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Publications

2005

  • Ability of some plant extracts , traditionally used to treat ciguatera fish poisoning, to prevent the in vitro neurotoxicity produced by sodium channel activators.
    • Boydron-Le Garrec Raphaële
    • Benoit Evelyne
    • Sauviat Martin-Pierre
    • J. Lewis Richard
    • Molgó Jordi
    • Laurent Dominique
    Toxicon, Elsevier, 2005, 46(6), pp.625-634. The effects of 31 plant extracts, which most are traditionally used to treat ciguatera fish poisoning in the Pacific area, were studied on the cytotoxicity of mouse neuroblastoma cells produced by ouabain, veratridine and/or brevetoxin-3 or Pacific ciguatoxin-1. The cell viability was determined using a quantitative colorimetric method. A marked cytotoxicity of seven of the 31 plant extracts studied, was observed. Despite this, these plant extracts were suspected to contain active compound(s) against the cytotoxicity produced by brevetoxin (2 extracts), brevetoxin, ouabain and/or veratridine (3 extracts), or only against that of ouabain and/or veratridine (2 extracts). Among the 24 plant extracts that exhibited by themselves no cytotoxicity, 22 were active against the effect of brevetoxin or against that of both veratridine and brevetoxin. Similar results were obtained when the seven most active plant extracts were reassayed using ciguatoxin instead of brevetoxin. In conclusion, the present work reports the first activity assessment of some plant extracts, achieved in vitro on a quite large scale. The fact that 27 plant extracts were found to exert, in vitro, a protective effect against the action of ciguatoxin and/or brevetoxin, paves the way for finding new active compounds to treat ciguatera fish poisoning, provided these compounds also reverse the effects of sodium channel activators. (10.1016/j.toxicon.2005.07.002)
    DOI : 10.1016/j.toxicon.2005.07.002
  • Mid-infrared electric field characterization using a visible charge-coupled-device-based spectrometer
    • Kubarych Kevin J.
    • Joffre Manuel
    • Moore Amy
    • Belabas Nadia
    • Jonas David
    Optics Letters, Optical Society of America - OSA Publishing, 2005, 30 (10), pp.1228-1230. We characterize ultrashort mid-infrared pulses through upconversion by using the stretched pulses obtained from the uncompressed output of a chirped-pulse amplifier. The power spectrum thus translated into the visible region can be readily measured with a standard silicon CCD camera-based spectrometer. The spectral phase is also characterized by a variant of zero-added-phase spectral phase interferometry for direct electric field reconstruction. This is a general method that provides a multiplex advantage over conventional infrared detector array-based methods. © 2005 Optical Society of America (10.1364/OL.30.001228)
    DOI : 10.1364/OL.30.001228
  • Activationless electron transfer through the hydrophobic core of cytochrome c oxidase
    • Jasaitis Audrius
    • Rappaport F.
    • Pilet Eric
    • Liebl Ursula
    • Vos Marten H.
    Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2005, 102 (31), pp.10882. Electron transfer (ET) within proteins occurs by means of chains of redox intermediates that favor directional and efficient electron delivery to an acceptor. Individual ET steps are energetically characterized by the electronic coupling V, driving force ΔG, and reorganization energy λ. λ reflects the nuclear rearrangement of the redox partners and their environment associated with the reactions; λ ≈ 700-1,100 meV (1 eV = 1.602 × 10-19 J) has been considered as a typical value for intraprotein ET. In nonphotosynthetic systems, functional ET is difficult to assess directly. However, using femtosecond flash photolysis of the CO-poised membrane protein cytochrome c oxidase, the intrinsic rate constant of the low-ΔG electron injection from heme a into the heme a 3-CuB active site was recently established at (1.4 ns)-1. Here, we determine the temperature dependence of both the rate constant and ΔG of this reaction and establish that this reaction is activationless. Using a quantum mechanical form of nonadiabatic ET theory and common assumptions for the coupled vibrational modes, we deduce that λ is <200 meV. It is demonstrated that the previously accepted value of 760 meV actually originates from the temperature dependence of CuB-CO bond breaking. We discuss that low-ΔG, low-λ reactions are common for efficiently channeling electrons through chains that are buried inside membrane proteins. (10.1073/pnas.0503001102)
    DOI : 10.1073/pnas.0503001102
  • Spectroscopic analysis of keratin endogenous signal for skin multiphoton microscopy: erratum
    • Pena Ana-Maria
    • Strupler Mathias
    • Boulesteix Thierry
    • Godeau G.
    • Schanne-Klein Marie-Claire
    Optics Express, Optical Society of America - OSA Publishing, 2005, 13 (17), pp.6667. We present corrected versions of the list of authors and of Section 2.1. (10.1364/OPEX.13.006667)
    DOI : 10.1364/OPEX.13.006667
  • Functionality of nitrated acetylcholine receptor: The two-step formation of nitrotyrosines reveals their differential role in effectors binding
    • Négrerie Michel
    • Martin Jean-Louis
    • Nghiêm H.-O.
    FEBS Letters, Wiley, 2005, 579 (12), pp.2643. The presence of nitrotyrosines is associated with several neurodegenerative pathologies. We evaluated the functionality of the nicotinic acetylcholine receptor possessing nitrotyrosines. The spectrum of the nitrated receptor displays an absorption band characteristic of ortho-nitrophenol. The presence of carbamylcholine in the agonist site prevented the effect of nitration by tetranitromethane in some conditions. The nitration occurred with two discrete steps and pointed out the differential involvement of tyrosines in the binding of acetylcholine and neurotoxin. We concluded that at least two residues involved in agonist binding can be nitrated, which bring similar contributions to the binding energy of the neurotransmitter. Cop. 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. (10.1016/j.febslet.2005.03.084)
    DOI : 10.1016/j.febslet.2005.03.084
  • Etudes spectroscopiques du senseur à oxygène FixL
    • Jasaitis Audrius
    • Vos Marten H.
    • Balland Véronique
    • Mattioli T. A.
    • Bouzhir-Sima Latifa
    • Liebl Ursula
    , 2005, pp.poster.
  • Sudden polarisation and coherent vibration in bacteriorhodopsin
    • Groma Geza
    • Colonna Anne
    • Joffre Manuel
    • Vos Marten H.
    • Martin Jean-Louis
    , 2005.
  • Téléphonie cellulaire et cancer: où en est-on? [Cellular phones and cancer: Current status]
    • Colonna Anne
    Bulletin du Cancer, Elsevier, 2005, 92 (7), pp.637. L'évaluation de l'impact des nouvelles technologies sur le corps humain est indispensable pour imposer les normes réglementaires limitant les risques sanitaires. L'apparition et l'évolution des téléphones cellulaires ont été parmi les plus rapides dans l'histoire des innovations. De nombreuses recherches ont été effectuées pour tenter d'évaluer le lien éventuel entre effet sur la santé et téléphonie mobile, au niveau du téléphone cellulaire mais également des stations de base. Cet article présente un aperçu des connaissances en matière de recherche sur l'incidence des ondes radiofréquences. Études épidémiologiques, cellulaires et animales se succèdent mais aucune conclusion définitive n'a pu être établie. Même si certains effets biologiques sur des cellules en culture ont été observés, le lien avec un possible développement de cancer chez l'homme reste encore loin d'être établi. Les études animales montrent pour la plupart des résultats négatifs. Quant aux études épidémiologiques, elles manquent d'un recul suffisant pour pouvoir évaluer l'effet des technologies utilisées aujourd'hui. Face à l'inquiétude des populations, opérateurs de téléphonie mobile, constructeurs et instances gouvernementales financent nombre de projets scientifiques afin de permettre une réglementation adaptée et efficace. [Evaluation of the impact of new technologies on the human body is essential in order to impose regulations to limit health risks. The appearance and evolution of cellular phones have been one of the fastest in the history of innovation. Research reported worldwide has tried to evaluate any potential link between adverse health effects and the mobile phone and its broadcasting stations. This article gives an overview of current research knowledge on the impact of radiofrequency waves on health. Epidemiologic, cellular and animal studies have been carried out, but none of them have reached definitive conclusions. Although some biological effects on cell culture have been observed, their link with human cancer development is far from established. Most of the animal studies show negative results. Epidemiologic studies lack a sufficient perspective to be able to evaluate the effect of evolving technologies used today. High levels of concern by the public have urged mobile phone operators, manufacturers and governmental authorities to finance a number of scientific projects aimed at defining adapted and effective regulations.] Cop. John Libbey Eurotext.
