Orientations between Red Antenna States of Photosystem I Monomers from Thermosynechococcus elongatus Revealed by Single-Molecule Spectroscopy.

Abstract

Single-molecule spectroscopy at low temperature was used to study the spectral properties, heterogeneities, and spectral dynamics of the chlorophyll a (Chl a) molecules responsible for the fluorescence emission of photosystem I monomers (PS I-M) from the cyanobacterium Thermosynechococcus elongatus. The fluorescence spectra of single PS I-M are dominated by several red-shifted chlorophyll a molecules named C708 and C719. The emission spectra show broad spectral distributions and several zero-phonon lines (ZPLs). Compared with the spectra of the single PS I trimers, some contributions are missing due to the lower number of C719 Chl's in monomers. Polarization-dependent measurements show an almost perpendicular orientation between the emitters corresponding to C708 and C719. These contributions can be assigned to chlorophyll dimers B18B19, B31B32, and B32B33.

DOI: 10.1021/acs.jpcb.5b04483

Cite this paper

@article{Skandary2015OrientationsBR, title={Orientations between Red Antenna States of Photosystem I Monomers from Thermosynechococcus elongatus Revealed by Single-Molecule Spectroscopy.}, author={Sepideh Skandary and Alexander Konrad and Martin Hussels and Alfred Johann Meixner and Marc Brecht}, journal={The journal of physical chemistry. B}, year={2015}, volume={119 43}, pages={13888-96} }