DNA STRUCTURAL PROBES BY DRUGS AND CROSSLINKING

拟议的研究在两个不同的领域进行，依赖于序列 用电子顺磁共振波谱和核酸研究核酸动力学 与双官能团烷基化试剂的相互作用。在以前的地区， 我们将继续努力合成有用的氮氧化物自旋探针 用于核酸动力学的EPR研究。这些研究提供了 关于DNA非基态构象可及性的信息 这可能在其被蛋白质和小分子识别中起重要作用 分子。提出的目标自旋探测器将克服 将测试目前可用的自旋探测器中的实质性缺陷 对于与B-DNA的结构兼容性，将使用EPR进行比较 在上一次赠款期间开发的探测器的技术，以及 将用于制备自旋标记发夹，四臂连接 (Holliday中间体)、错配和链间交联DNA 在动力学研究中使用。拟在以下方面进行的研究： 双功能DNA烷基化试剂将成为DNA研究的重点 抗肿瘤物质FR900482的链间交联反应 和FR66979，2，5-双(N-氮杂环丁基)-1，4-苯二酚(DZQ)，以及 生物调节物质一氧化氮。链间交联剂IS 通常被引用为目前使用的几种药物的毒性机制 癌症化疗。了解他们的代理人，我们将定义 交联剂的共识顺序，所需的官能团 用于交联，以及相关损伤的共价结构。 我们将使用Crothers PAGE延迟方法来评估弯曲和 各种链间交联中的扭转重组 DNA。与里德教授合作，我们将寻求确定 链间交联物的三维溶液结构 DNA

The proposed research is in two distinct areas, sequence dependent nucleic acid dynamics as studied using EPR spectroscopy and nucleic acid interactions with bifunctional alkylating agents. In the former area, we will continue our efforts to synthesize useful nitroxide spin probes for EPR studies of nucleic acid dynamics. These studies provide information on the accessibility of non-ground state conformations of DNA which may be important in its recognition by proteins and small molecules. The target spin probe, which it is proposed will overcome a substantial deficiency in currently available spin probes, will be tested for structural compatibility with B-DNA, will be compared using EPR techniques to a probe developed during the previous grant period, and will be used to prepare a spin labeled hairpin, four-arm junction (Holliday intermediate), mismatches, and interstrand cross-linked DNA for use in dynamics studies. The proposed studies in the area of bifunctional DNA alkylating agents will focus on the study of DNA interstrand cross-linking reactions of the antitumor substances FR900482 and FR66979, 2,5-bis-(N-aziridinyl)-1,4-benzoquinone (DZQ), and the bioregulatory substance nitric oxide. Interstrand cross-linking is commonly cited as a toxic mechanism for several agents presently used in cancer chemotherapy. An understanding of their agents, we will define the consensus sequence for cross-linking, the functional groups required for cross-linking, and the covalent structures of the relevant lesions. We will use the Crothers PAGE retardation method to assess bending and torsional reorganization in a wide variety of interstrand cross-linked DNAs. In collaboration with Professor Reid, we will seek to determine the three dimensional solution structure of an interstrand cross-linked DNA.