  • Nonlinear optical spectroscopy of chiral molecules
    • Fischer Peer
    • Hache François
    Chirality, Wiley, 2005, 17 (8), pp.421. We review nonlinear optical processes that are specific to chiral molecules in solution and on surfaces. In contrast to conventional natural optical activity phenomena, which depend linearly on the electric field strength of the optical field, we discuss how optical processes that are nonlinear (quadratic, cubic, and quartic) functions of the electromagnetic field strength may probe optically active centers and chiral vibrations. We show that nonlinear techniques open entirely new ways of exploring chirality in chemical and biological systems: The cubic processes give rise to nonlinear circular dichroism and nonlinear optical rotation and make it possible to observe dynamic chiral processes at ultrafast time scales. The quadratic second-harmonic and sum-frequency-generation phenomena and the quartic processes may arise entirely in the electric-dipole approximation and do not require the use of circularly polarized light to detect chirality. They provide surface selectivity and their observables can be relatively much larger than in linear optical activity. These processes also give rise to the generation of light at a new color, and in liquids this frequency conversion only occurs if the solution is optically active. We survey recent chiral nonlinear optical experiments and give examples of their application to problems of biophysical interest. Cop. 2005 Wiley-Liss, Inc. (10.1002/chir.20179)
    DOI : 10.1002/chir.20179
  • Ultrafast polarization and coherent charge motions in bacteriorhodopsin observed by infrared emission interferometry
    • Colonna Anne
    • Lambry Jean-Christophe
    • Groma Geza
    • Vos Marten H.
    • Martin Jean-Louis
    • Joffre Manuel
    , 2005.
  • Ligand transfer dynamics in cytochrome c oxidase using infrared femtosecond spectroscopy
    • Treuffet Johanne
    • Ogilvie Jennifer P.
    • Polack Thomas
    • Pilet Eric
    • Lambry Jean-Christophe
    • Joffre Manuel
    • Vos Marten H.
    • Martin Jean-Louis
    • Alexandrou Antigoni
    , 2005.
  • Toxines et douleurs
    • Bon Cassian
    • Goudey-Perriere F.
    • Goyffon Max
    • Sauviat Martin-Pierre
    , 2005, pp.238. Malgré les progrès récents réalisés au cours de la dernière décennie, les mécanismes cellulaires et les structures moléculaires impliqués dans la perception, la transmission et l'intégration des sensations douloureuses restent encore largement inconnus. D'un autre point de vue, des observations récentes ont démontré que des toxines issues d'organismes variés, et pour certaines connues depuis longtemps pour agir sur la propagation ou la transmission des influx nerveux, possèdent des propriétés antalgiques. L'identification de ces toxines actives contre la douleur est loin d'être achevée et leur inventaire se poursuit avec beaucoup de succès. Par ailleurs, les cibles moléculaires et les mécanismes d'action de ces toxines analgésiantes commencent à être identifiés. Elles apparaissent ainsi comme des outils précieux pour analyser et caractériser les structures moléculaires impliquées dans la perception et la transmission de la douleur. Certaines de ces toxines analgésiantes sont même à l'origine de médicaments puissants et originaux utilisables pour atténuer voire supprimer la sensibilité à la douleur. Sans prétendre pour autant couvrir la totalité de ce vaste sujet, le cinquième volume des Rencontres en Toxinologie illustre, au moyen de quelques exemples précis, l'ensemble de cette problématique et témoigne de la vitalité de la recherche, notamment française, dans ce domaine
  • Spectroscopic analysis of keratin endogenous signal for skin multiphoton microscopy
    • Pena Ana-Maria
    • Strupler Mathias
    • Boulesteix Thierry
    • Schanne-Klein Marie-Claire
    Optics Express, Optical Society of America - OSA Publishing, 2005, 13 (16), pp.6268-6274. We recorded one-photon excited fluorescence (1PEF) and two-photon excited fluorescence (2PEF) spectra of purified keratin from human epidermis, and determined the action cross section of this endogenous chromophore. We used this spectroscopic analysis to analyse multiphoton images of skin biopsies and assign the intrinsic fluorescence signals in the epidermis. We observed a good agreement between in situ and in vitro 2PEF spectra of keratin. This study provides a comprehensive characterization of the 2PEF signal of the keratins from the epidermis, and will be of practical interest for multiphoton imaging of the skin. © 2005 Optical Society of America (10.1364/OPEX.13.006268)
    DOI : 10.1364/OPEX.13.006268
  • Third harmonic generation microscopy for the velocimetric analysis of Drosophila embryo development
    • Débarre Delphine
    • Supatto Willy
    • Farge Emmanuel
    • Moulia Bruno B.
    • Schanne-Klein Marie-Claire
    • Beaurepaire Emmanuel
    , 2005.
  • Multiphoton microscopy of unstained living cardiac and vascular tissue
    • Pena Ana-Maria
    • Boulesteix Thierry
    • Pagès Nicole
    • Senni Karim
    • Godeau Gaston
    • Sauviat Martin-Pierre
    • Beaurepaire Emmanuel
    • Schanne-Klein Marie-Claire
    , 2005.
