THYLAKOID MEMBRANE-PROTEIN PHOSPHORYLATION MODIFIED THE EQUILIBRIUM BETWEEN PHOTOSYSTEM-II QUINONE ELECTRON-ACCEPTORS

作     者：HODGES, M BOUSSAC, A BRIANTAIS, JM 

作者机构：UNIV PARIS 11UTILISAT RAYONNMENT ELECTROMAGNET LABF-91405 ORSAYFRANCE 

出 版 物：《BIOCHIMICA ET BIOPHYSICA ACTA》 (Biochim. Biophys. Acta Bioenerg.)

年 卷 期：1987年第894卷第2期

页      面：138-145页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：Royal Society  (2274) 

主　　题：Chlorophyll fluorescence Electron transfer Photosynthesis Photosystem II Protein phosphorylation (Pea and lettuce chloroplast) Chl chlorophyll D1 herbicide-binding protein ( psbA gene product) D2 protein associated with PS II ( psbD gene product) DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea DPC diphenylcarbazide DPIP 2,6-dichlorophenolindophenol F 0 initial Chl fluorescence F M maximal Chl fluorescence Hepes N -2-hydroxyethylpiperazine- N ′-2-ethanesulphonic acid LHC light-harvesting Chl a b protein complex pBQ phenyl benzoquinone PQ plastoquinone PS Photosystem Q A primary quinone electron acceptor of PS II Q B secondary quinone electron acceptor of PS II 

摘      要：Chloroplast thylakoid membrane protein phosphorylation inhibits Photosystem-II-mediated electron transfer at saturating light intensities. Measurements of room temperature chlorophyll fluorescence have been used to monitor electron transfer reactions between the primary (Q A ) and secondary (Q B ) quinone acceptors of Photosystem II. The initial transfer from Q − A to Q B is not affected by the phosphorylation, although a second slow reoxidation phase is even slower after phosphorylation. After equilibrium is achieved between Q − A Q B and Q A Q − B there appears to be a higher concentration of Q − A in the phosphorylated membranes. This is explained by a phosphorylation-induced destabilisation of the anionic semiquinone, Q − B , as seen from the DCMU-stimulated fluorescence increase.