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

类胡萝卜素是必不可少的光吸收色素，在光合作用过程中帮助转化太阳光能量，此外，还提供光保护，使光合作用生物免受太阳的有害影响。有了这个奖项，化学部门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学项目将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。开发了高级计算方法来预测光收集如何影响这些蛋白质中类胡萝卜素的结构，并使用实验方法来测试这些预测。这些研究结果适用于太阳能捕获和存储的工程新材料，这些材料在吸收光方面更有效，同时不易受到光损伤。此外，该项目还增加了高中生和本科生的知识，包括那些来自代表性不足群体的学生，了解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。类胡萝卜素作为光收集色素，其独特的定位是吸收叶绿素（Chl）捕光范围以外的光。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用，作为光合装置的光保护剂。具有这两种功能的蛋白质复合物的两个例子是来自海洋藻类鞭毛藻的橄榄绿素-叶绿素a蛋白（PCP）和来自蓝藻的橙色类胡萝卜素蛋白（OCP）。尽管PCP、OCP和其他含类胡萝卜素的光收集蛋白的高分辨率结构的可用性，以及大量的实验和理论努力，由于几个领域长期存在的争议，对类胡萝卜素在能量传递和光保护中的作用的一般理解仍然不完全可用。本研究结合先进的蛋白质电子结构计算和先进的光谱学技术，对这些机制进行了系统和协同的研究，以发现光合蛋白质在光收集和光保护的第一个事件中控制光谱因素和类胡萝卜素的动态命运。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。

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.