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Xie Y, Chen M, Lai H, Zhang W, Zhao Z, Anwar CM. Neural Basis of Two Kinds of Social Influence: Obedience and Conformity. Front Hum Neurosci 2016; 10:51. [PMID: 26941632 PMCID: PMC4762203 DOI: 10.3389/fnhum.2016.00051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/01/2016] [Indexed: 12/02/2022] Open
Abstract
Event-related potentials (ERPs) were used in this study to explore the neural mechanism of obedience and conformity on the model of online book purchasing. Participants were asked to decide as quickly as possible whether to buy a book based on limited information including its title, keywords and number of positive and negative reviews. Obedience was induced by forcing participants to buy books which received mostly negative reviews. In contrast, conformity was aroused by majority influence (caused by positive and negative comments). P3 and N2, two kinds of ERP components related to social cognitive process, were measured and recorded with electroencephalogram (EEG) test. The results show that compared with conformity decisions, obedience decisions induced greater cognitive conflicts. In ERP measurements, greater amplitudes of N2 component were observed in the context of obedience. However, consistency level did not make a difference on P3 peak latency for both conformity and obedience. This shows that classification process is implicit in both conformity and obedience decision-making. In addition, for both conformity and obedience decisions, augmented P3 was observed when the reviews consistency (either negative or positive) was higher.
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Affiliation(s)
- Ying Xie
- School of Management, Zhejiang University Hangzhou, China
| | - Mingliang Chen
- School of Management, Zhejiang University Hangzhou, China
| | - Hongxia Lai
- School of Management, Zhejiang University Hangzhou, China
| | - Wuke Zhang
- School of Management, Zhejiang University Hangzhou, China
| | - Zhen Zhao
- School of Management, Zhejiang University Hangzhou, China
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2
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Benedé S, López-Expósito I, Molina E, López-Fandiño R. Egg proteins as allergens and the effects of the food matrix and processing. Food Funct 2016; 6:694-713. [PMID: 25598200 DOI: 10.1039/c4fo01104j] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Hen eggs are an important and inexpensive source of high-quality proteins in the human diet. Egg, either as a whole or its constituents (egg yolk and white), is a key ingredient in many food products by virtue of its nutritional value and unique functional properties, such as emulsifying, foaming, and gelling. Nevertheless, egg is also known because of its allergenic potential and, in fact, it is the second most frequent source of allergic reactions, particularly in children. This review deals with the structural or functional properties of egg proteins that make them strong allergens. Their ability to sensitize and/or elicit allergic reactions is linked to their resistance to gastroduodenal digestion, which ultimately allows them to interact with the intestinal mucosa where absorption occurs. The factors that affect protein digestibility, whether increasing it, decreasing it, or inducing a different proteolysis pattern, and their influence on their capacity to induce or trigger an allergic reaction are discussed. Special attention is paid to the effect of the food matrix and the processing practices on the capacity of egg proteins to modulate the immune response.
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Affiliation(s)
- S Benedé
- Instituto de Investigación en Ciencias de la Alimentación (CIAL, CSIC-UAM), Nicolás Cabrera 9, 28049 Madrid, Spain.
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3
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Rui L, Liu J, Li J, Weng Y, Dou Y, Yuan B, Yang K, Ma Y. Reduced graphene oxide directed self-assembly of phospholipid monolayers in liquid and gel phases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1203-11. [DOI: 10.1016/j.bbamem.2015.02.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/10/2015] [Accepted: 02/16/2015] [Indexed: 01/02/2023]
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Fernandes F, Coutinho A, Prieto M, Loura LMS. Electrostatically driven lipid-protein interaction: Answers from FRET. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1837-48. [PMID: 25769805 DOI: 10.1016/j.bbamem.2015.02.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 02/23/2015] [Indexed: 12/13/2022]
Abstract
Electrostatics govern the association of a large number of proteins with cellular membranes. In some cases, these proteins present specialized lipid-binding modules or membrane targeting domains while in other cases association is achieved through nonspecific interaction of unstructured clusters of basic residues with negatively charged lipids. Given its spatial resolution in the nanometer range, Förster resonance energy transfer (FRET) is a powerful tool to give insight into protein-lipid interactions and provide molecular level information which is difficult to retrieve with other spectroscopic techniques. In this review we present and discuss the basic formalisms of both hetero- and homo-FRET pertinent to the most commonly encountered problems in lipid-protein interaction studies and highlight some examples of implementations of different FRET methodologies to characterize lipid/protein systems in which electrostatic interactions play a crucial role. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Dep. Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Luís M S Loura
- Faculdade de Farmácia, Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Centro de Química de Coimbra, Largo D. Dinis, Rua Larga, 3004-535 Coimbra, Portugal.
