Aggregation of light-harvesting complex II leads to formation of efficient excitation energy traps in monomeric and trimeric complexes.
Non-photochemical quenching (NPQ) protects plants against photodamage by converting excess excitation energy into harmless heat. In vitro aggregation of the major light-harvesting complex (LHCII) induces similar quenching, the molecular mechanism of which is frequently considered to be the same. However, a very basic question regarding the aggregation-induced quenching has not been answered yet. Are excitation traps created upon aggregation, or do existing traps start quenching excitations more efficiently in aggregated LHCII where trimers are energetically coupled? Time-resolved fluorescence experiments presented here demonstrate that aggregation creates traps in a significant number of LHCII trimers, which subsequently also quench excitations in connected LHCIIs.
van Oort
Bart
B
Laboratory of Biophysics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands. bart.vanoort@wur.nl
van Hoek
Arie
A
Ruban
Alexander V
AV
van Amerongen
Herbert
H
D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D011485:Protein Binding; D013053:Spectrophotometry; D018724:Spinacia oleracea / Q000201:enzymology
D045342:Light-Harvesting Protein Complexes