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Wagner BD, Arnold AE, Gallant ST, Grinton CR, Locke JK, Mills ND, Snow CA, Uhlig TB, Vessey CN. The polarity sensitivity factor of some fluorescent probe molecules used for studying supramolecular systems and other heterogeneous environments. CAN J CHEM 2018. [DOI: 10.1139/cjc-2017-0727] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Fluorescence spectroscopy provides an excellent technique for investigating heterogeneous systems, due to its high sensitivity and the large effect of the local environment on molecular emission. In addition, the use of polarity-sensitive fluorescent probes as guests in supramolecular host–guest inclusion complexes can be exploited in fluorescent sensors. This paper identifies, tabulates, and quantifies a series of useful polarity-sensitive fluorescent probes, with a wide range of polarity-dependent fluorescence responses. The degree of polarity sensitivity is quantified using the polarity sensitivity factor (PSF), developed in our laboratory. In most cases, such polarity-sensitive probes show increased emission as the local polarity is decreased (PSF > 1); 10 such probes are described. However, less commonly, “reverse polarity dependence” can occur in which probe emission decreases with decreasing polarity (PSF < 1); four such probes are described. The mechanism for the observed polarity-induced fluorescence changes will also be discussed in selected representative cases. The purpose of this paper is to present details on a broad arsenal of polarity-sensitive fluorescence probes with varying properties, with potentially useful applications in the study of heterogeneous systems, including inclusion phenomena, and in practical applications such as fluorescent sensors, which will be useful to researchers studying supramolecular and other heterogeneous systems using fluorescence spectroscopy.
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Affiliation(s)
- Brian D. Wagner
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Amy E. Arnold
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Spencer T. Gallant
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Carmen R. Grinton
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Julia K. Locke
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Natasha D. Mills
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Carrie A. Snow
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Timara B. Uhlig
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
| | - Christen N. Vessey
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
- Department of Chemistry, University of Prince Edward Island, Charlottetown, PE C1E 1Z5, Canada
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2
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Nagy M, Rácz D, Kovács SL, Lázár L, Fehér PP, Purgel M, Zsuga M, Kéki S. New blue light-emitting isocyanobiphenyl based fluorophores: Their solvatochromic and biolabeling properties. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2015.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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3
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Jones JE, Diemer V, Adam C, Raftery J, Ruscoe RE, Sengel JT, Wallace MI, Bader A, Cockroft SL, Clayden J, Webb SJ. Length-Dependent Formation of Transmembrane Pores by 310-Helical α-Aminoisobutyric Acid Foldamers. J Am Chem Soc 2016; 138:688-95. [PMID: 26699898 PMCID: PMC4752191 DOI: 10.1021/jacs.5b12057] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
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The synthetic biology toolbox lacks
extendable and conformationally
controllable yet easy-to-synthesize building blocks that are long
enough to span membranes. To meet this need, an iterative synthesis
of α-aminoisobutyric acid (Aib) oligomers was used to create
a library of homologous rigid-rod 310-helical foldamers,
which have incrementally increasing lengths and functionalizable N-
and C-termini. This library was used to probe the inter-relationship
of foldamer length, self-association strength, and ionophoric ability,
which is poorly understood. Although foldamer self-association in
nonpolar chloroform increased with length, with a ∼14-fold
increase in dimerization constant from Aib6 to Aib11, ionophoric activity in bilayers showed a stronger length
dependence, with the observed rate constant for Aib11 ∼70-fold
greater than that of Aib6. The strongest ionophoric activity
was observed for foldamers with >10 Aib residues, which have end-to-end
distances greater than the hydrophobic width of the bilayers used
(∼2.8 nm); X-ray crystallography showed that Aib11 is 2.93 nm long. These studies suggest that being long enough to
span the membrane is more important for good ionophoric activity than
strong self-association in the bilayer. Planar bilayer conductance
measurements showed that Aib11 and Aib13, but
not Aib7, could form pores. This pore-forming behavior
is strong evidence that Aibm (m ≥ 10) building blocks can span bilayers.
