1
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Thakur GCN, Uday A, Cebecauer M, Roos WH, Cwiklik L, Hof M, Jurkiewicz P, Melcrová A. Charge of a transmembrane peptide alters its interaction with lipid membranes. Colloids Surf B Biointerfaces 2024; 235:113765. [PMID: 38309153 DOI: 10.1016/j.colsurfb.2024.113765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
Transmembrane (TM) proteins interact closely with the surrounding membrane lipids. Lipids in the vicinity of TM proteins were reported to have hindered mobility, which has been associated with lipids being caught up in the rough surface of the TM domains. These reports, however, neglect one important factor that largely influences the membrane behavior - electrostatics of the TM peptides that are usually positively charged at their cytosolic end. Here, we study on the example of a neutral and a positively charged WALP peptide, how the charge of a TM peptide influences the membrane. We investigate both its dynamics and mechanics by: (i) time dependent fluorescent shift in combination with classical and FRET generalized polarization to evaluate the mobility of lipids at short and long-range distance from the peptide, (ii) atomic force microscopy to observe the mechanical stability of the peptide-containing membranes, and (iii) molecular dynamics simulations to analyze the peptide-lipid interactions. We show that both TM peptides lower lipid mobility in their closest surroundings. The peptides cause lateral heterogeneity in lipid mobility, which in turn prevents free lipid rearrangement and lowers the membrane ability to seal ruptures after mechanical indentations. Introduction of a positive charge to the peptide largely enhances these effects, affecting the whole membrane. We thus highlight that unspecific peptide-lipid interactions, especially the electrostatics, should not be overlooked as they have a great impact on the mechanics and dynamics of the whole membrane.
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Affiliation(s)
- Garima C N Thakur
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Arunima Uday
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; University of Chemical and Technology, Technická 5, Dejvice, 160 00 Prague 6, Czech Republic
| | - Marek Cebecauer
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Wouter H Roos
- Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague 6, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic.
| | - Adéla Melcrová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, 182 23 Prague 8, Czech Republic; Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
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2
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Kim J. A Review of Continuum Mechanics for Mechanical Deformation of Lipid Membranes. MEMBRANES 2023; 13:membranes13050493. [PMID: 37233554 DOI: 10.3390/membranes13050493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023]
Abstract
Mechanical deformation of lipid membranes plays important roles in various cellular tasks. Curvature deformation and lateral stretching are two major energy contributions to the mechanical deformation of lipid membranes. In this paper, continuum theories for these two major membrane deformation events were reviewed. Theories based on curvature elasticity and lateral surface tension were introduced. Numerical methods as well as biological applications of the theories were discussed.
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Affiliation(s)
- Jichul Kim
- INTEGRITY Co., Ltd., 9, Gangnamseo-ro, Giheung-gu, Yongin-si 16977, Gyeonggi-do, Republic of Korea
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3
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Battista S, Köber M, Bellio P, Celenza G, Galantini L, Vargas-Nadal G, Fagnani L, Veciana J, Ventosa N, Giansanti L. Quatsomes Formulated with l-Prolinol-Derived Surfactants as Antibacterial Nanocarriers of (+)-Usnic Acid with Antioxidant Activity. ACS APPLIED NANO MATERIALS 2022; 5:6140-6148. [PMID: 35655931 PMCID: PMC9150064 DOI: 10.1021/acsanm.1c04365] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/21/2022] [Indexed: 06/15/2023]
Abstract
The efficacy of the treatment of bacterial infection is seriously reduced because of antibiotic resistance; thus, therapeutic solutions against drug-resistant microbes are necessary. Nanoparticle-based solutions are particularly promising for meeting this challenge because they can offer intrinsic antimicrobial activity and sustained drug release at the target site. Herein, we present a newly developed nanovesicle system of the quatsome family, composed of l-prolinol-derived surfactants and cholesterol, which has noticeable antibacterial activity even on Gram-negative strains, demonstrating great potential for the treatment of bacterial infections. We optimized the vesicle stability and antibacterial activity by tuning the surfactant chain length and headgroup charge (cationic or zwitterionic) and show that these quatsomes can furthermore serve as nanocarriers of pharmaceutical actives, demonstrated here by the encapsulation of (+)-usnic acid, a natural substance with many pharmacological properties.
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Affiliation(s)
- Sara Battista
- Dipartimento
di Scienze Fisiche e Chimiche, Università
degli Studi dell’Aquila, Via Vetoio, 67010 Coppito, L’Aquila, Italy
| | - Mariana Köber
- Institut
de Ciència de Materials de Barcelona (ICMAB-CSIC), Esfera Universitat Autónoma de Barcelona (UAB); Campus UAB s/n, E-08193 Cerdanyola del Vallès, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Campus Universitari de Bellaterra, E-08193 Cerdanyola, Spain
| | - Pierangelo Bellio
- Dipartimento
di Scienze Cliniche Applicate e Biotecnologie, Università degli Studi dell’Aquila, Via Vetoio, 67010 Coppito, L’Aquila, Italy
| | - Giuseppe Celenza
- Dipartimento
di Scienze Cliniche Applicate e Biotecnologie, Università degli Studi dell’Aquila, Via Vetoio, 67010 Coppito, L’Aquila, Italy
| | - Luciano Galantini
- Dipartimento
di Chimica, Università di Roma “Sapienza”, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Guillem Vargas-Nadal
- Institut
de Ciència de Materials de Barcelona (ICMAB-CSIC), Esfera Universitat Autónoma de Barcelona (UAB); Campus UAB s/n, E-08193 Cerdanyola del Vallès, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Campus Universitari de Bellaterra, E-08193 Cerdanyola, Spain
| | - Lorenza Fagnani
- Dipartimento
di Scienze Cliniche Applicate e Biotecnologie, Università degli Studi dell’Aquila, Via Vetoio, 67010 Coppito, L’Aquila, Italy
| | - Jaume Veciana
- Institut
de Ciència de Materials de Barcelona (ICMAB-CSIC), Esfera Universitat Autónoma de Barcelona (UAB); Campus UAB s/n, E-08193 Cerdanyola del Vallès, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Campus Universitari de Bellaterra, E-08193 Cerdanyola, Spain
| | - Nora Ventosa
- Institut
de Ciència de Materials de Barcelona (ICMAB-CSIC), Esfera Universitat Autónoma de Barcelona (UAB); Campus UAB s/n, E-08193 Cerdanyola del Vallès, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Campus Universitari de Bellaterra, E-08193 Cerdanyola, Spain
| | - Luisa Giansanti
- Dipartimento
di Scienze Fisiche e Chimiche, Università
degli Studi dell’Aquila, Via Vetoio, 67010 Coppito, L’Aquila, Italy
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4
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Zheng W, Xie R, Liang X, Liang Q. Fabrication of Biomaterials and Biostructures Based On Microfluidic Manipulation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2105867. [PMID: 35072338 DOI: 10.1002/smll.202105867] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Biofabrication technologies are of importance for the construction of organ models and functional tissue replacements. Microfluidic manipulation, a promising biofabrication technique with micro-scale resolution, can not only help to realize the fabrication of specific microsized structures but also build biomimetic microenvironments for biofabricated tissues. Therefore, microfluidic manipulation has attracted attention from researchers in the manipulation of particles and cells, biochemical analysis, tissue engineering, disease diagnostics, and drug discovery. Herein, biofabrication based on microfluidic manipulation technology is reviewed. The application of microfluidic manipulation technology in the manufacturing of biomaterials and biostructures with different dimensions and the control of the microenvironment is summarized. Finally, current challenges are discussed and a prospect of microfluidic manipulation technology is given. The authors hope this review can provide an overview of microfluidic manipulation technologies used in biofabrication and thus steer the current efforts in this field.
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Affiliation(s)
- Wenchen Zheng
- Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Ruoxiao Xie
- Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Xiaoping Liang
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangdong, 510006, China
| | - Qionglin Liang
- Department of Chemistry, Tsinghua University, Beijing, 100084, China
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5
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Lipid Self-Assemblies under the Atomic Force Microscope. Int J Mol Sci 2021; 22:ijms221810085. [PMID: 34576248 PMCID: PMC8467407 DOI: 10.3390/ijms221810085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 12/13/2022] Open
Abstract
Lipid model membranes are important tools in the study of biophysical processes such as lipid self-assembly and lipid–lipid interactions in cell membranes. The use of model systems to adequate and modulate complexity helps in the understanding of many events that occur in cellular membranes, that exhibit a wide variety of components, including lipids of different subfamilies (e.g., phospholipids, sphingolipids, sterols…), in addition to proteins and sugars. The capacity of lipids to segregate by themselves into different phases at the nanoscale (nanodomains) is an intriguing feature that is yet to be fully characterized in vivo due to the proposed transient nature of these domains in living systems. Model lipid membranes, instead, have the advantage of (usually) greater phase stability, together with the possibility of fully controlling the system lipid composition. Atomic force microscopy (AFM) is a powerful tool to detect the presence of meso- and nanodomains in a lipid membrane. It also allows the direct quantification of nanomechanical resistance in each phase present. In this review, we explore the main kinds of lipid assemblies used as model membranes and describe AFM experiments on model membranes. In addition, we discuss how these assemblies have extended our knowledge of membrane biophysics over the last two decades, particularly in issues related to the variability of different model membranes and the impact of supports/cytoskeleton on lipid behavior, such as segregated domain size or bilayer leaflet uncoupling.
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6
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Merminod S, Edison JR, Fang H, Hagan MF, Rogers WB. Avidity and surface mobility in multivalent ligand-receptor binding. NANOSCALE 2021; 13:12602-12612. [PMID: 34259699 PMCID: PMC8386892 DOI: 10.1039/d1nr02083h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Targeted drug delivery relies on two physical processes: the selective binding of a therapeutic particle to receptors on a specific cell membrane, followed by transport of the particle across the membrane. In this article, we address some of the challenges in controlling the thermodynamics and dynamics of these two processes by combining a simple experimental system with a statistical mechanical model. Specifically, we characterize and model multivalent ligand-receptor binding between colloidal particles and fluid lipid bilayers, as well as the surface mobility of membrane-bound particles. We show that the mobility of the receptors within the fluid membrane is key to both the thermodynamics and dynamics of binding. First, we find that the particle-membrane binding free energy-or avidity-is a strongly nonlinear function of the ligand-receptor affinity. We attribute the nonlinearity to a combination of multivalency and recruitment of fluid receptors to the binding site. Our results also suggest that partial wrapping of the bound particles by the membrane enhances avidity further. Second, we demonstrate that the lateral mobility of membrane-bound particles is also strongly influenced by the recruitment of receptors. Specifically, we find that the lateral diffusion coefficient of a membrane-bound particle is dominated by the hydrodynamic drag against the aggregate of receptors within the membrane. These results provide one of the first direct validations of the working theoretical framework for multivalent interactions. They also highlight that the fluidity and elasticity of the membrane are as important as the ligand-receptor affinity in determining the binding and transport of small particles attached to membranes.
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Affiliation(s)
- Simon Merminod
- Martin A. Fisher School of Physics, Brandeis University, Waltham, MA 02453, USA.
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7
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Paraschiv A, Lagny TJ, Campos CV, Coudrier E, Bassereau P, Šarić A. Influence of membrane-cortex linkers on the extrusion of membrane tubes. Biophys J 2021; 120:598-606. [PMID: 33460596 PMCID: PMC7896025 DOI: 10.1016/j.bpj.2020.12.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/10/2020] [Accepted: 12/30/2020] [Indexed: 01/06/2023] Open
Abstract
The cell membrane is an inhomogeneous system composed of phospholipids, sterols, carbohydrates, and proteins that can be directly attached to underlying cytoskeleton. The protein linkers between the membrane and the cytoskeleton are believed to have a profound effect on the mechanical properties of the cell membrane and its ability to reshape. Here, we investigate the role of membrane-cortex linkers on the extrusion of membrane tubes using computer simulations and experiments. In simulations, we find that the force for tube extrusion has a nonlinear dependence on the density of membrane-cortex attachments: at a range of low and intermediate linker densities, the force is not significantly influenced by the presence of the membrane-cortex attachments and resembles that of the bare membrane. For large concentrations of linkers, however, the force substantially increases compared with the bare membrane. In both cases, the linkers provided membrane tubes with increased stability against coalescence. We then pulled tubes from HEK cells using optical tweezers for varying expression levels of the membrane-cortex attachment protein Ezrin. In line with simulations, we observed that overexpression of Ezrin led to an increased extrusion force, while Ezrin depletion had a negligible effect on the force. Our results shed light on the importance of local protein rearrangements for membrane reshaping at nanoscopic scales.
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Affiliation(s)
- Alexandru Paraschiv
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London, United Kingdom; MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Thibaut J Lagny
- Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France; Sorbonne Université, Paris, France; Institut Curie, PSL Research University CNRS UMR 144, Paris, France
| | - Christian Vanhille Campos
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London, United Kingdom; MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Evelyne Coudrier
- Institut Curie, PSL Research University CNRS UMR 144, Paris, France
| | - Patricia Bassereau
- Laboratoire Physico-Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France; Sorbonne Université, Paris, France
| | - Anđela Šarić
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London, United Kingdom; MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom.
