• Title/Summary/Keyword: antibody engineering

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Redistribution of Intracellular Calcium Stores with Shear Stress-induced Cytoskeleton Organization in Human Endothelial Cell

  • Chung, Chan-Il;Chang, Hyun-A;Chang, Jun-Keun;Han, Dong-Chul;Min, Byoung-Goo
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.97-99
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    • 1996
  • Intracellular gradients of the free calcium concentration are thought to be critical for the localization of functional responses within a cell. The mechanism of mechanotransduction may be associated with the localized accumulation of calcium stores for shear stress-exposed endothelial cells. The distribution of the calcium stores and the formation of the stress fibers were investigated by the indirect double immunofluorescent staining method with the calreticulin antibody and rhodamine phalloidin under flow condition. The shear stress of steady flow reorganized the cytoskeleton structure including the bundling and translocation to focal contacts. The calcium stores translocated from the cytoplasm to the focal contacting area. Consequently. accumulation of the calcium stores may participate in the shear stress-induced cytoskeleton organization of endothelial cells.

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Combinatorial Solid Phase Peptide Synthesis and Bioassays

  • Shin, Dong-Sik;Kim, Do-Hyun;Chung, Woo-Jae;Lee, Yoon-Sik
    • BMB Reports
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    • v.38 no.5
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    • pp.517-525
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    • 2005
  • Solid phase peptide synthesis method, which was introduced by Merrifield in 1963, has spawned the concept of combinatorial chemistry. In this review, we summarize the present technologies of solid phase peptide synthesis (SPPS) that are related to combinatorial chemistry. The conventional methods of peptide library synthesis on polymer support are parallel synthesis, split and mix synthesis and reagent mixture synthesis. Combining surface chemistry with the recent technology of microelectronic semiconductor fabrication system, the peptide microarray synthesis methods on a planar solid support are developed, which leads to spatially addressable peptide library. There are two kinds of peptide microarray synthesis methodologies: pre-synthesized peptide immobilization onto a glass or membrane substrate and in situ peptide synthesis by a photolithography or the SPOT method. This review also discusses the application of peptide libraries for high-throughput bioassays, for example, peptide ligand screening for antibody or cell signaling, enzyme substrate and inhibitor screening as well as other applications.

Detection of Pathogenic Salmonella Using a Surface Plasmon Resonance Biosensor (표면플라즈몬공명 바이오센서를 이용한 살모넬라 검출)

  • Cho, Han-Keun;Kim, Gi-Young;Kim, Woon-Ho;Sung, Min-Sun
    • Journal of Biosystems Engineering
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    • v.35 no.2
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    • pp.116-123
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    • 2010
  • Rapid detection of foodborne pathogens has been a major challenge for the food industry. Salmonella contamination is well known in all foods including pasteurised milk. The possibility of specific detection of Salmonella Enteritidis by surface plasmon resonance (SPR) biosensor was explored using a commercially available portable SPR sensor. Self assembly technique was adopted to immobilize anti-Salmonella antibodies on the gold sensing surface of the SPR sensor. The concentration of polyclonal antibody for use in the SPR biosensor was chosen to 1.0 mg/mL. Experiments were conducted at near real-time with results obtained for one SPR biosensor assay within 1 hour. The limit of detection for Salmonella Enteritidis was determined to be $10^6$ CFU/mL in both PBS buffer and milk samples. The assay sensitivity was not significantly affected by milk matrix. Our results showed that it would be possible for employing the SPR biosensor to detect Salmonella Enteritidis in near real-time.

Pharmacological, Toxicological Studies of Antitumor Polysaccharides Obtained from Ganoderrna lucidurn IY 009 (Ganoderma lucidum IY 009로 부터 분리된 항암성 다당류의 약리 및 독성)

  • Lee, Kweon-Haeng;Lee, Chong-Ock;Lee, June-Woo;Jeong, Hoon;Han, Man-Deuk;Jeong, June-Ho;Oh, Doo-Hwan
    • Microbiology and Biotechnology Letters
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    • v.22 no.2
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    • pp.182-189
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    • 1994
  • The highest antitumor activity was observed in water soluble AS fraction of the Ganoderma lucidum IY 009. AS fraction did not show any cytotoxicity on sarcoma 180 cell but stimulated antibody production, opsonization of macrophage in ICR mouse and superoxide ion production from isolated macrophage. AS fraction activated complement C3 in human serum, and their antitumor activity was inhibited by EDTA, a chelator of cation related complementary activation. AS fraction exerted om prolong of life span and ingibition of tumor growth in the leukemia P388 or L1210 transplanted inbreed mouse,k BDF1 but krestin did not. AS fraction did not show any serious and lethal effects through oral administration on ICR mouse, and LD$_{50}$ of those was above 2,230 mg/kg.

