Hashimoto Hideki, Uragami Chiasa, Cogdell Richard J
The Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan.
Department of Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan.
Subcell Biochem. 2016;79:111-39. doi: 10.1007/978-3-319-39126-7_4.
Carotenoids are ubiquitous and essential pigments in photosynthesis. They absorb in the blue-green region of the solar spectrum and transfer the absorbed energy to (bacterio-)chlorophylls, and so expand the wavelength range of light that is able to drive photosynthesis. This is an example of singlet-singlet energy transfer, and so carotenoids serve to enhance the overall efficiency of photosynthetic light reactions. Carotenoids also act to protect photosynthetic organisms from the harmful effects of excess exposure to light. Triplet-triplet energy transfer from chlorophylls to carotenoids plays a key role in this photoprotective reaction. In the light-harvesting pigment-protein complexes from purple photosynthetic bacteria and chlorophytes, carotenoids have an additional role of structural stabilization of those complexes. In this article we review what is currently known about how carotenoids discharge these functions. The molecular architecture of photosynthetic systems will be outlined first to provide a basis from which to describe carotenoid photochemistry, which underlies most of their important functions in photosynthesis.
类胡萝卜素是光合作用中普遍存在且必不可少的色素。它们在太阳光谱的蓝绿色区域吸收光，并将吸收的能量传递给（细菌）叶绿素，从而扩大了能够驱动光合作用的光的波长范围。这是单线态-单线态能量转移的一个例子，因此类胡萝卜素有助于提高光合光反应的整体效率。类胡萝卜素还能保护光合生物免受过度光照的有害影响。叶绿素到类胡萝卜素的三线态-三线态能量转移在这种光保护反应中起关键作用。在紫色光合细菌和绿藻的捕光色素-蛋白质复合物中，类胡萝卜素还具有使这些复合物结构稳定的额外作用。在本文中，我们综述了目前已知的类胡萝卜素如何发挥这些功能的相关内容。首先将概述光合系统的分子结构，以便为描述类胡萝卜素光化学提供基础，而类胡萝卜素光化学是其在光合作用中大多数重要功能的基础。
