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Negi G, Sharma A, Chaudhary M, Parveen N. Disruption Mechanisms of Enveloped Viruses by Ionic and Nonionic Surfactants. J Phys Chem B 2024; 128:768-780. [PMID: 38228291 DOI: 10.1021/acs.jpcb.3c05531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The world has witnessed multiple pandemics and endemics caused by enveloped viruses in the past century. To name a few, the ongoing COVID-19 pandemic and other pandemics/endemics caused by coronaviruses, influenza viruses, HIV-1, etc. The external and topical applications of surfactants have been effective in limiting the spread of viruses. While it is well-known that surfactants inactivate virus particles (virions), the mechanism of action of surfactants against enveloped virions has not yet been established. In this work, we have evaluated the surfactant-induced disruption mechanism of a cocktail of enveloped viruses containing particles of mumps, measles, and rubella viruses. We applied the total internal reflection fluorescence microscopy technique to trace the temporal changes in the fluorescence signal from single virions upon the addition of a surfactant solution. We report that surfactants solubilize either the viral lipid membrane, proteins, or both. Ionic surfactants, depending on their charge and interaction type with the viral lipids and proteins, can cause bursting or perforation of the viral envelope, whereas a nonionic surfactant can cause either symmetric expansion or perforation of the viral envelope depending on the surfactant concentration.
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Affiliation(s)
- Geetanjali Negi
- Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India
| | - Anurag Sharma
- Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India
| | - Monika Chaudhary
- Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India
| | - Nagma Parveen
- Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India
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2
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Conteduca D, Brunetti G, Barth I, Quinn SD, Ciminelli C, Krauss TF. Multiplexed Near-Field Optical Trapping Exploiting Anapole States. ACS NANO 2023; 17:16695-16702. [PMID: 37603833 PMCID: PMC10510711 DOI: 10.1021/acsnano.3c03100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/15/2023] [Indexed: 08/23/2023]
Abstract
Optical tweezers have had a major impact on bioscience research by enabling the study of biological particles with high accuracy. The focus so far has been on trapping individual particles, ranging from the cellular to the molecular level. However, biology is intrinsically heterogeneous; therefore, access to variations within the same population and species is necessary for the rigorous understanding of a biological system. Optical tweezers have demonstrated the ability of trapping multiple targets in parallel; however, the multiplexing capability becomes a challenge when moving toward the nanoscale. Here, we experimentally demonstrate a resonant metasurface that is capable of trapping a high number of nanoparticles in parallel, thereby opening up the field to large-scale multiplexed optical trapping. The unit cell of the metasurface supports an anapole state that generates a strong field enhancement for low-power near-field trapping; importantly, the anapole state is also more angle-tolerant than comparable resonant modes, which allows its excitation with a focused light beam, necessary for generating the required power density and optical forces. We use the anapole state to demonstrate the trapping of 100's of 100 nm polystyrene beads over a 10 min period, as well as the multiplexed trapping of lipid vesicles with a moderate intensity of <250 μW/μm2. This demonstration will enable studies relating to the heterogeneity of biological systems, such as viruses, extracellular vesicles, and other bioparticles at the nanoscale.
