Professeur des Universités, Sorbonne Université
Responsable du pôle de Chimie Physique et Biologique de la Matière Vivante
PASTEUR, Département de chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS
24 rue Lhomond, 75005 Paris, France
Email: Ludovic.Jullien@ens.psl.eu or Ludovic.Jullien@sorbonne-universite.fr
Phone: +33 144323333
Office: E142c
Home page: https://ludovicjullien.org/
Publications
1997 |
Dynamic behavior of a perfunctionalized β-cyclodextrin as probed by NMR and molecular modeling Article de journal L Catoire; V Michon; L Monville; A Hocquet; L Jullien; J Canceill; J -M Lehn; M Piotto; C H Du Penhoat Carbohydrate Research, 303 (4), p. 379–393, 1997. @article{Catoire:1997a, title = {Dynamic behavior of a perfunctionalized β-cyclodextrin as probed by NMR and molecular modeling}, author = {L Catoire and V Michon and L Monville and A Hocquet and L Jullien and J Canceill and J -M Lehn and M Piotto and C H Du Penhoat}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030730720&doi=10.1016%2fS0008-6215%2897%2900188-2&partnerID=40&md5=5a1d95947c311db10fcad166684adcfe}, doi = {10.1016/S0008-6215(97)00188-2}, year = {1997}, date = {1997-01-01}, journal = {Carbohydrate Research}, volume = {303}, number = {4}, pages = {379--393}, abstract = {Conformational analysis of a perfunctionalized β-cyclodextrin by NMR and molecular modeling has revealed that this compound exists as an equilibrium mixture of C1 and C7 conformers in slow exchange. From carbon chemical shifts, interglycosidic vicinal heteronuclear coupling constants and NOESY volumes, it has been demonstrated that the macrocyclic conformation is responsable for the asymmetry in the C1 form. Several dynamic processes such as rapid conformational averaging, localized chemical exchange and the C1/C7 equilibrium have been shown to occur on widely separated timescales. In parallel, a molecular modeling study has revealed that the accessible conformational space of β-CDs is not significantly reduced with respect to that of the related disaccharide, β-maltose. All of the dynamic phenomena appear to be related to the macrocylic puckering and two distinct modes of variation in puckering have emerged from MD trajectories: transitions are either auto-compensated without perceptible change in macrocycle puckering or irreversible leading to considerable variation in macrocycle puckering. Optimization of the NMR-defined theoretical structures leads to auto- complexation of an exocyclic substituent.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Conformational analysis of a perfunctionalized β-cyclodextrin by NMR and molecular modeling has revealed that this compound exists as an equilibrium mixture of C1 and C7 conformers in slow exchange. From carbon chemical shifts, interglycosidic vicinal heteronuclear coupling constants and NOESY volumes, it has been demonstrated that the macrocyclic conformation is responsable for the asymmetry in the C1 form. Several dynamic processes such as rapid conformational averaging, localized chemical exchange and the C1/C7 equilibrium have been shown to occur on widely separated timescales. In parallel, a molecular modeling study has revealed that the accessible conformational space of β-CDs is not significantly reduced with respect to that of the related disaccharide, β-maltose. All of the dynamic phenomena appear to be related to the macrocylic puckering and two distinct modes of variation in puckering have emerged from MD trajectories: transitions are either auto-compensated without perceptible change in macrocycle puckering or irreversible leading to considerable variation in macrocycle puckering. Optimization of the NMR-defined theoretical structures leads to auto- complexation of an exocyclic substituent. |
pH-dependent specific binding and combing of DNA Article de journal J -F Allemand; D Bensimon; L Jullien; A Bensimon; V Croquette Biophysical Journal, 73 (4), p. 2064–2070, 1997. @article{Allemand:1997, title = {pH-dependent specific binding and combing of DNA}, author = {J -F Allemand and D Bensimon and L Jullien and A Bensimon and V Croquette}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030881494&doi=10.1016%2fS0006-3495%2897%2978236-5&partnerID=40&md5=67fabb87ba140361b6bc5c28e2ea523a}, doi = {10.1016/S0006-3495(97)78236-5}, year = {1997}, date = {1997-01-01}, journal = {Biophysical Journal}, volume = {73}, number = {4}, pages = {2064--2070}, abstract = {Recent developments in the rapid sequencing, mapping, and analysis of DNA rely on the specific binding of DNA to specially treated surfaces. We show here that specific binding of DNA via its unmodified extremities can be achieved on a great variety of surfaces by a judicious choice of the pH. On hydrophobic surfaces the best binding efficiency is reached at a pH of textasciitilde5.5. At that pH textasciitilde40-kbp DNA is 10 times more likely to