5GSQ

Crystal structure of IgG Fc with a homogeneous glycoform and Antibody-Dependent Cellular Cytotoxicity


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.229 

wwPDB Validation   3D Report Full Report



Literature

Crystal Structure of a Homogeneous IgG-Fc Glycoform with the N-Glycan Designed to Maximize the Antibody Dependent Cellular Cytotoxicity

Chen, C.-L.Hsu, J.-C.Lin, C.-W.Wang, C.-H.Tsai, M.-H.Wu, C.-Y.Wong, C.-H.Ma, C.

(2017) ACS Chem Biol 12: 1335-1345

  • DOI: 10.1021/acschembio.7b00140
  • Primary Citation of Related Structures:  
    5GSQ

  • PubMed Abstract: 
  • N-glycosylation on IgG modulates Fc conformation and effector functions. An IgG-Fc contains a human sialo-complex type (hSCT) glycan of biantennary structure with two α2,6-sialylations and without core-fucosylation is an optimized glycoform developed ...

    N-glycosylation on IgG modulates Fc conformation and effector functions. An IgG-Fc contains a human sialo-complex type (hSCT) glycan of biantennary structure with two α2,6-sialylations and without core-fucosylation is an optimized glycoform developed to enhance the antibody dependent cellular cytotoxicity (ADCC). hSCT modification not only enhances the binding affinity to Fc receptors in the presence of antigen but also in some cases provides gain-of-function effector activity. We used enzymatic glyco-engineering to prepare an IgG-Fc with homogeneous hSCT attached to each C H 2 domain and solved its crystal structure. A compact form and an open form were observed in an asymmetric unit in the crystal. In the compact structure, the double glycan latches from the two hSCT chains stabilize the C H 2 domains in a closed conformation. In the open structure, the terminal sialic acid (N-acetylneuraminic acid or NeuNAc) residue interacts through water-mediated hydrogen bonds with the D249-L251 helix, to modulate the pivot region of the C H 2-C H 3 interface. The double glycan latches and the sialic acid modulation may be mutually exclusive. This is the first crystal structure of glyco-engineered Fc with enhanced effector activities. This work provides insights into the relationship between the structural stability and effector functions affected by hSCT modification and the development of better antibodies for therapeutic applications.


    Organizational Affiliation

    Chemical Biology and Molecular Biophysics program, Taiwan International Graduate Program, Academia Sinica , Taipei, Taiwan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Ig gamma-1 chain C regionABCD225Homo sapiensMutation(s): 0 
Gene Names: IGHG1
Find proteins for P01857 (Homo sapiens)
Explore P01857 
Go to UniProtKB:  P01857
NIH Common Fund Data Resources
PHAROS  P01857
Protein Feature View
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
beta-D-galactopyranose-(1-4)-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)-2-acetamido-2-deoxy-beta-D-glucopyranose
E, F
7 N-Glycosylation Oligosaccharides Interaction
Entity ID: 3
MoleculeChainsChain 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)-[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
G
8 N-Glycosylation Oligosaccharides Interaction
Entity ID: 4
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-3)-alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
H
5 N-Glycosylation Oligosaccharides Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.229 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 50.183α = 90
b = 158.406β = 109.04
c = 66.905γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
Cootmodel building
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Academia SinicaTaiwan--

Revision History 

  • Version 1.0: 2017-06-28
    Type: Initial release
  • Version 1.1: 2017-10-04
    Changes: Data collection
  • Version 2.0: 2020-03-18
    Changes: Atomic model, Data collection, Derived calculations
  • Version 3.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary