• Title/Summary/Keyword: antibody activity

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Cloning of Xanthine Oxidase Gene from Mouse Liver cDNA Library

  • Lee, Chu-Hee;Lee, Sang-Il;Nam, Doo-Hyun;Heo, Geun
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.261-261
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    • 1994
  • Bovine milk xanthine oxidase (E.C.1.1.3.22, XO) purchased from Sigma Chemical Co. had the three protein fragments below 150 kDa on 7.5% SDS-PAGE, which did not show enzyme activity. To remove these fragments, the enzyme preparation was further purified through Sephadex G-200 column chromatography. Two peaks exhibiting enzymatic activity were separated very closely to the void volume, which were revealed as two different enzyme forms, dimeric and monomeric, confirmed by activity staining on native PAGE. Anti sera-against each of the two enzyme forms were raised by subcutaneous injection at multiple sites on the back of rabbits during 4 weeks. On the immunodiffusion test, it was found that both of the antisera of the two forms could react with each other, which implied that their epitopes were identical In the Western blot analysis of mouse liver cytosol fraction, it was found that rabbit anti-XO antibody bound well with the protein band of monomeric mouse liver XO of about 150kDa. Based on this result, mouse liver cDNA 1 ibrary was screened by in situ hybridizat ion wi th rabbi t anti -XO antibody as probe. Through the immunological screening, recombinant phages giving positive signal by the production of XO were selected and further purified. To validate these clones, purified phages were lysogenized in E. coli Y1089 and their lysates were analysed for enzyme activity and immunoreactivity, It was verified that lysates of the purified recombinant phage lysogens exhibited the enzymatic activity as well as bound wi th XO antibody, when induced by IPTG. The above results assert that selected recombinant phage carries mouse liver XO gene.

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Effect of the Crude Polysaccharides Fraction from Eleutherococcus senticosus as a Immunoadjuvant to Soluble Antigens (BSA and OVA) (오가피 조다당의 단백질 항원 (BSA and OVA)에 대한 면역증강효과)

  • 황수현;하은숙;유광원;신광순;이상훈;이재권;이경호;윤택준;박우문
    • YAKHAK HOEJI
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    • v.47 no.3
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    • pp.167-175
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    • 2003
  • Eleutherococcus senticosus is a typical oriental folk medicinal herb. It has been used clinically as a anti-rheumatic disease, anti-stress, ischemic heart disease and gastric ulcer. In the present study, we examined the adjuvant activity of the crude polysaccharides fraction from Eleutherococcus senticosus, EN-3, on the induction of humoral and cellular immune responses against bovine serum albumin (BSA) or ovalbumin (OVA). The thioglycollate-induced macrophages and silica-induced dendritic-like cells cultured with BSA and EN-3 synergistically increased the production of TNF-$\alpha$ and IL-12. When mice were subcutaneously immunized with BSA + EN-3, the antibody titer against BSA was showed significantly higher than those immunized with BSA alone. In addition, when mice were immunized with OVA + FIA + EN-3, the antibody titer was showed similar patterns with the FCA. The assay for determining subisotype of antibody revealed that EN-3 augmented OVA-specific antibody titer of IgG1 and IgG2b. The culture supernatant obtained from splenocytes of mice treated with OVA + FIA + EN-3 also showed a higher level of both OVA-specific Th1-type (IL-2, IFN-${\gamma}$ and GM-CSF) and Th2-type cytokine (IL-4, IL-6 and IL-10). In vitro analysis of T cell proliferation to OVA on 8 weeks, the splenocytes of mice treated with OVA + EN-3 showed a significantly higher proliferating activity than those treated with OVA alone. These results suggest that EN-3 may possess adjuvant activities to potentially to enhance humoral as well as cellular immune response.