bind by an extremity than by a midsegment. A model is proposed to account for the differential adsorption of the molecule extremities and midsection as a function of pH. The pH-dependent specific binding can be used to align anchored DNA molecules by a receding meniscus, a process called molecular combing. The resulting properties of the combed molecules will be discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent developments in the rapid sequencing, mapping, and analysis of DNA rely on the specific binding of DNA to specially treated surfaces. We show here that specific binding of DNA via its unmodified extremities can be achieved on a great variety of surfaces by a judicious choice of the pH. On hydrophobic surfaces the best binding efficiency is reached at a pH of textasciitilde5.5. At that pH textasciitilde40-kbp DNA is 10 times more likely to bind by an extremity than by a midsegment. A model is proposed to account for the differential adsorption of the molecule extremities and midsection as a function of pH. The pH-dependent specific binding can be used to align anchored DNA molecules by a receding meniscus, a process called molecular combing. The resulting properties of the combed molecules will be discussed. |
1996 |
Interaction, lipid exchange, and effect of vesicle size in systems of oppositely charged vesicles Article de journal V Marchi-Artzner; L Jullien; L Belloni; D Raison; L Lacombe; J -M Lehn Journal of Physical Chemistry, 100 (32), p. 13844–13856, 1996. @article{Marchi-Artzner:1996, title = {Interaction, lipid exchange, and effect of vesicle size in systems of oppositely charged vesicles}, author = {V Marchi-Artzner and L Jullien and L Belloni and D Raison and L Lacombe and J -M Lehn}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0000460872&doi=10.1021%2fjp960327f&partnerID=40&md5=3795a27b061ada113fcc14c7fe016f95}, doi = {10.1021/jp960327f}, year = {1996}, date = {1996-01-01}, journal = {Journal of Physical Chemistry}, volume = {100}, number = {32}, pages = {13844--13856}, abstract = {The interactions between charged unilamellar vesicles of different size prepared from mixtures of egg lecithin (EPC1), cholesterol, and a charged component, either stearylamine or dicetyl phosphate, were investigated. Several techniques, i.e. fluorescence spectroscopy, 133Cs-NMR, light scattering measurements, and electron and optical microscopies in dilute aqueous solutions, provided evidence that vesicles bearing opposite charges interact via contact followed by lipid exchange; the progressive charge neutralization is shown by 133Cs-NMR to occur without fusion of vesicle internal pools. Vesicle size determines as diverse features as contact duration, extent of lipid exchange, and final distribution of surface charge among the vesicle mixture. © 1996 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The interactions between charged unilamellar vesicles of different size prepared from mixtures of egg lecithin (EPC1), cholesterol, and a charged component, either stearylamine or dicetyl phosphate, were investigated. Several techniques, i.e. fluorescence spectroscopy, 133Cs-NMR, light scattering measurements, and electron and optical microscopies in dilute aqueous solutions, provided evidence that vesicles bearing opposite charges interact via contact followed by lipid exchange; the progressive charge neutralization is shown by 133Cs-NMR to occur without fusion of vesicle internal pools. Vesicle size determines as diverse features as contact duration, extent of lipid exchange, and final distribution of surface charge among the vesicle mixture. © 1996 American Chemical Society. |
Multichromophoric cyclodextrins. 3. Investigation of dynamics of energy hopping by frequency-domain fluorometry Article de journal M N Berberan-Santos; J Canceill; E Gratton; L Jullien; J -M Lehn; P So; J Sutin; B Valeur Journal of Physical Chemistry, 100 (1), p. 15–20, 1996. @article{Berberan-Santos:1996, title = {Multichromophoric cyclodextrins. 3. Investigation of dynamics of energy hopping by frequency-domain fluorometry}, author = {M N Berberan-Santos and J Canceill and E Gratton and L Jullien and J -M Lehn and P So and J Sutin and B Valeur}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0003019274&doi=10.1021%2fjp951598d&partnerID=40&md5=99ebe5d1e0d18c77b7580fe2784de54a}, doi = {10.1021/jp951598d}, year = {1996}, date = {1996-01-01}, journal = {Journal of Physical Chemistry}, volume = {100}, number = {1}, pages = {15--20}, abstract = {A β-cyclodextrin labeled with seven naphthoyloxy chromophores was studied by steady-state and time-resolved fluorescence spectroscopy in order to get information on the dynamics of energy hopping between chromophores. The steady-state fluorescence anisotropy was recorded as a function of excitation wavelength in a mixture of methanol and ethanol at 110 K (rigid glass). The