Photosystem spinach

Achnrne L, Pereda-Miranda R, Iglesias-Prieto R, Moreno-Sanchez R, Lotina-Hennsen B (1999) Tricolorin A, a Potent Natural Uncoupler and Inhibitor of Photosystem II Acceptor Side of Spinach Chloroplasts. Physiol Plant 106 246... 

Due to the anthraquinone moiety, we tested all compounds for photosystem II (PS II) inhibition using both spinach and com thylakoids. By using both monocot and dicot thylakoids, we accounted for any differences in activity. There was no effect on PS II activity for series 2 analogues (-CH3) (data not shown). However, for series 1 analogues (-OH), there was a 50% decrease in PS II activity at 0.1 pM in thylakoids isolated from spinach (Fig. 1.9A). This was similar for thylakoids isolated from corn (Fig. 1.9B). 

Photosystem II. Spinach and pea PSII particles coated on different Ti02 based electrodes were used for photocurrent measurements in the presence of PSII electron acceptor DMBQ. In all experiments, addition of DMBQ resulted in an increase in photocurrent which remained constant for long periods. In control experiments with no deposition of PSII on the electrodes, there was no change in the photocurrent pattern on addition of DMBQ. Addition of the PSII oxygen evolution inhibitor DCMU caused an immediate fall in photocurrent, suggesting that the electron transport to the Ti02 electrode is linked to water photolysis. 

Berthold, D.A., Babcock G.T. and Yocum C.F. 1981. A highly resolved, oxygenevolving photosystem II preparation from spinach thylakoid membranes. EPR and electron transport properties. FEBS Lett. 134,231-234. 

Melis, A. 1986. Functional properties of photosystem IIB in spinach chloroplasts. Biochim. Biophys. Acta 808, 334-342. 

The phenolic photoaffinity label azidodinoseb (Figure 4) binds less specifically than either azidoatrazine or azidotriazinone (14). In addition to other proteins, it labels predominantly the photosystem II reaction center proteins (spinach 43 and 47 kDa Chlamydomo-nas 47 and 51 kDa) (17). Because of the unspecific binding of azidodinoseb, this can best be seen in photosystem II preparations (17). Thus, the phenolic herbicides bind predominantly to the photosystem II reaction center, which might explain many of the differences observed between "DCMU-type" and phenolic herbicides (9). The photosystem II reaction center proteins and the 34 kDa herbicide binding protein must be located closely to and interact with each other in order to explain the mutual displacement of both types of herbicides (8,12,21). Furthermore, it should be noted that for phenolic herbicides, some effects at the donor side of photosystem II (22) and on carotenoid oxidation in the photosystem II reaction center have been found (23). 

Figure 6. Photograph of a Li-dodecylsulfate polyacrylamide electrophoresis gel (10-15%) and radioactivity distribution therein of a spinach photosystem II preparation labeled by 2 nmol/mg chlorophyll azidoplastoquinone.

Fig. 12.7. The onset of synthesis of the various subunits of photosystem I reaction center after the illumination of etiolated spinach seedlings. Spinach seedlings were grown in the dark. At time zero they were transferred to light. Leaves were removed at the indicated time points and processed as was described in Fig. 12.6 for yeast cells. The antibodies were against individual subunits of photosystem I reaction center. The amount of each subunit in light-grown spinach plants was taken as 100% [125].

Much effort has been put into the isolation, purification and reconstitution of both photosystems. Work on PSII has been concerned especially with the nature of the dioxygen-evolving site, which is thought to be a manganese protein. ESR studies on spinach chloroplasts have led to the postulate of the involvement in oxygen evolution of a pair (or possibly a tetramer) of antiferromagnetically... 

Larrson UK, Sundby C and Andersson B. (1987). Characterization of two different subpopulations of spinach light-harvesting chlorophyll a-i-protein complex (LHC-II) polypeptide composition, phosphorylation pattern and association with photosystem-II. 

Melis A. and Anderson J.M. (1983). Structural and functional organization of the photosystems in spinach chloroplasts antenna size, relative electron transport capacity, and chlorophyll composition. Biochim. Biophys. Acta 724, 473-484. 

Melis A, Spangfort M and Andersson B. (1987). Light-absorption and electron transport balance between photosystem-II and photosystem-I in spinach chloroplasts. Photochem. Photobiol. 45, 129-136. 

Resonance Raman data were used to study the change of iron spin state in horseradish peroxidase c - induced by the removal of calcium.238 Ligand modes for spin-state cycling of photosystem II from a cyanobacterium are very similar to those for related systems from spinach.239... 

