4BM7

Crystal Structure of IgG Fc F241A mutant with native glycosylation


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Engineering Hydrophobic Protein-Carbohydrate Interactions to Fine-Tune Monoclonal Antibodies.

Yu, X.Baruah, K.Harvey, D.J.Vasiljevic, S.Alonzi, D.S.Song, B.Higgins, M.K.Bowden, T.A.Scanlan, C.N.Crispin, M.

(2013) J Am Chem Soc 135: 9723

  • DOI: https://doi.org/10.1021/ja4014375
  • Primary Citation of Related Structures:  
    4BM7

  • PubMed Abstract: 

    Biologically active conformations of the IgG1 Fc homodimer are maintained by multiple hydrophobic interactions between the protein surface and the N-glycan. The Fc glycan modulates biological effector functions, including antibody-dependent cellular cytotoxicity (ADCC) which is mediated in part through the activatory Fc receptor, FcγRIIIA. Consistent with previous reports, we found that site-directed mutations disrupting the protein-carbohydrate interface (F241A, F243A, V262E, and V264E) increased galactosylation and sialylation of the Fc and, concomitantly, reduced the affinity for FcγRIIIA. We rationalized this effect by crystallographic analysis of the IgG1 Fc F241A mutant, determined here to a resolution of 1.9 Å, which revealed localized destabilization of this glycan-protein interface. Given that sialylation of Fc glycans decreases ADCC, one explanation for the effect of these mutants on FcγRIIIA binding is their increased sialylation. However, a glycan-engineered IgG1 with hypergalactosylated and hypersialylated glycans exhibited unchanged binding affinity to FcγRIIIA. Moreover, when we expressed these mutants as a chemically uniform (Man5GlcNAc2) glycoform, the individual effect of each mutation on FcγRIIIA affinity was preserved. This effect was broadly recapitulated for other Fc receptors (FcγRI, FcγRIIA, FcγRIIB, and FcγRIIIB). These data indicate that destabilization of the glycan-protein interactions, rather than increased galactosylation and sialylation, modifies the Fc conformation(s) relevant for FcγR binding. Engineering of the protein-carbohydrate interface thus provides an independent parameter in the engineering of Fc effector functions and a route to the synthesis of new classes of Fc domain with novel combinations of affinities for activatory and inhibitory Fc receptors.


  • Organizational Affiliation

    Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
IG GAMMA-1 CHAIN C REGION
A, B
233Homo sapiensMutation(s): 3 
UniProt & NIH Common Fund Data Resources
Find proteins for P01857 (Homo sapiens)
Explore P01857 
Go to UniProtKB:  P01857
PHAROS:  P01857
GTEx:  ENSG00000211896 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01857
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose
C
7N-Glycosylation
Glycosylation Resources
GlyTouCan:  G20449BJ
GlyCosmos:  G20449BJ
GlyGen:  G20449BJ
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download Ideal Coordinates CCD File 
D [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.868α = 90
b = 73.375β = 90
c = 135.951γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-07-03
    Type: Initial release
  • Version 1.1: 2013-07-17
    Changes: Database references
  • Version 1.2: 2019-04-03
    Changes: Data collection, Derived calculations, Other, Source and taxonomy
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Other, Structure summary
  • Version 2.1: 2023-12-20
    Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary