Laboratoire d'optique et biosciences
Laboratoire d'optique et biosciences
Laboratoire d'optique et biosciences

Articles

  • Optique non-linéaire et chiralité [Nonlinear optics and chirality]
    • Schanne-Klein Marie-Claire
    • Weisman H.
    • Gotzendorfer A.
    • Hache François
    Journal de Physique IV Proceedings, EDP Sciences , 2002, 12 (5), pp.77 . Nous étudions les propriétés physiques des molécules chirales en étendant les techniques d'optique non-linéaire aux effets chiroptiques pour ainsi mesurer une "activité optique non-linéaire". La génération de second harmonique en surface est particulièrement sensible à la chiralité moléculaire, avec des rotations de polarisation du second harmonique et des différences circulaires et linéaires très importantes. Pour comprendre l'origine physique de ces effets chiroptiques, nous généralisons les principaux modèles microscopiques de chiralité aux effets non-linéaires d'ordre deux et montrons qu'une chiralité à un électron n'a pas la même signature à l'ordre deux qu'une chiralité par couplage excitonique. Des expériences avec des molécules test pour ces deux types de chiralité montrent un bon accord avec ces modélisations théoriques. (10.1051/jp420020099)
    DOI : 10.1051/jp420020099
  • Interactions between heme d and heme b(595) in quinol oxidase bd from Escherichia coli: A photoselection study using femtosecond spectroscopy
    • Borisov Vitaly
    • Liebl Ursula
    • Rappaport F.
    • Martin Jean-Louis
    • Zhang Jie
    • Gennis Robert
    • Konstantinov Alexander
    • Vos Marten H.
    Biochemistry, American Chemical Society , 2002, 41 (5), pp.1654 . Femtosecond spectroscopy was performed on CO-liganded (fully reduced and mixed-valence states) and O-2-liganded quinol oxidase bd from Escherichia coli. Substantial polarization effects, unprecedented for optical studies of heme proteins, were observed in the CO photodissociation spectra, implying interactions between heme d (the chlorin ligand binding site) and the close-lying heme b(595) on the picosecond time scale; this general result is fully consistent with previous work [Vos, M. H., Borisov, V. B., Liebl, U., Martin, J.-L., and Konstantinov, A. A. (2000) Proc. Natl. Acad. Sci. U.S.A. 97, 15541559]. Analysis of the data obtained under isotropic and anisotropic polarization conditions and additional flash photolysis nanosecond experiments on a mutant of cytochrome bd mostly lacking heme b595 allow to attribute the features in the well-known but unusual CO dissociation spectrum of cytochrome bd to individual heme d and heme b595 transitions. This renders it possible to compare the spectra of CO dissociation from reduced and mixed-valence cytochrome bd under static conditions and on a picosecond time scale in much more detail than previously possible. CO binding/dissociation from heme d is shown to perturb ferrous heme b595, causing induction/loss of an absorption band centered at similar to435 nm. In addition, the CO photodissociation-induced absorption changes at 50 ps reveal a bathochromic shift of ferrous heme b595 relative to the static spectrum. No evidence for transient binding of CO to heme b595 after dissociation from heme d is found in the picosecond time range. The yield of CO photodissociation from heme d on a time scale of INFERIEUR 15 ps is found to be diminished more than 3-fold when heme b(595) is oxidized rather than reduced. In contrast to other known heme proteins, molecular oxygen cannot be photodissociated from the mixed-valence cytochrome bd at all, indicating a unique structural and electronic configuration of the diheme active site in the enzyme. (10.1021/bi0158019)
    DOI : 10.1021/bi0158019
  • Picosecond dynamics and mechanisms of photoexcited Cu(II)-5,10,15,20-meso-tetrakis(4-N-methylpyridyl)porphyrin quenching by oxygen-containing Lewis-base solvents
    • Chirvony V.
    • Martin Jean-Louis
    • Négrerie Michel
    • Turpin P.-Y.
