Fig. 6

Western Blot analysis of apoptotic proteases. Western Blot analysis confirmed the activation of apoptotic proteases in Mel501 cells treated with Pyr (8 μg/ml) and MBP (0.8, 8 μg/ml). Note that procaspase-8 (57 kDa) is early cleaved into the intermediate forms p43 and p41 and finally processed to the active p18 subunit (Fig. 5a, left panel), and procaspase 9 (47 kDa) is cleaved in 35 kDa subunit (Fig. 5b, left panel). The cleavage of caspase 3 (17 kDa) (Fig. 5c, left panel) and Cathepsin B (25 kDa) (Fig. 5d, left panel) occurred at later time points. The intensities of bands of active caspase fragments were quantified by densitometric analysis (Fig. 6 a-d right panels). The values were normalized to Tubulin and expressed as arbitrary units (AU). Columns, mean of three independent experiments; bars, SD. *, P < 0.05; **, P < 0.01