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5
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Melo AM, Loura LMS, Fernandes F, Villalaín J, Prieto M, Coutinho A. Electrostatically driven lipid-lysozyme mixed fibers display a multilamellar structure without amyloid features. SOFT MATTER 2014; 10:840-850. [PMID: 24651998 DOI: 10.1039/c3sm52586d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Understanding the interactions between anionic lipid membranes and amyloidogenic proteins/peptides is key to elucidate the molecular mechanisms underlying the membrane-driven amyloid fiber formation. Here, hen egg-white lysozyme was used as a model protein to test whether this same process also occurs with non-amyloidogenic lipid-binding proteins/peptides. A complementary set of biophysical techniques was employed to study the structure and dynamics of the lipid-lysozyme mixed fibers produced at a low lipid/protein molar ratio that have been proposed earlier to present "amyloid-like" characteristics. The multilamellar architecture of these elongated mesoscopic structures was established by performing time-resolved Förster resonance energy transfer measurements, at both bulk (ensemble) and single-fiber level. The predominantly oligomeric lysozyme and phospholipids were both found to display significantly decreased lateral mobility when embedded in these mixed fibers. Notably, two-photon microscopy of Laurdan revealed that a pronounced membrane surface dehydration/increased molecular interfacial packing was produced exclusively in these elongated mixed supramolecular fibers present in the highly polymorphic samples. Infrared spectroscopic studies of lysozyme in these samples further showed that this protein did not exhibit a rich β-sheet structure characteristic of amyloid fibrils. These results support the conclusion that negatively charged lipid membranes do not have the general ability to trigger amyloid fibril formation of non-amyloidogenic proteins.
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Affiliation(s)
- Ana M Melo
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
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6
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Melo AM, Ricardo JC, Fedorov A, Prieto M, Coutinho A. Fluorescence Detection of Lipid-Induced Oligomeric Intermediates Involved in Lysozyme “Amyloid-Like” Fiber Formation Driven by Anionic Membranes. J Phys Chem B 2013; 117:2906-17. [DOI: 10.1021/jp310396v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ana M. Melo
- Centro de Química-Física
Molecular and Institute of Nanoscience and Nanotechnology, I.S.T, Universidade Técnica de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
| | - Joana C. Ricardo
- Centro de Química-Física
Molecular and Institute of Nanoscience and Nanotechnology, I.S.T, Universidade Técnica de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
| | - Aleksander Fedorov
- Centro de Química-Física
Molecular and Institute of Nanoscience and Nanotechnology, I.S.T, Universidade Técnica de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
| | - Manuel Prieto
- Centro de Química-Física
Molecular and Institute of Nanoscience and Nanotechnology, I.S.T, Universidade Técnica de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- Centro de Química-Física
Molecular and Institute of Nanoscience and Nanotechnology, I.S.T, Universidade Técnica de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
- Dep. Química e Bioquímica, FCUL, Campo Grande, 1749-016 Lisboa, Portugal
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7
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Yano YF. Kinetics of protein unfolding at interfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:503101. [PMID: 23164927 DOI: 10.1088/0953-8984/24/50/503101] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The conformation of protein molecules is determined by a balance of various forces, including van der Waals attraction, electrostatic interaction, hydrogen bonding, and conformational entropy. When protein molecules encounter an interface, they are often adsorbed on the interface. The conformation of an adsorbed protein molecule strongly depends on the interaction between the protein and the interface. Recent time-resolved investigations have revealed that protein conformation changes during the adsorption process due to the protein-protein interaction increasing with increasing interface coverage. External conditions also affect the protein conformation. This review considers recent dynamic observations of protein adsorption at various interfaces and their implications for the kinetics of protein unfolding at interfaces.
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Affiliation(s)
- Yohko F Yano
- Department of Physics, Kinki University, Higashiosaka City, Osaka, Japan.
