1
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Kim SY, Guk D, Jeong Y, Kim E, Kim H, Kim ST. Engineered Hybrid Vesicles and Cellular Internalization in Mammary Cancer Cells. Pharmaceutics 2024; 16:440. [PMID: 38675102 PMCID: PMC11054022 DOI: 10.3390/pharmaceutics16040440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/22/2024] [Accepted: 03/19/2024] [Indexed: 04/28/2024] Open
Abstract
Extracellular vesicles play an important role in intercellular communication, with the potential to serve as biomaterials for nanocarriers. Combining such extracellular vesicles and liposomes results in advanced drug delivery carriers. In this study, we attempted to fabricate hybrid vesicles using a membrane fusion method and incorporated an anticancer drug. As a result, we successfully prepared nanosized uniform hybrid vesicles and evaluated their physicochemical characteristics and intracellular uptake mechanisms via endocytosis in various cell lines. Compared to liposomes, the hybrid vesicles showed better physical properties and a relatively higher reduction in cell viability, which was presumably dependent on the specific cell type. These findings suggest that fusion-based hybrid vesicles offer a novel strategy for delivering therapeutic agents and provide insights into the types of extracellular vesicles that are useful in fabricating hybrid vesicles to develop an advanced drug delivery system.
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Affiliation(s)
- So Yun Kim
- Department of Nanoscience and Engineering, Inje University, Gimhae 50834, Republic of Korea; (S.Y.K.); (E.K.); (H.K.)
| | - Dagyeong Guk
- Center for Advanced Biomolecular Recognition, KIST Biomedical Research Division, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; (D.G.); (Y.J.)
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
| | - Youngdo Jeong
- Center for Advanced Biomolecular Recognition, KIST Biomedical Research Division, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; (D.G.); (Y.J.)
- HY-KIST Department of Bioconvergence, Hanyang University, Seoul 04763, Republic of Korea
| | - Eunji Kim
- Department of Nanoscience and Engineering, Inje University, Gimhae 50834, Republic of Korea; (S.Y.K.); (E.K.); (H.K.)
| | - Hansol Kim
- Department of Nanoscience and Engineering, Inje University, Gimhae 50834, Republic of Korea; (S.Y.K.); (E.K.); (H.K.)
- Department of Pharmaceutical Engineering, Inje University, Gimhae 50834, Republic of Korea
| | - Sung Tae Kim
- Department of Nanoscience and Engineering, Inje University, Gimhae 50834, Republic of Korea; (S.Y.K.); (E.K.); (H.K.)
- Department of Pharmaceutical Engineering, Inje University, Gimhae 50834, Republic of Korea
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2
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Tero R, Hagiwara Y, Saito S. Domain Localization by Graphene Oxide in Supported Lipid Bilayers. Int J Mol Sci 2023; 24:ijms24097999. [PMID: 37175707 PMCID: PMC10178265 DOI: 10.3390/ijms24097999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 04/13/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
The gel-phase domains in a binary supported lipid bilayer (SLB) comprising dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) were localized on graphene oxide (GO) deposited on a SiO2/Si substrate. We investigated the distribution of the gel-phase domains and the liquid crystalline (Lα) phase regions in DOPC+DPPC-SLB on thermally oxidized SiO2/Si substrates with GO flakes to understand the mechanism of the domain localization on GO. Fluorescence microscopy and atomic force microscopy revealed that the gel-phase domains preferably distributed on GO flakes, whereas the fraction of the Lα-phase increased on the bare SiO2 surface which was not covered with the GO flakes. The gel-phase domain was condensed on GO more effectively at the lower cooling rate. We propose that nucleation of the gel-phase domain preferentially occurred on GO, whose surface has amphiphilic property, during the gel-phase domain formation. The domains of the liquid ordered (Lo) phase were also condensed on GO in a ternary bilayer containing cholesterol that was phase-separated to the Lo phase and the liquid disordered phase. Rigid domains segregates on GO during their formation process, leaving fluid components to the surrounding region of GO.
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Affiliation(s)
- Ryugo Tero
- Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan
| | - Yoshi Hagiwara
- Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan
| | - Shun Saito
- Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan
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3
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Alvarez AB, Caruso B, Petersen SB, Rodríguez PEA, Fidelio GD. Melittin-solid phospholipid mixed films trigger amyloid-like nano-fibril arrangements at air-water interface. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184048. [PMID: 36115495 DOI: 10.1016/j.bbamem.2022.184048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 08/22/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
We used the Langmuir monolayers technique to study the surface properties of melittin toxin mixed with either liquid-condensed DSPC or liquid-expanded POPC phospholipids. Pure melittin peptide forms stable insoluble monolayers at the air-water interface without interacting with Thioflavin T (Th-T), a sensitive probe to detect protein amyloid formation. When melittin peptide is mixed with DSPC lipid at 50 % of peptide area proportion at the surface, we observed the formation of fibril-like structures detected by Brewster angle microscopy (BAM), but they were not observable with POPC. The nano-structures in the melittin-DSPC mixtures became Th-T positive labeling when the arrangement was observed with fluorescence microscopy. In this condition, Th-T undergoes an unexpected shift in the typical emission wavelength of this amyloid marker when a 2D fluorescence analysis is conducted. Even when reflectivity analysis of BAM imaging evidenced that these structures would correspond to the DSPC lipid component of the mixture, the interpretation of ATR-FTIR and Th-T data suggested that both components were involved in a new lipid-peptide rearrangement. These nano-fibril arrangements were also evidenced by scanning electron and atomic force microscopy when the films were transferred to a mica support. The fibril formation was not detected when melittin was mixed with the liquid-expanded POPC lipid. We postulated that DSPC lipids can dynamically trigger the process of amyloid-like nano-arrangement formation at the interface. This process is favored by the relative peptide content, the quality of the interfacial environment, and the physical state of the lipid at the surface.
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Affiliation(s)
- Alain Bolaño Alvarez
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina; Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Argentina
| | - Benjamín Caruso
- Cátedra de Química Biológica, Departamento de Química, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT), CONICET, Universidad Nacional de Córdoba. Córdoba, Argentina
| | | | | | - Gerardo D Fidelio
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina; Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Argentina.
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4
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Bespalova M, Öz R, Westerlund F, Krishnan M. Single-Molecule Trapping and Measurement in a Nanostructured Lipid Bilayer System. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13923-13934. [PMID: 36326814 PMCID: PMC9671048 DOI: 10.1021/acs.langmuir.2c02203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 10/15/2022] [Indexed: 06/16/2023]
Abstract
The repulsive electrostatic force between a biomolecule and a like-charged surface can be geometrically tailored to create spatial traps for charged molecules in solution. Using a parallel-plate system composed of silicon dioxide surfaces, we recently demonstrated single-molecule trapping and high precision molecular charge measurements in a nanostructured free energy landscape. Here we show that surfaces coated with charged lipid bilayers provide a system with tunable surface properties for molecular electrometry experiments. Working with molecular species whose effective charge and geometry are well-defined, we demonstrate the ability to quantitatively probe the electrical charge density of a supported lipid bilayer. Our findings indicate that the fraction of charged lipids in nanoslit lipid bilayers can be significantly different from that in the precursor lipid mixtures used to generate them. We also explore the temporal stability of bilayer properties in nanofluidic systems. Beyond their relevance in molecular measurement, such experimental systems offer the opportunity to examine lipid bilayer formation and wetting dynamics on nanostructured surfaces.
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Affiliation(s)
- Maria Bespalova
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OxfordOX1 3QZ, United Kingdom
| | - Robin Öz
- Department
of Biology and Biological Engineering, Chalmers
University of Technology, 412 96Gothenburg, Sweden
| | - Fredrik Westerlund
- Department
of Biology and Biological Engineering, Chalmers
University of Technology, 412 96Gothenburg, Sweden
| | - Madhavi Krishnan
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OxfordOX1 3QZ, United Kingdom
- The
Kavli Institute for Nanoscience Discovery, Sherrington Road, OxfordOX1 3QU, United Kingdom
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5
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Sfera A, Hazan S, Anton JJ, Sfera DO, Andronescu CV, Sasannia S, Rahman L, Kozlakidis Z. Psychotropic drugs interaction with the lipid nanoparticle of COVID-19 mRNA therapeutics. Front Pharmacol 2022; 13:995481. [PMID: 36160443 PMCID: PMC9503827 DOI: 10.3389/fphar.2022.995481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/09/2022] [Indexed: 11/18/2022] Open
Abstract
The messenger RNA (mRNA) vaccines for COVID-19, Pfizer-BioNTech and Moderna, were authorized in the US on an emergency basis in December of 2020. The rapid distribution of these therapeutics around the country and the world led to millions of people being vaccinated in a short time span, an action that decreased hospitalization and death but also heightened the concerns about adverse effects and drug-vaccine interactions. The COVID-19 mRNA vaccines are of particular interest as they form the vanguard of a range of other mRNA therapeutics that are currently in the development pipeline, focusing both on infectious diseases as well as oncological applications. The Vaccine Adverse Event Reporting System (VAERS) has gained additional attention during the COVID-19 pandemic, specifically regarding the rollout of mRNA therapeutics. However, for VAERS, absence of a reporting platform for drug-vaccine interactions left these events poorly defined. For example, chemotherapy, anticonvulsants, and antimalarials were documented to interfere with the mRNA vaccines, but much less is known about the other drugs that could interact with these therapeutics, causing adverse events or decreased efficacy. In addition, SARS-CoV-2 exploitation of host cytochrome P450 enzymes, reported in COVID-19 critical illness, highlights viral interference with drug metabolism. For example, patients with severe psychiatric illness (SPI) in treatment with clozapine often displayed elevated drug levels, emphasizing drug-vaccine interaction.
