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

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• 作者：Sepideh Skandary ; Alexander Konrad ; Martin Hussels ; Alfred J. Meixner ; Marc Brecht
• 刊名：Journal of Physical Chemistry B
• 出版年：2015
• 出版时间：October 29, 2015
• 年：2015
• 卷：119
• 期：43
• 页码：13888-13896
• 全文大小：519K
• ISSN：1520-5207

文摘

Single-molecule spectroscopy at low temperature was used to study the spectral properties, heterogeneities, and spectral dynamics of the chlorophyll a (Chl聽a) molecules responsible for the fluorescence emission of photosystem I monomers (PS聽I-M) from the cyanobacterium Thermosynechococcus elongatus. The fluorescence spectra of single PS聽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聽I trimers, some contributions are missing due to the lower number of C719 Chl鈥檚 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.