报告摘要： 

　　Oxidative stress in the cell results in modifications to DNA and RNA bases and downstream events including effects on transcription and replication as well as signaling for repair. Ultimately, unrepaired damage in DNA leads to mutagenesis that is a contributing factor to cancer and other diseases. Our studies focus on base modifications arising from guanine(G) oxidation, including how and where they form in the genome. To investigate this, we have developed a single-molecule nanopore approach that is complementary to other biophysical techniques for interrogating nucleic acid structure. Specifically, the electrophoretic capture of DNA strands, either Watson-Crick duplexes or folded G-quadruplexes, inside a protein nanopore (alpha-hemolysin) provides information about the presence of oxidized bases as well as the dynamics of unfolding. We have applied this technique to examine guanine oxidation and folding dynamics of G-quadruplexes and the i-motif.