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Affiliation(s)
- Donato Conteduca
- School
of Physics, Engineering and Technology, University of York, Heslington, York YO10 5DD, United Kingdom
| | | | - Isabel Barth
- School
of Physics, Engineering and Technology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Steven D. Quinn
- School
of Physics, Engineering and Technology, University of York, Heslington, York YO10 5DD, United Kingdom
- York
Biomedical Research Institute, University
of York, Heslington, York YO10 5DD, United
Kingdom
| | | | - Thomas F. Krauss
- School
of Physics, Engineering and Technology, University of York, Heslington, York YO10 5DD, United Kingdom
- York
Biomedical Research Institute, University
of York, Heslington, York YO10 5DD, United
Kingdom
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3
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Bjørnestad V, Lund R. Pathways of Membrane Solubilization: A Structural Study of Model Lipid Vesicles Exposed to Classical Detergents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:3914-3933. [PMID: 36893452 PMCID: PMC10035035 DOI: 10.1021/acs.langmuir.2c03207] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Understanding the pathways of solubilization of lipid membranes is of high importance for their use in biotechnology and industrial applications. Although lipid vesicle solubilization by classical detergents has been widely investigated, there are few systematic structural and kinetic studies where different detergents are compared under varying conditions. This study used small-angle X-ray scattering to determine the structures of lipid/detergent aggregates at different ratios and temperatures and studied the solubilization in time using the stopped-flow technique. Membranes composed of either of two zwitterionic lipids, DMPC or DPPC, and their interactions with three different detergents, sodium dodecyl sulfate (SDS), n-dodecyl-beta-maltoside (DDM), and Triton X-100 (TX-100), were tested. The detergent TX-100 can cause the formation of collapsed vesicles with a rippled bilayer structure that is highly resistant to TX-100 insertion at low temperatures, while at higher temperatures, it partitions and leads to the restructuring of vesicles. DDM also causes this restructuring into multilamellar structures at subsolubilizing concentrations. In contrast, partitioning of SDS does not alter the vesicle structure below the saturation limit. Solubilization is more efficient in the gel phase for TX-100 but only if the cohesive energy of the bilayer does not prevent sufficient partitioning of the detergent. DDM and SDS show less temperature dependence compared to TX-100. Kinetic measurements reveal that solubilization of DPPC largely occurs through a slow extraction of lipids, whereas DMPC solubilization is dominated by fast and burst-like solubilization of the vesicles. The final structures obtained seem to preferentially be discoidal micelles where the detergent can distribute in excess along the rim of the disc, although we do observe the formation of worm- and rodlike micelles in the case of solubilization of DDM. Our results are in line with the suggested theory that bilayer rigidity is the main factor influencing which aggregate is formed.
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4
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Bjørnestad VA, Soto-Bustamante F, Tria G, Laurati M, Lund R. Beyond the standard model of solubilization: Non-ionic surfactants induce collapse of lipid vesicles into rippled bilamellar nanodiscs. J Colloid Interface Sci 2023; 641:553-567. [PMID: 36958276 DOI: 10.1016/j.jcis.2023.03.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/21/2023] [Accepted: 03/04/2023] [Indexed: 03/11/2023]
Abstract
HYPOTHESIS Although solubilization of lipid membranes has been studied extensively, questions remain regarding the structural pathways and metastable structures involved. This study investigated whether the non-ionic detergent Triton X-100 follows the classical solubilization pathway or if intermediate nanostructures are formed. EXPERIMENTS Small angle X-ray and neutron scattering (SAXS/SANS) was used in combination with transmission electron cryo-microscopy and cryo-tomography to deduce the structure of mixtures of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) vesicles and Triton X-100. Time-resolved SAXS and dynamic light scattering were used to investigate the kinetics of the process. FINDINGS Upon addition of moderate detergent amounts at low temperatures, the lipid vesicles implode into ordered rippled bilamellar disc structures. The bilayers arrange in a ripple phase to accommodate packing constraints caused by inserted TX-100 molecules. The collapse is suggested to occur through a combination of water structure destabilization by detergents flipping across the membrane and osmotic pressure causing interbilayer attraction internally. The subsequently induced ripples then stabilize the aggregates and prevent solubilization, supported by the observation that negatively charged vesicles undergo a different pathway upon TX-100 addition, forming large bicelles. The findings demonstrate the richness in assembly pathways of simple lipids and detergents and stimulate considerations for the use of certain detergents in membrane solubilization.
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Affiliation(s)
| | | | - Giancarlo Tria
- Department of Chemistry and CSGI, University of Florence, Sesto Fiorentino, Italy
| | - Marco Laurati
- Department of Chemistry and CSGI, University of Florence, Sesto Fiorentino, Italy
| | - Reidar Lund
- Department of Chemistry, University of Oslo, Sem Sælandsvei 26, 0371 Oslo, Norway.
