Photophysics in single light-harvesting complexes II: from micelle to native nanodisks

摘要: Most photosynthetic pigment-protein complexes of algae and higher plants are integral membrane proteins thus usually isolated in the presence detergent to provide a hydrophobic interface prevent aggregation. It was recently shown that styrene maleic acid (SMA) copolymer can be used instead solubilize isolate protein with their native lipid environment into nanodisk particles. We LHCII SMA compared photophysics trimeric β-DM micelles understand effect on function light-harvesting antennae. The triplet state kinetics calculated relative absorption cross section single indicate successful isolation nanodisks, confirming structure as likely configuration. survival time before they photobleach is increased which might explained by stabilizing co-purified lipids nanodisks. furthermore find an unquenched fluorescence lifetime 3.5 ns for nanodisks coincides notably differs from 2 typically found thylakoid structures. A large dynamic range partially quenched both demonstrated correlating intensity reflects conformational freedom these complexes. This further supports hypothesis intermittency intrinsic property may involved excess energy dissipation light-harvesting.