| Doctorant : |
Titouan JAUNET-LAHARY
|
| Directeur de thèse : | Denis Jacquemin, Professeur, CEISAM, Université de Nantes |
| co-directeur de thèse : |
Fabrice FLEURY ,
Professeur Université |
| Encadrant : | Adèle Laurent, Chargée de Recherche CNRS, CEISAM, Université de Nantes |
| Financement : |
|
| Date de la soutenance : |
lundi 02 octobre 2017, 10h00 |
| Modalité : |
- Lieu : Amphithéâtre Pasteur, bâtiment 2, campus Lombarderie
|
| Jury : |
- Président de jury : Daniel Vercauteren, Professeur, Université de Namur, Belgique
- Rapporteur : Elise Dumont, Professeure, ENS de Lyon
- Rapporteur : Nicolas Ferré, Professeur, Université d'Aix-Marseille
- Directeur de thèse : Denis Jacquemin, Professeur, CEISAM, Université de Nantes
- co-directeur de thèse :
Fabrice FLEURY ,
Professeur Université
- Encadrant : Adèle Laurent, Chargée de Recherche CNRS, CEISAM, Université de Nantes
|
La protéine RAD51 est l’un des acteurs majeurs des mécanismes de la résistance et de la reconstruction des cellules cancéreuses. La modulation de son activité ouvre une nouvelle voie dans la lutte contre le cancer. De nouveaux inhibiteurs potentiels de RAD51 ont été recensés, notamment, les dérives du stilbène disulfonique (SD). Dans cette thèse, nous étudions ces inhibiteurs dans différents milieux (solvant et protéine). La première partie de cette thèse est dédiée à l’étude des propriétés physico-chimiques en solution des dérivés SD. À l’aide de spectres optiques expérimentaux et de simulations par calculs quantiques (DFT et TD-DFT), nous avons montré que les SD se présentent sous leur forme dianionique en condition physiologique et la prise en compte du couplage vibronique est cruciale pour simuler des bandes des spectres d’absorption. La seconde partie se focalise sur la modélisation du complexe SD2- en interaction avec la protéine de transport albumine sérique humaine (ASH), qui joue un rôle prépondérant dans le transport de molécule au sein du corps humain. Elle apparaît être un excellent candidat pour acheminer des inhibiteurs SD2- vers les cellules cancéreuses. Sans donnée cristallographique du complexe ASH-SD2-, la modélisation moléculaire est le seul outil prédictif utilisable pour obtenir des données structurales, et nous avons associé ici des méthodes de docking moléculaire et de dynamique moléculaire. Cette méthodologie nous a permis (i) d’identifier le(s) résidu(s) important(s), (ii) d’évaluer les énergies d’interaction par des calculs MM-GBSA et (iii) d’identifier les sites d’accueil les plus adéquats pour les composés de type SD2-.
Publications
2019
Velic, Denis; Charlier, Cathy; Popova, Milena; Jaunet-Lahary, Titouan; Bouchouireb, Zakaria; Henry, Sébastien; Weigel, Pierre; Masson, Jean-Yves; Laurent, Adèle D; Nabiev, Igor; Fleury, Fabrice
Interactions of the Rad51 inhibitor DIDS with human and bovine serum albumins: Optical spectroscopy and isothermal calorimetry approaches Article de journal
Dans: Biochimie, vol. 167, p. 187–197, 2019, ISSN: 0300-9084.
