Institut de Biologie et de Technologies de Saclay, UMR 8221 CNRS, Université Paris Sud, Commissariat à l'Energie Atomique Saclay, 91191 Gif-sur-Yvette, France.
J Biol Chem. 2013 Jun 28;288(26):18758-65. doi: 10.1074/jbc.M112.423681. Epub 2013 May 17.
The electronic properties of carotenoid molecules underlie their multiple functions throughout biology, and tuning of these properties by their in vivo locus is of vital importance in a number of cases. This is exemplified by photosynthetic carotenoids, which perform both light-harvesting and photoprotective roles essential to the photosynthetic process. However, despite a large number of scientific studies performed in this field, the mechanism(s) used to modulate the electronic properties of carotenoids remain elusive. We have chosen two specific cases, the two β-carotene molecules in photosystem II reaction centers and the two luteins in the major photosystem II light-harvesting complex, to investigate how such a tuning of their electronic structure may occur. Indeed, in each case, identical molecular species in the same protein are seen to exhibit different electronic properties (most notably, shifted absorption peaks). We assess which molecular parameters are responsible for this in vivo tuning process and attempt to assign it to specific molecular events imposed by their binding pockets.
类胡萝卜素分子的电子性质是其在生物学中发挥多种功能的基础，而在许多情况下，通过其体内位置来调节这些性质至关重要。光合作用类胡萝卜素就是一个很好的例子，它们同时具有收集和保护光的作用，这对光合作用过程至关重要。然而，尽管在这一领域进行了大量的科学研究，但调节类胡萝卜素电子性质的机制仍然难以捉摸。我们选择了两个特定的例子，即光合作用系统 II 反应中心的两个β-胡萝卜素分子和主要光合作用系统 II 光收集复合物中的两个叶黄素，来研究这种电子结构的调节是如何发生的。事实上，在每种情况下，同一蛋白质中的相同分子物种表现出不同的电子性质（最显著的是吸收峰的位移）。我们评估了哪些分子参数对此体内调节过程负责，并试图将其归因于由其结合口袋施加的特定分子事件。
