CATION LABELING MASS SPECTROMETRY OF DNA ADDUCTS

我们提出了一种新的方法，化学标记和质谱（MS）的基础上发现和定性分析未知的DNA加合物在人体样本。 新型的，庞大的，非极性阳离子试剂将被合成和测试作为标记试剂的核苷酸和核苷的DNA加合物的版本。 化学标记的主要目的是使所有DNA加合物对MS分析具有高度和同等（或接近）的灵敏度。特别是激光解吸（包括MALDI），但也将使用MS的电喷雾形式。 在前一种情况下，将强调在傅里叶变换质谱仪（FTMS）上的大光斑激光解吸。 该项目的刺激部分是由我们未发表的观察，即庞大的，非极性的化合物，我们已经准备好是非常敏感的MALDI-MS。潜在的DNA加合物标记的这种类型的试剂也可以检测到高灵敏度。 如果这可以在R21中得到证明，那么随后的R33将涉及该技术的进一步优化，最终应用于从大型尸检人体组织样本中提取的DNA，以使整个方法完全成熟。

We propose new methodology based on chemical labeling and mass spectrometry (MS) for the discovery and qualitative analysis of unknown DNA adducts in human samples. Novel, bulky, nonpolar cationic reagents will be synthesized and tested as labeling reagents for both nucleotide and nucleoside versions of DNA adducts. The primary purpose of the chemical labeling is to make all DNA adducts highly and equally (or near so) sensitive for analysis by MS. Especially laser desorption (including MALDI) but also electrospray forms of MS will be used. In the former case, large spot laser desorption on a Fourier transform mass spectrometer (FTMS) will be emphasized. The project is stimulated in part by our unpublished observation that bulky, nonpolar compounds that we have prepared are very sensitive by MALDI-MS. Potentially a DNA adduct labeled with a reagent of this type also can be detected with high sensitivity. If this can be demonstrated in an R21, then the ensuing R33 would involve further optimization of the technique, with eventual application in the project to DNA extracted from large, autopsy, human tissue samples to bring the overall methodology to full maturity.