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Affiliation(s)
- Jennifer E Jones
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.,Manchester Institute of Biotechnology, University of Manchester , 131 Princess St, Manchester M1 7DN, United Kingdom
| | - Vincent Diemer
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.,Manchester Institute of Biotechnology, University of Manchester , 131 Princess St, Manchester M1 7DN, United Kingdom
| | - Catherine Adam
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.,School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - James Raftery
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Rebecca E Ruscoe
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Jason T Sengel
- Department of Chemistry, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Mark I Wallace
- Department of Chemistry, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Antoine Bader
- EaStCHEM School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Scott L Cockroft
- EaStCHEM School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Jonathan Clayden
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.,School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Simon J Webb
- School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.,Manchester Institute of Biotechnology, University of Manchester , 131 Princess St, Manchester M1 7DN, United Kingdom
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4
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Majumder R, Sarkar Y, Das S, Jewrajka SK, Ray A, Parui PP. A ratiometric solvent polarity sensing Schiff base molecule for estimating the interfacial polarity of versatile amphiphilic self-assemblies. Analyst 2016; 141:3246-50. [DOI: 10.1039/c6an00582a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple interfacial polarity detection method for versatile self-assemblies is introduced for the first time by exploiting the polarity induced interconversion between nonionic and zwitterionic forms of Schiff base molecule (PMP).
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Affiliation(s)
- Rini Majumder
- Department of Chemistry
- Jadavpur University
- Kolkata 700032
- India
| | - Yeasmin Sarkar
- Department of Chemistry
- Jadavpur University
- Kolkata 700032
- India
| | - Sanju Das
- Department of Chemistry
- Jadavpur University
- Kolkata 700032
- India
- Department of Chemistry
| | - Suresh K. Jewrajka
- Reverse Osmosis Division
- CSIR-Central Salt & Marine Chemicals Research Institute
- Gujarat-364002
- India
| | - Ambarish Ray
- Department of Chemistry
- Maulana Azad College
- Kolkata 700013
- India
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5
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Demchenko AP, Duportail G, Oncul S, Klymchenko AS, Mély Y. Introduction to fluorescence probing of biological membranes. Methods Mol Biol 2015; 1232:19-43. [PMID: 25331125 DOI: 10.1007/978-1-4939-1752-5_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fluorescence is one of the most powerful and commonly used tools in biophysical studies of biomembrane structure and dynamics that can be applied on different levels, from lipid monolayers and bilayers to living cells, tissues, and whole animals. Successful application of this method relies on proper design of fluorescence probes with optimized photophysical properties. These probes are efficient for studying the microscopic analogs of viscosity, polarity, and hydration, as well as the molecular order, environment relaxation, and electrostatic potentials at the sites of their location. Being smaller than the membrane width they can sense the gradients of these parameters across the membrane. We present examples of novel dyes that achieve increased spatial resolution and information content of the probe responses. In this respect, multiparametric environment-sensitive probes feature considerable promise.
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Affiliation(s)
- Alexander P Demchenko
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, 9 Leontovicha Street, Kiev, 01030, Ukraine,
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6
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7
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Zhytniakivska O, Trusova V, Gorbenko G, Kirilova E, Kalnina I, Kirilov G, Molotkovsky J, Tulkki J, Kinnunen P. Location of Novel Benzanthrone Dyes in Model Membranes as Revealed by Resonance Energy Transfer. J Fluoresc 2014; 24:899-907. [DOI: 10.1007/s10895-014-1370-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 02/24/2014] [Indexed: 01/21/2023]
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8
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Rácz D, Nagy M, Mándi A, Zsuga M, Kéki S. Solvatochromic properties of a new isocyanonaphthalene based fluorophore. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2013.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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9
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Kumari N, Dey N, Jha S, Bhattacharya S. Ratiometric, reversible, and parts per billion level detection of multiple toxic transition metal ions using a single probe in micellar media. ACS APPLIED MATERIALS & INTERFACES 2013; 5:2438-2445. [PMID: 23427918 DOI: 10.1021/am400063k] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present the selective sensing of multiple transition metal ions in water using a synthetic single probe. The probe is made up of pyrene and pyridine as signaling and interacting moiety, respectively. The sensor showed different responses toward metal ions just by varying the medium of detection. In organic solvent (acetonitrile), the probe showed selective detection of Hg2+ ion. In water, the fluorescence quenching was observed with three metal ions, Cu2+, Hg2+, and Ni2+. Further, just by varying the surface charge on the micellar aggregates, the probe could detect and discriminate the above-mentioned three different toxic metal ions appropriately. In neutral micelles (Brij 58), the probe showed a selective interaction with Hg2+ ion as observed in acetonitrile medium. However, in anionic micellar medium (sodium dodecyl sulfate, SDS), the probe showed changes with both Cu2+ and Ni2+ under UV-vis absorption spectroscopy. The discrimination between these two ions was achieved by recording their emission spectra, where it showed selective quenching with Cu2+.