    Journal of Physical Chemistry A, American Chemical Society , 2002, 106 (24), pp.5760 . Deactivation of the lowest excited triplet (pi,pi*) state, (3)(pi,pi*), of the cationic water-soluble Cu(II)-5,10,15,20-meso-tetrakis(4-N-methylpyridyl)porphyrin (CuTMpyP4) was studied by femtosecond transient absorption spectroscopy in three oxygen-containing solvents (Lewis bases) of various polarity, water, methanol, and dimethyl sulfoxide (DMSO). In all of these solvents, the (3)(pi,pi*) state depopulation follows biexponential kinetics. A majority of the (3)(pi,pi*) state population (similar to80%) deactivates very quickly with a time constant of about 1-2 ps to give rise to formation of an exciplex (CuTMpyP4)*-L between the porphyrin in its excited (d,d) state and a solvent molecule, L, the latter playing the role of porphyrin axial ligand. The exciplex lifetime is found to depend on the solvent dielectric constant E and increases from 7 ps in water (epsilon = 78.3) to 27 ps in methanol (epsilon = 32.7), through 23 ps in DMSO (epsilon = 46.5). A minor part of the initial (3)(pi,pi*) state population (similar to20%) deactivates to the ground state, without any detectable intermediate, with time constants of 25, 8, and 11 ps in water, DMSO, and methanol, respectively. These rather fast pathways (picosecond time scale) of excitation deactivation to the ground state are interpreted in terms of quenching influence of some low-lying intramolecular charge-transfer states that belong to four- and five-coordinate CuTMpyP4. A partitioning mechanism of (3)(pi,pi*) state CuTMpyP4 molecules into two populations decaying by different paths, that is, through exciplex formation and "directly" to the ground state, is proposed. (10.1021/jp0134998)
    DOI : 10.1021/jp0134998
  • Dynamics of nitric oxide in the active site of reduced cytochrome c oxidase aa3
    • Vos Marten H.
    • Lipowski Gérard
    • Lambry Jean-Christophe
    • Martin Jean-Louis
    • Liebl Ursula
    Biochemistry, American Chemical Society , 2001, 40 (26), pp.7806 . Nitric oxide (NO) is involved in the regulation of respiration by acting as a competitive ligand for molecular oxygen at the binuclear active site of cytochrome c oxidase. The dynamics of NO in and near this site are not well understood. We performed flash photolysis studies of NO from heme a3 in cytochrome c oxidase from Paracoccus denitrificans, using femtosecond transient absorption spectroscopy. The formation of the product state--the unliganded heme a3 ground state--occurs in a similar stepwise manner (period approximately 700 fs) as previously observed for carbon monoxide photolysis from this enzyme and interpreted in terms of ballistic ligand motions in the active site on the subpicosecond time scale [Liebl, U., Lipowski, G., Négrerie, M., Lambry, J.-C., Martin, J.-L., and Vos, M. H. (1999) Nature 401, 181-184]. A fraction (approximately 35% at very low NO concentrations) of the dissociated NO recombines with heme a3 in 200-300 ps. The presence of this recombination phase indicates that a transient bond to the second ligand-binding site, a copper atom (CuB), has a short lifetime or may not be formed. Increasing the NO concentration increases the recombination yield on the hundreds of picoseconds time scale. This effect, unprecedented for heme proteins, implies that, apart from the one NO molecule bound to heme a3, a second NO molecule can be accommodated in the active site, even at relatively low (submicromolar) concentrations. Models for NO accommodation in the active site, based on molecular dynamics energy minimizations are presented. Pathways for NO motion and their relevance for the regulation of respiration are discussed. (10.1021/bi010060x)
    DOI : 10.1021/bi010060x
  • Experimental observation of nonlinear circular dichroism in a pump-probe experiment
    • Mesnil H.
    • Schanne-Klein Marie-Claire
    • Hache François
    • Alexandre M.
    • Lemercier G.
    • Andraud Chantal
    Chemical Physics Letters, Elsevier , 2001, 338 (4-6), pp.269-276 . We present experimental evidence of nonlinear optical activity in a time-resolved pump-probe experiment carried out in a liquid of chiral molecules. By modulating the polarization of the probe or of the pump, we measure a variation of the circular dichroism (CD) induced by the pump. Application of these techniques to time-resolved spectroscopy of excited molecules is discussed. Cop. 2001 Elsevier Science B.V. (10.1016/S0009-2614(01)00239-1)
    DOI : 10.1016/S0009-2614(01)00239-1
  • Magnetic chiroptical effects in surface second harmonic reflection
    • Schanne-Klein Marie-Claire
    • Hache François
    • Brotin Thierry
    • Andraud Chantal
    • Collet A.
