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Abstract
Hierarchic self-assembly underpins much of the form and function seen in synthetic or biological soft materials. Lipids are paramount examples, building themselves in nature or synthetically in a variety of meso/nanostructures. Synthetic block copolymers capture many of lipid's structural and functional properties. Lipids are typically biocompatible and high molecular weight polymers are mechanically robust and chemically versatile. The development of new materials for applications like controlled drug/gene/protein delivery, biosensors, and artificial cells often requires the combination of lipids and polymers. The emergent composite material, a "polymer-lipid hybrid membrane", displays synergistic properties not seen in pure components. Specific examples include the observation that hybrid membranes undergo lateral phase separation that can correlate in registry across multiple layers into a three-dimensional phase-separated system with enhanced permeability of encapsulated drugs. It is timely to underpin these emergent properties in several categories of hybrid systems ranging from colloidal suspensions to supported hybrid films. In this review, we discuss the form and function of a vast number of polymer-lipid hybrid systems published to date. We rationalize the results to raise new fundamental understanding of hybrid self-assembling soft materials as well as to enable the design of new supramolecular systems and applications.
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Affiliation(s)
- Yoo Kyung Go
- Department of Materials Science and Engineering, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
| | - Cecilia Leal
- Department of Materials Science and Engineering, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
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2
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Sarmento MJ, Borges-Araújo L, Pinto SN, Bernardes N, Ricardo JC, Coutinho A, Prieto M, Fernandes F. Quantitative FRET Microscopy Reveals a Crucial Role of Cytoskeleton in Promoting PI(4,5)P 2 Confinement. Int J Mol Sci 2021; 22:11727. [PMID: 34769158 PMCID: PMC8583820 DOI: 10.3390/ijms222111727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 01/30/2023] Open
Abstract
Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) is an essential plasma membrane component involved in several cellular functions, including membrane trafficking and cytoskeleton organization. This function multiplicity is partially achieved through a dynamic spatiotemporal organization of PI(4,5)P2 within the membrane. Here, we use a Förster resonance energy transfer (FRET) approach to quantitatively assess the extent of PI(4,5)P2 confinement within the plasma membrane. This methodology relies on the rigorous evaluation of the dependence of absolute FRET efficiencies between pleckstrin homology domains (PHPLCδ) fused with fluorescent proteins and their average fluorescence intensity at the membrane. PI(4,5)P2 is found to be significantly compartmentalized at the plasma membrane of HeLa cells, and these clusters are not cholesterol-dependent, suggesting that membrane rafts are not involved in the formation of these nanodomains. On the other hand, upon inhibition of actin polymerization, compartmentalization of PI(4,5)P2 is almost entirely eliminated, showing that the cytoskeleton network is the critical component responsible for the formation of nanoscale PI(4,5)P2 domains in HeLa cells.
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Affiliation(s)
- Maria J. Sarmento
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal
| | - Luís Borges-Araújo
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (L.B.-A.); (S.N.P.); (N.B.); (J.C.R.); (A.C.); (M.P.)
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Sandra N. Pinto
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (L.B.-A.); (S.N.P.); (N.B.); (J.C.R.); (A.C.); (M.P.)
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Nuno Bernardes
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (L.B.-A.); (S.N.P.); (N.B.); (J.C.R.); (A.C.); (M.P.)
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Joana C. Ricardo
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (L.B.-A.); (S.N.P.); (N.B.); (J.C.R.); (A.C.); (M.P.)
| | - Ana Coutinho
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (L.B.-A.); (S.N.P.); (N.B.); (J.C.R.); (A.C.); (M.P.)
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
- Departamento de Química e Bioquímica, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Manuel Prieto
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (L.B.-A.); (S.N.P.); (N.B.); (J.C.R.); (A.C.); (M.P.)
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Fábio Fernandes
- IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal; (L.B.-A.); (S.N.P.); (N.B.); (J.C.R.); (A.C.); (M.P.)
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal
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3
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Pan XH, Chen M, Cao SH, Xu ZQ, Li Z, Li YQ. Plasmon Coupling Enhanced Micro-Spectroscopy and Imaging for Sensitive Discrimination of Membrane Domains of a Single Cell. Chemistry 2021; 27:17331-17335. [PMID: 34609776 DOI: 10.1002/chem.202103018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Indexed: 11/08/2022]
Abstract
Different cell membrane domains play different roles in many cell processes, and the discrimination of these domains is of considerable importance for the elucidation of cellular functions. However, the strategies available for distinguishing these cell membrane domains are limited. A novel technique called plasmon coupling enhanced micro-spectroscopy and imaging to discriminate basal and lateral membrane domains of a single cell combines the application of an additional plasmonic silver film for surface plasmon (SP) excitation to selectively excite and enhance the basal membranes in the near-field with directional enhanced microscopic imaging and spectroscopy. The SP and critical evanescent fields are induced upon excitation through a silver-coated semitransparent coverslip at the surface plasmon resonance and critical angles, respectively. The basal and lateral membrane domains located within the SP and critical evanescent fields can be selectively excited and distinguished by adjusting the incident angle of laser irradiation. Moreover, the brighter images and more intense spectra of membrane-targeting fluorescence-Raman probes under directional excitation than in conventional EPI mode allow clear identification of the membrane domains.
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Affiliation(s)
- Xiao-Hui Pan
- Department of Chemistry and, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, 422 Siming South Road, Siming District, Xiamen, 361005, P. R. China
| | - Min Chen
- Department of Chemistry and, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, 422 Siming South Road, Siming District, Xiamen, 361005, P. R. China
| | - Shuo-Hui Cao
- Department of Chemistry and, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, 422 Siming South Road, Siming District, Xiamen, 361005, P. R. China
| | - Zi-Qian Xu
- Department of Chemistry and, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, 422 Siming South Road, Siming District, Xiamen, 361005, P. R. China
| | - Zhao Li
- Department of Chemistry and, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, 422 Siming South Road, Siming District, Xiamen, 361005, P. R. China
| | - Yao-Qun Li
- Department of Chemistry and, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, 422 Siming South Road, Siming District, Xiamen, 361005, P. R. China
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4
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Yagi T, Sato H. A simple model of planar membrane: An integral equation investigation. J Comput Chem 2018; 39:2576-2581. [PMID: 30394542 DOI: 10.1002/jcc.25638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/03/2018] [Accepted: 09/17/2018] [Indexed: 11/08/2022]
Abstract
A simple model of a lipid membrane, a binary mixture of saturated lipids and unsaturated lipids, was studied using an integral equation theory. The planar membrane is modeled as mixture of linear and bent molecules in two-dimensional space, and site-site radial distribution function, Kirkwood-Buff (KB) integral and related quantities were computed over the whole range of the molar fraction to understand their mixing behavior. We found that a close packing of linear molecules is enhanced as the fraction of bent molecules increases, but a long range correlation between the linear molecules is weakened. A high concentration of linear molecules promotes the demixing of linear molecules and bent molecules, and enhances the long range correlation between molecules. This implies that, the higher the concentration of linear molecules, the larger clusters tend to be formed. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Tomoaki Yagi
- Department of Molecular Engineering, Kyoto University, Kyoto, 615-8510, Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Kyoto University, Kyoto, 615-8510, Japan
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Hooghoudt JO, Barroso M, Waagepetersen R. TOWARD BAYESIAN INFERENCE OF THE SPATIAL DISTRIBUTION OF PROTEINS FROM THREE-CUBE FÖRSTER RESONANCE ENERGY TRANSFER DATA. Ann Appl Stat 2018; 11:1711-1737. [PMID: 29861820 DOI: 10.1214/17-aoas1054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Förster resonance energy transfer (FRET) is a quantum-physical phenomenon where energy may be transferred from one molecule to a neighbor molecule if the molecules are close enough. Using fluorophore molecule marking of proteins in a cell, it is possible to measure in microscopic images to what extent FRET takes place between the fluorophores. This provides indirect information of the spatial distribution of the proteins. Questions of particular interest are whether (and if so to which extent) proteins of possibly different types interact or whether they appear independently of each other. In this paper we propose a new likelihood-based approach to statistical inference for FRET microscopic data. The likelihood function is obtained from a detailed modeling of the FRET data-generating mechanism conditional on a protein configuration. We next follow a Bayesian approach and introduce a spatial point process prior model for the protein configurations depending on hyperparameters quantifying the intensity of the point process. Posterior distributions are evaluated using Markov chain Monte Carlo. We propose to infer microscope-related parameters in an initial step from reference data without interaction between the proteins. The new methodology is applied to simulated and real datasets.
