4UIL

crystal structure of quinine-dependent Fab 314.1 with quinine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.335 
  • R-Value Work: 0.269 
  • R-Value Observed: 0.275 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural Basis for Quinine-Dependent Antibody Binding to Platelet Integrin Alphaiib Beta3

Zhu, J.Zhu, J.Bougie, D.W.Aster, R.H.Springer, T.A.

(2015) Blood 126: 2138

  • DOI: 10.1182/blood-2015-04-639351
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Drug-induced immune thrombocytopenia (DITP) is caused by antibodies that react with specific platelet-membrane glycoproteins when the provoking drug is present. More than 100 drugs have been implicated as triggers for this condition, quinine being on ...

    Drug-induced immune thrombocytopenia (DITP) is caused by antibodies that react with specific platelet-membrane glycoproteins when the provoking drug is present. More than 100 drugs have been implicated as triggers for this condition, quinine being one of the most common. The cause of DITP in most cases appears to be a drug-induced antibody that binds to a platelet membrane glycoprotein only when the drug is present. How a soluble drug promotes binding of an otherwise nonreactive immunoglobulin to its target, leading to platelet destruction, is uncertain, in part because of the difficulties of working with polyclonal human antibodies usually available only in small quantities. Recently, quinine-dependent murine monoclonal antibodies were developed that recognize a defined epitope on the β-propeller domain of the platelet integrin αIIb subunit (GPIIb) only when the drug is present and closely mimic the behavior of antibodies found in human patients with quinine-induced thrombocytopenia in vitro and in vivo. Here, we demonstrate specific, high-affinity binding of quinine to the complementarity-determining regions (CDRs) of these antibodies and define in crystal structures the changes induced in the CDR by this interaction. Because no detectable binding of quinine to the target integrin could be demonstrated in previous studies, the findings indicate that a hybrid paratope consisting of quinine and reconfigured antibody CDR plays a critical role in recognition of its target epitope by an antibody and suggest that, in this type of drug-induced immunologic injury, the primary reaction involves binding of the drug to antibody CDRs, causing it to acquire specificity for a site on a platelet integrin.


    Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA; Program in Cellular and Molecular Medicine, Children's Hospital Boston, Boston, MA;



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
FAB 314.1H222Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
FAB 314.1L213Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
QI9
Query on QI9

Download CCD File 
H
Quinine
C20 H24 N2 O2
LOUPRKONTZGTKE-WZBLMQSHSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.335 
  • R-Value Work: 0.269 
  • R-Value Observed: 0.275 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.31α = 90
b = 62.31β = 90
c = 232.719γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-09-02
    Type: Initial release
  • Version 1.1: 2015-11-11
    Changes: Database references