Relevant bibliographies by topics / Laurdan fluorescence

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  1. Journal articles
  2. Dissertations / Theses
  3. Book chapters
  4. Conference papers

Academic literature on the topic 'Laurdan fluorescence'

Author: Grafiati
Published: 4 June 2021
Last updated: 14 February 2022

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Journal articles on the topic "Laurdan fluorescence"

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Wasif Baig, Mirza, Marek Pederzoli, Piotr Jurkiewicz, Lukasz Cwiklik, and Jiri Pittner. "Orientation of Laurdan in Phospholipid Bilayers Influences Its Fluorescence: Quantum Mechanics and Classical Molecular Dynamics Study." Molecules 23, no. 7 (2018): 1707. http://dx.doi.org/10.3390/molecules23071707.

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Fluidity of lipid membranes is known to play an important role in the functioning of living organisms. The fluorescent probe Laurdan embedded in a lipid membrane is typically used to assess the fluidity state of lipid bilayers by utilizing the sensitivity of Laurdan emission to the properties of its lipid environment. In particular, Laurdan fluorescence is sensitive to gel vs liquid–crystalline phases of lipids, which is demonstrated in different emission of the dye in these two phases. Still, the exact mechanism of the environment effects on Laurdan emission is not understood. Herein, we utilize dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC) lipid bilayers, which at room temperature represent gel and liquid–crystalline phases, respectively. We simulate absorption and emission spectra of Laurdan in both DOPC and DPPC bilayers with quantum chemical and classical molecular dynamics methods. We demonstrate that Laurdan is incorporated in heterogeneous fashion in both DOPC and DPPC bilayers, and that its fluorescence depends on the details of this embedding.
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Mazeres, Serge, Etienne Joly, Andre Lopez, and Catherine Tardin. "Characterization of M-laurdan, a versatile probe to explore order in lipid membranes." F1000Research 3 (November 19, 2014): 172. http://dx.doi.org/10.12688/f1000research.4805.2.

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Microdomains corresponding to localized partition of lipids between ordered and less ordered environments are the subject of intensive investigations, because of their putative participation in modulating cellular responses. One popular approach in the field consists in labelling membranes with solvatochromic fluorescent probes such as laurdan and C-laurdan. In this report, we describe a high-yield procedure for the synthesis of laurdan, C-laurdan and two new fluorophores, called MoC-laurdan and M-laurdan, as well as their extensive photophysical characterization. We find that the latter probe, M-laurdan, is particularly suited to discriminate lipid phases independently of the chemical nature of the lipids, as measured by both fluorescence Generalized Polarization (GP) and anisotropy in large unilamellar vesicles made of various lipid compositions. In addition, staining of live cells with M-laurdan shows a good stability over time without any apparent toxicity, as well as a wider distribution in the various cell compartments than the other probes.
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Kozyra, K. A., J. R. Heldt, J. Heldt, M. Engelkec, and H. A. Diehl. "Concentration and Temperature Dependence of Laurdan Fluorescence in Glycerol." Zeitschrift für Naturforschung A 58, no. 9-10 (2003): 581–88. http://dx.doi.org/10.1515/zna-2003-9-1018.

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Steady-state and time-resolved fluorescence measurements have been performed on Laurdan, dissolved in viscous glycerol, as functions of temperature and concentration. The results indicate spectral heterogeneity of the Laurdan solution. The fluorescence decay time distribution is attributed to radiative deexcitation of spatial conformational forms of locally excited (LE) and charge transfer (CT) states, the S1(CT)EQ state being in thermodynamic and vibrational equilibrium. The lifetimes and contributions of the different fluorescence modes depend on concentration and temperature. The excitation and emission spectra show discontinuous changes with increase of the Laurdan concentration.We suppose that the observed changes are caused by the formation of Laurdan micelle aggregates.
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Hornum, Mick, Jacob Kongsted, and Peter Reinholdt. "Computational and photophysical characterization of a Laurdan malononitrile derivative." Physical Chemistry Chemical Physics 23, no. 15 (2021): 9139–46. http://dx.doi.org/10.1039/d1cp00831e.

