Professeur des Universités, Sorbonne Université
Responsable du pôle de Chimie Physique et Biologique de la Matière Vivante
PASTEUR, Département de chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS
24 rue Lhomond, 75005 Paris, France
Email: Ludovic.Jullien@ens.psl.eu or Ludovic.Jullien@sorbonne-universite.fr
Phone: +33 144323333
Office: E142c
Home page: https://ludovicjullien.org/
Publications
2016 |
Design and characterization of red fluorogenic push-pull chromophores holding great potential for bioimaging and biosensing Article de journal C Li; M -A Plamont; I Aujard; T Le Saux; L Jullien; A Gautier Organic and Biomolecular Chemistry, 14 (39), p. 9253–9261, 2016. @article{Li:2016, title = {Design and characterization of red fluorogenic push-pull chromophores holding great potential for bioimaging and biosensing}, author = {C Li and M -A Plamont and I Aujard and T Le Saux and L Jullien and A Gautier}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84990182453&doi=10.1039%2fc6ob01612j&partnerID=40&md5=7cea2c6d4aeeeef91e6a3a5bd0d6b5ad}, doi = {10.1039/c6ob01612j}, year = {2016}, date = {2016-01-01}, journal = {Organic and Biomolecular Chemistry}, volume = {14}, number = {39}, pages = {9253--9261}, abstract = {Fluorogenic chromophores have been used recently for fluorescence reporting and biosensing. Their ability to turn on upon specific interaction with a given target has been exploited in particular for the design of fluorogen-based reporters enabling biomolecule labeling and imaging. In this paper, we report the development and exhaustive characterization of a new family of red fluorogenic push-pull chromophores, holding great potential for the development of fluorogen-based reporters or intracellular fluorogenic markers. The proposed methodology is generic and should find general applicability in the discovery of new fluorogenic dyes suitable for the design of fluorogen-based reporters and biosensors. © The Royal Society of Chemistry 2016.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fluorogenic chromophores have been used recently for fluorescence reporting and biosensing. Their ability to turn on upon specific interaction with a given target has been exploited in particular for the design of fluorogen-based reporters enabling biomolecule labeling and imaging. In this paper, we report the development and exhaustive characterization of a new family of red fluorogenic push-pull chromophores, holding great potential for the development of fluorogen-based reporters or intracellular fluorogenic markers. The proposed methodology is generic and should find general applicability in the discovery of new fluorogenic dyes suitable for the design of fluorogen-based reporters and biosensors. © The Royal Society of Chemistry 2016. |
Kinetics of Reactive Modules Adds Discriminative Dimensions for Selective Cell Imaging Article de journal J Quérard; T Le Saux; A Gautier; D Alcor; V Croquette; A Lemarchand; C Gosse; L Jullien ChemPhysChem, 17 (10), p. 1396–1413, 2016. @article{Querard:2016, title = {Kinetics of Reactive Modules Adds Discriminative Dimensions for Selective Cell Imaging}, author = {J Qu\'{e}rard and T Le Saux and A Gautier and D Alcor and V Croquette and A Lemarchand and C Gosse and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957539317&doi=10.1002%2fcphc.201500987&partnerID=40&md5=4a514250af842ae7697b695eb73769fb}, doi = {10.1002/cphc.201500987}, year = {2016}, date = {2016-01-01}, journal = {ChemPhysChem}, volume = {17}, number = {10}, pages = {1396--1413}, abstract = {Living cells are chemical mixtures of exceptional interest and significance, whose investigation requires the development of powerful analytical tools fulfilling the demanding constraints resulting from their singular features. In particular, multiplexed observation of a large number of molecular targets with high spatiotemporal resolution appears highly desirable. One attractive road to address this analytical challenge relies on engaging the targets in reactions and exploiting the rich kinetic signature of the resulting reactive module, which originates from its topology and its rate constants. This review explores the various facets of this promising strategy. We first emphasize the singularity of the content of a living cell as a chemical mixture and suggest that its multiplexed observation is significant and timely. Then, we show that exploiting the kinetics of analytical processes is relevant to selectively detect a given analyte: upon perturbing the system, the kinetic window associated to response read-out has to be matched with that of the targeted reactive module. Eventually, we introduce the state-of-the-art of cell imaging exploiting protocols based on reaction kinetics and draw some promising perspectives. Live recording: In living cells, the multiplexed observation of a large number of targets has recently emerged as a desirable goal. To address this challenge, an attractive road relies on engaging the targets in reactions and exploiting the kinetic signature of the resulting reactive module. This review explores the facets of this strategy and draw some promising perspectives. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Living cells are chemical mixtures of exceptional interest and significance, whose investigation requires the development of powerful analytical tools fulfilling the demanding constraints resulting from their singular features. In particular, multiplexed observation of a large number of molecular targets with high spatiotemporal resolution appears highly desirable. One attractive road to address this analytical challenge relies on engaging the targets in reactions and exploiting the rich kinetic signature of the resulting reactive module, which originates from its topology and its rate constants. This review explores the various facets of this promising strategy. We first emphasize the singularity of the content of a living cell as a chemical mixture and suggest that its multiplexed observation is significant and timely. Then, we show that exploiting the kinetics of analytical processes is relevant to selectively detect a given analyte: upon perturbing the system, the kinetic window associated to response read-out has to be matched with that of the targeted reactive module. Eventually, we introduce the state-of-the-art of cell imaging exploiting protocols based on reaction kinetics and draw some promising perspectives. Live recording: In living cells, the multiplexed observation of a large number of targets has recently emerged as a desirable goal. To address this challenge, an attractive road relies on engaging the targets in reactions and exploiting the kinetic signature of the resulting reactive module. This review explores the facets of this strategy and draw some promising perspectives. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
2015 |
Control of brain patterning by engrailed paracrine transfer: A new function of the pbx interaction domain Article de journal C Rampon; C Gauron; T Lin; F Meda; E Dupont; A Cosson; E Ipendey; A Frerot; I Aujard; T Le Saux; D Bensimon; L Jullien; M Volovitch; S Vriz; A Joliot Development (Cambridge), 142 (10), p. 1840–1849, 2015. @article{Rampon:2015, title = {Control of brain patterning by engrailed paracrine transfer: A new function of the pbx interaction domain}, author = {C Rampon and C Gauron and T Lin and F Meda and E Dupont and A Cosson and E Ipendey and A Frerot and I Aujard and T Le Saux and D Bensimon and L Jullien and M Volovitch and S Vriz and A Joliot}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84929206944&doi=10.1242%2fdev.114181&partnerID=40&md5=016ff1da90c2292976a12fee82b3ed59}, doi = {10.1242/dev.114181}, year = {2015}, date = {2015-01-01}, journal = {Development (Cambridge)}, volume = {142}, number = {10}, pages = {1840--1849}, abstract = {Homeoproteins of the Engrailed family are involved in the patterning of mesencephalic boundaries through a mechanism classically ascribed to their transcriptional functions. In light of recent reports on the paracrine activity of homeoproteins, including Engrailed, we asked whether Engrailed intercellular transfer was also involved in brain patterning and boundary formation. Using time-controlled activation of Engrailed combined with tools that block its transfer, we show that the positioning of the diencephalic-mesencephalic boundary (DMB) requires Engrailed paracrine activity. Both zebrafish Eng2a and Eng2b are competent for intercellular transfer in vivo, but only extracellular endogenous Eng2b, and not Eng2a, participates in DMB positioning. In addition, disruption of the Pbx-interacting motif in Engrailed, known to strongly reduce the gain-of-function phenotype, also downregulates Engrailed transfer, thus revealing an unsuspected participation of the Pbx interaction domain in this pathway. © 2015. Published by The Company of Biologists Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Homeoproteins of the Engrailed family are involved in the patterning of mesencephalic boundaries through a mechanism classically ascribed to their transcriptional functions. In light of recent reports on the paracrine activity of homeoproteins, including Engrailed, we asked whether Engrailed intercellular transfer was also involved in brain patterning and boundary formation. Using time-controlled activation of Engrailed combined with tools that block its transfer, we show that the positioning of the diencephalic-mesencephalic boundary (DMB) requires Engrailed paracrine activity. Both zebrafish Eng2a and Eng2b are competent for intercellular transfer in vivo, but only extracellular endogenous Eng2b, and not Eng2a, participates in DMB positioning. In addition, disruption of the Pbx-interacting motif in Engrailed, known to strongly reduce the gain-of-function phenotype, also downregulates Engrailed transfer, thus revealing an unsuspected participation of the Pbx interaction domain in this pathway. © 2015. Published by The Company of Biologists Ltd. |
