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Královič-Kanjaková N, Asi Shirazi A, Hubčík L, Klacsová M, Keshavarzi A, Martínez JC, Combet S, Teixeira J, Uhríková D. Polymyxin B-Enriched Exogenous Lung Surfactant: Thermodynamics and Structure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:6847-6861. [PMID: 38501650 DOI: 10.1021/acs.langmuir.3c03746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
The use of an exogenous pulmonary surfactant (EPS) to deliver other relevant drugs to the lungs is a promising strategy for combined therapy. We evaluated the interaction of polymyxin B (PxB) with a clinically used EPS, the poractant alfa Curosurf (PSUR). The effect of PxB on the protein-free model system (MS) composed of four phospholipids (diC16:0PC/16:0-18:1PC/16:0-18:2PC/16:0-18:1PG) was examined in parallel to distinguish the specificity of the composition of PSUR. We used several experimental techniques (differential scanning calorimetry, small- and wide-angle X-ray scattering, small-angle neutron scattering, fluorescence spectroscopy, and electrophoretic light scattering) to characterize the binding of PxB to both EPS. Electrostatic interactions PxB-EPS are dominant. The results obtained support the concept of cationic PxB molecules lying on the surface of the PSUR bilayer, strengthening the multilamellar structure of PSUR as derived from SAXS and SANS. A protein-free MS mimics a natural EPS well but was found to be less resistant to penetration of PxB into the lipid bilayer. PxB does not affect the gel-to-fluid phase transition temperature, Tm, of PSUR, while Tm increased by ∼+ 2 °C in MS. The decrease of the thickness of the lipid bilayer (dL) of PSUR upon PxB binding is negligible. The hydrophobic tail of the PxB molecule does not penetrate the bilayer as derived from SANS data analysis and changes in lateral pressure monitored by excimer fluorescence at two depths of the hydrophobic region of the bilayer. Changes in dL of protein-free MS show a biphasic dependence on the adsorbed amount of PxB with a minimum close to the point of electroneutrality of the mixture. Our results do not discourage the concept of a combined treatment with PxB-enriched Curosurf. However, the amount of PxB must be carefully assessed (less than 5 wt % relative to the mass of the surfactant) to avoid inversion of the surface charge of the membrane.
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Affiliation(s)
- Nina Královič-Kanjaková
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, 832 32 Bratislava, Slovakia
| | - Ali Asi Shirazi
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, 832 32 Bratislava, Slovakia
| | - Lukáš Hubčík
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, 832 32 Bratislava, Slovakia
| | - Mária Klacsová
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, 832 32 Bratislava, Slovakia
| | - Atoosa Keshavarzi
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, 832 32 Bratislava, Slovakia
| | | | - Sophie Combet
- Laboratoire Léon-Brillouin (LLB), UMR12 CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette CEDEX, France
| | - José Teixeira
- Laboratoire Léon-Brillouin (LLB), UMR12 CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette CEDEX, France
| | - Daniela Uhríková
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, 832 32 Bratislava, Slovakia
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Dziura D, Dziura M, Marquardt D. Studying lipid flip-flop in asymmetric liposomes using 1H NMR and TR-SANS. Methods Enzymol 2024; 700:295-328. [PMID: 38971604 DOI: 10.1016/bs.mie.2024.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
The specific spatial and temporal distribution of lipids in membranes play a crucial role in determining the biochemical and biophysical properties of the system. In nature, the asymmetric distribution of lipids is a dynamic process with ATP-dependent lipid transporters maintaining asymmetry, and passive transbilayer diffusion, that is, flip-flop, counteracting it. In this chapter, two probe-free techniques, 1H NMR and time-resolved small angle neutron scattering, are described in detail as methods of investigating lipid flip-flop rates in synthetic liposomes that have been generated with an asymmetric bilayer composition.
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Affiliation(s)
- Dominik Dziura
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Maksymilian Dziura
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada; Department of Physics, University of Windsor, Windsor, ON, Canada.
