Statistical Mechanical Studies of Complex Systems

复杂系统的统计力学研究

• 批准号: 0314531
• 负责人: Udayan Mohanty
• 金额: $ 27.8万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0314531&HistoricalAwards=false
• 关键词: Statistical; Mechanical; Studies; Complex; Systems

Professor Udayan Mohanty is supported by the Theoretical and Computational Chemistry Program and the Molecular Biophysics program to perform statistical mechanical studies on complex systems. Using the theoretical and computational machinery of statistical mechanics, Mohanty will simulate the dynamics of circularly permuted DNA molecules, study how asymmetric charge neutralization induces bending in DNA molecules, and generalize the current understanding on the degree to which electrostatic polarization of DNA is governed by charge redistribution at the ends of the molecules. The goals of these studies are to describe the behavior of curved DNA sequences in gels and to determine which forces govern DNA bending in the nucleosome. A combination of theoretical techniques is used which include density functional theory, continuum models, integral equations and computer simulations.Sequencing and separating DNA fragments is often accomplished by electrophoretic induced migration of such fragments through gels. At the simplest level migration rates would be governed by friction coefficients and molecular weight. However fragments of certain sizes exhibit anomalous migration rates, which necessitate a more complete understanding of how size-dependent shape transitions, fragment polarization, and charge dependencies affect fragment migration. The ability to predict and understand these dependencies will aid in determining likely protein binding sites and help in unraveling DNA replication and recombination. Such studies rely on development of theoretical tools that probe the oligoelectrolyte properties of DNA. Parallel to the development of these tools is a strong educational outreach effort to high-school and undergraduate students in addition to undergraduate and graduate education.

Udayan Mohanty 教授在理论和计算化学项目和分子生物物理学项目的支持下对复杂系统进行统计力学研究。 Mohanty 将利用统计力学的理论和计算机制来模拟循环排列 DNA 分子的动力学，研究不对称电荷中和如何引起 DNA 分子弯曲，并概括目前对 DNA 静电极化受分子末端电荷重新分布控制程度的理解。 这些研究的目的是描述凝胶中弯曲 DNA 序列的行为，并确定哪些力控制核小体中的 DNA 弯曲。结合使用了理论技术，包括密度泛函理论、连续介质模型、积分方程和计算机模拟。DNA 片段的测序和分离通常是通过电泳诱导片段通过凝胶的迁移来完成的。 在最简单的水平上，迁移速率将由摩擦系数和分子量控制。 然而，某些尺寸的碎片表现出异常的迁移率，这需要更全面地了解尺寸相关的形状转变、碎片极化和电荷依赖性如何影响碎片迁移。 预测和理解这些依赖性的能力将有助于确定可能的蛋白质结合位点，并有助于解开 DNA 复制和重组的谜题。 此类研究依赖于探测 DNA 寡电解质特性的理论工具的开发。 与这些工具的开发并行的是，除了本科生和研究生教育之外，还针对高中生和本科生开展了强有力的教育推广工作。