Fig. 4.
The calpain-specific inhibitor, calpeptin, inhibited proteolysis of adducin.
Platelets were activated with thrombin (and 2.5 mM CaCl2) in the presence (lanes 6-8) or absence (lanes 3-5) of calpeptin (100 μg/mL preincubation for 10 minutes). Phosphorylation of adducin was more prominent in the samples treated with calpeptin (B) because the proteolysis of adducin was inhibited (C).