Binding of recombinant factor XI to activated platelets.

Direct binding studies were carried out as described in “Materials and methods.” ¹²⁵I-labeled recombinant factor XI preparations at various concentrations were tested for binding to activated platelets in the presence of 50 nM high-molecular-weight kininogen and 25 μM ZnCl₂. Wild-type recombinant factor XI (○), factor XI–R226 (•), and factor XI–N248 (▵) are shown. Data are mean values (± SEM) of total binding results for 3 separate experiments, each performed in triplicate.