学术报告 六十二
题目: [软物质物理重点实验室系列学术报告（六十二）]Towards understanding the solution dynamics using the combination of computer simulation and spectroscopy
时间: 2013年09月17日 15:00
地点: 中科院物理所 M楼253会议室
报告人: Wei Zhuang （庄巍）
大连化物所， E-mail : wzhuang@dicp.ac.cn
报告摘要：
Microscopic solution dynamics is a central topic in the condense matter sciences. Optical spectroscopies play important roles in the investigations in this field. Analysis and understanding of the solution spectra are usually non-trivial due to the complex nature of the systems.
We carried out series of spectral modeling based on the molecular dynamics simulation to help understanding the dynamic events in the protein aqueous solution and ionic solution systems. A technique combining the Markov State Model (MSM) and the Nonlinear Exciton Propagation (NEP) methods was developed to simulate the T-jump triggered long time peptide unfolding process and the related IR, 2DIR and fluorescence spectra. Furthermore, to overcome the convergence issue in the sampling and reduce the computational cost, implicit solvent model was introduced into the simulation, which generates converged temperature dependent peptide configuration distribution. We demonstrated that IR and 2DIR spectra simulated based on this distribution nicely reproduce the temperature dependences of experimental signals.
An important, but not yet clearly addressed, issue in ionic solution research is how the microscopic dynamics in the solution is influenced by the ionic density distribution. Molecular dynamics simulations were carried out to investigate the microscopic origin of the dynamical heterogeneities in the ionic solutions, which was probed recently using the ultrafast vibrational energy exchange and anisotropy measurements. Our simulations revealed that these dynamical heterogeneities observed originate from the inhomogeneous ion density distribution in the solution, and are detectable using the combination of the ultrafast infrared, the dielectric relaxation and the optical kerr effect techniques. Simulations further suggest that, in some of the solutions, the ion pairing effect has significant contribution to the ion distribution inhomogeneity. Our studies thus provide a microscopic insight on the origin of the inhomogeneous ion density distribution and its connection with various experimentally observable dynamical phenomena in the ionic solutions.
研究领域：
1.致病蛋白质误折叠动力学的计算机模拟及其实验光谱的计算
2.天然太阳能收集器中的能量传递以及蛋白质环境对其的调控作用
教育背景与工作经历：
1996-2000： 中国科技大学 本科
2000-2003： 美国罗切斯特大学 硕士
2004-2007： 美国加州大学欧文分校 博士
2007-2009： 美国加州劳伦斯伯克利国家实验室 博士后
1996-2000： 中国科技大学 学士学位
2000-2003： 美国罗切斯特大学 硕士学位
2004-2007： 美国加州大学欧文分校 博士学位
2000-2003： 美国罗切斯特大学
2004-2007： 美国加州大学欧文分校
2007-2009： 美国加州劳伦斯伯克利国家实验室
联 系 人：翁羽翔 82648118
报告摘要：
Microscopic solution dynamics is a central topic in the condense matter sciences. Optical spectroscopies play important roles in the investigations in this field. Analysis and understanding of the solution spectra are usually non-trivial due to the complex nature of the systems.
We carried out series of spectral modeling based on the molecular dynamics simulation to help understanding the dynamic events in the protein aqueous solution and ionic solution systems. A technique combining the Markov State Model (MSM) and the Nonlinear Exciton Propagation (NEP) methods was developed to simulate the T-jump triggered long time peptide unfolding process and the related IR, 2DIR and fluorescence spectra. Furthermore, to overcome the convergence issue in the sampling and reduce the computational cost, implicit solvent model was introduced into the simulation, which generates converged temperature dependent peptide configuration distribution. We demonstrated that IR and 2DIR spectra simulated based on this distribution nicely reproduce the temperature dependences of experimental signals.
An important, but not yet clearly addressed, issue in ionic solution research is how the microscopic dynamics in the solution is influenced by the ionic density distribution. Molecular dynamics simulations were carried out to investigate the microscopic origin of the dynamical heterogeneities in the ionic solutions, which was probed recently using the ultrafast vibrational energy exchange and anisotropy measurements. Our simulations revealed that these dynamical heterogeneities observed originate from the inhomogeneous ion density distribution in the solution, and are detectable using the combination of the ultrafast infrared, the dielectric relaxation and the optical kerr effect techniques. Simulations further suggest that, in some of the solutions, the ion pairing effect has significant contribution to the ion distribution inhomogeneity. Our studies thus provide a microscopic insight on the origin of the inhomogeneous ion density distribution and its connection with various experimentally observable dynamical phenomena in the ionic solutions.
研究领域：
1.致病蛋白质误折叠动力学的计算机模拟及其实验光谱的计算
2.天然太阳能收集器中的能量传递以及蛋白质环境对其的调控作用
教育背景与工作经历：
1996-2000： 中国科技大学 本科
2000-2003： 美国罗切斯特大学 硕士
2004-2007： 美国加州大学欧文分校 博士
2007-2009： 美国加州劳伦斯伯克利国家实验室 博士后
1996-2000： 中国科技大学 学士学位
2000-2003： 美国罗切斯特大学 硕士学位
2004-2007： 美国加州大学欧文分校 博士学位
2000-2003： 美国罗切斯特大学
2004-2007： 美国加州大学欧文分校
2007-2009： 美国加州劳伦斯伯克利国家实验室
联 系 人：翁羽翔 82648118