You will find below the list of publications of all the members of the Peptides, Glycoconjugates and Metals in Biology research pole. For individual or theme-specific publications, please consult the research or the personal pages via the members list using the sidebar navigation tool.
2014 |
Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress Article de journal Clotilde Policar; Anne-Sophie Bernard; Nicolas Delsuc; Geraldine Gazzah; Manon Guille; Frederic Lemaitre; Christian Amatore; Maria Bachelet; Joelle Masliah Journal of Biological Inorganic Chemistry, 19 , p. S739-S740, 2014, (Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich). @article{, title = {Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress}, author = {Clotilde Policar and Anne-Sophie Bernard and Nicolas Delsuc and Geraldine Gazzah and Manon Guille and Frederic Lemaitre and Christian Amatore and Maria Bachelet and Joelle Masliah}, year = {2014}, date = {2014-01-01}, journal = {Journal of Biological Inorganic Chemistry}, volume = {19}, pages = {S739-S740}, note = {Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2013 |
DNA Switches on the Two-Photon Efficiency of an Ultrabright Triphenylamine Fluorescent Probe Specific of AT Regions Article de journal Blaise Dumat; Guillaume Bordeau; Elodie Faurel-Paul; Florence Mahuteau-Betzer; Nicolas Saettel; Germain Metge; Céline Fiorini-Debuisschert; Fabrice Charra; Marie-Paule Teulade-Fichou Journal of the American Chemical Society, 135 (34), p. 12697-12706, 2013. @article{Dumat:2013, title = {DNA Switches on the Two-Photon Efficiency of an Ultrabright Triphenylamine Fluorescent Probe Specific of AT Regions}, author = {Blaise Dumat and Guillaume Bordeau and Elodie {Faurel-Paul} and Florence {Mahuteau-Betzer} and Nicolas Saettel and Germain Metge and C\'{e}line {Fiorini-Debuisschert} and Fabrice Charra and Marie-Paule {Teulade-Fichou}}, doi = {10.1021/ja404422z}, year = {2013}, date = {2013-08-01}, journal = {Journal of the American Chemical Society}, volume = {135}, number = {34}, pages = {12697-12706}, abstract = {We report on the design and synthesis of two-photon fluorescent triphenylamines bearing two or three vinyl branches terminated by a N-methyl benzimidazolium moiety. The new compounds (TP-2Bzim, TP-3Bzim) are light-up fluorescent DNA probes with a long wavelength emission ($>$580 nm). Compared to their pyridinium models, the TP-Bzim dyes exhibit a remarkable improvement of both their DNA affinity and fluorescence quantum yield, especially for the two-branch derivative (TP-2Bzim: $Phi$F = 0.54}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report on the design and synthesis of two-photon fluorescent triphenylamines bearing two or three vinyl branches terminated by a N-methyl benzimidazolium moiety. The new compounds (TP-2Bzim, TP-3Bzim) are light-up fluorescent DNA probes with a long wavelength emission ($>$580 nm). Compared to their pyridinium models, the TP-Bzim dyes exhibit a remarkable improvement of both their DNA affinity and fluorescence quantum yield, especially for the two-branch derivative (TP-2Bzim: $Phi$F = 0.54 |
Mantyl tagged oligo α (1 → 2) mannosides as Candida albicans β-mannosyl transferases substrates: A comparison between synthetic strategies Article de journal M Pourcelot; L Cattiaux; G Sfihi-Loualia; E Fabre; F Krzewinski; C Fradin; D Poulain; F Delplace; Y Guérardel; J -M Mallet RSC Advances, 3 (44), p. 22560–22571, 2013. @article{Pourcelot:2013, title = {Mantyl tagged oligo α (1 → 2) mannosides as Candida albicans β-mannosyl transferases substrates: A comparison between synthetic strategies}, author = {M Pourcelot and L Cattiaux and G Sfihi-Loualia and E Fabre and F Krzewinski and C Fradin and D Poulain and F Delplace and Y Gu\'{e}rardel and J -M Mallet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84886536287&doi=10.1039%2fc3ra43340d&partnerID=40&md5=b73f7b6c176f52b4062709e838ff88a4}, doi = {10.1039/c3ra43340d}, year = {2013}, date = {2013-01-01}, journal = {RSC Advances}, volume = {3}, number = {44}, pages = {22560--22571}, abstract = {Fluorescent oligomannosides are important tools for the evaluation of mannosyl transferase activities and selectivities. In a project dealing with Candida albicans β-mannosyl transferases, three mantyl tagged α (1 → 2) oligomannosides were prepared by different ways: using all ester strategy compatible with the presence of an azido group suitable for direct click chemistry; and alternatively using the more classic benzyl protecting groups. Although more elegant, the all ester strategy has shown important limitations: reduced reactivity of mannosyl donors, and 3 → 2 ester migration. Preliminary enzymatic studies have shown that the synthetic oligomannosides are efficient substrate of β-mannosyl transferases. © The Royal Society of Chemistry 2013.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fluorescent oligomannosides are important tools for the evaluation of mannosyl transferase activities and selectivities. In a project dealing with Candida albicans β-mannosyl transferases, three mantyl tagged α (1 → 2) oligomannosides were prepared by different ways: using all ester strategy compatible with the presence of an azido group suitable for direct click chemistry; and alternatively using the more classic benzyl protecting groups. Although more elegant, the all ester strategy has shown important limitations: reduced reactivity of mannosyl donors, and 3 → 2 ester migration. Preliminary enzymatic studies have shown that the synthetic oligomannosides are efficient substrate of β-mannosyl transferases. © The Royal Society of Chemistry 2013. |
Connecting dysbiosis, bile-acid dysmetabolism and Gut inflammation in inflammatory bowel diseases Article de journal H Duboc; S Rajca; D Rainteau; D Benarous; M -A Maubert; E Quervain; G Thomas; V Barbu; L Humbert; G Despras; C Bridonneau; F Dumetz; J -P Grill; J Masliah; L Beaugerie; J Cosnes; O Chazouillères; R Poupon; C Wolf; J -M Mallet; P Langella; G Trugnan; H Sokol; P Seksik Gut, 62 (4), p. 531–539, 2013. @article{Duboc:2013, title = {Connecting dysbiosis, bile-acid dysmetabolism and Gut inflammation in inflammatory bowel diseases}, author = {H Duboc and S Rajca and D Rainteau and D Benarous and M -A Maubert and E Quervain and G Thomas and V Barbu and L Humbert and G Despras and C Bridonneau and F Dumetz and J -P Grill and J Masliah and L Beaugerie and J Cosnes and O Chazouill\`{e}res and R Poupon and C Wolf and J -M Mallet and P Langella and G Trugnan and H Sokol and P Seksik}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874651768&doi=10.1136%2fgutjnl-2012-302578&partnerID=40&md5=d036f16b9e09906ec43ae9de440067a6}, doi = {10.1136/gutjnl-2012-302578}, year = {2013}, date = {2013-01-01}, journal = {Gut}, volume = {62}, number = {4}, pages = {531--539}, abstract = {Objective: Gut microbiota metabolises bile acids (BA). As dysbiosis has been reported in inflammatory bowel diseases (IBD), we aim to investigate the impact of IBD-associated dysbiosis on BA metabolism and its influence on the epithelial cell inflammation response. Design: Faecal and serum BA rates, expressed as a proportion of total BA, were assessed by highperformance liquid chromatography tandem mass spectrometry in colonic IBD patients (42) and healthy subjects (29). The faecal microbiota composition was assessed by quantitative real-time PCR. Using BA profiles and microbiota composition, cluster formation between groups was generated by ranking models. The faecal BA profiles in germ-free and conventional mice were compared. Direct enzymatic activities of BA biotransformation were measured in faeces. The impact of BA on the inflammatory response was investigated in vitro using Caco-2 cells stimulated by IL-1β. Results: IBD-associated dysbiosis was characterised by a decrease in the ratio between Faecalibacterium prausntizii and Escherichia coli. Faecal-conjugated BA rates were significantly higher in active IBD, whereas, secondary BA rates were significantly lower. Interestingly, active IBD patients exhibited higher levels of faecal 3-OH-sulphated BA. The deconjugation, transformation and desulphation activities of the microbiota were impaired in IBD patients. In vitro, secondary BA exerted antiinflammatory effects, but sulphation of secondary BAs abolished their anti-inflammatory properties. Conclusions: Impaired microbiota enzymatic activity observed in IBD-associated dysbiosis leads to modifications in the luminal BA pool composition. Altered BA transformation in the gut lumen can erase the antiinflammatory effects of some BA species on gut epithelial cells and could participate in the chronic inflammation loop of IBD.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objective: Gut microbiota metabolises bile acids (BA). As dysbiosis has been reported in inflammatory bowel diseases (IBD), we aim to investigate the impact of IBD-associated dysbiosis on BA metabolism and its influence on the epithelial cell inflammation response. Design: Faecal and serum BA rates, expressed as a proportion of total BA, were assessed by highperformance liquid chromatography tandem mass spectrometry in colonic IBD patients (42) and healthy subjects (29). The faecal microbiota composition was assessed by quantitative real-time PCR. Using BA profiles and microbiota composition, cluster formation between groups was generated by ranking models. The faecal BA profiles in germ-free and conventional mice were compared. Direct enzymatic activities of BA biotransformation were measured in faeces. The impact of BA on the inflammatory response was investigated in vitro using Caco-2 cells stimulated by IL-1β. Results: IBD-associated dysbiosis was characterised by a decrease in the ratio between Faecalibacterium prausntizii and Escherichia coli. Faecal-conjugated BA rates were significantly higher in active IBD, whereas, secondary BA rates were significantly lower. Interestingly, active IBD patients exhibited higher levels of faecal 3-OH-sulphated BA. The deconjugation, transformation and desulphation activities of the microbiota were impaired in IBD patients. In vitro, secondary BA exerted antiinflammatory effects, but sulphation of secondary BAs abolished their anti-inflammatory properties. Conclusions: Impaired microbiota enzymatic activity observed in IBD-associated dysbiosis leads to modifications in the luminal BA pool composition. Altered BA transformation in the gut lumen can erase the antiinflammatory effects of some BA species on gut epithelial cells and could participate in the chronic inflammation loop of IBD. |
