Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 7631-7637 |
| Number of pages | 7 |
| Journal | The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical |
| Volume | 111 |
| Issue number | 26 |
| DOIs | |
| Publication status | Published - 2007 |
Fingerprint
Keywords
- nonphotochemical energy-dissipation
- chlorophyll-protein complex
- photosystem-ii
- green plants
- chloroplast membranes
- excitation dynamics
- antenna complex
- molecular-basis
- lhcii
- absorption
Cite this
}
Equilibrium between quenched and nonquenched conformations of the major plant light-harvesting complex studied with high-pressure time-resolved fluorescence. / van Oort, B.F.; van Hoek, A.; Ruban, A.V.; van Amerongen, H.
In: The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical, Vol. 111, No. 26, 2007, p. 7631-7637.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Equilibrium between quenched and nonquenched conformations of the major plant light-harvesting complex studied with high-pressure time-resolved fluorescence
AU - van Oort, B.F.
AU - van Hoek, A.
AU - Ruban, A.V.
AU - van Amerongen, H.
PY - 2007
Y1 - 2007
N2 - Nonphotochemical quenching (NPQ) of chlorophyll fluorescence plays an important role in the protection of plants against excessive light. Fluorescence quenching of the major light-harvesting complex (LHCII) provides a model system to study the mechanism of NPQ. The existence of both quenched and nonquenched states of LHCII has been postulated. We used time-resolved fluorescence and hydrostatic pressure to study differences between these states. Pressure shifts the thermodynamic equilibrium between the two states. The estimated volume difference was 5 mL/mol, indicating a local conformational switch. The estimated free energy difference was 7.0 kJ/mol: high enough to keep the quenched state population low under normal conditions, but low enough to switch in a controlled way. These properties are physiologically relevant properties, because they guarantee efficient light harvesting, while at the same time maintaining the capacity to switch to a quenched state. These results indicate that conformational changes of LHCII can play an important role in NPQ.
AB - Nonphotochemical quenching (NPQ) of chlorophyll fluorescence plays an important role in the protection of plants against excessive light. Fluorescence quenching of the major light-harvesting complex (LHCII) provides a model system to study the mechanism of NPQ. The existence of both quenched and nonquenched states of LHCII has been postulated. We used time-resolved fluorescence and hydrostatic pressure to study differences between these states. Pressure shifts the thermodynamic equilibrium between the two states. The estimated volume difference was 5 mL/mol, indicating a local conformational switch. The estimated free energy difference was 7.0 kJ/mol: high enough to keep the quenched state population low under normal conditions, but low enough to switch in a controlled way. These properties are physiologically relevant properties, because they guarantee efficient light harvesting, while at the same time maintaining the capacity to switch to a quenched state. These results indicate that conformational changes of LHCII can play an important role in NPQ.
KW - nonphotochemical energy-dissipation
KW - chlorophyll-protein complex
KW - photosystem-ii
KW - green plants
KW - chloroplast membranes
KW - excitation dynamics
KW - antenna complex
KW - molecular-basis
KW - lhcii
KW - absorption
U2 - 10.1021/jp070573z
DO - 10.1021/jp070573z
M3 - Article
VL - 111
SP - 7631
EP - 7637
JO - The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical
JF - The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical
SN - 1520-6106
IS - 26
ER -