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 language | English |
|---|---|
| Pages (from-to) | 956-974 |
| Number of pages | 19 |
| Journal | Biochemistry (Moscow) |
| Volume | 77 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Sep 2012 |
| Externally published | Yes |
Fingerprint
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 journal › Article
}
TY - JOUR
T1 - Energetic and regulatory role of proton potential in chloroplasts
AU - Tikhonov, A. N.
PY - 2012/9
Y1 - 2012/9
N2 - 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.
AB - 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.
KW - Bioenergetics
KW - Chloroplasts
KW - Proton potential
KW - Regulation of photosynthesis
UR - http://www.scopus.com/inward/record.url?scp=84866605414&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84866605414&partnerID=8YFLogxK
U2 - 10.1134/S0006297912090027
DO - 10.1134/S0006297912090027
M3 - Article
VL - 77
SP - 956
EP - 974
JO - Biochemistry. Biokhimiia
JF - Biochemistry. Biokhimiia
SN - 0006-2979
IS - 9
ER -