Regulation of electron transport in isolated chloroplasts by sequential binding of adenine nucleotides to the coupling factor protein

1975 ◽  
Vol 7 (3) ◽  
pp. 91-102 ◽  
Author(s):  
Yasuo Mukohata ◽  
Takao Yagi ◽  
Yasuo Sugiyama ◽  
Akemi Matsuno ◽  
Mitsuhiro Higashida
Keyword(s):  
Electron Transport ◽  
Adenine Nucleotides ◽  
Coupling Factor ◽  
Sequential Binding ◽  
Isolated Chloroplasts

Über die Hemmung photosynthetischer Reaktionen isolierter Chloroplasten durch Chloroplasten-Antikörper

1966 ◽  
Vol 21 (11) ◽  
pp. 1057-1059 ◽  
Author(s):  
R. Berzborn ◽  
W. Menke ◽  
A. Trebst ◽  
E. Pistorius
Keyword(s):  
Electron Transport ◽  
Coupling Factor ◽  
Hill Reaction ◽  
Cyclic Electron Transport ◽  
Ferricyanide Reduction ◽  
Atp Formation ◽  
Unknown Factor ◽  
Photosynthetic Reactions ◽  
Photosynthetic Activities ◽  
Isolated Chloroplasts

The influence of two separated globuline fractions from rabbit antisera against isolated chloroplasts from Antirrhinum majus upon photosynthetic reactions of isolated chloroplasts from spinach has been investigated. The chloroplast antibodies had no effect on electron transport in a Hill reaction with ferricyanide, but one fraction inhibited noncyclic and cyclic ATP formation. This inhibition was reversed by preincubation of the antibody with coupling factor. Both globuline fractions inhibited photosynthetic NADP reduction; the inhibition of only one fraction was reversed by preincubation with ferredoxin-NADP-reductase. We conclude from these results that three components of photosynthetic activities are located on the surface of the thylakoids: the ATP forming system, the NADP-reductase, and an unknown factor participating in photosynthetic NADP reduction but not in ferricyanide reduction or cyclic electron transport

Photosystem I-abhängige Phosphorylierung isolierter Chloroplasten mit Ascorbat/2.6-Dichlorphenolindophenol als Elektronendonator und Methylviologen als Elektronenakzeptor / Photosystem I Dependent Phosphorylation of Isolated Chloroplasts with Ascorbate/2,6-Dichlorophenolindophenol as Electron Donor and Methylviologen as Electron Acceptor

1972 ◽  
Vol 27 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Heinrich Strotmann ◽  
Christa Von Gösseln
Keyword(s):  
Electron Transport ◽  
Linear System ◽  
Photosystem I ◽  
Electron Acceptor ◽  
Electron Flow ◽  
Phosphorylation Site ◽  
Cyclic System ◽  
Atp Production ◽  
Proton Uptake ◽  
Isolated Chloroplasts

Photosystem I related phosphorylation of isolated chloroplasts was investigated with special reference to the stoichiometry between ATP production and electron transprt (ATP: 2e⊖). The system studied contained DCMU to inhibit electron flow from photosystem II, ascorbate and DPIP to supply electrons to photosystem I, and methylviologen as electron acceptor. The following results were obtained:1. Basal electron transport is stimulated by the addition of the phosphorylating system, indicating that phosphorylation is really coupled to non-cyclic electron flow. The ratio ATP: 2e⊖ is 1, when the increase of electron flow obtained by the addition of ADP and phosphate is correlated to phosphorylation. This ratio is constant upon varying several parameters including DPIP concentration and light intensity.2. In the absence of methylviologen a DPIP catalyzed cyclic phosphorylation takes place (cf. I. c.7, 11, 12). Phosphorylation is not increased by the addition of methylviologen, indicating that both, the cyclic DPIP mediated and the non-cyclic system are coupled to the same phosphorylation site and limited by the same reaction step.3. In the absence of oxygen a methylviologen supported cyclic phosphorylation occurs. Comparing optimum rates, phosphorylation under these conditions is about twice as high as in the noncyclic system. Therefore we conclude that two phosphorylation sites are involved in methylviologen catalyzed cyclic electron transport. This system is sensitive against trypsin treatment of the chloroplasts, whereas the linear system is not.4. The two cyclic systems as well as the non-cyclic system are coupled to reversible proton uptake. Furthermore the linear system exhibits an irreversible uptake of hydrogen ions, which is stoichiometric to electron flow. From the reversible and the irreversible components of the pH changes the ratio of the proton pump to electron transprt can be calculated. Under steady state conditions the ration H⨁ : e⊖ approaches 1.

