LAUSR

The thermal stability of purified acid phosphatase from the germinating seedlings of Coronopus didymus (Jangli halon) was investigated by studying the impact of various thermodynamic parameters [(t1/2, Ed, ΔHº (Enthalpy), ΔGº (Free energy) and ΔSº (Entropy)) of heat treatment over a wide range of temperatures (55-75℃). The thermal denaturation of enzyme assessed by loss in activity, was evidently followed by first order kinetics which varies with time and product during denaturation process. The half-life of enzyme was 693 minutes at 55℃. The Ed (activation energy of denaturation) was calculated by Arrhenius plot (30 K cal mol-1) and Z-value was 17.3℃ respectively. Various thermodynamic parameters ΔHo the change in enthalpy of inactivation had 121.93 kJ mol-1 at 55℃, ΔGo the change in free energy of inactivation was 110.65 kJ mol-1 at 55℃ and ΔSo the change in entropy of inactivation was 34.39 J mol-1 k-1 at 55℃. This suggests that acid phosphatase activity is relatively thermostable to long heat treatment up to 60℃.