Application of Design of experiment to study the effects of some parameters on the enzyme behaviors

Design of experiments is frequently used to study chemical systems. If enzymatic reactions, as a chemical system, can be modeled using these methods, it will be possible to research with lower prices. Xanthine oxidase and xanthine were selected as enzyme and substrate, consequetively. Initial rate (V) of oxidation of xanthine was studied. Several experiments were designed using central composite design (CCD) method. Three parameters, temperature (T), pH and concentration of substrate, were selected and studied in this research. The reaction was started by adding the enzyme. Absorbance was recorded at 286 nm in different time then initial rate was calculated. Relation between response (initial rate) and selected parameters was studied and suitable mathematical equation was extracted and related response surfaces were plotted. The extracted equation was validated using some tests and other different experiments. CCD is one of the experimental methods that was used to study the oxidation reaction rate of xanthine as a function of T, pH and substrate concentration.These results show that the enzyme parameters can be predicted using extracted mathematical equation.