Unexpected remote effect in red fluorescent sensors based on extended APTRA Article de journal M Collot; A Lasoroski; A I Zamaleeva; A Feltz; R Vuilleumier; J -M Mallet Tetrahedron, 69 (48), p. 10482–10487, 2013. @article{Collot:2013, title = {Unexpected remote effect in red fluorescent sensors based on extended APTRA}, author = {M Collot and A Lasoroski and A I Zamaleeva and A Feltz and R Vuilleumier and J -M Mallet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84887051380&doi=10.1016%2fj.tet.2013.09.073&partnerID=40&md5=35d1266782ecad0b5d18db7baa238dc6}, doi = {10.1016/j.tet.2013.09.073}, year = {2013}, date = {2013-01-01}, journal = {Tetrahedron}, volume = {69}, number = {48}, pages = {10482--10487}, abstract = {Herein is described the synthesis and spectroscopic characterizations of three new OFF-ON red-emitting and water-soluble sensors, CAXR (Clicked APTRA X-Rhodamine). These dyes are based on an extended APTRA (aminophenol triacetic acid) motif. Three different side chains were added by click chemistry in order to complete the coordination sphere with a chelate moiety composed of a triazolyl and an iminol. The fluorescent response (F/F0) of these probes follows the order: Cd2+>Zn2+>Pb 2+>Hg2+. An important and unexpected effect of the side chain structure on the Kd was observed (up to one order of magnitude, Cadmium Kd from 252 to 21 μM). This remote effect of the side chains was studied by DFT calculations and was attributed to a twisted conformation of the CAXR-Py:Cd2+ complex. © 2013 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Herein is described the synthesis and spectroscopic characterizations of three new OFF-ON red-emitting and water-soluble sensors, CAXR (Clicked APTRA X-Rhodamine). These dyes are based on an extended APTRA (aminophenol triacetic acid) motif. Three different side chains were added by click chemistry in order to complete the coordination sphere with a chelate moiety composed of a triazolyl and an iminol. The fluorescent response (F/F0) of these probes follows the order: Cd2+>Zn2+>Pb 2+>Hg2+. An important and unexpected effect of the side chain structure on the Kd was observed (up to one order of magnitude, Cadmium Kd from 252 to 21 μM). This remote effect of the side chains was studied by DFT calculations and was attributed to a twisted conformation of the CAXR-Py:Cd2+ complex. © 2013 Elsevier Ltd. All rights reserved. |
Metal-free aerobic oxidation of benzazole derivatives Article de journal A Dos Santos; L El Kaïm; L Grimaud Organic and Biomolecular Chemistry, 11 (20), p. 3282–3287, 2013. @article{DosSantos:2013, title = {Metal-free aerobic oxidation of benzazole derivatives}, author = {A Dos Santos and L El Ka\"{i}m and L Grimaud}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877273564&doi=10.1039%2fc3ob27404g&partnerID=40&md5=ad6bf12ae7d3621858ff3d856b826cef}, doi = {10.1039/c3ob27404g}, year = {2013}, date = {2013-01-01}, journal = {Organic and Biomolecular Chemistry}, volume = {11}, number = {20}, pages = {3282--3287}, abstract = {2-Benzyl benzothiazoles and benzimidazoles are easily oxidized under air and basic conditions to give the corresponding ketones in good yields. The use of palladium acetate as a catalyst has little effect and even gives, in some cases, much lower yields. © 2013 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 2-Benzyl benzothiazoles and benzimidazoles are easily oxidized under air and basic conditions to give the corresponding ketones in good yields. The use of palladium acetate as a catalyst has little effect and even gives, in some cases, much lower yields. © 2013 The Royal Society of Chemistry. |
Lewis acid mediated fragmentation of tetrazoles towards triazoles Article de journal L El Kaïm; L Grimaud; P Pravin European Journal of Organic Chemistry, (22), p. 4752–4755, 2013. @article{ElKaim:2013, title = {Lewis acid mediated fragmentation of tetrazoles towards triazoles}, author = {L El Ka\"{i}m and L Grimaud and P Pravin}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880926249&doi=10.1002%2fejoc.201300620&partnerID=40&md5=af2865867497083758f53054120f261b}, doi = {10.1002/ejoc.201300620}, year = {2013}, date = {2013-01-01}, journal = {European Journal of Organic Chemistry}, number = {22}, pages = {4752--4755}, abstract = {If Ugi-azide adducts generated from tert-butyl isocyanide, primary amines, and aromatic aldehydes are oxidized by copper(II) salts, the resulting imino tetrazoles may be easily converted into triazoles through Lewis acid catalyzed fragmentation of the tetrazole under microwave conditions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } If Ugi-azide adducts generated from tert-butyl isocyanide, primary amines, and aromatic aldehydes are oxidized by copper(II) salts, the resulting imino tetrazoles may be easily converted into triazoles through Lewis acid catalyzed fragmentation of the tetrazole under microwave conditions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Substituent effects in ugi-smiles reactions Article de journal N Chéron; R Ramozzi; L El Kaïm; L Grimaud; P Fleurat-Lessard Journal of Physical Chemistry A, 117 (33), p. 8035–8042, 2013. @article{Cheron:2013, title = {Substituent effects in ugi-smiles reactions}, author = {N Ch\'{e}ron and R Ramozzi and L El Ka\"{i}m and L Grimaud and P Fleurat-Lessard}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883175431&doi=10.1021%2fjp4052227&partnerID=40&md5=ebecae65f895e7263d4627bc0de0a528}, doi = {10.1021/jp4052227}, year = {2013}, date = {2013-01-01}, journal = {Journal of Physical Chemistry A}, volume = {117}, number = {33}, pages = {8035--8042}, abstract = {In a recent communication, we described the mechanism of the well-known Ugi-type reactions with a model system (J. Org. Chem. 2012, 77, 1361-1366). Herein, focusing on the Ugi-Smiles coupling, we study the effects of each of the four reactants on the energy profile to further explain the experimental results. The variations observed with different carbonyl compounds rely on their influence on the formation of the aryl-imidate, whereas the variations on the amine preferentially affect the Smiles rearrangement. The effect of substituents on the phenol derivative is seen upon both aryl-imidate formation and the rearrangement. The effect of the isocyanide substituents is less pronounced. © 2013 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In a recent communication, we described the mechanism of the well-known Ugi-type reactions with a model system (J. Org. Chem. 2012, 77, 1361-1366). Herein, focusing on the Ugi-Smiles coupling, we study the effects of each of the four reactants on the energy profile to further explain the experimental results. The variations observed with different carbonyl compounds rely on their influence on the formation of the aryl-imidate, whereas the variations on the amine preferentially affect the Smiles rearrangement. The effect of substituents on the phenol derivative is seen upon both aryl-imidate formation and the rearrangement. The effect of the isocyanide substituents is less pronounced. © 2013 American Chemical Society. |
Homooligomers of substituted prolines and β-prolines: Syntheses and secondary structure investigation Article de journal C Caumes; N Delsuc; R B Azza; I Correia; F Chemla; F Ferreira; L Carlier; A P Luna; R Moumné; O Lequin; P Karoyan New Journal of Chemistry, 37 (5), p. 1312–1319, 2013. @article{Caumes:2013, title = {Homooligomers of substituted prolines and β-prolines: Syntheses and secondary structure investigation}, author = {C Caumes and N Delsuc and R B Azza and I Correia and F Chemla and F Ferreira and L Carlier and A P Luna and R Moumn\'{e} and O Lequin and P Karoyan}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876740702&doi=10.1039%2fc3nj00127j&partnerID=40&md5=dbda08d94a12bcb6b260393c90dd6af4}, doi = {10.1039/c3nj00127j}, year = {2013}, date = {2013-01-01}, journal = {New Journal of Chemistry}, volume = {37}, number = {5}, pages = {1312--1319}, abstract = {Homooligomers of enantiomerically pure (2S,3R)-3-methyl-proline, (3R,4R)-4-methyl-β-proline and (3R,4S)-3,4-dimethyl-β-proline were synthesized and studied using circular dichroism (CD) in water, methanol and propanol and using NMR in water. Changes in the far-UV CD spectrum were observed from dimers to hexamers, but little change was observed from hexamers to octa- or nonamers, both in water and methanol. CD and NMR data allowed us to conclude that oligomers of 3-substituted prolines with more than six residues adopt a characteristic PPII secondary structure both in water and aliphatic alcohols. Oligomers of (3R,4R)-4-methyl-β-proline bear the same CD signature as non-substituted β-proline oligomers, suggesting that substitution at position 3 is not sufficient to reduce conformational heterogeneity in β-proline oligomers. In the case of 3,4-disubstituted-β-proline oligomers, an atypical signature with an extra negative band at around 225 nm was observed, together with a concentration dependent CD spectrum indicating association properties. Nevertheless, NMR studies of 13C labelled oligomers of 3,4-disubstituted-β-prolines revealed a complex mixture of cis-trans conformers even for longer oligomers. © 2913 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Homooligomers of enantiomerically pure (2S,3R)-3-methyl-proline, (3R,4R)-4-methyl-β-proline and (3R,4S)-3,4-dimethyl-β-proline were synthesized and studied using circular dichroism (CD) in water, methanol and propanol and using NMR in water. Changes in the far-UV CD spectrum were observed from dimers to hexamers, but little change was observed from hexamers to octa- or nonamers, both in water and methanol. CD and NMR data allowed us to conclude that oligomers of 3-substituted prolines with more than six residues adopt a characteristic PPII secondary structure both in water and aliphatic alcohols. Oligomers of (3R,4R)-4-methyl-β-proline bear the same CD signature as non-substituted β-proline oligomers, suggesting that substitution at position 3 is not sufficient to reduce conformational heterogeneity in β-proline oligomers. In the case of 3,4-disubstituted-β-proline oligomers, an atypical signature with an extra negative band at around 225 nm was observed, together with a concentration dependent CD spectrum indicating association properties. Nevertheless, NMR studies of 13C labelled oligomers of 3,4-disubstituted-β-prolines revealed a complex mixture of cis-trans conformers even for longer oligomers. © 2913 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. |
