• 제목/요약/키워드: Antibody characterization

검색결과 247건 처리시간 0.027초

Affinity Maturation of an Epidermal Growth Factor Receptor Targeting Human Monoclonal Antibody ER414 by CDR Mutation

  • Chang, Ki-Hwan;Kim, Min-Soo;Hong, Gwang-Won;Seo, Mi-Sun;Shin, Yong-Nam;Kim, Se-Ho
    • IMMUNE NETWORK
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    • 제12권4호
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    • pp.155-164
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    • 2012
  • It is well established that blocking the interaction of EGFR with growth factors leads to the arrest of tumor growth, resulting in tumor cell death. ER414 is a human monoclonal antibody (mAb) derived by guided selection of the mouse mAb A13. The ER414 exhibited a ~17-fold lower affinity and, as a result, lower efficacy of inhibition of the EGF-mediated tyrosine phosphorylation of EGFR when compared with mAb A13 and cetuximab. We performed a stepwise in vitro affinity maturation to improve the affinity of ER414. We obtained a 3D model of ER414 to identify the amino acids in the CDRs that needed to be mutated. Clones were selected from the phage library with randomized amino acids in the CDRs and substitution of amino acids in the HCDR3 and LCDR1 of ER414 led to improved affinity. A clone, H3-14, with a ~20-fold increased affinity, was selected from the HCDR3 randomized library. Then three clones, ER2, ER78 and ER79, were selected from the LCDR1 randomized library based on the H3-14 but did not show further increased affinities compared to that of H3-14. Of the three, ER2 was chosen for further characterization due to its better expression than others. We successfully performed affinity maturation of ER414 and obtained antibodies with a similar affinity as cetuximab. And antibody from an affinity maturation inhibits the EGF-mediated tyrosine phosphorylation of EGFR in a manner similar to cetuximab.

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

  • 고광삼;이숙영;이근배
    • 미생물학회지
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    • 제23권1호
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    • pp.64-68
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    • 1985
  • 페디스토마 성충의 단백질을 정제하여 이를 항원으로 면역시킨 mouse의 spleen cell과 myeloma cell을 세포융합 시킨 결과 융합율은 56% 이었고. 3차 cloning한 후의 항체생산율은 89% 이였으며, 이들 융합세포로 부터 IgM을 생산하는 hybridoma clone과 IgG을 생산하는 hybridoma clone을 얻었다. IgM을 생산하는 hybridoma clone의 supernate는 antibody titer가 희석농도 1 : 64까지 양성이었고. IgG을 생산하는 hybridoma clone의 supernate는 1 : 256까지 양성이었다.

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Cloning and Characterization of a Single Chain Antibody to Glucose Oxidase from a Murine Hybridoma

  • Sellrie, Frank;Schenk, Jorg A.;Behrsing, Olaf;Drechsel, Oliver;Micheel, Burkhard
    • BMB Reports
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    • 제40권6호
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    • pp.875-880
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    • 2007
  • Glucose oxidase (GOD) is an oxidoreductase catalyzing the reaction of glucose and oxygen to peroxide and gluconolacton (EC 1.1.3.4.). GOD is a widely used enzyme in biotechnology. Therefore the production of monoclonal antibodies and antibody fragments to GOD are of interest in bioanalytics and even tumor therapy. We describe here the generation of a panel of monoclonal antibodies to native and heat inactivated GOD. One of the hybridomas, E13BC8, was used for cloning of a single chain antibody(scFv). This scFv was expressed in Escherichia coli XL1-blue with the help of the vector system pOPE101. The scFv was isolated from the periplasmic fraction and detected by western blotting. It reacts specifically with soluble active GOD but does not recognize denatured GOD adsorbed to the solid phase. The same binding properties were also found for the monoclonal antibody E13BC8.

