1
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Kepp KP, Robakis NK, Høilund-Carlsen PF, Sensi SL, Vissel B. The amyloid cascade hypothesis: an updated critical review. Brain 2023; 146:3969-3990. [PMID: 37183523 DOI: 10.1093/brain/awad159] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/20/2023] [Accepted: 04/23/2023] [Indexed: 05/16/2023] Open
Abstract
Results from recent clinical trials of antibodies that target amyloid-β (Aβ) for Alzheimer's disease have created excitement and have been heralded as corroboration of the amyloid cascade hypothesis. However, while Aβ may contribute to disease, genetic, clinical, imaging and biochemical data suggest a more complex aetiology. Here we review the history and weaknesses of the amyloid cascade hypothesis in view of the new evidence obtained from clinical trials of anti-amyloid antibodies. These trials indicate that the treatments have either no or uncertain clinical effect on cognition. Despite the importance of amyloid in the definition of Alzheimer's disease, we argue that the data point to Aβ playing a minor aetiological role. We also discuss data suggesting that the concerted activity of many pathogenic factors contribute to Alzheimer's disease and propose that evolving multi-factor disease models will better underpin the search for more effective strategies to treat the disease.
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Affiliation(s)
- Kasper P Kepp
- Section of Biophysical and Biomedicinal chemistry, DTU Chemistry, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Nikolaos K Robakis
- Icahn School of Medicine at Mount Sinai Medical Center, New York, NY 10029, USA
| | - Poul F Høilund-Carlsen
- Department of Nuclear Medicine, Odense University Hospital, 5000 Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, 5000 Odense C, Denmark
| | - Stefano L Sensi
- Center for Advanced Studies and Technology-CAST, and Institute for Advanced Biotechnology (ITAB), University G. d'Annunzio of Chieti-Pescara, Chieti, 66013, Italy
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, 66013, Italy
| | - Bryce Vissel
- St Vincent's Hospital Centre for Applied Medical Research, St Vincent's Hospital, Sydney, 2010, Australia
- School of Clinical Medicine, UNSW Medicine and Health, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and Health, Sydney, NSW 2052, Australia
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2
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Kaur A, Goyal B. In silico design and identification of new peptides for mitigating hIAPP aggregation in type 2 diabetes. J Biomol Struct Dyn 2023:1-16. [PMID: 37691445 DOI: 10.1080/07391102.2023.2254411] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/27/2023] [Indexed: 09/12/2023]
Abstract
The aberrant misfolding and self-aggregation of human islet amyloid polypeptide (hIAPP or amylin) into cytotoxic aggregates are implicated in the pathogenesis of type 2 diabetes (T2D). Among various inhibitors, short peptides derived from the amyloidogenic regions of hIAPP have been employed as hIAPP aggregation inhibitors due to their low immunogenicity, biocompatibility, and high chemical diversity. Recently, hIAPP fragment HSSNN18-22 was identified as an amyloidogenic sequence and displayed higher antiproliferative activity to RIN-5F cells. Various hIAPP aggregation inhibitors have been designed by chemical modifications of the highly amyloidogenic sequence (NFGAIL) of hIAPP. In this work, a library of pentapeptides based on fragment HSSNN18-22 was designed and assessed for their efficacy in blocking hIAPP aggregation using an integrated computational screening approach. The binding free energy calculations by molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method identified HSSQN and HSSNQ that bind to hIAPP monomer with a binding affinity of -21.25 ± 4.90 and -19.73 ± 3.10 kcal/mol, respectively, which is notably higher as compared to HSSNN (-11.90 ± 4.12 kcal/mol). The sampling of the non aggregation-prone helical conformation was notably increased from 23.5 ± 3.0 in the hIAPP monomer to 38.1 ± 3.6, and 33.8 ± 3.0% on the incorporation of HSSQN, and HSSNQ, respectively, which indicate reduced aggregation propensity of hIAPP monomer. The pentapeptides, HSSQN and HSSNQ, identified as hIAPP aggregation inhibitors in this work can be further conjugated with various metal chelating peptides to yield more efficacious and clinically relevant multifunctional modulators for targeting various pathological hallmarks of T2D.
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Affiliation(s)
- Apneet Kaur
- School of Chemistry & Biochemistry, Thapar Institute of Engineering & Technology, Patiala, India
| | - Bhupesh Goyal
- School of Chemistry & Biochemistry, Thapar Institute of Engineering & Technology, Patiala, India
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3
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Molecular basis of the anchoring and stabilization of human islet amyloid polypeptide in lipid hydroperoxidized bilayers. Biochim Biophys Acta Gen Subj 2022; 1866:130200. [PMID: 35820640 DOI: 10.1016/j.bbagen.2022.130200] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/25/2022] [Accepted: 07/02/2022] [Indexed: 01/18/2023]
Abstract
The molecular structure of membrane lipids is formed by mono- or polyunsaturations on their aliphatic tails that make them susceptible to oxidation, facilitating the incorporation of hydroperoxide (R-OOH) functional groups. Such groups promote changes in both composition and complexity of the membrane significantly modifying its physicochemical properties. Human Langerhans islets amyloid polypeptide (hIAPP) is the main component of amyloid deposits found in the pancreas of patients with type-2 diabetes (T2D). hIAPP in the presence of membranes with oxidized lipid species accelerates the formation of amyloid fibrils or the formation of intermediate oligomeric structures. However, the molecular bases at the initial stage of the anchoring and stabilization of the hIAPP in a hydroperoxidized membrane are not yet well understood. To shed some light on this matter, in this contribution, three bilayer models were modeled: neutral (POPC), anionic (POPS), and oxidized (POPCOOH), and full atom Molecular Dynamics (MD) simulations were performed. Our results show that the POPCOOH bilayer increases the helicity in hIAPP when compared to POPC or POPS bilayer. The modification in the secondary structure covers the residues of the so-called amyloidogenic core of the hIAPP. Overall, the hydroperoxidation of the neutral lipids modifies both the anchoring and the stabilization of the peptide hIAPP by reducing the random conformations of the peptide and increasing of hydrogen bond population with the hydroperoxidized lipids.
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4
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Burridge KM, Rahman MS, De Alwis Watuthanthrige N, Gordon E, Shah MZ, Chandrarathne BM, Lorigan GA, Page RC, Konkolewicz D. Network polymers incorporating lipid-bilayer disrupting polymers: towards antiviral functionality. Polym Chem 2022. [DOI: 10.1039/d2py00602b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Polymer based solid-state materials capable of disrupting lipid-bilayers are developed. The materials are mechanically robust and capable of outperforming a 10% small-molecule surfactant and modify filter materials.
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Affiliation(s)
- Kevin M. Burridge
- Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH 45056, USA
| | - Monica S. Rahman
- Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH 45056, USA
| | | | - Emma Gordon
- Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH 45056, USA
| | - Muhammad Zeeshan Shah
- Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH 45056, USA
| | | | - Gary A. Lorigan
- Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH 45056, USA
| | - Richard C. Page
- Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH 45056, USA
| | - Dominik Konkolewicz
- Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH 45056, USA
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5
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Calderón-Hernández MF, Altamirano-Bustamante NF, Revilla-Monsalve C, Mosquera-Andrade MB, Altamirano-Bustamante MM. What can we learn from β-cell failure biomarker application in diabetes in childhood? A systematic review. World J Diabetes 2021; 12:1325-1362. [PMID: 34512897 PMCID: PMC8394223 DOI: 10.4239/wjd.v12.i8.1325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/12/2021] [Accepted: 07/06/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The prevalence of diabetes as a catastrophic disease in childhood is growing in the world. The search for novel biomarkers of β-cell failure has been an elusive task because it requires several clinical and biochemical measurements in order to integrate the risk of metabolic syndrome.
AIM To determine which biomarkers are currently used to identify β-cell failure among children and adolescents with high risk factors for diabetes mellitus.
METHODS This systematic review was carried out using a modified version of the PICO protocol (Participants/Intervention/Comparison/Outcome). Once our research question was established, terms were individually researched on three different databases (PubMed, BIREME and Web of Science). The total articles obtained underwent a selection process from which the 78 most relevant articles were retrieved to undergo further analysis. They were assessed individually according to quality criteria.
RESULTS First, we made the classification of the β-cell-failure biomarkers by the target tissue and the evolution of the disease, separating the biomarkers in relation to the types of diabetes. Second, we demonstrated that most biomarkers currently used as early signs of β-cell failure are those that concern local or systemic inflammation processes and oxidative stress as well as those related to endothelial dysfunction processes. Third, we explored the novelties of diabetes as a protein conformational disease and the novel biomarker called real human islet amyloid polypeptide amyloid oligomers. Finally, we ended with a discussion about the best practice of validation and individual control of using different types of biomarkers in type 1 and type 2 diabetes in order to assess the role they play in the progress of diabetes in childhood.
CONCLUSION This review makes widely evident that most biomarkers currently used as early signs of β-cell failure are those that concern local or systemic inflammation processes and oxidative stress as well as those related to endothelial dysfunction processes. Landing in the clinical practice we propose that real human islet amyloid polypeptide amyloid oligomers is good for identifying patients with β-cell damage and potentially could substitute many biomarkers.
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Affiliation(s)
- María F Calderón-Hernández
- Unidad de Investigación en Enfermedades Metabólicas, Centro Médico Nacional Siglo XXI, IMSS, Mexico 06720, Mexico
| | | | - Cristina Revilla-Monsalve
- Unidad de Investigación en Enfermedades Metabólicas, Centro Médico Nacional Siglo XXI, IMSS, Mexico 06720, Mexico
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6
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García-Viñuales S, Sciacca MFM, Lanza V, Santoro AM, Grasso G, Tundo GR, Sbardella D, Coletta M, Grasso G, La Rosa C, Milardi D. The interplay between lipid and Aβ amyloid homeostasis in Alzheimer's Disease: risk factors and therapeutic opportunities. Chem Phys Lipids 2021; 236:105072. [PMID: 33675779 DOI: 10.1016/j.chemphyslip.2021.105072] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/15/2021] [Accepted: 03/01/2021] [Indexed: 12/19/2022]
Abstract
Alzheimer's Diseases (AD) is characterized by the accumulation of amyloid deposits of Aβ peptide in the brain. Besides genetic background, the presence of other diseases and an unhealthy lifestyle are known risk factors for AD development. Albeit accumulating clinical evidence suggests that an impaired lipid metabolism is related to Aβ deposition, mechanistic insights on the link between amyloid fibril formation/clearance and aberrant lipid interactions are still unavailable. Recently, many studies have described the key role played by membrane bound Aβ assemblies in neurotoxicity. Moreover, it has been suggested that a derangement of the ubiquitin proteasome pathway and autophagy is significantly correlated with toxic Aβ aggregation and dysregulation of lipid levels. Thus, studies focusing on the role played by lipids in Aβ aggregation and proteostasis could represent a promising area of investigation for the design of valuable treatments. In this review we examine current knowledge concerning the effects of lipids in Aβ aggregation and degradation processes, focusing on the therapeutic opportunities that a comprehensive understanding of all biophysical, biochemical, and biological processes involved may disclose.
