1
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McCarthy NLC, Chan CL, Mignini Urdaneta GECM, Liao Y, Law RV, Ces O, Seddon JM, Brooks NJ. The effect of hydrostatic pressure on lipid membrane lateral structure. Methods Enzymol 2024; 700:49-76. [PMID: 38971612 DOI: 10.1016/bs.mie.2024.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
High pressure is both an environmental challenge to which deep sea biology has to adapt, and a highly sensitive thermodynamic tool that can be used to trigger structural changes in biological molecules and assemblies. Lipid membranes are amongst the most pressure sensitive biological assemblies and pressure can have a large influence on their structure and properties. In this chapter, we will explore the use of high pressure small angle X-ray diffraction and high pressure microscopy to measure and quantify changes in the lateral structure of lipid membranes under both equilibrium high pressure conditions and in response to pressure jumps.
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Affiliation(s)
| | - Chi L Chan
- Department of Chemistry, Imperial College London, London, United Kingdom
| | | | - Yifei Liao
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Robert V Law
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Oscar Ces
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - John M Seddon
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Nicholas J Brooks
- Department of Chemistry, Imperial College London, London, United Kingdom.
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2
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Non-Polar Lipids as Regulators of Membrane Properties in Archaeal Lipid Bilayer Mimics. Int J Mol Sci 2021; 22:ijms22116087. [PMID: 34200063 PMCID: PMC8200183 DOI: 10.3390/ijms22116087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 11/17/2022] Open
Abstract
The modification of archaeal lipid bilayer properties by the insertion of apolar molecules in the lipid bilayer midplane has been proposed to support cell membrane adaptation to extreme environmental conditions of temperature and hydrostatic pressure. In this work, we characterize the insertion effects of the apolar polyisoprenoid squalane on the permeability and fluidity of archaeal model membrane bilayers, composed of lipid analogues. We have monitored large molecule and proton permeability and Laurdan generalized polarization from lipid vesicles as a function of temperature and hydrostatic pressure. Even at low concentration, squalane (1 mol%) is able to enhance solute permeation by increasing membrane fluidity, but at the same time, to decrease proton permeability of the lipid bilayer. The squalane physicochemical impact on membrane properties are congruent with a possible role of apolar intercalants on the adaptation of Archaea to extreme conditions. In addition, such intercalant might be used to cheaply create or modify chemically resistant liposomes (archeaosomes) for drug delivery.
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3
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Gunther G, Malacrida L, Jameson DM, Gratton E, Sánchez SA. LAURDAN since Weber: The Quest for Visualizing Membrane Heterogeneity. Acc Chem Res 2021; 54:976-987. [PMID: 33513300 PMCID: PMC8552415 DOI: 10.1021/acs.accounts.0c00687] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Any chemist studying the interaction of molecules with lipid assemblies will eventually be confronted by the topic of membrane bilayer heterogeneity and may ultimately encounter the heterogeneity of natural membranes. In artificial bilayers, heterogeneity is defined by phase segregation that can be in the nano- and micrometer range. In biological bilayers, heterogeneity is considered in the context of small (10-200 nm) sterol and sphingolipid-enriched heterogeneous and highly dynamic domains. Several techniques can be used to assess membrane heterogeneity in living systems. Our approach is to use a fluorescent reporter molecule immersed in the bilayer, which, by changes in its spectroscopic properties, senses physical-chemistry aspects of the membrane. This dye in combination with microscopy and fluctuation techniques can give information about membrane heterogeneity at different temporal and spatial levels: going from average fluidity to number and diffusion coefficient of nanodomains. LAURDAN (6-dodecanoyl-2-(dimethylamino) naphthalene), is a fluorescent probe designed and synthesized in 1979 by Gregorio Weber with the purpose to study the phenomenon of dipolar relaxation. The spectral displacement observed when LAURDAN is either in fluid or gel phase permitted the use of the technique in the field of membrane dynamics. The quantitation of the spectral displacement was first addressed by the generalized polarization (GP) function in the cuvette, a ratio of the difference in intensity at two wavelengths divided by their sum. In 1997, GP measurements were done for the first time in the microscope, adding to the technique the spatial resolution and allowing the visualization of lipid segregation both in liposomes and cells. A new prospective to the membrane heterogeneity was obtained when LAURDAN fluorescent lifetime measurements were done in the microscope. Two channel lifetime imaging provides information on membrane polarity and dipole relaxation (the two parameters responsible for the spectral shift of LAURDAN), and the application of phasor analysis allows pixel by pixel understanding of these two parameters in the membrane. To increase temporal resolution, LAURDAN GP was combined with fluctuation correlation spectroscopy (FCS) and the motility of nanometric highly packed structures in biological membranes was registered. Lately the application of phasor analysis to spectral images from membranes labeled with LAURDAN allows us to study the full spectra pixel by pixel in an image. All these methodologies, using LAURDAN, offer the possibility to address different properties of membranes depending on the question being asked. In this Account, we will focus on the principles, advantages, and limitations of different approaches to orient the reader to select the most appropriate technique for their research.
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Affiliation(s)
- German Gunther
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone P. 1007, Santiago 8380492, Chile
| | - Leonel Malacrida
- Advanced Microscopy and Biophotonics Unit, Hospital de Clínicas, Universidad de la República, Montevideo-Uruguay. Advanced Bioimaging Unit, Institut Pasteur Montevideo, Av. Italia s/n, 90600 Montevideo, Uruguay
| | - David M Jameson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Biosciences 222, Honolulu, Hawaii 96813, United States
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, 3210 Natural Sciences II, University of California, Irvine, Irvine, California 92697-2725, United States
| | - Susana A Sánchez
- Departamento de Polímeros, Facultad de Ciencias Químicas, Universidad de Concepción, Edmundo Larenas 129, Concepción 4070371, Chile
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4
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Páez-Pérez M, López-Duarte I, Vyšniauskas A, Brooks NJ, Kuimova MK. Imaging non-classical mechanical responses of lipid membranes using molecular rotors. Chem Sci 2020; 12:2604-2613. [PMID: 34164028 PMCID: PMC8179291 DOI: 10.1039/d0sc05874b] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Lipid packing in cellular membranes has a direct effect on membrane tension and microviscosity, and plays a central role in cellular adaptation, homeostasis and disease. According to conventional mechanical descriptions, viscosity and tension are directly interconnected, with increased tension leading to decreased membrane microviscosity. However, the intricate molecular interactions that combine to build the structure and function of a cell membrane suggest a more complex relationship between these parameters. In this work, a viscosity-sensitive fluorophore (‘molecular rotor’) is used to map changes in microviscosity in model membranes under conditions of osmotic stress. Our results suggest that the relationship between membrane tension and microviscosity is strongly influenced by the bilayer's lipid composition. In particular, we show that the effects of increasing tension are minimised for membranes that exhibit liquid disordered (Ld) – liquid ordered (Lo) phase coexistence; while, surprisingly, membranes in pure gel and Lo phases exhibit a negative compressibility behaviour, i.e. they soften upon compression. Viscosity-sensitive molecular rotors demonstrate that the non-classical mechanical behaviour of model lipid membranes is able to buffer external stress.![]()
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Affiliation(s)
- Miguel Páez-Pérez
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
| | - Ismael López-Duarte
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK .,Departamento de Química Orgánica, Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spain
| | - Aurimas Vyšniauskas
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK .,Center of Physical Sciences and Technology Saulėtekio av. 3 Vilnius Lithuania
| | - Nicholas J Brooks
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
| | - Marina K Kuimova
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
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5
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Ventura A, Varela A, Dingjan T, Santos T, Fedorov A, Futerman A, Prieto M, Silva L. Lipid domain formation and membrane shaping by C24-ceramide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183400. [DOI: 10.1016/j.bbamem.2020.183400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/05/2020] [Accepted: 06/15/2020] [Indexed: 01/29/2023]
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6
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Bourges AC, Lazarev A, Declerck N, Rogers KL, Royer CA. Quantitative High-Resolution Imaging of Live Microbial Cells at High Hydrostatic Pressure. Biophys J 2020; 118:2670-2679. [PMID: 32402241 DOI: 10.1016/j.bpj.2020.04.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/19/2020] [Accepted: 04/16/2020] [Indexed: 10/24/2022] Open
Abstract
The majority of the Earth's microbial biomass exists in the deep biosphere, in the deep ocean, and within the Earth's crust. Although other physical parameters in these environments, such as temperature or pH, can differ substantially, they are all under high pressures. Beyond emerging genomic information, little is known about the molecular mechanisms underlying the ability of these organisms to survive and grow at pressures that can reach over 1000-fold the pressure on the Earth's surface. The mechanisms of pressure adaptation are also important in food safety, with the increasing use of high-pressure food processing. Advanced imaging represents an important tool for exploring microbial adaptation and response to environmental changes. Here, we describe implementation of a high-pressure sample chamber with a two-photon scanning microscope system, allowing for the first time, to our knowledge, quantitative high-resolution two-photon imaging at 100 MPa of living microbes from all three kingdoms of life. We adapted this setup for fluorescence lifetime imaging microscopy with phasor analysis (FLIM/Phasor) and investigated metabolic responses to pressure of live cells from mesophilic yeast and bacterial strains, as well as the piezophilic archaeon Archaeoglobus fulgidus. We also monitored by fluorescence intensity fluctuation-based methods (scanning number and brightness and raster scanning imaging correlation spectroscopy) the effect of pressure on the chromosome-associated protein HU and on the ParB partition protein in Escherichia coli, revealing partially reversible dissociation of ParB foci and concomitant nucleoid condensation. These results provide a proof of principle that quantitative, high-resolution imaging of live microbial cells can be carried out at pressures equivalent to those in the deepest ocean trenches.
