Study on the Principle of Photosynthetic Light Energy Conversion Based on Divergence of Chlorophyll Molecules
| Autor: | Mimuro, Mamoru, Tomo, Tatsuya, Tsuchiya, Toru, Noguchi, Takumi, Okubo, Tatsunori, Akimoto, Seiji, Yokono, Makio, Inoue, Kazuhito |
|---|---|
| Jazyk: | japonština |
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Science Journal of Kanagawa University. 19:39-44 |
| ISSN: | 1880-0483 |
| Popis: | The composition of photosystem II (PSII) in the chlorophyll (Chl) d-dominated cyanobacterium Acaryochloris marina MBIC 11017 was investigated to enhance the general understanding of the energetics of the PSII reaction center. We first purified photochemically active complexes consisting of a 47 kDa chlorophyll protein (CP47), CP43’ (PcbC), D1, D2, cytochrome b559, PsbI, and an unknown small polypeptide. The pigment composition per two pheophytin (Phe) a molecules was 55 ± 7 Chl d, 3.0 ± 0.4 Chl a, 17 ± 3 α-carotene, and 1.4 ± 0.2 plastoquinone-9. A special pair was detected by a reversible absorption change at 713 nm (P713) together with a cation radical band at 842 nm. FTIR difference spectra of the specific bands of a 3-formyl group allowed assignment of the special pair. The combined results indicate that the special pair includes a Chl d homodimer. The primary electron acceptor was shown by photoaccumulation to be Phe a, and its potential was shifted to a higher value than that in the Chl a/Phe a system. The overall energetics of PSII in the Chl d system adapt to changes in the redox potentials, with P713 as the special pair utilizing lower light energy at 713 nm. Our findings support the idea that changes in photosynthetic pigments combine with modification of the redox potentials of electron transfer components to give rise to energy changes in the total reaction system. ■原 著■ 2007 年度神奈川大学総合理学研究所共同研究助成論文 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|