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Affiliation(s)
| | - Michele F M Sciacca
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Valeria Lanza
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Anna Maria Santoro
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Giulia Grasso
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy
| | - Grazia R Tundo
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | | | - Massimiliano Coletta
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Giuseppe Grasso
- Department of Chemistry, University of Catania, Catania, Italy
| | - Carmelo La Rosa
- Department of Chemistry, University of Catania, Catania, Italy
| | - Danilo Milardi
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Catania, Italy.
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7
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Milardi D, Gazit E, Radford SE, Xu Y, Gallardo RU, Caflisch A, Westermark GT, Westermark P, Rosa CL, Ramamoorthy A. Proteostasis of Islet Amyloid Polypeptide: A Molecular Perspective of Risk Factors and Protective Strategies for Type II Diabetes. Chem Rev 2021; 121:1845-1893. [PMID: 33427465 DOI: 10.1021/acs.chemrev.0c00981] [Citation(s) in RCA: 116] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The possible link between hIAPP accumulation and β-cell death in diabetic patients has inspired numerous studies focusing on amyloid structures and aggregation pathways of this hormone. Recent studies have reported on the importance of early oligomeric intermediates, the many roles of their interactions with lipid membrane, pH, insulin, and zinc on the mechanism of aggregation of hIAPP. The challenges posed by the transient nature of amyloid oligomers, their structural heterogeneity, and the complex nature of their interaction with lipid membranes have resulted in the development of a wide range of biophysical and chemical approaches to characterize the aggregation process. While the cellular processes and factors activating hIAPP-mediated cytotoxicity are still not clear, it has recently been suggested that its impaired turnover and cellular processing by proteasome and autophagy may contribute significantly toward toxic hIAPP accumulation and, eventually, β-cell death. Therefore, studies focusing on the restoration of hIAPP proteostasis may represent a promising arena for the design of effective therapies. In this review we discuss the current knowledge of the structures and pathology associated with hIAPP self-assembly and point out the opportunities for therapy that a detailed biochemical, biophysical, and cellular understanding of its aggregation may unveil.
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Affiliation(s)
- Danilo Milardi
- Istituto di Cristallografia, Consiglio Nazionale delle Ricerche, Via P. Gaifami 18, 95126 Catania, Italy
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Yong Xu
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Rodrigo U Gallardo
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
| | - Gunilla T Westermark
- Department of Medical Cell Biology, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Per Westermark
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Ayyalusamy Ramamoorthy
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 41809-1055, United States
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8
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Wang Y, Meng F, Lu T, Wang C, Li F. Regulation of divalent metal ions to the aggregation and membrane damage of human islet amyloid polypeptide oligomers. RSC Adv 2021; 11:12815-12825. [PMID: 35423832 PMCID: PMC8697352 DOI: 10.1039/d1ra00354b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/21/2021] [Indexed: 11/21/2022] Open
Abstract
The accumulation of human islet amyloid polypeptide (hIAPP) on the surface of pancreatic β cells is closely related to the death of the cells. Divalent metal ions play a significant role in the cytotoxicity of hIAPP. In this study, we examined the roles played by the divalent metal ions of zinc, copper and calcium in the aggregation of both hIAPP18-27 fragment and full-length hIAPP and the ability of their oligomers to damage the membrane of POPC/POPG 4 : 1 LUVs using the ThT fluorescence, TEM, AFM, CD, ANS binding fluorescence and dye leakage experiments. We prepared metal-free and metal-associated oligomers that are similar in size and aggregate slowly using the short peptide and confirmed that the ability of the peptide oligomers to damage the lipid membrane is reduced by the binding to the metal ions, which is closely linked to the reducing hydrophobic exposure of the metal-associated oligomers. The study on the full-length hIAPP showed that the observed membrane damage induced by hIAPP oligomers is either mitigated at a peptide-to-metal ratio of 1 : 0.33 or aggravated at a peptide-to-metal ratio of 1 : 1 in the presence of Zn(ii) and Cu(ii), while the surface hydrophobicity of hIAPP oligomers was reduced at both peptide-to-metal ratios. The observed results of the membrane damage were attributed to the counteraction between a decrease in the disruptive ability of metal-associated oligomer species and an increase in the quantity of oligomers promoted by the binding of the metal ions to hIAPP oligomers. The former could play a predominant role in reducing the membrane damage at a peptide-to-metal ratio of 1 : 0.33, while the latter could play a predominant role in enhancing the membrane damage at a peptide-to-metal ratio of 1 : 1. This study shows that an enhanced membrane damage could be caused by the oligomer species with a decreased instead of an increased disruptive ability, given that the abundance of the oligomer species is high enough. Their is a counteraction between a decrease in the disruptive ability of metal-associated oligomer species and an increase in the quantity of oligomers promoted by the metal binding in the activity of hIAPP induced membrane damage.![]()
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Affiliation(s)
- Yajie Wang
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Feihong Meng
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Tong Lu
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Chunyun Wang
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Fei Li
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
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9
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Chowdhary S, Moschner J, Mikolajczak DJ, Becker M, Thünemann AF, Kästner C, Klemczak D, Stegemann A, Böttcher C, Metrangolo P, Netz RR, Koksch B. The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation. Chembiochem 2020; 21:3544-3554. [PMID: 33405360 PMCID: PMC7756607 DOI: 10.1002/cbic.202000373] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/31/2020] [Indexed: 12/12/2022]
Abstract
The hexapeptide hIAPP22-27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild-type hIAPP's toxicity to β-cell death. In amyloid research, the role of hydrophobic and aromatic-aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic-aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) to study the impact of side-chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self-assembly process.
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Affiliation(s)
- Suvrat Chowdhary
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Johann Moschner
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Dorian J. Mikolajczak
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Maximilian Becker
- Department of PhysicsFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Andreas F. Thünemann
- Federal Institute for Materials Research and Testing (BAM)Unter den Eichen 8712205BerlinGermany
| | - Claudia Kästner
- Federal Institute for Materials Research and Testing (BAM)Unter den Eichen 8712205BerlinGermany
| | - Damian Klemczak
- Institute of PharmacyFreie Universität BerlinKönigin-Luise-Str. 2–414195BerlinGermany
| | - Anne‐Katrin Stegemann
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Christoph Böttcher
- Institute of Chemistry and Biochemistry and Core Facility BioSupraMolFreie Universität BerlinFabeckstraße 36a14195BerlinGermany
| | - Pierangelo Metrangolo
- Department of ChemistryMaterials and Chemical Engineering “Giulio Natta”Politecnico di MilanoVia L. Mancinelli 720131MilanItaly
| | - Roland R. Netz
- Department of PhysicsFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Beate Koksch
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
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10
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Saghir AE, Farrugia G, Vassallo N. The human islet amyloid polypeptide in protein misfolding disorders: Mechanisms of aggregation and interaction with biomembranes. Chem Phys Lipids 2020; 234:105010. [PMID: 33227292 DOI: 10.1016/j.chemphyslip.2020.105010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/06/2020] [Accepted: 11/09/2020] [Indexed: 02/09/2023]
Abstract
Human islet amyloid polypeptide (hIAPP), otherwise known as amylin, is a 37-residue peptide hormone which is reported to be a common factor in protein misfolding disorders such as type-2 diabetes mellitus, Alzheimer's disease and Parkinson's disease, due to deposition of insoluble hIAPP amyloid in the pancreas and brain. Multiple studies point to the importance of the peptide's interaction with biological membranes and the cytotoxicity of hIAPP species. Here, we discuss the aggregation pathways of hIAPP amyloid fibril formation and focus on the complex interplay between membrane-mediated assembly of hIAPP and the associated mechanisms of membrane damage caused by the peptide species. Mitochondrial membranes, which are unique in their lipid composition, are proposed as prime targets for the early intracellular formation of hIAPP toxic entities. We suggest that future studies should include more physiologically-relevant and in-cell studies to allow a more accurate model of in vivo interactions. Finally, we underscore an urgent need for developing effective therapeutic strategies aimed at hindering hIAPP-phospholipid interactions.
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Affiliation(s)
- Adam El Saghir
- Dept. of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Gianluca Farrugia
- Dept. of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Neville Vassallo
- Dept. of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta.
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11
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Zheng Q, Carty SN, Lazo ND. Helix Dipole and Membrane Electrostatics Delineate Conformational Transitions in the Self-Assembly of Amyloidogenic Peptides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8389-8397. [PMID: 32628488 PMCID: PMC8095063 DOI: 10.1021/acs.langmuir.0c00723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The self-assembly of amyloidogenic peptides on membrane surfaces is associated with the death of neurons and β-cells in Alzheimer's disease and type 2 diabetes, respectively. The early events of self-assembly in vivo are not known, but there is increasing evidence for the importance of the α-helix. To test the hypothesis that electrostatic interactions involving the helix dipole play a key role in membrane-mediated peptide self-assembly, we studied IAPP[11-25(S20G)-NH2] (R11LANFLVHSGNNFGA25-NH2), which under certain conditions self-assembles in hydro to form β-sheet assemblies through an α-helix-containing intermediate. In the presence of small unilamellar vesicles composed solely of zwitterionic lipids, the peptide does not self-assemble presumably because of the absence of stabilizing electrostatic interactions between the membrane surface and the helix dipole. In the presence of vesicles composed solely of anionic lipids, the peptide forms a long-lived α-helix presumably stabilized by dipole-dipole interactions between adjacent helix dipoles. This helix represents a kinetic trap that inhibits β-sheet formation. Intriguingly, when the amount of anionic lipids was decreased to mimic the ratio of zwitterionic and anionic lipids in cells, the α-helix was short-lived and underwent an α-helix to β-sheet conformational transition. Our work suggests that the helix dipole and membrane electrostatics delineate the conformational transitions occurring along the self-assembly pathway to the amyloid.