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Affiliation(s)
- Anais C Bourges
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York; Centre de Biochimie Structrurale (CBS), INSERM, CNRS, Université de Montpellier, Montpellier, France; INRAE, MICA Department, Jouy-en-Josas, France
| | | | - Nathalie Declerck
- Centre de Biochimie Structrurale (CBS), INSERM, CNRS, Université de Montpellier, Montpellier, France; INRAE, MICA Department, Jouy-en-Josas, France
| | - Karyn L Rogers
- Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Catherine A Royer
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York.
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7
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Robinson T, Dittrich PS. Observations of Membrane Domain Reorganization in Mechanically Compressed Artificial Cells. Chembiochem 2019; 20:2666-2673. [DOI: 10.1002/cbic.201900167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Tom Robinson
- ETH ZurichDepartment of Biosystems Science and Engineering Mattenstrasse 26 4058 Basel Switzerland
- Present address: Department of Theory, Bio-SystemsMax Planck Institute of Colloids and Interfaces Science Park Golm 14424 Potsdam Germany
| | - Petra S. Dittrich
- ETH ZurichDepartment of Biosystems Science and Engineering Mattenstrasse 26 4058 Basel Switzerland
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8
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Winter R. Interrogating the Structural Dynamics and Energetics of Biomolecular Systems with Pressure Modulation. Annu Rev Biophys 2019; 48:441-463. [DOI: 10.1146/annurev-biophys-052118-115601] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
High hydrostatic pressure affects the structure, dynamics, and stability of biomolecular systems and is a key parameter in the context of the exploration of the origin and the physical limits of life. This review lays out the conceptual framework for exploring the conformational fluctuations, dynamical properties, and activity of biomolecular systems using pressure perturbation. Complementary pressure-jump relaxation studies are useful tools to study the kinetics and mechanisms of biomolecular phase transitions and structural transformations, such as membrane fusion or protein and nucleic acid folding. Finally, the advantages of using pressure to explore biomolecular assemblies and modulate enzymatic reactions are discussed.
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Affiliation(s)
- Roland Winter
- Faculty of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, D-44227 Dortmund, Germany
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9
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Schneidereit D, Schürmann S, Friedrich O. PiezoGRIN: A High-Pressure Chamber Incorporating GRIN Lenses for High-Resolution 3D-Microscopy of living Cells and Tissues. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1801453. [PMID: 30828527 PMCID: PMC6382305 DOI: 10.1002/advs.201801453] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/15/2018] [Indexed: 05/30/2023]
Abstract
A high-pressure optical chamber, PiezoGRIN, that facilitates label-free 3D high-resolution live-cell multiphoton microscopy in thick tissue samples is presented. A set of two Gradient Index (GRIN) rod lenses is integrated into the chamber as an optical guide and allows for the adjustment of the focal plane through the sample providing a field of view volume of 450 × 450 × 500 µm (x, y, z). An optical lateral resolution of 0.8 µm is achieved by using two-photon excitation with 150 fs pulses of a 810 nm titanium-sapphire laser at hydrostatic pressures up to 200 MPa. With the PiezoGRIN setup, it is possible to follow pressure-induced changes in subcellular structure of unstained vital mouse skeletal muscle tissue up to 200 µm below the tissue surface.