Expanding discriminative dimensions for analysis and imaging Article de journal J Querard; A Gautier; T Le Saux; L Jullien Chemical Science, 6 (5), p. 2968–2978, 2015. @article{Querard:2015, title = {Expanding discriminative dimensions for analysis and imaging}, author = {J Querard and A Gautier and T Le Saux and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928139717&doi=10.1039%2fc4sc03955f&partnerID=40&md5=aeed36c64e258429fa7a7aa11b8baba8}, doi = {10.1039/c4sc03955f}, year = {2015}, date = {2015-01-01}, journal = {Chemical Science}, volume = {6}, number = {5}, pages = {2968--2978}, abstract = {Eliminating the contribution of interfering compounds is a key step in chemical analysis. In complex media, one possible approach is to perform a preliminary separation. However purification is often demanding, long, and costly; it may also considerably alter the properties of interacting components of the mixture (e.g. in a living cell). Hence there is a strong interest for developing separation-free non-invasive analytical protocols. Using photoswitchable probes as labelling and titration contrast agents, we demonstrate that the association of a modulated monochromatic light excitation with a kinetic filtering of the overall observable is much more attractive than constant excitation to read-out the contribution from a target probe under adverse conditions. An extensive theoretical framework enabled us to optimize the out-of-phase concentration first-order response of a photoswitchable probe to modulated illumination by appropriately matching the average light intensity and the radial frequency of the light modulation to the probe dynamics. Thus, we can selectively and quantitatively extract from an overall signal the contribution from a target photoswitchable probe within a mixture of species, photoswitchable or not. This simple titration strategy is more specifically developed in the context of fluorescence imaging, which offers promising perspectives. © The Royal Society of Chemistry 2015.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eliminating the contribution of interfering compounds is a key step in chemical analysis. In complex media, one possible approach is to perform a preliminary separation. However purification is often demanding, long, and costly; it may also considerably alter the properties of interacting components of the mixture (e.g. in a living cell). Hence there is a strong interest for developing separation-free non-invasive analytical protocols. Using photoswitchable probes as labelling and titration contrast agents, we demonstrate that the association of a modulated monochromatic light excitation with a kinetic filtering of the overall observable is much more attractive than constant excitation to read-out the contribution from a target probe under adverse conditions. An extensive theoretical framework enabled us to optimize the out-of-phase concentration first-order response of a photoswitchable probe to modulated illumination by appropriately matching the average light intensity and the radial frequency of the light modulation to the probe dynamics. Thus, we can selectively and quantitatively extract from an overall signal the contribution from a target photoswitchable probe within a mixture of species, photoswitchable or not. This simple titration strategy is more specifically developed in the context of fluorescence imaging, which offers promising perspectives. © The Royal Society of Chemistry 2015. |
2014 |
Disassembly kinetics of quinone-methide-based self-immolative spacers that contain aromatic nitrogen heterocycles Article de journal A Alouane; R Labruère; K J Silvestre; T Le Saux; F Schmidt; L Jullien Chemistry - An Asian Journal, 9 (5), p. 1334–1340, 2014. @article{Alouane:2014, title = {Disassembly kinetics of quinone-methide-based self-immolative spacers that contain aromatic nitrogen heterocycles}, author = {A Alouane and R Labru\`{e}re and K J Silvestre and T Le Saux and F Schmidt and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899466220&doi=10.1002%2fasia.201400051&partnerID=40&md5=a330e468d911417e1ffcc3eae297f08a}, doi = {10.1002/asia.201400051}, year = {2014}, date = {2014-01-01}, journal = {Chemistry - An Asian Journal}, volume = {9}, number = {5}, pages = {1334--1340}, abstract = {We prepared several pyridine- and pyrimidine-based self-immolative spacer groups to evaluate the significance of the resonance energy of the spacer aromatic ring on the kinetics of 1,4- and 1,6-elimination reactions, which govern spacer disassembly. Subsequently, we relied on a photoactivation procedure to accurately analyze the disassembly kinetics. Beyond providing new results that are relevant for deriving quantitative structure-property relationships, herein, we demonstrate that pH value can be used as an efficient parameter to finely control the disassembly time of a self-immolative spacer after an initial activation. Burn rubber: Kinetic analysis of the pH-dependent disassembly of self-immolative spacers that contain aromatic nitrogen heterocycles was performed. Electron-poor pyrimidine cores exhibited the longest disassembly times. This study confirms the trend that electron-rich aryl cores accelerate self-immolation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We prepared several pyridine- and pyrimidine-based self-immolative spacer groups to evaluate the significance of the resonance energy of the spacer aromatic ring on the kinetics of 1,4- and 1,6-elimination reactions, which govern spacer disassembly. Subsequently, we relied on a photoactivation procedure to accurately analyze the disassembly kinetics. Beyond providing new results that are relevant for deriving quantitative structure-property relationships, herein, we demonstrate that pH value can be used as an efficient parameter to finely control the disassembly time of a self-immolative spacer after an initial activation. Burn rubber: Kinetic analysis of the pH-dependent disassembly of self-immolative spacers that contain aromatic nitrogen heterocycles was performed. Electron-poor pyrimidine cores exhibited the longest disassembly times. This study confirms the trend that electron-rich aryl cores accelerate self-immolation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
How to prepare the minds at best? Article de journal L Jullien Actualite Chimique, (385), p. 15–17, 2014. @article{Jullien:2014, title = {How to prepare the minds at best?}, author = {L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901981303&partnerID=40&md5=663a293b401b02e84bb6994e38140f46}, year = {2014}, date = {2014-01-01}, journal = {Actualite Chimique}, number = {385}, pages = {15--17}, abstract = {How to prepare the minds at best? Each teacher has to conceive and implement her/his course. This article reports on the experience of a professor of chemistry, who significantly has devoted his time and his thoughts to this exercise upon constantly aiming at educating, emancipating, and freeing young pupils as well as confirmed students.}, keywords = {}, pubstate = {published}, tppubtype = {article} } How to prepare the minds at best? Each teacher has to conceive and implement her/his course. This article reports on the experience of a professor of chemistry, who significantly has devoted his time and his thoughts to this exercise upon constantly aiming at educating, emancipating, and freeing young pupils as well as confirmed students. |
Photocontrolled ionization in the corona of rodlike assemblies of diblock copolymers Article de journal J Sun; L Jia; M Emond; M -H Li; E Marie; L Jullien; C Tribet Macromolecules, 47 (5), p. 1684–1692, 2014. @article{Sun:2014, title = {Photocontrolled ionization in the corona of rodlike assemblies of diblock copolymers}, author = {J Sun and L Jia and M Emond and M -H Li and E Marie and L Jullien and C Tribet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900623616&doi=10.1021%2fma402591y&partnerID=40&md5=096eeaa435f309dc54c178b236d1de7c}, doi = {10.1021/ma402591y}, year = {2014}, date = {2014-01-01}, journal = {Macromolecules}, volume = {47}, number = {5}, pages = {1684--1692}, abstract = {To remotely control ionization of polymer assemblies, we tailored amphiphilic diblock polyacrylates with varying hydrophilic and hydrophobic block lengths and containing pendant 2-hydroxyazobenzene photoswitchable groups in the hydrophilic block. Formation in water of rodlike polymer micelles was obtained upon hydrophobic assembly of the pendant cholesterol groups present in the hydrophobic block. Phototriggered variation of both pH and UV-vis spectral properties confirmed that hydroxylazobenzene moieties, gathered in the hydrophilic corona, underwent both isomerization and ionization upon exposure to UV light. Dispersions of rods can accordingly be ionized on demand. © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } To remotely control ionization of polymer assemblies, we tailored amphiphilic diblock polyacrylates with varying hydrophilic and hydrophobic block lengths and containing pendant 2-hydroxyazobenzene photoswitchable groups in the hydrophilic block. Formation in water of rodlike polymer micelles was obtained upon hydrophobic assembly of the pendant cholesterol groups present in the hydrophobic block. Phototriggered variation of both pH and UV-vis spectral properties confirmed that hydroxylazobenzene moieties, gathered in the hydrophilic corona, underwent both isomerization and ionization upon exposure to UV light. Dispersions of rods can accordingly be ionized on demand. © 2014 American Chemical Society. |
