PHOTOPHYSICS OF RHODOPSIN AND BACTERIORHODOPSIN

视紫红质，负责将光转化为光学的蛋白质 神经冲动和细菌视紫红质，光传导蛋白 盐生盐杆菌的紫色膜，有显著的 不同的生物角色。然而，自然选择已经 这两种蛋白质的设计非常相似，而这些 相似之处促使比较实验和理论 学习。缺乏高分辨率的X射线结构数据 排除了对其中任何一个的三级结构的准确指认 蛋白质，因此我们对结合位点和初级 事件是基于对化学和光谱的间接分析 数据。尽管在过去十年中取得了一些重要的进展 还有许多有待理解的地方，以及一些有趣的实验 悖论仍未得到解释。生色团结合的性质 视紫红质的初级光化学事件的位置和性质 和细菌视紫红质的研究将使用光谱和 理论技术。我们的目标是理解光物理 结合发色团的性质以及蛋白质如何介导 结合生色团的光化学性质。校长 在这些研究中使用的实验方法包括双光子 光谱学，斯塔克效应光谱学，傅里叶变换近 红外光谱、微波光谱、脉冲激光 光热法和时间分辨光伏光谱分析。这个 理论方法包括半经验分子轨道理论和 分子动力学理论。此外，我们将寻求回答 以下具体问题：(1)水在多大程度上参与 在调节结合的发色团的光化学性质中 两种蛋白质？(2)快速光电信号的来源是什么？ 这是在视紫红质的初级光化学事件中产生的 细菌视紫红质呢？(3)我们可以观察和使用蛋白质发色团吗？ 有助于分析蛋白质性质的电荷转移带 蛋白质结合部位内的发色团相互作用？(4)什么是 细菌视紫红质强微波吸收能力的来源 M-BR微波差谱的起源？(5)什么？ 是视紫质和视紫红质的主要事件中能量储存的本质 细菌视紫红质？(6)环附近有带电荷的氨基酸吗？ 细菌视紫红质中的生色团？此外，我们会致力于 发展一种新的双光子光谱采集方法 基于傅里叶变换的光化学不稳定生物分子 光学技术。

Rhodopsin, the protein responsible for converting light into an optic nerve impulse, and bacteriorhodopsin, the light transducing protein of the purple membrane of Halobacterium halobium, have significantly different biological roles. Nevertheless, natural selection has converged on very similar designs for both proteins, and these similarities have prompted comparative experimental and theoretical studies. The lack of high resolution X-ray structural data has precluded precise assignment of the tertiary structure of either protein, and hence our knowledge of the binding sites and the primary events is based on indirect analyses of chemical and spectroscopic data. Despite a number of important advances during the past decade much remains to be understood and a number of interesting experimental paradoxes remain unexplained. The nature of the chromophore binding sites and the nature of the primary photochemical events of rhodopsin and bacteriorhodopsin will be studied by using spectroscopic and theoretical techniques. The goals are to understand the photophysical properties of the bound chromophores and how the proteins mediate the photochemical properties of the bound chromophores. The principal experimental methods to be used in these studies include two-photon spectroscopy, Stark effect spectroscopy, Fourier transform near infra-red spectroscopy, microwave spectroscopy, pulsed laser photocalorimetry, and time-resolved photovoltaic spectroscopy. The theoretical methods include semiempirical molecular orbital theory and molecular dynamics theory. In addition, we will seek to answer the following specific questions: (1) To what extent does water participate in mediating the photochemical properties of the bound chromophores in both proteins? (2) What is the origin of the fast photoelectric signal that is generated during the primary photochemical events in rhodopsin and bacteriorhodopsin? (3) Can we observe and use protein-chromophore charge transfer bands to help analyze the nature of the protein chromophore interactions within the protein binding site? (4) What is the origin of the strong microwave absorptivity of bacteriorhodopsin and the origin of the M - bR microwave difference spectrum? (5) What is the nature of energy storage in the primary events of rhodopsin and bacteriorhodopsin? (6) Are there charged amino acids near the ring of the chromophore in bacteriorhodopsin? Furthermore, we will seek to develop a new method of collecting two-photon spectra of photochemically labile biological molecules based on Fourier transform optical techniques.