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6
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Cabré EJ, Martínez-Calle M, Prieto M, Fedorov A, Olmeda B, Loura LMS, Pérez-Gil J. Homo- and hetero-oligomerization of hydrophobic pulmonary surfactant proteins SP-B and SP-C in surfactant phospholipid membranes. J Biol Chem 2018; 293:9399-9411. [PMID: 29700110 DOI: 10.1074/jbc.ra117.000222] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 03/28/2018] [Indexed: 11/06/2022] Open
Abstract
Pulmonary surfactant is a lipid/protein mixture that reduces surface tension at the respiratory air-water interface in lungs. Among its nonlipidic components are pulmonary surfactant-associated proteins B and C (SP-B and SP-C, respectively). These highly hydrophobic proteins are required for normal pulmonary surfactant function, and whereas past literature works have suggested possible SP-B/SP-C interactions and a reciprocal modulation effect, no direct evidence has been yet identified. In this work, we report an extensive fluorescence spectroscopy study of both intramolecular and intermolecular SP-B and SP-C interactions, using a combination of quenching and FRET steady-state and time-resolved methodologies. These proteins are compartmentalized in full surfactant membranes but not in pure 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) vesicles, in accordance with their previously described preference for liquid disordered phases. From the observed static self-quenching and homo-FRET of BODIPY-FL labeled SP-B, we conclude that this protein forms homoaggregates at low concentration (lipid:protein ratio, 1:1000). Increases in polarization of BODIPY-FL SP-B and steady-state intensity of WT SP-B were observed upon incorporation of under-stoichiometric amounts of WT SP-C. Conversely, Marina Blue-labeled SP-C is quenched by over-stoichiometric amounts of WT SP-B, whereas under-stoichiometric concentrations of the latter actually increase SP-C emission. Time-resolved hetero-FRET from Marina Blue SP-C to BODIPY-FL SP-B confirm distinct protein aggregation behaviors with varying SP-B concentration. Based on these multiple observations, we propose a model for SP-B/SP-C interactions, where SP-C might induce conformational changes on SP-B complexes, affecting its aggregation state. The conclusions inferred from the present work shed light on the synergic functionality of both proteins in the pulmonary surfactant system.
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Affiliation(s)
- Elisa J Cabré
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain
| | - Marta Martínez-Calle
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain.,the Hospital 12 Octubre Research Institute, Madrid 28041, Spain
| | - Manuel Prieto
- the CQFM-IN and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Alexander Fedorov
- the CQFM-IN and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Bárbara Olmeda
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain.,the Hospital 12 Octubre Research Institute, Madrid 28041, Spain
| | - Luís M S Loura
- the Faculty of Pharmacy, University of Coimbra, Coimbra 3000-548, Portugal, and .,the Centro de Química de Coimbra, University of Coimbra, Coimbra 3004-535, Portugal
| | - Jesús Pérez-Gil
- From the Department of Biochemistry, Faculty of Biology, Complutense University, Madrid 28040, Spain, .,the Hospital 12 Octubre Research Institute, Madrid 28041, Spain
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Lipid Driven Nanodomains in Giant Lipid Vesicles are Fluid and Disordered. Sci Rep 2017; 7:5460. [PMID: 28710349 PMCID: PMC5511215 DOI: 10.1038/s41598-017-05539-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/30/2017] [Indexed: 11/30/2022] Open
Abstract
It is a fundamental question in cell biology and biophysics whether sphingomyelin (SM)- and cholesterol (Chol)- driven nanodomains exist in living cells and in model membranes. Biophysical studies on model membranes revealed SM and Chol driven micrometer-sized liquid-ordered domains. Although the existence of such microdomains has not been proven for the plasma membrane, such lipid mixtures have been often used as a model system for ‘rafts’. On the other hand, recent super resolution and single molecule results indicate that the plasma membrane might organize into nanocompartments. However, due to the limited resolution of those techniques their unambiguous characterization is still missing. In this work, a novel combination of Förster resonance energy transfer and Monte Carlo simulations (MC-FRET) identifies directly 10 nm large nanodomains in liquid-disordered model membranes composed of lipid mixtures containing SM and Chol. Combining MC-FRET with solid-state wide-line and high resolution magic angle spinning NMR as well as with fluorescence correlation spectroscopy we demonstrate that these nanodomains containing hundreds of lipid molecules are fluid and disordered. In terms of their size, fluidity, order and lifetime these nanodomains may represent a relevant model system for cellular membranes and are closely related to nanocompartments suggested to exist in cellular membranes.
