2018
|
Clarifying the Copper Coordination Environment in a de Novo Designed Red Copper Protein Article de journal K J Koebke; L Ruckthong; J L Meagher; E Mathieu; J Harland; A Deb; N Lehnert; C Policar; C Tard; J E Penner-Hahn; J A Stuckey; V L Pecoraro Inorganic Chemistry, 57 (19), p. 12291–12302, 2018. @article{Koebke:2018,
title = {Clarifying the Copper Coordination Environment in a de Novo Designed Red Copper Protein},
author = {K J Koebke and L Ruckthong and J L Meagher and E Mathieu and J Harland and A Deb and N Lehnert and C Policar and C Tard and J E Penner-Hahn and J A Stuckey and V L Pecoraro},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053716026&doi=10.1021%2facs.inorgchem.8b01989&partnerID=40&md5=1ff4fcf88039da93326134a5ecf32822},
doi = {10.1021/acs.inorgchem.8b01989},
year = {2018},
date = {2018-01-01},
journal = {Inorganic Chemistry},
volume = {57},
number = {19},
pages = {12291--12302},
abstract = {Cupredoxins are copper-dependent electron-transfer proteins that can be categorized as blue, purple, green, and red depending on the spectroscopic properties of the Cu(II) bound forms. Interestingly, despite significantly different first coordination spheres and nuclearity, all cupredoxins share a common Greek Key β-sheet fold. We have previously reported the design of a red copper protein within a completely distinct three-helical bundle protein, α3DChC2.(1)While this design demonstrated that a β-barrel fold was not requisite to recapitulate the properties of a native cupredoxin center, the parent peptide α3D was not sufficiently stable to allow further study through additional mutations. Here we present the design of an elongated protein GRANDα3D (GRα3D) with ΔGu = -11.4 kcal/mol compared to the original design's -5.1 kcal/mol. Diffraction quality crystals were grown of GRα3D (a first for an α3D peptide) and solved to a resolution of 1.34 r{A}. Examination of this structure suggested that Glu41 might interact with the Cu in our previously reported red copper protein. The previous bis(histidine)(cysteine) site (GRα3DChC2) was designed into this new scaffold and a series of variant constructs were made to explore this hypothesis. Mutation studies around Glu41 not only prove the proposed interaction, but also enabled tuning of the constructs' hyperfine coupling constant from 160 to 127 × 10-4 cm-1. X-ray absorption spectroscopy analysis is consistent with these hyperfine coupling differences being the result of variant 4p mixing related to coordination geometry changes. These studies not only prove that an Glu41-Cu interaction leads to the α3DChC2 construct's red copper protein like spectral properties, but also exemplify the exact control one can have in a de novo construct to tune the properties of an electron-transfer Cu site. Copyright © 2018 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cupredoxins are copper-dependent electron-transfer proteins that can be categorized as blue, purple, green, and red depending on the spectroscopic properties of the Cu(II) bound forms. Interestingly, despite significantly different first coordination spheres and nuclearity, all cupredoxins share a common Greek Key β-sheet fold. We have previously reported the design of a red copper protein within a completely distinct three-helical bundle protein, α3DChC2.(1)While this design demonstrated that a β-barrel fold was not requisite to recapitulate the properties of a native cupredoxin center, the parent peptide α3D was not sufficiently stable to allow further study through additional mutations. Here we present the design of an elongated protein GRANDα3D (GRα3D) with ΔGu = -11.4 kcal/mol compared to the original design's -5.1 kcal/mol. Diffraction quality crystals were grown of GRα3D (a first for an α3D peptide) and solved to a resolution of 1.34 Å. Examination of this structure suggested that Glu41 might interact with the Cu in our previously reported red copper protein. The previous bis(histidine)(cysteine) site (GRα3DChC2) was designed into this new scaffold and a series of variant constructs were made to explore this hypothesis. Mutation studies around Glu41 not only prove the proposed interaction, but also enabled tuning of the constructs' hyperfine coupling constant from 160 to 127 × 10-4 cm-1. X-ray absorption spectroscopy analysis is consistent with these hyperfine coupling differences being the result of variant 4p mixing related to coordination geometry changes. These studies not only prove that an Glu41-Cu interaction leads to the α3DChC2 construct's red copper protein like spectral properties, but also exemplify the exact control one can have in a de novo construct to tune the properties of an electron-transfer Cu site. Copyright © 2018 American Chemical Society. |
A Metallo Pro-Drug to Target CuII in the Context of Alzheimer's Disease Article de journal A Conte-Daban; V Ambike; R Guillot; N Delsuc; C Policar; C Hureau Chemistry - A European Journal, 24 (20), p. 5095–5099, 2018. @article{Conte-Daban:2018,
title = {A Metallo Pro-Drug to Target CuII in the Context of Alzheimer's Disease},
author = {A Conte-Daban and V Ambike and R Guillot and N Delsuc and C Policar and C Hureau},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045131927&doi=10.1002%2fchem.201706049&partnerID=40&md5=5dc310a9e12535e296ba5429250159d3},
doi = {10.1002/chem.201706049},
year = {2018},
date = {2018-01-01},
journal = {Chemistry - A European Journal},
volume = {24},
number = {20},
pages = {5095--5099},
abstract = {Alzheimer's disease and oxidative stress are connected. In the present communication, we report the use of a MnII-based superoxide dismutase (SOD) mimic ([MnII(L)]+, 1+) as a pro-drug candidate to target CuII-associated events, namely, CuII-induced formation of reactive oxygen species (ROS) and modulation of the amyloid-β (Aβ) peptide aggregation. Complex 1+ is able to remove CuII from Aβ, stop ROS and prevent alteration of Aβ aggregation as would do the corresponding free ligand LH. Using 1+ instead of LH in further biological applications would have the double advantage to avoid the cell toxicity of LH and to benefit from its proved SOD-like activity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Alzheimer's disease and oxidative stress are connected. In the present communication, we report the use of a MnII-based superoxide dismutase (SOD) mimic ([MnII(L)]+, 1+) as a pro-drug candidate to target CuII-associated events, namely, CuII-induced formation of reactive oxygen species (ROS) and modulation of the amyloid-β (Aβ) peptide aggregation. Complex 1+ is able to remove CuII from Aβ, stop ROS and prevent alteration of Aβ aggregation as would do the corresponding free ligand LH. Using 1+ instead of LH in further biological applications would have the double advantage to avoid the cell toxicity of LH and to benefit from its proved SOD-like activity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim |
Rhenium tricarbonyl complexes with arenethiolate axial ligands Article de journal M He; H Y V Ching; C Policar; H C Bertrand New Journal of Chemistry, 42 (14), p. 11312–11323, 2018. @article{He:2018,
title = {Rhenium tricarbonyl complexes with arenethiolate axial ligands},
author = {M He and H Y V Ching and C Policar and H C Bertrand},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049750977&doi=10.1039%2fc8nj01960f&partnerID=40&md5=eac4613cb3f849f5a149c72a46384912},
doi = {10.1039/c8nj01960f},
year = {2018},
date = {2018-01-01},
journal = {New Journal of Chemistry},
volume = {42},
number = {14},
pages = {11312--11323},
abstract = {Due to their unique electronic and photophysical properties, rhenium(i) fac-tricarbonyl complexes of general formula [Re(NtextasciicircumN)(CO)3X]n+ have been arousing constant interest in many diverse fields and applications, such as CO2 (photo)electroreduction, organic light emitting diodes and materials, sensors, biological applications and bio-imaging. The photophysical properties of [Re(NtextasciicircumN)(CO)3X]n+ complexes can be modulated by structural variations of the ligands. Modifications of the NtextasciicircumN diimine ligand and of the axial X ligand have been deeply investigated. However, thiolate ligands have scarcely been used in the synthesis of rhenium tricarbonyl complexes. We describe the synthesis of a series of Pyta and Tapy-based Re(i) fac-tricarbonyl complexes with diversely para-substituted arenethiolates in the coordination sphere and report on the electrochemical, photophysical properties and DFT studies of such complexes. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Due to their unique electronic and photophysical properties, rhenium(i) fac-tricarbonyl complexes of general formula [Re(NtextasciicircumN)(CO)3X]n+ have been arousing constant interest in many diverse fields and applications, such as CO2 (photo)electroreduction, organic light emitting diodes and materials, sensors, biological applications and bio-imaging. The photophysical properties of [Re(NtextasciicircumN)(CO)3X]n+ complexes can be modulated by structural variations of the ligands. Modifications of the NtextasciicircumN diimine ligand and of the axial X ligand have been deeply investigated. However, thiolate ligands have scarcely been used in the synthesis of rhenium tricarbonyl complexes. We describe the synthesis of a series of Pyta and Tapy-based Re(i) fac-tricarbonyl complexes with diversely para-substituted arenethiolates in the coordination sphere and report on the electrochemical, photophysical properties and DFT studies of such complexes. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. |
Ferrocifens labelled with an infrared rhenium tricarbonyl tag: Synthesis, antiproliferative activity, quantification and nano IR mapping in cancer cells Article de journal Y Wang; F Heinemann; S Top; A Dazzi; C Policar; L Henry; F Lambert; G Jaouen; M Salmain; A Vessieres Dalton Transactions, 47 (29), p. 9824–9833, 2018. @article{Wang:2018c,
title = {Ferrocifens labelled with an infrared rhenium tricarbonyl tag: Synthesis, antiproliferative activity, quantification and nano IR mapping in cancer cells},
author = {Y Wang and F Heinemann and S Top and A Dazzi and C Policar and L Henry and F Lambert and G Jaouen and M Salmain and A Vessieres},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050854664&doi=10.1039%2fc8dt01582a&partnerID=40&md5=1eb695f8b77ceadad719c5ab75b11480},
