Immobilization of lactoperoxidase on ZnO nanoparticles with improved stability.


Department of Biology, Payame Noor University, P.O. Box 19395-4697, Tehran, Iran. [Email]


OBJECTIVE : 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 Km values of free LPO and LPO immobilized on ZnO were 53.19, 89.28 mM and their Vmax values were 0.629, 0.46 µmol/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 °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 °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.


Glutaraldehyde,Immobilization,Lactoperoxidase,Stability,ZnO nanoparticles,

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