• IMMUNE NETWORK
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• 제4권1호
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• pp.16-22
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• 2004

Background: To develop a novel treatment strategy for hepatitis B virus infection, a major cause of liver chirosis and cancer, we aimed to make human monoclonal antibodies inhibiting RNase H activity of P protein playing in important role in HBV replication. In this regard, phage display technology was employed and demonstrated as an efficient cloning method for human monoclonal antibody. So this study analysed the usability of human monoclonal antibody as protein based gene therapy. Methods: RNase H of HBV was expressed as fusion protein with maltose binding protein and purified with amylose resin column. Single chain Fv (scFv) phage antibody library was constructed by PCR cloning using total RNAs of PBMC from 50 healthy volunteers. Binders to RNase H were selected with BIAcore 2000 from the constructed library, and purified as soluble antibody fragment. The affinity and sequences of selected antibody fragments were analyzed with BIAcore and ABI automatic sequencer, respectively. And finally RNase H activity inhibiting assay was carried out. Results: Recombinant RNase H expressed in E. coli exhibited an proper enzyme activity. Naive library of $4.46{\times}10^9cfu$ was screened by BIAcore 2000. Two clones, RN41 and RN56, showed affinity of $4.5{\times}10^{-7}M$ and $1.9{\times}10^{-7}M$, respectively. But RNase H inhibiting activity of RN41 was higher than that of RN56. Conclusion: We cloned human monoclonal antibodies inhibiting RNase H activity of P protein of HBV. These antibodies can be expected to be a good candidate for protein-based antiviral therapy by preventing a replication of HBV if they can be expressed intracellularly in HBV-infected hepatocytes.

• Journal of Plant Biology
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• 제25권1호
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• pp.21-36
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• 1982

The activity of photosystem II in isolated chloroplast form the leaves of Sedum sarmentosum was measured. The photoreduction rate of DCPIP by photosystem II showed the circadian rhythm with a peak at near midday sample for a continuing fine day and at near afternoon between nidday and sunset sample for a continuing cloudy day in summer. The optimum light intensity of photoreduction by photosystem II in the chloroplast preparation was about 5~9$\times$$10^4$ lux. The saturated light intensity was over 9$\times$$10^1$lux. Photosystem II activity was inhibited by even the lowest concentration of lead. When Pi and ATP of the same concentration as Pb were added to the reaction mixture containing Tris buffer lacking of Pi prior to Pb incubation, photosystem II activity was protected from Pb-inhibiting effect by the pretreament of Pi and ATP. It was assumed that Pb inhibiiton was probably due to one, P-depriving by the precipitates of $Pb_3$ $($Pb_4$)_2$ in the reaction mixture and the other, partially Pb-combing with Pi groups of the active site of photosystem II.

• Preventive Nutrition and Food Science
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• 제12권3호
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• pp.177-180
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• 2007

Tocotrienols (T3) are minor plant constituents found abundantly in rice bran, which provide a significant source of vitamin E in animal feeds. T3 was reported to have an intrinsic hypocholesterolemic effect by inhibiting HMG-Co A reductase. It has similar antioxidative properties as tocopherols in food and biological system due to their similar chemical structures. However, the antioxidant activity and mechanism of T3 to scavenge free radicals and to inhibit the peroxidation of linoleic acid are less understood. The purpose of this study was to investigate the scavenging effect of T3 on free radicals and its inhibition of peroxide formation. Free radical scavenging activity was monitored by the DPPH (1,1-diphenyl-2-picrylhydrazyl) method whereas inhibition of linoleic acid peroxidation was evaluated using the thiocyanate method. Thiobarbituric acid (TBA) test was used to determine malonaldehyde formation from linoleic acid peroxidation. Free radical scavenging activity increased with increasing concentration levels of T3. T3 exhibited 38.2, 78.6, 92.7 and 96.2% radical scavenging activity at concentrations of 2, 8, 32 and 128 ppm, respectively. At 128 ppm, it was highly effective in inhibiting linoleic acid peroxidation. The activity of T3 evaluated by the thiocyanate method showed low absorbance values indicating a high level of antioxidant activity. All treatments showed similar trends in antioxidant activity when evaluated by both the thiocyanate method and TBA test.

• 대한미생물학회지
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• 제22권3호
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• pp.233-240
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• 1987

The amniotic fluid provides a medium in which the fetus can readily move, cushions him against possible injury and helps him maintain an even temperature. Besides above mentioned functions, investigators reported that human amniotic fluid contains host-resistance factors which prevent bacteria from producing infectious disease and this activity shows difference among human racial groups or bacterial genera, species and strains. 40 amniotic fluid specimens from Korean women in their second and third trimesters of pregnancy were examined for inhibiting the growth of Escherichia coli. And various factors which might affect bacterial growth inhibiting activity such as pH, initial inoculum size, concentration of amniotic fluid, and heat resistance, were also tested using a strongly inhibitory amniotic fluid specimen. Finally plate diffusion tests were carried out using other strongly inhibitory amniotic fluid. The following results were obtained: 1. Of the 40 fluid samples examined, 18 specimens(45%) had inhibitory activity and samples from women in their second trimester of pregnanancy showed non-inhibitory activity(2 specimens). 2. The pH of the fluids varied between 7.43 and 8.33. There was no correlation between pH and inhibitory activity. 3. No. 19 amniotic fluid showed bacteriostatic activity after 24 hours incubation when an inoculum of $10^2$ organisms per milliliter was used, but non-inhibitory with an inoculum of $10^3$ and $10^4$ bacteria per milliliter. 4. The content of amniotic fluid in culture media influenced E. coli growth. At 90 percent, E. coli was inhibited growth but at 10 percent and 50 percent. 5. Inhibitory activity of No. 19 amniotic fluid was retained after heating to $50^{\circ}C$ for 30 minutes or 100^{\circ}C$ for 30 minutes. 6. Plate diffusion tests with No. 27 amniotic fluid showed that 0.7ml amniotic fluid gave clear zone of growth inhibition around the central well but 0.2ml and 0.1ml amniotic fluids were not.

• 대한본초학회지
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• 제26권1호
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• pp.111-117
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• 2011

Objectives : The present study was designed to investigate effects of mixed extract from korean medicinal herbs (MIX) on oxidation/reduction reaction-related and aging-related enzyme in vitro. Methods : We performed MTT assay, collagenase inhibition assay, elastase inhibition assay, tyrosinase inhibition assay, DPPH free radical scavenging assay, SOD-like activity and xanthine oxidase inhibition assay. Results : Recently, many studies have reported that elastin is also involved in inhibiting or repairing wrinkle formation, although collagen is a major factor in the skin wrinkle formation. The MIX showed 97% inhibition of collagenase activity, and 64% inhibition of elastase activity at 1 mg/ml concentration of MIX, next only to positive control, which indicate good efficacy for anti-wrinkle ingredient. Also it's treatment showed 34% inhibition of tyrosinase activity, to relate whitening effect, at the same dose of MIX. Antioxidant activities were determined by DPPH radical scavenging, xanthine oxidase (XO) inhibiting activity and SOD-like activity. Also these scavenging, XO-inhibiting and SOD-like activities were measured in 91%, 80%, and 63% inhibition, respectively, at a treated dose of 1 mg/ml, compare to control. Conclusions : These results suggest that possibility of mixed korean medicinal herbs as a functional ingredient for anti-wrinkle and whitening, anti-oxidation and anti-aging cosmetic formula.

• KSBB Journal
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• 제18권1호
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• pp.45-50
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• 2003

송이의 공시균(KFR1432)과 실험실에서 자체 분리한 균(YxT, WxT, $\textrm{NK}_3\textrm{T}$)의 생장속도의 차이와 FE SEM으로 확인한 미세구조의 차이로 공시균과 자체 분리균이 서로 다른 균임을 확인할 수 있었다. Tyrosinase 활성 억제 실험을 위해 각각 균사체의 열수 추출물, 에탄올 추출물, 배양액을 hexane, chloroform, ethyl acetate로 분획하였다. 그 결과 모든 균의 ethyl acetate 분획층과 수층에서 tyrosinase 활성을 억제하는 것으로 나타났으며, KFR1432의 ethyl acetate 분획층과 YxT의 수층에서 억제율이 100%를 넘어 큰 저해 활성을 보였다. 또한 항산화제 처리 결과 ascorbic acid와 glutathion은 생장을 다소 증가시키거나 별 영향을 주지 못한 반면, tocopherol 의 경우 농도가 높아질수록 생장을 억제하는 것으로 나타났다. Tyrosinase 활성 억제에 있어서는 모든 항산화제 처리구에서 무처리구에 비해 높은 억제율을 보였다.

