Expanding biosensing systems through synthetic functional deoxyribonucleic acids

DNA或脱氧核糖核酸是一种天然聚合物，由四种不同类型的核苷酸组成。众所周知，DNA是一种遗传物质，地球上所有的生物都用它来储存遗传信息，这主要是因为DNA是一种高度稳定的聚合物，它可以通过一种被称为沃森-克里克碱基配对原理的可预测机制轻松复制。DNA的这两个突出特性也被许多科学家用来制造合成DNA分子来做有趣的事情。这一提议涉及两类合成DNA分子的研究，即DNA酶和DNA适体。DNAzymes可以被看作是DNA制造的“分子引擎”，能够加速化学反应，而DNA适配体是DNA构建的“分子侦探”，在从复杂的分子混合物中找到特定的分子靶标方面表现出色，比如我们饮用水中的有毒金属或血液中的疾病指标。它们统称为功能性dna。大自然并不产生DNA适体和DNA酵素，但我们可以使用“体外选择”技术从DNA分子的人才库中找到它们。“体外选择”是一种基于实验室的技术，它驱动DNA库中单个DNA分子的竞争。我在麦克马斯特大学的团队擅长使用这种技术来寻找这样的DNA人才。我们对这些分子感兴趣的关键原因是最终用它们来做有用的事情，比如用它们来开发治疗方法或诊断方法。然而，在我们将它们用于合适的应用之前，我们需要通过称为“分子表征”的过程了解它们的特性。这项NSERC发现基金旨在发现新的DNA酶和DNA适体，对它们进行表征，并让它们做有用的事情。我们将努力实现四个具体目标。首先，我们希望找到一组新的DNAzymes，并将它们作为分子工具来研究被称为“RNA修饰”的重要生物学过程。其次，我们想测试一个全新的想法，制造更好的DNA适配体，具有更敏锐的检测能力，这样它们就能比现有的DNA适配体做更有效的检测工作。第三，我们想开发一种方法，利用颜色变化来报告DNA适体的侦探工作，就像石蕊试纸一样。最后，我们想构建一系列环状DNA适体或DNAzyme系统，并将它们锁在一起，这样就可以同时做两件或更多的事情。总的来说，通过本提案中将要进行的工作，我们将产生关于DNA适体和DNAzymes的新知识，开发新的或更好的DNA适体和DNAzymes，并设计将DNAzymes和DNA适体用于环境，食品安全和医疗应用的新方法。除了取得重要的科学发现外，在这个项目中，我们将在未来五年内与几名年轻学生合作，培养他们成为加拿大未来的高技能科学家。

DNA, or deoxyribonucleic acid, is a natural polymer made of four different types of building blocks called nucleotides. DNA is widely known to us as the genetic material - it is used by all of the living organisms on Earth to store their genetic information, largely because DNA is a highly stable polymer and it can be easily replicated through a predictable mechanism called the Watson-Crick base-pairing principle. These two outstanding properties of DNA have also been utilized by many scientists to make synthetic DNA molecules to do interesting things. This proposal concerns the study of two classes of synthetic DNA molecules known as DNAzymes and DNA aptamers. DNAzymes can be viewed as DNA-made "molecular engines” capable of speeding up chemical reactions, whereas DNA aptamers are DNA-constructed “molecular detectives” that are excellent in finding a specific molecular target from a complex molecular mixture, like a toxic metal in our drinking water or a disease indicator in our blood. Collectively they are referred to as functional DNAs. Mother Nature does not produce DNA aptamers and DNAzymes, but we can find them from a talent pool of DNA molecules using "in vitro selection", a laboratory-based technique that drives the competition of individual DNA molecules in the DNA pool. My group at McMaster University is skilled in using this technique to find such DNA talents. The key reason that we are interested in these molecules is to eventually use them to do useful things, such as using them to develop therapeutics or diagnostics. However, before we can use them for suitable applications, we need to know their traits through a process known as "molecular characterization". This NSERC Discovery grant aims to find new DNAzymes and DNA aptamers, characterize them well, and get them to do useful things. We will pursue four specific goals. First, we want to find a new group of DNAzymes and use them as molecular tools to study an important biological process known as "RNA modification". Second, we want to test a brand new idea for making better DNA aptamers with a much sharper detecting capability so that they can do more efficient detective work than existing DNA aptamers. Third, we want to develop an approach that uses color change to report the detective work by DNA aptamers, like a litmus test. Finally we want to construct a series of ring-shaped DNA aptamer or DNAzyme systems and lock them together so that can do two or more things at once. Overall, through the work to be performed in this proposal, we will generate new knowledge about DNA aptamers and DNAzymes, develop new or better DNA aptamers and DNAzymes, and devise new approaches that employ DNAzymes and DNA aptamers for environmental, food safety, and medical applications. Besides making important scientific discoveries, in this project we will work with several young students over the next five years and train them to become highly skilled scientists for the future of Canada.