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Affiliation(s)
- Qiuchen Zheng
- Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610, United States
| | - Senegal N Carty
- Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610, United States
| | - Noel D Lazo
- Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610, United States
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12
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Pariary R, Ghosh B, Bednarikova Z, Varnava KG, Ratha BN, Raha S, Bhattacharyya D, Gazova Z, Sarojini V, Mandal AK, Bhunia A. Targeted inhibition of amyloidogenesis using a non-toxic, serum stable strategically designed cyclic peptide with therapeutic implications. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140378. [PMID: 32032759 DOI: 10.1016/j.bbapap.2020.140378] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/24/2020] [Accepted: 01/31/2020] [Indexed: 10/25/2022]
Abstract
Amyloidogenic disorders are currently rising as a global health issue, prompting more and more studies dedicated to the development of effective targeted therapeutics. The innate affinity of these amyloidogenic proteins towards the biomembranes adds further complexities to the systems. Our previous studies have shown that biologically active peptides can effectively target amyloidogenesis serving as an efficient therapeutic alternative in several amyloidogenic disorders. The structural uniqueness of the PWWP motif in the de novo designed heptapeptide, KR7 (KPWWPRR-NH2) was demonstrated to target insulin fiber elongation specifically. By working on insulin, an important model system in amyloidogenic studies, we gained several mechanistic insights into the inhibitory actions at the protein-peptide interface. Here, we report a second-generation non-toxic and serum stable cyclic peptide, based primarily on the PWWP motif that resulted in complete inhibition of insulin fibrillation both in the presence and absence of the model membranes. Using both low- and high-resolution spectroscopic techniques, we could delineate the specific mechanism of inhibition, at atomistic resolution. Our studies put forward an effective therapeutic intervention that redirects the default aggregation kinetics towards off-pathway fibrillation. Based on the promising results, this novel cyclic peptide can be considered an excellent lead to design pharmaceutical molecules against amyloidogenesis.
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Affiliation(s)
- Ranit Pariary
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India
| | - Baijayanti Ghosh
- Department of Molecular Medicine, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India
| | - Zuzana Bednarikova
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia
| | - Kyriakos Gabriel Varnava
- School of Chemical Sciences, The University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Bhisma N Ratha
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India
| | - Sreyan Raha
- Department of Physics, Bose Institute, 93/1 APC Road, Kolkata 700009, India
| | - Dipita Bhattacharyya
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India
| | - Zuzana Gazova
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia
| | - Vijayalekshmi Sarojini
- School of Chemical Sciences, The University of Auckland, Private Bag, 92019, Auckland, New Zealand
| | - Atin K Mandal
- Department of Molecular Medicine, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India.
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13
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Altamirano-Bustamante MM, Altamirano-Bustamante NF, Larralde-Laborde M, Lara-Martínez R, Leyva-García E, Garrido-Magaña E, Rojas G, Jiménez-García LF, Revilla-Monsalve C, Altamirano P, Calzada-León R. Unpacking the aggregation-oligomerization-fibrillization process of naturally-occurring hIAPP amyloid oligomers isolated directly from sera of children with obesity or diabetes mellitus. Sci Rep 2019; 9:18465. [PMID: 31804529 PMCID: PMC6895187 DOI: 10.1038/s41598-019-54570-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 11/14/2019] [Indexed: 12/14/2022] Open
Abstract
The formation of amyloid oligomers and fibrils of the human islet amyloid polypeptide (hIAPP) has been linked with β- cell failure and death which causes the onset, progression, and comorbidities of diabetes. We begin to unpack the aggregation-oligomerization-fibrillization process of these oligomers taken from sera of pediatric patients. The naturally occurring or real hIAPP (not synthetic) amyloid oligomers (RIAO) were successfully isolated, we demonstrated the presence of homo (dodecamers, hexamers, and trimers) and hetero-RIAO, as well as several biophysical characterizations which allow us to learn from the real phenomenon taking place. We found that the aggregation/oligomerization process is active in the sera and showed that it happens very fast. The RIAO can form fibers and react with anti-hIAPP and anti-amyloid oligomers antibodies. Our results opens the epistemic horizon and reveal real differences between the four groups (Controls vs obesity, T1DM or T2DM) accelerating the process of understanding and discovering novel and more efficient prevention, diagnostic, transmission and therapeutic pathways.
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Affiliation(s)
- Myriam M Altamirano-Bustamante
- Unidad de Investigación en Enfermedades Metabólicas, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico city, Mexico.
| | | | - Mateo Larralde-Laborde
- Unidad de Investigación en Enfermedades Metabólicas, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico city, Mexico
| | | | - Edgar Leyva-García
- Unidad de Investigación en Enfermedades Metabólicas, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico city, Mexico
| | - Eulalia Garrido-Magaña
- UMAE Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico city, Mexico
| | - Gerardo Rojas
- UMAE Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico city, Mexico
| | | | - Cristina Revilla-Monsalve
- Unidad de Investigación en Enfermedades Metabólicas, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico city, Mexico
| | - Perla Altamirano
- Unidad de Investigación en Enfermedades Metabólicas, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico city, Mexico
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14
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Study on the structure and membrane disruption of the peptide oligomers constructed by hIAPP 18-27 peptide and its d,l-alternating isomer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183108. [PMID: 31672548 DOI: 10.1016/j.bbamem.2019.183108] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/26/2019] [Accepted: 10/16/2019] [Indexed: 01/14/2023]
Abstract
Increasing lines of evidence show that the oligomeric intermediates of amyloid peptides/proteins are toxic to biological membranes. However, the structural features of the oligomers that are closely associated with the ability to damage biological membranes are far from understanding. In this study, we constructed two species of oligomers using hIAPP18-27 peptide and its d,l-alternating isomer, examined the disruptive ability of the oligomers to POPC/POPG 4:1 vesicles by leakage assay and 31P NMR spectroscopy, and characterized the structural features of the oligomers by CD, TEM, 1H NMR and fluorescence quenching experiments. We found that the d,l-alternating peptide oligomers are more disruptive than the all-L peptide oligomers to the lipid membrane. The characterization of the secondary structure revealed that the d,l-alternating peptide adopts an extended polyproline type-II (PPII) conformation, while the all-L peptide adopts a random coil conformation in oligomers. Compared with the all-L peptide oligomers, the d,l-alternating peptide oligomers are less compact and keep more hydrophobic groups water exposed. Both the changes from PPII to α-sheet in the structure of d,l-alternating peptide and from random coil to β-sheet in the structure of all-L peptide reduce the ability of the peptide oligomers to disrupt the lipid membrane. Our results suggest that an oligomer with extended peptide chains could be more potent in membrane disruption than an oligomer with folded peptide chains and an increase in peptide-peptide interaction could decrease the disruptive ability of oligomer.
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Levine ZA, Teranishi K, Okada AK, Langen R, Shea JE. The Mitochondrial Peptide Humanin Targets but Does Not Denature Amyloid Oligomers in Type II Diabetes. J Am Chem Soc 2019; 141:14168-14179. [DOI: 10.1021/jacs.9b04995] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Zachary A. Levine
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06520, United States
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, Connecticut 06520, United States
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16
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Lv W, Zhang J, Jiao A, Wang B, Chen B, Lin J. Resveratrol attenuates hIAPP amyloid formation and restores the insulin secretion ability in hIAPP-INS1 cell line via enhancing autophagy. Can J Physiol Pharmacol 2019; 97:82-89. [PMID: 30312115 DOI: 10.1139/cjpp-2016-0686] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
It has been proved that human islet amyloid polypeptide (hIAPP), the main constituent of islet amyloid deposition, is one of the important factors that can induce type 2 diabetes or graft failure after islet transplantation. As there is no research on whether resveratrol degrading the amyloid deposition by its special chemical structure or enhancing autophagy had been published, we decided to detect the function of resveratrol in degrading the amyloid deposition in pancreatic beta cells. We established stable hIAPP-INS1 cell line via transfecting INS1 cells by lentivirus that overexpresses hIAPP. Our research demonstrates that amyloid deposition existed in hIAPP-INS1 cell by the thioflavin S fluorescent staining, meanwhile the function of insulin secretion of hIAPP-INS1 cells was decreased significantly (p < 0.01). After treatment with resveratrol (20 μM) for 24 h, amyloid deposition in hIAPP-INS1 cells was decreased significantly, and the insulin secretion was restored significantly (p < 0.01). Once inhibited the autophagy of hIAPP-INS1 cells by 3-methyladenine for 24 h, resveratrol does not effectively remove hIAPP deposits again, and cannot improve the function of insulin secretion. These results provide a novel thought that resveratrol can degrade the amyloid deposition in type 2 diabetes and the graft after islet transplantation.
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Affiliation(s)
- Wu Lv
- Department of Hepatobiliary and Transplantation Surgery, The First Hospital of China Medical University, Shenyang, China
- Department of General Surgery, Liaoning Cancer Hospital and Institute, Shenyang, China
| | - Jialin Zhang
- Department of Hepatobiliary and Transplantation Surgery, The First Hospital of China Medical University, Shenyang, China
| | - Ao Jiao
- Department of Hepatobiliary and Transplantation Surgery, The First Hospital of China Medical University, Shenyang, China
| | - Bowen Wang
- Department of Hepatobiliary and Transplantation Surgery, The First Hospital of China Medical University, Shenyang, China
| | - Baomin Chen
- Department of Hepatobiliary and Transplantation Surgery, The First Hospital of China Medical University, Shenyang, China
| | - Jie Lin
- Department of General Surgery, Liaoning Cancer Hospital and Institute, Shenyang, China
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17
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Divakara MB, Martinez D, Ravi A, Bhavana V, Ramana V, Habenstein B, Loquet A, Santosh MS. Molecular mechanisms for the destabilization of model membranes by islet amyloid polypeptide. Biophys Chem 2018; 245:34-40. [PMID: 30576976 DOI: 10.1016/j.bpc.2018.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/29/2018] [Accepted: 12/10/2018] [Indexed: 12/30/2022]
Abstract
Misfolding of human islet amyloid polypeptide (hIAPP) into insoluble aggregates is associated with Type 2 diabetes. It has been suggested that hIAPP toxicity may be due to its accumulation in pancreatic islets, causing membrane disruption and cell permeabilization, however the molecular basis underlying its lipid association are still unclear. Here, we combine solid-state NMR, fluorescence and bright field microscopy to investigate hIAPP - lipid membrane interactions. Real-time microscopy highlights a time-dependent penetration of hIAPP oligomers toward the most buried layers of the lipid vesicles until the membrane disrupts. Deuterium NMR was conducted on liposomes at different hIAPP concentration to probe lipid internal order and thermotropism. The gel-to-fluid phase transition of the lipids is decreased by the presence of hIAPP, and site-specific analysis of the order parameter showed a significant increase of lipid order for the first eight positions of the acyl chain, suggesting a partial insertion of the peptide inside the bilayer. These results offer experimental insight into the membrane destabilization of hIAPP on model membrane vesicles.
