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Liu Z, Zou Y, Zhang Q, Chen P, Liu Y, Qian Z. Distinct Binding Dynamics, Sites and Interactions of Fullerene and Fullerenols with Amyloid-β Peptides Revealed by Molecular Dynamics Simulations. Int J Mol Sci 2019; 20:E2048. [PMID: 31027286 PMCID: PMC6514889 DOI: 10.3390/ijms20082048] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 04/21/2019] [Accepted: 04/24/2019] [Indexed: 12/12/2022] Open
Abstract
The pathology Alzheimer's disease (AD) is associated with the self-assembly of amyloid-β (Aβ) peptides into β-sheet enriched fibrillar aggregates. A promising treatment strategy is focused on the inhibition of amyloid fibrillization of Aβ peptide. Fullerene C60 is proved to effectively inhibit Aβ fibrillation while the poor water-solubility restricts its use as a biomedicine agent. In this work, we examined the interaction of fullerene C60 and water-soluble fullerenol C60(OH)6/C60(OH)12 (C60 carrying 6/12 hydroxyl groups) with preformed Aβ40/42 protofibrils by multiple molecular dynamics simulations. We found that when binding to the Aβ42 protofibril, C60, C60(OH)6 and C60(OH)12 exhibit distinct binding dynamics, binding sites and peptide interaction. The increased number of hydroxyl groups C60 carries leads to slower binding dynamics and weaker binding strength. Binding free energy analysis demonstrates that the C60/C60(OH)6 molecule primarily binds to the C-terminal residues 31-41, whereas C60(OH)12 favors to bind to N-terminal residues 4-14. The hydrophobic interaction plays a critical role in the interplay between Aβ and all the three nanoparticles, and the π-stacking interaction gets weakened as C60 carries more hydroxyls. In addition, the C60(OH)6 molecule has high affinity to form hydrogen bonds with protein backbones. The binding behaviors of C60/C60(OH)6/C60(OH)12 to the Aβ40 protofibril resemble with those to Aβ42. Our work provides a detailed picture of fullerene/fullerenols binding to Aβ protofibril, and is helpful to understand the underlying inhibitory mechanism.
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Affiliation(s)
- Zhiwei Liu
- Key Laboratory of Exercise and Health Sciences (Ministry of Education), School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, China.
| | - Yu Zou
- College of Physical Education and Training, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, China.
| | - Qingwen Zhang
- College of Physical Education and Training, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, China.
| | - Peijie Chen
- Key Laboratory of Exercise and Health Sciences (Ministry of Education), School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, China.
| | - Yu Liu
- Key Laboratory of Exercise and Health Sciences (Ministry of Education), School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, China.
| | - Zhenyu Qian
- Key Laboratory of Exercise and Health Sciences (Ministry of Education), School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, China.
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52
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Structure of amyloid β 25-35 in lipid environment and cholesterol-dependent membrane pore formation. Sci Rep 2019; 9:2689. [PMID: 30804528 PMCID: PMC6389947 DOI: 10.1038/s41598-019-38749-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/08/2019] [Indexed: 01/14/2023] Open
Abstract
The amyloid β (Aβ) peptide and its shorter variants, including a highly cytotoxic Aβ25–35 peptide, exert their neurotoxic effect during Alzheimer’s disease by various mechanisms, including cellular membrane permeabilization. The intrinsic polymorphism of Aβ has prevented the identification of the molecular basis of Aβ pore formation by direct structural methods, and computational studies have led to highly divergent pore models. Here, we have employed a set of biophysical techniques to directly monitor Ca2+-transporting Aβ25–35 pores in lipid membranes, to quantitatively characterize pore formation, and to identify the key structural features of the pore. Moreover, the effect of membrane cholesterol on pore formation and the structure of Aβ25–35 has been elucidated. The data suggest that the membrane-embedded peptide forms 6- or 8-stranded β-barrel like structures. The 8-stranded barrels may conduct Ca2+ ions through an inner cavity, whereas the tightly packed 6-stranded barrels need to assemble into supramolecular structures to form a central pore. Cholesterol affects Aβ25–35 pore formation by a dual mechanism, i.e., by direct interaction with the peptide and by affecting membrane structure. Collectively, our data illuminate the molecular basis of Aβ membrane pore formation, which should advance both basic and clinical research on Alzheimer’s disease and membrane-associated pathologies in general.