doi = {10.1039/c8dt01582a},
year = {2018},
date = {2018-01-01},
journal = {Dalton Transactions},
volume = {47},
number = {29},
pages = {9824--9833},
abstract = {Antiproliferative activities of several members of the ferrocifen family, both in vitro and in vivo, are well documented although their precise location in cancer cells has not yet been elucidated. However, two different infrared imaging techniques have been used to map the non-cytotoxic cyrhetrenyl analogue of ferrociphenol in a single cell. This observation prompted us to tag two ferrocifens with a cyrhetrenyl unit [CpRe(CO)3; Cp = η5-cyclopentadienyl] by grafting it, via an ester bond, either to one of the phenols (4, 5) or to the hydroxypropyl chain (6). Complexes 4-6 retained a high cytotoxicity on breast cancer cells (MDA-MB-231) with IC50 values in the range 0.32-2.5 μM. Transmission IR spectroscopy was used to quantify the amount of cyrhetrenyl tag present in cells incubated with 5 or 6. The results show that after a 1-hour incubation of cells at 37 °C, complexes 5 and 6 are mainly present within cells while only a limited percentage, quantified by ICP-OES, remained in the incubation medium. AFM-IR spectroscopy, a technique coupling infrared irradiation with near-field AFM detection, was used to map the cyrhetrenyl unit in a single MDA-MB-231 cell, incubated at 37 °C for 1 hour with 10 μM of 6. The results show that signal distribution of the characteristic band of the Re(CO)3 entity at 1950 cm-1 matched those of amide and phosphate, thus indicating a location of the complex mainly in the cell nucleus. © 2018 The Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Antiproliferative activities of several members of the ferrocifen family, both in vitro and in vivo, are well documented although their precise location in cancer cells has not yet been elucidated. However, two different infrared imaging techniques have been used to map the non-cytotoxic cyrhetrenyl analogue of ferrociphenol in a single cell. This observation prompted us to tag two ferrocifens with a cyrhetrenyl unit [CpRe(CO)3; Cp = η5-cyclopentadienyl] by grafting it, via an ester bond, either to one of the phenols (4, 5) or to the hydroxypropyl chain (6). Complexes 4-6 retained a high cytotoxicity on breast cancer cells (MDA-MB-231) with IC50 values in the range 0.32-2.5 μM. Transmission IR spectroscopy was used to quantify the amount of cyrhetrenyl tag present in cells incubated with 5 or 6. The results show that after a 1-hour incubation of cells at 37 °C, complexes 5 and 6 are mainly present within cells while only a limited percentage, quantified by ICP-OES, remained in the incubation medium. AFM-IR spectroscopy, a technique coupling infrared irradiation with near-field AFM detection, was used to map the cyrhetrenyl unit in a single MDA-MB-231 cell, incubated at 37 °C for 1 hour with 10 μM of 6. The results show that signal distribution of the characteristic band of the Re(CO)3 entity at 1950 cm-1 matched those of amide and phosphate, thus indicating a location of the complex mainly in the cell nucleus. © 2018 The Royal Society of Chemistry. |
Macrophage-derived superoxide production and antioxidant response following skeletal muscle injury Article de journal E Le Moal; G Juban; A S Bernard; T Varga; C Policar; B Chazaud; R Mounier Free Radical Biology and Medicine, 120 , p. 33–40, 2018. @article{LeMoal:2018,
title = {Macrophage-derived superoxide production and antioxidant response following skeletal muscle injury},
author = {E Le Moal and G Juban and A S Bernard and T Varga and C Policar and B Chazaud and R Mounier},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044047057&doi=10.1016%2fj.freeradbiomed.2018.02.024&partnerID=40&md5=3d7a016c57bd52dfee180ac22ee70ae8},
doi = {10.1016/j.freeradbiomed.2018.02.024},
year = {2018},
date = {2018-01-01},
journal = {Free Radical Biology and Medicine},
volume = {120},
pages = {33--40},
abstract = {Macrophages are key players of immunity that display different functions according to their activation states. In a regenerative context, pro-inflammatory macrophages (Ly6Cpos) are involved in the mounting of the inflammatory response whereas anti-inflammatory macrophages (Ly6Cneg) dampen the inflammation and promote tissue repair. Reactive oxygen species (ROS) production is a hallmark of tissue injury and of subsequent inflammation as described in a bacterial challenge context. However, whether macrophages produce ROS following a sterile tissue injury is uncertain. In this study, we used complementary in vitro, ex vivo and in vivo experiments in mouse to show that macrophages do not release ROS following a sterile injury in skeletal muscle. Furthermore, expression profiles of genes involved in the response to oxidative stress in Ly6Cpos and Ly6Cneg macrophage subsets did not indicate any antioxidant response in this context. Finally, in vivo, pharmacological antioxidant supplementation with N-Acetyl-cysteine (NAC) following skeletal muscle injury did not alter macrophage phenotype during skeletal muscle regeneration. Overall, these results indicate that following a sterile injury, macrophage-derived ROS release is not involved in the regulation of the inflammatory response in the regenerating skeletal muscle. © 2018 Elsevier Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Macrophages are key players of immunity that display different functions according to their activation states. In a regenerative context, pro-inflammatory macrophages (Ly6Cpos) are involved in the mounting of the inflammatory response whereas anti-inflammatory macrophages (Ly6Cneg) dampen the inflammation and promote tissue repair. Reactive oxygen species (ROS) production is a hallmark of tissue injury and of subsequent inflammation as described in a bacterial challenge context. However, whether macrophages produce ROS following a sterile tissue injury is uncertain. In this study, we used complementary in vitro, ex vivo and in vivo experiments in mouse to show that macrophages do not release ROS following a sterile injury in skeletal muscle. Furthermore, expression profiles of genes involved in the response to oxidative stress in Ly6Cpos and Ly6Cneg macrophage subsets did not indicate any antioxidant response in this context. Finally, in vivo, pharmacological antioxidant supplementation with N-Acetyl-cysteine (NAC) following skeletal muscle injury did not alter macrophage phenotype during skeletal muscle regeneration. Overall, these results indicate that following a sterile injury, macrophage-derived ROS release is not involved in the regulation of the inflammatory response in the regenerating skeletal muscle. © 2018 Elsevier Inc. |
Labeling of Hyaluronic Acids with a Rhenium-tricarbonyl Tag and Percutaneous Penetration Studied by Multimodal Imaging Article de journal L Henry; N Delsuc; C Laugel; F Lambert; C Sandt; S Hostachy; A -S Bernard; H C Bertrand; L Grimaud; A Baillet-Guffroy; C Policar Bioconjugate Chemistry, 29 (4), p. 987–991, 2018. @article{Henry:2018,
title = {Labeling of Hyaluronic Acids with a Rhenium-tricarbonyl Tag and Percutaneous Penetration Studied by Multimodal Imaging},
author = {L Henry and N Delsuc and C Laugel and F Lambert and C Sandt and S Hostachy and A -S Bernard and H C Bertrand and L Grimaud and A Baillet-Guffroy and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045549363&doi=10.1021%2facs.bioconjchem.7b00825&partnerID=40&md5=87140714a264358836c5f4c7734e49a3},
doi = {10.1021/acs.bioconjchem.7b00825},
year = {2018},
date = {2018-01-01},
journal = {Bioconjugate Chemistry},
volume = {29},
number = {4},
pages = {987--991},
abstract = {Hyaluronic acids were labeled with a rhenium-tricarbonyl used as single core multimodal probe for imaging and their penetration into human skin biopsies was studied using IR microscopy and fluorescence imaging (labeled SCoMPI). The penetration was shown to be dependent on the molecular weight of the molecule and limited to the upper layer of the skin. © 2018 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hyaluronic acids were labeled with a rhenium-tricarbonyl used as single core multimodal probe for imaging and their penetration into human skin biopsies was studied using IR microscopy and fluorescence imaging (labeled SCoMPI). The penetration was shown to be dependent on the molecular weight of the molecule and limited to the upper layer of the skin. © 2018 American Chemical Society. |
Graftable SCoMPIs enable the labeling and X-ray fluorescence imaging of proteins Article de journal S Hostachy; M Masuda; T Miki; I Hamachi; S Sagan; O Lequin; K Medjoubi; A Somogyi; N Delsuc; C Policar Chemical Science, 9 (19), p. 4483–4487, 2018. @article{Hostachy:2018,
title = {Graftable SCoMPIs enable the labeling and X-ray fluorescence imaging of proteins},
author = {S Hostachy and M Masuda and T Miki and I Hamachi and S Sagan and O Lequin and K Medjoubi and A Somogyi and N Delsuc and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047244059&doi=10.1039%2fc8sc00886h&partnerID=40&md5=4625eaa891ccc665a2357b73e20e3541},
doi = {10.1039/c8sc00886h},
year = {2018},
date = {2018-01-01},
journal = {Chemical Science},
volume = {9},
number = {19},
pages = {4483--4487},
abstract = {Bio-imaging techniques alternative to fluorescence microscopy are gaining increasing interest as complementary tools to visualize and analyze biological systems. Among them, X-ray fluorescence microspectroscopy provides information on the local content and distribution of heavy elements (Z ≥ 14) in cells or biological samples. In this context, similar tools to those developed for fluorescence microscopy are desired, including chemical probes or tags. In this work, we study rhenium complexes as a convenient and sensitive probe for X-ray fluorescence microspectroscopy. We demonstrate their ability to label and sense exogenously incubated or endogenous proteins inside cells. © The Royal Society of Chemistry 2018.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Bio-imaging techniques alternative to fluorescence microscopy are gaining increasing interest as complementary tools to visualize and analyze biological systems. Among them, X-ray fluorescence microspectroscopy provides information on the local content and distribution of heavy elements (Z ≥ 14) in cells or biological samples. In this context, similar tools to those developed for fluorescence microscopy are desired, including chemical probes or tags. In this work, we study rhenium complexes as a convenient and sensitive probe for X-ray fluorescence microspectroscopy. We demonstrate their ability to label and sense exogenously incubated or endogenous proteins inside cells. © The Royal Society of Chemistry 2018. |
