301
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Calibration of Distribution Analysis of the Depth of Membrane Penetration Using Simulations and Depth-Dependent Fluorescence Quenching. J Membr Biol 2014; 248:583-94. [PMID: 25107303 DOI: 10.1007/s00232-014-9709-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/15/2014] [Indexed: 10/24/2022]
Abstract
Determination of the depth of membrane penetration provides important information for studies of membrane protein folding and protein-lipid interactions. Here, we use a combination of molecular dynamics (MD) simulations and depth-dependent fluorescence quenching to calibrate the methodology for extracting quantitative information on membrane penetration. In order to investigate the immersion depth of the fluorescent label in lipid bilayer, we studied 7-nitrobenz-2-oxa-1,3-diazole (NBD) attached to the lipid headgroup in NBD-PE incorporated into POPC bilayer. The immersion depth of NBD was estimated by measuring steady-state and time-resolved fluorescence quenching with spin-labeled lipids co-incorporated into lipid vesicles. Six different spin-labeled lipids were utilized: one with headgroup-attached Tempo probe (Tempo-PC) and five with acyl chain-labeled n-Doxyl moieties (n-Doxyl-PC where n is a chain labeling position equal to 5, 7, 10, 12, and 14, respectively). The Stern-Volmer analysis revealed that NBD quenching in membranes occurs by both static and dynamic collisional quenching processes. Using the methodology of Distribution Analysis, the immersion depth and the apparent half-width of the transversal distributions of the NBD moiety were estimated to be 14.7 and 6.7 Å, respectively, from the bilayer center. This position is independently validated by atomistic MD simulations of NBD-PE lipids in a POPC bilayer (14.4 Å). In addition, we demonstrate that MD simulations of the transverse overlap integrals between dye and quencher distributions can be used for proper analysis of the depth-dependent quenching profile. Finally, we illustrate the application of this methodology by determining membrane penetration of site selectively labeled mutants of diphtheria toxin T-domain.
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302
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Nemésio H, Villalaín J. Membranotropic Regions of the Dengue Virus prM Protein. Biochemistry 2014; 53:5280-9. [DOI: 10.1021/bi500724k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Henrique Nemésio
- Instituto de Biología
Molecular y Celular, Universidad “Miguel Hernández”, E-03202 Elche-Alicante, Spain
| | - José Villalaín
- Instituto de Biología
Molecular y Celular, Universidad “Miguel Hernández”, E-03202 Elche-Alicante, Spain
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303
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Jiménez-Rojo N, Viguera AR, Collado MI, Sims KH, Constance C, Hill K, Shaw WA, Goñi FM, Alonso A. Sphingosine induces the aggregation of imine-containing peroxidized vesicles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2071-7. [DOI: 10.1016/j.bbamem.2014.04.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 01/09/2023]
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304
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Bustillo-Zabalbeitia I, Montessuit S, Raemy E, Basañez G, Terrones O, Martinou JC. Specific interaction with cardiolipin triggers functional activation of Dynamin-Related Protein 1. PLoS One 2014; 9:e102738. [PMID: 25036098 PMCID: PMC4103857 DOI: 10.1371/journal.pone.0102738] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 06/23/2014] [Indexed: 11/18/2022] Open
Abstract
Dynamin-Related Protein 1 (Drp1), a large GTPase of the dynamin superfamily, is required for mitochondrial fission in healthy and apoptotic cells. Drp1 activation is a complex process that involves translocation from the cytosol to the mitochondrial outer membrane (MOM) and assembly into rings/spirals at the MOM, leading to membrane constriction/division. Similar to dynamins, Drp1 contains GTPase (G), bundle signaling element (BSE) and stalk domains. However, instead of the lipid-interacting Pleckstrin Homology (PH) domain present in the dynamins, Drp1 contains the so-called B insert or variable domain that has been suggested to play an important role in Drp1 regulation. Different proteins have been implicated in Drp1 recruitment to the MOM, although how MOM-localized Drp1 acquires its fully functional status remains poorly understood. We found that Drp1 can interact with pure lipid bilayers enriched in the mitochondrion-specific phospholipid cardiolipin (CL). Building on our previous study, we now explore the specificity and functional consequences of this interaction. We show that a four lysine module located within the B insert of Drp1 interacts preferentially with CL over other anionic lipids. This interaction dramatically enhances Drp1 oligomerization and assembly-stimulated GTP hydrolysis. Our results add significantly to a growing body of evidence indicating that CL is an important regulator of many essential mitochondrial functions.
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Affiliation(s)
- Itsasne Bustillo-Zabalbeitia
- Biophysics Unit (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Sylvie Montessuit
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
| | - Etienne Raemy
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
| | - Gorka Basañez
- Biophysics Unit (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Oihana Terrones
- Biophysics Unit (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
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305
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Carlred L, Gunnarsson A, Solé-Domènech S, Johansson B, Vukojević V, Terenius L, Codita A, Winblad B, Schalling M, Höök F, Sjövall P. Simultaneous Imaging of Amyloid-β and Lipids in Brain Tissue Using Antibody-Coupled Liposomes and Time-of-Flight Secondary Ion Mass Spectrometry. J Am Chem Soc 2014; 136:9973-81. [DOI: 10.1021/ja5019145] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Louise Carlred
- Chemistry,
Materials and Surfaces, SP Technical Research Institute of Sweden, P.O. Box 857, SE-501 15 Borås, Sweden
- Department
of Applied Physics, Division of Biological Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Anders Gunnarsson
- Department
of Applied Physics, Division of Biological Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Santiago Solé-Domènech
- Department
of Molecular Medicine and Surgery, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Björn Johansson
- Department
of Molecular Medicine and Surgery, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Vladana Vukojević
- Department
of Clinical Neuroscience, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Lars Terenius
- Department
of Clinical Neuroscience, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Alina Codita
- Department
of Neurobiology, Care Sciences and Society, KI Alzheimer Disease Research
Center, Karolinska Institutet, SE-141 86 Stockholm, Sweden
| | - Bengt Winblad
- Department
of Neurobiology, Care Sciences and Society, KI Alzheimer Disease Research
Center, Karolinska Institutet, SE-141 86 Stockholm, Sweden
| | - Martin Schalling
- Department
of Molecular Medicine and Surgery, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Fredrik Höök
- Department
of Applied Physics, Division of Biological Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Peter Sjövall
- Chemistry,
Materials and Surfaces, SP Technical Research Institute of Sweden, P.O. Box 857, SE-501 15 Borås, Sweden
- Department
of Applied Physics, Division of Biological Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
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306
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Brüning BA, Prévost S, Stehle R, Steitz R, Falus P, Farago B, Hellweg T. Bilayer undulation dynamics in unilamellar phospholipid vesicles: effect of temperature, cholesterol and trehalose. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2412-9. [PMID: 24950248 DOI: 10.1016/j.bbamem.2014.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/02/2014] [Accepted: 06/09/2014] [Indexed: 10/25/2022]
Abstract
We report a combined dynamic light scattering (DLS) and neutron spin-echo (NSE) study on the local bilayer undulation dynamics of phospholipid vesicles composed of 1,2-dimyristoyl-glycero-3-phosphatidylcholine (DMPC) under the influence of temperature and the additives cholesterol and trehalose. The additives affect vesicle size and self-diffusion. Mechanical properties of the membrane and corresponding bilayer undulations are tuned by changing lipid headgroup or acyl chain properties through temperature or composition. On the local length scale, changes at the lipid headgroup influence the bilayer bending rigidity κ less than changes at the lipid acyl chain: We observe a bilayer softening around the main phase transition temperature Tm of the single lipid system, and stiffening when more cholesterol is added, in concordance with literature. Surprisingly, no effect on the mechanical properties of the vesicles is observed upon the addition of trehalose.
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Affiliation(s)
- Beate-Annette Brüning
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin, Germany; Radiation Science and Technology, Delft University of Technology, Mekelweg 15, JB 2629 Delft, The Netherlands.
| | - Sylvain Prévost
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin, Germany
| | - Ralf Stehle
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin, Germany
| | - Roland Steitz
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin, Germany
| | - Peter Falus
- Time-of-Flight and High Resolution, Institut Laue Langevin, B. P. 156, 38042 Grenoble, Cedex 9, France
| | - Bela Farago
- Time-of-Flight and High Resolution, Institut Laue Langevin, B. P. 156, 38042 Grenoble, Cedex 9, France
| | - Thomas Hellweg
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
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307
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Melo AM, Prieto M, Coutinho A. Quantifying lipid-protein interaction by fluorescence correlation spectroscopy (FCS). Methods Mol Biol 2014; 1076:575-95. [PMID: 24108645 DOI: 10.1007/978-1-62703-649-8_26] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Fluorescence correlation spectroscopy (FCS) is a powerful method to investigate molecular interactions based on the variation of diffusion properties at the single-molecule level. This technique allows studying quantitatively the interaction of fluorescently labeled proteins/peptides with lipid vesicles. Here, we describe how to acquire and analyze FCS partition data in order to accurately determine the protein/peptide partition coefficients between the aqueous and lipid phases. It is shown that the recovery of unbiased partition coefficients from FCS partition curves (fractional amplitude of the bound species versus lipid concentration) requires considering explicitly the Poissonian loading of the lipid vesicles with the fluorescently labeled protein in order to account for the variable liposome brightness in each sample. Additionally, the impact of a trace amount of a fluorescent non-binding component on the partition curves determined by FCS is also discussed.
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Affiliation(s)
- Ana M Melo
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisbon, Portugal
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308
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Singlet oxygen effects on lipid membranes: implications for the mechanism of action of broad-spectrum viral fusion inhibitors. Biochem J 2014; 459:161-70. [PMID: 24456301 DOI: 10.1042/bj20131058] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It was reported recently that a new aryl methyldiene rhodanine derivative, LJ001, and oxazolidine-2,4-dithione, JL103, act on the viral membrane, inhibiting its fusion with a target cell membrane. The aim of the present study was to investigate the interactions of these two active compounds and an inactive analogue used as a negative control, LJ025, with biological membrane models, in order to clarify the mechanism of action at the molecular level of these new broad-spectrum enveloped virus entry inhibitors. Fluorescence spectroscopy was used to quantify the partition and determine the location of the molecules on membranes. The ability of the compounds to produce reactive oxygen molecules in the membrane was tested using 9,10-dimethylanthracene, which reacts selectively with singlet oxygen (1O2). Changes in the lipid packing and fluidity of membranes were assessed by fluorescence anisotropy and generalized polarization measurements. Finally, the ability to inhibit membrane fusion was evaluated using FRET. Our results indicate that 1O2 production by LJ001 and JL103 is able to induce several changes on membrane properties, specially related to a decrease in its fluidity, concomitant with an increase in the order of the polar headgroup region, resulting in an inhibition of the membrane fusion necessary for cell infection.
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309
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Davis BM, Normando EM, Guo L, Turner LA, Nizari S, O'Shea P, Moss SE, Somavarapu S, Cordeiro MF. Topical delivery of Avastin to the posterior segment of the eye in vivo using annexin A5-associated liposomes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:1575-84. [PMID: 24596245 DOI: 10.1002/smll.201303433] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/31/2013] [Indexed: 05/25/2023]
Abstract
Effective delivery to the retina is presently one of the most challenging areas in drug development in ophthalmology, due to anatomical barriers preventing entry of therapeutic substances. Intraocular injection is presently the only route of administration for large protein therapeutics, including the anti-Vascular Endothelial Growth Factors Lucentis (ranibizumab) and Avastin (bevacizumab). Anti-VEGFs have revolutionised the management of age-related macular degeneration and have increasing indications for use as sight-saving therapies in diabetes and retinal vascular disease. Considerable resources have been allocated to develop non-invasive ocular drug delivery systems. It has been suggested that the anionic phospholipid binding protein annexin A5, may have a role in drug delivery. In the present study we demonstrate, using a combination of in vitro and in vivo assays, that the presence of annexin A5 can significantly enhance uptake and transcytosis of liposomal drug carrier systems across corneal epithelial barriers. This system is employed to deliver physiologically significant concentrations of Avastin to the posterior of the rat eye (127 ng/g) and rabbit retina (18 ng/g) after topical application. Our observations provide evidence to suggest annexin A5 mediated endocytosis can enhance the delivery of associated lipidic drug delivery vehicles across biological barriers, which may have therapeutic implications.
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Affiliation(s)
- Benjamin M Davis
- UCL Institute of Ophthalmology, University College London, Bath Street, London, EC1V 9EL, UK
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310
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Bermejo IL, Arnulphi C, Ibáñez de Opakua A, Alonso-Mariño M, Goñi FM, Viguera AR. Membrane partitioning of the pore-forming domain of colicin A. Role of the hydrophobic helical hairpin. Biophys J 2014; 105:1432-43. [PMID: 24047995 DOI: 10.1016/j.bpj.2013.08.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/08/2013] [Accepted: 08/12/2013] [Indexed: 10/26/2022] Open
Abstract
The colicins are bacteriocins that target Escherichia coli and kill bacterial cells through different mechanisms. Colicin A forms ion channels in the inner membranes of nonimmune bacteria. This activity resides exclusively in its C-terminal fragment (residues 387-592). The soluble free form of this domain is a 10 α-helix bundle. The hydrophobic helical hairpin, H8-H9, is buried inside the structure and shielded by eight amphipathic surface helices. The interaction of the C-terminal colicin A domain and several chimeric variants with lipidic vesicles was examined here by isothermal titration calorimetry. In the mutant constructions, natural sequences of the hydrophobic helices H8 and H9 were either removed or substituted by polyalanine or polyleucine. All the constructions fully associated with DOPG liposomes including the mutant that lacked helices H8 and H9, indicating that amphipathic rather than hydrophobic helices were the major determinants of the exothermic binding reactions. Alanine is not specially favored in the lipid-bound form; the chimeric construct with polyalanine produced lower enthalpy gain. On the other hand, the large negative heat capacities associated with partitioning, a characteristic feature of the hydrophobic effect, were found to be dependent on the sequence hydrophobicity of helices H8 and H9.
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Affiliation(s)
- Ivan L Bermejo
- Unidad de Biofísica (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Spain
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311
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Wiedman G, Fuselier T, He J, Searson PC, Hristova K, Wimley WC. Highly efficient macromolecule-sized poration of lipid bilayers by a synthetically evolved peptide. J Am Chem Soc 2014; 136:4724-31. [PMID: 24588399 PMCID: PMC3985440 DOI: 10.1021/ja500462s] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Indexed: 12/30/2022]
Abstract
Peptides that self-assemble, at low concentration, into bilayer-spanning pores which allow the passage of macromolecules would be beneficial in multiple areas of biotechnology. However, there are few, if any, natural or designed peptides that have this property. Here we show that the 26-residue peptide "MelP5", a synthetically evolved gain-of-function variant of the bee venom lytic peptide melittin identified in a high-throughput screen for small molecule leakage, enables the passage of macromolecules across bilayers under conditions where melittin and other pore-forming peptides do not. In surface-supported bilayers, MelP5 forms unusually high conductance, equilibrium pores at peptide:lipid ratios as low as 1:25000. The increase in bilayer conductance due to MelP5 is dramatically higher, per peptide, than the increase due to the parent sequence of melittin or other peptide pore formers. Here we also develop two novel assays for macromolecule leakage from vesicles, and we use them to characterize MelP5 pores in bilayers. We show that MelP5 allows the passage of macromolecules across vesicle membranes at peptide:lipid ratios as low as 1:500, and under conditions where neither osmotic lysis nor gross vesicle destabilization occur. The macromolecule-sized, equilibrium pores formed by MelP5 are unique as neither melittin nor other pore-forming peptides release macromolecules significantly under the same conditions. MelP5 thus appears to belong to a novel functional class of peptide that could form the foundation of multiple potential biotechnological applications.