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Acute Phase Protein Lipocalin-2 Is Associated with Formalin-induced Nociception and Pathological Pain

  • Jha, Mithilesh Kumar;Jeon, Sangmin;Jin, Myungwon;Lee, Won-Ha;Suk, Kyoungho
    • IMMUNE NETWORK
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    • v.13 no.6
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    • pp.289-294
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    • 2013
  • Lipocalin-2 (LCN2) is an acute-phase protein induced by injury, infection, or other inflammatory stimuli. LCN2 binds small hydrophobic ligands and interacts with cell surface receptor to regulate diverse cellular processes. The role of LCN2 as a chemokine inducer in the central nervous system (CNS) has been previously reported. Based on the previous participation of LCN2 in neuroinflammation, we investigated the role of LCN2 in formalin-induced nociception and pathological pain. Formalin-induced nociceptive behaviors (licking/biting) and spinal microglial activation were significantly reduced in the second or late phase of the formalin test in Lcn2 knockout mice. Likewise, antibody-mediated neutralization of spinal LCN2 attenuated the mechanical hypersensitivity induced by peripheral nerve injury in mice. Taken together, our results suggest that LCN2 can be therapeutically targeted, presumably for both prevention and reversal of acute inflammatory pain as well as pathological pain.

Uptake of Fibroin Microspheres by 3T3 Cells (3T3 세포에 의한 피브로인 마이크로스피어의 흡수)

  • Lee, Jin Sil;Go, Nam Kyung;Lee, Shin Young;Hur, Won
    • KSBB Journal
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    • v.29 no.5
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    • pp.328-335
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    • 2014
  • Vehicle toxicity is one of the main obstacles for intracellular delivery of bioactive compounds. Silk fibroin is a natural polymer proven to have high biocompatibility since being used as suture material. In this report, fibroin microspheres were prepared without any chemical modification or cross-linking not to affect its biocompatibility. The microspheres were taken up by more than 90% of 3T3 cells. Cellular uptake continued after medium replenishment with a different-colored fluorescent microsphere, suggesting that simultaneous ingestion and exocytosis occurred. Cellular uptake of fibroin microspheres did not affect cell viability. Intracellular trafficking of the microspheres using lysosome-specific fluorescent dye revealed that fibroin microspheres were localized both in the cytoplasm and in the lysosome. Accordingly, fibroin microspheres can be a potential vehicle for intracytoplasmic delivery of large cargos, such as mixtures of proteins, nutrients or artificial organelles.

Preparation and Characteristics of Phosphatidylcholine Liposomes Covalently Coupled with Immunoglobulin Fragments (이뮤노글로부린 토막과 결합된 포스파티딜콜린 리포솜의 제조와 특성)

  • Park, Jung-Hwan;Lee, Eun-Ok;Kim, Jong-Duk
    • Journal of Pharmaceutical Investigation
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    • v.22 no.2
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    • pp.115-124
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    • 1992
  • The characteristics and stabilities of phosphatidylcholine liposomes covalently coupled with immunoglobulin fragments prepared by the REV method were investigated by the dynamic light scattering, absorbance and calcein release. Using a sulfhydryl-reactive phospholipid derivative of N-[4$({\rho}-maleimido-phenyl)$ butyl] phosphatidylethanolamine (MPB-PE), Fab' antibody fragments were covalently combined with preformed large unilamellar vesicles (LUV), Coupling ratio was $250\;{\mu}g$ of $Fab'/{\mu}mol$ of phospholipid in vesicles, From dynamic light scattering, it was found that the size of the vesicles increases as the ratio of cholesterol to lipid increases, but that apparently, the size of liposomes was not sensitive to the existence of Fab' fragments. Regardless of inserting Fab' fragments, the absorbance of liposomes decreased as the amounts of bile salt (BS) added. At very low BS concentrations, BS/lipid aggregates would be formed in the outer vesicles monolayer, while, at the high BS concentrations, mixed micelles would be preferred. The vesicles incorporated with Fab' fragments, however, are more resistant to the bile salts than the MPB-PE vesicle are. The absorbance of vacant liposomes and calcein release resulted in that the Fab' vesicles and MPB-PE vesicles by the REV method are very stable, but that those by the sonication method sufferred the significant change of turbidities.

