scholarly journals Bicarbonate-reversible formate inhibition at the donor side of Photosystem II

1996 ◽  
Vol 1273 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Hanna Wincencjusz ◽  
Suleyman I. Allakhverdiev ◽  
Vyacheslav V. Klimov ◽  
Hans J. van Gorkom
Keyword(s):  
Photosystem Ii ◽  
Donor Side

pH Dependence of the Donor Side Reactions in Ca2+-Depleted Photosystem II†

Biochemistry ◽  
2003 ◽  
Vol 42 (20) ◽  
pp. 6185-6192 ◽  
Author(s):  
Stenbjörn Styring ◽  
Yashar Feyziyev ◽  
Fikret Mamedov ◽  
Warwick Hillier ◽  
Gerald T. Babcock
Keyword(s):  
Photosystem Ii ◽  
Ph Dependence ◽  
Side Reactions ◽  
Donor Side

Inhibition by Tetranitromethane of Photosynthetic Electron Transport from Water to Photosystem II in Chloroplasts

1980 ◽  
Vol 35 (3-4) ◽  
pp. 293-297 ◽  
Author(s):  
P. V. Sane ◽  
Udo Johanningmeier
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Electron Flow ◽  
Ph Dependence ◽  
Photosynthetic Electron Transport ◽  
Donor Side ◽  
Ps Ii ◽  
Diphenyl Carbazide ◽  
Low Concentrations ◽  
Sh Group

Abstract Low concentrations (10 µM) of tetranitromethane inhibit noncyclic electron transport in spinach chloroplasts. A study of different partial electron transport reactions shows that tetranitromethane primarily interferes with the electron flow from water to PS II. At higher concentrations the oxidation of plastohydroquinone is also inhibited. Because diphenyl carbazide but not Mn2+ ions can donate electrons efficiently to PS II in the presence of tetranitromethane it is suggested that it blocks the donor side of PS II prior to donation of electrons by diphenyl carbazide. The pH dependence of the inhibition by this protein modifying reagent may indicate that a functional-SH group is essential for a protein, which mediates electron transport between the water splitting complex and the reaction center of PS II.

The PsbP-like protein (sll1418) of Synechocystis sp. PCC 6803 stabilises the donor side of Photosystem II

2007 ◽  
Vol 93 (1-3) ◽  
pp. 101-109 ◽  
Author(s):  
Dmitry Sveshnikov ◽  
Christiane Funk ◽  
Wolfgang P. Schröder
Keyword(s):  
Photosystem Ii ◽  
Donor Side ◽  
Synechocystis Sp ◽  
Pcc 6803

Bicarbonate requirement for the donor side of photosystem II

FEBS Letters ◽  
1995 ◽  
Vol 363 (3) ◽  
pp. 251-255 ◽  
Author(s):  
V.V. Klimov ◽  
S.I. Allakhverdiev ◽  
Ya.M. Feyziev ◽  
S.V. Baranov
Keyword(s):  
Photosystem Ii ◽  
Donor Side

A possible relation between the function of photosystem II in oxygen evolution and the variable chlorophyll fluorescence

1989 ◽  
Vol 238 (1291) ◽  
pp. 127-136
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Reaction Centre ◽  
Redox Potentials ◽  
Donor Side ◽  
Hypothetical Model ◽  
Surplus Energy ◽  
Variable Chlorophyll Fluorescence ◽  
And Function ◽  
Energy Dependent

A hypothetical model for the structure and function of photosystem II is proposed that attempts to incorporate different phenomena related to the variable chlorophyll fluorescence inherent in this photosystem. The involvement of pheophytin redox chemistry on both the acceptor and donor side of photosystem II is postulated to achieve redox potentials high enough to oxidize water. The presence of this symmetry would be the cause of inefficient photochemistry in photosystem II when, under unbalanced carbon metabolism, a surplus charge remains on the reaction centre. In addition, such a scheme would enable an efficient dissipation of surplus energy in the reaction centre itself, and would be the origin ofthe ‘energy-dependent’ quenching of chlorophyll fluorescence, q ( E ).

Different sensitivities of photosystem II in green algae and cyanobacteria to phenylurea and phenol-type herbicides: effect on electron donor side

2017 ◽  
Vol 72 (7-8) ◽  
pp. 315-324 ◽  
Author(s):  
Ekaterina K. Yotsova ◽  
Martin A. Stefanov ◽  
Anelia G. Dobrikova ◽  
Emilia L. Apostolova
Keyword(s):  
Photosystem Ii ◽  
Kinetic Parameters ◽  
Oxygen Evolution ◽  
Oxygen Evolving Complex ◽  
Photosynthetic Oxygen Evolution ◽  
Donor Side ◽  
Short Term Treatment ◽  
Psii Photochemistry ◽  
Photosynthetic Oxygen ◽  
Oxygen Evolving

AbstractThe effects of short-term treatment with phenylurea (DCMU, isoproturon) and phenol-type (ioxynil) herbicides on the green algaChlorella kessleriand the cyanobacteriumSynechocystis salinawith different organizations of photosystem II (PSII) were investigated using pulse amplitude modulated (PAM) chlorophyll fluorescence and photosynthetic oxygen evolution measured by polarographic oxygen electrodes (Clark-type and Joliot-type). The photosynthetic oxygen evolution showed stronger inhibition than the PSII photochemistry. The effects of the studied herbicides on both algal and cyanobacterial cells decreased in the following order: DCMU>isoproturon>ioxynil. Furthermore, we observed that the number of blocked PSII centers increased significantly after DCMU treatment (204–250 times) and slightly after ioxynil treatment (19–35 times) in comparison with the control cells. This study suggests that the herbicides affect not only the acceptor side but also the donor side of PSII by modifications of the Mn cluster of the oxygen-evolving complex. We propose that one of the reasons for the different PSII inhibitions caused by herbicides is their influence, in different extents, on the kinetic parameters of the oxygen-evolving reactions (the initial S0−S1state distribution, the number of blocked centers SB, the turnover time of Sistates, misses and double hits). The relationship between the herbicide-induced inhibition and the changes in the kinetic parameters is discussed.

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