3-substituted prolines: From synthesis to structural applications, from peptides to foldamers Article de journal C Mothes; C Caumes; A Guez; H Boullet; T Gendrineau; S Darses; N Delsuc; R Moumné; B Oswald; O Lequin; P Karoyan Molecules, 18 (2), p. 2307–2327, 2013. @article{Mothes:2013, title = {3-substituted prolines: From synthesis to structural applications, from peptides to foldamers}, author = {C Mothes and C Caumes and A Guez and H Boullet and T Gendrineau and S Darses and N Delsuc and R Moumn\'{e} and B Oswald and O Lequin and P Karoyan}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874605320&doi=10.3390%2fmolecules18022307&partnerID=40&md5=05828aecf601bf07f9a0a6a3fec4e28c}, doi = {10.3390/molecules18022307}, year = {2013}, date = {2013-01-01}, journal = {Molecules}, volume = {18}, number = {2}, pages = {2307--2327}, abstract = {Among the twenty natural proteinogenic amino acids, proline is unique as its secondary amine forms a tertiary amide when incorporated into biopolymers, thus preventing hydrogen bond formation. Despite the lack of hydrogen bonds and thanks to conformational restriction of flexibility linked to the pyrrolidine ring, proline is able to stabilize peptide secondary structures such as -turns or polyproline helices. These unique conformational properties have aroused a great interest in the development of proline analogues. Among them, proline chimeras are tools combining the proline restriction of flexibility together with the information brought by natural amino acids side chains. This review will focus on the chemical syntheses of 3-substituted proline chimeras of potential use for peptide syntheses and as potential use as tools for SAR studies of biologically active peptides and the development of secondary structure mimetics. Their influence on peptide structure will be briefly described. © 2013 by the authors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Among the twenty natural proteinogenic amino acids, proline is unique as its secondary amine forms a tertiary amide when incorporated into biopolymers, thus preventing hydrogen bond formation. Despite the lack of hydrogen bonds and thanks to conformational restriction of flexibility linked to the pyrrolidine ring, proline is able to stabilize peptide secondary structures such as -turns or polyproline helices. These unique conformational properties have aroused a great interest in the development of proline analogues. Among them, proline chimeras are tools combining the proline restriction of flexibility together with the information brought by natural amino acids side chains. This review will focus on the chemical syntheses of 3-substituted proline chimeras of potential use for peptide syntheses and as potential use as tools for SAR studies of biologically active peptides and the development of secondary structure mimetics. Their influence on peptide structure will be briefly described. © 2013 by the authors. |
Peptide-coated nanoparticles: Adsorption and desorption studies of cationic peptides on nanodiamonds Article de journal J -M Swiecicki; J Tailhades; E Lepeltier; G Chassaing; S Lavielle; C Mansuy Colloids and Surfaces A: Physicochemical and Engineering Aspects, 431 , p. 73–79, 2013. @article{Swiecicki:2013, title = {Peptide-coated nanoparticles: Adsorption and desorption studies of cationic peptides on nanodiamonds}, author = {J -M Swiecicki and J Tailhades and E Lepeltier and G Chassaing and S Lavielle and C Mansuy}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878363538&doi=10.1016%2fj.colsurfa.2013.04.037&partnerID=40&md5=5dc6b2ab0e1acf49db97dcac5135e873}, doi = {10.1016/j.colsurfa.2013.04.037}, year = {2013}, date = {2013-01-01}, journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects}, volume = {431}, pages = {73--79}, abstract = {The functionalization of nanoparticle surfaces remains a major challenge for broader applications in biology. To study the physisorption of peptides on nanodiamonds (NDs), we developed reliable and facile methods: UV titration, MALDI-TOF mass spectrometry or fluorescence spectrophotometry. These readily applicable procedures allowed us to analyze the adsorption and desorption behaviors of different cationic peptides. A rough estimate led to propose that an average of three to four shells of amphiphilic peptides rapidly adsorbed on NDs surface: about half of the molecules being adsorbed with a high affinity, while the other half may be exchanged within a few minutes. If a photoactivatable amino acid was incorporated in the peptide sequence, the subsequent irradiation allowed similarly the coating of three to five shells of peptides on the NDs surface, but in that case peptides were not exchangeable at all, even after a few days. Stable cationic nanodiamonds may be obtained by simple physisorption of amphiphilic peptides, leading to nanoparticles with a positive zeta potential in the appropriate range for biological applications. © 2013 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The functionalization of nanoparticle surfaces remains a major challenge for broader applications in biology. To study the physisorption of peptides on nanodiamonds (NDs), we developed reliable and facile methods: UV titration, MALDI-TOF mass spectrometry or fluorescence spectrophotometry. These readily applicable procedures allowed us to analyze the adsorption and desorption behaviors of different cationic peptides. A rough estimate led to propose that an average of three to four shells of amphiphilic peptides rapidly adsorbed on NDs surface: about half of the molecules being adsorbed with a high affinity, while the other half may be exchanged within a few minutes. If a photoactivatable amino acid was incorporated in the peptide sequence, the subsequent irradiation allowed similarly the coating of three to five shells of peptides on the NDs surface, but in that case peptides were not exchangeable at all, even after a few days. Stable cationic nanodiamonds may be obtained by simple physisorption of amphiphilic peptides, leading to nanoparticles with a positive zeta potential in the appropriate range for biological applications. © 2013 Elsevier B.V. |
Synthesis and evaluation of cholecystokinin trimers: A multivalent approach to pancreatic cancer detection and treatment Article de journal N Brabez; K L Nguyen; K Saunders; R Lacy; L Xu; R J Gillies; R M Lynch; G Chassaing; S Lavielle; V J Hruby Bioorganic and Medicinal Chemistry Letters, 23 (8), p. 2422–2425, 2013. @article{Brabez:2013, title = {Synthesis and evaluation of cholecystokinin trimers: A multivalent approach to pancreatic cancer detection and treatment}, author = {N Brabez and K L Nguyen and K Saunders and R Lacy and L Xu and R J Gillies and R M Lynch and G Chassaing and S Lavielle and V J Hruby}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875411840&doi=10.1016%2fj.bmcl.2013.02.022&partnerID=40&md5=2259f811c7fa195254cd5eaccda23048}, doi = {10.1016/j.bmcl.2013.02.022}, year = {2013}, date = {2013-01-01}, journal = {Bioorganic and Medicinal Chemistry Letters}, volume = {23}, number = {8}, pages = {2422--2425}, abstract = {In the quest for novel tools for early detection and treatment of cancer, we propose the use of multimers targeting overexpressed receptors at the cancer cell surface. Indeed, multimers are prone to create multivalent interactions, more potent and specific than their corresponding monovalent versions, thus enabling the potential for early detection. There is a lack of tools for early detection of pancreatic cancer, one of the deadliest forms of cancer, but CCK2-R overexpression on pancreatic cancer cells makes CCK based multimers potential markers for these cells. In this Letter, we describe the synthesis and evaluation of CCK trimers targeting overexpressed CCK2-R. © 2013 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the quest for novel tools for early detection and treatment of cancer, we propose the use of multimers targeting overexpressed receptors at the cancer cell surface. Indeed, multimers are prone to create multivalent interactions, more potent and specific than their corresponding monovalent versions, thus enabling the potential for early detection. There is a lack of tools for early detection of pancreatic cancer, one of the deadliest forms of cancer, but CCK2-R overexpression on pancreatic cancer cells makes CCK based multimers potential markers for these cells. In this Letter, we describe the synthesis and evaluation of CCK trimers targeting overexpressed CCK2-R. © 2013 Elsevier Ltd. All rights reserved. |
Conformational properties of peptides incorporating a fluorinated pseudoproline residue Article de journal G Chaume; D Feytens; G Chassaing; S Lavielle; T Brigaud; E Miclet New Journal of Chemistry, 37 (5), p. 1336–1342, 2013. @article{Chaume:2013, title = {Conformational properties of peptides incorporating a fluorinated pseudoproline residue}, author = {G Chaume and D Feytens and G Chassaing and S Lavielle and T Brigaud and E Miclet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876725121&doi=10.1039%2fc3nj41084f&partnerID=40&md5=74cecd3b0e2995e361a5f32f90460346}, doi = {10.1039/c3nj41084f}, year = {2013}, date = {2013-01-01}, journal = {New Journal of Chemistry}, volume = {37}, number = {5}, pages = {1336--1342}, abstract = {We have recently reported the synthesis of enantiomerically pure CF 3-oxazolidine pseudoprolines (CF3-ΨPro). Complete NMR studies, together with DFT calculations, have highlighted the marked stereoelectronic effects of the CF3 group on these new proline surrogates. In this paper, we describe for the first time the conformational features of dipeptides incorporating one CF3-ΨPro residue. Extensive NMR analyses have been carried out in solution and revealed the presence of a stable type-VI β-turn in a pseudotetrapeptide sequence. © 2913 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We have recently reported the synthesis of enantiomerically pure CF 3-oxazolidine pseudoprolines (CF3-ΨPro). Complete NMR studies, together with DFT calculations, have highlighted the marked stereoelectronic effects of the CF3 group on these new proline surrogates. In this paper, we describe for the first time the conformational features of dipeptides incorporating one CF3-ΨPro residue. Extensive NMR analyses have been carried out in solution and revealed the presence of a stable type-VI β-turn in a pseudotetrapeptide sequence. © 2913 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. |
