SOLID STATE NMR STUDIES OF F1F0 ATP SYNTHASE

F1F0三磷酸腺苷合成酶对三磷酸腺苷的合成和水解对所有生物化学都是至关重要的：该复合体是生物能量货币的主要生产者。然而，关于质子转运如何与ATP合成耦合的细节还不是很清楚，因为还没有复合体的膜结合部分的高分辨率结构。这种组装的F0部分，像许多膜蛋白复合体一样，由于其异质性和较大的有效分子量，到目前为止一直拒绝用衍射法和溶液核磁共振进行研究。对ATP合成酶(特别是c亚基)的研究--通过13C、15N、19F和2H同位素标记以及固体核磁共振(SS核磁共振)距离、扭角和松弛测量-将确定F0的结构和动力学。特别是，将仔细研究在必需的天冬氨酸残基吸收和释放质子时，c亚基发生的构象变化。这些实验将加强对离子传导分子细节的理解，在此过程中开发和改进的方法学将直接适用于许多膜蛋白，负责能量转导、细胞识别和许多调节过程。因此，从这项工作中获得的结构数据和方法将有助于揭示癌症和艾滋病等与膜相关的疾病的分子机制。

The synthesis and hydrolysis of ATP by the F1F0 ATP synthase are of central importance to all of biochemistry: the complex is the primary producer of biology's energetic currency. However, the details of how proton translocation couples with ATP synthesis are not well understood, because a high-resolution structure of the membrane-bound portion of the complex is not available. This assembled F0 portion, like many membrane protein complexes, has thus far resisted study by diffraction methods and solution NMR due to its heterogeneity and large effective molecular weight. Studies of ATP synthase (especially subunit c)--by incorporation of 13C, 15N, 19F, and 2H isotopic labels and solid state nuclear magnetic resonance (SSNMR) distance, torsion angle and relaxation measurements-will determine F0 structure and dynamics. In particular, the conformational changes that take place in subunit c upon uptake and release of protons at the essential aspartic acid residue will be carefully explored. These experiments will enhance the understanding of the molecular details of ion conduction, and the methodology developed and refined in the process will be directly applicable to many membrane proteins, responsible for energy transduction, cellular recognition, and many regulatory processes. The structural data and methods derived from this work, therefore, will be of utility for revealing the molecular mechanisms underlying membrane-related diseases such as cancer and AIDS.