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Lipids in Mitochondrial Macroautophagy: Phase Behavior of Bilayers Containing Cardiolipin and Ceramide. Int J Mol Sci 2023; 24:ijms24065080. [PMID: 36982156 PMCID: PMC10049649 DOI: 10.3390/ijms24065080] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 03/09/2023] Open
Abstract
Cardiolipin (CL) is a key lipid for damaged mitochondrial recognition by the LC3/GABARAP human autophagy proteins. The role of ceramide (Cer) in this process is unclear, but CL and Cer have been proposed to coexist in mitochondria under certain conditions. Varela et al. showed that in model membranes composed of egg sphingomyelin (eSM), dioleoyl phosphatidylethanolamine (DOPE), and CL, the addition of Cer enhanced the binding of LC3/GABARAP proteins to bilayers. Cer gave rise to lateral phase separation of Cer-rich rigid domains but protein binding took place mainly in the fluid continuous phase. In the present study, a biophysical analysis of bilayers composed of eSM, DOPE, CL, and/or Cer was attempted to understand the relevance of this lipid coexistence. Bilayers were studied by differential scanning calorimetry, confocal fluorescence microscopy, and atomic force microscopy. Upon the addition of CL and Cer, one continuous phase and two segregated ones were formed. In bilayers with egg phosphatidylcholine instead of eSM, in which the binding of LC3/GABARAP proteins hardly increased with Cer in the former study, a single segregated phase was formed. Assuming that phase separation at the nanoscale is ruled by the same principles acting at the micrometer scale, it is proposed that Cer-enriched rigid nanodomains, stabilized by eSM:Cer interactions formed within the DOPE- and CL-enriched fluid phase, result in structural defects at the rigid/fluid nanointerfaces, thus hypothetically facilitatingLC3/GABARAP protein interaction.
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Sot J, García-Arribas AB, Abad B, Arranz S, Portune K, Andrade F, Martín-Nieto A, Velasco O, Arana E, Tueros I, Ferreri C, Gaztambide S, Goñi FM, Castaño L, Alonso A. Erythrocyte Membrane Nanomechanical Rigidity Is Decreased in Obese Patients. Int J Mol Sci 2022; 23:ijms23031920. [PMID: 35163842 PMCID: PMC8836476 DOI: 10.3390/ijms23031920] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/04/2022] [Accepted: 02/06/2022] [Indexed: 12/13/2022] Open
Abstract
This work intends to describe the physical properties of red blood cell (RBC) membranes in obese adults. The hypothesis driving this research is that obesity, in addition to increasing the amount of body fat, will also modify the lipid composition of membranes in cells other than adipocytes. Forty-nine control volunteers (16 male, 33 female, BMI 21.8 ± 5.6 and 21.5 ± 4.2 kg/m2, respectively) and 52 obese subjects (16 male and 36 female, BMI 38.2± 11.0 and 40.7 ± 8.7 kg/m2, respectively) were examined. The two physical techniques applied were atomic force microscopy (AFM) in the force spectroscopy mode, which allows the micromechanical measurement of penetration forces, and fluorescence anisotropy of trimethylammonium diphenylhexatriene (TMA-DPH), which provides information on lipid order at the membrane polar–nonpolar interface. These techniques, in combination with lipidomic studies, revealed a decreased rigidity in the interfacial region of the RBC membranes of obese as compared to control patients, related to parallel changes in lipid composition. Lipidomic data show an increase in the cholesterol/phospholipid mole ratio and a decrease in sphingomyelin contents in obese membranes. ω-3 fatty acids (e.g., docosahexaenoic acid) appear to be less prevalent in obese patient RBCs, and this is the case for both the global fatty acid distribution and for the individual major lipids in the membrane phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS). Moreover, some ω-6 fatty acids (e.g., arachidonic acid) are increased in obese patient RBCs. The switch from ω-3 to ω-6 lipids in obese subjects could be a major factor explaining the higher interfacial fluidity in obese patient RBC membranes.
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Affiliation(s)
- Jesús Sot
- Instituto BIOFISIKA (CSIC, UPV/EHU), Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Spain; (J.S.); (A.B.G.-A.); (F.M.G.)
| | - Aritz B. García-Arribas
- Instituto BIOFISIKA (CSIC, UPV/EHU), Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Spain; (J.S.); (A.B.G.-A.); (F.M.G.)
| | - Beatriz Abad
- SGIKER, Servicios Generales de Investigación (SGiker), Universidad del País Vasco, 48940 Leioa, Spain;
| | - Sara Arranz
- AZTI, Food Research, Basque Research and Technology Alliance (BRTA), Parque Tecnológico de Bizkaia, Astondo Bidea, Edificio 609, 48160 Derio, Spain; (S.A.); (K.P.); (I.T.)
| | - Kevin Portune
- AZTI, Food Research, Basque Research and Technology Alliance (BRTA), Parque Tecnológico de Bizkaia, Astondo Bidea, Edificio 609, 48160 Derio, Spain; (S.A.); (K.P.); (I.T.)
| | - Fernando Andrade
- Biocruces Bizkaia, Hospital Universitario Cruces, CIBERDEM, CIBERER, Endo-ERN, UPV-EHU, 48903 Barakaldo, Spain; (F.A.); (A.M.-N.); (O.V.); (E.A.); (S.G.); (L.C.)