Characterization of a Peptide Antibody Specific to the Adenylyl Cyclase-Associated Protein of Acanthamoeba castellanii

  • Kim, Min-Jeong;Lee, Hae-Ahm;Quan, Fu-Shi;Kong, Hyun-Hee;Moon, Eun-Kyung
    • Parasites, Hosts and Diseases
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    • 제60권1호
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    • pp.7-14
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    • 2022
  • Acanthamoeba keratitis (AK) is a rare infectious disease and accurate diagnosis has remained arduous as clinical manifestations of AK were similar to keratitis of viral, bacterial, or fungal origins. In this study, we described the production of a polyclonal peptide antibody against the adenylyl cyclase-associated protein (ACAP) of A. castellanii, and evaluated its differential diagnostic potential. Enzyme-linked immunosorbent assay revealed high titers of A. castellanii-specific IgG and IgA antibodies being present in low dilutions of immunized rabbit serum. Western blot analysis revealed that the ACAP antibody specifically interacted with A. castellanii, while not interacting with human corneal epithelial (HCE) cells and other causes of keratitis such as Fusarium solani, Pseudomonas aeruginosa, and Staphylococcus aureus. Immunocytochemistry (ICC) results confirmed the specific detection of trophozoites and cysts of A. castellanii co-cultured with HCE cells. The ACAP antibody also specifically interacted with the trophozoites and cysts of 5 other Acanthamoeba species. These results indicate that the ACAP antibody of A. castellanii can specifically detect multiple AK-causing members belonging to the genus Acanthamoeba and may be useful for differentially diagnosing Acanthamoeba infections.

Development and Characterization of a Specific Anti-Caveolin-1 Antibody for Caveolin-1 Functional Study in Human, Goat and Mouse

  • Ke, Meng-Wei;Jiang, Yan-Nian;Li, Yi-Hung;Tseng, Ting-Yu;Kung, Ming-Shung;Huang, Chiun-Sheng;Cheng, Winston Teng-Kuei;Hsu, Jih-Tay;Ju, Yu-Ten
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권6호
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    • pp.856-865
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    • 2007
  • Caveolin-1 of the caveolin family of proteins regulates mammary gland development and has been shown to play a contradictory role in breast tumor progression. A specific anti-Caveolin-1 antibody will be useful for functional study of Caveolin-1 in different tissues. In this study, we generated a rabbit polyclonal antibody that specifically recognizes the N-terminal amino acids 50-65 of Caveolin-1. This polyclonal antibody specifically reacted with Caveolin-1 extracted from cells of different species, including human epithelial A431 cells, goat primary mammary epithelial cells and mice fibroblast NIH 3T3 cells, by Western blotting. Endogenous Caveolin-1 protein expressing in cells and normal human tissues was detected by this polyclonal antibody using immunocytofluorescent and immunohistochemical staining, respectively. Furthermore, an apparent decrease in Caveolin-1 expression in tumorous breast and colon tissues was detected by this polyclonal antibody. In conclusion, we have identified amino acids 50-65 of Caveolin-1, which contains an epitope that is specific to Caveolin-1 and is conserved in the human, goat and mouse. In future, this anti-Caveolin-1 antibody can be used to examine the progression of breast and colon cancers and to study functions of Caveolin-1 in human, goat and mouse cells.

대장균의 내열성장독소 측정법개발을 위한 단세포군항체의 생산 (Production of the Monoclonal Antibodies to the Escherichia coli Heat-Stable Enterotoxin)

  • 장우현;이우곤;김석용;박정범
    • 대한미생물학회지
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    • 제22권4호
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    • pp.377-392
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    • 1987
  • Monoclonal antibody to the Escherichia coli heat-stable enterotoxin(ST) was produced to develop a rapid and convenient diagnostic method to the ST. The toxin was purified from culture supernatant of enterotoxigenic E. coli O148H28($ST^+/LT^+$) and conjugated to bovine serum albumin(BSA). The ST-BSA conjugate was used to immunize BALB/c mice and the immune spleen cells from these mice were fused with $P3{\times}63$ Ag8.V653 plasmacytoma cells. Hybridomas were screened by ELISA and positive hybridomas were cloned by limiting dilution. Finally, one stable clone (AS36) specific to ST was selected for further growth and characterization. Antibody titers of culture supernatant and ascitic fluid from BALB/c mice were 1:1,024 and 1:20,480 respectively in ELISA. The isotype and subclass of monoclonal antibody was IgG1 in sandwich ELISA. To test the neutralizing effect of monoclonal antibody on toxin activity of ST, mixture of ascitic fluid and ST was assayed by infant mouse assay and this monoclonel antibody was proved to be a neutralizing antibody. The titer of ascitic fluid which completely neutralized biological activity of 4 units of ST was 1:4. Purified ST was quantitatively measured by competitive ELISA and minimum amount of ST detectable by this assay was 250pg, which was an amount six-fold smaller than that detectable by infant mouse assay. Four reference strains of enterotoxigenic E. coli from WHO were detected by competitive ELISA and highly specific, sensitive and reproducible result was obtained.

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