title: Red pool chlorophylls of photosystem I of the cyanobacterium Thermosynechococcus elongatus: a single-molecule study.
abstract: Photosystem I reaction centers of the cyanobacterium Thermosynechococcus elongatus have been investigated using single-molecule spectroscopy. Single-molecule fluorescence emission spectra reveal a new fluorescence band located at 745 nm. Fluorescence polarization spectroscopy and fluorescence autocorrelation analysis show that only a few chlorophylls are responsible for the photoemission from the Photosystem I trimer at low temperature. Intersystem crossing parameters of the red pool chlorophylls have been determined via fluorescence autocorrelation measurements. The triplet yield of the red chlorophylls is strongly reduced in comparison to chlorophyll a in solution. Strong quenching of the triplet state indicates that the red chlorophylls are located in close contact to carotenoids.
authors.affiliation: Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany. A.Elli@physik.uni-stuttgart.de
authors.forename: Alexandra F
authors.initials: AF
authors.lastname: Elli
authors.forename: Fedor
authors.initials: F
authors.lastname: Jelezko
authors.forename: Carsten
authors.initials: C
authors.lastname: Tietz
authors.forename: Hauke
authors.initials: H
authors.lastname: Studier
authors.forename: Marc
authors.initials: M
authors.lastname: Brecht
authors.forename: Robert
authors.initials: R
authors.lastname: Bittl
authors.forename: Jörg
authors.initials: J
authors.lastname: Wrachtrup
mesh_terms: D002734:Chlorophyll / Q000737:chemistry*; D000458:Cyanobacteria / Q000737:chemistry*; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013052:Spectrometry, X-Ray Emission / Q000379:methods; D013696:Temperature
chemical_list: D045331:Photosystem I Protein Complex; D002734:Chlorophyll