SYNTHESIS OF NUCLEIC ACID AND NUCLEOTIDE METAL COMPLEXES

总体目标是a）继续阐明核酸的性质 金属物质，包括金属抗癌药物的结合，和B）与 开创了金属核酸领域的新途径，即金属 用于稳定不寻常寡核苷酸构象 推进我们的核酸生物化学的基础知识， 从长远来看，作为治疗剂可能有用。 一些 金属与核酸相互作用的重要性的无数原因 包括：广泛使用的金属的存在或要求 攻击DNA的广谱抗癌药物（如顺铂、博来霉素 （BLM））;金属物种的存在，可能在活性位点， 核酶;金属诱导诱变中的DNA相互作用， 致癌作用;金属离子在控制核酸中的重要作用 酸结构，e. G. tRNA、端粒、Z-DNA等;无处不在的 金属离子参与核苷酸生物化学和核酸 结合蛋白和加工酶，例如在转录因子中， 逆转录酶等;以及金属探针日益增长的实用性 用于核酸结构和生物化学。 因为我们知道 金属核酸相互作用还远未完成，我们提出了一些 基础研究的重点是金属-寡核苷酸物种， 而直接用核磁共振等方法对其进行的研究较少 谱 少数报道的直接方法的研究集中在 Pt化合物。我们建议更进一步， 金属-寡核苷酸物质，其中金属配位稳定了 寡核苷酸在一个不寻常的构象。 重点将放在 发夹结构，以建立控制 结构 在以后的几年里，我们建议将所获得的知识应用于 开发稳定的发夹型DNA/RNA杂交核酶模型。 人能 想象一下这种新方法的许多应用。e. G.稳定 针对病毒如HIV-1的核酶，稳定的DNA 与阻力因素紧密结合的结构部件等。 为采取合理办法综合这些建议奠定基础， 我们将在很大程度上依赖于基本原则， 配位化学和金属-核酸化学。 我们将使用一个 我们最近证明是可行的新概念，即 拆分的NH基团的取向的立体化学控制 不对称二胺配体与Pt（III）配位。 除了合成的 这种类型的复杂的价值，所获得的知识将增加我们的 自2000年以来，对铂类抗癌药物作用机制的理解 NH基团与DNA的相互作用是必不可少的（Pt化合物缺乏 NH基团不活跃）。 此外，这种复合物可以诱导新的 修复无法识别的扭曲DNA结构类型 癌细胞中的酶或抵抗因子。 其他基础研究 建议包括评估区分核碱基之间的因素 和磷酸盐配位，研究金属BLM的结构， 他来霉素复合物及其与寡核苷酸的结合，和 检查金属物质与B型DNA和DNA的结合 不寻常的结构特征，例如由其他物质引起的凸起或病变 毒品 这些研究旨在了解铂的协同作用， BLM药物 方法：多核（31 p，13 C，195 pt） NMR/距离几何方法，CD，分子力学计算， 凝胶电泳

Overall goals are a) to continue elucidating the nature of nucleic acid binding of metal species, including metal anticancer drugs, and b) to initiate a new approach in the metal nucleic acid field, namely metal stabilization of unusual oligonucleotide conformations useful in advancing our fundamental knowledge of nucleic acid biochemistry and potentially useful, in the long term, as therapeutics. Some of the myriad reasons for the significance of metal nucleic acid interactions include: the presence in or the requirement for metals in widely used DNA-attacking broad spectrum anticancer drugs (e.g.cisplatin, bleomycin (BLM)); the presence of metal species, probably at the active site, of ribozymes; DNA interactions in metal induced mutagenesis or carcinogenesis; the essential role metal ions play in controlling nucleic acid structures, e. g. tRNA, telomeres, Z-DNA, etc.; the ubiquitous involvement of metal ions in nucleotide biochemistry and in nucleic acid binding proteins and processing enzymes, e.g. in transcription factors, reverse transcriptases, etc.; and the growing utility of metalloprobes for nucleic acid structure and biochemistry. Since our knowledge of metal nucleic acid interactions is far from complete, we propose a number of fundamental studies with emphasis on metal-oligonucleotide species, which have received little study by direct methods such as NMR spectroscopy. The few reported studies with direct methods concentrate on Pt compounds. We propose to go further and to design metal-oligonucleotide species in which metal coordination stabilizes the oligonucleotide in an unusual conformation. Emphasis will be placed on hairpin structures in order to establish the principles needed to control structure. In later years, we propose to apply the knowledge gained to develop models of stable hairpin-type DNA/RNA hybrid ribozymes. One can imagine a number of applications of this new approach., e. g. stabilized ribozymes directed against viruses such as HIV-1, stabilized DNA structural components that bind tightly to resistance factors, etc. In laying the foundation for a rational approach to synthesize such structures, we will rely heavily on fundamental principles of coordination chemistry and metal-nucleic acid chemistry. We will use a new concept that we have recently shown to be feasible, namely the stereochemical control of the orientation of NH groups of resolved asymmetric diamine ligands coordinated to Pt(III). Besides the synthetic value of this type of complex, the knowledge gained will increase our understanding of the mode of action of Pt anticancer drugs since the interaction of the NH groups with DNA is essential (Pt compounds lacking NH groups are inactive). In addition, such complexes may induce new types of distorted DNA structures that are not recognized by repair enzymes or resistance factors in cancer cells. Other fundamental studies proposed include evaluating factors that differentiate between nucleobase and phosphate coordination, investigating the structure of metal BLM and tallysomycin complexes and their binding to oligonucleotides, and examining the binding of metal species to B-form DNA and to DNAs with unusual structural features such as bulges or lesions induced by other drugs. These include studies aimed at understanding synergism of Pt drugs with BLM. Methods include multinuclear (31p, 13C, 195pt) NMR/distance geometry methods, CD, molecular mechanics calculations, and gel electrophoresis.