fluorescence anisotropy decay was obtained under the same conditions by the multifrequency phase-modulation technique upon excitation at 290 nm. The data were analyzed and interpreted on the basis of a theoretical model involving a unique rate constant for energy hopping between nearest neighbors. In particular, this model predicts a long-time leveling-off of the emission anisotropy at 1/7th of the fundamental anisotropy, which is confirmed by both steady-state and time-resolved data and thus indicates that there is no preferred mutual orientation between the chromophores. As regards the rate of energy hopping, an average value of 2 × 109 s-1 can be deduced from the comparison between the theoretical and experimental decays. This value is shown to be consistent with a dipole-dipole mechanism of energy transfer. © 1996 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A β-cyclodextrin labeled with seven naphthoyloxy chromophores was studied by steady-state and time-resolved fluorescence spectroscopy in order to get information on the dynamics of energy hopping between chromophores. The steady-state fluorescence anisotropy was recorded as a function of excitation wavelength in a mixture of methanol and ethanol at 110 K (rigid glass). The fluorescence anisotropy decay was obtained under the same conditions by the multifrequency phase-modulation technique upon excitation at 290 nm. The data were analyzed and interpreted on the basis of a theoretical model involving a unique rate constant for energy hopping between nearest neighbors. In particular, this model predicts a long-time leveling-off of the emission anisotropy at 1/7th of the fundamental anisotropy, which is confirmed by both steady-state and time-resolved data and thus indicates that there is no preferred mutual orientation between the chromophores. As regards the rate of energy hopping, an average value of 2 × 109 s-1 can be deduced from the comparison between the theoretical and experimental decays. This value is shown to be consistent with a dipole-dipole mechanism of energy transfer. © 1996 American Chemical Society. |
Multichromophoric cyclodextrins. 4. Light conversion by antenna effect Article de journal L Jullien; J Canceill; B Valeur; E Bardez; J -P Lefèvre; J -M Lehn; V Marchi-Artzner; R Pansu Journal of the American Chemical Society, 118 (23), p. 5432–5442, 1996. @article{Jullien:1996, title = {Multichromophoric cyclodextrins. 4. Light conversion by antenna effect}, author = {L Jullien and J Canceill and B Valeur and E Bardez and J -P Lef\`{e}vre and J -M Lehn and V Marchi-Artzner and R Pansu}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029953291&doi=10.1021%2fja954332t&partnerID=40&md5=86be6c0094475ed11e09091268977ba1}, doi = {10.1021/ja954332t}, year = {1996}, date = {1996-01-01}, journal = {Journal of the American Chemical Society}, volume = {118}, number = {23}, pages = {5432--5442}, abstract = {A water soluble β-cyclodextrin (CD-NA) bearing seven naphthoyl chromophores forms very stable 1:1 complexes with a merocyanine laser dye DCM-OH (4-(dicyanomethylene)-2-methyl-6-(p-(bis(hydroxyethyl)amino)-styryl)-4 H-pyran). The antenna effect, i.e. energy transfer from the naphthoyl antenna chromophores to the encased dye, is shown to occur with 100% efficiency. The stability of the complexes is very high (K(s) textasciitilde 105) owing to the contribution of the naphthoate residues. The structural features of the complexes have been examined in detail: circular dichroism experiments confirm the expected axial orientation of DCM-OH in the cavity of CD-NA, and fluorescence anisotropy measurements together with 13C-NMR longitudinal relaxation time measurements show that the complex formed between CD-NA and DCM-OH is tight. The mechanisms of homotransfer (i.e., between naphthoate chromophores) and heterotransfer (i.e., from naphthoate chromophores to DCM-OH included in the cavity) are discussed in light of existing theories. In both cases, the major contribution arises more likely from Coulombic interaction than from short-range interactions. Such multichromophoric cyclodextrins are good models for mimicry of the antenna function in photosynthesis and show great promise as photochemical microreactors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A water soluble β-cyclodextrin (CD-NA) bearing seven naphthoyl chromophores forms very stable 1:1 complexes with a merocyanine laser dye DCM-OH (4-(dicyanomethylene)-2-methyl-6-(p-(bis(hydroxyethyl)amino)-styryl)-4 H-pyran). The antenna effect, i.e. energy transfer from the naphthoyl antenna chromophores to the encased dye, is shown to occur with 100% efficiency. The stability of the complexes is very high (K(s) textasciitilde 105) owing to the contribution of the naphthoate residues. The structural features of the complexes have been examined in detail: circular dichroism experiments confirm the expected axial orientation of DCM-OH in the cavity of CD-NA, and fluorescence anisotropy measurements together with 13C-NMR longitudinal relaxation time measurements show that the complex formed between CD-NA and DCM-OH is tight. The mechanisms of homotransfer (i.e., between naphthoate chromophores) and heterotransfer (i.e., from naphthoate chromophores to DCM-OH included in the cavity) are discussed in light of existing theories. In both cases, the major contribution arises more likely from Coulombic interaction than from short-range interactions. Such multichromophoric cyclodextrins are good models for mimicry of the antenna function in photosynthesis and show great promise as photochemical microreactors. |