2017
|
Synthesis of Homoditopic Ligands with an Incrementable Rodlike Backbone Article de journal P Demay-Drouhard; L -M Chamoreau; R Guillot; C Policar; H C Bertrand European Journal of Organic Chemistry, 2017 (1), p. 131–137, 2017. @article{Demay-Drouhard:2017,
title = {Synthesis of Homoditopic Ligands with an Incrementable Rodlike Backbone},
author = {P Demay-Drouhard and L -M Chamoreau and R Guillot and C Policar and H C Bertrand},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007178925&doi=10.1002%2fejoc.201601081&partnerID=40&md5=4e3e60591df3842d6c169cf43161de0f},
doi = {10.1002/ejoc.201601081},
year = {2017},
date = {2017-01-01},
journal = {European Journal of Organic Chemistry},
volume = {2017},
number = {1},
pages = {131--137},
abstract = {We describe the synthesis of architectures that consist of a symmetrical rodlike oligo(phenylene-ethynylene) (OPE) backbone of incrementable length connected to a pair of classical ligands for metal coordination. OPE spacers decorated with various end groups and incorporating up to seven phenylene-acetylene repeat units were quickly obtained through a bidirectional approach. Efficient further functionalization with useful coordinating groups were achieved. The resulting homoditopic platforms are of interest in numerous fields ranging from supramolecular chemistry to materials science. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We describe the synthesis of architectures that consist of a symmetrical rodlike oligo(phenylene-ethynylene) (OPE) backbone of incrementable length connected to a pair of classical ligands for metal coordination. OPE spacers decorated with various end groups and incorporating up to seven phenylene-acetylene repeat units were quickly obtained through a bidirectional approach. Efficient further functionalization with useful coordinating groups were achieved. The resulting homoditopic platforms are of interest in numerous fields ranging from supramolecular chemistry to materials science. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim |
Rhenium Complexes Based on 2-Pyridyl-1,2,3-triazole Ligands: A New Class of CO2 Reduction Catalysts Article de journal H Y V Ching; X Wang; M He; N Perujo Holland; R Guillot; C Slim; S Griveau; H C Bertrand; C Policar; F Bedioui; M Fontecave Inorganic Chemistry, 56 (5), p. 2966–2976, 2017. @article{Ching:2017,
title = {Rhenium Complexes Based on 2-Pyridyl-1,2,3-triazole Ligands: A New Class of CO2 Reduction Catalysts},
author = {H Y V Ching and X Wang and M He and N Perujo Holland and R Guillot and C Slim and S Griveau and H C Bertrand and C Policar and F Bedioui and M Fontecave},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014526293&doi=10.1021%2facs.inorgchem.6b03078&partnerID=40&md5=5aa6a6db21554e7bca56e0f1e1de9856},
doi = {10.1021/acs.inorgchem.6b03078},
year = {2017},
date = {2017-01-01},
journal = {Inorganic Chemistry},
volume = {56},
number = {5},
pages = {2966--2976},
abstract = {A series of [Re(NtextasciicircumN)(CO)3(X)] (NtextasciicircumN = diimine and X = halide) complexes based on 4-(2-pyridyl)-1,2,3-triazole (pyta) and 1-(2-pyridyl)-1,2,3-triazole (tapy) diimine ligands have been prepared and electrochemically characterized. The first ligand-based reduction process is shown to be highly sensitive to the nature of the isomer as well as to the substituents on the pyridyl ring, with the peak potential changing by up to 700 mV. The abilities of this class of complexes to catalyze the electroreduction and photoreduction of CO2 were assessed for the first time. It is found that only Re pyta complexes that have a first reduction wave with a peak potential at ca. −1.7 V vs SCE are active, producing CO as the major product, together with small amounts of H2 and formic acid. The catalytic wave that is observed in the CVs is enhanced by the addition of water or trifluoroethanol as a proton source. Long-term controlled potential electrolysis experiments gave total Faradaic yield close to 100%. In particular, functionalization of the triazolyl ring with a 2,4,6-tri-tert-butylphenyl group provided the catalyst with a remarkable stability. © 2017 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A series of [Re(NtextasciicircumN)(CO)3(X)] (NtextasciicircumN = diimine and X = halide) complexes based on 4-(2-pyridyl)-1,2,3-triazole (pyta) and 1-(2-pyridyl)-1,2,3-triazole (tapy) diimine ligands have been prepared and electrochemically characterized. The first ligand-based reduction process is shown to be highly sensitive to the nature of the isomer as well as to the substituents on the pyridyl ring, with the peak potential changing by up to 700 mV. The abilities of this class of complexes to catalyze the electroreduction and photoreduction of CO2 were assessed for the first time. It is found that only Re pyta complexes that have a first reduction wave with a peak potential at ca. −1.7 V vs SCE are active, producing CO as the major product, together with small amounts of H2 and formic acid. The catalytic wave that is observed in the CVs is enhanced by the addition of water or trifluoroethanol as a proton source. Long-term controlled potential electrolysis experiments gave total Faradaic yield close to 100%. In particular, functionalization of the triazolyl ring with a 2,4,6-tri-tert-butylphenyl group provided the catalyst with a remarkable stability. © 2017 American Chemical Society. |
Re(I) carbonyl complexes: Multimodal platforms for inorganic chemical biology Article de journal S Hostachy; C Policar; N Delsuc Coordination Chemistry Reviews, 351 , p. 172–188, 2017. @article{Hostachy:2017,
title = {Re(I) carbonyl complexes: Multimodal platforms for inorganic chemical biology},
author = {S Hostachy and C Policar and N Delsuc},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85020033654&doi=10.1016%2fj.ccr.2017.05.004&partnerID=40&md5=ea1241c6f9199448b3fbb2bfc259b363},
doi = {10.1016/j.ccr.2017.05.004},
year = {2017},
date = {2017-01-01},
journal = {Coordination Chemistry Reviews},
volume = {351},
pages = {172--188},
abstract = {Bio-imaging, by enabling the visualization of biomolecules of interest, has proved to be highly informative in the study of biological processes. Although fluorescence microscopy is probably one of the most used techniques, alternative methods of imaging, providing complementary information, are emerging. In this context, metal complexes represent valuable platforms for multimodal imaging, since they may combine interesting spectroscopic features and biologically relevant functionalization on a single molecular core. In particular, d6 low-spin rhenium tri-carbonyl complexes display unique luminescence and vibrational properties, and can be readily functionalized. Here we review their applications and potential as probes or drugs relying on their photophysical properties, before focusing on their use as multimodal probes for the labelling and imaging of peptides and proteins. © 2017 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Bio-imaging, by enabling the visualization of biomolecules of interest, has proved to be highly informative in the study of biological processes. Although fluorescence microscopy is probably one of the most used techniques, alternative methods of imaging, providing complementary information, are emerging. In this context, metal complexes represent valuable platforms for multimodal imaging, since they may combine interesting spectroscopic features and biologically relevant functionalization on a single molecular core. In particular, d6 low-spin rhenium tri-carbonyl complexes display unique luminescence and vibrational properties, and can be readily functionalized. Here we review their applications and potential as probes or drugs relying on their photophysical properties, before focusing on their use as multimodal probes for the labelling and imaging of peptides and proteins. © 2017 Elsevier B.V. |
A Cell-Penetrant Manganese Superoxide Dismutase (MnSOD) Mimic Is Able to Complement MnSOD and Exerts an Antiinflammatory Effect on Cellular and Animal Models of Inflammatory Bowel Diseases Article de journal E Mathieu; A -S Bernard; N Delsuc; E Quévrain; G Gazzah; B Lai; F Chain; P Langella; M Bachelet; J Masliah; P Seksik; C Policar Inorganic Chemistry, 56 (5), p. 2545–2555, 2017. @article{Mathieu:2017,
title = {A Cell-Penetrant Manganese Superoxide Dismutase (MnSOD) Mimic Is Able to Complement MnSOD and Exerts an Antiinflammatory Effect on Cellular and Animal Models of Inflammatory Bowel Diseases},
author = {E Mathieu and A -S Bernard and N Delsuc and E Qu\'{e}vrain and G Gazzah and B Lai and F Chain and P Langella and M Bachelet and J Masliah and P Seksik and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014763334&doi=10.1021%2facs.inorgchem.6b02695&partnerID=40&md5=acd51065ea36d5da707ec8c1915634a0},
doi = {10.1021/acs.inorgchem.6b02695},
year = {2017},
date = {2017-01-01},
journal = {Inorganic Chemistry},
volume = {56},
number = {5},
pages = {2545--2555},
