1
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Koynarev V, Borgos KKA, Kohlbrecher J, Porcar L, Nielsen JE, Lund R. Antimicrobial Peptides Increase Line Tension in Raft-Forming Lipid Membranes. J Am Chem Soc 2024; 146:20891-20903. [PMID: 39018511 PMCID: PMC11295182 DOI: 10.1021/jacs.4c05377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/19/2024]
Abstract
The formation of phase separated membrane domains is believed to be essential for the function of the cell. The precise composition and physical properties of lipid bilayer domains play crucial roles in regulating protein activity and governing cellular processes. Perturbation of the domain structure in human cells can be related to neurodegenerative diseases and cancer. Lipid rafts are also believed to be essential in bacteria, potentially serving as targets for antibiotics. An important question is how the membrane domain structure is affected by bioactive and therapeutic molecules, such as surface-active peptides, which target cellular membranes. Here we focus on antimicrobial peptides (AMPs), crucial components of the innate immune system, to gain insights into their interaction with model lipid membranes containing domains. Using small-angle neutron/X-ray scattering (SANS/SAXS), we show that the addition of several natural AMPs (indolicidin, LL-37, magainin II, and aurein 2.2) causes substantial growth and restructuring of the domains, which corresponds to increased line tension. Contrast variation SANS and SAXS results demonstrate that the peptide inserts evenly in both phases, and the increased line tension can be related to preferential and concentration dependent thinning of the unsaturated membrane phase. We speculate that the lateral restructuring caused by the AMPs may have important consequences in affecting physiological functions of real cells. This work thus shines important light onto the complex interactions and lateral (re)organization in lipid membranes, which is relevant for a molecular understanding of diseases and the action of antibiotics.
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Affiliation(s)
| | | | - Joachim Kohlbrecher
- Laboratory
for Neutron Scattering and Imaging, Paul
Scherrer Institut, Villigen 5232, Switzerland
| | - Lionel Porcar
- Institut
Laue-Langevin, 71 Av. des Martyrs, 38000 Grenoble, France
| | | | - Reidar Lund
- Department
of Chemistry, University of Oslo, Postboks 1033 Blindern, 0315 Oslo, Norway
- Hylleraas
Centre for Quantum Molecular Sciences, University
of Oslo, Postboks 1033 Blindern, 0315 Oslo, Norway
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2
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Wang K, Cai W. Binding mechanism of full-length Aβ40 peptide to a mixed lipid bilayer. Front Chem 2024; 12:1367793. [PMID: 38449479 PMCID: PMC10914957 DOI: 10.3389/fchem.2024.1367793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 02/05/2024] [Indexed: 03/08/2024] Open
Abstract
The destructive effect of Aβ peptides on membranes is an important source of its cytotoxicity in the pathogenesis of Alzheimer's disease. We have investigated the binding mechanism between the Aβ42 peptide and bilayer in our former work. However, as another abundant form of Aβ peptides in the physiological environment, the binding mechanism between Aβ40 peptide and the lipid bilayer still remains ambiguous. Hence, we performed all-atom simulations on the Aβ40 peptides with the lipid bilayer herein using replica exchange with the solute tempering 2 method. We obtained four major binding models with the hydrophobic C-terminus as the most preferable binding region. Hydrophobic residues and positively charged residues are the principal residues involved in the peptide-bilayer interactions. Aβ40 peptides in our simulation mainly adopt a β-rich conformation in both bound and unbound states. Besides, we determined peptide-water interactions and found that bound peptides prefer forming hydrogen bonds with water molecules than unbound peptides. Our findings herein may provide new insights for the in-depth understanding of the membrane-destructive mechanism of Aβ peptides.