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Affiliation(s)
- Madhihalli Basavaraju Divakara
- Center for Incubation, Innovation, Research and Consultancy (CIIRC), Jyothy Institute of Technology, Thataguni, Off Kanakapura Road, Bangalore 560082, Karnataka, India; Visvesvaraya Technological University, Regional Research Centre, Jnana Sangama, Belagavi 590018, Karnataka, India
| | - Denis Martinez
- Institute of Chemistry and Biology of Membranes and Nanoobjects, Institut Européen de Chimie et Biologie (CNRS UMR 5248), Université de Bordeaux, 2 Rue Robert Escarpit, 33600 Pessac, France
| | - Ashwini Ravi
- Center for Incubation, Innovation, Research and Consultancy (CIIRC), Jyothy Institute of Technology, Thataguni, Off Kanakapura Road, Bangalore 560082, Karnataka, India; Visvesvaraya Technological University, Regional Research Centre, Jnana Sangama, Belagavi 590018, Karnataka, India
| | - Veer Bhavana
- Center for Incubation, Innovation, Research and Consultancy (CIIRC), Jyothy Institute of Technology, Thataguni, Off Kanakapura Road, Bangalore 560082, Karnataka, India; Visvesvaraya Technological University, Regional Research Centre, Jnana Sangama, Belagavi 590018, Karnataka, India
| | - Venkata Ramana
- DRDO BU CLS, Bharathiar University Campus, Coimbatore 641046, Tamil Nadu, India
| | - Birgit Habenstein
- Institute of Chemistry and Biology of Membranes and Nanoobjects, Institut Européen de Chimie et Biologie (CNRS UMR 5248), Université de Bordeaux, 2 Rue Robert Escarpit, 33600 Pessac, France.
| | - Antoine Loquet
- Institute of Chemistry and Biology of Membranes and Nanoobjects, Institut Européen de Chimie et Biologie (CNRS UMR 5248), Université de Bordeaux, 2 Rue Robert Escarpit, 33600 Pessac, France.
| | - Mysore Sridhar Santosh
- Center for Incubation, Innovation, Research and Consultancy (CIIRC), Jyothy Institute of Technology, Thataguni, Off Kanakapura Road, Bangalore 560082, Karnataka, India.
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18
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Insulin–eukaryotic model membrane interaction: Mechanistic insight of insulin fibrillation and membrane disruption. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1917-1926. [DOI: 10.1016/j.bbamem.2018.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 02/05/2018] [Accepted: 02/05/2018] [Indexed: 12/26/2022]
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19
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Dong X, Qiao Q, Qian Z, Wei G. Recent computational studies of membrane interaction and disruption of human islet amyloid polypeptide: Monomers, oligomers and protofibrils. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018. [PMID: 29530482 DOI: 10.1016/j.bbamem.2018.03.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The amyloid deposits of human islet amyloid polypeptide (hIAPP) are found in type 2 diabetes patients. hIAPP monomer is intrinsically disordered in solution, whereas it can form amyloid fibrils both in vivo and in vitro. Extensive evidence suggests that hIAPP causes the disruption of cellular membrane, and further induces cytotoxicity and the death of islet β-cells in pancreas. The presence of membrane also accelerates the hIAPP fibril formation. hIAPP oligomers and protofibrils in the early stage of aggregation were reported to be the most cytotoxic, disrupting the membrane integrity and giving rise to the pathological process. The detailed molecular mechanisms of hIAPP-membrane interactions and membrane disruption are complex and remain mostly unknown. Here in this review, we focus on recent computational studies that investigated the interactions of full length and fragmentary hIAPP monomers, oligomers and protofibrils with anionic, zwitterionic and mixed anionic-zwitterionic lipid bilayers. We mainly discuss the binding orientation of monomers at membrane surface, the conformational ensemble and the oligomerization of hIAPP inside membranes, the effect of lipid composition on hIAPP oligomers/protofibrils-membrane interactions, and the hIAPP-induced membrane perturbation. This review provides mechanistic insights into the interactions between hIAPP and lipid bilayers with different lipid composition at an atomistic level, which is helpful to understand the hIAPP cytotoxicity mediated by membrane. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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Affiliation(s)
- Xuewei Dong
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Science (Ministry of Education), Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200433, China
| | - Qin Qiao
- Digital Medical Research Center, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, Shanghai 200032, China.
| | - Zhenyu Qian
- Key Laboratory of Exercise and Health Sciences (Ministry of Education) and School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Science (Ministry of Education), Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200433, China.
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20
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Jiang Z, Flynn JD, Teague WE, Gawrisch K, Lee JC. Stimulation of α-synuclein amyloid formation by phosphatidylglycerol micellar tubules. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1840-1847. [PMID: 29501608 DOI: 10.1016/j.bbamem.2018.02.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 02/23/2018] [Accepted: 02/25/2018] [Indexed: 10/25/2022]
Abstract
α-Synuclein (α-Syn) is a presynaptic protein that is accumulated in its amyloid form in the brains of Parkinson's patients. Although its biological function remains unclear, α-syn has been suggested to bind to synaptic vesicles and facilitate neurotransmitter release. Recently, studies have found that α-syn induces membrane tubulation, highlighting a potential mechanism for α-syn to stabilize highly curved membrane structures which could have both functional and dysfunctional consequences. To understand how membrane remodeling by α-syn affects amyloid formation, we have studied the α-syn aggregation process in the presence of phosphatidylglycerol (PG) micellar tubules, which were the first reported example of membrane tubulation by α-syn. Aggregation kinetics, β-sheet content, and macroscopic protein-lipid structures were observed by Thioflavin T fluorescence, circular dichroism spectroscopy and transmission electron microscopy, respectively. Collectively, the presence of PG micellar tubules formed at a stochiometric (L/P = 1) ratio was found to stimulate α-syn fibril formation. Moreover, transmission electron microscopy and solid-state nuclear magnetic resonance spectroscopy revealed the co-assembly of PG and α-syn into fibril structures. However, isolated micellar tubules do not form fibrils by themselves, suggesting an important role of free α-syn monomers during amyloid formation. In contrast, fibrils did not form in the presence of excess PG lipids (≥L/P = 50), where most of the α-syn molecules are in a membrane-bound α-helical form. Our results provide new mechanistic insights into how membrane tubules modulate α-syn amyloid formation and support a pivotal role of protein-lipid interaction in the dysfunction of α-syn.
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Affiliation(s)
- Zhiping Jiang
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jessica D Flynn
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Walter E Teague
- Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Klaus Gawrisch
- Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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21
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Naito A, Matsumori N, Ramamoorthy A. Dynamic membrane interactions of antibacterial and antifungal biomolecules, and amyloid peptides, revealed by solid-state NMR spectroscopy. Biochim Biophys Acta Gen Subj 2018; 1862:307-323. [PMID: 28599848 PMCID: PMC6384124 DOI: 10.1016/j.bbagen.2017.06.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 05/28/2017] [Accepted: 06/02/2017] [Indexed: 12/12/2022]
Abstract
A variety of biomolecules acting on the cell membrane folds into a biologically active structure in the membrane environment. It is, therefore, important to determine the structures and dynamics of such biomolecules in a membrane environment. While several biophysical techniques are used to obtain low-resolution information, solid-state NMR spectroscopy is one of the most powerful means for determining the structure and dynamics of membrane bound biomolecules such as antibacterial biomolecules and amyloidogenic proteins; unlike X-ray crystallography and solution NMR spectroscopy, applications of solid-state NMR spectroscopy are not limited by non-crystalline, non-soluble nature or molecular size of membrane-associated biomolecules. This review article focuses on the applications of solid-state NMR techniques to study a few selected antibacterial and amyloid peptides. Solid-state NMR studies revealing the membrane inserted bent α-helical structure associated with the hemolytic activity of bee venom melittin and the chemical shift oscillation analysis used to determine the transmembrane structure (with α-helix and 310-helix in the N- and C-termini, respectively) of antibiotic peptide alamethicin are discussed in detail. Oligomerization of an amyloidogenic islet amyloid polypeptide (IAPP, or also known as amylin) resulting from its aggregation in a membrane environment, molecular interactions of the antifungal natural product amphotericin B with ergosterol in lipid bilayers, and the mechanism of lipid raft formation by sphingomyelin studied using solid state NMR methods are also discussed in this review article. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato.
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Affiliation(s)
- Akira Naito
- Graduate School of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
| | - Nobuaki Matsumori
- Department of Chemistry, Graduate School of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, University of Michigan, Ann Arbor, MI 48109-1055, USA; Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
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22
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Lu T, Meng F, Wei Y, Li Y, Wang C, Li F. Exploring the relation between the oligomeric structure and membrane damage by a study on rat islet amyloid polypeptide. Phys Chem Chem Phys 2018; 20:8976-8983. [DOI: 10.1039/c7cp06468c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Membrane damage by rIAPP oligomers is related to the hydrophobic exposure of aggregates.
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Affiliation(s)
- Tong Lu
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Feihong Meng
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Ying Wei
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Yang Li
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Chunyu Wang
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Fei Li
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
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23
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van der Wel PCA. Insights into protein misfolding and aggregation enabled by solid-state NMR spectroscopy. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 88:1-14. [PMID: 29035839 PMCID: PMC5705391 DOI: 10.1016/j.ssnmr.2017.10.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 05/17/2023]
Abstract
The aggregation of proteins and peptides into a variety of insoluble, and often non-native, aggregated states plays a central role in many devastating diseases. Analogous processes undermine the efficacy of polypeptide-based biological pharmaceuticals, but are also being leveraged in the design of biologically inspired self-assembling materials. This Trends article surveys the essential contributions made by recent solid-state NMR (ssNMR) studies to our understanding of the structural features of polypeptide aggregates, and how such findings are informing our thinking about the molecular mechanisms of misfolding and aggregation. A central focus is on disease-related amyloid fibrils and oligomers involved in neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's disease. SSNMR-enabled structural and dynamics-based findings are surveyed, along with a number of resulting emerging themes that appear common to different amyloidogenic proteins, such as their compact alternating short-β-strand/β-arc amyloid core architecture. Concepts, methods, future prospects and challenges are discussed.
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Affiliation(s)
- Patrick C A van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA.
