and purified in Escherichia coli. Green fluorescence protein-AFP chimera was constructed by integrating gfp and afp genes. Produced GFP-AFP chimera protein was purified using polyhistidine tag which was inserted at C-terminus. By addition of GFP-AFP chimera protein, freezing point of elution buffer was decreased from $-13^{\circ}C$ to $-20^{\circ}C$. This result suggested that GFP-AFP chimera can be considered as a potential candidate of novel inhibitor for gas hydrates.

• Journal of Plant Biology
• /
• 제17권1호
• /
• pp.3-8
• /
• 1974

The experiments were conducted to examine the effects of sulfur dioxide on catalase activity in germinating seeds under dark conditions and in green plants under light conditions. Three kinds of plants, bean (Glycine max M.), cabbage (Brassica oleracea L. Chungbang No.1) and rice (Oryza sativa L. Suwon No.213-1) were used in this study. Both thegerminating seeds and the leaves were treated with various concentrations of sulfur dioxide for both one green plants with two and twelve hours. In the results of the measurement of catalase activity it was found that plant injuries by sulfur dioxide for the period of photosynthesis were higher than those for the period of respiration. In the control, apparent catalase activity under the light condition of photosynthesis showed a considerable decrease in comparison with catalase activity under the dark condition of respiration. This tendency also appeared markedly in the gas treatment. In the gas treatment for twelve hours, the decrease of catalase activity was higher than that of one hour in both photosynthesis and respiraton. It was thought that sulfur dioxide was an inhibitor of catalase activity in higher concentration of the gas.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.212.2-212.2
• /
• 2003

In the course of searching for BACE1 (${\beta}$-secretase) inhibitors from natural products, the ethyl acetate soluble fraction of green tea, which was suspected to be rich in catechin content, showed potent inhibitory activity. (-)-Epigallocatechin gallate, (-)-epicatechin gallate, and (-)-gallocatechin gallate ware isolated with IC$\_$50/ values of 1.6${\times}$10$\^$-6/ M, 4.5${\times}$10$\^$-6/ M, and 1.8${\times}$10$\^$-6/ M, respectively. Seven additional authentic catechins were tested for a fundamental structure-activity relationship. (-)-Catechin gallate, (-)-gallocatechin, and (-)-epigallocatechin significantly inhibited BACE1 activity with IC$\_$50/ values of 6.0${\times}$10$\^$-6/ M, 2.5${\times}$10$\^$-6/ M, and 2.4${\times}$10$\^$-6/ M, respectively. (omitted)

• Parasites, Hosts and Diseases
• /
• 제53권4호
• /
• pp.421-430
• /
• 2015

The parasite Plasmodium falciparum causes severe malaria and is the most dangerous to humans. However, it exhibits resistance to their drugs. Farnesyltransferase has been identified in pathogenic protozoa of the genera Plasmodium and the target of farnesyltransferase includes Ras family. Therefore, the inhibition of farnesyltransferase has been suggested as a new strategy for the treatment of malaria. However, the exact functional mechanism of this agent is still unknown. In addition, the effect of farnesyltransferase inhibitor (FTIs) on mitochondrial level of malaria parasites is not fully understood. In this study, therefore, the effect of a FTI R115777 on the function of mitochondria of P. falciparum was investigated experimentally. As a result, FTI R115777 was found to suppress the infection rate of malaria parasites under in vitro condition. It also reduces the copy number of mtDNA-encoded cytochrome c oxidase III. In addition, the mitochondrial membrane potential (${\Delta}{\Psi}m$) and the green fluorescence intensity of MitoTracker were decreased by FTI R115777. Chloroquine and atovaquone were measured by the mtDNA copy number as mitochondrial non-specific or specific inhibitor, respectively. Chloroquine did not affect the copy number of mtDNA-encoded cytochrome c oxidase III, while atovaquone induced to change the mtDNA copy number. These results suggest that FTI R115777 has strong influence on the mitochondrial function of P. falciparum. It may have therapeutic potential for malaria by targeting the mitochondria of parasites.

