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Principle design of reaction complex based on functions and structure of newly descovered photosynthesis.

基于新发现的光合作用功能和结构的反应复合物的原理设计。

基本信息

批准号：
15370067
负责人：
ITOH Shigeru
金额：
$ 9.98万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15370067/
关键词：
Photosynthesis cyanobacteria silica mesoscopic compounds World Exposition '06 arctic plants photosynthetic bacteria Zn-chlorophyll artificial photosynthesis アカリオクロリス chl d アシドフィリウム Zn-Chl 光化学系I 光化学系II 新型光合成エネルギー移動電子移動励

项目摘要

Structure and function of a wide variety of the photosynthetic reaction center pigment protein complexes, including those of newly discovered ones, are studied by ultra last laser spectroscopy up to 0.1 ps, fluorescence life time measurements at cryogenic temperature, electron spin resonance and by the single molecular confocal microscope spectroscopy. The biomaterials used were (1)Acaryochloris marina that can evolve oxygen even with near far-red light, (2)Zn-bacteriochlorophyll containing Acidiphillium rubrum, (3)Zooxanthellae that lives in corals, (4)photosynthetic green sulfur bacterium Chlorobium tepidum ant its site-directed mutants, (5)Chloroflexus aurantiacus, (6)cyanobacteria that are modified to be depleted of a phospholipid phosphatydil glycerol. Acaryochloris marina is shown to have a special photosystems I and II reaction centers in which chlorophyll d but not chlorophyll a functions as the special pair primary electron donor chlorophylls. This organism, thus, is an only one exceptional case in the oxygen evolving photosynthesis that can use 700-750 nm near far-red light. This makes a clear contrast to all the other oxygenic organisms that absorb only 650-690 nm red ight with chlorophyll a. A bacterium Acidiphilium rubrum uses Zn-bacteriochlorophyll a and was shown to undergo highly efficient photo-energy conversion even in the pico-to femto-second time ranges. These new photosynthesis indicated that pigment can be replaced rather easily in photosynthesis although now it is rather rare. On the other hand, the modifications of reaction center proteins yielded drastic decrease of efficiency indicating that the structure of the reaction center is highly optimized for the reaction. Reacion centers are shown to be functional even inside silica mesoscopic nanopores. A part of research to hunt for new organisms was exhibited with arctic plants from Alaska in Aichi World Exposition '06.

通过高达 0.1 ps 的超激光光谱、低温荧光寿命测量、电子自旋共振和单分子共焦显微镜光谱研究了各种光合反应中心色素蛋白复合物（包括新发现的复合物）的结构和功能。使用的生物材料是（1）即使在近远红光下也能释放氧气的Acaryocholis marina，（2）含有Acidihillium rubrum的Zn-细菌叶绿素，（3）生活在珊瑚中的虫黄藻，（4）光合绿色硫细菌Chlorobium tepidum及其定点突变体，（5）Chloroflexus aurantiacus，(6)蓝细菌，其被修饰为耗尽磷脂磷脂甘油。 Acaryocholis marina 具有特殊的光系统 I 和 II 反应中心，其中叶绿素 d 而不是叶绿素 a 充当特殊的初级电子供体叶绿素对。因此，这种生物体是产氧光合作用中唯一的一个例外，可以使用 700-750 nm 的近远红光。这与仅吸收 650-690 nm 红光和叶绿素 a 的所有其他含氧生物形成鲜明对比。红色嗜酸性细菌使用锌细菌叶绿素 a，即使在皮秒到飞秒的时间范围内也能进行高效的光能转换。这些新的光合作用表明，色素在光合作用中可以很容易地被替换，尽管现在这种情况相当罕见。另一方面，反应中心蛋白质的修饰导致效率急剧下降，表明反应中心的结构针对反应进行了高度优化。研究表明，即使在二氧化硅介观纳米孔内，反应中心也能发挥作用。寻找新生物的研究的一部分在'06爱知世界博览会上展出了来自阿拉斯加的北极植物。