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Barclay A, Kragelund BB, Arleth L, Pedersen MC. Modeling of flexible membrane-bound biomolecular complexes for solution small-angle scattering. J Colloid Interface Sci 2023; 635:611-621. [PMID: 36634513 DOI: 10.1016/j.jcis.2022.12.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/18/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022]
Abstract
Recent advances in protein expression protocols, sample handling, and experimental set up of small-angle scattering experiments have allowed users of the technique to structurally investigate biomolecules of growing complexity and structural disorder. Notable examples include intrinsically disordered proteins, multi-domain proteins and membrane proteins in suitable carrier systems. Here, we outline a modeling scheme for calculating the scattering profiles from such complex samples. This kind of modeling is necessary for structural information to be refined from the corresponding data. The scheme bases itself on a hybrid of classical form factor based modeling and the well-known spherical harmonics-based formulation of small-angle scattering amplitudes. Our framework can account for flexible domains alongside other structurally elaborate components of the molecular system in question. We demonstrate the utility of this modeling scheme through a recent example of a structural model of the growth hormone receptor membrane protein in a phospholipid bilayer nanodisc which is refined against experimental SAXS data. Additionally we investigate how the scattering profiles from the complex would appear under different scattering contrasts. For each contrast situation we discuss what structural information is contained and the related consequences for modeling of the data.
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Affiliation(s)
- Abigail Barclay
- Condensed Matter Physics, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, Copenhagen 2200, Denmark.
| | - Lise Arleth
- Condensed Matter Physics, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
| | - Martin Cramer Pedersen
- Condensed Matter Physics, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
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Kurakin S, Ivankov O, Skoi V, Kuklin A, Uhríková D, Kučerka N. Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area. Front Mol Biosci 2022; 9:926591. [PMID: 35898308 PMCID: PMC9312375 DOI: 10.3389/fmolb.2022.926591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Combining small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and densitometric measurements, we have studied the interactions of the divalent cations Ca2+ and Mg2+ with the lipid vesicles prepared of a mixed-chain palmitoyl-oleoyl-phosphatidylcholine (POPC) at 25°C. The structural parameters of the POPC bilayer, such as the bilayer thickness, lateral area, and volume per lipid, displayed no changes upon the ion addition at concentrations up to 30 mM and minor changes at > 30 mM Ca2+ and Mg2+, while some decrease in the vesicle radius was observed over the entire concentration range studied. This examination allows us to validate the concept of lipid–ion interactions governed by the area per lipid suggested previously and to propose the mixed mode of those interactions that emerge in the POPC vesicles. We speculate that the average area per POPC lipid that corresponds to the cutoff length of lipid–ion interactions generates an equal but opposite impact on ion bridges and separate lipid–ion pairs. As a result of the dynamic equilibrium, the overall structural properties of bilayers are not affected. As the molecular mechanism proposed is affected by the structural properties of a particular lipid, it might help us to understand the fundamentals of processes occurring in complex multicomponent membrane systems.
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Affiliation(s)
- Sergei Kurakin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Institute of Physics, Kazan Federal University, Kazan, Russia
| | - Oleksandr Ivankov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Vadim Skoi
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia
| | - Alexander Kuklin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia
| | - Daniela Uhríková
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, Slovakia
| | - Norbert Kučerka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, Slovakia
- *Correspondence: Norbert Kučerka,
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Kordyukova LV, Konarev PV, Fedorova NV, Shtykova EV, Ksenofontov AL, Loshkarev NA, Dadinova LA, Timofeeva TA, Abramchuk SS, Moiseenko AV, Baratova LA, Svergun DI, Batishchev OV. The Cytoplasmic Tail of Influenza A Virus Hemagglutinin and Membrane Lipid Composition Change the Mode of M1 Protein Association with the Lipid Bilayer. MEMBRANES 2021; 11:772. [PMID: 34677538 PMCID: PMC8541430 DOI: 10.3390/membranes11100772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 09/27/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022]
Abstract
Influenza A virus envelope contains lipid molecules of the host cell and three integral viral proteins: major hemagglutinin, neuraminidase, and minor M2 protein. Membrane-associated M1 matrix protein is thought to interact with the lipid bilayer and cytoplasmic domains of integral viral proteins to form infectious virus progeny. We used small-angle X-ray scattering (SAXS) and complementary techniques to analyze the interactions of different components of the viral envelope with M1 matrix protein. Small unilamellar liposomes composed of various mixtures of synthetic or "native" lipids extracted from Influenza A/Puerto Rico/8/34 (H1N1) virions as well as proteoliposomes built from the viral lipids and anchored peptides of integral viral proteins (mainly, hemagglutinin) were incubated with isolated M1 and measured using SAXS. The results imply that M1 interaction with phosphatidylserine leads to condensation of the lipid in the protein-contacting monolayer, thus resulting in formation of lipid tubules. This effect vanishes in the presence of the liquid-ordered (raft-forming) constituents (sphingomyelin and cholesterol) regardless of their proportion in the lipid bilayer. We also detected a specific role of the hemagglutinin anchoring peptides in ordering of viral lipid membrane into the raft-like one. These peptides stimulate the oligomerization of M1 on the membrane to form a viral scaffold for subsequent budding of the virion from the plasma membrane of the infected cell.
