Resonance Raman Studies of Electron-Nuclear Coupling, Time Resolved Dynamics, and Magnetic Perturbations of Biomolecules

本研究的目的是更好地了解生物分子的光学性质，无论是在平衡状态还是在平衡状态，并应用这些知识来阐明它们的作用机制。 共振拉曼散射及其时域模拟，飞秒相干光谱（FCS）将用于探测血红素蛋白质，如肌红蛋白，血红蛋白和细胞色素c的电子和核结构/功能关系。相关技术，如电子吸收，泵浦-探测动力学，荧光，红外，核共振振动（NRVS）光谱，和磁场扰动也将用于表征样品，并有助于分配低频运动揭示使用新的FCS技术开发的前一个奖项期间。 皮秒方法将开发使用同步自锁模钛：蓝宝石激光器进行时间分辨共振拉曼散射和扩展到ns制度的动力学研究的范围。 动态吸收线型将使用宽带连续技术进行测量，以便与时间相关的共振条件可以适当地纳入从斯托克斯和反斯托克斯拉曼散射获得的振动弛豫的分析。 在理解的绝对幅度和相位的共振FCS信号的理论进步将被利用，以消除非振荡的背景信号，并允许改善检测的低频模式。将进行相位和振幅激励剖面，以揭示与低频运动相关的不均匀性和非谐性。 将开发低温测量技术，使FCS实验能够作为样品“玻璃化”转变的函数进行。 该项目具有广泛的影响，是蛋白质动力学领域的基础，这对我们对生命系统的基本理解至关重要。 这项工作涉及 发展应用于生物分子系统的最先进的基于激光的光谱学。 仪器和理论的发展将提高基础设施做时间分辨的蛋白质动力学研究，通过生产一个有效的FCS系统，扩大使用这种实验技术，使其常规访问。这些研究不仅在它们与生物科学的关系上具有重要意义，而且在它们与我们对与凝聚相复杂系统相关的基本光-物质相互作用的理解方面也具有重要意义。 研究生和本科生将接受尖端光学和生物技术的培训，通过加强人力资源基础设施造福社会。 该项目由生物科学理事会分子和细胞生物科学部的分子生物物理学计划以及数学和物理科学理事会的物理学部支持。

The objectives of this research are to achieve a better understanding of the optical properties of biological molecules, both in and out of equilibrium, and to apply this knowledge to elucidate their mechanism of action. Resonance Raman scattering and its time domain analog, femtosecond coherence spectroscopy (FCS) will be used to probe the electronic and nuclear structure/function relationships in heme proteins like myoglobin, hemoglobin and cytochrome c. Related techniques such as electronic absorption, pump-probe kinetics, fluorescence, infrared, nuclear resonance vibrational (NRVS) spectroscopy, and magnetic field perturbations will also be used to characterize samples and aid in the assignment of the low frequency motions revealed using novel FCS techniques developed in the prior award period. Picosecond methodology will be developed using synchronized self-modelocked Ti:sapphire lasers to carry out both time resolved resonance Raman scattering and to extend the range of kinetic studies into the ns regime. Dynamic absorption lineshapes will be measured using broad-band continuum techniques so that time dependent resonance conditions can be properly incorporated into the analysis of vibrational relaxation obtained from the Stokes and anti-Stokes Raman scattering. Theoretical advances in understanding the absolute magnitude and phase of the resonant FCS signals will be exploited to eliminate non-oscillatory background signals and allow improved detection of low frequency modes. Phase and amplitude excitation profiles will be carried out to reveal inhomogeneities and anharmonicities associated with the low frequency motions. Low temperature measurement techniques will be developed so that FCS experiments can be carried out as a function of the sample "glass" transition. This project has a broad impact that underlies the field of protein dynamics that is crucial to our basic understanding of living systems. This work involves the development of state-of-the-art laser based spectroscopy that is applied to biomolecular systems. Instrumentation and theoretical development will enhance the infrastructure for doing time-resolved protein dynamics research by producing an effective FCS system that expands the use of this experimental technique by making it routinely accessible. These studies are significant not only in their relationship to the biological sciences, but also in their connection to our understanding of basic light-matter interaction associated with complex systems in the condensed phase. Graduate and undergraduate students will be trained in cutting edge optical and biological techniques that benefit society through the enhancement of the human resource infrastructure. This project is supported by the Molecular Biophysics Program in the Division of Molecular and Cellular Biosciences in the Directorate for Biological Sciences and the Division of Physics in the Mathematical and Physical Sciences Directorate.