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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.

各种各样的光合反应中心色素蛋白质复合物，包括那些新发现的，结构和功能的研究超最后激光光谱高达0.1 ps，荧光寿命测量在低温下，电子自旋共振和单分子共聚焦显微镜光谱。使用的生物材料是（1）Acaryochloris marina，其即使在近远红光下也可以释放氧气，（2）含锌细菌叶绿素的Acidiphilicarubrum rubrum，（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）经修饰以耗尽磷脂酰甘油的蓝细菌。Acaryochloris 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作为特殊的初级电子供体叶绿素对。因此，这种生物体是唯一一个可以使用700-750 nm近远红光的氧气释放光合作用的例外情况。这与所有其他仅吸收650-690 nm红光的含氧生物形成鲜明对比。一种细菌Acidiphilium rubrum使用锌-细菌叶绿素a，并被证明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，色素在光合作用中是很容易被取代的，尽管目前这种色素还很少见。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对于反应是高度优化的。反应中心被证明是功能性的，即使在二氧化硅介观纳米孔。在爱知世界博览会上，用阿拉斯加的北极植物展示了寻找新生物的一部分研究。