| | - Alicia Martín-Nieto
- Biocruces Bizkaia, Hospital Universitario Cruces, CIBERDEM, CIBERER, Endo-ERN, UPV-EHU, 48903 Barakaldo, Spain; (F.A.); (A.M.-N.); (O.V.); (E.A.); (S.G.); (L.C.)
| | - Olaia Velasco
- Biocruces Bizkaia, Hospital Universitario Cruces, CIBERDEM, CIBERER, Endo-ERN, UPV-EHU, 48903 Barakaldo, Spain; (F.A.); (A.M.-N.); (O.V.); (E.A.); (S.G.); (L.C.)
| | - Eunate Arana
- Biocruces Bizkaia, Hospital Universitario Cruces, CIBERDEM, CIBERER, Endo-ERN, UPV-EHU, 48903 Barakaldo, Spain; (F.A.); (A.M.-N.); (O.V.); (E.A.); (S.G.); (L.C.)
| | - Itziar Tueros
- AZTI, Food Research, Basque Research and Technology Alliance (BRTA), Parque Tecnológico de Bizkaia, Astondo Bidea, Edificio 609, 48160 Derio, Spain; (S.A.); (K.P.); (I.T.)
| | - Carla Ferreri
- ISOF, Consiglio Nazionale delle Ricerche, Via Piero Gobetti, 101, 40129 Bologna, Italy;
| | - Sonia Gaztambide
- Biocruces Bizkaia, Hospital Universitario Cruces, CIBERDEM, CIBERER, Endo-ERN, UPV-EHU, 48903 Barakaldo, Spain; (F.A.); (A.M.-N.); (O.V.); (E.A.); (S.G.); (L.C.)
| | - Félix M. Goñi
- Instituto BIOFISIKA (CSIC, UPV/EHU), Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Spain; (J.S.); (A.B.G.-A.); (F.M.G.)
| | - Luis Castaño
- Biocruces Bizkaia, Hospital Universitario Cruces, CIBERDEM, CIBERER, Endo-ERN, UPV-EHU, 48903 Barakaldo, Spain; (F.A.); (A.M.-N.); (O.V.); (E.A.); (S.G.); (L.C.)
| | - Alicia Alonso
- Instituto BIOFISIKA (CSIC, UPV/EHU), Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Spain; (J.S.); (A.B.G.-A.); (F.M.G.)
- Correspondence:
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Fonseka NM, Arce FT, Christie HS, Aspinwall CA, Saavedra SS. Nanomechanical Properties of Artificial Lipid Bilayers Composed of Fluid and Polymerizable Lipids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:100-111. [PMID: 34968052 DOI: 10.1021/acs.langmuir.1c02098] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Polymerization enhances the stability of a planar supported lipid bilayer (PSLB) but it also changes its chemical and mechanical properties, attenuates lipid diffusion, and may affect the activity of integral membrane proteins. Mixed bilayers composed of fluid lipids and poly(lipids) may provide an appropriate combination of polymeric stability coupled with the fluidity and elasticity needed to maintain the bioactivity of reconstituted receptors. Previously (Langmuir, 2019, 35, 12483-12491) we showed that binary mixtures of the polymerizable lipid bis-SorbPC and the fluid lipid DPhPC form phase-segregated PSLBs composed of nanoscale fluid and poly(lipid) domains. Here we used atomic force microscopy (AFM) to compare the nanoscale mechanical properties of these binary PSLBs with single-component PSLBs. The elastic (Young's) modulus, area compressibility modulus, and bending modulus of bis-SorbPC PSLBs increased upon polymerization. Before polymerization, breakthrough events at forces below 5 nN were observed, but after polymerization, the AFM tip could not penetrate the PSLB up to an applied force of 20 nN. These results are attributed to the polymeric network in poly(bis-SorbPC), which increases the bilayer stiffness and resists compression and bending. In binary DPhPC/poly(bis-SorbPC) PSLBs, the DPhPC domains are less stiff, more compressible, and are less resistant to rupture and bending compared to pure DPhPC bilayers. These differences are attributed to bis-SorbPC monomers and oligomers present in DPhPC domains that disrupt the packing of DPhPC molecules. In contrast, the poly(bis-SorbPC) domains are stiffer and less compressible relative to pure PSLBs; this difference is attributed to DPhPC filling the nm-scale pores in the polymerized domains that are created during bis-SorbPC polymerization. Thus, incomplete phase segregation increases the stability of poly(bis-SorbPC) but has the opposite, detrimental effect for DPhPC. Overall, these results provide guidance for the design of partially polymerized bilayers for technological uses.
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Affiliation(s)
- N Malithi Fonseka
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Fernando Teran Arce
- Department of Medicine, University of Arizona, Tucson, Arizona 85721, United States
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Hamish S Christie
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Craig A Aspinwall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
- BIO5 Institute and Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - S Scott Saavedra
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
- BIO5 Institute and Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
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Galluzzi M, Marfori L, Asperti S, De Vita A, Giannangeli M, Caselli A, Milani P, Podestà A. Interaction of imidazolium-based ionic liquids with supported phospholipid bilayers as model biomembranes. Phys Chem Chem Phys 2022; 24:27328-27342. [DOI: 10.1039/d2cp02866b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The cytotoxicity of ionic liquids (ILs) is receiving increasing attention due to their potential biological and environmental impact. We have used atomic force microscopy to investigate the interaction of ILs with supported phospholipid bilayers, as models of biomembranes.