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Affiliation(s)
- Larisa V. Kordyukova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.V.K.); (N.V.F.); (A.L.K.); (L.A.B.)
| | - Petr V. Konarev
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, 119333 Moscow, Russia; (P.V.K.); (E.V.S.); (L.A.D.)
| | - Nataliya V. Fedorova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.V.K.); (N.V.F.); (A.L.K.); (L.A.B.)
| | - Eleonora V. Shtykova
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, 119333 Moscow, Russia; (P.V.K.); (E.V.S.); (L.A.D.)
| | - Alexander L. Ksenofontov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.V.K.); (N.V.F.); (A.L.K.); (L.A.B.)
| | - Nikita A. Loshkarev
- Laboratory of Bioelectrochemistry, Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 119991 Moscow, Russia;
| | - Lubov A. Dadinova
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, 119333 Moscow, Russia; (P.V.K.); (E.V.S.); (L.A.D.)
| | - Tatyana A. Timofeeva
- Laboratory of Physiology of Viruses, D. I. Ivanovsky Institute of Virology, FSBI N. F. Gamaleya NRCEM, Ministry of Health of Russian Federation, 123098 Moscow, Russia;
| | - Sergei S. Abramchuk
- Department of Chemistry, Lomonosov Moscow State University, 119234 Moscow, Russia;
- Laboratory of Physical Chemistry of Polymers, A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, 119991 Moscow, Russia
| | - Andrei V. Moiseenko
- Laboratory of Electron Microscopy, Department of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia;
| | - Lyudmila A. Baratova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.V.K.); (N.V.F.); (A.L.K.); (L.A.B.)
| | | | - Oleg V. Batishchev
- Laboratory of Bioelectrochemistry, Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 119991 Moscow, Russia;
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Dargel C, Gräbitz-Bräuer F, Geisler R, Fandrich P, Hannappel Y, Porcar L, Hellweg T. Stable DOPG/Glycyrrhizin Vesicles with a Wide Range of Mixing Ratios: Structure and Stability as Seen by Scattering Experiments and Cryo-TEM. Molecules 2021; 26:molecules26164959. [PMID: 34443547 PMCID: PMC8399256 DOI: 10.3390/molecules26164959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 11/24/2022] Open
Abstract
Phosphatidylglycerols represent a large share of the lipids in the plasmamembrane of procaryotes. Therefore, this study investigates the role of charged lipids in the plasma membrane with respect to the interaction of the antiviral saponin glycyrrhizin with such membranes. Glycyrrhizin is a natural triterpenic-based surfactant found in licorice. Vesicles made of 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1’-glycerol) (DOPG)/glycyrrhizin are characterized by small-angle scattering with neutrons and X-rays (SANS and SAXS). Small-angle scattering data are first evaluated by the model-independent modified Kratky–Porod method and afterwards fitted by a model describing the shape of small unilamellar vesicles (SUV) with an internal head-tail contrast. Complete miscibility of DOPG and glycyrrhizin was revealed even at a ratio of lipid:saponin of 1:1. Additional information about the chain-chain correlation distance of the lipid/saponin mixtures in the SUV structures is obtained from wide-angle X-ray scattering (WAXS).