G Notas; M Kampa; V Pelekanou; M Troullinaki; Y Jacquot; G Leclercq; E Castanas Molecular Oncology, 7 (3), p. 595–610, 2013. @article{Notas:2013, title = {Whole transcriptome analysis of the ERα synthetic fragment P295-{T}311 (ERα17p) identifies specific ERα-isoform (ERα, ERα36)-dependent and -independent actions in breast cancer cells}, author = {G Notas and M Kampa and V Pelekanou and M Troullinaki and Y Jacquot and G Leclercq and E Castanas}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878112785&doi=10.1016%2fj.molonc.2013.02.012&partnerID=40&md5=e11531b7bb6516286daf4190cabd1525}, doi = {10.1016/j.molonc.2013.02.012}, year = {2013}, date = {2013-01-01}, journal = {Molecular Oncology}, volume = {7}, number = {3}, pages = {595--610}, abstract = {ERα17p is a peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ERα) and initially found to interfere with ERα-related calmodulin binding. ERα17p was subsequently found to elicit estrogenic responses in E2-deprived ERα-positive breast cancer cells, increasing proliferation and ERE-dependent gene transcription. Surprisingly, in E2-supplemented media, ERα17p-induced apoptosis and modified the actin network, influencing cell motility. Here, we report that ERα17p internalizes in breast cancer cells (T47D, MDA-MB-231, SKBR3) and induces a massive early (3 h) transcriptional activity. Remarkably, about 75% of significantly modified transcripts were also modified by E2, confirming the pro-estrogenic profile of ERα17p. The different ER spectra of the used cell lines allowed us to identify a specific ERα17p signature related to ERα as well as its variant ERα36. With respect to ERα, the peptide activates nuclear (cell cycle, cell proliferation, nucleic acid and protein synthesis) and extranuclear signaling pathways. In contrast, through ERα36, it mainly triggers inhibitory actions on inflammation. This is the first work reporting a detailed ERα36-specific transcriptional signature. In addition, we report that ERα17p-induced transcripts related to apoptosis and actin modifying effects of the peptide are independent from its estrogen receptor(s)-related actions. We discuss our findings in view of the potential use of ERα17p as a selective peptidomimetic estrogen receptor modulator (PERM). © 2013 Federation of European Biochemical Societies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } ERα17p is a peptide corresponding to the sequence P295LMIKRSKKNSLALSLT311 of the estrogen receptor alpha (ERα) and initially found to interfere with ERα-related calmodulin binding. ERα17p was subsequently found to elicit estrogenic responses in E2-deprived ERα-positive breast cancer cells, increasing proliferation and ERE-dependent gene transcription. Surprisingly, in E2-supplemented media, ERα17p-induced apoptosis and modified the actin network, influencing cell motility. Here, we report that ERα17p internalizes in breast cancer cells (T47D, MDA-MB-231, SKBR3) and induces a massive early (3 h) transcriptional activity. Remarkably, about 75% of significantly modified transcripts were also modified by E2, confirming the pro-estrogenic profile of ERα17p. The different ER spectra of the used cell lines allowed us to identify a specific ERα17p signature related to ERα as well as its variant ERα36. With respect to ERα, the peptide activates nuclear (cell cycle, cell proliferation, nucleic acid and protein synthesis) and extranuclear signaling pathways. In contrast, through ERα36, it mainly triggers inhibitory actions on inflammation. This is the first work reporting a detailed ERα36-specific transcriptional signature. In addition, we report that ERα17p-induced transcripts related to apoptosis and actin modifying effects of the peptide are independent from its estrogen receptor(s)-related actions. We discuss our findings in view of the potential use of ERα17p as a selective peptidomimetic estrogen receptor modulator (PERM). © 2013 Federation of European Biochemical Societies. |
Synthesis, structure, and estrogenic activity of 2- and 3-substituted 2,3-dihydro-4H-1-benzopyran-4-ones Article de journal Y Jacquot; C Byrne; A Xicluna; G Leclercq Medicinal Chemistry Research, 22 (2), p. 681–691, 2013. @article{Jacquot:2013, title = {Synthesis, structure, and estrogenic activity of 2- and 3-substituted 2,3-dihydro-4H-1-benzopyran-4-ones}, author = {Y Jacquot and C Byrne and A Xicluna and G Leclercq}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873985657&doi=10.1007%2fs00044-012-0058-2&partnerID=40&md5=19f7254063a0645479d6b0875b7eff31}, doi = {10.1007/s00044-012-0058-2}, year = {2013}, date = {2013-01-01}, journal = {Medicinal Chemistry Research}, volume = {22}, number = {2}, pages = {681--691}, abstract = {Molecules with potent estrogenic activity are textasciitilde270 r{A}3 hydrophobic structures that encompass two hydroxyls among which is at least one phenol. However, compounds with only one phenol or devoid of such a ring have been shown to enhance ERα-mediated transcription at concentrations much larger than those measured with E2. In this context, we show here that benzopyrans sharing one hydroxyl/methoxyl and containing an additional benzylidenyl or a spirocyclohexyl motif are able to induce ERE-dependent transcription in breast carcinoma cells. © 2012 Springer Science+Business Media, LLC.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Molecules with potent estrogenic activity are textasciitilde270 Å3 hydrophobic structures that encompass two hydroxyls among which is at least one phenol. However, compounds with only one phenol or devoid of such a ring have been shown to enhance ERα-mediated transcription at concentrations much larger than those measured with E2. In this context, we show here that benzopyrans sharing one hydroxyl/methoxyl and containing an additional benzylidenyl or a spirocyclohexyl motif are able to induce ERE-dependent transcription in breast carcinoma cells. © 2012 Springer Science+Business Media, LLC. |
Stabilisation of a short α-helical VIP fragment by side chain to side chain cyclisation: A comparison of common cyclisation motifs by circular dichroism Article de journal L Frankiewicz; C Betti; K Guillemyn; D Tourwé; Y Jacquot; S Ballet Journal of Peptide Science, 19 (7), p. 423–432, 2013. @article{Frankiewicz:2013, title = {Stabilisation of a short α-helical VIP fragment by side chain to side chain cyclisation: A comparison of common cyclisation motifs by circular dichroism}, author = {L Frankiewicz and C Betti and K Guillemyn and D Tourw\'{e} and Y Jacquot and S Ballet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878972564&doi=10.1002%2fpsc.2515&partnerID=40&md5=ef8bba66c2081b463439a0dde4d42b10}, doi = {10.1002/psc.2515}, year = {2013}, date = {2013-01-01}, journal = {Journal of Peptide Science}, volume = {19}, number = {7}, pages = {423--432}, abstract = {A model octapeptide segment derived from vasoactive intestinal peptide (VIP) was utilised to investigate the effect of several conventional cyclisation methods on the α-helical conformation in short peptide fragments. Three of the classical macrocyclisation techniques (i.e. lactamisation, ring-closing metathesis and Huisgen cycloaddition) were applied, and the conformations of the resulting cyclic peptides, as well as their linear precursors, were compared by CD analysis. The visibly higher folding propensity of the triazole-tethered peptide after azide-alkyne CuAAC macrocyclisation illustrates that the secondary structure of a short peptide fragment can differ significantly depending on the chemical strategy used to covalently cross-link side chain residues in a 'helical' fragment. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd. The effect of three classical macrocyclisation techniques (i.e. lactamisation, ring-closing metathesis and Huisgen cycloaddition) on inducing an alfa-helical conformation in short peptide fragments was investigated using a model octapeptide segment derived from vasoactive intestinal peptide (VIP).The conformations of the resulting cyclic peptides were compared by CD analysis. Based on this analysis, the triazole-tethered peptide after azide-alkyne CuAAC macrocyclisation shows a higher folding propensity in comparison with the two other cyclization methods. © 2013 European Peptide Society and John Wiley & Sons, Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A model octapeptide segment derived from vasoactive intestinal peptide (VIP) was utilised to investigate the effect of several conventional cyclisation methods on the α-helical conformation in short peptide fragments. Three of the classical macrocyclisation techniques (i.e. lactamisation, ring-closing metathesis and Huisgen cycloaddition) were applied, and the conformations of the resulting cyclic peptides, as well as their linear precursors, were compared by CD analysis. The visibly higher folding propensity of the triazole-tethered peptide after azide-alkyne CuAAC macrocyclisation illustrates that the secondary structure of a short peptide fragment can differ significantly depending on the chemical strategy used to covalently cross-link side chain residues in a 'helical' fragment. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd. The effect of three classical macrocyclisation techniques (i.e. lactamisation, ring-closing metathesis and Huisgen cycloaddition) on inducing an alfa-helical conformation in short peptide fragments was investigated using a model octapeptide segment derived from vasoactive intestinal peptide (VIP).The conformations of the resulting cyclic peptides were compared by CD analysis. Based on this analysis, the triazole-tethered peptide after azide-alkyne CuAAC macrocyclisation shows a higher folding propensity in comparison with the two other cyclization methods. © 2013 European Peptide Society and John Wiley & Sons, Ltd. |
