1
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Reagle T, Xie Y, Li Z, Carnero W, Baumgart T. Methyl-β-cyclodextrin asymmetrically extracts phospholipid from bilayers, granting tunable control over differential stress in lipid vesicles. SOFT MATTER 2024; 20:4291-4307. [PMID: 38758097 PMCID: PMC11135146 DOI: 10.1039/d3sm01772a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 05/01/2024] [Indexed: 05/18/2024]
Abstract
Lipid asymmetry - that is, a nonuniform lipid distribution between the leaflets of a bilayer - is a ubiquitous feature of biomembranes and is implicated in several cellular phenomena. Differential tension - that is, unequal lateral monolayer tensions comparing the leaflets of a bilayer- is closely associated with lipid asymmetry underlying these varied roles. Because differential tension is not directly measurable in combination with the fact that common methods to adjust this quantity grant only semi-quantitative control over it, a detailed understanding of lipid asymmetry and differential tension are impeded. To overcome these challenges, we leveraged reversible complexation of phospholipid by methyl-β-cyclodextrin (mbCD) to tune the direction and magnitude of lipid asymmetry in synthetic vesicles. Lipid asymmetry generated in our study induced (i) vesicle shape changes and (ii) gel-liquid phase coexistence in 1-component vesicles. By applying mass-action considerations to interpret our findings, we discuss how this approach provides access to phospholipid thermodynamic potentials in bilayers containing lipid asymmetry (which are coupled to the differential tension of a bilayer). Because lipid asymmetry yielded by our approach is (i) tunable and (ii) maintained over minute to hour timescales, we anticipate that this approach will be a valuable addition to the experimental toolbox for systematic investigation into the biophysical role(s) of lipid asymmetry (and differential tension).
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Affiliation(s)
- Tyler Reagle
- University of Pennsylvania, Chemistry Department, 231 South 34th Street, Philadelphia, PA, 19104, USA.
| | - Yuxin Xie
- University of Pennsylvania, Chemistry Department, 231 South 34th Street, Philadelphia, PA, 19104, USA.
| | - Zheyuan Li
- University of Pennsylvania, Chemistry Department, 231 South 34th Street, Philadelphia, PA, 19104, USA.
| | - Warner Carnero
- University of Pennsylvania, Chemistry Department, 231 South 34th Street, Philadelphia, PA, 19104, USA.
| | - Tobias Baumgart
- University of Pennsylvania, Chemistry Department, 231 South 34th Street, Philadelphia, PA, 19104, USA.
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2
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Pabst G, Keller S. Exploring membrane asymmetry and its effects on membrane proteins. Trends Biochem Sci 2024; 49:333-345. [PMID: 38355393 DOI: 10.1016/j.tibs.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/08/2024] [Accepted: 01/19/2024] [Indexed: 02/16/2024]
Abstract
Plasma membranes utilize free energy to maintain highly asymmetric, non-equilibrium distributions of lipids and proteins between their two leaflets. In this review we discuss recent progress in quantitative research enabled by using compositionally controlled asymmetric model membranes. Both experimental and computational studies have shed light on the nuanced mechanisms that govern the structural and dynamic coupling between compositionally distinct bilayer leaflets. This coupling can increase the membrane bending rigidity and induce order - or lipid domains - across the membrane. Furthermore, emerging evidence indicates that integral membrane proteins not only respond to asymmetric lipid distributions but also exhibit intriguing asymmetric properties themselves. We propose strategies to advance experimental research, aiming for a deeper, quantitative understanding of membrane asymmetry, which carries profound implications for cellular physiology.
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Affiliation(s)
- Georg Pabst
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria; BioTechMed-Graz, Graz, Austria; Field of Excellence BioHealth, University of Graz, Graz, Austria.