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Affiliation(s)
- Adonis Sfera
- Patton State Hospital, San Bernardino, CA, United States
- Department of Psychiatry, University of California, Riverside, Riverside, CA, United States
| | - Sabine Hazan
- Department of Psychiatry, University of California, Riverside, Riverside, CA, United States
| | - Jonathan J. Anton
- Patton State Hospital, San Bernardino, CA, United States
- Department of Biology, California Baptist University, Riverside, CA, United States
| | - Dan O. Sfera
- Patton State Hospital, San Bernardino, CA, United States
| | | | | | - Leah Rahman
- Department of Medicine, University of Oregon, Eugene, OR, United States
| | - Zisis Kozlakidis
- International Agency For Research On Cancer (IARC), Lyon, France
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6
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Altunayar-Unsalan C, Unsalan O, Mavromoustakos T. Molecular interactions of hesperidin with DMPC/cholesterol bilayers. Chem Biol Interact 2022; 366:110131. [PMID: 36037876 DOI: 10.1016/j.cbi.2022.110131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/05/2022] [Accepted: 08/20/2022] [Indexed: 11/03/2022]
Abstract
Since cell membranes are complex systems, the use of model lipid bilayers is quite important for the study of their interactions with bioactive molecules. Mammalian cell membranes require cholesterol (CHOL) for their structure and function. For this reason, the mixtures of phospholipid and cholesterol are necessary to use in model membrane studies to better simulate the real systems. In the present study, we investigated the effect of the incorporation of hesperidin in model membranes consisting of dimyristoylphosphatidylcholine (DMPC) and CHOL by using differential scanning calorimetry (DSC), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and atomic force microscopy (AFM). ATR-FTIR results demonstrated that hesperidin increases the fluidity of the DMPC/CHOL binary system. DSC findings indicated that the presence of 5 mol% hesperidin induces a broadening of the main phase transition consisting of three overlapping components. AFM experiments showed that hesperidin increases the thickness of DMPC/CHOL lipid bilayer model membranes. In addition to experimental results, molecular docking studies were conducted with hesperidin and human lanosterol synthase (LS), which is an enzyme found in the final step of cholesterol synthesis, to characterize hesperidin's interactions with its surrounding via its hydroxyl and oxygen groups. Then, hesperidin's ADME/Tox (absorption, distribution, metabolism, excretion and toxicity) profile was computed to see the potential impact on living system. In conclusion, considering the data obtained from experimental studies, this work ensures molecular insights in the interaction between a flavonoid, as an antioxidant drug model, and lipids mimicking those found in mammalian membranes. Moreover, computational studies demonstrated that hesperidin may be a great potential for use as a therapeutic agent for hypercholesterolemia due to its antioxidant property.
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Affiliation(s)
- Cisem Altunayar-Unsalan
- Ege University Central Research Testing and Analysis Laboratory Research and Application Center, 35100, Bornova, Izmir, Turkey.
| | - Ozan Unsalan
- Ege University, Faculty of Science, Department of Physics, 35100, Bornova, Izmir, Turkey.
| | - Thomas Mavromoustakos
- Section of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, 15771, Greece.
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7
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Yang F, Baldelli S. Chemical Imaging of Lipid Segregation: Determining Different Length Scales of Heterogeneity with Compressive-Sensing Sum Frequency Generation Microscopy and Brewster Angle Microscopy. J Phys Chem B 2022; 126:5637-5645. [DOI: 10.1021/acs.jpcb.2c03493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fangyuan Yang
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
| | - Steven Baldelli
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
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8
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Hammond K, Moffat J, Mulcahy C, Hoogenboom BW, Ryadnov MG. In situ nanoscale imaging reveals self-concentrating nanomolar antimicrobial pores. NANOSCALE 2022; 14:8586-8593. [PMID: 35574721 DOI: 10.1039/d2nr00434h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Host defence peptides are critical factors of immune systems in all life forms. Considered for therapeutic development in the post-antibiotic era, these molecules rupture microbial membranes at micromolar concentrations. Here we report a self-concentrating mechanism of membrane disruption, which occurs at therapeutically more relevant nanomolar concentrations. Induced by a four-helix bacteriocin the mechanism manifests in a multi-modal disruption pattern. Using in situ atomic force microscopy we show that the pattern and its kinetic profiles remain the same in a range of nano-to-micromolar concentrations. We reveal that the bacteriocin creates its own boundaries in phospholipid bilayers in which it self-concentrates to promote transmembrane poration. The findings offer an exploitable insight into nanomolar antimicrobial mechanisms.
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Affiliation(s)
- Katharine Hammond
- National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, UK.
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Department of Physics & Astronomy, University College London, London WC1E 6BT, UK
| | - Jonathan Moffat
- Oxford Instruments Asylum Research, Halifax Road, High Wycombe, HP12 3SE, UK
| | - Chris Mulcahy
- Oxford Instruments Asylum Research, Halifax Road, High Wycombe, HP12 3SE, UK
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
- Department of Physics & Astronomy, University College London, London WC1E 6BT, UK
| | - Maxim G Ryadnov
- National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, UK.
- Department of Physics, King's College London, London, WC2R 2LS, UK
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9
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Gabriunaite I, Valiuniene A, Ramanavicius S, Ramanavicius A. Biosensors Based on Bio-Functionalized Semiconducting Metal Oxides. Crit Rev Anal Chem 2022; 54:549-564. [PMID: 35714203 DOI: 10.1080/10408347.2022.2088226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Immobilization of biomaterials is a very important task in the development of biofuel cells and biosensors. Some semiconducting metal-oxide-based supporting materials can be used in these bioelectronics-based devices. In this article, we are reviewing some functionalization methods that are applied for the immobilization of biomaterials. The most significant attention is paid to the immobilization of biomolecules on the surface of semiconducting metal oxides. The improvement of biomaterials immobilization on metal oxides and analytical performance of biosensors by coatings based on conducting polymers, self-assembled monolayers and lipid membranes is discussed.
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Affiliation(s)
- Inga Gabriunaite
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Vilnius, Lithuania
| | - Ausra Valiuniene
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Vilnius, Lithuania
| | - Simonas Ramanavicius
- Centre for Physical Sciences and Technology, Department of Electrochemical Material Science, Vilnius, Lithuania
| | - Arunas Ramanavicius
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Vilnius, Lithuania
- Centre for Physical Sciences and Technology, Department of Electrochemical Material Science, Vilnius, Lithuania
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10
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Iriarte-Alonso MA, Bittner AM, Chiantia S. Influenza A virus hemagglutinin prevents extensive membrane damage upon dehydration. BBA ADVANCES 2022; 2:100048. [PMID: 37082591 PMCID: PMC10074934 DOI: 10.1016/j.bbadva.2022.100048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
While the molecular mechanisms of virus infectivity are rather well known, the detailed consequences of environmental factors on virus biophysical properties are poorly understood. Seasonal influenza outbreaks are usually connected to the low winter temperature, but also to the low relative air humidity. Indeed, transmission rates increase in cold regions during winter. While low temperature must slow degradation processes, the role of low humidity is not clear. We studied the effect of relative humidity on a model of Influenza A H1N1 virus envelope, a supported lipid bilayer containing the surface glycoprotein hemagglutinin (HA), which is present in the viral envelope in very high density. For complete cycles of hydration, dehydration and rehydration, we evaluate the membrane properties in terms of structure and dynamics, which we assess by combining confocal fluorescence microscopy, raster image correlation spectroscopy, line-scan fluorescence correlation spectroscopy and atomic force microscopy. Our findings indicate that the presence of HA prevents macroscopic membrane damage after dehydration. Without HA, fast membrane disruption is followed by irreversible loss of lipid and protein mobility. Although our model is principally limited by the membrane composition, the macroscopic effects of HA under dehydration stress reveal new insights on the stability of the virus at low relative humidity.
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11
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Chattopadhyay M, Krok E, Orlikowska H, Schwille P, Franquelim HG, Piatkowski L. Hydration Layer of Only a Few Molecules Controls Lipid Mobility in Biomimetic Membranes. J Am Chem Soc 2021; 143:14551-14562. [PMID: 34342967 PMCID: PMC8447254 DOI: 10.1021/jacs.1c04314] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
![]()
Self-assembly of
biomembranes results from the intricate interactions
between water and the lipids’ hydrophilic head groups. Therefore,
the lipid–water interplay strongly contributes to modulating
membrane architecture, lipid diffusion, and chemical activity. Here,
we introduce a new method of obtaining dehydrated, phase-separated,
supported lipid bilayers (SLBs) solely by controlling the decrease
of their environment’s relative humidity. This facilitates
the study of the structure and dynamics of SLBs over a wide range
of hydration states. We show that the lipid domain structure of phase-separated
SLBs is largely insensitive to the presence of the hydration layer.
In stark contrast, lipid mobility is drastically affected by dehydration,
showing a 6-fold decrease in lateral diffusion. At the same time,
the diffusion activation energy increases approximately 2-fold for
the dehydrated membrane. The obtained results, correlated with the
hydration structure of a lipid molecule, revealed that about six to
seven water molecules directly hydrating the phosphocholine moiety
play a pivotal role in modulating lipid diffusion. These findings
could provide deeper insights into the fundamental reactions where
local dehydration occurs, for instance during cell–cell fusion,
and help us better understand the survivability of anhydrobiotic organisms.