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Affiliation(s)
- Massimiliano Galluzzi
- Materials Interfaces Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, Guangdong, China
- C.I.Ma.I.Na and Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, via Celoria 16, 20133-Milano, Italy
| | - Lorenzo Marfori
- C.I.Ma.I.Na and Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, via Celoria 16, 20133-Milano, Italy
| | - Stefania Asperti
- C.I.Ma.I.Na and Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, via Celoria 16, 20133-Milano, Italy
| | - Alessandro De Vita
- C.I.Ma.I.Na and Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, via Celoria 16, 20133-Milano, Italy
| | - Matteo Giannangeli
- Dipartimento di Chimica and CNR-SCITEC, Università degli Studi di Milano, via Golgi 19, 20133-Milano, Italy
| | - Alessandro Caselli
- Dipartimento di Chimica and CNR-SCITEC, Università degli Studi di Milano, via Golgi 19, 20133-Milano, Italy
| | - Paolo Milani
- C.I.Ma.I.Na and Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, via Celoria 16, 20133-Milano, Italy
| | - Alessandro Podestà
- C.I.Ma.I.Na and Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, via Celoria 16, 20133-Milano, Italy
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Galluzzi M, Zhang B, Zhang H, Wang L, Lin Y, Yu XF, Chu Z, Li J. Unveiling a Hidden Event in Fluorescence Correlative Microscopy by AFM Nanomechanical Analysis. Front Mol Biosci 2021; 8:669361. [PMID: 34026842 PMCID: PMC8136518 DOI: 10.3389/fmolb.2021.669361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/22/2021] [Indexed: 11/18/2022] Open
Abstract
Fluorescent imaging combined with atomic force microscopy (AFM), namely AFM-fluorescence correlative microscopy, is a popular technology in life science. However, the influence of involved fluorophores on obtained mechanical information is normally underestimated, and such subtle changes are still challenging to detect. Herein, we combined AFM with laser light excitation to perform a mechanical quantitative analysis of a model membrane system labeled with a commonly used fluorophore. Mechanical quantification was additionally validated by finite element simulations. Upon staining, we noticed fluorophores forming a diffuse weakly organized overlayer on phospholipid supported membrane, easily detected by AFM mechanics. The laser was found to cause a degradation of mechanical stability of the membrane synergically with presence of fluorophore. In particular, a 30 min laser irradiation, with intensity similar to that in typical confocal scanning microscopy experiment, was found to result in a ∼40% decrease in the breakthrough force of the stained phospholipid bilayer along with a ∼30% reduction in its apparent elastic modulus. The findings highlight the significance of analytical power provided by AFM, which will allow us to “see” the “unseen” in correlative microscopy, as well as the necessity to consider photothermal effects when using fluorescent dyes to investigate, for example, the deformability and permeability of phospholipid membranes.
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Affiliation(s)
- Massimiliano Galluzzi
- Materials Interfaces Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Bokai Zhang
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,DGene (Dongjin Big Health (Shenzhen)) Co., Ltd., Shenzhen, China.,BenHealth Biopharmaceutical (Shenzhen) Co., Ltd., Shenzhen, China
| | - Han Zhang
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,State Key Laboratory of Traction Power, Southwest Jiaotong Univerisity, Chengdu, China
| | - Lingzhi Wang
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong
| | - Yuan Lin
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong.,Advanced Biomedical Instrumentation Centre, Shatin, Hong Kong
| | - Xue-Feng Yu
- Materials Interfaces Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Zhiqin Chu
- Department of Electrical and Electronic Engineering, Joint Appointment with School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Jiangyu Li
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, China
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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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Yang Y, Bu X, Zhang X. Regulation Mechanism of Bubbling Deformation and Fracture Toughness of the Membrane by Asymmetric Phospholipids: A Model System Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:10138-10146. [PMID: 32787040 DOI: 10.1021/acs.langmuir.0c01580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dynamic regulation of the deformation modulus and fracture toughness of a membrane is critical to organelles and cells for matching their conflicting needs of resilient and fractured behaviors. These properties implement the protection of the function in the normal condition and the fission function in the endocytosis condition of a membrane. Naturally, a membrane contains phospholipids that have different hydrophilic and hydrophobic group length. The diffusion and aggregation of the phospholipids with asymmetry of the hydrophilic-hydrophobic ratio on the membrane play a key role in regulating the mechanical behaviors passively to the external force. In present work, the effects of the asymmetry of phospholipids on the bubbling deformation and fracture toughness of the membrane to external stretching are investigated in a model system. A disk-shaped micelle formed from the blend of symmetric and asymmetric diblock copolymers in a selective solvent is considered as the membrane sheet. Its mechanically responsive behaviors are investigated by self-consistent field theory. By analyzing the evolution of different components during the stretching process, the mechanism of formation of the bubbling structure is revealed. Moreover, the fracture toughness depending on the asymmetry of the phospholipids is determined quantitatively.
