TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Skandary, Sepideh
A1  - Müh, Frank
A1  - Ashraf, Imran
A1  - Ibrahim, Mohamed
A1  - Metzger, Michael
A1  - Zouni, Athina
A1  - Meixner, Alfred
A1  - Brecht, Marc
T1  - Role of missing carotenoid in reducing the fluorescence of single monomeric photosystem II core complexes
JF  - Physical chemistry, chemical physics : PCCP ; a journal of European Chemical Societies
N2  - The fluorescence of monomeric photosystem II core complexes (mPSIIcc) of the cyanobacterium Thermosynechococcus elongatus, originating from redissolved crystals, is investigated by using single-molecule spectroscopy (SMS) at 1.6 K. The emission spectra of individual mPSIIcc are dominated by sharp zero-phonon lines, showing the existence of different emitters compatible with the F685, F689, and F695 bands reported formerly. The intensity of F695 is reduced in single mPSIIcc as compared to single PSIIcc-dimers (dPSIIcc). Crystal structures show that one of the β-carotene (β-Car) cofactors located at the monomer–monomer interface in dPSIIcc is missing in mPSIIcc. This β-Car in dPSIIcc is in van der Waals distance to chlorophyll (Chl) 17 in the CP47 subunit. We suggest that this Chl contributes to the F695 emitter. A loss of β-Car cofactors in mPSIIcc preparations will lead to an increased lifetime of the triplet state of Chl 17, which can explain the reduced singlet emission of F695 as observed in SMS.
Y1  - 2017
SN  - 1463-9076
SS  - 1463-9076
U6  - https://doi.org/10.1039/C6CP07748J
DO  - https://doi.org/10.1039/C6CP07748J
VL  - 19
IS  - 20
SP  - 13189
EP  - 13194
S1  - 6
PB  - The Royal Society of Chemistry
CY  - Cambridge
ER  -