Solution structure of the major factor VIII binding region on von Willebrand factor.
Although much of the function of von Willebrand factor (VWF) has been revealed, detailed insight into the molecular structure that enables VWF to orchestrate hemostatic processes, in particular factor VIII (FVIII) binding and stabilization in plasma, is lacking. Here, we present the high-resolution solution structure and structural dynamics of the D' region of VWF, which constitutes the major FVIII binding site. D' consists of 2 domains, trypsin-inhibitor-like (TIL') and E', of which the TIL' domain lacks extensive secondary structure, is strikingly dynamic and harbors a cluster of pathological mutations leading to decreased FVIII binding affinity (type 2N von Willebrand disease [VWD]). This indicates that the backbone malleability of TIL' is important for its biological activity. The principal FVIII binding site is localized to a flexible, positively charged region on TIL', which is supported by the rigid scaffold of the TIL' and E' domain β sheets. Furthermore, surface-charge mapping of the TIL'E' structure reveals a potential mechanism for the electrostatically guided, high-affinity VWF⋅FVIII interaction. Our findings provide novel insights into VWF⋅FVIII complex formation, leading to a greater understanding of the molecular basis of the bleeding diathesis type 2N VWD.
Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom;
Nuha
N
Shiltagh
Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom;
John
J
Kirkpatrick
Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom;
Lisa D
LD
Cabrita
Department of Haematology, Hammersmith Hospital Campus, Imperial College London, London, United Kingdom; and.
Tom A J
TA
McKinnon
Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom;
Konstantinos
K
Thalassinos
Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom; Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free Hospital NHS Trust, London, United Kingdom.
Edward G D
EG
Tuddenham
Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, United Kingdom;
D Flemming
DF
Hansen
D001665:Binding Sites; D018360:Crystallography, X-Ray; D005169:Factor VIII / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D055550:Protein Stability; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D055672:Static Electricity; D014841:von Willebrand Factor / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D014841:von Willebrand Factor; C078147:F8 protein, human; D005169:Factor VIII