Identification of polyproline II regions derived from the proline-rich nuclear receptor coactivators PNRC and PNRC2: New insights for ERα coactivator interactions Article de journal C Byrne; E Miclet; I Broutin; D Gallo; V Pelekanou; M Kampa; E Castanas; G Leclercq; Y Jacquot Chirality, 25 (10), p. 628–642, 2013. @article{Byrne:2013, title = {Identification of polyproline II regions derived from the proline-rich nuclear receptor coactivators PNRC and PNRC2: New insights for ERα coactivator interactions}, author = {C Byrne and E Miclet and I Broutin and D Gallo and V Pelekanou and M Kampa and E Castanas and G Leclercq and Y Jacquot}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883895838&doi=10.1002%2fchir.22188&partnerID=40&md5=19a4f15b5f544d367525c6d2d42739d5}, doi = {10.1002/chir.22188}, year = {2013}, date = {2013-01-01}, journal = {Chirality}, volume = {25}, number = {10}, pages = {628--642}, abstract = {Protein-protein interactions are crucial for signal transductions required for cell differentiation and proliferation. Their modulation is therefore key to the development of therapeutic alternatives, particularly in the context of cancer. According to literature data, the polyproline-rich nuclear receptor coactivators PNRC and PNRC2 interact with estrogen receptor (ERα) through their PxxP SH3-binding motifs. In a search to identify the molecular features governing this interaction, we explored using electronic circular dichroism (ECD) spectroscopy and molecular dynamics (MD) calculations, the capacity of a range of putative biologically active peptides derived from these proteins and containing this PxxP motif(s) to form polyproline II (PPII) domains. An additional more exhaustive structural study on a lead PPII peptide was also performed using 2D nuclear magnetic resonance (NMR) spectroscopy. With the exception of one of all the investigated peptides (PNRC-D), binding assays failed to detect any affinity for Grb2 SH3 domains, suggesting that PPII motifs issued from Grb2 antagonists have a binding mode distinct from those derived from Grb2 agonists. Instead, the peptides revealed a competitive binding ability against a synthetic peptide (ERα17p) with a putative PPII-cognate domain located within a coregulator recruitment region of ERα (AF-2 site). Our work, which constitutes the first structure-related interaction study concerning PNRC and PNRC2, supports not only the existence of PxxP-induced PPII sequences in these coregulators, but also confirms the presence of a PPII recognition site in the AF-2 of the steroid receptor ERα, a region important for transcription regulation. Chirality 25:628-642, 2013. © 2013 Wiley Periodicals, Inc. © 2013 Wiley Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Protein-protein interactions are crucial for signal transductions required for cell differentiation and proliferation. Their modulation is therefore key to the development of therapeutic alternatives, particularly in the context of cancer. According to literature data, the polyproline-rich nuclear receptor coactivators PNRC and PNRC2 interact with estrogen receptor (ERα) through their PxxP SH3-binding motifs. In a search to identify the molecular features governing this interaction, we explored using electronic circular dichroism (ECD) spectroscopy and molecular dynamics (MD) calculations, the capacity of a range of putative biologically active peptides derived from these proteins and containing this PxxP motif(s) to form polyproline II (PPII) domains. An additional more exhaustive structural study on a lead PPII peptide was also performed using 2D nuclear magnetic resonance (NMR) spectroscopy. With the exception of one of all the investigated peptides (PNRC-D), binding assays failed to detect any affinity for Grb2 SH3 domains, suggesting that PPII motifs issued from Grb2 antagonists have a binding mode distinct from those derived from Grb2 agonists. Instead, the peptides revealed a competitive binding ability against a synthetic peptide (ERα17p) with a putative PPII-cognate domain located within a coregulator recruitment region of ERα (AF-2 site). Our work, which constitutes the first structure-related interaction study concerning PNRC and PNRC2, supports not only the existence of PxxP-induced PPII sequences in these coregulators, but also confirms the presence of a PPII recognition site in the AF-2 of the steroid receptor ERα, a region important for transcription regulation. Chirality 25:628-642, 2013. © 2013 Wiley Periodicals, Inc. © 2013 Wiley Periodicals, Inc. |
Toward optimal spatial and spectral quality in widefield infrared spectromicroscopy of IR labelled single cells Article de journal E C Mattson; M Unger; S Clède; F Lambert; C Policar; A Imtiaz; R D'Souza; C J Hirschmugl Analyst, 138 (19), p. 5610–5618, 2013. @article{Mattson:2013, title = {Toward optimal spatial and spectral quality in widefield infrared spectromicroscopy of IR labelled single cells}, author = {E C Mattson and M Unger and S Cl\`{e}de and F Lambert and C Policar and A Imtiaz and R D'Souza and C J Hirschmugl}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883213711&doi=10.1039%2fc3an00383c&partnerID=40&md5=77ab18447e02b2a40b9a4b70fb8f05b0}, doi = {10.1039/c3an00383c}, year = {2013}, date = {2013-01-01}, journal = {Analyst}, volume = {138}, number = {19}, pages = {5610--5618}, abstract = {Advancements in widefield infrared spectromicroscopy have recently been demonstrated following the commissioning of IRENI (InfraRed ENvironmental Imaging), a Fourier Transform infrared (FTIR) chemical imaging beamline at the Synchrotron Radiation Center. The present study demonstrates the effects of magnification, spatial oversampling, spectral pre-processing and deconvolution, focusing on the intracellular detection and distribution of an exogenous metal tris-carbonyl derivative 1 in a single MDA-MB-231 breast cancer cell. We demonstrate here that spatial oversampling for synchrotron-based infrared imaging is critical to obtain accurate diffraction-limited images at all wavelengths simultaneously. Resolution criteria and results from raw and deconvoluted images for two Schwarzschild objectives (36×, NA 0.5 and 74×, NA 0.65) are compared to each other and to prior reports for raster-scanned, confocal microscopes. The resolution of the imaging data can be improved by deconvolving the instrumental broadening that is determined with the measured PSFs, which is implemented with GPU programming architecture for fast hyperspectral processing. High definition, rapidly acquired, FTIR chemical images of respective spectral signatures of the cell and 1 shows that 1 is localized next to the phosphate- and Amide-rich regions, in agreement with previous infrared and luminescence studies. The infrared image contrast, localization and definition are improved after applying proven spectral pre-processing (principal component analysis based noise reduction and RMie scattering correction algorithms) to individual pixel spectra in the hyperspectral cube. © The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Advancements in widefield infrared spectromicroscopy have recently been demonstrated following the commissioning of IRENI (InfraRed ENvironmental Imaging), a Fourier Transform infrared (FTIR) chemical imaging beamline at the Synchrotron Radiation Center. The present study demonstrates the effects of magnification, spatial oversampling, spectral pre-processing and deconvolution, focusing on the intracellular detection and distribution of an exogenous metal tris-carbonyl derivative 1 in a single MDA-MB-231 breast cancer cell. We demonstrate here that spatial oversampling for synchrotron-based infrared imaging is critical to obtain accurate diffraction-limited images at all wavelengths simultaneously. Resolution criteria and results from raw and deconvoluted images for two Schwarzschild objectives (36×, NA 0.5 and 74×, NA 0.65) are compared to each other and to prior reports for raster-scanned, confocal microscopes. The resolution of the imaging data can be improved by deconvolving the instrumental broadening that is determined with the measured PSFs, which is implemented with GPU programming architecture for fast hyperspectral processing. High definition, rapidly acquired, FTIR chemical images of respective spectral signatures of the cell and 1 shows that 1 is localized next to the phosphate- and Amide-rich regions, in agreement with previous infrared and luminescence studies. The infrared image contrast, localization and definition are improved after applying proven spectral pre-processing (principal component analysis based noise reduction and RMie scattering correction algorithms) to individual pixel spectra in the hyperspectral cube. © The Royal Society of Chemistry. |
