Ballottari Matteo, Girardon Julien, Dall'osto Luca, Bassi Roberto
Dipartimento di Biotecnologie, Università di Verona, Ca' Vignal 1, Strada le Grazie 15, I-37134 Verona, Italy.
Biochim Biophys Acta. 2012 Jan;1817(1):143-57. doi: 10.1016/j.bbabio.2011.06.005. Epub 2011 Jun 15.
Photoautotrophic organisms, the major agent of inorganic carbon fixation into biomass, convert light energy into chemical energy. The first step of photosynthesis consists of the absorption of solar energy by pigments binding protein complexes named photosystems. Within photosystems, a family of proteins called Light Harvesting Complexes (LHC), responsible for light harvesting and energy transfer to reaction centers, has evolved along with eukaryotic organisms. Besides light absorption, these proteins catalyze photoprotective reactions which allowed functioning of oxygenic photosynthetic machinery in the increasingly oxidant environment. In this work we review current knowledge of LHC proteins serving Photosystem II. Balance between light harvesting and photoprotection is critical in Photosystem II, due to the lower quantum efficiency as compared to Photosystem I. In particular, we focus on the role of each antenna complex in light harvesting, energy transfer, scavenging of reactive oxygen species, chlorophyll triplet quenching and thermal dissipation of excess energy. This article is part of a Special Issue entitled: Photosystem II.
光合自养生物是将无机碳固定到生物质中的主要媒介，它们将光能转化为化学能。光合作用的第一步是由与名为光系统的蛋白质复合物结合的色素吸收太阳能。在光系统中，一类名为捕光复合体（LHC）的蛋白质家族负责捕光并将能量传递到反应中心，它是随着真核生物一同进化而来的。除了吸收光之外，这些蛋白质还催化光保护反应，从而使含氧光合机制在日益氧化的环境中发挥作用。在这项工作中，我们综述了目前关于为光系统II服务的LHC蛋白质的知识。由于与光系统I相比量子效率较低，捕光与光保护之间的平衡在光系统II中至关重要。特别是，我们重点关注每个天线复合体在捕光、能量传递、活性氧清除、叶绿素三线态猝灭以及过剩能量的热耗散中的作用。本文是名为“光系统II”的特刊的一部分。
