1
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Akdag M, van Schijndel V, Sinnige T. Islet amyloid polypeptide tagged with green fluorescent protein localises to mitochondria and forms filamentous aggregates in Caenorhabditis elegans. Biophys Chem 2024; 307:107180. [PMID: 38241827 DOI: 10.1016/j.bpc.2024.107180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/22/2023] [Accepted: 01/12/2024] [Indexed: 01/21/2024]
Abstract
Type 2 diabetes (T2D) is the most common form of diabetes and represents a growing health concern. A characteristic feature of T2D is the aggregation of islet amyloid polypeptide (IAPP), which is thought to be associated with the death of pancreatic β-cells. Inhibiting IAPP aggregation is a promising therapeutic avenue to treat T2D, but the mechanisms of aggregation and toxicity are not yet fully understood. Caenorhabditis elegans is a well-characterised multicellular model organism that has been extensively used to study protein aggregation diseases. In this study, we aimed to develop a simple in vivo model to investigate IAPP aggregation and toxicity based on expression in the C. elegans body wall muscle cells. We show that IAPP tagged with green fluorescent protein (GFP) localises to mitochondria not only in muscle cells but also when expressed in the intestine, in line with previous observations in mouse and human pancreatic β-cells. The IAPP-GFP fusion protein forms solid aggregates, which have a filamentous appearance as seen by electron microscopy. However, the animals expressing IAPP-GFP in the body wall muscle cells do not display a strong motility phenotype, suggesting that the IAPP-GFP aggregates are not considerably toxic. Nevertheless, the mitochondrial localisation and aggregate formation may be useful read-outs to screen for IAPP-solubilizing compounds as a therapeutic strategy for T2D.
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Affiliation(s)
- Mehmet Akdag
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Vera van Schijndel
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Tessa Sinnige
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
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2
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Muñoz-Gutiérrez C, Adasme-Carreño F, Alzate-Morales J, Ireta J. Effect of strand register in the stability and reactivity of crystals from peptides forming amyloid fibrils. Phys Chem Chem Phys 2023; 25:23885-23893. [PMID: 37642522 DOI: 10.1039/d3cp01762a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Amyloids are cytotoxic protein aggregates that deposit in human tissues, leading to several health disorders. Their aggregates can also exhibit catalytic properties, and they have been used as candidates for the development of functional biomaterials. Despite being polymorphic, amyloids often assemble as cross-β fibrils formed by in-register β sheet layers. Recent studies of some amyloidogenic protein segments revealed that they crystallize as antiparallel out-of-register β sheets. Such arrangement has been proposed to be responsible for the cytotoxicity in amyloid diseases, however, there is still no consensus on the molecular mechanism. Interestingly, two amyloidogenic peptide segments, NFGAILS and FGAILSS, arrange into out-of-register and in-register β sheets, respectively, even though they solely differ by one aminoacid residue at both termini. In this work, we used density functional theory (DFT) to address how the strand register contributes into the packing and molecular properties of the NFGAILS and FGAILSS crystals. Our results show that the out-of-register structure is substantially more stable, at 0 K, than the in-register one due to stronger inter-strand contacts. Based on an analysis of the electrostatic potential of the crystal slabs, it is suggested that the out-of-register may potentially interact with negatively charged groups, like those found in cell membranes. Moreover, calculated reactivity descriptors indicate a similar outcome, where only the out-of-register peptide exhibits intrinsic reactive surface sites at the exposed amine and carboxylic groups. It is therefore suggested that the out-of-register arrangement may indeed be crucial for amyloid cytotoxicity. The findings presented here could help to further our understanding of amyloid aggregation, function, and toxicity.
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Affiliation(s)
- Camila Muñoz-Gutiérrez
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Campus Talca, 1 Poniente No. 1141, Box 721, Talca, Chile
| | - Francisco Adasme-Carreño
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3480112, Chile
- Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480112, Chile
| | - Jans Alzate-Morales
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Campus Talca, 1 Poniente No. 1141, Box 721, Talca, Chile
| | - Joel Ireta
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A.P. 55-534, Ciudad de México 09340, Mexico.
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3
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Tempra C, Scollo F, Pannuzzo M, Lolicato F, La Rosa C. A unifying framework for amyloid-mediated membrane damage: The lipid-chaperone hypothesis. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140767. [PMID: 35144022 DOI: 10.1016/j.bbapap.2022.140767] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 12/16/2022]
Abstract
Over the past thirty years, researchers have highlighted the role played by a class of proteins or polypeptides that forms pathogenic amyloid aggregates in vivo, including i) the amyloid Aβ peptide, which is known to form senile plaques in Alzheimer's disease; ii) α-synuclein, responsible for Lewy body formation in Parkinson's disease and iii) IAPP, which is the protein component of type 2 diabetes-associated islet amyloids. These proteins, known as intrinsically disordered proteins (IDPs), are present as highly dynamic conformational ensembles. IDPs can partially (mis) fold into (dys) functional conformations and accumulate as amyloid aggregates upon interaction with other cytosolic partners such as proteins or lipid membranes. In addition, an increasing number of reports link the toxicity of amyloid proteins to their harmful effects on membrane integrity. Still, the molecular mechanism underlying the amyloidogenic proteins transfer from the aqueous environment to the hydrocarbon core of the membrane is poorly understood. This review starts with a historical overview of the toxicity models of amyloidogenic proteins to contextualize the more recent lipid-chaperone hypothesis. Then, we report the early molecular-level events in the aggregation and ion-channel pore formation of Aβ, IAPP, and α-synuclein interacting with model membranes, emphasizing the complexity of these processes due to their different spatial-temporal resolutions. Next, we underline the need for a combined experimental and computational approach, focusing on the strengths and weaknesses of the most commonly used techniques. Finally, the last two chapters highlight the crucial role of lipid-protein complexes as molecular switches among ion-channel-like formation, detergent-like, and fibril formation mechanisms and their implication in fighting amyloidogenic diseases.
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Affiliation(s)
- Carmelo Tempra
- Institute of Organic Chemistry and Biochemistry, Prague, Czech Republic
| | - Federica Scollo
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Pannuzzo
- Laboratory of Nanotechnology for Precision Medicine, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy
| | - Fabio Lolicato
- Heidelberg University Biochemistry Center, Heidelberg, Germany; Department of Physics, University of Helsinki, Helsinki, Finland.
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy.
