4R9W

Crystal structure of platelet factor 4 complexed with fondaparinux


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.224 

wwPDB Validation   3D Report Full Report



Literature

Atomic description of the immune complex involved in heparin-induced thrombocytopenia.

Cai, Z.Yarovoi, S.V.Zhu, Z.Rauova, L.Hayes, V.Lebedeva, T.Liu, Q.Poncz, M.Arepally, G.Cines, D.B.Greene, M.I.

(2015) Nat Commun 6: 8277-8277

  • DOI: 10.1038/ncomms9277
  • Primary Citation of Related Structures:  
    4R97, 4R9W, 4R9Y

  • PubMed Abstract: 
  • Heparin-induced thrombocytopenia (HIT) is an autoimmune thrombotic disorder caused by immune complexes containing platelet factor 4 (PF4), antibodies to PF4 and heparin or cellular glycosaminoglycans (GAGs). Here we solve the crystal structures of the: ( ...

    Heparin-induced thrombocytopenia (HIT) is an autoimmune thrombotic disorder caused by immune complexes containing platelet factor 4 (PF4), antibodies to PF4 and heparin or cellular glycosaminoglycans (GAGs). Here we solve the crystal structures of the: (1) PF4 tetramer/fondaparinux complex, (2) PF4 tetramer/KKO-Fab complex (a murine monoclonal HIT-like antibody) and (3) PF4 monomer/RTO-Fab complex (a non-HIT anti-PF4 monoclonal antibody). Fondaparinux binds to the 'closed' end of the PF4 tetramer and stabilizes its conformation. This interaction in turn stabilizes the epitope for KKO on the 'open' end of the tetramer. Fondaparinux and KKO thereby collaborate to 'stabilize' the ternary pathogenic immune complex. Binding of RTO to PF4 monomers prevents PF4 tetramerization and inhibits KKO and human HIT IgG-induced platelet activation and platelet aggregation in vitro, and thrombus progression in vivo. The atomic structures provide a basis to develop new diagnostics and non-anticoagulant therapeutics for HIT.


    Organizational Affiliation

    Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Platelet factor 4 AB70Homo sapiensMutation(s): 0 
Gene Names: PF4CXCL4SCYB4
Find proteins for P02776 (Homo sapiens)
Explore P02776 
Go to UniProtKB:  P02776
NIH Common Fund Data Resources
PHAROS:  P02776
Protein Feature View
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-deoxy-6-O-sulfo-2-(sulfoamino)-alpha-D-glucopyranose-(1-4)-beta-D-glucopyranuronic acid-(1-4)-2-deoxy-3,6-di-O-sulfo-2-(sulfoamino)-alpha-D-glucopyranose-(1-4)-2-O-sulfo-alpha-L-idopyranuronic acid-(1-4)-methyl 2-deoxy-6-O-sulfo-2-(sulfoamino)-alpha-D-glucopyranoside
C
5 N/A Oligosaccharides Interaction
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 2
IDChainsNameType/Class2D Diagram3D Interactions
PRD_900028
Query on PRD_900028
CfondaparinuxOligosaccharide /  Anticoagulant

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.224 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 67.333α = 90
b = 67.333β = 90
c = 61.756γ = 120
Software Package:
Software NamePurpose
MAR345data collection
MOLREPphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-12-16
    Type: Initial release
  • Version 1.1: 2016-01-27
    Changes: Database references
  • Version 1.2: 2017-07-12
    Changes: Structure summary
  • Version 1.3: 2017-11-22
    Changes: Refinement description
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary