1
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Scollo F, Tempra C, Evci H, Riopedre-Fernandez M, Olżyńska A, Javanainen M, Uday A, Cebecauer M, Cwiklik L, Martinez-Seara H, Jungwirth P, Jurkiewicz P, Hof M. Can calmodulin bind to lipids of the cytosolic leaflet of plasma membranes? Open Biol 2024; 14:240067. [PMID: 39288811 DOI: 10.1098/rsob.240067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 07/23/2024] [Accepted: 08/05/2024] [Indexed: 09/19/2024] Open
Abstract
Calmodulin (CaM) is a ubiquitous calcium-sensitive messenger in eukaryotic cells. It was previously shown that CaM possesses an affinity for diverse lipid moieties, including those found on CaM-binding proteins. These facts, together with our observation that CaM accumulates in membrane-rich protrusions of HeLa cells upon increased cytosolic calcium, motivated us to perform a systematic search for unmediated CaM interactions with model lipid membranes mimicking the cytosolic leaflet of plasma membranes. A range of experimental techniques and molecular dynamics simulations prove unambiguously that CaM interacts with lipid bilayers in the presence of calcium ions. The lipids phosphatidylserine (PS) and phosphatidylethanolamine (PE) hold the key to CaM-membrane interactions. Calcium induces an essential conformational rearrangement of CaM, but calcium binding to the headgroup of PS also neutralizes the membrane negative surface charge. More intriguingly, PE plays a dual role-it not only forms hydrogen bonds with CaM, but also destabilizes the lipid bilayer increasing the exposure of hydrophobic acyl chains to the interacting proteins. Our findings suggest that upon increased intracellular calcium concentration, CaM and the cytosolic leaflet of cellular membranes can be functionally connected.
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Affiliation(s)
- Federica Scollo
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
| | - Carmelo Tempra
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2 , 166 10 Prague 6, Czech Republic
| | - Hüseyin Evci
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
- Department of Chemistry, Faculty of Science, University of South Bohemia in České Budějovice , 370 05 České Budějovice, Czech Republic
| | - Miguel Riopedre-Fernandez
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2 , 166 10 Prague 6, Czech Republic
| | - Agnieszka Olżyńska
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2 , 166 10 Prague 6, Czech Republic
- Institute of Biotechnology, University of Helsinki , 00790 Helsinki, Finland
| | - Arunima Uday
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
| | - Marek Cebecauer
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
| | - Hector Martinez-Seara
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2 , 166 10 Prague 6, Czech Republic
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nam. 2 , 166 10 Prague 6, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3 , 182 23 Prague 8, Czech Republic
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2
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Carabadjac I, Steigenberger J, Geudens N, De Roo V, Muangkaew P, Madder A, Martins JC, Heerklotz H. Time-resolved fluorescence of tryptophan characterizes membrane perturbation by cyclic lipopeptides. Biophys J 2024; 123:2557-2573. [PMID: 38909278 PMCID: PMC11365112 DOI: 10.1016/j.bpj.2024.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/17/2024] [Accepted: 06/20/2024] [Indexed: 06/24/2024] Open
Abstract
Viscosin is a membrane-permeabilizing, cyclic lipopeptide (CLiP) produced by Pseudomonas species. Here, we have studied four synthetic analogs (L1W, V4W, L5W, and L7W), each with one leucine (Leu; L) or valine residue exchanged for tryptophan (Trp; W) by means of time-resolved fluorescence spectroscopy of Trp. To this end, we recorded the average fluorescence lifetime, rotational correlation time and limiting anisotropy, dipolar relaxation time and limiting extent of relaxation, rate constant of acrylamide quenching, effect of H2O-D2O exchange, and time-resolved half-width of the spectrum in the absence and presence of POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) liposomes. Structure, localization, and hydration of the peptides were described by molecular dynamics simulations. The combination of the parameters provides a good description of the molecular environments of the Trp positions and the behavior of viscosin as a whole. Of particular value for characterizing the impact of viscosin on the membrane is the dipolar relaxation of Trp4 in V4W, which is deeply embedded in the hydrophobic core. The limiting relaxation level represents the membrane perturbation-unlike typical membrane probes-at the site of the perturbant. Fractions of Trp4 relax at different rates; the one not in contact with water upon excitation relaxes via recruitment of a water molecule on the 10-ns timescale. This rate is sensitive to the concerted membrane perturbation by more than one lipopeptide, which appears at high lipopeptide concentration and is assumed a prerequisite for the final formation of a membrane-permeabilizing defect. Trp7 relaxes primarily with respect to neighboring Ser residues. Trp5 flips between a membrane-inserted and surface-exposed orientation.
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Affiliation(s)
- Iulia Carabadjac
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany.
| | | | - Niels Geudens
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Vic De Roo
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium; Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Penthip Muangkaew
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Annemieke Madder
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - José C Martins
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Heiko Heerklotz
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany; Center for Biological Signaling Studies (BIOSS), University of Freiburg, Freiburg, Germany; Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.
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3
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Carabadjac I, Vormittag LC, Muszer T, Wuth J, Ulbrich MH, Heerklotz H. Transfer of ANS-Like Drugs from Micellar Drug Delivery Systems to Albumin Is Highly Favorable and Protected from Competition with Surfactant by "Reserved" Binding Sites. Mol Pharm 2024; 21:2198-2211. [PMID: 38625037 DOI: 10.1021/acs.molpharmaceut.3c00875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Micellar drug delivery systems (MDDS) for the intravenous administration of poorly soluble drugs have great advantages over alternative formulations in terms of the safety of their excipients, storage stability, and straightforward production. A classic example is mixed micelles of glycocholate (GC) and lecithin, both endogenous substances in human blood. What limits the use of MDDS is the complexity of the transitions after injection. In particular, as the MDDS disintegrate partially or completely after injection, the drug has to be transferred safely to endogenous carriers in the blood, such as human serum albumin (HSA). If this transfer is compromised, the drug might precipitate─a process that needs to be excluded under all circumstances. The key question of this paper is whether the high local concentration of GC at the moment and site of MDDS dissolution might transiently saturate HSA binding sites and, hence, endanger quick drug transfer. To address this question, we have used a new approach, which is time-resolved fluorescence spectroscopy of the single tryptophan in HSA, Trp-214, to characterize the competitive binding of GC and the drug substitute anilinonaphthalenesulfonate (ANS) to HSA. Time-resolved fluorescence of Trp-214 showed important advantages over established methods for tackling this problem. ANS has been the standard "model drug" to study albumin binding for decades, given its structural similarity to the class of naphthalene-containing acidic drugs and the fact that it is displaced from HSA by numerous drugs (which presumably bind to the same sites). Our complex global fit uses the critical approximation that the average lifetimes behave similarly to a single lifetime, but the resulting errors are found to be moderate and the results provide a convincing explanation of the, at first glance, counterintuitive behavior. Accordingly, and largely in line with the literature, we observed two types of sites binding ANS at HSA: 3 type A, rather peripheral, and 2 type B, likely more central sites. The latter quench Trp-214 by Förster Resonance Energy Transfer (FRET) with a rate constant of ≈0.4 ns-1 per ANS. Adding millimolar concentrations of GC displaces ANS from the A sites but not from B sites. At incomplete ANS saturation, this causes a GC-induced translocation of ANS from A to the more FRET-active B sites. This leads to the apparent paradox that the partial displacement of ANS from HSA increases its quenching effect on Trp-214. The most important conclusion is that (ANS-like) drugs cannot be displaced from the type-B sites, and consequently, drug transfer to these sites is not impaired by competitive binding of GC in the vicinity of a dissolving micelle. The second conclusion is that for unbound GC above the CMC (9 mM), ANS equilibrates between HSA and GC micelles but with a strong preference for free sites on HSA. That means that even persisting micelles would lose their cargo readily once exposed to HSA. For all MDDS sharing this property, targeted drug delivery approaches involving them as the nanocarrier would be pointless.
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Affiliation(s)
- Iulia Carabadjac
- Institute of Pharmaceutical Sciences, University of Freiburg, Hermann-Herder-Str. 9, 79104 Freiburg, Germany
| | - Leonie C Vormittag
- Institute of Pharmaceutical Sciences, University of Freiburg, Hermann-Herder-Str. 9, 79104 Freiburg, Germany
| | - Thomas Muszer
- Institute of Pharmaceutical Sciences, University of Freiburg, Hermann-Herder-Str. 9, 79104 Freiburg, Germany
| | - Jakob Wuth
- Institute of Pharmaceutical Sciences, University of Freiburg, Hermann-Herder-Str. 9, 79104 Freiburg, Germany
| | - Maximilian H Ulbrich
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Albertstr. 17, 79104 Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, Schan̈zlestr. 18, Freiburg 79104, Germany
| | - Heiko Heerklotz
- Institute of Pharmaceutical Sciences, University of Freiburg, Hermann-Herder-Str. 9, 79104 Freiburg, Germany
- Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto M5s 3M2, Ontario, Canada
- BIOSS Centre for Biological Signalling Studies, Schan̈zlestr. 18, Freiburg 79104, Germany
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4
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Okita K, Ito N, Morishita-Watanabe N, Umakoshi H, Kasahara K, Matubayasi N. Solvation dynamics on the diffusion timescale elucidated using energy-represented dynamics theory. Phys Chem Chem Phys 2024; 26:12852-12861. [PMID: 38623745 DOI: 10.1039/d4cp00235k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Photoexcitation of a solute alters the solute-solvent interaction, resulting in the nonequilibrium relaxation of the solvation structure, often called a dynamic Stokes shift or solvation dynamics. Thanks to the local nature of the solute-solvent interaction, the characteristics of the local solvent environment dissolving the solute can be captured by the observation of this process. Recently, we derived the energy-represented Smoluchowski-Vlasov (ERSV) equation, a diffusion equation for molecular liquids, which can be used to analyze the solvation dynamics on the diffusion timescale. This equation expresses the time development for the solvent distribution on the solute-solvent pair interaction energy (energy coordinate). Since the energy coordinate can effectively treat the solvent flexibility in addition to the position and orientation, the ERSV equation can be utilized in various solvent systems. Here, we apply the ERSV equation to the solvation dynamics of 6-propionyl-2-dimethylamino naphthalene (Prodan) in water and different alcohol solvents (methanol, ethanol, and 1-propanol) for clarifying the differences of the relaxation processes among these solvents. Prodan is a solvent-sensitive fluorescent probe and is thus widely utilized for investigating heterogeneous environments. On the long timescale, the ERSV equation satisfactorily reproduces the relaxation time correlation functions obtained from the molecular dynamics (MD) simulations for these solvents. We reveal that the relaxation time coefficient on the diffusion timescale linearly correlates with the inverse of the translational diffusion coefficients for the alcohol solvents because of the Prodan-solvent energy distributions among the alcohols. In the case of water, the time coefficient deviates from the linear relationship for the alcohols due to the difference in the extent of importance of the collective motion between the water and alcohol solvents.
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Affiliation(s)
- Kazuya Okita
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| | - Natsuumi Ito
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| | - Nozomi Morishita-Watanabe
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| | - Hiroshi Umakoshi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| | - Kento Kasahara
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| | - Nobuyuki Matubayasi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
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Thakur GCN, Uday A, Cebecauer M, Roos WH, Cwiklik L, Hof M, Jurkiewicz P, Melcrová A. Charge of a transmembrane peptide alters its interaction with lipid membranes. Colloids Surf B Biointerfaces 2024; 235:113765. [PMID: 38309153 DOI: 10.1016/j.colsurfb.2024.113765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
Transmembrane (TM) proteins interact closely with the surrounding membrane lipids. Lipids in the vicinity of TM proteins were reported to have hindered mobility, which has been associated with lipids being caught up in the rough surface of the TM domains. These reports, however, neglect one important factor that largely influences the membrane behavior - electrostatics of the TM peptides that are usually positively charged at their cytosolic end. Here, we study on the example of a neutral and a positively charged WALP peptide, how the charge of a TM peptide influences the membrane. We investigate both its dynamics and mechanics by: (i) time dependent fluorescent shift in combination with classical and FRET generalized polarization to evaluate the mobility of lipids at short and long-range distance from the peptide, (ii) atomic force microscopy to observe the mechanical stability of the peptide-containing membranes, and (iii) molecular dynamics simulations to analyze the peptide-lipid interactions. We show that both TM peptides lower lipid mobility in their closest surroundings. The peptides cause lateral heterogeneity in lipid mobility, which in turn prevents free lipid rearrangement and lowers the membrane ability to seal ruptures after mechanical indentations. Introduction of a positive charge to the peptide largely enhances these effects, affecting the whole membrane. We thus highlight that unspecific peptide-lipid interactions, especially the electrostatics, should not be overlooked as they have a great impact on the mechanics and dynamics of the whole membrane.