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4
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Pathak BK, Dey S, Mozumder S, Sengupta J. The role of membranes in function and dysfunction of intrinsically disordered amyloidogenic proteins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:397-434. [PMID: 35034725 DOI: 10.1016/bs.apcsb.2021.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Membrane-protein interactions play a major role in human physiology as well as in diseases pathology. Interaction of a protein with the membrane was previously thought to be dependent on well-defined three-dimensional structure of the protein. In recent decades, however, it has become evident that a large fraction of the proteome, particularly in eukaryotes, stays disordered in solution and these proteins are termed as intrinsically disordered proteins (IDPs). Also, a vast majority of human proteomes have been reported to contain substantially long disordered regions, called intrinsically disordered regions (IDRs), in addition to the structurally ordered regions. IDPs exist in an ensemble of conformations and the conformational flexibility enables IDPs to achieve functional diversity. IDPs (and IDRs) are found to be important players in cell signaling, where biological membranes act as anchors for signaling cascades. Therefore, IDPs modulate the membrane architectures, at the same time membrane composition also affects the binding of IDPs. Because of intrinsic disorders, misfolding of IDPs often leads to formation of oligomers, protofibrils and mature fibrils through progressive self-association. Accumulation of amyloid-like aggregates of some of the IDPs is a known causative agent for numerous diseases. In this chapter we highlight recent advances in understanding membrane interactions of some of the intrinsically disordered proteins involved in the pathogenesis of human diseases.
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Affiliation(s)
- Bani Kumar Pathak
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Sandip Dey
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Sukanya Mozumder
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Jayati Sengupta
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
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5
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C subunit of the ATP synthase is an amyloidogenic calcium dependent channel-forming peptide with possible implications in mitochondrial permeability transition. Sci Rep 2021; 11:8744. [PMID: 33888826 PMCID: PMC8062469 DOI: 10.1038/s41598-021-88157-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/06/2021] [Indexed: 01/18/2023] Open
Abstract
The c subunit is an inner mitochondrial membrane (IMM) protein encoded by three nuclear genes. Best known as an integral part of the F0 complex of the ATP synthase, the c subunit is also present in other cytoplasmic compartments in ceroid lipofuscinoses. Under physiological conditions, this 75 residue-long peptide folds into an α-helical hairpin and forms oligomers spanning the lipid bilayer. In addition to its physiological role, the c subunit has been proposed as a key participant in stress-induced IMM permeabilization by the mechanism of calcium-induced permeability transition. However, the molecular mechanism of the c subunit participation in IMM permeabilization is not completely understood. Here we used fluorescence spectroscopy, atomic force microscopy and black lipid membrane methods to gain insights into the structural and functional properties of unmodified c subunit protein that might make it relevant to mitochondrial toxicity. We discovered that c subunit is an amyloidogenic peptide that can spontaneously fold into β-sheets and self-assemble into fibrils and oligomers in a Ca2+-dependent manner. C subunit oligomers exhibited ion channel activity in lipid membranes. We propose that the toxic effects of c subunit might be linked to its amyloidogenic properties and are driven by mechanisms similar to those of neurodegenerative polypeptides such as Aβ and α-synuclein.
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Abstract
Protein aggregation and amyloid formation are pathogenic events underlying the development of an increasingly large number of human diseases named “proteinopathies”. Abnormal accumulation in affected tissues of amyloid β (Aβ) peptide, islet amyloid polypeptide (IAPP), and the prion protein, to mention a few, are involved in the occurrence of Alzheimer’s (AD), type 2 diabetes mellitus (T2DM) and prion diseases, respectively. Many reports suggest that the toxic properties of amyloid aggregates are correlated with their ability to damage cell membranes. However, the molecular mechanisms causing toxic amyloid/membrane interactions are still far to be completely elucidated. This review aims at describing the mutual relationships linking abnormal protein conformational transition and self-assembly into amyloid aggregates with membrane damage. A cross-correlated analysis of all these closely intertwined factors is thought to provide valuable insights for a comprehensive molecular description of amyloid diseases and, in turn, the design of effective therapies.
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7
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Tempra C, La Rosa C, Lolicato F. The role of alpha-helix on the structure-targeting drug design of amyloidogenic proteins. Chem Phys Lipids 2021; 236:105061. [PMID: 33610597 DOI: 10.1016/j.chemphyslip.2021.105061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/26/2021] [Accepted: 02/12/2021] [Indexed: 12/17/2022]
Abstract
The most accredited hypothesis links the toxicity of amyloid proteins to their harmful effects on membrane integrity through the formation of prefibrillar-transient oligomers able to disrupt cell membranes. However, damage mechanisms necessarily assume a first step in which the amyloidogenic protein transfers from the aqueous phase to the membrane hydrophobic core. This determinant step is still poorly understood. However, according to our lipid-chaperon hypothesis, free lipids in solution play a crucial role in facilitating this footfall. Free phospholipid concentration in the aqueous phase acts as a switch between ion channel-like pore and fibril formation, so that high free lipid concentration in solution promotes pore and repress fibril formation. Conversely, low free lipids in the solution favor fibril and repress pore formation. This behavior is due to the formation of stable lipid-protein complexes. Here, we hypothesize that the helix propensity is a fundamental requirement to fulfill the lipid-chaperon model. The alpha-helix region seems to be responsible for the binding with amphiphilic molecules fostering the proposed mechanism. Indeed, our results show the dependency of protein-lipid binding from the helical structure presence. When the helix content is substantially lower than the wild type, the contact probability decreases. Instead, if the helix is broadening, the contact probability increases. Our findings open a new perspective for in silico screening of secondary structure-targeting drugs of amyloidogenic proteins.
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Affiliation(s)
- Carmelo Tempra
- Institute of Organic Chemistry and Biochemistry, Prague, Czech Republic
| | | | - Fabio Lolicato
- Heidelberg University Biochemistry Center, Heidelberg, Germany; Department of Physics, University of Helsinki, Helsinki, Finland.
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8
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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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Sciacca MF, Lolicato F, Tempra C, Scollo F, Sahoo BR, Watson MD, García-Viñuales S, Milardi D, Raudino A, Lee JC, Ramamoorthy A, La Rosa C. Lipid-Chaperone Hypothesis: A Common Molecular Mechanism of Membrane Disruption by Intrinsically Disordered Proteins. ACS Chem Neurosci 2020; 11:4336-4350. [PMID: 33269918 DOI: 10.1021/acschemneuro.0c00588] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
An increasing number of human diseases has been shown to be linked to aggregation and amyloid formation by intrinsically disordered proteins (IDPs). Amylin, amyloid-β, and α-synuclein are, indeed, involved in type-II diabetes, Alzheimer's, and Parkinson's, respectively. Despite the correlation of the toxicity of these proteins at early aggregation stages with membrane damage, the molecular events underlying the process is quite complex to understand. In this study, we demonstrate the crucial role of free lipids in the formation of lipid-protein complex, which enables an easy membrane insertion for amylin, amyloid-β, and α-synuclein. Experimental results from a variety of biophysical methods and molecular dynamics results reveal that this common molecular pathway in membrane poration is shared by amyloidogenic (amylin, amyloid-β, and α-synuclein) and nonamyloidogenic (rat IAPP, β-synuclein) proteins. Based on these results, we propose a "lipid-chaperone" hypothesis as a unifying framework for protein-membrane poration.