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Affiliation(s)
- Yang Yang
- School of Science, Beijing Jiaotong University, Beijing 100044, PR China
| | - Xiangyu Bu
- School of Science, Beijing Jiaotong University, Beijing 100044, PR China
| | - Xinghua Zhang
- School of Science, Beijing Jiaotong University, Beijing 100044, PR China
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Obeid S, Guyomarc'h F. Atomic force microscopy of food assembly: Structural and mechanical insights at the nanoscale and potential opportunities from other fields. FOOD BIOSCI 2020. [DOI: 10.1016/j.fbio.2020.100654] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Mescola A, Dauvin M, Amoroso A, Duwez AS, Joris B. Single-molecule force spectroscopy to decipher the early signalling step in membrane-bound penicillin receptors embedded into a lipid bilayer. NANOSCALE 2019; 11:12275-12284. [PMID: 31211302 DOI: 10.1039/c9nr02466b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Understanding the molecular mechanism by which the signal of the presence of an antibiotic is transduced from outside to inside the bacterial cell is of fundamental interest for the β-lactam antibiotic resistance problem, but remains difficult to accomplish. No approach has ever addressed entire penicillin receptors in a membrane environment. Here we describe a method to investigate the purified Bacillus licheniformis BlaR1 receptor -a membrane-bound penicillin receptor involved in β-lactam resistance- embedded into a lipid bilayer in absence or presence of penicillin. By selecting a mutated receptor blocked in its signal transduction pathway just after its activation by penicillin, we revealed the very first step of receptor signalling by unfolding the receptor from its C-terminal end by AFM-based single-molecule force spectroscopy. We showed that the presence of the antibiotic entails significant conformational changes within the receptor. Our approach opens an avenue to study signal-transduction pathways mediated by membrane-bound proteins in a membrane environment.
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Affiliation(s)
- Andrea Mescola
- Molecular Systems, Department of Chemistry, University of Liège, 4000 Liège, Belgium.
| | - Marjorie Dauvin
- Bacterial physiology and genetics - Centre d'Ingénierie des Protéines-Integrative Biological Sciences, Department of Life Sciences, University of Liège, 4000 Liège, Belgium
| | - Ana Amoroso
- Bacterial physiology and genetics - Centre d'Ingénierie des Protéines-Integrative Biological Sciences, Department of Life Sciences, University of Liège, 4000 Liège, Belgium
| | - Anne-Sophie Duwez
- Molecular Systems, Department of Chemistry, University of Liège, 4000 Liège, Belgium.
| | - Bernard Joris
- Bacterial physiology and genetics - Centre d'Ingénierie des Protéines-Integrative Biological Sciences, Department of Life Sciences, University of Liège, 4000 Liège, Belgium
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Role of Lipid Composition, Physicochemical Interactions, and Membrane Mechanics in the Molecular Actions of Microbial Cyclic Lipopeptides. J Membr Biol 2019; 252:131-157. [PMID: 31098678 DOI: 10.1007/s00232-019-00067-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 05/02/2019] [Indexed: 10/26/2022]
Abstract
Several experimental and theoretical studies have extensively investigated the effects of a large diversity of antimicrobial peptides (AMPs) on model lipid bilayers and living cells. Many of these peptides disturb cells by forming pores in the plasma membrane that eventually lead to the cell death. The complexity of these peptide-lipid interactions is mainly related to electrostatic, hydrophobic and topological issues of these counterparts. Diverse studies have shed some light on how AMPs act on lipid bilayers composed by different phospholipids, and how mechanical properties of membranes could affect the antimicrobial effects of such compounds. On the other hand, cyclic lipopeptides (cLPs), an important class of microbial secondary metabolites, have received comparatively less attention. Due to their amphipathic structures, cLPs exhibit interesting biological activities including interactions with biofilms, anti-bacterial, anti-fungal, antiviral, and anti-tumoral properties, which deserve more investigation. Understanding how physicochemical properties of lipid bilayers contribute and determining the antagonistic activity of these secondary metabolites over a broad spectrum of microbial pathogens could establish a framework to design and select effective strategies of biological control. This implies unravelling-at the biophysical level-the complex interactions established between cLPs and lipid bilayers. This review presents, in a systematic manner, the diversity of lipidated antibiotics produced by different microorganisms, with a critical analysis of the perturbing actions that have been reported in the literature for this specific set of membrane-active lipopeptides during their interactions with model membranes and in vivo. With an overview on the mechanical properties of lipid bilayers that can be experimentally determined, we also discuss which parameters are relevant in the understanding of those perturbation effects. Finally, we expose in brief, how this knowledge can help to design novel strategies to use these biosurfactants in the agronomic and pharmaceutical industries.