1995 |
Drug delivery: Piercing vesicles by their adsorption onto a porous medium Article de journal M -A Guedeau-Boudeville; L Jullien; J -M Di Meglio Proceedings of the National Academy of Sciences of the United States of America, 92 (21), p. 9590–9592, 1995. @article{Guedeau-Boudeville:1995, title = {Drug delivery: Piercing vesicles by their adsorption onto a porous medium}, author = {M -A Guedeau-Boudeville and L Jullien and J -M Di Meglio}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028820145&doi=10.1073%2fpnas.92.21.9590&partnerID=40&md5=251b948d8859e06857263108f1f5e581}, doi = {10.1073/pnas.92.21.9590}, year = {1995}, date = {1995-01-01}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {92}, number = {21}, pages = {9590--9592}, abstract = {Experimental evidence is presented that supports the possibility of building a 'molecular drill.' By the adsorption of a vesicle onto a porous substrate (specifically, a lycopode grain), it was possible to increase the permeability of the vesicle by locally stretching its membrane. Molecules contained within the vesicle, which could not cross the membrane, were delivered to the porous substrate upon adsorption. This general process could provide another method for drug delivery and targeting.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Experimental evidence is presented that supports the possibility of building a 'molecular drill.' By the adsorption of a vesicle onto a porous substrate (specifically, a lycopode grain), it was possible to increase the permeability of the vesicle by locally stretching its membrane. Molecules contained within the vesicle, which could not cross the membrane, were delivered to the porous substrate upon adsorption. This general process could provide another method for drug delivery and targeting. |
Formation of highly stable heterodimers in aqueous solution between β-cyclodextrin derivatives bearing multiple opposite charges Article de journal B Hamelin; L Jullien; F Guillo; J -M Lehn; A Jardy; L De Robertis; H Driguez Journal of Physical Chemistry, 99 (51), p. 17877–17885, 1995. @article{Hamelin:1995, title = {Formation of highly stable heterodimers in aqueous solution between β-cyclodextrin derivatives bearing multiple opposite charges}, author = {B Hamelin and L Jullien and F Guillo and J -M Lehn and A Jardy and L De Robertis and H Driguez}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0000285072&partnerID=40&md5=34255c509ef04ce2b93b4a7f1cf9684a}, year = {1995}, date = {1995-01-01}, journal = {Journal of Physical Chemistry}, volume = {99}, number = {51}, pages = {17877--17885}, abstract = {Two water-soluble perfunctionalized β-cyclodextrins bearing amino or carboxyl groups were used to examine the possibility of obtaining stable heterodimers in water. The acidobasic properties of both compounds may be accounted for on the basis of a theoretical interpretation of the potentiometric titration of polyelectrolytes. The association constants between positively and negatively charged β-cyclodextrins were determined by potentiometric titrations. The Gibbs energies of association between cyclodextrins are shown to depend on the product of elementary charges borne by each interacting species. The results obtained are significant for evaluation of electrostatic contributions to molecular recognition. © 1995 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two water-soluble perfunctionalized β-cyclodextrins bearing amino or carboxyl groups were used to examine the possibility of obtaining stable heterodimers in water. The acidobasic properties of both compounds may be accounted for on the basis of a theoretical interpretation of the potentiometric titration of polyelectrolytes. The association constants between positively and negatively charged β-cyclodextrins were determined by potentiometric titrations. The Gibbs energies of association between cyclodextrins are shown to depend on the product of elementary charges borne by each interacting species. The results obtained are significant for evaluation of electrostatic contributions to molecular recognition. © 1995 American Chemical Society. |