Agathe ESPAGNE

@article{Changenet-Barret:2005,
title = {Investigations of the primary events in a bacterial photoreceptor for photomotility: Photoactive yellow protein (PYP)},
author = {P Changenet-Barret and A Espagne and P Plaza and K J Hellingwerf and M M Martin},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-17444406349&doi=10.1039%2fb418134d&partnerID=40&md5=9d0e9b7ebb687d0a3c802932712fef79},
doi = {10.1039/b418134d},
year = {2005},
date = {2005-01-01},
journal = {New Journal of Chemistry},
volume = {29},
number = {4},
pages = {527--534},
abstract = {PYP, the Photoactive Yellow Protein, is a small water-soluble protein extracted from the cytosol of the halophilic purple bacterium Halorhodospira halophila. PYP is thought to mediate the phototactic response of the bacterium against blue light. Its chromophore is the deprotonated trans-p-hydroxycinnamic acid covalently linked, via a thioester bond, to the unique cysteine residue of the protein. Upon blue-light irradiation, PYP undergoes a photocycle. As for rhodopsins, the trans to cis isomerization of the chromophore was shown to be the first overall step of this photocycle. From time-resolved spectroscopy measurements on native PYP in solution, it emerged that the reaction involves a series of fast events on the subpicosecond and picosecond timescales, but the reaction path that leads to the formation of the cis isomer is not clear yet. A few years ago, we initiated a comparative study of native PYP and several chromophore analogues in solution in order to try to further clarify the early steps of the photocycle. Our experimental approach consists in probing, in real-time, the ultrafast photoinduced events by transient absorption and gain spectroscopy using the pump-probe technique. In the present paper, we review our experimental results and discuss them within the context of the recent literature. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@inproceedings{RN88,
title = {Chemical structure effect on the excited-state relaxation dynamics of the PYP chromophore},
author = {A Espagne and P Changenet-Barret and S Charier and J -B Baudin and L Jullien and P Plaza and M M Martin},
editor = {M M Martin and J T Hynes},
year = {2004},
date = {2004-01-01},
booktitle = {VIth International Conference on Femtochemistry},
pages = {421-424},
publisher = {Elsevier},
series = {Femtochemistry and Femtobiology: Ultrafast Events in Molecular Science},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@article{Changenet-Barret:2004,
title = {Early molecular events in the photoactive yellow protein: Role of the chromophore photophysics},
author = {P Changenet-Barret and A Espagne and S Charier and J -B Baudin and L Jullien and P Plaza and K J Hellingwerf and M M Martin},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-4644243446&doi=10.1039%2fb400398e&partnerID=40&md5=45520bcadbdf2612c16ef874b207d73b},
doi = {10.1039/b400398e},
year = {2004},
date = {2004-01-01},
journal = {Photochemical and Photobiological Sciences},
volume = {3},
number = {8},
pages = {823--829},
abstract = {We report a comparative study of the isomerization reaction in native and denatured photoactive yellow protein (PYP) and in various chromophore analogues in their trans deprotonated form. The excited-state relaxation dynamics was followed by subpicosecond transient absorption and gain spectroscopy. The free p-hydroxycinnamate (pCA2−) and its amide analogue (pCM-) are found to display a quite different transient spectroscopy from that of PYP. The excited-state deactivation leads to the formation of the ground-state cis isomer without any detectable intermediate with a mechanism comparable to trans-stilbene photoisomerization. On the contrary, the early stage of the excited-state deactivation of the free thiophenyl-p-hydroxycinnamate (pCT-) and of the denatured PYP is similar to that of the native protein. It involves the formation of an intermediate absorbing in the spectral region located between the bleaching and gain bands in less than 2 ps. However, in these two cases, the formation of the cis isomer has not been proved yet. This difference with pCA- and pCM- might result from the fact that, in the thioester substituted chromophore, simultaneous population of two quasi-degenerate excited states occurs upon excitation. This comparative study highlights the determining role of the chromophore structure and of its intrinsic properties in the primary molecular events in native PYP. © 2004 The Royal Society of Chemistry and Owner Societies.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@inproceedings{RN87,
title = {Isomerization process in the native and denatured Photoactive Yellow Protein probed by subpicosecond absorption spectroscopy},
author = {P Changenet-Barret and A Espagne and P Plaza and M M Martin and Y J Hellingwerf},
editor = {M M Martin and J T Hynes},
year = {2004},
date = {2004-01-01},
booktitle = {VIth International Conference on Femtochemistry},
pages = {417-420},
publisher = {Elsevier},
series = {Femtochemistry and Femtobiology: Ultrafast Events in Molecular Science},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@article{Changenet-Barret:2002,
title = {Excited-state relation dynamics of a PYP chromophore model in solution: Influence of the thioester group},
author = {P Changenet-Barret and A Espagne and N Katsonis and S Charier and J -B Baudin and L Jullien and P Plaza and M M Martin},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037109026&doi=10.1016%2fS0009-2614%2802%2901480-X&partnerID=40&md5=5fdfd4c614229bacad91377caee585a1},
doi = {10.1016/S0009-2614(02)01480-X},
year = {2002},
date = {2002-01-01},
journal = {Chemical Physics Letters},
volume = {365},
number = {3-4},
pages = {285--291},
abstract = {Cis-trans photoisomerization of a photoactive yellow protein chromophore model, the deprotonated trans S-phenyl thio-p-hydroxycinnamate, is studied in aqueous solution by subpicosecond transient absorption and gain spectroscopy. The excited-state deactivation is found to involve the formation, in 1.7 ps, of an intermediate state which decays in 2.8 ps. A persistent bleaching signal is observed at longer times indicating that the excited state not only relaxes to the ground state but also partly forms a stable photoproduct, possibly the cis isomer. This behavior is analogous to that of the native photoactive yellow protein. © 2002 Elsevier Science B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{RN55,
title = {Ionized Aminohydroxycarbene and Its Isomers: Relative Stability and Unimolecular Reactivity},
author = {G Bouchoux and A Espagne},
doi = {10.1016/s0009-2614(01)01117-4},
issn = {0009-2614},
year = {2001},
date = {2001-01-01},
journal = {Chemical Physics Letters},
volume = {348},
number = {3-4},
pages = {329-336},
keywords = {},
pubstate = {published},
tppubtype = {article}
}