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Affiliation(s)
- Garima C N Thakur
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Arunima Uday
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Marek Cebecauer
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Wouter H Roos
- Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic.
| | - Adéla Melcrová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
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6
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Bacalum M, Radu M, Osella S, Knippenberg S, Ameloot M. Generalized polarization and time-resolved fluorescence provide evidence for different populations of Laurdan in lipid vesicles. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 250:112833. [PMID: 38141326 DOI: 10.1016/j.jphotobiol.2023.112833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
The solvatochromic dye Laurdan is widely used in sensing the lipid packing of both model and biological membranes. The fluorescence emission maximum shifts from about 440 nm (blue channel) in condensed membranes (So) to about 490 nm (green channel) in the liquid-crystalline phase (Lα). Although the fluorescence intensity based generalized polarization (GP) is widely used to characterize lipid membranes, the fluorescence lifetime of Laurdan, in the blue and the green channel, is less used for that purpose. Here we explore the correlation between GP and fluorescence lifetimes by spectroscopic measurements on the So and Lα phases of large unilamellar vesicles of DMPC and DPPC. A positive correlation between GP and the lifetimes is observed in each of the optical channels for the two lipid phases. Microfluorimetric determinations on giant unilamellar vesicles of DPPC and DOPC at room temperature are performed under linearly polarized two-photon excitation to disentangle possible subpopulations of Laurdan at a scale below the optical resolution. Fluorescence intensities, GP and fluorescence lifetimes depend on the angle between the orientation of the linear polarization of the excitation light and the local normal to the membrane of the optical cross-section. This angular variation depends on the lipid phase and the emission channel. GP and fluorescence intensities in the blue and green channel in So and in the blue channel in Lα exhibit a minimum near 90o. Surprisingly, the intensity in the green channel in Lα reaches a maximum near 90o. The fluorescence lifetimes in the two optical channels also reach a pronounced minimum near 90o in So and Lα, apart from the lifetime in the blue channel in Lα where the lifetime is short with minimal angular variation. To our knowledge, these experimental observations are the first to demonstrate the existence of a bent conformation of Laurdan in lipid membranes, as previously suggested by molecular dynamics calculations.
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Affiliation(s)
- Mihaela Bacalum
- Department of Life and Environmental Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, Reactorului, 30, Măgurele 077125, Romania
| | - Mihai Radu
- Department of Life and Environmental Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, Reactorului, 30, Măgurele 077125, Romania
| | - Silvio Osella
- Chemical and Biological Systems Simulation Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| | - Stefan Knippenberg
- Biomedical Research Institute, Hasselt University, Agoralaan Bldg. C, 3590 Diepenbeek, Belgium; Theory Lab, Hasselt University, Agoralaan Bldg. D, 3590 Diepenbeek, Belgium
| | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University, Agoralaan Bldg. C, 3590 Diepenbeek, Belgium.
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7
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Thakur GCN, Uday A, Jurkiewicz P. FRET-GP - A Local Measure of the Impact of Transmembrane Peptide on Lipids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:18390-18402. [PMID: 38048524 DOI: 10.1021/acs.langmuir.3c02505] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Reconstitution of a transmembrane protein in model lipid systems allows studying its structure and dynamics in isolation from the complexity of the natural environment. This approach also provides a well-defined environment for studying the interactions of proteins with lipids. In this work, we describe the FRET-GP method, which utilizes Förster resonance energy transfer (FRET) to specifically probe the nanoenvironment of a transmembrane domain. The tryptophan residues flanking this domain act as efficient FRET donors, while Laurdan acts as acceptor. The fluorescence of this solvatochromic probe is quantified using generalized polarization (GP) to report on lipid mobility in the vicinity of the transmembrane domain. We applied FRET-GP to study the transmembrane peptide WALP incorporated in liposomes. We found that the direct excitation of Laurdan to its second singlet state strongly contributes to GP values measured in FRET conditions. Removal of this parasitic contribution was essential for proper determination of GPFRET - the local analogue of classical GP parameter. The presence of WALP significantly increased both parameters but the local effects were considerably stronger (GPFRET ≫ GP). We conclude that WALP restricts lipid movement in its vicinity, inducing lateral inhomogeneity in membrane fluidity. WALP was also found to influence lipid phase transition. Our findings demonstrated that FRET-GP simultaneously provides local and global results, thereby enhancing the depth of information obtained from the measurement. We highlight the simplicity and sensitivity of the method, but also discuss its potential and limitations in studying protein-lipid interactions.
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Affiliation(s)
- Garima C N Thakur
- J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague 182 00, Czech Republic
| | - Arunima Uday
- J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague 182 00, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague 182 00, Czech Republic
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8
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Dobrynina EA, Zykova VA, Surovtsev NV. In-plane and out-of-plane gigahertz sound velocities of saturated and unsaturated phospholipid bilayers from cryogenic to room temperatures. Chem Phys Lipids 2023; 256:105335. [PMID: 37579988 DOI: 10.1016/j.chemphyslip.2023.105335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/23/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
Here, we examined the gigahertz sound velocities of hydrated multibilayers of saturated (1,2-dimyristoyl-sn-glycero-3-phosphocholine, DMPC) and unsaturated (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC) phospholipids by Brillouin spectroscopy. Out-of-plane and in-plane (lateral) phonons were studied independently of each other. Similar strong temperature dependences of the sound velocities were found for phonons of both types. The sound velocities in the low-temperature limit were two-fold higher than that at physiological temperatures; a significant part of the changes in sound velocity occurs in the solid-like gel phase. The factors that may be involved in the peculiar behavior of sound velocity include changes in the chain conformational state, relaxation susceptibility, changes in the elastic modulus at infinite frequencies, and lateral packing of molecules.
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Affiliation(s)
- E A Dobrynina
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - V A Zykova
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - N V Surovtsev
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia.
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9
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Abhinav, Jurkiewicz P, Hof M, Allolio C, Sýkora J. Modulation of Anionic Lipid Bilayers by Specific Interplay of Protons and Calcium Ions. Biomolecules 2022; 12:1894. [PMID: 36551322 PMCID: PMC9775051 DOI: 10.3390/biom12121894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Biomembranes, important building blocks of living organisms, are often exposed to large local fluctuations of pH and ionic strength. To capture changes in the membrane organization under such harsh conditions, we investigated the mobility and hydration of zwitterionic and anionic lipid bilayers upon elevated H3O+ and Ca2+ content by the time-dependent fluorescence shift (TDFS) technique. While the zwitterionic bilayers remain inert to lower pH and increased calcium concentrations, anionic membranes are responsive. Specifically, both bilayers enriched in phosphatidylserine (PS) and phosphatidylglycerol (PG) become dehydrated and rigidified at pH 4.0 compared to at pH 7.0. However, their reaction to the gradual Ca2+ increase in the acidic environment differs. While the PG bilayers exhibit strong rehydration and mild loosening of the carbonyl region, restoring membrane properties to those observed at pH 7.0, the PS bilayers remain dehydrated with minor bilayer stiffening. Molecular dynamics (MD) simulations support the strong binding of H3O+ to both PS and PG. Compared to PS, PG exhibits a weaker binding of Ca2+ also at a low pH.
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Affiliation(s)
- Abhinav
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 2155/3, 182 23 Prague, Czech Republic
| | - Piotr Jurkiewicz
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 2155/3, 182 23 Prague, Czech Republic
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 2155/3, 182 23 Prague, Czech Republic
| | - Christoph Allolio
- Mathematical Institute of Charles University, Faculty of Mathematics and Physics, Charles University, Sokolovská 49/83, 186 75 Prague, Czech Republic
| | - Jan Sýkora
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 2155/3, 182 23 Prague, Czech Republic
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10
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Bacha K, Chemotti C, Monboisse JC, Robert A, Furlan AL, Smeralda W, Damblon C, Estager J, Brassart-Pasco S, Mbakidi JP, Pršić J, Bouquillon S, Deleu M. Encapsulation of Vitamin C by Glycerol-Derived Dendrimers, Their Interaction with Biomimetic Models of Stratum corneum and Their Cytotoxicity. Molecules 2022; 27:8022. [PMID: 36432124 PMCID: PMC9698622 DOI: 10.3390/molecules27228022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022] Open
Abstract
Vitamin C is one of the most sensitive cosmetic active ingredients. To avoid its degradation, its encapsulation into biobased carriers such as dendrimers is one alternative of interest. In this work, we wanted to evaluate the potential of two biobased glycerodendrimer families (GlyceroDendrimers-Poly(AmidoAmine) (GD-PAMAMs) or GlyceroDendrimers-Poly(Propylene Imine) (GD-PPIs)) as a vitamin C carrier for topical application. The higher encapsulation capacity of GD-PAMAM-3 compared to commercial PAMAM-3 and different GD-PPIs, and its absence of cytotoxicity towards dermal cells, make it a good candidate. Investigation of its mechanism of action was done by using two kinds of biomimetic models of stratum corneum (SC), lipid monolayers and liposomes. GD-PAMAM-3 and VitC@GD-PAMAM-3 (GD-PAMAM-3 with encapsulated vitamin C) can both interact with the lipid representatives of the SC lipid matrix, whichever pH is considered. However, only pH 5.0 is suggested to be favorable to release vitamin C into the SC matrix. Their binding to SC-biomimetic liposomes revealed only a slight effect on membrane permeability in accordance with the absence of cytotoxicity but an increase in membrane rigidity, suggesting a reinforcement of the SC barrier property. Globally, our results suggest that the dendrimer GD-PAMAM-3 could be an efficient carrier for cosmetic applications.
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Affiliation(s)
- Katia Bacha
- Molecular Chemistry Reims Institute UMR CNRS 7312, Reims Champagne-Ardenne University, Boîte n° 44, B.P. 1039, F-51687 Reims, France
- Laboratory of Molecular Biophysics at Interfaces (LBMI), Gembloux Agro-Bio Tech-University of Liege, Passage des Déportés, 2 B-5030 Gembloux, Belgium
| | - Catherine Chemotti
- Laboratory of Molecular Biophysics at Interfaces (LBMI), Gembloux Agro-Bio Tech-University of Liege, Passage des Déportés, 2 B-5030 Gembloux, Belgium
| | - Jean-Claude Monboisse
- Laboratoire de Biochimie Médicale et de Biologie Moléculaire, UMR CNRS/URCA 7369 (MEDyC), UFR Médecine, Reims Champagne Ardenne University, 51 Rue Cognacq Jay, F-51095 Reims, France
| | - Anthony Robert
- Molecular Chemistry Reims Institute UMR CNRS 7312, Reims Champagne-Ardenne University, Boîte n° 44, B.P. 1039, F-51687 Reims, France
| | - Aurélien L. Furlan
- Laboratory of Molecular Biophysics at Interfaces (LBMI), Gembloux Agro-Bio Tech-University of Liege, Passage des Déportés, 2 B-5030 Gembloux, Belgium
| | - Willy Smeralda
- Laboratory of Molecular Biophysics at Interfaces (LBMI), Gembloux Agro-Bio Tech-University of Liege, Passage des Déportés, 2 B-5030 Gembloux, Belgium
| | - Christian Damblon
- Structural Biological Chemistry Laboratory, MolSys Research Unity, University of Liege, 11, Allée du six Août, 4000 Liège, Belgium
| | - Julien Estager
- Certech, Rue Jules Bordet, 45-Zone Industrielle C, B 7180 Seneffe, Belgium
| | - Sylvie Brassart-Pasco
- Laboratoire de Biochimie Médicale et de Biologie Moléculaire, UMR CNRS/URCA 7369 (MEDyC), UFR Médecine, Reims Champagne Ardenne University, 51 Rue Cognacq Jay, F-51095 Reims, France
| | - Jean-Pierre Mbakidi
- Molecular Chemistry Reims Institute UMR CNRS 7312, Reims Champagne-Ardenne University, Boîte n° 44, B.P. 1039, F-51687 Reims, France
| | - Jelena Pršić
- Laboratory of Molecular Biophysics at Interfaces (LBMI), Gembloux Agro-Bio Tech-University of Liege, Passage des Déportés, 2 B-5030 Gembloux, Belgium
| | - Sandrine Bouquillon
- Molecular Chemistry Reims Institute UMR CNRS 7312, Reims Champagne-Ardenne University, Boîte n° 44, B.P. 1039, F-51687 Reims, France
| | - Magali Deleu
- Laboratory of Molecular Biophysics at Interfaces (LBMI), Gembloux Agro-Bio Tech-University of Liege, Passage des Déportés, 2 B-5030 Gembloux, Belgium
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11
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Zykova VA, Surovtsev NV. Brillouin Spectroscopy of Binary Phospholipid-Cholesterol Bilayers. APPLIED SPECTROSCOPY 2022; 76:1206-1215. [PMID: 35712869 DOI: 10.1177/00037028221111147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Multicomponent lipid bilayers are used as models for searching the origin of spatial heterogeneities in biomembranes called lipid rafts, implying the coexistence of domains of different phases and compositions within the lipid bilayer. The spatial organization of multicomponent lipid bilayers on a scale of a hundred nanometers remains unknown. Brillouin spectroscopy providing information about the acoustic phonons with the wavelength of several hundred nanometers has an unexplored potential for this problem. Here, we applied Brillouin spectroscopy for three binary bilayers composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-palmitoyl-sn-glycero-3-phosphocholine (DPPC), and cholesterol. The Brillouin experiment for the oriented planar multibilayers was realized for two scattering geometries involving phonons for the lateral and normal directions of the propagation. The DPPC-DOPC mixtures known for the coexistence of the solid-ordered and liquid-disordered phases had bimodal Brillouin peaks, revealing the phase domains with sizes more than a hundred nanometers. Analysis of the Brillouin data for the binary mixtures concluded that the lateral phonons are preferable for testing the lateral homogeneity of the bilayers, while the phonons spreading across the bilayers are sensitive to the layered packing at the mesoscopic scale.