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Affiliation(s)
- Carina Dargel
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany; (C.D.); (F.G.-B.); (R.G.); (P.F.); (Y.H.)
| | - Friederike Gräbitz-Bräuer
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany; (C.D.); (F.G.-B.); (R.G.); (P.F.); (Y.H.)
| | - Ramsia Geisler
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany; (C.D.); (F.G.-B.); (R.G.); (P.F.); (Y.H.)
| | - Pascal Fandrich
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany; (C.D.); (F.G.-B.); (R.G.); (P.F.); (Y.H.)
| | - Yvonne Hannappel
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany; (C.D.); (F.G.-B.); (R.G.); (P.F.); (Y.H.)
| | - Lionel Porcar
- Institut Laue-Langevin, 71 Avenue des Martyrs CS 20156, CEDEX 9, 38042 Grenoble, France;
| | - Thomas Hellweg
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany; (C.D.); (F.G.-B.); (R.G.); (P.F.); (Y.H.)
- Correspondence: ; Tel.: +49-0521-106-2055
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7
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Petukhov MV, Konarev PV, Dadinova LA, Fedorova NV, Volynsky PE, Svergun DI, Batishchev OV, Shtykova EV. Quasi-Atomistic Approach to Modeling of Liposomes. CRYSTALLOGR REP+ 2020. [DOI: 10.1134/s1063774520020182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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Nguyen MHL, DiPasquale M, Rickeard BW, Doktorova M, Heberle FA, Scott HL, Barrera FN, Taylor G, Collier CP, Stanley CB, Katsaras J, Marquardt D. Peptide-Induced Lipid Flip-Flop in Asymmetric Liposomes Measured by Small Angle Neutron Scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11735-11744. [PMID: 31408345 PMCID: PMC7393738 DOI: 10.1021/acs.langmuir.9b01625] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Despite the prevalence of lipid transbilayer asymmetry in natural plasma membranes, most biomimetic model membranes studied are symmetric. Recent advances have helped to overcome the difficulties in preparing asymmetric liposomes in vitro, allowing for the examination of a larger set of relevant biophysical questions. Here, we investigate the stability of asymmetric bilayers by measuring lipid flip-flop with time-resolved small-angle neutron scattering (SANS). Asymmetric large unilamellar vesicles with inner bilayer leaflets containing predominantly 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and outer leaflets composed mainly of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) displayed slow spontaneous flip-flop at 37 ◦C (half-time, t1/2 = 140 h). However, inclusion of peptides, namely, gramicidin, alamethicin, melittin, or pHLIP (i.e., pH-low insertion peptide), accelerated lipid flip-flop. For three of these peptides (i.e., pHLIP, alamethicin, and melittin), each of which was added externally to preformed asymmetric vesicles, we observed a completely scrambled bilayer in less than 2 h. Gramicidin, on the other hand, was preincorporated during the formation of the asymmetric liposomes and showed a time resolvable 8-fold increase in the rate of lipid asymmetry loss. These results point to a membrane surface-related (e.g., adsorption/insertion) event as the primary driver of lipid scrambling in the asymmetric model membranes of this study. We discuss the implications of membrane peptide binding, conformation, and insertion on lipid asymmetry.
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Affiliation(s)
- Michael H. L. Nguyen
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
| | - Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
| | - Brett W. Rickeard
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
| | - Milka Doktorova
- Department of Integrative Biology and Pharmacology,
University of Texas Health Science Center at Houston, Houston, Texas 77225, United
States
| | - Frederick A. Heberle
- Department of Integrative Biology and Pharmacology,
University of Texas Health Science Center at Houston, Houston, Texas 77225, United
States
- Center for Environmental Biotechnology, University
of Tennessee, Knoxville, Tennessee 37996, United States
| | - Haden L. Scott
- Center for Environmental Biotechnology, University
of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Biochemistry & Cellular and
Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United
States
| | - Francisco N. Barrera
- Department of Biochemistry & Cellular and
Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United
States
| | - Graham Taylor
- The Bredesen Center, University of Tennessee,
Knoxville, Tennessee 37996, United States
| | - Charles P. Collier
- The Bredesen Center, University of Tennessee,
Knoxville, Tennessee 37996, United States
- Center for Nanophase Materials Sciences, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Christopher B. Stanley
- Neutron Scattering Division, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
| | - John Katsaras
- Large Scale Structures Group, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
- Shull Wollan Center, a Joint Institute for Neutron
Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United
