Comparison of the kinetics of the GPIbα–VWF-A1 tether bond for PT-VWD versus type 2B VWD. (A) Platelet accumulation on WT versus type 2B mutant VWF-A1 substrate at the indicated wall shear rates. (B) The frequency of tether bond formation and cellular off-rates (Table 2) for beads coated with either WT or type 2B VWF-A1 protein (5 μg/mL) interacting with the indicated platelet substrate was performed as described in panel A. Data represent the mean ± SD for 5 independent experiments at each wall shear stress tested. *P > .1.