Ju, Man-Seok Na, Jung-Hyun Yu, Yeon Gyu Kim, Jae-Yeol Jeong, Cherlhyun Jung, Sang Taek 2024-01-20T06:02:10Z 2024-01-20T06:02:10Z 2021-09-05 2015-10 0161-5890 https://pubs.kist.re.kr/handle/201004/124927 In contrast to the glycosylated IgG antibodies secreted by human plasma cells, the aglycosylated IgG antibodies produced by bacteria are unable to bind Fc gamma Rs expressed on the surface of immune effector cells and cannot trigger immune effector functions. To avoid glycan heterogeneity problems, elicit novel effector functions, and produce therapeutic antibodies with effector function using a simple bacterial expression system, Fc gamma RI-specific Fc-engineered aglycosylated antibodies, Fc11 (E382V) and Fc (E382V/M428I), containing mutations in the CH3 region, were isolated in a previous study. To elucidate the relationship between Fc gamma RI binding affinity and the structural dynamics of the upper CH2 region of Fc induced by the CH3 mutations, the conformational variation of Fc variants was observed by single-molecule Forster resonance energy transfer (FRET) analysis using alternating-laser excitation (ALEX). In sharp contrast to wild-type Fc, which exhibits a highly dynamic upper CH2 region, the mutations in the CH3 region significantly stabilized the upper CH2 region. The results indicate that conformational plasticity, as well as the openness of the upper CH2 region, is critical for Fc gamma R binding and therapeutic effector functions of IgG antibodies. (C) 2015 Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD RESONANCE ENERGY-TRANSFER MONOCLONAL-ANTIBODY CONFORMATIONAL STABILITY ESCHERICHIA-COLI GLYCOSYLATION DEGLYCOSYLATION FRAGMENT COMPLEX THERAPEUTICS RECOGNITION Structural consequences of aglycosylated IgG Fc variants evolved for Fc gamma RI binding Article 10.1016/j.molimm.2015.06.020 1 MOLECULAR IMMUNOLOGY, v.67, no.2, pp.350 - 356 MOLECULAR IMMUNOLOGY 67 2 350 356 scie scopus 000361922400019 2-s2.0-84940959004 Biochemistry & Molecular Biology Immunology Biochemistry & Molecular Biology Immunology Article RESONANCE ENERGY-TRANSFER MONOCLONAL-ANTIBODY CONFORMATIONAL STABILITY ESCHERICHIA-COLI GLYCOSYLATION DEGLYCOSYLATION FRAGMENT COMPLEX THERAPEUTICS RECOGNITION Antibody engineering Aglycosylated antibody Effector function Single-molecule analysis Forster resonance energy transfer Alternative laser excitation