Binding of purified vβ3 to immobilized alboaggregin B, echistatin, and eristostatin. A 96-well microplate was coated with various concentrations of alboaggregin B, eristostatin, and echistatin. The plate was then blocked with PBS containing 0.05% Tween (TPBS) and 5% nonfat dry milk for at least 1 hour. Seven hundred nanograms of purified vβ3 receptors was then added to each well and the plate was then incubated for 30 minutes at 37°C. Extensive washing with TPBS followed. Polyclonal rabbit IgG against vβ3 was used as primary antibody. After 1 hour of incubation at 37°C and subsequent washing, a biotinylated goat antirabbit IgG was used as secondary antibody. (•) vβ3 binding to immobilized echistatin; (▴) binding to immobilized eristostatin; (▪) binding to immobilized alboaggregin.