Figure 3. Effect of the hit compounds on the activity of recombinant WT-PAH.

Activity was measured with 100 μM l-Phe and 10 μM BH₄ (A) or 1 mM l-Phe and 200 μM BH₄ (B), in the presence of 100 μM of each compound in 2.5% DMSO (also present in control sample [C]). Samples were preincubated (black bars) or not preincubated (white bars) with the corresponding l-Phe concentration for 5 minutes at 25°C prior to the addition of compounds and of BH₄ to start activity measurements. Data are mean ± SD of triplicate experiments.