• Journal of Plant Biotechnology
• /
• 제47권2호
• /
• pp.118-123
• /
• 2020

The black seed coat of soybeans contain anthocyanins which promote health. However, mature soybean seeds contain anti-nutritional factors like lipoxygenase, lectin and Kunitz Trypsin Inhibitor (KTI) proteins. Furthermore, these seeds can be used only after the genetic elimination of these proteins. Therefore, the objective of this study was to develop novel soybean genotypes with black seed coat and triple recessive alleles (lx1lx1lx2lx2lx3lx3, titilele) for lipoxygenase, lectin, and KTI proteins. From a cross of parent1 (lx1lx2lx3/lx1lx2lx3, ti/ti, Le/Le) and parent2 (lx1lx2lx3/lx1lx2lx3, Ti/Ti, le/le), 132 F₂ seeds were obtained. A 3:1 segregation ratio was observed during F₂ seed generation for the inheritance of lectin and KTI proteins. Between a cross of the Le and Ti genes, the observed independent inheritance ratio in the F₂ seed generation was 9: 3 : 3 : 1 (69 Le_Ti_: 32 leleTi_: 22 Le_titi: 9 leletiti) (χ²=2.87, P=0.5 - 0.1). From nine F₂ seeds with triple recessive alleles (lx1lx1lx2lx2lx3lx3, titilele genotype), one novel strain posessing black seed coat, and free of lipoxygenase, lectin and KTI proteins, was selected. The seed coat color of the new strain was black and the cotyledon color of the mature seed was green. The weight of 100 seeds belonging to the new strain was 35.4 g. This black soybean strain with lx1lx1lx2lx2lx3lx3, titilele genotype is a novel strain free of lipoxygenase, lectin, and KTI proteins.

• Journal of Microbiology and Biotechnology
• /
• 제33권6호
• /
• pp.788-796
• /
• 2023

Canine parvovirus type 2 (CPV-2) has high morbidity and mortality rates in canines. Nonstructural protein 1 (NS1) of CPV-2 has endonuclease activity, initiates viral DNA replication, and is highly conserved. Thus, it is a promising target for antiviral inhibitor development. We overexpressed a 41.9 kDa active recombinant endonuclease in Escherichia coli and designed a nicking assay using carboxyfluorescein and quencher-linked ssDNA as substrates. The optimal temperature and pH of the endonuclease were 37℃ and pH 7, respectively. Curcumin, bisdemethoxycurcumin, demethoxycurcumin, linoleic acid, tannic acid, and α-tocopherol inhibited CPV-2 NS1 endonuclease with IC₅₀ values of 0.29 to 8.03 µM. The extracted turmeric, yerba mate, and sesame cake suppressed CPV-2 NS1 endonuclease with IC₅₀ values of 1.48, 7.09, and 52.67 ㎍/ml, respectively. The binding affinity between curcumin, the strongest inhibitor, and CPV-2 NS1 endonuclease by molecular docking was -6.4 kcal/mol. Curcumin inhibited CPV-2 NS1 endonuclease via numerous hydrophobic interactions and two hydrogen bonds with Lys97 and Pro111 in the allosteric site. These results suggest that adding curcuminoids, linoleic acid, tannic acid, α-tocopherol, extracted turmeric, sesame cake, and yerba to the diet could prevent CPV-2 infection.

• 생명과학회지
• /
• 제18권2호
• /
• pp.273-278
• /
• 2008

콜레스테롤 생합성 과정에 있어서 속도조절 단계 효소의 하나인 squalene synthase에 대한 저해물질의 탐색을 목적으로, 30종의 다양한 천연물을 대상으로 squalene synthase에 대해 저해효과를 검토한 결과 녹차추출물에서 비교적 저해활성이 높고 재현성이 있게 저해효과를 나타내는 것으로 확인되었다. 녹차에 함유되어 있는 squalene synaase에 대한 저해물질의 용매추출성을 검토한 결과 ethyl acetate와 n-butanol 층에 저해물질이 많이 함유되어 있는 것으로 확인되었으며 저해물질은 녹차의 polyphenol 화합물인 catechin에 의한 것으로 추정되었다. Catechin 표준용액의 각 농도에 따른 squalene synthase 저해작용을 살펴 본 결과, (-)-epigallocatechin gallate, (-)-epicatechin gallate, (-)-epigauocatechin, (-)-epicatechin, (+)-catechin의 순으로 저해활성이 강한 것으로 나타났으며 가장 강한 저해활성을 나타내는 (-)-epigallocatechin gallate의 $IC_{50}$값은 $90{\mu}M$이었다.

• Animal cells and systems
• /
• 제13권2호
• /
• pp.133-139
• /
• 2009

Green tea seed was extracted with absolute ethanol,and the green tea seed extract(GTSE)was subjected to assays for toxicity, antioxidant ability, angiogenesis inhibitory effects and cell adhesion, as well as western blotting, and an in vivo experiment against 4 high-ranking adult cancers in Korea. Our series of experimental data demonstrated that GTSE has an antioxidant ability superior to that of EGCG in the green tea leaf, and also exhibits a profound high tumor growth inhibitory activity on a variety of cancer cell lines, as well as nude mice infected with cancer cells. GTSE was identified as a natural anticancer compound showing excellent angiogenesis inhibition and cancer cell suppression abilities. Our preliminary observations also indicate that GTSE may be another potential source of natural dietary antioxidants and also may be applicable as a novel natural anticancer agent.