Finally, the strong dependence of lipid mobility on the number of
hydrating water molecules opens up an application potential for SLBs
as very precise, nanoscale hydration sensors.
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Affiliation(s)
- Madhurima Chattopadhyay
- Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznan, Poland
| | - Emilia Krok
- Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznan, Poland
| | - Hanna Orlikowska
- Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznan, Poland
| | - Petra Schwille
- Department of Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Henri G Franquelim
- Department of Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Lukasz Piatkowski
- Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznan, Poland
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12
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Liu P, Zabala-Ferrera O, Beltramo PJ. Fabrication and electromechanical characterization of freestanding asymmetric membranes. Biophys J 2021; 120:1755-1764. [PMID: 33675759 PMCID: PMC8204216 DOI: 10.1016/j.bpj.2021.02.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/12/2021] [Accepted: 02/24/2021] [Indexed: 01/07/2023] Open
Abstract
All biological cell membranes maintain an electric transmembrane potential of around 100 mV, due in part to an asymmetric distribution of charged phospholipids across the membrane. This asymmetry is crucial to cell health and physiological processes such as intracell signaling, receptor-mediated endocytosis, and membrane protein function. Experimental artificial membrane systems incorporate essential cell membrane structures, such as the phospholipid bilayer, in a controllable manner in which specific properties and processes can be isolated and examined. Here, we describe an approach to fabricate and characterize planar, freestanding, asymmetric membranes and use it to examine the effect of headgroup charge on membrane stiffness. The approach relies on a thin film balance used to form a freestanding membrane by adsorbing aqueous phase lipid vesicles to an oil-water interface and subsequently thinning the oil to form a bilayer. We validate this lipid-in-aqueous approach by analyzing the thickness and compressibility of symmetric membranes with varying zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and anionic 1,2-dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) sodium salt (DOPG) content as compared with previous lipid-in-oil methods. We find that as the concentration of DOPG increases, membranes become thicker and stiffer. Asymmetric membranes are fabricated by controlling the lipid vesicle composition in the aqueous reservoirs on either side of the oil. Membrane compositional asymmetry is qualitatively demonstrated using a fluorescence quenching assay and quantitatively characterized through voltage-dependent capacitance measurements. Stable asymmetric membranes with DOPC on one side and DOPC-DOPG mixtures on the other were created with transmembrane potentials ranging from 15 to 80 mV. Introducing membrane charge asymmetry decreases both the thickness and stiffness in comparison with symmetric membranes with the same overall phospholipid composition. These initial successes demonstrate a viable pathway to quantitatively characterize asymmetric bilayers that can be extended to accommodate more complex membranes and membrane processes in the future.
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Affiliation(s)
- Paige Liu
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Oscar Zabala-Ferrera
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Peter J Beltramo
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts.
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13
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Ayesa U, Chong PLG. Polar Lipid Fraction E from Sulfolobus acidocaldarius and Dipalmitoylphosphatidylcholine Can Form Stable yet Thermo-Sensitive Tetraether/Diester Hybrid Archaeosomes with Controlled Release Capability. Int J Mol Sci 2020; 21:ijms21218388. [PMID: 33182284 PMCID: PMC7664881 DOI: 10.3390/ijms21218388] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/31/2020] [Accepted: 11/04/2020] [Indexed: 12/29/2022] Open
Abstract
Archaeosomes have drawn increasing attention in recent years as novel nano-carriers for therapeutics. The main obstacle of using archaeosomes for therapeutics delivery has been the lack of an efficient method to trigger the release of entrapped content from the otherwise extremely stable structure. Our present study tackles this long-standing problem. We made hybrid archaeosomes composed of tetraether lipids, called the polar lipid fraction E (PLFE) isolated from the thermoacidophilic archaeon Sulfolobus acidocaldarius, and the synthetic diester lipid dipalmitoylphosphatidylcholine (DPPC). Differential polarized phase-modulation and steady-state fluorometry, confocal fluorescence microscopy, zeta potential (ZP) measurements, and biochemical assays were employed to characterize the physical properties and drug behaviors in PLFE/DPPC hybrid archaeosomes in the presence and absence of live cells. We found that PLFE lipids have an ordering effect on fluid DPPC liposomal membranes, which can slow down the release of entrapped drugs, while PLFE provides high negative charges on the outer surface of liposomes, which can increase vesicle stability against coalescence among liposomes or with cells. Furthermore, we found that the zeta potential in hybrid archaeosomes with 30 mol% PLFE and 70 mol% DPPC (designated as PLFE/DPPC(3:7) archaeosomes) undergoes an abrupt increase from −48 mV at 37 °C to −16 mV at 44 °C (termed the ZP transition), which we hypothesize results from DPPC domain melting and PLFE lipid ‘flip-flop’. The anticancer drug doxorubicin (DXO) can be readily incorporated into PLFE/DPPC(3:7) archaeosomes. The rate constant of DXO release from PLFE/DPPC(3:7) archaeosomes into Tris buffer exhibited a sharp increase (~2.5 times), when the temperature was raised from 37 to 42 °C, which is believed to result from the liposomal structural changes associated with the ZP transition. This thermo-induced sharp increase in drug release was not affected by serum proteins as a similar temperature dependence of drug release kinetics was observed in human blood serum. A 15-min pre-incubation of PLFE/DPPC(3:7) archaeosomal DXO with MCF-7 breast cancer cells at 42 °C caused a significant increase in the amount of DXO entering into the nuclei and a considerable increase in the cell’s cytotoxicity under the 37 °C growth temperature. Taken together, our data suggests that PLFE/DPPC(3:7) archaeosomes are stable yet potentially useful thermo-sensitive liposomes wherein the temperature range (from 37 to 42–44 °C) clinically used for mild hyperthermia treatment of tumors can be used to trigger drug release for medical interventions.
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14
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Kamble S, Patil S, Appala VRM. Nano-mechanical characterization of asymmetric DLPC/DSPC supported lipid bilayers. Chem Phys Lipids 2020; 234:105007. [PMID: 33160952 DOI: 10.1016/j.chemphyslip.2020.105007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/13/2020] [Accepted: 11/02/2020] [Indexed: 11/25/2022]
Abstract
Asymmetric distribution of lipid molecules in the inner and outer leaflets of the plasma membrane is a common occurrence in the membrane formation. Such asymmetric arrangement is a crucial parameter to manipulate the properties of the cell membrane. It controls signal transduction, endocytosis, exocytosis in the cells. The artificial membrane is often used to study the lateral and transverse arrangement of the lipid molecules in place of the cell membrane. Nano-mechanical characterization of the model membrane helps to understand the mechanical stability of the lipid bilayer. The stability is sensitive to the variations in the lipid composition and their local organization. In this article, we present both topographical and nano-mechanical properties of lipid bilayer characterized by atomic force microscopy (AFM). The results show that the asymmetric lipid bilayer formation is an intrinsic character. We have selected a bi-component fluid-gel phase 1,2-dilauroyl-sn-glycero-3-phosphocholine:1,2-disteroyl-sn-glycero-3-phosphocholine (DLPC: DSPC) system for our studies. We have observed domain formation and phase separation in the bilayer by increasing the composition of the gel phase DSPC. In force spectroscopy studies, we determine the mechanical strength of the bilayer for unique mixtures of DLPC: DSPC by measuring the breakthrough force. These results also show the effect of asymmetry in the lipid bilayer. Besides AFM studies, we have implemented a coarse-grained (CG) molecular dynamics (MD) simulation using the gromacs package at room temperature and 1 bar pressure. The results from the simulation study have been compared with AFM study. It was found that the simulation studies corroborated the findings from AFM such as an increase in the bilayer thickness, change in the phase state, asymmetric and symmetric domain formation in the lipid bilayer.
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Affiliation(s)
- Sagar Kamble
- Department of Applied Physics, Defence Institute of Advanced Technology (DIAT) DU., Girinagar, Pune, India
| | - Snehal Patil
- Department of Applied Physics, Defence Institute of Advanced Technology (DIAT) DU., Girinagar, Pune, India
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15
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Flowering Poration-A Synergistic Multi-Mode Antibacterial Mechanism by a Bacteriocin Fold. iScience 2020; 23:101423. [PMID: 32795916 PMCID: PMC7424198 DOI: 10.1016/j.isci.2020.101423] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 07/10/2020] [Accepted: 07/27/2020] [Indexed: 11/21/2022] Open
Abstract
Bacteriocins are a distinct family of antimicrobial proteins postulated to porate bacterial membranes. However, direct experimental evidence of pore formation by these proteins is lacking. Here we report a multi-mode poration mechanism induced by four-helix bacteriocins, epidermicin NI01 and aureocin A53. Using a combination of crystallography, spectroscopy, bioassays, and nanoscale imaging, we established that individual two-helix segments of epidermicin retain antibacterial activity but each of these segments adopts a particular poration mode. In the intact protein these segments act synergistically to balance out antibacterial and hemolytic activities. The study sets a precedent of multi-mode membrane disruption advancing the current understanding of structure-activity relationships in pore-forming proteins. Bacteriocins are antibacterial proteins believed to form pores in bacterial membranes A multi-helix bacteriocin fold induces a multi-mode poration mechanism Each of two-helix segments of the bacteriocin adopts a particular poration mode These segments act synergistically balancing out antibacterial and hemolytic activities
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16
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Sarmento MJ, Ricardo JC, Amaro M, Šachl R. Organization of gangliosides into membrane nanodomains. FEBS Lett 2020; 594:3668-3697. [DOI: 10.1002/1873-3468.13871] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Maria J. Sarmento
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences Prague 8 Czech Republic
| | - Joana C. Ricardo
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences Prague 8 Czech Republic
| | - Mariana Amaro
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences Prague 8 Czech Republic
| | - Radek Šachl
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences Prague 8 Czech Republic
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17
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Wu A, Wojtowicz K, Savary S, Hamon Y, Trombik T. Do ABC transporters regulate plasma membrane organization? Cell Mol Biol Lett 2020; 25:37. [PMID: 32647530 PMCID: PMC7336681 DOI: 10.1186/s11658-020-00224-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/05/2020] [Indexed: 12/29/2022] Open
Abstract
The plasma membrane (PM) spatiotemporal organization is one of the major factors controlling cell signaling and whole-cell homeostasis. The PM lipids, including cholesterol, determine the physicochemical properties of the membrane bilayer and thus play a crucial role in all membrane-dependent cellular processes. It is known that lipid content and distribution in the PM are not random, and their transversal and lateral organization is highly controlled. Mainly sphingolipid- and cholesterol-rich lipid nanodomains, historically referred to as rafts, are extremely dynamic “hot spots” of the PM controlling the function of many cell surface proteins and receptors. In the first part of this review, we will focus on the recent advances of PM investigation and the current PM concept. In the second part, we will discuss the importance of several classes of ABC transporters whose substrates are lipids for the PM organization and dynamics. Finally, we will briefly present the significance of lipid ABC transporters for immune responses.
