SYNTHESIS & STRUCTURE OF OLIGODEOXYNUCLEOTIDES WITH DEFINED DNA DAMAGE

该项目中的有机化学研究和合成化学共同为该计划的其他成员所描述的结构和生物研究提供了一个平台。与过去一样，主要目标之一是合成含有位点特异性定位的修饰的2 '-脱氧核苷酸的DNA寡聚体，其代表遗传毒性环境因子引起的损伤。这些修饰的脱氧核苷酸中的许多仅从它们的生物来源已知，并且从未以使广泛的生物学工作可行的量合成。合成的一个特别贫乏的领域是致癌胺，特别是食品诱变剂。在解决了较简单的N2-dG氨基芳基加合物的合成问题后，C8-dG食品诱变剂加合物的合成方法将有很大的发展。第二个研究领域是将已知的烷基化lexitropsin应用于寡聚DNA，以便在“合成后”过程中产生脱氧腺苷和卡巴-脱氧腺苷的N3-烷基化形式。这些加合物预不稳定性和以前缺乏任何方法来产生它们在一个控制的方式。使用NMR光谱和计算方法的结构研究将进行低聚物含有致癌的胺加合物，并分别对低聚物含有N3-烷基化卡巴dA残基。这些研究将通过加合物的研究确定DNA局部错位的程度，并允许与诱变和DNA修复过程相关。第三个研究领域涉及DNA中的化学反应位点（热点）及其与造成损害的物质的关系。这项研究将试图阐明为什么DNA中的特定核苷序列比其他序列更具反应性。最后，由于双酚A在环境中普遍存在，任何由其代谢产物形成的核苷加合物都将被合成并掺入DNA中用于生物学研究。

The organic chemical investigations and the synthetic chemistry in the Project together provide a platform for the structural and biological research studies described by other members of the program. As in the past, one of the principle objectives is the synthesis of DNA oligomers that contain modified 2'-deoxynucleotides, located site-specifically, and which represent damage caused by genotoxic environmental agents. Many of these modified deoxynucleotides are known only from their biological origin and have never been synthesized in the quantities that make extensive biological work feasible. A specific area of synthesis that has been particularly barren is that of the carcinogenic amines, especially the food mutagens. Now having solved the synthetic problem of the simpler N 2-dG aminoaryl adducts, a significant effort will be made to general methods for the C8-dG food mutagen adducts. A second area of investigation will be to apply the known alkylating lexitropsins to oligomeric DNA so as to generate N3-alkylating forms of deoxyadenosine and carba-deoxyadenosine in a "post-synthetic" process. These adducts pre instability and the previous lack of any method to generate them in a controlled manner. Structural studies using NMR spectroscopy and computational methods will be carried out on oligomers containing carcinogenic amine adducts and separately, on oligomers containing N3-alkylated carba dA residues. These studies will establish the degree of local dislocation of DNA by this study of adduct and allow a correlation with mutagenesis and DNA-repair processes. A third area of investigation concerns the chemically reactive sites in DNA (hot-spots) and their relationship to agents that cause damage. This study will attempt to clarify why specific nucleoside sequences in DNA are more reactive than others. Finally, because of the universal presence of bisphenol-A in the environment, any nucleoside adducts that form from its metabolites will be synthesized and incorporated into DNA for biological studies.