States
- Department of Physics and Astronomy, University of
Tennessee, Knoxville, Tennessee 37996, United States
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
- Department of Physics, University of Windsor, Windsor, N9B
3P4 ON Canada
- Corresponding Author:
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Aescin-Cholesterol Complexes in DMPC Model Membranes: A DSC and Temperature-Dependent Scattering Study. Sci Rep 2019; 9:5542. [PMID: 30944386 PMCID: PMC6447539 DOI: 10.1038/s41598-019-41865-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 03/19/2019] [Indexed: 11/09/2022] Open
Abstract
The saponin aescin, a mixture of triterpenoid saponins, is obtained from the seeds of the horse chestnut tree Aesculus hippocastanum. The β-form employed in this study is haemolytically active. The haemolytic activity results from the ability of aescin to form strong complexes with cholesterol in the red blood cell membrane. In this study, we provide a structural analysis on the complex formation of aescin and cholesterol when embedded in a phospholipid model membrane formed by 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). In this work, the temperatures investigated extend from DMPC’s Lβ′ to its Lα phase in dependence of different amounts of the saponin (0–6 mol% for calorimetric and 0–1 mol% for structural analyses) and the steroid (1–10 mol%). At these aescin contents model membranes are conserved in the form of small unilamellar vesicles (SUVs) and major overall structural modifications are avoided. Additionally, interactions between aescin and cholesterol can be studied for both phase states of the lipid, the gel and the fluid state. From calorimetric experiments by differential scanning calorimetry (DSC), it could be shown that both, the steroid and the saponin content, have a significant impact on the cooperative phase transition behaviour of the DMPC molecules. In addition, it becomes clearly visible that the entire phase behaviour is dominated by phase separation which indeed also depends on the complexes formed between aescin and cholesterol. We show by various methods that the addition of cholesterol alters the impact of aescin on structural parameters ranging from the acyl chain correlation to vesicle-vesicle interactions. While the specific saponin-phospholipid interaction is reduced, addition of cholesterol leads to deformation of SUVs. The analyses of the structures formed were performed by wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS).
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10
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Kiselev MA, Zemlyanaya EV. Dimethyl sulfoxide-induced dehydration of the intermembrane space of dipalmitoylphosphatidylcholine multilamellar vesicles: Neutron and synchrotron diffraction study. CRYSTALLOGR REP+ 2017. [DOI: 10.1134/s106377451705011x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Mamusa M, Sitia L, Barbero F, Ruyra A, Calvo TD, Montis C, Gonzalez-Paredes A, Wheeler GN, Morris CJ, McArthur M, Berti D. Cationic liposomal vectors incorporating a bolaamphiphile for oligonucleotide antimicrobials. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1767-1777. [PMID: 28610721 DOI: 10.1016/j.bbamem.2017.06.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/10/2017] [Accepted: 06/08/2017] [Indexed: 01/01/2023]
Abstract
Antibacterial resistance has become a serious crisis for world health over the last few decades, so that new therapeutic approaches are strongly needed to face the threat of resistant infections. Transcription factor decoys (TFD) are a promising new class of antimicrobial oligonucleotides with proven in vivo activity when combined with a bolaamphiphilic cationic molecule, 12-bis-THA. These two molecular species form stable nanoplexes which, however, present very scarce colloidal stability in physiological media, which poses the challenge of drug formulation and delivery. In this work, we reformulated the 12-bis-THA/TFD nanoplexes in a liposomal carrier, which retains the ability to protect the oligonucleotide therapeutic from degradation and deliver it across the bacterial cell wall. We performed a physical-chemical study to investigate how the incorporation of 12-bis-THA and TFD affects the structure of POPC- and POPC/DOPE liposomes. Analysis was performed using dynamic light scattering (DLS), ζ-potential measurements, small-angle x-ray scattering (SAXS), and steady-state fluorescence spectroscopy to better understand the structure of the liposomal formulations containing the 12-bis-THA/TFD complexes. Oligonucleotide delivery to model Escherichia coli bacteria was assessed by means of confocal scanning laser microscopy (CLSM), evidencing the requirement of a fusogenic helper lipid for transfection. Preliminary biological assessments suggested the necessity of further development by modulation of 12-bis-THA concentration in order to optimize its therapeutic index, i.e. the ratio of antibacterial activity to the observed cytotoxicity. In summary, POPC/DOPE/12-bis-THA liposomes appear as promising formulations for TFD delivery.