Rapidly tunable and compact coherent Raman scattering light source for molecular spectroscopy Article de journal S Saint-Jalm; P Berto; L Jullien; E R Andresen; H Rigneault Journal of Raman Spectroscopy, 45 (7), p. 515–520, 2014. @article{Saint-Jalm:2014, title = {Rapidly tunable and compact coherent Raman scattering light source for molecular spectroscopy}, author = {S Saint-Jalm and P Berto and L Jullien and E R Andresen and H Rigneault}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904215402&doi=10.1002%2fjrs.4514&partnerID=40&md5=4cb0181caada13d4877cdcb5ab9d00f8}, doi = {10.1002/jrs.4514}, year = {2014}, date = {2014-01-01}, journal = {Journal of Raman Spectroscopy}, volume = {45}, number = {7}, pages = {515--520}, abstract = {We present a rapidly tunable (over 400 cm -1) and compact (0.7 m 2 footprint) coherent Raman scattering light source performing both coherent anti-Stokes Raman scattering and stimulated Raman scattering microspectroscopy. We use spectral focusing of a femtosecond Ti:Sapphire pulse and a redshifted soliton generated in a photonic crystal fiber to reach suitable spectral resolution and to rapidly acquire spectra by means of a delay line translation. The coherent Raman scattering light source is used to monitor the molecular equilibrium shift between hydrogen phosphate and dihydrogen phosphate ions under pH change. Copyright © 2014 John Wiley & Sons, Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a rapidly tunable (over 400 cm -1) and compact (0.7 m 2 footprint) coherent Raman scattering light source performing both coherent anti-Stokes Raman scattering and stimulated Raman scattering microspectroscopy. We use spectral focusing of a femtosecond Ti:Sapphire pulse and a redshifted soliton generated in a photonic crystal fiber to reach suitable spectral resolution and to rapidly acquire spectra by means of a delay line translation. The coherent Raman scattering light source is used to monitor the molecular equilibrium shift between hydrogen phosphate and dihydrogen phosphate ions under pH change. Copyright © 2014 John Wiley & Sons, Ltd. |
2013 |
A blue-absorbing photolabile protecting group for in vivo chromatically orthogonal photoactivation Article de journal L Fournier; C Gauron; L Xu; I Aujard; T Le Saux; N Gagey-Eilstein; S Maurin; S Dubruille; J -B Baudin; D Bensimon; M Volovitch; S Vriz; L Jullien ACS Chemical Biology, 8 (7), p. 1528–1536, 2013. @article{Fournier:2013a, title = {A blue-absorbing photolabile protecting group for in vivo chromatically orthogonal photoactivation}, author = {L Fournier and C Gauron and L Xu and I Aujard and T Le Saux and N Gagey-Eilstein and S Maurin and S Dubruille and J -B Baudin and D Bensimon and M Volovitch and S Vriz and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880534465&doi=10.1021%2fcb400178m&partnerID=40&md5=a6d82b0b12d74445d9235b43207903ed}, doi = {10.1021/cb400178m}, year = {2013}, date = {2013-01-01}, journal = {ACS Chemical Biology}, volume = {8}, number = {7}, pages = {1528--1536}, abstract = {The small and synthetically easily accessible 7-diethylamino-4- thiocoumarinylmethyl photolabile protecting group has been validated for uncaging with blue light. It exhibits a significant action cross-section for uncaging in the 470-500 nm wavelength range and a low light absorption between 350 and 400 nm. These attractive features have been implemented in living zebrafish embryos to perform chromatic orthogonal photoactivation of two biologically active species controlling biological development with UV and blue-cyan light sources, respectively. © 2013 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The small and synthetically easily accessible 7-diethylamino-4- thiocoumarinylmethyl photolabile protecting group has been validated for uncaging with blue light. It exhibits a significant action cross-section for uncaging in the 470-500 nm wavelength range and a low light absorption between 350 and 400 nm. These attractive features have been implemented in living zebrafish embryos to perform chromatic orthogonal photoactivation of two biologically active species controlling biological development with UV and blue-cyan light sources, respectively. © 2013 American Chemical Society. |
