| Abstrakt: |
Immobilization of horseradish peroxidase and glucose oxidase on biotinylated layered silicates resulted in high catalytic activity and improved thermal behavior. The immobilization approach involves a simple step, taking advantage of the high affinity of the biotinylated support to avidinylated enzymes. The Kmof immobilized horseradish peroxidase-avidin conjugate was different from the Kmof the native conjugate. Assuming Arrhenius behavior for the Km, the activation energy, Ea, of the immobilized enzyme was 33.3 KJ/mol with a pre-exponential factor, A, 23 M. The values for the native enzyme-avidin conjugate were 16.8 KJ/mol and 0.04 M. The immobilization resulted in higher activity for the immobilized conjugate at higher temperatures compared to the native. Also, glucose oxidase-avidin conjugate immobilized on layered silicates exhibited improved thermal behavior. The immobilized enzyme conjugate retained 65% of its initial activity at 58°C, while the native conjugate retained 20% under the same conditions. |
