Figure 3. Dose-dependent inhibition by GSH and cysteine of the caspase-activating ability of oxidized cyt c.

After pre-incubation of oxidized cyt c with various concentrations of GSH or cysteine for 1 h at 37 °C, a cell-free caspase (Casp)-activation assay was performed. The activities of caspase-9 (A) and -3 (B) are shown. An immunoblot analysis was performed for the caspase assay mixture containing cyt c treated with either GSH (C) or cysteine (D) using specific antibodies against caspase-9, -3 or cyt c (1:1000 dilution). The arrowheads indicate the processed, active form of the enzymes.