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Affiliation(s)
- Dominik Schneidereit
- Institute of Medical BiotechnologyFriedrich‐Alexander University Erlangen‐NürnbergPaul‐Gordan Strasse 3Erlangen91052Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT)Friedrich‐Alexander‐University Erlangen‐NürnbergErlangen91052Germany
| | - Sebastian Schürmann
- Institute of Medical BiotechnologyFriedrich‐Alexander University Erlangen‐NürnbergPaul‐Gordan Strasse 3Erlangen91052Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT)Friedrich‐Alexander‐University Erlangen‐NürnbergErlangen91052Germany
| | - Oliver Friedrich
- Institute of Medical BiotechnologyFriedrich‐Alexander University Erlangen‐NürnbergPaul‐Gordan Strasse 3Erlangen91052Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT)Friedrich‐Alexander‐University Erlangen‐NürnbergErlangen91052Germany
- Muscle Research Center Erlangen (MURCE)Paul‐Gordan Strasse 3Erlangen91052Germany
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10
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Schneider S, Paulsen H, Reiter KC, Hinze E, Schiene-Fischer C, Hübner CG. Single molecule FRET investigation of pressure-driven unfolding of cold shock protein A. J Chem Phys 2018; 148:123336. [DOI: 10.1063/1.5009662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Sven Schneider
- Institute of Physics, University of Lübeck, Lübeck D-23562, Germany
| | - Hauke Paulsen
- Institute of Physics, University of Lübeck, Lübeck D-23562, Germany
| | - Kim Colin Reiter
- Institute of Physics, University of Lübeck, Lübeck D-23562, Germany
| | - Erik Hinze
- Max Planck Research Unit for Enzymology of Protein Folding Halle, Halle/Saale D-06120, Germany
| | - Cordelia Schiene-Fischer
- Department of Enzymology, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale D-06120, Germany
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11
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Di Venere A, Nicolai E, Sinibaldi F, Di Pierro D, Caccuri AM, Mei G. Studying the TRAF2 binding to model membranes: The role of subunits dissociation. Biotechnol Appl Biochem 2018; 65:38-45. [PMID: 28960521 DOI: 10.1002/bab.1615] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/24/2017] [Indexed: 11/08/2022]
Abstract
The ability of a C-terminal truncated form of TRAF2 to bind synthetic vesicles has been quantitatively studied by steady-state fluorescence energy transfer from the protein to large unilamellar vesicles (LUVs) prepared with different lipid mixtures. The dissociation constants, the free energy of binding, and the average number of phospholipids interacting with truncated TRAF2 have been evaluated from the corresponding binding curves. The results indicate that the protein strongly interacts with the lipid bilayer, preferentially in the monomeric state. These findings have been discussed in terms of their possible role in the activity of TRAF2 in vivo.
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Affiliation(s)
- Almerinda Di Venere
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.,NAST Center, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, Rome, Italy
| | - Eleonora Nicolai
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.,NAST Center, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, Rome, Italy
| | - Federica Sinibaldi
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy
| | - Donato Di Pierro
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Anna Maria Caccuri
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.,NAST Center, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, Rome, Italy
| | - Giampiero Mei
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.,NAST Center, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, Rome, Italy
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12
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Noothalapati H, Iwasaki K, Yoshimoto C, Yoshikiyo K, Nishikawa T, Ando M, Hamaguchi HO, Yamamoto T. Imaging phospholipid conformational disorder and packing in giant multilamellar liposome by confocal Raman microspectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 187:186-190. [PMID: 28689162 DOI: 10.1016/j.saa.2017.06.060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 06/01/2017] [Accepted: 06/30/2017] [Indexed: 06/07/2023]
Abstract
Liposomes are closed phospholipid bilayer systems that have profound applications in fundamental cell biology, pharmaceutics and medicine. Depending on the composition (pure or mixture of phospholipids, presence of cholesterol) and preparation protocol, intra- and inter-chain molecular interactions vary leading to changes in the quality (order and packing) of liposomes. So far it is not possible to image conformational disorders and packing densities within a liposome in a straightforward manner. In this study, we utilized confocal Raman microspectroscopy to visualize structural disorders and packing efficiency within a giant multilamellar liposome model by focusing mainly on three regions in the vibrational spectrum (CC stretching, CH deformation and CH stretching). We estimated properties such as trans/gauche isomers and lateral packing probability. Interestingly, our Raman imaging studies revealed gel phase rich domains and heterogeneous lateral packing within the giant multilamellar liposome.
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Affiliation(s)
- Hemanth Noothalapati
- Raman Project Center for Medical and Biological Applications, Shimane University, Matsue 690-8504, Japan.
| | - Keita Iwasaki
- Faculty of Life and Environmental Science, Shimane University, Matsue 690-8504, Japan
| | - Chikako Yoshimoto
- Faculty of Life and Environmental Science, Shimane University, Matsue 690-8504, Japan
| | - Keisuke Yoshikiyo
- Faculty of Life and Environmental Science, Shimane University, Matsue 690-8504, Japan
| | - Tomoe Nishikawa
- Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1 Bunkyo-ku Tokyo, 113-0033, Japan
| | - Masahiro Ando
- Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, Tokyo 162-0041, Japan
| | - Hiro-O Hamaguchi
- Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1 Bunkyo-ku Tokyo, 113-0033, Japan; Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, Tokyo 162-0041, Japan; Institute of Molecular Science and Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Tatsuyuki Yamamoto
- Raman Project Center for Medical and Biological Applications, Shimane University, Matsue 690-8504, Japan; Faculty of Life and Environmental Science, Shimane University, Matsue 690-8504, Japan.