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The ketone group of the traditional push–pull dye Laurdan is replaced with a malononitrile group. The new probe is less bright than Laurdan due to a large drop in the fluorescence quantum yield but functions well as a molecular rotor.
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Titova, T. Yu, Ju P. Morozova, and B. V. Korolev. "Fluorescence of laurdan in water-micellar solutions." Izvestiya vysshikh uchebnykh zavedenii. Fizika, no. 12 (December 1, 2019): 156–64. http://dx.doi.org/10.17223/00213411/62/12/156.

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Ramani, Karthik, and Sathyamangalam V. Balasubramanian. "Fluorescence properties of Laurdan in cochleate phases." Biochimica et Biophysica Acta (BBA) - Biomembranes 1618, no. 1 (2003): 67–78. http://dx.doi.org/10.1016/j.bbamem.2003.10.009.

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Kantar, A., P. L. Giorgi, and R. Fiorini. "Effect of PAF on polyrnorphonuclear leucocyte plasma membrane polarity: a fluorescence study." Mediators of Inflammation 2, no. 2 (1993): 149–51. http://dx.doi.org/10.1155/s0962935193000225.

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The effect of PAF on the plasma membrane polarity of polymorphonuclear leukocytes (PMNs) was investigated by measuring the steady-state fluorescence emission spectra of 2-dimethylamino(6-1auroyl) naphthalene (Laurdan), which is known to be incorporated at the hydrophobic-hydrophilic interface of the bilayer, displaying spectral sensitivity to the polarity of its surrounding. Laurdan shows a marked steady-state emission blue-shift in non-polar solvents, with respect to polar solvents. Our results demonstrate that PAF (10−7M) induces a blue shift of the fluorescence emission spectra of Laurdan. These changes are blocked in the presence of the PAF antagonist, L-659,989. Our data indicate that the interaction between PAF and PMNs is accompanied by a decrease in polarity in the hydrophobic-hydrophilic interface of the plasma membrane.
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Cheniour, M., D. Gueyrard, P. G. Goekjian, T. Granjon, and O. Marcillat. "A convenient and versatile synthesis of Laurdan-like fluorescent membrane probes: characterization of their fluorescence properties." RSC Advances 6, no. 7 (2016): 5547–57. http://dx.doi.org/10.1039/c5ra20369d.

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A simple and versatile synthetic scheme leading to Laurdan-derived fluorescent probes for biological membranes. Libraries of Laurdan derivatives will allow addressing the effect of the polar group on probes capacity to monitor lipids physical state.
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Bonanno, Alexander, Robert C. Blake, and Parkson Lee-Gau Chong. "Sulfolobus acidocaldarius Microvesicles Exhibit Unusually Tight Packing Properties as Revealed by Optical Spectroscopy." International Journal of Molecular Sciences 20, no. 21 (2019): 5308. http://dx.doi.org/10.3390/ijms20215308.