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Affiliation(s)
- Ambroise Wu
- Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | | | - Stephane Savary
- Lab. Bio-PeroxIL EA7270, University of Bourgogne Franche-Comté, Dijon, France
| | - Yannick Hamon
- Aix Marseille University, CNRS, INSERM, CIML, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Tomasz Trombik
- Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
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18
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Rinaldin M, Fonda P, Giomi L, Kraft DJ. Lipid exchange enhances geometric pinning in multicomponent membranes on patterned substrates. SOFT MATTER 2020; 16:4932-4940. [PMID: 32435786 DOI: 10.1039/c9sm02393c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Experiments on supported lipid bilayers featuring liquid ordered/disordered domains have shown that the spatial arrangement of the lipid domains and their chemical composition are strongly affected by the curvature of the substrate. Furthermore, theoretical predictions suggest that both these effects are intimately related with the closed topology of the bilayer. In this work, we test this hypothesis by fabricating supported membranes consisting of colloidal particles of various shapes lying on a flat substrate. A single lipid bilayer coats both colloids and substrate, allowing local lipid exchange between them, thus rendering the system thermodynamically open, i.e. able to exchange heat and molecules with an external reservoir in the neighborhood of the colloid. By reconstructing the Gibbs phase diagram for this system, we demonstrate that the free-energy landscape is directly influenced by the geometry of the colloid. In addition, we find that local lipid exchange enhances the pinning of the liquid disordered phase in highly curved regions. This allows us to provide estimates of the bending moduli difference of the domains. Finally, by combining experimental and numerical data, we forecast the outcome of possible experiments on catenoidal and conical necks and show that these geometries could greatly improve the precision of the current estimates of the bending moduli.
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Affiliation(s)
- Melissa Rinaldin
- Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands.
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19
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Gupta A, Phang IY, Wohland T. To Hop or not to Hop: Exceptions in the FCS Diffusion Law. Biophys J 2020; 118:2434-2447. [PMID: 32333863 PMCID: PMC7231916 DOI: 10.1016/j.bpj.2020.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Diffusion obstacles in membranes have not been directly visualized because of fast membrane dynamics and the occurrence of subresolution molecular complexes. To understand the obstacle characteristics, mobility-based methods are often used as an indirect way of assessing the membrane structure. Molecular movement in biological plasma membranes is often characterized by anomalous diffusion, but the exact underlying mechanisms are still elusive. Imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) is a well-established mobility-based method that provides spatially resolved diffusion coefficient maps and is combined with FCS diffusion law analysis to examine subresolution membrane organization. In recent years, although FCS diffusion law analysis has been instrumental in providing new insights into the membrane structure below the optical diffraction limit, there are certain exceptions and anomalies that require further clarification. To this end, we correlate the membrane structural features imaged by atomic force microscopy (AFM) with the dynamics measured using ITIR-FCS. We perform ITIR-FCS measurements on supported lipid bilayers (SLBs) of various lipid compositions to characterize the anomalous diffusion of lipid molecules in distinct obstacle configurations, along with the high-resolution imaging of the membrane structures with AFM. Furthermore, we validate our experimental results by performing simulations on image grids with experimentally determined obstacle configurations. This study demonstrates that FCS diffusion law analysis is a powerful tool to determine membrane heterogeneities implied from dynamics measurements. Our results corroborate the commonly accepted interpretations of imaging FCS diffusion law analysis, and we show that exceptions happen when domains reach the percolation threshold in a biphasic membrane and a network of domains behaves rather like a meshwork, resulting in hop diffusion.
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Affiliation(s)
- Anjali Gupta
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Inn Yee Phang
- Institute of Materials Research and Engineering, Singapore, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore; Department of Chemistry, National University of Singapore, Singapore, Singapore.
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20
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Nguyen-Tri P, Ghassemi P, Carriere P, Nanda S, Assadi AA, Nguyen DD. Recent Applications of Advanced Atomic Force Microscopy in Polymer Science: A Review. Polymers (Basel) 2020; 12:E1142. [PMID: 32429499 PMCID: PMC7284686 DOI: 10.3390/polym12051142] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/26/2022] Open
Abstract
Atomic force microscopy (AFM) has been extensively used for the nanoscale characterization of polymeric materials. The coupling of AFM with infrared spectroscope (AFM-IR) provides another advantage to the chemical analyses and thus helps to shed light upon the study of polymers. This paper reviews some recent progress in the application of AFM and AFM-IR in polymer science. We describe the principle of AFM-IR and the recent improvements to enhance its resolution. We also discuss the latest progress in the use of AFM-IR as a super-resolution correlated scanned-probe infrared spectroscopy for the chemical characterization of polymer materials dealing with polymer composites, polymer blends, multilayers, and biopolymers. To highlight the advantages of AFM-IR, we report several results in studying the crystallization of both miscible and immiscible blends as well as polymer aging. Finally, we demonstrate how this novel technique can be used to determine phase separation, spherulitic structure, and crystallization mechanisms at nanoscales, which has never been achieved before. The review also discusses future trends in the use of AFM-IR in polymer materials, especially in polymer thin film investigation.
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Affiliation(s)
- Phuong Nguyen-Tri
- Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam
- Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC G8Z 4M3, Canada;
| | - Payman Ghassemi
- Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC G8Z 4M3, Canada;
| | - Pascal Carriere
- Laboratoire MAPIEM (EA 4323), Matériaux Polymères Interfaces Environnement Marin, Université de Toulon, CEDEX 9, 83041 Toulon, France;
| | - Sonil Nanda
- Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A2, Canada;
| | - Aymen Amine Assadi
- ENSCR—Institut des Sciences Chimiques de Rennes (ISCR)—UMR CNRS 6226, Univ Rennes, 35700 Rennes, France;
| | - Dinh Duc Nguyen
- Faculty of Environmental and Food Engineering, Nguyen Tat Thanh University, 300A Nguyen Tat Thanh, District 4, Ho Chi Minh City 755414, Vietnam;
- Department of Environmental Energy Engineering, Kyonggi University, Suwon 16227, Korea
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21
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Sarmento MJ, Hof M, Šachl R. Interleaflet Coupling of Lipid Nanodomains - Insights From in vitro Systems. Front Cell Dev Biol 2020; 8:284. [PMID: 32411705 PMCID: PMC7198703 DOI: 10.3389/fcell.2020.00284] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 04/02/2020] [Indexed: 01/09/2023] Open
Abstract
The plasma membrane is a complex system, consisting of two layers of lipids and proteins compartmentalized into small structures called nanodomains. Despite the asymmetric composition of both leaflets, coupling between the layers is surprisingly strong. This can be evidenced, for example, by recent experimental studies performed on phospholipid giant unilamellar vesicles showing that nanodomains formed in the outer layer are perfectly registered with those in the inner leaflet. Similarly, microscopic phase separation in one leaflet can induce phase separation in the opposing leaflet that would otherwise be homogeneous. In this review, we summarize the current theoretical and experimental knowledge that led to the current view that domains are – irrespective of their size – commonly registered across the bilayer. Mechanisms inducing registration of nanodomains suggested by theory and calculations are discussed. Furthermore, domain coupling is evidenced by experimental studies based on the sparse number of methods that can resolve registered from independent nanodomains. Finally, implications that those findings using model membrane studies might have for cellular membranes are discussed.