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Oroskar PA, Jameson CJ, Murad S. Molecular-Level "Observations" of the Behavior of Gold Nanoparticles in Aqueous Solution and Interacting with a Lipid Bilayer Membrane. Methods Mol Biol 2019; 2000:303-359. [PMID: 31148024 DOI: 10.1007/978-1-4939-9516-5_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We use coarse-grained molecular dynamics simulations to "observe" details of interactions between ligand-covered gold nanoparticles and a lipid bilayer model membrane. In molecular dynamics simulations, one puts the individual atoms and groups of atoms of the physical system to be "observed" into a simulation box, specifies the forms of the potential energies of interactions between them (ultimately quantum based), and lets them individually move classically according to Newton's equations of motion, based on the forces arising from the assumed potential energy forms. The atoms that are chemically bonded to each other stay chemically bonded, following known potentials (force fields) that permit internal degrees of freedom (internal rotation, torsion, vibrations), and the interactions between nonbonded atoms are simplified to Lennard-Jones forms (in our case) and coulombic (where electrical charges are present) in which the parameters are previously optimized to reproduce thermodynamic properties or are based on quantum electronic calculations. The system is started out at a reasonable set of coordinates for all atoms or groups of atoms, and then permitted to develop according to the equations of motion, one small step (usually 10 fs time step) at a time, for millions of steps until the system is at a quasi-equilibrium (usually reached after hundreds of nanoseconds). We then let the system play out its motions further for many nanoseconds to observe the behavior, periodically taking snapshots (saving all positions and energies), and post-processing the snapshots to obtain various average descriptions of the system. Alkanethiols of various lengths serve as examples of hydrophobic ligands and methyl-terminated PEG with various numbers of monomer units serve as examples of hydrophilic ligands. Spherical gold particles of various diameters as well as gold nanorods form the core to which ligands are attached. The nanoparticles are characterized at the molecular level, especially the distributions of ligand configurations and their dependence on ligand length, and surface coverage. Self-assembly of the bilayer from an isotropic solution and observation of membrane properties that correspond well to experimental values validate the simulations. The mechanism of permeation of a gold NP coated with either a hydrophobic or a hydrophilic ligand, and its dependence on surface coverage, ligand length, core diameter, and core shape, is investigated. Lipid response such as lipid flip-flops, lipid extraction, and changes in order parameter of the lipid tails are examined in detail. The mechanism of permeation of a PEGylated nanorod is shown to occur by tilting, lying down, rotating, and straightening up. The nature of the information provided by molecular dynamics simulations permits understanding of the detailed behavior of gold nanoparticles interacting with lipid membranes which in turn helps to understand why some known systems work better than others and aids the design of new particles and improvement of methods for preparing existing ones.
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Affiliation(s)
- Priyanka A Oroskar
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Cynthia J Jameson
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Sohail Murad
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL, USA.
- Department of Chemical Engineering, Illinois Institute of Technology, Chicago, IL, USA.
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Effects of the peptide Magainin H2 on Supported Lipid Bilayers studied by different biophysical techniques. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2635-2643. [DOI: 10.1016/j.bbamem.2018.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 11/24/2022]
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13
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Lee CW, Chiang YL, Liu JT, Chen YX, Lee CH, Chen YL, Hwang IS. Emerging Roles of Air Gases in Lipid Bilayers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1802133. [PMID: 30168661 DOI: 10.1002/smll.201802133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/31/2018] [Indexed: 06/08/2023]
Abstract
Recent studies indicate that changing the physical properties of lipid bilayers may profoundly change the function of membrane proteins. Here, the effects of dissolved nitrogen and oxygen molecules on the mechanical properties and stability of lipid bilayers are investigated using differential confocal microscopy, atomic force microscopy, and molecular dynamics simulations. All experiments evidence the presence of dissolved air gas in lipid bilayers prepared without gas control. The lipid bilayers in degassed solutions are softer and less stable than those in ambient solutions. High concentrations of nitrogen increase the bending moduli and stability of the lipid bilayers and impede phase separation in ternary lipid bilayers. The effect of oxygen is less prominent. Molecular dynamics simulations indicate that higher nitrogen affinity accounts for increased rigidity. These findings have fundamental and wide implications for phenomena related to lipid bilayers and cell membranes, including the origin of life.
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Affiliation(s)
- Chia-Wei Lee
- Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Ya-Ling Chiang
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
| | - Ji-Ting Liu
- Institute of Biophotonics, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Yi-Xian Chen
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
| | - Chau-Hwang Lee
- Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan
- Institute of Biophotonics, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Yeng-Long Chen
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
| | - Ing-Shouh Hwang
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
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14
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Hall AR, Geoghegan M. Polymers and biopolymers at interfaces. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:036601. [PMID: 29368695 DOI: 10.1088/1361-6633/aa9e9c] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This review updates recent progress in the understanding of the behaviour of polymers at surfaces and interfaces, highlighting examples in the areas of wetting, dewetting, crystallization, and 'smart' materials. Recent developments in analysis tools have yielded a large increase in the study of biological systems, and some of these will also be discussed, focussing on areas where surfaces are important. These areas include molecular binding events and protein adsorption as well as the mapping of the surfaces of cells. Important techniques commonly used for the analysis of surfaces and interfaces are discussed separately to aid the understanding of their application.
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Affiliation(s)
- A R Hall
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH, United Kingdom. Fraunhofer Project Centre for Embedded Bioanalytical Systems, Dublin City University, Glasnevin, Dublin 9, Ireland
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15
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Franzé S, Donadoni G, Podestà A, Procacci P, Orioli M, Carini M, Minghetti P, Cilurzo F. Tuning the Extent and Depth of Penetration of Flexible Liposomes in Human Skin. Mol Pharm 2017; 14:1998-2009. [PMID: 28409629 DOI: 10.1021/acs.molpharmaceut.7b00099] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work we made an attempt to assess the effect of drug-induced changes of flexibility on the penetration of deformable vesicles into the human skin. Eight cationic liposomes with different degrees of flexibility were obtained by entrapping unfractionated heparin, enoxaparin, and nadroparin. The deformability was studied by a novel, facile, and reliable extrusion assay appositely developed and validated by means of quantitative nanoscale mechanical AFM measurements of vesicle elastic modulus (log10(YM)). The proposed extrusion assay, determining the forces involved in vesicles deformation, resulted very sensitive to evidence of minimal changes in bilayer rigidity (σ) and vesicle deformation (K). The drug loading caused a reduction of liposome flexibility with respect to the reference plain liposomes and in accordance to the heparin type, drug to cationic lipid (DOTAP) ratio, and drug distribution within the vesicles. Interestingly, the σ and log10(YM) values perfectly correlated (R2 = 0.935), demonstrating the reliability of the deformability data obtained with both approaches. The combination of TEM and LC-MS/MS spectrometry allowed the pattern of the penetration of the entire vesicles into the skin to be followed. In all cases, intact liposomes in the epidermis layers were observed and a relationship between the depth of penetration and the liposome flexibility was found, supporting the hypothesis of the whole vesicle penetration mechanism. Moreover, the results of the extent (R24) of vesicle penetration in the human skin samples showed a direct relation to the flexibility values (σ1 = 0.65 ± 0.10 MPa → R24 = 3.33 ± 0.02 μg/mg; σ2 = 0.95 ± 0.04 MPa → R24 = 1.18 ± 0.26 μg/mg; σ3 = 1.89 ± 0.30 MPa → R24 = 0.53 ± 0.33 μg/mg).
