Mathematical modeling of the voltage driven translocation of polyelectrolytes thr

描述（由申请人提供）：最近在生物技术中出现了纳米级孔的许多应用，部分受到它们在生物学背景下的功能的启发。该提议涉及一种通过使用电场驱动DNA和其他具有生物学意义的线性聚电解质通过单个纳米孔来对它们进行测序的探索性方法。类似的场介导的跨纳米孔的转移被认为是真核细胞的正常分子水平机制的一部分。自Kasianowicz、Brandin、Branton和Deamer的里程碑式的1996年论文[Proc.Natl. Acad. sci. 93，13770 - 13773（1996）]。证明了通过观察电流信号检测单个分子通过纳米孔的可能性。最近的原子水平的分子动力学模拟增强了我们对这些易位背后的详细机制的理解。然而，能够给出诸如移位速度和标度指数等明确公式的简单分析模型却很少见。这项建议旨在填补我们知识上的这一空白。有人提出，易位过程可以理解为带电物体通过离子流体中的受限空间的电泳问题。使用这样的描述，再加上漂移扩散模型来描述布朗波动，定量预测，可以直接与实验数据进行比较。初步结果表明，这种方法的成功。拟议活动的预期广泛影响是：（A）正在开发的理论模型将为开发基于纳米孔想法的可行超快速DNA测序技术的实验工作提供急需的指导。以目前方法的一小部分成本对DNA进行测序的能力对人类健康具有广泛而广泛的影响，这是众所周知的。(B)理论模型将导致对活细胞分子水平功能的重要和基本部分的有价值的见解。这种理解具有各种已知和未知的实际影响：例如，它可以改进基因治疗中将DNA注入细胞核的方法，它可以导致基于破坏病原体细胞周期中蛋白质易位步骤的原理开发新药，反过来通过设计化学品来治疗易位过程失败引起的疾病，纠正缺陷。公共卫生相关性：拟议的活动旨在进一步了解电压介导的线性聚电解质跨纳米孔转移的生物物理过程。这个过程是一种超快速DNA测序方法的基础，该方法已经成为近十年来深入研究的主题，也是真核细胞正常功能的基本步骤。除了超快速DNA测序技术，其巨大的潜在影响已被广泛讨论，对易位过程的更好理解可能导致基因治疗技术的改进以及旨在促进或破坏（在病原体的情况下）细胞易位过程的药物设计。

DESCRIPTION (provided by applicant): A number of applications of nanometer scale pores have emerged recently in biotechnology inspired partly by their function in the biological context. This proposal relates to an exploratory method for sequencing DNA and other linear polyelectrolytes of biological significance by driving them through a single nanopore using an electric field. Analogous field mediated transfer across nanopores is believed to be part of the normal molecular level machinery of eukaryotic cells. A fair amount of experimental data has accumulated since the landmark 1996 paper by Kasianowicz, Brandin, Branton and Deamer [Proc. Natl. Acad. Sci. 93, 13770 - 13773 (1996)]. demonstrating the possibility of detecting the passage of individual molecules through a nanopore by observing the current signal. Recent atomic level molecular dynamic simulations have enhanced our understanding of the detailed mechanism behind these translocations. Simple analytical models that result in explicit formulas for such things as translocation speeds and scaling exponents are however rare. This proposal seeks to address this gap in our knowledge. It is proposed that the translocation process may be understood as a problem of electrophoresis of charged objects through confined spaces in an ionic fluid. Using such a description, coupled with a drift diffusion model to describe the Brownian fluctuations, quantitative predictions are sought that can be directly compared to experimental data. Preliminary results indicating the success of such an approach are presented. The expected broad impact of the proposed activity are: (A) The theoretical models being developed would provide much needed guidance in the experimental efforts to develop a viable ultra rapid DNA sequencing technology based on the nanopore idea. The ability to sequence DNA at a fraction of the cost of current methods has vast and broad implications for human health that are well known. (B) The theoretical models would lead to valuable insight on a vital and essential part of the molecular level functioning of a living cell. Such understanding has a variety of known and as yet unknown practical implications: it could, for example, lead to improved methods of injecting DNA into the cell nucleus in gene therapy, it could result in the development of new drugs based on the principle of disrupting the protein translocation step in the cell cycle of pathogens and conversely cure diseases caused by the failure of the translocation process by designing chemicals to rectify the defect. PUBLIC HEALTH RELEVANCE: The proposed activity is aimed at furthering fundamental understanding of the biophysical process of voltage mediated transfer of linear polyelectrolytes across nanopores. This process is the basis for a proposed ultra-fast DNA sequencing method that has been the subject of intensive research for about a decade and is also a basic step in the normal functioning of a eukaryotic cell. Besides the ultra-fast DNA sequencing technology, the enormous potential impact of which has been widely discussed, improved understanding of the translocation process could lead to improvements in techniques of gene therapy as well as the designing of drugs meant to promote or disrupt (in case of pathogens) the translocation process in cells.