Modulation of the Properties of Nucleic Acids through Structural Modifications

通过结构修饰调节核酸的性质

• 批准号: RGPIN-2015-05656
• 负责人: Yan, Hongbin
• 金额: $ 2.55万
• 依托单位: Brock University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613673
• 关键词: Modulation; Properties; Nucleic; Acids; through

Nucleic acids are crucial for many fundamental biological processes. They carry genetic information, and transmit it through replication, transcription and translation. These molecules are also recognized for their regulatory roles in many cellular processes. This proposal aims at approaches to introduce unique structural moieties into nucleic acids and consequently, confer properties to these molecules that will further our knowledge on the fundamental biological processes. In this regard, three chemical methods will be investigated. First, a methodology to metabolically label nucleic acids will be explored. This chemistry is based on the inverse Electron Demand Diels-Alder reaction between tetrazine and strained alkenes. It is proposed that a strained alkene moiety will be incorporated into nucleosides and subsequently, incorporated into nucleic acids enzymatically. Upon this incorporation, tetrazine that is covalently linked to a BODIPY fluorophore (non-fluorescent in the form of tetrazine-BODIPY conjugate) will be added, where an inverse Electron Demand Diels-Alder reaction takes place to restore the fluorescence. As such reactions are typically very fast, this chemistry will virtually allow for real-time tracking of cellular processes involving nucleic acids, and importantly, with minimal fluorescent background. Second, a chemical mimetic of restriction enzymes that will cleave nucleic acids in a sequence-specific manner is proposed. This approach is based on the Bergman cyclization of enediyne moieties that generate reactive biradicals during the cyclization. By covalently linking enediyne moieties to synthetic oligonucleotides, Bergman cyclization of enediyne can be directed towards the desired cleavage site due to the complementarity of the oligonucleotides with the target nucleic acids. This approach will be particularly useful in fragmenting large nucleic acids, such as genomic DNAs, in cell and molecular biology studies. Last, a methodology to regulate nucleic acid properties by light will be explored through the incorporation of cyclic azobenzene into nucleic acids. Due to the structural changes in cyclic azobenzene as a result of external light stimuli, nucleic acids bearing this modification will respond to light of specific wavelengths. This chemistry will be explored for spatiotemporal regulation of processes such as hybridization and transcription, and in the long term gene functions in living systems. The proposed research will provide a training ground for over a dozen much-needed highly qualified personnel. Work from the proposed research will further our knowledge on some fundamental biological processes that will benefit the wellbeing of Canadians, and contribute to Canada's knowledge-driven economy.

核酸对许多基本的生物过程至关重要。它们携带遗传信息，并通过复制、转录和翻译传递信息。这些分子在许多细胞过程中也被认为具有调节作用。该建议旨在将独特的结构片段引入核酸，从而赋予这些分子特性，从而进一步了解基本的生物过程。在这方面，将研究三种化学方法。首先，一种方法代谢标记核酸将探讨。这种化学反应是基于四嗪和张力烯烃之间的反电子需求diols - alder反应。有人提出，一个紧张的烯烃部分将并入核苷，随后，并入核酸酶。结合后，将加入与BODIPY荧光团（四氮-BODIPY共轭形式的非荧光）共价连接的四氮，其中发生反向电子需求Diels-Alder反应以恢复荧光。由于这些反应通常非常快，这种化学几乎可以实时跟踪涉及核酸的细胞过程，重要的是，在最小的荧光背景下。其次，提出了一种限制性内切酶的化学模拟物，它将以序列特异性的方式切割核酸。这种方法是基于在环化过程中产生活性双基的烯二炔部分的伯格曼环化。通过将烯二因部分与合成的寡核苷酸共价连接，由于寡核苷酸与靶核酸的互补性，烯二因的Bergman环化可以指向所需的裂解位点。在细胞和分子生物学研究中，这种方法将特别适用于分割大的核酸，例如基因组dna。最后，通过将环偶氮苯掺入核酸，探索一种通过光调节核酸性质的方法。由于外界光刺激导致环偶氮苯的结构变化，承受这种修饰的核酸会对特定波长的光做出反应。这种化学将探索过程的时空调节，如杂交和转录，以及在生命系统中的长期基因功能。拟议的研究将为十几名急需的高素质人才提供培训场地。拟议的研究工作将进一步加深我们对一些基本生物过程的了解，这将有利于加拿大人的福祉，并为加拿大的知识驱动型经济做出贡献。