2XA8

Crystal structure of the Fab domain of omalizumab at 2.41A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.42 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.223 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural and Physical Basis for Anti-IgE Therapy.

Wright, J.D.Chu, H.M.Huang, C.H.Ma, C.Chang, T.W.Lim, C.

(2015) Sci Rep 5: 11581-11581

  • DOI: 10.1038/srep11581
  • Primary Citation of Related Structures:  
    2XA8

  • PubMed Abstract: 
  • Omalizumab, an anti-IgE antibody, used to treat severe allergic asthma and chronic idiopathic urticaria, binds to IgE in blood or membrane-bound on B lymphocytes but not to IgE bound to its high (FcεRI) or low (CD23) affinity receptor. Mutagenesis studies indicate overlapping FcεRI and omalizumab-binding sites in the Cε3 domain, but crystallographic studies show FcεRI and CD23-binding sites that are far apart, so how can omalizumab block IgE from binding both receptors? We report a 2 ...

    Omalizumab, an anti-IgE antibody, used to treat severe allergic asthma and chronic idiopathic urticaria, binds to IgE in blood or membrane-bound on B lymphocytes but not to IgE bound to its high (FcεRI) or low (CD23) affinity receptor. Mutagenesis studies indicate overlapping FcεRI and omalizumab-binding sites in the Cε3 domain, but crystallographic studies show FcεRI and CD23-binding sites that are far apart, so how can omalizumab block IgE from binding both receptors? We report a 2.42-Å omalizumab-Fab structure, a docked IgE-Fc/omalizumab-Fab structure consistent with available experimental data, and the free energy contributions of IgE residues to binding omalizumab, CD23, and FcεRI. These results provide a structural and physical basis as to why omalizumab cannot bind receptor-bound IgE and why omalizumab-bound IgE cannot bind to CD23/FcεRI. They reveal the key IgE residues and their roles in binding omalizumab, CD23, and FcεRI.


    Organizational Affiliation

    1] Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan [2] Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
OMALIZUMAB HEAVY CHAINA [auth H]219Homo sapiensMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
OMALIZUMAB LIGHT CHAINB [auth L]218Homo sapiensMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.42 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.223 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.6α = 90
b = 73.851β = 90
c = 141.126γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-05-11
    Type: Initial release
  • Version 1.1: 2016-01-27
    Changes: Database references, Version format compliance
  • Version 1.2: 2019-09-18
    Changes: Data collection, Database references, Experimental preparation