Issledovanie élektronnogo transporta v fotosinteticheskikh sistemakh metodom élektronnogo paramagnitnogo rezonansa. X. Vliianie ionov magniia na strukturnoe sostoianie tilakoidonǐ membrany i kinetiku élektronnogo transporta mezhdu dvumia fotosistemami v khloroplastakh bobob.

Translated title of the contribution: Electron paramagnetic study of electron transport in photosynthetic systems. X. Effect of magnesium ions on the structural state of thylakoid membranes and the kinetics of electron transport between the two photosystems in bean chloroplasts

A. N. Tikhonov, G. B. Khomutov, E. K. Ruuge

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The effect of Mg2+-ions on the physical state of thylakoid membrane and kinetics of electron transport between two photosystems were studied. The rate of electron transport from photosystem 2 to P700+ and the activity of photosystem 2 were obtained from the kinetics of P700 redox transients induced by flashes of white light (t1/2 = 7 musec or 0.75 msec) fired simultaneously with the background continuous far-red light (707 nm). The spin-labeled stearic acids (I1.14 and I12.3) were used as indicators of Mg2+-induced structural changes. Addition of MgCl2 stimulates incorporation of spin-labels into the lipid region of the thylakoid membrane. It was found that Mg2+-ions modify the ESR spectrum of I12.3. The results evidence that the screening of charged groups on the thylakoid membrane surface induces structural changes in the lipid region of the membrane. We have concluded that these structural changes result in reorientation of lipid molecules in the thylakoid membrane. There is a correlation between Mg2+-induced structural changes and electron transport in chloroplasts. Addition of Mg2+-ions stimulates the photochemical activity of photosystem 2 by increasing the amount of active reaction centres and modifies the rate constant of electron transport from photosystem 2 to P700+. It has been demonstrated that ion regulation of electron transport in more effective in the oxidising side than in the reducing side of plastoquinone shuttle.

Original languageRussian
Pages (from-to)1065-1069
Number of pages5
JournalMolekulyarnaya Biologiya
Volume14
Issue number5
Publication statusPublished - Sep 1980
Externally publishedYes

Fingerprint

Thylakoids
Chloroplasts
Electron Transport
Magnesium
Electrons
Ions
Plastoquinone
Stearic Acids
Lipids
Spin Labels
Light
Magnesium Chloride
Membrane Lipids
Oxidation-Reduction

ASJC Scopus subject areas

  • Molecular Biology

Cite this

@article{3941d64836b546ffb666b4cf41766fe9,
title = "Issledovanie {\'e}lektronnogo transporta v fotosinteticheskikh sistemakh metodom {\'e}lektronnogo paramagnitnogo rezonansa. X. Vliianie ionov magniia na strukturnoe sostoianie tilakoidonǐ membrany i kinetiku {\'e}lektronnogo transporta mezhdu dvumia fotosistemami v khloroplastakh bobob.",
abstract = "The effect of Mg2+-ions on the physical state of thylakoid membrane and kinetics of electron transport between two photosystems were studied. The rate of electron transport from photosystem 2 to P700+ and the activity of photosystem 2 were obtained from the kinetics of P700 redox transients induced by flashes of white light (t1/2 = 7 musec or 0.75 msec) fired simultaneously with the background continuous far-red light (707 nm). The spin-labeled stearic acids (I1.14 and I12.3) were used as indicators of Mg2+-induced structural changes. Addition of MgCl2 stimulates incorporation of spin-labels into the lipid region of the thylakoid membrane. It was found that Mg2+-ions modify the ESR spectrum of I12.3. The results evidence that the screening of charged groups on the thylakoid membrane surface induces structural changes in the lipid region of the membrane. We have concluded that these structural changes result in reorientation of lipid molecules in the thylakoid membrane. There is a correlation between Mg2+-induced structural changes and electron transport in chloroplasts. Addition of Mg2+-ions stimulates the photochemical activity of photosystem 2 by increasing the amount of active reaction centres and modifies the rate constant of electron transport from photosystem 2 to P700+. It has been demonstrated that ion regulation of electron transport in more effective in the oxidising side than in the reducing side of plastoquinone shuttle.",
author = "Tikhonov, {A. N.} and Khomutov, {G. B.} and Ruuge, {E. K.}",
year = "1980",
month = "9",
language = "Russian",
volume = "14",
pages = "1065--1069",
journal = "Molekulyarnaya Biologiya",
issn = "0026-8984",
publisher = "Russian Academy of Sciences",
number = "5",