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Affiliation(s)
- Gregory Wiedman
- Department
of Materials Science and Engineering, Johns
Hopkins University, Baltimore, Maryland 21218, United States
- Institute
for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Taylor Fuselier
- Department
of Biochemistry and Molecular Biology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Jing He
- Department
of Biochemistry and Molecular Biology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Peter C. Searson
- Department
of Materials Science and Engineering, Johns
Hopkins University, Baltimore, Maryland 21218, United States
- Institute
for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kalina Hristova
- Department
of Materials Science and Engineering, Johns
Hopkins University, Baltimore, Maryland 21218, United States
- Institute
for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - William C. Wimley
- Department
of Biochemistry and Molecular Biology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
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312
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Gao W, Vecchio D, Li J, Zhu J, Zhang Q, Fu V, Li J, Thamphiwatana S, Lu D, Zhang L. Hydrogel containing nanoparticle-stabilized liposomes for topical antimicrobial delivery. ACS NANO 2014; 8:2900-7. [PMID: 24483239 PMCID: PMC4004330 DOI: 10.1021/nn500110a] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 02/01/2014] [Indexed: 05/18/2023]
Abstract
Adsorbing small charged nanoparticles onto the outer surfaces of liposomes has become an effective strategy to stabilize liposomes against fusion prior to "seeing" target bacteria, yet allow them to fuse with the bacteria upon arrival at the infection sites. As a result, nanoparticle-stabilized liposomes have become an emerging drug delivery platform for treatment of various bacterial infections. To facilitate the translation of this platform for clinical tests and uses, herein we integrate nanoparticle-stabilized liposomes with hydrogel technology for more effective and sustained topical drug delivery. The hydrogel formulation not only preserves the structural integrity of the nanoparticle-stabilized liposomes, but also allows for controllable viscoeleasticity and tunable liposome release rate. Using Staphylococcus aureus bacteria as a model pathogen, we demonstrate that the hydrogel formulation can effectively release nanoparticle-stabilized liposomes to the bacterial culture, which subsequently fuse with bacterial membrane in a pH-dependent manner. When topically applied onto mouse skin, the hydrogel formulation does not generate any observable skin toxicity within a 7-day treatment. Collectively, the hydrogel containing nanoparticle-stabilized liposomes hold great promise for topical applications against various microbial infections.
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Affiliation(s)
- Weiwei Gao
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Drew Vecchio
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Jieming Li
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Jingying Zhu
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Qiangzhe Zhang
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Victoria Fu
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Jiayang Li
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Soracha Thamphiwatana
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
| | - Diannan Lu
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Liangfang Zhang
- Department of NanoEngineering, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, United States
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313
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Zhang T, Muraih JK, Tishbi N, Herskowitz J, Victor RL, Silverman J, Uwumarenogie S, Taylor SD, Palmer M, Mintzer E. Cardiolipin prevents membrane translocation and permeabilization by daptomycin. J Biol Chem 2014; 289:11584-11591. [PMID: 24616102 DOI: 10.1074/jbc.m114.554444] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Daptomycin is an acidic lipopeptide antibiotic that, in the presence of calcium, forms oligomeric pores on membranes containing phosphatidylglycerol. It is clinically used against various Gram-positive bacteria such as Staphylococcus aureus and Enterococcus species. Genetic studies have indicated that an increased content of cardiolipin in the bacterial membrane may contribute to bacterial resistance against the drug. Here, we used a liposome model to demonstrate that cardiolipin directly inhibits membrane permeabilization by daptomycin. When cardiolipin is added at molar fractions of 10 or 20% to membranes containing phosphatidylglycerol, daptomycin no longer forms pores or translocates to the inner membrane leaflet. Under the same conditions, daptomycin continues to form oligomers; however, these oligomers contain only close to four subunits, which is approximately half as many as observed on membranes without cardiolipin. The collective findings lead us to propose that a daptomycin pore consists of two aligned tetramers in opposite leaflets and that cardiolipin prevents the translocation of tetramers to the inner leaflet, thereby forestalling the formation of complete, octameric pores. Our findings suggest a possible mechanism by which cardiolipin may mediate resistance to daptomycin, and they provide new insights into the action mode of this important antibiotic.
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Affiliation(s)
- TianHua Zhang
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L3G1, Canada
| | - Jawad K Muraih
- Department of Chemistry, University of Al-Muthanna, Samawah, Al-Muthanna, Iraq
| | - Nasim Tishbi
- Department of Chemistry and Biochemistry, Stern College for Women, Yeshiva University, New York, New York 10033
| | - Jennifer Herskowitz
- Department of Chemistry and Biochemistry, Stern College for Women, Yeshiva University, New York, New York 10033
| | - Rachel L Victor
- Department of Chemistry and Biochemistry, Stern College for Women, Yeshiva University, New York, New York 10033
| | | | | | - Scott D Taylor
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L3G1, Canada
| | - Michael Palmer
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L3G1, Canada.
| | - Evan Mintzer
- Department of Chemistry and Biochemistry, Stern College for Women, Yeshiva University, New York, New York 10033
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314
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Jackman JA, Zhao Z, Zhdanov VP, Frank CW, Cho NJ. Vesicle adhesion and rupture on silicon oxide: influence of freeze-thaw pretreatment. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2152-60. [PMID: 24512463 DOI: 10.1021/la404582n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We have investigated the effect of freeze-thaw (FT) pretreatment on the adhesion and rupture of extruded vesicles over a wide range of vesicle sizes. To characterize the size distributions of vesicles obtained with and without FT pretreatment, dynamic light scattering (DLS) experiments were performed. The interaction between extruded vesicles and a silicon oxide substrate was investigated by quartz crystal microbalance with dissipation (QCM-D) monitoring, with a focus on comparative analysis of similar-sized vesicles with and without FT pretreatment. Under this condition, there was a smaller mass load at the critical coverage associated with untreated vesicles, as compared to vesicles which had been subjected to FT pretreatment. In addition, the rupture of treated vesicles generally resulted in formation of a complete planar bilayer, while the adlayer was more heterogeneous when employing untreated vesicles. Combined with kinetic analysis and extended-DLVO model calculations, the experimental evidence suggests that the differences arising from FT pretreatment are due to characteristics of the vesicle size distribution and also multilamellarity of an appreciable fraction of untreated vesicles. Taken together, our findings clarify the influence of FT pretreatment on model membrane fabrication on solid supports.
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Affiliation(s)
- Joshua A Jackman
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue, 639798 Singapore
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315
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Khmelinskaia A, Ibarguren M, de Almeida RFM, López DJ, Paixão VA, Ahyayauch H, Goñi FM, Escribá PV. Changes in membrane organization upon spontaneous insertion of 2-hydroxylated unsaturated fatty acids in the lipid bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2117-2128. [PMID: 24490728 DOI: 10.1021/la403977f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Recent research regarding 2-hydroxylated fatty acids (2OHFAs) showed clear evidence of their benefits in the treatment of cancer, inflammation, and neurodegenerative disorders such as Alzheimer's disease. Monolayer compressibility isotherms and isothermal titration calorimetry of 2OHFA (C18-C22) in phosphatidylcholine/phosphatidylethanolamine/sphingomyelin/cholesterol (1:1:1:1 mole ratio), a mixture that mimics the composition of mammalian plasma membrane, were performed to assess the membrane binding capacity of 2OHFAs and their natural, nonhydroxylated counterparts. The results show that 2OHFAs are surface-active substances that bind membranes through exothermic, spontaneous processes. The main effects of 2OHFAs are a decrease in lipid order, with a looser packing of the acyl chains, and a decreased dipole potential, regardless of the 2OHFAs' relative affinity for the lipid bilayer. The strongest effects are usually observed for 2-hydroxyarachidonic (C20:4) acid, and the weakest one, for 2-hydroxydocosahexaenoic acid (C22:6). In addition, 2OHFAs cause increased hydration, except in gel-phase membranes, which can be explained by the 2OHFA preference for membrane defects. Concerning the membrane dipole potential, the magnitude of the reduction induced by 2OHFAs was particularly marked in the liquid-ordered (lo) phase (cholesterol/sphingomyelin-rich) membranes, those where order reduction was the smallest, suggesting a disruption of cholesterol-sphingolipid interactions that are responsible for the large dipole potential in those membranes. Moreover, 2OHFA effects were larger than for both lo and ld phases separately in model membranes with liquid disordered (ld)/lo coexistence when both phases were present in significant amounts, possibly because of the facilitating effect of ld/lo domain interfaces. The specific and marked changes induced by 2OHFAs in several membrane properties suggest that the initial interaction with the membrane and subsequent reorganization might constitute an important step in their mechanisms of action.
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Affiliation(s)
- Alena Khmelinskaia
- Centro de Quimica e Bioquimica, DQB, Faculdade de Ciências da Universidade de Lisboa , Campo Grande, Ed. C8, 1749-016 Lisboa Portugal
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316
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Pomorski TG, Nylander T, Cárdenas M. Model cell membranes: discerning lipid and protein contributions in shaping the cell. Adv Colloid Interface Sci 2014; 205:207-20. [PMID: 24268587 DOI: 10.1016/j.cis.2013.10.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/24/2013] [Accepted: 10/24/2013] [Indexed: 01/01/2023]
Abstract
The high complexity of biological membranes has motivated the development and application of a wide range of model membrane systems to study biochemical and biophysical aspects of membranes in situ under well defined conditions. The aim is to provide fundamental understanding of processes controlled by membrane structure, permeability and curvature as well as membrane proteins by using a wide range of biochemical, biophysical and microscopic techniques. This review gives an overview of some currently used model biomembrane systems. We will also discuss some key membrane protein properties that are relevant for protein-membrane interactions in terms of protein structure and how it is affected by membrane composition, phase behavior and curvature.
