TRANSLOCATION IN ENERGY CONVERSION--STRUCTURAL STUDIES

该项目的总体目标是确定 分子内和分子间结构在生物能量中的作用 转换. 这里提出的结构研究涉及 确定圆柱平均轮廓结构的 特定双分子复合物中的膜分子组分 在中等分辨率下参与能量转换（约10 埃）;这些组件之间的空间关系，相对 彼此之间以及膜的整体轮廓结构;以及 氧化还原中心之间的空间关系与这些 组分，相对于这些复合物内的彼此以及相对于 膜的整体轮廓结构，精度为+/-l-2 愤怒。 通过这些结构参数与 这些组分和/或其复合物表现出 有效的电子传递和跨膜的产生 电化学电位（并最终合成ATP） 重组，矢量定向单膜系统，我们希望， 获得实质性的洞察机制的能量耦合， 生物膜 非共振和共振X射线技术 衍射、中子衍射、EXAFS（扩展X射线吸收精细 结构）和偏振EXAFS光谱和光学线性二向色性 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及其各种形式的双分子复合物 矢量定向的单膜系统。 反应 中心-细胞色素B/c1-细胞色素c复合物表现出有效的 光驱动的电子转移反应的循环系列。

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.