Reaction centers of photosystem II with a chemically‐modified pigment composition: exchange of pheophytins with 131‐deoxo‐131‐hydroxy‐pheophytin a

FEBS Letters

Shkuropatov, A.Ya.²  Shuvalov, V.A.²  Owens, T.G.¹  Khatypov, R.A.²  Shkuropatova, V.A.²  Zvereva, M.G.² 

[1] Section of Plant Biology, Cornell University, Ithaca, NY 14853, USA;Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino 142292, Russia

关键词: Photosynthesis;    Photosystem II;    Reaction center;    Pheophytin a;    131-deoxo-131-hydroxy-pheophytin a;    Pigment exchange;    Chl;    chlorophyll a;    cyt;    cytochrome;    DM;    n-dodecyl β-D-maltoside;    P680;    primary electron donor in PS II;    Pheo;    pheophytin a;    Pheoactive;    Pheo active in charge separation;    Pheoinactive;    Pheo inactive in charge separation;    PS II;    photosystem II;    RC;    reaction center;    TM buffer;    50 mM Tris HCl (pH7.2)/0.05% DM;    131-OH-Pheo;    131-deoxo-131-hydroxy-pheophytin a;   

DOI  :  10.1016/S0014-5793(99)00486-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Isolated reaction centers of photosystem II with an altered pigment content were obtained by chemical exchange of the native pheophytin a molecules with externally added 13¹-deoxo-13¹-hydroxy-pheophytin a. Judged from a comparison of the absorption spectra and photochemical activities of exchanged and control reaction centers, 70–80% of the pheophytin molecules active in charge separation are replaced by 13¹-deoxo-13¹-hydroxy-pheophytin a after double application of the exchange procedure. The new molecule at the active branch was not active photochemically. This appears to be the first stable preparation in which a redox active chromophore of the reaction center of photosystem II was modified by chemical substitution. The data are compatible with the presence of an active and inactive branch of cofactors, as in bacterial reaction centers. Possible applications of the 13¹-deoxo-13¹-hydroxy-pheophytin a-exchanged preparation to the spectral and functional analysis of native reaction centers of photosystem II are discussed.

【 授权许可】

Unknown