Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Thermal stability of trimeric light-harvesting chlorophyll a/b complex (LHCIIb) in liposomes of thylakoid lipids


Haase,  Winfried
Department of Structural Biology, Max Planck Institute of Biophysics, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Yang, C., Boggasch, S., Haase, W., & Paulsen, H. (2006). Thermal stability of trimeric light-harvesting chlorophyll a/b complex (LHCIIb) in liposomes of thylakoid lipids. Biochimica et Biophysica Acta, Bioenergetics, 1757, 1642-1648. doi:10.1016/j.bbabio.2006.08.010.

Cite as: https://hdl.handle.net/11858/00-001M-0000-0024-D98B-0
The major light-harvesting chlorophyll a/b complex (LHCIIb) of photosystem (PS) II functions by harvesting light energy and by limiting and balancing the energy flow directed towards the PSI and PSII reaction centers. The complex is predominantly trimeric; however, the monomeric form may play a role in one or several of the regulatory functions of LHCIIb. In this work the dissociation temperature was measured of trimeric LHCIIb isolated from Pisum thylakoids and inserted into liposomes made of various combinations of thylakoid lipids at various protein densities. Dissociation was measured by monitoring a trimer-specific circular dichroism signal in the visible range. The LHCIIb density in the membrane significantly affected the trimer dissociation temperature ranging from 70 degrees C at an LHCIIb concentration comparable to or higher than the one in thylakoid grana, to 65 degrees C at the density estimated in stromal lamellae. Omitting one thylakoid lipid from the liposomes had virtually no effect on the thermal trimer stability in most cases except when digalactosyl diacylglycerol (DGDG) was omitted which caused a drop in the apparent dissociation temperature by 2 degrees C. In liposomes containing only one lipid species, DGDG and, even more so, monogalactosyl diacylglycerol (MGDG) increased the thermal stability of LHCIIb trimers whereas phosphatidyl diacylglycerol (PG) significantly decreased it. The lateral pressure exerted by the non-bilayer lipid MGDG did not significantly influence LHCII trimer stability.