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8
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Plochberger B, Sych T, Weber F, Novacek J, Axmann M, Stangl H, Sezgin E. Lipoprotein Particles Interact with Membranes and Transfer Their Cargo without Receptors. Biochemistry 2020; 59:4421-4428. [PMID: 33147967 PMCID: PMC7677925 DOI: 10.1021/acs.biochem.0c00748] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Lipid transfer from lipoprotein particles to cells is essential for lipid homeostasis. High-density lipoprotein (HDL) particles are mainly captured by cell membrane-associated scavenger receptor class B type 1 (SR-B1) from the bloodstream, while low-density and very-low-density lipoprotein (LDL and VLDL, respectively) particles are mostly taken up by receptor-mediated endocytosis. However, the role of the target lipid membrane itself in the transfer process has been largely neglected so far. Here, we study how lipoprotein particles (HDL, LDL, and VLDL) interact with synthetic lipid bilayers and cell-derived membranes and transfer their cargo subsequently. Employing cryo-electron microscopy, spectral imaging, and fluorescence (cross) correlation spectroscopy allowed us to observe integration of all major types of lipoprotein particles into the membrane and delivery of their cargo in a receptor-independent manner. Importantly, the biophysical properties of the target cell membranes change upon delivery of cargo. The concept of receptor-independent interaction of lipoprotein particles with membranes helps us to better understand lipoprotein particle biology and can be exploited for novel treatments of dyslipidemia diseases.
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Affiliation(s)
- Birgit Plochberger
- TU Wien, Institute of Applied Physics, Vienna 1040, Austria.,Johannes Kepler University Linz, Institute of Biophysics, Linz 4020, Austria.,Upper Austria University of Applied Sciences, Campus Linz, Linz 4020, Austria
| | - Taras Sych
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
| | - Florian Weber
- Upper Austria University of Applied Sciences, Campus Linz, Linz 4020, Austria.,Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
| | - Jiri Novacek
- CEITEC, Masaryk University, University Campus Bohunice, Brno 62500, Czech Republic
| | - Markus Axmann
- Medical University of Vienna, Center for Pathobiochemistry and Genetics, Institute of Medical Chemistry, Vienna 1090, Austria
| | - Herbert Stangl
- Medical University of Vienna, Center for Pathobiochemistry and Genetics, Institute of Medical Chemistry, Vienna 1090, Austria
| | - Erdinc Sezgin
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden.,MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, U.K
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9
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Redondo-Morata L, Losada-Pérez P, Giannotti MI. Lipid bilayers: Phase behavior and nanomechanics. CURRENT TOPICS IN MEMBRANES 2020; 86:1-55. [PMID: 33837691 DOI: 10.1016/bs.ctm.2020.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lipid membranes are involved in many physiological processes like recognition, signaling, fusion or remodeling of the cell membrane or some of its internal compartments. Within the cell, they are the ultimate barrier, while maintaining the fluidity or flexibility required for a myriad of processes, including membrane protein assembly. The physical properties of in vitro model membranes as model cell membranes have been extensively studied with a variety of techniques, from classical thermodynamics to advanced modern microscopies. Here we review the nanomechanics of solid-supported lipid membranes with a focus in their phase behavior. Relevant information obtained by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM) as complementary techniques in the nano/mesoscale interface is presented. Membrane morphological and mechanical characterization will be discussed in the framework of its phase behavior, phase transitions and coexistence, in simple and complex models, and upon the presence of cholesterol.
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Affiliation(s)
- Lorena Redondo-Morata
- Center for Infection and Immunity of Lille, INSERM U1019, CNRS UMR 8204, Lille, France
| | - Patricia Losada-Pérez
- Experimental Soft Matter and Thermal Physics (EST) Group, Department of Physics, Université Libre de Bruxelles, Brussels, Belgium
| | - Marina Inés Giannotti
- Biomedical Research Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain; Institut de Bioenginyeria de Catalunya (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; Departament de Ciència de Materials i Química Física, Universitat de Barcelona, Barcelona, Spain.
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10
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Saavedra V O, Fernandes TFD, Milhiet PE, Costa L. Compression, Rupture, and Puncture of Model Membranes at the Molecular Scale. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5709-5716. [PMID: 32427478 DOI: 10.1021/acs.langmuir.0c00247] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Elastic properties of biological membranes are involved in a large number of membrane functionalities and activities. Conventionally characterized in terms of Young's modulus, bending stiffness and stretching modulus, membrane mechanics can be assessed at high lateral resolution by means of atomic force microscopy (AFM). Here we show that the mechanical response of biomimetic model systems such as supported lipid bilayers (SLBs) is highly affected by the size of the AFM tip employed as a membrane indenter. Our study is focused on phase-separated fluid-gel lipid membranes at room temperature. In a small tip radius regime (≈ 2 nm) and in the case of fluid phase membranes, we show that the tip can penetrate through the membrane minimizing molecular vertical compression and in absence of molecular membrane rupture. In this case, AFM indentation experiments cannot assess the vertical membrane Young's modulus. In agreement with the data reported in the literature, in the case of larger indenters (>2 nm) SLBs can be compressed leading to an evaluation of Young's modulus and membrane maximal withstanding force before rupture. We show that such force increases with the indenter in agreement with the existing theoretical frame. Finally, we demonstrate that the latter has no influence on the number of molecules involved in the rupture process that is observed to be constant and rather dependent on the indenter chemical composition.