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Affiliation(s)
- Namita Kumari
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India
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10
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Nanoscale measurement of the dielectric constant of supported lipid bilayers in aqueous solutions with electrostatic force microscopy. Biophys J 2013; 104:1257-62. [PMID: 23528085 DOI: 10.1016/j.bpj.2013.02.011] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/23/2013] [Accepted: 02/11/2013] [Indexed: 12/31/2022] Open
Abstract
We present what is, to our knowledge, the first experimental demonstration of dielectric constant measurement and quantification of supported lipid bilayers in electrolyte solutions with nanoscale spatial resolution. The dielectric constant was quantitatively reconstructed with finite element calculations by combining thickness information and local polarization forces which were measured using an electrostatic force microscope adapted to work in a liquid environment. Measurements of submicrometric dipalmitoylphosphatidylcholine lipid bilayer patches gave dielectric constants of ε(r) ~ 3, which are higher than the values typically reported for the hydrophobic part of lipid membranes (ε(r) ~ 2) and suggest a large contribution of the polar headgroup region to the dielectric response of the lipid bilayer. This work opens apparently new possibilities in the study of biomembrane electrostatics and other bioelectric phenomena.
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11
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The New Fluorescent Membrane Probe Ahba: A Comparative Study with the Largely Used Laurdan. J Fluoresc 2013; 23:479-86. [DOI: 10.1007/s10895-013-1172-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 01/31/2013] [Indexed: 10/27/2022]
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12
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Lin JH, Lin CH, Yang DY. Synthesis of 4-hydroxy-7-dimethylamino-3-pyrazolinylcoumarins and their polarity-sensitive properties. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2011.11.142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Fluorescence Probing in Structurally Anisotropic Materials. ADVANCED FLUORESCENCE REPORTERS IN CHEMISTRY AND BIOLOGY III 2011. [DOI: 10.1007/978-3-642-18035-4_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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Quantitative assessment of peptide–lipid interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1999-2012. [DOI: 10.1016/j.bbamem.2010.07.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 07/13/2010] [Accepted: 07/13/2010] [Indexed: 11/23/2022]
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15
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Mansfeld FM, Au-Yeung HY, Sanders JKM, Otto S. Dynamic combinatorial chemistry at the phospholipid bilayer interface. ACTA ACUST UNITED AC 2010. [DOI: 10.1186/1759-2208-1-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abstract
Background
Molecular recognition at the environment provided by the phospholipid bilayer interface plays an important role in biology and is subject of intense investigation. Dynamic combinatorial chemistry is a powerful approach for exploring molecular recognition, but has thus far not been adapted for use in this special microenvironment.
Results
Thioester exchange was found to be a suitable reversible reaction to achieve rapid equilibration of dynamic combinatorial libraries at the egg phosphatidyl choline bilayer interface. Competing thioester hydrolysis can be minimised by judicial choice of the structure of the thioesters and the experimental conditions. Comparison of the library compositions in bulk solution with those in the presence of egg PC revealed that the latter show a bias towards the formation of library members rich in membrane-bound building blocks. This leads to a shift away from macrocyclic towards linear library members.
Conclusions
The methodology to perform dynamic combinatorial chemistry at the phospholipid bilayer interface has been developed. The spatial confinement of building blocks to the membrane interface can shift the ring-chain equilibrium in favour of chain-like compounds. These results imply that interfaces may be used as a platform to direct systems to the formation of (informational) polymers under conditions where small macrocycles would dominate in the absence of interfacial confinement.
