Bioinorganic Chemistry and Redox Homeostasis
Our website :
Metals in Biology and Redox Homeostasis
A new name for our research group: METROX
CONGRATULATIONS to our former PhD students:
Jean Bouvet for his selection to the MBA « collège des ingénieurs » (jan. 2024)
Paul Demay-Drouhard, who was appointed as a CNRS researcher (section 12, ICOA Orléans) in 2023
Martha Zoumpoulaki for her selection to the MBA « collège des ingénieurs » (oct. 2021) and her recruitment at Air Liquide in 2023.
Koudedja Coulibaly, who was recruited by Air Liquide in 2021
Emilie Mathieu, who was appointed as a CNRS researcher (section 16, LCC Toulouse) in 2021
Sarah Hostachy, who was appointed as a CEAEA researcher (LCBM, Grenoble) in 2020
Our personal webpages and resumes:
Alice Balfourier (ORCID: 0000-0002-4801-1388)
Hélène Bertrand (ORCID: 0000-0002-3841-022X)
Nicolas Delsuc (ORCID: 0000-0001-5570-8311)
Clotilde Policar (ORCID: 0000-0003-0255-1650)
Christine Rampon (ORCID: 0000-0002-1444-3166)
Michel Volovitch (ORCID: 0000-0002-7488-764X)
Sophie Vriz
Some news about our work:
About our work and equity in science (in French): https://www.youtube.com/watch?v=ZfyFIkh_G4k
https://www.inc.cnrs.fr/fr/cnrsinfo/des-complexes-bio-inspires-dans-le-vent
https://www.ens.psl.eu/actualites/des-catalyseurs-bio-inspires-pour-lutter-contre-le-stress-oxydant
Publications of the group:
((Go back to the publication page of the ens-bic website))
2015 |
Photoswitching Kinetics and Phase-Sensitive Detection Add Discriminative Dimensions for Selective Fluorescence Imaging Article de journal Jérôme Querard; Tal-Zvi Markus; Marie-Aude Plamont; Carole Gauron; Pengcheng Wang; Agathe Espagne; Michel Volovitch; Sophie Vriz; Vincent Croquette; Arnaud Gautier; Thomas Le Saux; Ludovic Jullien Angewandte Chemie International Edition, 54 (9), p. 2633-2637, 2015, ISSN: 1433-7851. @article{RN43b, title = {Photoswitching Kinetics and Phase-Sensitive Detection Add Discriminative Dimensions for Selective Fluorescence Imaging}, author = {J\'{e}r\^{o}me Querard and Tal-Zvi Markus and Marie-Aude Plamont and Carole Gauron and Pengcheng Wang and Agathe Espagne and Michel Volovitch and Sophie Vriz and Vincent Croquette and Arnaud Gautier and Thomas Le Saux and Ludovic Jullien}, doi = {10.1002/anie.201408985}, issn = {1433-7851}, year = {2015}, date = {2015-01-01}, journal = {Angewandte Chemie International Edition}, volume = {54}, number = {9}, pages = {2633-2637}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2014 |
PMI: a $Delta$$Psi$m independent pharmacological regulator of mitophagy Article de journal Daniel A East; Francesca Fagiani; James Crosby; Nikolaos D Georgakopoulos; Hélène Bertrand; Marjolein Schaap; Adrian Fowkes; Geoff Wells; Michelangelo Campanella Chemistry & biology, 21 (11), p. 1585–1596, 2014, ISSN: 1879-1301. @article{East2014, title = {PMI: a $Delta$$Psi$m independent pharmacological regulator of mitophagy}, author = {Daniel A East and Francesca Fagiani and James Crosby and Nikolaos D Georgakopoulos and H\'{e}l{\`{e}}ne Bertrand and Marjolein Schaap and Adrian Fowkes and Geoff Wells and Michelangelo Campanella}, url = {https://www.ncbi.nlm.nih.gov/pubmed/25455860 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4245710/}, doi = {10.1016/j.chembiol.2014.09.019}, issn = {1879-1301}, year = {2014}, date = {2014-11-01}, journal = {Chemistry & biology}, volume = {21}, number = {11}, pages = {1585--1596}, publisher = {Elsevier}, abstract = {Mitophagy is central to mitochondrial and cellular homeostasis and operates via the PINK1/Parkin pathway targeting mitochondria devoid of membrane potential ($Delta$$Psi$m) to autophagosomes. Although mitophagy is recognized as a fundamental cellular process, selective pharmacologic modulators of mitophagy are almost nonexistent. We developed a compound that increases the expression and signaling of the autophagic adaptor molecule P62/SQSTM1 and forces mitochondria into autophagy. The compound, P62-mediated mitophagy inducer (PMI), activates mitophagy without recruiting Parkin or collapsing $Delta$$Psi$m and retains activity in cells devoid of a fully functional PINK1/Parkin pathway. PMI drives mitochondria to a process of quality control without compromising the bio-energetic competence of the whole network while exposing just those organelles to be recycled. Thus, PMI circumvents the toxicity and some of the nonspecific effects associated with the abrupt dissipation of $Delta$$Psi$m by ionophores routinely used to induce mitophagy and represents a prototype pharmacological tool to investigate the molecular mechanisms of mitophagy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Mitophagy is central to mitochondrial and cellular homeostasis and operates via the PINK1/Parkin pathway targeting mitochondria devoid of membrane potential ($Delta$$Psi$m) to autophagosomes. Although mitophagy is recognized as a fundamental cellular process, selective pharmacologic modulators of mitophagy are almost nonexistent. We developed a compound that increases the expression and signaling of the autophagic adaptor molecule P62/SQSTM1 and forces mitochondria into autophagy. The compound, P62-mediated mitophagy inducer (PMI), activates mitophagy without recruiting Parkin or collapsing $Delta$$Psi$m and retains activity in cells devoid of a fully functional PINK1/Parkin pathway. PMI drives mitochondria to a process of quality control without compromising the bio-energetic competence of the whole network while exposing just those organelles to be recycled. Thus, PMI circumvents the toxicity and some of the nonspecific effects associated with the abrupt dissipation of $Delta$$Psi$m by ionophores routinely used to induce mitophagy and represents a prototype pharmacological tool to investigate the molecular mechanisms of mitophagy. |
Influence of the side-chain length on the cellular uptake and the cytotoxicity of rhenium triscarbonyl derivatives: A bimodal infrared and luminescence quantitative study Article de journal S Clède; F Lambert; R Saint-Fort; M -A Plamont; H Bertrand; A Vessières; C Policar Chemistry - A European Journal, 20 (28), p. 8714–8722, 2014. @article{Clede:2014, title = {Influence of the side-chain length on the cellular uptake and the cytotoxicity of rhenium triscarbonyl derivatives: A bimodal infrared and luminescence quantitative study}, author = {S Cl\`{e}de and F Lambert and R Saint-Fort and M -A Plamont and H Bertrand and A Vessi\`{e}res and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903724808&doi=10.1002%2fchem.201402471&partnerID=40&md5=7334edd420d748a4418df936173a79b9}, doi = {10.1002/chem.201402471}, year = {2014}, date = {2014-01-01}, journal = {Chemistry - A European Journal}, volume = {20}, number = {28}, pages = {8714--8722}, abstract = {Rhenium triscarbonyl complexes fac-[Re(CO)3(NtextasciicircumN)] with appropriate ancillary NtextasciicircumN ligands are relevant for fluorescent bio-imaging. Recently, we have shown that [Re(CO)3] cores can also be efficiently mapped inside cells using their IR signature and that they can thus be used in a bimodal approach. To describe them we have coined the term SCoMPIs for single-core multimodal probes for imaging. In the context of the use of these SCoMPIs in bio-imaging, the questions of their cellular uptake and cytotoxicity are critical. We report here a series of compounds derived from the [Re(CO) 3Cl(pyta)] core (pyta=4-(2-pyridyl)-1,2,3-triazole). The pyta ligand is of interest because it can be easily functionalized. Aliphatic side chains (C4, C8, and C12) were appended to this core. A correlative study involving IR and luminescence was performed to monitor and quantify their cellular internalization. We studied the relationship between lipophilicity (log P(o/w)), cytotoxicity (IC50), and cellular uptake, and we showed that both uptake and cytotoxicity increase with the length of the side chain, with a higher uptake for the C12 derivative. This study stresses the distinction that has to be made between apparent toxicity, determined as an incubation concentration IC50, and intrinsic toxicity. Indeed, the intrinsic toxicity of a compound can remain hidden if it is not cell permeable. Therefore it must be kept in mind that IC50 values are composite values, reflecting both cellular uptake and intrinsic toxicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Rhenium triscarbonyl complexes fac-[Re(CO)3(NtextasciicircumN)] with appropriate ancillary NtextasciicircumN ligands are relevant for fluorescent bio-imaging. Recently, we have shown that [Re(CO)3] cores can also be efficiently mapped inside cells using their IR signature and that they can thus be used in a bimodal approach. To describe them we have coined the term SCoMPIs for single-core multimodal probes for imaging. In the context of the use of these SCoMPIs in bio-imaging, the questions of their cellular uptake and cytotoxicity are critical. We report here a series of compounds derived from the [Re(CO) 3Cl(pyta)] core (pyta=4-(2-pyridyl)-1,2,3-triazole). The pyta ligand is of interest because it can be easily functionalized. Aliphatic side chains (C4, C8, and C12) were appended to this core. A correlative study involving IR and luminescence was performed to monitor and quantify their cellular internalization. We studied the relationship between lipophilicity (log P(o/w)), cytotoxicity (IC50), and cellular uptake, and we showed that both uptake and cytotoxicity increase with the length of the side chain, with a higher uptake for the C12 derivative. This study stresses the distinction that has to be made between apparent toxicity, determined as an incubation concentration IC50, and intrinsic toxicity. Indeed, the intrinsic toxicity of a compound can remain hidden if it is not cell permeable. Therefore it must be kept in mind that IC50 values are composite values, reflecting both cellular uptake and