Isolation and characterization of physiologically relevant DNA-protein crosslinks | Poster Board #412

DNA-protein crosslinks are a major possible consequence of oxidative damage to DNA. When DNA is damaged by oxidation reactions, the covalent adducts formed between DNA and protein can lead to potential distortions to the DNA helix and disruptions in fundamental cellular DNA processes. Given that oxidative damage has implications in aging as well as a number of molecular diseases, it is of increasing importance and interest to have rich structural characterization of these oxidative DNA-protein crosslink products. In this project, we focus on the isolation and structural characterization of physiologically relevant DNA-protein crosslinks.

In DNA, the DNA base guanine is most susceptible to oxidation and formation of DNA-protein crosslinks as it has the lowest oxidation potential of the DNA bases. In order to prepare DNA- protein crosslinks, a photochemical technique called the Flash-Quench technique will be used to selectively oxidize the guanine base(s) in DNA which will in turn form a cross-link with protein. The DNA-protein crosslink product will be isolated and identified by liquid chromatography- mass spectrometry (LC-MS) and electrospray ionization-mass spectrometry (ESI-MS), followed by purification by high-performance liquid chromatography (HPLC). Purity of the DNA-protein crosslinks will also be confirmed by 1-Dimensional (1D) ¹H Nuclear Magnetic Resonance (NMR) spectroscopy. The structural characterization of the DNA-protein crosslinks will be conducted by 1D and 2-Dimensional (2D) ¹H NMR spectroscopy.