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16
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Müller S, Nebe-von-Caron G. Functional single-cell analyses: flow cytometry and cell sorting of microbial populations and communities. FEMS Microbiol Rev 2010; 34:554-87. [DOI: 10.1111/j.1574-6976.2010.00214.x] [Citation(s) in RCA: 266] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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17
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Zhang TL, Han BH. The visualized polarity-sensitive magnetic nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8893-8900. [PMID: 20143867 DOI: 10.1021/la9046512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Three polarity-sensitive organic molecules (DIAA, DIUA, and DISA) were designed and synthesized for functionalizing high-quality superparamagnetic Fe(3)O(4) nanoparticles (NPs) via the ligand exchange strategy to prepare polarity-sensitive Fe(3)O(4) NPs. The functional group is chosen to be the carboxyl group (one for DIAA and DIUA, two for DISA) that is a universal coordinating site for iron oxide NPs. The method for binding these functional molecules onto the surface of the NPs is simple and straightforward. Among the three molecules, the DISA molecules passivate the NPs' surface most efficiently owing to their particular structure with two carboxyl groups and a general good solubility. The DISA-functionalized Fe(3)O(4) NPs (DISA-Fe(3)O(4) NPs) display distinctly different fluorescence emissions in various solvents of different polarities with the magnetism well preserving. The prepared polarity-sensitive Fe(3)O(4) NPs that are dual functional can be used as a visualized polarity sensor and perform NPs' superparamagnetic properties simultaneously. It also provides a conceptual design for preparing the polarity-sensitive nanomaterials with multifunction.
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Affiliation(s)
- Tian-Long Zhang
- National Center for Nanoscience and Technology, Beijing 100190, China
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18
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Przybylo M, Borowik T, Langner M. Fluorescence Techniques for Determination of the Membrane Potentials in High Throughput Screening. J Fluoresc 2010; 20:1139-57. [DOI: 10.1007/s10895-010-0665-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 04/05/2010] [Indexed: 01/14/2023]
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19
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Gruber B, Stadlbauer S, Woinaroschy K, König B. Luminescent vesicular receptors for the recognition of biologically important phosphate species. Org Biomol Chem 2010; 8:3704-14. [DOI: 10.1039/c004916f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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20
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Profiling of dynamics in protein-lipid-water systems: a time-resolved fluorescence study of a model membrane protein with the label BADAN at specific membrane depths. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:647-56. [PMID: 19760185 PMCID: PMC2841254 DOI: 10.1007/s00249-009-0538-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 08/19/2009] [Accepted: 08/26/2009] [Indexed: 12/03/2022]
Abstract
Profiles of lipid-water bilayer dynamics were determined from picosecond time-resolved fluorescence spectra of membrane-embedded BADAN-labeled M13 coat protein. For this purpose, the protein was labeled at seven key positions. This places the label at well-defined locations from the water phase to the center of the hydrophobic acyl chain region of a phospholipid model membrane, providing us with a nanoscale ruler to map membranes. Analysis of the time-resolved fluorescence spectroscopic data provides the characteristic time constant for the twisting motion of the BADAN label, which is sensitive to the local flexibility of the protein–lipid environment. In addition, we obtain information about the mobility of water molecules at the membrane–water interface. The results provide an unprecedented nanoscale profiling of the dynamics and distribution of water in membrane systems. This information gives clear evidence that the actual barrier of membranes for ions and aqueous solvents is located at the region of carbonyl groups of the acyl chains.
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21
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Sachl R, Stepánek M, Procházka K, Humpolícková J, Hof M. Fluorescence study of the solvation of fluorescent probes prodan and laurdan in poly(epsilon-caprolactone)-block-poly(ethylene oxide) vesicles in aqueous solutions with tetrahydrofurane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:288-95. [PMID: 18044937 DOI: 10.1021/la702277t] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Steady-state and time-resolved fluorescence measurements were used to study the relaxation of the microenvironment of hydrophobic probes 6-propionyl-2-(dimethylamino)naphthalene (prodan) and 6-dodecanoyl-2-(dimethylamino)naphthalene (laurdan) in systems containing vesicles formed by the amphiphilic diblock copolymer poly(epsilon-caprolactone)-block-poly(ethylene oxide) (PCL-PEO) and water/tetrahydrofurane (THF) solvent mixtures. It was found that in case of prodan, both steady-state and time-resolved emission spectra were composed of two subspectra corresponding to the emission of prodan molecules located (i) in fairly rigid (effectively viscous) and hydrophobic domains of the vesicles close to the PCL/PEO interface and (ii) in a more polar and less viscous medium (in the bulk solution). The fraction of the emission from the more polar microenvironment increases with increasing content of THF in the system. Laurdan, in contrast to prodan, appeared to be solubilized preferentially in the hydrophobic domains up to 30 vol % of THF content, and its emission spectra changed only due to swelling of hydrophobic PCL domains by added THF. The study shows that the analysis of the time-resolved emission from a probe distributed in two media is, in principle, possible, but it is quite complex and appreciably less accurate, and the relaxation times are ill-defined averages of several processes. The bimodal or shoulder-containing time-resolved spectra have to be decomposed in pertinent time-resolved subspectra and treated separately. Another important result of the study is a piece of knowledge concerning the motion of the probe with respect to the vesicle. In the studied complex system, not only the relaxation of the solvent and reorganization of polymer segments around the fluorescent headgroup of the probe affect the emission but also a lateral motion of the probe with respect to the nanoparticle within the lifetime of the excited state contributes significantly to the relaxation and to the relatively slow time-resolved Stokes shift.
