Crystal structure of a chemoenzymatic glycoengineered disialylated Fc (di-sFc)

Experimental Data Snapshot

  • Resolution: 3.00 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.260 

Starting Model: experimental
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Structural characterization of anti-inflammatory immunoglobulin g fc proteins.

Ahmed, A.A.Giddens, J.Pincetic, A.Lomino, J.V.Ravetch, J.V.Wang, L.X.Bjorkman, P.J.

(2014) J Mol Biol 426: 3166-3179

  • DOI: https://doi.org/10.1016/j.jmb.2014.07.006
  • Primary Citation of Related Structures:  
    4Q6Y, 4Q74, 4Q7D

  • PubMed Abstract: 

    Immunoglobulin G (IgG) is a central mediator of host defense due to its ability to recognize and eliminate pathogens. The recognition and effector responses are encoded on distinct regions of IgGs. The diversity of the antigen recognition Fab domains accounts for IgG's ability to bind with high specificity to essentially any antigen. Recent studies have indicated that the Fc effector domain also displays considerable heterogeneity, accounting for its complex effector functions of inflammation, modulation, and immune suppression. Therapeutic anti-tumor antibodies, for example, require the pro-inflammatory properties of the IgG Fc to eliminate tumor cells, while the anti-inflammatory activity of intravenous IgG requires specific Fc glycans for activity. In particular, the anti-inflammatory activity of intravenous IgG is ascribed to a small population of IgGs in which the Asn297-linked complex N-glycans attached to each Fc CH2 domain include terminal α2,6-linked sialic acids. We used chemoenzymatic glycoengineering to prepare fully disialylated IgG Fc and solved its crystal structure. Comparison of the structures of asialylated Fc, sialylated Fc, and F241A Fc, a mutant that displays increased glycan sialylation, suggests that increased conformational flexibility of the CH2 domain is associated with the switch from pro-inflammatory to anti-inflammatory activity of the Fc.

  • Organizational Affiliation

    Division of Biology and Biological Engineering 114-96, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Ig gamma-1 chain C region
A, B, C, D
221Homo sapiensMutation(s): 0 
Gene Names: IGHG1
UniProt & NIH Common Fund Data Resources
Find proteins for P01857 (Homo sapiens)
Explore P01857 
Go to UniProtKB:  P01857
GTEx:  ENSG00000211896 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01857
Sequence Annotations
  • Reference Sequence


Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
Glycosylation Resources
GlyTouCan:  G39213VZ
GlyCosmos:  G39213VZ
GlyGen:  G39213VZ
Entity ID: 3
MoleculeChains Length2D Diagram Glycosylation3D Interactions
N-acetyl-alpha-neuraminic acid-(2-6)-beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
F, G
Glycosylation Resources
GlyTouCan:  G90725ZC
GlyCosmos:  G90725ZC
GlyGen:  G90725ZC
Entity ID: 4
MoleculeChains Length2D Diagram Glycosylation3D Interactions
Glycosylation Resources
GlyTouCan:  G89993FE
GlyCosmos:  G89993FE
GlyGen:  G89993FE
Experimental Data & Validation

Experimental Data

  • Resolution: 3.00 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.260 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.73α = 90
b = 154.22β = 110.78
c = 66.12γ = 90
Software Package:
Software NamePurpose
BOSdata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-07-23
    Type: Initial release
  • Version 1.1: 2014-07-30
    Changes: Database references
  • Version 1.2: 2014-08-13
    Changes: Derived calculations
  • Version 1.3: 2014-09-03
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2023-09-20
    Changes: Advisory, Data collection, Database references, Refinement description, Structure summary