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Capping effects on polymorphic Aβ 16-21 amyloids depend on their size: A molecular dynamics simulation study. Biophys Chem 2017; 232:1-11. [PMID: 29046256 DOI: 10.1016/j.bpc.2017.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 11/24/2022]
Abstract
Understanding Aβ amyloid oligomers associated with neuro-degenerative diseases is needed due to their toxic characteristics and mediation of amyloid fibril growth. Depending on various physiological circumstances such as ionic strength, metal ion, and point-residue mutation, oligomeric amyloids exhibit polymorphic behavior and structural stabilities, i.e. showing different conformation and stabilities. Specifically, experimental and computational researchers have found that the capping modulates the physical and chemical properties of amyloids by preserving electrostatic energy interactions, which is one of the dominant factors for amyloid stability. Still, there is no detailed knowledge for the polymorphic amyloids with reflecting the terminal capping effects. In the present study, we investigated the role of terminal capping (i.e. N-terminal acetylation and C-terminal amidation) on polymorphic Aβ16-21 amyloid oligomer and protofibrils via molecular dynamics (MD) simulations. We found that the capping effects have differently altered the conformation of polymorphic antiparallel-homo and -hetero Aβ16-21 amyloid oligomer, but not Aβ16-21 amyloid protofibrils. However, regardless of polymorphic composition of the amyloids, the capping induces the thermodynamic instabilities of Aβ16-21 amyloid oligomers, but does not show any distinct affect on Aβ16-21 amyloid protofibrils. Specifically, among the molecular mechanic factors, electrostatic energy dominantly contributes the thermodynamic stability of the Aβ16-21 amyloids. We hope that our computation study about the role of the capping effects on the polymorphic amyloids will facilitate additional efforts to enhance degradation of amyloids and to design a selective drug in the future.
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Zhang M, Ren B, Liu Y, Liang G, Sun Y, Xu L, Zheng J. Membrane Interactions of hIAPP Monomer and Oligomer with Lipid Membranes by Molecular Dynamics Simulations. ACS Chem Neurosci 2017; 8:1789-1800. [PMID: 28585804 DOI: 10.1021/acschemneuro.7b00160] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Interaction of human islet amyloid polypeptide (hIAPP) peptides with cell membrane is crucial for the understanding of amyloid toxicity associated with Type II diabetes (T2D). While it is known that the hIAPP-membrane interactions are considered to promote hIAPP aggregation into fibrils and induce membrane disruption, the membrane-induced conformation, orientation, aggregation, and adsorption behaviors of hIAPP peptides have not been well understood at the atomic level. Herein, we perform all-atom explicit-water molecular dynamics (MD) simulations to study the adsorption, orientation, and surface interaction of hIAPP aggregates with different sizes (monomer to tetramer) and conformations (monomer with α-helix and tetramer with β-sheet-rich U-turn) upon adsorption on the lipid bilayers composed of both pure zwitterionic POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and mixed anionic POPC/POPE (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine) (3:1) lipids. MD simulation results show that hIAPP monomer with α-helical conformation and hIAPP pentamer with β-sheet conformation can adsorb on both POPC and POPC/POPE bilayers via a preferential orientation of N-terminal residues facing toward the bilayer surface. The hIAPP aggregates show stronger interactions with mixed POPC/POPE lipids than pure POPC lipids, consistent with experimental observation that hIAPP adsorption and fibrililation are enhanced on mixed lipid bilayers. While electrostatic interactions are main attractive forces to drive the hIAPP aggregates to adsorb on both bilayers, the introduction of the more hydrophilic head groups of POPE lipids further promote the formation of the interfacial hydrogen bonds. Complement to our previous studies of hIAPP aggregates in bulk solution, this computational work increases our knowledge about the mechanism of amyloid peptide-membrane interactions that is central to the understanding the progression of all amyloid diseases.
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Affiliation(s)
- Mingzhen Zhang
- College
of Life Sciences and Chemistry Hunan University of Technology, Zhuzhou 412007, China
- Department
of Chemical and Biomolecular Engineering The University of Akron, Akron, Ohio 44325, United States
| | - Baiping Ren
- Department
of Chemical and Biomolecular Engineering The University of Akron, Akron, Ohio 44325, United States
| | - Yonglan Liu
- Department
of Chemical and Biomolecular Engineering The University of Akron, Akron, Ohio 44325, United States
| | - Guizhao Liang
- Department
of Chemical and Biomolecular Engineering The University of Akron, Akron, Ohio 44325, United States
| | - Yan Sun
- Department
of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education School
of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Lijian Xu
- College
of Life Sciences and Chemistry Hunan University of Technology, Zhuzhou 412007, China
- Department
of Chemical and Biomolecular Engineering The University of Akron, Akron, Ohio 44325, United States
| | - Jie Zheng
- Department
of Chemical and Biomolecular Engineering The University of Akron, Akron, Ohio 44325, United States
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26
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Tracking the amyloidogenic core of IAPP amyloid fibrils: Insights from micro-Raman spectroscopy. J Struct Biol 2017; 199:140-152. [PMID: 28602716 DOI: 10.1016/j.jsb.2017.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/19/2017] [Accepted: 06/03/2017] [Indexed: 12/14/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is the major protein component of extracellular amyloid deposits, located in the islets of Langerhans, a hallmark of type II diabetes. The underlying mechanisms of IAPP aggregation have not yet been clearly defined, although the highly amyloidogenic sequence of the protein has been extensively studied. Several segments have been highlighted as aggregation-prone regions (APRs), with much attention focused on the central 8-17 and 20-29 stretches. In this work, we employ micro-Raman spectroscopy to identify specific regions that are contributing to or are excluded from the amyloidogenic core of IAPP amyloid fibrils. Our results demonstrate that both the N-terminal region containing a conserved disulfide bond between Cys residues at positions 2 and 7, and the C-terminal region containing the only Tyr residue are excluded from the amyloid core. Finally, by performing detailed aggregation assays and molecular dynamics simulations on a number of IAPP variants, we demonstrate that point mutations within the central APRs contribute to the reduction of the overall amyloidogenic potential of the protein but do not completely abolish the formation of IAPP amyloid fibrils.
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27
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Hajiraissi R, Giner I, Grundmeier G, Keller A. Self-Assembly, Dynamics, and Polymorphism of hIAPP(20-29) Aggregates at Solid-Liquid Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:372-381. [PMID: 27935715 DOI: 10.1021/acs.langmuir.6b03288] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The misfolding and subsequent assembly of proteins and peptides into insoluble amyloid structures play important roles in the development of numerous diseases. The dynamics of self-assembly and the morphology of the resulting aggregates critically depend on various environmental factors and especially on the presence of interfaces. Here, we show in detail how the presence of surfaces with different physicochemical properties influences the assembly dynamics and especially the aggregate morphology of hIAPP(20-29), an amyloidogenic fragment of the peptide hormone human islet amyloid polypeptide (hIAPP), which is involved in the development of type 2 diabetes. Time-lapse atomic force microscopy is employed to study the assembly dynamics of hIAPP(20-29) and the morphology of the resulting aggregates in bulk solution as well as at hydrophilic and hydrophobic model surfaces. We find that the presence of hydrophilic mica surfaces promotes fibrillation when compared with the assembly in bulk solution and results in a more pronounced polymorphism. Three fibrillar species are found to coexist on the mica surface, that is, straight, coiled, and ribbon-like fibrils, whereas only the straight and coiled fibrils are observed in bulk solution after comparable incubation times. In addition, the straight and coiled fibrils assembled at the mica surface have significantly different dimensions compared with those assembled in bulk solution. The three fibrillar species found on the mica surface most likely form independently by lateral association of arbitrary numbers of protofibrils with about 2 nm height. On hydrophobic hydrocarbon surfaces, fibrillation is retarded but not completely suppressed, in contrast to previous observations for full-length hIAPP(1-37). Our results show that peptide-surface interactions may induce diverse, peptide-specific alterations of amyloid assembly dynamics and fibrillar polymorphism. They may therefore contribute to a deeper understanding of the molecular processes that govern amyloid aggregation at different surfaces.
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Affiliation(s)
- Roozbeh Hajiraissi
- Technical and Macromolecular Chemistry, Paderborn University , Warburger Strasse 100, 33098 Paderborn, Germany
| | - Ignacio Giner
- Technical and Macromolecular Chemistry, Paderborn University , Warburger Strasse 100, 33098 Paderborn, Germany
| | - Guido Grundmeier
- Technical and Macromolecular Chemistry, Paderborn University , Warburger Strasse 100, 33098 Paderborn, Germany
| | - Adrian Keller
- Technical and Macromolecular Chemistry, Paderborn University , Warburger Strasse 100, 33098 Paderborn, Germany
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28
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Woo SY, Lee H. Effect of lipid shape on toroidal pore formation and peptide orientation in lipid bilayers. Phys Chem Chem Phys 2017; 19:21340-21349. [DOI: 10.1039/c7cp02708g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Disordered and thinner bilayer w/lyso-lipids; tilted orientation of peptides in bilayer w/lyso-lipids; toroidal pores stabilized by peptides and lyso-lipids.
