SYNTHESIS OF SPECIFICALLY MODIFIED OLIGONUCLEOTIDES

本计画将探讨多重标记DNA的合成与应用 包括15 N和13 C标记的片段。 通过掺入 多个标签，我们应该能够大大增加的数量， 可以从NMR实验获得的信息。 这多- 标记方法将通过结合多个- 标记的单体，并且还通过掺入多于一种标记的单体， 单体的 我们已经开发的路线， 单标记的15 N脱氧核苷将作为起始点 用于制备多重标记的化合物。 新的被标记 此时的目标化合物如下： 1. [7- 15 N]-次黄嘌呤 2. [6，7 - 15 N]-腺嘌呤 3. [6，7 - 15 N]-脱氧腺苷 4. [3，6 - 15 N]-腺嘌呤 5. [3，6 - 15 N]-脱氧腺苷 6. [1，6，7 - 15 N]-脱氧腺苷 7. [2- 13 C]-[2，3 - 15 N]-脱氧鸟苷 8. [2- 13 C]-[1，2 - 15 N]-脱氧鸟苷 9. [2- 13 C]-[1，2，7 - 15 N]-脱氧鸟苷 10. [2- 13 C]-[2，3 - 15 N]-O 6-甲基脱氧鸟苷 11. [2- 13 C]-[1，2 - 15 N]-O 6-甲基脱氧鸟苷 12. [2- 13 C]-[1，2，7 - 15 N]-O 6-甲基脱氧鸟苷 将这些化合物与[4- 15 N]-脱氧胞苷一起沿着掺入 DNA片段进行核磁共振研究 [1- 15 N]-、[2- 15 N]-和[6- 15 N]- 标签监测沃森-克里克面的相互作用，而[7- 15 N]- 和[3- 15 N]-标记监测大沟和小沟中的相互作用。 [2- 13 C]原子将提供有关环电流效应的信息， 并将用于检测分子中的15 N化学位移， 存在与15 N标记偶联的不可交换质子。 具体来说，我们将定义O 6 MeG. A中存在的碱基配对， O6MeG.G错配，以及平行DNA中的碱基配对。 我们会调查 药物。DNA和肽。DNA相互作用，包括DNA。DNA和 配体。DNA氢键，以及排除水发生在 药物对肽结合的影响。 此外，在这些系统中，我们将 试图将氢键受体（O或N）的身份与 供体NH基团的化学位移变化。 此外，随着这些 多标记化合物，我们也将能够监测变化， 水化发生在病变部位，配体的部位， 结合，或在复合物的其他地方。

This project will explore the synthesis and use of multiply labeled DNA fragments that include both 15N and 13C labels. By incorporation of multiple labels we should be able to increase dramatically the amount of information that can be obtained from an NMR experiment. This multi- labeling approach will be accomplished both by incorporation of multiple- labeled monomers, and also by incorporation of more than one labeled monomer. The routes that we have already developed for preparation of the singly-labeled 15N deoxynucleosides will serve as a starting point for preparation of the multiply labeled compounds. The new labeled compounds targeted at this time are listed below: 1. [7-15N]-Hypoxanthine 2. [6,7-15N]-Adenine 3. [6,7-15N]-Deoxyadenosine 4. [3,6-15N]-Adenine 5. [3,6-15N]-Deoxyadenosine 6. [1,6,7-15N]-Deoxyadenosine 7. [2-13C]-[2,3-15N]-Deoxyguanosine 8. [2-13C]-[1,2-15N]-Deoxyguanosine 9. [2-13C]-[1,2,7-15N]-Deoxyguanosine 10. [2-13C]-[2,3-15N]-O6-Methyldeoxyguanosine 11. [2-13C]-[1,2-15N]-O6-Methyldeoxyguanosine 12. [2-13C]-[1,2,7-15N]-O6-Methyldeoxyguanosine These compounds, along with [4-15N]-deoxycytidine, will be incorporated into DNA fragments for NMR studies. The [1-15N]-, [2-15N]-, and [6-15N]- labels monitor interactions of the Watson-Crick face, while the [7-15N]- and [3-15N]-labels monitor interactions in the major and minor grooves. The [2-13C] atom will provide information about ring current effects, and will be used to detect the 15N chemical shift in molecules where there is non-exchangeable proton coupled to the 15N label. Specifically, we will define the base pairing present in O6MeG.A and O6MeG.G mismatches, and the base pairing in parallel-DNA. We will probe drug.DNA and peptide.DNA interactions, including both DNA.DNA and ligand.DNA H-bonding, as well as the exclusion of water that occurs upon drug on peptide binding. Further, in each of these systems, we will attempt to correlate the identity of the H-bond acceptor (O or N) with the chemical shift change of the donor NH group. In addition, with these multi-labeled compounds, we will also be able to monitor changes in hydration which occur at the site of the lesion, the site of ligand binding, or elsewhere in the complex.