abstract = {Inorganic complexes are increasingly used for biological and medicinal applications, and the question of the cell penetration and distribution of metallodrugs is key to understanding their biological activity. Oxidative stress is known to be involved in inflammation and in inflammatory bowel diseases for which antioxidative defenses are weakened. We report here the study of the manganese complex Mn1 mimicking superoxide dismutase (SOD), a protein involved in cell protection against oxidative stress, using an approach in inorganic cellular chemistry combining the investigation of Mn1 intracellular speciation using mass spectrometry and of its quantification and distribution using electron paramagnetic resonance and spatially resolved X-ray fluorescence with evaluation of its biological activity. More precisely, we have looked for and found the MS signature of Mn1 in cell lysates and quantified the overall manganese content. Intestinal epithelial cells activated by bacterial lipopolysaccharide were taken as a cellular model of oxidative stress and inflammation. DNBS-induced colitis in mice was used to investigate Mn1 activity in vivo. Mn1 exerts an intracellular antiinflammatory activity, remains at least partially coordinated, with diffuse distribution over the whole cell, and functionally complements mitochondrial MnSOD. © 2017 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Inorganic complexes are increasingly used for biological and medicinal applications, and the question of the cell penetration and distribution of metallodrugs is key to understanding their biological activity. Oxidative stress is known to be involved in inflammation and in inflammatory bowel diseases for which antioxidative defenses are weakened. We report here the study of the manganese complex Mn1 mimicking superoxide dismutase (SOD), a protein involved in cell protection against oxidative stress, using an approach in inorganic cellular chemistry combining the investigation of Mn1 intracellular speciation using mass spectrometry and of its quantification and distribution using electron paramagnetic resonance and spatially resolved X-ray fluorescence with evaluation of its biological activity. More precisely, we have looked for and found the MS signature of Mn1 in cell lysates and quantified the overall manganese content. Intestinal epithelial cells activated by bacterial lipopolysaccharide were taken as a cellular model of oxidative stress and inflammation. DNBS-induced colitis in mice was used to investigate Mn1 activity in vivo. Mn1 exerts an intracellular antiinflammatory activity, remains at least partially coordinated, with diffuse distribution over the whole cell, and functionally complements mitochondrial MnSOD. © 2017 American Chemical Society. |
2016
|
The Use of Mn(II) Bound to His-tags as Genetically Encodable Spin-Label for Nanometric Distance Determination in Proteins Article de journal H Y V Ching; F C Mascali; H C Bertrand; E M Bruch; P Demay-Drouhard; R M Rasia; C Policar; L C Tabares; S Un Journal of Physical Chemistry Letters, 7 (6), p. 1072–1076, 2016. @article{Ching:2016,
title = {The Use of Mn(II) Bound to His-tags as Genetically Encodable Spin-Label for Nanometric Distance Determination in Proteins},
author = {H Y V Ching and F C Mascali and H C Bertrand and E M Bruch and P Demay-Drouhard and R M Rasia and C Policar and L C Tabares and S Un},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962539336&doi=10.1021%2facs.jpclett.6b00362&partnerID=40&md5=16161dac85830ffcae821a41e6480d4c},
doi = {10.1021/acs.jpclett.6b00362},
year = {2016},
date = {2016-01-01},
journal = {Journal of Physical Chemistry Letters},
volume = {7},
number = {6},
pages = {1072--1076},
abstract = {A genetically encodable paramagnetic spin-label capable of self-assembly from naturally available components would offer a means for studying the in-cell structure and interactions of a protein by electron paramagnetic resonance (EPR). Here, we demonstrate pulse electron-electron double resonance (DEER) measurements on spin-labels consisting of Mn(II) ions coordinated to a sequence of histidines, so-called His-tags, that are ubiquitously added by genetic engineering to facilitate protein purification. Although the affinity of His-tags for Mn(II) was low (800 μM), Mn(II)-bound His-tags yielded readily detectable DEER time traces even at concentrations expected in cells. We were able to determine accurately the distance between two His-tag Mn(II) spin-labels at the ends of a rigid helical polyproline peptide of known structure, as well as at the ends of a completely cell-synthesized 3-helix bundle. This approach not only greatly simplifies the labeling procedure but also represents a first step towards using self-assembling metal spin-labels for in-cell distance measurements. © 2016 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A genetically encodable paramagnetic spin-label capable of self-assembly from naturally available components would offer a means for studying the in-cell structure and interactions of a protein by electron paramagnetic resonance (EPR). Here, we demonstrate pulse electron-electron double resonance (DEER) measurements on spin-labels consisting of Mn(II) ions coordinated to a sequence of histidines, so-called His-tags, that are ubiquitously added by genetic engineering to facilitate protein purification. Although the affinity of His-tags for Mn(II) was low (800 μM), Mn(II)-bound His-tags yielded readily detectable DEER time traces even at concentrations expected in cells. We were able to determine accurately the distance between two His-tag Mn(II) spin-labels at the ends of a rigid helical polyproline peptide of known structure, as well as at the ends of a completely cell-synthesized 3-helix bundle. This approach not only greatly simplifies the labeling procedure but also represents a first step towards using self-assembling metal spin-labels for in-cell distance measurements. © 2016 American Chemical Society. |
Bioinspired superoxide-dismutase mimics: The effects of functionalization with cationic polyarginine peptides Article de journal H Y V Ching; I Kenkel; N Delsuc; E Mathieu; I Ivanović-Burmazović; C Policar Journal of Inorganic Biochemistry, 160 , p. 172–179, 2016. @article{Ching:2016a,
title = {Bioinspired superoxide-dismutase mimics: The effects of functionalization with cationic polyarginine peptides},
author = {H Y V Ching and I Kenkel and N Delsuc and E Mathieu and I Ivanovi\'{c}-Burmazovi\'{c} and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84964372716&doi=10.1016%2fj.jinorgbio.2016.01.025&partnerID=40&md5=035d0c2b5ffd4ee0b6fb74df285838da},
doi = {10.1016/j.jinorgbio.2016.01.025},
year = {2016},
date = {2016-01-01},
journal = {Journal of Inorganic Biochemistry},
volume = {160},
pages = {172--179},
abstract = {Continuing a bio-mimetic approach, we have prepared peptide conjugates of a superoxide dismutase (SOD) mimic [MnL]+ (where HL = N-(2-hydroxybenzyl)-N,N'-bis[2-(N-methylimidazolyl)methyl]ethane-1,2-diamine), namely [MnL'-Arg(n-1)]n+ (where n = 2, 4, 7 and 10) and [MnL'-Gly1]+. [MnL'-Arg(n-1)]n+ contained cationic residue(s) that emulate the electrostatic channel of the enzyme. Physicochemical methods showed that functionalization at the secondary amine of HL did not impair coordination to MnII with association constants (Kassoc) between 1.6 and 3.3 × 106 M- 1. The MnIII/MnII redox potential of the conjugates was between 0.27 and 0.30 V vs SCE, slightly higher than [MnL]+ under the same conditions, but remain at a value that facilitates O2•- dismutation. The catalytic rate constant (kcat) of the dismutation for the series was studied using a direct stopped-flow method, which showed that for compounds with the same overall charge, the alkylation of the secondary amine of [MnL]+ (kcat = 5.0 ± 0.1 × 106 M- 1 s- 1) led to a lower value (i.e. for [MnL'Gly]+},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Continuing a bio-mimetic approach, we have prepared peptide conjugates of a superoxide dismutase (SOD) mimic [MnL]+ (where HL = N-(2-hydroxybenzyl)-N,N'-bis[2-(N-methylimidazolyl)methyl]ethane-1,2-diamine), namely [MnL'-Arg(n-1)]n+ (where n = 2, 4, 7 and 10) and [MnL'-Gly1]+. [MnL'-Arg(n-1)]n+ contained cationic residue(s) that emulate the electrostatic channel of the enzyme. Physicochemical methods showed that functionalization at the secondary amine of HL did not impair coordination to MnII with association constants (Kassoc) between 1.6 and 3.3 × 106 M- 1. The MnIII/MnII redox potential of the conjugates was between 0.27 and 0.30 V vs SCE, slightly higher than [MnL]+ under the same conditions, but remain at a value that facilitates O2•- dismutation. The catalytic rate constant (kcat) of the dismutation for the series was studied using a direct stopped-flow method, which showed that for compounds with the same overall charge, the alkylation of the secondary amine of [MnL]+ (kcat = 5.0 ± 0.1 × 106 M- 1 s- 1) led to a lower value (i.e. for [MnL'Gly]+ |
Bimodal X-ray and Infrared Imaging of an Organometallic Derivative of Praziquantel in Schistosoma mansoni Article de journal S Clède; N Cowan; F Lambert; H C Bertrand; R Rubbiani; M Patra; J Hess; C Sandt; N Trcera; G Gasser; J Keiser; C Policar ChemBioChem, 17 (11), p. 1004–1007, 2016. @article{Clede:2016,
title = {Bimodal X-ray and Infrared Imaging of an Organometallic Derivative of Praziquantel in Schistosoma mansoni},
author = {S Cl\`{e}de and N Cowan and F Lambert and H C Bertrand and R Rubbiani and M Patra and J Hess and C Sandt and N Trcera and G Gasser and J Keiser and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973124415&doi=10.1002%2fcbic.201500688&partnerID=40&md5=608b1bb28a5237e0717a29ee815e73bc},
doi = {10.1002/cbic.201500688},
year = {2016},
date = {2016-01-01},
journal = {ChemBioChem},
volume = {17},
number = {11},
pages = {1004--1007},
