4DTG image
Deposition Date 2012-02-21
Release Date 2012-06-13
Last Version Date 2024-11-27
Entry Detail
PDB ID:
4DTG
Title:
Hemostatic effect of a monoclonal antibody mAb 2021 blocking the interaction between FXa and TFPI in a rabbit hemophilia model
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Host Organism:
Method Details:
Experimental Method:
Resolution:
1.80 Å
R-Value Free:
0.23
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
I 2 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Humanized recombinant FAB fragment, FAB 2021, of a murine antibody, heavy chain
Chain IDs:B (auth: H)
Chain Length:222
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Tissue factor pathway inhibitor
Gene (Uniprot):TFPI
Chain IDs:C (auth: K)
Chain Length:66
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Humanized recombinant FAB fragment, FAB 2021, of a murine antibody, light chain
Chain IDs:A (auth: L)
Chain Length:219
Number of Molecules:1
Biological Source:Homo sapiens
Primary Citation
Hemostatic effect of a monoclonal antibody mAb 2021 blocking the interaction between FXa and TFPI in a rabbit hemophilia model.
Blood 119 5871 5878 (2012)
PMID: 22563084 DOI: 10.1182/blood-2012-01-401620

Abstact

Hemophilia is treated by IV replacement therapy with Factor VIII (FVIII) or Factor IX (FIX), either on demand to resolve bleeding, or as prophylaxis. Improved treatment may be provided by drugs designed for subcutaneous and less frequent administration with a reduced risk of inhibitor formation. Tissue factor pathway inhibitor (TFPI) down-regulates the initiation of coagulation by inhibition of Factor VIIa (FVIIa)/tissue factor/Factor Xa (FVIIa/TF/FXa). Blockage of TFPI inhibition may facilitate thrombin generation in a hemophilic setting. A high-affinity (K(D) = 25pM) mAb, mAb 2021, against TFPI was investigated. Binding of mAb 2021 to TFPI effectively prevented inhibition of FVIIa/TF/FXa and improved clot formation in hemophilia blood and plasma. The binding epitope on the Kunitz-type protease inhibitor domain 2 of TFPI was mapped by crystallography, and showed an extensive overlap with the FXa contact region highlighting a structural basis for its mechanism of action. In a rabbit hemophilia model, an intravenous or subcutaneous dose significantly reduced cuticle bleeding. mAb 2021 showed an effect comparable with that of rFVIIa. Cuticle bleeding in the model was reduced for at least 7 days by a single intravenous dose of mAb 2021. This study suggests that neutralization of TFPI by mAb 2021 may constitute a novel treatment option in hemophilia.

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Primary Citation of related structures