A study on production of early pregnancy diagnostic kit in cattle 1. Production of polyclonal antibody to progesterone and removal of anti-bovine serum albumin antisera (소의 조기임신진단 kit의 개발 1. Progesterone의 항체생산(抗體生産) 및 항(抗) BSA항체(抗體)의 제거)

  • Kang, Chung-boo;Lee, Hyo-jong;Choe, Sang-yong
    • Korean Journal of Veterinary Research
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    • v.31 no.2
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    • pp.217-222
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    • 1991
  • Most progesterone enzyme immunoassays(EIA) are used liquid phase double-antibody separation. These methods consume considerable time and reagents because of the requirements for several washing and centrifugation steps involving the reactants. Because of there several problems, we were prompted to develop an effective EIA system by the use of higher titer of progesterone antiserum free of anti-bovine serum albumin antibodies (anti-BSA). The results obtained were as follows. 1. The antibody of progesterone antiserum was high as $1.5{\times}10^5$. 2. Percent activity bound of progesterone antiserum was about 77 at a dilution to $5{\times}10^3$ times. 3. Progesterone antiserum was contained a large amount of anti-BSA antibodies. 4. The anti-BSA was completely absorbed by using of polymerised BSA. 5. The molecular weight of albumin polymer (polymerised BSA) obtained by using 2.5% glut. araldehyde was $5{\times}10^5$.

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Characterization of Mouse Hybridoma Producing Monoclonal Antibody Paragonimus westermani (폐디스토마에 대한 Mmonoclonal Antibody생산 세포주개발에 대한 연구)

  • 고광삼;이숙영;이근배
    • Korean Journal of Microbiology
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    • v.23 no.1
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    • pp.64-68
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    • 1985
  • In this study, hybridoma techniques were applied to produce monoclonal antobodies to Paragonimus westermani, commonly known as lung distoma. Balb/c mice were immunized intraperitoneally every week with increasing doses of purfied protein of Paragonimus westermani adult worms begining with 0.3/mg/mouse/7 days and ending with 0.5mg at 28th day. Spleen cells from these immunized mice were hybridized with myeloma cells (NS-1) and the hybridized cells were selected in HAT media. The antibody secreting cells among the hybrid cells were initially selected by ELISA. Those initially selected cells were further screened by the criteria of antibody producing activity, and seneral cell lines among them were further tested with immunodiffusion method. One hybridoma clone produced IgM and another clone produced IgG1. The supernatant of the hybridoma clone producing IgM had titer 1:64 and the hybridoma clone producing IgG1 had titer 1:256 measured by immunofluorescence technique.

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Effects of Prunella vulgaris labiatae extract on specific and non-specific immune responses in tilapia (Oreochromis niloticus)

  • Park, Kwan-Ha;Choi, Sanghoon
    • Journal of Animal Science and Technology
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    • v.56 no.1
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    • pp.3.1-3.7
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    • 2014
  • We examined the effects of Prunella vulgaris Labiatae (P. vulgaris L.) on specific and non-specific immune responses of Nile tilapia, Oreochromis niloticus. The optimal concentration without toxicity of P. vulgaris was determined to $30-40{\mu}g/ml$ in vitro and $120{\mu}g$/100 g of fish in vivo. P. vulgaris significantly elicited an antibody titer compared to FCA or ${\beta}$-glucan. ${\beta}$-glucan plus P. vulgaris group synergistically enhanced antibody production. No significant difference in antibody production was observed between P. vulgaris and P. vulgaris plus ${\beta}$-glucan group. A respiratory burst activity of head kidney (HK) leucocytes of tilapia administered with 300 or $500{\mu}g$ P. vulgaris was significantly (p < 0.05) enhanced compared with the PBS-injected control group and FCA-treated group. Maximum increase in the NBT reduction value was observed in $500{\mu}g$ P. vulgaris group but no significant difference was found between 300 and $500{\mu}g$ P. vulgaris group. The level of serum lysozyme activity was significantly (p < 0.05) higher in the 300 and $500{\mu}g$ P. vulgaris than $100{\mu}g$ P. vulgaris and FCA group. The phagocytic activities of HK leucocytes from tilapia administered with 300 and $500{\mu}g$ P. vulgaris were significantly (p < 0.05) higher than $100{\mu}g$ P. vulgaris and the control group. P. vulgaris was revealed with a good immunoadjuvant evoking the specific and non-specific immune responses of tilapia.