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Affiliation(s)
- Oscar Saavedra V
- Centre de Biochimie Structurale (CBS), CNRS, INSERM, Univ. Montpellier, 34090 Montpellier, France
| | - Thales F D Fernandes
- Centre de Biochimie Structurale (CBS), CNRS, INSERM, Univ. Montpellier, 34090 Montpellier, France
| | - Pierre-Emmanuel Milhiet
- Centre de Biochimie Structurale (CBS), CNRS, INSERM, Univ. Montpellier, 34090 Montpellier, France
| | - Luca Costa
- Centre de Biochimie Structurale (CBS), CNRS, INSERM, Univ. Montpellier, 34090 Montpellier, France
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11
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Nanomechanical properties of steric zipper globular structures. Proc Natl Acad Sci U S A 2019; 116:22478-22484. [PMID: 31636220 DOI: 10.1073/pnas.1908782116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The term amyloid defines a group of proteins that aggregate into plaques or fibers. Amyloid fibers gained their fame mostly due to their relation with neurodegenerative diseases in humans. However, secreted by lower organisms, such as bacteria and fungi, amyloid fibers play a functional role: for example, when they serve as cement in the extracellular matrix of biofilms. Originating either in humans or in microorganisms, the sequence of amyloid proteins is decorated with hexapeptides with high propensity to form fibers, known as steric zippers. We have found that steric zippers form globular structures on route to making fibers and exhibit a characteristic force-distance (F-D) fingerprint when pulled with an atomic force microscope (AFM) tip. Particularly, the F-D pulling curves showed force plateau steps, suggesting that the globular structures were composed of chains that were unwound like a yarn ball. Force plateau analysis showed that the F-D characteristic parameters were sequence sensitive, representing differences in the packing of the hexapeptides within the globules. These unprecedented findings show that steric zippers exhibit a characteristic nanomechanical signature in solution in addition to previously observed characteristic crystallographic structure. Getting to the fundamental interactions that govern the unzipping of full-length amyloid fibers may initiate the development of antiamyloid methods that target the physical in addition to the structural properties of steric zippers.
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12
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Gumí-Audenis B, Illa-Tuset S, Grimaldi N, Pasquina-Lemonche L, Ferrer-Tasies L, Sanz F, Veciana J, Ratera I, Faraudo J, Ventosa N, Giannotti MI. Insights into the structure and nanomechanics of a quatsome membrane by force spectroscopy measurements and molecular simulations. NANOSCALE 2018; 10:23001-23011. [PMID: 30500043 DOI: 10.1039/c8nr07110a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Quatsomes (QS) are unilamellar nanovesicles constituted by quaternary ammonium surfactants and sterols in defined molar ratios. Unlike conventional liposomes, QS are stable upon long storage such as for several years, they show outstanding vesicle-to-vesicle homogeneity regarding size and lamellarity, and they have the structural and physicochemical requirements to be a potential platform for site-specific delivery of hydrophilic and lipophilic molecules. Knowing in detail the structure and mechanical properties of the QS membrane is of great importance for the design of deformable and flexible nanovesicle alternatives, highly pursued in nanomedicine applications such as the transdermal administration route. In this work, we report the first study on the detailed structure of the cholesterol : CTAB QS membrane at the nanoscale, using atomic force microscopy (AFM) and spectroscopy (AFM-FS) in a controlled liquid environment (ionic medium and temperature) to assess the topography of supported QS membranes (SQMs) and to evaluate the local membrane mechanics. We further perform molecular dynamics (MD) simulations to provide an atomistic interpretation of the obtained results. Our results are direct evidence of the bilayer nature of the QS membrane, with characteristics of a fluid-like membrane, compact and homogeneous in composition, and with structural and mechanical properties that depend on the surrounding environment. We show how ions alter the lateral packing, modifying the membrane mechanics. We observe that according to the ionic environment and temperature, different domains may coexist in the QS membranes, ascribed to variations in molecular tilt angles. Our results indicate that QS membrane properties may be easily tuned by altering the lateral interactions with either different environmental ions or counterions.
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Affiliation(s)
- Berta Gumí-Audenis
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
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