DNA STRUCTURAL PROBES BY DRUGS AND CROSSLINKING

拟议的研究是在两个不同的领域，序列依赖 使用EPR光谱学和核酸动力学研究的核酸动力学 与双官能烷基化剂的相互作用。 在前一个地区， 我们将继续努力合成有用的氮氧自旋探针， 用于核酸动力学的EPR研究。 这些研究提供 关于DNA非基态构象可及性的信息 这可能是重要的，在其识别的蛋白质和小 分子。 所提出的靶自旋探针将克服 目前可用的自旋探针的实质性缺陷，将被测试 对于与B-DNA的结构相容性，将使用EPR进行比较 在前一个授权期内开发的探测技术，以及 将用于制备自旋标记的发夹，四臂结 （霍利迪中间体），错配，和链间交联的DNA， 用于动力学研究。 拟议的研究领域包括： 双功能DNA烷基化试剂将是DNA研究的热点 抗肿瘤物质FR 900482的链间交联反应 和FR 66979，2，5-双-（N-氮丙啶基）-1，4-苯醌（DZQ），和 生物调节物质一氧化氮。 链间交联是 通常被认为是目前用于治疗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 用于交联的共有序列，所需的官能团， 以及相关病变的共价结构。 我们将使用Crothers PAGE阻滞法来评估弯曲， 扭转重组在各种各样的股间交联 DNA 与里德教授合作，我们将寻求确定 股间交联的三维溶液结构 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.