Immobilization of Penaeus vannamei protease on ZnO nanoparticles for long-term use

The activity, stability, and kinetics of immobilized enzymes are influenced by the nature of the support or carrier material. In this research, zinc oxide nanoparticles were synthesized by chemical precipitation, and the purified protease from shrimp Penaeus vanamei was immobilized on the nanoparticles. Size, structure, and morphology of the ZnO nanoparticles, and the immobilization of the protease were studied by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, UV-Vis spectroscopy, and dynamic light scattering (DLS). The immobilization of protease on ZnO nanoparticles improved the long-term and thermal stability, plus its stability at extreme pH values, and it increased the optimum functional temperature of the enzyme. The optimum pH value of the immobilized protease was shifted from 7.0 to 8.0 upon immobilization. Additionally, and due to the immobilization an increased K_m was observed, whereas its catalytic efficiency was estimated a little less as compared to that of free enzyme. These results show that the immobilization of Penaeus vanamei protease on zinc oxide nanoparticles enhanced its appropriateness for a future use in various biotechnological and industrial applications.