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Affiliation(s)
- Silvia Franzé
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , via G. Colombo 71, 20133 Milano, Italy
| | - Giulia Donadoni
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , via G. Colombo 71, 20133 Milano, Italy
| | - Alessandro Podestà
- Department of Physics and CIMaINa, Università degli Studi di Milano , via Celoria 16, 20133 Milano, Italy
| | - Patrizia Procacci
- Biomedical Sciences for Health, Università degli Studi di Milano , via G. Colombo 71, 20133 Milano, Italy
| | - Marica Orioli
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , via G. Colombo 71, 20133 Milano, Italy
| | - Marina Carini
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , via G. Colombo 71, 20133 Milano, Italy
| | - Paola Minghetti
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , via G. Colombo 71, 20133 Milano, Italy
| | - Francesco Cilurzo
- Department of Pharmaceutical Sciences, Università degli Studi di Milano , via G. Colombo 71, 20133 Milano, Italy
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16
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Gumí-Audenis B, Costa L, Carlá F, Comin F, Sanz F, Giannotti MI. Structure and Nanomechanics of Model Membranes by Atomic Force Microscopy and Spectroscopy: Insights into the Role of Cholesterol and Sphingolipids. MEMBRANES 2016; 6:E58. [PMID: 27999368 PMCID: PMC5192414 DOI: 10.3390/membranes6040058] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/12/2016] [Accepted: 12/14/2016] [Indexed: 11/17/2022]
Abstract
Biological membranes mediate several biological processes that are directly associated with their physical properties but sometimes difficult to evaluate. Supported lipid bilayers (SLBs) are model systems widely used to characterize the structure of biological membranes. Cholesterol (Chol) plays an essential role in the modulation of membrane physical properties. It directly influences the order and mechanical stability of the lipid bilayers, and it is known to laterally segregate in rafts in the outer leaflet of the membrane together with sphingolipids (SLs). Atomic force microscope (AFM) is a powerful tool as it is capable to sense and apply forces with high accuracy, with distance and force resolution at the nanoscale, and in a controlled environment. AFM-based force spectroscopy (AFM-FS) has become a crucial technique to study the nanomechanical stability of SLBs by controlling the liquid media and the temperature variations. In this contribution, we review recent AFM and AFM-FS studies on the effect of Chol on the morphology and mechanical properties of model SLBs, including complex bilayers containing SLs. We also introduce a promising combination of AFM and X-ray (XR) techniques that allows for in situ characterization of dynamic processes, providing structural, morphological, and nanomechanical information.
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Affiliation(s)
- Berta Gumí-Audenis
- Nanoprobes and Nanoswitches group, Institute for Bioengineering of Catalunya (IBEC), Barcelona 08028, Spain.
- Physical Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain.
- European Synchrotron Radiation Facility (ESRF), Grenoble 38043, France.
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28028, Spain.
| | - Luca Costa
- Structure and Dynamics of Nucleoproteic and Membrane Assemblies, Centre de Biochimie Structurale (CBS), Montpellier 34090, France.
| | - Francesco Carlá
- European Synchrotron Radiation Facility (ESRF), Grenoble 38043, France.
| | - Fabio Comin
- European Synchrotron Radiation Facility (ESRF), Grenoble 38043, France.
| | - Fausto Sanz
- Nanoprobes and Nanoswitches group, Institute for Bioengineering of Catalunya (IBEC), Barcelona 08028, Spain.
- Physical Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain.
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28028, Spain.
| | - Marina I Giannotti
- Nanoprobes and Nanoswitches group, Institute for Bioengineering of Catalunya (IBEC), Barcelona 08028, Spain.
- Physical Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain.
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28028, Spain.