| | - Sandro Keller
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria; BioTechMed-Graz, Graz, Austria; Field of Excellence BioHealth, University of Graz, Graz, Austria
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3
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Eckhardt D, Semeraro EF, Steigenberger J, Schnur J, Kalie L, Massing U, Pabst G, Heerklotz H. Eutectic Resolves Lysolipid Paradox in Thermoresponsive Liposomes. Mol Pharm 2024; 21:1768-1776. [PMID: 38381374 DOI: 10.1021/acs.molpharmaceut.3c01094] [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: 02/22/2024]
Abstract
A better molecular understanding of the temperature-triggered drug release from lysolipid-based thermosensitive liposomes (LTSLs) is needed to overcome the recent setbacks in developing this important drug delivery system. Enhanced drug release was previously rationalized in terms of detergent-like effects of the lysolipid monostearyl lysophosphatidylcholine (MSPC), stabilizing local membrane defects upon LTSL lipid melting. This is highly surprising and here referred to as the 'lysolipid paradox,' because detergents usually induce the opposite effect─they cause leakage upon freezing, not melting. Here, we aim at better answers to (i) why lysolipid does not compromise drug retention upon storage of LTSLs in the gel phase, (ii) how lysolipids can enhance drug release from LTSLs upon lipid melting, and (iii) why LTSLs typically anneal after some time so that not all drug gets released. To this end, we studied the phase transitions of mixtures of dipalmitoylphosphatidylcholine (DPPC) and MSPC by a combination of differential scanning and pressure perturbation calorimetry and identified the phase structures with small- and wide-angle X-ray scattering (SAXS and WAXS). The key result is that LTSLs, which contain the standard amount of 10 mol % MSPC, are at a eutectic point when they release their cargo upon melting at about 41 °C. The eutectic present below 41 °C consists of a MSPC-depleted gel phase as well as small domains of a hydrocarbon chain interdigitated gel phase containing some 30 mol % MSPC. In these interdigitated domains, the lysolipid is stored safely without compromising membrane integrity. At the eutectic temperature, both the MSPC-depleted bilayer and interdigitated MSPC-rich domains melt at once to fluid bilayers, respectively. Intact, fluid membranes tolerate much less MSPC than interdigitated domains─where the latter have melted, the high local MSPC content causes transient pores. These pores allow for fast drug release. However, these pores disappear, and the membrane seals again as the MSPC distributes more evenly over the membrane so that its local concentration decreases below the pore-stabilizing threshold. We provide a pseudobinary phase diagram of the DPPC-MSPC system and structural and volumetric data for the interdigitated phase.
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Affiliation(s)
- Daniel Eckhardt
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Enrico F Semeraro
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- Field of Excellence BioHealth, University of Graz, Graz 8010, Austria
| | - Jessica Steigenberger
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Johannes Schnur
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Louma Kalie
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Ulrich Massing
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
| | - Georg Pabst
- Biophysics, Institute of Molecular Bioscience (IMB), NAWI Graz, University of Graz, Graz 8010, Austria
- Field of Excellence BioHealth, University of Graz, Graz 8010, Austria
| | - Heiko Heerklotz
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg D79104, Germany
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- BIOSS Signaling Research Center, Freiburg D79104, Germany
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4
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Hua L, Kaiser M, Carabadjac I, Meister A, Hause G, Heerklotz H. Vesicle budding caused by lysolipid-induced asymmetry stress. Biophys J 2023; 122:4011-4022. [PMID: 37649254 PMCID: PMC10598287 DOI: 10.1016/j.bpj.2023.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 08/10/2023] [Accepted: 08/28/2023] [Indexed: 09/01/2023] Open
Abstract
Lysolipids such as lauroyl, myristoyl, and palmitoyl lysophosphatidylcholine (LPC) insert into the outer leaflet of liposomes but do not flip to the inner leaflet over many hours. This way, they create asymmetry stress between the intrinsic areas of the two leaflets. We have studied how this stress is relaxed with particular emphasis on the budding and fission of small (diameter 20-30 nm) daughter vesicles (DVs). Asymmetric flow field-flow fractionation was utilized to quantify the extent of budding from large unilamellar vesicles after exposure to LPC. Budding starts at a low threshold of the order of 2 mol% LPC in the outer (and ≈0 mol% LPC in the inner) leaflet. We see reason to assume that the fractional fluorescence intensity from DVs is a good approximation for the fraction of membrane lipid, POPC, transferred into DVs. Accordingly, budding starts with a "budding power" of ≈6 POPC molecules budding off per LPC added, corresponding to a more than 10-fold accumulation of LPC in the outer leaflet of DVs to ≈24 mol%. As long as budding is possible, little strain is built up in the membranes, a claim supported by the lack of changes in limiting fluorescence anisotropy, rotational correlation time, and fluorescence lifetime of symmetrically and asymmetrically inserted TMA-DPH. At physiological osmolarity, budding is typically limited to 20-30% of budded fraction with some batch-to-batch variation, but independent of the LPC species. We hypothesize that the budding limit is determined by the excess area of the liposomes upon preparation, which is then used up upon budding given the larger area-to-volume ratio of smaller liposomes. As the mother vesicles approach ideal spheres, budding must stop. This is qualitatively supported by increased and decreased budding limits of osmotically predeflated and preinflated vesicles, respectively.