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Affiliation(s)
- Thomas Günther Pomorski
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
| | - Tommy Nylander
- Department of Chemistry, Division of Physical Chemistry, Lund University, Gettingevägen 60, SE-22100 Lund, Sweden
| | - Marité Cárdenas
- Department of Chemistry/Nano-Science Center, University of Copenhagen, DK-2100 Copenhagen, Denmark.
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317
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Yamamoto N, Tamura A. Designing cell-aggregating peptides without cytotoxicity. Biomacromolecules 2014; 15:512-23. [PMID: 24432760 DOI: 10.1021/bm4014414] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have designed α-helical peptides de novo that can induce aggregation of various kinds of cells by focusing on physicochemical properties such as hydrophobicity, net charges, and amphipathicity. It is shown that peptide hydrophobicity is the key factor to determine capabilities for cell aggregation while peptide net charges contribute to nonspecific electrostatic interactions with cells. On the other hand, amphipathic peptides tend to exhibit cytotoxicity such as antimicrobial activity and hemolysis, which are competitive with cell-aggregation capabilities. Different from the cases of living cells, aggregation of artificial anionic liposomes appears to be mainly determined by electrostatic interactions. This discrepancy might be due to the complex structure of surfaces of cell membranes consisting of macromolecular chains such as peptidoglycans, polysaccharides, or glycocalyx, which coexist with lipid bilayers. Our design strategy would pave the way to design peptides that lead aggregation of living cells without cytotoxicity.
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Affiliation(s)
- Naoki Yamamoto
- Department of Chemistry, Graduate School of Science, Kobe University , 1-1 Rokkodai-cho, Nada, Kobe 657-8501, Japan
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318
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Augusto MT, Hollmann A, Castanho MARB, Porotto M, Pessi A, Santos NC. Improvement of HIV fusion inhibitor C34 efficacy by membrane anchoring and enhanced exposure. J Antimicrob Chemother 2014; 69:1286-97. [PMID: 24464268 DOI: 10.1093/jac/dkt529] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES The aim of the present work was to evaluate the interaction of two new HIV fusion inhibitors {HIVP3 [C34-polyethylene glycol (PEG)₄-cholesterol] and HIVP4 [(C34-PEG₄)₂-cholesterol]} with membrane model systems and human blood cells in order to clarify where and how the fusion inhibitors locate, allowing us to understand their mechanism of action at the molecular level, and which strategies may be followed to increase efficacy. METHODS Lipid vesicles with defined compositions were used for peptide partition and localization studies, based on the intrinsic fluorescence of HIVP3 and HIVP4. Lipid monolayers were employed in surface pressure studies. Finally, human erythrocytes and peripheral blood mononuclear cells (PBMCs) isolated from blood samples were used in dipole potential assays. RESULTS Membrane partition, dipole potential and surface pressure assays indicate that the new fusion inhibitors interact preferentially with cholesterol-rich liquid-ordered membranes, mimicking biological membrane microdomains known as lipid rafts. HIVP3 and HIVP4 are able to interact with human erythrocytes and PBMCs to a similar degree as a previously described simpler drug with monomeric C34 and lacking the PEG spacer, C34-cholesterol. However, the pocket-binding domain (PBD) of both HIVP3 and HIVP4 is more exposed to the aqueous environment than in C34-cholesterol. CONCLUSIONS The present data allow us to conclude that more efficient blocking of HIV entry results from the synergism between the membranotropic behaviour and the enhanced exposure of the PBD.
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Affiliation(s)
- Marcelo T Augusto
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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319
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Flor-Parra I, Bernal M, Zhurinsky J, Daga RR. Cell migration and division in amoeboid-like fission yeast. Biol Open 2014; 3:108-15. [PMID: 24357230 PMCID: PMC3892166 DOI: 10.1242/bio.20136783] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Yeast cells are non-motile and are encased in a cell wall that supports high internal turgor pressure. The cell wall is also essential for cellular morphogenesis and cell division. Here, we report unexpected morphogenetic changes in a Schizosaccharomyces pombe mutant defective in cell wall biogenesis. These cells form dynamic cytoplasmic protrusions caused by internal turgor pressure and also exhibit amoeboid-like cell migration resulting from repeated protrusive cycles. The cytokinetic ring responsible for cell division in wild-type yeast often fails in these cells; however, they were still able to divide using a ring-independent alternative mechanism relying on extrusion of the cell body through a hole in the cell wall. This mechanism of cell division may resemble an ancestral mode of division in the absence of cytokinetic machinery. Our findings highlight how a single gene change can lead to the emergence of different modes of cell growth, migration and division.
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Affiliation(s)
- Ignacio Flor-Parra
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, 41013 Sevilla, Spain
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320
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Chong SSY, Taneva SG, Lee JMC, Cornell RB. The Curvature Sensitivity of a Membrane-Binding Amphipathic Helix Can Be Modulated by the Charge on a Flanking Region. Biochemistry 2014; 53:450-61. [DOI: 10.1021/bi401457r] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Sharon S. Y. Chong
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Svetla G. Taneva
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Joseph M. C. Lee
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Rosemary B. Cornell
- Department
of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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321
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Novel methods for liposome preparation. Chem Phys Lipids 2014; 177:8-18. [DOI: 10.1016/j.chemphyslip.2013.10.011] [Citation(s) in RCA: 373] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/24/2013] [Accepted: 10/30/2013] [Indexed: 12/18/2022]
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322
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Rondeau E, Holzapfel S, Engel H, Windhab EJ. Vesicles and Composite Particles by Rotating Membrane Pore Extrusion. UPSCALING OF BIO-NANO-PROCESSES 2014. [DOI: 10.1007/978-3-662-43899-2_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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323
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Muñoz F, Palomares-Jerez MF, Daleo G, Villalaín J, Guevara MG. Possible mechanism of structural transformations induced by StAsp-PSI in lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:339-47. [DOI: 10.1016/j.bbamem.2013.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 08/02/2013] [Accepted: 08/06/2013] [Indexed: 01/19/2023]
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324
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Wilson DR, Zhang N, Silvers AL, Forstner MB, Bader RA. Synthesis and evaluation of cyclosporine A-loaded polysialic acid–polycaprolactone micelles for rheumatoid arthritis. Eur J Pharm Sci 2014; 51:146-56. [DOI: 10.1016/j.ejps.2013.09.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 09/17/2013] [Accepted: 09/17/2013] [Indexed: 12/31/2022]
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325
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Membrane lipid modifications and therapeutic effects mediated by hydroxydocosahexaenoic acid on Alzheimer's disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:1680-92. [PMID: 24374316 DOI: 10.1016/j.bbamem.2013.12.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/16/2013] [Accepted: 12/18/2013] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative pathology with relevant unmet therapeutic needs. Both natural aging and AD have been associated with a significant decline in the omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA), and accordingly, administration of DHA has been proposed as a possible treatment for this pathology. However, recent clinical trials in mild-to-moderately affected patients have been inconclusive regarding the real efficacy of DHA in halting this disease. Here, we show that the novel hydroxyl-derivative of DHA (2-hydroxydocosahexaenoic acid - OHDHA) has a strong therapeutic potential to treat AD. We demonstrate that OHDHA administration increases DHA levels in the brain of a transgenic mouse model of AD (5xFAD), as well as those of phosphatidylethanolamine (PE) species that carry long polyunsaturated fatty acids (PUFAs). In 5xFAD mice, administration of OHDHA induced lipid modifications that were paralleled with a reduction in amyloid-β (Αβ) accumulation and full recovery of cognitive scores. OHDHA administration also reduced Aβ levels in cellular models of AD, in association with alterations in the subcellular distribution of secretases and reduced Aβ-induced tau protein phosphorylation as well. Furthermore, OHDHA enhanced the survival of neuron-like differentiated cells exposed to different insults, such as oligomeric Aβ and NMDA-mediated neurotoxicity. These results were supported by model membrane studies in which incorporation of OHDHA into lipid-raft-like vesicles was shown to reduce the binding affinity of oligomeric and fibrillar Aβ to membranes. Finally, the OHDHA concentrations used here did not produce relevant toxicity in zebrafish embryos in vivo. In conclusion, we demonstrate the pleitropic effects of OHDHA that might prove beneficial to treat AD, which suggests that an upstream event, probably the modulation of the membrane lipid composition and structure, influences cellular homeostasis reversing the neurodegenerative process. This Article is Part of a Special Issue Entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.