Coumarinylmethyl caging groups with redshifted absorption Article de journal L Fournier; I Aujard; T Le Saux; S Maurin; S Beaupierre; J -B Baudin; L Jullien Chemistry - A European Journal, 19 (51), p. 17494–17507, 2013. @article{Fournier:2013, title = {Coumarinylmethyl caging groups with redshifted absorption}, author = {L Fournier and I Aujard and T Le Saux and S Maurin and S Beaupierre and J -B Baudin and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84890121904&doi=10.1002%2fchem.201302630&partnerID=40&md5=2dc2ad1b5ad79b030bc0b916107658cc}, doi = {10.1002/chem.201302630}, year = {2013}, date = {2013-01-01}, journal = {Chemistry - A European Journal}, volume = {19}, number = {51}, pages = {17494--17507}, abstract = {The small and synthetically easily accessible coumarinylmethyl backbone has been modified to generate a family of photolabile protecting groups with redshifted absorption. We relied on introducing electron-donating groups in the 7 position and electron-withdrawing groups in the 2-, and 2- and 3 positions. In particular, we showed that the diethylamino-thiocoumarylmethyl and the diethylamino-coumarylidenemalononitrilemethyl are relevant for uncaging with cyan light. They both exhibit a significant action cross section for uncaging in the 470-500 nm wavelength range and a low light absorption between 350 and 400 nm. These attractive features are favorable to perform chromatic orthogonal photoactivation with UV and blue-cyan light sources, respectively. Revealing protecting groups: The coumarinylmethyl backbone was used to generate a family of photolabile protecting groups with redshifted absorption (see scheme). Several members exhibit a significant action cross section for uncaging in the 470-500 nm wavelength range and a low light absorption between 350 and 400 nm. These features are favorable for chromatic orthogonal photoactivation with UV and blue-cyan light sources, respectively. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The small and synthetically easily accessible coumarinylmethyl backbone has been modified to generate a family of photolabile protecting groups with redshifted absorption. We relied on introducing electron-donating groups in the 7 position and electron-withdrawing groups in the 2-, and 2- and 3 positions. In particular, we showed that the diethylamino-thiocoumarylmethyl and the diethylamino-coumarylidenemalononitrilemethyl are relevant for uncaging with cyan light. They both exhibit a significant action cross section for uncaging in the 470-500 nm wavelength range and a low light absorption between 350 and 400 nm. These attractive features are favorable to perform chromatic orthogonal photoactivation with UV and blue-cyan light sources, respectively. Revealing protecting groups: The coumarinylmethyl backbone was used to generate a family of photolabile protecting groups with redshifted absorption (see scheme). Several members exhibit a significant action cross section for uncaging in the 470-500 nm wavelength range and a low light absorption between 350 and 400 nm. These features are favorable for chromatic orthogonal photoactivation with UV and blue-cyan light sources, respectively. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Identification of two-step chemical mechanisms and determination of thermokinetic parameters using frequency responses to small temperature oscillations Article de journal F Closa; C Gosse; L Jullien; A Lemarchand Journal of Chemical Physics, 138 (24), 2013. @article{Closa:2013, title = {Identification of two-step chemical mechanisms and determination of thermokinetic parameters using frequency responses to small temperature oscillations}, author = {F Closa and C Gosse and L Jullien and A Lemarchand}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879925744&doi=10.1063%2f1.4811288&partnerID=40&md5=cc245cf42ac7990ee3793cafb50dfdfd}, doi = {10.1063/1.4811288}, year = {2013}, date = {2013-01-01}, journal = {Journal of Chemical Physics}, volume = {138}, number = {24}, abstract = {Increased focus on kinetic signatures in biology, coupled with the lack of simple tools for chemical dynamics characterization, lead us to develop an efficient method for mechanism identification. A small thermal modulation is used to reveal chemical dynamics, which makes the technique compatible with in cellulo imaging. Then, the detection of concentration oscillations in an appropriate frequency range followed by a judicious analytical treatment of the data is sufficient to determine the number of chemical characteristic times, the reaction mechanism, and the full set of associated rate constants and enthalpies of reaction. To illustrate the scope of the method, dimeric protein folding is chosen as a biologically relevant example of nonlinear mechanism with one or two characteristic times. © 2013 AIP Publishing LLC.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Increased focus on kinetic signatures in biology, coupled with the lack of simple tools for chemical dynamics characterization, lead us to develop an efficient method for mechanism identification. A small thermal modulation is used to reveal chemical dynamics, which makes the technique compatible with in cellulo imaging. Then, the detection of concentration oscillations in an appropriate frequency range followed by a judicious analytical treatment of the data is sufficient to determine the number of chemical characteristic times, the reaction mechanism, and the full set of associated rate constants and enthalpies of reaction. To illustrate the scope of the method, dimeric protein folding is chosen as a biologically relevant example of nonlinear mechanism with one or two characteristic times. © 2013 AIP Publishing LLC. |
