Photosynthetic Electron Transfer from Reaction Center Pigment−Protein Complex in Silica Nanopores

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• 作者：Ippei Oda ; Masayo Iwaki ; Daiju Fujita ; Yasutaka Tsutsui ; Souji Ishizaka ; Makiko Dewa ; Mamoru Nango ; Tsutomu Kajino ; Yoshiaki Fukushima ; Shigeru Itoh
• 刊名：Langmuir
• 出版年：2010
• 出版时间：August 17, 2010
• 年：2010
• 卷：26
• 期：16
• 页码：13399-13406
• 全文大小：949K
• 年卷期：v.26,no.16(August 17, 2010)
• ISSN：1520-5827

文摘

A photosynthetic reaction center (RC) pigment−protein complex purified from a thermophilic purple photosynthetic bacterium, Thermochromatium tepidum, was adsorbed to a folded-sheet silica mesoporous material (FSM). The RC has a molecular structure with a 7.0 × 5.0 × 13 nm diameter. The amount of RC adsorbed to the FSM compound with an average internal pore diameter of 7.9 nm (FSM_7.9) was high at 0.29 gRC/gFSM, while that to the FSM_2.7 (2.7 nm diameter) was low at 0.02 gRC/gFSM, suggesting the specific binding of the RC into the 7.9 nm pores of FSM_7.9. An N₂-adsorption isotherm study indicated the incorporation of the RC into the 7.9 nm pores. The RC inside FSM_7.9 showed absorption spectra in the visible and infrared regions similar to those of the RC in solution, indicating almost no structural changes induced by the adsorption. The RC−FSM_7.9 conjugate showed the high photochemical activity with the increased thermal stability up to 50 °C in the measurements by laser spectroscopy. The conjugates rapidly provided electrons to a dye in the outer medium or showed electric current on the ITO electrode upon the illumination. The RC−FSM conjugate will be useful for the construction of artificial photosynthetic systems and new photodevices.