Immobilization of lactoperoxidase on ZnO nanoparticles with improved stability.

Abstract

The study aimed to develop a facile and effectual method to enhance the stability of lactoperoxidase (LPO) by immobilizing it on ZnO Nanoparticles (ZnO NPs). The successful immobilization of LPO on ZnO NPs was confirmed by using Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). The Km values of free LPO and LPO immobilized on ZnO were 53.19, 89.28mM and their Vmax values were 0.629, 0.46µmol/mL min, respectively. The overall results showed that the stability of the immobilized LPO was significantly improved compared to free LPO. The LPO immobilized on ZnO (LPO-ZnO) retained 18% of the initial activity within 30days at 25°C whereas the free enzyme lost its activity after 7days at the same temperature. Moreover, evaluation of the thermal stability of LPO at 75°C determined the conservation of 12% of the initial activity of LPO in the LPO-ZnO sample after 60min whereas the free enzyme lost its activity after 5min. According to the present results, ZnO nanoparticles are suitable for the immobilization of LPO.