abstract = {An organometallic derivative of praziquantel was studied directly in worms by using inductively coupled plasma-mass spectrometry (ICP-MS) for quantification and synchrotron-based imaging. X-ray fluorescence (XRF) and IR absorption spectromicroscopy were used for the first time in combination to directly locate this organometallic drug candidate in schistosomes. The detection of both CO (IR) and Cr (XRF) signatures proved that the Cr(CO)3 core remained intact in the worms. Images showed a preferential accumulation at the worm's tegument, consistent with a possible targeting of the calcium channel but not excluding other biological targets inside the worm. Imaginative imaging: Two synchrotron-based techniques - X-ray fluorescence and IR absorption spectroscopy - were used in combination for the first time to directly locate an organometallic drug candidate in schistosomes. This represents a novel approach to examine mechanisms of actions for organometallic compounds and might lead to the discovery of new drug candidates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An organometallic derivative of praziquantel was studied directly in worms by using inductively coupled plasma-mass spectrometry (ICP-MS) for quantification and synchrotron-based imaging. X-ray fluorescence (XRF) and IR absorption spectromicroscopy were used for the first time in combination to directly locate this organometallic drug candidate in schistosomes. The detection of both CO (IR) and Cr (XRF) signatures proved that the Cr(CO)3 core remained intact in the worms. Images showed a preferential accumulation at the worm's tegument, consistent with a possible targeting of the calcium channel but not excluding other biological targets inside the worm. Imaginative imaging: Two synchrotron-based techniques - X-ray fluorescence and IR absorption spectroscopy - were used in combination for the first time to directly locate an organometallic drug candidate in schistosomes. This represents a novel approach to examine mechanisms of actions for organometallic compounds and might lead to the discovery of new drug candidates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
A Bis-Manganese(II)–DOTA Complex for Pulsed Dipolar Spectroscopy Article de journal P Demay-Drouhard; H Y V Ching; D Akhmetzyanov; R Guillot; L C Tabares; H C Bertrand; C Policar ChemPhysChem, p. 2066–2078, 2016. @article{Demay-Drouhard:2016,
title = {A Bis-Manganese(II)\textendashDOTA Complex for Pulsed Dipolar Spectroscopy},
author = {P Demay-Drouhard and H Y V Ching and D Akhmetzyanov and R Guillot and L C Tabares and H C Bertrand and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84977597209&doi=10.1002%2fcphc.201600234&partnerID=40&md5=38a2466ad0f00d0edb158d200429986c},
doi = {10.1002/cphc.201600234},
year = {2016},
date = {2016-01-01},
journal = {ChemPhysChem},
pages = {2066--2078},
abstract = {High-spin gadolinium(III) and manganese(II) complexes have emerged as alternatives to standard nitroxide radical spin labels for measuring nanometric distances by using pulsed electron\textendashelectron double resonance (PELDOR or DEER) at high fields/frequencies. For certain complexes, particularly those with relatively small zero-field splitting (ZFS) and short distances between the two metal centers, the pseudosecular term of the dipolar coupling Hamiltonian is non-negligible. However, in general, the contribution from this term during conventional data analysis is masked by the flexibility of the molecule of interest and/or the long tethers connecting them to the spin labels. The efficient synthesis of a model system consisting of two [Mn(dota)]2− (MnDOTA; DOTA4−=1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) directly connected to the ends of a central rodlike oligo(phenylene\textendashethynylene) (OPE) spacer is reported. The rigidity of the OPE is confirmed by Q-band PELDOR measurements on a bis-nitroxide analogue. The MnII−MnII distance distribution profile determined by W-band PELDOR is in reasonable agreement with one simulated by using a simple rotamer analysis. The small degree of flexibility arising from the linking MnDOTA arm appears to outweigh the contribution from the pseudosecular term at this interspin distance. This study illustrates the potential of MnDOTA-based spin labels for measuring fairly short nanometer distances, and also presents an interesting candidate for in-depth studies of pulsed dipolar spectroscopy methods on MnII−MnII systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
High-spin gadolinium(III) and manganese(II) complexes have emerged as alternatives to standard nitroxide radical spin labels for measuring nanometric distances by using pulsed electron–electron double resonance (PELDOR or DEER) at high fields/frequencies. For certain complexes, particularly those with relatively small zero-field splitting (ZFS) and short distances between the two metal centers, the pseudosecular term of the dipolar coupling Hamiltonian is non-negligible. However, in general, the contribution from this term during conventional data analysis is masked by the flexibility of the molecule of interest and/or the long tethers connecting them to the spin labels. The efficient synthesis of a model system consisting of two [Mn(dota)]2− (MnDOTA; DOTA4−=1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) directly connected to the ends of a central rodlike oligo(phenylene–ethynylene) (OPE) spacer is reported. The rigidity of the OPE is confirmed by Q-band PELDOR measurements on a bis-nitroxide analogue. The MnII−MnII distance distribution profile determined by W-band PELDOR is in reasonable agreement with one simulated by using a simple rotamer analysis. The small degree of flexibility arising from the linking MnDOTA arm appears to outweigh the contribution from the pseudosecular term at this interspin distance. This study illustrates the potential of MnDOTA-based spin labels for measuring fairly short nanometer distances, and also presents an interesting candidate for in-depth studies of pulsed dipolar spectroscopy methods on MnII−MnII systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim |
Human TTR conformation altered by rhenium tris-carbonyl derivatives Article de journal L Ciccone; C Policar; E A Stura; W Shepard Journal of Structural Biology, 195 (3), p. 353–364, 2016. @article{Ciccone:2016,
title = {Human TTR conformation altered by rhenium tris-carbonyl derivatives},
author = {L Ciccone and C Policar and E A Stura and W Shepard},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991363542&doi=10.1016%2fj.jsb.2016.07.002&partnerID=40&md5=86e7e8d956bfdb39ae832e52b01a9dea},
doi = {10.1016/j.jsb.2016.07.002},
year = {2016},
date = {2016-01-01},
journal = {Journal of Structural Biology},
volume = {195},
number = {3},
pages = {353--364},
abstract = {Transthyretin (TTR) is a 54 kDa homotetrameric serum protein that transports thyroxine (T4) and retinol. TTR is potentially amyloidogenic due to homotetramer dissociation into monomeric intermediates that self-assemble as amyloid deposits and insoluble fibrils. Most crystallographic structures, including those of amyloidogenic variants show the same tetramer without major variations in the monomer-monomer interface nor in the volume of the interdimeric cavity. Soaking TTR crystals in a solution containing rhenium tris-carbonyl derivatives yields a TTR conformer never observed before. Only one of the two monomers of the crystallographic dimer is significantly altered, and the inner part of the T4 binding cavity is expanded at one end and shrunk at the other. The result redefines the mechanism of allosteric communication between the two sites, suggesting that negative cooperativity is a function of dimer asymmetry, which can be induced through internal or external binding. An aspect that remains unexplained is why the conformational changes are ubiquitous throughout the crystal although the heavy metal content of the derivatized crystals is relatively low. The conformational changes observed, which include Leu82, may represent a form of TTR better at scavenging β-Amyloid. At a resolution of 1.69 r{A}, with excellent refinement statistics and well defined electron density for all parts of the structure, it is possible to envisage answering important questions that range from protein cooperative behavior to heavy atom induced protein conformational modifications that can result in crystallographic non-isomorphism. © 2016 Elsevier Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Transthyretin (TTR) is a 54 kDa homotetrameric serum protein that transports thyroxine (T4) and retinol. TTR is potentially amyloidogenic due to homotetramer dissociation into monomeric intermediates that self-assemble as amyloid deposits and insoluble fibrils. Most crystallographic structures, including those of amyloidogenic variants show the same tetramer without major variations in the monomer-monomer interface nor in the volume of the interdimeric cavity. Soaking TTR crystals in a solution containing rhenium tris-carbonyl derivatives yields a TTR conformer never observed before. Only one of the two monomers of the crystallographic dimer is significantly altered, and the inner part of the T4 binding cavity is expanded at one end and shrunk at the other. The result redefines the mechanism of allosteric communication between the two sites, suggesting that negative cooperativity is a function of dimer asymmetry, which can be induced through internal or external binding. An aspect that remains unexplained is why the conformational changes are ubiquitous throughout the crystal although the heavy metal content of the derivatized crystals is relatively low. The conformational changes observed, which include Leu82, may represent a form of TTR better at scavenging β-Amyloid. At a resolution of 1.69 Å, with excellent refinement statistics and well defined electron density for all parts of the structure, it is possible to envisage answering important questions that range from protein cooperative behavior to heavy atom induced protein conformational modifications that can result in crystallographic non-isomorphism. © 2016 Elsevier Inc. |
Monitoring bicosomes containing antioxidants in normal and irradiated skin Article de journal E Fernández; S Hostachy; C Sandt; G Rodríguez; H C Bertrand; S Clède; M Cócera; A D L Maza; F Lambert; C Policar; O López RSC Advances, 6 (76), p. 72559–72567, 2016. @article{Fernandez:2016,
title = {Monitoring bicosomes containing antioxidants in normal and irradiated skin},
author = {E Fern\'{a}ndez and S Hostachy and C Sandt and G Rodr\'{i}guez and H C Bertrand and S Cl\`{e}de and M C\'{o}cera and A D L Maza and F Lambert and C Policar and O L\'{o}pez},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84982684419&doi=10.1039%2fc6ra11170j&partnerID=40&md5=126bef944046a09450ae86ce5985c07f},
doi = {10.1039/c6ra11170j},
year = {2016},
date = {2016-01-01},
journal = {RSC Advances},
volume = {6},
number = {76},
pages = {72559--72567},
