Induced temperature-dependent DNA degradation by C_(60) without photoactivation  

作　　者：WANG Chang LIN Yan WANG Ying LIANG Yong MENG LingZhi ZHANG Jie ZHOU QunFang JIANG GuiBin 

机构地区：[1]State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China [2]Key Laboratory of Subtropical Agriculture and Environment of the Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China [3]School of Medicine, Jianghan University, Wuhan 430056, China [4]Department of Chemistry, Wuhan University, Wuhan 430072, China

出　　处：《Chinese Science Bulletin》2011年第28期3100-3107,共8页

基　　金：the National Natural Science Foundation of China (20907017, 20890112);the National Basic Research Program of China (2009CB421605);the National High Technology Research and Development Program of China (2007BAC27B01)

摘　　要：This study shows that C_(60) can degrade pBR322 plasmid DNA at room temperature without photoactivation. The degradation was enhanced by increasing incubation temperature, reaction time or C_(60) concentration. We also found that superoxide radical anions (O 2 · ) were formed in the C_(60) solution. Superoxide dismutase significantly inhibited DNA cleavage and O 2 · generation induced by C_(60) . These results suggest that DNA cleavage was caused by the formation of reactive oxygen species induced by C_(60) at room temperature. Furthermore, we demonstrate that the DNA degradation was significantly inhibited by acid amide chemicals such as formamide, and by increased ionic strength of the reaction solution. These results indicate that the DNA conformation stability and the surface properties of C_(60) are important factors regulating DNA degradation. We propose that C_(60) can bind DNA, decrease DNA conformation stability, and induce the formation of reactive oxygen species and DNA cleavage at room temperature. Our results provide a possible explanation for the genotoxicity of C_(60) , which should be considered in future use of this particular nano-material.This study shows that C60 can degrade pBR322 plasmid DNA at room temperature without photoactivation. The degradation was enhanced by increasing incubation temperature, reaction time or C60 concentration. We also found that superoxide radical anions （02＂） were formed in the C60 solution. Superoxide dismutase significantly inhibited DNA cleavage and O2^- generation induced by C60. These results suggest that DNA cleavage was caused by the formation of reactive oxygen species induced by C60 at room temperature. Furthermore, we demonstrate that the DNA degradation was significantly inhibited by acid amide chemicals such as formamide, and by increased ionic strength of the reaction solution. These results indicate that the DNA conformation stability and the surface properties of C60 are important factors regulating DNA degradation. We propose that C6o can bind DNA, decrease DNA conformation stability, and induce the formation of reactive oxygen species and DNA cleavage at room temperature. Our results provide a possible explanation for the genotoxicity of C60, which should be considered in future use of this particular nano-material.

关 键 词：质粒DNA 可降解 温度依赖 超氧化物歧化酶 DNA裂解 DNA降解 DNA构象 PBR322 

分 类 号：TQ320.721[化学工程—合成树脂塑料工业] Q781[生物学—分子生物学]