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Affiliation(s)
- Lisa Hua
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany.
| | - Michael Kaiser
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany
| | - Iulia Carabadjac
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany
| | - Annette Meister
- ZIK HALOmem and Institute of Biochemistry and Biotechnology, MLU Halle-Wittenberg, Halle, Germany
| | - Gerd Hause
- Biozentrum, MLU Halle-Wittenberg, Halle, Germany
| | - Heiko Heerklotz
- Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany; Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada; Signaling Research Center BIOSS, University of Freiburg, Freiburg, Germany.
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5
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Caritá AC, Cavalcanti RRM, Oliveira MSS, Riske KA. Solubilization of biomimetic lipid mixtures by some commonly used non-ionic detergents. Chem Phys Lipids 2023; 255:105327. [PMID: 37442532 DOI: 10.1016/j.chemphyslip.2023.105327] [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: 04/12/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023]
Abstract
Detergents are amphiphilic molecules often used to solubilize biological membranes and separate their components. Here we investigate the solubilization of lipid vesicles by the commonly used non-ionic detergents polyoxyethylene (20) oleyl ether (Brij 98), n-octyl-β-D-glucoside (OG), and n-dodecyl β-D maltoside (DDM) and compare the results with the standard detergent Triton X-100 (TX-100). The vesicles were composed of palmitoyl oleoyl phosphatidylcholine (POPC) or of a biomimetic ternary mixture of POPC, egg sphingomyelin (SM) and cholesterol (2:1:2 molar ratio). To follow the solubilization profile of large unilamellar vesicles (LUVs), 90° light scattering measurements were done along the titration of LUVs with the detergents. Then, giant unilamellar vesicles (GUVs) were observed with optical microscopy during exposure to the detergents, to allow direct visualization of the solubilization process. Isothermal titration calorimetry (ITC) was used to assess the binding constant of the detergents in POPC bilayers. The results show that the incorporation of TX-100, Brij 98 and, to a lesser extent, OG in the pure POPC liposomes leads to an increase in the vesicle area, which indicates their ability to redistribute between the two leaflets of the membrane in a short scale of time. On the other hand, DDM incorporates mainly in the external leaflet causing an increase in vesicle curvature/tension leading ultimately to vesicle burst. Only TX-100 and OG were able to completely solubilize the POPC vesicles, whereas the biomimetic ternary mixture was partially insoluble in all detergents tested. TX-100 and OG were able to incorporate in the bilayer of the ternary mixture and induce macroscopic phase separation of liquid-ordered (Lo) and liquid-disordered (Ld) domains, with selective solubilization of the latter. Combination of ITC data with turbidity results showed that TX-100 and OG can be incorporated up to almost 0.3 detergent/lipid, significantly more than Brij 98 and DDM. This fact seems to be directly related to their higher capacity to solubilize POPC membranes and their ability to induce macroscopic phase separation in the biomimetic lipid mixture.
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Affiliation(s)
- Amanda C Caritá
- Universidade Federal de São Paulo, Department of Biophysics, São Paulo, Brazil
| | | | | | - Karin A Riske
- Universidade Federal de São Paulo, Department of Biophysics, São Paulo, Brazil.
