Energetic and regulatory role of proton potential in chloroplasts

Research output: Contribution to journalArticle

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Abstract

The review focuses on the energetic and regulatory role of proton potential in the activity of chloroplasts, the light energy-converting organelles of plant cells. Mechanisms of generation of the transmembrane difference of electrochemical potentials of hydrogen ions (δμH+) in the chloroplast thylakoid membranes are considered. Methods for measuring the intrathylakoid pH in chloroplasts are described. It is shown that under conditions of phosphorylation in chloroplasts, the pH of the intrathylakoid space decreases moderately (pHin > 6.0-6.2, at the stroma pHout ≈ 7.8-8.0), with a corresponding concentration component of δμH + equal to δpH ≤ 1.6-2.0. On analyzing the energy and structural features of ATP synthase of chloroplasts, we conclude that the energy stored as the concentration component of the proton potential ?pH is sufficient to sustain ATP synthesis. The mechanisms of pH-dependent regulation of electron transport in chloroplasts (photo-synthetic control of electron transport, enhancement of non-photochemical quenching of chlorophyll excitation in the light-harvesting antenna, light-induced activation of the Calvin-Benson cycle reactions, activation of ATP synthase) are considered briefly.

Original languageEnglish
Pages (from-to)956-974
Number of pages19
JournalBiochemistry (Moscow)
Volume77
Issue number9
DOIs
Publication statusPublished - Sep 2012
Externally publishedYes

Fingerprint

Chloroplasts
Protons
Adenosine Triphosphate
Chloroplast Proton-Translocating ATPases
Chemical activation
Electron Transport
Phosphorylation
Light
Chlorophyll
Quenching
Thylakoids
Antennas
Membranes
Photosynthesis
Plant Cells
Organelles
Membrane Potentials

Keywords

  • Bioenergetics
  • Chloroplasts
  • Proton potential
  • Regulation of photosynthesis

ASJC Scopus subject areas

  • Biochemistry
  • Medicine(all)

Cite this

Energetic and regulatory role of proton potential in chloroplasts. / Tikhonov, A. N.

In: Biochemistry (Moscow), Vol. 77, No. 9, 09.2012, p. 956-974.

Research output: Contribution to journalArticle

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