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53
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Nishikawa N, Sakae Y, Gouda T, Tsujimura Y, Okamoto Y. Structural Analysis of a Trimer of β 2-Microgloblin Fragment by Molecular Dynamics Simulations. Biophys J 2019; 116:781-790. [PMID: 30771855 DOI: 10.1016/j.bpj.2018.11.3143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 06/08/2018] [Accepted: 11/06/2018] [Indexed: 01/22/2023] Open
Abstract
A peptide β2-m21-31, which is a fragment from residue 21 to residue 31 of β2-microgloblin, is experimentally known to self-assemble and form amyloid fibrils. In order to understand the mechanism of amyloid fibril formations, we applied the replica-exchange molecular dynamics method to the system consisting of three fragments of β2-m21-31. From the analyses on the temperature dependence, we found that there is a clear phase transition temperature in which the peptides aggregate with each other. Moreover, we found by the free energy analyses that there are two major stable states: One of them is like amyloid fibrils and the other is amorphous aggregates.
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Affiliation(s)
- Naohiro Nishikawa
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan; Department of Theoretical and Computational Molecular Science, Institute for Molecular Science, Okazaki, Aichi, Japan
| | - Yoshitake Sakae
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Takuya Gouda
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Yuichiro Tsujimura
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Yuko Okamoto
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan; Structural Biology Research Center, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan; Center for Computational Science, Graduate School of Engineering, Nagoya University, Nagoya, Aichi, Japan; Information Technology Center, Nagoya University, Nagoya, Aichi, Japan; JST-CREST, Nagoya, Aichi, Japan.
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54
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Sun Y, Kakinen A, Xing Y, Pilkington EH, Davis TP, Ke PC, Ding F. Nucleation of β-rich oligomers and β-barrels in the early aggregation of human islet amyloid polypeptide. Biochim Biophys Acta Mol Basis Dis 2018; 1865:434-444. [PMID: 30502402 DOI: 10.1016/j.bbadis.2018.11.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/10/2018] [Accepted: 11/26/2018] [Indexed: 10/27/2022]
Abstract
The self-assembly of human islet amyloid polypeptide (hIAPP) into β-sheet rich amyloid aggregates is associated with pancreatic β-cell death in type 2 diabetes (T2D). Prior experimental studies of hIAPP aggregation reported the early accumulation of α-helical intermediates before the rapid conversion into β-sheet rich amyloid fibrils, as also corroborated by our experimental characterizations with transmission electron microscopy and Fourier transform infrared spectroscopy. Although increasing evidence suggests that small oligomers populating early hIAPP aggregation play crucial roles in cytotoxicity, structures of these oligomer intermediates and their conformational conversions remain unknown, hindering our understanding of T2D disease mechanism and therapeutic design targeting these early aggregation species. We further applied large-scale discrete molecule dynamics simulations to investigate the oligomerization of full-length hIAPP, employing multiple molecular systems of increasing number of peptides. We found that the oligomerization process was dynamic, involving frequent inter-oligomeric exchanges. On average, oligomers had more α-helices than β-sheets, consistent with ensemble-based experimental measurements. However, in ~4-6% independent simulations, β-rich oligomers expected as the fibrillization intermediates were observed, especially in the pentamer and hexamer simulations. These β-rich oligomers could adopt β-barrel conformations, recently postulated to be the toxic oligomer species but only observed computationally in the aggregates of short amyloid protein fragments. Free-energy analysis revealed high energies of these β-rich oligomers, supporting the nucleated conformational changes of oligomers in amyloid aggregation. β-barrel oligomers of full-length hIAPP with well-defined three-dimensional structures may play an important pathological role in T2D etiology and may be a therapeutic target for the disease.
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Affiliation(s)
- Yunxiang Sun
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Aleksandr Kakinen
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Yanting Xing
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Emily H Pilkington
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Thomas P Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
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55
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β-barrel Oligomers as Common Intermediates of Peptides Self-Assembling into Cross-β Aggregates. Sci Rep 2018; 8:10353. [PMID: 29985420 PMCID: PMC6037789 DOI: 10.1038/s41598-018-28649-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/22/2018] [Indexed: 12/22/2022] Open
Abstract
Oligomers populated during the early amyloid aggregation process are more toxic than mature fibrils, but pinpointing the exact toxic species among highly dynamic and heterogeneous aggregation intermediates remains a major challenge. β-barrel oligomers, structurally-determined recently for a slow-aggregating peptide derived from αB crystallin, are attractive candidates for exerting amyloid toxicity due to their well-defined structures as therapeutic targets and compatibility to the "amyloid-pore" hypothesis of toxicity. To assess whether β-barrel oligomers are common intermediates to amyloid peptides - a necessary step toward associating β-barrel oligomers with general amyloid cytotoxicity, we computationally studied the oligomerization and fibrillization dynamics of seven well-studied fragments of amyloidogenic proteins with different experimentally-determined aggregation morphologies and cytotoxicity. In our molecular dynamics simulations, β-barrel oligomers were only observed in five peptides self-assembling into the characteristic cross-β aggregates, but not the other two that formed polymorphic β-rich aggregates as reported experimentally. Interestingly, the latter two peptides were previously found nontoxic. Hence, the observed correlation between β-barrel oligomers formation and cytotoxicity supports the hypothesis of β-barrel oligomers as the common toxic intermediates of amyloid aggregation.
