title: High-light induced superoxide radical formation in cytochrome b₆f complex from Bryopsis corticulans as detected by EPR spectroscopy.
abstract: The generation of superoxide radical (O₂·⁻) in Cyt b₆f of Bryopsis corticulans under high light illumination was studied using electron paramagnetic resonance (EPR) spectroscopy. This could be evidenced by the addition of SOD which specifically reacted with O₂·⁻. The generation of O₂·⁻ was lost in the absence of oxygen and was found to be suppressed in the presence of NaN₃ and be scavenged by extraneous antioxidants such as ascorbate, β-carotene and glutathione which could also scavenged ¹O₂*. These results indicated that O₂·⁻ which produced under high light illumination in Cyt b₆f of B. corticulans might rise from a reaction which ¹O₂* could participated in. Also the photo-protection mechanism to Cyt b₆f complex by antioxidants which might contain in thylakoid was speculated.
authors.affiliation: Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; Institute of Hydrobiology, Ji' nan University, Guangzhou 510632, P.R.China.
authors.forename: Min
authors.initials: M
authors.lastname: Sang
authors.forename: Jie
authors.initials: J
authors.lastname: Xie
authors.forename: Xiao-Chun
authors.initials: XC
authors.lastname: Qin
authors.forename: Wen-Da
authors.initials: WD
authors.lastname: Wang
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Chen
authors.forename: Ke-Bin
authors.initials: KB
authors.lastname: Wang
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Zhang
authors.forename: Liang-Bi
authors.initials: LB
authors.lastname: Li
authors.forename: Ting-Yun
authors.initials: TY
authors.lastname: Kuang
mesh_terms: D000460:Chlorophyta / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects*; D045346:Cytochrome b6f Complex / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D016166:Free Radical Scavengers / Q000378:metabolism; D008027:Light; D010100:Oxygen / Q000378:metabolism; D021122:Protein Subunits / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*
chemical_list: D016166:Free Radical Scavengers; D021122:Protein Subunits; D013481:Superoxides; D045346:Cytochrome b6f Complex; D010100:Oxygen