Stability and Structure of Nucleic Acid Triple Helices

核酸三螺旋的稳定性和结构

• 批准号: 9218687
• 负责人: Richard Shafer
• 金额: $ 30万
• 依托单位: University of California-San Francisco
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-02-01 至 1996-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218687&HistoricalAwards=false
• 关键词: Stability; Structure; Nucleic; Acid; Triple

This proposal focusses on the structure and stability of DNA, RNA, and mixed DNA/RNA triple helices. These novel DNA structures are of great current interest due to the large number of possible applications of targeting duplex DNA with a third strand as well as the possible in vivo role of such structure in, for example, gene regulation. The long-term goals of this work include understanding the role of nucleotide sequence and composition, cation and ionic strength in determining the stability of both pyrimidine-purine- pyrimidine and purine-purine-pyrimidine triplexes and establishing a high resolution model for the molecular structure of intermolecular triplexes. In particular, we propose to determine the sequence and composition requirements for formation of purine- purine-pyrimidine triplexes using capillary and slab gel electrophoresis, along with circular dichroism and imino proton NMR. Evaluation of the thermodynamic stability of triplexes will be carried out both by UV melting analysis and by calorimetry, thereby permitting assessment of the validity of the all-or-none model for triplex formation. Additional stability studies will consider the effects of RNA strands, mismatches and base modification on triplex stability. Finally, high resolution 2D and 3D NMR methods will be applied to the problem of determining the structure of triplexes at a molecular level. %%% These studies will provide fundamental data on the stability and structure of nucleic acid triplexes, which will be of importance in a large number of potential applications of this unusual nucleic acid structure.

该提案的重点是DNA，RNA， 和混合的DNA/RNA三螺旋。 这些新的DNA结构是 由于大量的可能性， 用第三链靶向双链体DNA的应用以及 这种结构在例如基因中可能体内作用 调控 这项工作的长期目标包括了解 核苷酸序列和组成、阳离子和离子 在确定嘧啶-嘌呤- 嘧啶和嘌呤-嘌呤-嘧啶三链体并建立 分子结构的高分辨率模型 分子间三链体。 特别是，我们建议确定 形成嘌呤的顺序和组成要求- 使用毛细管和平板凝胶的嘌呤-嘧啶三链体 电泳，沿着与圆二色性和亚氨基质子 匪r 三链体的热力学稳定性的评估将 通过UV熔融分析和量热法进行， 从而允许评估全或无的有效性 三链体形成的模型。 其他稳定性研究将 考虑RNA链、错配和碱基的影响 对三链体稳定性的修饰。 最后，高分辨率2D和 3D NMR方法将应用于确定的问题， 在分子水平上的三链体结构。 %%% 这些研究将提供有关稳定性和 核酸三链体的结构，这将是重要的， 这种不寻常的核酸的大量潜在应用 酸性结构