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Affiliation(s)
- Radek Sachl
- Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, 128 40 Prague 2, Czech Republic
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22
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De Vequi-Suplicy CC, Benatti CR, Lamy MT. Laurdan in fluid bilayers: position and structural sensitivity. J Fluoresc 2006; 16:431-9. [PMID: 16791507 DOI: 10.1007/s10895-005-0059-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 12/23/2005] [Indexed: 11/26/2022]
Abstract
Laurdan (2-dimethylamino-6-lauroylnaphthalene) is a hydrophobic fluorescent probe widely used in lipid systems. This probe was shown to be highly sensitive to lipid phases, and this sensitivity related to the probe microenvironment polarity and viscosity. In the present study, Laurdan was incorporated in 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DPPG), which has a phase transition around 41 degrees C, and DLPC (1,2-dilauroyl-sn-glycero-3-phosphocholine), which is in the fluid phase at all temperatures studied. The temperature dependence of Laurdan fluorescent emission was analyzed via the decomposition into two gaussian bands, a short- and a long-wavelength band, corresponding to a non-relaxed and a water-relaxed excited state, respectively. As expected, Laurdan fluorescence is highly sensitive to DPPG gel-fluid transition. However, it is shown that Laurdan fluorescence, in DLPC, is also dependent on the temperature, though the bilayer phase does not change. This is in contrast to the rather similar fluorescent emission obtained for the analogous hydrophilic probe, Prodan (2-dimethylamino-6-propionylnaphthalene), when free in aqueous solution, over the same range of temperature. Therefore, Laurdan fluorescence seems to be highly dependent on the lipid bilayer packing, even for fluid membranes. This is supported by Laurdan fluorescence anisotropy and spin labels incorporated at different positions in the fluid lipid bilayer of DLPC. The latter were used both as structural probes for bilayer packing, and as Laurdan fluorescence quenchers. The results confirm the high sensitivity of Laurdan fluorescence emission to membrane packing, and indicate a rather shallow position for Laurdan in the membrane.
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23
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Abstract
The ability of a vesicle-bound receptor to associate with a water-soluble ligand increases with membrane loading level and the presence of membrane additives with cationic N-CH3 groups.
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Affiliation(s)
- Hua Jiang
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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Halskau O, Underhaug J, Frøystein NA, Martínez A. Conformational flexibility of alpha-lactalbumin related to its membrane binding capacity. J Mol Biol 2005; 349:1072-86. [PMID: 15913646 DOI: 10.1016/j.jmb.2005.04.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 04/04/2005] [Accepted: 04/12/2005] [Indexed: 10/25/2022]
Abstract
Different folding states of the small, globular milk protein bovine alpha-lactalbumin (BLA) induced by the anionic surfactant sodium dodecylsulphate (SDS) have been examined by fluorescence spectroscopy, CD and NMR. The solution structure of the protein in the absence of SDS was also determined, indicating fluidity even under native conditions. BLA is partly denatured to a molten globule (MG)-like state by micromolar concentrations of SDS, and the transitions from native to MG-like state are dependent on pH, the protein being more sensitive to the surfactant at pH 6.5. As indicated by measurements of the intrinsic emission fluorescence, the tertiary structure disappears at lower concentrations of SDS than most of the secondary structure, as estimated from CD data. The MG-like state induced by low concentrations of SDS is not observable by NMR, and is probably fluctuating and/or aggregating. At higher concentrations of SDS above the critic concentration of micelles, an NMR-observable state reappears. This micelle-associated conformer was partially assigned, and found to bear strong resemblance to the acid-tri-fluoroethanol state, retaining weakened versions of the A and C helix of native BLA. We discuss the results in terms of the inherent flexibility of the protein, and its ability to form multiple folding states and to bind to membranes. Also, we propose that proteins with stable MG-like conformers can have these states stabilized by low levels of compounds with surfactant properties in vivo.
