Chemical and Structural Analysis of an Antibody Folding Intermediate Trapped During Glycan Biosynthesis.
Bowden, T.A., Baruah, K., Coles, C.H., Harvey, D.J., Yu, X., Song, B.D., Stuart, D.I., Aricescu, A.R., Scanlan, C.N., Jones, E.Y., Crispin, M.(2012) J Am Chem Soc 134: 17554
- PubMed: 23025485
- DOI: https://doi.org/10.1021/ja306068g
- Primary Citation of Related Structures:
4B7I - PubMed 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 Cγ2 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.
Organizational Affiliation:
Division of Structural Biology, University of Oxford, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom. thomas.bowden@strubi.ox.ac.uk