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In this study, we used optical spectroscopy to characterize the physical properties of microvesicles released from the thermoacidophilic archaeon Sulfolobus acidocaldarius (Sa-MVs). The most abundant proteins in Sa-MVs are the S-layer proteins, which self-assemble on the vesicle surface forming an array of crystalline structures. Lipids in Sa-MVs are exclusively bipolar tetraethers. We found that when excited at 275 nm, intrinsic protein fluorescence of Sa-MVs at 23 °C has an emission maximum at 303 nm (or 296 nm measured at 75 °C), which is unusually low for protein samples containing multiple tryptophans and tyrosines. In the presence of 10–11 mM of the surfactant n-tetradecyl-β-d-maltoside (TDM), Sa-MVs were disintegrated, the emission maximum of intrinsic protein fluorescence was shifted to 312 nm, and the excitation maximum was changed from 288 nm to 280.5 nm, in conjunction with a significant decrease (>2 times) in excitation band sharpness. These data suggest that most of the fluorescent amino acid residues in native Sa-MVs are in a tightly packed protein matrix and that the S-layer proteins may form J-aggregates. The membranes in Sa-MVs, as well as those of unilamellar vesicles (LUVs) made of the polar lipid fraction E (PLFE) tetraether lipids isolated from S. acidocaldarius (LUVPLFE), LUVs reconstituted from the tetraether lipids extracted from Sa-MVs (LUVMV) and LUVs made of the diester lipids, were investigated using the probe 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan). The generalized polarization (GP) values of Laurdan in tightly packed Sa-MVs, LUVMV, and LUVPLFE were found to be much lower than those obtained from less tightly packed DPPC gel state, which echoes the previous finding that the GP values from tetraether lipid membranes cannot be directly compared with the GP values from diester lipid membranes, due to differences in probe disposition. Laurdan’s GP and red-edge excitation shift (REES) values in Sa-MVs and LUVMV decrease with increasing temperature monotonically with no sign for lipid phase transition. Laurdan’s REES values are high (9.3–18.9 nm) in the tetraether lipid membrane systems (i.e., Sa-MVs, LUVMV and LUVPLFE) and low (0.4–5.0 nm) in diester liposomes. The high REES and low GP values suggest that Laurdan in tetraether lipid membranes, especially in the membrane of Sa-MVs, is in a very motionally restricted environment, bound water molecules and the polar moieties in the tetraether lipid headgroups strongly interact with Laurdan’s excited state dipole moment, and “solvent” reorientation around Laurdan’s chromophore in tetraether lipid membranes occurs very slowly compared to Laurdan’s lifetime.
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Ambrosini, Annarina, Giovanna Zolese, Giancarlo Balercia, Enrico Bertoli, Giorgio Arnaldi, and Franco Mantero. "Laurdan∗∗Laurdan, Molecular Probes, Eugene, Oregon. fluorescence: a simple method to evaluate sperm plasma membrane alterations." Fertility and Sterility 76, no. 3 (2001): 501–5. http://dx.doi.org/10.1016/s0015-0282(01)01970-7.

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Dissertations / Theses on the topic "Laurdan fluorescence"

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Palomares, Cristofher Victor Vivas. "Caracterização estrutural de dispersões aquosas de vesículas lipídicas catiônicas com oligonucleotídeos." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-08102018-144022/.

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No presente trabalho foi investigado o efeito do oligonucleotídeo-modelo 5-AAAAAAAAAA-3(ODN) sobre a estabilidade e estrutura de vesículas catiônicas de brometo de dioctadecildimetilamônio (DODAB), extrusadas através filtros de 100 nm, em dispersão aquosa, com as técnicas de espalhamento de luz dinâmico (DLS), medidas de potencial de superfície (potencial zeta), calorimetria diferencial de varredura (DSC), espalhamento de raios-X a baixos ângulos (SAXS), espectroscopias de absorção óptica e de fluorescência do estado estacionário da sonda Laurdan incorporada a vesículas de DODAB-ODN. Este fluoróforo monitora a polaridade e estrutura da superfície da membrana de DODAB. Variando a concentração de ODN, três diferentes regimes foram observados. Para baixas concentrações de ODN, ([ODN]/[DODAB]) 0.025 mM, a dispersão é estável, límpida, apesar do diâmetro médio das vesículas aumentar, um aumento de turbidez ser observado por medidas de Absorbância, e o SAXS já acusar a presença de algumas poucas multilamelas. As vesículas mistas apresentam potencial de superfície positivo, semelhante ao potencial medido para vesículas de puro DODAB. A calorimetria mostra a coexistência de regiões da bicamada de puro DODAB, e regiões mistas, com DODAB-ODN, sendo estas últimas mais estáveis, apresentando maior temperatura de transição gel-fluido. A forma e posição da banda de fluorescência do Laurdan incorporado às vesículas não são alteradas pela presença do oligonucleotídeo, indicando pouca variação na polaridade e estrutura da superfície da membrana mista monitorada pela sonda. Um segundo regime é observado para ([ODN]/[DODAB]) 0.05 mM, onde não é mais observado por calorimetria a presença significativa de domínios de puro DODAB, e a dispersão mostra-se instável, turva, com agregação/fusão das vesículas. Finalmente, o terceiro regime, para altas concentrações de ODN, ([ODN]/[DODAB]) 0.075 mM, onde é observado um potencial de superfície negativo, portanto, com predominância da carga do oligonucleotídeo, e a dispersão volta a ser estável, apresentando baixa turbidez. Neste regime, a calorimetria indica uma grande estabilidade da fase gel, medidas de SAXS mostram a formação de estruturas multilamelares, porém DLS indica a presença de vesículas pequenas, com dimensões às observadas para DODAB puro. Neste regime, a sonda Laurdan monitora variações na superfície da membrana, possivelmente indicando a diminuição da quantidade de moléculas de água na superfície e/ou um enrijecimento da bicamada. Os estudos aqui apresentados fazem parte de um amplo esforço para entender as características estruturais de agregados lipídio-material genético, com o objetivo de seu uso futuro em terapias gênicas.
In the present work the effect of 5\'-AAAAAAAAAA-3 \'oligonucleotide model (ODN) was investigated on the stability and structure of dioctadecyldimethylammonium bromide (DODAB) cationic vesicles, extruded through 100 nm filters in aqueous dispersion, with dynamic scattering techniques (DLS), surface potential measurements (zeta potential), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), optical absorption spectrometry and stationary-state fluorescence spectroscopy of Laurdan incorporated into DODAB-ODN vesicles. This fluorophore monitors the polarity and surface structure of the DODAB membrane. Varying the ODN concentration, three different behaviors were observed. For low concentrations of ODN, ([ODN] / [DODAB]) 0.025 mM, the dispersion is stable, clear, although the mean diameter of the vesicles increases, an increase in turbidity is observed by Absorbance measurements, and SAXS already shows the presence of a few multilamellar structure. The mixed vesicles present positive surface potential, similar to the potential measured for pure DODAB vesicles. Calorimetry shows the coexistence of regions of the pure DODAB bilayer, and mixed regions, with DODAB-ODN, the latter being more stable, presenting a higher gel-fluid transition temperature. The shape and position of the Laurdan fluorescence band incorporated into the vesicles are not altered by the presence of the oligonucleotide, indicating minor variation in the polarity and surface structure of the mixed membrane monitored by the probe. A second behavior is observed for ([ODN] / [DODAB]) 0.05 mM, where the presence of pure DODAB domains is no longer detected by calorimetry, and the dispersion is unstable, cloudy, displaying vesicle aggregation/fusion. Finally, the third behavior is detected at high concentrations of ODN, ([ODN] / [DODAB]) 0.075 mM, where a negative surface potential is observed, therefore, with predominance of the charge of the oligonucleotide, and the dispersion is stable, exibiting low turbidity. In this regime, the calorimetry indicates a great stability of the gel phase, SAXS measurements show the formation of multilamellar structures, however DLS indicates the presence of small vesicles, with dimensions to those observed for pure DODAB. In this region, the Laurdan probe monitors variations at the surface of the membrane, possibly indicating the decrease in the amount of water molecules on the surface and/or a stiffening of the bilayer. The studies presented here are part of a broad effort to understand the structural characteristics of \"lipid-genetic material\", aggregates, with the aim of their future use in gene therapies.
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Černá, Ladislava. "Časově rozlišená fluorescence ve výzkumu kapalných a kondenzovaných systémů na bázi biopolymer-tenzid." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217033.

