Collaborative Research: Combining Theory and Experiment to Understand Carotenoid Photophysics in Photosynthetic Light-Harvesting

类胡萝卜素是必需的光吸收色素，有助于在光合作用过程中转换阳光能量，此外，还为光合生物提供光保护，使其免受阳光的破坏作用。有了这个奖项，化学部的生命过程化学项目和分子与细胞生物科学部的分子生物物理项目资助康涅狄格大学的Gascon博士和密歇根州立大学的Beck博士研究此类生物蛋白质中类胡萝卜素的能量转移和光保护功能。高层次的计算方法被开发来预测光捕获如何影响这些蛋白质中类胡萝卜素的结构，实验方法被用来测试这些预测。这些研究的结果适用于设计用于太阳能捕获和存储的新材料，这些材料在吸收光方面更有效，同时不易受光损伤的影响。此外，该项目还增加了高中和本科生的知识，包括那些来自代表性不足的群体，关于计算方法如何帮助回答生物学和化学中的重要问题，以及计算机建模如何流行并影响我们的日常生活。 类胡萝卜素作为捕光色素，其独特的定位是吸收叶绿素（Chl）的捕光范围之外的光。同样重要的是类胡萝卜素通过非光化学猝灭机制和单线态氧猝灭作为光合机构的光保护剂的作用。具有这两种能力的蛋白质复合物的两个例子是来自海藻甲藻的多甲藻素-叶绿素a-蛋白（PCP）和来自蓝细菌的橙子类胡萝卜素蛋白（OCP）。尽管PCP，OCP和其他含类胡萝卜素的捕光蛋白的高分辨率结构的可用性，以及相当大的实验和理论努力，由于在几个领域长期存在的争议，对类胡萝卜素如何在能量传递和光保护中发挥作用的一般理解仍然没有完全可用。这项研究对这些机制进行了系统和协同的检查，结合先进的蛋白质电子结构计算和先进的光谱技术，发现控制光谱因素和类胡萝卜素在光合作用蛋白质的光捕获和光保护的第一个事件的动态命运。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的评估支持，知识价值和更广泛的影响审查标准。

Carotenoids are essential light-absorbing pigments that help conversion of sunlight energy during photosynthesis and, in addition, provide photoprotection from the sun's damaging effects to photosynthetic organisms. With this award, the Chemistry of Life Processes Program in the Chemistry Division and the Molecular Biophysics Program in the Division of Molecular and Cellular Biosciences is funding Dr. Gascon from University of Connecticut and Dr. Beck from Michigan State University to investigate the energy transfer and photoprotection functions of carotenoids in the proteins of such organisms. High-level computational methods are developed to predict how light harvesting affects the structure of carotenoids within these proteins and experimental methods are used to test these predictions. Results from these studies are applicable to engineering new materials for solar energy capture and storage that are more efficient at absorbing light, while being less susceptible to photodamage. In addition, the project increases the knowledge of high school and undergraduate students, including those from underrepresented groups, on how computational methods help to answer important questions in biology and chemistry, and how computer modeling is prevalent and impacts our daily lives. Carotenoids act as light-harvesting pigments, which are uniquely positioned to absorb light outside the light-capturing range of Chlorophylls (Chl). Equally important is the role of carotenoids as photo-protectors of the photosynthetic apparatus via non-photochemical quenching mechanisms and quenching of singlet oxygen. Two examples of protein complexes with these two capabilities are the peridinin-chlorophyll a-protein (PCP) from marine algae dinoflagellates and the orange carotenoid protein (OCP) from cyanobacteria. Despite the availability of high-resolution structures of PCP, OCP, and other carotenoid-containing light-harvesting proteins, and considerable experimental and theoretical efforts, a general understanding of how the carotenoids function in energy transfer and photoprotection is still not fully available due to longstanding controversies in several areas. This research produces a systematic and synergistic examination of these mechanisms, combining advanced electronic structure calculations in proteins and advanced spectroscopy techniques to discover the controlling spectral factors and the dynamical fate of carotenoids during the first events of light harvesting and photoprotection in photosynthetic proteins.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.