Nadia DOZOVA

@article{RN123b,
title = {Ultrafast Dynamics of Fully Reduced Flavin in Catalytic Structures of Thymidylate Synthase ThyX},
author = {Nadia Dozova and Fabien Lacombat and Murielle Lombard and Djemel Hamdane and Pascal Plaza},
url = {http://dx.doi.org/10.1039/D1CP03379D},
doi = {10.1039/D1CP03379D},
issn = {1463-9076},
year = {2021},
date = {2021-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {23},
pages = {22692-22702},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{RN632,
title = {Ultrafast photoreduction dynamics of a new class of CPD photolyases},
author = {Fabien Lacombat and Agathe Espagne and Nadia Dozova and Pascal Plaza and Pavel M\"{u}ller and Hans-Joachim Emmerich and Martin Saft and Lars-Oliver Essen},
url = {https://doi.org/10.1007/s43630-021-00048-4},
doi = {10.1007/s43630-021-00048-4},
issn = {1474-9092},
year = {2021},
date = {2021-01-01},
journal = {Photochemical & Photobiological Sciences},
volume = {20},
number = {6},
pages = {733-746},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{RN479,
title = {Ultrafast Oxidation of a Tyrosine by Proton-Coupled Electron Transfer Promotes Light Activation of an Animal-like Cryptochrome},
author = {Fabien Lacombat and Agathe Espagne and Nadia Dozova and Pascal Plaza and Pavel M\"{u}ller and Klaus Brettel and Sophie Franz-Badur and Lars-Oliver Essen},
url = {https://doi.org/10.1021/jacs.9b03680},
doi = {10.1021/jacs.9b03680},
issn = {0002-7863},
year = {2019},
date = {2019-01-01},
journal = {Journal of the American Chemical Society},
volume = {141},
number = {34},
pages = {13394-13409},
abstract = {The animal-like cryptochrome of Chlamydomonas reinhardtii (CraCRY) is a recently discovered photoreceptor that controls the transcriptional profile and sexual life cycle of this alga by both blue and red light. CraCRY has the uncommon feature of efficient formation and longevity of the semireduced neutral form of its FAD cofactor upon blue light illumination. Tyrosine Y373 plays a crucial role by elongating , as fourth member, the electron transfer (ET) chain found in most other cryptochromes and DNA photolyases, which comprises a conserved tryptophan triad. Here, we report the full mechanism of light-induced FADH• formation in CraCRY using transient absorption spectroscopy from hundreds of femtoseconds to seconds. Electron transfer starts from ultrafast reduction of excited FAD to FAD•\textendash by the proximal tryptophan (0.4 ps) and is followed by delocalized migration of the produced WH•+ radical along the tryptophan triad (∼4 and ∼50 ps). Oxidation of Y373 by coupled ET to WH•+ and deprotonation then proceeds in ∼800 ps, without any significant kinetic isotope effect, nor a pH effect between pH 6.5 and 9.0. The FAD•\textendash/Y373• pair is formed with high quantum yield (∼60%); its intrinsic decay by recombination is slow (∼50 ms), favoring reduction of Y373• by extrinsic agents and protonation of FAD•\textendash to form the long-lived, red-light absorbing FADH• species. Possible mechanisms of tyrosine oxidation by ultrafast proton-coupled ET in CraCRY, a process about 40 times faster than the archetypal tyrosine-Z oxidation in photosystem II, are discussed in detail.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{RN115,
title = {Ultrafast photoinduced flavin dynamics in the unusual active site of the tRNA methyltransferase TrmFO},
author = {N Dozova and F Lacombat and C Bou-Nader and D Hamdane and P Plaza},
doi = {10.1039/c8cp06072j},
issn = {1463-9076},
year = {2019},
date = {2019-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {21},
number = {17},
pages = {8743-8756},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Dozova:2018,
title = {A novel diarylethene-based photoswitchable chelator for reversible release and capture of Ca2+ in aqueous media},
author = {N Dozova and G Pousse and B Barnych and J -M Mallet and J Cossy and B Valeur and P Plaza},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046375200&doi=10.1016%2fj.jphotochem.2018.04.029&partnerID=40&md5=acfff9bc55e2d0bb41580e84374018fc},
doi = {10.1016/j.jphotochem.2018.04.029},
year = {2018},