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This thesis studies properties of hydrogel, which arises on the basis of electrostatic and hydrophobic interactions between hyaluronan chain and micelles of cationic surfactant. A native sodium hyaluronan at molecular weight 750–1 000 kDa and a cationic surfactant CTAB (cetyltrimethylammonium bromide) were used. This hydrogel was assessed as a material for drug delivery systems. The hydrogels were made by mixing 200mM CTAB with 0.5% hyaluronan, both dissolved in 0.15M aqueous solution of NaCl simulating physiological solution. Methods used in this study were steady-state and time-resolved fluorescence spectroscopy, more accurately time-resolved emission spectra (TRES) and deconvolution of steady-state emission spectra of a whole sample by means of parameters gained from fluorescence intensity decays at a set of wavelenghts. Selected systems were investigated by three fluorescent probes, prodan, laurdan and rhodamine 6G. The first two mentioned probes were in hydrogel localized only within micelles in three different microenvironments. Rhodamine 6G pointed out that in hydrogel the aqueous environment is significantly restricted in comparison to purely micellar solution. In addition, rhodamine informed about less available micelle surfaces, caused by hyaluronan chains occupation. There were no interactions between the probes and hyaluronan chains. Freshly made hydrogels showed almost the same results as after a week of maturation under its supernatant.
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Moslerová, Lenka. "Studium mikroviskozity membránových systémů na bázi iontových amfifilních párů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449402.

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In this master ‘s thesis, catanionic vesicles formed by the pseudo-double-chain complex CTA – DS were investigated from the point of view of microviscosity. Samplesand of cationic vesicles contained 23, 43 and 53 mol. % of cholesterol and the double-chain surfactant DODAC. Cationic vesicles were prepared for visual observation, their stability was determined by DLS and the prepared system was further investigated. Microviscosity was determined from fluorescence anisotropy. To study the outer part of the membrane, laurdan fluorescent probes were used whereas diphenylhexatriene was used for the inner part of the membrane. This method has been proven to be suitable because it reflects the conditions of the membrane. Moreover, a 1,3-bispyrenylpropane probe forming intramolecular excimers was used to study the microviscosity in the vesicle bilayer. The dicyanovinyljulolidine (DCVJ) probe was applied in the case of the molecular rotor technique. It has been shown that in the case of the DCVJ probe, the molecular rotor technique is practically unusable, due to the fact that the probe has a low quantum yield at low temperatures. Also, the excimer formation of P3P probes does not lead to the expected results. The cationic vesicles do not seem to support this formation, as they are too closely related. This type of probe can be used for the selected system with some restrictions.
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Zbořilová, Hana. "Studium membránových vlastností liposomálních systémů pomocí fluorescenční spektroskopie." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449373.

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The presented diploma thesis is focused on the preparation, characterization and study of membrane properties of liposomal systems which were composed of the neutral phosphatidylcholine (DPPC), cholesterol, negatively charged phosphatidylglycerol (DPPG), polyethylenglycol bounded to phosphatidylethanolamine (PEG5000–PE) and polycation N,N,N-trimethylchitosan (TMC). The influence of individual components and their concentrations on the average particle size, zeta potential and changes in the outer and inner part of the bilayer was investigated. In this matter, methods of dynamic and electrophoretic light scattering and fluorescence spectroscopy with the application of laurdan and DPH probes were used. Based on the above-mentioned parameters, concentrations of components that most suitably influence properties of liposomes in terms of the intended application were selected for the definite complex. It was managed to prepare a liposomal complex stealth liposome–N,N,N-trimethylchitosan, which, due to the optimized composition, could have suitable attributes as a drug delivery system for inhalation administration of biologically active substances.
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Barucha-Kraszewska, Justyna. "Experimental and stimulation analyses of fluorescent solvent relaxation process in biomembranes : Inflence of ions and molecular interpretation of the dye dynamics." Thesis, Besançon, 2012. http://www.theses.fr/2012BESA3010/document.

