Collaborative Research: Dynamics of Circular Macromolecules (DNA): From Single Molecules to Highly Entangled States

合作研究：圆形大分子（DNA）动力学：从单分子到高度纠缠态

• 批准号: 1603943
• 负责人: Gregory McKenna
• 金额: $ 17.37万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1603943&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamics; Circular; Macromolecules

PI: McKenna, Gregory B. / Schroeder, Charles / Anderson, RaeProposal Number: 1603943/ 1604038 / 1603925 The goal of this proposal is to explore the behavior of polymer molecules that form large rings, instead of the usual linear polymer molecules. Such polymers, an example of which can be the DNA molecule, behave in a different way than linear molecules when processed or when they flow in a solution, because there are no ends in the chains. Results of this work can lead to improved polymer materials, to understanding in detail the behavior of bio-molecules, and to new technologies for DNA sequencing. Circular polymers are fascinating materials that have inspired polymer theorists and experimentalists for decades. The dynamics of circular chains differ fundamentally from their linear counterparts due to the absence of chain ends. Despite recent progress, however, the effects of circular topology on polymer dynamics remain a key unresolved problem in the field. In this proposal, the PIs are poised to make major progress in our understanding by preparing circular and linear DNA molecules that are monodisperse and of high topological purity. The assembled team has the expertise to synthesize and characterize circular and linear DNA, and will study the rheological behavior of these materials over a wider range of concentrations and molecular weights than previously achieved. A comprehensive approach is proposed that will include macroscopic and micro-rheology, single molecule polymer dynamics, and DNA synthesis, to provide new information regarding the dynamics of linear and circular DNA. Beyond providing a point of departure for understanding their circular counterparts, the parallel study of linear entangled DNA will provide unprecedented data using perfectly monodisperse DNA samples to directly test predictions from reptation theory, such as the cross-over to reptative behavior at extremely high entanglement densities. In addition to graduate student participation, educational activities are proposed in all three collaborating institutions, ranging from underrepresented minority student involvement at Texas Tech, to high school teacher engagement at Illinois and undergraduate student participation at the U of San Diego, a mainly undergraduate institution.

PI: McKenna, Gregory B. / Schroeder, Charles / Anderson, Rae 提案编号：1603943/ 1604038 / 1603925 该提案的目标是探索形成大环的聚合物分子的行为，而不是通常的线性聚合物分子。此类聚合物（例如 DNA 分子）在加工时或在溶液中流动时的行为方式与线性分子不同，因为链中没有末端。这项工作的结果可以改进聚合物材料、详细了解生物分子的行为以及 DNA 测序新技术。圆形聚合物是一种令人着迷的材料，几十年来一直激励着聚合物理论家和实验家。由于没有链端，圆形链的动力学与线性链有根本的不同。然而，尽管最近取得了进展，圆形拓扑对聚合物动力学的影响仍然是该领域尚未解决的关键问题。在这项提案中，PI 准备通过制备单分散且具有高拓扑纯度的环状和线性 DNA 分子，在我们的理解方面取得重大进展。组建的团队拥有合成和表征环状和线性 DNA 的专业知识，并将研究这些材料在比以前更广泛的浓度和分子量范围内的流变行为。提出了一种综合方法，包括宏观和微观流变学、单分子聚合物动力学和 DNA 合成，以提供有关线性和环状 DNA 动力学的新信息。除了为理解其圆形对应物提供一个出发点之外，线性纠缠 DNA 的并行研究还将提供前所未有的数据，使用完全单分散的 DNA 样本来直接测试爬行理论的预测，例如在极高纠缠密度下与爬行行为的交叉。除了研究生参与之外，所有三个合作机构还提议开展教育活动，从德克萨斯理工大学代表性不足的少数族裔学生的参与，到伊利诺伊州高中教师的参与，以及主要本科院校圣地亚哥大学的本科生参与。