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56
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Chen Y, Chen Z, Sun Y, Lei J, Wei G. Mechanistic insights into the inhibition and size effects of graphene oxide nanosheets on the aggregation of an amyloid-β peptide fragment. NANOSCALE 2018; 10:8989-8997. [PMID: 29725676 DOI: 10.1039/c8nr01041b] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The aggregation of amyloid-β (Aβ), which involves the formation of small oligomers and mature fibrils, has received considerable attention in the past few decades due to its close link with Alzheimer's disease (AD). The inhibition of β-sheet formation has been considered as the primary therapeutic strategy for AD. In this respect, graphene oxide (GO) has gained significant attention because of its high solubility, good biocompatibility and inhibitory effect on the aggregation of Aβ and the 33-42 fragment (Aβ33-42). However, the inhibitory mechanism at the atomic level remains elusive. Herein, we investigated the oligomerization of Aβ33-42 by performing replica exchange molecular dynamics simulations on four Aβ33-42 peptide chains in the absence and presence of two different sizes of GO. Our simulations show that isolated Aβ33-42 can form fibril-prone extended β-sheets and barrel-like structures, whereas they are suppressed in the presence of GO nanosheets. Our data reveal that GO inhibits Aβ33-42 oligomerization by making Aβ33-42 peptides separate from each other through strong interactions with M35. With the same total number of atoms, GO120 displays better inhibitory effect than GO60 by providing a larger effective contact surface area. This study provides the molecular mechanism of GO in inhibiting the aggregation of Aβ33-42, which might offer a theoretical insight into the design of drugs against AD at the atomic level.
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Affiliation(s)
- Yujie Chen
- 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, People's Republic of China.
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57
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Foroutanpay B, Kumar J, Kang S, Danaei N, Westaway D, Sim V, Kar S. The Effects of N-terminal Mutations on β-amyloid Peptide Aggregation and Toxicity. Neuroscience 2018; 379:177-188. [DOI: 10.1016/j.neuroscience.2018.03.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 03/01/2018] [Accepted: 03/12/2018] [Indexed: 12/31/2022]
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58
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Salveson PJ, Haerianardakani S, Thuy-Boun A, Kreutzer AG, Nowick JS. Controlling the Oligomerization State of Aβ-Derived Peptides with Light. J Am Chem Soc 2018; 140:5842-5852. [PMID: 29627987 DOI: 10.1021/jacs.8b02658] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A key challenge in studying the biological and biophysical properties of amyloid-forming peptides is that they assemble to form heterogeneous mixtures of soluble oligomers and insoluble fibrils. Photolabile protecting groups have emerged as tools to control the properties of biomolecules with light. Blocking intermolecular hydrogen bonds that stabilize amyloid oligomers provides a general strategy to control the biological and biophysical properties of amyloid-forming peptides. In this paper we describe the design, synthesis, and characterization of macrocyclic β-hairpin peptides that are derived from amyloidogenic peptides and contain the N-2-nitrobenzyl photolabile protecting group. Each peptide contains two heptapeptide segments from Aβ16-36 or Aβ17-36 constrained into β-hairpins. The N-2-nitrobenzyl group is appended to the amide backbone of Gly33 to disrupt the oligomerization of the peptides by disrupting intermolecular hydrogen bonds. X-ray crystallography reveals that N-2-nitrobenzyl groups can either block assembly into discrete oligomers or permit formation of trimers, hexamers, and dodecamers. Photolysis of the N-2-nitrobenzyl groups with long-wave UV light unmasks the amide backbone and alters the assembly and the biological properties of the macrocyclic β-hairpin peptides. SDS-PAGE studies show that removing the N-2-nitrobenzyl groups alters the assembly of the peptides. MTT conversion and LDH release assays show that decaging the peptides induces cytotoxicity. Circular dichroism studies and dye leakage assays with liposomes reveal that decaging modulates interactions of the peptides with lipid bilayers. Collectively, these studies demonstrate that incorporating N-2-nitrobenzyl groups into macrocyclic β-hairpin peptides provides a new strategy to probe the structures and the biological properties of amyloid oligomers.
