Flash-Induced pH Changes in Photosystem I-Enriched Vesicles Monitored with Neutral Red and Cresol Red

1984 ◽  
pp. 321-324
Author(s):  
Frits A. De Wolf ◽  
Leo P. A. Van Houte ◽  
Fons A. L. J. Peters ◽  
Ruud Kraayenhof
Keyword(s):  
Photosystem I ◽  
Neutral Red ◽  
Ph Changes ◽  
Cresol Red

Protolytic Reactions in Photosystem II: a New Model for the Release of Protons Accompanying the Photooxidation of Water

1977 ◽  
Vol 32 (7-8) ◽  
pp. 617-626 ◽  
Author(s):  
Satham Saphon ◽  
Antony R. Crofts
Keyword(s):  
Electron Acceptor ◽  
Neutral Red ◽  
Glass Electrode ◽  
Ph Indicator ◽  
Ph Change ◽  
Benzyl Viologen ◽  
Ph Changes ◽  
The Third ◽  
Cresol Red ◽  
Indicator Dye

Using pH indicator dye techniques we have investigated the pH changes in dark-adapted chloro- plasts following excitation by short flashes. Two types of pH indicator, cresol red and neutral red, were used, to follow the pH changes either inside or outside the thylakoids, or the net change when the membrane was made permeable to protons by uncoupling agents. (1)With cresol red which showed the net pH changes inside and outside the thylakoids, an oscillation of the flash yield of H+ occurred with a periodicity of 4 (minima on the first and fifth flashes, the yield on the third being not significantly different from the yields on the second and fourth flashes). The pH changes did not occur in synchrony with O2-evolution. (2)The net flash yields without addition of electron acceptor were similar to those with benzyl- viologen. The results were comparable with those obtained with the glass electrode technique by Fowler and Kok (C. F. Fowler and B. Kok, Biochim. Biophys. Acta 357, 299 - 307 [1974]). (3)The net flash yields with ferricyanide as electron acceptor of photosystem I were higher than those in the absence of acceptor, or with benzylviologen. On the first and fifth flashes a net acidification was always observed. (4)In the presence of 3- (3,4-dichlorphenyl) -1,1-dimethylurea (DCMU) a rapid acidification also occured on the first flash, while the pH changes induced by subsequent flashes were inhibited. (5)The uncoupler methylamine did not inhibit the proton uptake outside the thylakoids. (6)With neutral red as indicator for the net pH change inside and outside the thylakoids, the same oscillation of the flash yield occured as with cresol red. (7)With neutral red in the precense of an external buffer, as a pH indicator for the internal aqueous phase alone, an oscillation of the flash yield with a periodicity of 4 also occured. The first and second flash yields were higher compared with the third than the equivalent yields of oxygen. (8)We discuss the results with respect to a model for the release of protons in the water- splitting enzyme reactions, in which protons are not released in synchrony with O2 , but in the transitions of all the states of the watersplitting enzyme with the exception of S1 → S2 . Our results are consistent with this model when account is taken of the release of protons inside the thylakoids with a periodicity of 2, associated with electron transfer from reduced plastoquinone.

Antisera to the Coupling Factor of Photophosphorylation and Its Subunits

1978 ◽  
Vol 33 (7-8) ◽  
pp. 529-536 ◽  
Author(s):  
Friederike Koenig ◽  
Alfons Radunz ◽  
Georg H. Schmid ◽  
Wilhelm Menke
Keyword(s):  
Electron Transport ◽  
Photosystem I ◽  
Fluorescence Yield ◽  
Coupling Factor ◽  
Proton Channel ◽  
Α Subunit ◽  
Ph Changes ◽  
Γ Subunit ◽  
Suspension Medium ◽  
Dosis Effect

Abstract Stroma-freed chloroplasts were extracted with sucrose palmitate-stearate containing buffer. After the addition of dodecyl sulfate and mercaptoethanol to the extract a series of polypeptides was isolated from the mixture by gel filtration. These polypeptides were later used for immunization. Antisera to four polypeptides reacted in the Ouchterlony double diffusion test with authentic coupling factor yielding a precipitation band. According to the observed apparent molecular weights the polypeptides are the α, β , δ and ε subunits of the coupling factor. An antiserum to the γ subunit has been obtained already previously. All antisera inhibit photophosphorylation reactions and electron transport considerably. Addition of gramicidin inhibits photophosphorylation completely whereas gramicidin restores electron transport in the assays with the antisera to the α, β , γ and δ subunit. In the case of the antiserum to the ε subunit gramicidin does not regenerate electron transport. As in the presence of the serum to the ε subunit pH changes in the suspension medium are not observed, this serum seems to open a proton channel. Also, upon addition of dicyclohexyl carbodiimide (DCCD) pH changes in the suspension medium in the assay with antiserum do not reoccur. According to these unexpected results the identity of the antigen with the ε subunit of the coupling factor is not certain. ATP-ase reactions are only inhibited by the antisera to the α and γ subunit and what is thought to be the ε subunit. The antiserum to the α subunit uncouples electron transport as the only one when used in sufficient concentrations. The dosis-effect curves of the inhibition of the electron transport exhibits a maximum. The dosis-effect curves for the other components rise after a lag phase in an approximately hyperbolic manner. The inhibitory action on electron transport is exerted by all antisera in the region of the reaction center I or in its immediate vicinity. This is thought to be due to the fact that a protein of the reation center I is inhibited in its function by the increasing proton concentration inside the thylakoid. The inhibition of electron transport by the antiserum to the ε subunit is considered to be a direct serum effect. Besides the increase in fluorescence yield, due to the inhibition of electron transport in the region of photosystem I, decreases of the fluorescence yield are observed in the presence of DCMU, which do not depend on the redox state of Q but rather on the condition of the thylakoid mem­brane. Moreover, the antisera affect in a differing manner the energy spill-over of excitation from photosystem II to photosystem I.