Polypyrrole functionalized with new copper complex as platform for His-tag antibody immobilization and direct antigen detection Article de journal S Chebil; A Miodek; V Ambike; H Sauriat-Dorizon; C Policar; H Korri-Youssoufi Sensors and Actuators, B: Chemical, 185 , p. 762–770, 2013. @article{Chebil:2013, title = {Polypyrrole functionalized with new copper complex as platform for His-tag antibody immobilization and direct antigen detection}, author = {S Chebil and A Miodek and V Ambike and H Sauriat-Dorizon and C Policar and H Korri-Youssoufi}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879243477&doi=10.1016%2fj.snb.2013.05.024&partnerID=40&md5=3d177c3bfb5d34b53cdc0265fd462968}, doi = {10.1016/j.snb.2013.05.024}, year = {2013}, date = {2013-01-01}, journal = {Sensors and Actuators, B: Chemical}, volume = {185}, pages = {762--770}, abstract = {A biomaterial based on a copper complex covalently attached to a polypyrrole backbone was designed for monitoring a glycoprotein, D-dimer, used as a marker of the deep vein thrombosis (DVT) condition. For this purpose a new copper complex has been developed based on the ligand N-(2-hydroxybenzyl)- N′-(6-aminohexyl)-N,N′-bis[2-(N-methylimidazolyl)methyl]ethane-1, 2-diamine (3) that is able to coordinate copper ions through two imidazole, two amine and one phenolato moieties - this coordination sphere will be labeled enPI2. The complex conjugated with a polypyrrole layer allows the His-tag antibody immobilization onto the conducting polymer substrate and immunosensor evaluation. The biomaterial shows a remarkable variation in redox activity of the Cu(II) complex after the D-dimer interaction. The redox activity of the [(enPi2)Cu(II)] complex decreases after the antigen interaction providing a linear response between 0.01 and 500 ng mL-1 with a detection limit of 10 pg mL-1. The chemical structure of copper complex demonstrates the ability to avoid non specific-interaction leading to anti fouling surface. Such biolayer architecture offers high measurement stability over time and the biomaterial could be stocked for several weeks without any modification of the electrochemical properties. © 2013 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A biomaterial based on a copper complex covalently attached to a polypyrrole backbone was designed for monitoring a glycoprotein, D-dimer, used as a marker of the deep vein thrombosis (DVT) condition. For this purpose a new copper complex has been developed based on the ligand N-(2-hydroxybenzyl)- N′-(6-aminohexyl)-N,N′-bis[2-(N-methylimidazolyl)methyl]ethane-1, 2-diamine (3) that is able to coordinate copper ions through two imidazole, two amine and one phenolato moieties - this coordination sphere will be labeled enPI2. The complex conjugated with a polypyrrole layer allows the His-tag antibody immobilization onto the conducting polymer substrate and immunosensor evaluation. The biomaterial shows a remarkable variation in redox activity of the Cu(II) complex after the D-dimer interaction. The redox activity of the [(enPi2)Cu(II)] complex decreases after the antigen interaction providing a linear response between 0.01 and 500 ng mL-1 with a detection limit of 10 pg mL-1. The chemical structure of copper complex demonstrates the ability to avoid non specific-interaction leading to anti fouling surface. Such biolayer architecture offers high measurement stability over time and the biomaterial could be stocked for several weeks without any modification of the electrochemical properties. © 2013 Elsevier B.V. |
Synchrotron radiation FTIR detection of a metal-carbonyl tamoxifen analog. Correlation with luminescence microscopy to study its subcellular distribution Article de journal S Clède; F Lambert; C Sandt; Z Gueroui; N Delsuc; P Dumas; A Vessières; C Policar Biotechnology Advances, 31 (3), p. 393–395, 2013. @article{Clede:2013, title = {Synchrotron radiation FTIR detection of a metal-carbonyl tamoxifen analog. Correlation with luminescence microscopy to study its subcellular distribution}, author = {S Cl\`{e}de and F Lambert and C Sandt and Z Gueroui and N Delsuc and P Dumas and A Vessi\`{e}res and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875055388&doi=10.1016%2fj.biotechadv.2012.01.023&partnerID=40&md5=064b36e2db4e1260e17d3abc8b07bbd6}, doi = {10.1016/j.biotechadv.2012.01.023}, year = {2013}, date = {2013-01-01}, journal = {Biotechnology Advances}, volume = {31}, number = {3}, pages = {393--395}, abstract = {1,1-Di(4-hydroxyphenyl)-2-cyrhetrenylbut-1-ene 1 is an organometallic conjugate where a [(Cp)Re(CO)3] unit is linked to a hydroxytamoxifen-like structure. Its subcellular nuclear distribution was previously observed in a single cell using the near-field technique AFMIR. We show here that synchrotron radiation FTIR spectromicroscopy (SR-FTIR-SM) enabled the mapping of 1 based on its IR-signature (characteristic bands in the 1850-2200cm-1 range) and pointed out the colocalization of 1 with an area of high amide density. Fluorescence microscopy using DAPI staining performed on the same cells confirmed that this area corresponds to the cell nucleus. © 2012 Elsevier Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 1,1-Di(4-hydroxyphenyl)-2-cyrhetrenylbut-1-ene 1 is an organometallic conjugate where a [(Cp)Re(CO)3] unit is linked to a hydroxytamoxifen-like structure. Its subcellular nuclear distribution was previously observed in a single cell using the near-field technique AFMIR. We show here that synchrotron radiation FTIR spectromicroscopy (SR-FTIR-SM) enabled the mapping of 1 based on its IR-signature (characteristic bands in the 1850-2200cm-1 range) and pointed out the colocalization of 1 with an area of high amide density. Fluorescence microscopy using DAPI staining performed on the same cells confirmed that this area corresponds to the cell nucleus. © 2012 Elsevier Inc. |
An intrinsically fluorescent glycoligand for direct imaging of ligand trafficking in artificial and living cell systems Article de journal L Garcia; M Lazzaretti; A Diguet; F Mussi; F Bisceglie; J Xie; G Pelosi; A Buschini; D Baigl; C Policar New Journal of Chemistry, 37 (10), p. 3030–3034, 2013. @article{Garcia:2013, title = {An intrinsically fluorescent glycoligand for direct imaging of ligand trafficking in artificial and living cell systems}, author = {L Garcia and M Lazzaretti and A Diguet and F Mussi and F Bisceglie and J Xie and G Pelosi and A Buschini and D Baigl and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884338239&doi=10.1039%2fc3nj00380a&partnerID=40&md5=227adf277b66a18d63bfec3b8a13ff09}, doi = {10.1039/c3nj00380a}, year = {2013}, date = {2013-01-01}, journal = {New Journal of Chemistry}, volume = {37}, number = {10}, pages = {3030--3034}, abstract = {Glycoligands, sugar-based molecules able to complex metal cations, constitute a new class of molecules with great potential for biological and biochemical applications. To analyze their behaviour in a biological environment, we have synthesized an intrinsically fluorescent glycoligand and analyzed its trafficking in both living (U937 human cancer cells) and artificial (giant unilamellar vesicles) cell systems. We have found that this ligand has moderate cytotoxicity accompanied by specific accumulation in both living and reconstituted membranes, which it can cross to reach inner compartments. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Glycoligands, sugar-based molecules able to complex metal cations, constitute a new class of molecules with great potential for biological and biochemical applications. To analyze their behaviour in a biological environment, we have synthesized an intrinsically fluorescent glycoligand and analyzed its trafficking in both living (U937 human cancer cells) and artificial (giant unilamellar vesicles) cell systems. We have found that this ligand has moderate cytotoxicity accompanied by specific accumulation in both living and reconstituted membranes, which it can cross to reach inner compartments. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. |
S Clède; F Lambert; C Sandt; S Kascakova; M Unger; E Harté; M -A Plamont; R Saint-Fort; A Deniset-Besseau; Z Gueroui; C Hirschmugl; S Lecomte; A Dazzi; A Vessières; C Policar Analyst, 138 (19), p. 5627–5638, 2013. @article{Clede:2013a, title = {Detection of an estrogen derivative in two breast cancer cell lines using a single core multimodal probe for imaging (SCoMPI) imaged by a panel of luminescent and vibrational techniques}, author = {S Cl\`{e}de and F Lambert and C Sandt and S Kascakova and M Unger and E Hart\'{e} and M -A Plamont and R Saint-Fort and A Deniset-Besseau and Z Gueroui and C Hirschmugl and S Lecomte and A Dazzi and A Vessi\`{e}res and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883254315&doi=10.1039%2fc3an00807j&partnerID=40&md5=02420b772ef22a07206b5ae31c42dd2e}, doi = {10.1039/c3an00807j}, year = {2013}, date = {2013-01-01}, journal = {Analyst}, volume = {138}, number = {19}, pages = {5627--5638}, abstract = {3-Methoxy-17α-ethynylestradiol or mestranol is a prodrug for ethynylestradiol and the estrogen component of some oral contraceptive formulations. We demonstrate here that a single core multimodal probe for imaging-SCoMPI-can be efficiently grafted onto mestranol allowing its tracking in two breast cancer cell lines, MDA-MB-231 and MCF-7 fixed cells. Correlative imaging studies based on luminescence (synchrotron UV spectromicroscopy, wide field and confocal fluorescence microscopies) and vibrational (AFMIR, synchrotron FTIR spectromicroscopy, synchrotron-based multiple beam FTIR imaging, confocal Raman microspectroscopy) spectroscopies were consistent with one another and showed a Golgi apparatus distribution of the SCoMPI-mestranol conjugate in both cell lines. © The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 3-Methoxy-17α-ethynylestradiol or mestranol is a prodrug for ethynylestradiol and the estrogen component of some oral contraceptive formulations. We demonstrate here that a single core multimodal probe for imaging-SCoMPI-can be efficiently grafted onto mestranol allowing its tracking in two breast cancer cell lines, MDA-MB-231 and MCF-7 fixed cells. Correlative imaging studies based on luminescence (synchrotron UV spectromicroscopy, wide field and confocal fluorescence microscopies) and vibrational (AFMIR, synchrotron FTIR spectromicroscopy, synchrotron-based multiple beam FTIR imaging, confocal Raman microspectroscopy) spectroscopies were consistent with one another and showed a Golgi apparatus distribution of the SCoMPI-mestranol conjugate in both cell lines. © The Royal Society of Chemistry. |
2012 |
