title: Fluorescence blinking of the RC-LH1 complex from Rhodopseudomonas palustris.
abstract: We investigate fluorescence blinking of individual RC-LH1 (reaction-centre-light-harvesting 1) complexes from the photosynthetic purple bacterium Rhodopseudomonas palustris. For both the on- and off-periods the telegraph-like intermittency of the fluorescence intensity follows power-law statistics with exponents between 1 and 2. Yet, this behaviour was only observed for a small fraction of the complexes studied. We argue that the majority of the complexes reside in a prolonged on-state, due to a mechanism that is similar to the Coulomb blockade in semiconductor quantum dots, and which results here from the photoinduced charges located within the RC upon photoexcitation of the LH1 antenna.
authors.affiliation: Experimental Physics IV, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Unterkofler
authors.forename: Tobias
authors.initials: T
authors.lastname: Pflock
authors.forename: June
authors.initials: J
authors.lastname: Southall
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cogdell
authors.forename: Jürgen
authors.initials: J
authors.lastname: Köhler
mesh_terms: D018360:Crystallography, X-Ray; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D045663:Quantum Dots; D012241:Rhodopseudomonas / Q000201:enzymology*; D012666:Semiconductors; D013050:Spectrometry, Fluorescence
chemical_list: D045342:Light-Harvesting Protein Complexes