3GIZ

Crystal structure of the Fab fragment of anti-CD20 antibody Ofatumumab


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 

Starting Model: experimental
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This is version 1.3 of the entry. See complete history


Literature

Structure of the Fab fragment of therapeutic antibody Ofatumumab provides insights into the recognition mechanism with CD20

Du, J.Yang, H.Guo, Y.Ding, J.

(2009) Mol Immunol 46: 2419-2423

  • DOI: https://doi.org/10.1016/j.molimm.2009.04.009
  • Primary Citation of Related Structures:  
    3GIZ

  • PubMed Abstract: 

    CD20 is an important drug target for B-cell depletion therapy against certain B-cell lymphomas and autoimmune diseases. The success of anti-CD20 antibody drugs such as Rituximab, Ibritumomab, and Tositumomab has promoted the development of new generation of anti-CD20 antibodies for therapeutic applications. Ofatumumab is a fully human anti-CD20 antibody that is currently in phase III clinical trial for several types of malignancies and autoimmune diseases and is one of the most promising anti-CD20 drugs. Here we report the crystal structure of the Fab fragment of Ofatumumab at 2.2A resolution. The antigen combining site is composed of a large, deep pocket formed by six CDR loops. The pocket has a hydrophobic periphery and a positively charged bottom. Structure analysis and comparison with other antibodies suggest that the hydrophobic periphery might interact with the epitope on CD20 that is enriched with hydrophobic residues and very close to cell membrane, and the positively charged bottom might interact with Glu(150) of CD20 which is the only negatively charged residue within the epitope. These results provide some insights into the recognition of Ofatumumab with CD20 and explain how the antibody can recognize an epitope so close to the cell membrane.


  • Organizational Affiliation

    State Key Laboratory of Molecular Biology and Research Center for Structural Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Fab fragment of anti-CD20 antibody Ofatumumab, light chainA [auth L]211Homo sapiensMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Fab fragment of anti-CD20 antibody Ofatumumab, heavy chainB [auth H]222Homo sapiensMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 136.33α = 90
b = 55.944β = 122.17
c = 79.78γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
PHASERphasing
REFMACrefinement
CrystalCleardata reduction
CrystalCleardata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-05-26
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.3: 2024-10-16
    Changes: Structure summary