Controllable model membranes and new quantitative analyses to interrogate light harvesting proteins

这项提议将开发新的模型系统和分析方法，以量化具有高时空分辨率的重要光采集(LH)蛋白质的生物物理性质。这将提供对光合作用过程的物理基础的洞察，光合作用过程对地球上的生命至关重要，但人们对此知之甚少。它还将对黄体生成素蛋白在纳米技术、光子学和等离子体学中的潜在用途具有更广泛的相关性。我们需要开发一套“模型膜”(理想的生物膜实验模型)，它包含了黄体生成素蛋白，并提供了复杂性、可控性和适应性之间的平衡，以及可以量化结构和光学性质的工具。我们需要能够控制这些模型膜中的黄体生成素蛋白的密度。我们需要量化这些黄体生成素蛋白的组织和光学性质是如何变化的，以响应重要的物理化学刺激。拟议的项目将开发三种用于研究黄体生成素蛋白的模型膜，它们从主要是人工合成的膜发展到接近自然的膜。这些“模型膜”将首次通过施加外加电场来指导黄体生成素蛋白在膜内的迁移。这些黄体生成素蛋白的纳米尺度组织和光物理性质将通过先进的显微镜和光谱组合系统在每种类型的膜中进行比较。我之前的研究已经证明，黄体生成素蛋白的聚集与能量耗散(荧光猝灭)有关，我在相关显微镜和光谱分析工具方面的专业知识使我在进行能量转移过程的定量研究方面处于独特的有利地位。在利兹，我们有一种新的结合原子力显微镜的荧光寿命成像显微镜(FLIM+AFM)仪器，它将允许前所未有的光学性质和纳米级组织的直接关联和量化(我是获得该仪器的赠款的联合研究员)。这种组合显微镜是研究黄体生成素蛋白的理想选择，并为我们提供了竞争优势。总而言之，该项目将对新的膜模型的优点和局限性进行比较分析，并在这样做的同时，量化光捕获蛋白的组织和光学性质之间的关键关系。这些新模型可以应用于与健康和农业相关的细菌和哺乳动物的膜。此外，对重要的LHCII蛋白的了解可能与替代太阳能纳米技术的开发或增强作物的生产有关。

This proposal will develop new model systems and analysis methods to quantify the biophysical properties of important Light Harvesting (LH) proteins with high spatiotemporal resolution. This will provide insight into the physical basis of photosynthetic processes which are crucial for life on Earth but poorly understood. It will also have wider relevance for the potential use of LH proteins in nanotechnology, photonics and plasmonics. We need to develop a suite of "model membranes" (idealized experimental models of biomembranes) which incorporate LH proteins and offer a balance between complexity, controllability and amenability to tools that can quantify structure and optical properties. We need the ability to manipulate the density of LH proteins within these model membranes. We need to quantify how the organization and optical properties of these LH proteins change in response to important physicochemical stimuli. The proposed project will develop three types of model membranes for studying LH proteins, which progress from mostly synthetic to close-to-natural membranes. These "model membranes" will be manipulated by applying external electric fields to direct the migration of LH proteins within membranes, for the first time. The nanoscale organization and photophysical properties of these LH proteins will be compared in each type of membrane by an advanced microscopy and spectroscopy combined system. My previous research has demonstrated that the clustering of LH proteins is correlated to energy dissipation (fluorescence quenching) and my expertise with correlative microscopy and spectroscopy tools make me uniquely well-placed for performing quantitative studies of energy transfer processes. In Leeds, we have a new Fluorescence Lifetime Imaging Microscope combined with Atomic Force Microscopy (FLIM+AFM) instrument which will allow unprecedented direct correlation and quantification of optical properties and nanoscale organization (I was co-investigator on the grant acquiring this instrument). This combined microscope is ideal to study LH proteins and gives us a competitive edge. In summary, this project will provide a comparative analysis of the advantages and limitations of new membrane models and, in doing so, quantify the crucial relationship between organization and optical properties of light harvesting proteins. These new models could be applied to bacterial and mammalian membranes of relevance for health and agriculture. Furthermore, knowledge of the important LHCII protein could be relevant for the development of alternative solar nanotechnologies or the production of enhanced crops.