Figure 4

NADP-reductase activity of rFlaR. (a) A significant reduction of NADP by rFlaR refolded in the presence Fe²⁺ was measured over a period of 16 hours at A₃₄₀ at the presence of FAD (Spearman correlation, r = 1, **p = 0.0014). The reaction mixtures without individual components (w/o rFlaR, w/o FAD, w/o NADP) served as controls and no redox activity could be detected (whole graph comparisons using one way ANOVA with Dunnett’s post hoc test, ****p = 0.0001). (b) NADP-reductase activities of rFlaR refolded at the presence (rFlaR (Fe²⁺)) and rFlaR refolded at pH 8.0 (rFlaR (pH 8)) at the absence of Fe²⁺ were compared. In the control reaction mixture rFlaR was replaced with BSA. The difference between the absorbance at 340 nm after 90 min incubation and the absorbance at 340 nm at time 0 (Δ A₃₄₀ nm) was calculated. The results presented are the mean of three different experiments (one way ANOVA with Dunnett’s Post Hoc multiple comparisons test, n = 3 in each group, *p = 0.02; ****p = 0.0001).