scholarly journals Neutral red, a rapid indicator for pH-changes in the inner phase of thylakoids

FEBS Letters ◽  
1975 ◽  
Vol 59 (2) ◽  
pp. 310-315 ◽  
Author(s):  
Winfried Ausländer ◽  
Wolfgang Junge
Keyword(s):  
Neutral Red ◽  
Ph Changes

Studies on well-coupled Photosystem I-enriched subchloroplast vesicles. Neutral red as a probe for external surface charge rather than internal protonation

1985 ◽  
Vol 809 (2) ◽  
pp. 204-214 ◽  
Author(s):  
Frits A. de Wolf ◽  
Brenda H. Groen ◽  
Leo P.A. van Houte ◽  
Fons A.L.J. Peters ◽  
Klaas Krab ◽  
...  
Keyword(s):  
Surface Charge ◽  
Photosystem I ◽  
External Surface ◽  
Neutral Red

Proton Translocations in Isolated Spinach Chloroplasts after Single-turnover Actinic Flashes

1979 ◽  
Vol 6 (3) ◽  
pp. 289
Author(s):  
A.B Hope ◽  
A Morland
Keyword(s):  
Steady State ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Neutral Red ◽  
Plastoquinone Pool ◽  
Single Turnover ◽  
Transport Chain ◽  
Initial Reduction ◽  
Proton Uptake ◽  
Cresol Red

Proton movements were monitored with cresol red and neutral red. Absorbance changes of these dyes following actinic flashes were measured both for the steady state and for sequences of 6-9 flashes given to separate dark-adapted suspensions of chloroplasts. The cresol red changes corresponded to a steady-state proton uptake (�H*+ss) of 0.0015-0.0017 mol H+/mol Chl per flash (ferricyanide as electron acceptor) or 0.0031 mol H+/mol Chl per flash (methyl viologen). Assuming 600 Chl per electron transport chain, these uptakes corresponded to H+/e- = 1 or 2 respectively. In flash sequences with ferricyanide, a minimum of about 0.6 �H*+ss was noted after flash No. 3. Controls, and considerations of the partitioning of unprotonated neutral red into the thylakoid membrane phase, strongly indicated that neutral red was responding to an acidification of the intrathylakoid aqueous phase. The steady-state signal was interpreted as 2 H+ deposited per electron transport chain per flash (H+/e- = 2), one proton from the oxidation of water and one from the oxidation of plastoquinone. Patterns of proton deposition following sequences of flashes and their change upon adding dibromothymoquinone suggested that (a) protons are produced one at a time in the advance of the 'S-states' (Z*n+ � Z(n+1)+ ); and (b) the precursor to the plastoquinone pool, B, is a special plastoquinone, requiring 1 e- and 1 H+ for its initial reduction but passing on to the plastoquinone pool 2 e- upon the next flash. The proton deposition on flash No. 1 corresponded to a small proportion of reduced B in dark-adapted chloroplasts, as previously postulated.

Transfer of Neutral Red into the Stomach

1958 ◽  
Vol 35 (4) ◽  
pp. 357-368 ◽  
Author(s):  
V. Varró ◽  
T. Jávor
Keyword(s):  
Neutral Red

Photosystem I polypeptides

1990 ◽  
Vol 78 (3) ◽  
pp. 484-494 ◽  
Author(s):  
Henrik Vibe Scheller ◽  
Birger Lindberg Moller
Keyword(s):  
Photosystem I

Activation of the non-electrochromic component in the 518 nm absorbance change by photosystem I

1991 ◽  
Vol 82 (4) ◽  
pp. 569-574
Author(s):  
Jaap J. J. Ooms ◽  
Wilma Versluis ◽  
Wim J. Vredenberg
Keyword(s):  
Photosystem I ◽  
Absorbance Change

Identification of a single-copy gene encoding a Type I chlorophyll a/b-binding polypeptide of photosystem I in Arabidopsis thaliana

1992 ◽  
Vol 84 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Poul E. Jensen ◽  
Michael Kristensen ◽  
Tine Hoff ◽  
Jan Lehmbeck ◽  
Bjarne M. Stummann ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Chlorophyll A ◽  
Photosystem I ◽  
Single Copy ◽  
Type I ◽  
Single Copy Gene ◽  
Gene Encoding ◽  
Copy Gene
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