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Nandi R, Amdursky N. The Dual Use of the Pyranine (HPTS) Fluorescent Probe: A Ground-State pH Indicator and an Excited-State Proton Transfer Probe. Acc Chem Res 2022; 55:2728-2739. [PMID: 36053265 PMCID: PMC9494743 DOI: 10.1021/acs.accounts.2c00458] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Indexed: 01/19/2023]
Abstract
Molecular fluorescent probes are an essential experimental tool in many fields, ranging from biology to chemistry and materials science, to study the localization and other environmental properties surrounding the fluorescent probe. Thousands of different molecular fluorescent probes can be grouped into different families according to their photophysical properties. This Account focuses on a unique class of fluorescent probes that distinguishes itself from all other probes. This class is termed photoacids, which are molecules exhibiting a change in their acid-base transition between the ground and excited states, resulting in a large change in their pKa values between these two states, which is thermodynamically described using the Förster cycle. While there are many different photoacids, we focus only on pyranine, which is the most used photoacid, with pKa values of ∼7.4 and ∼0.4 for its ground and excited states, respectively. Such a difference between the pKa values is the basis for the dual use of the pyranine fluorescent probe. Furthermore, the protonated and deprotonated states of pyranine absorb and emit at different wavelengths, making it easy to focus on a specific state. Pyranine has been used for decades as a fluorescent pH indicator for physiological pH values, which is based on its acid-base equilibrium in the ground state. While the unique excited-state proton transfer (ESPT) properties of photoacids have been explored for more than a half-century, it is only recently that photoacids and especially pyranine have been used as fluorescent probes for the local environment of the probe, especially the hydration layer surrounding it and related proton diffusion properties. Such use of photoacids is based on their capability for ESPT from the photoacid to a nearby proton acceptor, which is usually, but not necessarily, water. In this Account, we detail the photophysical properties of pyranine, distinguishing between the processes in the ground state and the ones in the excited state. We further review the different utilization of pyranine for probing different properties of the environment. Our main perspective is on the emerging use of the ESPT process for deciphering the hydration layer around the probe and other parameters related to proton diffusion taking place while the molecule is in the excited state, focusing primarily on bio-related materials. Special attention is given to how to perform the experiments and, most importantly, how to interpret their results. We also briefly discuss the breadth of possibilities in making pyranine derivatives and the use of pyranine for controlling dynamic reactions.
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Affiliation(s)
- Ramesh Nandi
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Haifa 3200003, Israel
| | - Nadav Amdursky
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Haifa 3200003, Israel
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Effectiveness of and Perspectives for the Sedimentation Analysis Method in Grain Quality Evaluation in Various Cereal Crops for Breeding Purposes. PLANTS 2022; 11:plants11131640. [PMID: 35807592 PMCID: PMC9269319 DOI: 10.3390/plants11131640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/17/2022] [Accepted: 06/20/2022] [Indexed: 11/17/2022]
Abstract
The existing standardized methods for assessing the quality of marketable grain do not always meet the requirements of the breeding, such as the method’s rapidity, sufficiency of the minimum amount of experimental material, the minimal modifying influence of the external environment on the degree of expression of a criterion, and genetic determination and heritability of the latter. One of the methods that meets these requirements is the sediment volume test. The present study offers an analysis and examples of methodological developments in relation to the assessment of winter bread wheat grain in arid regions of cultivation, as well as of winter triticale. The fluorescent probing method was used as an example for demonstrating the prospects for assessing the swelling of ground grain products of both bread and durum wheat, and for such crops with a less-strong complex of storage polymers as triticale, rye, and millet. A two-stage sedimentation procedure that allows a successful differentiation of samples has been developed for sorghum and maize grain. It is presented here alongside with methodological works on wheat from different countries of the world. Examples of the proven high reproducibility of the sediment volume test in the offspring, and its genetic determination are provided. In general, the data obtained and the material accumulated by various researchers indicate that a modification of the sedimentation method, correctly chosen for specific goals and objectives, solves the problem of assessing grain quality in breeding samples starting from early progenies. All these circumstances make the sedimentation testing the leading or most promising method for assessing grain quality when breeding of a broad range of grain crops is carried out.
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Pritzl SD, Pschunder F, Ehrat F, Bhattacharyya S, Lohmüller T, Huergo MA, Feldmann J. Trans-membrane Fluorescence Enhancement by Carbon Dots: Ionic Interactions and Energy Transfer. NANO LETTERS 2019; 19:3886-3891. [PMID: 31046295 DOI: 10.1021/acs.nanolett.9b01071] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report on trans-membrane interactions between blue-emitting carbon dots (CDs) and fluorescein. Hydrophobic CDs with a positive surface charge are embedded as-synthesized in the lipophilic sheet of the bilayer membrane of large synthetic phospholipid vesicles. The vesicles are prepared by mixing DOPC phospholipids and lipid molecules that contain anionic fluorescein attached to their hydrophilic head. Due to attractive electrostatic interactions, the CDs and fluorescein conjoin within the vesicle membrane, which leads to photoluminescence enhancement of fluorescein and facilitates trans-membrane energy transfer between the CDs and the dye.
