Abstract
Ultrafast time resolved emission spectra were measured in whole cells of a PSI-deficient mutant of Synechocystis sp. PCC 6803 at room temperature and at 77K to study excitation energy transfer and trapping. By means of a target analysis it was estimated that the terminal emitter of the phycobilisome, termed allophycocyanin 680, transfers its energy with a rate of (20 ps)–1 to PSII. This is faster than the intraphycobilisome energy transfer rates between a rod and a core cylinder, or between the core cylinders.
| Original language | English |
|---|---|
| Pages (from-to) | 265-274 |
| Number of pages | 10 |
| Journal | Photosynthetica |
| Volume | 56 |
| Issue number | 1 |
| Early online date | 10 Jan 2018 |
| DOIs | |
| Publication status | Published - Mar 2018 |
Funding
Abbreviations: APC – allophycocyanin; DAS – decay-associated spectrum; ∆PSI – PSI-deficient mutant of Synechocystis sp. PCC 6803; EAS – evolution-associated spectrum; ET – electron transfer; EET – excitation energy transfer; FWHM – full width at half maximum; IRF – instrument response function; PB – phycobilisome; PC – phycocyanin; rms – root mean square; RP – radical pair; SAS – species-associated spectrum; SNR – signal to noise ratio; SS – steady-state spectra; SVD – singular value decomposition; TRES – time resolved emission spectrum; WT – wild type. Acknowledgments: The ΔPSI mutant which was originally constructed by Wim Vermaas (Arizona State University, Tempe, Arizona, USA) was kindly provided to us by Christiane Funk (Umeå University, Sweden). This research was performed as part of the BioSolar Cells research program, sponsored by the Dutch Ministry of Economic Affairs. This work is part of the research program of the Netherlands Organization for Scientific Research (NWO, previously FOM). IHMvS and RvG acknowledge financial support of the European Research Council [Advanced Grant proposal 267333 (PHOTPROT) to RvG]. © The Author(s). This article is published with open access at link.springer.com Fig. 1. Cartoon of possible fluorescent species in the Synechocystis ΔPSI mutant. Depicted are a PB-PSII complex with both PSII RCs open (A), both closed (B), a PB that is not coupled to any PSII (C) as well as an uncoupled PSII dimer with open (D) and closed (E) RCs. Key: blue, rods consisting of three hexamers; top and basal core cylinders respectively in magenta, red and orange; green, PSII dimer. Dark arrows represent intra-PB EET; yellow arrows represent EET from the PB core to PSII. An “X” stands for a closed PSII RC.
| Funders | Funder number |
|---|---|
| European Research Council | 267333 |
| Ministerie van Economische Zaken | |
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek |
Keywords
- excitation energy transfer
- global analysis
- light harvesting
- target analysis
