Immobilization of lactoperoxidase on ZnO nanoparticles with improved stability

Abstract

Objectives 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). Results 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 K-m values of free LPO and LPO immobilized on ZnO were 53.19, 89.28 mM and their V-max values were 0.629, 0.46 mu mol/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 30 days at 25 degrees C whereas the free enzyme lost its activity after 7 days at the same temperature. Moreover, evaluation of the thermal stability of LPO at 75 degrees C determined the conservation of 12 of the initial activity of LPO in the LPO-ZnO sample after 60 min whereas the free enzyme lost its activity after 5 min. Conclusions According to the present results, ZnO nanoparticles are suitable for the immobilization of LPO.