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8
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Dao TPT, Fernandes F, Ibarboure E, Ferji K, Prieto M, Sandre O, Le Meins JF. Modulation of phase separation at the micron scale and nanoscale in giant polymer/lipid hybrid unilamellar vesicles (GHUVs). SOFT MATTER 2017; 13:627-637. [PMID: 27991638 DOI: 10.1039/c6sm01625a] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Phase separation in giant polymer/lipid hybrid unilamellar vesicles (GHUVs) has been described over the last few years. However there is still a lack of understanding on the physical and molecular factors governing the phase separation in such systems. Among these parameters it has been suggested that in analogy to multicomponent lipid vesicles hydrophobic mismatches as well as lipid fluidity play a role. In this work, we aim to map a global picture of phase separation and domain formation in the membrane of GHUVs by using various copolymers based on poly(dimethylsiloxane) (PDMS) and poly(ethylene glycol) (PEO) with different architectures (grafted, triblock) and molar masses, combined with phospholipids in the fluid (POPC) or gel state (DPPC) at room temperature. From confocal imaging and fluorescence lifetime imaging microscopy (FLIM) techniques, the phase separation into either micro- or nano-domains within GHUVs was studied. In particular, our systematic studies demonstrate that in addition to the lipid/polymer fraction or the lipid physical state, important factors such as line tension at lipid polymer/lipid boundaries can be finely modulated by the molar mass and the architecture of the copolymer and lead to the formation of stable lipid domains with different sizes and morphologies in such GHUVs.
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Affiliation(s)
- Thi Phuong Tuyen Dao
- University of Bordeaux, LCPO UMR 5629, 16 avenue PeyBerland, F-33600 Pessac, France. and CNRS, Laboratoire de Chimie des Polymères Organiques, UMR 5629, F-33600, Pessac, France and Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Universidade de Lisboa Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
| | - Fabio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Universidade de Lisboa Instituto Superior Técnico, 1049-001 Lisboa, Portugal. and UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 32829-516, Caparica, Lisbon, Portugal
| | - Emmanuel Ibarboure
- University of Bordeaux, LCPO UMR 5629, 16 avenue PeyBerland, F-33600 Pessac, France. and CNRS, Laboratoire de Chimie des Polymères Organiques, UMR 5629, F-33600, Pessac, France
| | - Khalid Ferji
- University of Bordeaux, LCPO UMR 5629, 16 avenue PeyBerland, F-33600 Pessac, France. and CNRS, Laboratoire de Chimie des Polymères Organiques, UMR 5629, F-33600, Pessac, France
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Universidade de Lisboa Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
| | - Olivier Sandre
- University of Bordeaux, LCPO UMR 5629, 16 avenue PeyBerland, F-33600 Pessac, France. and CNRS, Laboratoire de Chimie des Polymères Organiques, UMR 5629, F-33600, Pessac, France
| | - Jean-François Le Meins
- University of Bordeaux, LCPO UMR 5629, 16 avenue PeyBerland, F-33600 Pessac, France. and CNRS, Laboratoire de Chimie des Polymères Organiques, UMR 5629, F-33600, Pessac, France
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9
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Trusova VM, Gorbenko GP, Deligeorgiev T, Gadjev N. Probing protein-lipid interactions by FRET between membrane fluorophores. Methods Appl Fluoresc 2016; 4:034014. [PMID: 28355160 DOI: 10.1088/2050-6120/4/3/034014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Förster resonance energy transfer (FRET) is a powerful fluorescence technique that has found numerous applications in medicine and biology. One area where FRET proved to be especially informative involves the intermolecular interactions in biological membranes. The present study was focused on developing and verifying a Monte-Carlo approach to analyzing the results of FRET between the membrane-bound fluorophores. This approach was employed to quantify FRET from benzanthrone dye ABM to squaraine dye SQ-1 in the model protein-lipid system containing a polycationic globular protein lysozyme and negatively charged lipid vesicles composed of phosphatidylcholine and phosphatidylglycerol. It was found that acceptor redistribution between the lipid bilayer and protein binding sites resulted in the decrease of FRET efficiency. Quantification of this effect in terms of the proposed methodology yielded both structural and binding parameters of lysozyme-lipid complexes.
