Fig. 2. Effect of TPA and mßCD (A) or mßCD/chol (B) on the activity of PKC. A431 cells were washed twice with DMEM medium, serum-starved for 4 hours and preincubated with or without 5 mM mßCD or mßCD/chol for 30 minutes at 37°C before addition of 1 µM TPA. After 10 minutes at 37°C, the PKC activity was measured using the Protein Kinase C Assay System according to the manufacturer's instructions. The error bars show deviations between duplicates of a typical experiment.