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Affiliation(s)
- Maria J Sarmento
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova, Prague, Czechia
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova, Prague, Czechia
| | - Radek Šachl
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova, Prague, Czechia
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22
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Gupta A, Korte T, Herrmann A, Wohland T. Plasma membrane asymmetry of lipid organization: fluorescence lifetime microscopy and correlation spectroscopy analysis. J Lipid Res 2020; 61:252-266. [PMID: 31857388 PMCID: PMC6997606 DOI: 10.1194/jlr.d119000364] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 12/03/2019] [Indexed: 02/06/2023] Open
Abstract
A fundamental feature of the eukaryotic cell membrane is the asymmetric arrangement of lipids in its two leaflets. A cell invests significant energy to maintain this asymmetry and uses it to regulate important biological processes, such as apoptosis and vesiculation. The dynamic coupling of the inner or cytoplasmic and outer or exofacial leaflets is a challenging open question in membrane biology. Here, we combined fluorescence lifetime imaging microscopy (FLIM) with imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) to differentiate the dynamics and organization of the two leaflets of live mammalian cells. We characterized the biophysical properties of fluorescent analogs of phosphatidylcholine, sphingomyelin, and phosphatidylserine in the plasma membrane of two mammalian cell lines (CHO-K1 and RBL-2H3). Because of their specific transverse membrane distribution, these probes allowed leaflet-specific investigation of the plasma membrane. We compared the results of the two methods having different temporal and spatial resolution. Fluorescence lifetimes of fluorescent lipid analogs were in ranges characteristic for the liquid ordered phase in the outer leaflet and for the liquid disordered phase in the inner leaflet. The observation of a more fluid inner leaflet was supported by free diffusion in the inner leaflet, with high average diffusion coefficients. The liquid ordered phase in the outer leaflet was accompanied by slower diffusion and diffusion with intermittent transient trapping. Our results show that the combination of FLIM and ITIR-FCS with specific fluorescent lipid analogs is a powerful tool for investigating lateral and transbilayer characteristics of plasma membrane in live cell lines.
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Affiliation(s)
- Anjali Gupta
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences National University of Singapore, Singapore
| | - Thomas Korte
- Institute for Biology/Biophysics, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Herrmann
- Institute for Biology/Biophysics, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Thorsten Wohland
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences National University of Singapore, Singapore
- Department of Chemistry, National University of Singapore, Singapore
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23
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Jiang Y, Pryse KM, Singamaneni S, Genin GM, Elson EL. Atomic force microscopy of phase separation on ruptured, giant unilamellar vesicles, and a mechanical pathway for the co-existence of lipid gel phases. J Biomech Eng 2019; 141:2735310. [PMID: 31141589 PMCID: PMC6611346 DOI: 10.1115/1.4043871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/26/2019] [Indexed: 11/08/2022]
Abstract
Giant unilamellar vesicles (GUVs) and supported lipid bilayers (SLBs) are synthetic model systems widely used in biophysical studies of lipid membranes. Although SLBs are advantageous for biophysical analysis, phase separation behaviors of lipid species in these two model systems can differ due to the lipid-substrate interactions that are present only for SLBs. In the present study, we report that in binary systems, certain phase domains on GUVs retain their original shapes and patterns after the GUVs rupture on glass surfaces. This enabled atomic force microscopy (AFM) experiments on phase domains, a procedure difficult to perform and interpret when applied to GUVs. Unusual phase behavior was evident in binary GUVs containing DLPC and either DPPC or DSPC. These DLPC/DSPC and DLPC/DPPC GUVs both presented the thermodynamic anomaly of having two co-existing gel phases. One phase (a bright phase) included a relatively high concentration of DiI-C20 but excluded Bodipy-HPC, and the other (dark phase) excluded both probes. The bright phases are of interest because they seem to stabilize dark phases against coalescence. Results suggested that the gel phases labeled by DiIC20 in the DLPC/DSPC membrane, which surround the dark gel phase, is an extra layer of membrane, indicating a highly curved structure that might stabilize the interior dark domains, thereby enabling the co-existence of two different gel phases. Results show the utility of AFM on collapsed GUVs, and suggest a possible mechanism for stabilization of lipid domains.
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Affiliation(s)
- Yanfei Jiang
- Department of Biochemistry and
Molecular Biophysics,
School of Medicine,
Washington University,
St. Louis, MO 63110
| | - Kenneth M. Pryse
- Department of Mechanical Engineering
and Materials Science,
Washington University,
St. Louis, MO 63110
| | - Srikanth Singamaneni
- Department of Mechanical Engineering
and Materials Science,
Washington University,
St. Louis, MO 63110
| | - Guy M. Genin
- Department of Mechanical Engineeringand Materials Science,
Washington University,
St. Louis, MO 63110
- NSF Science and Technology,Center for Engineering Mechanobiology,
Washington University,
St. Louis, MO 63110
e-mail:
| | - Elliot L. Elson
- Department of Biochemistry and
Molecular Biophysics,
School of Medicine,
Washington University,
St. Louis, MO 63110
e-mail:
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Electrophysiological interrogation of asymmetric droplet interface bilayers reveals surface-bound alamethicin induces lipid flip-flop. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:335-343. [DOI: 10.1016/j.bbamem.2018.07.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/06/2018] [Accepted: 07/09/2018] [Indexed: 01/16/2023]
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25
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Effects of Passive Phospholipid Flip-Flop and Asymmetric External Fields on Bilayer Phase Equilibria. Biophys J 2018; 115:1956-1965. [PMID: 30393103 DOI: 10.1016/j.bpj.2018.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/21/2018] [Accepted: 10/01/2018] [Indexed: 11/20/2022] Open
Abstract
Compositional asymmetry between the leaflets of bilayer membranes modifies their phase behavior and is thought to influence other important features such as mechanical properties and protein activity. We address here how phase behavior is affected by passive phospholipid flip-flop, such that the compositional asymmetry is not fixed. We predict transitions from "pre-flip-flop" behavior to a restricted set of phase equilibria that can persist in the presence of passive flip-flop. Surprisingly, such states are not necessarily symmetric. We further account for external symmetry breaking, such as a preferential substrate interaction, and show how this can stabilize strongly asymmetric equilibrium states. Our theory explains several experimental observations of flip-flop-mediated changes in phase behavior and shows how domain formation and compositional asymmetry can be controlled in concert, by manipulating passive flip-flop rates and applying external fields.
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26
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Shahzadi Z, Das S, Bala T, Mukhopadhyay C. Phase Behavior of GM1-Containing DMPC-Cholesterol Monolayer: Experimental and Theoretical Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11602-11611. [PMID: 30173524 DOI: 10.1021/acs.langmuir.8b02621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Organization and distribution of lipids in cellular membranes play an important role in a diverse range of biological processes, such as membrane trafficking and signaling. Here, we present the combined experimental and simulated results to elucidate the phase behavioral features of ganglioside monosialo 1 (GM1)-containing mixed monolayer of the lipids 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) and cholesterol (CHOL). Two monolayers having compositions DMPC-CHOL and GM1-DMPC-CHOL are investigated at air-water and air-solid interfaces using Langmuir-Blodgett experiments and scanning electron microscopy (SEM), respectively, to ascertain the phase behavior change of the monolayers. Surface pressure isotherms and SEM imaging of domain formation indicate that addition of GM1 to the monolayer at low surface pressure causes a fluidization of the system but once the system attains the surface pressure corresponding to its liquid-condensed phase, the monolayer becomes more ordered than the system devoid of GM1 and interacts among each other more cooperatively. Besides, the condensing effect of cholesterol on the DMPC monolayer was also verified by our experiments. Apart from these, the effects induced by GM1 on the phase behavior of the binary mixture of DMPC-CHOL were studied with and without applying liquid-expanded (LE)-liquid-condensed (LC) equilibrium surface pressure using molecular dynamics (MD) simulation. Our molecular dynamics (MD) simulation results give an atomistic-level explanation of our experimental findings and furnish a similar conclusion.
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Affiliation(s)
- Zarrin Shahzadi
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
| | - Subhasis Das
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
| | - Tanushree Bala
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
| | - Chaitali Mukhopadhyay
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
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27
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Li J, Cao W, Wang Z, Ma M, Luo J. Origin of hydration lubrication of zwitterions on graphene. NANOSCALE 2018; 10:16887-16894. [PMID: 30175359 DOI: 10.1039/c8nr05724a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Formation of a hydration layer on charge sites can support normal pressure, and meanwhile it retains excellent fluidity to provide efficient boundary lubrication; however, it is limited to the sliding system between two similarly charged surfaces. In the present study, we report extremely low friction as the zwitterions in a lipid bilayer slide on the topmost graphene layer of graphite across pure water, with the friction coefficient falling to the level of 0.001, which provides direct evidence that hydration lubrication is effective even between such dissimilar surfaces. The origin of hydration lubrication on graphene was studied by atomic force microscopy and molecular dynamics simulation simultaneously. It reveals that a subnanometer hydration layer is confined between zwitterions and graphene, which remains as a liquid phase under normal pressure. The shear occurs between water molecules and graphene because of the extremely low shear strength of the water/graphene interface, which contributes to extremely low friction. Our finding demonstrates that the formation of a hydration layer is possible to lubricate layered materials efficiently, which has potential implications for designing efficient boundary lubrication with layered materials.
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Affiliation(s)
- Jinjin Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China.
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Peyret A, Zhao H, Lecommandoux S. Preparation and Properties of Asymmetric Synthetic Membranes Based on Lipid and Polymer Self-Assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:3376-3385. [PMID: 29486556 DOI: 10.1021/acs.langmuir.7b04233] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cell membrane asymmetry is a common structural feature of all biological cells. Researchers have tried for decades to better study its formation and its function in membrane-regulated phenomena. In particular, there has been increasing interest in developing synthetic asymmetric membrane models in the laboratory, with the aim of studying basic physical chemistry properties that may be correlated to a relevant biological function. The present article aims to summarize the main presented approaches to prepare asymmetric membranes, which are most often made from lipids, polymers, or a combination of both.