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Affiliation(s)
- Stefanie D Pritzl
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics , Ludwig-Maximilians-Universität (LMU) , Königinstraße 10 , 80539 Munich , Germany
- Nanosystems Initiative Munich (NIM) and Center for Nanoscience (CeNS) , Schellingstraße 4 , 80799 Munich , Germany
| | - Fernando Pschunder
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata-CONICET , Sucursal 4 Casilla de Correo 16 , 1900 La Plata , Argentina
| | - Florian Ehrat
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics , Ludwig-Maximilians-Universität (LMU) , Königinstraße 10 , 80539 Munich , Germany
- Nanosystems Initiative Munich (NIM) and Center for Nanoscience (CeNS) , Schellingstraße 4 , 80799 Munich , Germany
| | - Santanu Bhattacharyya
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics , Ludwig-Maximilians-Universität (LMU) , Königinstraße 10 , 80539 Munich , Germany
- Nanosystems Initiative Munich (NIM) and Center for Nanoscience (CeNS) , Schellingstraße 4 , 80799 Munich , Germany
| | - Theobald Lohmüller
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics , Ludwig-Maximilians-Universität (LMU) , Königinstraße 10 , 80539 Munich , Germany
- Nanosystems Initiative Munich (NIM) and Center for Nanoscience (CeNS) , Schellingstraße 4 , 80799 Munich , Germany
| | - Maria Ana Huergo
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics , Ludwig-Maximilians-Universität (LMU) , Königinstraße 10 , 80539 Munich , Germany
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata-CONICET , Sucursal 4 Casilla de Correo 16 , 1900 La Plata , Argentina
| | - Jochen Feldmann
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics , Ludwig-Maximilians-Universität (LMU) , Königinstraße 10 , 80539 Munich , Germany
- Nanosystems Initiative Munich (NIM) and Center for Nanoscience (CeNS) , Schellingstraße 4 , 80799 Munich , Germany
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Haque N, Baratam K, Prabhu NP. Analysing the microenvironment of 2-p-toluidinylnaphthalene-6-sulfonate (TNS) in solvents and in different conformational states of proteins in relation to its fluorescence properties: a computational study. Phys Chem Chem Phys 2017; 19:24656-24666. [PMID: 28857104 DOI: 10.1039/c7cp03951d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Characterization of different conformational states of proteins is essential to understand their stability and activity. Biophysical techniques aid in analysing these conformational states and molecular fluorescence is one of the most reliable and quickly accessible methods. Apart from the intrinsic fluorescence of proteins, external fluorescence dyes such as TNS, ANS, nile red and thioflavin are also used to characterize partially unfolded, aggregated and fibrillar states of proteins, though their exact molecular-level interactions with proteins are yet to be completely unravelled. The present study attempts to investigate the binding of TNS molecules on different conformational states of proteins. Unconstrained molecular dynamics simulation of 50 molecules of TNS with the native state of BSA, native and two partially unfolded states of RNase A and α-lactalbumin in water was carried out. Dynamics simulation of TNS alone in different solvents such as water, ethanol, DMF and DMSO was also performed. Binding environments in all the proteins and the solvents were analysed in terms of H-bonding interactions, order of contacts, amino acid specificity and conformational changes of TNS, and correlated with experimentally observed fluorescence changes of the dye. The results suggest that TNS forms aggregates in water whereas in non-aqueous solvents the order of aggregates is lower which might result in an enhancement of its fluorescence intensity. Further, TNS preferably interacts with basic and aromatic amino acid residues of the proteins. In RNase A and α-lactalbumin, most of the TNS molecules tend to form aggregates even with the unfolded conformations of the proteins. However in BSA, the number of aggregated TNS molecules is less and TNS molecules in monomeric form are found in the hydrophobic crevices of the protein. This might result in an enhancement of the fluorescence in BSA compared to the other proteins. The distributions of angles and dihedrals of TNS in different environments suggest that the bending movement between the naphthyl and tolyl rings is constrained whereas significant planar rotations could be observed both in solvents and in protein-bound states.
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Affiliation(s)
- Neshatul Haque
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad - 500046, India.
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Synaptotagmin 1 and Ca2+ drive trans SNARE zippering. Sci Rep 2014; 4:4575. [PMID: 24694579 PMCID: PMC3974132 DOI: 10.1038/srep04575] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 03/17/2014] [Indexed: 12/21/2022] Open
Abstract
Synaptotagmin 1 (Syt1) is a major Ca2+-sensor that evokes neurotransmitter release. Here we used site-specific fluorescence resonance energy transfer (FRET) assay to investigate the effects of Syt1 on SNAREpin assembly. C2AB, a soluble version of Syt1, had virtually no stimulatory effect on the rate of the FRET at N-terminus of SNARE complex both with and without Ca2+, indicating C2AB does not interfere with the initial nucleation of SNARE assembly. However, C2AB-Ca2+ accelerated the FRET rate significantly at membrane proximal region, indicating C2AB-Ca2+ promotes the transition from a partially assembled SNARE complex to the fusion-competent SNAREpin. Similar enhancement was also observed at the end of the transmembrane domain of SNARE proteins. The stimulatory effect disappeared if there was no membrane or only neutral membrane present.
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de Souza Lopes JL, Hissa DC, Melo VMM, Beltramini LM. Interaction of antimicrobial peptide Plantaricin149a and four analogs with lipid bilayers and bacterial membranes. Braz J Microbiol 2014; 44:1291-8. [PMID: 24688525 PMCID: PMC3958201 DOI: 10.1590/s1517-83822014005000007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 04/04/2013] [Indexed: 11/25/2022] Open
Abstract
The amidated analog of Plantaricin149, an antimicrobial peptide from Lactobacillus plantarum NRIC 149, directly interacts with negatively charged liposomes and bacterial membranes, leading to their lysis. In this study, four Pln149-analogs were synthesized with different hydrophobic groups at their N-terminus with the goal of evaluating the effect of the modifications at this region in the peptide’s antimicrobial properties. The interaction of these peptides with membrane models, surface activity, their hemolytic effect on red blood cells, and antibacterial activity against microorganisms were evaluated. The analogs presented similar action of Plantaricin149a; three of them with no hemolytic effect (< 5%) until 0.5 mM, in addition to the induction of a helical element when binding to negative liposomes. The N-terminus difference between the analogs and Plantaricin149a retained the antibacterial effect on S. aureus and P. aeruginosa for all peptides (MIC50 of 19 μM and 155 μM to Plantaricin149a, respectively) but resulted in a different mechanism of action against the microorganisms, that was bactericidal for Plantaricin149a and bacteriostatic for the analogs. This difference was confirmed by a reduction in leakage action for the analogs. The lytic activity of Plantaricin149a is suggested to be a result of the peptide-lipid interactions from the amphipathic helix and the hydrophobic residues at the N-terminus of the antimicrobial peptide.
