SPECTROSCOPIC INVESTIGATIONS OF BIOLOGICAL SYSTEMS

生物系统的光谱研究

• 批准号: 3484137
• 负责人: GEORGE FEHER
• 金额: $ 31.74万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1976
• 资助国家: 美国
• 起止时间: 1976-05-10 至 1991-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3484137
• 关键词: Rhodopseudomonas; X ray crystallography; bioenergetics; chlorophyll; crystallization; divalent cations; electron spin resonance spectroscopy; electron transport; electronic spectra; enzyme structure; iron; lysozyme; membrane proteins; neutron diffraction; photosynthesis; photosynthetic bacteria; point mutation; protein engineering; protein sequence; protein structure; quinones; respiratory protein; spectrometry; thermodynamics

Our research objectives are to understand biological processes and phenomena in terms of physical mechanisms and to explore the adaptation of physical techniques to problems in biology. The more specific goals and problems to which we are addressing ourselves are the following: 1.) The mechanism of energy conversion in a protein-chlorophyll complex solubilized frm the membranes of photosynthetic bacteria and the characterization and determination of the structure function relation of this complex called the reaction center (RC). Specific aims are to: (a) complete the amino acid sequence of the RC protein, (b) to obtain the three-dimensional structure of the RC by X-ray diffraction, (c) to investigate the effect of protein modifications on the structure and funciton of the RC, and (d) to extend the investigation to other membrane proteins. Some of the findings and methodologies are expected to be relevant to other electron-transfer processes, most notably the respiratory chain in mitochondria. 2.) Electronic Structure of Biomolecules: We want to extend our understanding of the non-heme iron center of RCs to the atomic (molecular) level. EPR and ENDOR experiments will be used to determine the parameters characterizing the electronic state of the Fe2+. 3.) Crystallization of Biological Macromolecules, with special emphasis on proteins. Our goal is to understand the detailed mechanisms leading to the formation of single crystals. The three temporal phases of crystallization, i.e., a.) nucleation, b.) post-nucleation growth, and c.) cessation of growth, will be investigated on the water-soluble model compound. lysozyme. We plan to extend the methodology to other proteins, including integral membrane proteins. The long-term objective is to arrive at a systematic procedure to obtain large, high-quality crystals for X-ray diffraction studies.

我们的研究目标是了解生物过程和 现象的物理机制并探索适应 解决生物学问题的物理技术。 更具体的目标和 我们正在解决的问题如下： 1.) 蛋白质-叶绿素复合物中能量转换的机制 从光合细菌的膜和 结构函数关系的表征和确定 这个复合体称为反应中心（RC）。 具体目标是： (a) 完成RC蛋白的氨基酸序列，(b)以获得 通过 X 射线衍射分析 RC 的三维结构，(c) 研究蛋白质修饰对结构的影响 RC 的功能，以及 (d) 将研究扩展到其他膜 蛋白质。 一些研究结果和方法预计将 与其他电子传递过程相关，最显着的是呼吸 线粒体中的链。 2.) 生物分子的电子结构：我们希望扩展我们的研究 从原子（分子）角度理解RC的非血红素铁中心 等级。 EPR和ENDOR实验将用于确定参数 表征 Fe2+ 的电子态。 3.) 生物大分子的结晶，特别强调 蛋白质。 我们的目标是了解导致这一现象的详细机制 单晶的形成。 三个时间阶段 结晶，即 a.) 成核，b.) 成核后生长，以及 c.) 生长停止，将在水溶性模型上进行研究 化合物。溶菌酶。 我们计划将该方法扩展到其他蛋白质， 包括整合膜蛋白。 长期目标是达到 通过系统化程序获得用于 X 射线的大型、高质量晶体 衍射研究。