Photosynthetic oxygen evolution in mesoporous silica material: Adsorption of photosystem II reaction center complex into 23 nm nanopores in SBA

Tomoyasu Noji, Chihiro Kamidaki, Keisuke Kawakami, Jian Ren Shen, Tsutomu Kajino, Yoshiaki Fukushima, Takeshi Sekitoh, Shigeru Itoh

    Research output: Contribution to journalArticlepeer-review

    37 Citations (Scopus)

    Abstract

    An oxygen-evolving photosynthetic reaction center complex (PSII) was adsorbed into nanopores in SBA, a mesoporous silica compound. We purified the dimer of PSII complex from a thermophilic cyanobacterium, Thermosynechococcus vulcanus, which grows optimally at 57 °C. The thermally stable PSII dimeric complex has a diameter of 20 nm and a molecular mass of 756 kDa and binds more than 60 chlorophylls. The SBA particles, with average internal pore diameters of 15 nm (SBA 15) and 23 nm (SBA 23), adsorbed 4.7 and 15 mg of PSII/g SBA, respectively. Measurement with a confocal laser-scanning microscope indicated the adsorption of PSII to the surface and the inner space of the SBA 23 particles, indicating the adsorption of PSII into the 23 nm silica nanopores. PSII did not bind to the inner pores of SBA 15. PSII bound to SBA 23 showed the high and stable activity of a photosynthetic oxygen-evolving reaction, indicating the light-driven electron transport from water to the quinone molecules added in the outer medium. The PSII-SBA conjugate can be a new material for photosensors and artificial photosynthetic systems.

    Original languageEnglish
    Pages (from-to)705-713
    Number of pages9
    JournalLangmuir
    Volume27
    Issue number2
    DOIs
    Publication statusPublished - Jan 18 2011

    ASJC Scopus subject areas

    • Materials Science(all)
    • Condensed Matter Physics
    • Surfaces and Interfaces
    • Spectroscopy
    • Electrochemistry

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