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Affiliation(s)
- Oyvind Halskau
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
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Mukherjee S, Raghuraman H, Dasgupta S, Chattopadhyay A. Organization and dynamics of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-labeled lipids: a fluorescence approach. Chem Phys Lipids 2004; 127:91-101. [PMID: 14706743 DOI: 10.1016/j.chemphyslip.2003.09.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Lipids that are labeled with the NBD (7-nitrobenz-2-oxa-1,3-diazol-4-yl) group are widely used as fluorescent analogues of native lipids in biological and model membranes to monitor a variety of processes. NBD-labeled lipids have previously been used to monitor the organization and dynamics of molecular assemblies such as membranes, micelles and reverse micelles utilizing the wavelength-selective fluorescence approach. In this paper, we have characterized the organization and dynamics of various NBD-labeled lipids using red edge excitation shift (REES) and other fluorescence approaches which include analysis of membrane penetration depths of the NBD group using the parallax method. We show here that the environment and location experienced by the NBD group of the NBD-labeled lipids could depend on the ionization state of the lipid. This could have potentially important implications in future studies involving NBD-labeled lipids as tracers in a cellular context.
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Affiliation(s)
- Soumi Mukherjee
- Centre for Cellular and Molecular Biology, Hyderabad 500 007, India
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26
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Zhu M, Li J, Fink AL. The association of alpha-synuclein with membranes affects bilayer structure, stability, and fibril formation. J Biol Chem 2003; 278:40186-97. [PMID: 12885775 DOI: 10.1074/jbc.m305326200] [Citation(s) in RCA: 258] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The aggregation of alpha-synuclein is believed to be a critical factor in the etiology of Parkinson's disease. alpha-Synuclein is an abundant neuronal protein of unknown function, which is enriched in the presynaptic terminals of neurons. Although alpha-synuclein is found predominantly in the cytosolic fractions, membrane-bound alpha-synuclein has been suggested to play an important role in fibril formation. The effects of alpha-synuclein on lipid bilayers of different compositions were determined using fluorescent environment-specific probes located at various depths. alpha-Synuclein-membrane interactions were found to affect both protein and membrane properties. Our results indicate that in addition to electrostatic interactions, hydrophobic interactions are important in the association of the protein with the bilayer, and lead to disruption of the membrane. The latter was observed by atomic force microscopy and fluorescent dye leakage from vesicles. The kinetics of alpha-synuclein fibril formation were significantly affected by the protein association and subsequent membrane disruption, and reflected the conformation of alpha-synuclein. The ability of alpha-synuclein to disrupt membranes correlated with the binding affinity of alpha-synuclein for the particular membrane composition, and to the induced helical conformation of alpha-synuclein. Protofibrillar or fibrillar alpha-synuclein caused a much more rapid destruction of the membrane than soluble monomeric alpha-synuclein, indicating that protofibrils (oligomers) or fibrils are likely to be significantly neurotoxic.
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Affiliation(s)
- Min Zhu
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
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27
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Singh Y, Gulyani A, Bhattacharya S. A new ratiometric fluorescence probe as strong sensor of surface charge of lipid vesicles and micelles. FEBS Lett 2003; 541:132-6. [PMID: 12706833 DOI: 10.1016/s0014-5793(03)00314-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We report on the ability of a new fluorescent probe, 4-(2-pyren-1-yl-vinyl) pyridine, 1, to respond to micelles and phospholipid vesicles of different surface charge. The probe gets incorporated into micellar and membranous assemblies and shows a large red-shift in the fluorescence emission maxima especially when the surface charge of the organized media is anionic. The effect on the photo-excitation of the probe is very clear and pronounced as it can be easily visualized. The sample color upon photo-excitation changes from blue to orange/red once the probe experiences negatively charged vesicular or micellar surfaces. These results make the probe molecule useful as a reporter for sensing electrostatic environment in biological membranes and related organized assemblies.
