PICOSECOND TR3 SPECTROSCOPY OF BACTERIORHODOPSIN

该研究计划旨在阐明分子动力学 与细菌视紫红质（BR）相关，因为它与其作为一种 质子和离子泵在生物化学膜中的作用，以及它作为 结构和构象模型。 时间分辨 共振拉曼（TR3）光谱是主要的实验技术 因为它可以用来提供结构、构象和 动态信息同时 这里提出的许多测量方法 现在是可行的，因为最近开发了一种多功能 皮秒TR3光谱仪。 其中一个重要的后果是， 扩展的仪器能力是PTR3光谱可以记录 在波长和强度条件下的室温样品， 模仿那些正常的BR光循环。 将开展的项目包括：（1）记录 中间体作为反应时间的函数 分别针对激发和探测进行优化的配置，（2） 时间分辨反斯托克斯拉曼研究温度效应所产生的 在光激发过程中的快速分子内加热，（3）检查 对视网膜兴奋的时间依赖性蛋白质反应，以及（4） 测量研究中间体的时间分辨激发分布 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.