Imperial College London
Dr Alison Telfer

Dr Alison Telfer

Faculty of Natural Sciences, Department of Life Sciences

Honorary Research Fellow
 
 
 
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Contact

 

+44 (0)20 7594 1774a.telfer

 
 
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Location

 

704Sir Ernst Chain BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inproceedings{Schlodder:2007:10.1016/j.bbabio.2007.02.018,
author = {Schlodder, E and Çetin, M and Eckert, HJ and Schmitt, FJ and Barber, J and Telfer, A},
doi = {10.1016/j.bbabio.2007.02.018},
pages = {589--595},
title = {Both chlorophylls a and d are essential for the photochemistry in photosystem II of the cyanobacteria, Acaryochloris marina},
url = {http://dx.doi.org/10.1016/j.bbabio.2007.02.018},
year = {2007}
}
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RIS format (EndNote, RefMan)

TY  - CPAPER
AB  - We have measured the flash-induced absorbance difference spectrum attributed to the formation of the secondary radical pair, P+Q-, between 270 nm and 1000 nm at 77 K in photosystem II of the chlorophyll d containing cyanobacterium, Acaryochloris marina. Despite the high level of chlorophyll d present, the flash-induced absorption difference spectrum of an approximately 2 ms decay component shows a number of features which are typical of the difference spectrum seen in oxygenic photosynthetic organisms containing no chlorophyll d. The spectral shape in the near-UV indicates that a plastoquinone is the secondary acceptor molecule (QA). The strong C-550 change at 543 nm confirms previous reports that pheophytin a is the primary electron acceptor. The bleach at 435 nm and increase in absorption at 820 nm indicates that the positive charge is stabilized on a chlorophyll a molecule. In addition a strong electrochromic band shift, centred at 723 nm, has been observed. It is assigned to a shift of the Qy band of the neighbouring accessory chlorophyll d, ChlD1. It seems highly likely that it accepts excitation energy from the chlorophyll d containing antenna. We therefore propose that primary charge separation is initiated from this chlorophyll d molecule and functions as the primary electron donor. Despite its lower excited state energy (0.1 V less), as compared to chlorophyll a, this chlorophyll d molecule is capable of driving the plastoquinone oxidoreductase activity of photosystem II. However, chlorophyll a is used to stabilize the positive charge and ultimately to drive water oxidation. © 2007 Elsevier B.V. All rights reserved.
AU  - Schlodder,E
AU  - Çetin,M
AU  - Eckert,HJ
AU  - Schmitt,FJ
AU  - Barber,J
AU  - Telfer,A
DO  - 10.1016/j.bbabio.2007.02.018
EP  - 595
PY  - 2007///
SN  - 0005-2728
SP  - 589
TI  - Both chlorophylls a and d are essential for the photochemistry in photosystem II of the cyanobacteria, Acaryochloris marina
UR  - http://dx.doi.org/10.1016/j.bbabio.2007.02.018
ER  -
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