Immobilization of alkaline phosphatase using chitosan nanoparticles

Abstract

Enzyme immobilization is an operative method for improving enzyme properties. There are various supports to enzyme immobilization. In the present study chitosan nanoparticles have been applied to alkaline phosphatase (ALP) immobilize due to their special properties. Firstly, the Ionic Gelation method was used to synthesize Chitosan nanoparticles, and were characterized using XRD and Zetasizer Nano. Then, chitosan nanoparticles were activated with 1-ethyl-3-(3-dimethylaminopropyl carbodiimide (EDC) and ALP was such- cessfully immobilized on them. The influences of time, pH, and concentration of enzyme, and EDC on the efficiency of immobilization have been investigated. The stability studied against organic solvents and high temperature, which has indicated the stability of the immobilized enzyme, was increased during the immobilization. The surface topography of the bare and immobilized enzyme nanoparticles was studied by AFM. The calculation of binding efficiency showed that the immobilized ALP has conserved 71% of its native activity. The improvement of the enzyme stability by immobilization has indicated that chitosan nanoparticles were suitable support for immobilization.