• 한국가축번식학회지
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• 제26권2호
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• pp.165-171
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• 2002

난포액에는 난자의 성숙을 억제하는 인자를 함유하고 있으나 화학적 성질이 정확히 알려져 있지않다. 본 연구에서는 1차 난모세포에서 난구세포의 해리와 제1극체의 형성을 억제하는 난포액 성분을 화학적으로 동정하기 위하여 수행되었다 이를 위하여 돼지 난포액을 methanol로 추출한 다음이 추출물을 Superose 12 및 Superdex column을 이용 연속적으로 분리하였으며, Superdex 분절은 PITC로 처리한 다음 아미노산 분석용 column을 이용 분석하였다. 얻어진 결과는 다음과 같다. 난포액은 1차 난모세포에서 난구세포의 해리와 제1극체의 형성을 억제하였다 난포액에서 추출 분리한 Superdex분절 RV2.11 역시 난구세포의 해리와 제1극체의 형성을 억제하였다. 아미노산 분석 결과, 분절 RV2.11은 proline으로 추정되며, proline은 난구세포의 해리와 제1극체의 형성을 억제하였다. 결론적으로 난포액에는 난구세포의 해리와 제1극체의 형성을 억제하는 성분인 proline을 함유하고 있으며, 이는 난자의 성숙을 억제하는 성분일 것으로 추정된다.

• Journal of Microbiology and Biotechnology
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• 제16권12호
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• pp.1977-1983
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• 2006

Kaempferol was isolated and identified from the methanol extract of the flowers of Impatiens balsamina. Kaempferol showed inhibitory activity against mushroom tyrosinase with an $ID_{50}$ of 0.042 mM. Inhibition kinetics, as determined using a Lineweaver-Burk plot, showed kaempferol to be a competitive inhibitor of mushroom tyrosinase with a $K_i$ value of 0.011 mM. The lag phase of tyrosine hydroxylation catalyzed by mushroom tyrosinase clearly increased on increasing the concentration of kaempferol. In addition to its tyrosinase inhibiting activity, kaempferol strongly inhibited melanin production by Streptomyces bikiniensis, in a dose-dependent manner, without inhibiting cell growth. For comparative purposes, the tyrosinase inhibitory activity of kaempferol was also assayed versus quercetin, a positive standard.

• Bulletin of the Korean Chemical Society
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• 제17권2호
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• pp.101-103
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• 1996

• Mycobiology
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• 제51권1호
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• pp.60-66
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• 2023

In this study, the α-amylase inhibitory activity, α-glucosidase inhibitory activity, pancreatic lipase inhibitory activity, and Xanthine Oxidase inhibitory activity of the fruiting body extracts of 5 varieties of Agaricus bisporus (AB) were confirmed. First, the α-amylase inhibitory activity of AB12, AB13, AB18, AB34, and AB40 methanol extracts was lower than that of acarbose, a positive control, in all concentration ranges. The α-glucosidase inhibitory activity of the AB40, AB13, and AB12 methanol extracts at the extract concentration of 1.0 mg/mL was 80.5%, 81.3%, and 78.5%, respectively, similar to that of acarbose, a positive control. The pancreatic lipase inhibitory activity of the methanol extract of Agaricus bisporus fruiting body was significantly lower than that of the positive control orlistat in the concentration range of 50~1.000 (mg/mL). The Xanthine Oxidase inhibitory activity was 0.5~8.0 mg/mL of each extract, which was significantly lower than that of the positive control allopurinol in the same concentration range. However, the Xanthine Oxidase inhibitory activity of AB13 and AB40 at 8.0 mg/mL was about 70%, which was higher than that of other mushrooms. In conclusion, five kinds of Agaricus bisporus fruiting bodies seem to have inhibitory effects on enzymes such as α-amylase, α-glucosidase, pancreatic lipase, and Xanthine Oxidase that degrade starch and protein. In particular, it has an inhibitory effect and a reduction effect on xanthine oxidase that causes gout, so it is expected that it can be developed and used as a food or health supplement with health functional properties through future research.