PHOTOBIOLOGY OF RHODOPSIN, BACTERIORHODOPSIN & VIODOPSIN

描述：生色团结合部位的性质和主要的 视紫红质、细菌视紫红质和非洲爪哇紫光化学事件 将用光谱学和光谱学方法研究锥形色素--紫草素。 理论技术。我们的目标是理解光物理 结合生色团的性质。主要的光谱方法 用于这些研究的包括双光子光谱学、斯塔克效应 光谱学、傅里叶变换红外光谱、微波 光谱学和脉冲激光光热法。主要的化学物质 将进行的研究包括有机阳离子和生色团类似物 替换，以及定点突变。理论上的 方法包括半经验分子轨道理论和分子轨道理论。 动力学理论。其目标是将实验和理论结合在一起 增强两者的协同计划。除了更全球化的 以上概述的目标，Birge博士将寻求回答以下具体问题 问题：(1)波长调制的主要机制是什么？ 蓝色和紫色的锥体？(2)阳离子结合部位在哪里 细菌视紫红质，以及这些位点如何调节 结合的发色团？(3)在Vodopsin中是否有氯结合部位，以及 这个地点对地球的光物理性质有什么影响？ 发色团？(4)能量储存的分子来源是什么？ 这三种蛋白质的主要事件？(5)主要的分子是什么？ 脊椎动物和无脊椎动物视觉中暗噪声的机制？(6)什么是 4-酮类化合物异常光化学性质的分子起源 视网膜细菌视紫红质类似物？(7)能否提高 从头算MNDO-PSDCI半经验分子轨道理论 有效的哈密顿参数化？

DESCRIPTION: The nature of the chromophore binding sites and the primary photochemical events of rhodopsin, bacteriorhodopsin and the Xenopus violet cone pigment, viodopsin, will be studied by using spectroscopic and theoretical techniques. The goals are to understand the photophysical properties of the bound chromophores. The principal spectroscopic methods to be used in these studies include two-photon spectroscopy, Stark effect spectroscopy, Fourier transform infra-red spectroscopy, microwave spectroscopy, and pulsed laser photocalorimetry. The principal chemical studies to be undertaken include organic cation and chromophore analog substitutions, as well as site directed mutagenesis. The theoretical methods include semiempirical molecular orbital theory and molecular dynamics theory. The goal is to combine experiment and theory in a synergistic program which enhances both. In addition to the more global goals outlined above, Dr. Birge will seek to answer the following specific questions: (1) What is the principal mechanism of wavelength modulation in the blue and violet cones? (2) Where are the cation binding sites in bacteriorhodopsin, and how do these sites mediate the properties of the bound chromophore? (3) Is there a chloride binding site in viodopsin, and what impact does this site have on the photophysical properties of the chromophore? (4) What are the molecular origins of energy storage in the primary events of these three proteins? (5) What is the principal molecular mechanism of dark noise in vertebrate and invertebrate vision? (6) What are the molecular origins of the unusual photochemical properties of the 4-keto retinal bacteriorhodopsin analog? (7) Can one improve the accuracy of the MNDO-PSDCI semi-empirical molecular orbital theory by using ab-initio effective Hamiltonian parameterizaion?