}

TY - JOUR

T1 - Issledovanie élektronnogo transporta v fotosinteticheskikh sistemakh metodom élektronnogo paramagnitnogo rezonansa. X. Vliianie ionov magniia na strukturnoe sostoianie tilakoidonǐ membrany i kinetiku élektronnogo transporta mezhdu dvumia fotosistemami v khloroplastakh bobob.

AU - Tikhonov, A. N.

AU - Khomutov, G. B.

AU - Ruuge, E. K.

PY - 1980/9

Y1 - 1980/9

N2 - The effect of Mg2+-ions on the physical state of thylakoid membrane and kinetics of electron transport between two photosystems were studied. The rate of electron transport from photosystem 2 to P700+ and the activity of photosystem 2 were obtained from the kinetics of P700 redox transients induced by flashes of white light (t1/2 = 7 musec or 0.75 msec) fired simultaneously with the background continuous far-red light (707 nm). The spin-labeled stearic acids (I1.14 and I12.3) were used as indicators of Mg2+-induced structural changes. Addition of MgCl2 stimulates incorporation of spin-labels into the lipid region of the thylakoid membrane. It was found that Mg2+-ions modify the ESR spectrum of I12.3. The results evidence that the screening of charged groups on the thylakoid membrane surface induces structural changes in the lipid region of the membrane. We have concluded that these structural changes result in reorientation of lipid molecules in the thylakoid membrane. There is a correlation between Mg2+-induced structural changes and electron transport in chloroplasts. Addition of Mg2+-ions stimulates the photochemical activity of photosystem 2 by increasing the amount of active reaction centres and modifies the rate constant of electron transport from photosystem 2 to P700+. It has been demonstrated that ion regulation of electron transport in more effective in the oxidising side than in the reducing side of plastoquinone shuttle.

AB - The effect of Mg2+-ions on the physical state of thylakoid membrane and kinetics of electron transport between two photosystems were studied. The rate of electron transport from photosystem 2 to P700+ and the activity of photosystem 2 were obtained from the kinetics of P700 redox transients induced by flashes of white light (t1/2 = 7 musec or 0.75 msec) fired simultaneously with the background continuous far-red light (707 nm). The spin-labeled stearic acids (I1.14 and I12.3) were used as indicators of Mg2+-induced structural changes. Addition of MgCl2 stimulates incorporation of spin-labels into the lipid region of the thylakoid membrane. It was found that Mg2+-ions modify the ESR spectrum of I12.3. The results evidence that the screening of charged groups on the thylakoid membrane surface induces structural changes in the lipid region of the membrane. We have concluded that these structural changes result in reorientation of lipid molecules in the thylakoid membrane. There is a correlation between Mg2+-induced structural changes and electron transport in chloroplasts. Addition of Mg2+-ions stimulates the photochemical activity of photosystem 2 by increasing the amount of active reaction centres and modifies the rate constant of electron transport from photosystem 2 to P700+. It has been demonstrated that ion regulation of electron transport in more effective in the oxidising side than in the reducing side of plastoquinone shuttle.

UR - http://www.scopus.com/inward/record.url?scp=0019056406&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019056406&partnerID=8YFLogxK

M3 - Article

C2 - 6252448

AN - SCOPUS:0019056406

VL - 14

SP - 1065

EP - 1069

JO - Molekulyarnaya Biologiya

JF - Molekulyarnaya Biologiya

SN - 0026-8984

IS - 5

ER -