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17
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Stetter FW, Hyun SH, Brander S, Urban JM, Thompson DH, Hugel T. Nanomechanical characterization of lipid bilayers with AFM-based methods. POLYMER 2016. [DOI: 10.1016/j.polymer.2015.11.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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García-Arribas AB, Ahyayauch H, Sot J, López-González PL, Alonso A, Goñi FM. Ceramide-Induced Lamellar Gel Phases in Fluid Cell Lipid Extracts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:9053-9063. [PMID: 27486830 DOI: 10.1021/acs.langmuir.6b01579] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effects of increasing amounts of palmitoylceramide (pCer) on human red blood cell lipid membranes have been studied using atomic force microscopy of supported lipid bilayers, in both imaging (bilayer thickness) and force-spectroscopy (nanomechanical resistance) modes. Membranes appeared homogeneous with pCer concentrations up to 10 mol % because of the high concentration of cholesterol (Chol) present in the membrane (∼45 mol %). However, the presence of pCer at 30 mol % gave rise to a clearly distinguishable segregated phase with a nanomechanical resistance 7-fold higher than the continuous phase. These experiments were validated using differential scanning calorimetry. Furthermore, Chol depletion of the bilayers caused lipid domain generation in the originally homogeneous samples, and Chol-depleted domain stiffness significantly increased with higher amounts of pCer. These results point to the possibility of different kinds of transient and noncompositionally constant, complex gel-like phases present in RBC lipid membranes rich in both pCer and Chol, in contrast to the widespread opinion about the displacements between pCer-enriched "gel-like" domains and liquid-ordered "raft-like" Chol-enriched phases. Changes in the biophysical properties of these complex gel-like phases governed by local modulation of pCer:Chol ratios could be a cell mechanism for fine-tuning the properties of membranes as required.
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Affiliation(s)
- Aritz B García-Arribas
- Biofisika Institute (CSIC, UPV/EHU) , 48940 Leioa, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48940 Leioa, Spain
| | - Hasna Ahyayauch
- Biofisika Institute (CSIC, UPV/EHU) , 48940 Leioa, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48940 Leioa, Spain
- Institut Supérieur Des Professions Infirmières Et Des Techniques De Santé Rabat, Km 4.5 route de Casa, Rabat, Morocco
| | - Jesús Sot
- Biofisika Institute (CSIC, UPV/EHU) , 48940 Leioa, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48940 Leioa, Spain
| | - Pablo L López-González
- Biofisika Institute (CSIC, UPV/EHU) , 48940 Leioa, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48940 Leioa, Spain
| | - Alicia Alonso
- Biofisika Institute (CSIC, UPV/EHU) , 48940 Leioa, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48940 Leioa, Spain
| | - Félix M Goñi
- Biofisika Institute (CSIC, UPV/EHU) , 48940 Leioa, Spain
- Departamento de Bioquímica, University of the Basque Country (UPV/EHU) , 48940 Leioa, Spain
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19
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The temperature-dependent physical state of polar lipids and their miscibility impact the topography and mechanical properties of bilayer models of the milk fat globule membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2181-2190. [DOI: 10.1016/j.bbamem.2016.06.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/19/2016] [Accepted: 06/22/2016] [Indexed: 11/23/2022]
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20
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Hu X, Lei H, Zhang X, Zhang Y. Strong hydrophobic interaction between graphene oxide and supported lipid bilayers revealed by AFM. Microsc Res Tech 2016; 79:721-6. [PMID: 27252153 DOI: 10.1002/jemt.22690] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 02/27/2016] [Accepted: 05/19/2016] [Indexed: 01/30/2023]
Abstract
Understanding the interaction between graphene oxide (GO) and lipid membranes is of great importance for its various applications in biotechnology. Here, we investigated the interaction between GO and charged supported lipid bilayers (SLBs) by in situ atomic force microscope (AFM) imaging. It was found that GO could peel off a single layer of positively charged SLBs and deposited on the hydrophobic part of the remaining sublayer. Then free lipid molecules would assemble on GO surface and formed 1.5 bilayers in a lipid-GO-lipid manner. For negatively charged lipid bilayers, however, GO deposited to the SLBs only when its concentration was very high. These results indicate that, in addition to electrostatic interaction, the hydrophobic interaction plays an important role when GO sheets deposit onto the charged lipid bilayers, and should be helpful to understand possible cytotoxicity and antibiosis of graphene-related nanomaterials. Microsc. Res. Tech. 79:721-726, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiuyuan Hu
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Haozhi Lei
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xueqiang Zhang
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi Zhang
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China
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21
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García-Arribas AB, Busto JV, Alonso A, Goñi FM. Atomic force microscopy characterization of palmitoylceramide and cholesterol effects on phospholipid bilayers: a topographic and nanomechanical study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3135-3145. [PMID: 25693914 DOI: 10.1021/la504047n] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Supported planar bilayers (SPBs) on mica substrates have been studied at 23 °C under atomic force microscopy (AFM)-based surface topography and force spectroscopy with two main objectives: (i) to characterize palmitoylceramide (pCer)-induced gel (Lβ) domains in binary mixtures with either its sphingolipid relative palmitoylsphingomyelin (pSM) or the glycerophospholipid dipalmitoylphosphorylcholine (DPPC) and (ii) to evaluate effects of incorporating cholesterol (Chol) into the previous mixtures in terms of Cer and Chol cooperation for the generation of lamellar gel (Lβ) phases of ternary composition. Binary phospholipid/pCer mixtures at XpCer < 0.33 promote the generation of laterally segregated micron-sized pCer-rich domains. Their analysis at different phospholipid/pCer ratios, by means of domain thickness, roughness, and mechanical resistance to tip piercing, reveals unvarying AFM-derived features over increasing pCer concentrations. These results suggest that the domains grow in size with increasing pCer concentrations while keeping a constant phospholipid/pCer stoichiometry. Moreover, the data show important differences between pCer interactions with pSM or DPPC. Gel domains generated in pSM/pCer bilayers are thinner than the pSM-rich surrounding phase, while the opposite is observed in DPPC/pCer mixtures. Furthermore, a higher breakthrough force is observed for pSM/pCer as compared to DPPC/pCer domains, which can be associated with the preferential pCer interaction with its sphingolipid relative pSM. Cholesterol incorporation into both binary mixtures at a high Chol and pCer ratio abolishes any phospholipid/pCer binary domains. Bilayers with properties different from any of the pure or binary samples are observed instead. The data support no displacement of Chol by pCer or vice versa under these conditions, but rather a preferential interaction between the two hydrophobic lipids.