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5
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Quinn SD, Dresser L, Graham S, Conteduca D, Shepherd J, Leake MC. Crowding-induced morphological changes in synthetic lipid vesicles determined using smFRET. Front Bioeng Biotechnol 2022; 10:958026. [PMID: 36394015 PMCID: PMC9650091 DOI: 10.3389/fbioe.2022.958026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 10/13/2022] [Indexed: 12/02/2022] Open
Abstract
Lipid vesicles are valuable mesoscale molecular confinement vessels for studying membrane mechanics and lipid–protein interactions, and they have found utility among bio-inspired technologies, including drug delivery vehicles. While vesicle morphology can be modified by changing the lipid composition and introducing fusion or pore-forming proteins and detergents, the influence of extramembrane crowding on vesicle morphology has remained under-explored owing to a lack of experimental tools capable of capturing morphological changes on the nanoscale. Here, we use biocompatible polymers to simulate molecular crowding in vitro, and through combinations of FRET spectroscopy, lifetime analysis, dynamic light scattering, and single-vesicle imaging, we characterize how crowding regulates vesicle morphology. We show that both freely diffusing and surface-tethered vesicles fluorescently tagged with the DiI and DiD FRET pair undergo compaction in response to modest concentrations of sorbitol, polyethylene glycol, and Ficoll. A striking observation is that sorbitol results in irreversible compaction, whereas the influence of high molecular weight PEG-based crowders was found to be reversible. Regulation of molecular crowding allows for precise control of the vesicle architecture in vitro, with vast implications for drug delivery and vesicle trafficking systems. Furthermore, our observations of vesicle compaction may also serve to act as a mechanosensitive readout of extramembrane crowding.
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Affiliation(s)
- Steven D. Quinn
- School of Physics, Engineering and Technology, University of York, York, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom
| | - Lara Dresser
- School of Physics, Engineering and Technology, University of York, York, United Kingdom
| | - Sarah Graham
- School of Physics, Engineering and Technology, University of York, York, United Kingdom
| | - Donato Conteduca
- School of Physics, Engineering and Technology, University of York, York, United Kingdom
| | - Jack Shepherd
- School of Physics, Engineering and Technology, University of York, York, United Kingdom
- Department of Biology, University of York, York, United Kingdom
| | - Mark C. Leake
- School of Physics, Engineering and Technology, University of York, York, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom
- Department of Biology, University of York, York, United Kingdom
- *Correspondence: Mark C. Leake,
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6
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Bertokova A, Svecova N, Kozics K, Gabelova A, Vikartovska A, Jane E, Hires M, Bertok T, Tkac J. Exosomes from prostate cancer cell lines: Isolation optimisation and characterisation. Biomed Pharmacother 2022; 151:113093. [PMID: 35576661 DOI: 10.1016/j.biopha.2022.113093] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/24/2022] [Accepted: 05/04/2022] [Indexed: 11/02/2022] Open
Abstract
Exosomes are considered to be a rich source of biomarkers, hence in this article we examine the best procedure for their isolation. We examine several isolation procedures, exosome storage conditions and other conditions affecting exosome production by prostate cell lines. We selected four different commercially available kits based on different principles to achieve exosome isolation, the best being magnetic-based. In addition, we found storage at - 20 °C to be good for storing isolated exosomes and that exosomes were produced from the cancerous prostate cell line 22Rv1 in much greater amounts than the non-cancerous prostate cell line RWPE1. We also found differences in the response of both cell lines in the production of exosomes as a result of stress, i.e. exposure to hydrogen peroxide and starvation. The effect of Triton X-100 on exosome lysis was examined using two different surfactant concentrations by analysis of the exosome count and change in the exosome size. The final part of the article details the advantages of the use of a 2D biochip prepared in-house over a commercially available 3D biochip for monitoring the interaction of exosomes via its surface receptors (CD63) with an immobilised ligand (anti-CD63 antibodies) using surface plasmon resonance. The final experiment shows the potential of lectin fluorescent microarrays for the analysis of glycans present in lysed exosomes.