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Affiliation(s)
- Valeria A Zykova
- 104673Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, Russia
| | - Nikolay V Surovtsev
- 104673Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, Russia
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12
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Ragaller F, Andronico L, Sykora J, Kulig W, Rog T, Urem YB, Abhinav, Danylchuk DI, Hof M, Klymchenko A, Amaro M, Vattulainen I, Sezgin E. Dissecting the mechanisms of environment sensitivity of smart probes for quantitative assessment of membrane properties. Open Biol 2022; 12:220175. [PMID: 36099931 PMCID: PMC9470265 DOI: 10.1098/rsob.220175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The plasma membrane, as a highly complex cell organelle, serves as a crucial platform for a multitude of cellular processes. Its collective biophysical properties are largely determined by the structural diversity of the different lipid species it accommodates. Therefore, a detailed investigation of biophysical properties of the plasma membrane is of utmost importance for a comprehensive understanding of biological processes occurring therein. During the past two decades, several environment-sensitive probes have been developed and become popular tools to investigate membrane properties. Although these probes are assumed to report on membrane order in similar ways, their individual mechanisms remain to be elucidated. In this study, using model membrane systems, we characterized the probes Pro12A, NR12S and NR12A in depth and examined their sensitivity to parameters with potential biological implications, such as the degree of lipid saturation, double bond position and configuration (cis versus trans), phospholipid headgroup and cholesterol content. Applying spectral imaging together with atomistic molecular dynamics simulations and time-dependent fluorescent shift analyses, we unravelled individual sensitivities of these probes to different biophysical properties, their distinct localizations and specific relaxation processes in membranes. Overall, Pro12A, NR12S and NR12A serve together as a toolbox with a wide range of applications allowing to select the most appropriate probe for each specific research question.
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Affiliation(s)
- Franziska Ragaller
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
| | - Luca Andronico
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
| | - Jan Sykora
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Waldemar Kulig
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Tomasz Rog
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Yagmur Balim Urem
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
| | - Abhinav
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Dmytro I Danylchuk
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, 74 Route du Rhin, 67401 Illkirch, France
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Andrey Klymchenko
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, 74 Route du Rhin, 67401 Illkirch, France
| | - Mariana Amaro
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Erdinc Sezgin
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
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13
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Dziuba D. Environmentally sensitive fluorescent nucleoside analogues as probes for nucleic acid - protein interactions: molecular design and biosensing applications. Methods Appl Fluoresc 2022; 10. [PMID: 35738250 DOI: 10.1088/2050-6120/ac7bd8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 06/23/2022] [Indexed: 11/12/2022]
Abstract
Fluorescent nucleoside analogues (FNAs) are indispensable in studying the interactions of nucleic acids with nucleic acid-binding proteins. By replacing one of the poorly emissive natural nucleosides, FNAs enable real-time optical monitoring of the binding interactions in solutions, under physiologically relevant conditions, with high sensitivity. Besides that, FNAs are widely used to probe conformational dynamics of biomolecular complexes using time-resolved fluorescence methods. Because of that, FNAs are tools of high utility for fundamental biological research, with potential applications in molecular diagnostics and drug discovery. Here I review the structural and physical factors that can be used for the conversion of the molecular binding events into a detectable fluorescence output. Typical environmentally sensitive FNAs, their properties and applications, and future challenges in the field are discussed.
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Affiliation(s)
- Dmytro Dziuba
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, 74 Route du Rhin, Illkirch-Graffenstaden, Grand Est, 67401, FRANCE
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14
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Tempra C, Scollo F, Pannuzzo M, Lolicato F, La Rosa C. A unifying framework for amyloid-mediated membrane damage: The lipid-chaperone hypothesis. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140767. [PMID: 35144022 DOI: 10.1016/j.bbapap.2022.140767] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 12/16/2022]
Abstract
Over the past thirty years, researchers have highlighted the role played by a class of proteins or polypeptides that forms pathogenic amyloid aggregates in vivo, including i) the amyloid Aβ peptide, which is known to form senile plaques in Alzheimer's disease; ii) α-synuclein, responsible for Lewy body formation in Parkinson's disease and iii) IAPP, which is the protein component of type 2 diabetes-associated islet amyloids. These proteins, known as intrinsically disordered proteins (IDPs), are present as highly dynamic conformational ensembles. IDPs can partially (mis) fold into (dys) functional conformations and accumulate as amyloid aggregates upon interaction with other cytosolic partners such as proteins or lipid membranes. In addition, an increasing number of reports link the toxicity of amyloid proteins to their harmful effects on membrane integrity. Still, the molecular mechanism underlying the amyloidogenic proteins transfer from the aqueous environment to the hydrocarbon core of the membrane is poorly understood. This review starts with a historical overview of the toxicity models of amyloidogenic proteins to contextualize the more recent lipid-chaperone hypothesis. Then, we report the early molecular-level events in the aggregation and ion-channel pore formation of Aβ, IAPP, and α-synuclein interacting with model membranes, emphasizing the complexity of these processes due to their different spatial-temporal resolutions. Next, we underline the need for a combined experimental and computational approach, focusing on the strengths and weaknesses of the most commonly used techniques. Finally, the last two chapters highlight the crucial role of lipid-protein complexes as molecular switches among ion-channel-like formation, detergent-like, and fibril formation mechanisms and their implication in fighting amyloidogenic diseases.
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Affiliation(s)
- Carmelo Tempra
- Institute of Organic Chemistry and Biochemistry, Prague, Czech Republic
| | - Federica Scollo
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Pannuzzo
- Laboratory of Nanotechnology for Precision Medicine, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy
| | - Fabio Lolicato
- Heidelberg University Biochemistry Center, Heidelberg, Germany; Department of Physics, University of Helsinki, Helsinki, Finland.
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy.
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15
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Pokorna S, Ventura AE, Santos TCB, Hof M, Prieto M, Futerman AH, Silva LC. Laurdan in live cell imaging: Effect of acquisition settings, cell culture conditions and data analysis on generalized polarization measurements. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 228:112404. [PMID: 35196617 DOI: 10.1016/j.jphotobiol.2022.112404] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/05/2022] [Accepted: 01/29/2022] [Indexed: 06/14/2023]
Abstract
Cell function is highly dependent on membrane structure, organization, and fluidity. Therefore, methods to probe the biophysical properties of biological membranes are required. Determination of generalized polarization (GP) values using Laurdan in fluorescence microscopy studies is one of the most widely-used methods to investigate changes in membrane fluidity in vitro and in vivo. In the last couple of decades, there has been a major increase in the number of studies using Laurdan GP, where several different methodological approaches are used. Such differences interfere with data interpretation inasmuch as it is difficult to validate if Laurdan GP variations actually reflect changes in membrane organization or arise from biased experimental approaches. To address this, we evaluated the influence of different methodological details of experimental data acquisition and analysis on Laurdan GP. Our results showed that absolute GP values are highly dependent on several of the parameters analyzed, showing that incorrect data can result from technical and methodological inconsistencies. Considering these differences, we further analyzed the impact of cell variability on GP determination, focusing on basic cell culture conditions, such as cell confluency, number of passages and media composition. Our results show that GP values can report alterations in the biophysical properties of cell membranes caused by cellular adaptation to the culture conditions. In summary, this study provides thorough analysis of the factors that can lead to Laurdan GP variability and suggests approaches to improve data quality, which would generate more precise interpretation and comparison within individual studies and among the literature on Laurdan GP.
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Affiliation(s)
- Sarka Pokorna
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel; J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic.
| | - Ana E Ventura
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel; iMed.ULisboa - Research Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal
| | - Tânia C B Santos
- iMed.ULisboa - Research Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Manuel Prieto
- iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal; Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Liana C Silva
- iMed.ULisboa - Research Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
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16
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Pospíšil P, Cwiklik L, Sýkora J, Hof M, Greetham GM, Towrie M, Vlček A. Solvent-Dependent Excited-State Evolution of Prodan Dyes. J Phys Chem B 2021; 125:13858-13867. [PMID: 34914398 DOI: 10.1021/acs.jpcb.1c09030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Excited-state character and dynamics of two 6-(dimethylamino)-2-acylnaphthalene dyes (Prodan and Badan-SCH2CH2OH) were studied by picosecond time-resolved IR spectroscopy (TRIR) in solvents of different polarity and relaxation times: hexane, CD3OD, and glycerol-d8. In all these solvents, near-UV excitation initially produced the same S1(ππ*) excited state characterized by a broad TRIR signal. A very fast decay (3, ∼100 ps) followed in hexane, whereas conversion to a distinct IR spectrum with a ν(C═O) band downshifted by 76 cm-1 occurred in polar/H-bonding solvents, slowing down on going from CD3OD (1, 23 ps) to glycerol-d8 (5.5, 51, 330 ps). The final relaxed excited state was assigned as planar Me2N → C═O intramolecular charge transfer S1(ICT) by comparing experimental and TDDFT-calculated spectra. TRIR conversion kinetics are comparable to those of early stages of multiexponential fluorescence decay and dynamic fluorescence red-shift. This work presents a strong evidence that Prodan-type dyes undergo solvation-driven charge separation in their S1 state, which is responsible for the dynamic fluorescence Stokes shift observed in polar/H-bonding solvents. The time evolution of the optically prepared S1(ππ*) state to the S1(ICT) final state reflects environment relaxation and solvation dynamics. This finding rationalizes the widespread use of Prodan-type dyes as probes of environment dynamics and polarity.
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Affiliation(s)
- Petr Pospíšil
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, CZ-18223 Prague, Czech Republic
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, CZ-18223 Prague, Czech Republic
| | - Jan Sýkora
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, CZ-18223 Prague, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, CZ-18223 Prague, Czech Republic
| | - Gregory M Greetham
- Central Laser Facility, Research Complex at Harwell, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - Antonín Vlček
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, CZ-18223 Prague, Czech Republic.,Department of Chemistry, Queen Mary University of London, E1 4NS London, United Kingdom
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17
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Schönfeldová T, Piller P, Kovacik F, Pabst G, Okur HI, Roke S. Lipid Melting Transitions Involve Structural Redistribution of Interfacial Water. J Phys Chem B 2021; 125:12457-12465. [PMID: 34730965 PMCID: PMC8607985 DOI: 10.1021/acs.jpcb.1c06868] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/15/2021] [Indexed: 11/29/2022]
Abstract
Morphological and gel-to-liquid phase transitions of lipid membranes are generally considered to primarily depend on the structural motifs in the hydrophobic core of the bilayer. Structural changes in the aqueous headgroup phase are typically not considered, primarily because they are difficult to quantify. Here, we investigate structural changes of the hydration shells around large unilamellar vesicles (LUVs) in aqueous solution, using differential scanning calorimetry (DSC), and temperature-dependent ζ-potential and high-throughput angle-resolved second harmonic scattering measurements (AR-SHS). Varying the lipid composition from 1,2-dimyristoyl-sn-glycero-3-phosphocholine(DMPC) to 1,2-dimyristoyl-sn-glycero-3-phosphate (DMPA), to 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS), we observe surprisingly distinct behavior for the different systems that depend on the chemical composition of the hydrated headgroups. These differences involve changes in hydration following temperature-induced counterion redistribution, or changes in hydration following headgroup reorientation and Stern layer compression.
