Rotational Dynamics of the Photsynthetic ATP Synthase

光合 ATP 合成酶的旋转动力学

• 批准号: 0818743
• 负责人: Mark Richter
• 金额: $ 45.89万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0818743&HistoricalAwards=false
• 关键词: Rotational; Dynamics; Photsynthetic; ATP; Synthase

The photosynthetic ATP synthase of higher plants is a tiny molecular rotary motor with several unique properties that separate it from its mitochondrial and bacterial counterparts and offer unique inroads to examine the mechanism of energy coupling. One such property is the presence of a special regulatory domain within the gamma subunit which, via the reversible oxidation/reduction of an intrinsic dithiol, governs an interaction with the inhibitory epsilon subunit. This interaction provides a molecular switch mechanism that tightly controls the catalytic activity of the enzyme, preventing futile hydrolysis of ATP in the absence of a membrane potential. The objective of this project is to identify the productive binding interactions between the gamma and epsilon subunits, and between these two subunits and the other F1 subunits, that are involved in the molecular switch mechanism. Specific aims are: 1) To determine the inter-subunit conformational interplay that results in CF1 activation and proton coupling using dithiol cross-linking and dynamic single molecule fluorescence approaches; and 2) To determine the three-dimensional structures of the epsilon, delta and gamma subunits using solution NMR and x-ray crystallographic approaches. The intellectual merit of the project stems from the fact that the ATP synthase plays a central role in energy capture and inter-conversion in living systems. The results from this work is likely to provide an understanding of natural processes that have evolved to gate the motor, in identifying the mechanism of elastic coupling between the FO and F1 segments, and in designing gated nanodevices for future industrial applications. This project will have a number of broader impacts including training of undergraduate and graduate students and postdoctoral associates in emerging areas of nanotechnology including advanced molecular engineering and analysis methods. The research will dovetail with a newly established, NSF-funded, multidisciplinary and interdisciplinary undergraduate training program in nanoscience and will be integrated with ongoing diversity and outreach programs on the university campus and within the state of Kansas.

高等植物的光合ATP合成酶是一种微小的分子旋转马达，具有几种独特的性质，使其与线粒体和细菌的对应物分开，并为研究能量耦合机制提供了独特的进展。 一种这样的性质是在γ亚基内存在特殊的调节结构域，其通过内在二硫醇的可逆氧化/还原来控制与抑制性γ亚基的相互作用。 这种相互作用提供了一种分子开关机制，严格控制酶的催化活性，防止在缺乏膜电位的情况下ATP的无效水解。 该项目的目的是确定γ和γ-亚基之间的生产性结合相互作用，以及这两个亚基和其他F1亚基之间的相互作用，参与分子开关机制。 具体目标是：1）使用二硫醇交联和动态单分子荧光方法确定导致CF 1活化和质子偶联的亚基间构象相互作用;和2）使用溶液NMR和X射线晶体学方法确定α、δ和γ亚基的三维结构。该项目的智力价值源于ATP合酶在生命系统中的能量捕获和相互转换中发挥核心作用的事实。这项工作的结果可能会提供一个理解的自然过程，已经发展到门电机，在确定FO和F1段之间的弹性耦合的机制，并在设计门控纳米器件为未来的工业应用。 该项目将产生一些更广泛的影响，包括在纳米技术的新兴领域，包括先进的分子工程和分析方法的本科生和研究生以及博士后助理的培训。 该研究将与新成立的，NSF资助的，多学科和跨学科的纳米科学本科培训计划相吻合，并将与大学校园和堪萨斯州内正在进行的多样性和外展计划相结合。