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Affiliation(s)
| | - Fabio Lolicato
- Heidelberg University Biochemistry Center, Heidelberg 69120, Germany
- Department of Physics, University of Helsinki, P.O. Box 64, Helsinki FI-00014, Finland
| | - Carmelo Tempra
- Institute of Organic Chemistry and Biochemistry, Prague 160 00, Czech Republic
- Department of Chemical Sciences, University of Catania, Catania 95124, Italy
| | - Federica Scollo
- Department of Chemical Sciences, University of Catania, Catania 95124, Italy
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague 117 20, Czech Republic
| | - Bikash R. Sahoo
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Matthew D. Watson
- National Institutes of Health, Bethesda, Maryland 20892-0001, United States
| | | | | | - Antonio Raudino
- Department of Chemical Sciences, University of Catania, Catania 95124, Italy
| | - Jennifer C. Lee
- National Institutes of Health, Bethesda, Maryland 20892-0001, United States
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Carmelo La Rosa
- Department of Chemical Sciences, University of Catania, Catania 95124, Italy
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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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Roy R, Paul S. Theoretical Investigation of the Inhibitory Mechanism of Norepinephrine on hIAPP Amyloid Aggregation and the Destabilization of Protofibrils. J Phys Chem B 2020; 124:10913-10929. [DOI: 10.1021/acs.jpcb.0c07830] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Rituparna Roy
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
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12
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Evidence of cadmium and mercury involvement in the Aβ42 aggregation process. Biophys Chem 2020; 266:106453. [DOI: 10.1016/j.bpc.2020.106453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/30/2020] [Accepted: 08/02/2020] [Indexed: 12/11/2022]
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13
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Araújo AR, Reis RL, Pires RA. Natural Polyphenols as Modulators of the Fibrillization of Islet Amyloid Polypeptide. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1250:159-176. [PMID: 32601944 DOI: 10.1007/978-981-15-3262-7_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Diabetes mellitus type 2 (type-2 diabetes) is a metabolic disorder characterized by the increased blood glucose concentration and insulin resistance in peripheral tissues (e.g., muscles and adipose tissue). The initiation of the pathological cascade of events that lead to type-2 diabetes has been subject of debate; however, it has been commonly accepted that the oversecretion of human islet amyloid polypeptide (hIAPP, a hormone co-secreted with insulin) by the pancreatic 𝛽-cells is the main trigger of type-2 diabetes. In fact, 90% of the type-2 diabetes patients present hIAPP deposits in the extracellular space of the 𝛽-cells. These hIAPP supramolecular arrangements (both fibrillar and oligomeric) have been reported to be the origin of cytotoxicity, which leads to 𝛽-cell dysfunction through a series of different mechanisms, including the interaction of hIAPP oligomers with the cell membrane that leads to the influx of Ca2+ and increase in the cellular oxidative stress, among others. This overview shows the importance of developing type-2 diabetes treatment strategies able to (1) remodel of the secondary structure of cytotoxic hIAPP oligomers entrapping them into off-pathway nontoxic species and (2) reestablish physiological levels of oxidative stress. Natural polyphenols are a class of antioxidant compounds that are able to perform both functions. Herein we review the published literature of the most studied polyphenols, in particular for their ability to remodel the hIAPP aggregation pathway, to rescue the in vitro pancreatic 𝛽-cell viability and function, as well as to perform under a complex biological environment, i.e., in vivo animal models and clinical trials. Overall, natural polyphenols are able to control the cytotoxic hIAPP aggregation and minimize hIAPP-mediated cellular dysfunction and can be considered as important lead compounds for the treatment of type-2 diabetes.
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Affiliation(s)
- Ana R Araújo
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal.,The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, Guimarães, Portugal
| | - Rui L Reis
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal.,The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, Guimarães, Portugal
| | - Ricardo A Pires
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal. .,The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, Guimarães, Portugal.
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14
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Amyloidogenic Intrinsically Disordered Proteins: New Insights into Their Self-Assembly and Their Interaction with Membranes. Life (Basel) 2020; 10:life10080144. [PMID: 32784399 PMCID: PMC7459996 DOI: 10.3390/life10080144] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/02/2020] [Accepted: 08/06/2020] [Indexed: 12/21/2022] Open
Abstract
Aβ, IAPP, α-synuclein, and prion proteins belong to the amyloidogenic intrinsically disordered proteins’ family; indeed, they lack well defined secondary and tertiary structures. It is generally acknowledged that they are involved, respectively, in Alzheimer’s, Type II Diabetes Mellitus, Parkinson’s, and Creutzfeldt–Jakob’s diseases. The molecular mechanism of toxicity is under intense debate, as many hypotheses concerning the involvement of the amyloid and the toxic oligomers have been proposed. However, the main role is represented by the interplay of protein and the cell membrane. Thus, the understanding of the interaction mechanism at the molecular level is crucial to shed light on the dynamics driving this phenomenon. There are plenty of factors influencing the interaction as mentioned above, however, the overall view is made trickier by the apparent irreproducibility and inconsistency of the data reported in the literature. Here, we contextualized this topic in a historical, and even more importantly, in a future perspective. We introduce two novel insights: the chemical equilibrium, always established in the aqueous phase between the free and the membrane phospholipids, as mediators of protein-transport into the core of the bilayer, and the symmetry-breaking of oligomeric aggregates forming an alternating array of partially ordered and disordered monomers.
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15
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Gao LP, Chen HC, Ma ZL, Chen AD, Du HL, Yin J, Jing YH. Fibrillation of human islet amyloid polypeptide and its toxicity to pancreatic β-cells under lipid environment. Biochim Biophys Acta Gen Subj 2019; 1864:129422. [PMID: 31491457 DOI: 10.1016/j.bbagen.2019.129422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/20/2019] [Accepted: 08/27/2019] [Indexed: 01/19/2023]
Abstract
BACKGROUND Previous studies suggested that fibrillar human IAPP (hIAPP) is more likely to deposit in β-cells, resulting in β-cell injury. However, the changes in the conformation of hIAPP in lipid environment and the mechanism involved in β-cell damage are unclear. METHODS Synthetic hIAPP was incubated with five types of free fatty acids and phospholipids 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS), which constitute the cell membrane. Thioflavin-T fluorescence assay was conducted to analyze the degree of hIAPP fibrosis, and circular dichroism spectroscopy was performed to detect the β-fold formation of hIAPP. Furthermore, INS-1 cells were infected with human IAPP delivered by a GV230-EGFP plasmid. The effects of endogenous hIAPP overexpression induced by sodium palmitate on the survival, endoplasmic reticulum (ER) stress, and apoptosis of INS-1 cells were evaluated. RESULTS The five types of free fatty acids can accelerate the fibrosis of hIAPP. Sodium palmitate also maintained the stability of fibrillar hIAPP. POPS, not POPC, accelerated hIAPP fibrosis. Treatment of INS-1 cells with sodium palmitate increased the expression of hIAPP, activated ER stress and ER stress-dependent apoptosis signaling pathways, and increased the apoptotic rate. CONCLUSION Free fatty acids and anionic phospholipid can promote β-fold formation and fibrosis in hIAPP. High lipid induced the overexpression of hIAPP and aggravated ER stress and apoptosis in INS-1 cells, which caused β-cell death in high lipid environment. GENERAL SIGNIFICANCE Our study reveals free fatty acids and hIAPP synergistically implicated in endoplasmic reticulum stress and apoptosis of islet β-cells.
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Affiliation(s)
- Li-Ping Gao
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou City, Gansu province 730000, People's Republic of China
| | - Hai-Chao Chen
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, Lanzhou City, Gansu Province 730000, People's Republic of China
| | - Ze-Lin Ma
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou City, Gansu province 730000, People's Republic of China
| | - An-Di Chen
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou City, Gansu province 730000, People's Republic of China
| | - Hong-Li Du
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou City, Gansu province 730000, People's Republic of China
| | - Jie Yin
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, Lanzhou City, Gansu Province 730000, People's Republic of China
| | - Yu-Hong Jing
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, Lanzhou City, Gansu Province 730000, People's Republic of China; Key Laboratory of Preclinical Study for New Drugs of Gansu province, Lanzhou University, Lanzhou City, Gansu Province 730000, People's Republic of China.
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16
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Christensen M, Schiøtt B. Revealing a Dual Role of Ganglioside Lipids in the Aggregation of Membrane-Associated Islet Amyloid Polypeptide. J Membr Biol 2019; 252:343-356. [DOI: 10.1007/s00232-019-00074-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 06/09/2019] [Indexed: 12/31/2022]
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17
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Scollo F, Tempra C, Lolicato F, Sciacca MFM, Raudino A, Milardi D, La Rosa C. Phospholipids Critical Micellar Concentrations Trigger Different Mechanisms of Intrinsically Disordered Proteins Interaction with Model Membranes. J Phys Chem Lett 2018; 9:5125-5129. [PMID: 30133296 DOI: 10.1021/acs.jpclett.8b02241] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Amyloidogenic proteins are involved in many diseases, including Alzheimer's, Parkinson's, and type II diabetes. These proteins are thought to be toxic for cells because of their abnormal interaction with the cell membrane. Simpler model membranes (LUVs) have been used to study the early steps of membrane-protein interactions and their subsequent evolution. Phospholipid LUVs formed in water solution establish a chemical equilibrium between self-assembled LUVs and a small amount of phospholipids in water solution (CMC). Here, using both experimental and molecular dynamics simulations approach we demonstrate that the insertion of IAPP, an amyloidogenic peptide involved in diabetes, in membranes is driven by free lipids in solution in dynamic equilibrium with the self-assembled lipids of the bilayer. It is suggested that this could be a general mechanism lying at the root of membrane insertion processes of self-assembling peptides.
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Affiliation(s)
- Federica Scollo
- Department of Chemical Sciences , University of Catania , Viale A. Doria 6 , 95125 Catania , Italy
| | - Carmelo Tempra
- Department of Chemical Sciences , University of Catania , Viale A. Doria 6 , 95125 Catania , Italy
| | - Fabio Lolicato
- Department of Physics , University of Helsinki , P.O. Box 64, FI-00014 , Helsinki , Finland
| | - Michele F M Sciacca
- Istituto di Biostrutture e Bioimmagini, Sede Secondaria di Catania , Via P. Gaifami 18 , I-95126 , Catania , Italy
| | - Antonio Raudino
- Department of Chemical Sciences , University of Catania , Viale A. Doria 6 , 95125 Catania , Italy
| | - Danilo Milardi
- Istituto di Biostrutture e Bioimmagini, Sede Secondaria di Catania , Via P. Gaifami 18 , I-95126 , Catania , Italy
| | - Carmelo La Rosa
- Department of Chemical Sciences , University of Catania , Viale A. Doria 6 , 95125 Catania , Italy
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18
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Qian Z, Zou Y, Zhang Q, Chen P, Ma B, Wei G, Nussinov R. Atomistic-level study of the interactions between hIAPP protofibrils and membranes: Influence of pH and lipid composition. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:1818-1825. [PMID: 29428499 PMCID: PMC6408309 DOI: 10.1016/j.bbamem.2018.02.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/01/2018] [Accepted: 02/03/2018] [Indexed: 01/25/2023]
Abstract
The pathology of type 2 diabetes mellitus is associated with the aggregation of human islet amyloid polypeptide (hIAPP) and aggregation-mediated membrane disruption. The interactions of hIAPP aggregates with lipid membrane, as well as the effects of pH and lipid composition at the atomic level, remain elusive. Herein, using molecular dynamics simulations, we investigate the interactions of hIAPP protofibrillar oligomers with lipids, and the membrane perturbation that they induce, when they are partially inserted in an anionic dipalmitoyl-phosphatidylglycerol (DPPG) membrane or a mixed dipalmitoyl-phosphatidylcholine (DPPC)/DPPG (7:3) lipid bilayer under acidic/neutral pH conditions. We observed that the tilt angles and insertion depths of the hIAPP protofibril are strongly correlated with the pH and lipid composition. At neutral pH, the tilt angle and insertion depth of hIAPP protofibrils at a DPPG bilayer reach ~52° and ~1.62 nm with respect to the membrane surface, while they become ~77° and ~1.75 nm at a mixed DPPC/DPPG membrane. The calculated tilt angle of hIAPP at DPPG membrane is consistent with a recent chiral sum frequency generation spectroscopic study. The acidic pH induces a smaller tilt angle of ~40° and a shallower insertion depth (~1.24 nm) of hIAPP at the DPPG membrane surface, mainly due to protonation of His18 near the turn region. These differences mainly result from a combination of distinct electrostatic, van der Waals, hydrogen bonding and salt-bridge interactions between hIAPP and lipid bilayers. The hIAPP-membrane interaction energy analysis reveals that besides charged residues K1, R11 and H18, aromatic residues Phe15 and Phe23 also exhibit strong interactions with lipid bilayers, revealing the crucial role of aromatic residues in stabilizing the membrane-bound hIAPP protofibrils. hIAPP-membrane interactions disturb the lipid ordering and the local bilayer thickness around the peptides. Our results provide atomic-level information of membrane interaction of hIAPP protofibrils, revealing pH-dependent and membrane-modulated hIAPP aggregation at the early stage.