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Affiliation(s)
| | - Wensheng Cai
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin, China
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3
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Wang K, Cai W. Aggregation, structure and water permeability of membrane-embedded helical Aβ oligomers. Phys Chem Chem Phys 2024; 26:5128-5140. [PMID: 38259193 DOI: 10.1039/d3cp05317b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
It is widely recognized that membranes can facilitate the aggregation of amyloid-β (Aβ) peptides, while Aβ can in turn cause membrane damage. Many studies focus on the peptide-membrane interactions of Aβ oligomers with β-rich structures. However, the exact aggregation and toxicity mechanism of the membrane-embedded helical Aβ oligomers remain ambiguous. Herein, the molecular dynamics simulations were performed on membrane-embedded helical Aβ42 peptides. Initiated by eight Aβ42 monomers embedded in a lipid bilayer, the monomers aggregate into oligomers with stable transmembrane helix structures. With the aggregation of peptides, the membrane perturbations caused by Aβ aggregates decrease. The molecular architectures of oligomers were characterized and a helix-rich octamer stabilized by an annular network of hydrogen bonds was observed. The oligomers demonstrate the capability to assist transmembrane water transport. Our study may provide new insights for the investigation of transmembrane Aβ oligomers.
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Affiliation(s)
- Ke Wang
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin 300071, China.
| | - Wensheng Cai
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin 300071, China.
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4
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John T, Piantavigna S, Dealey TJA, Abel B, Risselada HJ, Martin LL. Lipid oxidation controls peptide self-assembly near membranes through a surface attraction mechanism. Chem Sci 2023; 14:3730-3741. [PMID: 37035708 PMCID: PMC10074436 DOI: 10.1039/d3sc00159h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
The self-assembly of peptides into supramolecular structures has been linked to neurodegenerative diseases but has also been observed in functional roles. Peptides are physiologically exposed to crowded environments of biomacromolecules, and particularly cellular membrane lipids. Previous research has shown that membranes can both accelerate and inhibit peptide self-assembly. Here, we studied the impact of membrane models that mimic cellular oxidative stress and compared this to mammalian and bacterial membranes. Using molecular dynamics simulations and experiments, we propose a model that explains how changes in peptide-membrane binding, electrostatics, and peptide secondary structure stabilization determine the nature of peptide self-assembly. We explored the influence of zwitterionic (POPC), anionic (POPG) and oxidized (PazePC) phospholipids, as well as cholesterol, and mixtures thereof, on the self-assembly kinetics of the amyloid β (1-40) peptide (Aβ40), linked to Alzheimer's disease, and the amyloid-forming antimicrobial peptide uperin 3.5 (U3.5). We show that the presence of an oxidized lipid had similar effects on peptide self-assembly as the bacterial mimetic membrane. While Aβ40 fibril formation was accelerated, U3.5 aggregation was inhibited by the same lipids at the same peptide-to-lipid ratio. We attribute these findings and peptide-specific effects to differences in peptide-membrane adsorption with U3.5 being more strongly bound to the membrane surface and stabilized in an α-helical conformation compared to Aβ40. Different peptide-to-lipid ratios resulted in different effects. We found that electrostatic interactions are a primary driving force for peptide-membrane interaction, enabling us to propose a model for predicting how cellular changes might impact peptide self-assembly in vivo.
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Affiliation(s)
- Torsten John
- School of Chemistry, Monash University Clayton VIC 3800 Australia
- Leibniz Institute of Surface Engineering (IOM) Permoserstraße 15 04318 Leipzig Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Institute of Chemical Technology, Leipzig University Linnéstraße 3 04103 Leipzig Germany
| | | | - Tiara J A Dealey
- School of Chemistry, Monash University Clayton VIC 3800 Australia
| | - Bernd Abel
- Leibniz Institute of Surface Engineering (IOM) Permoserstraße 15 04318 Leipzig Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Institute of Chemical Technology, Leipzig University Linnéstraße 3 04103 Leipzig Germany
| | - Herre Jelger Risselada
- Leibniz Institute of Surface Engineering (IOM) Permoserstraße 15 04318 Leipzig Germany
- Institute for Theoretical Physics, Georg-August-Universität Göttingen Friedrich-Hund-Platz 1 37077 Göttingen Germany
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5
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Wang K, Shao X, Cai W. Binding Models of Aβ42 Peptide with Membranes Explored by Molecular Simulations. J Chem Inf Model 2022; 62:6482-6493. [PMID: 35984710 DOI: 10.1021/acs.jcim.2c00444] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
One of the factors contributing to the toxicity of amyloid-β (Aβ) peptides is the destruction of membrane integrity through Aβ peptide-membrane interactions. The binding of Aβ peptides to membranes has been studied by experiments and theoretical simulations extensively. The exact binding mechanism, however, still remains elusive. In the present study, the molecular basis of the peptide-bilayer binding mechanism of the full-length Aβ42 monomer with POPC/POPS/CHOL bilayers is investigated by all-atom (AA) simulations. Three main binding models in coil, bend, and turn structures are obtained. Model 1 of the three models with the central hydrophobic core (CHC) buried inside the membrane is the dominant binding model. The structural features of the peptide, the peptide-bilayer interacting regions, the intrapeptide interactions, and peptide-water interactions are studied. The binding of the Aβ42 monomer to the POPC/POPS/CHOL bilayer is also explored by coarse-grained (CG) simulations as a complement. Both the AA and CG simulations show that residues in CHC prefer forming interactions with the bilayer, indicating the crucial role of CHC in peptide-bilayer binding. Our results can provide new insights for the investigation of the peptide-bilayer binding mechanism of the Aβ peptide.