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6
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Mahler F, Meister A, Vargas C, Durand G, Keller S. Self-Assembly of Protein-Containing Lipid-Bilayer Nanodiscs from Small-Molecule Amphiphiles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2103603. [PMID: 34674382 DOI: 10.1002/smll.202103603] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 08/24/2021] [Indexed: 06/13/2023]
Abstract
When membrane proteins are removed from their natural environment, the quality of the membrane-solubilizing agent used is critical for preserving their native structures and functions. Nanodiscs that retain a lipid-bilayer core around membrane proteins have attracted great attention because they offer a much more native-like environment than detergent micelles. Here, two small-molecule amphiphiles with diglucose headgroups and either a hydrocarbon or a fluorocarbon hydrophobic chain are shown to directly assemble lipids and membrane proteins to form native nanodiscs rather than mixed micelles. Self-assembly of nanodiscs of increasing complexity from both defined, artificial vesicles as well as complex, cellular membranes is demonstrated. A detailed investigation of bilayer integrity and membrane-protein activity in these nanodiscs reveals gentle effects on the encapsulated bilayer core. The fluorinated amphiphile appears particularly promising because its lipophobicity results in gentle, non-perturbing interactions with the nanoscale lipid bilayer. A sequential model of nanodisc self-assembly is proposed that proceeds through perforation of the original membrane followed by saturation and complete solubilization of the bilayer. On this basis, pseudophase diagrams are established for mixtures of lipids and nanodisc-forming diglucoside amphiphiles, and the latter are used for the extraction of a broad range of membrane proteins from cellular membranes.
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Affiliation(s)
- Florian Mahler
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), 67663, Kaiserslautern, Germany
| | - Annette Meister
- HALOmem and Institute of Biochemistry, Martin-Luther-Universität Halle-Wittenberg, 06108, Halle (Saale), Germany
| | - Carolyn Vargas
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), 67663, Kaiserslautern, Germany
- Biophysics, Institute of Molecular Biosciences (IMB), NAWI Graz, University of Graz, Graz, 8010, Austria
- Field of Excellence BioHealth, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Grégory Durand
- Equipe Chimie Bioorganique et Systèmes Amphiphiles, Institut des Biomolécules Max Mousseron, Avignon University, Avignon, 84916, France
- CHEM2STAB, Avignon, 84916, France
| | - Sandro Keller
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), 67663, Kaiserslautern, Germany
- Biophysics, Institute of Molecular Biosciences (IMB), NAWI Graz, University of Graz, Graz, 8010, Austria
- Field of Excellence BioHealth, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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7
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Steigenberger J, Verleysen Y, Geudens N, Martins JC, Heerklotz H. The Optimal Lipid Chain Length of a Membrane-Permeabilizing Lipopeptide Results From the Balance of Membrane Partitioning and Local Damage. Front Microbiol 2021; 12:669709. [PMID: 34594308 PMCID: PMC8476953 DOI: 10.3389/fmicb.2021.669709] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Pseudodesmin A (PSD) is a cyclic lipodepsipeptide produced by Pseudomonas that kills certain bacteria at MIC1/2 in the single micromolar range, probably by permeabilizing their cellular membranes. Synthetic PSD variants, where the native decanoic (C10) acyl chain is varied in length from C4 to C8 and C12 to C14 carbons, were described to be not or less active against a panel of gram-positive strains, as compared to native PSD-C10. Here, we test the membrane-permeabilizing activity of PSD-C4 through PSD-C14 in terms of calcein release from liposomes, which is characterized in detail by the fluorescence-lifetime based leakage assay. Antagonistic concentrations and their chain length dependence agree well for liposome leakage and antimicrobial activity. The optimal chain length is governed by a balance between membrane partitioning (favoring longer chains) and the local perturbation or “damage” inflicted by a membrane-bound molecule (weakening for longer chains). Local perturbation, in turn, may involve at least two modes of action. Asymmetry stress between outer and inner leaflet builds up as the lipopeptides enter the outer leaflet and when it reaches a system-specific stability threshold, it causes a transient membrane failure that allows for the flip of some molecules from the outer to the inner leaflet. This cracking-in may be accompanied by transient, incomplete leakage from the aqueous cores of the liposomes observed, typically, for some seconds or less. The mismatch of the lipopeptide with the lipid leaflet geometry, expressed for example in terms of a spontaneous curvature, has two effects. First, it affects the threshold for transient leakage as described. Second, it controls the rate of equilibrium leakage proceeding as the lipopeptide has reached sufficient local concentrations in both leaflets to form quasi-toroidal defects or pores. Both modes of action, transient and equilibrium leakage, synergize for intermediate chain lengths such as the native, i.e., for PSD-C10. These mechanisms may also account for the reported chain-length dependent specificities of antibiotic action against the target bacteria.
