Carotenoid Photooxidation in Photosystem II

• Published in: Archives of Biochemistry and Biophysics Vol. 385; no. 1; pp. 61 - 69
• Main Authors: Tracewell, Cara A., Vrettos, John S., Bautista, James A., Frank, Harry A., Brudvig, Gary W.
• Format: Book Review Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2001
• Subjects: beta Carotene - metabolism; carotenoid; Carotenoids - metabolism; cation radical; Cations; Cyanobacteria - metabolism; Electron Spin Resonance Spectroscopy; electron transfer; Electrons; Free Radicals; Light; Models, Biological; Models, Chemical; Oxidation-Reduction; Oxygen - metabolism; photoprotection; Photosynthetic Reaction Center Complex Proteins - metabolism; photosystem II; Photosystem II Protein Complex; Spectrophotometry; Spectrum Analysis, Raman; photoprotection; photosystem II; carotenoid; electron transfer; cation radical
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1006/abbi.2000.2150

Carotenoids are known to function as light-harvesting pigments and they play important roles in photoprotection in both plant and bacterial photosynthesis. These functions are also important for carotenoids in photosystem II. In addition, β-carotene recently has been found to function as a redox intermediate in an alternate pathway of electron transfer within photosystem II. This redox role of a carotenoid in photosystem II is unique among photosynthetic reaction centers and stems from the very highly oxidizing intermediates that form in the process of water oxidation. In this minireview, an overview of the electron-transfer reactions in photosystem II is presented, with an emphasis on those involving carotenoids. The carotenoid composition of photosystem II and the physical methods used to study the structure of the redox-active carotenoid are reviewed. Possible roles of carotenoid cations in photoprotection of photosystem II are discussed.