date = {2018-01-01},
journal = {Journal of Photochemistry and Photobiology A: Chemistry},
volume = {360},
pages = {181--187},
abstract = {The synthesis and characterisation of a novel Reversibly Photoswitchable Chelator (RPC) of calcium ions, designed as a stepping stone towards producing pulses of calcium concentration in an aqueous environment, is reported. This RPC is constituted of a photochromic diarylethene core connected on one side to a BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid) calcium chelator and, on the other side, to an electron-withdrawing group. The operation principle consists in photoswitching on and off an intramolecular charge transfer between one nitrogen atom of the BAPTA moiety and the electron-withdrawing group, thereby modulating the chelating affinity of BAPTA for calcium ions. Solubility of the compound in a partially aqueous solvent was achieved by grafting a short PEG (polyethylene glycol) tail to the electron-withdrawing group. A reduction of the affinity for calcium ions upon photoswitching by a factor of 3\textendash4, in the hundred nM range of dissociation constant, is reported and constitutes a proof of concept of this type of RPC. © 2018 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{RN114,
title = {Delocalized hole transport coupled to sub-ns tryptophanyl deprotonation promotes photoreduction of class II photolyases},
author = {F Lacombat and A Espagne and N Dozova and P Plaza and E Ignatz and S Kiontke and L O Essen},
url = {<Go to ISI>://WOS:000448345400028},
doi = {10.1039/c8cp04548h},
issn = {1463-9076},
year = {2018},
date = {2018-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {20},
number = {39},
pages = {25446-25457},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Martin:2017a,
title = {Ultrafast flavin photoreduction in an oxidized animal (6-4) photolyase through an unconventional tryptophan tetrad},
author = {P R Martin and F Lacombat and A Espagne and N Dozova and P Plaza and J Yamamoto and P M\"{u}ller and K Brettel and A De La Lande},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029817108&doi=10.1039%2fc7cp04555g&partnerID=40&md5=b5966e02f7c4f4fa9b385f15647311c3},
doi = {10.1039/c7cp04555g},
year = {2017},
date = {2017-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {19},
number = {36},
pages = {24493--24504},
abstract = {Photolyases are flavoenzymes repairing UV-induced lesions in DNA, which may be activated by a photoreduction of their FAD cofactor. In most photolyases, this photoreduction proceeds by electron transfer along a chain of three tryptophan (Trp) residues, connecting the flavin to the protein surface. Much less studied, animal (6-4) photolyases (repairing pyrimidine-pyrimidone (6-4) photoproducts) are particularly interesting as they were recently shown to have a longer electron transfer chain, counting four Trp residues. Using femtosecond polarized transient absorption spectroscopy, we performed a detailed analysis of the photoactivation reaction in the (6-4) photolyase of Xenopus laevis with oxidized FAD. We showed that the excited flavin is very quickly reduced (∼0.5 ps) by a nearby tryptophan residue, yielding FAD•- and WH•+ radicals. Subsequent kinetic steps in the picosecond regime were assigned to the migration of the positive charge along the Trp tetrad, in competition with charge recombination. We propose that the positive charge is actually delocalized over various Trp residues during most of the dynamics and that charge recombination essentially occurs through the proximal tryptophanyl radical. Oxidation of the fourth tryptophan is thought to be reached about as fast as that of the third one (∼40 ps), based on a comparison with a mutant protein lacking the distal Trp, implying ultrafast electron transfer between these two residues. This unusual mechanism sheds light on the rich diversity of electron transfer pathways found in various photolyases, and evolution-related cryptochromes alike. © the Owner Societies 2017.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Dozova:2016,