intrinsic toxicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Electrochemical formation and reactivity of a manganese peroxo complex: Acid driven Ħ2O2 generation vs. O-O bond cleavage Article de journal H Y V Ching; E Anxolabéhère-Mallart; H E Colmer; C Costentin; P Dorlet; T A Jackson; C Policar; M Robert Chemical Science, 5 (6), p. 2304–2310, 2014. @article{Ching:2014, title = {Electrochemical formation and reactivity of a manganese peroxo complex: Acid driven {H}2O2 generation vs. O-O bond cleavage}, author = {H Y V Ching and E Anxolab\'{e}h\`{e}re-Mallart and H E Colmer and C Costentin and P Dorlet and T A Jackson and C Policar and M Robert}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900329910&doi=10.1039%2fc3sc53469c&partnerID=40&md5=8b4ecc598d6455d82b1681e608484bc1}, doi = {10.1039/c3sc53469c}, year = {2014}, date = {2014-01-01}, journal = {Chemical Science}, volume = {5}, number = {6}, pages = {2304--2310}, abstract = {The formation of a side-on peroxo [MnIIIL(O2)] complex (L = phenolato-containing pentadentate ligand), resulting from the reaction of electrochemically reduced O2 and [MnIIL] +, is monitored in DMF using cyclic voltammetry, low temperature electronic absorption spectroscopy and electron paramagnetic resonance spectroscopy. Mechanistic studies based on cyclic voltammetry reveal that upon addition of a strong acid the Mn-O bond is broken, resulting in the release of H2O2, whereas in the presence of a weak acid the O-O bond is cleaved via a concerted dissociative electron transfer. This dichotomy of M-O versus O-O bond cleavage is unprecedented for peroxomanganese(iii) complexes and the latter offers a route for electrochemical O2 activation by a manganese(ii) complex. This journal is © the Partner Organisations 2014.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The formation of a side-on peroxo [MnIIIL(O2)] complex (L = phenolato-containing pentadentate ligand), resulting from the reaction of electrochemically reduced O2 and [MnIIL] +, is monitored in DMF using cyclic voltammetry, low temperature electronic absorption spectroscopy and electron paramagnetic resonance spectroscopy. Mechanistic studies based on cyclic voltammetry reveal that upon addition of a strong acid the Mn-O bond is broken, resulting in the release of H2O2, whereas in the presence of a weak acid the O-O bond is cleaved via a concerted dissociative electron transfer. This dichotomy of M-O versus O-O bond cleavage is unprecedented for peroxomanganese(iii) complexes and the latter offers a route for electrochemical O2 activation by a manganese(ii) complex. This journal is © the Partner Organisations 2014. |
Conjugation of a new series of dithiocarbazate schiff base copper(II) complexes with vectors selected to enhance antibacterial activity Article de journal M L Low; L Maigre; P Dorlet; R Guillot; J -M Pagès; K A Crouse; C Policar; N Delsuc Bioconjugate Chemistry, 25 (12), p. 2269–2284, 2014. @article{Low:2014, title = {Conjugation of a new series of dithiocarbazate schiff base copper(II) complexes with vectors selected to enhance antibacterial activity}, author = {M L Low and L Maigre and P Dorlet and R Guillot and J -M Pag\`{e}s and K A Crouse and C Policar and N Delsuc}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84918505283&doi=10.1021%2fbc5004907&partnerID=40&md5=d51ad81235fa7fd9aec14b7acd2c908a}, doi = {10.1021/bc5004907}, year = {2014}, date = {2014-01-01}, journal = {Bioconjugate Chemistry}, volume = {25}, number = {12}, pages = {2269--2284}, abstract = {A new series of six Schiff bases derived from S-methyldithiocarbazate (SMDTC) and S-benzyldithiocarbazate (SBDTC) with methyl levulinate (SMML, SBML), levulinic acid (SMLA, SBLA), and 4-carboxybenzaldehyde (SM4CB, SB4CB) were reacted with copper(II), producing complexes of general formula MLtextlessinftextgreater2textless/inftextgreater (M = Cu(II)}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new series of six Schiff bases derived from S-methyldithiocarbazate (SMDTC) and S-benzyldithiocarbazate (SBDTC) with methyl levulinate (SMML, SBML), levulinic acid (SMLA, SBLA), and 4-carboxybenzaldehyde (SM4CB, SB4CB) were reacted with copper(II), producing complexes of general formula MLtextlessinftextgreater2textless/inftextgreater (M = Cu(II) |
Apo-neocarzinostatin: A protein carrier for Cu(II) glycocomplexes and Cu(II) into U937 and HT29 cell lines Article de journal L Garcia; S Franzoni; F Mussi; M Aumont-Niçaise; H Bertrand; M Desmadril; G Pelosi; A Buschini; C Policar Journal of Inorganic Biochemistry, 135 , p. 40–44, 2014. @article{Garcia:2014, title = {Apo-neocarzinostatin: A protein carrier for Cu(II) glycocomplexes and Cu(II) into U937 and HT29 cell lines}, author = {L Garcia and S Franzoni and F Mussi and M Aumont-Ni\c{c}aise and H Bertrand and M Desmadril and G Pelosi and A Buschini and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896943429&doi=10.1016%2fj.jinorgbio.2014.02.006&partnerID=40&md5=81ab9f0bb44feb00966cfb5735d8901a}, doi = {10.1016/j.jinorgbio.2014.02.006}, year = {2014}, date = {2014-01-01}, journal = {Journal of Inorganic Biochemistry}, volume = {135}, pages = {40--44}, abstract = {In the field of pharmaceuticals there is an increasing need for new delivery systems to overcome the issues of solubility, penetration, toxicity and drug resistance. One of the possible strategies is to use biocarriers such as proteins to encourage the cell-penetration of drugs. In this paper, the use of the apo-protein neocarzinostatin (apo-NCS) as a carrier-protein for two Cu(II) glycocomplexes, previously characterized, and Cu(II) ions was investigated. Its interaction with the metallic compounds was analyzed using microcalorimetry. The dissociation constants were shown to be in the micromolar range. The Cu(II) glycocomplexes, in absence of apo-NCS, were found to be cytotoxic in the U937 and HT29 cell lines whereas the corresponding glycoligands showed no toxicity. The leukemic cell line (U937) seems to be more sensitive to glycocomplexes than the colon cancer cell line (HT29). Interestingly, apo-NCS was shown to increase systematically the antiproliferative activity by a factor of 2 and 3 for Cu(II) glycocomplexes and Cu(II) respectively. The antiproliferative activity detected was not related to proteasome inhibition. This result stresses the importance of new molecular tools for the delivery of Cu(II) to tumor cells using non-covalent association with carriers proteins. © 2014 Elsevier Inc. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the field of pharmaceuticals there is an increasing need for new delivery systems to overcome the issues of solubility, penetration, toxicity and drug resistance. One of the possible strategies is to use biocarriers such as proteins to encourage the cell-penetration of drugs. In this paper, the use of the apo-protein neocarzinostatin (apo-NCS) as a carrier-protein for two Cu(II) glycocomplexes, previously characterized, and Cu(II) ions was investigated. Its interaction with the metallic compounds was analyzed using microcalorimetry. The dissociation constants were shown to be in the micromolar range. The Cu(II) glycocomplexes, in absence of apo-NCS, were found to be cytotoxic in the U937 and HT29 cell lines whereas the corresponding glycoligands showed no toxicity. The leukemic cell line (U937) seems to be more sensitive to glycocomplexes than the colon cancer cell line (HT29). Interestingly, apo-NCS was shown to increase systematically the antiproliferative activity by a factor of 2 and 3 for Cu(II) glycocomplexes and Cu(II) respectively. The antiproliferative activity detected was not related to proteasome inhibition. This result stresses the importance of new molecular tools for the delivery of Cu(II) to tumor cells using non-covalent association with carriers proteins. © 2014 Elsevier Inc. All rights reserved. |
Luminescence modulations of rhenium tricarbonyl complexes induced by structural variations Article de journal H C Bertrand; S Clède; R Guillot; F Lambert; C Policar Inorganic Chemistry, 53 (12), p. 6204–6223, 2014. @article{Bertrand:2014, title = {Luminescence modulations of rhenium tricarbonyl complexes induced by structural variations}, author = {H C Bertrand and S Cl\`{e}de and R Guillot and F Lambert and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902530649&doi=10.1021%2fic5007007&partnerID=40&md5=f3030a715ad7c095b013503a9d5b44a8}, doi = {10.1021/ic5007007}, year = {2014}, date = {2014-01-01}, journal = {Inorganic Chemistry}, volume = {53}, number = {12}, pages = {6204--6223}, abstract = {Octahedral d6 low-spin Re(I) tricarbonyl complexes are of considerable interest as noninvasive imaging probes and have been deeply studied owing to their biological stability, low toxicity, large Stokes shifts, and long luminescence lifetimes. We reported recently the bimodal IR and luminescence imaging of a Re(I) tricarbonyl complex with a Pyta ligand (4-(2-pyridyl)-1,2,3-triazole) in cells and labeled such metal-carbonyl complexes SCoMPIs for single-core multimodal probes for imaging. Re(I) tricarbonyl complexes have unique photophysical properties allowing for their unequivocal detection in cells but also present some weaknesses such as a very low luminescence quantum yield in aqueous medium. Further optimizations would thus be desirable. We therefore developed new Re(I) tricarbonyl complexes prepared from different ancillary ligands. Complexes with benzothiadiazole- triazole ligands show interesting luminescent quantum yields in acetonitrile and may constitute valuable luminescent metal complexes in organic media. A series of complexes with bidentate 1-(2-quinolinyl)-1,2,3-triazole (Taquin) and 1-(2-pyridyl)-1,2,3-triazole (Tapy) ligands bearing various 4-substituted alkyl side chains has been designed and synthesized with efficient procedures. Their photophysical properties