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Affiliation(s)
- Jessica Steigenberger
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg, Freiburg, Germany
| | - Yentl Verleysen
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Niels Geudens
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - José C Martins
- NMR and Structure Analysis Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Heiko Heerklotz
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg, Freiburg, Germany.,Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.,Signaling Research Centers BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
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8
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Evaluation of release and pharmacokinetics of hexadecylphosphocholine (miltefosine) in phosphatidyldiglycerol-based thermosensitive liposomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183698. [PMID: 34283999 DOI: 10.1016/j.bbamem.2021.183698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 12/18/2022]
Abstract
Hexadecylphosphocholine (HePC, Miltefosine) is a drug from the class of alkylphosphocholines with an antineoplastic and antiprotozoal activity. We previously reported that HePC uptake from thermosensitive liposomes (TSL) containing 1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol (DPPG2) into cancer cells is accelerated at mild hyperthermia (HT) resulting in increased cytotoxicity. In this study, we compared HePC release of different TSL formulations in serum. HePC showed rapid but incomplete release below the transition temperature (Tm) of investigated TSL formulations in serum. Short heating (5 min) to 42 °C increased HePC release from DPPG2-TSL (Tm = 41 °C) by a factor of two in comparison to body temperature (37 °C). Bovine serum albumin (BSA) induced HePC release from DPPG2-TSL comparable to serum. Furthermore, multilamellar vesicles (MLV) were capable to extract HePC from DPPG2-TSL in a concentration- and temperature-dependent manner. Repetitive exposure of DPPG2-TSL to MLV at 37 °C led to a fast initial release of HePC which slowed down after subsequent extraction cycles finally reaching approx. 50% HePC release. A pharmacokinetic study in rats revealed a biphasic pattern with an immediate clearance of approx. 50% HePC whereas the remaining 50% HePC showed a prolonged circulation time. We speculate that HePC located in the external leaflet of DPPG2-TSL is rapidly released upon contact with suitable biological acceptors. As demonstrated by MLV transfer experiments, asymmetric incorporation of HePC into the internal leaflet of DPPG2-TSL might improve HePC retention in presence of complex biological media and still give rise to HT-induced HePC release.
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9
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Dalgarno PA, Juan-Colás J, Hedley GJ, Piñeiro L, Novo M, Perez-Gonzalez C, Samuel IDW, Leake MC, Johnson S, Al-Soufi W, Penedo JC, Quinn SD. Unveiling the multi-step solubilization mechanism of sub-micron size vesicles by detergents. Sci Rep 2019; 9:12897. [PMID: 31501469 PMCID: PMC6733941 DOI: 10.1038/s41598-019-49210-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/21/2019] [Indexed: 11/09/2022] Open
Abstract
The solubilization of membranes by detergents is critical for many technological applications and has become widely used in biochemistry research to induce cell rupture, extract cell constituents, and to purify, reconstitute and crystallize membrane proteins. The thermodynamic details of solubilization have been extensively investigated, but the kinetic aspects remain poorly understood. Here we used a combination of single-vesicle Förster resonance energy transfer (svFRET), fluorescence correlation spectroscopy and quartz-crystal microbalance with dissipation monitoring to access the real-time kinetics and elementary solubilization steps of sub-micron sized vesicles, which are inaccessible by conventional diffraction-limited optical methods. Real-time injection of a non-ionic detergent, Triton X, induced biphasic solubilization kinetics of surface-immobilized vesicles labelled with the Dil/DiD FRET pair. The nanoscale sensitivity accessible by svFRET allowed us to unambiguously assign each kinetic step to distortions of the vesicle structure comprising an initial fast vesicle-swelling event followed by slow lipid loss and micellization. We expect the svFRET platform to be applicable beyond the sub-micron sizes studied here and become a unique tool to unravel the complex kinetics of detergent-lipid interactions.