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Affiliation(s)
- Ke Wang
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Xueguang Shao
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Wensheng Cai
- Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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6
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Tian Y, Liu J, Yang F, Lian C, Zhang H, Viles JH, Li Z. Therapeutic potential for amyloid surface inhibitor: only amyloid-β oligomers formed by secondary nucleation disrupt lipid membrane integrity. FEBS J 2022; 289:6767-6781. [PMID: 35670622 DOI: 10.1111/febs.16550] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/11/2022] [Accepted: 06/06/2022] [Indexed: 01/01/2023]
Abstract
Inhibition of amyloid-β peptide (Aβ) aggregation is a promising therapeutic strategy for Alzheimer's disease (AD), as Aβ aggregation is generally believed to trigger AD pathology. Pre-fibril Aβ-oligomers induce membrane disruption and are crucial to neurotoxicity. We have previously designed a short peptide called cyclic helical amyloid surface inhibitor (cHASI) that can selectively bind to the Aβ fibril surface. Here, we use cHASI to efficiently inhibit the surface-catalysed secondary nucleation process of Aβ in a lipid membrane environment. By incubating Aβ monomers with lipid vesicles, we show that during the assembly of Aβ into amyloid fibrils, oligomers are formed that markedly disrupt the lipid bilayer. Remarkably, when Aβ monomers are incubated with cHASI, although Aβ forms amyloid fibrils via primary nucleation and elongation, this pathway to fibrils does not damage the lipid bilayer. This indicates that only oligomers produced during secondary surface nucleation disrupt membrane integrity. The protective effect of cHASI is confirmed by cytotoxicity assays. Our study highlights the therapeutic potential for inhibiting the secondary nucleation process in Aβ aggregation, rather than inhibiting all pathways to fibril formation.
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Affiliation(s)
- Yao Tian
- School of Biological and Chemical Sciences, Queen Mary University of London, UK
| | - Jianbo Liu
- Pingshan Translational Medicine Center, Shenzhen Bay Laboratory, China
| | - Fadeng Yang
- State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, China
| | - Chenshan Lian
- Pingshan Translational Medicine Center, Shenzhen Bay Laboratory, China
| | - Huawei Zhang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - John H Viles
- School of Biological and Chemical Sciences, Queen Mary University of London, UK
| | - Zigang Li
- Pingshan Translational Medicine Center, Shenzhen Bay Laboratory, China.,State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, China
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7
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Hashemi M, Banerjee S, Lyubchenko YL. Free Cholesterol Accelerates Aβ Self-Assembly on Membranes at Physiological Concentration. Int J Mol Sci 2022; 23:ijms23052803. [PMID: 35269945 PMCID: PMC8911190 DOI: 10.3390/ijms23052803] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 02/27/2022] [Accepted: 03/01/2022] [Indexed: 02/06/2023] Open
Abstract
The effects of membranes on the early-stage aggregation of amyloid β (Aβ) have come to light as potential mechanisms by which neurotoxic species are formed in Alzheimer’s disease. We have shown that direct Aβ-membrane interactions dramatically enhance the Aβ aggregation, allowing for oligomer assembly at physiologically low concentrations of the monomer. Membrane composition is also a crucial factor in this process. Our results showed that apart from phospholipids composition, cholesterol in membranes significantly enhances the aggregation kinetics. It has been reported that free cholesterol is present in plaques. Here we report that free cholesterol, along with its presence inside the membrane, further accelerate the aggregation process by producing aggregates more rapidly and of significantly larger sizes. These aggregates, which are formed on the lipid bilayer, are able to dissociate from the surface and accumulate in the bulk solution; the presence of free cholesterol accelerates this dissociation as well. All-atom molecular dynamics simulations show that cholesterol binds Aβ monomers and significantly changes the conformational sampling of Aβ monomer; more than doubling the fraction of low-energy conformations compared to those in the absence of cholesterol, which can contribute to the aggregation process. The results indicate that Aβ-lipid interaction is an important factor in the disease prone amyloid assembly process.