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Affiliation(s)
- Aniko Bertokova
- Glycanostics, Ltd., Kudlákova 7, Bratislava 841 01, Slovak Republic
| | - Natalia Svecova
- Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 845 38, Slovak Republic
| | - Katarina Kozics
- Biomedical Research Centre, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovak Republic
| | - Alena Gabelova
- Biomedical Research Centre, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovak Republic
| | - Alica Vikartovska
- Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 845 38, Slovak Republic
| | - Eduard Jane
- Glycanostics, Ltd., Kudlákova 7, Bratislava 841 01, Slovak Republic; Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 845 38, Slovak Republic
| | - Michal Hires
- Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 845 38, Slovak Republic
| | - Tomas Bertok
- Glycanostics, Ltd., Kudlákova 7, Bratislava 841 01, Slovak Republic; Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 845 38, Slovak Republic
| | - Jan Tkac
- Glycanostics, Ltd., Kudlákova 7, Bratislava 841 01, Slovak Republic; Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 845 38, Slovak Republic.
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7
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Dresser L, Graham SP, Miller LM, Schaefer C, Conteduca D, Johnson S, Leake MC, Quinn SD. Tween-20 Induces the Structural Remodeling of Single Lipid Vesicles. J Phys Chem Lett 2022; 13:5341-5350. [PMID: 35678387 PMCID: PMC9208007 DOI: 10.1021/acs.jpclett.2c00704] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/31/2022] [Indexed: 05/04/2023]
Abstract
The solubilization of lipid membranes by Tween-20 is crucial for a number of biotechnological applications, but the mechanistic details remain elusive. Evidence from ensemble assays supports a solubilization model that encompasses surfactant association with the membrane and the release of mixed micelles to solution, but whether this process also involves intermediate transitions between regimes is unanswered. In search of mechanistic origins, increasing focus is placed on identifying Tween-20 interactions with controllable membrane mimetics. Here, we employed ultrasensitive biosensing approaches, including single-vesicle spectroscopy based on fluorescence and energy transfer from membrane-encapsulated molecules, to interrogate interactions between Tween-20 and submicrometer-sized vesicles below the optical diffraction limit. We discovered that Tween-20, even at concentrations below the critical micellar concentration, triggers stepwise and phase-dependent structural remodeling events, including permeabilization and swelling, in both freely diffusing and surface-tethered vesicles, highlighting the substantial impact the surfactant has on vesicle conformation and stability prior to lysis.
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Affiliation(s)
- Lara Dresser
- Department
of Physics, University of York, York YO10 5DD, U.K.
| | - Sarah P. Graham
- Department
of Physics, University of York, York YO10 5DD, U.K.
| | - Lisa M. Miller
- Department
of Electronic Engineering, University of
York, York YO10 5DD, U.K.
| | | | | | - Steven Johnson
- Department
of Electronic Engineering, University of
York, York YO10 5DD, U.K.
- York
Biomedical Research Institute, University
of York, York YO10 5DD, U.K.
| | - Mark C. Leake
- Department
of Physics, University of York, York YO10 5DD, U.K.
- Department
of Biology, University of York, York YO10 5DD, U.K.
- York
Biomedical Research Institute, University
of York, York YO10 5DD, U.K.
| | - Steven D. Quinn
- Department
of Physics, University of York, York YO10 5DD, U.K.
- York
Biomedical Research Institute, University
of York, York YO10 5DD, U.K.