    Chemical Physics Letters, Elsevier , 2001, 338 (2-3), pp.159-166 . We perform surface second harmonic reflection (SHR) to study a chiral stilbene. It exhibits a strong circular intensity difference in the second harmonic signal, but no linear intensity difference and no rotation of polarization. This SHR optical activity is characteristic of strong magnetic effects and proves that the molecule under study exhibits a one-electron chirality. (C) 2001 Elsevier Science B.V. All rights reserved. (10.1016/S0009-2614(01)00275-5)
    DOI : 10.1016/S0009-2614(01)00275-5
  • Alterations of transmembrane currents in frog atrial heart muscle induced by photoexcited gymnochrome a purified from the crinoid, Gymnochrinus richeri
    • Sauviat Martin-Pierre
    • Benoit Anne-Gaëlle
    • Debitus Cécile
    • Pouny I.
    • Laurent Dominique
    Photochemistry and Photobiology, Blackwell Wiley [1962-....] , 2001, 74 (2), pp.115-119 . The effects of gymnochrome A were tested on the electrical activity of the frog atrial heart muscle. Gymnochrome A (1-5 µM) did not alter the resting potential. Gymnochrome A (5 µM) slowed the initial depolarizing phase of the spontaneously beating action potential. Under voltage-clamp conditions gymnochrome A (5 µM) did not affect the electrical constant of the membrane and the kinetic parameters of the peak Na+ current (INa) recorded in the Ringer solution containing tetraethylammonium (2 mM) and Cd2+ (1 mM) but shifted the membrane potential at which the current both activated and reached its maximal value toward more negative membrane potentials. It did not alter the reversal potential for INa, indicating that the selectivity of the Na+ channels had not changed. These observations suggest that gymnochrome A binds to the membrane and shifts the activation of INa on the voltage axis by modifying the free negative fixed charges present at the membrane surface rather than by occupying a specific site on the Na+ channel. Photoexcited gymnochrome A transiently triggered an early outward current which lengthened the time-to-peak of INa and decreased its amplitude. In addition, photoexcited gymnochrome A blocked the background K+ current. This is, to our knowledge, the first time that such effects are reported on the cardiac muscle. These observations suggest that the photoexcitation of gymnochrome produces physico-chemical effects which lead to intracellular changes. Further experiments are required to determine their nature. (10.1562/0031-8655(2001)0740115AOTCIF2.0.CO2)
    DOI : 10.1562/0031-8655(2001)0740115AOTCIF2.0.CO2
  • Coherent broadband pulse shaping in the mid infrared
    • Belabas Nadia
    • Likforman Jean-Pierre
    • Canioni Lionel
    • Bousquet Bruno
    • Joffre Manuel
    Optics Letters, Optical Society of America - OSA Publishing , 2001, 26 (10), pp.743 . We demonstrate broadband infrared pulse shaping by difference-frequency mixing of two visible phase-locked linearly chirped pulses in GaAs. Control of the temporal profile of the emitted field is achieved through this direct tailoring of the exciting visible intensity. The results are in agreement with a simulation with no adjustable parameter. (C) 2001 Optical Society of America. (10.1364/OL.26.000743)
    DOI : 10.1364/OL.26.000743
  • Application of classical models of chirality to surface second harmonic generation
    • Hache François
    • Mesnil H.
