Collaborative Research: Combining Theory and Experiment to Understand the First Photophysical Events in the Photoactivation of the Orange Carotenoid Protein

在化学系生命过程化学项目的支持下，来自康涅狄格大学（UConn）的José Gascón教授和Warren F。来自密歇根州立大学的Beck将研究蓝藻保护自身免受过度暴露于阳光下的损害的机制。这个项目将确定如何酮类胡萝卜素绑定到橙子类胡萝卜素蛋白（OCP）作为光强度和颜色的传感器。主要目标是确定OCP从静止的橙子形式（OCPO）转化为活性的红色形式（OCPR）的生物物理机制;这种转化通过减缓光合能量储存的速率在高强度太阳照射期间保护生物体。这项工作将提供深入了解蓝藻和绿色植物光合装置的组成部分如何共同工作，以分子形式储存太阳能，并避免光驱动的副反应造成损害。这些新知识可能会影响可用于太阳能应用的材料的设计和工程。该研究将为相关研究生提供一个绝佳的机会，学习先进的计算机建模和光谱技术及其在分子结构和功能高级研究中的应用。此外，本发明还提供了一种方法，该项目将为探索性化学研究与培训学院（SECRET）的高中生和参加美国国家科学基金会资助的康州大学化学本科生研究经验（REU）网站的本科生创造研究机会。计划中的研究涉及国家的组合-现有技术的飞秒多维电子光谱学和超灵敏荧光方法，以感测当OCPO吸收蓝光时，类胡萝卜素酮在OCPO中经历的构象变化，绿色光。电子结构计算和分子动力学模拟，然后将被用来开发一个分子模型的第一个结构事件，以下的类胡萝卜素的光激发。该研究计划将测试光驱动的类胡萝卜素的构象变化启动蛋白质的结构重组的假设。这些研究有望提供酮类胡萝卜素如何感知周围太阳光照的分子细节。该奖项反映了NSF的法定使命，并被认为值得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来支持。

With the support of the Chemistry of Life Processes Program in the Chemistry Division, Professor José Gascón from University of Connecticut (UConn) and Professor Warren F. Beck from Michigan State University will investigate the mechanisms that cyanobacteria employ to protect themselves from damage due to excessive exposure to sunlight. This project will determine how a ketocarotenoid bound to the orange carotenoid protein (OCP) serves as a sensor for the light intensity and color. The main goal is to determine the photophysical mechanism that converts the OCP from a resting, orange form (OCPO) to an active, red form (OCPR); this conversion protects the organism during high intensity solar illumination by slowing the rate of photosynthetic energy storage. The work will provide insight in how the components in the photosynthetic apparatus of cyanobacteria and green plants work together to store solar energy in molecular form and to avoid light-driven side reactions that cause damage. The new knowledge could impact the design and engineering of materials that can be used in solar energy applications. The research will afford an excellent opportunity for graduate students involved to learn advanced computer modeling and spectroscopy techniques and their application to advanced studies of molecular structure and function. In addition, the project will create research opportunities for high school students from the School of Exploratory Chemical Research and Training (SECRET) and undergraduate students who participate in the NSF-funded Research Experiences for Undergraduates (REU) site in Chemistry at UConn.The planned research involves a combination of state-of-the-art femtosecond multidimensional electronic spectroscopy and ultrasensitive fluorescence methods to sense the conformational changes that the ketocarotenoid undergoes in OCPO when it absorbs blue-green light. Electronic structure calculations and molecular dynamics simulations will then be used to develop a molecular model for the first structural events that follow photoexcitation of the ketocarotenoid. The research plan will test the hypothesis that light-driven conformational changes of the ketocarotenoid initiate the structural reorganization of the protein. These studies are expected to provide molecular details of how the ketocarotenoid senses ambient solar illumination.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.