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Affiliation(s)
- Sun Young Woo
- Department of Chemical Engineering
- Dankook University
- Yongin
- South Korea
| | - Hwankyu Lee
- Department of Chemical Engineering
- Dankook University
- Yongin
- South Korea
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29
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Lee M, Chang HJ, Baek I, Na S. Structural analysis of oligomeric and protofibrillar Aβ amyloid pair structures considering F20L mutation effects using molecular dynamics simulations. Proteins 2016; 85:580-592. [PMID: 28019690 DOI: 10.1002/prot.25232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/12/2016] [Accepted: 11/23/2016] [Indexed: 12/20/2022]
Abstract
Aβ amyloid proteins are involved in neuro-degenerative diseases such as Alzheimer's, Parkinson's, and so forth. Because of its structurally stable feature under physiological conditions, Aβ amyloid protein disrupts the normal cell function. Because of these concerns, understanding the structural feature of Aβ amyloid protein in detail is crucial. There have been some efforts on lowering the structural stabilities of Aβ amyloid fibrils by decreasing the aromatic residues characteristic and hydrophobic effect. Yet, there is a lack of understanding of Aβ amyloid pair structures considering those effects. In this study, we provide the structural characteristics of wildtype (WT) and phenylalanine residue mutation to leucine (F20L) Aβ amyloid pair structures using molecular dynamics simulation in detail. We also considered the polymorphic feature of F20L and WT Aβ pair amyloids based on the facing β-strand directions between the amyloid pairs. As a result, we were able to observe the varying effects of mutation, polymorphism, and protofibril lengths on the structural stability of pair amyloids. Furthermore, we have also found that opposite structural stability exists on a certain polymorphic Aβ pair amyloids depending on its oligomeric or protofibrillar state, which can be helpful for understanding the amyloid growth mechanism via repetitive fragmentation and elongation mechanism. Proteins 2017; 85:580-592. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Myeongsang Lee
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Hyun Joon Chang
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Inchul Baek
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Sungsoo Na
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
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30
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Kepp KP. Ten Challenges of the Amyloid Hypothesis of Alzheimer’s Disease. J Alzheimers Dis 2016; 55:447-457. [DOI: 10.3233/jad-160550] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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31
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Strømland Ø, Jakubec M, Furse S, Halskau Ø. Detection of misfolded protein aggregates from a clinical perspective. J Clin Transl Res 2016; 2:11-26. [PMID: 30873457 PMCID: PMC6410640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 03/22/2016] [Accepted: 03/22/2016] [Indexed: 11/29/2022] Open
Abstract
Neurodegenerative Protein Misfolding Diseases (PMDs), such as Alzheimer's (AD), Parkinson's (PD) and prion diseases, are generally difficult to diagnose before irreversible damage to the central nervous system damage has occurred. Detection of the misfolded proteins that ultimately lead to these conditions offers a means for providing early detection and diagnosis of this class of disease. In this review, we discuss recent developments surrounding protein misfolding diseases with emphasis on the cytotoxic oligomers implicated in their aetiology. We also discuss the relationship of misfolded proteins with biological membranes. Finally, we discuss how far techniques for providing early diagnoses for PMDs have advanced and describe promising clinical approaches. We conclude that antibodies with specificity towards oligomeric species of AD and PD and lectins with specificity for particular glycosylation, show promise. However, it is not clear which approach may yield a reliable clinical test first. Relevance for patients: Individuals suffering from protein misfolding diseases will likely benefit form earlier, less- or even non-invasive diagnosis techniques. The current state and possible future directions for these are subject of this review.
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Affiliation(s)
- Øyvind Strømland
- Department of Molecular Biology, University of Bergen, Bergen, Norway
| | - Martin Jakubec
- Department of Molecular Biology, University of Bergen, Bergen, Norway
| | - Samuel Furse
- Department of Molecular Biology, University of Bergen, Bergen, Norway
| | - Øyvind Halskau
- Department of Molecular Biology, University of Bergen, Bergen, Norway
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32
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Li X, Wan M, Gao L, Fang W. Mechanism of Inhibition of Human Islet Amyloid Polypeptide-Induced Membrane Damage by a Small Organic Fluorogen. Sci Rep 2016; 6:21614. [PMID: 26887358 PMCID: PMC4757883 DOI: 10.1038/srep21614] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 01/27/2016] [Indexed: 11/09/2022] Open
Abstract
Human islet amyloid polypeptide (hIAPP) is believed to be responsible for the death of insulin-producing β-cells. However, the mechanism of membrane damage at the molecular level has not been fully elucidated. In this article, we employ coarse- grained dissipative particle dynamics simulations to study the interactions between a lipid bilayer membrane composed of 70% zwitterionic lipids and 30% anionic lipids and hIAPPs with α-helical structures. We demonstrated that the key factor controlling pore formation is the combination of peptide charge-induced electroporation and peptide hydrophobicity-induced lipid disordering and membrane thinning. According to these mechanisms, we suggest that a water-miscible tetraphenylethene BSPOTPE is a potent inhibitor to rescue hIAPP-induced cytotoxicity. Our simulations predict that BSPOTPE molecules can bind directly to the helical regions of hIAPP and form oligomers with separated hydrophobic cores and hydrophilic shells. The micelle-like hIAPP-BSPOTPE clusters tend to be retained in the water/membrane interface and aggregate therein rather than penetrate into the membrane. Electrostatic attraction between BSPOTPE and hIAPP also reduces the extent of hIAPP binding to the anionic lipid bilayer. These two modes work together and efficiently prevent membrane poration.
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Affiliation(s)
- Xiaoxu Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Mingwei Wan
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Lianghui Gao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Weihai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
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33
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Lim L, Wei Y, Lu Y, Song J. ALS-Causing Mutations Significantly Perturb the Self-Assembly and Interaction with Nucleic Acid of the Intrinsically Disordered Prion-Like Domain of TDP-43. PLoS Biol 2016; 14:e1002338. [PMID: 26735904 PMCID: PMC4703307 DOI: 10.1371/journal.pbio.1002338] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 11/25/2015] [Indexed: 12/13/2022] Open
Abstract
TAR-DNA-binding protein-43 (TDP-43) C-terminus encodes a prion-like domain widely presented in RNA-binding proteins, which functions to form dynamic oligomers and also, amazingly, hosts most amyotrophic lateral sclerosis (ALS)-causing mutations. Here, as facilitated by our previous discovery, by circular dichroism (CD), fluorescence and nuclear magnetic resonance (NMR) spectroscopy, we have successfully determined conformations, dynamics, and self-associations of the full-length prion-like domains of the wild type and three ALS-causing mutants (A315E, Q331K, and M337V) in both aqueous solutions and membrane environments. The study decodes the following: (1) The TDP-43 prion-like domain is intrinsically disordered only with some nascent secondary structures in aqueous solutions, but owns the capacity to assemble into dynamic oligomers rich in β-sheet structures. By contrast, despite having highly similar conformations, three mutants gained the ability to form amyloid oligomers. The wild type and three mutants all formed amyloid fibrils after incubation as imaged by electron microscopy. (2) The interaction with nucleic acid enhances the self-assembly for the wild type but triggers quick aggregation for three mutants. (3) A membrane-interacting subdomain has been identified over residues Met311-Gln343 indispensable for TDP-43 neurotoxicity, which transforms into a well-folded Ω-loop-helix structure in membrane environments. Furthermore, despite having very similar membrane-embedded conformations, three mutants will undergo further self-association in the membrane environment. Our study implies that the TDP-43 prion-like domain appears to have an energy landscape, which allows the assembly of the wild-type sequence into dynamic oligomers only under very limited condition sets, and ALS-causing point mutations are sufficient to remodel it to more favor the amyloid formation or irreversible aggregation, thus supporting the emerging view that the pathologic aggregation may occur via the exaggeration of functionally important assemblies. Furthermore, the coupled capacity of TDP-43 in aggregation and membrane interaction may critically account for its high neurotoxicity, and therefore its decoupling may represent a promising therapeutic strategy to treat TDP-43 causing neurodegenerative diseases. The prion-like domain of TDP-43 appears to have an energy landscape that allows oligomerisation only under very limited conditions; however, TDP-43 mutations that cause amyotrophic lateral sclerosis are sufficient to remodel the protein in favor of amyloid formation. Amyotrophic lateral sclerosis (ALS) is the most prevalent fatal motor neuron disease. It was identified ~140 years ago, but the exact mechanism underlying the disease has still not been well defined. TAR-DNA-binding protein-43 (TDP-43) was identified as the major component of the proteinaceous inclusions present in ~97% ALS and ~45% frontotemporal dementia (FTD) patients, and has also been observed in an increasing spectrum of other neurodegenerative disorders, including Alzheimer disease. The TDP-43 C-terminus is a key domain—it encodes a prion-like domain and, crucially, hosts almost all ALS-causing mutations. Here we have successfully determined the conformations, dynamics, and self-associations of the prion-like domains of both wild type and three ALS-causing mutants in both aqueous solutions and membrane environments. The study suggests that the TDP-43 prion-like domain appears to have a unique energy landscape, which allows the assembly of the wild-type sequence into specific oligomers only under very limited conditions. Intriguingly, ALS-causing point mutations remodel the energy landscape to favor amyloid formation or irreversible aggregation, thus supporting the emerging view that pathologic aggregation may occur via the exaggeration of functionally important assemblies. Furthermore, the coupled capacity of TDP-43 in aggregation and membrane interaction may partly account for its high neurotoxicity; decoupling these may therefore represent a promising therapeutic strategy to treat TDP-43-mediated neurodegenerative diseases.
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Affiliation(s)
- Liangzhong Lim
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Yuanyuan Wei
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
| | - Yimei Lu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Jianxing Song
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
- * E-mail:
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34
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Wei Y, Lu J, Lu T, Meng F, Xu J, Wang L, Li Y, Wang L, Li F. Formation of lamellar micelle-like oligomers and membrane disruption revealed by the study of short peptide hIAPP18–27. Phys Chem Chem Phys 2016; 18:29847-29857. [DOI: 10.1039/c6cp04431j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An oligomer species with a lamellar crystalline structure is identified to disrupt the membrane containing the anionic component strongly.
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Affiliation(s)
- Ying Wei
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Jun Lu
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Tong Lu
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Feihong Meng
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Jia Xu
- College of Life Science
- Jilin University
- Changchun
- P. R. China
| | - Li Wang
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Yang Li
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
| | - Liping Wang
- College of Life Science
- Jilin University
- Changchun
- P. R. China
| | - Fei Li
- State Key Laboratory of Supramolecular Structure and Materials
- Jilin University
- Changchun 130012
- P. R. China
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35
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Qian Z, Jia Y, Wei G. Binding Orientations and Lipid Interactions of Human Amylin at Zwitterionic and Anionic Lipid Bilayers. J Diabetes Res 2016; 2016:1749196. [PMID: 26649316 PMCID: PMC4663351 DOI: 10.1155/2016/1749196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 03/22/2015] [Accepted: 04/15/2015] [Indexed: 11/17/2022] Open
Abstract
Increasing evidence suggests that the interaction of human islet amyloid polypeptide (hIAPP) with lipids may facilitate hIAPP aggregation and cause the death of pancreatic islet β-cells. However, the detailed hIAPP-membrane interactions and the influences of lipid compositions are unclear. In this study, as a first step to understand the mechanism of membrane-mediated hIAPP aggregation, we investigate the binding behaviors of hIAPP monomer at zwitterionic palmitoyloleoyl-phosphatidylcholine (POPC) bilayer by performing atomistic molecular dynamics simulations. The results are compared with those of hIAPP at anionic palmitoyloleoyl-phosphatidylglycerol (POPG) bilayers. We find that the adsorption of hIAPP to POPC bilayer is mainly initiated from the C-terminal region and the peptide adopts a helical structure with multiple binding orientations, while the adsorption to POPG bilayer is mostly initiated from the N-terminal region and hIAPP displays one preferential binding orientation, with its hydrophobic residues exposed to water. hIAPP monomer inserts into POPC lipid bilayers more readily than into POPG bilayers. Peptide-lipid interaction analyses show that the different binding features of hIAPP at POPC and POPG bilayers are attributed to different magnitudes of electrostatic and hydrogen-bonding interactions with lipids. This study provides mechanistic insights into the different interaction behaviors of hIAPP with zwitterionic and anionic lipid bilayers.
