title: 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.
authors.affiliation: Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China; Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China.
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Zhang
authors.affiliation: Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China; Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Cao
authors.affiliation: Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China; Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China.
authors.forename: Bo-Ping
authors.initials: BP
authors.lastname: Tang
authors.affiliation: Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China; Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China. Electronic address: wyqing76@126.com.
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Wang
mesh_terms: D002374:Catalase / Q000378:metabolism*; D002942:Circular Dichroism; D004789:Enzyme Activation / Q000187:drug effects*; D006801:Humans; D053758:Nanoparticles / Q000378:metabolism* / Q000627:therapeutic use; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D014025:Titanium / Q000378:metabolism* / Q000633:toxicity
chemical_list: C009495:titanium dioxide; D014025:Titanium; D002374:Catalase
keywords: Activity; Catalase; Conformation change; TiO(2)