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Affiliation(s)
- José Luiz de Souza Lopes
- Grupo de Biofísica Molecular "Sérgio Mascarenhas", Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
| | | | | | - Leila Maria Beltramini
- Grupo de Biofísica Molecular "Sérgio Mascarenhas", Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
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Saitoh T, Ono N, Hiraide M. Effective collection of hydrophobic organic pollutants in water with aluminum hydroxide and hydrophobically modified polyacrylic acid. CHEMOSPHERE 2012; 89:759-763. [PMID: 22840533 DOI: 10.1016/j.chemosphere.2012.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/04/2012] [Accepted: 07/06/2012] [Indexed: 06/01/2023]
Abstract
Polyacrylic acid was hydrophobically modified with dodecylamine and used as a coagulant for coprecipitation of hydrophobic organic pollutants from water. The polymer coagulant induced effective aggregation of aluminum hydroxide having hydrophobic regions which are essential for the incorporation of hydrophobic organic pollutants. Recoveries of the organic pollutants increased with increasing the dodecylamine content, which indicated that the dodecylamine moiety played an important role in the formation of hydrophobic area on the precipitate. Different hydrophobic organic pollutants that had hardly been removed by the conventional coprecipitation were successfully collected by the proposed method.
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Affiliation(s)
- Tohru Saitoh
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Fro-cho, Chikusa-ku, Nagoya 464-8603, Japan.
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Tsuji T, Kawasaki Y, Takeshima S, Sekiya T, Tanaka S. A new fluorescence staining assay for visualizing living microorganisms in soil. Appl Environ Microbiol 2010; 61:3415-21. [PMID: 16535127 PMCID: PMC1388581 DOI: 10.1128/aem.61.9.3415-3421.1995] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
5- (and 6-)Sulfofluorescein diacetate (SFDA), which is converted to a fluorescent product by intracellular esterase activity, was used to stain living microorganisms, including bacteria, Saccharomyces cerevisiae, and fungi, in soil. SFDA (1 mM) dissolved in ethyl alcohol was added to an intact soil sample, and the preparation was examined with an epifluorescence microscope. Bright single cells and colonies of live bacteria were observed without interference from the autofluorescence of soil minerals and detritus. Cultured Escherichia coli was killed through heat treatment; thus, SFDA was concluded to stain only living cells. Microbial colonies obtained from natural soils and various cultured strains were tested. It was found that 151 of 154 colonies from natural soils were stained and that hyphae and spores from 1 of 28 cultured microbial strains were not stained. The SFDA method was successfully used to visualize and count bacteria in soil samples from Mount Shiga in Japan.
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Sinkeldam RW, Greco NJ, Tor Y. Fluorescent analogs of biomolecular building blocks: design, properties, and applications. Chem Rev 2010; 110:2579-619. [PMID: 20205430 PMCID: PMC2868948 DOI: 10.1021/cr900301e] [Citation(s) in RCA: 658] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Renatus W. Sinkeldam
- Department of Chemistry and Biochemistry, University of California, San Diego 9500 Gilman Drive, La Jolla, California 92093-0358
| | | | - Yitzhak Tor
- Department of Chemistry and Biochemistry, University of California, San Diego 9500 Gilman Drive, La Jolla, California 92093-0358
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Affiliation(s)
- J. J. Ramsden
- a Department of Biophysical Chemistry , Biozentrum , CH-4056 , Basel , Switzerland
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11
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Saitoh T, Kondo T, Hiraide M. Concentration of chlorophenols in water to dialkyated catinonic surfactant–silica gel admicelles. J Chromatogr A 2007; 1164:40-7. [PMID: 17678937 DOI: 10.1016/j.chroma.2007.07.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Revised: 07/09/2007] [Accepted: 07/11/2007] [Indexed: 10/23/2022]
Abstract
Chlorophenols including monochlorophenol, dichlorophenol, trichlorophenol, tetrachlorophenol, and pentachlorophenol in water were extracted into dialkylated cationic surfactant-silica gel admicelles. The dialkylated cationic surfactants such as didecyldimethylammonium bromide (DC10) and didodedyldimethylammonium bromide (DC12) sorbed on silica gel surfaces to form admicelles at pH 9. Approximately 200mg of DC10 was quantitatively sorbed on 1g of silica gel. The sorption further increased by further addition of DC10. This is in contrast to the fact that the maximum sorption of mono-alkylated cetyltrimethyammonium chloride (CTAC) was only ca. 100mg. Based on the fluorescent spectra of a molecular probe, N-phenyl-1-naphthylamine, DC10- and DC12-silica gel admicelles were more hydrophobic than CTAC-silica gel admicelles. The extents of the extraction of chlorophenols into DC10-silica gel admicelles were greater than those into CTAC-silica gel admicelles. However, the extractions to DC12-silica gel admicelles were insufficient due to leakage of DC12 vesicles. Consequently, DC10-silica gel admicelles were the most adequate for concentrating chlorophenols in water. An admicelle column was prepared by passing aqueous buffer solution of DC10 through a Bond Elut Jr. silica gel solid-phase extraction cartridge. It was successfully applied to the 500-fold concentration of chlorophenols including hydrophilic mono-substituted chlorophenol in water samples prior to their HPLC analysis.
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Affiliation(s)
- Tohru Saitoh
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan.
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12
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Deuticke B. Properties and structural basis of simple diffusion pathways in the erythrocyte membrane. Rev Physiol Biochem Pharmacol 2005; 78:1-97. [PMID: 322240 DOI: 10.1007/bfb0027721] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Jemioła-Rzemińska M, Kruk J, Strzałka K. Anisotropy measurements of intrinsic fluorescence of prenyllipids reveal much higher mobility of plastoquinol than alpha-tocopherol in model membranes. Chem Phys Lipids 2003; 123:233-43. [PMID: 12691855 DOI: 10.1016/s0009-3084(03)00018-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As an alternative to a fluorescent probe approach, the intrinsic fluorescence of reduced forms of prenylquinones has been exploited, which offers a convenient means of determining directly motional properties of these molecules. The steady-state fluorescence anisotropy measurements of plastoquinols (PQH(2)) and alpha-tocopherol (alpha-Toc) incorporated into phospholipid liposomes have been performed. The effect of prenyllipid concentration, PQH(2) side chain length and the composition of the membranes has been studied. For the data interpretation, the fundamental anisotropy of alpha-Toc, PQH(2), ubiquinol-10 and alpha-tocopherolquinol, as well as the angles between the absorption and emission transition moments have been also determined. It was concluded that alpha-Toc shows very low mobility in the lipid bilayer, whereas PQH(2)-9 displays significant motional freedom in dipalmitoylphosphatidylcholine vesicles and even higher in egg yolk lecithin membranes.
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Affiliation(s)
- Małgorzata Jemioła-Rzemińska
- Department of Plant Physiology and Biochemistry, The Jan Zurzycki Institute of Molecular Biology and Biotechnology, Jagiellonian University, Gronostajowa Street 7, 30-387, Krakow, Poland
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14
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Microviscosity measurements of phospholipid bilayers using fluorescent dyes that undergo torsional relaxation. Biochemistry 2002. [DOI: 10.1021/bi00368a042] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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May P, Sibbett W, Taylor J. Picosecond relaxation of the fluorescence probes ANS and TNS in aqueous solutions. FEBS Lett 2001. [DOI: 10.1016/0014-5793(81)80610-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Caetano W, Tabak M. Interaction of Chlorpromazine and Trifluoperazine with Anionic Sodium Dodecyl Sulfate (SDS) Micelles: Electronic Absorption and Fluorescence Studies. J Colloid Interface Sci 2000; 225:69-81. [PMID: 10767147 DOI: 10.1006/jcis.2000.6720] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The characteristics of binding of two phenothiazine antipsychothic drugs, chlorpromazine (CPZ) and trifluoperazine (TFP), to anionic sodium dodecyl sulfate (SDS) monomers and/or micelles were investigated using electronic absorption and fluorescence spectroscopies. Binding constants K(b) and pK(a) values for the drugs in SDS micelles were estimated using the red shifts of the maximum absorption and changes in absorption upon alkalization or in the presence of surfactant. The pK(a) shift of CPZ due to its interaction with SDS micelles is about 0.7 unit to higher values, as compared to the reported value of pK(a) obtained in buffer around 9.3. For TFP the pK(a) shift is 0.4 unit to higher values compared to that in buffer, reported as 4.0. The electronic absorption spectroscopic data suggest a biphasic interaction as a function of detergent concentration which is quite dependent of the protonation states of the drugs. In the case of TFP a very strong binding takes place when the drug is fully protonated (pH 2.0) and a distinct binding takes place at stoichiometric (low) surfactant concentrations (interaction via surfactant monomers) and at higher concentrations (in the presence of micelles). Static fluorescence probe analysis using pyrene was used to study the nature of the phenothiazine-surfactant premicellar and self-aggregates. The I(3)/I(1) and I(475)/I(1) ratios associated to pyrene fluorescence vibronic bands and excimer intensities ratios, respectively, were monitored for several ratios [SDS]/[drug] and significant changes, dependent of the drug presence and its protonation state, have been observed revealing a hydrophobic microenvironment provided by TFP-SDS aggregates in comparison with CPZ both at pH 7.0 and 4.0. Static anisotropy was also used to monitor the changes of the self-aggregates and micellar packing in the presence of the phenothiazine drugs. In aqueous solutions the anisotropy of the fluorescent probe dipyridamole (DIP) is quite low, being around 0.005 at pH 7.0 and 0.025 at pH 4.0, and the addition of detergent leads to an increase in the values of anisotropy to 0.030 at pH 7.0 and 0.070 at pH 4.0. In the presence of the phenothiazine drugs, and in the premicellar detergent concentration range, the anisotropy of DIP increases to 0.134 and 0.111 (dependent on drug concentration) for CPZ and TFP, respectively, at pH 4.0. These results suggest that the presence of both phenotiazine drugs makes the premicellar aggregates more rigid by decreasing the probe mobility, and are consistent with a more polar localization of the CPZ in the micelles as compared with TFP. At pH 7.0 the anisotropy changes are smaller, suggesting a slight decrease in CMC induced by the phenothiazines. Copyright 2000 Academic Press.
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Affiliation(s)
- W Caetano
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP, 13560-970, Brazil
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Chizmadzhev YA, Kumenko DA, Kuzmin PI, Chernomordik LV, Zimmerberg J, Cohen FS. Lipid flow through fusion pores connecting membranes of different tensions. Biophys J 1999; 76:2951-65. [PMID: 10354423 PMCID: PMC1300267 DOI: 10.1016/s0006-3495(99)77450-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
When two membranes fuse, their components mix; this is usually described as a purely diffusional process. However, if the membranes are under different tensions, the material will spread predominantly by convection. We use standard fluid mechanics to rigorously calculate the steady-state convective flux of lipids. A fusion pore is modeled as a toroid shape, connecting two planar membranes. Each of the membrane monolayers is considered separately as incompressible viscous media with the same shear viscosity, etas. The two monolayers interact by sliding past each other, described by an intermonolayer viscosity, etar. Combining a continuity equation with an equation that balances the work provided by the tension difference, Deltasigma, against the energy dissipated by flow in the viscous membrane, yields expressions for lipid velocity, upsilon, and area of lipid flux, Phi. These expressions for upsilon and Phi depend on Deltasigma, etas, etar, and geometrical aspects of a toroidal pore, but the general features of the theory hold for any fusion pore that has a roughly hourglass shape. These expressions are readily applicable to data from any experiments that monitor movement of lipid dye between fused membranes under different tensions. Lipid velocity increases nonlinearly from a small value for small pore radii, rp, to a saturating value at large rp. As a result of velocity saturation, the flux increases linearly with pore radius for large pores. The calculated lipid flux is in agreement with available experimental data for both large and transient fusion pores.
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Zubiri D, Domecq A, Bernik D. Phase behavior of phosphatidylglycerol bilayers as a function of buffer composition: fluorescence studies using Laurdan probe. Colloids Surf B Biointerfaces 1999. [DOI: 10.1016/s0927-7765(98)00106-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Puchkov EO, Yurkova TV, Golubev WI. Effects of Cryptococcus humicola killer toxin upon Cryptococcus terreus envelope: combined fluorometric and microscopic studies. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1381:61-7. [PMID: 9659372 DOI: 10.1016/s0304-4165(98)00012-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Killer toxin (microcin) produced by Cryptococcus humicola 9-6 induced interaction of the fluorogenic dyes, ethidium bromide, propidium iodide, and hemimagnesium 8-anilino-1-naphtalenesulfonate, with the sensitive strain of Cryptococcus terreus VKM Y-2253. The toxin also made the cells susceptible to cetyltrimethylammonium bromide and leaky for K+. When excited at 360 nm, cell-bound ethidium (propidium) fluorescence was enhanced by 8-anilino-1-naphtalensulfonate, and cell-bound 8-anilino-1-naphtalensulfonate fluorescence was quenched by ethidium (propidium), indicating energy transfer from 8-anilino-1-naphtalensulfonate to ethidium (propidium). These results suggest that at least a portion of the probe molecules had the same binding site, possibly the cytoplasmic membrane. The parameters of kinetics of microcin action were evaluated fluorometrically. They were found to be identical for all probes and depended on microcin concentration. The fluorescence increment of ethidium and 8-anilino-1-naphtalensulfonate upon binding to microcin-treated cells correlated with the fraction of stainable cells and viability.
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Affiliation(s)
- E O Puchkov
- Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Russian Federation.
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20
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Das R, Guha D, Mitra S, Kar S, Lahiri S, Mukherjee S. Intramolecular Charge Transfer as Probing Reaction: Fluorescence Monitoring of Protein−Surfactant Interaction. J Phys Chem A 1997. [DOI: 10.1021/jp9625669] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- R. Das
- Department of Physical Chemsitry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032, India
| | - D. Guha
- Department of Physical Chemsitry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032, India
| | - S. Mitra
- Department of Physical Chemsitry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032, India
| | - S. Kar
- Department of Physical Chemsitry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032, India
| | - S. Lahiri
- Department of Physical Chemsitry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032, India
| | - S. Mukherjee
- Department of Physical Chemsitry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700 032, India
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21
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Sujatha J, Mishra A. Bis-MSB, a laser dye as a polarization probe for microheterogeneous media. J Photochem Photobiol A Chem 1996. [DOI: 10.1016/s1010-6030(96)04301-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Das R, Mitra S, Nath D, Mukherjee S. Excited State Proton Transfer Reaction as a Probe for the Microenvironment of a Binding Site of Bovine Serum Albumin: Effect of Urea. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp952204l] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ranjan Das
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-7000 32, India
| | - Sivaprasad Mitra
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-7000 32, India
| | - Debnarayan Nath
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-7000 32, India
| | - Samaresh Mukherjee
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-7000 32, India
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23
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Kalninsh K, Pestov D, Roshchina Y. Absorption and fluorescence spectra of the probe Hoechst 33258. J Photochem Photobiol A Chem 1994. [DOI: 10.1016/1010-6030(94)03797-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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25
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Reynaud JA, Grivet JP, Sy D, Trudelle Y. Interactions of basic amphiphilic peptides with dimyristoylphosphatidylcholine small unilamellar vesicles: optical, NMR, and electron microscopy studies and conformational calculations. Biochemistry 1993; 32:4997-5008. [PMID: 8494875 DOI: 10.1021/bi00070a005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The interactions of DMPC small unilamellar vesicles with four amphiphilic polypeptides [(LKKL)n, (LRRL)n, (LKKL)4, and (YKKY)n] have been investigated by circular and infrared dichroism, turbidimetry, electron microscopy, and fluorescence, 1H, and 31P nuclear magnetic resonance spectroscopy. The main results obtained are the following: (1) Well-defined complexes are formed by the association of one amino acid residue with approximately two lipid molecules. (2) In the presence of polypeptides fusions are observed between SUVs when the molar ratio p is less than 0.05, and a clearance effect is observed when p is higher than 0.05. (3) The anchoring sites of the polypeptides on DMPC molecules are the negative phosphate groups through electrostatic interactions with the terminal NH3+ of lysine residues. (4) The polypeptides adopt an alpha-helical conformation with their axis parallel to the membrane surface. The hydrophobic part of the amphiphilic alpha helix can penetrate the outer lipid leaflet down to the C5 position. (5) Choline methyl groups are not involved in the interactions between lipid molecules and amino acid residues. (6) Phosphorus atom mobility around the P-O-glycerol bond is strongly reduced whereas that of methylene groups is progressively weakened when going up from C13 to C1. Finally, using modeling and energy calculations a model of possible Ac(LKKL)4NHEt-DMPC SUV complexes is presented.
