Boranophosphate DNA: RNA Hybrids as Probes of RNase H

硼磷酸 DNA：作为 RNase H 探针的 RNA 杂交体

• 批准号: 6700766
• 负责人: BARBARA RAMSAY SHAW
• 金额: $ 31.57万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6700766
• 关键词: antisense nucleic acid; boron; chemical stability; endoribonucleases; enzyme activity; nucleic acid chemical synthesis; nucleic acid metabolism; nucleic acid probes; nucleic acid structure; nucleoside analog; oligonucleotides; pharmacokinetics; phosphates; ribonuclease H; synthetic nucleic acid

DESCRIPTION (provided by applicant): The oligonucleoside boranophosphates (BH3--ODN) are a new class of phosphorus modified oligonucleotides that differ chemically from natural DNA in that a borane (BH-) group replaces one of the non-bridging oxygens in the phosphodiester backbone. BH3--ODN are more lipophilic and much more resistant to nucleases than natural DNA; they form Watson-Crick duplexes, and activate the Rnase H-mediated cleavage of complementary RNA. The boranophosphates join the natural phosphodiester, the (mono-and di-) thioates, and the more-nuclease-susceptible 2'-F-arabinonucleic acids, as the only classes of oligonucleotides that by themselves can orchestrate mRNA degradation in RNA/oligonucleotide hybrids via the enzyme RNase H. Despite recent improvements in the utility of antisense oligonucleotides in vivo, further progress is still needed. The goals of the proposed work are: (1) To synthesize a set of borano phosphate oligonucleotides and mixed-backbone chimeras targeted against the ras gene; (2) To evaluate the potential of BH3--ODN and chimeras to activate Tnase H1; (3) To evaluate biophysical properties of BH3--ODN including the thermodynamics, structure, and kinetics of their hybridization with RNA oligonucleotides and to study the kinetics of hydrolysis of RNA in BH3--ODN /RNA/Rnase H complexes. (4) To examine penetration of BH3-ODN and localization in cells, and other pharmacological properties; and (5) to probe the sequence and structural requirements for Rnase H specificity through our chemistry. The boranophosphates provide a new platform for probing the subtle effects of structure and sequence on RNase H catalysis. Our overall goals are to better understand the unique chemical and biological properties of boranophosphate oligonucleotides and gain further insight into the mechanism of action of RNase H and antisense agents. This information should allow us to design more potent antisense drugs for treating cancer and viral diseases.

描述（由申请人提供）：寡核苷硼磷酸酯 (BH3--ODN) 是一类新型磷修饰寡核苷酸，其不同之处在于 以化学方式从天然 DNA 中提取，其中硼烷 (BH-) 基团取代了其中一个 磷酸二酯主链中的非桥氧。 BH3--ODN较多 亲脂性，比天然 DNA 更能抵抗核酸酶；他们形成 Watson-Crick 双链体，并激活 Rnase H 介导的切割 互补RNA。硼磷酸盐与天然磷酸二酯一起， （单和二）硫代酸盐，以及对核酸酶更敏感的 2'-F-阿拉伯核酸 酸，作为唯一一类本身可以 通过该酶协调 RNA/寡核苷酸杂交体中 mRNA 的降解 RNase H。尽管反义的实用性最近有所改进 体内寡核苷酸的研究仍需要进一步进展。的目标 建议的工作是：（1）合成一组硼烷磷酸寡核苷酸 以及针对 ras 基因的混合骨架嵌合体； (2) 评估 BH3--ODN 和嵌合体激活 Tnase H1 的潜力； (3) 评估 BH3--ODN 的生物物理特性，包括热力学、结构和 它们与 RNA 寡核苷酸杂交的动力学并研究 BH3--ODN /RNA/Rnase H 复合物中 RNA 水解动力学。 (4) 至 检查 BH3-ODN 的渗透和细胞中的定位，以及其他 药理特性； (5) 探测序列和结构 我们的化学反应对 RNA 酶 H 特异性的要求。这 硼磷酸盐提供了一个新的平台来探索其微妙的影响 RNase H 催化的结构和序列。我们的总体目标是更好 了解硼磷酸盐独特的化学和生物特性 寡核苷酸并进一步了解 RNase 的作用机制 H和反义剂。这些信息应该使我们能够设计出更有效的 用于治疗癌症和病毒性疾病的反义药物。