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13
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Development and Validation of Capillary Electrophoresis Method for Simultaneous Determination of Six Pharmaceuticals in Different Food Samples Combining On-line and Off-line Sample Enrichment Techniques. FOOD ANAL METHOD 2017. [DOI: 10.1007/s12161-017-1024-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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14
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Ceccarelli A, Di Venere A, Nicolai E, De Luca A, Rosato N, Gratton E, Mei G, Caccuri AM. New insight into the interaction of TRAF2 C-terminal domain with lipid raft microdomains. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:813-822. [PMID: 28499815 DOI: 10.1016/j.bbalip.2017.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 05/02/2017] [Accepted: 05/06/2017] [Indexed: 11/16/2022]
Abstract
In this study we provide the first evidence of the interaction of a truncated-TRAF2 with lipid raft microdomains. We have analyzed this interaction by measuring the diffusion coefficient of the protein in large and giant unilamellar vesicles (LUVs and GUVs, respectively) obtained both from synthetic lipid mixtures and from natural extracts. Steady-state fluorescence measurements performed with synthetic vesicles indicate that this truncated form of TRAF2 displays a tighter binding to raft-like LUVs with respect to the control (POPC-containing LUVs), and that this process depends on the protein oligomeric state. Generalized Polarization measurements and spectral phasor analysis revealed that truncated-TRAF2 affects the membrane fluidity, especially when vesicles are heated up at physiological temperature. The addition of nanomolar concentration of TRAF2 in GUVs also seems to exert a mechanical action, as demonstrated by the formation of intraluminal vesicles, a process in which ganglioside GM1 plays a crucial role.
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Affiliation(s)
- Arianna Ceccarelli
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Almerinda Di Venere
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; Center NAST, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Eleonora Nicolai
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Anastasia De Luca
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Nicola Rosato
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; Center NAST, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California at Irvine, Irvine, CA, USA
| | - Giampiero Mei
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; Center NAST, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, 00133 Rome, Italy.
| | - Anna Maria Caccuri
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; Center NAST, Nanoscience, Nanotechnology, Innovative Instrumentation, University of Rome Tor Vergata, 00133 Rome, Italy.
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15
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Choleva TG, Kappi FA, Tsogas GZ, Vlessidis AG, Giokas DL. In-situ suspended aggregate microextraction of gold nanoparticles from water samples and determination by electrothermal atomic absorption spectrometry. Talanta 2016; 151:91-99. [DOI: 10.1016/j.talanta.2016.01.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 10/22/2022]
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16
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Hayashi M, Nishiyama M, Kazayama Y, Toyota T, Harada Y, Takiguchi K. Reversible Morphological Control of Tubulin-Encapsulating Giant Liposomes by Hydrostatic Pressure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3794-3802. [PMID: 27023063 DOI: 10.1021/acs.langmuir.6b00799] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Liposomes encapsulating cytoskeletons have drawn much recent attention to develop an artificial cell-like chemical-machinery; however, as far as we know, there has been no report showing isothermally reversible morphological changes of liposomes containing cytoskeletons because the sets of various regulatory factors, that is, their interacting proteins, are required to control the state of every reaction system of cytoskeletons. Here we focused on hydrostatic pressure to control the polymerization state of microtubules (MTs) within cell-sized giant liposomes (diameters ∼10 μm). MT is the cytoskeleton formed by the polymerization of tubulin, and cytoskeletal systems consisting of MTs are very dynamic and play many important roles in living cells, such as the morphogenesis of nerve cells and formation of the spindle apparatus during mitosis. Using real-time imaging with a high-pressure microscope, we examined the effects of hydrostatic pressure on the morphology of tubulin-encapsulating giant liposomes. At ambient pressure (0.1 MPa), many liposomes formed protrusions due to tubulin polymerization within them. When high pressure (60 MPa) was applied, the protrusions shrank within several tens of seconds. This process was repeatedly inducible (around three times), and after the pressure was released, the protrusions regenerated within several minutes. These deformation rates of the liposomes are close to the velocities of migrating or shape-changing living cells rather than the shortening and elongation rates of the single MTs, which have been previously measured. These results demonstrate that the elongation and shortening of protrusions of giant liposomes is repeatedly controllable by regulating the polymerization state of MTs within them by applying and releasing hydrostatic pressure.
