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Dependence of chlorophyll fluorescence quenching on the lipid-to-protein ratio in reconstituted light-harvesting complex II membranes containing lipid labels

DOI: 10.1016/j.chemphys.2019.03.012 DOI Help

Authors: Parveen Akhtar (Hungarian Academy of Sciences) , Fanni Görföl (Hungarian Academy of Sciences) , Gyozo Garab (Hungarian Academy of Sciences; University of Ostrava) , Petar H. Lambrev (Hungarian Academy of Sciences)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemical Physics

State: Published (Approved)
Published: March 2019
Diamond Proposal Number(s): 19120

Abstract: The quenching of chlorophyll-a fluorescence was investigated in plant light-harvesting complex II (LHCII) embedded in reconstituted membranes containing thylakoid lipids and a lipid label. The proteoliposomes were further separated by density and the protein and lipid contents of the fractions were quantified spectrophotometrically, allowing tighter control over the L/P ratios in a wide range of values. Using time-resolved fluorescence, we found a strong correlation between the fluorescence quenching and the L/P ratio, in line with other studies reporting progressive quenching at low L/P ratios, presumably triggered by self-clustering in the membrane. The average fluorescence lifetimes decreased to 0.3 ns at L/P ratios below 50:1; these values are comparable to the quenching observed in plants under excess-light conditions and are accompanied by a similar far-red fluorescence signature. It is hypothesized that plants can exploit the intrinsic quenching propensity of LHCII-only membrane domains to safely store extra antenna units.

Journal Keywords: circular dichroism; non-photochemical quenching; protein-lipid interactions; proteoliposomes; time-resolved fluorescence; thylakoid lipids

Diamond Keywords: Photosynthesis

Subject Areas: Chemistry

Instruments: B23-Circular Dichroism

Added On: 21/03/2019 11:16

Discipline Tags:

Physical Chemistry Chemistry

Technical Tags:

Spectroscopy Circular Dichroism (CD)