have been characterized in acetonitrile and in a H 2O/DMSO (98/2) mixture and compared with those of the parent Quinta- and Pyta-based complexes. Tapy complexes bearing long alkyl chains show impressive enhancement of their luminescent properties relative to the parent Pyta complex. Theoretical calculations have been performed to further characterize this new class of rhenium tricarbonyl complexes. Preliminary cellular imaging studies in MDA-MB231 breast cancer cells reveal a strong increase in the luminescence signal in cells incubated with the Tapy complex substituted with a C12 alkyl chain. This study points out the interesting potential of the Tapy ligand in coordination chemistry, which has been so far underexploited. © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Octahedral d6 low-spin Re(I) tricarbonyl complexes are of considerable interest as noninvasive imaging probes and have been deeply studied owing to their biological stability, low toxicity, large Stokes shifts, and long luminescence lifetimes. We reported recently the bimodal IR and luminescence imaging of a Re(I) tricarbonyl complex with a Pyta ligand (4-(2-pyridyl)-1,2,3-triazole) in cells and labeled such metal-carbonyl complexes SCoMPIs for single-core multimodal probes for imaging. Re(I) tricarbonyl complexes have unique photophysical properties allowing for their unequivocal detection in cells but also present some weaknesses such as a very low luminescence quantum yield in aqueous medium. Further optimizations would thus be desirable. We therefore developed new Re(I) tricarbonyl complexes prepared from different ancillary ligands. Complexes with benzothiadiazole- triazole ligands show interesting luminescent quantum yields in acetonitrile and may constitute valuable luminescent metal complexes in organic media. A series of complexes with bidentate 1-(2-quinolinyl)-1,2,3-triazole (Taquin) and 1-(2-pyridyl)-1,2,3-triazole (Tapy) ligands bearing various 4-substituted alkyl side chains has been designed and synthesized with efficient procedures. Their photophysical properties have been characterized in acetonitrile and in a H 2O/DMSO (98/2) mixture and compared with those of the parent Quinta- and Pyta-based complexes. Tapy complexes bearing long alkyl chains show impressive enhancement of their luminescent properties relative to the parent Pyta complex. Theoretical calculations have been performed to further characterize this new class of rhenium tricarbonyl complexes. Preliminary cellular imaging studies in MDA-MB231 breast cancer cells reveal a strong increase in the luminescence signal in cells incubated with the Tapy complex substituted with a C12 alkyl chain. This study points out the interesting potential of the Tapy ligand in coordination chemistry, which has been so far underexploited. © 2014 American Chemical Society. |
Fourier transform infrared (FT-IR) spectromicroscopy to identify cell organelles: Correlation with fluorescence staining in MCF-7 breast cancer cells Article de journal S Clède; C Policar; C Sandt Applied Spectroscopy, 68 (1), p. 113–117, 2014. @article{Clede:2014a, title = {Fourier transform infrared (FT-IR) spectromicroscopy to identify cell organelles: Correlation with fluorescence staining in MCF-7 breast cancer cells}, author = {S Cl\`{e}de and C Policar and C Sandt}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893060662&doi=10.1366%2f13-07139&partnerID=40&md5=f492b0918395dff47f71071460ac1f20}, doi = {10.1366/13-07139}, year = {2014}, date = {2014-01-01}, journal = {Applied Spectroscopy}, volume = {68}, number = {1}, pages = {113--117}, abstract = {Biomolecules display specific vibrational signatures in the infrared (IR) range, and organelles that concentrate these biomolecules can be identified by these IR signatures. Subcellular identification and location of cell organelles using IR signatures is attractive as it does not require the use of any specific trackers and is thus noninvasive and non-destructive. We show here that endogenous IR absorptions are relevant to detecting and imaging the nucleus, the cytoplasm, and the Golgi apparatus/endoplasmic reticulum in MCF- 7 breast cancer cells, and we compare these results with our previous work on the HeLa cell line. We correlate maps of fixed and dried cells obtained by synchrotron radiation Fourier transform infrared (SR FT-IR) spectromicroscopy with epifluorescence images using fluorescent trackers for Golgi apparatus and nucleus, namely BODIPY TR C5-ceramide complexed to BSA and DAPI, respectively. Interestingly, the ratios of the IR bands CH2:CH 3 (both asymmetric and symmetric) and CO(ester):amide I were shown to be reliable gauges of the lipidic character of a cellular compartment, the -CH2 and the CO(ester) absorptions increasing with the presence of inner membranes like in the Golgi apparatus. © 2014 Society for Applied Spectroscopy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biomolecules display specific vibrational signatures in the infrared (IR) range, and organelles that concentrate these biomolecules can be identified by these IR signatures. Subcellular identification and location of cell organelles using IR signatures is attractive as it does not require the use of any specific trackers and is thus noninvasive and non-destructive. We show here that endogenous IR absorptions are relevant to detecting and imaging the nucleus, the cytoplasm, and the Golgi apparatus/endoplasmic reticulum in MCF- 7 breast cancer cells, and we compare these results with our previous work on the HeLa cell line. We correlate maps of fixed and dried cells obtained by synchrotron radiation Fourier transform infrared (SR FT-IR) spectromicroscopy with epifluorescence images using fluorescent trackers for Golgi apparatus and nucleus, namely BODIPY TR C5-ceramide complexed to BSA and DAPI, respectively. Interestingly, the ratios of the IR bands CH2:CH 3 (both asymmetric and symmetric) and CO(ester):amide I were shown to be reliable gauges of the lipidic character of a cellular compartment, the -CH2 and the CO(ester) absorptions increasing with the presence of inner membranes like in the Golgi apparatus. © 2014 Society for Applied Spectroscopy. |
From IR-Spectromicroscopy using AFM-IR and SR-FTIR to Bimodal Spectromicroscopy using SCoMPIs - Single Core Multimodal Probe for Imaging Article de journal C Policar; C Sylvain; F Lambert; N Delsuc; C Sandt; P Dumas; M Refregiers; M Plamont; A Vessieres; Z Gueroui; A Dazzi Journal of Biological Inorganic Chemistry, 19 , p. S182-S182, 2014, ISSN: 0949-8257. @article{RN23c, title = {From IR-Spectromicroscopy using AFM-IR and SR-FTIR to Bimodal Spectromicroscopy using SCoMPIs - Single Core Multimodal Probe for Imaging}, author = {C Policar and C Sylvain and F Lambert and N Delsuc and C Sandt and P Dumas and M Refregiers and M Plamont and A Vessieres and Z Gueroui and A Dazzi}, url = {<Go to ISI>://WOS:000332835300124}, issn = {0949-8257}, year = {2014}, date = {2014-01-01}, journal = {Journal of Biological Inorganic Chemistry}, volume = {19}, pages = {S182-S182}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
How to Control Proteins with Light in Living Systems Article de journal Arnaud Gautier; Carole Gauron; Michel Volovitch; David Bensimon; Ludovic Jullien; Sophie Vriz Nature Chemical Biology, 10 , p. 533, 2014. @article{RN42, title = {How to Control Proteins with Light in Living Systems}, author = {Arnaud Gautier and Carole Gauron and Michel Volovitch and David Bensimon and Ludovic Jullien and Sophie Vriz}, doi = {10.1038/nchembio.1534}, year = {2014}, date = {2014-01-01}, journal = {Nature Chemical Biology}, volume = {10}, pages = {533}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress Article de journal Clotilde Policar; Anne-Sophie Bernard; Nicolas Delsuc; Geraldine Gazzah; Manon Guille; Frederic Lemaitre; Christian Amatore; Maria Bachelet; Joelle Masliah Journal of Biological Inorganic Chemistry, 19 , p. S739-S740, 2014, (Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich). @article{, title = {Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress}, author = {Clotilde Policar and Anne-Sophie Bernard and Nicolas Delsuc and Geraldine Gazzah and Manon Guille and Frederic Lemaitre and Christian Amatore and Maria Bachelet and Joelle Masliah}, year = {2014}, date = {2014-01-01}, journal = {Journal of Biological Inorganic Chemistry}, volume = {19}, pages = {S739-S740}, note = {Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2013 |