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Affiliation(s)
- Ariane Peyret
- Laboratoire de Chimie des Polymères Organiques, LCPO, Université de Bordeaux, CNRS, Bordeaux INP, UMR 5629 , 16 Avenue Pey Berland F-33600 Pessac , France
| | - Hang Zhao
- Laboratoire de Chimie des Polymères Organiques, LCPO, Université de Bordeaux, CNRS, Bordeaux INP, UMR 5629 , 16 Avenue Pey Berland F-33600 Pessac , France
| | - Sébastien Lecommandoux
- Laboratoire de Chimie des Polymères Organiques, LCPO, Université de Bordeaux, CNRS, Bordeaux INP, UMR 5629 , 16 Avenue Pey Berland F-33600 Pessac , France
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29
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Zeno WF, Ogunyankin MO, Longo ML. Scaling relationships for translational diffusion constants applied to membrane domain dissolution and growth. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1994-2003. [PMID: 29501605 DOI: 10.1016/j.bbamem.2018.02.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/24/2018] [Accepted: 02/26/2018] [Indexed: 01/10/2023]
Abstract
We compare the way that relationships for diffusion constants scale with the size of diffusing membrane domains and the geometry of their environments. Then, we review our experimental work on the dynamics of dissolution/growth of membrane domains in crowding induced mixing, phase separation, and Ostwald ripening in a highly confined environment. Overall, the scaling relationships applied to diffusion constants obtained by fits to our dynamic data indicate that dissolution and growth is influenced by the diffusion of clusters or small domains of lipids, in addition to kinetic processes and geometrical constraints.
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Affiliation(s)
- Wade F Zeno
- Department of Chemical Engineering, University of California Davis, Davis, CA 95616, United States
| | - Maria O Ogunyankin
- Department of Chemical Engineering, University of California Davis, Davis, CA 95616, United States
| | - Marjorie L Longo
- Department of Chemical Engineering, University of California Davis, Davis, CA 95616, United States.
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30
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Cholesterol induced asymmetry in DOPC bilayers probed by AFM force spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:953-959. [PMID: 29408513 DOI: 10.1016/j.bbamem.2018.01.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 01/24/2018] [Accepted: 01/28/2018] [Indexed: 11/21/2022]
Abstract
Cholesterol induced mechanical effects on artificial lipid bilayers are well known and have been thoroughly investigated by AFM force spectroscopy. However, dynamics of cholesterol impingement into bilayers at various cholesterol concentrations and their effects have not been clearly understood. In this paper we present, the effect of cholesterol as a function of its concentration in a simple single component dioleoylphosphatidylcholine (DOPC) bilayer. The nature of measured breakthrough forces on a bilayer with the addition of cholesterol, suggested that it is not just responsible to increase the mechanical stability but also introduces irregularities across the leaflets of the bilayer. This cholesterol induced asymmetry across the (in the inner and outer leaflets) bilayer is related to the phenomena of interleaflet coupling and is a function of cholesterol concentration probed by AFM can provide an unprecedented direction on mechanical properties of lipid membrane as it can be directly correlated to biophysical properties of a cell membrane.
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31
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Peyret A, Ibarboure E, Le Meins J, Lecommandoux S. Asymmetric Hybrid Polymer-Lipid Giant Vesicles as Cell Membrane Mimics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1700453. [PMID: 29375971 PMCID: PMC5770682 DOI: 10.1002/advs.201700453] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/17/2017] [Indexed: 05/29/2023]
Abstract
Lipid membrane asymmetry plays an important role in cell function and activity, being for instance a relevant signal of its integrity. The development of artificial asymmetric membranes thus represents a key challenge. In this context, an emulsion-centrifugation method is developed to prepare giant vesicles with an asymmetric membrane composed of an inner monolayer of poly(butadiene)-b-poly(ethylene oxide) (PBut-b-PEO) and outer monolayer of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). The formation of a complete membrane asymmetry is demonstrated and its stability with time is followed by measuring lipid transverse diffusion. From fluorescence spectroscopy measurements, the lipid half-life is estimated to be 7.5 h. Using fluorescence recovery after photobleaching technique, the diffusion coefficient of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) (DOPE-rhod, inserted into the POPC leaflet) is determined to be about D = 1.8 ± 0.50 μm2 s-1 at 25 °C and D = 2.3 ± 0.7 μm2 s-1 at 37 °C, between the characteristic values of pure POPC and pure polymer giant vesicles and in good agreement with the diffusion of lipids in a variety of biological membranes. These results demonstrate the ability to prepare a cell-like model system that displays an asymmetric membrane with transverse and translational diffusion properties similar to that of biological cells.
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Affiliation(s)
- Ariane Peyret
- Laboratoire de Chimie des Polymères OrganiquesLCPOUniversité de BordeauxCNRSBordeaux INPUMR 562916 Avenue Pey BerlandF‐33600PessacFrance
| | - Emmanuel Ibarboure
- Laboratoire de Chimie des Polymères OrganiquesLCPOUniversité de BordeauxCNRSBordeaux INPUMR 562916 Avenue Pey BerlandF‐33600PessacFrance
| | - Jean‐François Le Meins
- Laboratoire de Chimie des Polymères OrganiquesLCPOUniversité de BordeauxCNRSBordeaux INPUMR 562916 Avenue Pey BerlandF‐33600PessacFrance
| | - Sebastien Lecommandoux
- Laboratoire de Chimie des Polymères OrganiquesLCPOUniversité de BordeauxCNRSBordeaux INPUMR 562916 Avenue Pey BerlandF‐33600PessacFrance
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32
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Abstract
The spread of bacterial resistance to antibiotics poses the need for antimicrobial discovery. With traditional search paradigms being exhausted, approaches that are altogether different from antibiotics may offer promising and creative solutions. Here, we introduce a de novo peptide topology that—by emulating the virus architecture—assembles into discrete antimicrobial capsids. Using the combination of high-resolution and real-time imaging, we demonstrate that these artificial capsids assemble as 20-nm hollow shells that attack bacterial membranes and upon landing on phospholipid bilayers instantaneously (seconds) convert into rapidly expanding pores causing membrane lysis (minutes). The designed capsids show broad antimicrobial activities, thus executing one primary function—they destroy bacteria on contact. With the growing threat of antibiotic resistance, unconventional approaches to antimicrobial discovery are needed. Here, the authors present a peptide topology that mimics virus architecture and assembles into antimicrobial capsids that disrupt bacterial membranes upon contact.
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33
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C R, Basu JK. Emergence of compositionally tunable nanoscale dynamical heterogeneity in model binary lipid biomembranes. SOFT MATTER 2017; 13:4598-4606. [PMID: 28604915 DOI: 10.1039/c7sm00581d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
While the existence of nanoscale dynamical heterogeneity in biological membranes has been suggested to act as an active functional platform for enabling various cellular processes like signal transduction and viral or bacterial entry, it has been extremely difficult to detect the existence of such domains. Model lipid bilayer membranes have been widely used to detect such dynamical heterogeneity in order to avoid complications arising from the compositional heterogeneity of cellular membranes. However, even in model biological membranes the issue of nanoscale lipid dynamics has remained controversial and unresolved due to the difficulty of detecting the existence of such dynamical heterogeneity on the scale of 10-300 nm. Here we report direct evidence of nanoscale lipid dynamical heterogeneity in model binary lipid bilayer membranes using a combination of super-resolution stimulated emission depletion (STED) microscopy and fluorescence correlation spectroscopy (FCS). We control the phase behavior of the lipid bilayers by varying their composition and discuss how this leads to the emergence of dynamical lipid domains on the scale of 80-150 nm, which is also dependent on the lipid phase in which such dynamics are observed. Notably, our work shows that the presence of cholesterol is not required for the existence of such domains even in fluid like bilayers, as has been widely believed, and specifies the minimal conditions required for the emergence of such dynamical heterogeneity in cellular membranes. Our work will thus not only be of great significance towards understanding the nanoscale dynamic organizing principles of cellular membranes but could also be useful in understanding the dynamics of related soft matter systems and nanoparticle-cell membrane interactions.
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Affiliation(s)
- Roobala C
- Department of Physics, Indian Institute of Science, Bangalore, 560 012, India.
| | - Jaydeep K Basu
- Department of Physics, Indian Institute of Science, Bangalore, 560 012, India.
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34
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Guyomarc’h F, Chen M, Et-Thakafy O, Zou S, Lopez C. Gel-gel phase separation within milk sphingomyelin domains revealed at the nanoscale using atomic force microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:949-958. [DOI: 10.1016/j.bbamem.2017.02.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 02/10/2017] [Accepted: 02/14/2017] [Indexed: 11/24/2022]
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35
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Sizes of lipid domains: What do we know from artificial lipid membranes? What are the possible shared features with membrane rafts in cells? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:789-802. [DOI: 10.1016/j.bbamem.2017.01.030] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/21/2017] [Accepted: 01/26/2017] [Indexed: 12/13/2022]
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36
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Lim SK, Wong ASW, de Hoog HPM, Rangamani P, Parikh AN, Nallani M, Sandin S, Liedberg B. Spontaneous formation of nanometer scale tubular vesicles in aqueous mixtures of lipid and block copolymer amphiphiles. SOFT MATTER 2017; 13:1107-1115. [PMID: 28058411 DOI: 10.1039/c6sm01753c] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Many common amphiphiles self-assemble in water to produce heterogeneous populations of discrete and symmetric but polydisperse and multilamellar vesicles isolating the encapsulated aqueous core from the surrounding bulk. But when mixtures of amphiphiles of vastly different elastic properties co-assemble, their non-uniform molecular organization can stabilize lower symmetries and produce novel shapes. Here, using high resolution electron cryomicroscopy and tomography, we identify the spontaneous formation of a membrane morphology consisting of unilamellar tubular vesicles in dilute aqueous solutions of binary mixtures of two different amphiphiles of vastly different origins. Our results show that aqueous phase mixtures of a fluid-phase phospholipid and an amphiphilic block copolymer spontaneously assume a bimodal polymorphic character in a composition dependent manner: over a broad range of compositions (15-85 mol% polymer component), a tubular morphology co-exists with spherical vesicles. Strikingly, in the vicinity of equimolar compositions, an exclusively tubular morphology (Lt; diameter, ∼15 nm; length, >1 μm; core, ∼2.0 nm; wall, ∼5-6 nm) emerges in an apparent steady state. Theory suggests that the spontaneous stabilization of cylindrical vesicles, unaided by extraneous forces, requires a significant spontaneous bilayer curvature, which in turn necessitates a strongly asymmetric membrane composition. We confirm that such dramatic compositional asymmetry is indeed produced spontaneously in aqueous mixtures of a lipid and polymer through two independent biochemical assays - (1) reduction in the quenching of fluorophore-labeled lipids and (2) inhibition in the activity of externally added lipid-hydrolyzing phospholipase A2, resulting in a significant enrichment of the polymer component in the outer leaflet. Taken together, these results illustrate the coupling of the membrane shape with local composition through spontaneous curvature generation under conditions of asymmetric distribution of mixtures of disparate amphiphiles.