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Affiliation(s)
- Valeriya M Trusova
- Department of Nuclear and Medical Physics, V.N. Karazin Kharkiv National University, 4 Svobody Sq., Kharkiv 61022, Ukraine. Address to whom any correspondence should be addressed: Valeriya M. Trusova, 19-32 Geroyev Truda Str., Kharkiv 61144, Ukraine
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10
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Fernandes F, Coutinho A, Prieto M, Loura LMS. Electrostatically driven lipid-protein interaction: Answers from FRET. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1837-48. [PMID: 25769805 DOI: 10.1016/j.bbamem.2015.02.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 02/23/2015] [Indexed: 12/13/2022]
Abstract
Electrostatics govern the association of a large number of proteins with cellular membranes. In some cases, these proteins present specialized lipid-binding modules or membrane targeting domains while in other cases association is achieved through nonspecific interaction of unstructured clusters of basic residues with negatively charged lipids. Given its spatial resolution in the nanometer range, Förster resonance energy transfer (FRET) is a powerful tool to give insight into protein-lipid interactions and provide molecular level information which is difficult to retrieve with other spectroscopic techniques. In this review we present and discuss the basic formalisms of both hetero- and homo-FRET pertinent to the most commonly encountered problems in lipid-protein interaction studies and highlight some examples of implementations of different FRET methodologies to characterize lipid/protein systems in which electrostatic interactions play a crucial role. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Dep. Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Luís M S Loura
- Faculdade de Farmácia, Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Centro de Química de Coimbra, Largo D. Dinis, Rua Larga, 3004-535 Coimbra, Portugal.
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11
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Dao TPT, Fernandes F, Er-Rafik M, Salva R, Schmutz M, Brûlet A, Prieto M, Sandre O, Le Meins JF. Phase Separation and Nanodomain Formation in Hybrid Polymer/Lipid Vesicles. ACS Macro Lett 2015; 4:182-186. [PMID: 35596428 DOI: 10.1021/mz500748f] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hybrid polymer/lipid large unilamellar vesicles (LUVs) were studied by small angle neutron scattering (SANS), time-resolved Förster resonance energy transfer (TR-FRET), and cryo-transmission electron microscopy (cryo-TEM). For the first time in hybrid vesicles, evidence for phase separation at the nanoscale was obtained, leading to the formation of stable nanodomains enriched either in lipid or polymer. This stability was allowed by using vesicle-forming copolymer with a membrane thickness close to the lipid bilayer thickness, thereby minimizing the hydrophobic mismatch at the domain periphery. Hybrid giant unilamellar vesicles (GUVs) with the same composition have been previously shown to be unstable and susceptible to fission, suggesting a role of curvature in the stabilization of nanodomains in these structures.
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Affiliation(s)
- T. P. Tuyen Dao
- University of Bordeaux, LCPO UMR 5629, 16 avenue Pey Berland, F-33600 Pessac, France
- CNRS, Laboratoire de Chimie des Polymères
Organiques,
UMR 5629, F-33600, Pessac, France
- Centro
de Química-Física Molecular and Institute of Nanoscience
and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - F. Fernandes
- Centro
de Química-Física Molecular and Institute of Nanoscience
and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - M. Er-Rafik
- Institut
Charles Sadron, UPR 22 CNRS, Université de Strasbourg, 23 rue
du Loess, 67034 Strasbourg, France
| | - R. Salva
- University of Bordeaux, LCPO UMR 5629, 16 avenue Pey Berland, F-33600 Pessac, France
- CNRS, Laboratoire de Chimie des Polymères
Organiques,
UMR 5629, F-33600, Pessac, France
| | - M. Schmutz
- Institut
Charles Sadron, UPR 22 CNRS, Université de Strasbourg, 23 rue
du Loess, 67034 Strasbourg, France
| | - A. Brûlet
- Laboratoire
Léon Brillouin, UMR12 CEA-CNRS, CEA Saclay, F-91191 Gif-sur-Yvette Cedex, France
| | - M. Prieto
- Centro
de Química-Física Molecular and Institute of Nanoscience
and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - O. Sandre
- University of Bordeaux, LCPO UMR 5629, 16 avenue Pey Berland, F-33600 Pessac, France
- CNRS, Laboratoire de Chimie des Polymères
Organiques,
UMR 5629, F-33600, Pessac, France
| | - J.-F. Le Meins
- University of Bordeaux, LCPO UMR 5629, 16 avenue Pey Berland, F-33600 Pessac, France
- CNRS, Laboratoire de Chimie des Polymères
Organiques,
UMR 5629, F-33600, Pessac, France
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12
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Abstract
All biological membranes consist of a complex composite of macromolecules and macromolecular assemblies, of which the fluid lipid-bilayer component is a core element with regard to cell encapsulation and barrier properties. The fluid lipid bilayer also supports the functional machinery of receptors, channels and pumps that are associated with the membrane. This bilayer is stabilized by weak physical and colloidal forces, and its nature is that of a self-assembled system of amphiphiles in water. Being only approximately 5 nm in thickness and still encapsulating a cell that is three orders of magnitude larger in diameter, the lipid bilayer as a material has very unusual physical properties, both in terms of structure and dynamics. Although the lipid bilayer is a fluid, it has a distinct and structured trans-bilayer profile, and in the plane of the bilayer the various molecular components, viz different lipid species and membrane proteins, have the capacity to organize laterally in terms of differentiated domains on different length and time scales. These elements of small-scale structure and order are crucial for the functioning of the membrane. It has turned out to be difficult to quantitatively study the small-scale structure of biological membranes. A major part of the insight into membrane micro- and nano-domains and the concepts used to describe them have hence come from studies of simple lipid bilayers as models of membranes, by use of a wide range of theoretical, experimental and simulational approaches. Many questions remain to be answered as to which extent the result from model studies can carry over to real biological membranes.