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Affiliation(s)
- Mohtadin Hashemi
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE 68198-6025, USA; (M.H.); (S.B.)
| | - Siddhartha Banerjee
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE 68198-6025, USA; (M.H.); (S.B.)
- Department of Chemistry and Biochemistry, The University of Alabama, Shelby Hall, Tuscaloosa, AL 35487, USA
| | - Yuri L. Lyubchenko
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE 68198-6025, USA; (M.H.); (S.B.)
- Correspondence:
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8
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Alvarez AB, Rodríguez PEA, Fidelio GD. Gangliosides smelt nanostructured amyloid Aβ(1-40) fibrils in a membrane lipid environment. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183749. [PMID: 34506795 DOI: 10.1016/j.bbamem.2021.183749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/03/2021] [Accepted: 08/22/2021] [Indexed: 06/13/2023]
Abstract
Gangliosides induced a smelting process in nanostructured amyloid fibril-like films throughout the surface properties contributed by glycosphingolipids when mixed with 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC)/Aβ(1-40) amyloid peptide. We observed a dynamical smelting process when pre-formed amyloid/phospholipid mixture is laterally mixed with gangliosides. This particular environment, gangliosides/phospholipid/Aβ(1-40) peptide mixed interfaces, showed complex miscibility behavior depending on gangliosides content. At 0% of ganglioside covered surface respect to POPC, Aβ(1-40) peptide forms fibril-like structure. In between 5 and 15% of gangliosides, the fibrils dissolve into irregular domains and they disappear when the proportion of gangliosides reach the 20%. The amyloid interfacial dissolving effect of gangliosides is taken place at lateral pressure equivalent to the organization of biological membranes. Domains formed at the interface are clearly evidenced by Brewster Angle Microscopy and Atomic Force Microscopy when the films are transferred onto a mica support. The domains are thioflavin T (ThT) positive when observed by fluorescence microscopy. We postulated that the smelting process of amyloids fibrils-like structure at the membrane surface provoked by gangliosides is a direct result of a new interfacial environment imposed by the complex glycosphingolipids. We add experimental evidence, for the first time, how a change in the lipid environment (increase in ganglioside proportion) induces a rapid loss of the asymmetric structure of amyloid fibrils by a simple modification of the membrane condition (a more physiological situation).
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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
| | | | - 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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9
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Alfredsson V, Lo Nostro P, Ninham B, Nylander T. Morphologies and Structure of Brain Lipid Membrane Dispersions. Front Cell Dev Biol 2021; 9:675140. [PMID: 34195192 PMCID: PMC8236638 DOI: 10.3389/fcell.2021.675140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/30/2021] [Indexed: 11/13/2022] Open
Abstract
This study aims to explore the variety of previously unknown morphologies that brain lipids form in aqueous solutions. We study how these structures are dependent on cholesterol content, salt solution composition, and temperature. For this purpose, dispersions of porcine sphingomyelin with varying amounts of cholesterol as well as dispersions of porcine brain lipid extracts were investigated. We used cryo-TEM to investigate the dispersions at high-salt solution content together with small-angle (SAXD) and wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) for dispersions in the corresponding salt solution at high lipid content. Sphingomyelin forms multilamellar vesicles in large excess of aqueous salt solution. These vesicles appear as double rippled bilayers in the images and as split Bragg peaks in SAXD together with a very distinct lamellar phase pattern. These features disappear with increasing temperature, and addition of cholesterol as the WAXD data shows that the peak corresponding to the chain crystallinity disappears. The dispersions of sphingomyelin at high cholesterol content form large vesicular type of structures with smooth bilayers. The repeat distance of the lamellar phase depends on temperature, salt solution composition, and slightly with cholesterol content. The brain lipid extracts form large multilamellar vesicles often attached to assemblies of higher electron density. We think that this is probably an example of supra self-assembly with a multiple-layered vesicle surrounding an interior cubic microphase. This is challenging to resolve. DSC shows the presence of different kinds of water bound to the lipid aggregates as a function of the lipid content. Comparison with the effect of lithium, sodium, and calcium salts on the structural parameters of the sphingomyelin and the morphologies of brain lipid extract morphologies demonstrate that lithium has remarkable effects also at low content.