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Affiliation(s)
- Tereza Schönfeldová
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Paulina Piller
- Institute
of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstrasse 50/III, Graz 8010, Austria
| | - Filip Kovacik
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Georg Pabst
- Institute
of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstrasse 50/III, Graz 8010, Austria
| | - Halil I. Okur
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Department
of Chemistry and National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
| | - Sylvie Roke
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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18
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Scollo F, Evci H, Amaro M, Jurkiewicz P, Sykora J, Hof M. What Does Time-Dependent Fluorescence Shift (TDFS) in Biomembranes (and Proteins) Report on? Front Chem 2021; 9:738350. [PMID: 34778202 PMCID: PMC8586494 DOI: 10.3389/fchem.2021.738350] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
The organization of biomolecules and bioassemblies is highly governed by the nature and extent of their interactions with water. These interactions are of high intricacy and a broad range of methods based on various principles have been introduced to characterize them. As these methods view the hydration phenomena differently (e.g., in terms of time and length scales), a detailed insight in each particular technique is to promote the overall understanding of the stunning “hydration world.” In this prospective mini-review we therefore critically examine time-dependent fluorescence shift (TDFS)—an experimental method with a high potential for studying the hydration in the biological systems. We demonstrate that TDFS is very useful especially for phospholipid bilayers for mapping the interfacial region formed by the hydrated lipid headgroups. TDFS, when properly applied, reports on the degree of hydration and mobility of the hydrated phospholipid segments in the close vicinity of the fluorophore embedded in the bilayer. Here, the interpretation of the recorded TDFS parameters are thoroughly discussed, also in the context of the findings obtained by other experimental techniques addressing the hydration phenomena (e.g., molecular dynamics simulations, NMR spectroscopy, scattering techniques, etc.). The differences in the interpretations of TDFS outputs between phospholipid biomembranes and proteins are also addressed. Additionally, prerequisites for the successful TDFS application are presented (i.e., the proper choice of fluorescence dye for TDFS studies, and TDFS instrumentation). Finally, the effects of ions and oxidized phospholipids on the bilayer organization and headgroup packing viewed from TDFS perspective are presented as application examples.
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Affiliation(s)
- Federica Scollo
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Hüseyin Evci
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Mariana Amaro
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Jan Sykora
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
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19
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Dmitriev RI, Intes X, Barroso MM. Luminescence lifetime imaging of three-dimensional biological objects. J Cell Sci 2021; 134:1-17. [PMID: 33961054 PMCID: PMC8126452 DOI: 10.1242/jcs.254763] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A major focus of current biological studies is to fill the knowledge gaps between cell, tissue and organism scales. To this end, a wide array of contemporary optical analytical tools enable multiparameter quantitative imaging of live and fixed cells, three-dimensional (3D) systems, tissues, organs and organisms in the context of their complex spatiotemporal biological and molecular features. In particular, the modalities of luminescence lifetime imaging, comprising fluorescence lifetime imaging (FLI) and phosphorescence lifetime imaging microscopy (PLIM), in synergy with Förster resonance energy transfer (FRET) assays, provide a wealth of information. On the application side, the luminescence lifetime of endogenous molecules inside cells and tissues, overexpressed fluorescent protein fusion biosensor constructs or probes delivered externally provide molecular insights at multiple scales into protein-protein interaction networks, cellular metabolism, dynamics of molecular oxygen and hypoxia, physiologically important ions, and other physical and physiological parameters. Luminescence lifetime imaging offers a unique window into the physiological and structural environment of cells and tissues, enabling a new level of functional and molecular analysis in addition to providing 3D spatially resolved and longitudinal measurements that can range from microscopic to macroscopic scale. We provide an overview of luminescence lifetime imaging and summarize key biological applications from cells and tissues to organisms.
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Affiliation(s)
- Ruslan I. Dmitriev
- Tissue Engineering and Biomaterials Group, Department of
Human Structure and Repair, Faculty of Medicine and Health Sciences,
Ghent University, Ghent 9000,
Belgium
| | - Xavier Intes
- Department of Biomedical Engineering, Center for
Modeling, Simulation and Imaging for Medicine (CeMSIM),
Rensselaer Polytechnic Institute, Troy, NY
12180-3590, USA
| | - Margarida M. Barroso
- Department of Molecular and Cellular
Physiology, Albany Medical College,
Albany, NY 12208, USA
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20
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Zafer JB, Dede S, Karakuş E. α-Amylase assay with starch-iodine-sodium fluorescein-based fluorometric method in human serum samples. Prep Biochem Biotechnol 2021; 51:599-606. [PMID: 33427021 DOI: 10.1080/10826068.2020.1843177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A new fluorometric method was developed for the determination of α-amylase activity in human serum samples. Firstly, a saturated starch-iodine complex (SI) was prepared. The SI complex was combined with sodium fluorescein to form a starch-iodine-sodium fluorescein complex (SIF). As the SIF complex decomposes with the α-amylase enzymatic hydrolysis of starch, the intensity of its fluorescence emission increases. The α-amylase activity is determined using the increased fluorescence emission intensity following hydrolysis of the SIF complex by α-amylase. The optimum pH, optimum buffer concentration, optimum temperature, and interference effect were identified for the developed fluorometric measurement method. Under the optimum conditions, a linear calibration curve was obtained between 0.18 and 9.00 U/L for α-amylase. The α-amylase activity in the human serum sample was also determined by our prepared measurement system and compared with the result from a medical center. Both methods are in good agreement with each other. Because this newly developed fluorometric method for α-amylase activity in serum samples is inexpensive, easy to use, and carried out to detect a very low amount of human serum α-amylase with sensitivity, it can be proposed this method for alpha-amylase activity assay in all other biological samples.
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Affiliation(s)
- Julide Buse Zafer
- Department of Chemistry, Yildiz Technical University, Istanbul, Turkey
| | - Süreyya Dede
- Department of Chemistry, Yildiz Technical University, Istanbul, Turkey
| | - Emine Karakuş
- Department of Chemistry, Yildiz Technical University, Istanbul, Turkey
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21
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Shi S, Quarta N, Zhang H, Lu Z, Hof M, Šachl R, Liu R, Hoernke M. Hidden complexity in membrane permeabilization behavior of antimicrobial polycations. Phys Chem Chem Phys 2021; 23:1475-1488. [DOI: 10.1039/d0cp05651k] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There are diverse membrane permeabilization behaviors of antimicrobial polycations in zwitterionic or charged vesicles; different mechanisms may occur over time.
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Affiliation(s)
- Shuai Shi
- Chemistry and Pharmacy
- Albert-Ludwigs-Universität
- 79104 Freiburg i.Br
- Germany
| | - Ndjali Quarta
- Chemistry and Pharmacy
- Albert-Ludwigs-Universität
- 79104 Freiburg i.Br
- Germany
- Department of Chemistry, Biochemistry
| | - Haodong Zhang
- State Key Laboratory of Bioreactor Engineering
- Frontiers Science Center for Materiobiology and Dynamic Chemistry
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Ziyi Lu
- State Key Laboratory of Bioreactor Engineering
- Frontiers Science Center for Materiobiology and Dynamic Chemistry
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences
- 182 23 Prague
- Czech Republic
| | - Radek Šachl
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences
- 182 23 Prague
- Czech Republic
| | - Runhui Liu
- State Key Laboratory of Bioreactor Engineering
- Frontiers Science Center for Materiobiology and Dynamic Chemistry
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Maria Hoernke
- Chemistry and Pharmacy
- Albert-Ludwigs-Universität
- 79104 Freiburg i.Br
- Germany
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22
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Páez-Pérez M, López-Duarte I, Vyšniauskas A, Brooks NJ, Kuimova MK. Imaging non-classical mechanical responses of lipid membranes using molecular rotors. Chem Sci 2020; 12:2604-2613. [PMID: 34164028 PMCID: PMC8179291 DOI: 10.1039/d0sc05874b] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/22/2020] [Indexed: 12/15/2022] Open
Abstract
Lipid packing in cellular membranes has a direct effect on membrane tension and microviscosity, and plays a central role in cellular adaptation, homeostasis and disease. According to conventional mechanical descriptions, viscosity and tension are directly interconnected, with increased tension leading to decreased membrane microviscosity. However, the intricate molecular interactions that combine to build the structure and function of a cell membrane suggest a more complex relationship between these parameters. In this work, a viscosity-sensitive fluorophore ('molecular rotor') is used to map changes in microviscosity in model membranes under conditions of osmotic stress. Our results suggest that the relationship between membrane tension and microviscosity is strongly influenced by the bilayer's lipid composition. In particular, we show that the effects of increasing tension are minimised for membranes that exhibit liquid disordered (Ld) - liquid ordered (Lo) phase coexistence; while, surprisingly, membranes in pure gel and Lo phases exhibit a negative compressibility behaviour, i.e. they soften upon compression.
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Affiliation(s)
- Miguel Páez-Pérez
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
| | - Ismael López-Duarte
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
- Departamento de Química Orgánica, Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spain
| | - Aurimas Vyšniauskas
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
- Center of Physical Sciences and Technology Saulėtekio av. 3 Vilnius Lithuania
| | - Nicholas J Brooks
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
| | - Marina K Kuimova
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
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23
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Sot J, Esnal I, Monasterio BG, León-Irra R, Niko Y, Goñi FM, Klymchenko A, Alonso A. Phase-selective staining of model and cell membranes, lipid droplets and lipoproteins with fluorescent solvatochromic pyrene probes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183470. [PMID: 32898535 DOI: 10.1016/j.bbamem.2020.183470] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 10/23/2022]
Abstract
The push-pull solvatochromic pyrene derivatives PA and PK have been applied to the study of model membrane vesicles, cells and purified human serum lipoproteins, using both confocal fluorescence microscopy and fluorescence spectroscopy. These polarity-sensitive probes provide information similar to that obtained by Laurdan or Prodan, i.e. mainly lipid order in biomembranes, but they have the essential advantage of being excitable by a standard 405 nm laser light, bypassing the use of multiphoton excitation. In addition, they are brighter and much more photostable than those dimethylamino naphthalene derivatives. Our results with model membrane spectroscopy (multilamellar vesicles) and with microscopy (giant unilamellar vesicles) showed the capacity of PA and PK to report differently on liquid-disordered, liquid-ordered and gel phase bilayers. Moreover, a ratiometric parameter, the Red/Blue Intensity Ratio (RBIR) could be used for inter-domain, inter-vesicle and even inter-technique comparison, and the appropriate microscopy-spectroscopy conversion coefficients could be estimated. In studies at the cellular level, PA probe stained almost exclusively the plasma membrane of red blood cells, revealing its high degree of lipid order. Using Chinese Hamster Ovary cells PA was shown to be an excellent probe for the detection of cytoplasmic lipid droplets, superior to Nile Red in that PA provides simultaneously a detailed information of membrane order in the whole cell, in which the lipid droplets appear with a very good contrast. Moreover, spectrofluorometric data of PA-stained serum lipoproteins indicated an essentially identical value of RBIR for lipid droplets and for high-density lipoproteins.
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Affiliation(s)
- Jesús Sot
- Instituto Biofisika (CSIC, UPV/EHU), Campus Universitario, 48940 Leioa, Spain
| | - Ixone Esnal
- Instituto Biofisika (CSIC, UPV/EHU), Campus Universitario, 48940 Leioa, Spain
| | - Bingen G Monasterio
- Instituto Biofisika (CSIC, UPV/EHU), Campus Universitario, 48940 Leioa, Spain
| | - Rocío León-Irra
- Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, CP 83000 Hermosillo, Sonora, Mexico
| | - Yosuke Niko
- Research and Education Faculty, Multidisciplinary Science Cluster, Interdisciplinary Science Unit, Kochi University, Kochi 780-8520, Japan
| | - Félix M Goñi
- Instituto Biofisika (CSIC, UPV/EHU), Campus Universitario, 48940 Leioa, Spain; Departamento de Bioquímica, Universidad del País Vasco, B. Sarriena, 48940 Leioa, Spain
| | - Andrey Klymchenko
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
| | - Alicia Alonso
- Instituto Biofisika (CSIC, UPV/EHU), Campus Universitario, 48940 Leioa, Spain; Departamento de Bioquímica, Universidad del País Vasco, B. Sarriena, 48940 Leioa, Spain.
