Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - Periodicity and structural flexibility of the stroma lamellae

Dorthe Posselt, Gergely Nagy, Jacob J. K. Kirkensgaard, Jens Kai Holm, Thomas H Aagaard, Peter Timmins, Eszter Retfalvi, Laszlo Rosta, Laszlo Kovacs, Gyozo Garab

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The multilamellar organization of freshly isolated spinach and pea chloroplast thylakoid membranes was studied using small-angle neutron scattering. A broad peak at similar to 0.02 angstrom(-1) is ascribed to diffraction from domains of ordered, unappressed stroma lamellae, revealing a repeat distance of 294 angstrom +/- 7 angstrom in spinach and 345 angstrom +/- 11 angstrom in pea. The peak position and hence the repeat distance of stroma lamellae is strongly dependent on the osmolarity and the ionic strength of the suspension medium, as demonstrated by varying the sorbitol and the Mg++-concentration in the sample. For pea thylakoid membranes, we show that the repeat distance decreases when illuminating the sample with white light, in accordance with our earlier results on spinach, also regarding the observation that addition of an uncoupler prohibits the light-induced structural changes, a strong indication that these changes are driven by the transmembrane proton gradient. We show that the magnitude of the shrinkage is strongly dependent on light intensity and that the repeat distance characteristic of the dark state after illumination is different from the initial dark state. Prolonged strong illumination leads to irreversible changes and swelling as reflected in increased repeat distances. The observed reorganizations are discussed within the frames of the current structural models of the granum-stroma thylakoid membrane assembly and the regulatory mechanisms in response to variations in the environmental conditions in vivo.
OriginalsprogEngelsk
TidsskriftB B A - Bioenergetics
Vol/bind1817
Udgave nummer8
Sider (fra-til)1220-1228
ISSN0005-2728
DOI
StatusUdgivet - 2012

Citer dette

Posselt, Dorthe ; Nagy, Gergely ; Kirkensgaard, Jacob J. K. ; Holm, Jens Kai ; Aagaard, Thomas H ; Timmins, Peter ; Retfalvi, Eszter ; Rosta, Laszlo ; Kovacs, Laszlo ; Garab, Gyozo. / Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - Periodicity and structural flexibility of the stroma lamellae. I: B B A - Bioenergetics. 2012 ; Bind 1817, Nr. 8. s. 1220-1228.
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title = "Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - Periodicity and structural flexibility of the stroma lamellae",
abstract = "The multilamellar organization of freshly isolated spinach and pea chloroplast thylakoid membranes was studied using small-angle neutron scattering. A broad peak at similar to 0.02 angstrom(-1) is ascribed to diffraction from domains of ordered, unappressed stroma lamellae, revealing a repeat distance of 294 angstrom +/- 7 angstrom in spinach and 345 angstrom +/- 11 angstrom in pea. The peak position and hence the repeat distance of stroma lamellae is strongly dependent on the osmolarity and the ionic strength of the suspension medium, as demonstrated by varying the sorbitol and the Mg++-concentration in the sample. For pea thylakoid membranes, we show that the repeat distance decreases when illuminating the sample with white light, in accordance with our earlier results on spinach, also regarding the observation that addition of an uncoupler prohibits the light-induced structural changes, a strong indication that these changes are driven by the transmembrane proton gradient. We show that the magnitude of the shrinkage is strongly dependent on light intensity and that the repeat distance characteristic of the dark state after illumination is different from the initial dark state. Prolonged strong illumination leads to irreversible changes and swelling as reflected in increased repeat distances. The observed reorganizations are discussed within the frames of the current structural models of the granum-stroma thylakoid membrane assembly and the regulatory mechanisms in response to variations in the environmental conditions in vivo.",
author = "Dorthe Posselt and Gergely Nagy and Kirkensgaard, {Jacob J. K.} and Holm, {Jens Kai} and Aagaard, {Thomas H} and Peter Timmins and Eszter Retfalvi and Laszlo Rosta and Laszlo Kovacs and Gyozo Garab",
year = "2012",
doi = "10.1016/j.bbabio.2012.01.012",
language = "English",
volume = "1817",
pages = "1220--1228",
journal = "B B A - Bioenergetics",
issn = "0005-2728",
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Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - Periodicity and structural flexibility of the stroma lamellae. / Posselt, Dorthe; Nagy, Gergely; Kirkensgaard, Jacob J. K.; Holm, Jens Kai; Aagaard, Thomas H; Timmins, Peter; Retfalvi, Eszter; Rosta, Laszlo; Kovacs, Laszlo ; Garab, Gyozo.