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De nombreux processus biologiques liés aux membranes cellulaires lipidiques sont encore très mal connus. La présence d'eau et d'ions à l'interface influence les propriétés structurelles et dynamiques de la bicouche lipidique. Les techniques de fluorescence sont très utiles pour étudier les membranes en raison de la grande sensibilité des sondes à leur environnement. Nous avons utilisé la technique de relaxation de solvant (SR) pour explorer l'hydratation et la mobilité de l'eau. Nous avons également réalisé des calculs quantiques (QM) et des dynamiques moléculaires (DM) pour étayer nos expériences. Les résultats SR montrent qu'un petit cation (Na+) est très attiré par la membrane et augmente sa rigidité à l'opposé des cations (NH4+, Cs+) plus gros. Les anions (CI04-, SCN-) s'adsorbent à l'interface plus facilement que Cl-. Ces anions changent la mobilité et l'hydratation des têtes polaires des lipides de la bicouche. Les études SR de la zone hydrophobe de la membrane montrent que les processus de relaxation sont ici très complexes. lis reflètent des processus rapides intramoléculaire (relaxation de torsion, transferts de charge) et des processus intermoléculaires lents. Les calculs QM ont permis de créer les champs de force de trois sondes fluorescentes (Prodan, Laurdan et C-laurdan). Les simulations DM ont permis de déterminer les positions des sondes dans une membrane DOPC. La modélisation reproduit correctement les résultats SR, en particulier les temps de relaxation : de l'ordre de la ps en solvant aqueux et de la ns dans la membrane. Les simulations MD sont complémentaires des méthodes SR et permettent de surveiller le comportement de molécules uniques
Many biologically important processes and phcnomena in lipid membranes are still not fully understood. The presence of ions and water molœules has a significant influence on the structural and dynamical properties of lipid bilayers. Fluorescent techniques are versatile tools for studying the lipid membranes, because the fluorescence emission is strongly sensitive to dye environment. We have conducted fluorescent solvent relaxation (SR) experiments to explore the hydration and mobility properties in lipid membranes in the presence of different chaotropic ions. We have also carried out Quantum Mechanical (QM) calculations and Molecular Dynamics (MD) simulations for supporting the SR experiments. SR experiments show that small cation (Na+) is attracted to the membrane and increases rigidity ofbilayer, while larger cations (NH/, Cs+) should not. Large anions (CI04·, SCN') adsorl, at the membrane interface more easily than smaller ones (Cl') and significantly change tl!e mobility and hydration of the headgroup region oflipid bilayer. SR study ofhydrophobic part of the membrane show that SR processes are complex there and reflect botl!: faster, intramolecular (torsional relaxation or fonnation of charge transfer state) and slower, intermolecular (SR) relaxation processes. QM calculatiom were used to create force-field for three fluorescent dyes (Prodan, Laurdan and C-laurdan). MD simulations allow detennining position of the dye in the lipid membrane in the ground state and after excitation and reproduce correctly SR timescale- ps in water and ns in the membrane. MD simulations extend the capabilities of SR method and allow observing the behaviour of individual molecules
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Suplicy, Cíntia Cristina de Vequi. "Estudos experimentais e teóricos dos espectros eletrônicos das sondas fluorescentes Prodan e Laurdan em solventes e bicamadas lipídicas." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21102010-094046/.