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326
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Sundar SK, Tirumkudulu MS. Synthesis of Sub-100-nm Liposomes via Hydration in a Packed Bed of Colloidal Particles. Ind Eng Chem Res 2013. [DOI: 10.1021/ie402567p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. K. Sundar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai-400076, India
| | - Mahesh S. Tirumkudulu
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai-400076, India
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327
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Jackman JA, Zan GH, Zhdanov VP, Cho NJ. Rupture of Lipid Vesicles by a Broad-Spectrum Antiviral Peptide: Influence of Vesicle Size. J Phys Chem B 2013; 117:16117-28. [DOI: 10.1021/jp409716p] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joshua A. Jackman
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
- Centre
for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang
Drive 637553, Singapore
| | - Goh Haw Zan
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
- Centre
for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang
Drive 637553, Singapore
| | - Vladimir P. Zhdanov
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
- Centre
for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang
Drive 637553, Singapore
- Boreskov
Institute of Catalysis, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Nam-Joon Cho
- School
of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
- Centre
for Biomimetic Sensor Science, Nanyang Technological University, 50 Nanyang
Drive 637553, Singapore
- School
of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive 637459, Singapore
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328
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Sarmento MJ, Coutinho A, Fedorov A, Prieto M, Fernandes F. Ca(2+) induces PI(4,5)P2 clusters on lipid bilayers at physiological PI(4,5)P2 and Ca(2+) concentrations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:822-30. [PMID: 24316170 DOI: 10.1016/j.bbamem.2013.11.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/22/2013] [Accepted: 11/26/2013] [Indexed: 01/22/2023]
Abstract
Calcium has been shown to induce clustering of PI(4,5)P2 at high and non-physiological concentrations of both the divalent ion and the phosphatidylinositol, or on supported lipid monolayers. In lipid bilayers at physiological conditions, clusters are not detected through microscopic techniques. Here, we aimed to determine through spectroscopic methodologies if calcium plays a role in PI(4,5)P2 lateral distribution on lipid bilayers under physiological conditions. Using several different approaches which included information on fluorescence quantum yield, polarization, spectra and diffusion properties of a fluorescent derivative of PI(4,5)P2 (TopFluor(TF)-PI(4,5)P2), we show that Ca(2+) promotes PI(4,5)P2 clustering in lipid bilayers at physiological concentrations of both Ca(2+) and PI(4,5)P2. Fluorescence depolarization data of TF-PI(4,5)P2 in the presence of calcium suggests that under physiological concentrations of PI(4,5)P2 and calcium, the average cluster size comprises ~15 PI(4,5)P2 molecules. The presence of Ca(2+)-induced PI(4,5)P2 clusters is supported by FCS data. Additionally, calcium mediated PI(4,5)P2 clustering was more pronounced in liquid ordered (lo) membranes, and the PI(4,5)P2-Ca(2+) clusters presented an increased affinity for lo domains. In this way, PI(4,5)P2 could function as a lipid calcium sensor and the increased efficiency of calcium-mediated PI(4,5)P2 clustering on lo domains might provide targeted nucleation sites for PI(4,5)P2 clusters upon calcium stimulus.
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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, Lisbon, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal; Departamento de Química e Bioquímica, FCUL, University of Lisbon, Lisbon, Portugal
| | - Aleksander Fedorov
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Fabio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal.
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329
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Liposome co-encapsulation of synergistic combination of irinotecan and doxorubicin for the treatment of intraperitoneally grown ovarian tumor xenograft. J Control Release 2013. [DOI: 10.1016/j.jconrel.2013.10.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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330
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Abstract
While electrophoresis in lipid bilayers has been performed since the 1970s, the technique has until now been unable to accurately measure the charge on lipids and proteins within the membrane based on drift velocity measurements. Part of the problem is caused by the use of the Einstein-Smoluchowski equation to estimate the electrophoretic mobility of such species. The source of the error arises from the fact that a lipid headgroup is typically smaller than the Debye length of the adjacent aqueous solution in most electrophoresis experiments. Instead, the Henry equation can more accurately predict the electrophoretic mobility at sufficient ionic strength. This was done for three dye-labeled lipids with different sized head groups and a charge on each lipid of -1. Also, the charge was measured as a function of pH for two titratable lipids that were fluorescently labeled. Finally, it was shown that the Henry equation also has difficulties measuring the correct lipid charge at salt concentrations below 5 mM, where electroosmotic forces are more significant.
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Affiliation(s)
- Matthew F Poyton
- Department of Chemistry, Department of Biochemistry and Molecular Biology, Penn State University , State College, Pennsylvania 16802, United States
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331
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Tansi FL, Rüger R, Rabenhold M, Steiniger F, Fahr A, Kaiser WA, Hilger I. Liposomal encapsulation of a near-infrared fluorophore enhances fluorescence quenching and reliable whole body optical imaging upon activation in vivo. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:3659-3669. [PMID: 23650267 DOI: 10.1002/smll.201203211] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/18/2013] [Indexed: 06/02/2023]
Abstract
In the past decade, there has been significant progress in the development of water soluble near-infrared fluorochromes for use in a wide range of imaging applications. Fluorochromes with high photo and thermal stability, sensitivity, adequate pharmacological properties and absorption/emission maxima within the near infrared window (650-900 nm) are highly desired for in vivo imaging, since biological tissues show very low absorption and auto-fluorescence at this spectrum window. Taking these properties into consideration, a myriad of promising near infrared fluorescent probes has been developed recently. However, a hallmark of most of these probes is a rapid clearance in vivo, which hampers their application. It is hypothesized that encapsulation of the near infrared fluorescent dye DY-676-COOH, which undergoes fluorescence quenching at high concentrations, in the aqueous interior of liposomes will result in protection and fluorescence quenching, which upon degradation by phagocytes in vivo will lead to fluorescence activation and enable imaging of inflammation. Liposomes prepared with high concentrations of DY-676-COOH reveal strong fluorescence quenching. It is demonstrated that the non-targeted PEGylated fluorescence-activatable liposomes are taken up predominantly by phagocytosis and degraded in lysosomes. Furthermore, in zymosan-induced edema models in mice, the liposomes are taken up by monocytes and macrophages which migrate to the sites of inflammation. Opposed to free DY-676-COOH, prolonged stability and retention of liposomal-DY-676-COOH is reflected in a significant increase in fluorescence intensity of edema. Thus, protected delivery and fluorescence quenching make the DY-676-COOH-loaded liposomes a highly promising contrast agent for in vivo optical imaging of inflammatory diseases.
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Affiliation(s)
- Felista L Tansi
- Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich, Schiller University Jena, Erlanger Allee 101, 07747 Jena, Germany.
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332
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Futó K, Bódis E, Machesky LM, Nyitrai M, Visegrády B. Membrane binding properties of IRSp53-missing in metastasis domain (IMD) protein. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1831:1651-5. [PMID: 23872532 DOI: 10.1016/j.bbalip.2013.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/05/2013] [Accepted: 07/10/2013] [Indexed: 12/31/2022]
Abstract
The 53-kDa insulin receptor substrate protein (IRSp53) organizes the actin cytoskeleton in response to stimulation of small GTPases, promoting the formation of cell protrusions such as filopodia and lamellipodia. IMD is the N-terminal 250 amino acid domain (IRSp53/MIM Homology Domain) of IRSp53 (also called I-BAR), which can bind to negatively charged lipid molecules. Overexpression of IMD induces filopodia formation in cells and purified IMD assembles finger-like protrusions in reconstituted lipid membranes. IMD was shown by several groups to bundle actin filaments, but other groups showed that it also binds to membranes. IMD binds to negatively charged lipid molecules with preference to clusters of PI(4,5)P2. Here, we performed a range of different in vitro fluorescence experiments to determine the binding properties of the IMD to phospholipids. We used different constructs of large unilamellar vesicles (LUVETs), containing neutral or negatively charged phospholipids. We found that IMD has a stronger binding interaction with negatively charged PI(4,5)P2 or PS lipids than PS/PC or neutral PC lipids. The equilibrium dissociation constant for the IMD-lipid interaction falls into the 78-170μM range for all the lipids tested. The solvent accessibility of the fluorescence labels on the IMD during its binding to lipids is also reduced as the lipids become more negatively charged. Actin affects the IMD-lipid interaction, depending on its polymerization state. Monomeric actin partially disrupts the binding, while filamentous actin can further stabilize the IMD-lipid interaction.