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Deleu M, Crowet JM, Nasir MN, Lins L. Complementary biophysical tools to investigate lipid specificity in the interaction between bioactive molecules and the plasma membrane: A review. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:3171-3190. [DOI: 10.1016/j.bbamem.2014.08.023] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 08/05/2014] [Accepted: 08/21/2014] [Indexed: 02/08/2023]
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Suárez-Germà C, Hernández-Borrell J, Prieto M, Loura LMS. Modeling FRET to investigate the selectivity of lactose permease ofEscherichia colifor lipids. Mol Membr Biol 2014; 31:120-30. [DOI: 10.3109/09687688.2014.915351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Lorent J, Lins L, Domenech Ò, Quetin-Leclercq J, Brasseur R, Mingeot-Leclercq MP. Domain formation and permeabilization induced by the saponin α-hederin and its aglycone hederagenin in a cholesterol-containing bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4556-4569. [PMID: 24690040 DOI: 10.1021/la4049902] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Saponins and triterpenic acids have been shown to be able to interact with lipid membranes and domains enriched with cholesterol (rafts). How saponins are able to modulate lipid phase separation in membranes and the role of the sugar chains for this activity is unknown. We demonstrate in a binary membrane model composed of DMPC/Chol (3:1 mol/mol) that the saponin α-hederin and its aglycone presenting no sugar chain, the triterpenic acid hederagenin, are able to induce the formation of lipid domains. We show on multilamellar vesicles (MLV), giant unilamellar vesicles (GUV), and supported planar bilayers (SPB) that the presence of sugar units on the sapogenin accelerates domain formation and increases the proportion of sterols within these domains. The domain shape is also influenced by the presence of sugars because α-hederin and hederagenin induce the formation of tubular and spherical domains, respectively. These highly curved structures should result from the induction of membrane curvature by both compounds. In addition to the formation of domains, α-hederin and hederagenin permeabilize GUV. The formation of membrane holes by α-hederin comes along with the accumulation of lipids into nonbilayer structures in SPB. This process might be responsible for the permeabilizing activity of both compounds. In LUV, permeabilization by α-hederin was sterol-dependent. The biological implications of our results and the mechanisms involved are discussed in relation to the activity of saponins and triterpenic acids on membrane rafts, cancer cells, and hemolysis.
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Affiliation(s)
- Joseph Lorent
- Université Catholique de Louvain , Louvain Drug Research Institute, Cellular and Molecular Pharmacology, B1.73.05, Avenue E. Mounier 73, B-1200 Brussels, Belgium
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Bernardini C, Stoyanov SD, Arnaudov LN, Cohen Stuart MA. Colloids in Flatland: a perspective on 2D phase-separated systems, characterisation methods, and lineactant design. Chem Soc Rev 2013; 42:2100-29. [DOI: 10.1039/c2cs35269a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Šachl R, Johansson LBÅ, Hof M. Förster resonance energy transfer (FRET) between heterogeneously distributed probes: application to lipid nanodomains and pores. Int J Mol Sci 2012. [PMID: 23203189 PMCID: PMC3546683 DOI: 10.3390/ijms131216141] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The formation of membrane heterogeneities, e.g., lipid domains and pores, leads to a redistribution of donor (D) and acceptor (A) molecules according to their affinity to the structures formed and the remaining bilayer. If such changes sufficiently influence the Förster resonance energy transfer (FRET) efficiency, these changes can be further analyzed in terms of nanodomain/pore size. This paper is a continuation of previous work on this theme. In particular, it is demonstrated how FRET experiments should be planned and how data should be analyzed in order to achieve the best possible resolution. The limiting resolution of domains and pores are discussed simultaneously, in order to enable direct comparison. It appears that choice of suitable donor/acceptor pairs is the most crucial step in the design of experiments. For instance, it is recommended to use DA pairs, which exhibit an increased affinity to pores (i.e., partition coefficients K(D,A) > 10) for the determination of pore sizes with radii comparable to the Förster radius R(0). On the other hand, donors and acceptors exhibiting a high affinity to different phases are better suited for the determination of domain sizes. The experimental setup where donors and acceptors are excluded from the domains/pores should be avoided.