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8
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Gordon F, Casamayou-Boucau Y, Ryder AG. Evaluating the interaction of human serum albumin (HSA) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes in different aqueous environments using anisotropy resolved multi-dimensional emission spectroscopy (ARMES). Colloids Surf B Biointerfaces 2022; 211:112310. [PMID: 35007857 DOI: 10.1016/j.colsurfb.2021.112310] [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: 08/10/2021] [Revised: 12/09/2021] [Accepted: 12/26/2021] [Indexed: 11/28/2022]
Abstract
Studying the interaction between plasma proteins and liposomes is critical, particularly for their use as drug delivery systems. Here, the efficacy of anisotropy resolved multidimensional emission spectroscopy (ARMES) for investigating the interaction of human serum albumin (HSA) with liposomes was explored and compared to conventional spectroscopic techniques. Dynamic Light Scattering (DLS) and absorbance spectroscopy (with Multivariate Curve Resolution (MCR) modeling) indicated that the highest degree of liposome rupturing, and aggregation occurred in water, with less in ammonium bicarbonate buffer (ABC) and phosphate buffered saline (PBS). Fluorescence emission spectra of HSA-liposome mixtures revealed significant hypsochromic shifts for water and ABC, but much less in PBS, where the data suggests a non-penetrating protein layer was formed. Average fluorescence lifetimes decreased upon liposome interaction in water (6.2→5.2 ns) and ABC buffer (6.3→5.6 ns) but increased slightly for PBS (5.6→5.8 ns). ARMES using polarized Total Synchronous Fluorescence Scan measurements with parallel factor (PARAFAC) analysis resolved intrinsic HSA fluorescence into two components for interactions in water and ABC buffer, but only one component for PBS. These components, in water and ABC buffer, corresponded to two different HSA populations, one blue-shifted and penetrating the liposomes (λex/em = ~ 280/320 nm) and a second, similar to free HSA in solution (λex/em = ~ 282/356 nm). PARAFAC scores for water and ABC buffer suggested that a large proportion of HSA interacted in an end on configuration. ARMES provides a new way for investigating protein-liposome interactions that exploits the full intrinsic emission space of the protein and thus avoids the use of extrinsic labels. The use of multivariate data analysis provided a comprehensive and structured framework to extract a variety of useful information (resolving different fluorescent species, quantifying their signal contribution, and extracting light scatter signals) all of which can be used to discriminate between interaction mechanisms.
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Affiliation(s)
- Fiona Gordon
- Nanoscale BioPhotonics Laboratory, School of Chemistry, National University of Ireland, Galway, Galway H91 CF50, Ireland
| | - Yannick Casamayou-Boucau
- Nanoscale BioPhotonics Laboratory, School of Chemistry, National University of Ireland, Galway, Galway H91 CF50, Ireland
| | - Alan G Ryder
- Nanoscale BioPhotonics Laboratory, School of Chemistry, National University of Ireland, Galway, Galway H91 CF50, Ireland.
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9
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Supported Lipid Bilayer Platform for Characterizing the Membrane-Disruptive Behaviors of Triton X-100 and Potential Detergent Replacements. Int J Mol Sci 2022; 23:ijms23020869. [PMID: 35055053 PMCID: PMC8775805 DOI: 10.3390/ijms23020869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/08/2022] [Accepted: 01/12/2022] [Indexed: 02/07/2023] Open
Abstract
Triton X-100 (TX-100) is a widely used detergent to prevent viral contamination of manufactured biologicals and biopharmaceuticals, and acts by disrupting membrane-enveloped virus particles. However, environmental concerns about ecotoxic byproducts are leading to TX-100 phase out and there is an outstanding need to identify functionally equivalent detergents that can potentially replace TX-100. To date, a few detergent candidates have been identified based on viral inactivation studies, while direct mechanistic comparison of TX-100 and potential replacements from a biophysical interaction perspective is warranted. Herein, we employed a supported lipid bilayer (SLB) platform to comparatively evaluate the membrane-disruptive properties of TX-100 and a potential replacement, Simulsol SL 11W (SL-11W), and identified key mechanistic differences in terms of how the two detergents interact with phospholipid membranes. Quartz crystal microbalance-dissipation (QCM-D) measurements revealed that TX-100 was more potent and induced rapid, irreversible, and complete membrane solubilization, whereas SL-11W caused more gradual, reversible membrane budding and did not induce extensive membrane solubilization. The results further demonstrated that TX-100 and SL-11W both exhibit concentration-dependent interaction behaviors and were only active at or above their respective critical micelle concentration (CMC) values. Collectively, our findings demonstrate that TX-100 and SL-11W have distinct membrane-disruptive effects in terms of potency, mechanism of action, and interaction kinetics, and the SLB platform approach can support the development of biophysical assays to efficiently test potential TX-100 replacements.