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24
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De Vleeschouwer M, Van Kersavond T, Verleysen Y, Sinnaeve D, Coenye T, Martins JC, Madder A. Identification of the Molecular Determinants Involved in Antimicrobial Activity of Pseudodesmin A, a Cyclic Lipopeptide From the Viscosin Group. Front Microbiol 2020; 11:646. [PMID: 32373092 PMCID: PMC7187754 DOI: 10.3389/fmicb.2020.00646] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 03/20/2020] [Indexed: 12/24/2022] Open
Abstract
Cyclic lipo(depsi)peptides (CLiPs) from Pseudomonas constitute a class of natural products involved in a broad range of biological functions for their producers. They also display interesting antimicrobial potential including activity against Gram-positive bacteria. Literature has indicated that these compounds can induce membrane permeabilization, possibly through pore-formation, leading to the general view that the cellular membrane constitutes the primary target in their mode of action. In support of this view, we previously demonstrated that the enantiomer of pseudodesmin A, a member of the viscosin group of CLiPs, shows identical activity against a test panel of six Gram-positive bacterial strains. Here, a previously developed total organic synthesis route is used and partly adapted to generate 20 novel pseudodesmin A analogs in an effort to derive links between molecular constitution, structure and activity. From these, the importance of a macrocycle closed by an ester bond as well as a critical length of β-OH fatty acid chain capping the N-terminus is conclusively demonstrated, providing further evidence for the importance of peptide-membrane interactions in the mode of action. Moreover, an alanine scan is used to unearth the contribution of specific amino acid residues to biological activity. Subsequent interpretation in terms of a structural model describing the location and orientation of pseudodesmin A in a membrane environment, allows first insight in the peptide-membrane interactions involved. The biological screening also identified residue positions that appear less sensitive to conservative modifications, allowing the introduction of a non-perturbing tryptophan residue which will pave the way toward biophysical studies using fluorescence spectroscopy.
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Affiliation(s)
- Matthias De Vleeschouwer
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium.,NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Tim Van Kersavond
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium.,NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Yentl Verleysen
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium.,NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Davy Sinnaeve
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Department of Pharmaceutical Analysis, Ghent University, Ghent, Belgium
| | - José C Martins
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Annemieke Madder
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
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25
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Stulz A, Vogt A, Saar JS, Akil L, Lienkamp K, Hoernke M. Quantified Membrane Permeabilization Indicates the Lipid Selectivity of Membrane-Active Antimicrobials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:16366-16376. [PMID: 31710807 DOI: 10.1021/acs.langmuir.9b01849] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Most antimicrobial peptides (AMPs) and their synthetic mimics (SMAMPs) are thought to act by permeabilizing cell membranes. For antimicrobial therapy, selectivity for pathogens over mammalian cells is a key requirement. Understanding membrane selectivity is thus essential for designing AMPs and SMAMPs to complement classical antibiotics in the future. This study focuses on membrane permeabilization induced by SMAMPs and their selectivity for membranes with different lipid compositions. We measure release and fluorescence lifetime of a self-quenching dye in lipid vesicles. Apart from the dose-response, we quantify the strength of individual leakage events, and, employing cumulative kinetics, categorize permeabilization behavior. We propose that differing selectivities in a series of SMAMPs arise from a combination of the effect of the antimicrobial agent and the susceptibility of the membrane (with a given lipid composition) for certain types of leakage behavior. The unselective and hemolytic SMAMP is found to act mainly by the asymmetry stress mechanism, mediated by hydrophobic insertion of SMAMPs into lipid layers. The more selective SMAMPs induced leakage events occurring stochastically over several hours. Lipid intrinsic properties might additionally amplify the efficiency of leakage events. Leakage behavior changes with both the design of the SMAMP and the lipid composition of the membrane. Understanding how leakage behavior contributes to the selectivity and activity of antimicrobial agents will aid the design and screening of antimicrobials. An understanding of the underlying processes facilitates the comparison of membrane permeabilization across in vitro and in vivo assays.
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Affiliation(s)
- Anja Stulz
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Annika Vogt
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
- Faculty of Applied Chemistry , Reutlingen University , Reutlingen , Germany
| | - Julia Selina Saar
- Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Larissa Akil
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Karen Lienkamp
- Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Maria Hoernke
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
- BIOSS Centre for Biological Signalling Studies , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
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26
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Bechoua S, Winckler P, Jossier A, Peltier C, Delize F, Devaux N, Perrier Cornet JM, Simonin H. Time-resolved Fluorescence and Generalized Polarization: Innovative tools to assess bull sperm membrane dynamics during slow freezing. Cryobiology 2019; 91:69-76. [PMID: 31678178 DOI: 10.1016/j.cryobiol.2019.10.196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 09/06/2019] [Accepted: 10/20/2019] [Indexed: 11/15/2022]
Abstract
During slow freezing, spermatozoa undergo membrane alterations that compromise their ability of fertilizing. These alterations are cause either by cold shock or by the use of cryoprotectants known to be cytotoxic. However, little is known about the membrane changes that occurred during freezing. Here, we combined Generalized Polarization (GP), Time-resolved Fluorescence and laurdan fluorescence properties to investigate the changes in membrane fluidity and dynamics during slow freezing of bull sperm. We successfully demonstrated that laurdan may be distributed in three different local environments that correspond to different membrane lipid composition. These environments wont behave the same way when the cells will be subjected to either a chemical treatment (adding the cryoprotectants) or a physical treatment (freezing).
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Affiliation(s)
- Shaliha Bechoua
- Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, F21000, Dijon, France; CRB Ferdinand Cabanne, CHU Dijon Bourgogne, Dijon, France.
| | - Pascale Winckler
- Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, F21000, Dijon, France; Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, DimaCell Imaging Facility, F21000, Dijon, France
| | - Audrey Jossier
- Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, F21000, Dijon, France
| | - Caroline Peltier
- Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, F21000, Dijon, France
| | | | | | - Jean Marie Perrier Cornet
- Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, F21000, Dijon, France; Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, DimaCell Imaging Facility, F21000, Dijon, France
| | - Hélène Simonin
- Univ Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A02.2012, F21000, Dijon, France
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27
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Melcrová A, Pokorna S, Vošahlíková M, Sýkora J, Svoboda P, Hof M, Cwiklik L, Jurkiewicz P. Concurrent Compression of Phospholipid Membranes by Calcium and Cholesterol. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11358-11368. [PMID: 31393734 DOI: 10.1021/acs.langmuir.9b00477] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Regulation of cell metabolism, membrane fusion, association of proteins with cellular membranes, and cellular signaling altogether would not be possible without Ca2+ ions. The distribution of calcium within the cell is uneven with the negatively charged inner leaflet of the plasma membrane being one of the primary targets of its accumulation. Therefore, we decided to map the influence of Ca2+ on the properties of lipid bilayers closely resembling natural lipid membranes. We combined fluorescence spectroscopy (analysis of time-resolved emission spectra of Laurdan probe and derived parameters: integrated relaxation time related to local lipid mobility, and total emission shift reflecting membrane polarity and hydration) with molecular dynamics simulations to determine the effect of the increasing CaCl2 concentration on model lipid membranes containing POPC, POPS, and cholesterol. On top of that, the impact of calcium on the plasma membranes isolated from HEK293 cells was investigated using the steady-state fluorescence of Laurdan. We found that calcium increases rigidity of all the model lipid membranes used, elevates their thickness, increases lipid packing and ordering, and impedes the local lipid mobility. All these effects were to a great extent similar to those elicited by cholesterol. However, the changes of the membrane properties induced by calcium and cholesterol seem largely independent from each other. At sufficiently high concentrations of calcium or cholesterol, the steric effects hindered a further alteration of membrane organization, i.e., the compressibility limit of membrane structures was reached. We found no indication for mutual interaction between Ca2+ and cholesterol, nor competition of Ca2+ ions and hydroxyl groups of cholesterol for binding to phospholipids. Fluorescence measurements indicated that Ca2+ adsorption decreases mobility within the carbonyl region of model bilayers more efficiently than monovalent ions do (Ca2+ ≫ Li+ > Na+ > K+ > Cs+). The effects of calcium ions were to a great extent mitigated in the plasma membranes isolated from HEK293 cells when compared to the model lipid membranes. Noticeably, the plasma membranes showed remarkably higher resistance toward rigidification induced by calcium ions even when compared with the model membranes containing cholesterol.
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Affiliation(s)
- Adéla Melcrová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , 182 23 Prague 8 , Czech Republic
| | - Sarka Pokorna
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , 182 23 Prague 8 , Czech Republic
| | - Miroslava Vošahlíková
- Institute of Physiology of the Czech Academy of Sciences , Vídeňská 1083 , 14220 Prague 4 , Czech Republic
| | - Jan Sýkora
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , 182 23 Prague 8 , Czech Republic
| | - Petr Svoboda
- Institute of Physiology of the Czech Academy of Sciences , Vídeňská 1083 , 14220 Prague 4 , Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , 182 23 Prague 8 , Czech Republic
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , 182 23 Prague 8 , Czech Republic
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , 166 10 Prague 6 , Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , 182 23 Prague 8 , Czech Republic
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28
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Peltier C, Winckler P, Dujourdy L, Bechoua S, Perrier-Cornet JM. Analysis of multivariate images in fluorescence microscopy. Methods Appl Fluoresc 2019; 7:035004. [PMID: 30974420 DOI: 10.1088/2050-6120/ab1886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A multivariate image is an image stack in which each pixel contains several variables. Such images are common in many fields (medicine, imaging microscopy, satellite imaging...) and their analysis requires adapted multivariate statistical methods. In fluorescence imaging microscopy, different probes or different measurements such as intensity, fluorescence lifetime or spectral information can be observed from one view. However, this is not yet analysed as multivariate images. Here, we are presenting a full approach of multivariate analysis of fluorescence microscopy images and we are proposing a free R package (multifluo) to conduct it.
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Affiliation(s)
- Caroline Peltier
- Univ. Bourgogne Franche-Comte, Agrosup Dijon, PAM UMR A 02.102, F21000 Dijon, France
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29
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Singh P, Sharma VK, Singha S, García Sakai V, Mukhopadhyay R, Das R, Pal SK. Unraveling the Role of Monoolein in Fluidity and Dynamical Response of a Mixed Cationic Lipid Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:4682-4692. [PMID: 30807692 DOI: 10.1021/acs.langmuir.9b00043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The maintenance of cell membrane fluidity is of critical importance for various cellular functions. At lower temperatures when membrane fluidity decreases, plants and cyanobacteria react by introducing unsaturation in the lipids, so that the membranes return to a more fluidic state. To probe how introduction of unsaturation leads to reduced membrane fluidity, a model cationic lipid dioctadecyldimethylammonium bromide (DODAB) has been chosen, and the effects of an unsaturated lipid monoolein (MO) on the structural dynamics and phase behavior of DODAB have been monitored by quasielastic neutron scattering and time-resolved fluorescence measurements. In the coagel phase, fluidity of the lipid bilayer increases significantly in the presence of MO relative to pure DODAB vesicles and becomes manifest in significantly enhanced dynamics of the constituent lipids along with faster hydration and orientational relaxation dynamics of a fluorophore. On the contrary, MO restricts both lateral and internal motions of the lipid molecules in the fluid phase (>330 K), which is consistent with relatively slow hydration and orientational relaxation dynamics of the fluorophore embedded in the mixed lipid bilayer. The present study illustrates how incorporation of an unsaturated lipid at lower temperatures (below the phase transition) assists the model lipid (DODAB) in regulating fluidity via enhancement of dynamics of the constituent lipids.
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Affiliation(s)
- Priya Singh
- Department of Chemical, Biological & Macromolecular Sciences , S. N. Bose National Centre for Basic Sciences , Block JD, Sector III , Salt Lake, Kolkata 700106 , India
| | | | - Subhankar Singha
- Department of Chemistry , Pohang University of Science and Technology (POSTECH) , 77 Cheongam-Ro , Nam-Gu, Pohang , Gyungbuk 37673 , Republic of Korea
| | - Victoria García Sakai
- ISIS Pulsed Neutron and Muon Facility, Rutherford Appleton Laboratory , Science and Technology Facilities Council , Didcot OX11 0DE , U.K
| | | | - Ranjan Das
- Department of Chemistry , West Bengal State University , Barasat, Kolkata 700126 , India
| | - Samir Kumar Pal
- Department of Chemical, Biological & Macromolecular Sciences , S. N. Bose National Centre for Basic Sciences , Block JD, Sector III , Salt Lake, Kolkata 700106 , India
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30
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Taylor EL, Metcalf KJ, Carlotti B, Lai CT, Modica JA, Schatz GC, Mrksich M, Goodson T. Long-Range Energy Transfer in Protein Megamolecules. J Am Chem Soc 2018; 140:15731-15743. [PMID: 30375862 PMCID: PMC6710013 DOI: 10.1021/jacs.8b08208] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this investigation, we report evidence for energy transfer in new protein-based megamolecules with tunable distances between donor and acceptor fluorescent proteins. The megamolecules used in this work are monodisperse oligomers, with molecular weights of ∼100-300 kDa and lengths of ∼5-20 nm, and are precisely defined structures of fusion protein building blocks and covalent cross-linkers. Such structures are promising because the study of energy transfer in protein complexes is usually difficult in this long length regime due to synthetic limitations. We incorporated fluorescent proteins into the megamolecule structure and varied the separation distance between donor and acceptor by changing the length of the cross-linker in dimer conjugates and inserting nonfluorescent spacer proteins to create oligomers. Two-photon absorption measurements demonstrated strong coupling between donor and acceptor dipoles in the megamolecules. For the dimer systems, no effect of the cross-linker length on energy transfer efficiency was observed with the steady-state fluorescence investigation. However, for the same dimer conjugates, energy transfer rates decreased upon increasing cross-linker length, as evaluated by fluorescence up-conversion. Molecular dynamics simulations were used to rationalize the results, providing quantitative agreement between measured and calculated energy transfer lengths for steady-state results, and showing that the differences between the time-resolved and steady-state measurements arise from the long time scale for large-scale fluctuations in the megamolecule structure. Our results show an increase in energy transfer length with increasing megamolecule size. This is evidence for long-range energy transfer in large protein megamolecules.