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As moléculas Prodan (6-propionil-2-dimetilamino-naftaleno) e Laurdan (6- dodecanoil-2-dimetilamina-naftaleno) são muito usadas como sondas fluorescentes em bicamadas lipídicas e, mais raramente, em membranas celulares. Esta tese de doutorado teve por objetivo realizar um estudo dessas sondas em diferentes ambientes, para ampliar o entendimento de suas estruturas e características espectroscópicas em diferentes solventes e em bicamadas lipídicas. Este estudo foi feito utilizando duas abordagens, uma experimental e outra teórica. Com resultados teóricos e experimentais, mostramos que o cromóforo é o mesmo para as duas moléculas. Experimentalmente, foram medidos e comparados os espectros de absorção eletrônica em solventes de diferentes polaridades e em bicamadas lipídicas. Foi construído um modelo teórico para o estado fundamental do Prodan em diferentes solventes, onde verificamos que a geometria molecular é planar e a molécula sofre uma grande polarização em solventes de maior polaridade. Teoricamente, reproduzimos os espectros de absorção em todos os solventes, mostrando que eles são compostos por três transições eletrônicas. Verificamos, experimental e teoricamente, que o Prodan forma agregados quando colocado em solução aquosa, em todas as concentrações estudadas (0.9 a 20.0 uM). Adicionalmente, foram medidos e comparados os espectros de emissão fluorescente, e mostramos que eles apresentam duas bandas de emissão em todos os solventes estudados e em bicamada lipídicas. Essas bandas estão relacionadas com dois tempos de vida, evidenciando a presença de dois estados excitados para essas sondas. Porém, a natureza dos estados excitados em solventes homogêneos e em bicamadas lipídicas parece ser diferente. Uma metodologia de análise dos espectros de emissão fluorescente foi proposta. A comparação dos espectros de emissão do Prodan e do Laurdan em bicamadas lipídicas mostrou que as sondas monitoram micro-ambientes ligeiramente diferentes. Nossos resultados indicam que os dois fluoróforos posicionam-se próximos à superfície da bicamada lipídica, porém o Prodan parece estar mais exposto à água. Além disso, o Prodan apresenta uma pequena partição em água, quando a bicamada está na fase gel.
Prodan (6-propionyl-2-dimethylamino-naphthalene) and Laurdan (6-dodecanoyl-2- dimethylamino-naphthalene) molecules are frequently used as fluorescent probes in lipid bilayers and, more rarely, in cell membranes. The objective of this PhD thesis was to study these probes in several environments, to increase the understanding about its structures and spectroscopic characteristics in several solvents and lipid bilayers. This study was carried out using two approaches: experimental and theoretical. With experimental and theoretical results, we demonstrated that the two molecules have the same chromophore. Experimentally, electronic absorption spectra were measured and compared in solvents of several polarities and lipid bilayers, for both molecules. A theoretical model was constructed for Prodans fundamental state in several solvents, in which we found that its molecular geometry is planar and that the molecule undergoes a great deal of polarization in solvents of higher polarity. Theoretically, we emulated the absorption spectra in all solvents studied, showing that they are well described by three electronic transitions. We verified, experimental and theoretically, that Prodan aggregates in aqueous solution at all concentration ranges (0.9 a 20.0 uM). Additionally, the fluorescent emission spectra were measured and compared, and we demonstrated that they are composed by two emission bands in all solvents and lipid bilayers. These bands were related to two fluorescent lifetimes, evidencing the presence of two excitation states for these probes. However, the nature of the excited states in homogeneous solvents and in lipid bilayers seems to be different. A methodology to analyze the emission spectra was proposed. The comparison of Prodans and Laurdans emission spectra in lipid bilayers showed that the probes monitor a slightly different micro-environment. Our results indicated that both fluorophores are located near the bilayers surface, although Prodan seems to be more exposed to water molecules. Besides that, Prodan partitions in water, when the bilayer is in the gel phase.
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Jess, Laura Shirin [Verfasser], and Peter Jomo [Akademischer Betreuer] Walla. "Fluorescence microscopy for interference lithography: Set-up design and pattern characterization by fluorescence modulation / Laura Shirin Jess ; Betreuer: Peter Jomo Walla." Braunschweig : Technische Universität Braunschweig, 2017. http://d-nb.info/1175817643/34.

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Bec, Julien [Verfasser], Jürgen [Gutachter] Popp, and Laura [Gutachter] Marcu. "Intravascular Fluorescence lifetime characterization of Atherosclerosis / Julien Bec ; Gutachter: Jürgen Popp, Laura Marcu." Jena : Friedrich-Schiller-Universität Jena, 2019. http://d-nb.info/1207273023/34.

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Seidel, Marco Thomas. "Solvatationsdynamik an biologischen Grenzschichten." Doctoral thesis, [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969974124.

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VIARD, MATHIAS. "Solubilisation et reconstitution de membranes biologiques artificielles et naturelles : - etude d'une sonde fluorescente membranaire, le laurdan, et application a la transition vesicule-micelle. - controle de la solubilisation et de la reconstitution de la proteine g du virus de la stomatite vesiculaire." Paris 6, 1998. http://www.theses.fr/1998PA066358.