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Affiliation(s)
- Marianna Mamusa
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence. Via della Lastruccia 3, 50019 Sesto Fiorentino, (FI), Italy.
| | - Leopoldo Sitia
- Procarta Biosystems Ltd, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | | | - Angels Ruyra
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Teresa Díaz Calvo
- Procarta Biosystems Ltd, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Costanza Montis
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence. Via della Lastruccia 3, 50019 Sesto Fiorentino, (FI), Italy
| | | | - Grant N Wheeler
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Christopher J Morris
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Michael McArthur
- Procarta Biosystems Ltd, Norwich Research Park, Norwich NR4 7UH, United Kingdom; Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, United Kingdom
| | - Debora Berti
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence. Via della Lastruccia 3, 50019 Sesto Fiorentino, (FI), Italy
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Narayanan T, Weerakkody D, Karabadzhak AG, Anderson M, Andreev OA, Reshetnyak YK. pHLIP Peptide Interaction with a Membrane Monitored by SAXS. J Phys Chem B 2016; 120:11484-11491. [PMID: 27726396 PMCID: PMC5209755 DOI: 10.1021/acs.jpcb.6b06643] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
pH (Low) Insertion Peptides (pHLIP peptides) find application in studies of membrane-associated folding because spontaneous insertion of these peptides is conveniently triggered by varying pH. Here, we employed small-angle X-ray scattering (SAXS) to investigate a wild-type (WT) pHLIP peptide oligomeric state in solution at high concentrations and monitor changes in the liposome structure upon peptide insertion into the bilayer. We established that even at high concentrations (up to 300 μM) the WT pHLIP peptide at pH 8.0 does not form oligomers larger than tetramers (which exhibit concentration-dependent transfer to the monomeric state, as was shown previously). This finding has significance for medical applications when high concentration of the peptide is injected into blood and diluted in blood circulation. The interaction of WT pHLIP peptide with liposomes does not alter the unilamellar vesicle structure upon peptide adsorption by the lipid bilayer at high pH or upon insertion across the bilayer at low pH. At the same time, SAXS data clearly demonstrate the insertion of the peptide into the membrane at low pH, which opens the possibility of investigating the kinetic process of polypeptide insertion and exit from the membrane in real time by time-resolved SAXS.
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Affiliation(s)
| | - Dhammika Weerakkody
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | | | - Michael Anderson
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Oleg A. Andreev
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Yana K. Reshetnyak
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, United States
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Neutron Scattering at the Intersection of Heart Health Science and Biophysics. J Cardiovasc Dev Dis 2015; 2:125-140. [PMID: 29371515 PMCID: PMC5753099 DOI: 10.3390/jcdd2020125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 05/25/2015] [Indexed: 01/04/2023] Open
Abstract
There is an urgent quest for improved heart health. Here, we review how neutron radiation can provide insight into the molecular basis of heart health. Lower cholesterol, a daily intake of aspirin and supplemental vitamin E are argued to all improve heart health. However, the mechanisms behind these common regimens, and others, are not entirely understood. It is not clear why a daily intake of aspirin can help some people with heart disease, and the benefits of vitamin E in the treatment of reperfusion injury have been heavily debated. The molecular impact of cholesterol in the body is still a hot topic. Neutron scattering experiments present a unique opportunity for biophysicists attempting to address these problems. We review some recently published studies that are advancing our understanding of how cholesterol, vitamin E and aspirin work at the molecular level, by studying the impact of these molecules on the cell membrane. These insights engage the broader health science community with new ways of thinking about these molecules.
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14
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Carvalho JMP, Toniazzo T, Cavalcanti LP, Moraes ICF, Oliveira CLP, Pinho SC. Physico-chemical stability and structural characterization of thickened multilamellar beta-carotene-loaded liposome dispersions produced using a proliposome method. Colloid Polym Sci 2015. [DOI: 10.1007/s00396-015-3594-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Drolle E, Kučerka N, Hoopes M, Choi Y, Katsaras J, Karttunen M, Leonenko Z. Effect of melatonin and cholesterol on the structure of DOPC and DPPC membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2247-54. [DOI: 10.1016/j.bbamem.2013.05.015] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 12/14/2022]
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