Studies about the Mechanism of Herbicidal Interaction with Photosystem II in Isolated Chloroplasts

1979 ◽  
Vol 34 (11) ◽  
pp. 1010-1014 ◽  
Author(s):  
Gernot Renger
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Excitation Energy ◽  
Electron Acceptor ◽  
Functional Organization ◽  
Regulatory Element ◽  
Release Kinetics ◽  
Acceptor Side ◽  
Receptor Sites ◽  
Isolated Chloroplasts

Abstract Based on the functional organization scheme of system-II-electron transport and its modification by different procedures a proteinaceous component enwrapping the redox components (plastoquinone molecules) of the acceptor side (thereby acting as regulatory element) is inferred to be the unique target for herbicidal interaction with system II. This proteinaceous component, which is attacked by trypsin, provides the receptor sites for the herbicides. Studies of the release kinetics in trypsinated chloroplasts of the inhibition of oxygen evolution with K3 [Fe (CN)6] as electron acceptor indicates, that there exists a binding area with different specific subreceptor sites rather than a unique binding site for the various types of inhibitors. Furthermore, trypsination of the proteinaceous component enhances the efficiency of the plastoquinone pool to act as a non-photochemical quencher for excitation energy.

Effects of N,N′-Dibutylurea on Photosynthetic Electron Transport Reactions in Isolated Chloroplasts

1998 ◽  
Vol 59 (3) ◽  
pp. 129-135 ◽  
Author(s):  
R. Querns ◽  
G.E. MacDonald ◽  
J.F. Gaffney ◽  
C.A. Chase ◽  
H.A. Moye ◽  
...  
Keyword(s):  
Electron Transport ◽  
Photosynthetic Electron Transport ◽  
Isolated Chloroplasts

Counteraction of Paraquat Toxicity at the Chloroplast Level

1987 ◽  
Vol 42 (6) ◽  
pp. 824-828 ◽  
Author(s):  
Brad L. Upham ◽  
Kriton K. Hatzios
Keyword(s):  
Electron Transport ◽  
Pisum Sativum ◽  
Heme Iron ◽  
Hill Reaction ◽  
Ion Toxicity ◽  
Plastoquinone Pool ◽  
Pisum Sativum L ◽  
Paraquat Toxicity ◽  
Isolated Chloroplasts

Six pyridyl derivatives [benzylviologen, 2-anilinopyridine, 1,2-bis(4-pyridyl)ethane, 1,2-bis(4-pyridyl)ethylene, 2-benzoylpyridine, and 2-benzylaminopyridine] and five heme-iron derivatives [hemoglobin, hemin, hematin, ferritin, and ferrocene] were screened for their potential to counteract paraquat (1,1′-dimethyl-4.4′-bipyridinium ion) toxicity on pea (Pisum sativum L.) isolated chloroplasts. The H2O → methylviologen(MV)/O2 and H2O → ferredoxin(Fd)/NADP+ were two Hill reactions assayed with these compounds. Antagonists of paraquat toxicity should inhibit the first Hill reaction but not the latter. AU pyridyl derivatives examined did not inhibit the reaction H2O → MV/O2. Ferritin and ferrocene were also ineffective as inhibitors of this reaction. Hemoglobin inhibited the reaction H2O → MV/O2 without inhibiting the reaction H2O → Fd/NADP+, providing protection to pea chloroplasts against paraquat. Hemin and hematin inhibited both Hill reactions examined. They also inhibited H2O → diaminodurene(DAD)ox and durohydro- quinone → MV/O2 Hill reactions but not the dichlorophenol indophenolred → MV/O2 and DADred → MV/O2 Hill reactions. These results suggest that hemin and hematin are inhibiting the photo- synthetic electron transport in the plastoquinone-pool region.

Counteraction of Paraquat Toxicity at the Chloroplast Level

1987 ◽  
Vol 42 (7-8) ◽  
pp. 824-828 ◽  
Author(s):  
Brad L. Upham ◽  
Kriton K. Hatzios
Keyword(s):  
Electron Transport ◽  
Pisum Sativum ◽  
Photosynthetic Electron Transport ◽  
Heme Iron ◽  
Hill Reaction ◽  
Ion Toxicity ◽  
Plastoquinone Pool ◽  
Pisum Sativum L ◽  
Paraquat Toxicity ◽  
Isolated Chloroplasts

Six pyridyl derivatives [benzylviologen, 2-anilinopyridine, 1,2-bis(4-pyridyl)ethane, 1,2-bis(4- pyridyl)ethylene, 2-benzoylpyridine, and 2-benzylaminopyridine] and five heme-iron derivatives [hemoglobin, hemin, hematin, ferritin, and ferrocene] were screened for their potential to coun- teract paraquat (1,1′-dimethyl-4.4′-bipyridinium ion) toxicity on pea (Pisum sativum L.) isolated chloroplasts. The H2O -> methylviologen(MV)/O2 and H2O → ferredoxin(Fd)/NADP+ were two Hill reactions assayed with these compounds. Antagonists of paraquat toxicity should inhibit the first Hill reaction but not the latter. All pyridyl derivatives examined did not inhibit the reaction H2O → MV/O2. Ferritin and ferrocene were also ineffective as inhibitors of this reaction. Hemoglobin inhibited the reaction H2O → MV/O2 without inhibiting the reaction H2O → Fd/NADP+, providing protection to pea chloroplasts against paraquat. Hemin and hematin inhibited both Hill reactions examined. They also inhibited H2O → diaminodurene(DAD)ox and durohydro-quinone → MV/O2 Hill reactions but not the dichlorophenol indophenolred → MV/O2 and DADred → MV/O2 Hill reactions. These results suggest that hemin and hematin are inhibiting the photosynthetic electron transport in the plastoquinone-pool region.

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