title: Alumina plate containing photosystem I reaction center complex oriented inside plate-penetrating silica nanopores.
abstract: The photosynthetic photosystem I reaction center complex (PSI-RC), which has a molecular diameter of 21 nm with 100 pigments, was incorporated into silica nanopores with a 100-nm diameter that penetrates an alumina plate of 60-μm thickness to make up an inorganic-biological hybrid photocell. PSI-RCs, purified from a thermophilic cyanobacterium, were stable inside the nanopores and rapidly photoreduced a mediator dye methyl viologen. The reduced dye was more stable inside nanopores suggesting the decrease of dissolved oxygen. The analysis by a cryogenic electron spin paramagnetic resonance indicated the oriented arrangement of RCs inside the 100-nm nanopores, with their surface parallel to the silica wall and perpendicular to the plane of the alumina plate. PSI RC complex in the semicrystalline orientation inside silica nanopores can be a new type of light energy conversion unit to supply strong reducing power selectively to other molecules inside or outside nanopores.
authors.affiliation: Division of Material Science (Physics), Graduate School of Science, Nagoya University, Chikusa-ku Nagoya, Ai-chi, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kamidaki
authors.forename: Toru
authors.initials: T
authors.lastname: Kondo
authors.forename: Tomoyasu
authors.initials: T
authors.lastname: Noji
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Itoh
authors.forename: Akira
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Itoh
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000458:Cyanobacteria / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D058608:Nanopores; D010084:Oxidation-Reduction; D010269:Paraquat / Q000737:chemistry; D045331:Photosystem I Protein Complex / Q000737:chemistry* / Q000378:metabolism; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D045331:Photosystem I Protein Complex; D012822:Silicon Dioxide; D000537:Aluminum Oxide; D010269:Paraquat