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Affiliation(s)
- Yashveer Singh
- Department of Organic Chemistry, Indian Institute of Science, Bangalore, India
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28
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Doyle EL, Hunter CA, Phillips HC, Webb SJ, Williams NH. Cooperative binding at lipid bilayer membrane surfaces. J Am Chem Soc 2003; 125:4593-9. [PMID: 12683831 DOI: 10.1021/ja021048a] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The binding of copper(II) ions to membrane-bound synthetic receptors has been investigated. Complexation fitted a 4:1 receptor:copper(II) model, and the observed binding constants are significantly enhanced at the membrane relative to solution; these effects can be explained by the lower polarity of the membrane-water interface and the concentrating effect of the membrane, with no observed contribution from receptor preorganization. The stoichiometry of the complex formed is very sensitive to the concentration of the receptor in the membrane, and at low concentrations, binding is reduced relative to solution controls. This implies that by increasing or decreasing the number of receptors in their membranes, cells can finely tune biological responses such as chemotaxis that depend on the size of the receptor-ligand clusters formed.
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Affiliation(s)
- Emma L Doyle
- Centre for Chemical Biology, Krebs Institute for Biomolecular Science, Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, U.K
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29
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Bhattacharya S, Dileep PV. Membrane-Forming Properties of Cationic Lipids Bearing Oxyethylene-Based Linkages. J Phys Chem B 2003. [DOI: 10.1021/jp0272771] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Santanu Bhattacharya
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India
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30
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Zolese G, Wozniak M, Mariani P, Saturni L, Bertoli E, Ambrosini A. Different modulation of phospholipase A2 activity by saturated and monounsaturated N-acylethanolamines. J Lipid Res 2003; 44:742-53. [PMID: 12562826 DOI: 10.1194/jlr.m200395-jlr200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The physiological functions of N-acylethanolamines (NAEs) are poorly understood, although many functions were suggested for these naturally occurring membrane components of plants and animals. The binding with cannabinoid receptors CB1 and CB2 was demonstrated for some NAEs, such as anandamide. However, the chemical nature of these molecules suggests that some of their biological effects on biomembranes could be related, at least partially, to physical interactions with the lipid bilayer. The present work studies the effect of saturated and monounsaturated NAEs on phospholipase A2 (PLA2) activity, which is dependent on lipid bilayer features. The present study, performed by 2-dimethylamino-(6-lauroyl)-naphthalene (Laurdan) fluorescence, demonstrates that the acyl chain length and the presence of a single double bond are crucial for the enzymatic activity modulation by NAEs. In fact, saturated NAEs with 10 carbon atoms don't affect the PLA2 activity, while NAEs with 12 and 16 carbon atoms largely activate the enzyme. On the other hand, an acyl chain length of 18 carbon atoms, with or without the presence of a double bond, only slightly affects the enzymatic activity. A structural model for NAE-lipid interactions is proposed in order to explain the differences in PLA2 activity modulation by these fatty acid derivatives.
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31
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Bürsing H, Kundu S, Vöhringer P. Solvation Dynamics at Aqueous Lipid−Membrane Interfaces Explored by Temperature-Dependent 3-Pulse-Echo Peak Shifts: Influence of the Lipid Polymorphism. J Phys Chem B 2003. [DOI: 10.1021/jp027036t] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Helge Bürsing
- Biomolecular and Chemical Dynamics Group, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 3700 Göttingen, Germany, and Université Louis Pasteur, Institut Le Bel, 4 rue Blaise Pascal, F-67000 Strasbourg, France
| | - Santi Kundu
- Biomolecular and Chemical Dynamics Group, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 3700 Göttingen, Germany, and Université Louis Pasteur, Institut Le Bel, 4 rue Blaise Pascal, F-67000 Strasbourg, France
| | - Peter Vöhringer
- Biomolecular and Chemical Dynamics Group, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 3700 Göttingen, Germany, and Université Louis Pasteur, Institut Le Bel, 4 rue Blaise Pascal, F-67000 Strasbourg, France
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32
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Klymchenko AS, Duportail G, Ozturk T, Pivovarenko VG, Mély Y, Demchenko AP. Novel two-band ratiometric fluorescence probes with different location and orientation in phospholipid membranes. CHEMISTRY & BIOLOGY 2002; 9:1199-208. [PMID: 12445770 DOI: 10.1016/s1074-5521(02)00244-2] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
3-hydroxyflavone (3-HF) derivatives are very attractive fluorescence sensors due to their ability to respond to small changes in their microenvironment via a dramatic alteration of the relative intensities of their two well-separated emission bands. We developed fluorescence probes with locations at different depths and orientations of 3-HF moiety in the phospholipid bilayer, which determine their fluorescence behavior. While the spectral shifts of the probes correlate with their binding site polarity, the intensity ratio is a complex parameter that is also sensitive to the local hydration. We demonstrate that even the deeply located probes sense this hydration effect, which can be modulated by the charge of the lipid heads and is anisotropic with respect to the bilayer plane. Thus the two-band ratiometric fluorescence probes can provide multiparametric information on the properties of lipid membranes at different depths.
