Thiol-oligonucleotides for reversible chemical ligation and replication

寡核苷酸模板合成在序列特异性可编程反应中提供了多种应用。设计了化学产生的人工谷胱甘肽系统，其存在于基因诊断、药物筛选或纳米构建体应用中。尽管已建立的寡核苷酸连接反应种类繁多，但可逆或可转换共价连接方法的数量有限。该项目旨在为这里的新连接化学做出贡献。连接基于硫醇-二硫键交换反应，其利用3-5-磷酸二酯键对3 -5-二硫键的电子等排置换的基本思想。在这种情况下，可以实现秒级的半衰期。该连接具有序列选择性，可以形成可逆或不可逆的，并且对氧化还原状态和pH值敏感。该项目旨在开发可逆二硫键的全部潜力。一组核酸修饰将用现有的化学合成方法完成，并用于新的连接实验。本论文研究了定向化学连接、模板定向聚合和动态DNA文库的可行性。此外，硫醇化学应开发用于新的点击连接反应。该项目的创新之处在于将寡核苷酸连接成可逆和不可逆方向的可配置性，可用于从动态系统中制备稳定的寡聚体。结合已经显示的二硫键寡核苷酸的PCR扩增，可以产生在生物医学和DNA纳米技术背景下的新应用。

Oligonucleotide templated syntheses offer a variety of applications in sequence specific programmable reactions. Chemically produced artificial oligonucleotide-systems were designed, which exist in gene diagnostics, drug screening or nano-constructs applications. Despite the wide variety of established ligation reactions of oligonucleotides, the number of reversible or switchable covalent linkage methods is limited. The project aims to contribute with a new ligation chemistry here. The ligation is based on thiol-disulfide exchange reactions that make use of the basic idea of the isosteric replacement of a 3-5-phosphodiester bond against a 3-5-disulfide bond. In this case, half-lives in the order of seconds could be achieved. The ligation is sequence selective, it can be shaped reversible or irreversible, and it proves to be sensitive to the redox state and pH-value. The project aims to exploit the full potential of the reversible disulfide linkage. A set of nucleic acid modifications is to be completed with the existent chemical synthesis methods and used in new ligation experiments. The feasibility of a directed chemical ligation, a template-directed polymerization and a dynamic DNA library is to be investigated. Furthermore, the thiol chemistry should be developed for new click-ligation reactions. The innovation of the project can be found in the configurability of the oligonucleotide ligation into reversible and irreversible direction, which can be used for the preparation of stable oligomeres out of dynamic systems. In combination with an already shown PCR amplification of disulfide oligonucleotides new applications in the context of biomedicine and DNA-nanotechnology can result.