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Affiliation(s)
- Masahito Hayashi
- Division of Biological Science, Graduate School of Science, Nagoya University , Nagoya 464-8602, Japan
| | | | | | | | | | - Kingo Takiguchi
- Division of Biological Science, Graduate School of Science, Nagoya University , Nagoya 464-8602, Japan
- Structural Biology Research Center, Nagoya University , Nagoya 464-8601, Japan
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17
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McCarthy NLC, Ces O, Law RV, Seddon JM, Brooks NJ. Separation of liquid domains in model membranes induced with high hydrostatic pressure. Chem Commun (Camb) 2016; 51:8675-8. [PMID: 25907808 DOI: 10.1039/c5cc02134k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have imaged the formation of membrane microdomains immediately after their induction using a novel technology platform coupling high hydrostatic pressure to fluorescence microscopy. After formation, the ordered domains are small and highly dynamic. This will enhance links between model lipid assemblies and dynamic processes in cellular membranes.
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Affiliation(s)
- Nicola L C McCarthy
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
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18
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McCarthy N, Brooks N. Using High Pressure to Modulate Lateral Structuring in Model Lipid Membranes. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2016. [DOI: 10.1016/bs.abl.2016.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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19
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In-situ suspended aggregate microextraction: A sample preparation approach for the enrichment of organic compounds in aqueous solutions. J Chromatogr A 2015. [DOI: 10.1016/j.chroma.2015.07.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Purushothaman S, Cicuta P, Ces O, Brooks NJ. Influence of High Pressure on the Bending Rigidity of Model Membranes. J Phys Chem B 2015; 119:9805-10. [DOI: 10.1021/acs.jpcb.5b05272] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sowmya Purushothaman
- Department
of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
| | - Pietro Cicuta
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K
| | - Oscar Ces
- Department
of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
| | - Nicholas J. Brooks
- Department
of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
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21
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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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22
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Brooks NJ. Pressure effects on lipids and bio-membrane assemblies. IUCRJ 2014; 1:470-7. [PMID: 25485127 PMCID: PMC4224465 DOI: 10.1107/s2052252514019551] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 08/28/2014] [Indexed: 05/06/2023]
Abstract
Membranes are amongst the most important biological structures; they maintain the fundamental integrity of cells, compartmentalize regions within them and play an active role in a wide range of cellular processes. Pressure can play a key role in probing the structure and dynamics of membrane assemblies, and is also critical to the biology and adaptation of deep-sea organisms. This article presents an overview of the effect of pressure on the mesostructure of lipid membranes, bilayer organization and lipid-protein assemblies. It also summarizes recent developments in high-pressure structural instrumentation suitable for experiments on membranes.
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Affiliation(s)
- Nicholas J. Brooks
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
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23
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Di Venere A, Nicolai E, Ivanov I, Dainese E, Adel S, Angelucci BC, Kuhn H, Maccarrone M, Mei G. Probing conformational changes in lipoxygenases upon membrane binding: fine-tuning by the active site inhibitor ETYA. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:1-10. [PMID: 24012824 DOI: 10.1016/j.bbalip.2013.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 07/29/2013] [Accepted: 08/14/2013] [Indexed: 11/27/2022]
Abstract
Lipoxygenases (LOXs) are lipid-peroxidizing enzymes that are involved in the metabolism of polyunsaturated fatty acids. Their biological activity includes a membrane binding process whose molecular details are not completely understood. The mechanism of enzyme-membrane interactions is thought to involve conformational changes at the level of the protein tertiary structure, and the extent of such alterations depends on the degree of structural flexibility of the different LOX isoforms. In this study, we have tested the resilience properties of a plant and a mammalian LOX, by using high pressure fluorescence measurements at different temperatures. The binding of LOXs to the lipid bilayer has been characterized using both large and giant unilamellar vesicles and electron transfer particles (inner mitochondrial membranes) as model membranes. The data indicate that the degree of LOXs' flexibility is strictly dependent on the two distinct N- and C-terminal domains that characterize the 3D structure of these enzymes. Furthermore, they demonstrate that increasing the rigidity of protein scaffolding by the presence of an active site ligand impairs the membrane binding ability of LOXs. These findings provide evidence that the amphitropic nature of LOXs is finely tuned by the interaction of the substrate with the residues of the active site, suggesting new strategies for the design of enzyme inhibitors.
