1L6X

FC FRAGMENT OF RITUXIMAB BOUND TO A MINIMIZED VERSION OF THE B-DOMAIN FROM PROTEIN A CALLED Z34C


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.206 

wwPDB Validation 3D Report Full Report



Literature

Mapping of the C1q binding site on rituxan, a chimeric antibody with a human IgG1 Fc.

Idusogie, E.E.Presta, L.G.Gazzano-Santoro, H.Totpal, K.Wong, P.Y.Ultsch, M.Meng, Y.G.Mulkerrin, M.G.

(2000) J Immunol 164: 4178-4184

  • DOI: 10.4049/jimmunol.164.8.4178
  • Primary Citation of Related Structures:  
    1L6X

  • PubMed Abstract: 
  • Rituxan (Rituximab) is a chimeric mAb with human IgG1 constant domains used in the therapy of non-Hodgkin's B cell lymphomas. This Ab targets B cells by binding to the cell-surface receptor, CD20. In our investigation of the mechanism of B cell deple ...

    Rituxan (Rituximab) is a chimeric mAb with human IgG1 constant domains used in the therapy of non-Hodgkin's B cell lymphomas. This Ab targets B cells by binding to the cell-surface receptor, CD20. In our investigation of the mechanism of B cell depletion mediated by Rituximab, we first constructed mutants of Rituximab defective in complement activation but with all other effector functions intact. Our results demonstrate that the previously described C1q binding motif in murine IgG2b constituting residues E318, K320, and K322 is not applicable to a human IgG1 when challenged with either human, rabbit, or guinea pig complement. Alanine substitution at positions E318 and K320 in Rituximab had little or no effect on C1q binding and complement activation, whereas alanine substitution at positions D270, K322, P329, and P331 significantly reduced the ability of Rituximab to bind C1q and activate complement. We have also observed that concentrations of complement approaching physiological levels are able to rescue >60% of the activity of these mutant Abs with low affinity for C1q. These data localize the C1q binding epicenter on human IgG1 and suggest that there are species-specific differences in the C1q binding site of Igs.


    Related Citations: 
    • Engineered Antibodies with Increased Activity to Recruit Complement
      Idusogie, E.E., Wong, P.Y., Presta, L.G., Santoro-Gazzano, H., Totpal, K., Ultsch, M., Mullkerrin, M.G.
      (2001) J Immunol 166: 2571
    • Crystal Structure at 2.8A of an FcRn/Heterodimeric Fc Complex: Mechanism of pH-Dependent Binding
      Martin, W.L., West Jr., A.P., Gan, L., Bjorkman, P.J.
      (2001) Mol Cell 7: 867
    • Structural mimicry of a native protein by a minimized binding domain
      Starovasnik, M.A., Braisted, A.C., Wells, J.A.
      (1997) Proc Natl Acad Sci U S A 94: 10080

    Organizational Affiliation

    Departments of Analytical Chemistry, Immunology, QC Clinical Development, BioAnalytical Technology, and Protein Engineering, Genentech, South San Francisco, CA 94080, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
IMMUNOGLOBULIN GAMMA-1 HEAVY CHAIN CONSTANT REGIONA207Homo 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
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Minimized B-domain of Protein A Z34CB34N/AMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Oligosaccharides

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Entity ID: 3
MoleculeChainsChain Length2D Diagram Glycosylation
beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[beta-D-galactopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)]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
10 N-Glycosylation
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.206 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.023α = 90
b = 124.774β = 90
c = 90.131γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
X-PLORrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-04-10
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary