Figure 1
From: Anthracyclines, proteasome activity and multi-drug-resistance

Verapamil is an inhibitor of 26S proteasome function. Incubation of crude extracts of ECV304 cells containing proteasomes with different doses of verapamil (50, 60, 80, 100, 200 μM) inhibited proteolysis of the chymotrypsin-like substrate SucLLVY-AMC in a dose-dependent manner, indicating inhibition of 26S proteasome function.