Light activation for the versatile and accurate kinetic analysis of disassembly of self-immolative spacers Article de journal A Alouane; R Labruère; T Le Saux; I Aujard; S Dubruille; F Schmidt; L Jullien Chemistry - A European Journal, 19 (35), p. 11717–11724, 2013. @article{Alouane:2013, title = {Light activation for the versatile and accurate kinetic analysis of disassembly of self-immolative spacers}, author = {A Alouane and R Labru\`{e}re and T Le Saux and I Aujard and S Dubruille and F Schmidt and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84882877857&doi=10.1002%2fchem.201301298&partnerID=40&md5=d2c00551ce1409fe58d0716e0cc747c8}, doi = {10.1002/chem.201301298}, year = {2013}, date = {2013-01-01}, journal = {Chemistry - A European Journal}, volume = {19}, number = {35}, pages = {11717--11724}, abstract = {Three procedures that rely on photoactivation are introduced to accurately analyze the disassembly kinetics of a collection of self-immolative spacer groups within the window 10-2-103 s. Our results are relevant for deriving quantitative structure-property relationships. In particular, we have been able to access 20 ms temporal resolution, which made possible the measurement of the shortest ever reported disassembly time for an activated self-immolative spacer. Quick as lightning! Accurate kinetic analysis of the disassembly of various self-immolative spacers in a 10 -2-103 s window was achieved. An epifluorescence setup allowed the measurement of the shortest time (20 ms) for a self-immolation event. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Three procedures that rely on photoactivation are introduced to accurately analyze the disassembly kinetics of a collection of self-immolative spacer groups within the window 10-2-103 s. Our results are relevant for deriving quantitative structure-property relationships. In particular, we have been able to access 20 ms temporal resolution, which made possible the measurement of the shortest ever reported disassembly time for an activated self-immolative spacer. Quick as lightning! Accurate kinetic analysis of the disassembly of various self-immolative spacers in a 10 -2-103 s window was achieved. An epifluorescence setup allowed the measurement of the shortest time (20 ms) for a self-immolation event. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Photochemical properties of Spinach and its use in selective imaging Article de journal P Wang; J Querard; S Maurin; S S Nath; T Le Saux; A Gautier; L Jullien Chemical Science, 4 (7), p. 2865–2873, 2013. @article{Wang:2013a, title = {Photochemical properties of Spinach and its use in selective imaging}, author = {P Wang and J Querard and S Maurin and S S Nath and T Le Saux and A Gautier and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878785970&doi=10.1039%2fc3sc50729g&partnerID=40&md5=1deeb79d383d404915eba832d5c4b9a6}, doi = {10.1039/c3sc50729g}, year = {2013}, date = {2013-01-01}, journal = {Chemical Science}, volume = {4}, number = {7}, pages = {2865--2873}, abstract = {The progress in imaging instrumentation and probes has revolutionized the way biologists look at living systems. Current tools enable both observation and quantification of biomolecules, allowing the measurement of their complex spatial organization and the dynamic processes in which they are involved. Here, we report reversible photoconversion in the Spinach system, a recently described fluorescent probe for RNA imaging. Upon irradiation with blue light, the Spinach system undergoes photoconversion to a less fluorescent state and fully recovers its signal in the dark. Through thermodynamic titration, stopped-flow, and light-jump experiments, we propose a dynamic model that accounts for the photochemical behavior of the Spinach system. We exploit the dynamic fluorogen exchange and the unprecedented photoconversion properties in a non-covalent fluorescence turn-on system to significantly improve signal-to-background ratio during long-term microscopy imaging. © 2013 Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The progress in imaging instrumentation and probes has revolutionized the way biologists look at living systems. Current tools enable both observation and quantification of biomolecules, allowing the measurement of their complex spatial organization and the dynamic processes in which they are involved. Here, we report reversible photoconversion in the Spinach system, a recently described fluorescent probe for RNA imaging. Upon irradiation with blue light, the Spinach system undergoes photoconversion to a less fluorescent state and fully recovers its signal in the dark. Through thermodynamic titration, stopped-flow, and light-jump experiments, we propose a dynamic model that accounts for the photochemical behavior of the Spinach system. We exploit the dynamic fluorogen exchange and the unprecedented photoconversion properties in a non-covalent fluorescence turn-on system to significantly improve signal-to-background ratio during long-term microscopy imaging. © 2013 Royal Society of Chemistry. |