    • Schanne-Klein Marie-Claire
    The Journal of Chemical Physics, American Institute of Physics , 2001, 115 (14), pp.6707 . Two classical models (Kuhn and Kauzmann) are extended to calculate the second-order nonlinear response of an isotropic layer of chiral molecules. Calculation of the various nonlinear susceptibilities (electric dipolar, magnetic dipolar, and electric quadrupolar) is performed and applied to the derivation of the second harmonic field radiated by the molecules. It is shown that the two models give strikingly different results about the origin of the chiral response in such experiments. Previously published results are analyzed in view of this calculation which allows to understand the different interpretations proposed. This calculation emphasizes the interest of surface second harmonic generation to access information about the microscopic origin of optical activity in chiral molecules. © 2001 American Institute of Physics. (10.1063/1.1404983)
    DOI : 10.1063/1.1404983
  • Control of Nitric Oxide Dynamics by Guanylate Cyclase in Its Activated State
    • Négrerie Michel
    • Bouzhir Latifa
    • Martin Jean-Louis
    • Liebl Ursula
    Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology , 2001, 276 (50), pp.46815 . Soluble guanylate cyclase (sGC) is the target of nitric oxide (NO) released by nitric-oxide synthase in endothelial cells, inducing an increase of cGMP synthesis in response. This heterodimeric protein possesses a regulatory subunit carrying a heme where NO binding occurs, while the second subunit harbors the catalytic site. The binding of NO and the subsequent breaking of the bond between the proximal histidine and the heme-Fe2+ are assumed to induce conformational changes, which are the origin of the catalytic activation. At the molecular level, the activation and deactivation mechanisms are unknown, as is the dynamics of NO once in the heme pocket. Using ultrafast time-resolved absorption spectroscopy, we measured the kinetics of NO rebinding to sGC after photodissociation. The main spectral transient in the Soret band does not match the equilibrium difference spectrum of NO-liganded minus unliganded sGC, and the geminate rebinding was found to be monoexponential and ultrafast (t = 7.5 ps), with a relative amplitude close to unity (0.97). These characteristics, so far not observed in other hemoproteins, indicate that NO encounters a high energy barrier for escaping from the heme pocket once the His-Fe2+ bond has been cleaved; this bond does not reform before NO recombination. The deactivation of isolated sGC cannot occur by only simple diffusion of NO from the heme; therefore, several allosteric states may be inferred, including a desensitized one, to induce NO release. Thus, besides the structural change leading to activation, a consequence of the decoupling of the proximal histidine may also be to induce a change of the heme pocket distal geometry, which raises the energy barrier for NO escape, optimizing the efficiency of NO trapping. The nonsingle exponential character of the NO picosecond rebinding coexists only with the presence of the protein structure surrounding the heme, and the single exponential rate observed in sGC is very likely to be due to a closed conformation of the heme pocket. Our results emphasize the physiological importance of NO geminate recombination in hemoproteins like nitric-oxide synthase and sGC and show that the protein structure controls NO dynamics in a manner adapted to their function. This control of ligand dynamics provides a regulation at molecular level in the function of these enzymes. (10.1074/jbc.M102224200)
    DOI : 10.1074/jbc.M102224200
  • Stimulated scattering and its dynamics in semiconductor microcavities at 80 K under nonresonant excitation conditions
    • Alexandrou Antigoni
    • Bianchi G.
    • Peronne Emmanuel
    • Hallé B.
    • Boeuf F.
    • André R.
    • Romestain R.
    • Dang Le Si
    Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society , 2001, 64 (23), pp.2333181 . We have observed stimulated scattering in a II-VI microcavity at 80 K under nonresonant excitation conditions. This stimulated scattering manifests itself through probe amplification in a pump-probe reflectivity experiment and through a highly nonlinear emission at an energy corresponding to a k? ? 0 state on the lower polariton branch. We were able to follow the onset and decline of stimulated scattering by measuring the temporal evolution of the probe amplification. (10.1103/PhysRevB.64.233318)
    DOI : 10.1103/PhysRevB.64.233318
  • Characterization of the spectral phase of ultrashort light pulses
    • Dorrer C.
