• Title/Summary/Keyword: antibody activity

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Studies on Setting up of Radioimmunoassay System of Thyroid Stimulating Hormone (갑상선자극(甲狀腺刺戟)호르몬의 방사면역측정법(放射免疫測定法) 확립(確立)에 관한 연구(硏究))

  • Kim, Jae-Rok;Park, Kyung-Bae;Awh, Ok-Doo
    • The Korean Journal of Nuclear Medicine
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    • v.20 no.1
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    • pp.75-83
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    • 1986
  • Various TSH RIA kit components were prepared. Conditions for $^{125}I$ labelling of h-TSH were optimized by diminishing the amount of chloramine-T, ertending reaction time and lowering reaction temperature. Yield, specific activity, and immunological activity could be maintained moderately under such mild reaction conditions. The mixture of polyethyleneglycol(PEG) and second antibody worked effectively as a B/F separation agent. Even though the mixture was made with more diluted PEG and second antibody than those of using the sole component separately, the tine required for the B/F separation was shorter in case of using the mixture. The sequential saturation technique was efficient than those of applying ordinary equilibrium saturation technique in assay sensitivity and assay precision points of view.

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Expression of Recombinant HBV Pol Proteins in HepG2 Cells

  • Cho, Ginam;Na, Seun-Gon;Suh, Se-Won;Jung, Gu-Hung
    • BMB Reports
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    • v.33 no.6
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    • pp.440-447
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    • 2000
  • In this study HepG2 cells were used to express and purify HBV pol proteins. In order to facilitate purification of HBV pol proteins, HBV pol and its deletion mutants were fused to MBP (Maltose Binding Protein). As a result we successfully expressed and partially purified both wild type and mutant recombinant HBV pol proteins by using an amylose resin and anti-MBP antibody. In the case of wild type, the anti-MBP antibody detected three bands. One was full-length and the others were generated by proteolysis of the terminal domain region. The expressed MBP/POL proteins were localized both in the cytoplasm and in the perinuclear region. The purified proteins had polymerase activity toward an exogenous homo-polymer template. The MBP/POL protein also had DNA synthesis activity in vivo, since the MBP/POL expression construct was able to complement a HBV polymerase mutant in trans.

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Suppression of Skin Anaphylactic Reaction by Chungdaesan (靑黛散에 의한 皮膚 아나필락시 反應의 抑制)

  • Kim, Jin;Kim, Jong-han;Kim, Nam-Kwen;Lim, Gyu-sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.11 no.1
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    • pp.69-81
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    • 1998
  • The aim of this study was to investigate the effects of Chungdaesan(CDS) by various administration routes on skin anaphylactic reaction. The most classic and popular skin reaction in vivo is passive cutaneous anaphylaxis(PCA) In this study, therefore, the author investigated the effect of CDS on PCA reaction activated by anti-dinitrophenyl immunoglobulin E antibody The results showed that CDS potently suppressed orally, topically, intraperitoneally, and intradermally administered. However, it did not show suppressive activity when intravenously administered. In addition CDS significantly inhibited anti-DNP IgE induced mast degranulation in mice skin. Moreover, CDS suppressed anaphylactic histamine release from mast cells induced by anti-dinitrophenyl immunoglobulin E antibody. These results indicate that CDS suppresses the PCA reaction by stabilization of mast cells in vivo and in vitro am] also suggest that the differential activity following administration routes may be caused by the difference of bioavailability.

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Monoclonal Antibody Refolding and Assembly: Protein Disulfide Isomerase Reaction Kinetics

  • Park, Sun-Ho;Ryu, Dewey D.Y.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.2
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    • pp.59-63
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    • 2003
  • The protein disulfide isomerase (PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody (Mab) refolding and assembly which accompanies disulfide bend formation. The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb in-termediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant fur a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

Monoclonal Antibody Refolding and Assembly: Protein Disulfide Isomerase Reaction Kinetics

  • Park, Sun-Ho;Ryu, Dewey D.Y.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.1 no.1
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    • pp.13-17
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    • 1996
  • The protein disulfide isomerase(PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody(MAb) refolding and assembly which accompanies disulfide bond formation The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb intermediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant for a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

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SPR-based Antibody-Antigen Interaction for Real Time Analysis of Carbamate Pesticide Residues

  • Yang, Gil-Mo;Kang, Suk-Won
    • Food Science and Biotechnology
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    • v.17 no.1
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    • pp.15-19
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    • 2008
  • This research was conducted to develop a quick and sensitive method of detecting carbamate residues using the immobilization of antibody-antigen interactions with surface plasmon resonance (SPR). We have used commercialized surface plasmon resonance equipment (Biacore 3000). The antibody used for the immunoassay was specific for glutathione-s-transferase (GST) and the antigens included several carbamate pesticides (carbofuran, carbaryl, and benfuracarb). When antigens were applied to the protein GST, the detection limit was 2 ng/mL of carbamate pesticide. The fabricated protein GST maintained its activity for over 200 measurements. Thus we determined that the SPR biosensors could detect the specific reversible binding of a reactant in solution to a binding partner immobilized on the surface of the sensor and allow real-time detection and monitoring.

