Organization and Dynamics in Photosynthetic Reaction Centers and Model Membrane Architectures

光合反应中心（RC）是一种非凡的机器，它吸收光并通过生物膜传递电子。膜是非常薄的绝缘体，所以这个过程就像给电容器充电一样。一旦充电，电容器通过驱动稳定的高能分子或燃料的生物合成而放电。地球上所有的生命都依赖于这个过程。这项研究将有助于更好地理解光合反应中心收集和储存太阳能的机制，以及模拟天然生物膜及其相互作用的模型膜组件的开发。该项目将调节RC中靠近反应性发色团的关键氨基酸的性质，以系统地理解为什么电子采取它们所采取的途径以及通过什么精确的机制。这项工作的一个重要部分涉及发展新的实验和理论方法，这些方法将对其他科学和技术领域产生广泛的影响。该研究项目将继续支持具有不同背景的一代年轻科学家的发展，主要是研究生，他们将在物理科学与生物学、生物技术和能源相关科学的界面上从事富有成效的职业。该项目侧重于两个相关主题；细菌光合反应中心的电荷分离机制，以及膜结构组装和成像新方法的发展。该项目将使用非规范氨基酸对功能重要的氨基酸进行特定位点的修饰，并引入用于电子转移和膜电位的腈旁观者探针。该项目将继续开发一种“膜干涉仪”，用于同时对单个积分膜蛋白（如离子通道）进行光学和电子测量，并开发新的方法来测量亚微米尺寸膜上的脂质扩散，以探索曲率对扩散的影响。该项目得到了生物科学理事会分子和细胞生物科学部分子生物物理集群的支持。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Photosynthetic reaction center (RC) is a remarkable machine that absorbs light and transfers electrons across a biological membrane. Membranes are very thin insulators, so this process is like charging a capacitor. Once charged, the capacitor discharges by driving the biosynthesis of stable energetic molecules or fuels. All life on earth depends on this process. This research will lead to a better understanding of the mechanisms by which photosynthetic reaction centers harvest and store solar energy, and the development of model membrane assemblies that mimic natural biological membranes and their interactions. This project will modulate the properties of key amino acids near to the reactive chromophores in the RC to systematically understand why electrons take the pathway they do and by what precise mechanism. A significant part of this work involves the development of new experimental and theoretical methods that will have a broad impact in other areas of science and technology. This research program will continue to support the development of a generation of young scientists with diverse backgrounds, primarily graduate students, who go on to productive careers at the interface of the physical sciences and biology, biotechnology, and energy-related science.This project focuses on two related topics; the mechanism of charge separation in bacterial photosynthetic reaction centers, and the development of novel methods to assemble and image model membrane architectures. This project will implement site specific modification of functionally important amino acids with non-canonical amino acids and the introduction of nitrile spectator probes for electron transfer and membrane potential. This project will continue development of a "membrane interferometer", designed for simultaneous optical and electrical measurements on single integral membrane proteins such as ion channels, and develop novel methods to measure lipid diffusion on sub-micron sized membranes to explore the effects of curvature on diffusion. This project is supported by the Molecular Biophysics Cluster of the Molecular and Cellular Biosciences Division in the Biological Sciences Directorate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.