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Affiliation(s)
- Elijah L. Taylor
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kevin J. Metcalf
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Benedetta Carlotti
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia 06123, Italy
| | - Cheng-Tsung Lai
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Justin A. Modica
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - George C. Schatz
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Milan Mrksich
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Theodore Goodson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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31
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Catte A, White GF, Wilson MR, Oganesyan VS. Direct Prediction of EPR Spectra from Lipid Bilayers: Understanding Structure and Dynamics in Biological Membranes. Chemphyschem 2018; 19:2183-2193. [PMID: 29858887 PMCID: PMC6175124 DOI: 10.1002/cphc.201800386] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Indexed: 11/16/2022]
Abstract
Of the many biophysical techniques now being brought to bear on studies of membranes, electron paramagnetic resonance (EPR) of nitroxide spin probes was the first to provide information about both mobility and ordering in lipid membranes. Here, we report the first prediction of variable temperature EPR spectra of model lipid bilayers in the presence and absence of cholesterol from the results of large scale fully atomistic molecular dynamics (MD) simulations. Three types of structurally different spin probes were employed in order to study different parts of the bilayer. Our results demonstrate very good agreement with experiment and thus confirm the accuracy of the latest lipid force fields. The atomic resolution of the simulations allows the interpretation of the molecular motions and interactions in terms of their impact on the sensitive EPR line shapes. Direct versus indirect effects of cholesterol on the dynamics of spin probes are analysed. Given the complexity of structural organisation in lipid bilayers, the advantage of using a combined MD-EPR simulation approach is two-fold. Firstly, prediction of EPR line shapes directly from MD trajectories of actual phospholipid structures allows unambiguous interpretation of EPR spectra of biological membranes in terms of complex motions. Secondly, such an approach provides an ultimate test bed for the up-to-date MD simulation models employed in the studies of biological membranes, an area that currently attracts great attention.
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Affiliation(s)
- Andrea Catte
- School of ChemistryUniversity of East AngliaNorwichNR4 7TJUK
| | - Gaye F. White
- School of ChemistryUniversity of East AngliaNorwichNR4 7TJUK
| | - Mark R. Wilson
- Department of ChemistryDurham University, Lower MountjoySouth RoadDurhamDH1 3 LEUK
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32
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Pick H, Alves AC, Vogel H. Single-Vesicle Assays Using Liposomes and Cell-Derived Vesicles: From Modeling Complex Membrane Processes to Synthetic Biology and Biomedical Applications. Chem Rev 2018; 118:8598-8654. [PMID: 30153012 DOI: 10.1021/acs.chemrev.7b00777] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The plasma membrane is of central importance for defining the closed volume of cells in contradistinction to the extracellular environment. The plasma membrane not only serves as a boundary, but it also mediates the exchange of physical and chemical information between the cell and its environment in order to maintain intra- and intercellular functions. Artificial lipid- and cell-derived membrane vesicles have been used as closed-volume containers, representing the simplest cell model systems to study transmembrane processes and intracellular biochemistry. Classical examples are studies of membrane translocation processes in plasma membrane vesicles and proteoliposomes mediated by transport proteins and ion channels. Liposomes and native membrane vesicles are widely used as model membranes for investigating the binding and bilayer insertion of proteins, the structure and function of membrane proteins, the intramembrane composition and distribution of lipids and proteins, and the intermembrane interactions during exo- and endocytosis. In addition, natural cell-released microvesicles have gained importance for early detection of diseases and for their use as nanoreactors and minimal protocells. Yet, in most studies, ensembles of vesicles have been employed. More recently, new micro- and nanotechnological tools as well as novel developments in both optical and electron microscopy have allowed the isolation and investigation of individual (sub)micrometer-sized vesicles. Such single-vesicle experiments have revealed large heterogeneities in the structure and function of membrane components of single vesicles, which were hidden in ensemble studies. These results have opened enormous possibilities for bioanalysis and biotechnological applications involving unprecedented miniaturization at the nanometer and attoliter range. This review will cover important developments toward single-vesicle analysis and the central discoveries made in this exciting field of research.
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Affiliation(s)
- Horst Pick
- Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
| | - Ana Catarina Alves
- Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
| | - Horst Vogel
- Institute of Chemical Sciences and Engineering , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
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33
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The use of styrene-maleic acid copolymer (SMA) for studies on T cell membrane rafts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:130-141. [PMID: 30463696 DOI: 10.1016/j.bbamem.2018.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 08/09/2018] [Accepted: 08/13/2018] [Indexed: 02/06/2023]
Abstract
An emerging alternative to the use of detergents in biochemical studies on membrane proteins is apparently the use styrene-maleic acid (SMA) amphipathic copolymers. These cut the membrane into nanodiscs (SMA-lipid particles, SMALPs), which contain membrane proteins possibly surrounded by their native lipid environment. We examined this approach for studies on several types of T cell membrane proteins, previously defined as raft or non-raft associated, to see whether the properties of the raft derived SMALPs differ from non-raft SMALPs. Our results indicate that two types of raft proteins, GPI-anchored proteins and two Src family kinases, are markedly present in membrane fragments much larger (>250 nm) than those containing non-raft proteins (<20 nm). Lipid probes sensitive to membrane fluidity (membrane order) indicate that the lipid environment in the large SMALPs is less fluid (more ordered) than in the small ones which may indicate the presence of a more ordered lipid Lo phase which is characteristic of membrane rafts. Also the lipid composition of the small vs. large SMALPs is markedly different - the large ones are enriched in cholesterol and lipids containing saturated fatty acids. In addition, we confirm that T cell membrane proteins present in SMALPs can be readily immunoisolated. Our results support the use of SMA as a potentially better (less artifact prone) alternative to detergents for studies on membrane proteins and their complexes, including membrane rafts.
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34
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Bag SS, Gogoi H. Design of "Click" Fluorescent Labeled 2'-deoxyuridines via C5-[4-(2-Propynyl(methyl)amino)]phenyl Acetylene as a Universal Linker: Synthesis, Photophysical Properties, and Interaction with BSA. J Org Chem 2018; 83:7606-7621. [PMID: 29877080 DOI: 10.1021/acs.joc.7b03097] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microenvironment-sensitive fluorescent nucleosides present attractive advantages over single-emitting dyes for sensing inter-biomolecular interactions involving DNA. Herein, we report the rational design and synthesis of triazolyl push-pull fluorophore-labeled uridines via the intermediacy of C5-[4-(2-propynyl(methyl)amino)]phenyl acetylene as a universal linker. The synthesized nucleosides showed interesting solvatochromic characteristic and/or intramolecular charge transfer (ICT) features. A few of them also exhibited dual-emitting characteristics evidencing our designing concept. The HOMO-LUMO distribution showed that the emissive states of these nucleosides were characterized with more significant electron redistribution between the C5-[4-(2-propynyl(methyl)amino)]phenyl triazolyl donor moiety and the aromatic chromophores linked to it, leading to modulated emission property. The solvent polarity sensitivity of these nucleosides was also tested. The synthesized triazolyl benzonitrile (10C), naphthyl (10E), and pyrenyl (10G) nucleosides were found to exhibit interesting ICT and dual (LE/ICT) emission properties. The dual-emitting pyrenyl nucleoside maintained a good ratiometric response in the BSA protein microenvironment, enabling the switch-on ratiometric sensing of BSA as the only protein biomolecule. Thus, it is expected that the new fluorescent nucleoside analogues would be useful in designing DNA probes for nucleic acid analysis or studying DNA-protein interactions via a drastic change in fluorescence response due to a change in micropolarity.
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Affiliation(s)
- Subhendu Sekhar Bag
- Bioorganic Chemistry Laboratory, Department of Chemistry , Indian Institute of Technology Guwahati 781039 , India
| | - Hiranya Gogoi
- Bioorganic Chemistry Laboratory, Department of Chemistry , Indian Institute of Technology Guwahati 781039 , India
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35
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Frotscher E, Krainer G, Schlierf M, Keller S. Dissecting Nanosecond Dynamics in Membrane Proteins with Dipolar Relaxation upon Tryptophan Photoexcitation. J Phys Chem Lett 2018; 9:2241-2245. [PMID: 29652505 DOI: 10.1021/acs.jpclett.8b00834] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The structural dynamics of proteins on the nanosecond time scale can be probed with dipolar relaxation in response to photoexcitation of intrinsic tryptophan (Trp) residues. For membrane proteins, however, the complexity due to overlapping contributions from the protein itself, the membrane mimic, and the aqueous solvent impairs detailed analysis and interpretation. To disentangle these contributions, we measured time-resolved emission spectra of Trp in the protein Mistic in detergent micelles of various polarities. By comparison with Trp analogues in water and micelles, we could dissect the contributions from hydration, micelle, and protein matrix to dipolar relaxation on the nanosecond time scale. Our results demonstrate that ultrafast, subnanosecond relaxation reports on the extent of Trp shielding from water, with micelle and protein moieties making additive contributions. By contrast, relaxation in the low nanosecond regime is due to dipolar rearrangement of micelle and protein moieties upon photoexcitation, thereby probing conformational dynamics around the intrinsic fluorophore.
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Affiliation(s)
- Erik Frotscher
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
| | - Georg Krainer
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
- B CUBE - Center for Molecular Bioengineering , Technische Universität Dresden , Arnoldstr. 18 , 01307 Dresden , Germany
| | - Michael Schlierf
- B CUBE - Center for Molecular Bioengineering , Technische Universität Dresden , Arnoldstr. 18 , 01307 Dresden , Germany
| | - Sandro Keller
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
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36
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Gulyani A, Dey N, Bhattacharya S. A unique self-assembly-driven probe for sensing a lipid bilayer: ratiometric probing of vesicle to micelle transition. Chem Commun (Camb) 2018; 54:5122-5125. [DOI: 10.1039/c8cc01635f] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Membrane-driven self-assembly of an amphiphilic pyrene–terpyridine probe efficiently reports on vesicle–micelle transition through ratiometric changes.
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Affiliation(s)
- Akash Gulyani
- Department of Organic Chemistry, Indian Institute of Science
- Bangalore 560012
- India
- Institute for Stem Cell Biology & Regenerative Medicine, GKVK Post Bangalore
- India
| | - Nilanjan Dey
- Department of Organic Chemistry, Indian Institute of Science
- Bangalore 560012
- India
- Institute for Stem Cell Biology & Regenerative Medicine, GKVK Post Bangalore
- India
| | - Santanu Bhattacharya
- Department of Organic Chemistry, Indian Institute of Science
- Bangalore 560012
- India
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37
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Sezgin E, Schneider F, Zilles V, Urbančič I, Garcia E, Waithe D, Klymchenko AS, Eggeling C. Polarity-Sensitive Probes for Superresolution Stimulated Emission Depletion Microscopy. Biophys J 2017; 113:1321-1330. [PMID: 28734477 PMCID: PMC5607142 DOI: 10.1016/j.bpj.2017.06.050] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/22/2017] [Accepted: 06/27/2017] [Indexed: 11/17/2022] Open
Abstract
The lateral organization of molecules in the cellular plasma membrane plays an important role in cellular signaling. A critical parameter for membrane molecular organization is how the membrane lipids are packed. Polarity-sensitive dyes are powerful tools to characterize such lipid membrane order, employing, for example, confocal and two-photon microscopy. The investigation of potential nanodomains, however, requires the use of superresolution microscopy. Here, we test the performance of the polarity-sensitive membrane dyes Di-4-ANEPPDHQ, Di-4-AN(F)EPPTEA, and NR12S in superresolution stimulated emission depletion microscopy. Measurements on cell-derived membrane vesicles, in the plasma membrane of live cells, and on single virus particles, show the high potential of these dyes for probing nanoscale membrane heterogeneity.