2012 |
"Self-immolative" spacer for uncaging with fluorescence reporting Article de journal R Labruère; A Alouane; T Le Saux; I Aujard; P Pelupessy; A Gautier; S Dubruille; F Schmidt; L Jullien Angewandte Chemie - International Edition, 51 (37), p. 9344–9347, 2012. @article{Labruere:2012, title = {"Self-immolative" spacer for uncaging with fluorescence reporting}, author = {R Labru\`{e}re and A Alouane and T Le Saux and I Aujard and P Pelupessy and A Gautier and S Dubruille and F Schmidt and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865847445&doi=10.1002%2fanie.201204032&partnerID=40&md5=b61369ac1effc61c29106c6a64c6cd44}, doi = {10.1002/anie.201204032}, year = {2012}, date = {2012-01-01}, journal = {Angewandte Chemie - International Edition}, volume = {51}, number = {37}, pages = {9344--9347}, abstract = {Dual photoliberation: A caged, branched, self-immolative spacer (see scheme, gray box) was designed to rapidly and simultaneously release a desired compound (green) and a fluorophore (red) upon photoactivation. Careful kinetic analysis of the disassembly of the spacer shows that it occurs on the shortest time scale reported to date. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Dual photoliberation: A caged, branched, self-immolative spacer (see scheme, gray box) was designed to rapidly and simultaneously release a desired compound (green) and a fluorophore (red) upon photoactivation. Careful kinetic analysis of the disassembly of the spacer shows that it occurs on the shortest time scale reported to date. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Chemical mechanism identification from frequency response to small temperature modulation Article de journal A Lemarchand; H Berthoumieux; L Jullien; C Gosse Journal of Physical Chemistry A, 116 (33), p. 8455–8463, 2012. @article{Lemarchand:2012, title = {Chemical mechanism identification from frequency response to small temperature modulation}, author = {A Lemarchand and H Berthoumieux and L Jullien and C Gosse}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84866372438&doi=10.1021%2fjp305737&partnerID=40&md5=69f2cc8fb4aa802f8af8abbf2e0a8d1d}, doi = {10.1021/jp305737}, year = {2012}, date = {2012-01-01}, journal = {Journal of Physical Chemistry A}, volume = {116}, number = {33}, pages = {8455--8463}, abstract = {The description of interactions between biochemical species and the elucidation of the corresponding chemical mechanisms encounter an increasing interest both for the comprehension of biological pathways at the molecular scale and for the rationalization of drug design. Relying on powerful experimental tools such as thermal microfluidics and fluorescence detection, we propose a methodology to determine the chemical mechanism of a reaction without fitting parameters. A mechanism consistent with the accessible knowledge is assumed, and the assumption is checked through an iterative protocol. The test is based on the frequency analysis of the response of a targeted reactive species to temperature modulation. We build specific functions of the frequency that are constant for the assumed mechanism and show that the graph of these functions can be drawn from appropriate data analysis. The method is general and can be applied to any complex mechanism. It is here illustrated in detail in the case of single relaxation time mechanisms. © 2012 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The description of interactions between biochemical species and the elucidation of the corresponding chemical mechanisms encounter an increasing interest both for the comprehension of biological pathways at the molecular scale and for the rationalization of drug design. Relying on powerful experimental tools such as thermal microfluidics and fluorescence detection, we propose a methodology to determine the chemical mechanism of a reaction without fitting parameters. A mechanism consistent with the accessible knowledge is assumed, and the assumption is checked through an iterative protocol. The test is based on the frequency analysis of the response of a targeted reactive species to temperature modulation. We build specific functions of the frequency that are constant for the assumed mechanism and show that the graph of these functions can be drawn from appropriate data analysis. The method is general and can be applied to any complex mechanism. It is here illustrated in detail in the case of single relaxation time mechanisms. © 2012 American Chemical Society. |