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8
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Yuan B, Hu SX, Lu NY, Xu F, Zhou K, Ma YQ, Li M. Electrical bistability in self-assembled hybrid multilayers of phospholipid and nanoparticles. NANOTECHNOLOGY 2011; 22:315303. [PMID: 21747161 DOI: 10.1088/0957-4484/22/31/315303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A novel kind of biomolecule-based electrical bistable device composed of phospholipid-CdTe nanoparticle multilayered films was demonstrated. The composite film was fabricated by a facile solution-cast method. X-ray reflectivity and transmission electron microscopy measurements showed the homogeneous distribution of nanoparticles within the lamellar lipid matrix with long-range ordering. Current-voltage scans on the Al/(lipid-nanoparticle composite film)/ITO/glass structures at room temperature exhibited an obvious current bistable phenomenon. Further investigation of such bionanoparticle composite film promises to show its importance for applications in future memory nanodevices with tailored performance.
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Affiliation(s)
- Bing Yuan
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou, People's Republic of China
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9
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Jiménez-Saiz R, Martos G, Carrillo W, López-Fandiño R, Molina E. Susceptibility of lysozyme to in-vitro digestion and immunoreactivity of its digests. Food Chem 2011. [DOI: 10.1016/j.foodchem.2011.02.047] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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10
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Coutinho A, Loura LMS, Prieto M. FRET studies of lipid-protein aggregates related to amyloid-like fibers. J Neurochem 2011; 116:696-701. [PMID: 21214548 DOI: 10.1111/j.1471-4159.2010.07000.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acidic lipids are known to both catalyze amyloid fiber formation by amyloidogenic peptides/proteins and induce formation of 'amyloid-like' fibrils by non-amyloidogenic proteins. In this work, we describe the application of state-of-the-art time-resolved Förster resonance energy transfer methodologies to the characterization of the supramolecular structure of the aggregates formed by both a cationic peptide (hexalysyltryptophan) and a basic non-amyloidogenic protein (lysozyme) upon their interaction with negatively-charged fluid membranes (mixtures of zwitterionic phosphatidylcholine and anionic phosphatidylserine). It was concluded that both the peptide and protein induce the formation of multistacked lipid bilayers. Furthermore, upon using conditions that are described in the literature to cause the formation of amyloid-like fibers, lysozyme was found to induce the formation of a 'pinched lamellar' structure, with reduced interbilayer distance in the regions where there is bound protein, and increased interbilayer distance (stabilized by hydration repulsion) outside these areas. No significant lateral domains (lipid demixing) were induced in the membrane by either the cationic peptide or lysozyme.
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Affiliation(s)
- Ana Coutinho
- Centro de Química Física Molecular and IN, Complexo I, Instituto Superior Técnico, Lisboa, Portugal.
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11
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Yuan B, Zhu T, Zhang Z, Jiang Z, Ma Y. Self-assembly of multilayered functional films based on graphene oxide sheets for controlled release. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm03643a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Lu Y, Hu SX, Li M. Structure and phase transformation of oligodeoxynucleotide/lipid lipoplexes on solid supports. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:3539-3543. [PMID: 20092344 DOI: 10.1021/la9032173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Lipoplexes are composed of lipids and nucleic acids and have an ordered multilamellar structure with a periodic 1D array of parallel nucleic acid strands in the lipid bilayers. We report a low-angle X-ray diffraction study on solid-supported lipoplex films composed of synthetic single-stranded oligodeoxynucleotides (ssODN) and lipids. The ssODN molecules distribute sparsely in the headgroup regions when the weight concentration of the ssODN in the lipoplex is low. The lipoplex separates into two phases, an ODN-poor phase and an ODN-rich phase, when the weight concentration of the ssODN is increased beyond a level at which the ssODN molecules contact each other so that some regions of the lipid bilayers must accommodate two layers of the ssODN. The phase separation is a result of the fusion of such regions to minimize the total interfacial energy of the system. The ssODN molecules distort the lipid bilayers in the ODN-poor phase. The local area per lipid molecule is increased by the distortions so that the interbilayer distance of the lipoplex film is smaller than that of the lipid film without the ssODN. The ODN-rich phase has a much larger interbilayer distance because two layers of ssODN are intercalated into each lipid bilayer. The ssODN molecules are tightly compacted, and the lipid bilayers are not distorted in the ODN-rich phase.
