Fig. 6
From: Platelet adhesion and aggregate formation controlled by immobilised and soluble VWF
Proposed mechanism of aggregate formation. VWF stretching. Conformation of a single VWF molecule changes under high shear flow conditions from globular to elongated form. b Cooperative association. Stretched VWF binds to a rotating platelet. Only if the bond-lifetime τbind is sufficiently long (τbind > τrot) compared to the period of rotation τrot, VWF will begin to “wrap” around the platelet. This will allow forming multiple bounds, which stabilises the association against shear induced bond dissociation. c Aggregate formation. Partially VWF coated platelets will cross-interact with further platelets. If the platelet concentration cplatelets and hence collision rates are sufficient, this will initiate the reversible formation of aggregates