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Affiliation(s)
- Paul A Dalgarno
- SUPA School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK.,Institute of Biological Physics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - José Juan-Colás
- Department of Electronic Engineering, University of York, Heslington, York, YO10 5DD, UK
| | - Gordon J Hedley
- SUPA School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK.,School of Chemistry, University of Glasgow, Glasgow, Scotland, G12 8QQ, United Kingdom
| | - Lucas Piñeiro
- Department of Physical Chemistry, Faculty of Science, University of Santiago de Compostela, Lugo, E-27002, Spain
| | - Mercedes Novo
- Department of Physical Chemistry, Faculty of Science, University of Santiago de Compostela, Lugo, E-27002, Spain
| | - Cibran Perez-Gonzalez
- SUPA School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
| | - Ifor D W Samuel
- SUPA School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
| | - Mark C Leake
- Department of Physics, University of York, Heslington, York, England, YO10 5DD, UK.,Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Steven Johnson
- Department of Electronic Engineering, University of York, Heslington, York, YO10 5DD, UK
| | - Wajih Al-Soufi
- Department of Physical Chemistry, Faculty of Science, University of Santiago de Compostela, Lugo, E-27002, Spain
| | - J Carlos Penedo
- SUPA School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK. .,Biomedical Sciences Research Complex, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, UK.
| | - Steven D Quinn
- SUPA School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK. .,Department of Physics, University of York, Heslington, York, England, YO10 5DD, UK. .,Department of Biology, University of York, Heslington, York, YO10 5DD, UK.
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10
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Lete MG, Monasterio BG, Collado MI, Medina M, Sot J, Alonso A, Goñi FM. Fast and slow biomembrane solubilizing detergents: Insights into their mechanism of action. Colloids Surf B Biointerfaces 2019; 183:110430. [PMID: 31419637 DOI: 10.1016/j.colsurfb.2019.110430] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/15/2019] [Accepted: 08/06/2019] [Indexed: 02/03/2023]
Abstract
Detergents are water-soluble amphiphiles. Above a critical concentration they self-organize in micelles and in the presence of phospholipids mixed micelles are formed. Much information is available on the structure of these self-assemblies and on the thermodynamics of their formation. The aim of this study was to deepen our understanding of the mechanisms of solubilization. Solubilization of lipid vesicles made of egg phosphatidylcholine (PC) by twenty one commercially available, structurally heterogeneous detergents, has been assessed by a decrease in turbidity of the vesicle suspension. Both steady-state and time-resolved measurements have been performed. The results show that the detergents under study fall into one of two categories, namely fast-solubilizing and slow-solubilizing detergents. This categorization is independent of detergent concentration, i.e. a "slow" cannot be converted into a "fast" surfactant by increasing its bulk concentration. 31P-NMR spectra indicate that slow-acting detergents cause either a gradual, monotonic micellization of bilayers (sodium dodecyl sulphate), or formation of more complex, perhaps non-lamellar, non-micellar intermediates (dodecylmaltoside). In contrast, fast detergents (e.g. Triton X-100) cause lysis and reassembly of vesicles before bulk solubilization takes place. These results support the idea that membrane solubilization by detergents is rapid only when surfactant transbilayer (flipping) motion is easy.
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Affiliation(s)
- Marta G Lete
- Instituto Biofisika (UPV/EHU, CSIC), Barrio Sarriena s/n, 48940, Leioa, Spain; Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Bingen G Monasterio
- Instituto Biofisika (UPV/EHU, CSIC), Barrio Sarriena s/n, 48940, Leioa, Spain; Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, Barrio Sarriena s/n, 48940, Leioa, Spain
| | - M Isabel Collado
- SGIKER, Universidad del País Vasco, Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Milagros Medina
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos, Unidades Asociadas BIFI-IQFR and CBsC-CSIC, Universidad de Zaragoza, Zaragoza, Spain
| | - Jesús Sot
- Instituto Biofisika (UPV/EHU, CSIC), Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Alicia Alonso
- Instituto Biofisika (UPV/EHU, CSIC), Barrio Sarriena s/n, 48940, Leioa, Spain; Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Félix M Goñi
- Instituto Biofisika (UPV/EHU, CSIC), Barrio Sarriena s/n, 48940, Leioa, Spain; Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, Barrio Sarriena s/n, 48940, Leioa, Spain.
