Degradation of D2 protein due to UV‐B irradiation of the reaction centre of photosystem II

FEBS Letters

Barbato, R.²  Giacometti, G.M.²  Friso, G.²  Barber, J.¹ 

[1] AFRC Photosynthesis Research Group, Biochemistry Department, The Wolfson Laboratories, Imperial College of Science, Technology & Medicine, London SW7 2 AY, UK;Dipartimento dl Biologia, Universita di Padova, Via Trieste 75, 1-35121, Italy

关键词: UVB light;    Photosystem II;    D2 protein;    Photoinactivation;    Chl;    chlorophyll;    DBMIB;    2;    5-dibromo-3-methyl-6-isopropyl-p-benzoquinone;    PAGE;    polyacrylamide gel electrophoresis;    pheo;    pheophytin;    P680;    primary donor in photosystem II;    PSII;    photosystem II;    PVDF;    polyvinylidenedifluoride;    SDS;    sodium dodecyi sulphate;   

DOI  :  10.1016/0014-5793(94)80419-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Exposure of isolated reaction centres of photosystem II to UV-B radiation generates specific breakdown products of the D2 protein. When the quinone, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone is present a 22 kDa fragment containing the N-terminus of the mature protein is generated. Concomitant with the appearance of the N-terminal fragment, two fragments containing the C-terminus of the D2 protein having apparent molecular masses around 10–12 kDa are observed. It is concluded that the primary cleavage occurs in the hydrophilic loop linking putative transmembrane segments IV and V. No such cleavage was observed when silicomolybdate was used as an electron acceptor, suggesting that this UV-B damage is dependent on binding of the added quinone to the Q_A site.

【 授权许可】

Unknown