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Affiliation(s)
- Seng Koon Lim
- Centre for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore 637553.
| | - Andrew S W Wong
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore 639798
| | - Hans-Peter M de Hoog
- Centre for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore 637553.
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, California 92093, USA
| | - Atul N Parikh
- Centre for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore 637553. and Departments of Biomedical Engineering and Materials Science & Engineering, University of California, Davis, California 95616, USA.
| | - Madhavan Nallani
- Centre for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore 637553.
| | - Sara Sandin
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore 639798 and School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Bo Liedberg
- Centre for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore 637553.
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37
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Manna M, Javanainen M, Monne HMS, Gabius HJ, Rog T, Vattulainen I. Long-chain GM1 gangliosides alter transmembrane domain registration through interdigitation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:870-878. [PMID: 28143757 DOI: 10.1016/j.bbamem.2017.01.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/02/2017] [Accepted: 01/27/2017] [Indexed: 12/25/2022]
Abstract
Extracellular and cytosolic leaflets in cellular membranes are distinctly different in lipid composition, yet they contribute together to signaling across the membranes. Here we consider a mechanism based on long-chain gangliosides for coupling the extracellular and cytosolic membrane leaflets together. Based on atomistic molecular dynamics simulations, we find that long-chain GM1 in the extracellular leaflet exhibits a strong tendency to protrude into the opposing bilayer leaflet. This interdigitation modulates the order in the cytosolic monolayer and thereby strengthens the interaction and coupling across a membrane. Coarse-grained simulations probing longer time scales in large membrane systems indicate that GM1 in the extracellular leaflet modulates the phase behavior in the cytosolic monolayer. While short-chain GM1 maintains phase-symmetric bilayers with a strong membrane registration effect, the situation is altered with long-chain GM1. Here, the significant interdigitation induced by long-chain GM1 modulates the behavior in the cytosolic GM1-free leaflet, weakening and slowing down the membrane registration process. The observed physical interaction mechanism provides a possible means to mediate or foster transmembrane communication associated with signal transduction.
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Affiliation(s)
- Moutusi Manna
- Department of Physics, Tampere University of Technology, P. O. Box 692, FI- 33101 Tampere, Finland
| | - Matti Javanainen
- Department of Physics, Tampere University of Technology, P. O. Box 692, FI- 33101 Tampere, Finland; Department of Physics, POB 64, FI-00014 University of Helsinki, Finland
| | - Hector Martinez-Seara Monne
- Department of Physics, Tampere University of Technology, P. O. Box 692, FI- 33101 Tampere, Finland; Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, CZ-16610, Prague, Czech Republic
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig Maximilian University, D-80539 Munchen, Germany
| | - Tomasz Rog
- Department of Physics, Tampere University of Technology, P. O. Box 692, FI- 33101 Tampere, Finland; Department of Physics, POB 64, FI-00014 University of Helsinki, Finland
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, P. O. Box 692, FI- 33101 Tampere, Finland; Department of Physics, POB 64, FI-00014 University of Helsinki, Finland; MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, Odense, Denmark.
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38
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Hoiles W, Gupta R, Cornell B, Cranfield C, Krishnamurthy V. The Effect of Tethers on Artificial Cell Membranes: A Coarse-Grained Molecular Dynamics Study. PLoS One 2016; 11:e0162790. [PMID: 27736860 PMCID: PMC5063460 DOI: 10.1371/journal.pone.0162790] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 08/29/2016] [Indexed: 11/18/2022] Open
Abstract
Tethered bilayer lipid membranes (tBLMs) provide a stable platform for modeling the dynamics and order of biological membranes where the tethers mimic the cytoskeletal supports present in biological cell membranes. In this paper coarse-grained molecular dynamics (CGMD) is applied to study the effects of tethers on lipid membrane properties. Using results from the CGMD model and the overdamped Fokker-Planck equation, we show that the diffusion tensor and particle density of water in the tBLM is spatially dependent. Further, it is shown that the membrane thickness, lipid diffusion, defect density, free energy of lipid flip-flop, and membrane dielectric permittivity are all dependent on the tether density. The numerically computed results from the CGMD model are in agreement with the experimentally measured results from tBLMs containing different tether densities and lipids derived from Archaebacteria. Additionally, using experimental measurements from Escherichia coli bacteria and Saccharomyces Cerevisiae yeast tethered membranes, we illustrate how previous molecular dynamics results can be combined with the proposed model to estimate the dielectric permittivity and defect density of these membranes as a function of tether density.
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Affiliation(s)
- William Hoiles
- Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Rini Gupta
- Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Bruce Cornell
- Director of Science and Technology, Surgical Diagnostics Pty Ltd., Unit 6 30-32 Barcoo Street, Roseville, New South Wales, 2069, Australia
| | - Charles Cranfield
- School of Life Sciences, University of Technology Sydney, Broadway, New South Wales, Australia
| | - Vikram Krishnamurthy
- Electrical and Computer Engineering, Cornell University, New York, New York, United States of America
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39
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Pyne A, Pfeil MP, Bennett I, Ravi J, Iavicoli P, Lamarre B, Roethke A, Ray S, Jiang H, Bella A, Reisinger B, Yin D, Little B, Muñoz-García JC, Cerasoli E, Judge PJ, Faruqui N, Calzolai L, Henrion A, Martyna GJ, Grovenor CRM, Crain J, Hoogenboom BW, Watts A, Ryadnov MG. Engineering monolayer poration for rapid exfoliation of microbial membranes. Chem Sci 2016; 8:1105-1115. [PMID: 28451250 PMCID: PMC5369539 DOI: 10.1039/c6sc02925f] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 09/25/2016] [Indexed: 12/04/2022] Open
Abstract
A novel mechanism of monolayer poration leading to the rapid exfoliation and lysis of microbial membranes is reported.
The spread of bacterial resistance to traditional antibiotics continues to stimulate the search for alternative antimicrobial strategies. All forms of life, from bacteria to humans, are postulated to rely on a fundamental host defense mechanism, which exploits the formation of open pores in microbial phospholipid bilayers. Here we predict that transmembrane poration is not necessary for antimicrobial activity and reveal a distinct poration mechanism that targets the outer leaflet of phospholipid bilayers. Using a combination of molecular-scale and real-time imaging, spectroscopy and spectrometry approaches, we introduce a structural motif with a universal insertion mode in reconstituted membranes and live bacteria. We demonstrate that this motif rapidly assembles into monolayer pits that coalesce during progressive membrane exfoliation, leading to bacterial cell death within minutes. The findings offer a new physical basis for designing effective antibiotics.
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Affiliation(s)
- Alice Pyne
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK . .,London Centre for Nanotechnology and Department of Physics and Astronomy , University College London , London WC1E 6BT , UK
| | - Marc-Philipp Pfeil
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK . .,Department of Biochemistry , University of Oxford , Oxford OX1 3QU , UK
| | - Isabel Bennett
- London Centre for Nanotechnology and Department of Physics and Astronomy , University College London , London WC1E 6BT , UK
| | - Jascindra Ravi
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK .
| | - Patrizia Iavicoli
- European Commission , Joint Research Centre , Institute for Health and Consumer Protection , Ispra (VA) , Italy
| | - Baptiste Lamarre
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK .
| | - Anita Roethke
- Physikalisch-Technische Bundesanstalt , 38116 Braunschweig , Germany
| | - Santanu Ray
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK .
| | - Haibo Jiang
- Centre for Microscopy , Characterisation and Analysis , The University of Western Australia , Crawley , Western Australia 6009 , Australia
| | - Angelo Bella
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK .
| | - Bernd Reisinger
- Physikalisch-Technische Bundesanstalt , 38116 Braunschweig , Germany
| | - Daniel Yin
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK . .,Department of Biochemistry , University of Oxford , Oxford OX1 3QU , UK
| | - Benjamin Little
- School of Physics and Astronomy , University of Edinburgh , Edinburgh EH9 3JZ , UK
| | | | - Eleonora Cerasoli
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK .
| | - Peter J Judge
- Department of Biochemistry , University of Oxford , Oxford OX1 3QU , UK
| | - Nilofar Faruqui
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK .
| | - Luigi Calzolai
- European Commission , Joint Research Centre , Institute for Health and Consumer Protection , Ispra (VA) , Italy
| | - Andre Henrion
- Physikalisch-Technische Bundesanstalt , 38116 Braunschweig , Germany
| | - Glenn J Martyna
- IBM T. J. Watson Research Center , Yorktown Heights , NY 10598 , USA
| | | | - Jason Crain
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK . .,School of Physics and Astronomy , University of Edinburgh , Edinburgh EH9 3JZ , UK
| | - Bart W Hoogenboom
- London Centre for Nanotechnology and Department of Physics and Astronomy , University College London , London WC1E 6BT , UK
| | - Anthony Watts
- Department of Biochemistry , University of Oxford , Oxford OX1 3QU , UK
| | - Maxim G Ryadnov
- National Physical Laboratory , Teddington , Middlesex TW11 0LW , UK .