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Affiliation(s)
- Zhenyu Qian
- Key Laboratory of Exercise and Health Sciences (Ministry of Education) and School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China; Department of Physics, State Key Laboratory of Surface physics, Key Laboratory for Computational Physical Science (Ministry of Education), and Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200433, China
| | - Yu Zou
- College of Physical Education and Training, Shanghai University of Sport, Shanghai 200438, China
| | - Qingwen Zhang
- College of Physical Education and Training, Shanghai University of Sport, Shanghai 200438, China
| | - Peijie Chen
- Key Laboratory of Exercise and Health Sciences (Ministry of Education) and School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, United States
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface physics, Key Laboratory for Computational Physical Science (Ministry of Education), and Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200433, China.
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, United States; Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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19
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Guo AZ, Fluitt AM, de Pablo JJ. Early-stage human islet amyloid polypeptide aggregation: Mechanisms behind dimer formation. J Chem Phys 2018; 149:025101. [DOI: 10.1063/1.5033458] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Ashley Z. Guo
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Aaron M. Fluitt
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Juan J. de Pablo
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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20
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Sciacca MFM, Chillemi R, Sciuto S, Greco V, Messineo C, Kotler SA, Lee DK, Brender JR, Ramamoorthy A, La Rosa C, Milardi D. A blend of two resveratrol derivatives abolishes hIAPP amyloid growth and membrane damage. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1793-1802. [PMID: 29555190 DOI: 10.1016/j.bbamem.2018.03.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/31/2018] [Accepted: 03/13/2018] [Indexed: 12/14/2022]
Abstract
Type II diabetes mellitus (T2DM) is characterized by the presence of amyloid deposits of the human islet amyloid polypeptide (hIAPP) in pancreatic β-cells. A wealth of data supports the hypothesis that hIAPP's toxicity is related to an abnormal interaction of amyloids with islet cell membranes. Thus, many studies aimed at finding effective therapies for T2DM focus on the design of molecules that are able to inhibit hIAPP's amyloid growth and the related membrane damage as well. Based on this view and inspired by its known anti-amyloid properties, we have functionalized resveratrol with a phosphoryl moiety (4'-O-PR) that improves its solubility and pharmacological properties. A second resveratrol derivative has also been obtained by conjugating resveratrol with a dimyristoylphosphatidyl moiety (4'-DMPR). The use of both compounds resulted in abolishing both amyloid growth and amyloid mediated POPC/POPS membrane damage in tube tests. We propose that a mixture of a water-soluble anti-aggregating compound and its lipid-anchored derivative may be employed as a general strategy to prevent and/or to halt amyloid-related membrane damage.
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Affiliation(s)
- Michele F M Sciacca
- Istituto CNR di Biostrutture e Bioimmagini- Sede Secondaria di Catania, Via Paolo Gaifami 18, 95126 Catania, Italy
| | - Rosa Chillemi
- Università degli Studi di Catania, Dipartimento di Scienze Chimiche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Sebastiano Sciuto
- Università degli Studi di Catania, Dipartimento di Scienze Chimiche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Valentina Greco
- Università degli Studi di Catania, Dipartimento di Scienze Chimiche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Concetta Messineo
- Università degli Studi di Catania, Dipartimento di Scienze Chimiche, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Samuel A Kotler
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Dong-Kuk Lee
- Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea
| | - Jeffrey R Brender
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Carmelo La Rosa
- Università degli Studi di Catania, Dipartimento di Scienze Chimiche, Viale Andrea Doria 6, 95125 Catania, Italy.
| | - Danilo Milardi
- Istituto CNR di Biostrutture e Bioimmagini- Sede Secondaria di Catania, Via Paolo Gaifami 18, 95126 Catania, Italy.
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21
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Amyloid growth and membrane damage: Current themes and emerging perspectives from theory and experiments on Aβ and hIAPP. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1625-1638. [PMID: 29501606 DOI: 10.1016/j.bbamem.2018.02.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 12/15/2022]
Abstract
Alzheimer's Disease (AD) and Type 2 diabetes mellitus (T2DM) are two incurable diseases both hallmarked by an abnormal deposition of the amyloidogenic peptides Aβ and Islet Amyloid Polypeptide (IAPP) in affected tissues. Epidemiological data demonstrate that patients suffering from diabetes are at high risk of developing AD, thus making the search for factors common to the two pathologies of special interest for the design of new therapies. Accumulating evidence suggests that the toxic properties of both Aβ or IAPP are ascribable to their ability to damage the cell membrane. However, the molecular details describing Aβ or IAPP interaction with membranes are poorly understood. This review focuses on biophysical and in silico studies addressing these topics. Effects of calcium, cholesterol and membrane lipid composition in driving aberrant Aβ or IAPP interaction with the membrane will be specifically considered. The cross correlation of all these factors appears to be a key issue not only to shed light in the countless and often controversial reports relative to this area but also to gain valuable insights into the central events leading to membrane damage caused by amyloidogenic peptides. 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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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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D’Urso L, Condorelli M, Puglisi O, Tempra C, Lolicato F, Compagnini G, La Rosa C. Detection and characterization at nM concentration of oligomers formed by hIAPP, Aβ(1–40) and their equimolar mixture using SERS and MD simulations. Phys Chem Chem Phys 2018; 20:20588-20596. [DOI: 10.1039/c7cp08552d] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We report a structural investigation on IAPP, Aβ(1–40) and their equimolar mixture at nM concentration using SERS spectroscopy and molecular dynamic simulations.