Synthesis, Properties, and Remarkable 2 D Self-Assembly at the Liquid/Solid Interface of a Series of Triskele-Shaped 5,11,17-Triazatrinaphthylenes (TrisK) Article de journal Hélène Bertrand; Régis Guillot; Marie-Paule Teulade-Fichou; Denis Fichou Chemistry – A European Journal, 19 (43), p. 14654–14664, 2013, ISSN: 0947-6539. @article{Bertrand2013, title = {Synthesis, Properties, and Remarkable 2 D Self-Assembly at the Liquid/Solid Interface of a Series of Triskele-Shaped 5,11,17-Triazatrinaphthylenes (TrisK)}, author = {H\'{e}l{\`{e}}ne Bertrand and R\'{e}gis Guillot and Marie-Paule Teulade-Fichou and Denis Fichou}, url = {https://doi.org/10.1002/chem.201300705}, doi = {10.1002/chem.201300705}, issn = {0947-6539}, year = {2013}, date = {2013-10-01}, journal = {Chemistry \textendash A European Journal}, volume = {19}, number = {43}, pages = {14654--14664}, publisher = {John Wiley & Sons, Ltd}, abstract = {Abstract A series of 5,11,17-triazatrinaphthylene (TrisK) derivatives, large disk-like $pi$-conjugated molecules with C3h symmetry, has been synthesised by following an optimised synthetic pathway. The synthesis was performed by a four-step protocol based on the N-arylation of 1,3,5-tribromobenzene with appropriate anthranilate derivatives. This strategy permits the generation of either chlorinated (TrisK-Cl-OCn) or non-chlorinated (TrisK-H-OCn) alkoxy-substituted derivatives (OCnH2n+1 with n=3, 10, 12 and 16), thus providing additional versatility in the control of the structure?property relationships. The electronic properties of the various TrisK compounds have been characterised in solution by absorption and emission spectroscopies as well as cyclic voltammetry. The crystal structure of 2,8,14-propyloxy-5,11,17-triazatrinaphthylene TrisK-H-OC3 has been determined by X-ray diffraction analysis, which revealed the presence of stabilising weak intermolecular H bonds. Scanning tunnelling microscopy (STM) at the liquid/solid interface has revealed the remarkable 2D self-assembling properties of the TrisK compounds. In particular, it has shown that TrisK-H-OC12 forms three concomitant self-organised 2D phases with different row-packing arrangements. This 2D polymorphism arises from slow ordering due to the presence of three long dodecyloxy chains on the molecular backbone. Individual molecules can be imaged with spectacular intramolecular resolution, thus providing the possibility of correlating the STM features with the calculated charge density distribution.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract A series of 5,11,17-triazatrinaphthylene (TrisK) derivatives, large disk-like $pi$-conjugated molecules with C3h symmetry, has been synthesised by following an optimised synthetic pathway. The synthesis was performed by a four-step protocol based on the N-arylation of 1,3,5-tribromobenzene with appropriate anthranilate derivatives. This strategy permits the generation of either chlorinated (TrisK-Cl-OCn) or non-chlorinated (TrisK-H-OCn) alkoxy-substituted derivatives (OCnH2n+1 with n=3, 10, 12 and 16), thus providing additional versatility in the control of the structure?property relationships. The electronic properties of the various TrisK compounds have been characterised in solution by absorption and emission spectroscopies as well as cyclic voltammetry. The crystal structure of 2,8,14-propyloxy-5,11,17-triazatrinaphthylene TrisK-H-OC3 has been determined by X-ray diffraction analysis, which revealed the presence of stabilising weak intermolecular H bonds. Scanning tunnelling microscopy (STM) at the liquid/solid interface has revealed the remarkable 2D self-assembling properties of the TrisK compounds. In particular, it has shown that TrisK-H-OC12 forms three concomitant self-organised 2D phases with different row-packing arrangements. This 2D polymorphism arises from slow ordering due to the presence of three long dodecyloxy chains on the molecular backbone. Individual molecules can be imaged with spectacular intramolecular resolution, thus providing the possibility of correlating the STM features with the calculated charge density distribution. |
Toward optimal spatial and spectral quality in widefield infrared spectromicroscopy of IR labelled single cells Article de journal E C Mattson; M Unger; S Clède; F Lambert; C Policar; A Imtiaz; R D'Souza; C J Hirschmugl Analyst, 138 (19), p. 5610–5618, 2013. @article{Mattson:2013, title = {Toward optimal spatial and spectral quality in widefield infrared spectromicroscopy of IR labelled single cells}, author = {E C Mattson and M Unger and S Cl\`{e}de and F Lambert and C Policar and A Imtiaz and R D'Souza and C J Hirschmugl}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883213711&doi=10.1039%2fc3an00383c&partnerID=40&md5=77ab18447e02b2a40b9a4b70fb8f05b0}, doi = {10.1039/c3an00383c}, year = {2013}, date = {2013-01-01}, journal = {Analyst}, volume = {138}, number = {19}, pages = {5610--5618}, abstract = {Advancements in widefield infrared spectromicroscopy have recently been demonstrated following the commissioning of IRENI (InfraRed ENvironmental Imaging), a Fourier Transform infrared (FTIR) chemical imaging beamline at the Synchrotron Radiation Center. The present study demonstrates the effects of magnification, spatial oversampling, spectral pre-processing and deconvolution, focusing on the intracellular detection and distribution of an exogenous metal tris-carbonyl derivative 1 in a single MDA-MB-231 breast cancer cell. We demonstrate here that spatial oversampling for synchrotron-based infrared imaging is critical to obtain accurate diffraction-limited images at all wavelengths simultaneously. Resolution criteria and results from raw and deconvoluted images for two Schwarzschild objectives (36×, NA 0.5 and 74×, NA 0.65) are compared to each other and to prior reports for raster-scanned, confocal microscopes. The resolution of the imaging data can be improved by deconvolving the instrumental broadening that is determined with the measured PSFs, which is implemented with GPU programming architecture for fast hyperspectral processing. High definition, rapidly acquired, FTIR chemical images of respective spectral signatures of the cell and 1 shows that 1 is localized next to the phosphate- and Amide-rich regions, in agreement with previous infrared and luminescence studies. The infrared image contrast, localization and definition are improved after applying proven spectral pre-processing (principal component analysis based noise reduction and RMie scattering correction algorithms) to individual pixel spectra in the hyperspectral cube. © The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Advancements in widefield infrared spectromicroscopy have recently been demonstrated following the commissioning of IRENI (InfraRed ENvironmental Imaging), a Fourier Transform infrared (FTIR) chemical imaging beamline at the Synchrotron Radiation Center. The present study demonstrates the effects of magnification, spatial oversampling, spectral pre-processing and deconvolution, focusing on the intracellular detection and distribution of an exogenous metal tris-carbonyl derivative 1 in a single MDA-MB-231 breast cancer cell. We demonstrate here that spatial oversampling for synchrotron-based infrared imaging is critical to obtain accurate diffraction-limited images at all wavelengths simultaneously. Resolution criteria and results from raw and deconvoluted images for two Schwarzschild objectives (36×, NA 0.5 and 74×, NA 0.65) are compared to each other and to prior reports for raster-scanned, confocal microscopes. The resolution of the imaging data can be improved by deconvolving the instrumental broadening that is determined with the measured PSFs, which is implemented with GPU programming architecture for fast hyperspectral processing. High definition, rapidly acquired, FTIR chemical images of respective spectral signatures of the cell and 1 shows that 1 is localized next to the phosphate- and Amide-rich regions, in agreement with previous infrared and luminescence studies. The infrared image contrast, localization and definition are improved after applying proven spectral pre-processing (principal component analysis based noise reduction and RMie scattering correction algorithms) to individual pixel spectra in the hyperspectral cube. © The Royal Society of Chemistry. |
Polypyrrole functionalized with new copper complex as platform for His-tag antibody immobilization and direct antigen detection Article de journal S Chebil; A Miodek; V Ambike; H Sauriat-Dorizon; C Policar; H Korri-Youssoufi Sensors and Actuators, B: Chemical, 185 , p. 762–770, 2013. @article{Chebil:2013, title = {Polypyrrole functionalized with new copper complex as platform for His-tag antibody immobilization and direct antigen detection}, author = {S Chebil and A Miodek and V Ambike and H Sauriat-Dorizon and C Policar and H Korri-Youssoufi}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879243477&doi=10.1016%2fj.snb.2013.05.024&partnerID=40&md5=3d177c3bfb5d34b53cdc0265fd462968}, doi = {10.1016/j.snb.2013.05.024}, year = {2013}, date = {2013-01-01}, journal = {Sensors and Actuators, B: Chemical}, volume = {185}, pages = {762--770}, abstract = {A biomaterial based on a copper complex covalently attached to a polypyrrole backbone was designed for monitoring a glycoprotein, D-dimer, used as a marker of the deep vein thrombosis (DVT) condition. For this purpose a new copper complex has been developed based on the ligand N-(2-hydroxybenzyl)- N′-(6-aminohexyl)-N,N′-bis[2-(N-methylimidazolyl)methyl]ethane-1, 2-diamine (3) that is able to coordinate copper ions through two imidazole, two amine and one phenolato moieties - this coordination sphere will be labeled enPI2. The complex conjugated with a polypyrrole layer allows the His-tag antibody immobilization onto the conducting polymer substrate and immunosensor evaluation. The biomaterial shows a remarkable variation in redox activity of the Cu(II) complex after the D-dimer interaction. The redox activity of the [(enPi2)Cu(II)] complex decreases after the antigen interaction providing a linear response between 0.01 and 500 ng mL-1 with a detection limit of 10 pg mL-1. The chemical structure of copper complex demonstrates the ability to avoid non specific-interaction leading to anti fouling surface. Such biolayer architecture offers high measurement stability over time and the biomaterial could be stocked for several weeks without any modification of the electrochemical properties. © 2013 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A biomaterial based on a copper complex covalently attached to a polypyrrole backbone was designed for monitoring a glycoprotein, D-dimer, used as a marker of the deep vein thrombosis (DVT) condition. For this purpose a new copper complex has been developed based on the ligand N-(2-hydroxybenzyl)- N′-(6-aminohexyl)-N,N′-bis[2-(N-methylimidazolyl)methyl]ethane-1, 2-diamine (3) that is able to coordinate copper ions through two imidazole, two amine and one phenolato moieties - this coordination sphere will be labeled enPI2. The complex conjugated with a polypyrrole layer allows the His-tag antibody immobilization onto the conducting polymer substrate and immunosensor evaluation. The biomaterial shows a remarkable variation in redox activity of the Cu(II) complex after the D-dimer interaction. The redox activity of the [(enPi2)Cu(II)] complex decreases after the antigen interaction providing a linear response between 0.01 and 500 ng mL-1 with a detection limit of 10 pg mL-1. The chemical structure of copper complex demonstrates the ability to avoid non specific-interaction leading to anti fouling surface. Such biolayer architecture offers high measurement stability over time and the biomaterial could be stocked for several weeks without any modification of the electrochemical properties. © 2013 Elsevier B.V. |
