High-light induced superoxide radical formation in cytochrome b₆f complex from Bryopsis corticulans as detected by EPR spectroscopy

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 102; no. 3; pp. 177 - 181
• Main Authors: Sang, Min, Xie, Jie, Qin, Xiao-Chun, Wang, Wen-Da, Chen, Xiao-Bo, Wang, Ke-Bin, Zhang, Jian-Ping, Li, Liang-Bi, Kuang, Ting-Yun
• Format: Journal Article
• Language: English
• Published: Switzerland 02.03.2011
• Subjects: Chlorophyta - enzymology; Chlorophyta - metabolism; Chlorophyta - radiation effects; Cytochrome b6f Complex - metabolism; Electron Spin Resonance Spectroscopy - methods; Free Radical Scavengers - metabolism; Light; Oxygen - metabolism; Protein Subunits - metabolism; Superoxides - metabolism
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2010.11.002

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.