  • Nonlinear spectroscopy of chiral molecules
    • Fischer P.
    • Hache François
    Chirality, Wiley, 2005, 17, pp.421-437.
  • Etudes fonctionnelles du senseur à oxygène bactérien Dos
    • Bouzhir-Sima Latifa
    • Jasaitis Audrius
    • Vos Marten H.
    • Liebl Ursula
    , 2005.
  • Calculation of the circular dichroism spectra of carbon monoxy- and deoxy myoglobin: interpretation of a time-resolved circular dichroism experiment.
    • Dartigalongue Thibault
    • Hache François
    The Journal of Chemical Physics, American Institute of Physics, 2005, 123 (18), pp.184901. A calculation of the circular dichroism (CD) spectra of carbon monoxy- and deoxy myoglobin is carried out in relation with a time-resolved CD experiment. The calculation is based on the polarizability theory and the parameters are adjusted to fit the experimental absorption and CD spectra. By performing the calculation for intermediate configurations of the protein, we are able to propose an explanation of the CD structure observed on a sub-100 ps time scale. The role of the proximal histidine is, in particular, clearly demonstrated in the first step of the myoglobin relaxation from its liganded to it deliganded form. (10.1063/1.2041467)
    DOI : 10.1063/1.2041467
  • Functionalized luminescent oxide nanoparticles for single Na+ channel imaging
    • Casanova Didier
    • Giaume D.
    • Beaurepaire Emmanuel
    • Sauviat Martin-Pierre
    • Auksorius Egidijus
    • Buissette V.
    • Lahlil K.
    • Martin Jean-Louis
    • Gacoin Thierry
    • Boilot Jean-Pierre
    • Alexandrou Antigoni
    , 2005.
  • Geminate carbon monoxide rebinding to a c-type haem
    • Silkstone G.
    • Jasaitis Audrius
    • Vos Marten H.
    • Wilson M.
    Dalton Transactions, Royal Society of Chemistry, 2005, 21 (7), pp.3489. A chemically modified form of cytochrome c (cyt. c), termed carboxymethyl cytochrome c (cm cyt. c), possesses a vacant sixth coordination site to the haem iron that is available to bind external ligands. We present data on the rapid flash photolysis of CO from the ferrous haem iron of cm cyt. c and describe the kinetics and spectral transitions that accompany the recombination. This was achieved using 30-femtosecond laser pulses and a white light continuum to monitor spectral transitions. Whereas the photo-dissociation quantum yield is close to 1, the yield of CO escape from the protein (the apparent quantum yield, φ) relative to myoglobin (φ = 1) is small due to rapid geminate recombination of CO. On ligand photo-dissociation the haem undergoes a spin-state transition from low-spin ferrous CO bound to penta-coordinate high-spin. Subsequently the system reverts to the CO bound form. The data were fitted with a minimum number of exponentials using global analysis. Recombination of CO with the haem iron of cm cyt. c is multiphasic (τ = 16 ps, 120 ps and 1 ns), involving three spectrally distinct components. The fraction of haem (0.11) not recombining with CO within 4 ns is similar to the value of φ (0.12) measured on the same preparation by the "pulse method" (M. Brunori, G. Giacometti, E. Antonini and J. Wyman, Proc. Natl. Acad. Sci. USA, 1973, 70, 3141-3144, ). This implies that no further geminate recombination occurs at t > 4 ns. This unusually efficient CO-haem geminate recombination indicates the sterically hindered ("caged") nature of the distal haem pocket in cm cyt. c from which it is difficult for CO to escape. The large geminate phase may be contrasted with the behaviour of myoglobin in which geminate recombination is small. This is in general agreement with the well-documented extensive structural dynamics in myoglobin that allow ligand passage, and a higher structural rigidity in cyt. c imposed by the restraints of minimising reorganisation energy for electron transfer (M. Brunori, D. Bourgeois and D. Vallone, J. Struct. Biol., 2004, 147, 223-234, ). The high pH ferrous form of cm cyt. c is a low-spin species having a lysine bound to the central iron atom of the haem (M. Brunori, M. Wilson and E. Antonini, J. Biol. Chem., 1972, 247, 6076-6081; G. Silkstone, G. Stanway, P. Brzezinski and M. Wilson, Biophys. Chem., 2002, 98, 65-77, ). This high pH (pH 8) form of deoxy cm cyt. c undergoes photo-dissociation of lysine (although the proximal histidine is possible) after photo-excitation. Recombination occurs with a time constant (τ) of 7 ps. This is similar to that observed for the geminate rebinding of the Met80 residue in native ferrous cyt. c (τ 6 ps) following its photo-dissociation (S. Cianetti, M. Negrerie, M. Vos, J.-L. Martin and S. Kruglik, J. Am. Chem. Soc., 2004, 126, 13932-13933; W. Wang, X. Ye, A. Demidov, F. Rosca, T. Sjodin, W. Cao, M. Sheeran and P. Champion, J. Phys. Chem., 2000, 104, 10789-10801, ). (10.1039/B508183C)
    DOI : 10.1039/B508183C
  • Retinal isomerization dynamics in dry bacteriorhodopsin films
    • Colonna Anne
    • Groma Geza I.
