This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.106.085068v1 91/10/3776    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Broess, K. Articles by van Amerongen, H. Search for Related Content PubMed PubMed Citation Articles by Broess, K. Articles by van Amerongen, H.

Excitation Energy Transfer and Charge Separation in Photosystem II Membranes Revisited

Koen Broess ^*, Gediminas Trinkunas ^* , Chantal D. van der Weij-de Wit , Jan P. Dekker , Arie van Hoek ^*  and Herbert van Amerongen ^* 

^* Wageningen University, Laboratory of Biophysics, 6700 ET Wageningen, The Netherlands; Institute of Physics, Vilnius 02300, Lithuania; Department of Biophysics, Division of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands; and MicroSpectroscopy Centre, Wageningen University, 6703 HA Wageningen, The Netherlands

Correspondence: Address reprint requests to Herbert van Amerongen, E-mail: herbert.vanamerongen{at}wur.nl.

We have performed time-resolved fluorescence measurements on photosystem II (PSII) containing membranes (BBY particles) from spinach with open reaction centers. The decay kinetics can be fitted with two main decay components with an average decay time of 150 ps. Comparison with recent kinetic exciton annihilation data on the major light-harvesting complex of PSII (LHCII) suggests that excitation diffusion within the antenna contributes significantly to the overall charge separation time in PSII, which disagrees with previously proposed trap-limited models. To establish to which extent excitation diffusion contributes to the overall charge separation time, we propose a simple coarse-grained method, based on the supramolecular organization of PSII and LHCII in grana membranes, to model the energy migration and charge separation processes in PSII simultaneously in a transparent way. All simulations have in common that the charge separation is fast and nearly irreversible, corresponding to a significant drop in free energy upon primary charge separation, and that in PSII membranes energy migration imposes a larger kinetic barrier for the overall process than primary charge separation.

This article has been cited by other articles:

				C. D. van der Weij-De Wit, A. B. Doust, I. H. M. van Stokkum, J. P. Dekker, K. E. Wilk, P. M. G. Curmi, and R. van Grondelle Phycocyanin Sensitizes both Photosystem I and Photosystem II in Cryptophyte Chroomonas CCMP270 Cells Biophys. J., March 15, 2008; 94(6): 2423 - 2433. [Abstract] [Full Text] [PDF]