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Affiliation(s)
- Luisa D’Urso
- Department of Chemical Sciences
- Viale A. Doria 6-95125 Catania
- Italy
| | | | - Orazio Puglisi
- Department of Chemical Sciences
- Viale A. Doria 6-95125 Catania
- Italy
| | - Carmelo Tempra
- Department of Chemical Sciences
- Viale A. Doria 6-95125 Catania
- Italy
| | - Fabio Lolicato
- Department of Physics
- University of Helsinki
- FI-00014 Helsinki
- Finland
- Laboratory of Physics
| | | | - Carmelo La Rosa
- Department of Chemical Sciences
- Viale A. Doria 6-95125 Catania
- Italy
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24
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Christensen M, Skeby KK, Schiøtt B. Identification of Key Interactions in the Initial Self-Assembly of Amylin in a Membrane Environment. Biochemistry 2017; 56:4884-4894. [PMID: 28786287 DOI: 10.1021/acs.biochem.7b00344] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Islet amyloid polypeptide, also known as amylin, forms aggregates that reduce the amount of insulin-producing cells in patients with type II diabetes mellitus. Much remains unknown about the process of aggregation and cytotoxicity, but it is known that certain cell membrane components can alter the rate of aggregation. Using atomistic molecular dynamics simulations combined with the highly mobile membrane mimetic model incorporating enhanced sampling of lipid diffusion, we investigate interaction of amylin peptides with the membrane components as well as the self-assembly of amylin. Consistent with experimental evidence, we find that an initial membrane-bound α-helical state folds into stable β-sheet structures upon self-assembly. Our results suggest the following mechanism for the initial phase of amylin self-assembly. The peptides move around on the membrane with the positively charged N-terminus interacting with the negatively charged lipid headgroups. When the peptides start to interact, they partly unfold and break some of the contacts with the membrane. The initial interactions between the peptides are dominated by aromatic and hydrophobic interactions. Oligomers are formed showing both intra- and interpeptide β-sheets, initially with interactions mainly in the C-terminal domain of the peptides. Decreasing the pH to 5.5 is known to inhibit amyloid formation. At low pH, His18 is protonated, adding a fourth positive charge at the peptide. With His18 protonated, no oligomerization is observed in the simulations. The additional charge gives a strong midpoint anchoring of the peptides to negatively charged membrane components, and the peptides experience additional interpeptide repulsion, thereby preventing interactions.
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Affiliation(s)
- Mikkel Christensen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , DK-8000 Aarhus, Denmark.,Sino-Danish Center for Education and Research , Beijing, China
| | - Katrine K Skeby
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , DK-8000 Aarhus, Denmark
| | - Birgit Schiøtt
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , DK-8000 Aarhus, Denmark
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25
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Structural Properties of Human IAPP Dimer in Membrane Environment Studied by All-Atom Molecular Dynamics Simulations. Sci Rep 2017; 7:7915. [PMID: 28801684 PMCID: PMC5554177 DOI: 10.1038/s41598-017-08504-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 07/12/2017] [Indexed: 12/27/2022] Open
Abstract
The aggregation of human islet amyloid polypeptide (hIAPP) can damage the membrane of the β-cells in the pancreatic islets and induce type 2 diabetes (T2D). Growing evidences indicated that the major toxic species are small oligomers of IAPP. Due to the fast aggregation nature, it is hard to characterize the structures of IAPP oligomers by experiments, especially in the complex membrane environment. On the other side, molecular dynamics simulation can provide atomic details of the structure and dynamics of the aggregation of IAPP. In this study, all-atom bias-exchange metadynamics (BE-Meta) and unbiased molecular dynamics simulations were employed to study the structural properties of IAPP dimer in the membranes environments. A number of intermediates, including α-helical states, β-sheet states, and fully disordered states, are identified. The formation of N-terminal β-sheet structure is prior to the C-terminal β-sheet structure towards the final fibril-like structures. The α-helical intermediates have lower propensity in the dimeric hIAPP and are off-pathway intermediates. The simulations also demonstrate that the β-sheet intermediates induce more perturbation on the membrane than the α-helical and disordered states and thus pose higher disruption ability.
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26
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Sciacca MFM, Lolicato F, Di Mauro G, Milardi D, D'Urso L, Satriano C, Ramamoorthy A, La Rosa C. The Role of Cholesterol in Driving IAPP-Membrane Interactions. Biophys J 2017; 111:140-51. [PMID: 27410742 DOI: 10.1016/j.bpj.2016.05.050] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 05/15/2016] [Accepted: 05/26/2016] [Indexed: 01/01/2023] Open
Abstract
Our knowledge of the molecular events underlying type 2 diabetes mellitus-a protein conformational disease characterized by the aggregation of islet amyloid polypeptide (IAPP) in pancreatic β cells-is limited. However, amyloid-mediated membrane damage is known to play a key role in IAPP cytotoxicity, and therefore the effects of lipid composition on modulating IAPP-membrane interactions have been the focus of intense research. In particular, membrane cholesterol content varies with aging and consequently with adverse environmental factors such as diet and lifestyle, but its role in the development of the disease is controversial. In this study, we employ a combination of experimental techniques and in silico molecular simulations to shed light on the role of cholesterol in IAPP aggregation and the related membrane disruption. We show that if anionic POPC/POPS vesicles are used as model membranes, cholesterol has a negligible effect on the kinetics of IAPP fibril growth on the surface of the bilayer. In addition, cholesterol inhibits membrane damage by amyloid-induced poration on membranes, but enhances leakage through fiber growth on the membrane surface. Conversely, if 1:2 DOPC/DPPC raft-like model membranes are used, cholesterol accelerates fiber growth. Next, it enhances pore formation and suppresses fiber growth on the membrane surface, leading to leakage. Our results highlight a twofold effect of cholesterol on the amyloidogenicity of IAPP and help explain its debated role in type 2 diabetes mellitus.
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Affiliation(s)
- Michele F M Sciacca
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Catania, Italy
| | - Fabio Lolicato
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy; Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Giacomo Di Mauro
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy
| | - Danilo Milardi
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Catania, Italy
| | - Luisa D'Urso
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy
| | - Cristina Satriano
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy
| | - Ayyalusamy Ramamoorthy
- Biophysics, University of Michigan, Ann Arbor, Michigan; Department of Chemistry, University of Michigan, Ann Arbor, Michigan; Institute for Advanced Study, Technische Universität München, Lichtenbergstrasse, Garching, Germany.
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy.