    • Joffre Manuel
    Comptes Rendus de l'Academie des Sciences. Série IV, Physique, Astronomie, Elsevier , 2001, 2 (10), pp.1415-1426 . The complete characterization of a short light pulse requires the measurement of the value of the electric field as a function of time, or conversely, as a function of the optical frequency. Many different techniques have been demonstrated for this purpose. They fall in two main categories, whether a known reference pulse whose spectrum encompasses that of the unknown pulse is available or not. In the first case, linear techniques such as time-domain or frequency-domain interferometry can be directly used, with the advantage of a high sensitivity. In the latter case, non-stationary filters can be implemented using optical non-linearities, in techniques such as Frequency Resolved Optical Gating (FROG) or Spectral Phase Interferometry for Direct Electric-field Reconstruction (SPIDER). Cop. 2001 Académie des sciences/Éditions scientifiques et médicales Elsevier SAS. (10.1016/S1296-2147(01)01279-3)
    DOI : 10.1016/S1296-2147(01)01279-3
  • NFkappaB decoy oligodeoxynucleotides reduce monocyte infiltration in renal allografts.
    • Vos M
    • Govers R
    • Gröne H J
    • Kleij L
    • Schurink M
    • de Weger R
    • Goldschmeding R
    • Rabelink T J
    FASEB Journal, Federation of American Society of Experimental Biology , 2000, pp.815-22 . Monocyte influx secondary to ischemia-reperfusion conditions the renal allograft to rejection by presentation of antigens and production of cytokines. Monocyte influx depends on NFkappaB-dependent transcription of genes encoding adhesion molecules and chemokines. Here we demonstrate that cationic liposomes containing phosphorothioated oligodeoxynucleotides (ODN) with the kappaB binding site serving as competitive binding decoy, can prevent TNF-alpha-induced NFkappaB activity in endothelial cells in vitro. In an allogenic rat kidney transplantation model (BN to LEW), we show that perfusing the renal allograft with this decoy prior to transplantation abolishes nuclear NFkappaB activity in vivo and inhibits VCAM-1 expression in the donor endothelium (P<0.05). At 24 h postreperfusion, periarterial infiltration of monocytes/macrophages was significantly reduced in decoy ODN-treated allografts compared to control allografts (3.7+/-0.7 vs. 9.2+/-1.2 macrophages/vessel; P<0.01). At 72 h, there was a reduction of tubulointerstitial macrophage infiltration in decoy ODN-treated kidneys compared to controls (75.6+/-13.9 vs. 120.0+/-11.2 macrophages/tubulointerstitial area; P<0.05). In conclusion, perfusion of the renal allograft with NFkappaB decoy ODN prior to transplantation decreases the initial inflammatory response in a stringent, nonimmunosuppressed allogenic transplantation model. Therefore, the NFkappaB decoy approach may be useful to explore the role of endothelium and macrophages in graft rejection and may be developed into a graft-specific immunosuppressive strategy allowing reduction of systemic immunosuppression on organ transplantation.
  • Insensitivity to anti–Müllerian hormone due to a mutation in the human anti–Müllerian hormone receptor
    • Imbeaud Sandrine
    • Faure Emmanuelle
    • Lamarre Isabelle
    • Mattei Marie-Geneviève
    • Di Clemente Nathalie
    • Tizard Richard
    • Carré-Eusèbe Danièle
    • Carré-Eusèbe C
    • Belville Corinne
    • Tragethon Lars
    • Tonkin Christopher
    • Nelson Janice
    • Mcauliffe A
    • Bidart Jean-Michel
    • Lababidi Abdul
    • Josso Nathalie
    • Cate Richard
    • Picard Jean-Yves
    Nature Genetics, Nature Publishing Group , 1995, 11 (4), pp.382 - 388 . Anti-Müllerian hormone (AMH) and its receptor are involved in the regression of Müllerian ducts in male fetuses. We have now cloned and mapped the human AMH receptor gene and provide genetic proof that it is required for AMH signalling, by identifying a mutation in the AMH receptor in a patient with persistent Müllerian duct syndrome. The mutation destroys the invariant dinucleotide at the 5' end of the second intron, generating two abnormal mRNAs, one missing the second exon, required for ligand binding, and the other incorporating the first 12 bases of the second intron. The similar phenotypes observed in AMH-deficient and AMH receptor-deficient individuals indicate that the AMH signalling machinery is remarkably simple, consisting of one ligand and one type II receptor. (10.1038/ng1295-382)
    DOI : 10.1038/ng1295-382