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 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

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

  • Also Cited By: 5U52

  • 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: 
    • 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.USA 94: 10080
    • 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
    • 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


    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
IMMUNOGLOBULIN GAMMA-1 HEAVY CHAIN CONSTANT REGION
A
207Homo sapiensMutation(s): 0 
Gene Names: IGHG1
Find proteins for P01857 (Homo sapiens)
Go to UniProtKB:  P01857
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Minimized B-domain of Protein A Z34C
B
34N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MAN
Query on MAN

Download SDF File 
Download CCD File 
A
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
GAL
Query on GAL

Download SDF File 
Download CCD File 
A
BETA-D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-FPRJBGLDSA-N
 Ligand Interaction
BMA
Query on BMA

Download SDF File 
Download CCD File 
A
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
FUL
Query on FUL

Download SDF File 
Download CCD File 
A
BETA-L-FUCOSE
6-DEOXY-BETA-L-GALACTOSE
C6 H12 O5
SHZGCJCMOBCMKK-KGJVWPDLSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.206 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 54.023α = 90.00
b = 124.774β = 90.00
c = 90.131γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-04-10
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance