FIG. 4.

Role of oxidative stress in the activity of sampangine in S. cerevisiae. (A) S. cerevisiae S288C cells in early exponential phase were grown in the presence or absence of sampangine (SMP) for the indicated amount of time. Cells were harvested, protein extracts were prepared, and 20 μg of protein from each extract was derivatized with DNPH. The derivatized proteins were separated by SDS-polyacrylamide gel electrophoresis, blotted to polyvinylidene difluoride membrane, and detected with anti-DNP antibody. A stained protein gel on which aliquots of the same samples were separated is shown on the right. (B) Dilutions (fivefold) of wild-type (BY4743), yap1Δ/Δ, and sod2Δ/Δ strains grown as described in Materials and Methods were inoculated onto SC agar medium and incubated for 2 days at 30°C. −SMP, medium containing solvent (DMSO); +SMP, medium containing sampangine at 1.25 μg/ml.