Synchrotron radiation FTIR detection of a metal-carbonyl tamoxifen analog. Correlation with luminescence microscopy to study its subcellular distribution Article de journal S Clède; F Lambert; C Sandt; Z Gueroui; N Delsuc; P Dumas; A Vessières; C Policar Biotechnology Advances, 31 (3), p. 393–395, 2013. @article{Clede:2013, title = {Synchrotron radiation FTIR detection of a metal-carbonyl tamoxifen analog. Correlation with luminescence microscopy to study its subcellular distribution}, author = {S Cl\`{e}de and F Lambert and C Sandt and Z Gueroui and N Delsuc and P Dumas and A Vessi\`{e}res and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875055388&doi=10.1016%2fj.biotechadv.2012.01.023&partnerID=40&md5=064b36e2db4e1260e17d3abc8b07bbd6}, doi = {10.1016/j.biotechadv.2012.01.023}, year = {2013}, date = {2013-01-01}, journal = {Biotechnology Advances}, volume = {31}, number = {3}, pages = {393--395}, abstract = {1,1-Di(4-hydroxyphenyl)-2-cyrhetrenylbut-1-ene 1 is an organometallic conjugate where a [(Cp)Re(CO)3] unit is linked to a hydroxytamoxifen-like structure. Its subcellular nuclear distribution was previously observed in a single cell using the near-field technique AFMIR. We show here that synchrotron radiation FTIR spectromicroscopy (SR-FTIR-SM) enabled the mapping of 1 based on its IR-signature (characteristic bands in the 1850-2200cm-1 range) and pointed out the colocalization of 1 with an area of high amide density. Fluorescence microscopy using DAPI staining performed on the same cells confirmed that this area corresponds to the cell nucleus. © 2012 Elsevier Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 1,1-Di(4-hydroxyphenyl)-2-cyrhetrenylbut-1-ene 1 is an organometallic conjugate where a [(Cp)Re(CO)3] unit is linked to a hydroxytamoxifen-like structure. Its subcellular nuclear distribution was previously observed in a single cell using the near-field technique AFMIR. We show here that synchrotron radiation FTIR spectromicroscopy (SR-FTIR-SM) enabled the mapping of 1 based on its IR-signature (characteristic bands in the 1850-2200cm-1 range) and pointed out the colocalization of 1 with an area of high amide density. Fluorescence microscopy using DAPI staining performed on the same cells confirmed that this area corresponds to the cell nucleus. © 2012 Elsevier Inc. |
An intrinsically fluorescent glycoligand for direct imaging of ligand trafficking in artificial and living cell systems Article de journal L Garcia; M Lazzaretti; A Diguet; F Mussi; F Bisceglie; J Xie; G Pelosi; A Buschini; D Baigl; C Policar New Journal of Chemistry, 37 (10), p. 3030–3034, 2013. @article{Garcia:2013, title = {An intrinsically fluorescent glycoligand for direct imaging of ligand trafficking in artificial and living cell systems}, author = {L Garcia and M Lazzaretti and A Diguet and F Mussi and F Bisceglie and J Xie and G Pelosi and A Buschini and D Baigl and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884338239&doi=10.1039%2fc3nj00380a&partnerID=40&md5=227adf277b66a18d63bfec3b8a13ff09}, doi = {10.1039/c3nj00380a}, year = {2013}, date = {2013-01-01}, journal = {New Journal of Chemistry}, volume = {37}, number = {10}, pages = {3030--3034}, abstract = {Glycoligands, sugar-based molecules able to complex metal cations, constitute a new class of molecules with great potential for biological and biochemical applications. To analyze their behaviour in a biological environment, we have synthesized an intrinsically fluorescent glycoligand and analyzed its trafficking in both living (U937 human cancer cells) and artificial (giant unilamellar vesicles) cell systems. We have found that this ligand has moderate cytotoxicity accompanied by specific accumulation in both living and reconstituted membranes, which it can cross to reach inner compartments. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Glycoligands, sugar-based molecules able to complex metal cations, constitute a new class of molecules with great potential for biological and biochemical applications. To analyze their behaviour in a biological environment, we have synthesized an intrinsically fluorescent glycoligand and analyzed its trafficking in both living (U937 human cancer cells) and artificial (giant unilamellar vesicles) cell systems. We have found that this ligand has moderate cytotoxicity accompanied by specific accumulation in both living and reconstituted membranes, which it can cross to reach inner compartments. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. |
S Clède; F Lambert; C Sandt; S Kascakova; M Unger; E Harté; M -A Plamont; R Saint-Fort; A Deniset-Besseau; Z Gueroui; C Hirschmugl; S Lecomte; A Dazzi; A Vessières; C Policar Analyst, 138 (19), p. 5627–5638, 2013. @article{Clede:2013a, title = {Detection of an estrogen derivative in two breast cancer cell lines using a single core multimodal probe for imaging (SCoMPI) imaged by a panel of luminescent and vibrational techniques}, author = {S Cl\`{e}de and F Lambert and C Sandt and S Kascakova and M Unger and E Hart\'{e} and M -A Plamont and R Saint-Fort and A Deniset-Besseau and Z Gueroui and C Hirschmugl and S Lecomte and A Dazzi and A Vessi\`{e}res and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883254315&doi=10.1039%2fc3an00807j&partnerID=40&md5=02420b772ef22a07206b5ae31c42dd2e}, doi = {10.1039/c3an00807j}, year = {2013}, date = {2013-01-01}, journal = {Analyst}, volume = {138}, number = {19}, pages = {5627--5638}, abstract = {3-Methoxy-17α-ethynylestradiol or mestranol is a prodrug for ethynylestradiol and the estrogen component of some oral contraceptive formulations. We demonstrate here that a single core multimodal probe for imaging-SCoMPI-can be efficiently grafted onto mestranol allowing its tracking in two breast cancer cell lines, MDA-MB-231 and MCF-7 fixed cells. Correlative imaging studies based on luminescence (synchrotron UV spectromicroscopy, wide field and confocal fluorescence microscopies) and vibrational (AFMIR, synchrotron FTIR spectromicroscopy, synchrotron-based multiple beam FTIR imaging, confocal Raman microspectroscopy) spectroscopies were consistent with one another and showed a Golgi apparatus distribution of the SCoMPI-mestranol conjugate in both cell lines. © The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 3-Methoxy-17α-ethynylestradiol or mestranol is a prodrug for ethynylestradiol and the estrogen component of some oral contraceptive formulations. We demonstrate here that a single core multimodal probe for imaging-SCoMPI-can be efficiently grafted onto mestranol allowing its tracking in two breast cancer cell lines, MDA-MB-231 and MCF-7 fixed cells. Correlative imaging studies based on luminescence (synchrotron UV spectromicroscopy, wide field and confocal fluorescence microscopies) and vibrational (AFMIR, synchrotron FTIR spectromicroscopy, synchrotron-based multiple beam FTIR imaging, confocal Raman microspectroscopy) spectroscopies were consistent with one another and showed a Golgi apparatus distribution of the SCoMPI-mestranol conjugate in both cell lines. © The Royal Society of Chemistry. |
Homooligomers of substituted prolines and β-prolines: Syntheses and secondary structure investigation Article de journal C Caumes; N Delsuc; R B Azza; I Correia; F Chemla; F Ferreira; L Carlier; A P Luna; R Moumné; O Lequin; P Karoyan New Journal of Chemistry, 37 (5), p. 1312–1319, 2013. @article{Caumes:2013, title = {Homooligomers of substituted prolines and β-prolines: Syntheses and secondary structure investigation}, author = {C Caumes and N Delsuc and R B Azza and I Correia and F Chemla and F Ferreira and L Carlier and A P Luna and R Moumn\'{e} and O Lequin and P Karoyan}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876740702&doi=10.1039%2fc3nj00127j&partnerID=40&md5=dbda08d94a12bcb6b260393c90dd6af4}, doi = {10.1039/c3nj00127j}, year = {2013}, date = {2013-01-01}, journal = {New Journal of Chemistry}, volume = {37}, number = {5}, pages = {1312--1319}, abstract = {Homooligomers of enantiomerically pure (2S,3R)-3-methyl-proline, (3R,4R)-4-methyl-β-proline and (3R,4S)-3,4-dimethyl-β-proline were synthesized and studied using circular dichroism (CD) in water, methanol and propanol and using NMR in water. Changes in the far-UV CD spectrum were observed from dimers to hexamers, but little change was observed from hexamers to octa- or nonamers, both in water and methanol. CD and NMR data allowed us to conclude that oligomers of 3-substituted prolines with more than six residues adopt a characteristic PPII secondary structure both in water and aliphatic alcohols. Oligomers of (3R,4R)-4-methyl-β-proline bear the same CD signature as non-substituted β-proline oligomers, suggesting that substitution at position 3 is not sufficient to reduce conformational heterogeneity in β-proline oligomers. In the case of 3,4-disubstituted-β-proline oligomers, an atypical signature with an extra negative band at around 225 nm was observed, together with a concentration dependent CD spectrum indicating association properties. Nevertheless, NMR studies of 13C labelled oligomers of 3,4-disubstituted-β-prolines revealed a complex mixture of cis-trans conformers even for longer oligomers. © 2913 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Homooligomers of enantiomerically pure (2S,3R)-3-methyl-proline, (3R,4R)-4-methyl-β-proline and (3R,4S)-3,4-dimethyl-β-proline were synthesized and studied using circular dichroism (CD) in water, methanol and propanol and using NMR in water. Changes in the far-UV CD spectrum were observed from dimers to hexamers, but little change was observed from hexamers to octa- or nonamers, both in water and methanol. CD and NMR data allowed us to conclude that oligomers of 3-substituted prolines with more than six residues adopt a characteristic PPII secondary structure both in water and aliphatic alcohols. Oligomers of (3R,4R)-4-methyl-β-proline bear the same CD signature as non-substituted β-proline oligomers, suggesting that substitution at position 3 is not sufficient to reduce conformational heterogeneity in β-proline oligomers. In the case of 3,4-disubstituted-β-proline oligomers, an atypical signature with an extra negative band at around 225 nm was observed, together with a concentration dependent CD spectrum indicating association properties. Nevertheless, NMR studies of 13C labelled oligomers of 3,4-disubstituted-β-prolines revealed a complex mixture of cis-trans conformers even for longer oligomers. © 2913 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. |
