Resonance Raman spectroscopy of the photosystem II light-harvesting complex of green plants: a comparison of trimeric and aggregated states.
Resonance Raman spectroscopy was performed on photosystem II light-harvesting complex (LHCII) in trimeric and oligomeric states with various excitation conditions. From these studies, it can be concluded that the structure of LHCII is altered during the trimer/oligomer transition. These structural changes affect the conformation of a population of carotenoid within the complex, which becomes twisted in the oligomeric form. Moreover, the interactions assumed by a chlorophyll a and a chlorophyll b are modified during the oligomerization process. This induces the formation of an H-bond to a formyl group of a chlorophyll b molecule and to a keto group of a chlorophyll a molecule. The extent to which these H-bonds to chlorophyll relate to the formation of the quencher cannot yet be precisely established. However, the structural changes they evidence may play a role in the control of the energy flux by LHCII complexes.
Robert Hill Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, U.K.
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Ruban
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Horton
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Robert
D002338:Carotenoids / Q000737:chemistry; D002734:Chlorophyll / Q000737:chemistry; D000077194:Chlorophyll A; D006860:Hydrogen Bonding; D066298:In Vitro Techniques; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D045332:Photosystem II Protein Complex; D013059:Spectrum Analysis, Raman; D018724:Spinacia oleracea
D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D002338:Carotenoids; C037184:chlorophyll b; D000077194:Chlorophyll A