Catalytic nucleic acids that highlight surprising fundamental properties of DNA and RNA

催化核酸凸显 DNA 和 RNA 令人惊讶的基本特性

• 批准号: RGPIN-2017-03971
• 负责人: Sen, Dipankar
• 金额: $ 5.17万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710632
• 关键词: Catalytic; nucleic; acids; highlight; surprising

The thrust of my research program is to explore the universe of chemical catalysis available to RNA and DNA, the "nucleic acids" that are the shared genetic material of all living organisms. Nobel-winning discoveries have revealed that these biopolymers, thought for long to operate solely as agents for storing and expressing genetic information, can also catalyze metabolic reactions. My own research group uses varied methodologies to try and define what reactions such enzymes made out of RNA and DNA ("ribozymes" and "DNAzymes") can indeed catalyze. Our goals are fourfold: to test the validity of the powerful "RNA World Hypothesis", which posits that very early life forms used nucleic acids for both genetic and metabolic purposes; to define how well enzymes made from these biopolymers can function, vis-a-vis protein enzymes; to generate useful reagents for application in the clinic, in industry, and in biomedical research; and, to recognize what our catalytic RNAs and DNAs may be telling us about their possible roles in biology. My lab has used the methods of "in vitro selection" to define three new classes of nucleic acid enzymes: (1) those that bind and activate the ubiquitous cellular cofactor, heme, to catalyze oxidative chemistry; (2) A "photolyase" DNAzyme, that harnesses light to repair UV-induced lesions in DNA linked to cancer; and (3) a ribozyme that utilizes the unique capabilities of vitamin B1 to catalyze a difficult metabolic reaction. In a surprising development, it is now becoming clear that some of these newly identified catalytic properties actually reflect fundamental properties of RNA and DNA, that are likely in operation in living organisms. I propose to use a variety of biochemical, chemical, and biological approaches to investigate the above-stated goals. Specifically, we will use the methods of in vitro selection to test whether a photolyase enzyme made out of RNA or DNA can rival the catalytic prowess of protein photolyase enzymes; and, to determine rigorously whether there are privileged nucleotide sequences within standard, double-helical DNA that are particularly resistant to UV light-mediated damage. We will also attempt to define the classes of reactions that heme-utilizing ribozymes and DNAzymes are capable of catalyzing, and how they compare to nature's own Cytochrome P450 enzymes. And, develop a very promising biochemical tool that we have identified for probing heme's interaction with RNA and DNA within living cells, in disease as well as in healthy contexts. In addition to its purely scientific goals, my proposed research program will provide excellent and rounded training for highly qualified personnel, to set them up for careers in medicine, biotech, and academia, as well as in diverse other careers options in Canada.

我的研究计划的目的是探索RNA和DNA可用的化学催化宇宙，RNA和DNA是所有生物体的共享遗传物质的“核酸”。获胜的发现表明，这些生物聚合物长期以来只能作为存储和表达遗传信息的药物运作，还可以催化代谢反应。我自己的研究小组使用各种方法来尝试定义由RNA和DNA（“核酶”和“脂肪酶”）制成的这种反应确实可以催化。我们的目标是四重：测试强大的“ RNA世界假设”的有效性，该假设认为，生命形式非常早期的形式使用核酸来遗传和代谢目的；为了定义这些生物聚合物制成的酶的功能，相对于蛋白质酶的作用；为在诊所，工业和生物医学研究中生成有用的试剂；并且，要认识到我们的催化RNA和DNA可能会告诉我们它们在生物学中的可能作用。我的实验室已使用“体外选择”方法定义了三种新的核酸酶：（1）那些结合并激活无处不在的细胞辅助因子血红素的酶，以催化氧化化学； （2）一种“光溶解酶” dnazyme，可利用光修复与癌症相关的DNA中的紫外线诱导的病变； （3）利用维生素B1独特能力来催化困难的代谢反应的核酶。在令人惊讶的发展中，现在越来越清楚的是，这些新鉴定的催化特性实际上反映了RNA和DNA的基本特性，这些特性可能在生物体中运行。 我建议使用各种生化，化学和生物学方法来研究上述目标。具体而言，我们将使用体外选择的方法来测试由RNA或DNA制成的光溶酶是否可以与蛋白质光溶解酶酶的催化能力相媲美。并且，要严格确定标准的双螺旋DNA中是否有特权核苷酸序列，这些序列对紫外线介导的损伤特别有抵抗力。我们还将尝试定义血红素利用核酶和dnazymes能够催化的反应类别，以及它们如何与自然自然的细胞色素P450酶进行比较。并且，开发了一种非常有前途的生化工具，我们已经确定了用于探测血红素与活细胞中RNA和DNA的相互作用，在疾病和健康环境中。 除了纯粹的科学目标外，我提出的研究计划还将为高素质的人员提供出色而圆的培训，以使他们从事医学，生物技术和学术界的职业以及加拿大其他各种职业选择。