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11
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Curvophilic-curvophobic balance of monoalkyl-mannosides determines the magnitude of disturbance promoted in synthetic bilayers. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.03.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Hildmann A, Kairaliyeva T, Danker K, Shmanai V, Fainerman V, Miller R. Adsorption characteristics of the alkyl phospholipid Inositol-C2-PAF at the solution/air interface. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.03.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Fan HY, Heerklotz H. Digitonin does not flip across cholesterol-poor membranes. J Colloid Interface Sci 2017; 504:283-293. [DOI: 10.1016/j.jcis.2017.05.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/09/2017] [Accepted: 05/11/2017] [Indexed: 01/18/2023]
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14
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Metola A, Bouchet AM, Alonso-Mariño M, Diercks T, Mäler L, Goñi FM, Viguera AR. Purification and characterization of the colicin A immunity protein in detergent micelles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2181-2192. [PMID: 28803731 DOI: 10.1016/j.bbamem.2017.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/06/2017] [Accepted: 08/09/2017] [Indexed: 11/18/2022]
Abstract
The immunity proteins against pore-forming colicins represent a family of integral membrane proteins that reside in the inner membrane of producing cells. Cai, the colicin A immunity protein, was characterized here in detergent micelles by circular dichroism (CD), size exclusion chromatography, chemical cross-linking, nuclear magnetic resonance (NMR) spectroscopy, cysteine accessibility, and colicin A binding in detergent micelles. Bile-salt derivatives induced extensive protein polymerization that precluded further investigation. The physical characterization of detergent-solubilized protein indicates that phosphate-containing detergents are more efficient in extracting, solubilizing and maintaining Cai in a monomeric state. Yet, their capacity to ensure protein activity, reconstitution, helix packing, and high-quality NMR spectra was inferior to that of milder detergents. Solvent ionic strength and composition greatly modified the solubilizing capacity of milder detergents. Most importantly, binding to the colicin A pore-forming domain (pf-ColA) occurred almost exclusively in sugar-derived detergents. The relative performance of the different detergents in each experiment depends on their impact not only on Cai structure, solubility and oligomerization state, but also on other reaction components and technical aspects. Thus, proteoliposomes were best obtained from protein in LDAO micelles, possibly also due to indirect effects on the lipidic bilayer. The compatibility of a detergent with Cai/pf-ColA complex formation is influenced by its effect on the conformational landscape of each protein, where detergent-mediated pf-ColA denaturation could also lead to negative results. The NMR spectra were greatly affected by the solubility, monodispersity, fold and dynamics of the protein-detergent complexes, and none of those tested here provided NMR spectra of sufficient quality to allow for peak assignment. Cai function could be proven in alkyl glycosides and not in those detergents that afforded the best solubility, reconstitution efficiency or spectral quality indicating that these criteria cannot be taken as unambiguous proof of nativeness without the support of direct activity measurements.
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Affiliation(s)
- Ane Metola
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Ana M Bouchet
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Marian Alonso-Mariño
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Tammo Diercks
- Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Ed. 800, 48160 Derio, Spain
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, The Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
| | - Félix M Goñi
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa. Spain
| | - Ana R Viguera
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain.
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15
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Pizzirusso A, De Nicola A, Sevink GJA, Correa A, Cascella M, Kawakatsu T, Rocco M, Zhao Y, Celino M, Milano G. Biomembrane solubilization mechanism by Triton X-100: a computational study of the three stage model. Phys Chem Chem Phys 2017; 19:29780-29794. [DOI: 10.1039/c7cp03871b] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The solubilization mechanism of lipid membranes in the presence of Triton X-100 (TX-100) is investigated at molecular resolution using hybrid particle field–self consistence field simulations.
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Affiliation(s)
| | - Antonio De Nicola
- Dipartimento di Chimica e Biologia
- Università di Salerno
- Fisciano
- Italy
| | - G. J. Agur Sevink
- Leiden Institute of Chemistry
- Leiden University
- 2300 RA Leiden
- The Netherlands
| | - Andrea Correa
- Department of Chemical Science
- Federico II University of Naples
- 80126 Napoli
- Italy
| | - Michele Cascella
- Department of Chemistry and Hylleraas Centre for Quantum Molecular Sciences
- University of Oslo
- 0371 Oslo
- Norway
| | | | - Mattia Rocco
- Biopolimeri e Proteomica
- Ospedale Policlinico San Martino
- Genova
- Italy
| | - Ying Zhao
- Institute of Nano-Photonics
- School of Physics and Materials Engineering
- Dalian Minzu University
- Dalian 116600
- China
| | | | - Giuseppe Milano
- Dipartimento di Chimica e Biologia
- Università di Salerno
- Fisciano
- Italy
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