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Affiliation(s)
- J A Reynaud
- Centre de Biophysique Moléculaire, CNRS, Orleans, France
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26
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Ehrenberg B, Pevzner E. SPECTROSCOPIC PROPERTIES OF THE POTENTIOMETRIC PROBE MEROCYANINE-540 IN SOLUTIONS AND IN LIPOSOMES. Photochem Photobiol 1993. [DOI: 10.1111/j.1751-1097.1993.tb02280.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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27
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Niebrój-Dobosz IM. Fluorescent probe analysis of muscle plasmalemma in Duchenne's progressive muscular dystrophy. J Neurol 1992; 239:267-9. [PMID: 1607889 DOI: 10.1007/bf00810350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The relationship between fluorescence intensity and binding of 1-anilino-naphthalene-8-sulphonate (ANS) to muscle plasmalemma in patients with Duchenne's muscular dystrophy (DD) and controls was studied. The fluorescence of ANS was markedly enhanced in DD as compared with controls. The magnitude of this enhancement was increased by monovalent and divalent cations; treatment of DD plasmalemma with trypsin caused an opposite effect. Treatment with phospholipase A and C altered the ANS fluorescence in DD and controls equally. These findings may indicate an increase of the hydrophobic character in the apolar-polar interface of DD plasmalemma. The relationship of these changes to a lack of dystrophin in DD remains to be established.
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28
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Ricchelli F, Beltramini M, Bubacco L, Salvato B, Filippi B. Circular dichroism and fluorescence studies to probe the conformational properties of Rhus vernicifera laccase. Inorganica Chim Acta 1992. [DOI: 10.1016/s0020-1693(00)80358-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Menguy L, Christon R, Van Dorsselaer A, Léger CL. Apparent relative retention of the phosphatidylethanolamine molecular species 18:0-20:5(n-3), 16:0-22:6(n-3) and the sum 16:0-20:4(n-6) plus 16:0-20:3(n-9) in the liver microsomes of pig on an essential fatty acid deficient diet. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1123:41-50. [PMID: 1730045 DOI: 10.1016/0005-2760(92)90169-v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Attempts at a better understanding of the cell membrane organization and functioning need to assess the physical properties which partly depend (i) on the positional distribution of the fatty acids in the membrane phospholipids (PLs) and (ii) on the way by which the PL molecular species are affected by exogenous fatty acids. To do that, the effects of essential (polyunsaturated) fatty acid (EFA) deficiency and enrichment were studied in the liver microsomes of piglets feeding on either an EFA-deficient diet or an EFA-enriched diet containing hydrogenated coconut oil or a mixture of soya + corn oils, respectively. After derivatization, the diacylated forms of choline and ethanolamine PLs were analyzed using a combination of chromatographic techniques and fast-atom bombardment-mass spectrometry. The dinitrobenzoyl-diacylglycerol derivatives corresponding to the molecular species of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were identified. It appears that three factors brought about a marked apparent relative retention: the nature of (i) the base of the polar head, (ii) fatty acids at the sn-1 position and (iii) fatty acids at the sn-2 position. The highest apparent relative retentions were displayed by the 18:0-20:5(n-3)-PE and 16:0-22:6(n-3)-PE. It is noteworthy that the behavior of 20:3 n-9--which is synthesized during the EFA-deficient diet by the same bioconversion system as 20:4 n-6--was very similar to that of 20:4 n-6 during the formation of PC and PE molecular species and that the molecular species of PE containing 20:4(n-6) and 20:3(n-9), gathered together as metabolical homologues, were also apparently retained, particularly in association with 16:0. Present observations are consistent with some others showing retention or preferential distribution of EFA in PE and suggest that specific acyltransferase(s), ethanolamine phosphotransferase and methyltransferase would be mainly involved for PE and PC formation in liver endoplasmic reticulum. Fast-atom bombardment-mass spectrometry of intact phospholipids enables us to show that there is no very long chain dipolyunsaturated phospholipid in liver endoplasmic reticulum.
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Affiliation(s)
- L Menguy
- INRA, Centre de Recherches de Jouy-en-Josas, France
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30
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Kinetics of partly diffusion controlled reactions XXIV: Unidimensionalization of diffusion in cylindrical symmetry systems: Applications to membranes. J Biol Phys 1992. [DOI: 10.1007/bf00419422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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31
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Ehrenberg B, Johnson FM. Spectroscopic studies of tetrabenzoporphyrins: MgTBP, ZnTBP and H2TBP. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0584-8539(90)80066-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Chazotte B, Hackenbrock CR. The multicollisional, obstructed, long-range diffusional nature of mitochondrial electron transport. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68228-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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33
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Pastor RW, Venable RM, Karplus M. Brownian dynamics simulation of a lipid chain in a membrane bilayer. J Chem Phys 1988. [DOI: 10.1063/1.455218] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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34
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Pastor RW, Venable RM, Karplus M, Szabo A. A simulation based model of NMRT1relaxation in lipid bilayer vesicles. J Chem Phys 1988. [DOI: 10.1063/1.455219] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Bhattacharyya M, Bhowmik BB, Nandy P. Microviscosity in lecithin liposomes: effect of nicotinic acid. Arch Biochem Biophys 1988; 263:117-20. [PMID: 3369856 DOI: 10.1016/0003-9861(88)90619-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have studied the effect of nicotinic acid, a drug commonly used as a vasodilatory agent and also for the treatment of hypercholesterolemia, on the fluidity profile of liposomes of egg lecithin and dipalmitoyl lecithin, using a fluorescent polarization probe. In both cases the drug decreases the membrane fluidity and for cholesterol-probed liposomes, it disrupts the "intermediate fluid condition" induced by cholesterol. The drug also affects the activation energy for diffusion in the hydrophobic region of the liposomes.
