A Novel Strategy for Active Control of DNA Recognition by External Stimulates -Peptide Ribonucleic Acids (PRNA)-

在开发用于下一代功能材料的核酸模型时，如果能够通过新的核酸模型实现核酸的识别控制和/或可逆识别控制，则可以实现关于外部刺激和/或因子的功能的动态表达/抑制。因此，本工作的主题是通过外部因素和/或刺激对核酸识别的动态和可逆控制，这是基于核酸结构的常规核酸模型化合物不能实现的。本文针对可逆DNA识别依赖性的重要性，提出了一种利用肽核糖核酸（PRNAs）改变pH体系控制可逆DNA识别的新策略。作者建立了一系列PRNA单体的合成路线，这些单体携带腺嘌呤、胞嘧啶、次黄嘌呤和尿嘧啶核碱基作为识别位点。这使我们能够充分扩大范围， ...更多信息 g可用的PRNA单体。作者进一步证明了新合成的Fmoc保护的PRNA单体与标准固相肽合成方案相容，并且可以制备具有嘌呤-嘧啶混合序列的寡聚PRNA。证明了嘧啶-嘌呤混合序列PRNAs的方向转换。在这项研究和以前的研究中，我们提出了一种新的方法和有效的工具，通过使用外部代理控制DNA/RNA识别。该策略采用新型核酸类似物，即β-肽核糖核酸（β-PRNAs），作为具有由外部因素触发的内置开关的识别部分。在不仅是高嘧啶PRNAs而且是嘧啶-嘌呤混合序列的PRNAs的情况下，核糖的顺式-2 '，3'-二醇的硼酸酯的形成以及5 '-酰胺质子和2-羰基氧之间的同时氢键相互作用充当外部和内部开关装置。这些研究中获得的结果令人鼓舞，表明^-PRNA与互补寡核苷酸形成稳定的杂交复合物，在加入三聚氰胺或硼酸后，这些复合物很容易解离。此外，还研究了多肽骨架的手性效应对PRNA结构和DNA识别行为的影响。通过添加作为外部控制因子的β-氨基丁酸，可以容易地将连接到L-和D-0-谷氨酸主链的PRNA单体和寡聚体的取向从反式切换到顺式。齐聚反应促进了协同取向转换和硼酸盐的形成。此外，D-，L-PRNA寡聚体诱导不同的高级结构。D-、L-PRNA分别为右旋和左旋卷曲结构。右旋螺旋D-PRNA与互补DNA的复合物比左旋螺旋D-PRNA与互补DNA的复合物更稳定，说明右旋螺旋D-PRNA与互补DNA之间形成的复合物更好。在此基础上，研究了嘧啶-嘌呤混合序列PRNA对DNA识别的开关机制。混合序列的PRNA与互补DNA形成的复合物比天然DNA更稳定。研究还表明，PRNA对DNA识别的开关是通过2 '，3'-二醇的硼酸化和嘧啶核苷2位上5 '-酰胺质子与羰基氧形成氢键而使碱基取向由反式向顺式转变而实现的。此外，核酸模型在提高识别选择性的同时，也提高了识别能力。PRNA能与互补DNA形成更稳定的复合物，且结合具有序列特异性，这是首次在生理条件下进行的可逆核酸识别研究。这些结果将证明为下一代设计反义分子的策略，该分子通过细胞和/或细胞核中的环境刺激做出反应。少

In the development of nucleic acid models for the next generation of functional materials, if the recognition control and/or reversible recognition control of nucleic acids by a novel nucleic acid model could be achieved, the dynamic expression/suppression of functions as to external stimulates and/or factor could be materialized. Thus, the subject of this work was dynamic and reversible control of nucleic acid recognition by an external factor and/or stimulate, which cannot be realized by the conventional nucleic acid model compounds based on a structure of nucleic acids. In this work, focusing on the importance of reversible DNA recognition dependent, the author found the novel strategy for reversible DNA recognition control by change of pH system with peptide ribonucleic acids (PRNAs). The author established the synthetic routes to a series of PRNA monomers, carrying adenine, cytosine, hypoxanthine, and uracil nucleobases as recognition sites. This enabled us to fully expand the ran … More ge of available PRNA monomers. The author further demonstrated that the newly synthesized Fmoc-protected PRNA monomers are compatible with the standard solid-phase peptide synthesis protocol, and oligomeric PRNAs with purine-pyrimidine mixed sequences can be prepared. It was demonstrated that the orientation switching of pyrimidine-purine mixed sequence PRNAs. In this and preceding studies, we have proposed a new methodology and effective tools for controlling DNA/RNA recognition through the use of an external agent. This-strategy employs novel nucleic acid analogues, i.e. □-peptide ribonucleic acids (^-PRNAs), as the recognition moiety which has a built-in switch triggered by an external factor. In the cases of not only homo-pyrimidine PRNAs but also pyrimidine-purine mixed sequenced PRNAs, the formation of a borate ester of the ribose's cis-2',3'-diol and the simultaneous hydrogen-bonding interaction between the 5'-amide proton and the 2-carbonyl oxygen act as the external and internal switching devices. The results obtained in these studies are encouraging, demonstrating that ^-PRNA form stable hybrid complexes with the complementary oligonucleotides, which are readily dissociated upon addition of borax or boric acid. Moreover, it was investigated that the chirality effect of peptide backbone upon the structure and DNA recognition behavior of PRNA. The orientation of PRNA monomers and oligomers tethered to L-and D-0-glutamic acid backbone could readily be switched from anti to syn by adding borax as an external controlling factor. The cooperative orientation switching and borate formation were enhanced by oligomerization. Furthermore, D-, L-PRNA oligomers were induced different higher-order structure each other. Certainly, D-, L-PRNA were determined right-handed and left-handed coiled structure respectively. The complex of right-handed coiled D-PRNA with complementary DNA was more stable than that of L-PRNA with DNA to indicate that the complexation, which was formed between same right-handed coiled structures of D-PRNA and DNA, was preferable. Then, the on-off switching of DNA recognition with pyrimidine-purine mixed sequence PRNA was demonstrated. PRNA with mixed sequence formed more stable complex with complementary DNA than natural DNA. Moreover, it was revealed that the on-off switching of the DNA recognition of PRNA could be materialized by the synergistic puckering change through borate formation of 2',3'-diol and base orientation switching from anti to syn through the hydrogen bonding formation between 5'-amide proton and carbonyl oxygen at 2 position of pyrimidine nucleoside. Furthermore, nucleic acid models were improved the recognition selectivity as well as its recognition ability. PRNA formed a more stable complex with complementary DNA and binding of PRNA with complementary DNA was sequence specific.This study was the first work for reversible nucleic acid recognition in the rage of physiological condition. These results will demonstrate a strategy for designing the antisense molecule for the next generation, which reacts by environmental stimulation in cell and/or nucleus. Less