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Affiliation(s)
- Radek Šachl
- Department of Biophysical Chemistry, Jaroslav Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 2155/3, Prague 8, 182 23, Czech Republic; E-Mail:
| | - Lennart B.-Å. Johansson
- Biophysical Chemistry, Department of Chemistry, Umeå University, S-901 87 Umeå, Sweden; E-Mail:
| | - Martin Hof
- Department of Biophysical Chemistry, Jaroslav Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 2155/3, Prague 8, 182 23, Czech Republic; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +420-26605-3264; Fax: +420-28658-2307
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Sarmento M, Prieto M, Fernandes F. Reorganization of lipid domain distribution in giant unilamellar vesicles upon immobilization with different membrane tethers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2605-15. [DOI: 10.1016/j.bbamem.2012.05.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/22/2012] [Accepted: 05/25/2012] [Indexed: 10/28/2022]
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Loura LMS, Prieto M. Lateral Membrane Heterogeneity Probed by FRET Spectroscopy and Microscopy. SPRINGER SERIES ON FLUORESCENCE 2012. [DOI: 10.1007/4243_2012_59] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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20
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Loura LMS, Prieto M. FRET in Membrane Biophysics: An Overview. Front Physiol 2011; 2:82. [PMID: 22110442 PMCID: PMC3216123 DOI: 10.3389/fphys.2011.00082] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 10/26/2011] [Indexed: 12/31/2022] Open
Abstract
Förster resonance energy transfer (FRET), in most applications used as a “spectroscopic ruler,” allows an easy determination of the donor-acceptor intermolecular distance. However, the situation becomes complex in membranes, since around each donor there is an ensemble of acceptors at non-correlated distances. In this review, state-of-the-art methodologies for this situation are presented, usually involving time-resolved data and model fitting. This powerful approach can be used to study the occurrence of phase separation (“rafts” or other type of domains), allowing their detection as well as size evaluation. Formalisms for studying lipid–protein and protein–protein interactions according to specific topologies are also addressed. The advantages and added complexity of a specific type of FRET (energy homotransfer or energy migration) are described, as well as applications of FRET under the microscope.
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Affiliation(s)
- Luís M S Loura
- Faculdade de Farmácia, Universidade de Coimbra Coimbra, Portugal
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Bocchinfuso G, Bobone S, Mazzuca C, Palleschi A, Stella L. Fluorescence spectroscopy and molecular dynamics simulations in studies on the mechanism of membrane destabilization by antimicrobial peptides. Cell Mol Life Sci 2011; 68:2281-301. [PMID: 21584808 PMCID: PMC11114703 DOI: 10.1007/s00018-011-0719-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 04/26/2011] [Accepted: 04/26/2011] [Indexed: 10/18/2022]
Abstract
Since their initial discovery, 30 years ago, antimicrobial peptides (AMPs) have been intensely investigated as a possible solution to the increasing problem of drug-resistant bacteria. The interaction of antimicrobial peptides with the cellular membrane of bacteria is the key step of their mechanism of action. Fluorescence spectroscopy can provide several structural details on peptide-membrane systems, such as partition free energy, aggregation state, peptide position and orientation in the bilayer, and the effects of the peptides on the membrane order. However, these "low-resolution" structural data are hardly sufficient to define the structural requirements for the pore formation process. Molecular dynamics simulations, on the other hand, provide atomic-level information on the structure and dynamics of the peptide-membrane system, but they need to be validated experimentally. In this review we summarize the information that can be obtained by both approaches, highlighting their versatility and complementarity, suggesting that their synergistic application could lead to a new level of insight into the mechanism of membrane destabilization by AMPs.