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Affiliation(s)
- Aritz B García-Arribas
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - Jon V Busto
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - Alicia Alonso
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - Félix M Goñi
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
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22
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Bozó T, Brecska R, Gróf P, Kellermayer MSZ. Extreme resilience in cochleate nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:839-845. [PMID: 25521248 DOI: 10.1021/la504428x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cochleates, prospective nanoscale drug delivery vehicles, are rolls of negatively charged phospholipid membrane layers. The membrane layers are held together by calcium ions; however, neither the magnitude of membrane interaction forces nor the overall mechanical properties of cochleates have been known. Here, we manipulated individual nanoparticles with atomic force microscopy to characterize their nanomechanical behavior. Their stiffness (4.2-12.5 N/m) and membrane-rupture forces (45.3-278 nN) are orders of magnitude greater than those of the tough viral nanoshells. Even though the fundamental building material of cochleates is a fluid membrane, the combination of supramolecular geometry, the cross-linking action of calcium, and the tight packing of the ions apparently lead to extreme mechanical resilience. The supramolecular design of cochleates may provide efficient protection for encapsulated materials and give clues to understanding biomolecular structures of similar design, such as the myelinated axon.
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Affiliation(s)
- Tamás Bozó
- Department of Biophysics and Radiation Biology, and ‡MTA-SE Molecular Biophysics Research Group, Semmelweis University , Tűzoltó utca 37-47, Budapest 1094, Hungary
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23
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Abstract
Recent progress in surface science, nanotechnology and biophysics has cast new light on the correlation between the physicochemical properties of biomaterials and the resulting biological response. One experimental tool that promises to generate an increasingly more sophisticated knowledge of how proteins, cells and bacteria interact with nanostructured surfaces is the atomic force microscope (AFM). This unique instrument permits to close in on interfacial events at the scale at which they occur, the nanoscale. This perspective covers recent developments in the exploitation of the AFM, and suggests insights on future opportunities that can arise from the exploitation of this powerful technique.
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Affiliation(s)
- Fabio Variola
- Faculty of Engineering, Department of Mechanical Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
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Alessandrini A, Facci P. Phase transitions in supported lipid bilayers studied by AFM. SOFT MATTER 2014; 10:7145-7164. [PMID: 25090108 DOI: 10.1039/c4sm01104j] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We review the capabilities of Atomic Force Microscopy (AFM) in the study of phase transitions in Supported Lipid Bilayers (SLBs). AFM represents a powerful technique to cover the resolution range not available to fluorescence imaging techniques and where spectroscopic data suggest what the relevant lateral scale for domain formation might be. Phase transitions of lipid bilayers involve the formation of domains characterized by different heights with respect to the surrounding phase and are therefore easily identified by AFM in liquid solution once the bilayer is confined to a flat surface. Even if not endowed with high time resolution, AFM allows light to be shed on some aspects related to lipid phase transitions in the case of both a single lipid component and lipid mixtures containing sterols also. We discuss here the obtained results in light of the peculiarities of supported lipid bilayer model systems.
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Affiliation(s)
- Andrea Alessandrini
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Via Campi 213/A, 41125, Modena, Italy.
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25
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Suárez-Germà C, Morros A, Montero M, Hernández-Borrell J, Domènech Ò. Combined force spectroscopy, AFM and calorimetric studies to reveal the nanostructural organization of biomimetic membranes. Chem Phys Lipids 2014; 183:208-17. [DOI: 10.1016/j.chemphyslip.2014.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/14/2014] [Accepted: 07/28/2014] [Indexed: 01/12/2023]
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26
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Picas L, Milhiet PE, Hernández-Borrell J. Atomic force microscopy: a versatile tool to probe the physical and chemical properties of supported membranes at the nanoscale. Chem Phys Lipids 2012. [PMID: 23194897 DOI: 10.1016/j.chemphyslip.2012.10.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Atomic force microscopy (AFM) was developed in the 1980s following the invention of its precursor, scanning tunneling microscopy (STM), earlier in the decade. Several modes of operation have evolved, demonstrating the extreme versatility of this method for measuring the physicochemical properties of samples at the nanoscopic scale. AFM has proved an invaluable technique for visualizing the topographic characteristics of phospholipid monolayers and bilayers, such as roughness, height or laterally segregated domains. Implemented modes such as phase imaging have also provided criteria for discriminating the viscoelastic properties of different supported lipid bilayer (SLB) regions. In this review, we focus on the AFM force spectroscopy (FS) mode, which enables determination of the nanomechanical properties of membrane models. The interpretation of force curves is presented, together with newly emerging techniques that provide complementary information on physicochemical properties that may contribute to our understanding of the structure and function of biomembranes. Since AFM is an imaging technique, some basic indications on how real-time AFM imaging is evolving are also presented at the end of this paper.
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Affiliation(s)
- Laura Picas
- Institut Curie, CNRS UMR 144, 26 rue d'Ulm, 75248 Paris, France
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