Theoretical Molecular Biophysics Section, National Heart, Lung and Blood Institute, National Institutes of Health , Bethesda, Maryland 20892, United States.
Theoretical Molecular Biophysics Group, Max Planck Institute of Biophysics , 60438 Frankfurt am Main, Germany.
J Phys Chem B. 2017 Apr 20;121(15):3297-3307. doi: 10.1021/acs.jpcb.6b08051. Epub 2016 Oct 24.
Recent years have witnessed a renewed interest in the ATP synthase as a drug target against human pathogens. Indeed, clinical, biochemical, and structural data indicate that hydrophobic inhibitors targeting the membrane-embedded proton-binding sites of the c-subunit ring could serve as last-resort antibiotics against multidrug resistant strains. However, because inhibition of the mitochondrial ATP synthase in humans is lethal, it is essential that these inhibitors be not only potent but also highly selective for the bacterial enzyme. To this end, a detailed understanding of the structure of this protein target is arguably instrumental. Here, we use computational methods to predict the atomic structures of the proton-binding sites in two prototypical c-rings: that of the ATP synthase from Saccharomyces cerevisiae, which is a model system for mitochondrial enzymes, and that from Escherichia coli, which can be pathogenic for humans. Our study reveals the structure of these binding sites loaded with protons and in the context of the membrane, that is, in the state that would mediate the recognition of a potential inhibitor. Both structures reflect a mode of proton coordination unlike those previously observed in other c-ring structures, whether experimental or modeled.
近年来，人们对 ATP 合酶作为针对人类病原体的药物靶点重新产生了兴趣。事实上，临床、生化和结构数据表明，针对 c 亚基环中嵌入膜的质子结合位点的疏水性抑制剂可以作为针对多药耐药菌株的最后手段抗生素。然而，由于抑制人类线粒体 ATP 合酶是致命的，因此这些抑制剂不仅必须有效，而且还必须对细菌酶具有高度选择性。为此，对该蛋白质靶标的详细结构的理解可以说是至关重要的。在这里，我们使用计算方法来预测两个典型 c 环中质子结合位点的原子结构：来自酿酒酵母的 ATP 合酶，这是线粒体酶的模型系统，以及来自大肠杆菌的 ATP 合酶，大肠杆菌对人类可能是致病的。我们的研究揭示了这些结合位点在质子负载下以及在膜中的结构，即介导潜在抑制剂识别的状态。这两种结构都反映了不同于以前观察到的其他 c 环结构的质子协调模式，无论是实验的还是建模的。
