SYNTHESIS OF OLIGODEOXYNUCLEOTIDES BEARING MUTAGENS AS SITE-SPECIFIED ADDUCTS

本节所述的合成有机化学构成了 该计划的其他成员所描述的研究项目。一 基本目标是合成一系列修饰的DNA 将被位点特异性地掺入到 使用自动化固态方法制备寡核苷酸。修改后的 选择用于研究的脱氧核苷分为两类。第一 组与我们对氧化性DNA损伤的研究有关。这些 物质将用于（a）构建亲和层析 用于纯化和分离DNA修复酶（MutM）的底物 和MutY蛋白），以及（B）研究与氧化损伤有关的 这些酶（主要是MutY）在修复中的作用机制 过程第二组脱氧核苷具有相关的修饰， 致癌的胺和硝基化合物。它们被细分为两个 类别：（a）与C8-dG加合物相关的类别和（B）升高的类别 通过攻击的N2-位置的最终致癌物 脱氧鸟苷。这些定义的加合物将用于建立 原致癌物产生的致突变谱。此外，本发明还提供了一种方法， 它们应该有助于解决与这两个方面有关的结构性问题， 与核苷本身和含有它们的寡聚DNA结合。 为了这些目的，将合成13 C和15 N标记的核苷。 对DNA合成中使用新保护基的研究也将 被追求。这应该允许其他困难的合成后 将碱基敏感性损伤引入DNA。分析研究将 研究新的氧化产物的形成，包括交叉- 连接的脱氧核苷二聚体，其结构尚未被表征， 并将建立准确、灵敏的氧化产物分析方法， 来源于细胞核和线粒体DNA。

The synthetic organic chemistry described in this section forms a basis for the research projects described by other members of the Program. A fundamental objective is the synthesis of a series of modified DNA nucleosides that will be incorporated site-specifically into oligonucleotides using automated, solid-state methods. The modified deoxynucleosides selected for study fall into two classes. The first group is related to our investigations on oxidative DNA damage. These substances will be used (a) to construct affinity chromatography substrates for the purification and isolation of DNA repair enzymes (MutM and MutY proteins) that deal with oxidative lesions and (b) to study the mechanisms of action of these enzymes (principally MutY) in the repair process. The second group of deoxynucleosides have modifications related to carcinogenic amines and nitro compounds. They are subdivided into two classes: (a) those that relate to C8-dG adducts and (b) those that rise by attack of the ultimate carcinogen on the N2-position of deoxyguanosine. These defined adducts will be used to establish the mutagenic spectrum generated by the original carcinogen. In addition, they should aid in the solution of structural problems associated both with the nucleosides themselves and with oligomeric DNA containing them. For these purposes, 13C and 15N-labeled nucleosides will be synthesized. Research on the use of new protecting groups for DNA synthesis also will be pursued. This should allow otherwise difficult post-synthetic introduction of base-sensitive lesions into DNA. Analytical studies will investigate the formation of new oxidation products, including cross- linked deoxynucleoside dimers whose structure has not been characterized, and will establish accurate, sensitive assays for oxidation products derived from nuclear and mitochondrial DNA.