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Affiliation(s)
- Andrey S Klymchenko
- TUBITAK Research Institute for Genetic Engineering and Biotechnology, Gebze-Kocaeli 41470, Turkey
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33
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Ercelen S, Klymchenko AS, Demchenko AP. Ultrasensitive fluorescent probe for the hydrophobic range of solvent polarities. Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(02)00493-2] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Duportail G, Klymchenko A, Mely Y, Demchenko A. Neutral fluorescence probe with strong ratiometric response to surface charge of phospholipid membranes. FEBS Lett 2001; 508:196-200. [PMID: 11718715 DOI: 10.1016/s0014-5793(01)03055-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We report on dramatic differences in fluorescence spectra of 4'-dimethylamino-3-hydroxyflavone (probe F) studied in phospholipid membranes of different charge (phosphatidyl glycerol, phosphatidylcholine (PC), their mixture and the mixture of PC with a cationic lipid). The effect consists in variations of relative intensities at two well-separated band maxima at 520 and 570 nm belonging to normal (N*) and tautomer (T*) excited states of flavone chromophore. Based on these studies we propose a new approach to measure electrostatic potential at the surface layer of phospholipid membranes, which is based on potential-dependent changes of bilayer hydration and involves very sensitive and convenient ratiometric measurements in fluorescence emission.
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Affiliation(s)
- G Duportail
- Laboratoire de Pharmacologie et Physicochimie, UMR 7034 du CNRS, Faculté de Pharmacie, Université Louis Pasteur, Illkirch, France
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Fiorini R, Littarru GP, Coppa GV, Kantar A. Plasma membrane polarity of polymorphonuclear leucocytes from children with primary ciliary dyskinesia. Eur J Clin Invest 2000; 30:519-25. [PMID: 10849021 DOI: 10.1046/j.1365-2362.2000.00670.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Polymorphonuclear leucocytes (PMN) from subjects with primary ciliary dyskinesia (PCD) can have abnormal locomotory systems. The locomotory activity of PMN is the result of biochemical events mediated by the plasma membrane. In this study we investigated plasma membrane polarity of PMN from children with PCD. DESIGN Membrane polarity was studied in 11 children with PCD and in healthy controls by measuring the steady-state fluorescence excitation and emission spectra of 2-dimethylamino[6-lauroyl]naphthalene (Laurdan), which is known to be incorporated at the hydrophobic-hydrophilic interface of the bilayer, displaying spectral sensitivity to the polarity of its surroundings. Laurdan shows a marked steady-state emission red shift in polar solvents, with respect to nonpolar solvents. Moreover, the effect of the microtubule disassembling agent colchicine on PMN membrane polarity was evaluated. RESULT Our results show a red shift of the fluorescence excitation and emission spectra of Laurdan in PMN from the PCD group with respect to the control group. These data indicate an increase in membrane polarity of PMN from the PCD group. Treatment of PMN with colchicine induced a red shift in the Laurdan excitation and emission spectra with the same trend observed in PMN from the PCD group. CONCLUSION PMN from children with PCD are characterized by an increased plasma membrane polarity. These changes could be the basis of the modifications in the locomotory activities of PMN. The observed alterations may be attributed to abnormalities in the cytoskeleton.
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Affiliation(s)
- R Fiorini
- Department of Biochemistry, University of Ancona, Ancona, Italy
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