Chitosan Co-polymeric nanostructures for catalase immobilization

Catalase is an industrial enzyme used in different areas including medical, textile, food and pharmaceutic industries. In the study, synthetic-natural copolymer in nanosize was synthesized using 2-hydroxyethyl methacrylate (HEMA) as a synthetic material and chitosan (CTS) as a natural material. Immobilized metal-chelate affinity chromatography (IMAC) material was prepared by chelating Cu(II) ions onto p(HEMA-CTS) nanostructures. Characterization studies such as Zeta sizer analysis, Fourier transform infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA) were performed during the preparation of IMAC nanostructures. The effects of some parameters (time, polymer amount, pH, initial catalase concentration, ionic strength and temperature) were identified and optimum immobilization conditions were determined as 75 min, 0.1 mg p(HEMA-CTS)-Cu, pH 6.0, and 25 degrees C. Maximum amount of immobilized catalase was detected as 11.29 g/g p(HEMA-CTS)-Cu. Immobilized catalase was desorbed successfully and it was detected that p(HEMA-CTS)-Cu nanostructures can be used repeatedly in catalase immobilization. Immobilization changed optimum temperature value from 37 degrees C to 25 degrees C while it did not change the optimum pH for catalase activity. Furthermore, it was detected that kinetic parameters of catalase changed by immobilization. Finally, operational and storage stabilities of immobilized catalase were investigated.