2014 08 29 I²CNER Seminar Series : Prof. Jian-Ren Shen скачать в хорошем качестве

2014 08 29 I²CNER Seminar Series : Prof. Jian-Ren Shen

［Title］Mechanism of light-induced water-splitting in natural photosynthesis ［Speaker］Prof. Jian-Ren Shen, Professor, Director Photosynthesis Research Center, Graduate School of Natural Science and Technology, Okayama University ［Date & Time］Friday, August 29, 2014 ［Place］I2CNER Hall, Ito campus, Kyushu University ［Abstract］Photosynthetic water-splitting generates electrons, protons, and oxygen, which are the sources for energy and oxygen indispensible for maintaining almost all life forms on the earth. This reaction is catalyzed by photosystem II (PSII), a large membrane-protein complex consisting of 20 subunits with a total molecular mass of 350 kDa for a monomer. The crystal structure of PSII was solved at 1.9 Å resolution, revealing a clear picture of the catalytic center, a Mn4CaO5-cluster, for photosynthetic water-splitting, which was organized into a distorted chair form. This feature of the distorted shape suggested a remarkable flexibility in the structure, which would be needed for structural changes expected to occur during the catalytic water-splitting cycle (S-state cycle). Based on the high-resolution crystal structure as well as results obtained from a number of other techniques, the mechanism of photosynthetic water-splitting is emerging which may have important consequences on the design and synthesis of artificial catalysts for light-induced water-splitting. I will introduce the structure of photosystem II and the water-splitting catalyst and discuss the possible mechanism for photosynthetic water-splitting. ［Host］Associate Professor Ki-Seok Yoon -- I2CNER　http://i2cner.kyushu-u.ac.jp/ ICER　http://icer.kyushu-u.ac.jp/