I: B B A - Bioenergetics, Bind 1817, Nr. 8, 2012, s. 1220-1228.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - Periodicity and structural flexibility of the stroma lamellae

AU - Posselt, Dorthe

AU - Nagy, Gergely

AU - Kirkensgaard, Jacob J. K.

AU - Holm, Jens Kai

AU - Aagaard, Thomas H

AU - Timmins, Peter

AU - Retfalvi, Eszter

AU - Rosta, Laszlo

AU - Kovacs, Laszlo

AU - Garab, Gyozo

PY - 2012

Y1 - 2012

N2 - The multilamellar organization of freshly isolated spinach and pea chloroplast thylakoid membranes was studied using small-angle neutron scattering. A broad peak at similar to 0.02 angstrom(-1) is ascribed to diffraction from domains of ordered, unappressed stroma lamellae, revealing a repeat distance of 294 angstrom +/- 7 angstrom in spinach and 345 angstrom +/- 11 angstrom in pea. The peak position and hence the repeat distance of stroma lamellae is strongly dependent on the osmolarity and the ionic strength of the suspension medium, as demonstrated by varying the sorbitol and the Mg++-concentration in the sample. For pea thylakoid membranes, we show that the repeat distance decreases when illuminating the sample with white light, in accordance with our earlier results on spinach, also regarding the observation that addition of an uncoupler prohibits the light-induced structural changes, a strong indication that these changes are driven by the transmembrane proton gradient. We show that the magnitude of the shrinkage is strongly dependent on light intensity and that the repeat distance characteristic of the dark state after illumination is different from the initial dark state. Prolonged strong illumination leads to irreversible changes and swelling as reflected in increased repeat distances. The observed reorganizations are discussed within the frames of the current structural models of the granum-stroma thylakoid membrane assembly and the regulatory mechanisms in response to variations in the environmental conditions in vivo.

AB - The multilamellar organization of freshly isolated spinach and pea chloroplast thylakoid membranes was studied using small-angle neutron scattering. A broad peak at similar to 0.02 angstrom(-1) is ascribed to diffraction from domains of ordered, unappressed stroma lamellae, revealing a repeat distance of 294 angstrom +/- 7 angstrom in spinach and 345 angstrom +/- 11 angstrom in pea. The peak position and hence the repeat distance of stroma lamellae is strongly dependent on the osmolarity and the ionic strength of the suspension medium, as demonstrated by varying the sorbitol and the Mg++-concentration in the sample. For pea thylakoid membranes, we show that the repeat distance decreases when illuminating the sample with white light, in accordance with our earlier results on spinach, also regarding the observation that addition of an uncoupler prohibits the light-induced structural changes, a strong indication that these changes are driven by the transmembrane proton gradient. We show that the magnitude of the shrinkage is strongly dependent on light intensity and that the repeat distance characteristic of the dark state after illumination is different from the initial dark state. Prolonged strong illumination leads to irreversible changes and swelling as reflected in increased repeat distances. The observed reorganizations are discussed within the frames of the current structural models of the granum-stroma thylakoid membrane assembly and the regulatory mechanisms in response to variations in the environmental conditions in vivo.

U2 - 10.1016/j.bbabio.2012.01.012

DO - 10.1016/j.bbabio.2012.01.012

M3 - Journal article

VL - 1817

SP - 1220

EP - 1228

JO - B B A - Bioenergetics

JF - B B A - Bioenergetics

SN - 0005-2728

IS - 8

ER -