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Affiliation(s)
- M Bhattacharyya
- Department of Physics and Chemistry, Jadavpur University, Calcutta, India
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36
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Sanadi S, Pandey R, Khuller GK. Lipids of dermatophytes. III. Sterol-induced changes in the lipid composition and functional properties of Epidermophyton floccosum. Lipids 1988; 23:435-8. [PMID: 3412123 DOI: 10.1007/bf02535516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Sterol supplementation, alone or in the presence of cerulenin, resulted in an increase in the total sterol content of Epidermophyton floccosum. While the total phospholipid levels of E. floccosum exhibited only marginal changes with sterol supplementation, the fatty acid profiles of these phospholipids were highly varied. In the presence or absence of cerulenin, the oleic acid content of phospholipids were increased significantly by cholesterol supplementation, whereas linoleic acid levels were enhanced by ergosterol supplementation. These variations resulted in higher unsaturated/saturated phospholipid fatty acid ratios in sterol-supplemented cells. The uptake of labeled amino acids (aspartic acid, lysine, glycine) was influenced by sterol supplementation. Alterations in the number of binding sites for the membrane probe, 1-anilino-naphthalene-8-sulfonate (ANS), were seen based on Scatchard plot calculations. The results indicate a correlation between sterol-induced changes in membrane lipid composition and function.
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Affiliation(s)
- S Sanadi
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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37
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Beastall J, Hadgraft J, Washington C. Mechanism of action of Azone as a percutaneous penetration enhancer: Lipid bilayer fluidity and transition temperature effects. Int J Pharm 1988. [DOI: 10.1016/0378-5173(88)90275-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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38
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Proulx P. Fluorescence studies on prokaryotic membranes. Subcell Biochem 1988; 13:281-321. [PMID: 2577858 DOI: 10.1007/978-1-4613-9359-7_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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39
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Pandey R, Verma RS, Khuller GK. Effect of choline, ethanolamine and serine supplementation on the membrane properties of Microsporum gypseum. Lipids 1987; 22:530-4. [PMID: 3114585 DOI: 10.1007/bf02540370] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Phospholipid bases, choline and ethanolamine, when supplemented in the growth medium of Microsporum gypseum resulted in an increase in the corresponding phospholipid and total phospholipid content. However, when serine was supplemented, marginal changes were observed. The fatty acid profile of phospholipids remained almost unchanged. The uptake of lysine, leucine and aspartic acid in the spheroplasts of choline- and ethanolamine-grown cells was higher as compared to the control. 1-Anilinonaphathalene-8-sulfonate (ANS) binding to the spheroplast membrane, as calculated from Scatchard plots, demonstrated an increase in the number of binding sites in choline- and ethanolamine-grown cells, while a decrease was observed in the serine-supplemented cells. The results are discussed in terms of the effect of phospholipid polar head group composition on the membrane structure and function of this fungus.
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40
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Abstract
This article reviews the biophysical consequences of lipid peroxidation in biological membranes. In the lipid domain, lipid peroxidation (a) causes an increase in the order and "viscosity" of the membrane bilayer, particularly at the depth around acyl-carbon 12, (b) changes the thermotropic phase behaviour, (c) decreases the electrical resistance, and (d) facilitates phospholipid exchange between the two monolayers. Upon lipid peroxidation membrane proteins are crosslinked, and their rotational and lateral mobility is decreased. Studies with microsomal cytochrome P-450 suggest protein aggregation but not the increased lipid order to be the major cause of protein immobilization in peroxidized membranes.
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Affiliation(s)
- C Richter
- Laboratory of Biochemistry, Swiss Federal Institute of Technology (ETH), Zürich
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Chefurka W, Gnidec EP. Binding of [14C] DDT by submitochondrial particles. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C, COMPARATIVE PHARMACOLOGY AND TOXICOLOGY 1987; 88:213-7. [PMID: 2890486 DOI: 10.1016/0742-8413(87)90071-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. Binding of [14C] DDT by submitochondrial particles and by liposomes prepared from lipids extracted from the particles was studied by the discontinuous sucrose gradient method. 2. Binding of the insecticide was a biphasic linear function of the biomembrane- and liposome-concentration with a break in the binding curve occurring at identical concentrations of phospholipid for both the biomembrane and vesicle. The biphasic binding curve is interpreted in terms of decreased availability of binding sites as a result of particle-particle interaction. 3. [14C] DDT was bound mainly by the membrane lipids and only negligible binding was detected for the delipidated membrane. 4. A 100-200-fold excess of unlabeled DDT had no effect on the binding of [14C] DDT and a 600-fold excess of unlabeled DDT reduced the binding by 20% suggesting that binding of [14C] DDT by lipids was nonspecific. 5. These results are discussed in relation to the strong inhibition by DDT of mitochondrial bioenergetics.