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Affiliation(s)
- Viveka Alfredsson
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Lund, Sweden
| | - Pierandrea Lo Nostro
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence, Sesto Fiorentino, Italy
| | - Barry Ninham
- Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT, Australia
| | - Tommy Nylander
- Physical Chemistry, Department of Chemistry, Lund University, Lund, Sweden.,NanoLund, Lund University, Lund, Sweden.,Lund Institute of Advanced Neutron and X-ray Science, Lund, Sweden
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10
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Banerjee S, Hashemi M, Zagorski K, Lyubchenko YL. Cholesterol in Membranes Facilitates Aggregation of Amyloid β Protein at Physiologically Relevant Concentrations. ACS Chem Neurosci 2021; 12:506-516. [PMID: 33492944 DOI: 10.1021/acschemneuro.0c00688] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The formation of amyloid β (1-42) (Aβ42) oligomers is considered to be a critical step in the development of Alzheimer's disease (AD). However, the mechanism underlying this process at physiologically low concentrations of Aβ42 remains unclear. We have previously shown that oligomers assemble at such low Aβ42 monomer concentrations in vitro on phospholipid membranes. We hypothesized that membrane composition is the factor controlling the aggregation process. Accumulation of cholesterol in membranes is associated with AD development, suggesting that insertion of cholesterol into membranes may initiate the Aβ42 aggregation, regardless of a low monomer concentration. We used atomic force microscopy (AFM) to test the hypothesis and directly visualize the aggregation process of Aβ42 on the surface of a lipid bilayer depending on the cholesterol presence. Time-lapse AFM imaging unambiguously demonstrates that cholesterol in the lipid bilayer significantly enhances the aggregation process of Aβ42 at nanomolar monomer concentration. Quantitative analysis of the AFM data shows that both the number of Aβ42 oligomers and their sizes grow when cholesterol is present. Importantly, the aggregation process is dynamic, so the aggregates assembled on the membrane can dissociate from the bilayer surface into the bulk solution. Computational modeling demonstrated that the lipid bilayer containing cholesterol had an elevated affinity to Aβ42. Moreover, monomers adopted the aggregation-prone conformations present in amyloid fibrils. The results lead to the model for the on-surface aggregation process in which the self-assembly of Aβ oligomers is controlled by the lipid composition of cellular membranes.
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Affiliation(s)
- Siddhartha Banerjee
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Mohtadin Hashemi
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Karen Zagorski
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Yuri L. Lyubchenko
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
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11
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D’Onofrio M, Munari F, Assfalg M. Alpha-Synuclein-Nanoparticle Interactions: Understanding, Controlling and Exploiting Conformational Plasticity. Molecules 2020; 25:E5625. [PMID: 33260436 PMCID: PMC7731430 DOI: 10.3390/molecules25235625] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/25/2020] [Accepted: 11/27/2020] [Indexed: 12/29/2022] Open
Abstract
Alpha-synuclein (αS) is an extensively studied protein due to its involvement in a group of neurodegenerative disorders, including Parkinson's disease, and its documented ability to undergo aberrant self-aggregation resulting in the formation of amyloid-like fibrils. In dilute solution, the protein is intrinsically disordered but can adopt multiple alternative conformations under given conditions, such as upon adsorption to nanoscale surfaces. The study of αS-nanoparticle interactions allows us to better understand the behavior of the protein and provides the basis for developing systems capable of mitigating the formation of toxic aggregates as well as for designing hybrid nanomaterials with novel functionalities for applications in various research areas. In this review, we summarize current progress on αS-nanoparticle interactions with an emphasis on the conformational plasticity of the biomolecule.
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Affiliation(s)
| | | | - Michael Assfalg
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (M.D.); (F.M.)
