PICOSECOND TR3 SPECTROSCOPY OF BACTERIORHODOPSIN

这项研究计划旨在阐明分子动力学 与细菌视紫红质(BR)相关，因为它与其作为 生化膜中的质子和离子泵及其在生物化学中的作用 视觉色素的结构和构象模型。时间分辨率 共振拉曼光谱(TR3)是一种光谱分析的实验技术 兴趣，因为它可以用来提供结构、构象和 同时获得动态信息。这里提出的许多衡量标准 现在是可行的，因为最近开发了一种多功能的 皮秒TR3(PTR3)光谱仪。这些事件的一个重要后果是 扩展的仪器功能是可以记录PTR3谱 在波长和强度条件下的室温样品 模拟正常的BR光循环。 将开展的项目包括：(1)记录PTR3谱 泵浦-探针式反应时间对中间体的影响 分别优化激励和探测的配置，(2) 温度效应的时间分辨反斯托克斯拉曼研究 光激发过程中的快速分子内加热，(3)检测 视网膜刺激的时间依赖性蛋白质反应，以及(4) 中间体时间分辨激发谱的测量研究 蛋白质环境对视网膜构象和质子化的影响 优化单个中间体的共振拉曼检测。

The research program is intended to elucidate the molecular dynamics associated with bacteriorhodopsin (BR) as it relates to its function as a proton and ion pump in biochemical membranes and to its role as a structural and conformational model for visual pigments. Time-resolved resonance Raman (TR3) spectroscopy is the experimental technique of primary interest since it can be used to provide structural, conformational, and kinetic information simultaneously. Many of the measurements proposed here are now feasible because of the recent development of a versatile picosecond TR3 (PTR3) spectrometer. One important consequence of these expanded instrumental capabilities is that PTR3 spectra can be recorded for room temperature samples under wavelength and intensity conditions which emulate those of the normal BR photocycle. Projects to be undertaken include the: (1) recording of PTR3 spectra of intermediates as a function of reaction time with a pump-probe configuration optimized for excitation and probing separately, (2) time-resolved antistokes Raman studies of temperature effects arising from rapid intramolecular heating during optical excitation, (3) examination of the time-dependent protein response to retinal excitation, and (4) measurement of time-resolved excitation profiles of intermediates to study protein environment effects on retinal conformation and protonation and to optimize resonance Raman detection for individual intermediates.