abstract = {This study evaluates the penetration of bicosome systems incorporating two different antioxidants into normal skin and skin exposed to ultraviolet-visible radiation (UV-VIS) by Fourier-transform infrared microspectroscopy (FT-IR) using synchrotron radiation. Bicosomes are phospholipid assemblies based on mixtures of discoidal lipid structures protected by spherical lipid vesicles able to incorporate different molecules. In the current work, the antioxidants incorporated in these systems were β-carotene and a Mn complex as a superoxide dismutase (SOD) mimic. Additionally, a rhenium tri-carbonyl derivative was incorporated in the bicosome systems in order to map their penetration following the tag specific carbonyl signal by FT-IR microspectroscopy. The characterization of bicosome systems using the dynamic light scattering technique (DLS) showed a modification in the size of the systems containing β-carotene (Bcβ) or MnII complex (BcMn). After skin permeation, FT-IR results indicated a higher and deeper penetration of the BcMn system than the Bcβ system into the skin. Likely, the different physicochemical properties of both antioxidants could be responsible for this effect. Moreover, the penetration of both bicosome systems in irradiated skin was lower in comparison with the normal skin. This fact could be a consequence of the alteration of water transport in the skin during the irradiation process. In conclusion, these results indicated the effectiveness of bicosome systems as skin carriers, and provide information to protect skin under radiation using antioxidants. © The Royal Society of Chemistry 2016.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study evaluates the penetration of bicosome systems incorporating two different antioxidants into normal skin and skin exposed to ultraviolet-visible radiation (UV-VIS) by Fourier-transform infrared microspectroscopy (FT-IR) using synchrotron radiation. Bicosomes are phospholipid assemblies based on mixtures of discoidal lipid structures protected by spherical lipid vesicles able to incorporate different molecules. In the current work, the antioxidants incorporated in these systems were β-carotene and a Mn complex as a superoxide dismutase (SOD) mimic. Additionally, a rhenium tri-carbonyl derivative was incorporated in the bicosome systems in order to map their penetration following the tag specific carbonyl signal by FT-IR microspectroscopy. The characterization of bicosome systems using the dynamic light scattering technique (DLS) showed a modification in the size of the systems containing β-carotene (Bcβ) or MnII complex (BcMn). After skin permeation, FT-IR results indicated a higher and deeper penetration of the BcMn system than the Bcβ system into the skin. Likely, the different physicochemical properties of both antioxidants could be responsible for this effect. Moreover, the penetration of both bicosome systems in irradiated skin was lower in comparison with the normal skin. This fact could be a consequence of the alteration of water transport in the skin during the irradiation process. In conclusion, these results indicated the effectiveness of bicosome systems as skin carriers, and provide information to protect skin under radiation using antioxidants. © The Royal Society of Chemistry 2016. |
New insight into the structural, electrochemical and biological aspects of macroacyclic Cu(II) complexes derived from S-substituted dithiocarbazate schiff bases Article de journal M L Low; L Maigre; M I M Tahir; E R T Tiekink; P Dorlet; R Guillot; T B Ravoof; R Rosli; J -M Pagès; C Policar; N Delsuc; K A Crouse European Journal of Medicinal Chemistry, 120 , p. 1–12, 2016. @article{Low:2016,
title = {New insight into the structural, electrochemical and biological aspects of macroacyclic Cu(II) complexes derived from S-substituted dithiocarbazate schiff bases},
author = {M L Low and L Maigre and M I M Tahir and E R T Tiekink and P Dorlet and R Guillot and T B Ravoof and R Rosli and J -M Pag\`{e}s and C Policar and N Delsuc and K A Crouse},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84967102584&doi=10.1016%2fj.ejmech.2016.04.027&partnerID=40&md5=71cde180942655ac9c57205e82887fcf},
doi = {10.1016/j.ejmech.2016.04.027},
year = {2016},
date = {2016-01-01},
journal = {European Journal of Medicinal Chemistry},
volume = {120},
pages = {1--12},
abstract = {Copper (II) complexes synthesized from the products of condensation of S-methyl- and S-benzyldithiocarbazate with 2,5-hexanedione (SMHDH2 and SBHDH2 respectively) have been characterized using various physicochemical (elemental analysis, molar conductivity, magnetic susceptibility) and spectroscopic (infrared, electronic) methods. The structures of SMHDH2, its copper (II) complex, CuSMHD, and the related CuSBHD complex as well as a pyrrole byproduct, SBPY, have been determined by single crystal X-ray diffraction. In order to provide more insight into the behaviour of the complexes in solution, electron paramagnetic resonance (EPR) and electrochemical experiments were performed. Antibacterial activity and cytotoxicity were evaluated. The compounds, dissolved in 0.5% and 5% DMSO, showed a wide range of antibacterial activity against 10 strains of Gram-positive and Gram-negative bacteria. Investigations of the effects of efflux pumps and membrane penetration on antibacterial activity are reported herein. Antiproliferation activity was observed to be enhanced by complexation with copper. Preliminary screening showed Cu complexes are strongly active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7. © 2016 Published by Elsevier Masson SAS.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Copper (II) complexes synthesized from the products of condensation of S-methyl- and S-benzyldithiocarbazate with 2,5-hexanedione (SMHDH2 and SBHDH2 respectively) have been characterized using various physicochemical (elemental analysis, molar conductivity, magnetic susceptibility) and spectroscopic (infrared, electronic) methods. The structures of SMHDH2, its copper (II) complex, CuSMHD, and the related CuSBHD complex as well as a pyrrole byproduct, SBPY, have been determined by single crystal X-ray diffraction. In order to provide more insight into the behaviour of the complexes in solution, electron paramagnetic resonance (EPR) and electrochemical experiments were performed. Antibacterial activity and cytotoxicity were evaluated. The compounds, dissolved in 0.5% and 5% DMSO, showed a wide range of antibacterial activity against 10 strains of Gram-positive and Gram-negative bacteria. Investigations of the effects of efflux pumps and membrane penetration on antibacterial activity are reported herein. Antiproliferation activity was observed to be enhanced by complexation with copper. Preliminary screening showed Cu complexes are strongly active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7. © 2016 Published by Elsevier Masson SAS. |
Photophysical properties of single core multimodal probe for imaging (SCoMPI) in a membrane model and in cells Article de journal S Hostachy; J -M Swiecicki; C Sandt; N Delsuc; C Policar Dalton Transactions, 45 (7), p. 2791–2795, 2016. @article{Hostachy:2016,
title = {Photophysical properties of single core multimodal probe for imaging (SCoMPI) in a membrane model and in cells},
author = {S Hostachy and J -M Swiecicki and C Sandt and N Delsuc and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958064177&doi=10.1039%2fc5dt03819g&partnerID=40&md5=fb027086e6424b54b23cc2c11098e273},
doi = {10.1039/c5dt03819g},
year = {2016},
date = {2016-01-01},
journal = {Dalton Transactions},
volume = {45},
number = {7},
pages = {2791--2795},
abstract = {The spectroscopic properties of two luminescent Re(i) tricarbonyl complexes conjugated with two cell-penetrating peptides were examined. Fluorescence experiments and IR quantification in membrane models and in cells showed unexpectedly strong luminescence enhancement for one of the complexes in a lipid environment. © The Royal Society of Chemistry 2016.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The spectroscopic properties of two luminescent Re(i) tricarbonyl complexes conjugated with two cell-penetrating peptides were examined. Fluorescence experiments and IR quantification in membrane models and in cells showed unexpectedly strong luminescence enhancement for one of the complexes in a lipid environment. © The Royal Society of Chemistry 2016. |
RIDME spectroscopy on high-spin Mn2+ centers Article de journal D Akhmetzyanov; H Y V Ching; V Denysenkov; P Demay-Drouhard; H C Bertrand; L C Tabares; C Policar; T F Prisner; S Un Physical Chemistry Chemical Physics, 18 (44), p. 30857–30866, 2016. @article{Akhmetzyanov:2016,
title = {RIDME spectroscopy on high-spin Mn2+ centers},
author = {D Akhmetzyanov and H Y V Ching and V Denysenkov and P Demay-Drouhard and H C Bertrand and L C Tabares and C Policar and T F Prisner and S Un},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85025823502&doi=10.1039%2fc6cp05239h&partnerID=40&md5=d3a6cd609c88b382cf0297ed361d4003},
doi = {10.1039/c6cp05239h},
year = {2016},
date = {2016-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {18},
number = {44},
pages = {30857--30866},