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12
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Alvarez AB, Caruso B, Rodríguez PEA, Petersen SB, Fidelio GD. Aβ-Amyloid Fibrils Are Self-Triggered by the Interfacial Lipid Environment and Low Peptide Content. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8056-8065. [PMID: 32551671 DOI: 10.1021/acs.langmuir.0c00468] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We studied the surface properties of Aβ(1-40) amyloid peptides mixed with 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) (liquid state) or 1,2-disteraoyl-phosphatidylcholine (DSPC) (solid state) phospholipids by using nanostructured lipid/peptide films (Langmuir monolayers). Pure Aβ(1-40) amyloid peptides form insoluble monolayers without forming fibril-like structures. In a lipid environment [phospholipid/Aβ(1-40) peptide mixtures], we observed that both miscibility and stability of the films depend on the peptide content. At low Aβ(1-40) amyloid peptide proportion (from 2.5 to 10% of peptide area proportion), we observed the formation of a fibril-like structure when mixed only with POPC lipids. The stability acquired by these mixed films is within 20-35 mN·m-1 compatible with the equivalent surface pressure postulated for natural biomembranes. Fibrils are clearly evidenced directly from the monolayers by using Brewster angle microscopy. The so-called nanostructured fibrils are thioflavin T positive when observed by fluorescence microscopy. The amyloid fibril network at the surface was also evidenced by atomic force microscopy when the films are transferred onto a mica support. Aβ(1-40) amyloid mixed with the solid DSPC lipid showed an immiscible behavior in all peptide proportions without fibril formation. We postulated that the amyloid fibrillogenesis at the membrane can be dynamically nano-self-triggered at the surface by the quality of the interfacial environment, that is, the physical state of the water-lipid interface and the relative content of amyloid protein present at the interface.
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Affiliation(s)
- Alain Bolaño Alvarez
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
| | - Benjamín Caruso
- Cátedra de Química Biológica, Departamento de Química, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba X5016GCA, Argentina
- Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT), CONICET, Universidad Nacional de Córdoba, Córdoba X5016GCA, Argentina
| | - Pablo E A Rodríguez
- Ministerio de Ciencia y Tecnología de la Provincia de Córdoba, Cordoba X5004AAP, Argentina
| | - Steffen B Petersen
- Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg 9220, Denmark
| | - Gerardo D Fidelio
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
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13
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Barracchia CG, Tira R, Parolini F, Munari F, Bubacco L, Spyroulias GA, D’Onofrio M, Assfalg M. Unsaturated Fatty Acid-Induced Conformational Transitions and Aggregation of the Repeat Domain of Tau. Molecules 2020; 25:molecules25112716. [PMID: 32545360 PMCID: PMC7321374 DOI: 10.3390/molecules25112716] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 12/20/2022] Open
Abstract
Background: The intrinsically disordered, amyloidogenic protein Tau associates with diverse classes of molecules, including proteins, nucleic acids, and lipids. Mounting evidence suggests that fatty acid molecules could play a role in the dysfunction of this protein, however, their interaction with Tau remains poorly characterized. Methods: In a bid to elucidate the association of Tau with unsaturated fatty acids at the sub-molecular level, we carried out a variety of solution NMR experiments in combination with circular dichroism and fluorescence measurements. Our study shows that Tau4RD, the highly basic four-repeat domain of Tau, associates strongly with arachidonic and oleic acid assemblies in a high lipid/protein ratio, perturbing their supramolecular states and itself undergoing time-dependent structural adaptation. The structural signatures of Tau4RD/fatty acid aggregates appear similar for arachidonic acid and oleic acid, however, they are distinct from those of another prototypical intrinsically disordered protein, α-synuclein, when bound to these lipids, revealing protein-specific conformational adaptations. Both fatty acid molecules are found to invariably promote the self-aggregation of Tau4RD and of α-synuclein. Conclusions: This study describes the reciprocal influence that Tau4RD and fatty acids exert on their conformational states, contributing to our understanding of fundamental aspects of Tau/lipid co-assembly.
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Affiliation(s)
- Carlo Giorgio Barracchia
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Roberto Tira
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Francesca Parolini
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Francesca Munari
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Luigi Bubacco
- Department of Biology, University of Padova, 35131 Padova, Italy;
| | | | - Mariapina D’Onofrio
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Michael Assfalg
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
- Correspondence:
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