Characterization of a D1‐D2‐cyt b‐559 complex containing 4 chlorophyll a/2 pheophytin a isolated with the use of MgSO4

FEBS Letters

Yruela, I.¹  van Kan, P.J.M.¹  Holzwarth, A.R.¹  Müller, M.G.¹ 

[1] Max-Planck Institut für Strahlenchemie, Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany

关键词: Photosystem II;    Reaction center;    Pigment composition;    Chl;    chlorophyll;    cyt;    cytochrome;    CP47;    chlorophyllprotein in the core complex of photosystem II with apparent molecular mass of 47 kDa;    D1-D2-cyt b-559: reaction center complex of photosystem II;    FWHM;    full width at half maximum;    PAGE;    polyacrylamide gel electrophoresis;    Pheo;    pheophytin;    PS II;    photosystem II;    P680;    primary electron donor;    RC;    reaction center;    SDS;    sodium dodecyl sulfate;    Tris;    Tris(hydroxymethyl)aminomethane;   

DOI  :  10.1016/0014-5793(94)80377-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A D1-D2-cyt b-559 complex containing 4 chlorophyll a, 1 β-carotene and 1 cytochrome b-559 per 2 pheophytin a has been isolated from spinach with 30% yield using a Q-Sepharose Fast-Flow anion-exchange column equilibrated with 0.1% Triton X-100, 10 mM MgSO₄ and 50 mM Tris-HCl (pH 7.2). The preparation was then stabilized with 0.1% dodecyl-β-d-maltoside. This method gave a yield 10 times higher than that using a Fractogel TSK-DEAE 650(S) column equilibrated with 0.1% Triton X-100, 30 mM NaCl and 50 mM Tris-HCl (pH 7.2). The PS II RC complex was characterized using absorption and fluorescence spectroscopy at 277 and 77 K. A selective reversible bleaching under reducing conditions with maximum at 682 nm, associated with pheophytin a reduction, and light-induced absorption differences with a lifetime of 1.0 ms, ascribed to the triplet state of P680 were measured and indicated that the isolated Dl-D2-cyt b-559 complex is active in charge separation. The results are compared with the data obtained for a PS II RC preparation containing 6 chlorophyll a, 2 β-carotene and 1 cyt b-559 per 2 pheophytin a.

【 授权许可】

Unknown