VIBRATIONAL STUDIES OF ENERGY TRANSDUCING PROTEINS

能量转换蛋白的振动研究

• 批准号: 3296958
• 负责人: DAVID F. BOCIAN
• 金额: $ 10.59万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3296958
• 关键词: Raman spectrometry; Rhodospirillales; bacterial pigment; biophysics; chemical bond resonance; chemical structure function; chlorophyll; conformation; electron transport; electronic spectra; infrared radiation; membrane proteins; molecular orbital; mutant; oxidation; photosynthetic bacteria; photosynthetic reaction centers; porphyrins; protein engineering; protein sequence; species difference; temperature; ultraviolet radiation; visible light

The specific aim of the proposed research is to characterize the structural and electronic properties of the active pigments in energy transducing proteins. The bacterial photosynthetic reaction center (RC) has been chosen for study because this class of proteins represents a prototypical model system for investigating the properties that facilitate fast electron transfer over distances on the order of the width of the biological membrane. In addition, the RC is the only integral membrane protein for which the macromolecular arrangement of the active pigments in the protein matrix is known. The principal investigative tool that will be used is resonance Raman (RR) spectroscopy. The first objective is to characterize the UV-vis-excitation (ca. 350-700 nm) RR spectra of the bacterochlorphyll (BChl) and bacteriopheophytin (BPh) pigments is RCs from Rb. sphaeroides, Rb. capsulatus and Rps. viridis wild-type. The goal of these studies is to examine the individual BChl and BPh molecules with as much selectivity as possible in order to assess the structural similarities and/or differences between the various pigments in RCs from a given species and between RCs from different species. The second objective is to characterize the UV- vis-excitation RR spectra of a number of genetically modified RCs from Rb. capsulatus. These studies will focus on systems in which genetic modifications have been made in the amino acid residues in the vicinity of the primary electron donor and acceptor and also the accessory BChls. These studies will be conducted in parallel with those on the wild-type systems in order to assess the structural consequences of the various site- specific mutations. The third objective is to probe the red-most, Qy absorptions (ca. 750-1000 nm) of the BChls and BPhs by using RR techniques. The red-most band of the primary donor (ca. 850-1000 nm) will be the focal point of the near-infrared (NIR) RR studies. The goal of these studies is to characterize the vibrational and electronic properties of the lowest- energy electronic states. The fourth objective is to obtain NIR-excitation RR spectra of RCs in which genetical modifications have been made in the vicinity of the photophysically active pigments. The goal of these studies is to determine how modifications in specific amino acids influence the vibrational and electronic properties of the electron-donating excited state of RCs.

拟议研究的具体目的是表征结构 能量转换中活性色素的电子性质 proteins. 细菌光合反应中心（RC） 之所以选择研究，是因为这类蛋白质代表了一种典型的 研究促进快电子的性质的模型系统 在生物体宽度的数量级上的距离上转移 膜的 此外，RC是唯一的整合膜蛋白， 蛋白质中活性色素的大分子排列 矩阵已知。 将使用的主要调查工具是 共振拉曼（RR）光谱。 第一个目标是描述 UV-可见光激发（ca. 350-700 nm）的RR光谱 （BChl）和细菌脱镁叶绿素（BPh）色素是来自Rb的RCs。类球形， RB. capsulatus和Rps. viridis野生型 这些研究的目的是 检查单个BChl和BPh分子的选择性， 为了评估结构相似性和/或差异， 来自给定物种的RC中的各种颜料之间以及RC之间 来自不同的物种 第二个目标是表征UV- 可见光激发RR光谱的一些基因修饰的RC从Rb。 囊状的 这些研究将集中在遗传系统中， 已经在邻近的氨基酸残基中进行了修饰， 主电子给体和受体以及辅助BChl。 这些研究将与野生型的研究平行进行。 系统，以评估各种网站的结构后果- 特定的突变 第三个目标是探测最红的Qy （约）750-1000 nm）的BChl和BPhs的。 第一供体的最红带（ca。850-1000 nm）将成为焦点 近红外（NIR）RR研究。 这些研究的目的是 来表征最低能量的振动和电子性质- 能量电子态 第四个目标是获得NIR激发 其中已在基因组中进行遗传修饰的RC的RR谱 在荧光活性颜料附近。 这些研究的目的 是确定特定氨基酸的修饰如何影响 激发态给电子分子的振动和电子性质 RC状态。