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Affiliation(s)
- Gianfranco Bocchinfuso
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Sara Bobone
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Claudia Mazzuca
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Antonio Palleschi
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
- IRCCS Neuromed, 86077 Pozzilli, IS Italy
| | - Lorenzo Stella
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
- IRCCS Neuromed, 86077 Pozzilli, IS Italy
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Coutinho A, Loura LMS, Prieto M. FRET studies of lipid-protein aggregates related to amyloid-like fibers. J Neurochem 2011; 116:696-701. [PMID: 21214548 DOI: 10.1111/j.1471-4159.2010.07000.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acidic lipids are known to both catalyze amyloid fiber formation by amyloidogenic peptides/proteins and induce formation of 'amyloid-like' fibrils by non-amyloidogenic proteins. In this work, we describe the application of state-of-the-art time-resolved Förster resonance energy transfer methodologies to the characterization of the supramolecular structure of the aggregates formed by both a cationic peptide (hexalysyltryptophan) and a basic non-amyloidogenic protein (lysozyme) upon their interaction with negatively-charged fluid membranes (mixtures of zwitterionic phosphatidylcholine and anionic phosphatidylserine). It was concluded that both the peptide and protein induce the formation of multistacked lipid bilayers. Furthermore, upon using conditions that are described in the literature to cause the formation of amyloid-like fibers, lysozyme was found to induce the formation of a 'pinched lamellar' structure, with reduced interbilayer distance in the regions where there is bound protein, and increased interbilayer distance (stabilized by hydration repulsion) outside these areas. No significant lateral domains (lipid demixing) were induced in the membrane by either the cationic peptide or lysozyme.
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Affiliation(s)
- Ana Coutinho
- Centro de Química Física Molecular and IN, Complexo I, Instituto Superior Técnico, Lisboa, Portugal.
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In vivo composition of NMDA receptor signaling complexes differs between membrane subdomains and is modulated by PSD-95 and PSD-93. J Neurosci 2010; 30:8162-70. [PMID: 20554866 DOI: 10.1523/jneurosci.1792-10.2010] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Lipid rafts are dynamic membrane microdomains enriched in cholesterol and sphingolipids involved in the compartmentalization of signaling pathways, trafficking and sorting of proteins. At synapses, the glutamatergic NMDA receptor and its cytoplasmic scaffold protein PSD-95 move between postsynaptic density (PSD) and rafts following learning or ischemia. However it is not known whether the signaling complexes formed by these proteins are different in rafts nor the molecular mechanisms that govern their localization. To examine these issues in vivo we used mice carrying genetically encoded tags for purification of protein complexes and specific mutations in NMDA receptors, PSD-95 and other postsynaptic scaffold proteins. Isolation of PSD-95 complexes from mice carrying tandem affinity purification tags showed differential composition in lipid rafts, postsynaptic density and detergent-soluble fractions. Raft PSD-95 complexes showed less CaMKIIalpha and SynGAP and enrichment in Src and Arc/Arg3.1 compared with PSD complexes. Mice carrying knock-outs of PSD-95 or PSD-93 show a key role for PSD-95 in localizing NR2A-containing NMDA receptor complexes to rafts. Deletion of the NR2A C terminus or the C-terminal valine residue of NR2B, which prevents all PDZ interactions, reduced the NR1 association with rafts. Interestingly, the deletion of the NR2B valine residue increased the total amount of lipid rafts. These data show critical roles for scaffold proteins and their interactions with NMDA receptor subunits in organizing the differential expression in rafts and postsynaptic densities of synaptic signaling complexes.
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Loura LMS, Prieto M, Fernandes F. Quantification of protein-lipid selectivity using FRET. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2010; 39:565-78. [PMID: 20238256 PMCID: PMC2841278 DOI: 10.1007/s00249-009-0532-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 07/30/2009] [Accepted: 08/04/2009] [Indexed: 12/11/2022]
Abstract
Membrane proteins exhibit different affinities for different lipid species, and protein-lipid selectivity regulates the membrane composition in close proximity to the protein, playing an important role in the formation of nanoscale membrane heterogeneities. The sensitivity of Förster resonance energy transfer (FRET) for distances of 10 A up to 100 A is particularly useful to retrieve information on the relative distribution of proteins and lipids in the range over which protein-lipid selectivity is expected to influence membrane composition. Several FRET-based methods applied to the quantification of protein-lipid selectivity are described herein, and different formalisms applied to the analysis of FRET data for particular geometries of donor-acceptor distribution are critically assessed.
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Affiliation(s)
- Luís M. S. Loura
- Faculdade de Farmácia, Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
- Centro de Química de Évora, Rua Romão Ramalho, 59, 7000-671 Evora, Portugal
| | - Manuel Prieto
- Centro de Química Física Molecular and Institute of Nanosciences and Nanotechnologies, Complexo I, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Fábio Fernandes
- Department of Membrane Biophysics, Max-Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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