IMMOBILIZATION OF ENZYMES ON ELECTROSTATIC MEDIUM OF POSITIVELY CHARGED DIMETHYLAMINO NYLON GEL

Urease and glucose oxidase were immobilized by positively charged nylon gel matrix made from dimethylaminated nylon. The stability of the immobilized enzyme after preheating and incubation in organic solvent were measured and compared with that of native enzymes. Also, pH dependency of the immobilized enzymes was examined. The pH activity curves of the immobilized enzyme shift toward a low pH compared with that of the native enzyme. Using the pH difference, the electrostatic potential of the positively charged nylon gel was estimated. The estimated values of the positively charged gel were +90 and +102 mV for the immobilized urease and immobilized glucose oxidase, respectively. In the presence of buffer salt, they decreased to +30 and +24 mV, respectively.