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Affiliation(s)
- Zhenyu Qian
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yan Jia
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), and Department of Physics, Fudan University, Shanghai 200433, China
| | - Guanghong Wei
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), and Department of Physics, Fudan University, Shanghai 200433, China
- *Guanghong Wei:
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36
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Baek I, Lee M, Na S. Understanding structural characteristics of out-of-register hIAPP amyloid proteins via molecular dynamics. RSC Adv 2016. [DOI: 10.1039/c6ra19100b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We investigated characteristics of out-of-register (OOR) hIAPP amyloids. By varying the length size of OOR hIAPP, we found 8 layers is most stable. In addition, OOR hIAPP has relative structural instability than in-register hAIPP.
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Affiliation(s)
- Inchul Baek
- Department of Mechanical Engineering
- Korea University
- Seoul 02841
- Republic of Korea
| | - Myeongsang Lee
- Department of Mechanical Engineering
- Korea University
- Seoul 02841
- Republic of Korea
| | - Sungsoo Na
- Department of Mechanical Engineering
- Korea University
- Seoul 02841
- Republic of Korea
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37
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Lee M, Na S. End Capping Alters the Structural Characteristics and Mechanical Properties of Transthyretin (105-115) Amyloid Protofibrils. Chemphyschem 2015; 17:425-32. [DOI: 10.1002/cphc.201500945] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 11/16/2015] [Indexed: 12/28/2022]
Affiliation(s)
- Myeongsang Lee
- Department of Mechanical Engineering; Korea University; Seoul 02841 Republic of Korea
| | - Sungsoo Na
- Department of Mechanical Engineering; Korea University; Seoul 02841 Republic of Korea
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38
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Zhang M, Hu R, Chen H, Chang Y, Ma J, Liang G, Mi J, Wang Y, Zheng J. Polymorphic cross-seeding amyloid assemblies of amyloid-β and human islet amyloid polypeptide. Phys Chem Chem Phys 2015; 17:23245-56. [PMID: 26283068 DOI: 10.1039/c5cp03329b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Epidemiological studies have shown that the development of Alzheimer's disease (AD) is associated with type 2 diabetes (T2D), but it still remains unclear how AD and T2D are connected. Heterologous cross-seeding between the causative peptides of Aβ and hIAPP may represent a molecular link between AD and T2D. Here, we computationally modeled and simulated a series of cross-seeding double-layer assemblies formed by Aβ and hIAPP peptides using all-atom and coarse-gained molecular dynamics (MD) simulations. The cross-seeding Aβ-hIAPP assemblies showed a wide range of polymorphic structures via a combination of four β-sheet-to-β-sheet interfaces and two packing orientations, focusing on a comparison of different matches of β-sheet layers. Two cross-seeding Aβ-hIAPP assemblies with different interfacial β-sheet packings exhibited high structural stability and favorable interfacial interactions in both oligomeric and fibrillar states. Both Aβ-hIAPP assemblies displayed interfacial dehydration to different extents, which in turn promoted Aβ-hIAPP association depending on interfacial polarity and geometry. Furthermore, computational mutagenesis studies revealed that disruption of interfacial salt bridges largely disfavor the β-sheet-to-β-sheet association, highlighting the importance of salt bridges in the formation of cross-seeding assemblies. This work provides atomic-level information on the cross-seeding interactions between Aβ and hIAPP, which may be involved in the interplay between these two disorders.
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Affiliation(s)
- Mingzhen Zhang
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, USA.
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39
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Kegulian NC, Sankhagowit S, Apostolidou M, Jayasinghe SA, Malmstadt N, Butler PC, Langen R. Membrane Curvature-sensing and Curvature-inducing Activity of Islet Amyloid Polypeptide and Its Implications for Membrane Disruption. J Biol Chem 2015; 290:25782-93. [PMID: 26283787 DOI: 10.1074/jbc.m115.659797] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Indexed: 11/06/2022] Open
Abstract
Islet amyloid polypeptide (IAPP) is a 37-amino acid amyloid protein intimately associated with pancreatic islet β-cell dysfunction and death in type II diabetes. In this study, we combine spectroscopic methods and microscopy to investigate α-helical IAPP-membrane interactions. Using light scattering and fluorescence microscopy, we observe that larger vesicles become smaller upon treatment with human or rat IAPP. Electron microscopy shows the formation of various highly curved structures such as tubules or smaller vesicles in a membrane-remodeling process, and spectrofluorometric detection of vesicle leakage shows disruption of membrane integrity. This effect is stronger for human IAPP than for the less toxic rat IAPP. From CD spectra in the presence of different-sized vesicles, we also uncover the membrane curvature-sensing ability of IAPP and find that it transitions from inducing to sensing membrane curvature when lipid negative charge is decreased. Our in vivo EM images of immunogold-labeled rat IAPP and human IAPP show both forms to localize to mitochondrial cristae, which contain not only locally curved membranes but also phosphatidylethanolamine and cardiolipin, lipids with high spontaneous negative curvature. Disruption of membrane integrity by induction of membrane curvature could apply more broadly to other amyloid proteins and be responsible for membrane damage observed in other amyloid diseases as well.
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Affiliation(s)
- Natalie C Kegulian
- From the Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Shalene Sankhagowit
- the Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, and
| | - Melania Apostolidou
- From the Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Sajith A Jayasinghe
- From the Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Noah Malmstadt
- the Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, and
| | - Peter C Butler
- the Larry Hillblom Islet Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Ralf Langen
- From the Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033,
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40
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Tiwari MK, Kepp KP. Modeling the Aggregation Propensity and Toxicity of Amyloid-β Variants. J Alzheimers Dis 2015; 47:215-29. [DOI: 10.3233/jad-150046] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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41
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Chang HJ, Baek I, Lee M, Na S. Influence of Aromatic Residues on the Material Characteristics of Aβ Amyloid Protofibrils at the Atomic Scale. Chemphyschem 2015; 16:2403-14. [DOI: 10.1002/cphc.201500244] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/27/2015] [Indexed: 11/06/2022]
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42
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Louros NN, Tsiolaki PL, Zompra AA, Pappa EV, Magafa V, Pairas G, Cordopatis P, Cheimonidou C, Trougakos IP, Iconomidou VA, Hamodrakas SJ. Structural studies and cytotoxicity assays of “aggregation-prone” IAPP8-16and its non-amyloidogenic variants suggest its important role in fibrillogenesis and cytotoxicity of human amylin. Biopolymers 2015; 104:196-205. [DOI: 10.1002/bip.22650] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/10/2015] [Accepted: 03/30/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Nikolaos N. Louros
- Department of Cell Biology and Biophysics; Faculty of Biology, University of Athens; Panepistimiopolis Athens 157 01 Greece
| | - Paraskevi L. Tsiolaki
- Department of Cell Biology and Biophysics; Faculty of Biology, University of Athens; Panepistimiopolis Athens 157 01 Greece
| | | | - Eleni V. Pappa
- Department of Pharmacy; University of Patras; Patras 26504 Greece
| | - Vassiliki Magafa
- Department of Pharmacy; University of Patras; Patras 26504 Greece
| | - George Pairas
- Department of Pharmacy; University of Patras; Patras 26504 Greece
| | - Paul Cordopatis
- Department of Pharmacy; University of Patras; Patras 26504 Greece
| | - Christina Cheimonidou
- Department of Cell Biology and Biophysics; Faculty of Biology, University of Athens; Panepistimiopolis Athens 157 01 Greece
| | - Ioannis P. Trougakos
- Department of Cell Biology and Biophysics; Faculty of Biology, University of Athens; Panepistimiopolis Athens 157 01 Greece
| | - Vassiliki A. Iconomidou
- Department of Cell Biology and Biophysics; Faculty of Biology, University of Athens; Panepistimiopolis Athens 157 01 Greece
| | - Stavros J. Hamodrakas
- Department of Cell Biology and Biophysics; Faculty of Biology, University of Athens; Panepistimiopolis Athens 157 01 Greece
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43
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Kim JI, Lee M, Baek I, Yoon G, Na S. The mechanical response of hIAPP nanowires based on different bending direction simulations. Phys Chem Chem Phys 2015; 16:18493-500. [PMID: 25073067 DOI: 10.1039/c4cp02494j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Amyloid proteins, implicated in numerous aging-related diseases, possess remarkable mechanical properties. Polymorphism leads to different arrangements of β sheets in amyloid fibrils, which changes the characteristics of the hydrogen bond network that determines their mechanical properties and structural characteristics. We performed bending simulations using molecular dynamics methods under constant-velocity conditions in different bending directions. Two different fibril structures, parallel/homo and parallel/hetero, of hIAPP amyloids were considered. Though the bending configuration influences the toughness of the material, our results indicate that the basic material behavior is affected by the β-sheet arrangement that is determined by the type of polymorphism in amyloid fibrils.
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Affiliation(s)
- J I Kim
- Department of Mechanical Engineering, Korea University, Seoul 136-701, Republic of Korea.
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44
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Yang PW, Lin TL, Hu Y, Jeng US. A time-resolved study on the interaction of oppositely charged bicelles--implications on the charged lipid exchange kinetics. SOFT MATTER 2015; 11:2237-2242. [PMID: 25649711 DOI: 10.1039/c4sm02886d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Time-resolved small-angle X-ray scattering was applied to study charged lipid exchange between oppositely charged disc-shaped bicelles. The exchange of charged lipids gradually reduces the surface charge density and weakens the electrostatic attraction between the oppositely charged bicelles which form alternately stacked aggregates upon mixing. Initially, at a high surface charge density with almost no free water layer between the stacked bicelles, fast exchange kinetics dominate the exchange process. At a later stage with a lower surface charge density and a larger water gap between the stacked bicelles, slow exchange kinetics take over. The fast exchange kinetics are correlated with the close contact of the bicelles when there is almost no free water layer between the tightly bound bicelles with a charged lipid exchange time constant as short as 20-40 min. When the water gap becomes large enough to have a free water layer between the stacked bicelles, the fast lipid exchange kinetics are taken over by slow lipid exchange kinetics with time constants around 200-300 min, which are comparable to the typical time constant of lipid exchange between vesicles in aqueous solution. These two kinds of exchange mode fit well with the lipid exchange models of transient hemifusion for the fast mode and monomer exchange for the slow mode.