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Affiliation(s)
- Erdinc Sezgin
- MRC Human Immunology UnitWeatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Falk Schneider
- MRC Human Immunology UnitWeatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Victoria Zilles
- MRC Human Immunology UnitWeatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Iztok Urbančič
- MRC Human Immunology UnitWeatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Esther Garcia
- MRC Human Immunology UnitWeatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Dominic Waithe
- Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Andrey S Klymchenko
- CNRS UMR 7213, Laboratoire de Biophotonique et Pharmacologie, University of Strasbourg, Illkirch Cedex, France
| | - Christian Eggeling
- MRC Human Immunology UnitWeatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom; Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom.
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38
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Chao WC, Shen JY, Yang CH, Lan YK, Yuan JH, Lin LJ, Yang HC, Lu JF, Wang JS, Wee K, Chen YH, Chou PT. The In Situ Tryptophan Analogue Probes the Conformational Dynamics in Asparaginase Isozymes. Biophys J 2017; 110:1732-1743. [PMID: 27119634 DOI: 10.1016/j.bpj.2016.03.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 03/10/2016] [Accepted: 03/21/2016] [Indexed: 11/19/2022] Open
Abstract
Dynamic water solvation is crucial to protein conformational reorganization and hence to protein structure and functionality. We report here the characterization of water dynamics on the L-asparaginase structural homology isozymes L-asparaginases I (AnsA) and II (AnsB), which are shown via fluorescence spectroscopy and dynamics in combination with molecular dynamics simulation to have distinct catalytic activity. By use of the tryptophan (Trp) analog probe 2,7-diaza-tryptophan ((2,7-aza)Trp), which exhibits unique water-catalyzed proton-transfer properties, AnsA and AnsB are shown to have drastically different local water environments surrounding the single Trp. In AnsA, (2,7-aza)Trp exhibits prominent green N(7)-H emission resulting from water-catalyzed excited-state proton transfer. In stark contrast, the N(7)-H emission is virtually absent in AnsB, which supports a water-accessible and a water-scant environment in the proximity of Trp for AnsA and AnsB, respectively. In addition, careful analysis of the emission spectra and corresponding relaxation dynamics, together with the results of molecular dynamics simulations, led us to propose two structural states associated with the rearrangement of the hydrogen-bond network in the vicinity of Trp for the two Ans. The water molecules revealed in the proximity of the Trp residue have semiquantitative correlation with the observed emission spectral variations of (2,7-aza)Trp between AnsA and AnsB. Titration of aspartate, a competitive inhibitor of Ans, revealed an increase in N(7)-H emission intensity in AnsA but no obvious spectral changes in AnsB. The changes in the emission profiles reflect the modulation of structural states by locally confined environment and trapped-water collective motions.
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Affiliation(s)
- Wei-Chih Chao
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jiun-Yi Shen
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Cheng-Han Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Yi-Kang Lan
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jui-Hung Yuan
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Li-Ju Lin
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Hsiao-Ching Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan.
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jinn-Shyan Wang
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Kevin Wee
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - You-Hua Chen
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan.
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39
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Mazeres S, Fereidouni F, Joly E. Using spectral decomposition of the signals from laurdan-derived probes to evaluate the physical state of membranes in live cells. F1000Res 2017; 6:763. [PMID: 28663788 PMCID: PMC5473435 DOI: 10.12688/f1000research.11577.2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/28/2017] [Indexed: 01/22/2023] Open
Abstract
Background: We wanted to investigate the physical state of biological membranes in live cells under the most physiological conditions possible. Methods: For this we have been using laurdan, C-laurdan or M-laurdan to label a variety of cells, and a biphoton microscope equipped with both a thermostatic chamber and a spectral analyser. We also used a flow cytometer to quantify the 450/530 nm ratio of fluorescence emissions by whole cells. Results: We find that using all the information provided by spectral analysis to perform spectral decomposition dramatically improves the imaging resolution compared to using just two channels, as commonly used to calculate generalized polarisation (GP). Coupled to a new plugin called Fraction Mapper, developed to represent the fraction of light intensity in the first component in a stack of two images, we obtain very clear pictures of both the intra-cellular distribution of the probes, and the polarity of the cellular environments where the lipid probes are localised. Our results lead us to conclude that, in live cells kept at 37°C, laurdan, and M-laurdan to a lesser extent, have a strong tendency to accumulate in the very apolar environment of intra-cytoplasmic lipid droplets, but label the plasma membrane (PM) of mammalian cells ineffectively. On the other hand, C-laurdan labels the PM very quickly and effectively, and does not detectably accumulate in lipid droplets. Conclusions: From using these probes on a variety of mammalian cell lines, as well as on cells from
Drosophila and
Dictyostelium discoideum, we conclude that, apart from the lipid droplets, which are very apolar, probes in intracellular membranes reveal a relatively polar and hydrated environment, suggesting a very marked dominance of liquid disordered states. PMs, on the other hand, are much more apolar, suggesting a strong dominance of liquid ordered state, which fits with their high sterol contents.
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Affiliation(s)
- Serge Mazeres
- Membrane and DNA Dynamics Team, Institut de Pharmacologie et de Biologie Structurale, CNRS, Université de Toulouse, Toulouse, F-31077, France
| | - Farzad Fereidouni
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, CA 95817, CA, 4400, USA
| | - Etienne Joly
- Membrane and DNA Dynamics Team, Institut de Pharmacologie et de Biologie Structurale, CNRS, Université de Toulouse, Toulouse, F-31077, France
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40
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Mazeres S, Fereidouni F, Joly E. Using spectral decomposition of the signals from laurdan-derived probes to evaluate the physical state of membranes in live cells. F1000Res 2017; 6:763. [PMID: 28663788 DOI: 10.12688/f1000research.11577.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/26/2017] [Indexed: 12/13/2022] Open
Abstract
Background: We wanted to investigate the physical state of biological membranes in live cells under the most physiological conditions possible. Methods: For this we have been using laurdan, C-laurdan or M-laurdan to label a variety of cells, and a biphoton microscope equipped with both a thermostatic chamber and a spectral analyser. We also used a flow cytometer to quantify the 450/530 nm ratio of fluorescence emissions by whole cells. Results: We find that using all the information provided by spectral analysis to perform spectral decomposition dramatically improves the imaging resolution compared to using just two channels, as commonly used to calculate generalized polarisation (GP). Coupled to a new plugin called Fraction Mapper, developed to represent the fraction of light intensity in the first component in a stack of two images, we obtain very clear pictures of both the intra-cellular distribution of the probes, and the polarity of the cellular environments where the lipid probes are localised. Our results lead us to conclude that, in live cells kept at 37°C, laurdan, and M-laurdan to a lesser extent, have a strong tendency to accumulate in the very apolar environment of intra-cytoplasmic lipid droplets, but label the plasma membrane (PM) of mammalian cells ineffectively. On the other hand, C-laurdan labels the PM very quickly and effectively, and does not detectably accumulate in lipid droplets. Conclusions: From using these probes on a variety of mammalian cell lines, as well as on cells from Drosophila and Dictyostelium discoideum, we conclude that, apart from the lipid droplets, which are very apolar, probes in intracellular membranes reveal a relatively polar and hydrated environment, suggesting a very marked dominance of liquid disordered states. PMs, on the other hand, are much more apolar, suggesting a strong dominance of liquid ordered state, which fits with their high sterol contents.
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Affiliation(s)
- Serge Mazeres
- Membrane and DNA Dynamics Team, Institut de Pharmacologie et de Biologie Structurale, CNRS, Université de Toulouse, Toulouse, F-31077, France
| | - Farzad Fereidouni
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, CA 95817, CA, 4400, USA
| | - Etienne Joly
- Membrane and DNA Dynamics Team, Institut de Pharmacologie et de Biologie Structurale, CNRS, Université de Toulouse, Toulouse, F-31077, France
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41
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Amaro M, Reina F, Hof M, Eggeling C, Sezgin E. Laurdan and Di-4-ANEPPDHQ probe different properties of the membrane. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2017; 50:134004. [PMID: 29449744 PMCID: PMC5802044 DOI: 10.1088/1361-6463/aa5dbc] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 01/02/2017] [Accepted: 02/02/2017] [Indexed: 05/22/2023]
Abstract
Lipid packing is a crucial feature of cellular membranes. Quantitative analysis of membrane lipid packing can be achieved using polarity sensitive probes whose emission spectrum depends on the lipid packing. However, detailed insights into the exact mechanisms that cause the changes in the spectra are necessary to interpret experimental fluorescence emission data correctly. Here, we analysed frequently used polarity sensitive probes, Laurdan and di-4-ANEPPDHQ, to test whether the underlying physical mechanisms of their spectral changes are the same and, thus, whether they report on the same physico-chemical properties of the cell membrane. Steady-state spectra as well as time-resolved emission spectra of the probes in solvents and model membranes revealed that they probe different properties of the lipid membrane. Our findings are important for the application of these dyes in cell biology.
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Affiliation(s)
- Mariana Amaro
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the C.A.S, v.v.i., Dolejskova 3, 182 23 Prague, Czechia
| | - Francesco Reina
- MRC Human Immunology Unit, OX39DS, University of Oxford, Oxford, United Kingdom
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the C.A.S, v.v.i., Dolejskova 3, 182 23 Prague, Czechia
| | - Christian Eggeling
- MRC Human Immunology Unit, OX39DS, University of Oxford, Oxford, United Kingdom
| | - Erdinc Sezgin
- MRC Human Immunology Unit, OX39DS, University of Oxford, Oxford, United Kingdom
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42
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Magarkar A, Jurkiewicz P, Allolio C, Hof M, Jungwirth P. Increased Binding of Calcium Ions at Positively Curved Phospholipid Membranes. J Phys Chem Lett 2017; 8:518-523. [PMID: 28067523 DOI: 10.1021/acs.jpclett.6b02818] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Calcium ion is the ubiquitous messenger in cells and plays a key role in neuronal signaling and fusion of synaptic vesicles. These vesicles are typically ∼20-50 nm in diameter, and thus their interaction with calcium ions cannot be modeled faithfully with a conventional flat membrane bilayer setup. Within our newly developed molecular dynamics simulations setup, we characterize here interactions of the calcium ion with curved membrane interfaces with atomistic detail. The present molecular dynamics simulations together with time-dependent fluorescence shift experiments suggest that the mode and strength of interaction of calcium ion with a phospholipid bilayer depends on its curvature. Potential of mean force calculations demonstrate that the binding of calcium ion to the positively curved side of the bilayer is significantly stronger compared with that to a flat membrane.
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Affiliation(s)
- Aniket Magarkar
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Faculty of Pharmacy, University of Helsinki , Viikinkaari 5E, Helsinki 00014, Finland
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , v.v.i., Dolejškova 3, CZ-182 23 Prague, Czech Republic
| | - Christoph Allolio
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg , 93040 Regensburg, Germany
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , v.v.i., Dolejškova 3, CZ-182 23 Prague, Czech Republic
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Department of Physics, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
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43
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Javanainen M, Melcrová A, Magarkar A, Jurkiewicz P, Hof M, Jungwirth P, Martinez-Seara H. Two cations, two mechanisms: interactions of sodium and calcium with zwitterionic lipid membranes. Chem Commun (Camb) 2017; 53:5380-5383. [DOI: 10.1039/c7cc02208e] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Adsorption of metal cations onto a cellular membrane changes its properties, such as interactions with charged moieties or the propensity for membrane fusion.
