Effect of phosphoprotein phosphatase inhibition by OA on dephosphorylation of the 67-kD protein band. ³²P-labeled platelets (6 × 10⁸ platelets/mL) were incubated for 10 minutes at 37°C with 0.1 and 1 μmol/L OA or with buffer for 10 minutes and then used for adhesion experiment as in Fig 1. Adhesion (as a percentage) is shown for the control and OA-treated cells. Lysates from 1.5 × 10⁷ platelets were applied per each lane and analyzed by 8% SDS-PAGE full-size gels. Phosphorylation patterns for the 47-(pleckstrin), 50-, 67-, and 95-kD protein bands are shown on the left. An autoradiogram representative of three experiments is presented.