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27
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Korshavn KJ, Satriano C, Lin Y, Zhang R, Dulchavsky M, Bhunia A, Ivanova MI, Lee YH, La Rosa C, Lim MH, Ramamoorthy A. Reduced Lipid Bilayer Thickness Regulates the Aggregation and Cytotoxicity of Amyloid-β. J Biol Chem 2017; 292:4638-4650. [PMID: 28154182 DOI: 10.1074/jbc.m116.764092] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/31/2017] [Indexed: 11/06/2022] Open
Abstract
The aggregation of amyloid-β (Aβ) on lipid bilayers has been implicated as a mechanism by which Aβ exerts its toxicity in Alzheimer's disease (AD). Lipid bilayer thinning has been observed during both oxidative stress and protein aggregation in AD, but whether these pathological modifications of the bilayer correlate with Aβ misfolding is unclear. Here, we studied peptide-lipid interactions in synthetic bilayers of the short-chain lipid dilauroyl phosphatidylcholine (DLPC) as a simplified model for diseased bilayers to determine their impact on Aβ aggregate, protofibril, and fibril formation. Aβ aggregation and fibril formation in membranes composed of dioleoyl phosphatidylcholine (DOPC) or 1- palmitoyl-2-oleoyl phosphatidylcholine mimicking normal bilayers served as controls. Differences in aggregate formation and stability were monitored by a combination of thioflavin-T fluorescence, circular dichroism, atomic force microscopy, transmission electron microscopy, and NMR. Despite the ability of all three lipid bilayers to catalyze aggregation, DLPC accelerates aggregation at much lower concentrations and prevents the fibrillation of Aβ at low micromolar concentrations. DLPC stabilized globular, membrane-associated oligomers, which could disrupt the bilayer integrity. DLPC bilayers also remodeled preformed amyloid fibrils into a pseudo-unfolded, molten globule state, which resembled on-pathway, protofibrillar aggregates. Whereas the stabilized, membrane-associated oligomers were found to be nontoxic, the remodeled species displayed toxicity similar to that of conventionally prepared aggregates. These results provide mechanistic insights into the roles that pathologically thin bilayers may play in Aβ aggregation on neuronal bilayers, and pathological lipid oxidation may contribute to Aβ misfolding.
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Affiliation(s)
- Kyle J Korshavn
- From the Department of Chemistry.,Program in Biophysics, and
| | - Cristina Satriano
- the Department of Chemical Sciences, University of Catania, Catania 95124, Italy
| | - Yuxi Lin
- the Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | | | - Mark Dulchavsky
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109
| | - Anirban Bhunia
- the Department of Biophysics, Bose Institute, Kolkata 700009, India, and
| | - Magdalena I Ivanova
- Program in Biophysics, and.,Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109
| | - Young-Ho Lee
- the Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Carmelo La Rosa
- the Department of Chemical Sciences, University of Catania, Catania 95124, Italy
| | - Mi Hee Lim
- the Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
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La Rosa C, Scalisi S, Lolicato F, Pannuzzo M, Raudino A. Lipid-assisted protein transport: A diffusion-reaction model supported by kinetic experiments and molecular dynamics simulations. J Chem Phys 2016; 144:184901. [DOI: 10.1063/1.4948323] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Carmelo La Rosa
- Department of Chemical Science, University of Catania, Viale A. Doria 6, I-95125 Catania, Italy
| | - Silvia Scalisi
- Department of Chemical Science, University of Catania, Viale A. Doria 6, I-95125 Catania, Italy
| | - Fabio Lolicato
- Department of Chemical Science, University of Catania, Viale A. Doria 6, I-95125 Catania, Italy
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Martina Pannuzzo
- Department of Physics, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213, USA
| | - Antonio Raudino
- Department of Chemical Science, University of Catania, Viale A. Doria 6, I-95125 Catania, Italy
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Skeby KK, Andersen OJ, Pogorelov TV, Tajkhorshid E, Schiøtt B. Conformational Dynamics of the Human Islet Amyloid Polypeptide in a Membrane Environment: Toward the Aggregation Prone Form. Biochemistry 2016; 55:2031-42. [PMID: 26953503 PMCID: PMC5733697 DOI: 10.1021/acs.biochem.5b00507] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is a 37-residue peptide hormone, which upon misfolding changes from the physiologically active monomer into pathological amyloid fibril aggregates in the pancreas of type 2 diabetes mellitus patients. During this process, the insulin-producing pancreatic β-cells are damaged; however, the underlying mechanism of this mode of cytotoxicity remains elusive. It is known that anionic lipids accelerate amyloid fibril formation, implicating the importance of the cellular membrane in the process, and that a pH close to the level in the β-cell secretory granules (pH 5.5) inhibits amyloid fibril formation. Using all-atom molecular dynamics simulations, we have investigated the membrane-associated monomer state of α-helical hIAPP, analyzed specific interactions of hIAPP with a mixed anionic-zwitterionic lipid membrane and examined the influence of pH on the structure and dynamics of hIAPP and its interaction with the membrane. We find that hIAPP primarily interacts with the membrane by forming favorable interactions between anionic lipids and the positively charged residues in the N-terminal part of the peptide. Rationalizing experimental findings, the simulations show that the N-terminal part of the peptide interacts with the membrane in the lipid headgroup region. At neutral pH, the C-terminal part of the peptide, which contains the residues that initiate fibril formation, displays a highly dynamic, unfolded state, which interacts with the membrane significantly less than the N-terminal part. Such an unfolded form can be proposed to contribute to the acceleration of fibril formation. At low pH, protonation of His18 mediates a stronger interaction of the C-terminal part with the membrane, resulting in the immobilization of the C-terminal part on the membrane surface that might constitute a mechanism by which low pH inhibits fibril formation.
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Affiliation(s)
- Katrine Kirkeby Skeby
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO) and the Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus, Denmark
| | - Ole Juul Andersen
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO) and the Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus, Denmark
| | - Taras V. Pogorelov
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Emad Tajkhorshid
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Birgit Schiøtt
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO) and the Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus, Denmark
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Abstract
The aggregation of human amylin has been strongly implicated in the progression of Type II diabetes. This 37-residue peptide forms a variety of secondary structures, including random coils, α-helices, and β-hairpins. The balance between these structures depends on the chemical environment, making amylin an ideal candidate to examine inherent biases in force fields. Rat amylin differs from human amylin by only 6 residues; however, it does not form fibrils. Therefore it provides a useful complement to human amylin in studies of the key events along the aggregation pathway. In this work, the free energy of rat and human amylin was determined as a function of α-helix and β-hairpin content for the Gromos96 53a6, OPLS-AA/L, CHARMM22/CMAP, CHARMM22*, Amberff99sb*-ILDN, and Amberff03w force fields using advanced sampling techniques, specifically bias exchange metadynamics. This work represents a first systematic attempt to evaluate the conformations and the corresponding free energy of a large, clinically relevant disordered peptide in solution across force fields. The NMR chemical shifts of rIAPP were calculated for each of the force fields using their respective free energy maps, allowing us to quantitatively assess their predictions. We show that the predicted distribution of secondary structures is sensitive to the choice of force-field: Gromos53a6 is biased towards β-hairpins, while CHARMM22/CMAP predicts structures that are overly α-helical. OPLS-AA/L favors disordered structures. Amberff99sb*-ILDN, AmberFF03w and CHARMM22* provide the balance between secondary structures that is most consistent with available experimental data. In contrast to previous reports, our findings suggest that the equilibrium conformations of human and rat amylin are remarkably similar, but that subtle differences arise in transient alpha-helical and beta-strand containing structures that the human peptide can more readily adopt. We hypothesize that these transient states enable dynamic pathways that facilitate the formation of aggregates and, eventually, amyloid fibrils.