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10
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Božič D, Hočevar M, Kisovec M, Pajnič M, Pađen L, Jeran M, Bedina Zavec A, Podobnik M, Kogej K, Iglič A, Kralj-Iglič V. Stability of Erythrocyte-Derived Nanovesicles Assessed by Light Scattering and Electron Microscopy. Int J Mol Sci 2021; 22:ijms222312772. [PMID: 34884574 PMCID: PMC8657685 DOI: 10.3390/ijms222312772] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/12/2021] [Accepted: 11/22/2021] [Indexed: 12/12/2022] Open
Abstract
Extracellular vesicles (EVs) are gaining increasing amounts of attention due to their potential use in diagnostics and therapy, but the poor reproducibility of the studies that have been conducted on these structures hinders their breakthrough into routine practice. We believe that a better understanding of EVs stability and methods to control their integrity are the key to resolving this issue. In this work, erythrocyte EVs (hbEVs) were isolated by centrifugation from suspensions of human erythrocytes that had been aged in vitro. The isolate was characterised by scanning (SEM) and cryo-transmission electron microscopy (cryo-TEM), flow cytometry (FCM), dynamic/static light scattering (LS), protein electrophoresis, and UV-V spectrometry. The hbEVs were exposed to various conditions (pH (4–10), osmolarity (50–1000 mOsm/L), temperature (15–60 °C), and surfactant Triton X-100 (10–500 μM)). Their stability was evaluated by LS by considering the hydrodynamic radius (Rh), intensity of scattered light (I), and the shape parameter (ρ). The morphology of the hbEVs that had been stored in phosphate-buffered saline with citrate (PBS–citrate) at 4 °C remained consistent for more than 6 months. A change in the media properties (50–1000 mOsm/L, pH 4–10) had no significant effect on the Rh (=100–130 nm). At pH values below 6 and above 8, at temperatures above 45 °C, and in the presence of Triton X-100, hbEVs degradation was indicated by a decrease in I of more than 20%. Due to the simple preparation, homogeneous morphology, and stability of hbEVs under a wide range of conditions, they are considered to be a suitable option for EV reference material.
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Affiliation(s)
- Darja Božič
- Laboratory of Clinical Biophysics, Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (D.B.); (M.P.); (L.P.); (M.J.)
| | - Matej Hočevar
- Department of Physics and Chemistry of Materials, Institute of Metals and Technology, SI-1000 Ljubljana, Slovenia;
| | - Matic Kisovec
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (M.K.); (A.B.Z.); (M.P.)
| | - Manca Pajnič
- Laboratory of Clinical Biophysics, Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (D.B.); (M.P.); (L.P.); (M.J.)
| | - Ljubiša Pađen
- Laboratory of Clinical Biophysics, Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (D.B.); (M.P.); (L.P.); (M.J.)
| | - Marko Jeran
- Laboratory of Clinical Biophysics, Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (D.B.); (M.P.); (L.P.); (M.J.)
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
| | - Apolonija Bedina Zavec
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (M.K.); (A.B.Z.); (M.P.)
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (M.K.); (A.B.Z.); (M.P.)
| | - Ksenija Kogej
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
- Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Veronika Kralj-Iglič
- Laboratory of Clinical Biophysics, Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (D.B.); (M.P.); (L.P.); (M.J.)
