| Abstract: | The kinetic study of the thermal stability of three kinds of invertases: native, immobilized on porous glass covalently, and on ion-exchange resin ionically, has been carried out, measuring their enzymatic activity for sucrose hydrolysis. Thermal deactivations of all invertases obeyed first-order kinetics, being independent of substrate concentration, with kd and ΔEd, ΔSd* as shown in Tables I and II, respectively. Based on these parameter values, the effects of immobilization and pH at deactivation on the stability have been considered, and it was suggested that the ionic bond gives a more loosely deformed enzyme than the covalent bond. |
