Role of missing carotenoid in reducing the fluorescence of single monomeric photosystem II core complexes

Sepideh Skandary; Frank Müh; Imran Ashraf; Mohamed Ibrahim; Michael Metzger; A. Zouni; Alfred J. Meixner; Marc Brecht

doi:10.1039/c6cp07748j

Role of missing carotenoid in reducing the fluorescence of single monomeric photosystem II core complexes

Sepideh Skandary, Frank Müh, Imran Ashraf, Mohamed Ibrahim, Michael Metzger, A. Zouni, Alfred J. Meixner, Marc Brecht

Department of Theoretical Biophysics

Research output: Contribution to journal › Article › peer-review

Abstract

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 beta-carotene (beta-Car) cofactors located at the monomer-monomer interface in dPSIIcc is missing in mPSIIcc. This beta-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 beta-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.

Original language	English
Pages (from-to)	13189-13194
Number of pages	6
Journal	PCCP - Physical Chemistry Chemical Physics
Volume	19
DOIs	https://doi.org/10.1039/c6cp07748j
Publication status	Published - May 2017

Fields of science

103 Physics, Astronomy

JKU Focus areas

Nano-, Bio- and Polymer-Systems: From Structure to Function
Engineering and Natural Sciences (in general)

Access to Document

10.1039/c6cp07748j

Cite this

@article{f60ae6185bfc4f188b8803f4f7d776a9,

title = "Role of missing carotenoid in reducing the fluorescence of single monomeric photosystem II core complexes",

abstract = "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 beta-carotene (beta-Car) cofactors located at the monomer-monomer interface in dPSIIcc is missing in mPSIIcc. This beta-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 beta-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.",

author = "Sepideh Skandary and Frank M{\"u}h and Imran Ashraf and Mohamed Ibrahim and Michael Metzger and A. Zouni and Meixner, \{Alfred J.\} and Marc Brecht",

year = "2017",

month = may,

doi = "10.1039/c6cp07748j",

language = "English",

volume = "19",

pages = "13189--13194",

journal = "PCCP - Physical Chemistry Chemical Physics",

issn = "1463-9076",

publisher = "RSC Publishing",

}

TY - JOUR

T1 - Role of missing carotenoid in reducing the fluorescence of single monomeric photosystem II core complexes

AU - Skandary, Sepideh

AU - Müh, Frank

AU - Ashraf, Imran

AU - Ibrahim, Mohamed

AU - Metzger, Michael

AU - Zouni, A.

AU - Meixner, Alfred J.

AU - Brecht, Marc

PY - 2017/5

Y1 - 2017/5

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 beta-carotene (beta-Car) cofactors located at the monomer-monomer interface in dPSIIcc is missing in mPSIIcc. This beta-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 beta-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.

AB - 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 beta-carotene (beta-Car) cofactors located at the monomer-monomer interface in dPSIIcc is missing in mPSIIcc. This beta-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 beta-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.

U2 - 10.1039/c6cp07748j

DO - 10.1039/c6cp07748j

M3 - Article

SN - 1463-9076

VL - 19

SP - 13189

EP - 13194

JO - PCCP - Physical Chemistry Chemical Physics

JF - PCCP - Physical Chemistry Chemical Physics

ER -