INACTIVATION AND REGENERATION KINETICS OF HORSERADISH-PEROXIDASE HEATED AT HIGH-TEMPERATURES

The inactivation kinetics of horseradish peroxidase (HRP) heated in ca pillary tubes in the range 110 to 135 degrees C was studied. Its regen eration kinetics when stored at 4 and 25 degrees C was also considered , As the severity of the treatment increased, the absolute value of th e regeneration decreased. The storage temperature of the enzyme did no t affect the percentage of maximum activity regenerable, although when this temperature was raised from 4 to 25 degrees C the speed of regen eration increased. Kinetics of HRP inactivation determined after heati ng and after regeneration were compared. Both forms of the enzyme show ed similar behavior with first-order inactivation kinetics, with E-a = 19.5 +/- 1.0 kcal/mol and k(120 degrees C) = 3.7 +/- 0.2 min(-1), and E-a = 18.8 +/- 1.2 kcal/mol and k(120 degrees C) = 3.7 +/- 0.2 min(-1 ), respectively.