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Abstract:
Les preoccupations de l'equipe dans laquelle j'ai effectue ma these s'inscrivent dans le theme general de la transition vesicule-micelle et de la modelisation de membranes biologiques naturelles. Les mecanismes de la transition vesicule-micelle de systemes phospholipide-amphiphile sont intimement relies aux mecanismes de reconstitution des proteines membranaires dans des membranes artificielles lorsque des protocoles utilisant des detergents sont utilises. Le travail de these se separe ainsi en deux parties. L'une porte sur l'etude approfondie d'une sonde fluorescente membranaire, le laurdan, extremement sensible a la transition vesicule-micelle et l'autre sur la solubilisation d'un virus, la reconstitution de son enveloppe et l'incorporation dans des liposomes de l'unique proteine intrinseque de l'enveloppe de ce virus. Au cours de cette seconde partie, le laurdan a ete utilise pour suivre la solubilisation du virus. La premiere partie de mon travail avait pour objet d'obtenir de nouvelles informations concernant la transition vesicule-micelle. Dans un premier temps, nous avons realise une etude fondamentale du comportement du laurdan dilue dans differents solvants. Cette etude nous a permis de determiner les parametres auxquels la sonde etait sensible et de proposer un schema reactionnel pour la desexcitation du laurdan. Dans un second temps, le laurdan a ete insere dans des agregats d'amphiphiles rencontres lors de la transition vesicule-micelle pour obtenir des informations supplementaires sur cette transition. La seconde partie de mon travail a porte sur la reconstitution de l'activite fusogene liee a la proteine g de l'enveloppe du virus de la stomatite vesiculaire. La litterature a montre que les reconstitutions de l'enveloppe virale apres solubilisation par l'octylglucoside (og) n'aboutissaient qu'a des systemes dont l'activite fusogenique differait de celle du virus natif. Nous avons montre que le controle de la solubilisation des virus par l'og conduisait, apres elimination du detergent, a des virosomes dont l'activite fusogene est similaire a celle des virus intacts. Nous avons ensuite reconstitue cette proteine purifiee dans des liposomes preformes destabilises par l'og. Les proteoliposomes obtenus presentent une activite fusogene comparable a celle du virus intact.
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Book chapters on the topic "Laurdan fluorescence"

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Bagatolli, L. A. "LAURDAN Fluorescence Properties in Membranes: A Journey from the Fluorometer to the Microscope." In Springer Series on Fluorescence. Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/4243_2012_42.

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Learmonth, R. P., and E. Gratton. "Assessment of Membrane Fluidity in Individual Yeast Cells by Laurdan Generalised Polarisation and Multi-photon Scanning Fluorescence Microscopy." In Fluorescence Spectroscopy, Imaging and Probes. Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-642-56067-5_14.

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Scheinpflug, Kathi, Oxana Krylova, and Henrik Strahl. "Measurement of Cell Membrane Fluidity by Laurdan GP: Fluorescence Spectroscopy and Microscopy." In Methods in Molecular Biology. Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-6634-9_10.

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Bagatolli, Luis A., Susana A. Sanchez, Theodore Hazlett, and Enrico Gratton. "[20] Giant vesicles, laurdan, and two-photon fluorescence microscopy: Evidence of lipid lateral separation in bilayers." In Methods in Enzymology. Elsevier, 2003. http://dx.doi.org/10.1016/s0076-6879(03)60124-2.

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Conference papers on the topic "Laurdan fluorescence"

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Schneckenburger, Herbert, Karl Stock, Joerg Eickholz, Wolfgang S. L. Strauss, Marco Lyttek, and Reinhard Sailer. "Time-resolved total internal reflection fluorescence spectroscopy: application to the membrane marker laurdan." In EOS/SPIE European Biomedical Optics Week, edited by Karsten Koenig, Hans J. Tanke, and Herbert Schneckenburger. SPIE, 2000. http://dx.doi.org/10.1117/12.410626.

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Khoroshyy, Petro. "Orientation of laurdan in the lipid bilayer studied using fluorescence detected two photon linear dichroism microscopy." In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.1217.

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