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Affiliation(s)
- Kinga Futó
- Department of Biophysics, Medical School, University of Pécs, Szigeti str. 12, Pécs H-7624, Hungary
| | - Emőke Bódis
- Department of Biophysics, Medical School, University of Pécs, Szigeti str. 12, Pécs H-7624, Hungary
| | - Laura M Machesky
- Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Miklós Nyitrai
- Department of Biophysics, Medical School, University of Pécs, Szigeti str. 12, Pécs H-7624, Hungary; Szentágothai Research Center, Pécs, Ifjúság str. 34, H-7624, Hungary; Hungarian Academy of Sciences, Office for Subsidized Research Units, Budapest, Nádor str. 7, H-1051, Hungary
| | - Balázs Visegrády
- Department of Biophysics, Medical School, University of Pécs, Szigeti str. 12, Pécs H-7624, Hungary.
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333
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Domingues MM, Bianconi ML, Barbosa LR, Santiago PS, Tabak M, Castanho MA, Itri R, Santos NC. rBPI21 interacts with negative membranes endothermically promoting the formation of rigid multilamellar structures. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2419-27. [DOI: 10.1016/j.bbamem.2013.06.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 05/30/2013] [Accepted: 06/10/2013] [Indexed: 10/26/2022]
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334
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Cytotoxicity of bovine α-lactalbumin: Oleic acid complexes correlates with the disruption of lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2691-9. [DOI: 10.1016/j.bbamem.2013.07.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 07/18/2013] [Accepted: 07/22/2013] [Indexed: 12/21/2022]
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335
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Engel H, Rondeau E, Windhab EJ, Walde P. External surface area determination of lipid vesicles using trinitrobenzene sulfonate and ultraviolet/visible spectrophotometry. Anal Biochem 2013; 442:262-71. [DOI: 10.1016/j.ab.2013.07.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/05/2013] [Accepted: 07/30/2013] [Indexed: 12/23/2022]
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336
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Vargas-Uribe M, Rodnin MV, Ladokhin AS. Comparison of membrane insertion pathways of the apoptotic regulator Bcl-xL and the diphtheria toxin translocation domain. Biochemistry 2013; 52:7901-9. [PMID: 24134052 DOI: 10.1021/bi400926k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The diphtheria toxin translocation domain (T-domain) and the apoptotic repressor Bcl-xL are membrane proteins that adopt their final topology by switching folds from a water-soluble to a membrane-inserted state. While the exact molecular mechanisms of this transition are not clearly understood in either case, the similarity in the structures of soluble states of the T-domain and Bcl-xL led to the suggestion that their membrane insertion pathways will be similar, as well. Previously, we have applied an array of spectroscopic methods to characterize the pH-triggered refolding and membrane insertion of the diphtheria toxin T-domain. Here, we use the same set of methods to describe the membrane insertion pathway of Bcl-xL, which allows us to make a direct comparison between both systems with respect to the thermodynamic stability in solution, pH-dependent membrane association, and transmembrane insertion. Thermal denaturation measured by circular dichroism indicates that, unlike the T-domain, Bcl-xL does not undergo a pH-dependent destabilization of the structure. Förster resonance energy transfer measurements demonstrate that Bcl-xL undergoes reversible membrane association modulated by the presence of anionic lipids, suggesting that formation of the membrane-competent form occurs close to the membrane interface. Membrane insertion of the main hydrophobic helical hairpin of Bcl-xL, α5-α6, was studied by site-selective attachment of environment-sensitive dye NBD. In contrast to the insertion of the corresponding TH8-TH9 hairpin into the T-domain, insertion of α5-α6 was found not to depend strongly on the presence of anionic lipids. Taken together, our results indicate that while Bcl-xL and the T-domain share structural similarities, their modes of conformational switching and membrane insertion pathways are distinctly different.
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Affiliation(s)
- Mauricio Vargas-Uribe
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center , Kansas City, Kansas 66160, United States
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337
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Bouchet AM, Iannucci NB, Pastrian MB, Cascone O, Santos NC, Disalvo EA, Hollmann A. Biological activity of antibacterial peptides matches synergism between electrostatic and non electrostatic forces. Colloids Surf B Biointerfaces 2013; 114:363-71. [PMID: 24257688 DOI: 10.1016/j.colsurfb.2013.10.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/07/2013] [Accepted: 10/16/2013] [Indexed: 11/19/2022]
Abstract
Substitution of Ala 108 and Ala 111 in the 107-115 human lysozyme (hLz) fragment results in a 20-fold increased anti-staphylococcal activity while its hemolytic activity becomes significant (30%) at very high concentrations. This analog displays an additional positive charge near the N-terminus (108) and an extra Trp residue at the center of the molecule (111), indicating that this particular amino acid sequence improves its interaction with the bacterial plasma membrane. In order to understand the role of this arrangement in the membrane interaction, studies with model lipid membranes were carried out. The interactions of peptides, 107-115 hLz and the novel analog ([K(108)W(111)]107-115 hLz) with liposomes and lipid monolayers were evaluated by monitoring the changes in the fluorescence of the Trp residues and the variation of the monolayers surface pressure, respectively. Results obtained with both techniques revealed a significant affinity increase of [K(108)W(111)]107-115 hLz for lipids, especially when the membranes containing negatively charged lipids, such as phosphatidylglycerol. However, there is also a significant interaction with zwitterionic lipids, suggesting that other forces in addition to electrostatic interactions are involved in the binding. The analysis of adsorption isotherms and the insertion kinetics suggest that relaxation processes of the membrane structure are involved in the insertion process of novel peptide [K(108)W(111)]107-115 hLz but not in 107-115 hLz, probably by imposing a reorganization of water at the interphases. In this regard, the enhanced activity of peptide [K(108)W(111)]107-115 hLz may be explained by a synergistic effect between the increased electrostatic forces as well as the increased hydrophobic interactions.
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Affiliation(s)
- Ana M Bouchet
- Laboratory of Biointerfaces and Biomimetic Systems, CITSE-University of Santiago del Estero, 4200 Santiago del Estero and CONICET, Argentina
| | - Nancy B Iannucci
- School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires 1113, Argentina; Therapeutic Peptides Research and Development Laboratory, Chemo-Romikin, 1605 Buenos Aires, Argentina
| | - María B Pastrian
- School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires 1113, Argentina
| | - Osvaldo Cascone
- School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires 1113, Argentina
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Edgardo A Disalvo
- Laboratory of Biointerfaces and Biomimetic Systems, CITSE-University of Santiago del Estero, 4200 Santiago del Estero and CONICET, Argentina
| | - Axel Hollmann
- Laboratory of Biointerfaces and Biomimetic Systems, CITSE-University of Santiago del Estero, 4200 Santiago del Estero and CONICET, Argentina; Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal; Laboratory of Molecular Microbiology, Institute of Basic and Applied Microbiology, University of Quilmes, B1876BXD Bernal, Argentina.
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338
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Thamphiwatana S, Fu V, Zhu J, Lu D, Gao W, Zhang L. Nanoparticle-stabilized liposomes for pH-responsive gastric drug delivery. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:12228-33. [PMID: 23987129 PMCID: PMC4059759 DOI: 10.1021/la402695c] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We report a novel pH-responsive gold nanoparticle-stabilized liposome system for gastric antimicrobial delivery. By adsorbing small chitosan-modified gold nanoparticles (diameter ~10 nm) onto the outer surface of negatively charged phospholipid liposomes (diameter ~75 nm), we show that at gastric pH the liposomes have excellent stability with limited fusion ability and negligible cargo releases. However, when the stabilized liposomes are present in an environment with neutral pH, the gold stabilizers detach from the liposomes, resulting in free liposomes that can actively fuse with bacterial membranes. Using Helicobacter pylori as a model bacterium and doxycycline as a model antibiotic, we demonstrate such pH-responsive fusion activity and drug release profile of the nanoparticle-stabilized liposomes. Particularly, at neutral pH the gold nanoparticles detach, and thus the doxycycline-loaded liposomes rapidly fuse with bacteria and cause superior bactericidal efficacy as compared to the free doxycycline counterpart. Our results suggest that the reported liposome system holds a substantial potential for gastric drug delivery; it remains inactive (stable) in the stomach lumen but actively interacts with bacteria once it reaches the mucus layer of the stomach where the bacteria may reside.
