Lipid polymorphism in chloroplast thylakoid membranes - as revealed by 31P-NMR and time-resolved merocyanine fluorescence spectroscopy
Chloroplast thylakoid membranes contain virtually all components of the energy-converting photosynthetic machinery. Their energized state, driving ATP synthesis, is enabled by the bilayer organization of the membrane. However, their most abundant lipid species is a non-bilayer-forming lipid, monogalactosyl-diacylglycerol; the role of lipid polymorphism in these membranes is poorly understood. Earlier 31P-NMR experiments revealed the coexistence of a bilayer and a non-bilayer, isotropic lipid phase in spinach thylakoids. Packing of lipid molecules, tested by fluorescence spectroscopy of the lipophilic dye, merocyanine-540 (MC540), also displayed heterogeneity. Now, our 31P-NMR experiments on spinach thylakoids uncover the presence of a bilayer and three non-bilayer lipid phases; time-resolved fluorescence spectroscopy of MC540 also reveals the presence of multiple lipidic environments. It is also shown by 31P-NMR that: (i) some lipid phases are sensitive to the osmolarity and ionic strength of the medium, (ii) a lipid phase can be modulated by catalytic hydrogenation of fatty acids and (iii) a marked increase of one of the non-bilayer phases upon lowering the pH of the medium is observed. These data provide additional experimental evidence for the polymorphism of lipid phases in thylakoids and suggest that non-bilayer phases play an active role in the structural dynamics of thylakoid membranes.
Main Authors: | Garab, Gyozo, Ughy, Bettina, De Waard, Pieter, Akhtar, Parveen, Javornik, Uroš, Kotakis, Christos, Šket, Primož, Karlický, Václav, Materová, Zuzana, Špunda, Vladimír, Plavec, Janez, Van Amerongen, Herbert, Vígh, László, van As, Henk, Lambrev, Petar H. |
---|---|
Format: | Article/Letter to editor biblioteca |
Language: | English |
Subjects: | Life Science, |
Online Access: | https://research.wur.nl/en/publications/lipid-polymorphism-in-chloroplast-thylakoid-membranes-as-revealed |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Similar Items
-
Temperature dependence of the lipid packing in thylakoid membranes studied by time- and spectrally resolved fluorescence of Merocyanine 540
by: Krumova, S.K.B., et al. -
Phase behavior of phosphatidylglycerol in spinach thylakoid membranes as revealed by 31P-NMR
by: Krumova, S.K.B., et al. -
Fingerprinting the macro-organisation of pigment-protein complexes in plant thylakoid membranes in vivo by circular-dichroism spectroscopy
by: Tóth, Tünde N., et al. -
Digalactosyl-diacylglycerol-deficiency lowers the thermal stability of thylakoid membranes
by: Krumova, S.K.B., et al. -
The effect of annulation upon the solvatochromic behaviour of related merocyanines
by: Rezende,Marcos Caroli
Published: (1997)