abstract = {Pulsed EPR dipolar spectroscopy is a powerful tool for determining the structure and conformational dynamics of biological macromolecules, as it allows precise measurements of distances in the range of 1.5-10 nm. Utilization of high-spin Mn2+ species as spin probes for distance measurements is of significant interest, because they are biologically compatible and endogenous in numerous biological systems. However, to date dipolar spectroscopy experiments with this kind of species have been underexplored. Here we present pulsed electron electron double resonance (PELDOR also called DEER) and relaxation-induced dipolar modulation enhancement (RIDME) experiments, which have been performed at W-band (94 GHz) and J-band frequencies (263 GHz) on a bis-MnDOTA (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) model system. The distances obtained from these experiments are in good agreement with predictions. RIDME experiments reveal a significantly higher modulation depth compared to PELDOR, which is an important consideration for biological samples. These experiments also feature higher harmonics of the dipolar coupling frequency due to effective multiple-quantum relaxation of high-spin Mn2+ as well as the multiple-component background function. Harmonics of the dipolar coupling frequency were taken into account by including additional terms in the kernel function of Tikhonov regularization analysis. © The Owner Societies 2016.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pulsed EPR dipolar spectroscopy is a powerful tool for determining the structure and conformational dynamics of biological macromolecules, as it allows precise measurements of distances in the range of 1.5-10 nm. Utilization of high-spin Mn2+ species as spin probes for distance measurements is of significant interest, because they are biologically compatible and endogenous in numerous biological systems. However, to date dipolar spectroscopy experiments with this kind of species have been underexplored. Here we present pulsed electron electron double resonance (PELDOR also called DEER) and relaxation-induced dipolar modulation enhancement (RIDME) experiments, which have been performed at W-band (94 GHz) and J-band frequencies (263 GHz) on a bis-MnDOTA (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate) model system. The distances obtained from these experiments are in good agreement with predictions. RIDME experiments reveal a significantly higher modulation depth compared to PELDOR, which is an important consideration for biological samples. These experiments also feature higher harmonics of the dipolar coupling frequency due to effective multiple-quantum relaxation of high-spin Mn2+ as well as the multiple-component background function. Harmonics of the dipolar coupling frequency were taken into account by including additional terms in the kernel function of Tikhonov regularization analysis. © The Owner Societies 2016. |
2015
|
Nanometric distance measurements between Mn(II)DOTA centers Article de journal H Y Vincent Ching; P Demay-Drouhard; H C Bertrand; C Policar; L C Tabares; S Un Physical Chemistry Chemical Physics, 17 (36), p. 23368–23377, 2015. @article{VincentChing:2015,
title = {Nanometric distance measurements between Mn(II)DOTA centers},
author = {H Y Vincent Ching and P Demay-Drouhard and H C Bertrand and C Policar and L C Tabares and S Un},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941299721&doi=10.1039%2fc5cp03487f&partnerID=40&md5=bfd7a9aac0fc115147eb207f0fbeb05b},
doi = {10.1039/c5cp03487f},
year = {2015},
date = {2015-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {17},
number = {36},
pages = {23368--23377},
abstract = {Pulse electron-electron double resonance (PELDOR) is a versatile technique for probing the structures and functions of complex biological systems. Despite the recent interest in high-spin metal-ions for high field/frequency applications, PELDOR measurements of Mn(II) remain relatively underexplored. Here we present Mn(II)-Mn(II) PELDOR distance measurements at 94 GHz on polyproline II (PPII) helices doubly spin-labeled with Mn(II)DOTA, which are distinguished by their small zero-field interaction. The measured Mn-Mn distances and distribution profiles were in good agreement with the expected values from molecular models. Additional features in the frequency-domain spectra became apparent at certain combinations of detect and pump frequencies. Spin-Hamiltonian calculations showed that they likely arose from contributions from the pseudo-secular component of the dipolar interaction that were found to be non-negligible for Mn(II)DOTA. However, the influence of the pseudo-secular component on the distance distribution profiles apparently was limited. The results show the potential of Mn(II)DOTA spin labels for high-field PELDOR distance measurements in proteins and other biological systems. © the Owner Societies 2015.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pulse electron-electron double resonance (PELDOR) is a versatile technique for probing the structures and functions of complex biological systems. Despite the recent interest in high-spin metal-ions for high field/frequency applications, PELDOR measurements of Mn(II) remain relatively underexplored. Here we present Mn(II)-Mn(II) PELDOR distance measurements at 94 GHz on polyproline II (PPII) helices doubly spin-labeled with Mn(II)DOTA, which are distinguished by their small zero-field interaction. The measured Mn-Mn distances and distribution profiles were in good agreement with the expected values from molecular models. Additional features in the frequency-domain spectra became apparent at certain combinations of detect and pump frequencies. Spin-Hamiltonian calculations showed that they likely arose from contributions from the pseudo-secular component of the dipolar interaction that were found to be non-negligible for Mn(II)DOTA. However, the influence of the pseudo-secular component on the distance distribution profiles apparently was limited. The results show the potential of Mn(II)DOTA spin labels for high-field PELDOR distance measurements in proteins and other biological systems. © the Owner Societies 2015. |
Synthesis, characterization and biological activity of Cu(II), Zn(II) and Re(I) complexes derived from S-benzyldithiocarbazate and 3-acetylcoumarin Article de journal M L Low; G Paulus; P Dorlet; R Guillot; R Rosli; N Delsuc; K A Crouse; C Policar BioMetals, 28 (3), p. 553–566, 2015. @article{Low:2015,
title = {Synthesis, characterization and biological activity of Cu(II), Zn(II) and Re(I) complexes derived from S-benzyldithiocarbazate and 3-acetylcoumarin},
author = {M L Low and G Paulus and P Dorlet and R Guillot and R Rosli and N Delsuc and K A Crouse and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939939059&doi=10.1007%2fs10534-015-9831-2&partnerID=40&md5=8d0220a2a88cc9eb122f191d65c87199},
doi = {10.1007/s10534-015-9831-2},
year = {2015},
date = {2015-01-01},
journal = {BioMetals},
volume = {28},
number = {3},
pages = {553--566},
abstract = {Cu(II), Zn(II) and Re(I) complexes have been synthesized with the Schiff base, N′-[1-(2-oxo-2H-chromen-3-yl)-ethylidene]-hydrazinecarbodithioic acid benzyl ester (SBCM-H) which was prepared by condensation of S-benzyldithiocarbazate and 3-acetylcoumarin. The metal complexes were characterized on the basis of various physico-chemical and spectroscopic techniques including elemental analysis and electrochemical studies, and FT-IR, UV-Vis, NMR, EPR and mass spectroscopy. The Schiff base was found to behave as a bidentate ligand coordinating with Cu(II) and Zn(II) in the thiolate form with 1:2 metal to ligand stoichiometry. Crystals suitable for X-ray diffractometry (XRD) were obtained from the reaction of ReCl(CO)5 with SBCM-H forming a centrosymmetric dimeric complex Re2L2(CO)6 linked by Re-S-Re bridges, where S is the thiolate sulfur of the N,S-bidentate ligand. This Re(I) complex is the first metal carbonyl complex with a bidentate dithiocarbazate ligand to have been characterized by XRD. Cytotoxicity assays revealed enhancement of the bioactivity of SBCM-H upon complexation. Both Cu(II) and Re(I) complexes are found to be active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7. Graphical Abstract: TOC diagram [Figure not available: see fulltext.] © 2015 Springer Science+Business Media New York.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cu(II), Zn(II) and Re(I) complexes have been synthesized with the Schiff base, N′-[1-(2-oxo-2H-chromen-3-yl)-ethylidene]-hydrazinecarbodithioic acid benzyl ester (SBCM-H) which was prepared by condensation of S-benzyldithiocarbazate and 3-acetylcoumarin. The metal complexes were characterized on the basis of various physico-chemical and spectroscopic techniques including elemental analysis and electrochemical studies, and FT-IR, UV-Vis, NMR, EPR and mass spectroscopy. The Schiff base was found to behave as a bidentate ligand coordinating with Cu(II) and Zn(II) in the thiolate form with 1:2 metal to ligand stoichiometry. Crystals suitable for X-ray diffractometry (XRD) were obtained from the reaction of ReCl(CO)5 with SBCM-H forming a centrosymmetric dimeric complex Re2L2(CO)6 linked by Re-S-Re bridges, where S is the thiolate sulfur of the N,S-bidentate ligand. This Re(I) complex is the first metal carbonyl complex with a bidentate dithiocarbazate ligand to have been characterized by XRD. Cytotoxicity assays revealed enhancement of the bioactivity of SBCM-H upon complexation. Both Cu(II) and Re(I) complexes are found to be active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7. Graphical Abstract: TOC diagram [Figure not available: see fulltext.] © 2015 Springer Science+Business Media New York. |
Fast magnetically driven electrodeposition of amorphous metal oxide water oxidation catalysts from carbon-coated metallic nanoparticles Article de journal J Zhu; F Lambert; C Policar; F Mavré; B Limoges Journal of Materials Chemistry A, 3 (31), p. 16190–16197, 2015. @article{Zhu:2015,
title = {Fast magnetically driven electrodeposition of amorphous metal oxide water oxidation catalysts from carbon-coated metallic nanoparticles},
author = {J Zhu and F Lambert and C Policar and F Mavr\'{e} and B Limoges},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938100019&doi=10.1039%2fc5ta03430b&partnerID=40&md5=ac4e0e0dc5c94a4c574b14d5b17ac552},
doi = {10.1039/c5ta03430b},
year = {2015},
date = {2015-01-01},
journal = {Journal of Materials Chemistry A},
volume = {3},
number = {31},
pages = {16190--16197},
