FIGURE 2.

PAH protein synthesized by cells transfected with MmPah mRNA is functional. (A) Effect of increasing Phe concentrations on PHA enzyme activity was evaluated. Bars represent the amount of Tyr production quantified at the end of the assay period. Data are the means ± SEM obtained in 3 independent experiments. Significantly different from the value obtained at the adjacent lower Phe concentration: no significant differences (ns); **p < 0.01; ***p < 0.001 (one-way ANOVA, Tukey’s multiple comparisons test). (B) Effect of increasing BH₄ concentrations on enzyme activity assessed for Tyr production. Phe concentration was fixed to 500 μM. (C) BHK-21 and (D) HepG2 cell lysates were transfected with MmPah mRNA or control. Enzymatic activity and Tyr production were assessed at times indicated. Results are the means ± SEM Tyr concentration obtained in 2 independent experiments. Significance tested compared to the untransfected condition: no significant differences (ns); **p < 0.01; ****p < 0.0001 (one-way ANOVA, Tukey’s multiple comparisons test).