Architecture of a charge-transfer state regulating light harvesting in a plant antenna protein
Architecture of a charge-transfer state regulating light harvesting in a plant antenna protein
复制标题
DOI：
10.1126/science.1154800
复制
发表时间：
2008-05-09
期刊：
影响因子：
56.9
通讯作者：
Fleming, Graham R.
中科院分区：
文献类型：
--
作者：
Ahn, Tae Kyu;Avenson, Thomas J.;Fleming, Graham R.
过量吸收光能的能量依赖性猝灭是高等植物光合捕光的重要调控机制。qE的所有生理特性都与光系统II（PSII）捕光天线中耦合的叶绿素和玉米黄质分子之间的电荷转移正相关。我们发现的证据，在所有三个单独的小天线复合物的PSII（CP 29，CP 26和CP 24）的电荷转移猝灭，我们得出结论，电荷转移猝灭在CP 29涉及离域状态的激子耦合叶绿素二聚体。我们提出，CP 29中的可逆构象变化可以“调谐”该二聚体中叶绿素之间的电子耦合，从而调节叶绿素-玉米黄质电荷转移状态的能量，并在qE期间打开和关闭电荷转移猝灭。
Energy- dependent quenching of excess absorbed light energy ( qE) is a vital mechanism for regulating photosynthetic light harvesting in higher plants. All of the physiological characteristics of qE have been positively correlated with charge transfer between coupled chlorophyll and zeaxanthin molecules in the light- harvesting antenna of photosystem II ( PSII). We found evidence for charge- transfer quenching in all three of the individual minor antenna complexes of PSII ( CP29, CP26, and CP24), and we conclude that charge- transfer quenching in CP29 involves a delocalized state of an excitonically coupled chlorophyll dimer. We propose that reversible conformational changes in CP29 can "tune" the electronic coupling between the chlorophylls in this dimer, thereby modulating the energy of the chlorophyll-zeaxanthin charge- transfer state and switching on and off the charge- transfer quenching during qE.