abstract = {We report a new approach for efficient electrodeposition of amorphous metal oxide water oxidation catalysts on an electrode surface. A catalytic metal-based film was obtained by means of anodic oxidation of metallic nanoparticles, namely carbon-coated cobalt nanoparticles or carbon-coated nickel nanoparticles. Interestingly, these particles are intrinsically conductive and possess magnetic properties which make it easy to collect them on an electrode surface using a simple magnet to form a porous conductive particulate film. Upon anodic polarization in an appropriate electrolyte, the particulate film is rapidly converted into an amorphous metal-based catalytic film that efficiently catalyzes the oxidation of water at neutral pH. Compared to Nocera's method based on anodic electrodeposition of a metal salt in solution, this new electrodeposition strategy offers the key advantage of supplying metal ions in a solid and metallic form, leading to a fast release of high local concentrations of metal ions right at the spot of the film formation (i.e., in the vicinity of the electrode surface). This plays a decisive role in the formation rate of the catalytic film, allowing the deposition of the oxygen-evolving catalyst in a remarkably short-time. Moreover, the methodology can be easily extended to a wide range of metal particles of different nature and sizes, and also to their mixtures, finally offering a new degree of flexibility and opportunities not only in the preparation of metal-based water oxidation catalysts, but also in the preparation of inorganic metal-based catalysts for hydrogen or oxygen evolution. © 2015 The Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report a new approach for efficient electrodeposition of amorphous metal oxide water oxidation catalysts on an electrode surface. A catalytic metal-based film was obtained by means of anodic oxidation of metallic nanoparticles, namely carbon-coated cobalt nanoparticles or carbon-coated nickel nanoparticles. Interestingly, these particles are intrinsically conductive and possess magnetic properties which make it easy to collect them on an electrode surface using a simple magnet to form a porous conductive particulate film. Upon anodic polarization in an appropriate electrolyte, the particulate film is rapidly converted into an amorphous metal-based catalytic film that efficiently catalyzes the oxidation of water at neutral pH. Compared to Nocera's method based on anodic electrodeposition of a metal salt in solution, this new electrodeposition strategy offers the key advantage of supplying metal ions in a solid and metallic form, leading to a fast release of high local concentrations of metal ions right at the spot of the film formation (i.e., in the vicinity of the electrode surface). This plays a decisive role in the formation rate of the catalytic film, allowing the deposition of the oxygen-evolving catalyst in a remarkably short-time. Moreover, the methodology can be easily extended to a wide range of metal particles of different nature and sizes, and also to their mixtures, finally offering a new degree of flexibility and opportunities not only in the preparation of metal-based water oxidation catalysts, but also in the preparation of inorganic metal-based catalysts for hydrogen or oxygen evolution. © 2015 The Royal Society of Chemistry. |
An easy-to-detect nona-arginine peptide for epidermal targeting Article de journal S Clède; N Delsuc; C Laugel; F Lambert; C Sandt; A Baillet-Guffroy; C Policar Chemical Communications, 51 (13), p. 2687–2689, 2015. @article{Clede:2015a,
title = {An easy-to-detect nona-arginine peptide for epidermal targeting},
author = {S Cl\`{e}de and N Delsuc and C Laugel and F Lambert and C Sandt and A Baillet-Guffroy and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922637409&doi=10.1039%2fc4cc08737b&partnerID=40&md5=a0e333e8498570e4d4ceb500066d9c1e},
doi = {10.1039/c4cc08737b},
year = {2015},
date = {2015-01-01},
journal = {Chemical Communications},
volume = {51},
number = {13},
pages = {2687--2689},
abstract = {A correlative approach combining synchrotron radiation based IR microscopy and fluorescence microscopy enabled the successful detection and quantification of a nona-arginine peptide labelled with a Single Core Multimodal Probe for Imaging (SCoMPI) in skin biopsies. The topical penetration of the conjugate appeared to be time dependent and occurred most probably via the extracellular matrix. This journal is © The Royal Society of Chemistry 2015.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A correlative approach combining synchrotron radiation based IR microscopy and fluorescence microscopy enabled the successful detection and quantification of a nona-arginine peptide labelled with a Single Core Multimodal Probe for Imaging (SCoMPI) in skin biopsies. The topical penetration of the conjugate appeared to be time dependent and occurred most probably via the extracellular matrix. This journal is © The Royal Society of Chemistry 2015. |
Metal-carbonyl units for vibrational and luminescence imaging: Towards multimodality Article de journal S Clède; C Policar Chemistry - A European Journal, 21 (3), p. 942–958, 2015. @article{Clede:2015,
title = {Metal-carbonyl units for vibrational and luminescence imaging: Towards multimodality},
author = {S Cl\`{e}de and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84920784874&doi=10.1002%2fchem.201404600&partnerID=40&md5=eaf7654638733b121ed1fe744e71b7b5},
doi = {10.1002/chem.201404600},
year = {2015},
date = {2015-01-01},
journal = {Chemistry - A European Journal},
volume = {21},
number = {3},
pages = {942--958},
abstract = {Metal-carbonyl complexes are attractive structures for bio-imaging. In addition to unique vibrational properties due to the CO moieties enabling IR and Raman cell imaging, the appropriate choice of ancillary ligands opens up the opportunity for luminescence detection. Through a classification by techniques, past and recent developments in the application of metal-carbonyl complexes for vibrational and luminescence bio-imaging are reviewed. Finally, their potential as bimodal IR and luminescent probes is addressed. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Metal-carbonyl complexes are attractive structures for bio-imaging. In addition to unique vibrational properties due to the CO moieties enabling IR and Raman cell imaging, the appropriate choice of ancillary ligands opens up the opportunity for luminescence detection. Through a classification by techniques, past and recent developments in the application of metal-carbonyl complexes for vibrational and luminescence bio-imaging are reviewed. Finally, their potential as bimodal IR and luminescent probes is addressed. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. |
Entasis through Hook-and-Loop fastening in a glycoligand with cumulative weak forces stabilizing CuI Article de journal L Garcia; F Cisnetti; N Gillet; R Guillot; M Aumont-Nicaise; J -P Piquemal; M Desmadril; F Lambert; C Policar Journal of the American Chemical Society, 137 (3), p. 1141–1146, 2015. @article{Garcia:2015,
title = {Entasis through Hook-and-Loop fastening in a glycoligand with cumulative weak forces stabilizing CuI},
author = {L Garcia and F Cisnetti and N Gillet and R Guillot and M Aumont-Nicaise and J -P Piquemal and M Desmadril and F Lambert and C Policar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921832039&doi=10.1021%2fja510259p&partnerID=40&md5=eb31b469985f0f4759bf0f0869f067c9},
doi = {10.1021/ja510259p},
year = {2015},
date = {2015-01-01},
journal = {Journal of the American Chemical Society},
volume = {137},
number = {3},
pages = {1141--1146},
abstract = {The idea of a possible control of metal ion properties by constraining the coordination sphere geometry was introduced by Vallee and Williams with the concept of entasis, which is frequently postulated to be at stake in metallobiomolecules. However, the interactions controlling the geometry at metal centers remain often elusive. In this study, the coordination properties toward copper ions - CuII or CuI - of a geometrically constrained glycoligand centered on a sugar scaffold were compared with those of an analogous ligand built on an unconstrained alkyl chain. The sugar-centered ligand was shown to be more preorganized for CuII coordination than its open-chain analogue, with an unusual additional stabilization of the CuI redox state. This preference for CuI was suggested to arise from geometric constraints favoring an optimized folding of the glycoligand minimizing steric repulsions. In other words, the CuI d10 species is stabilized by valence shell electron pair repulsion (VSEPR). This idea was rationalized by a theoretical noncovalent interactions (NCI) analysis. The cumulative effects of weak forces were shown to create an efficient buckle as in a hook-and-loop fastener, and fine structural features within the glycoligand reduce repulsive interactions for the CuI state. This study emphasizes that monosaccharide platforms are appropriate ligand backbones for a delicate geometric control at the metal center, with a network of weak interactions within the ligand. This structuration availing in glycoligands makes them attractive for metallic entasis. © 2015 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The idea of a possible control of metal ion properties by constraining the coordination sphere geometry was introduced by Vallee and Williams with the concept of entasis, which is frequently postulated to be at stake in metallobiomolecules. However, the interactions controlling the geometry at metal centers remain often elusive. In this study, the coordination properties toward copper ions - CuII or CuI - of a geometrically constrained glycoligand centered on a sugar scaffold were compared with those of an analogous ligand built on an unconstrained alkyl chain. The sugar-centered ligand was shown to be more preorganized for CuII coordination than its open-chain analogue, with an unusual additional stabilization of the CuI redox state. This preference for CuI was suggested to arise from geometric constraints favoring an optimized folding of the glycoligand minimizing steric repulsions. In other words, the CuI d10 species is stabilized by valence shell electron pair repulsion (VSEPR). This idea was rationalized by a theoretical noncovalent interactions (NCI) analysis. The cumulative effects of weak forces were shown to create an efficient buckle as in a hook-and-loop fastener, and fine structural features within the glycoligand reduce repulsive interactions for the CuI state. This study emphasizes that monosaccharide platforms are appropriate ligand backbones for a delicate geometric control at the metal center, with a network of weak interactions within the ligand. This structuration availing in glycoligands makes them attractive for metallic entasis. © 2015 American Chemical Society. |
2014
|
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. |
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. |
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. |
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}
}
|