Vinyl-Triphenylamine Dyes, a New Family of Switchable Fluorescent Probes for Targeted Two-Photon Cellular Imaging: From DNA to Protein Labeling Article de journal Blaise Dumat; Guillaume Bordeau; Ana I Aranda; Florence Mahuteau-Betzer; Yara El Harfouch; Germain Metgé; Fabrice Charra; Céline Fiorini-Debuisschert; Marie-Paule Teulade-Fichou Organic & Biomolecular Chemistry, 10 (30), p. 6054-6054, 2012. @article{Dumat:2012, title = {Vinyl-Triphenylamine Dyes, a New Family of Switchable Fluorescent Probes for Targeted Two-Photon Cellular Imaging: From DNA to Protein Labeling}, author = {Blaise Dumat and Guillaume Bordeau and Ana I Aranda and Florence {Mahuteau-Betzer} and Yara El Harfouch and Germain Metg\'{e} and Fabrice Charra and C\'{e}line {Fiorini-Debuisschert} and Marie-Paule {Teulade-Fichou}}, doi = {10.1039/c2ob25515d}, year = {2012}, date = {2012-08-01}, journal = {Organic & Biomolecular Chemistry}, volume = {10}, number = {30}, pages = {6054-6054}, abstract = {On the basis of our previous work on vinyl-triphenylamine derived DNA fluorophores we explored the structure space around this core by coupling it to diverse cationic, anionic and zwitterionic groups in the aim of targeting different classes of biomolecules. In parallel core modifications were performed to optimize the photophysical properties (quantum yield, two-photon absorption). The resulting water soluble $pi$-conjugated molecules are called TP dyes and display an exceptional combination of optical properties: high two-photon absorption cross-section, high photostability, no self-quenching, and switchable fluorescence emission when bound to a biopolymer matrix. The linear and nonlinear optical properties of the TP dyes were studied in vitro in presence of DNA and in presence of a model protein (human serum albumin) using complementary absorption and fluorescence spectroscopy characterization tools. Structure modifications enabled to switch from DNA probes (cationic TP-pyridinium series) to protein probes (anionic TP-rhodanine series) without affecting the optical properties. Finally most TP compounds appear cell-permeant and show an intracellular localization consistent with their in vitro target specificity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } On the basis of our previous work on vinyl-triphenylamine derived DNA fluorophores we explored the structure space around this core by coupling it to diverse cationic, anionic and zwitterionic groups in the aim of targeting different classes of biomolecules. In parallel core modifications were performed to optimize the photophysical properties (quantum yield, two-photon absorption). The resulting water soluble $pi$-conjugated molecules are called TP dyes and display an exceptional combination of optical properties: high two-photon absorption cross-section, high photostability, no self-quenching, and switchable fluorescence emission when bound to a biopolymer matrix. The linear and nonlinear optical properties of the TP dyes were studied in vitro in presence of DNA and in presence of a model protein (human serum albumin) using complementary absorption and fluorescence spectroscopy characterization tools. Structure modifications enabled to switch from DNA probes (cationic TP-pyridinium series) to protein probes (anionic TP-rhodanine series) without affecting the optical properties. Finally most TP compounds appear cell-permeant and show an intracellular localization consistent with their in vitro target specificity. |
Calcium rubies: A family of red-emitting functionalizable indicators suitable for two-photon Ca2+ imaging Article de journal M Collot; C Loukou; A V Yakovlev; C D Wilms; D Li; A Evrard; A Zamaleeva; L Bourdieu; J -F Léger; N Ropert; J Eilers; M Oheim; A Feltz; J -M Mallet Journal of the American Chemical Society, 134 (36), p. 14923–14931, 2012. @article{Collot:2012, title = {Calcium rubies: A family of red-emitting functionalizable indicators suitable for two-photon Ca2+ imaging}, author = {M Collot and C Loukou and A V Yakovlev and C D Wilms and D Li and A Evrard and A Zamaleeva and L Bourdieu and J -F L\'{e}ger and N Ropert and J Eilers and M Oheim and A Feltz and J -M Mallet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84866388600&doi=10.1021%2fja304018d&partnerID=40&md5=fd6690919500a6e4f88691b43646ef90}, doi = {10.1021/ja304018d}, year = {2012}, date = {2012-01-01}, journal = {Journal of the American Chemical Society}, volume = {134}, number = {36}, pages = {14923--14931}, abstract = {We designed Calcium Rubies, a family of functionalizable BAPTA-based red-fluorescent calcium (Ca2+) indicators as new tools for biological Ca2+ imaging. The specificity of this Ca2+-indicator family is its side arm, attached on the ethylene glycol bridge that allows coupling the indicator to various groups while leaving open the possibility of aromatic substitutions on the BAPTA core for tuning the Ca2+-binding affinity. Using this possibility we now synthesize and characterize three different CaRubies with affinities between 3 and 22 μM. Their long excitation and emission wavelengths (peaks at 586/604 nm) allow their use in otherwise challenging multicolor experiments, e.g., when combining Ca2+ uncaging or optogenetic stimulation with Ca2+ imaging in cells expressing fluorescent proteins. We illustrate this capacity by the detection of Ca2+ transients evoked by blue light in cultured astrocytes expressing CatCh, a light-sensitive Ca2+-translocating channelrhodopsin linked to yellow fluorescent protein. Using time-correlated single-photon counting, we measured fluorescence lifetimes for all CaRubies and demonstrate a 10-fold increase in the average lifetime upon Ca2+ chelation. Since only the fluorescence quantum yield but not the absorbance of the CaRubies is Ca2+-dependent, calibrated two-photon fluorescence excitation measurements of absolute Ca2+ concentrations are feasible. © 2012 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We designed Calcium Rubies, a family of functionalizable BAPTA-based red-fluorescent calcium (Ca2+) indicators as new tools for biological Ca2+ imaging. The specificity of this Ca2+-indicator family is its side arm, attached on the ethylene glycol bridge that allows coupling the indicator to various groups while leaving open the possibility of aromatic substitutions on the BAPTA core for tuning the Ca2+-binding affinity. Using this possibility we now synthesize and characterize three different CaRubies with affinities between 3 and 22 μM. Their long excitation and emission wavelengths (peaks at 586/604 nm) allow their use in otherwise challenging multicolor experiments, e.g., when combining Ca2+ uncaging or optogenetic stimulation with Ca2+ imaging in cells expressing fluorescent proteins. We illustrate this capacity by the detection of Ca2+ transients evoked by blue light in cultured astrocytes expressing CatCh, a light-sensitive Ca2+-translocating channelrhodopsin linked to yellow fluorescent protein. Using time-correlated single-photon counting, we measured fluorescence lifetimes for all CaRubies and demonstrate a 10-fold increase in the average lifetime upon Ca2+ chelation. Since only the fluorescence quantum yield but not the absorbance of the CaRubies is Ca2+-dependent, calibrated two-photon fluorescence excitation measurements of absolute Ca2+ concentrations are feasible. © 2012 American Chemical Society. |
Challenging 50 Years of Established Views on Ugi Reaction: A Theoretical Approach Article de journal N Chéron; R Ramozzi; L E Ka"im; L Grimaud; P Fleurat-Lessard Journal of Organic Chemistry, 77 (3), p. 1361-1366, 2012. @article{Cheron:2012a, title = {Challenging 50 Years of Established Views on Ugi Reaction: A Theoretical Approach}, author = {N Ch\'{e}ron and R Ramozzi and L E Ka{"i}m and L Grimaud and P {Fleurat-Lessard}}, doi = {10.1021/jo2021554}, year = {2012}, date = {2012-01-01}, journal = {Journal of Organic Chemistry}, volume = {77}, number = {3}, pages = {1361-1366}, abstract = {The Ugi reaction is one of the most famous multicomponent couplings, and its efficiency is still explained by the original mechanism suggested by Ugi in the 60s. This article aims to present a thorough theoretical study of this reaction. It describes how the imine is activated and how the new stereogenic center is formed. Our calculations strongly suggest alternatives to some commonly accepted features, such as the reversibility of the intermediate steps, and temper the nature of the driving force of the reaction. textcopyright 2012 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Ugi reaction is one of the most famous multicomponent couplings, and its efficiency is still explained by the original mechanism suggested by Ugi in the 60s. This article aims to present a thorough theoretical study of this reaction. It describes how the imine is activated and how the new stereogenic center is formed. Our calculations strongly suggest alternatives to some commonly accepted features, such as the reversibility of the intermediate steps, and temper the nature of the driving force of the reaction. textcopyright 2012 American Chemical Society. |
Evaluation of the anti-oxidant properties of a SOD-mimic Mn-complex in activated macrophages Article de journal Anne-Sophie Bernard; Claire Giroud; Vincent H Y Ching; Anne Meunier; Vinita Ambike; Christian Amatore; Manon Guille-Collignon; Frederic Lemaitre; Clotilde Policar Dalton Transactions, 41 (21), p. 6399-6403, 2012, (Times Cited: 23). @article{, title = {Evaluation of the anti-oxidant properties of a SOD-mimic Mn-complex in activated macrophages}, author = {Anne-Sophie Bernard and Claire Giroud and Vincent H Y Ching and Anne Meunier and Vinita Ambike and Christian Amatore and Manon Guille-Collignon and Frederic Lemaitre and Clotilde Policar}, year = {2012}, date = {2012-01-01}, journal = {Dalton Transactions}, volume = {41}, number = {21}, pages = {6399-6403}, note = {Times Cited: 23}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Improving the selectivity of the phosphoric acid β-elimination on a biotinylated phosphopeptide Article de journal L Matheron; S Clavier; O Diebate; P Karoyan; G Bolbach; D Guianvarc'h; E Sachon Journal of the American Society for Mass Spectrometry, 23 (11), p. 1981–1990, 2012. @article{Matheron:2012, title = {Improving the selectivity of the phosphoric acid β-elimination on a biotinylated phosphopeptide}, author = {L Matheron and S Clavier and O Diebate and P Karoyan and G Bolbach and D Guianvarc'h and E Sachon}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84868219215&doi=10.1007%2fs13361-012-0467-y&partnerID=40&md5=557ac35da1df3982563ddbf8f0de181f}, doi = {10.1007/s13361-012-0467-y}, year = {2012}, date = {2012-01-01}, journal = {Journal of the American Society for Mass Spectrometry}, volume = {23}, number = {11}, pages = {1981--1990}, abstract = {This study aims at improving the MALDI-TOF detection of a phosphorylated peptide containing a cysteine residue by β-elimination of H 3PO4 hardly enriched by classical methods. The experimental conditions were optimized on this phosphopeptide (biot-pAdd) and its nonphosphorylated counterpart (biot-Add). The major side-reactions were H2S elimination on the cysteine residues and H2O elimination on the non phosphorylated serine residue of biot-Add. The former dilutes the MALDI-TOF signal for the desired species. The latter gives a product similar to what is obtained by H3PO4 elimination and should prompt to caution when working with a mixture between phosphorylated and non phosphorylated peptides. Modifications on the solvent, the reaction temperature and time, the nature, and concentration of the base were made. Major improvement of the selectivity of the reaction was observed in 30 % ACN, at room temperature for 4 h. However, these optimizations are specific to these sequences and should be performed anew for different peptides. The selectivity of the reaction towards H3PO4 elimination is improved, but the persistence of side-reactions renders a previous sample fractionation necessary. In these optimized conditions, the ionization enhancement is 3-fold and the detection limits for biot-pAdd are similar to biot-Add (100 fmol). © American Society for Mass Spectrometry, 2012.