3-substituted prolines: From synthesis to structural applications, from peptides to foldamers Article de journal C Mothes; C Caumes; A Guez; H Boullet; T Gendrineau; S Darses; N Delsuc; R Moumné; B Oswald; O Lequin; P Karoyan Molecules, 18 (2), p. 2307–2327, 2013. @article{Mothes:2013, title = {3-substituted prolines: From synthesis to structural applications, from peptides to foldamers}, author = {C Mothes and C Caumes and A Guez and H Boullet and T Gendrineau and S Darses and N Delsuc and R Moumn\'{e} and B Oswald and O Lequin and P Karoyan}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874605320&doi=10.3390%2fmolecules18022307&partnerID=40&md5=05828aecf601bf07f9a0a6a3fec4e28c}, doi = {10.3390/molecules18022307}, year = {2013}, date = {2013-01-01}, journal = {Molecules}, volume = {18}, number = {2}, pages = {2307--2327}, abstract = {Among the twenty natural proteinogenic amino acids, proline is unique as its secondary amine forms a tertiary amide when incorporated into biopolymers, thus preventing hydrogen bond formation. Despite the lack of hydrogen bonds and thanks to conformational restriction of flexibility linked to the pyrrolidine ring, proline is able to stabilize peptide secondary structures such as -turns or polyproline helices. These unique conformational properties have aroused a great interest in the development of proline analogues. Among them, proline chimeras are tools combining the proline restriction of flexibility together with the information brought by natural amino acids side chains. This review will focus on the chemical syntheses of 3-substituted proline chimeras of potential use for peptide syntheses and as potential use as tools for SAR studies of biologically active peptides and the development of secondary structure mimetics. Their influence on peptide structure will be briefly described. © 2013 by the authors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Among the twenty natural proteinogenic amino acids, proline is unique as its secondary amine forms a tertiary amide when incorporated into biopolymers, thus preventing hydrogen bond formation. Despite the lack of hydrogen bonds and thanks to conformational restriction of flexibility linked to the pyrrolidine ring, proline is able to stabilize peptide secondary structures such as -turns or polyproline helices. These unique conformational properties have aroused a great interest in the development of proline analogues. Among them, proline chimeras are tools combining the proline restriction of flexibility together with the information brought by natural amino acids side chains. This review will focus on the chemical syntheses of 3-substituted proline chimeras of potential use for peptide syntheses and as potential use as tools for SAR studies of biologically active peptides and the development of secondary structure mimetics. Their influence on peptide structure will be briefly described. © 2013 by the authors. |
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. |
2012 |
A rhenium tris-carbonyl derivative as a single core multimodal probe for imaging (SCoMPI) combining infrared and luminescent properties Article de journal S Clède; F Lambert; C Sandt; Z Gueroui; M Réfrégiers; M -A Plamont; P Dumas; A Vessières; C Policar Chemical Communications, 48 (62), p. 7729–7731, 2012. @article{Clede:2012, title = {A rhenium tris-carbonyl derivative as a single core multimodal probe for imaging (SCoMPI) combining infrared and luminescent properties}, author = {S Cl\`{e}de and F Lambert and C Sandt and Z Gueroui and M R\'{e}fr\'{e}giers and M -A Plamont and P Dumas and A Vessi\`{e}res and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863947366&doi=10.1039%2fc2cc32163g&partnerID=40&md5=289388c6720aee80e800fb8ad80cdb27}, doi = {10.1039/c2cc32163g}, year = {2012}, date = {2012-01-01}, journal = {Chemical Communications}, volume = {48}, number = {62}, pages = {7729--7731}, abstract = {A rhenium tris-carbonyl derivative has been designed to couple infrared and luminescent detection in cells. Both spectroscopies are consistent with one another; they point out the reliability of the present SCoMPI (for Single Core Multimodal Probe for Imaging) for bimodal imaging and unambiguously indicate a localization at the Golgi apparatus in MDA-MB-231 breast cancer cells. © 2012 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A rhenium tris-carbonyl derivative has been designed to couple infrared and luminescent detection in cells. Both spectroscopies are consistent with one another; they point out the reliability of the present SCoMPI (for Single Core Multimodal Probe for Imaging) for bimodal imaging and unambiguously indicate a localization at the Golgi apparatus in MDA-MB-231 breast cancer cells. © 2012 The Royal Society of Chemistry. |
Glycosiderophores: Synthesis of tris-hydroxamate siderophores based on a galactose or glycero central scaffold, Fe(III) complexation studies Article de journal C Neff; F Bellot; J -B Waern; F Lambert; J Brandel; G Serratrice; F Gaboriau; C Policar Journal of Inorganic Biochemistry, 112 , p. 59–67, 2012. @article{Neff:2012, title = {Glycosiderophores: Synthesis of tris-hydroxamate siderophores based on a galactose or glycero central scaffold, Fe(III) complexation studies}, author = {C Neff and F Bellot and J -B Waern and F Lambert and J Brandel and G Serratrice and F Gaboriau and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84860271202&doi=10.1016%2fj.jinorgbio.2012.02.030&partnerID=40&md5=67094ead67163b2ab05f9eed02b54bbd}, doi = {10.1016/j.jinorgbio.2012.02.030}, year = {2012}, date = {2012-01-01}, journal = {Journal of Inorganic Biochemistry}, volume = {112}, pages = {59--67}, abstract = {A series of five new hexadentate tris-hydroxamate ligands based on a d-galactose or a glycerol scaffold have been synthesized. Protonation and ferric complex formation constants have been determined from solution studies by potentiometric and spectrophotometric titrations. All ligands form 1:1 Fe:L complexes. The calculated pFe values at pH 7.4 span over the range 19.2-23.0 depending on the scaffold and on the length of the spacers between hydroxamate and central scaffold and on the N-methyl substitution. This new kind of artificial siderophores based on a glycoscaffold is of interest as it opens up an easy way to modulate the pFe. © 2012 Elsevier Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A series of five new hexadentate tris-hydroxamate ligands based on a d-galactose or a glycerol scaffold have been synthesized. Protonation and ferric complex formation constants have been determined from solution studies by potentiometric and spectrophotometric titrations. All ligands form 1:1 Fe:L complexes. The calculated pFe values at pH 7.4 span over the range 19.2-23.0 depending on the scaffold and on the length of the spacers between hydroxamate and central scaffold and on the N-methyl substitution. This new kind of artificial siderophores based on a glycoscaffold is of interest as it opens up an easy way to modulate the pFe. © 2012 Elsevier Inc. |
Recent analytical applications of molecular spectroscopy in bioorganometallic chemistrypart I: Metal carbonyls Article de journal I S Butler; R P Kengne-Momo; G Jaouen; C Policar; A Vessières Applied Spectroscopy Reviews, 47 (7), p. 531–549, 2012. @article{Butler:2012, title = {Recent analytical applications of molecular spectroscopy in bioorganometallic chemistrypart I: Metal carbonyls}, author = {I S Butler and R P Kengne-Momo and G Jaouen and C Policar and A Vessi\`{e}res}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865204418&doi=10.1080%2f05704928.2012.673189&partnerID=40&md5=520598e533375e3ff67b73f9e50d4386}, doi = {10.1080/05704928.2012.673189}, year = {2012}, date = {2012-01-01}, journal = {Applied Spectroscopy Reviews}, volume = {47}, number = {7}, pages = {531--549}, abstract = {This is the first part of a two-part review on the analytical applications of molecular spectroscopy in bioorganometallic chemistry since 2005. In this case, radiopharmaceutical studies are included and the review is focused particularly on biological molecules labeled with metal carbonyl fragments. Copyright © Taylor & Francis Group, LLC.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This is the first part of a two-part review on the analytical applications of molecular spectroscopy in bioorganometallic chemistry since 2005. In this case, radiopharmaceutical studies are included and the review is focused particularly on biological molecules labeled with metal carbonyl fragments. Copyright © Taylor & Francis Group, LLC. |