@article{VELIC2019187,
title = {Interactions of the Rad51 inhibitor DIDS with human and bovine serum albumins: Optical spectroscopy and isothermal calorimetry approaches},
author = {Denis Velic and Cathy Charlier and Milena Popova and Titouan Jaunet-Lahary and Zakaria Bouchouireb and Sébastien Henry and Pierre Weigel and Jean-Yves Masson and Adèle D Laurent and Igor Nabiev and Fabrice Fleury},
url = {http://www.sciencedirect.com/science/article/pii/S0300908419302743},
doi = {https://doi.org/10.1016/j.biochi.2019.09.016},
issn = {0300-9084},
year = {2019},
date = {2019-01-01},
journal = {Biochimie},
volume = {167},
pages = {187--197},
abstract = {Rad51 is a key protein in DNA repair by homologous recombination and an important target for development of drugs in cancer therapy. 4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) has been used in clinic during the past 30 years as an inhibitor of anion transporters and channels. Recently DIDS has been demonstrated to affect Rad51-mediated homologous pairing and strand exchange, key processes in homologous recombination. Consequently, DIDS has been considered as a potential revertant of radio- and chemo-resistance of cancer cells, the major causes of therapy failure. Here, we have investigated the behavior of DIDS towards serum albumins. The effects of environmental factors, primarily, solvent polarity, on DIDS stability were evaluated, and the mechanisms of interaction of DIDS with human or bovine serum albumin were analyzed using isothermal calorimetry, circular dichroism and fluorescence spectroscopies. DIDS interaction with both serum albumins have been demonstrated, and the interaction characteristics have been determined. By comparing these characteristics for several DIDS derivatives, we have identified the DIDS moiety essential for the interaction. Furthermore, site competition data indicate that human albumin has two DIDS-binding sites: a high-affinity site in the IIIA subdomain and a low-affinity one in the IB subdomain. Molecular docking has revealed the key molecular moieties of DIDS responsible for its interactions in each site and shown that the IB site can bind two ligands. These findings show that binding of DIDS to serum albumin may change the balance between the free and bound DIDS forms, thereby affecting its bioavailability and efficacy against Rad51.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rad51 is a key protein in DNA repair by homologous recombination and an important target for development of drugs in cancer therapy. 4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) has been used in clinic during the past 30 years as an inhibitor of anion transporters and channels. Recently DIDS has been demonstrated to affect Rad51-mediated homologous pairing and strand exchange, key processes in homologous recombination. Consequently, DIDS has been considered as a potential revertant of radio- and chemo-resistance of cancer cells, the major causes of therapy failure. Here, we have investigated the behavior of DIDS towards serum albumins. The effects of environmental factors, primarily, solvent polarity, on DIDS stability were evaluated, and the mechanisms of interaction of DIDS with human or bovine serum albumin were analyzed using isothermal calorimetry, circular dichroism and fluorescence spectroscopies. DIDS interaction with both serum albumins have been demonstrated, and the interaction characteristics have been determined. By comparing these characteristics for several DIDS derivatives, we have identified the DIDS moiety essential for the interaction. Furthermore, site competition data indicate that human albumin has two DIDS-binding sites: a high-affinity site in the IIIA subdomain and a low-affinity one in the IB subdomain. Molecular docking has revealed the key molecular moieties of DIDS responsible for its interactions in each site and shown that the IB site can bind two ligands. These findings show that binding of DIDS to serum albumin may change the balance between the free and bound DIDS forms, thereby affecting its bioavailability and efficacy against Rad51.
2018
Jaunet-Lahary, Titouan; Vercauteren, Daniel P; Fleury, Fabrice; Laurent, Adèle D
Computational simulations determining disulfonic stilbene derivative bioavailability within human serum albumin Article de journal
Dans: Physical Chemistry Chemical Physics, vol. 20, no. 26, p. 18020–18030, 2018, ISSN: 14639076.
@article{Jaunet-Lahary2018,
title = {Computational simulations determining disulfonic stilbene derivative bioavailability within human serum albumin},
author = {Titouan Jaunet-Lahary and Daniel P Vercauteren and Fabrice Fleury and Adèle D Laurent},
doi = {10.1039/c8cp00704g},
issn = {14639076},
year = {2018},
date = {2018-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {20},
number = {26},
pages = {18020--18030},
publisher = {Royal Society of Chemistry},
