SOLID STATE NMR STUDIES OF F1F0 ATP SYNTHASE

F1F0 ATP合成酶对ATP的合成和水解对所有生物化学都至关重要：这个复合体是生物能量货币的主要生产者。然而，质子易位如何与ATP合成耦合的细节尚不清楚，因为复合物的膜结合部分的高分辨率结构是不可用的。与许多膜蛋白复合物一样，这种组装的F0部分由于其非均质性和较大的有效分子量，迄今为止无法通过衍射方法和溶液核磁共振进行研究。通过结合13C、15N、19F和2H同位素标记以及固态核磁共振（SSNMR）距离、扭转角和弛豫测量，对ATP合酶（尤其是亚基c）的研究将确定F0的结构和动力学。特别是，将仔细探讨在必需的天冬氨酸残基上质子摄取和释放时亚基c中发生的构象变化。这些实验将增强对离子传导分子细节的理解，并且在此过程中开发和完善的方法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膜相关疾病（如癌症和艾滋病）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.