This Article Full Text Full Text (PDF) 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 Larsen, D. S. Articles by van Grondelle, R. Search for Related Content PubMed PubMed Citation Articles by Larsen, D. S. Articles by van Grondelle, R.

Photoisomerization and Photoionization of the Photoactive Yellow Protein Chromophore in Solution

Delmar S. Larsen ^*, Mikas Vengris ^*, Ivo H. M. van Stokkum ^*, Michael A. van der Horst , Frank L. de Weerd ^*, Klaas J. Hellingwerf  and Rienk van Grondelle ^*

^* Faculty of Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands; and Department of Microbiology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1018 WS Amsterdam, The Netherlands

Correspondence: Address reprint requests to Delmar S. Larsen, Fax: 31-20-444-7999; E-mail: dslarsen{at}nat.vu.nl.

Dispersed pump-dump-probe spectroscopy has the ability to characterize and identify the underlying ultrafast dynamical processes in complicated chemical and biological systems. This technique builds on traditional pump-probe techniques by exploring both ground- and excited-state dynamics and characterizing the connectivity between constituent transient states. We have used the dispersed pump-dump-probe technique to investigate the ground-state dynamics and competing excited-state processes in the excitation-induced ultrafast dynamics of thiomethyl p-coumaric acid, a model chromophore for the photoreceptor photoactive yellow protein. Our results demonstrate the parallel formation of two relaxation pathways (with multiple transient states) that jointly lead to two different types of photochemistry: cis-trans isomerization and detachment of a hydrated electron. The relative transition rates and quantum yields of both pathways have been determined. We find that the relaxation of the photoexcited chromophores involves multiple, transient ground-state intermediates and the chromophore in solution does not generate persistent photoisomerized products, but instead undergoes photoionization resulting in the generation of detached electrons and radicals. These results are of great value in interpreting the more complex dynamical changes in the optical properties of the photoactive yellow protein.

This article has been cited by other articles:

				I. B. Nielsen, S. Boye-Peronne, M. O. A. El Ghazaly, M. B. Kristensen, S. Brondsted Nielsen, and L. H. Andersen Absorption Spectra of Photoactive Yellow Protein Chromophores in Vacuum Biophys. J., October 1, 2005; 89(4): 2597 - 2604. [Abstract] [Full Text] [PDF]

				J. T. M. Kennis, D. S. Larsen, I. H. M. van Stokkum, M. Vengris, J. J. van Thor, and R. van Grondelle Uncovering the hidden ground state of green fluorescent protein PNAS, December 28, 2004; 101(52): 17988 - 17993. [Abstract] [Full Text] [PDF]

				M. Vengris, M. A. van der Horst, G. Zgrablic, I. H. M. van Stokkum, S. Haacke, M. Chergui, K. J. Hellingwerf, R. van Grondelle, and D. S. Larsen Contrasting the Excited-State Dynamics of the Photoactive Yellow Protein Chromophore: Protein versus Solvent Environments Biophys. J., September 1, 2004; 87(3): 1848 - 1857. [Abstract] [Full Text] [PDF]

				D. S. Larsen, I. H. M. van Stokkum, M. Vengris, M. A. van der Horst, F. L. de Weerd, K. J. Hellingwerf, and R. van Grondelle Incoherent Manipulation of the Photoactive Yellow Protein Photocycle with Dispersed Pump-Dump-Probe Spectroscopy Biophys. J., September 1, 2004; 87(3): 1858 - 1872. [Abstract] [Full Text] [PDF]