Peroxynitrite Scavenging Activity and its Mechanism of Cheonga-hwan (청아환의 Peroxynitrite 제거 활성 및 기전)

  • 김성호;정지천
    • The Journal of Korean Medicine
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    • v.23 no.4
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    • pp.55-63
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    • 2002
  • Objectives: Peroxynitrite ($ONOO^{-}$), formed from the reaction of superoxide <${\cdot}O_2^{-}$) and nitric oxide (NO), is a cytotoxic species that can oxidize several cellular components such as proteins, lipids and DNA. It has been implicated in diseases such as aging process, Alzheimer's disease, rheumatoid arthritis, cancer and arteriosclerosis. Due to the lack of endogenous enzymes responsible for $ONOO^{-}$ inactivation, developing a specific $ONOO^{-}$ scavenger is of considerable importance. The aim of this study was to evaluate $ONOO^{-}$ scavenging activity and its mechanism in Cheonga-hwan (CAH). Methods: The $ONOO^{-}$ scavenging activity in CAH was assayed by measuring oxidized dihydrorhodamine 123 (DHR 123) by fluorescence. The scavenging efficacy was expressed as $IC_{50}$, showing the concentration of each sample required to cause 50% inhibition of DHR 123 oxidation. In a separate study, the protective effect of CAR on $ONOO^{-}$-induced nitration of bovine serum albumin (BSA) was investigated using immunoassay with a monoclonal anti-nitrotyrosine antibody, and a horseradish peroxidase-conjugated anti-mouse secondary antibody from sheep. Results: CAH showed potent scavenging activities of $ONOO^{-}$, NO and ${\cdot}O_2^{-}$. The data demonstrated that CAH led to decreased $ONOO^{-}$-mediated nitration of tyrosine through electron donation. CAH showed significant inhibition on nitration of bovine serum albumin by $ONOO^{-}$ in a dose-dependent manner. Conclusions: CAH can be developed as an effective peroxynitrite scavenger for the prevention of the $ONOO^{-}$ involved diseases.

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Stabilization of Dry Immuno-Diagnostic Kit with Immobilized Antibody and Determination of Its Shelf-Life (항체가 건조상태로 고정된 면역진단키트의 안정화와 Shelf-Life 결정)

  • 이창우;조정환;육순학;권오협;박영남;박세환
    • KSBB Journal
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    • v.13 no.5
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    • pp.502-510
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    • 1998
  • Stabilization of antibody, which is specific to Salmonella typhimurium antigens, present in dry states on membranes was accomplished, and its shelf-life, i.e., duration for maintaining minimum 90% of the initial activity, under optimal conditions was determined. To prepare two major components of an immuno-strip, the antibody was not only immobilized on nitrocellulose membrane surfaces but also placed within the pores of glass fiber membrane after conjugating it with old colloids as signal generator. Among potential stabilizers of the immuno-components, a disaccharide, trehalose, showed a significant protection effect of immunoglobulin structure from thermal energy. Optimal concentrations of trehalose for the respective component were significantly different (8-fold higher for the antibody-gold conjugate than for the immobilized antibody), which probably resulted from distinct densities and configurations of antibody present on the membranes. An additional requirement for the gold conjugate was freeze-drying of this substance such that the conjugate can be readily resolubilized upon contact with aqueous medium. By using the components prepared under optimal conditions, immuno-strips were constructed and exposed to thermal energy. Signals with less than 10% decrease in the intensity were maintained for approximately 21 days at 60$^{\circ}C$. Compared to previous reports, this result represented a 2-year shelf-life at room temperature. it was, however, two times longer if determined from thermal acceleration tests based on the theory of inactivation rate of protein. Such discrepancy between the two estimates could be mainly attributed to errors in accurately controlling temperatures and also to changes in the physical properties of membranes due to a high thermal energy.

