Inhibition of binding of ¹²⁵I-vWF to human fibrillar type-III collagen by bitiscetin (○) or botrocetin (▪). Collagen was used at the final concentration of 1 mg/mL and¹²⁵I-vWF at 1 μg/mL. Nonspecific binding estimated using denatured heated collagen was substracted from the total binding to obtain specific binding. Results are expressed as the percent of the specific binding estimated in the absence of competitor (100%). This value of specific binding represents a bound radioactivity of ≠40%.