title = {Excited-state symmetry breaking of linear quadrupolar chromophores: A transient absorption study},
author = {N Dozova and L Ventelon and G Clermont and M Blanchard-Desce and P Plaza},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991648542&doi=10.1016%2fj.cplett.2016.10.020&partnerID=40&md5=93f48fbad7f0a0a40b036bef2e73147a},
doi = {10.1016/j.cplett.2016.10.020},
year = {2016},
date = {2016-01-01},
journal = {Chemical Physics Letters},
volume = {664},
pages = {56--62},
abstract = {The photophysical properties of two highly symmetrical quadrupolar chromophores were studied by both steady-state and transient absorption spectroscopy. Their excited-state behavior is dominated by the solvent-induced Stokes shift of the stimulated-emission band. The origin of this shift is attributed to symmetry breaking that confers a non-vanishing dipole moment to the excited state of both compounds. This dipole moment is large and constant in DMSO, whereas symmetry breaking appears significantly slower and leading to smaller excited-state dipole in toluene. Time-dependant increase of the excited-state dipole moment induced by weak solvation is proposed to explain the results in toluene. © 2016 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Dozova:2015,
title = {Photo-induced cation translocation in a molecular shuttle based on a calix[4]-biscrown including DCM and DMABN chromophores},
author = {N Dozova and R Kumar and T Pradhan and F Lacombat and B Valeur and J S Kim and P Plaza},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84942474410&doi=10.1039%2fc5cc06054k&partnerID=40&md5=857b5558380ed42e21e82790184d89cb},
doi = {10.1039/c5cc06054k},
year = {2015},
date = {2015-01-01},
journal = {Chemical Communications},
volume = {51},
number = {80},
pages = {14859--14861},
abstract = {We present a new molecular shuttle, consisting of a calixarene core attached to two different photoactive centers, DCM and DMABN. We show that a K+ ion bound to the DCM-grafted crown is translocated towards the other site of the molecule upon photoexcitation, but not released to the bulk. © The Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Yadav:2015,
title = {Real-time monitoring of chromophore isomerization and deprotonation during the photoactivation of the fluorescent protein Dronpa},
author = {D Yadav and F Lacombat and N Dozova and F Rappaport and P Plaza and A Espagne},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922794115&doi=10.1021%2fjp507094f&partnerID=40&md5=6618718bf1ba6e1f5e5f2194c9480d5b},
doi = {10.1021/jp507094f},
year = {2015},
date = {2015-01-01},
journal = {Journal of Physical Chemistry B},
volume = {119},
number = {6},
pages = {2404--2414},
abstract = {Dronpa is a photochromic green fluorescent protein (GFP) homologue used as a probe in super-resolution microscopy. It is known that the photochromic reaction involves cis/trans isomerization of the chromophore and protonation/deprotonation of its phenol group, but the sequence in time of the two steps and their characteristic time scales are still the subject of much debate. We report here a comprehensive UV-visible transient absorption spectroscopy study of the photoactivation mechanism of Dronpa, covering all relevant time scales from ∼100 fs to milliseconds. The Dronpa-2 variant was also studied and showed the same behavior. By carefully controlling the excitation energy to avoid multiphoton processes, we could measure both the spectrum and the anisotropy of the first photoactivation intermediate. We show that the observed few nanometer blue-shift of this intermediate is characteristic for a neutral cis chromophore, and that its anisotropy of ∼0.2 is in good agreement with the reorientation of the transition dipole moment expected upon isomerization. These data constitute the first clear evidence that trans → cis isomerization of the chromophore precedes its deprotonation and occurs on the picosecond time scale, concomitantly to the excited-state decay. We found the deprotonation step to follow in ∼10 μs and lead directly from the neutral cis intermediate to the final state. © 2014 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}