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Affiliation(s)
- Soracha Thamphiwatana
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Victoria Fu
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jingying Zhu
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Diannan Lu
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, P. R. China
| | - Weiwei Gao
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Liangfang Zhang
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA
- Corresponding author, Tel: 858-246-0999,
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339
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Kuznetsova NR, Svirshchevskaya EV, Sitnikov NS, Abodo L, Sutorius H, Zapke J, Velder J, Thomopoulou P, Oschkinat H, Prokop A, Schmalz HG, Fedorov AY, Vodovozova EL. Lipophilic prodrugs of a triazole-containing colchicine analogue in liposomes: Biological effects on human tumor cells. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2013. [DOI: 10.1134/s1068162013050105] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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340
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Jackman JA, Choi JH, Zhdanov VP, Cho NJ. Influence of osmotic pressure on adhesion of lipid vesicles to solid supports. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:11375-84. [PMID: 23901837 DOI: 10.1021/la4017992] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The adhesion of lipid vesicles to solid supports represents an important step in the molecular self-assembly of model membrane platforms. A wide range of experimental parameters are involved in controlling this process, including substrate material and topology, lipid composition, vesicle size, solution pH, ionic strength, and osmotic pressure. At present, it is not well understood how the magnitude and direction of the osmotic pressure exerted on a vesicle influence the corresponding adsorption kinetics. In this work, using quartz crystal microbalance with dissipation (QCM-D) monitoring, we have experimentally studied the role of osmotic pressure in the adsorption of zwitterionic vesicles onto silicon oxide. The osmotic pressure was induced by changing the ionic strength of the solvent across an appreciably wider range (from 25 to 1000 mM NaCl outside of the vesicle, and 125 mM NaCl inside of the vesicle, unless otherwise noted) compared to that used in earlier works. Our key finding is demonstration that, by changing osmotic pressure, all three generic types of the kinetics of vesicle adsorption and rupture can be observed in one system, including (i) adsorption of intact vesicles, (ii) adsorption and rupture after reaching a critical vesicle coverage, and (iii) rupture just after adsorption. Furthermore, theoretical analysis of pressure-induced deformation of adsorbed vesicles and a DLVO-type analysis of the vesicle-substrate interaction qualitatively support our observations. Taken together, the findings in this work demonstrate that osmotic pressure can either promote or impede the rupture of adsorbed vesicles on silicon oxide, and offer experimental evidence to support adhesion energy-based models that describe the adsorption and spontaneous rupture of vesicles on solid supports.
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Affiliation(s)
- Joshua A Jackman
- School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue 639798, Singapore
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341
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Needham D, Park JY, Wright AM, Tong J. Materials characterization of the low temperature sensitive liposome (LTSL): effects of the lipid composition (lysolipid and DSPE-PEG2000) on the thermal transition and release of doxorubicin. Faraday Discuss 2013; 161:515-34; discussion 563-89. [PMID: 23805756 DOI: 10.1039/c2fd20111a] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This paper describes how we have used material science, physical chemistry, and some luck, to design a new thermal-sensitive liposome (the low temperature sensitive liposome (LTSL)) that responds at clinically attainable hyperthermic temperatures releasing its drug in a matter of seconds as it passes through the microvasculature of a warmed tumor. The LTSL is composed of a judicial combination of three component lipids, each with a specific function and each affecting specific material properties, including a sharp thermal transition and a rapid on-set of membrane permeability to small ions, drugs and small dextran polymers. Experimentally, the paper describes how bilayer-concentration changes involving the lysolipid and the presence or absence of DSPE-PEG2000 affect both the lipid transition temperature and the drug release. While the inclusion of 4 mol% DSPE-PEG2000 raises the transition temperature peak (T(m)) by about 1 degrees C, the inclusion of 5.0, 9.7, 12.7 and 18.0 mol% MSPC slightly lowered this peak back to 41.7 degrees C, while not further broadening the peak breadth. As for drug release, in the absence of MSPC, the encapsulated doxorubicin-citrate is hardly released at all. Increasing the composition of MSPC in the lipid mixture (5.0, 7.4, 8.5 and 9.3 mol% MSPC) shows faster and faster initial doxorubicin release rates, with 8.5 and 9.3 mol% MSPC formulations giving 80% of encapsulated drug released in 4 and 3 min, respectively. The Thermodox formulation (9.7 mol% MSPC) gives 60% released in the first 20 s. The presence of PEG-lipid is found to be essential in order for the lysolipid-induced permeability to reach these very fast times. From drug and dextran release experiments, and estimates of the molecular and pore size, the conclusions are that: in order to induce lasting nanopores in lipid bilayers -10 nm diameter, they initially require the presence (from the solid phase structure) of grain boundary defects at the DPPC transition and the permeabilizing component(s) can either be a pore forming lysolipid/surfactant plus a PEG-lipid, or can be generated by a PEG-surfactant incorporated at -4-5 mol%. The final discussion is centered around the postulated defect structures that result in membrane leakage and the permeability of doxorubicin and H+ ions.
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Affiliation(s)
- David Needham
- Duke University, Department of Mechanical Engineering and Materials Science, Box 90300 3391 CIEMAS, Durham, NC 27708, USA
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342
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Balhara V, Schmidt R, Gorr SU, DeWolf C. Membrane selectivity and biophysical studies of the antimicrobial peptide GL13K. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2193-203. [DOI: 10.1016/j.bbamem.2013.05.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/24/2013] [Accepted: 05/27/2013] [Indexed: 01/27/2023]
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343
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Chattopadhyay S, Ehrman SH, Venkataraman C. Size distribution and dye release properties of submicron liposome aerosols. POWDER TECHNOL 2013. [DOI: 10.1016/j.powtec.2013.06.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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344
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Cabrera I, Elizondo E, Esteban O, Corchero JL, Melgarejo M, Pulido D, Córdoba A, Moreno E, Unzueta U, Vazquez E, Abasolo I, Schwartz S, Villaverde A, Albericio F, Royo M, García-Parajo MF, Ventosa N, Veciana J. Multifunctional nanovesicle-bioactive conjugates prepared by a one-step scalable method using CO2-expanded solvents. NANO LETTERS 2013; 13:3766-74. [PMID: 23829208 DOI: 10.1021/nl4017072] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The integration of therapeutic biomolecules, such as proteins and peptides, in nanovesicles is a widely used strategy to improve their stability and efficacy. However, the translation of these promising nanotherapeutics to clinical tests is still challenged by the complexity involved in the preparation of functional nanovesicles and their reproducibility, scalability, and cost production. Here we introduce a simple one-step methodology based on the use of CO2-expanded solvents to prepare multifunctional nanovesicle-bioactive conjugates. We demonstrate high vesicle-to-vesicle homogeneity in terms of size and lamellarity, batch-to-batch consistency, and reproducibility upon scaling-up. Importantly, the procedure is readily amenable to the integration/encapsulation of multiple components into the nanovesicles in a single step and yields sufficient quantities for clinical research. The simplicity, reproducibility, and scalability render this one-step fabrication process ideal for the rapid and low-cost translation of nanomedicine candidates from the bench to the clinic.
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Affiliation(s)
- Ingrid Cabrera
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus Universitari de Bellaterra, 08193 Cerdanyola del Vallès, Spain
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345
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Cho NJ, Hwang LY, Solandt JJR, Frank CW. Comparison of Extruded and Sonicated Vesicles for Planar Bilayer Self-Assembly. MATERIALS (BASEL, SWITZERLAND) 2013; 6:3294-3308. [PMID: 28811437 PMCID: PMC5521307 DOI: 10.3390/ma6083294] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 01/27/2023]
Abstract
Lipid vesicles are an important class of biomaterials that have a wide range of applications, including drug delivery, cosmetic formulations and model membrane platforms on solid supports. Depending on the application, properties of a vesicle population such as size distribution, charge and permeability need to be optimized. Preparation methods such as mechanical extrusion and sonication play a key role in controlling these properties, and yet the effects of vesicle preparation method on vesicular properties and integrity (e.g., shape, size, distribution and tension) remain incompletely understood. In this study, we prepared vesicles composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid by either extrusion or sonication, and investigated the effects on vesicle size distribution over time as well as the concomitant effects on the self-assembly of solid-supported planar lipid bilayers. Dynamic light scattering (DLS), quartz crystal microbalance with dissipation (QCM-D) monitoring, fluorescence recovery after photobleaching (FRAP) and atomic force microscopy (AFM) experiments were performed to characterize vesicles in solution as well as their interactions with silicon oxide substrates. Collectively, the data support that sonicated vesicles offer more robust control over the self-assembly of homogenous planar lipid bilayers, whereas extruded vesicles are vulnerable to aging and must be used soon after preparation.
