Artificial produced [7-formyl]-chlorophyll d functions as an antenna pigment in the photosystem II isolated from the chlorophyllide a oxygenase-expressing Acaryochloris marina
Artificial produced [7-formyl]-chlorophyll d functions as an antenna pigment in the photosystem II isolated from the chlorophyllide a oxygenase-expressing Acaryochloris marina
复制标题
人工产生的[7-甲酰基]-叶绿素 d 在光系统 II 中充当天线色素，该光系统 II 是从表达加氧酶的 Acaryo绿藻海洋中分离出的叶绿素
DOI：
10.1016/j.bbabio.2012.02.021
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
T. Tsuchiya
中科院分区：
文献类型：
--
作者：
Tohru Tsuchiya;Tadashi Mizoguchi;Seiji Akimoto;Tatsuya Tomo;Hitoshi Tamiaki;Mamoru Mimuro;T. Tsuchiya
无叶绿藻是一种以叶绿素(Chl)d为主的蓝藻，是利用Chl d研究远红光驱动光合作用的模式生物。此外，对Acaryo氯is marina的研究可能会为理解光合作用生物在获得新Chl后如何适应提供了启示。为了了解其独特的光合作用反应机理，从滨海海藻中分离并分析了光系统(PS)II复合体。然而，由于缺乏对滨海拟青霉的分子遗传学方法，我们无法进行进一步的研究。我们最近开发了一种滨海拟青霉的转化系统，并将加氧酶基因--叶绿素内酯基因导入到滨海拟青霉。得到的转化子积累了自然界中从未发现的[7-甲酰基]-Chl d。在本研究中，我们分离了含有[7-甲酰基]-Chl d的PSⅡ复合体，其色素组成分别为1.96±0.04 Chla、53.21±1.00 Chl d和5.48±0.33[7-甲酰基]-Chl d。而对照PSⅡ复合体的组成为2.01±0.06 Chla和62.96±2.49 Chl d.稳态荧光光谱和激发光谱表明，[7-甲酰基]-Chl d向主要Chl d物种发生了能量转移，但电子传递不受[7-甲酰基]-Chl d的影响.这些结果表明，人工合成的[7-甲酰基]-Chl d分子取代了部分Chl d分子，起到了天线的作用.这篇文章是题为：光合作用的可持续性研究：从自然到人工的特刊的一部分。
Acaryochloris marina, a chlorophyll (Chl) d-dominated cyanobacterium, is a model organism for studying photosynthesis driven by far-red light using Chl d. Furthermore, studies on A. marina may provide insights into understanding how the oxygenic photosynthetic organisms adapt after the acquisition of new Chl. To solve the reaction mechanism of its unique photosynthesis, photosystem (PS) II complexes were isolated from A. marina and analyzed. However, the lack of a molecular genetic method for A. marina prevented us from conducting further studies. We recently developed a transformation system for A. marina and we introduced a chlorophyllide a oxygenase gene into A. marina. The resultant transformant accumulated [7-formyl]-Chl d, which has never been found in nature. In the current study, we isolated PS II complexes that contained [7-formyl]-Chl d. The pigment composition of the [7-formyl]-Chl d-containing PS II complexes was 1.96±0.04 Chl a, 53.21±1.00 Chl d, and 5.48±0.33 [7-formyl]-Chl d per two pheophytin a molecules. In contrast, the composition of the control PS II complexes was 2.01±0.06 Chl a and 62.96±2.49 Chl d. The steady-state fluorescence and excitation spectra of the PS II complexes revealed that energy transfer occurred from [7-formyl]-Chl d to the major Chl d species; however, the electron transfer was not affected by the presence of [7-formyl]-Chl d. These findings demonstrate that artificially produced [7-formyl]-Chl d molecules that are incorporated into PS II replace part of the Chl d molecules and function as the antenna. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.