TRANSLOCATION IN ENERGY CONVERSION--STRUCTURAL STUDIES

能量转换中的易位--结构研究

• 批准号: 2177048
• 负责人: J. KENT BLASIE
• 金额: $ 21.05万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-08-01 至 1997-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2177048
• 关键词: X ray crystallography; X ray spectrometry; bioenergetics; chemical kinetics; cytochrome b; cytochrome c; cytochrome oxidase; dichroism; electron transport; flash photolysis; heme; hemoprotein structure; intermolecular interaction; lipid bilayer membrane; membrane proteins; membrane reconstitution /synthesis; membrane structure; molecular film; neutron diffraction; oxidation reduction reaction; photochemistry; photosynthetic reaction centers; photosystem; protein structure function; structural biology; time resolved data

The overall goal of this project is to determine important aspects of the role of intramolecular and intermolecular structure in biological energy conversion. The structural studies proposed here concern the determination of the cylindrically-averaged profile structures of the membrane molecular components within specific bimolecular complexes involved in energy conversion at moderate resolution (approximately 10 angstroms); the spatial relationships between these components, relative to each other and to the overall profile structure of the membrane; and the spatial relationships among the redox centers associated with these components, relative to each other within these complexes and relative to the overall profile structure of the membrane, with an accuracy of +/-l-2 Angstroms. Through a correlation of such structural parameters with the capabilities of these components and/or complexes thereof to exhibit efficient electron transport and the generation of transmembrane electrochemical potentials (and ultimately the synthesis of ATP) in reconstituted,vectorially oriented single membrane systems, we hope to gain substantial insight into the mechanism of energy coupling in biological membranes. The techniques of nonresonance and resonance x-ray diffraction, neutron diffraction, EXAFS (Extended X-ray Absorption Fine Structure) and polarized EXAFS spectroscopy and optical linear dichroism will be utilized to study the relevant membrane proteins, including photosynthetic reaction centers, cytochrome oxidase, cytochrome c and cytochrome b/c1 and various bimolecular complexes thereof in the form of vectorially oriented, single membrane systems. The reaction center-cytochrome b/c1-cytochrome c complexes exhibit an efficient light-driven cyclic series of electron transfer reactions.

该项目的总体目标是确定 分子内和分子间结构在生物能中的作用 转换。 这里提出的结构研究涉及 确定圆柱冲积的轮廓结构 特定双分子复合物中的膜分子成分 参与中等分辨率的能量转化（约10 埃斯特罗姆）;这些组件，相对的空间关系 彼此以及膜的整体剖面结构；和 与这些相关的氧化还原中心之间的空间关系 组成部分，相对于这些复合物，相对于 膜的整体剖面结构，精度为+/- L-2 埃埃斯特罗姆。 通过这种结构参数的相关性 这些组件的功能和/或其复合物可以展示 有效的电子传输和跨膜的产生 电化学潜力（最终是ATP的合成） 重构，以矢量为导向的单膜系统，我们希望 对能量耦合机理的实质性深入了解 生物膜。 非共振和共振X射线的技术 衍射，中子衍射，EXAFS（扩展的X射线吸收精细 结构）和极化EXAFS光谱和光学线性二色性 将用于研究相关的膜蛋白，包括 光合反应中心，细胞色素氧化酶，细胞色素C和 细胞色素b/c1和各种双分子络合物的形式 以矢量为导向的单膜系统。 反应 中心环状b/c1-cytochrome c络合物表现出有效的 电动循环系列电子转移反应。