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Affiliation(s)
- Nam-Joon Cho
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
| | - Lisa Y Hwang
- Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, CA 94305, USA.
| | - Johan J R Solandt
- Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, CA 94305, USA.
| | - Curtis W Frank
- Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, CA 94305, USA.
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346
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Krauson AJ, He J, Wimley WC. Determining the mechanism of membrane permeabilizing peptides: identification of potent, equilibrium pore-formers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1818:1625-32. [PMID: 22365969 DOI: 10.1016/j.bbamem.2012.02.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 01/30/2012] [Accepted: 02/08/2012] [Indexed: 10/28/2022]
Abstract
To enable selection and characterization of highly potent pore-forming peptides, we developed a set of novel assays to probe 1) the potency of peptide pores at very low peptide concentration; 2) the presence or absence of pores in membranes after equilibration; 3) the interbilayer exchangeability of pore-forming peptides; and 4) the degree to which pore-forming peptides disrupt the bilayer organization at equilibrium. Here, we use these assays to characterize, in parallel, six membrane-permeabilizing peptides belonging to multiple classes. We tested the antimicrobial peptides LL37 and dermaseptin S1, the well-known natural lytic peptides melittin and alamethicin, and the very potent lentivirus lytic peptides LLP1 and LLP2 from the cytoplasmic domain of HIV GP41. The assays verified that that the antimicrobial peptides are not potent pore formers, and form only transient permeabilization pathways in bilayers which are not detectable at equilibrium. The other peptides are far more potent and form pores that are still detectable in vesicles after many hours. Among the peptides studies, alamethicin is unique in that it is very potent, readily exchanges between vesicles, and disturbs the local bilayer structure even at very low concentration. The equally potent LLP peptides do not exchange readily and do not perturb the bilayer at equilibrium. Comparison of these classes of pore forming peptides in parallel using the set of assays we developed demonstrates our ability to detect differences in their mechanism of action. Importantly, these assays will be very useful in high-throughput screening where highly potent pore-forming peptides can be selected based on their mechanism of action.
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Affiliation(s)
- Aram J Krauson
- Department of Biochemistry SL43, Tulane University School of Medicine, New Orleans, 1A 70112, USA
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347
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Wietek J, Haralampiev I, Amoussouvi A, Herrmann A, Stöckl M. Membrane bound α-synuclein is fully embedded in the lipid bilayer while segments with higher flexibility remain. FEBS Lett 2013; 587:2572-7. [PMID: 23831067 DOI: 10.1016/j.febslet.2013.06.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/28/2013] [Accepted: 06/25/2013] [Indexed: 12/15/2022]
Abstract
Cellular pathways involving α-synuclein (αS) seem to be causative for development of Parkinson's disease. Interactions between αS and lipid membranes appear to be important for the physiological function of the protein and influence the pathological aggregation of αS leading to the formation of amyloid plaques. Upon membrane binding the unstructured αS folds into amphipathic helices. In our work we characterized the penetration depth and probed the local environment of Trp-residues introduced along the αS sequence. We could show that while the entire helix is well embedded in the lipid bilayer, segments with a shallower penetration and supposable higher flexibility exist.
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Affiliation(s)
- Jonas Wietek
- Department of Biology, Faculty of Mathematics and Natural Sciences I, Humboldt University Berlin, Invalidenstr. 42, 10115 Berlin, Germany
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348
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Mäler L. Solution NMR studies of cell-penetrating peptides in model membrane systems. Adv Drug Deliv Rev 2013; 65:1002-11. [PMID: 23137785 DOI: 10.1016/j.addr.2012.10.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/17/2012] [Accepted: 10/22/2012] [Indexed: 12/29/2022]
Abstract
Cell-penetrating peptides (CPPs) are a class of short, often cationic peptides that have the capability to translocate across cellular membranes, and although the translocation most likely involves several pathways, they interact directly with membranes, as well as with model bilayers. Most CPPs attain a three-dimensional structure when interacting with bilayers, while they are more or less unstructured in aqueous solution. To understand the relationship between structure and the effect that CPPs have on membranes it is of great importance to investigate CPPs at atomic resolution in a suitable membrane model. Moreover, the location in bilayers is likely to be correlated with the translocation mechanism. Solution-state NMR offers a unique possibility to investigate structure, dynamics and location of proteins and peptides in bilayers. This review focuses on solution NMR as a tool for investigating CPP-lipid interactions. Structural propensities and cell-penetrating capabilities can be derived from a combination of CPP solution structures and studies of the effect that the peptides have on bilayers and the localization in a bilayer.
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Affiliation(s)
- Lena Mäler
- Department of Biochemistry and Biophysics, The Arrhenius Laboratory, Stockholm University, Stockholm, Sweden.
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349
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Ibarguren M, López DJ, Encinar JA, González-Ros JM, Busquets X, Escribá PV. Partitioning of liquid-ordered/liquid-disordered membrane microdomains induced by the fluidifying effect of 2-hydroxylated fatty acid derivatives. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2553-63. [PMID: 23792066 DOI: 10.1016/j.bbamem.2013.06.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 05/19/2013] [Accepted: 06/10/2013] [Indexed: 01/15/2023]
Abstract
Cellular functions are usually associated with the activity of proteins and nucleic acids. Recent studies have shown that lipids modulate the localization and activity of key membrane-associated signal transduction proteins, thus regulating the cell's physiology. Membrane Lipid Therapy aims to reverse cell dysfunctions (i.e., diseases) by modulating the activity of membrane signaling proteins through regulation of the lipid bilayer structure. The present work shows the ability of a series of 2-hydroxyfatty acid (2OHFA) derivatives, varying in the acyl chain length and degree of unsaturation, to regulate the membrane lipid structure. These molecules have shown greater therapeutic potential than their natural non-hydroxylated counterparts. We demonstrated that both 2OHFA and natural FAs induced reorganization of lipid domains in model membranes of POPC:SM:PE:Cho, modulating the liquid-ordered/liquid-disordered structures ratio and the microdomain lipid composition. Fluorescence spectroscopy, confocal microscopy, Fourier transform infrared spectroscopy and differential detergent solubilization experiments showed a destabilization of the membranes upon addition of the 2OHFAs and FAs which correlated with the observed disordering effect. The changes produced by these synthetic fatty acids on the lipid structure may constitute part of their mechanism of action, leading to changes in the localization/activity of membrane proteins involved in signaling cascades, and therefore modulating cell responses.
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Affiliation(s)
- Maitane Ibarguren
- Laboratory of Molecular Cell Biomedicine, University of the Balearic Islands-Lipopharma Therapeutics, S.L., Palma, Spain
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350
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Pace HP, Sherrod SD, Monson CF, Russell DH, Cremer PS. Coupling supported lipid bilayer electrophoresis with matrix-assisted laser desorption/ionization-mass spectrometry imaging. Anal Chem 2013; 85:6047-52. [PMID: 23731179 PMCID: PMC3717335 DOI: 10.1021/ac4008804] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Herein, we describe a new analytical platform utilizing advances in heterogeneous supported lipid bilayer (SLB) electrophoresis and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) imaging. This platform allowed for the separation and visualization of both charged and neutral lipid membrane components without the need for extrinsic labels. A heterogeneous SLB was created using vesicles containing monosialoganglioside GM1, disialoganglioside GD1b, POPC, as well as the ortho and para isomers of Texas Red-DHPE. These components were then separated electrophoretically into five resolved bands. This represents the most complex separation by SLB electrophoresis performed to date. The SLB samples were flash frozen in liquid ethane and dried under vacuum before imaging with MALDI-MS. Fluorescence microscopy was employed to confirm the position of the Texas Red labeled lipids, which agreed well with the MALDI-MS imaging results. These results clearly demonstrate this platform's ability to isolate and identify nonlabeled membrane components within an SLB.
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Affiliation(s)
- Hudson P. Pace
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Stacy D. Sherrod
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | | | - David H. Russell
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Paul S. Cremer
- Department of Chemistry, Texas A&M University, College Station, TX 77843
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