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

类胡萝卜素是一种基本的光吸收色素，有助于光合作用过程中太阳光能量的转化，此外，它还提供光保护，使其免受太阳对光合作用生物的破坏。该奖项将资助康涅狄格大学的加斯康博士和密歇根州立大学的贝克博士研究这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，并使用实验方法来验证这些预测。这些研究的结果适用于设计新的太阳能捕获和存储材料，这些材料在吸收光方面更有效，同时不太容易受到光损害。此外，该项目增加了高中生和本科生的知识，包括那些来自代表不足的群体的学生，关于计算方法如何帮助回答生物和化学中的重要问题，以及计算机建模如何普遍存在并影响我们的日常生活。类胡萝卜素作为捕光色素，在吸收叶绿素(Chl)捕光范围以外的光方面具有独特的地位。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，作为光合作用装置的光保护剂发挥作用。具有这两种功能的蛋白质复合体的两个例子是来自海藻甲藻的膜-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和其他类胡萝卜素捕光蛋白的高分辨率结构已经可用，并进行了大量的实验和理论工作，但由于几个领域长期存在的争议，对于类胡萝卜素如何在能量转移和光保护中发挥作用的一般理解仍然不完全。这项研究对这些机制进行了系统和协同的检验，结合蛋白质中先进的电子结构计算和先进的光谱技术，以发现控制光谱因素和在光合蛋白的光收集和光保护的第一事件期间类胡萝卜素的动态命运。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.