biostudies-literatureManna PU.S. Department of EnergyHuman Frontier Science ProgramBasic Energy SciencesChemical Sciences, Geosciences, and Biosciences Division3091-3102https://www.ebi.ac.uk/biostudies/studies/S-EPMC8390968biostudies-literatureUnknown120(15)In green plants, light harvesting complex of Photosystem II (LHCII) absorbs and transports excitation energy toward the photosynthetic reaction centers and serves as a site for energy-dependent nonphotochemical quenching (qE), the photoprotective dissipation of energy as heat. LHCII is thought to activate dissipation through conformational changes that change the photophysical behaviors. Understanding this balance requires a characterization of how the conformations of LHCII, and thus its photophysics, are influenced by individual factors within the membrane environment. Here, we used ensemble and single-molecule fluorescence to characterize the excited-state lifetimes and switching kinetics of LHCII embedded in nanodisc- and liposome-based model membranes of various sizes and lipid composBiophysical journalMembrane-dependent heterogeneity of LHCII characterized using single-molecule spectroscopy.PMC8390968RGY0076DE-SC0018097Johnson MPManna PHoffmann MSchlau-Cohen GSDavies TfalseMembrane-dependent heterogeneity of LHCII characterized using single-molecule spectroscopy.In green plants, light harvesting complex of Photosystem II (LHCII) absorbs and transports excitation energy toward the photosynthetic reaction centers and serves as a site for energy-dependent nonphotochemical quenching (qE), the photoprotective dissipation of energy as heat. LHCII is thought to activate dissipation through conformational changes that change the photophysical behaviors. Understanding this balance requires a characterization of how the conformations of LHCII, and thus its photophysics, are influenced by individual factors within the membrane environment. Here, we used ensemble and single-molecule fluorescence to characterize the excited-state lifetimes and switching kinetics of LHCII embedded in nanodisc- and liposome-based model membranes of various sizes and lipid compos2021-01-01T00:00:00Z2021 Aug2026-06-01T02:18:34.789Z2025-04-05T23:23:00.025ZS-EPMC83909683421452710.1016/j.bpj.2021.06.010