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study aims at improving the MALDI-TOF detection of a phosphorylated peptide containing a cysteine residue by β-elimination of H 3PO4 hardly enriched by classical methods. The experimental conditions were optimized on this phosphopeptide (biot-pAdd) and its nonphosphorylated counterpart (biot-Add). The major side-reactions were H2S elimination on the cysteine residues and H2O elimination on the non phosphorylated serine residue of biot-Add. The former dilutes the MALDI-TOF signal for the desired species. The latter gives a product similar to what is obtained by H3PO4 elimination and should prompt to caution when working with a mixture between phosphorylated and non phosphorylated peptides. Modifications on the solvent, the reaction temperature and time, the nature, and concentration of the base were made. Major improvement of the selectivity of the reaction was observed in 30 % ACN, at room temperature for 4 h. However, these optimizations are specific to these sequences and should be performed anew for different peptides. The selectivity of the reaction towards H3PO4 elimination is improved, but the persistence of side-reactions renders a previous sample fractionation necessary. In these optimized conditions, the ionization enhancement is 3-fold and the detection limits for biot-pAdd are similar to biot-Add (100 fmol). © American Society for Mass Spectrometry, 2012. |
Self-assembling mini cell-penetrating peptides enter by both direct translocation and glycosaminoglycan-dependent endocytosis Article de journal S A Bode; M Thévenin; C Bechara; S Sagan; S Bregant; S Lavielle; G Chassaing; F Burlina Chemical Communications, 48 (57), p. 7179–7181, 2012. @article{Bode:2012, title = {Self-assembling mini cell-penetrating peptides enter by both direct translocation and glycosaminoglycan-dependent endocytosis}, author = {S A Bode and M Th\'{e}venin and C Bechara and S Sagan and S Bregant and S Lavielle and G Chassaing and F Burlina}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84862849271&doi=10.1039%2fc2cc33240j&partnerID=40&md5=bb59ccbc72e49dc4c346c957608283d9}, doi = {10.1039/c2cc33240j}, year = {2012}, date = {2012-01-01}, journal = {Chemical Communications}, volume = {48}, number = {57}, pages = {7179--7181}, abstract = {A small library of cell-penetrating peptides (CPPs) containing a minimized cationic domain and a lipophilic domain of different size was studied. CPPs that could self-assemble were found to enter cells more efficiently, triggering a glycosaminoglycan-dependent pathway. © 2012 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A small library of cell-penetrating peptides (CPPs) containing a minimized cationic domain and a lipophilic domain of different size was studied. CPPs that could self-assemble were found to enter cells more efficiently, triggering a glycosaminoglycan-dependent pathway. © 2012 The Royal Society of Chemistry. |
Local control of the cis-trans isomerization and backbone dihedral angles in peptides using trifluoromethylated pseudoprolines Article de journal D Feytens; G Chaume; G Chassaing; S Lavielle; T Brigaud; B J Byun; Y K Kang; E Miclet Journal of Physical Chemistry B, 116 (13), p. 4069–4079, 2012. @article{Feytens:2012, title = {Local control of the cis-trans isomerization and backbone dihedral angles in peptides using trifluoromethylated pseudoprolines}, author = {D Feytens and G Chaume and G Chassaing and S Lavielle and T Brigaud and B J Byun and Y K Kang and E Miclet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84859582215&doi=10.1021%2fjp300284u&partnerID=40&md5=f3f43098c11734e78e366b75e0cd4848}, doi = {10.1021/jp300284u}, year = {2012}, date = {2012-01-01}, journal = {Journal of Physical Chemistry B}, volume = {116}, number = {13}, pages = {4069--4079}, abstract = {NMR studies and theoretical calculations have been performed on model peptides Ac-Ser(φPro)-NHMe, (S,S)Ac-Ser(φH,CF3Pro)-NHMe, and (R,S)Ac-Ser(φCF3,HPro)-NHMe. Their thermodynamic and kinetic features have been analyzed in chloroform, DMSO, and water, allowing a precise description of their conformational properties. We found that trifluoromethyl Cδ-substitutions of oxazolidine-based pseudoprolines can strongly influence the cis-trans rotational barriers with only moderate effects on the cis/trans population ratio. In CHCl3, the configuration of the CF3-Cδ entirely controls the φ-dihedral angle, allowing the stabilization of γ-turn-like or PPI/PPII-like backbone conformations. Moreover, in water and DMSO, this Cδ- configuration can be used to efficiently constrain the ring puckering without affecting the cis/trans population ratio. Theoretical calculations have ascertained the electronic and geometric properties induced by the trifluoromethyl substituent and provided a rational understanding of the NMR observations. © 2012 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } NMR studies and theoretical calculations have been performed on model peptides Ac-Ser(φPro)-NHMe, (S,S)Ac-Ser(φH,CF3Pro)-NHMe, and (R,S)Ac-Ser(φCF3,HPro)-NHMe. Their thermodynamic and kinetic features have been analyzed in chloroform, DMSO, and water, allowing a precise description of their conformational properties. We found that trifluoromethyl Cδ-substitutions of oxazolidine-based pseudoprolines can strongly influence the cis-trans rotational barriers with only moderate effects on the cis/trans population ratio. In CHCl3, the configuration of the CF3-Cδ entirely controls the φ-dihedral angle, allowing the stabilization of γ-turn-like or PPI/PPII-like backbone conformations. Moreover, in water and DMSO, this Cδ- configuration can be used to efficiently constrain the ring puckering without affecting the cis/trans population ratio. Theoretical calculations have ascertained the electronic and geometric properties induced by the trifluoromethyl substituent and provided a rational understanding of the NMR observations. © 2012 American Chemical Society. |
ERα17p, a peptide reproducing the hinge region of the estrogen receptor α associates to biological membranes: A biophysical approach Article de journal C Byrne; L Khemtémourian; V Pelekanou; M Kampa; G Leclercq; S Sagan; E Castanas; F Burlina; Y Jacquot Steroids, 77 (10), p. 979–987, 2012. @article{Byrne:2012, title = {ERα17p, a peptide reproducing the hinge region of the estrogen receptor α associates to biological membranes: A biophysical approach}, author = {C Byrne and L Khemt\'{e}mourian and V Pelekanou and M Kampa and G Leclercq and S Sagan and E Castanas and F Burlina and Y Jacquot}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863986217&doi=10.1016%2fj.steroids.2012.02.022&partnerID=40&md5=ba77e90253f27eac8d9a0fb906a192c4}, doi = {10.1016/j.steroids.2012.02.022}, year = {2012}, date = {2012-01-01}, journal = {Steroids}, volume = {77}, number = {10}, pages = {979--987}, abstract = {Recently, we identified a peptide (ERα17p, P 295LMIKRSKKNSLALSLT311) that corresponds to the 295-311 sequence of the estrogen receptor α (ERα, hinge region) and which exerts a panel of pharmacological effects in breast cancer cells. Remarkably, these effects can result from the interaction of ERα17p with the plasma membrane. Herein, we show that ERα17p adopts a β-sheet secondary structure when in contact with anionic phospholipids and that it is engulfed within the lipid bilayer. While ERα17p increases the fluidity of membrane mimics, it weakly internalizes in living cells. In light of the above, one may evoke one important role of the 295-311 region of the ERα: the corresponding peptide could be secreted/delivered to the extracellular medium to interact with neighboring cells, both intracellularly and at the membrane level. Finally, the 295-311 region of ERα being in proximity to the cystein-447, the palmitoylation site of the ERα raises the question of its involvement in the interaction/stabilization of the protein with the membrane. © 2011 Elsevier Inc. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recently, we identified a peptide (ERα17p, P 295LMIKRSKKNSLALSLT311) that corresponds to the 295-311 sequence of the estrogen receptor α (ERα, hinge region) and which exerts a panel of pharmacological effects in breast cancer cells. Remarkably, these effects can result from the interaction of ERα17p with the plasma membrane. Herein, we show that ERα17p adopts a β-sheet secondary structure when in contact with anionic phospholipids and that it is engulfed within the lipid bilayer. While ERα17p increases the fluidity of membrane mimics, it weakly internalizes in living cells. In light of the above, one may evoke one important role of the 295-311 region of the ERα: the corresponding peptide could be secreted/delivered to the extracellular medium to interact with neighboring cells, both intracellularly and at the membrane level. Finally, the 295-311 region of ERα being in proximity to the cystein-447, the palmitoylation site of the ERα raises the question of its involvement in the interaction/stabilization of the protein with the membrane. © 2011 Elsevier Inc. All rights reserved. |