Influence of temperature (A) and pH (B) on the enzymatic activity of soluble and immobilized NOX forms. In the case of the temperature, activity assays were performed in 50 mM sodium phosphate at pH 7, FAD 150 μM and temperatures ranging 25-90°C. On the contrary, pH effect on activity was analyzed keeping constant the temperature at 65°C at different pH values, ranging between 5-9, in presence of FAD 150 μM. In both experiments, soluble (empty rhombus) and immobilized (on CNBr-agarose) NOX (full squares) preparations were analyzed. For both graphs, relative activity was calculated assigning 100% of activity to the highest measured activity at one particular temperature and pH.