abstract = {Disulfonic stilbene (DS) derivatives are a member of the large family of compounds widely employed in medicine and biology as modulators for membrane transporters or inhibitors of a protein involved in DNA repair. They constitute interesting compounds that have not yet been investigated within the bioavailability framework. No crystallographic structures exist involving such compounds embedded in the most common drug carrier, human serum albumin (HSA). The present work studies, for the first time, the physico-chemical features driving the inclusion of three DS derivatives (amino, nitro and acetamido, named DADS, DNDS and DATDS, respectively) within the four common HSA binding sites using combined molecular docking and molecular dynamics simulations. A careful analysis of each ligand within each of the studied binding sites is carried out, highlighting specific interactions and key residues playing a role in stabilizing the ligand within each pocket. The comparison between DADS, DNDS and DATDS reveals that depending on the binding site, the conclusions are rather different. For instance, the IB binding site shows a specificity to DADS compounds while IIIA is the most favorable site for DNDS and DATDS. 2018},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Disulfonic stilbene (DS) derivatives are a member of the large family of compounds widely employed in medicine and biology as modulators for membrane transporters or inhibitors of a protein involved in DNA repair. They constitute interesting compounds that have not yet been investigated within the bioavailability framework. No crystallographic structures exist involving such compounds embedded in the most common drug carrier, human serum albumin (HSA). The present work studies, for the first time, the physico-chemical features driving the inclusion of three DS derivatives (amino, nitro and acetamido, named DADS, DNDS and DATDS, respectively) within the four common HSA binding sites using combined molecular docking and molecular dynamics simulations. A careful analysis of each ligand within each of the studied binding sites is carried out, highlighting specific interactions and key residues playing a role in stabilizing the ligand within each pocket. The comparison between DADS, DNDS and DATDS reveals that depending on the binding site, the conclusions are rather different. For instance, the IB binding site shows a specificity to DADS compounds while IIIA is the most favorable site for DNDS and DATDS. 2018
2016
Jaunet-Lahary, Titouan; Goupille, Anaïs; Jacquemin, Denis; Fleury, Fabrice; Graton, Jérôme; Laurent, Adèle D
A Joint Theoretical and Experimental Study of the Behavior of the DIDS Inhibitor and its Derivatives Article de journal
Dans: ChemPhysChem, vol. 3, p. 2434–2445, 2016, ISSN: 14397641.
@article{Jaunet-Lahary2016,
title = {A Joint Theoretical and Experimental Study of the Behavior of the DIDS Inhibitor and its Derivatives},
author = {Titouan Jaunet-Lahary and Anaïs Goupille and Denis Jacquemin and Fabrice Fleury and Jérôme Graton and Adèle D Laurent},
doi = {10.1002/cphc.201600107},
issn = {14397641},
year = {2016},
date = {2016-01-01},
journal = {ChemPhysChem},
volume = {3},
pages = {2434--2445},
abstract = {4,4′-Diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) is a well-known ion-exchange inhibitor targeting cardiac functions and indirectly impeding both radio- and chemo-resistance. A joint computational and experimental study is presented to provide deeper insights into DIDS and other members of this family of compounds. To this end, we applied state-of-the-art density functional theory (DFT) and time-dependent DFT methods, in addition to measuring the optical properties. The experimental data show that such compounds are highly sensitive to their environment and that the optical properties change within as little time as 7 h. However, the optical properties of DIDS are similar in various acidic/basic environments, which were confirmed by pKa computations on both cis and trans isomers. The protonation analysis also highlights that the singly protonated form of DIDS behaves like a proton sponge compound. The experimentally observed redshift that can be seen when going from water to DMSO was reproduced solely by using the solvation model based on density, although the polarization continuum model and implicit/explicit hybrid schemes were also tested. The characteristic broadening of the absorption peak in water and the vibronic fine structure in DMSO were also reproduced thanks to vibronic coupling simulations associated with the solvent reorganization energy. For other stilbene derivatives, a correlation is found between the maximum absorption wavelength and the Hammett parameters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
4,4′-Diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) is a well-known ion-exchange inhibitor targeting cardiac functions and indirectly impeding both radio- and chemo-resistance. A joint computational and experimental study is presented to provide deeper insights into DIDS and other members of this family of compounds. To this end, we applied state-of-the-art density functional theory (DFT) and time-dependent DFT methods, in addition to measuring the optical properties. The experimental data show that such compounds are highly sensitive to their environment and that the optical properties change within as little time as 7 h. However, the optical properties of DIDS are similar in various acidic/basic environments, which were confirmed by pKa computations on both cis and trans isomers. The protonation analysis also highlights that the singly protonated form of DIDS behaves like a proton sponge compound. The experimentally observed redshift that can be seen when going from water to DMSO was reproduced solely by using the solvation model based on density, although the polarization continuum model and implicit/explicit hybrid schemes were also tested. The characteristic broadening of the absorption peak in water and the vibronic fine structure in DMSO were also reproduced thanks to vibronic coupling simulations associated with the solvent reorganization energy. For other stilbene derivatives, a correlation is found between the maximum absorption wavelength and the Hammett parameters.