Fig. 19. Chloroplast thylakoid-membrane structure revealed by freeze-fracture electron microscopy. The oxygen-evolving (BBY) PS-II particle its preparation (A) and electron micrographs (B). The inside-out and rightside-out vesicles preparation, structure, and properties (C) and electron micrographs (D). Figure source (A) and (B) Dunahay, Staehelin, Seibert, Ogilvie and Berg (1984) Structural, biochemical and biophysical characterization of four oxygen-evolving photosystem II preparations from spinach. Biochim Biophys Acta 764 190, 185 (C) and (D) from Andersson and Akerlund (1978) Inside-out membrane vesicles isolated from spinach thylakoids. Biochim Biophys Acta 503 465, 468. Figure (B) kindly furnished by Dr. Andrew Staehelin.

TG Dunahay, LA Staehelin, M Seibert, PD Ogilvie and SP Berg (1984) Structural, biochemical and biophysical characterization of four oxygen-evolving photosystem II preparations from spinach. Biochim Biophys Acta 764 179-193... 

B Andersson and JM Anderson (1980) Lateral heterogeneity in the distribution of chlorophyll-protein complexes of the thylakoid membranes of spinach chloroplasts. Biochim Biophys Acta 593 427-440 P-" Albertsson (1985) Partition of Cell Particles and Macromolecules (3rd edition) John Wiley H-E "kerlund, B Andersson and P-" Albertsson (1976) Isolation of photosystem II enriched membrane vesicles from spinach chloroplasts by phase partition. Biochim Biophys Acta 449 525-535 P Grber, A Zickler and H-E "kerlund (1978) Electric evidence for the isolation of inside-out vesicles from spinach chloroplasts. FEES Lett 96 233-237... 

H Fujiwara, H Hayashi, M Tasumi, M Kanji, YKoyamaand (Ki) Satoh (1987) Structural studies on a photosystem II reaction center complex consisting ofD-1 and D-2 polypeptides and cytochrome b-559 by resonance Raman spectroscopy and high-performance liquid chromatography. Chem Lett 10 2005-2008 GE Bialek-Bylka, T Tomo, (Ki) Satoh and Y Koyama (1995) 15-cis-carotene found in the reaction center of spinach photosystem II. FEES Lett 363 137-140... 

Fig. 6. Cytochrome bS59 photooxidation in spinach chioropiasts (A), photoreduction in TSF2a particles (B) and in D1/D2/Cyt bS59 complex (C). See text for discussion. Figure (A) from Knaff and Arnon (1969) Light-induced oxidation of chloroplast b-type cytochrome at-189 °C. Proc Nat Acad Sci, USA 63 959, 960 (B) Ke, Vernon and Cheney (1972) Photoreduction of cytochrome b5S9 in a photosystem-ll subchloroplast particle. Biochim Biophys Acta 256 350 (C) Barber and De Las Rivas (1993) A functional model for the role of cytochrome (3559 in the protection against donor and acceptor side photoinhibition. Proc Nat Acad Sci, USA 90 10943, 10944.

Fig. 2. (A) Fluorescence yield (in arbitrary units) for isolated, dark-adapted chloroplasts as a function of time in the absence (a) and presence (b) of DCMU. (B) Light-induced fluorescence-yield change in lyophilized chloroplasts (control), in hexane-methanol extracted chloroplasts, and in extracted chloroplasts reconstituted with PQ-9. Small upward arrows indicate weak, modulated green monitoring light turned on larger arrows for intense actinic light on (upward arrow) and off (downward arrow). (A) adapted from Zankel and Kok (1972) Estimation of pool size and kinetic constants. In A San Pietro (ed) Methods in Enzymology 24 222 (B) from Liu, Hoff, Gu, Li and Zhou (1991) The relationship between the structure of plastoquinone derivatives and their biological activity in photosystem II of spinach. Photosynthesis Res 30 100.

B Bouges-Bocquet (1973) Electron transfer between two photosystems in spinach chloroplasts. Biochim Biophys Acta 314 250-256... 

Fig. 7. (A) Absorbance difference spectra of PS-II particles measured at 0 ps (a), 200 ps (b) and 1 ns (c) after excitation with 35-ps, 532-nm pulses. (B) the solid-dot absorbance-difference spectrum of the PS-II particles was obtained by subtracting the 1-ns spectrum (c) from the 200-ps spectrum (b) in (A) the empty-circie spectrum was obtained by subtracting the 1 -ns spectrum (c) in (A) from a 200-ps difference spectrum of PS-II particle containing dithionite [not shown], (C) kinetics of absorbance changes at 655 nm in the presence of ferricyanide (solid dots) or dithionite (empty circles). See text for discussion. Figure source Nuijs, van Gorkom, Plijter and Duysens (1986) Primary-charge separation and excitation of chlorophyll a in photosystem II particles from spinach as studied by picosecond absorbance-difference spectroscopy. Biochim BiophysActa 848 170,171.

AM Nuijs, HJ van Gorkom, JJ Plijter and LNM Duysens (1986) Primary-charge separation and excitation of chlorophyll a in photosystem II particles from spinach as studied by picosecond absorbance-difference spectroscopy. Biochim Biophys Acta 848 170-171... 

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