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Affiliation(s)
- Po-Wei Yang
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.
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45
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Tomasello MF, Sinopoli A, Pappalardo G. On the Environmental Factors Affecting the Structural and Cytotoxic Properties of IAPP Peptides. J Diabetes Res 2015; 2015:918573. [PMID: 26582441 PMCID: PMC4637107 DOI: 10.1155/2015/918573] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/05/2015] [Indexed: 12/18/2022] Open
Abstract
Pancreatic islets in type 2 diabetes mellitus (T2DM) patients are characterized by reduced β-cells mass and diffuse extracellular amyloidosis. Amyloid deposition involves the islet amyloid polypeptide (IAPP), a neuropancreatic hormone cosecreted with insulin by β-cells. IAPP is physiologically involved in glucose homeostasis, but it may turn toxic to β-cells owing to its tendency to misfold giving rise to oligomers and fibrils. The process by which the unfolded IAPP starts to self-assemble and the overall factors promoting this conversion are poorly understood. Other open questions are related to the nature of the IAPP toxic species and how exactly β-cells die. Over the last decades, there has been growing consensus about the notion that early molecular assemblies, notably small hIAPP oligomers, are the culprit of β-cells decline. Numerous environmental factors might affect the conformational, aggregation, and cytotoxic properties of IAPP. Herein we review recent progress in the field, focusing on the influences that membranes, pH, and metal ions may have on the conformational conversion and cytotoxicity of full-length IAPP as well as peptide fragments thereof. Current theories proposed for the mechanisms of toxicity will be also summarized together with an outline of the underlying molecular links between IAPP and amyloid beta (Aβ) misfolding.
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Affiliation(s)
| | - Alessandro Sinopoli
- International PhD Program in Translational Biomedicine, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Pappalardo
- CNR Institute of Biostructures and Bioimaging, Via P. Gaifami 18, 95126 Catania, Italy
- *Giuseppe Pappalardo:
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46
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Losada-Pérez P, Khorshid M, Hermans C, Robijns T, Peeters M, Jiménez-Monroy K, Truong L, Wagner P. Melittin disruption of raft and non-raft-forming biomimetic membranes: A study by quartz crystal microbalance with dissipation monitoring. Colloids Surf B Biointerfaces 2014; 123:938-44. [DOI: 10.1016/j.colsurfb.2014.10.048] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 10/20/2014] [Accepted: 10/24/2014] [Indexed: 10/24/2022]
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47
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Jang H, Arce FT, Ramachandran S, Kagan BL, Lal R, Nussinov R. Disordered amyloidogenic peptides may insert into the membrane and assemble into common cyclic structural motifs. Chem Soc Rev 2014; 43:6750-64. [PMID: 24566672 PMCID: PMC4143503 DOI: 10.1039/c3cs60459d] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aggregation of disordered amyloidogenic peptides into oligomers is the causative agent of amyloid-related diseases. In solution, disordered protein states are characterized by heterogeneous ensembles. Among these, β-rich conformers self-assemble via a conformational selection mechanism to form energetically-favored cross-β structures, regardless of their precise sequences. These disordered peptides can also penetrate the membrane, and electrophysiological data indicate that they form ion-conducting channels. Based on these and additional data, including imaging and molecular dynamics simulations of a range of amyloid peptides, Alzheimer's amyloid-β (Aβ) peptide, its disease-related variants with point mutations and N-terminal truncated species, other amyloidogenic peptides, as well as a cytolytic peptide and a synthetic gel-forming peptide, we suggest that disordered amyloidogenic peptides can also present a common motif in the membrane. The motif consists of curved, moon-like β-rich oligomers associated into annular organizations. The motif is favored in the lipid bilayer since it permits hydrophobic side chains to face and interact with the membrane and the charged/polar residues to face the solvated channel pores. Such channels are toxic since their pores allow uncontrolled leakage of ions into/out of the cell, destabilizing cellular ionic homeostasis. Here we detail Aβ, whose aggregation is associated with Alzheimer's disease (AD) and for which there are the most abundant data. AD is a protein misfolding disease characterized by a build-up of Aβ peptide as senile plaques, neurodegeneration, and memory loss. Excessively produced Aβ peptides may directly induce cellular toxicity, even without the involvement of membrane receptors through Aβ peptide-plasma membrane interactions.
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Affiliation(s)
- Hyunbum Jang
- Cancer and Inflammation Program, National Cancer Institute at Frederick, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, U.S.A
| | - Fernando Teran Arce
- Departments of Bioengineering and of Mechanical and Aerospace Engineering, and Materials Science Program, University of California, San Diego, La Jolla, California 92093, U.S.A
| | - Srinivasan Ramachandran
- Departments of Bioengineering and of Mechanical and Aerospace Engineering, and Materials Science Program, University of California, San Diego, La Jolla, California 92093, U.S.A
| | - Bruce L. Kagan
- Department of Psychiatry, David Geffen School of Medicine, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, California 90024, U.S.A
| | - Ratnesh Lal
- Departments of Bioengineering and of Mechanical and Aerospace Engineering, and Materials Science Program, University of California, San Diego, La Jolla, California 92093, U.S.A
| | - Ruth Nussinov
- Cancer and Inflammation Program, National Cancer Institute at Frederick, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, U.S.A
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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48
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Navarro S, Ventura S. Fluorescent dye ProteoStat to detect and discriminate intracellular amyloid-like aggregates in Escherichia coli. Biotechnol J 2014; 9:1259-66. [PMID: 25112199 DOI: 10.1002/biot.201400291] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/24/2014] [Accepted: 08/11/2014] [Indexed: 12/22/2022]
Abstract
The formation of amyloid aggregates is linked to the onset of an increasing number of human disorders. Thus, there is an increasing need for methodologies able to provide insights into protein deposition and its modulation. Many approaches exist to study amyloids in vitro, but the techniques available for the study of amyloid aggregation in cells are still limited and non-specific. In this study we developed a methodology for the detection of amyloid-like aggregates inside cells that discriminates these ordered assemblies from other intracellular aggregates. We chose bacteria as model system, since the inclusion bodies formed by amyloid proteins in the cytosol of bacteria resemble toxic amyloids both structurally and functionally. Using confocal microscopy, fluorescence spectroscopy, and flow cytometry, we show that the recently developed red fluorescent dye ProteoStat can detect the presence of intracellular amyloid-like deposits in living bacterial cells with high specificity, even when the target proteins are expressed at low levels. This methodology allows quantitation of the intracellular amyloid content, shows the potential to replace in vitro screenings in the search for therapeutic anti-amyloidogenic compounds, and might be useful for identifying conditions that prevent the aggregation of therapeutic recombinant proteins.
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Affiliation(s)
- Susanna Navarro
- Institut de Biotecnologia i Biomedicina and Departament de Bioquimica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
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49
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Lee J, Gillman AL, Jang H, Ramachandran S, Kagan BL, Nussinov R, Teran Arce F. Role of the fast kinetics of pyroglutamate-modified amyloid-β oligomers in membrane binding and membrane permeability. Biochemistry 2014; 53:4704-14. [PMID: 24950761 PMCID: PMC4215883 DOI: 10.1021/bi500587p] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
![]()
Membrane
permeability to ions and small molecules is believed to
be a critical step in the pathology of Alzheimer’s disease
(AD). Interactions of oligomers formed by amyloid-β (Aβ)
peptides with the plasma cell membrane are believed to play a fundamental
role in the processes leading to membrane permeability. Among the
family of Aβs, pyroglutamate (pE)-modified Aβ peptides
constitute the most abundant oligomeric species in the brains of AD
patients. Although membrane permeability mechanisms have been studied
for full-length Aβ1–40/42 peptides, these
have not been sufficiently characterized for the more abundant AβpE3–42 fragment. Here we have compared the adsorbed
and membrane-inserted oligomeric species of AβpE3–42 and Aβ1–42 peptides. We find lower concentrations
and larger dimensions for both species of membrane-associated AβpE3–42 oligomers. The larger dimensions are attributed
to the faster self-assembly kinetics of AβpE3–42, and the lower concentrations are attributed to weaker interactions
with zwitterionic lipid headgroups. While adsorbed oligomers produced
little or no significant membrane structural damage, increased membrane
permeabilization to ionic species is understood in terms of enlarged
membrane-inserted oligomers. Membrane-inserted AβpE3–42 oligomers were also found to modify the mechanical properties of
the membrane. Taken together, our results suggest that membrane-inserted
oligomers are the primary species responsible for membrane permeability.
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Affiliation(s)
- Joon Lee
- Department of Bioengineering, University of California at San Diego , La Jolla, California 92093, United States
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50
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Eddy MT, Yu TY. Membranes, peptides, and disease: unraveling the mechanisms of viral proteins with solid state nuclear magnetic resonance spectroscopy. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2014; 61-62:1-7. [PMID: 24837131 DOI: 10.1016/j.ssnmr.2014.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 04/22/2014] [Accepted: 04/22/2014] [Indexed: 06/03/2023]
Abstract
The interplay between peptides and lipid bilayers drives crucial biological processes. For example, a critical step in the replication cycle of enveloped viruses is the fusion of the viral membrane and host cell endosomal membrane, and these fusion events are controlled by viral fusion peptides. Thus such membrane-interacting peptides are of considerable interest as potential pharmacological targets. Deeper insight is needed into the mechanisms by which fusion peptides and other viral peptides modulate their surrounding membrane environment, and also how the particular membrane environment modulates the structure and activity of these peptides. An important step toward understanding these processes is to characterize the structure of viral peptides in environments that are as biologically relevant as possible. Solid state nuclear magnetic resonance (ssNMR) is uniquely well suited to provide atomic level information on the structure and dynamics of both membrane-associated peptides as well as the lipid bilayer itself; further ssNMR can delineate the contribution of specific membrane components, such as cholesterol, or changing cellular conditions, such as a decrease in pH on membrane-associating peptides. This paper highlights recent advances in the study of three types of membrane associated viral peptides by ssNMR to illustrate the more general power of ssNMR in addressing important biological questions involving membrane proteins.
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Affiliation(s)
- Matthew T Eddy
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037 USA
| | - Tsyr-Yan Yu
- Institute of Atomic and Molecular Sciences, Academia Sinica, No. 1 Sec. 4. Rooservelt Rd., Taipei, 10617, Taiwan.
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