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Affiliation(s)
- Almerinda Di Venere
- Department of Experimental Medicine and Surgery, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy
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24
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Kapoor S, Werkmüller A, Goody RS, Waldmann H, Winter R. Pressure modulation of Ras-membrane interactions and intervesicle transfer. J Am Chem Soc 2013; 135:6149-56. [PMID: 23560466 DOI: 10.1021/ja312671j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proteins attached to the plasma membrane frequently encounter mechanical stresses, including high hydrostatic pressure (HHP) stress. Signaling pathways involving membrane-associated small GTPases (e.g., Ras) have been identified as critical loci for pressure perturbation. However, the impact of mechanical stimuli on biological outputs is still largely terra incognita. The present study explores the effect of HHP on the membrane association, dissociation, and intervesicle transfer process of N-Ras by using a FRET-based assay to obtain the kinetic parameters and volumetric properties along the reaction path of these processes. Notably, membrane association is fostered upon pressurization. Conversely, depending on the nature and lateral organization of the lipid membrane, acceleration or retardation is observed for the dissociation step. In addition, HHP can be inferred as a positive regulator of N-Ras clustering, in particular in heterogeneous membranes. The susceptibility of membrane interaction to pressure raises the idea of a role of lipidated signaling molecules as mechanosensors, transducing mechanical stimuli to chemical signals by regulating their membrane binding and dissociation. Finally, our results provide first insights into the influence of pressure on membrane-associated Ras-controlled signaling events in organisms living under extreme environmental conditions such as those that are encountered in the deep sea and sub-seafloor environments, where pressures reach the kilobar (100 MPa) range.
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Affiliation(s)
- Shobhna Kapoor
- Physical Chemistry I-Biophysical Chemistry, Faculty of Chemistry, TU Dortmund University, Otto-Hahn-Strasse 6, D-44227 Dortmund, Germany
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25
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Hofstetter S, Denter C, Winter R, McMullen LM, Gänzle MG. Use of the fluorescent probe LAURDAN to label and measure inner membrane fluidity of endospores of Clostridium spp. J Microbiol Methods 2012; 91:93-100. [PMID: 22884687 DOI: 10.1016/j.mimet.2012.07.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 07/17/2012] [Accepted: 07/17/2012] [Indexed: 11/29/2022]
Abstract
A method for measuring the fluidity of inner membranes of populations of endospores of Clostridium spp. with a fluorescent dye was developed. Cells of Clostridium beijerinckii ATCC 8260 and Clostridium sporogenes ATCC 7955 were allowed to sporulate in the presence of 6-dodecanoyl-2-dimethylaminonaphthalene (LAURDAN) on a soil-based media. Labeling of endospores with LAURDAN did not affect endospore viability. Removal of the outer membranes of endospores was done using a chemical treatment and confirmed using transmission electron microscopy (TEM). Two-photon confocal laser scanning microscopy (CLSM), and generalized polarization (GP) measurements were used to assess fluorescence of endospores. Lipid composition analysis of cells and endospores was done to determine whether differences in GP values are attributable to differences in membrane composition. Removal of the outer membranes of endospores did not significantly impact GP values. Decoated, labeled endospores of C. sporogenes ATCC 7955 and C. beijerinckii ATCC 8260 exhibited GP values of 0.77±0.031 and 0.74±0.027 respectively. Differences in ratios of fatty acids between cells and endospores are unlikely to be responsible for high GP values observed in endospores. These GP values indicate high levels of lipid order and the exclusion of water from within inner membranes of endospores.
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Affiliation(s)
- Simmon Hofstetter
- University of Alberta, Department of Agricultural, Food and Nutritional Science, Edmonton, Alberta, Canada, T6G 2P5.
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26
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Brooks NJ, Ces O, Templer RH, Seddon JM. Pressure effects on lipid membrane structure and dynamics. Chem Phys Lipids 2010; 164:89-98. [PMID: 21172328 DOI: 10.1016/j.chemphyslip.2010.12.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 12/07/2010] [Accepted: 12/09/2010] [Indexed: 11/30/2022]
Abstract
The effect of hydrostatic pressure on lipid structure and dynamics is highly important as a tool in biophysics and bio-technology, and in the biology of deep sea organisms. Despite its importance, high hydrostatic pressure remains significantly less utilised than other thermodynamic variables such as temperature and chemical composition. Here, we give an overview of some of the theoretical aspects which determine lipid behaviour under pressure and the techniques and technology available to study these effects. We also summarise several recent experiments which highlight the information available from these approaches.