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Resveratrol interferes with the aggregation of membrane-bound human-IAPP: A molecular dynamics study. Eur J Med Chem 2015; 92:876-81. [DOI: 10.1016/j.ejmech.2015.01.047] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 01/22/2015] [Accepted: 01/23/2015] [Indexed: 01/08/2023]
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Milardi D, Sciacca MFM, Randazzo L, Raudino A, La Rosa C. The role of calcium, lipid membranes and islet amyloid polypeptide in the onset of type 2 diabetes: innocent bystanders or partners in a crime? Front Endocrinol (Lausanne) 2014; 5:216. [PMID: 25566188 PMCID: PMC4268396 DOI: 10.3389/fendo.2014.00216] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/01/2014] [Indexed: 12/15/2022] Open
Affiliation(s)
- Danilo Milardi
- Istituto CNR di Biostrutture e Bioimmagini-Sezione di Catania, Catania, Italy
| | - Michele F. M. Sciacca
- Dipartimento di Scienze Chimiche Viale Andrea Doria 6, Università Degli Studi di Catania, Catania, Italy
| | - Loredana Randazzo
- Istituto CNR di Biostrutture e Bioimmagini-Sezione di Catania, Catania, Italy
| | - Antonino Raudino
- Dipartimento di Scienze Chimiche Viale Andrea Doria 6, Università Degli Studi di Catania, Catania, Italy
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche Viale Andrea Doria 6, Università Degli Studi di Catania, Catania, Italy
- *Correspondence:
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33
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α-helical structures drive early stages of self-assembly of amyloidogenic amyloid polypeptide aggregate formation in membranes. Sci Rep 2013; 3:2781. [PMID: 24071712 PMCID: PMC3784961 DOI: 10.1038/srep02781] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/03/2013] [Indexed: 12/17/2022] Open
Abstract
The human islet amyloid polypeptide (hIAPP) is the primary component in the toxic islet amyloid deposits in type-2 diabetes. hIAPP self-assembles to aggregates that permeabilize membranes and constitutes amyloid plaques. Uncovering the mechanisms of amyloid self-assembly is the key to understanding amyloid toxicity and treatment. Although structurally similar, hIAPP's rat counterpart, the rat islet amyloid polypeptide (rIAPP), is non-toxic. It has been a puzzle why these peptides behave so differently. We combined multiscale modelling and theory to explain the drastically different dynamics of hIAPP and rIAPP: The differences stem from electrostatic dipolar interactions. hIAPP forms pentameric aggregates with the hydrophobic residues facing the membrane core and stabilizing water-conducting pores. We give predictions for pore sizes, the number of hIAPP peptides, and aggregate morphology. We show the importance of curvature-induced stress at the early stages of hIAPP assembly and the α-helical structures over β-sheets. This agrees with recent fluorescence spectroscopy experiments.
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34
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Cations as switches of amyloid-mediated membrane disruption mechanisms: calcium and IAPP. Biophys J 2013; 104:173-84. [PMID: 23332070 DOI: 10.1016/j.bpj.2012.11.3811] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 11/09/2012] [Accepted: 11/21/2012] [Indexed: 12/15/2022] Open
Abstract
Disruption of the integrity of the plasma membrane by amyloidogenic proteins is linked to the pathogenesis of a number of common age-related diseases. Although accumulating evidence suggests that adverse environmental stressors such as unbalanced levels of metal ions may trigger amyloid-mediated membrane damage, many features of the molecular mechanisms underlying these events are unknown. Using human islet amyloid polypeptide (hIAPP, aka amylin), an amyloidogenic peptide associated with β-cell death in type 2 diabetes, we demonstrate that the presence of Ca(2+) ions inhibits membrane damage occurring immediately after the interaction of freshly dissolved hIAPP with the membrane, but significantly enhances fiber-dependent membrane disruption. In particular, dye leakage, quartz crystal microbalance, atomic force microscopy, and NMR experiments show that Ca(2+) ions promote a shallow membrane insertion of hIAPP, which leads to the removal of lipids from the bilayer through a detergent-like mechanism triggered by fiber growth. Because both types of membrane-damage mechanisms are common to amyloid toxicity by most amyloidogenic proteins, it is likely that unregulated ion homeostasis, amyloid aggregation, and membrane disruption are all parts of a self-perpetuating cycle that fuels amyloid cytotoxicity.
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Sciacca MFM, Brender JR, Lee DK, Ramamoorthy A. Phosphatidylethanolamine enhances amyloid fiber-dependent membrane fragmentation. Biochemistry 2012; 51:7676-84. [PMID: 22970795 DOI: 10.1021/bi3009888] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The toxicity of amyloid-forming peptides has been hypothesized to reside in the ability of protein oligomers to interact with and disrupt the cell membrane. Much of the evidence for this hypothesis comes from in vitro experiments using model membranes. However, the accuracy of this approach depends on the ability of the model membrane to accurately mimic the cell membrane. The effect of membrane composition has been overlooked in many studies of amyloid toxicity in model systems. By combining measurements of membrane binding, membrane permeabilization, and fiber formation, we show that lipids with the phosphatidylethanolamine (PE) headgroup strongly modulate the membrane disruption induced by IAPP (islet amyloid polypeptide protein), an amyloidogenic protein involved in type II diabetes. Our results suggest that PE lipids hamper the interaction of prefibrillar IAPP with membranes but enhance the membrane disruption correlated with the growth of fibers on the membrane surface via a detergent-like mechanism. These findings provide insights into the mechanism of membrane disruption induced by IAPP, suggesting a possible role of PE and other amyloids involved in other pathologies.
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Affiliation(s)
- Michele F M Sciacca
- Departments of Biophysics and Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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36
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Sasahara K, Morigaki K, Okazaki T, Hamada D. Binding of Islet Amyloid Polypeptide to Supported Lipid Bilayers and Amyloid Aggregation at the Membranes. Biochemistry 2012; 51:6908-19. [DOI: 10.1021/bi300542g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Kenji Sasahara
- Division of Structural Biology
(G-COE), Department of Biochemistry and Molecular Biology, Graduate
School of Medicine, Kobe University, Kobe
650-0017, Japan
| | - Kenichi Morigaki
- National Institute of Advanced Industrial Science and Technology (AIST), Ikeda 563-8577, Japan
- Research Center for Environmental
Genomics, Kobe University, Kobe 657-8501,
Japan
| | - Takashi Okazaki
- National Institute of Advanced Industrial Science and Technology (AIST), Ikeda 563-8577, Japan
| | - Daizo Hamada
- Division of Structural Biology
(G-COE), Department of Biochemistry and Molecular Biology, Graduate
School of Medicine, Kobe University, Kobe
650-0017, Japan
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