Effect of TiO2 nanoparticles on the structure and activity of catalase

Abstract

TiO2 nanoparticles are the most widely used metal oxide nanoparticles and have oxidative toxicity. Catalase is an important antioxidant enzyme. Here the understanding of an effect of TiO2 nanoparticles on the activity and structure of catalase is crucial to characterize the toxicity of TiO2 nanoparticles. These experimental data revealed that TiO2 nanoparticles could bind to catalase by the electrostatic and hydrogen bonding forces. On binding TiO2 nanoparticles, catalase got destabilized with the decrease of α-helices content, the solvent polarity of environment around the fluorescence chromophores on catalase were also affected. In addition, TiO2 nanoparticles also affected the activity of catalase. TiO2 nanoparticles acted as an activator of catalase activity at a low molar concentration and as an inhibitor at a higher molar concentration. With regard to human health, the present study could provide a better understanding of the potential nanotoxicity of TiO2 nanoparticles.