Recent applications of molecular spectroscopy in bioorganometallic chemistry-Part 2: Ferrocenes and other organometallic complexes Article de journal I S Butler; R P Kengne-Momo; A Vessières; G Jaouen; C Policar Applied Spectroscopy Reviews, 47 (8), p. 620–632, 2012. @article{Butler:2012a, title = {Recent applications of molecular spectroscopy in bioorganometallic chemistry-Part 2: Ferrocenes and other organometallic complexes}, author = {I S Butler and R P Kengne-Momo and A Vessi\`{e}res and G Jaouen and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84867002904&doi=10.1080%2f05704928.2012.697088&partnerID=40&md5=9a894613d259bfe47cd1f47469a86497}, doi = {10.1080/05704928.2012.697088}, year = {2012}, date = {2012-01-01}, journal = {Applied Spectroscopy Reviews}, volume = {47}, number = {8}, pages = {620--632}, abstract = {This is the second part of an overview of the applications of the various molecular spectroscopic methods that have been employed in bioorganometallic chemistry research since 2005 focusing on ferrocenes and other non-metal carbonyl organometallic complexes. These spectroscopic methods encompass infrared (IR), nuclear magnetic resonance (NMR), mass, Raman, ultraviolet-visible (UV-Vis), and several other less common spectroscopic techniques. © 2012 Taylor & Francis Group, LLC.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This is the second part of an overview of the applications of the various molecular spectroscopic methods that have been employed in bioorganometallic chemistry research since 2005 focusing on ferrocenes and other non-metal carbonyl organometallic complexes. These spectroscopic methods encompass infrared (IR), nuclear magnetic resonance (NMR), mass, Raman, ultraviolet-visible (UV-Vis), and several other less common spectroscopic techniques. © 2012 Taylor & Francis Group, LLC. |
Metal complexation of a Đ -ribose-based ligand decoded by experimental and theoretical studies Article de journal F Cisnetti; J -D Maréchal; M Nicaise; R Guillot; M Desmadril; F Lambert; C Policar European Journal of Inorganic Chemistry, (20), p. 3308–3319, 2012. @article{Cisnetti:2012, title = {Metal complexation of a {D} -ribose-based ligand decoded by experimental and theoretical studies}, author = {F Cisnetti and J -D Mar\'{e}chal and M Nicaise and R Guillot and M Desmadril and F Lambert and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863687434&doi=10.1002%2fejic.201200322&partnerID=40&md5=0682fc752866de140dd4439a4be02cdd}, doi = {10.1002/ejic.201200322}, year = {2012}, date = {2012-01-01}, journal = {European Journal of Inorganic Chemistry}, number = {20}, pages = {3308--3319}, abstract = {A combination of experimental and theoretical methods have been used to elucidate the complexation properties of a new sugar-derived hexadentate ligand, namely methyl 2,3,4-tri-O-(2-picolyl)-β-D-ribopyranoside (L). The coordination bond lengths in the complexes with Mn II, Co II, Ni II, and Zn II show substantial deviations from ideal octahedra with deformation towards trigonal-prismatic geometries, which is indicative of a conformationally constrained ligand. The metal-cation-ligand interactions were studied for L and the acyclic analogue L' [1,2,3-tri-O-(2-picolyl)-1,2,3-propanetriol] by spectroscopic methods and isothermal calorimetric titrations for the series Mn II, Co II, Ni II, Zn II, and Cu II. The results indicate a stabilization of the complexes obtained with L compared with L', depending on the nature of the metal. Molecular modeling studies showed that the presence of the sugar moiety strongly favors conformations compatible with metal binding, which suggests an entropic origin of the stabilization of L complexes with regards to L' complexes. Moreover, the differences in the metal chelation profiles of L and L' are related to the constraints in the sugar group in the metal-bound structures. This study shows that foreseeing the degree of preorganization of flexible ligands may drive the design of a new generation of chelating compounds. A new sugar-derived ligand, with its coordination site embedded in a pyranoside cycle in the chair conformation, has been designed. Its transition-metal complexes were characterized by experimental and complexation methods and revealed a dramatic impact of the preorganization and complementarity of the carbohydrate scaffold on the metal binding. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A combination of experimental and theoretical methods have been used to elucidate the complexation properties of a new sugar-derived hexadentate ligand, namely methyl 2,3,4-tri-O-(2-picolyl)-β-D-ribopyranoside (L). The coordination bond lengths in the complexes with Mn II, Co II, Ni II, and Zn II show substantial deviations from ideal octahedra with deformation towards trigonal-prismatic geometries, which is indicative of a conformationally constrained ligand. The metal-cation-ligand interactions were studied for L and the acyclic analogue L' [1,2,3-tri-O-(2-picolyl)-1,2,3-propanetriol] by spectroscopic methods and isothermal calorimetric titrations for the series Mn II, Co II, Ni II, Zn II, and Cu II. The results indicate a stabilization of the complexes obtained with L compared with L', depending on the nature of the metal. Molecular modeling studies showed that the presence of the sugar moiety strongly favors conformations compatible with metal binding, which suggests an entropic origin of the stabilization of L complexes with regards to L' complexes. Moreover, the differences in the metal chelation profiles of L and L' are related to the constraints in the sugar group in the metal-bound structures. This study shows that foreseeing the degree of preorganization of flexible ligands may drive the design of a new generation of chelating compounds. A new sugar-derived ligand, with its coordination site embedded in a pyranoside cycle in the chair conformation, has been designed. Its transition-metal complexes were characterized by experimental and complexation methods and revealed a dramatic impact of the preorganization and complementarity of the carbohydrate scaffold on the metal binding. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Evaluation of the anti-oxidant properties of a SOD-mimic Mn-complex in activated macrophages Article de journal Anne-Sophie Bernard; Claire Giroud; Vincent H Y Ching; Anne Meunier; Vinita Ambike; Christian Amatore; Manon Guille-Collignon; Frederic Lemaitre; Clotilde Policar Dalton Transactions, 41 (21), p. 6399-6403, 2012, (Times Cited: 23). @article{, title = {Evaluation of the anti-oxidant properties of a SOD-mimic Mn-complex in activated macrophages}, author = {Anne-Sophie Bernard and Claire Giroud and Vincent H Y Ching and Anne Meunier and Vinita Ambike and Christian Amatore and Manon Guille-Collignon and Frederic Lemaitre and Clotilde Policar}, year = {2012}, date = {2012-01-01}, journal = {Dalton Transactions}, volume = {41}, number = {21}, pages = {6399-6403}, note = {Times Cited: 23}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2011 |
Recognition of G-Quadruplex DNA by Triangular Star-Shaped Compounds: With or Without Side Chains? Article de journal Hélène Bertrand; Anton Granzhan; David Monchaud; Nicolas Saettel; Régis Guillot; Sarah Clifford; Aurore Guédin; Jean-Louis Mergny; Marie-Paule Teulade-Fichou Chemistry – A European Journal, 17 (16), p. 4529–4539, 2011, ISSN: 0947-6539. @article{Bertrand2011a, title = {Recognition of G-Quadruplex DNA by Triangular Star-Shaped Compounds: With or Without Side Chains?}, author = {H\'{e}l{\`{e}}ne Bertrand and Anton Granzhan and David Monchaud and Nicolas Saettel and R\'{e}gis Guillot and Sarah Clifford and Aurore Gu\'{e}din and Jean-Louis Mergny and Marie-Paule Teulade-Fichou}, url = {https://doi.org/10.1002/chem.201002810}, doi = {10.1002/chem.201002810}, issn = {0947-6539}, year = {2011}, date = {2011-04-01}, journal = {Chemistry \textendash A European Journal}, volume = {17}, number = {16}, pages = {4529--4539}, publisher = {John Wiley & Sons, Ltd}, abstract = {Abstract We report the synthesis of two new series of triangular aromatic platforms, either with three aminoalkyl side chains (triazatrinaphthylene series, TrisK: six compounds), or without side chains (triazoniatrinaphthylene, TrisQ). The quadruplex?DNA binding behavior of the two series, which differ essentially by the localization of the cationic charges, was evaluated by means of FRET-melting and G4-FID assays. For the trisubstituted triazatrinaphthylenes (TrisK), the length of the substituents and the presence of terminal hydrogen-bond-donor groups (NH2) were shown to be crucial for ensuring a high quadruplex affinity (?T1/2 values of up to 20?°C at 1??M for the best candidate, TrisK3-NH) and selectivity versus duplex DNA. Subsequently, comparison of data collected on both the telomeric- and c-myc-quadruplex showed that the nonsubstituted TrisQ is even more efficient than TrisK3-NH, both in terms of quadruplex affinity (?T1/2=26?°C in K+ buffer) and selectivity versus duplex DNA. Structural considerations conducted with the c-myc quadruplex indicate that both TrisK3-NH and TrisQ stack well onto the G-quartet but in an offset position, which might be influenced by the formation of multiple hydrogen bonds with the target in the former case. Finally, the nonsubstituted TrisQ displays a binding profile very similar to some of the best quadruplex binders, BRACO-19 and bisquinolinium 360A, used herein as references, and thereby represents a highly promising novel molecular design for quadruplex recognition.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract We report the synthesis of two new series of triangular aromatic platforms, either with three aminoalkyl side chains (triazatrinaphthylene series, TrisK: six compounds), or without side chains (triazoniatrinaphthylene, TrisQ). The quadruplex?DNA binding behavior of the two series, which differ essentially by the localization of the cationic charges, was evaluated by means of FRET-melting and G4-FID assays. For the trisubstituted triazatrinaphthylenes (TrisK), the length of the substituents and the presence of terminal hydrogen-bond-donor groups (NH2) were shown to be crucial for ensuring a high quadruplex affinity (?T1/2 values of up to 20?°C at 1??M for the best candidate, TrisK3-NH) and selectivity versus duplex DNA. Subsequently, comparison of data collected on both the telomeric- and c-myc-quadruplex showed that the nonsubstituted TrisQ is even more efficient than TrisK3-NH, both in terms of quadruplex affinity (?T1/2=26?°C in K+ buffer) and selectivity versus duplex DNA. Structural considerations conducted with the c-myc quadruplex indicate that both TrisK3-NH and TrisQ stack well onto the G-quartet but in an offset position, which might be influenced by the formation of multiple hydrogen bonds with the target in the former case. Finally, the nonsubstituted TrisQ displays a binding profile very similar to some of the best quadruplex binders, BRACO-19 and bisquinolinium 360A, used herein as references, and thereby represents a highly promising novel molecular design for quadruplex recognition. |