    • Vos Marten H.
    Chemical Physics Letters, Elsevier, 2005, 415 (1-3), pp.69-73. The primary photoprocesses in neutral and acid forms of oriented dried bacteriorhodopsin films were investigated by femtosecond absorption spectroscopy. The excitation energy dependence of the signals was used to distinguish photochemistry from processes involving photophysics of photocycle intermediates. Both the kinetics and the quantum yield of all-trans excited state decay by retinal photoisomerization and subsequent J → K transition were found to be very similar as in hydrated environments. Therefore, unlike slower photocycle phases, communication of the retinal with the environment does not play a role in retinal isomerization. Our results are important for understanding recent nonlinear optical applications of such films. (10.1016/j.cplett.2005.08.132)
    DOI : 10.1016/j.cplett.2005.08.132
  • Dynamique ultrarapide au sein des protéines vue par spectroscopie optique: interactions hémoprotéines-ligands
    • Vos Marten H.
    , 2005.
  • 11th Congress of the European Society for Photobiology
    • Dartigalongue Thibault
    • Hache François
    , 2005.
  • Electrical activity alterations induced by chronic absorption of lindane (gamma-hexachlorocyclohexane) trace concentrations in adult rat heart
    • Sauviat Martin-Pierre
    • Bouvet Suzanne
    • Godeau Gaston
    • Pages Nicole
    Canadian Journal of Physiology and Pharmacology, NRC Research Press, 2005, 83 (3), pp.243. The heart of adult rat offspring, born to mothers treated with trace concentrations of lindane (0.5 to 2 ppb) through a beverage and to mothers chronically treated with lindane (CL-T) with the same trace concentration, also through a beverage, during lactation and growth has a round shape and accumulates lindane. The left ventricle (LV) presents a hypertrophied area, atrophied papillary muscles, and unorganized collagen bundles and layers. These observations led us to study the electrical activity of their left ventricle papillary muscles (LVPM) by recording action potential using intracellular microelectrodes. CL-T shortened LVPM action potential duration (APD): 1 ppb shortened the plateau; 2 ppb shortened the plateau and the slow repolarizing phase. In CL-T (2 ppb) and untreated groups, low temperature (22 degrees C) decreased the resting potential and prolonged APD. TEA (tetraethylammonium; 1-2 mmol/L) partially lengthened CL-T (2 ppb lindane) APD. Quinidine (0.2 mmol/L) and E-4031 (10 nmol/L) prolonged CL-T APD, suggesting that the rapid delayed outward K+ current (I-Kr) was increased. Our results indicate the silent effects of chronic exposure to trace concentrations of lindane on the morphological and electrical activity of heart muscle. They demonstrate that chronic lindane treatment of female rats alters the tissue integrity and electrical activity in the LV of their offspring. (10.1139/Y04-132)
    DOI : 10.1139/Y04-132
  • Chiroptical effects in the second harmonic signal of collagens I and IV
    • Pena Ana-Maria
    • Boulesteix Thierry
    • Dartigalongue Thibault
    • Schanne-Klein Marie-Claire
    Journal of the American Chemical Society, American Chemical Society, 2005, 127 (29), pp.10314. We performed polarization-resolved surface second harmonic generation (SHG) experiments on thin films of collagen I and IV molecules, as well as conventional CD measurements. We found that collagen IV presents little CD and no SHG optical activity, whereas collagen I exhibits large chiroptical effects involving both one-electron and excitonic coupling mechanisms. We estimated that these chiral components enhance the SHG signal from fibrillar collagen in biological tissues by typically a factor of 2. By comparing the distinct behaviors of collagens I and IV in SHG microscopy and in surface SHG experiments, we concluded that SHG microscopy is a sensitive probe of the micrometer-scale structural organization of collagen in biological tissues. Cop. 2005 American Chemical Society. (10.1021/ja0520969)
    DOI : 10.1021/ja0520969