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Affiliation(s)
- Nicholas J Brooks
- Membrane Biophysics Platform and Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington Campus, UK
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27
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Winter R. Exploring the Energy and Conformational Landscape of Biomolecules Under Extreme Conditions. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/978-90-481-9258-8_47] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2023]
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28
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Demchenko AP, Mély Y, Duportail G, Klymchenko AS. Monitoring biophysical properties of lipid membranes by environment-sensitive fluorescent probes. Biophys J 2009; 96:3461-70. [PMID: 19413953 DOI: 10.1016/j.bpj.2009.02.012] [Citation(s) in RCA: 301] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 02/11/2009] [Accepted: 02/17/2009] [Indexed: 01/21/2023] Open
Abstract
We review the main trends in the development of fluorescence probes to obtain information about the structure, dynamics, and interactions in biomembranes. 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. Progress is being made in increasing the information content and spatial resolution of the probe responses. Multichannel environment-sensitive probes that can distinguish between different membrane physicochemical properties through multiple spectroscopic parameters show considerable promise.
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29
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Yasuhara K, Sasaki Y, Kikuchi JI. Fluorescent sensor responsive to local viscosity and its application to the imaging of liquid-ordered domain in lipid membranes. Colloids Surf B Biointerfaces 2008; 67:145-9. [DOI: 10.1016/j.colsurfb.2008.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 07/31/2008] [Accepted: 08/05/2008] [Indexed: 11/28/2022]
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30
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Haver T, Raber EC, Urayama P. An application of spatial deconvolution to a capillary-based high-pressure chamber for fluorescence microscopy imaging. J Microsc 2008; 230:363-71. [PMID: 18503661 DOI: 10.1111/j.1365-2818.2008.01994.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Capillary-based high-pressure chambers for which the wall serves as both the optical window and mechanical support have been reported for fluorescence microscopy imaging. Although capillary chambers are straightforward and economical to construct, the curved capillary wall introduces image aberrations. The significance of these aberrations in imaging sub-cellular-dimension objects has yet to be assessed. Using a capillary chamber that is routinely pressurized to between 20 and 30 MPa, a pressure range suitable for studying a wide variety of cellular processes, we demonstrate sub-cellular-dimension spatial resolution in the imaging of fluorescent micro-spheres. Objectives with a range of numerical apertures (0.5-1.3) and working distances (0.1-7.4 mm) are considered. We show that spatial (or point-spread function, PSF) deconvolution improves image contrast in capillary-based images by comparing deconvolution results with those obtained from slide-mounted controls. Furthermore, similar deconvolution results between a measured PSF and a calculated, flat-geometry PSF indicate that the capillary wall is optically flat on cellular length scales. Results here facilitate the application of contemporary techniques in fluorescence microscopy to high-pressure imaging fields.
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Affiliation(s)
- T Haver
- Department of Physics, Miami University, Oxford, OH, USA
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31
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The temperature–pressure phase diagram of a DPPC–ergosterol fungal model membrane—a SAXS and FT-IR spectroscopy study. Chem Phys Lipids 2008; 152:57-63. [DOI: 10.1016/j.chemphyslip.2008.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2007] [Revised: 12/29/2007] [Accepted: 01/04/2008] [Indexed: 11/18/2022]
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32
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Li F, Ketelaar T, Cohen Stuart MA, Sudhölter EJR, Leermakers FAM, Marcelis ATM. Gentle immobilization of nonionic polymersomes on solid substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:76-82. [PMID: 18052397 DOI: 10.1021/la702546b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Vesicles from Pluronic L121 (PEO5-PPO68-PEO5) triblock copolymers were first stabilized by a permanent interpenetrating polymer network and then gently immobilized onto a glass or mica surface. Fluorescence-labeled micrometer-sized vesicles were visualized with confocal laser scanning microscopy, and smaller sized capsules, around 100 nm, were probed by liquid atomic force microscopy. The immobilized vesicles were weakly attached to a negatively charged surface via negatively charged polyelectrolytes in combination with Mg2+ ions and can be reversibly detached from the surface by slightly elevated temperatures. To illustrate that the immobilized vesicles remain responsive to external stimuli, we show that it is possible to transform their shape from spherical to cylindrical by introducing a second Pluronic, namely, P123 (PEO20-PPO70-PEO20). The detailed transition process has been recorded in real time by confocal laser scanning microscopy. Electron microscopy studies confirmed that a similar morphology change also occurs in the bulk.
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Affiliation(s)
- Feng Li
- Laboratory of Organic Chemistry, Laboratory of Physical Chemistry and Colloid Science, and Laboratory of Plant Cell Biology, Wageningen University, Dreijenplein 8, Wageningen, The Netherlands
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