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Affiliation(s)
- Ying Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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13
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Jing HY, Hong DH, Kwak BD, Choi DJ, Shin K, Yu CJ, Kim JW, Noh DY, Seo YS. X-ray reflectivity study on the structure and phase stability of mixed phospholipid multilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4198-4202. [PMID: 19714836 DOI: 10.1021/la802868r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Vertically oriented multilayers composed of two saturated phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoserine (DPPS), were deposited on silicon. X-ray reflectivity was used to investigate the structures of the variously mixed phospholipid multilayers as a function of composition. Then, the phase stability was investigated at various annealing temperatures under humid conditions. The results indicated that the lipid spacing of the mixed phospholipid multilayers varied systematically as a function of the DPPC/DPPS ratio and that no macroscopic phase separation occurred during the annealing process under both dry and humid conditions.
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Affiliation(s)
- H Y Jing
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang-HANARO Joint Center for Biological Interfaces, Sogang University, Seoul 121-742, Korea
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14
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Campbell AS, Yu Y, Granick S, Gewirth AA. PCB association with model phospholipid bilayers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:7496-7501. [PMID: 18939592 DOI: 10.1021/es8011063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We compare the association of an ortho-substituted and a planar PCB (polychlorinated biphenyls PCB-52 and PCB-77, respectively) with single-component phospholipid bilayers terminated with phosphocholine headgroups. First, fluorescence correlation spectroscopy (FCS) studies of diffusion on supported fluid-phase DLPC show that the ortho-substituted PCB diffuses more slowly, indicating either complex formation or obstructed diffusion. Differential scanning calorimetry (DSC) of vesicles formed from DMPC shows that the gel-to-fluid phase transition temperature is lower for vesicles containing this ortho-substituted PCB. Atomic force microscopy (AFM) shows that, whereas supported bilayers of DMPC containing this ortho-substituted PCB display two melting points, bilayers containing the coplanar PCB display just a single melting point. A model is proposed in which the ortho-substituted PCB resides within the lipid tails of these phospholipid bilayers but the coplanar PCB associates preferentially with the headgroups. This model is consistent with the known membrane disruptive ability of the ortho substituted isomer.
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Affiliation(s)
- Andrew S Campbell
- Department of Chemistry and Department of Materials Science and Engineering, University of Illinois, 600 S. Mathews Avenue, Urbana, Illinois 61801, USA
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Pinched multilamellar structure of aggregates of lysozyme and phosphatidylserine-containing membranes revealed by FRET. Biophys J 2008; 95:4726-36. [PMID: 18658231 DOI: 10.1529/biophysj.108.134379] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Electrostatic interactions between negatively charged membranes and basic peptides/protein domains have been implicated as the driving force for several important processes, often involving membrane aggregation, fusion, or phase separation. Recently, acidic lipids were reported to both catalyze amyloid fiber formation by amyloidogenic proteins/peptides and induce formation of "amyloid-like" fibrils by nonamyloidogenic proteins. This study aims to characterize the structure of the aggregates of a basic protein (lysozyme) and negatively charged membranes (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine 4:1 mixture) at the molecular level, using Förster resonance energy transfer. It is concluded that lysozyme induced formation of a "pinched lamellar" structure, with reduced interbilayer distance in the regions where there is bound protein and increased interbilayer distance (stabilized by hydration repulsion) outside these areas.
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Euston SR, Hughes P, Naser MA, Westacott RE. Comparison of the Adsorbed Conformation of Barley Lipid Transfer Protein at the Decane−Water and Vacuum−Water Interface: A Molecular Dynamics Simulation. Biomacromolecules 2008; 9:1443-53. [DOI: 10.1021/bm701227g] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. R. Euston
- School of Life Sciences, International Centre for Brewing and Distilling, and School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
| | - P. Hughes
- School of Life Sciences, International Centre for Brewing and Distilling, and School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
| | - Md. A. Naser
- School of Life Sciences, International Centre for Brewing and Distilling, and School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
| | - R. E. Westacott
- School of Life Sciences, International Centre for Brewing and Distilling, and School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
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