Subcellular IR imaging of a metal-carbonyl moiety using photothermally induced resonance Article de journal C Policar; J B Waern; M -A Plamont; S Clède; C Mayet; R Prazeres; J -M Ortega; A Vessières; A Dazzi Angewandte Chemie - International Edition, 50 (4), p. 860–864, 2011. @article{Policar:2011, title = {Subcellular IR imaging of a metal-carbonyl moiety using photothermally induced resonance}, author = {C Policar and J B Waern and M -A Plamont and S Cl\`{e}de and C Mayet and R Prazeres and J -M Ortega and A Vessi\`{e}res and A Dazzi}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650905440&doi=10.1002%2fanie.201003161&partnerID=40&md5=68f3379717f4b84ab8336cdb50461a5f}, doi = {10.1002/anie.201003161}, year = {2011}, date = {2011-01-01}, journal = {Angewandte Chemie - International Edition}, volume = {50}, number = {4}, pages = {860--864}, abstract = {Some like it hot! The photothermally induced resonance technique, in which an AFM microscope is coupled to a tunable pulsed IR laser, allows IR mapping and gives access to local IR spectra at the subcellular level. A metal-carbonyl compound was internalized in cells and detected in the cell nucleus thanks to its IR signature. The local IR spectrum at the nucleus showed the characteristic IR bands of the Re(CO)3 unit. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Some like it hot! The photothermally induced resonance technique, in which an AFM microscope is coupled to a tunable pulsed IR laser, allows IR mapping and gives access to local IR spectra at the subcellular level. A metal-carbonyl compound was internalized in cells and detected in the cell nucleus thanks to its IR signature. The local IR spectrum at the nucleus showed the characteristic IR bands of the Re(CO)3 unit. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Proton-coupled electron transfers in biomimetic water bound metal complexes. the electrochemical approach Article de journal E Anxolabéhère-Mallart; C Costentin; C Policar; M Robert; J -M Savéant; A -L Teillout Faraday Discussions, 148 , p. 83–95, 2011. @article{Anxolabehere-Mallart:2011, title = {Proton-coupled electron transfers in biomimetic water bound metal complexes. the electrochemical approach}, author = {E Anxolab\'{e}h\`{e}re-Mallart and C Costentin and C Policar and M Robert and J -M Sav\'{e}ant and A -L Teillout}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79952268478&doi=10.1039%2fc004276e&partnerID=40&md5=24036168d6b9ca482d1b9f949b3a5995}, doi = {10.1039/c004276e}, year = {2011}, date = {2011-01-01}, journal = {Faraday Discussions}, volume = {148}, pages = {83--95}, abstract = {Water-bound metal (M) complexes play a central role in the catalytic centers of natural systems such as Photosystem II (PSII), superoxide dismutase, cytochrome c oxidase and others. In these systems, electron transfer reactions involving the metal center are coupled to proton transfers. Besides its fundamental interest, comprehension of these reactions and of possible bio-inspired catalytic devices is an additional motivation for studying the coupling between proton and electron transfer (proton-coupled electron transfers, PCET), starting with an aqua-MII/hydroxo-MIII couple, and going to higher oxidation degrees as in the case of PSII (hydroxo-MIII/oxo-MIV couple). Factors that determine the occurrence of the stepwise and concerted pathways are recalled from the illustrating example of a recently described mononuclear osmium complex, thus opening perspectives for further studies of the biomimicking complex. PCET in a mononuclear aqua/hydroxo manganese couple was then studied using the electrochemical approach. © 2011 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Water-bound metal (M) complexes play a central role in the catalytic centers of natural systems such as Photosystem II (PSII), superoxide dismutase, cytochrome c oxidase and others. In these systems, electron transfer reactions involving the metal center are coupled to proton transfers. Besides its fundamental interest, comprehension of these reactions and of possible bio-inspired catalytic devices is an additional motivation for studying the coupling between proton and electron transfer (proton-coupled electron transfers, PCET), starting with an aqua-MII/hydroxo-MIII couple, and going to higher oxidation degrees as in the case of PSII (hydroxo-MIII/oxo-MIV couple). Factors that determine the occurrence of the stepwise and concerted pathways are recalled from the illustrating example of a recently described mononuclear osmium complex, thus opening perspectives for further studies of the biomimicking complex. PCET in a mononuclear aqua/hydroxo manganese couple was then studied using the electrochemical approach. © 2011 The Royal Society of Chemistry. |
Intrinsically fluorescent glycoligands to study metal selectivity Article de journal L Garcia; S Maisonneuve; J Oudinet-Sin Marcu; R Guillot; F Lambert; J Xie; C Policar Inorganic Chemistry, 50 (22), p. 11353–11362, 2011. @article{Garcia:2011, title = {Intrinsically fluorescent glycoligands to study metal selectivity}, author = {L Garcia and S Maisonneuve and J Oudinet-Sin Marcu and R Guillot and F Lambert and J Xie and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-81255195281&doi=10.1021%2fic200897v&partnerID=40&md5=2d82616942d473b2774c71363fb8ff6a}, doi = {10.1021/ic200897v}, year = {2011}, date = {2011-01-01}, journal = {Inorganic Chemistry}, volume = {50}, number = {22}, pages = {11353--11362}, abstract = {Glycoligands are a versatile family of ligands centered on a sugar platform and functionalized by Lewis bases. In this article, pentofuranoses were appended with the fluoroionophores 4-(pyridin-2′-yl)-1,2,3-triazol-1-yl and 4-(2′,1′,3′-benzothiadiazol-4′-yl)-1,2,3-triazol-1- yl using the "click-like" cycloaddition [2 + 3] of Huisgen catalyzed by copper(I). Their fluorescence properties were used to study metal cation complexation. A possible selective functionalization of furanoscaffolds allows the synthesis of "mixed" glycoligands with the successive insertion of these different fluoroionophores. The metal selectivity and the chelating behavior of these six resulting intrinsically fluorescent glycoligands were investigated. The change in the configuration at the carbon C3 of furanose did not influence either the metal selectivity or the binding constants. However, different selectivities and binding constants were found to depend on the nature of the fluoroionophore moieties. Overall, the triazolylbenzothiadiazolyl chelating group was shown to be less efficient than the triazolylpyridyl claw for complexation. Interestingly enough, the triazolylbenzothiadiazolyl claw, which fluoresces in the visible range, did not interfere in the binding and selectivity of the more efficient triazolylpyridyl claw. This study suggests that the triazolylbenzothiadiazolyl moiety could be used as an adequate fluorescent reporter to qualitatively monitor complexation of other moieties. © 2011 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Glycoligands are a versatile family of ligands centered on a sugar platform and functionalized by Lewis bases. In this article, pentofuranoses were appended with the fluoroionophores 4-(pyridin-2′-yl)-1,2,3-triazol-1-yl and 4-(2′,1′,3′-benzothiadiazol-4′-yl)-1,2,3-triazol-1- yl using the "click-like" cycloaddition [2 + 3] of Huisgen catalyzed by copper(I). Their fluorescence properties were used to study metal cation complexation. A possible selective functionalization of furanoscaffolds allows the synthesis of "mixed" glycoligands with the successive insertion of these different fluoroionophores. The metal selectivity and the chelating behavior of these six resulting intrinsically fluorescent glycoligands were investigated. The change in the configuration at the carbon C3 of furanose did not influence either the metal selectivity or the binding constants. However, different selectivities and binding constants were found to depend on the nature of the fluoroionophore moieties. Overall, the triazolylbenzothiadiazolyl chelating group was shown to be less efficient than the triazolylpyridyl claw for complexation. Interestingly enough, the triazolylbenzothiadiazolyl claw, which fluoresces in the visible range, did not interfere in the binding and selectivity of the more efficient triazolylpyridyl claw. This study suggests that the triazolylbenzothiadiazolyl moiety could be used as an adequate fluorescent reporter to qualitatively monitor complexation of other moieties. © 2011 American Chemical Society. |