Red pool chlorophylls of photosystem I of the cyanobacterium Thermosynechococcus elongatus: a single-molecule study.
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.
Elli
Alexandra F
AF
Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany. A.Elli@physik.uni-stuttgart.de
Jelezko
Fedor
F
Tietz
Carsten
C
Studier
Hauke
H
Brecht
Marc
M
Bittl
Robert
R
Wrachtrup
Jörg
J
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
D045331:Photosystem I Protein Complex; D002734:Chlorophyll