학술논문
Structural basis for improved efficacy of therapeutic antibodies on defucosylation of their Fc glycans.
Document Type
Article
Author
Source
Subject
*IMMUNOGLOBULIN G
*ANTIBODY-dependent cell cytotoxicity
*GLYCOSYLATION
*RADIOLIGAND assay
*STERIC hindrance
*FC receptors
*MOLECULAR structure
*BINDING sites
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Language
ISSN
1356-9597
Abstract
Removal of the fucose residue from the N-glycans of the Fc portion of immunoglobulin G (IgG) results in a dramatic enhancement of antibody-dependent cellular cytotoxicity (ADCC) through improved affinity for Fcγ receptor IIIa (FcγRIIIa). Here, we present the 2.2-Å structure of the complex formed between nonfucosylated IgG1-Fc and a soluble form of FcγRIIIa (sFcγRIIIa) with two N-glycosylation sites. The crystal structure shows that one of the two N-glycans of sFcγRIIIa mediates the interaction with nonfucosylated Fc, thereby stabilizing the complex. However, fucosylation of the Fc N-glycans inhibits this interaction, because of steric hindrance, and furthermore, negatively affects the dynamics of the receptor binding site. Our results offer a structural basis for improvement in ADCC of therapeutic antibodies by defucosylation. [ABSTRACT FROM AUTHOR]