SYNTHESIS OF SPECIFICALLY MODIFIED OLIGONUCLEOTIDES

该项目的长期目标是开发和演示 合成和利用15N所需的合成策略 标记的核酸。氮-15标记寡核苷酸，核糖核酸 脱氧核糖核酸，将是核酸结构的宝贵探针，药物- 结合和蛋白质-核酸相互作用。事实上，有一些 只能从这种15N探头获得的信息类型。 此外，尽管现代高场核磁共振光谱仪已经有了一些 计时所需的能力，所需的15N标记寡核苷酸 一直无法联系到。这些15N标记的潜力 在实际路线到达之前，寡核苷酸不可能开始实现 它们是可用的。将制定的方法和程序将 对15N标记寡核苷酸的可用性有重大影响， 这使得它们第一次被广泛使用。此外， ~(15)N核磁共振标记寡核苷酸的制备和分析 提供有关DNA结构、药物结合和 蛋白质与DNA的相互作用。 这项研究的第一阶段将是开发15N的路线 标记的嘌呤脱氧核苷，特别是15N标记的06- 甲基脱氧鸟苷。15N将分别有选择地引入 除糖苷氮外，其余为氮素。15N个导数中的每一个 脱氧腺苷、脱氧鸟苷和O6-甲基脱氧鸟苷 准备好了。此外，2-氨基嘌呤，2，6-二氨基嘌呤， 次黄嘌呤和O6-甲基次黄嘌呤脱氧核苷也将 由建议的路线提供。为了使这些15N标记 化合物普遍可用，合成路线将设计为 尽可能地节约。 第二阶段是将这些15N标记为 将脱氧核苷转化为寡核苷酸。一种规模化的氢膦酸根 方法，其中标记的脱氧核苷的有效使用是 强调，将用于寡核苷酸的合成。这些 程序将适用于任何符合以下条件的寡核苷酸合成 规模和经济效益很重要。最后一个阶段将是 用15N核磁共振研究了O6 MeG的碱基配对、O6 MeG的碱基配对 错配，可能包括Hoogsteen配对的新DNA结构 可由[3-]监测的7位药物与DNA的相互作用 [15N]和[2-15N]，以及蛋白质与DNA的相互作用 可通过主槽中的[7-15N]进行监控。

The long-term goals of this project are to develop and demonstrate the synthetic strategies necessary for the synthesis and utilization of 15N labeled nucleic acids. Nitrogen-15 labeled oligonucleotides, ribo or deoxyribo, will be invaluable probes of nucleic acid structure, drug- binding, and protein-nucleic acid interaction. In fact, there are some types of information which may be available only from such 15N probes. Moreover, although modern high-field nmr spectrometers have had for some time the necessary capabilities, the 15N labeled oligonucleotides needed have been unavailable. The potential of these 15N labeled oligonucleotides cannot begin to be realized until practical routes to them are available. The methods and procedures to be developed will have a major impact on the availability of 15N labeled oligonucleotides, allowing them to be widely used for the first time. In addition, the labeled oligonucleotides to be prepared and analyzed by 15N nmr will provide important information about DNA structure, drug-binding, and protein-DNA interactions. The first phase of this research will be to develop routes of 15N labeled purine deoxynucleosides, in particular to 15N labeled 06- methyldeoxyguanosine. The 15 N is to be introduced selectively at each nitrogen except the glycosidic nitrogen. Each of the 15N derivatives of deoxyadenosine, deoxyguanosine, and O6-methyldeoxyguanosine will be prepared. Furthermore, the 2-aminopurine, 2,6-diaminopurine, hypoxanthine and O6-methylhypoxanthine deoxyribosides also will be available by the routes proposed. In order to make these 15N labeled compounds generally available, the synthetic routes will be designed to be as economical as possible. The second phase will be incorporation of these 15N labeled deoxynucleosides into oligonucleotides. A large-scale H-phosphonate method, in which efficient use of the labeled deoxynucleosides is emphasized, will be used for the oligonucleotide synthesis. These procedures would be applicable to any oligonucleotide synthesis in which scale and economy are important. The final phase will be to investigate, by 15N nmr, the base pairing of O6MeG, base pairing of mismatches, novel DNA structures which may include Hoogsteen pairing at the 7-position, drug-DNA interactions which may be monitored by the [3- 15N] and [2-15N] in the minor groove, and protein-DNA interactions which may be monitored by the [7-15N] in the major groove.