US EPA

157526 

Journal Article 

Nano titanium dioxide photocatalytic protein tyrosine nitration: a potential hazard of TiO2 on skin 

Lu, N; Zhu, Z; Zhao, X; Tao, R; Yang, X; Gao, Z 

2008 

Yes 

Biochemical and Biophysical Research Communications
ISSN: 0006-291X
EISSN: 1090-2104 

370 

4 

675-680 

English 

18407831 

10.1016/j.bbrc.2008.04.010 

WOS:000255883900028 

Protein tyrosine nitration is a prevalent post-translational modification which occurs as a result of oxidative and nitrative stress, it may be directly involved in the onset and/or progression of diseases. Considering the existence of nano titanium dioxide (TiO(2)) in environment and sunscreen products along with the high content of nitrite in sweat, the UV-exposed skin may be a significant target for the photosensitized damage. In this paper, tyrosine nitration of bovine serum albumin (BSA) was initiated in the UV-irradiated reaction mixture containing 0.2-3.0mg/ml of three commercially nano TiO(2) products and 0.25-1.0mM NO2-. It was found that anatase TiO(2) and Degussa P25 TiO(2) showed prominent photocatalytic activity on promoting the formation of protein tyrosine nitration, and the optimum condition for the reaction was around physiological pH. Meanwhile, the photocatalytic effect of rutile on protein tyrosine nitration was subtle. The potential physiological significance of nano TiO(2)-photocatalytic protein nitration was also demonstrated in mouse skin homogenate. Although the relationship between photocatalytic protein tyrosine nitration and chronic cutaneous diseases needs further study, the toxicity of nano TiO(2) to the skin disease should be paid more attention in the production and utilization process. 

nitrite; protein nitration; titanium dioxide; UV exposure