Organization and Dynamics in Photosynthetic Reaction Centers and Model Membrane Architectures

光合作用反应中心(RC)是一种非凡的机器，它吸收光并在生物膜上传递电子。薄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来放电。地球上的所有生命都依赖于这一过程。这项研究将有助于更好地理解光合作用反应中心获取和存储太阳能的机制，并开发模拟天然生物膜及其相互作用的膜组件模型。这个项目将调节RC中活性生色团附近的关键氨基酸的性质，以系统地了解电子为什么走上它们所做的路径，以及通过什么精确的机制。这项工作的一个重要部分涉及开发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影响。这项研究计划将继续支持一代具有不同背景的年轻科学家的发展，他们主要是研究生，他们将在物理科学和生物学、生物技术和能源相关科学的交界处从事富有成效的职业生涯。该项目专注于两个相关的主题：细菌光合作用反应中心的电荷分离机制，以及组装和成像模型膜结构的新方法的开发。该项目将实施非规范氨基酸对重要功能氨基酸的定点修饰，并引入用于电子转移和膜电位的丁腈旁观探针。该项目将继续开发“膜干涉仪”，旨在对离子通道等单一完整的膜蛋白进行同时光学和电学测量，并开发新的方法来测量亚微米级膜上的脂质扩散，以探索曲率对扩散的影响。该项目由生物科学局分子和细胞生物科学部的分子生物物理组支持。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为是值得支持的。

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.