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Fiber-Optic Sensor Simultaneously Detecting Localized Surface Plasmon Resonance and Surface-Enhanced Raman Scattering

  • Norov, Erdene;Jeong, Hyeon-Ho;Park, Jae-Hyoung;Lee, Seung-Ki;Jeong, Dae Hong
    • Rapid Communication in Photoscience
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    • v.2 no.2
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    • pp.46-51
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    • 2013
  • This study reports a fiber-optic sensor detecting biomolecule by simultaneously monitoring localized surface plasmon resonance (LSPR) from gold nanoparticles (Au NPs) of ca. $50{\pm}5$ nm attached on one end of optical fiber and surface enhanced Raman scattering (SERS) of the reporter molecules adsorbed on the gold surfaces as an additional sensing tool. The sensor was fabricated by immobilizing Au NPs on one end of an optical fiber by chemical reaction. LSPR and SERS signals of the sensor were measured using various refractive indices solutions. Finally, the sensor was applied to observe real-time LSPR sensor-gram and SERS spectra of the reporter molecule of 4-aminothiphenol during the antibody-antigen reaction of interferon-gamma (IFN-${\gamma}$) as a proof-concept experiment of biological applications.

Characterization and Identification of Bacillus thuringiensis subsp. tenebrionis SR6 and SR8

  • Kim, Il-Gi;Lee, Jae-Wook;Suh, Suk-Chul;Rhim, Seong-Lyul
    • Journal of Microbiology and Biotechnology
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    • v.14 no.4
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    • pp.772-776
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    • 2004
  • Physiological and molecular characteristics of Bacillus thuringiensis SR6 and SR8 were investigated, and phase contrast and electron microscopies revealed that a large rhomboidal crystal protein was present in the sporulating cells. SDS-PAGE and Western blot analyses showed that B. thuringiensis SR8 produced 70 kDa protein much more than other proteins, and that the 70 kDa protein could bind to the antibody of B. thuringiensis subsp. tenebrionis-crystal toxin protein, indicating that the crystal 70 kDa protein has an immunological homology with B. thuringiensis subsp. tenebrionis-crystal toxin protein. The DNA fragment of B. thuringiensis subsp. tenebrionis-toxin gene was detected in B. thuringiensis SR6 and SR8 by using PCR amplification analysis. Furthermore, the insect bioassay showed the insecticidal activity against Colorado potato beetle larvae. Based on the physiological and molecular similarities to B. thuringiensis subsp. tenebrionis, it is suggested that the B. thuringiensis SR6 and SR8 may be mutants of the B. thuringiensis subsp. tenebrionis strain overexpressing the crystal of 70 kDa toxin protein.

Glyco-engineering of Biotherapeutic Proteins in Plants

  • Ko, Kisung;Ahn, Mi-Hyun;Song, Mira;Choo, Young-Kug;Kim, Hyun Soon;Ko, Kinarm;Joung, Hyouk
    • Molecules and Cells
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    • v.25 no.4
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    • pp.494-503
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    • 2008
  • Many therapeutic glycoproteins have been successfully generated in plants. Plants have advantages regarding practical and economic concerns, and safety of protein production over other existing systems. However, plants are not ideal expression systems for the production of biopharmaceutical proteins, due to the fact that they are incapable of the authentic human N-glycosylation process. The majority of therapeutic proteins are glycoproteins which harbor N-glycans, which are often essential for their stability, folding, and biological activity. Thus, several glyco-engineering strategies have emerged for the tailor-making of N-glycosylation in plants, including glycoprotein subcellular targeting, the inhibition of plant specific glycosyltranferases, or the addition of human specific glycosyltransferases. This article focuses on plant N-glycosylation structure, glycosylation variation in plant cell, plant expression system of glycoproteins, and impact of glycosylation on immunological function. Furthermore, plant glyco-engineering techniques currently being developed to overcome the limitations of plant expression systems in the production of therapeutic glycoproteins will be discussed in this review.