MODIFIED NUCLEOTIDES IN GENE REGULATION--ANTISENSE DUPL

拟议研究的目的是了解以下原则 决定结构稳定性的特定分子识别 以及含有修饰残基的寡核苷酸双链的灵活性。 这些寡核苷酸类似物被用来作为反义药物 核酸酶抗性和靶向基因的高结合亲和力 序列。具有无手性和中性骨架的DNA二聚体合成子 连接，例如多肽或硫代甲缩醛连接的二聚体和嘧啶 衍生物将被合成并并入十二聚体中 序列。由此产生的寡核苷酸类似物将在 DNA-DNA和杂交DNA-RNA双链的高分辨率研究 多维核磁共振波谱。通过使用具有良好特征的 未修改的双工设置基本方案，然后系统 在指定位置引入核苷酸类似物，化学， 改性的结构扰动和构象柔性 将对寡核苷酸双链进行检查和比较。各种核磁共振 偶极耦合和标量耦合以及弛豫速率等参数将 进行了详细的测量和分析。相应的质子-质子 在建模中将使用距离和二面体扭转角度 寡核苷酸类似物的计算用于阐明 三维结构。这样系统而细致的结构 目前还没有关于反义双链的信息。这些 结果应提供对主干或基础的影响的洞察 对局部和全局结构和动态的修改 修饰的寡核苷酸双链。这项研究构成了 核苷酸类似物预测模型的持续研究 在基因调控方面的潜在治疗应用。

The aim of the proposed research is to understand the principles of specific molecular recognition that determine the structural stability and flexibility of oligonucleotide duplexes containing modified residues. These oligonucleotide analogs are intended to be antisense agents with nuclease resistance and high binding affinity for targeting gene sequences. DNA dimer synthons with achiral and neutral backbone linkages, such as peptide or thioformacetal linked dimers, and pyrimidine derivatives will be synthesized and incorporated into dodecamer sequences. The resulting oligonucleotide analogs will be studied in the context of DNA-DNA and hybrid DNA-RNA duplexes by using high resolution multidimensional NMR spectroscopy. By using well-characterized unmodified duplexes to set the basic scheme and then systematically introducing nucleotide analogs at designated sites, the chemistry, structural perturbation and conformational flexibility of modified oligonucleotide duplexes will be examined and compared. Various NMR parameters such as dipolar and scalar couplings and relaxation rates will be measured and analyzed in detail. The corresponding proton-proton distances and dihedral torsion angles will be utilized in modeling computations of oligonucleotide analogs for elucidation of three-dimensional structures. Such systematic and detailed structural information is presently not available for antisense duplexes. These results should provide insights into the effects of backbone or base modifications on local as well as global structure and dynamics of modified oligonucleotide duplexes. This study forms a basis for continuing research in predictive modeling of nucleotide analogs of potential therapeutic applications in gene regulation.