Chemical and Structural Analysis of an Antibody Folding Intermediate Trapped during Glycan Biosynthesis

DOI: 10.1021/ja306068g
PMID: 23025485

Authors: Thomas A. Bowden (Division of Structural Biology, University of Oxford) , Kavitha Baruah (University of Oxford) , Charlotte H. Coles (Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford) , David J. Harvey (Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford) , Xiaojie Yu (Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford) , Byeong-doo Song (Scripps Korea Antibody Institute) , Dave Stuart (Diamond Light Source) , A Radu Aricescu (Division of Structural Biology, University of Oxford, Wellcome Trust Centre for Human Genetics) , Christopher N. Scanlan (Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford) , E. Yvonne Jones (University of Oxford) , Max Crispin (Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of The American Chemical Society , VOL 134 (42) , PAGES 5723-5729

State: Published (Approved)
Published: October 2012

Abstract: Human IgG Fc glycosylation modulates immunological effector functions such as antibody-dependent cellular cytotoxicity and phagocytosis. Engineering of Fc glycans therefore enables fine-tuning of the therapeutic properties of monoclonal antibodies. The N-linked glycans of Fc are typically complex-type, forming a network of noncovalent interactions along the protein surface of the C?2 domain. Here, we manipulate the mammalian glycan-processing pathway to trap IgG1 Fc at sequential stages of maturation, from oligomannose- to hybrid- to complex-type glycans, and show that the Fc is structurally stabilized following the transition of glycans from their hybrid- to complex-type state. X-ray crystallographic analysis of this hybrid-type intermediate reveals that N-linked glycans undergo conformational changes upon maturation, including a flip within the trimannosyl core. Our crystal structure of this intermediate reveals a molecular basis for antibody biogenesis and provides a template for the structure-guided engineering of the protein–glycan interface of therapeutic antibodies.

Subject Areas: Biology and Bio-materials


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