Fig. 1.

Inhibition of cathepsin B, L and S activity by protease inhibitors. 293T cells were incubated with the indicated inhibitors and cathepsin activity was determined 8 h later using commercially available kits. The cathepsin B, L and S activity in cells treated with protease inhibitors is shown relative to that measured upon treatment of cells with PBS, which was set as 100%. Results for cathepsin B and L activity represent the average of three independent experiments. Error bars indicate standard error of the mean. The results of a representative experiment performed in duplicates are shown for cathepsin S and were confirmed in a separate experiment. Error bars indicate standard deviation (SD). CatB, cathepsin B; CatL, cathepsin L; CatS, cathepsin S.