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40
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Understanding the formation of supported lipid bilayers via vesicle fusion—A case that exemplifies the need for the complementary method approach (Review). Biointerphases 2016; 11:020801. [DOI: 10.1116/1.4944830] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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41
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Tian J, Nickels J, Katsaras J, Cheng X. Behavior of Bilayer Leaflets in Asymmetric Model Membranes: Atomistic Simulation Studies. J Phys Chem B 2016; 120:8438-48. [DOI: 10.1021/acs.jpcb.6b02148] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - John Katsaras
- The Bredesen Center for Interdisciplinary Research and Graduate Education, 444 Greve Hall, 821 Volunteer Boulevard, Knoxville, Tennessee 37996-3394, United States
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42
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Okamoto R, Kanemori Y, Komura S, Fournier JB. Relaxation dynamics of two-component fluid bilayer membranes. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2016; 39:52. [PMID: 27145960 DOI: 10.1140/epje/i2016-16052-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 06/05/2023]
Abstract
We theoretically investigate the relaxation dynamics of a nearly flat binary lipid bilayer membrane by taking into account the membrane tension, hydrodynamics of the surrounding fluid, inter-monolayer friction and mutual diffusion. Mutual diffusion is the collective irreversible process that leads to homogenization of the density difference between the two lipid species. We find that two relaxation modes associated with the mutual diffusion appear in addition to the three previously discussed relaxation modes reflecting the bending and compression of the membrane. Because of the symmetry, only one of the two diffusive modes is coupled to the bending mode. The two diffusive modes are much slower than the bending and compression modes in the entire realistic wave number range. This means that the long time relaxation behavior is dominated by the mutual diffusion in binary membranes. The two diffusive modes become even slower in the vicinity of the unstable region towards phase separation, while the other modes are almost unchanged. In short time scales, on the other hand, the lipid composition heterogeneity induces in-plane compression and bending of the bilayer.
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Affiliation(s)
- Ryuichi Okamoto
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 192-0397, Tokyo, Japan.
- Université Paris Diderot, Sorbonne Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205, Paris, France.
| | - Yuichi Kanemori
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 192-0397, Tokyo, Japan
| | - Shigeyuki Komura
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 192-0397, Tokyo, Japan
- Université Paris Diderot, Sorbonne Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205, Paris, France
| | - Jean-Baptiste Fournier
- Université Paris Diderot, Sorbonne Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205, Paris, France
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43
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Williamson JJ, Olmsted PD. Registered and antiregistered phase separation of mixed amphiphilic bilayers. Biophys J 2016; 108:1963-76. [PMID: 25902436 DOI: 10.1016/j.bpj.2015.03.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 01/19/2023] Open
Abstract
We derive a mean-field free energy for the phase behavior of coupled bilayer leaflets, which is implicated in cellular processes and important to the design of artificial membranes. Our model accounts for amphiphile-level structural features, particularly hydrophobic mismatch, which promotes antiregistration, in competition with the direct transmidplane coupling usually studied, which promotes registration. We show that the phase diagram of coupled leaflets allows multiple metastable coexistences, and we illustrate the kinetic implications of this with a detailed study of a bilayer of equimolar overall composition. For approximate parameters estimated to apply to phospholipids, equilibrium coexistence is typically registered, but metastable antiregistered phases can be kinetically favored by hydrophobic mismatch. Thus, a bilayer in the spinodal region can require nucleation to equilibrate, in a novel manifestation of Ostwald's rule of stages. Our results provide a framework for understanding disparate existing observations in the literature, elucidating a subtle competition of couplings and a key role for phase-transition kinetics in bilayer phase behavior.
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Affiliation(s)
- John J Williamson
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, D.C..
| | - Peter D Olmsted
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, D.C..
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Williamson JJ, Olmsted PD. Nucleation of symmetric domains in the coupled leaflets of a bilayer. SOFT MATTER 2015; 11:8948-8959. [PMID: 26412192 DOI: 10.1039/c5sm01328c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We study the kinetics governing the attainment of inter-leaflet domain symmetry in a phase-separating amphiphilic bilayer. "Indirect" inter-leaflet coupling via hydrophobic mismatch can induce an instability towards a metastable pattern of locally asymmetric domains upon quenching from high temperature. This necessitates a nucleation step to form the conventional symmetric domains, which are favoured by a "direct" inter-leaflet coupling. We model the energetics for a symmetric domain to nucleate from the metastable state, and find that an interplay between hydrophobic mismatch and thickness stretching/compression causes the effective hydrophobic mismatch, and thus line tension, to depend on domain size. This leads to strong departure from classical nucleation theory. We speculate on implications for cell membrane rafts or clusters, whose size may be of similar magnitude to estimated critical radii for domain symmetry.
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Affiliation(s)
- J J Williamson
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, 37th and O Streets, N.W., Washington, D.C. 20057, USA.
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Nickels JD, Smith JC, Cheng X. Lateral organization, bilayer asymmetry, and inter-leaflet coupling of biological membranes. Chem Phys Lipids 2015; 192:87-99. [DOI: 10.1016/j.chemphyslip.2015.07.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/20/2015] [Accepted: 07/25/2015] [Indexed: 11/28/2022]
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Williamson JJ, Olmsted PD. Kinetics of symmetry and asymmetry in a phase-separating bilayer membrane. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:052721. [PMID: 26651737 DOI: 10.1103/physreve.92.052721] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 06/05/2023]
Abstract
We simulate a phase-separating bilayer in which the leaflets experience a direct coupling favoring local compositional symmetry ("registered" bilayer phases), and an indirect coupling due to hydrophobic mismatch that favors strong local asymmetry ("antiregistered" bilayer phases). For wide ranges of overall leaflet compositions, multiple competing states are possible. For estimated physical parameters, a quenched bilayer may first evolve toward a metastable state more asymmetric than if the leaflets were uncorrelated; subsequently, it must nucleate to reach its equilibrium, more symmetric, state. These phase-transition kinetics exhibit characteristic signatures through which fundamental and opposing interleaflet interactions may be probed. We emphasize how bilayer phase diagrams with a separate axis for each leaflet can account for overall and local symmetry or asymmetry, and capture a range of observations in the experiment and simulation literature.
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Affiliation(s)
- J J Williamson
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, 37th and O Streets, N.W., Washington, D.C. 20057, USA
| | - P D Olmsted
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, 37th and O Streets, N.W., Washington, D.C. 20057, USA
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47
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Brown KL, Conboy JC. Phosphatidylglycerol Flip-Flop Suppression due to Headgroup Charge Repulsion. J Phys Chem B 2015. [DOI: 10.1021/acs.jpcb.5b05523] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Krystal L. Brown
- Department
of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84103, United States
| | - John C. Conboy
- Department
of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84103, United States
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48
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Mangiarotti A, Wilke N. Energetics of the Phase Transition in Free-Standing versus Supported Lipid Membranes. J Phys Chem B 2015; 119:8718-24. [DOI: 10.1021/acs.jpcb.5b04397] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Agustín Mangiarotti
- Centro
de Investigaciones
en Química Biológica de Córdoba (CIQUIBIC, UNC−CONICET),
Departamento de Química Biológica, Facultad de Ciencias
Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina
Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Natalia Wilke
- Centro
de Investigaciones
en Química Biológica de Córdoba (CIQUIBIC, UNC−CONICET),
Departamento de Química Biológica, Facultad de Ciencias
Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina
Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina
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Jing Y, Trefná HD, Persson M, Svedhem S. Heat-activated liposome targeting to streptavidin-coated surfaces. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1417-23. [DOI: 10.1016/j.bbamem.2015.02.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 02/01/2015] [Accepted: 02/20/2015] [Indexed: 12/23/2022]
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50
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Marquardt D, Geier B, Pabst G. Asymmetric lipid membranes: towards more realistic model systems. MEMBRANES 2015; 5:180-96. [PMID: 25955841 PMCID: PMC4496639 DOI: 10.3390/membranes5020180] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 04/28/2015] [Indexed: 01/23/2023]
Abstract
Despite the ubiquity of transbilayer asymmetry in natural cell membranes, the vast majority of existing research has utilized chemically well-defined symmetric liposomes, where the inner and outer bilayer leaflets have the same composition. Here, we review various aspects of asymmetry in nature and in model systems in anticipation for the next phase of model membrane studies.
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Affiliation(s)
- Drew Marquardt
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstr 50/III, Graz, 8010, Austria.
- BioTechMed-Graz, Graz, 8010, Austria.
| | - Barbara Geier
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstr 50/III, Graz, 8010, Austria.
- BioTechMed-Graz, Graz, 8010, Austria.
| | - Georg Pabst
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstr 50/III, Graz, 8010, Austria.
- BioTechMed-Graz, Graz, 8010, Austria.
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