- Correspondence: ; Tel.: +386-4172-0766
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11
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Dienerowitz M, Howard JAL, Quinn SD, Dienerowitz F, Leake MC. Single-molecule FRET dynamics of molecular motors in an ABEL trap. Methods 2021; 193:96-106. [PMID: 33571667 DOI: 10.1016/j.ymeth.2021.01.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/22/2021] [Accepted: 01/29/2021] [Indexed: 02/07/2023] Open
Abstract
Single-molecule Förster resonance energy transfer (smFRET) of molecular motors provides transformative insights into their dynamics and conformational changes both at high temporal and spatial resolution simultaneously. However, a key challenge of such FRET investigations is to observe a molecule in action for long enough without restricting its natural function. The Anti-Brownian ELectrokinetic Trap (ABEL trap) sets out to combine smFRET with molecular confinement to enable observation times of up to several seconds while removing any requirement of tethered surface attachment of the molecule in question. In addition, the ABEL trap's inherent ability to selectively capture FRET active molecules accelerates the data acquisition process. In this work we exemplify the capabilities of the ABEL trap in performing extended timescale smFRET measurements on the molecular motor Rep, which is crucial for removing protein blocks ahead of the advancing DNA replication machinery and for restarting stalled DNA replication. We are able to monitor single Rep molecules up to 6 seconds with sub-millisecond time resolution capturing multiple conformational switching events during the observation time. Here we provide a step-by-step guide for the rational design, construction and implementation of the ABEL trap for smFRET detection of Rep in vitro. We include details of how to model the electric potential at the trap site and use Hidden Markov analysis of the smFRET trajectories.
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Affiliation(s)
- Maria Dienerowitz
- Single-Molecule Microscopy Group, Universitätsklinikum Jena, Nonnenplan 2 - 4, 07743 Jena, Germany.
| | - Jamieson A L Howard
- Department of Physics, University of York, Heslington, York YO10 5DD, UK; Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Steven D Quinn
- Department of Physics, University of York, Heslington, York YO10 5DD, UK; York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, UK
| | - Frank Dienerowitz
- Ernst-Abbe-Hochschule Jena, University of Applied Sciences, Carl-Zeiss-Promenade 2, 07745 Jena, Germany
| | - Mark C Leake
- Department of Physics, University of York, Heslington, York YO10 5DD, UK; Department of Biology, University of York, Heslington, York YO10 5DD, UK; York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, UK
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Come B, Donato M, Potenza LF, Mariani P, Itri R, Spinozzi F. The intriguing role of rhamnolipids on plasma membrane remodelling: From lipid rafts to membrane budding. J Colloid Interface Sci 2021; 582:669-677. [DOI: 10.1016/j.jcis.2020.08.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/24/2020] [Accepted: 08/06/2020] [Indexed: 01/26/2023]
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Juan-Colás J, Dresser L, Morris K, Lagadou H, Ward RH, Burns A, Tear S, Johnson S, Leake MC, Quinn SD. The Mechanism of Vesicle Solubilization by the Detergent Sodium Dodecyl Sulfate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:11499-11507. [PMID: 32870686 DOI: 10.1021/acs.langmuir.0c01810] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Membrane solubilization by sodium dodecyl sulfate (SDS) is indispensable for many established biotechnological applications, including viral inactivation and protein extraction. Although the ensemble thermodynamics have been thoroughly explored, the underlying molecular dynamics have remained inaccessible, owing to major limitations of traditional measurement tools. Here, we integrate multiple advanced biophysical approaches to gain multiangle insight into the time-dependence and fundamental kinetic steps associated with the solubilization of single submicron sized vesicles in response to SDS. We find that the accumulation of SDS molecules on intact vesicles triggers biphasic solubilization kinetics comprising an initial vesicle expansion event followed by rapid lipid loss and micellization. Our findings support a general mechanism of detergent-induced membrane solubilization, and we expect that the framework of correlative biophysical technologies presented here will form a general platform for elucidating the complex kinetics of membrane perturbation induced by a wide variety of surfactants and disrupting agents.
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Affiliation(s)
- José Juan-Colás
- Department of Electronic Engineering, University of York, Heslington, York YO10 5DD, U.K
| | - Lara Dresser
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
| | - Katie Morris
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
| | - Hugo Lagadou
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
| | - Rebecca H Ward
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
| | - Amy Burns
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
| | - Steve Tear
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
| | - Steven Johnson
- Department of Electronic Engineering, University of York, Heslington, York YO10 5DD, U.K
- York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, U.K
| | - Mark C Leake
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
- Department of Biology, University of York, Heslington, York YO10 5DD, U.K
- York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, U.K
| | - Steven D Quinn
- Department of Physics, University of York, Heslington, York YO10 5DD, U.K
- York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, U.K
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