Gemtuzumab ozogamicin and Antibody Engineering (Gemtuzumab ozogamicin과 항체공학)

  • Kim, Eun-Young
    • Korean Journal of Clinical Pharmacy
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    • v.19 no.2
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    • pp.89-95
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    • 2009
  • Gemtuzumab ozogamicin (GO) is an antibody-targeted chemotherapeutic agent consisting of calicheamicin, a potent cytotoxic antibiotic linked to a recombinant humanized anti CD33 monoclonal antibody directed against the CD33 antigen present on leukemic myeloblasts in most patients with acute myeloid leukemia (AML). GO is indicated for the treatment of patients with CD33 positive AML in first relapse who are 60 years of age or older and who are not considered candidates for cytotoxic chemotherapy. GO has shown moderate activity as a single agent in patients with CD33-positive refractory or relapsed acute myeloid leukaemia, with more promising results in acute promyelocytic leukaemia. The side effect profile may be an improvement on conventional chemotherapy, except for a higher frequency of veno-occlusive disease or sinusoidal obstructive syndrome, especially after a subsequent haematopoietic stem cell transplantation. Because of the different mechanisms of action and non-overlapping toxicities, the integration of this immunoconjugate with standard chemotherapy is a rational approach.

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Production and characterization of monoclonal antibody against bovine coronavirus (소 코로나바이러스에 대한 단크론항체 생산과 특성)

  • Ahn, Jae-moon;Kang, Shien-young
    • Korean Journal of Veterinary Research
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    • v.38 no.3
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    • pp.581-588
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    • 1998
  • Eight monoclonal antibodies(MAbs) against bovine coronavirus(BCV) were produced and characterized. Three MAbs(1G9, 4H12, 5C1) specific to the S glycoprotein and two HE glycoprotein-specific MAbs(2A5, 5G4) were found to neutralize the BCV in fluorescence focus neutralization(FFN) test. Two HE-specific MAbs from the neutralizing MAbs inhibited the hemagglutinating activity of the BCV. None of the N protein-specific MAbs(1C1, 5A12, 6H1) neutralized the virus infectivity. Bovine coronavirus and mouse hepatitis virus, which belong to group II coronaviruses, were differentiated from other groups of coronaviruses(porcine transmissible gastroenteritis virus, porcine epidemic diarrhea virus, canine coronavirus) by all MAbs in fluorescence antibody test(FA), but not in FFN test.

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Establishement of Antibody Selection by Ribosome Display (Ribosome Display를 이용한 항체선별 방법의 확립)

  • Lee, Myung-Shin;Kwon, Myung-Hee;Hwang Kim, Kyongmin;Park, Sun;Shin, Ho-Joon;Kim, Hyung-Il
    • IMMUNE NETWORK
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    • v.3 no.3
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    • pp.219-226
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    • 2003
  • Background: Phage display is the most widely used technique among display methods to produce monoclonal antibody fragment with a specific binding activity. Having a large library for efficient antibody display/selection is quite laborious process to have more than $10^9$ members of transformants. To overcome these limitations, several in vitro selection approaches have been reported. Ribosome display that links phenotypes, proteins, directly to genotype, mRNA, is one of the in vitro display methods. Ribosome display can reach the size of scFv library up to $10^{14}$ molecules and it can be further diversified during PCR steps. To select the high affinity scFv from one pot library, we established ribosome display technique by modifying the previously reported eukaryotic translation system. Methods: To establish the antibody selection system by ribosome display, we used 3D8, anti-DNA antibody. A 3D8 scFv was synthesized in vitro by an in vitro transcription-translation system. The translated 3D8 scFv and the encoding 3D8 mRNA are connected to the ribosome. These scFv-ribosome-mRNA complexes were selected by binding to their specific antigens. The eluted mRNAs from the complexes are reverse transcribed and re-amplified by PCR. To apply this system, antibody library from immunized mouse with terminal protein (TP)-peptide of hepatitis B virus DNA polymerase TP domain was also used. This TP-peptide encompasses the 57~80 amino acid residues of TP. These mRNA/ribosome/scFv complexes by our system were panned three times against TP-peptide. The enrichment of antibody from library was determined by radioimmunoassay. Results: We specifically selected 3D8, anti-DNA antibody, against ssDNA as a model system. The selected 3D8 RNAs sequences from translation complexes were recovered by RT-PCR. By applying this model system, we enriched TP-peptide-specific scFv pools through three cycles of panning from immunized library. Conclusion: We show that our translating ribosome complexes are well maintained and we can enrich the TP-specific scFv pools. This system can be applied to select specific antibody from an antibody library.