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Increased Refolding Yield of Disulfide Bond Bridged Fab-Toxin Homodimers by the Insertion of CH3 Domains

  • Song Jeong-Wha;Won Jae-Seon;Lee Yong-Chan;Choe Mu-Hyeon
    • Journal of Microbiology and Biotechnology
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    • v.16 no.7
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    • pp.1104-1110
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    • 2006
  • Recombinant antibody-toxin is a bifunctional protein that binds and kills a target cell expressing a specific antigen on the surface of the cell, and its structure is chimeric, in which a toxin is fused to an antigen-binding domain such as scFv or Fab. Divalent antibody-toxin molecules showed higher cytotoxicities against cancer cell lines than monovalent molecules. However, the yields of the divalent molecules were very low. In this study, we introduced the CH2, CH3, or CH2-CH3 (=Fc) domain of antibody in the middle of the Fab-toxin between the hinge region of human IgG1 and the toxin domain to increase the yield. The covalently bonded dimer could be formed by three disulfide bridges from cysteine residues in the hinge region. The molecule with the CH3 domain showed about 3-fold higher dimerization yield than previously constructed Fab-toxin molecules, while maintaining the cytotoxic activity comparable to that of scFv-toxin. However, the introduction of CH2 or Fc domain to the same position showed little effect on the dimerization yield. We also observed that the introduction of the CH3 region made it possible to form noncovalently associated dimer molecules.

Studies on Antitumor and Immunopotentiation Activities of Polysaccharides from Trichosanthes Rhizome

  • Chung, Yeoun-Bong;Lee, Chong-Chull;Park, Soo-Wan;Lee, Chung-Kyu
    • Archives of Pharmacal Research
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    • v.13 no.3
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    • pp.285-288
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    • 1990
  • The polysaccharide fraction from the rhizome of Trichosanthes kirilowii (Cu-curbitaceae) showed marked antitumor and cytotoxic activity with immunopotentiating activity. It was evidenced by the increase in the number of circulating leucocytes and peritoneal exudate cells and the recovery of lowered antibody forming activity in mice. The polysaccharide was mainly composed of glucose, galactose, fructose, manmose and xylose and a small amount of protein.

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Substitution of Heavy Complementarity Determining Region 3 (CDR-H3) Residues Can Synergistically Enhance Functional Activity of Antibody and Its Binding Affinity to HER2 Antigen

  • Moon, Seung Kee;Park, So Ra;Park, Ami;Oh, Hyun Mi;Shin, Hyun Jung;Jeon, Eun Ju;Kim, Seiwhan;Park, Hyun June;Yeon, Young Joo;Yoo, Young Je
    • Molecules and Cells
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    • v.39 no.3
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    • pp.217-228
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    • 2016
  • To generate a biobetter that has improved therapeutic activity, we constructed scFv libraries via random mutagenesis of several residues of CDR-H3 and -L3 of hu4D5. The scFv clones were isolated from the phage display libraries by stringent panning, and their antiproliferative activity against HER2-positive cancer cells was evaluated as a primary selection criterion. Consequently, we selected AH06 as a biobetter antibody that had a 7.2-fold increase in anti-proliferative activity ($IC_{50}$: 0.81 nM) against the gastric cancer cell line NCI-N87 and a 7.4-fold increase in binding affinity ($K_D$: 60 pM) to HER2 compared to hu4D5. The binding energy calculation and molecular modeling suggest that the substitution of residues of CDR-H3 to W98, F100c, A101 and L102 could stabilize binding of the antibody to HER2 and there could be direct hydrophobic interactions between the aromatic ring of W98 and the aliphatic group of I613 within HER2 domain IV as well as the heavy and light chain hydrophobic interactions by residues F100c, A101 and L102 of CDR-H3. Therefore, we speculate that two such interactions were exerted by the residues W98 and F100c. A101 and L102 may have a synergistic effect on the increase in the binding affinity to HER2. AH06 specifically binds to domain IV of HER2, and it decreased the phosphorylation level of HER2 and AKT. Above all, it highly increased the overall level of p27 compared to hu4D5 in the gastric cancer cell line NCIN82, suggesting that AH06 could potentially be a more efficient therapeutic agent than hu4D5.