3.7. Catalase Activity Assay

CAT activity was measured by monitoring the decrease of absorbance at 240 nm, 25 °C, due to the decomposition of H₂O₂ (ε_mM = 0.0436 mM^–1 cm^–1). The reaction mixture (1 mL final volume) contained 19 mM hydrogen peroxide (H₂O₂) in 50 mM potassium phosphate buffer (pH 7.0); the reaction was started by adding 50 μg quantity of protein extract. Catalase specific activity is defined in terms of μmoles of hydrogen peroxide consumed per minute per mg of protein sample.