PROTON TRANSLOCATION THROUGH F1F0 ATP SYNTHASE

改变线粒体DNA的突变与衰老有关， 退行性疾病，以及特定的遗传性疾病。一些 患有这些疾病的患者在ATP酶-6亚基基因中存在突变， F1 F0 ATP合成酶。 ATP酶-6-leu 156-arg突变检测在 四个不相关的病人家庭， Leigh综合征（NARP）。 研究发现， 症状，发病年龄和线粒体缺陷的百分比 基因组 我们通过以下方式为理解疾病突变做出了贡献： 在大肠杆菌F1 F0 ATP合酶中模拟它，并确定 该酶功能由于质子（H+）缺陷而丧失 易位 线粒体突变对衰老的影响更多 脆弱 然而，大量的错义突变影响了a 亚基导致E.杆菌 类似观点 毫无疑问，人类ATP酶-6基因发生突变， 氧化磷酸化，大多数将保持未检测到的， 临床设置。 我们的长期目标是了解 质子（H+）转运和H+转运与 F1 F0腺苷三磷酸（ATP）合酶中的催化。 实验室 致力于使用诱变方法来研究结构 和F0亚基的功能。 目前的建议集中在使用 分子生物学方法来研究F0内的分子相互作用。 我们提出的研究涉及第二位抑制基因的产生 突变，深入研究F0突变对F1的影响 研究B亚基中可能参与 将H+易位与催化作用耦合，并采取新的方法 为了考虑亚基之间的分子相互作用 将F1扇区连接到F0扇区。

Mutations altering mitochondrial DNA have been linked to aging and degenerative diseases, as well as, to specific inherited disorders. Some patients with these disorders have mutations in the ATPase-6 subunit gene of F1F0 ATP synthase. The ATPase-6-leu156-arg mutation was detected in four unrelated families of patients with diseases variously diagnosed as Leigh Syndrome (NARP). A correlation was drawn between severity of symptoms, age of onset and the percentage of defective mitochondrial genomes. We contributed to the understanding of the disease mutation by modeling it in the Escherichia coli F1F0 ATP synthase, and determining that enzyme function was lost due to a defect in proton (H+) translocation. The effects of mitochondrial mutations on aging is more tenuous. However, a large number of missense mutations affecting the a subunit result in a loss of F1F0 ATP synthase in E. coli. Similar point mutations undoubtedly occur in the human ATPase-6 gene resulting in loss of oxidative phosphorylation, and most will remain undetected in the clinical setting. Our long-term goal is to gain an understanding of the mechanisms of proton (H+) translocation and the coupling of H+ translocation to catalysis in F1F0 adenosine triphosphate (ATP) synthase. The laboratory is committed to using a mutagenesis approach for investigating structure and function of the F0 subunits. The present proposal centers on using the molecular biology approach to study molecular interactions within F0. We propose studies involving the generation of second-site suppressor mutations, study of the effects of F0 mutations on F1, in depth investigation of a site in the b subunit likely to be involved in the coupling of H+ translocation to catalysis, and to take a novel approach for considering the molecular interactions between the subunits connecting the F1 sector to the F0 sector.