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Affiliation(s)
- Matti Javanainen
- Laboratory of Physics
- Tampere University of Technology
- FI-33101 Tampere
- Finland
- Department of Physics
| | - Adéla Melcrová
- J. Heyrovský Institute of Physical Chemistry
- Czech Academy of Sciences
- 182 23 Prague 8
- Czech Republic
| | - Aniket Magarkar
- Institute of Organic Chemistry and Biochemistry
- Czech Academy of Sciences
- 166 10 Prague 6
- Czech Republic
- Faculty of Pharmacy
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry
- Czech Academy of Sciences
- 182 23 Prague 8
- Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry
- Czech Academy of Sciences
- 182 23 Prague 8
- Czech Republic
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry
- Czech Academy of Sciences
- 166 10 Prague 6
- Czech Republic
- Laboratory of Physics
| | - Hector Martinez-Seara
- Institute of Organic Chemistry and Biochemistry
- Czech Academy of Sciences
- 166 10 Prague 6
- Czech Republic
- Laboratory of Physics
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44
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Carugo D, Aron M, Sezgin E, Bernardino de la Serna J, Kuimova MK, Eggeling C, Stride E. Modulation of the molecular arrangement in artificial and biological membranes by phospholipid-shelled microbubbles. Biomaterials 2017; 113:105-117. [DOI: 10.1016/j.biomaterials.2016.10.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/22/2016] [Accepted: 10/23/2016] [Indexed: 12/17/2022]
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45
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Amaro M, Filipe HAL, Prates Ramalho JP, Hof M, Loura LMS. Fluorescence of nitrobenzoxadiazole (NBD)-labeled lipids in model membranes is connected not to lipid mobility but to probe location. Phys Chem Chem Phys 2016; 18:7042-54. [PMID: 26727975 DOI: 10.1039/c5cp05238f] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Nitrobenzoxadiazole (NBD)-labeled lipids are popular fluorescent membrane probes. However, the understanding of important aspects of the photophysics of NBD remains incomplete, including the observed shift in the emission spectrum of NBD-lipids to longer wavelengths following excitation at the red edge of the absorption spectrum (red-edge excitation shift or REES). REES of NBD-lipids in membrane environments has been previously interpreted as reflecting restricted mobility of solvent surrounding the fluorophore. However, this requires a large change in the dipole moment (Δμ) of NBD upon excitation. Previous calculations of the value of Δμ of NBD in the literature have been carried out using outdated semi-empirical methods, leading to conflicting values. Using up-to-date density functional theory methods, we recalculated the value of Δμ and verified that it is rather small (∼2 D). Fluorescence measurements confirmed that the value of REES is ∼16 nm for 1,2-dioleoyl-sn-glycero-3-phospho-l-serine-N-(NBD) (NBD-PS) in dioleoylphosphatidylcholine vesicles. However, the observed shift is independent of both the temperature and the presence of cholesterol and is therefore insensitive to the mobility and hydration of the membrane. Moreover, red-edge excitation leads to an increased contribution of the decay component with a shorter lifetime, whereas time-resolved emission spectra of NBD-PS displayed an atypical blue shift following excitation. This excludes restrictions to solvent relaxation as the cause of the measured REES and TRES of NBD, pointing instead to the heterogeneous transverse location of probes as the origin of these effects. The latter hypothesis was confirmed by molecular dynamics simulations, from which the calculated heterogeneity of the hydration and location of NBD correlated with the measured fluorescence lifetimes/REES. Globally, our combination of theoretical and experiment-based techniques has led to a considerably improved understanding of the photophysics of NBD and a reinterpretation of its REES in particular.
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Affiliation(s)
- Mariana Amaro
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Dolejskova 3, 182 23 Prague, Czech Republic.
| | - Hugo A L Filipe
- Centro de Química de Coimbra, Largo D. Dinis, Rua Larga, 3004-535 Coimbra, Portugal. and Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, Largo D. Dinis, Rua Larga, 3004-535 Coimbra, Portugal and Centro de Neurociências e Biologia Celular, Universidade de Coimbra, 3004-504 Coimbra, Portugal
| | - J P Prates Ramalho
- Departamento de Química and Centro de Química de Évora, Escola de Ciências e Tecnologia, Universidade de Évora, Rua Romão Ramalho, 59, 7000-671 Évora, Portugal
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Dolejskova 3, 182 23 Prague, Czech Republic.
| | - Luís M S Loura
- Centro de Química de Coimbra, Largo D. Dinis, Rua Larga, 3004-535 Coimbra, Portugal. and Centro de Neurociências e Biologia Celular, Universidade de Coimbra, 3004-504 Coimbra, Portugal and Faculdade de Farmácia, Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
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46
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Fiedler S, Heerklotz H. Vesicle Leakage Reflects the Target Selectivity of Antimicrobial Lipopeptides from Bacillus subtilis. Biophys J 2016; 109:2079-89. [PMID: 26588567 DOI: 10.1016/j.bpj.2015.09.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/17/2015] [Accepted: 09/21/2015] [Indexed: 11/30/2022] Open
Abstract
Cyclic lipopeptides act against a variety of plant pathogens and are thus highly efficient crop-protection agents. Some pesticides contain Bacillus subtilis strains that produce lipopeptide families, such as surfactins (SF), iturins (IT), and fengycins (FE). The antimicrobial activity of these peptides is mainly mediated by permeabilizing cellular membranes. We used a fluorescence-lifetime based leakage assay to examine the effect of individual lipid components in model membranes on lipopeptide activity. Leakage induction by FE was strongly inhibited by cholesterol (CHOL) as well as by phosphatidylethanolamine (PE) and -glycerol (PG) lipids. Already moderate amounts of CHOL increased the tolerable FE content in membranes by an order of magnitude to 0.5 FE per PC + CHOL. This indicates reduced FE-lipid demixing and aggregation, which is known to be required for membrane permeabilization and explains the strong inhibition by CHOL. Ergosterol (ERG) had a weak antagonistic effect. This confirms results of microbiological tests and agrees with the fungicidal activity and selectivity of FE. SF is known to be much less selective in its antimicrobial action. In line with this, liposome leakage by SF was little affected by sterols and PE. Interestingly, PG increased SF activity and changed its leakage mechanism toward all-or-none, suggesting more specific, larger, and/or longer-lived defect structures. This may be because of the reduced energetic cost of locally accumulating anionic SF in an anionic lipid matrix. IT was found largely inactive in our assays. B. subtilis QST713 produces the lipopeptides in a ratio of 6 mol SF: 37 mol FE: 57 mol IT. Leakage induced by this native mixture was inhibited by CHOL and PE, but unaffected by ERG and by PG in the absence of PE. Note that fungi contain anionic lipids, but little PE. Hence, our data explain the strong, fungicidal activity and selectivity of B. subtilis QST713 lipopeptides.
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Affiliation(s)
- Sebastian Fiedler
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada.
| | - Heiko Heerklotz
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada; Institute for Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Freiburg, Germany.
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47
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Dziuba D, Pospíšil P, Matyašovský J, Brynda J, Nachtigallová D, Rulíšek L, Pohl R, Hof M, Hocek M. Solvatochromic fluorene-linked nucleoside and DNA as color-changing fluorescent probes for sensing interactions. Chem Sci 2016; 7:5775-5785. [PMID: 30034716 PMCID: PMC6021979 DOI: 10.1039/c6sc02548j] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 06/20/2016] [Indexed: 12/16/2022] Open
Abstract
A nucleoside bearing a solvatochromic push-pull fluorene fluorophore (dCFL ) was designed and synthesized by the Sonogashira coupling of alkyne-linked fluorene 8 with 5-iodo-2'-deoxycytidine. The fluorene building block 8 and labeled nucleoside dCFL exerted bright fluorescence with significant solvatochromic effect providing emission maxima ranging from 421 to 544 nm and high quantum yields even in highly polar solvents, including water. The solvatochromism of 8 was studied by DFT and ADC(2) calculations to show that, depending on the polarity of the solvent, emission either from the planar or the twisted conformation of the excited state can occur. The nucleoside was converted to its triphosphate variant dCFLTP which was found to be a good substrate for DNA polymerases suitable for the enzymatic synthesis of oligonucleotide or DNA probes by primer extension or PCR. The fluorene-linked DNA can be used as fluorescent probes for DNA-protein (p53) or DNA-lipid interactions, exerting significant color changes visible even to the naked eye. They also appear to be suitable for time-dependent fluorescence shift studies on DNA, yielding information on DNA hydration and dynamics.
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Affiliation(s)
- Dmytro Dziuba
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Gilead & IOCB Research Center , Flemingovo nam. 2 , CZ-16610 Prague 6 , Czech Republic .
| | - Petr Pospíšil
- J. H eyrovský Institute of Physical Chemistry , Czech Academy of Sciences , Dolejskova 3 , CZ-182 23 Prague , Czech Republic
| | - Ján Matyašovský
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Gilead & IOCB Research Center , Flemingovo nam. 2 , CZ-16610 Prague 6 , Czech Republic .
| | - Jiří Brynda
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Gilead & IOCB Research Center , Flemingovo nam. 2 , CZ-16610 Prague 6 , Czech Republic .
| | - Dana Nachtigallová
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Gilead & IOCB Research Center , Flemingovo nam. 2 , CZ-16610 Prague 6 , Czech Republic .
| | - Lubomír Rulíšek
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Gilead & IOCB Research Center , Flemingovo nam. 2 , CZ-16610 Prague 6 , Czech Republic .
| | - Radek Pohl
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Gilead & IOCB Research Center , Flemingovo nam. 2 , CZ-16610 Prague 6 , Czech Republic .
| | - Martin Hof
- J. H eyrovský Institute of Physical Chemistry , Czech Academy of Sciences , Dolejskova 3 , CZ-182 23 Prague , Czech Republic
| | - Michal Hocek
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Gilead & IOCB Research Center , Flemingovo nam. 2 , CZ-16610 Prague 6 , Czech Republic .
- Department of Organic Chemistry , Faculty of Science , Charles University in Prague , Hlavova 8 , CZ-12843 Prague 2 , Czech Republic
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48
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Amaro M, Šachl R, Aydogan G, Mikhalyov II, Vácha R, Hof M. GM1 Ganglioside Inhibits β-Amyloid Oligomerization Induced by Sphingomyelin. Angew Chem Int Ed Engl 2016; 55:9411-5. [PMID: 27295499 PMCID: PMC5089616 DOI: 10.1002/anie.201603178] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Indexed: 01/02/2023]
Abstract
β-Amyloid (Aβ) oligomers are neurotoxic and implicated in Alzheimer's disease. Neuronal plasma membranes may mediate formation of Aβ oligomers in vivo. Membrane components sphingomyelin and GM1 have been shown to promote aggregation of Aβ; however, these studies were performed under extreme, non-physiological conditions. We demonstrate that physiological levels of GM1 , organized in nanodomains do not seed oligomerization of Aβ40 monomers. We show that sphingomyelin triggers oligomerization of Aβ40 and that GM1 is counteractive thus preventing oligomerization. We propose a molecular explanation that is supported by all-atom molecular dynamics simulations. The preventive role of GM1 in the oligomerization of Aβ40 suggests that decreasing levels of GM1 in the brain, for example, due to aging, could reduce protection against Aβ oligomerization and contribute to the onset of Alzheimer's disease.
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Affiliation(s)
- Mariana Amaro
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i., Prague, Czech Republic.
| | - Radek Šachl
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i., Prague, Czech Republic
| | - Gokcan Aydogan
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i., Prague, Czech Republic
| | - Ilya I Mikhalyov
- Shemyakin-Ovchinnikov Inst. Bioorganic Chemistry of the R.A.S., Moscow, GSP-7, Russian Fed
| | - Robert Vácha
- Faculty of Science and CEITEC, Masaryk University, Brno, Czech Republic
| | - Martin Hof
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i., Prague, Czech Republic.
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49
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Amaro M, Šachl R, Aydogan G, Mikhalyov II, Vácha R, Hof M. GM
1
‐Gangliosid hemmt die β‐Amyloid‐Oligomerisation, während Sphingomyelin diese initiiert. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mariana Amaro
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prag Tschechien
| | - Radek Šachl
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prag Tschechien
| | - Gokcan Aydogan
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prag Tschechien
| | - Ilya I. Mikhalyov
- Shemyakin-Ovchinnikov Inst. Bioorganic Chemistry of the R.A.S. Moskau GSP-7 Russland
| | - Robert Vácha
- Faculty of Science and CEITECMasaryk University Brno Tschechien
| | - Martin Hof
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. Prag Tschechien
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50
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Cheniour M, Gueyrard D, Goekjian PG, Granjon T, Marcillat O. A convenient and versatile synthesis of Laurdan-like fluorescent membrane probes: characterization of their fluorescence properties. RSC Adv 2016. [DOI: 10.1039/c5ra20369d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
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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Affiliation(s)
- M. Cheniour
- Université Claude Bernard Lyon 1
- F-69622 Villeurbanne
- France
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires
- ICBMS
| | - D. Gueyrard
- Université Claude Bernard Lyon 1
- F-69622 Villeurbanne
- France
- Université de Lyon
- Laboratoire Chimie Organique 2 – Glyco
| | - P. G. Goekjian
- Université Claude Bernard Lyon 1
- F-69622 Villeurbanne
- France
- Université de Lyon
- Laboratoire Chimie Organique 2 – Glyco
| | - T. Granjon
- Université Claude Bernard Lyon 1
- F-69622 Villeurbanne
- France
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires
- ICBMS
| | - O. Marcillat
- Université Claude Bernard Lyon 1
- F-69622 Villeurbanne
- France
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires
- ICBMS
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