IDENTIFICATION OF THE VON WILLEBRAND FACTOR BINDING SITE IN COLLAGEN USING TRIPLE HELICAL PEPTIDES

摘要

The interaction of collagen with von Willebrand Factor (VWF) requires unique structural properties in both proteins . Optimal haemostatic function requires multimerisation of up to fifty VWF monomers in circulating plasma; higher-order multimers bind collagen more tightly than smaller assemblies of VWF. Several collagens occur in the vessel wall, of which collagens I and III are considered most important in supporting platelet adhesion to the damaged vasculature . We have identified the residues in the VWF A3 domain that bind collagen III, using site-directed mutagenesis guided by the crystal structure of the VWF A3 domain in complex with a monoclonal antibody (RU5) that inhibits its interaction with collagen . However, the VWF-binding site(s) in collagen are unknown, although progress in understanding how collagen interacts with integrin α2β1 and GPVI has been made using short synthetic triple-helical peptide analogues of collagen , including the Collagen III Toolkit . We used the same approach to identify the high-affinity VWF-binding site in human collagen III, information which may help to develop the collagen-VWF interaction as an anti-thrombotic target.