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Affiliation(s)
- W Chefurka
- Agriculture Canada, Research Centre, London, Ontario
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42
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Au S, Schacht J, Weiner N. Membrane effects of aminoglycoside antibiotics measured in liposomes containing the fluorescent probe, 1-anilino-8-naphthalene sulfonate. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 862:205-10. [PMID: 3021220 DOI: 10.1016/0005-2736(86)90484-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The mechanism of membrane disturbance by aminoglycoside antibiotics was investigated in liposomes containing the fluorescent probe, 1-anilino-8-naphthalene sulfonate (ANS). Liposomes of PC and different anionic phospholipids (1:1 to 15:1 molar ratios) were challenged with aminoglycosides in the presence of low (1 microM) and high (3 mM) concentrations of calcium. Liposomes containing PIP2 showed the greatest drug-induced changes in ANS fluorescence in the presence of high and low concentrations of calcium and at all PC:PIP2 molar ratios tested. Liposomes containing other anionic phospholipids (PS, PI and PIP) were not reactive toward aminoglycosides in the presence of 3 mM calcium or when the ratio of PC to anionic lipid was increased to 10:1. The aminoglycoside-induced changes of ANS fluorescence were not due to any changes in the emission spectrum of ANS, nor to changes in quantum yield, nor to a change in the binding affinity of ANS. It is concluded that a specific aminoglycoside-PIP2 interaction results in phase separation of PC and PIP2 and thus increases the number of available ANS binding sites in PC:PIP2 liposomes.
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43
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Han SK, Lee YS. Fluorescence probe study on the solubilization sites of aniline derivatives in triton X-100 and zephiramine micelles. Arch Pharm Res 1986. [DOI: 10.1007/bf02899997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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44
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45
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Abstract
Thermotropic phase transitions in single planar bilayers of glycerol mono-oleate have been investigated using quasi-elastic light scattering from thermally excited membrane fluctuations. In certain cases both spectroscopic and intensity information were derived from the observations. For solvent-free bilayers transitional changes were observed in several membrane parameters: in tension, viscosity and thickness, in a combination of lipid orientational order parameter and dielectric anisotropy, and in the lateral compression modulus. These changes, particularly those in membrane thickness and in the anisotropy/order combination, were clearly indicative of a chain-melting transition in the lipid molecules. The chain-melting transition temperature was identified as 16.6 +/- 0.03 degrees C (delta T 1/2 = 1.5 degrees C). The other changes tended to cluster around 12.5 and 16.6 degrees C, suggesting that a two-stage transition was involved. Analysis of pretransitional fluctuations in membrane viscosity, based on a Landau approach, suggested that at the transition the membrane was close to a critical point (T = 12.7 degrees C). Less information was accessible for membranes containing n-decane within their structure. In this case, the change in membrane tension was much smaller than in the solvent-free case and the transition was considerably broadened. These effects accord with an increase in 'interactive volume' within the bilayer due to solvent inclusion.
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46
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Gutowicz J, Krawczyk A. Effect of 1-anilinonaphthalene-8-sulphonate on phase transition temperature of dipalmitoylphosphatidylcholine liposomes. Chem Phys Lipids 1986; 39:357-64. [PMID: 3755383 DOI: 10.1016/0009-3084(86)90117-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of 1-anilinonaphthalene-8-sulfonate (ANS) on the thermotropic phase transition of dipalmitoylphosphatidylcholine (DPPC) bilayers was examined by differential scanning calorimetry. The main phase transition temperature was found to be shifted to lower values in the presence of the probe. The shift strongly depends on pH and the presence of salts. This indicates that the penetration of the probe of the hydrocarbon moiety of the bilayer is influenced by coulombic interactions. Pretransition phenomena are also affected. The implications for the interpretation of experimental data of biomembrane studies are discussed.
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47
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Electron Transfer Effects and the Mechanism of the Membrane Potential. Rev Physiol Biochem Pharmacol 1986. [DOI: 10.1007/978-1-4613-1791-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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48
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Ehrenberg B. Spectroscopic methods for the determination of membrane surface charge density. Methods Enzymol 1986; 127:678-96. [PMID: 3016476 DOI: 10.1016/0076-6879(86)27053-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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49
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Harder A, Debuch H. Changes of transition temperatures of phosphatidylcholine and phosphatidylglycerol in presence of amphiphilic drugs. Chem Phys Lipids 1986; 39:65-71. [PMID: 3948293 DOI: 10.1016/0009-3084(86)90100-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The transition temperature of phosphatidylglycerol (PG) was reduced to lower temperatures in presence of propranolol, imipramine, amitriptyline and chlorpromazine. This effect was dependent on drug concentration and was smallest with propranolol. The fluidizing effect, however, increased from propranolol to chlorpromazine according to the octanol/H2O partition coefficients. When the two phospholipids PG and phosphatidylcholine (PC) were compared, the presence of drug lead to a more pronounced reduction of the transition temperature in the case of the acidic phospholipid than in the case of the neutral one.
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50
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Demchenko AP, Shcherbatska NV. Nanosecond dynamics of charged fluorescent probes at the polar interface of a membrane phospholipid bilayer. Biophys Chem 1985; 22:131-43. [PMID: 4052570 DOI: 10.1016/0301-4622(85)80035-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Molecular relaxation fluorescence methods were applied to analyze the nature and characteristic times of motions of amphiphilic molecules absorbed in the polar region of a phospholipid bilayer. The fluorescence probes 2-toluidinonaphthalene-6-sulfonate and 1-anilinonaphthalene-8-sulfonate in egg phosphatidylcholine vesicles were studied. The methods of edge excitation fluorescence red shifts, nanosecond time-resolved spectroscopy, fluorescence quenching by hydrophilic and hydrophobic quenchers and emission wavelength dependence of polarization were used. The structural (dipolar) relaxation is shown to be a very rapid (subnanosecond) process. The observed nanosecond phenomena are related to translational movement of the chromophore itself towards a more polar environment and its rotation. The polar surface area of the phospholipid membrane appears to be a highly mobile liquid-like system.
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