Fig. 3

Effect of pH on the inhibitory activity of the ppFhCL3 against cathepsin peptidases. The activity of the recombinant F. hepatica cathepsin peptidases, FhCL1, FhCL2, FhCL3, and human cathepsin L and K, HsCL and HsCK, was assayed in the presence of ppFhCL3 (10 nM) at various pH, 4.5–7.0, represented by the white, grey-scale and black bars. The percentage inhibition is presented relative to the total activity of each enzyme without inhibitor at the respective pH. The experiments were performed in triplicate and the results are presented as mean ± standard deviation