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Affiliation(s)
- Patrick J Salveson
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - Sepehr Haerianardakani
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - Alexander Thuy-Boun
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - Adam G Kreutzer
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - James S Nowick
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
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59
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Ge X, Sun Y, Ding F. Structures and dynamics of β-barrel oligomer intermediates of amyloid-beta16-22 aggregation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1687-1697. [PMID: 29550287 DOI: 10.1016/j.bbamem.2018.03.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 03/06/2018] [Accepted: 03/07/2018] [Indexed: 01/13/2023]
Abstract
Accumulating evidence suggests that soluble oligomers are more toxic than final fibrils of amyloid aggregations. Among the mixture of inter-converting intermediates with continuous distribution of sizes and secondary structures, oligomers in the β-barrel conformation - a common class of protein folds with a closed β-sheet - have been postulated as the toxic species with well-defined three-dimensional structures to perform pathological functions. A common mechanism for amyloid toxicity, therefore, implies that all amyloid peptides should be able to form β-barrel oligomers as the aggregation intermediates. Here, we applied all-atom discrete molecular dynamics (DMD) simulations to evaluate the formation of β-barrel oligomers and characterize their structures and dynamics in the aggregation of a seven-residue amyloid peptide, corresponding to the amyloid core of amyloid-β with a sequence of 16KLVFFAE22 (Aβ16-22). We carried out aggregation simulations with various numbers of peptides to study the size dependence of aggregation dynamics and assembly structures. Consistent with previous computational studies, we observed the formation of β-barrel oligomers in all-atom DMD simulations. Using a network-based approach to automatically identify β-barrel conformations, we systematically characterized β-barrels of various sizes. Our simulations revealed the conformational inter-conversion between β-barrels and double-layer β-sheets due to increased structural strains upon forming a closed β-barrel while maximizing backbone hydrogen bonds. The potential of mean force analysis further characterized the free energy barriers between these two states. The obtained structural and dynamic insights of β-barrel oligomers may help better understand the molecular mechanism of oligomer toxicities and design novel therapeutics targeting the toxic β-barrel oligomers. 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)
- Xinwei Ge
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Yunxiang Sun
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States.
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60
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Do TD, Sangwan S, de Almeida NEC, Ilitchev AI, Giammona M, Sawaya MR, Buratto SK, Eisenberg DS, Bowers MT. Distal amyloid β-protein fragments template amyloid assembly. Protein Sci 2018; 27:1181-1190. [PMID: 29349888 DOI: 10.1002/pro.3375] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/16/2018] [Accepted: 01/16/2018] [Indexed: 01/06/2023]
Abstract
Amyloid formation is associated with devastating diseases such as Alzheimer's, Parkinson's and Type-2 diabetes. The large amyloid deposits found in patients suffering from these diseases have remained difficult to probe by structural means. Recent NMR models also predict heterotypic interactions from distinct peptide fragments but limited evidence of heterotypic packed sheets is observed in solution. Here we characterize two segments of the protein amyloid β (Aβ) known to form fibrils in Alzheimer's disease patients. We designed two variants of Aβ(19-24) and Aβ(27-32), IFAEDV (I6V) and NKGAIF (N6F) to lower the aggregation propensity of individual peptides while maintaining the similar interactions between the two segments in their native forms. We found that the variants do not form significant amyloid fibrils individually but a 1:1 mixture forms abundant fibrils. Using ion mobility-mass spectrometry (IM-MS), hetero-oligomers up to decamers were found in the mixture while the individual peptides formed primarily dimers and some tetramers consistent with a strong heterotypic interaction between the two segments. We showed by X-ray crystallography that I6V formed a Class 7 zipper with a weakly packed pair of β-sheets and no segregated dry interface, while N6F formed a more stable Class 1 zipper. In a mixture of equimolar N6F:I6V, I6V forms a more stable zipper than in I6V alone while no N6F or hetero-typic zippers are observed. These data are consistent with a mechanism where N6F catalyzes assembly of I6V into a stable zipper and perhaps into stable, pure I6V fibrils that are observed in AFM measurements.
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Affiliation(s)
- Thanh D Do
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California
| | - Smriti Sangwan
- Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, University of California, 611 Charles Young Drive East, Los Angeles, California
| | - Natália E C de Almeida
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California
| | - Alexandre I Ilitchev
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California
| | - Maxwell Giammona
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California
| | - Michael R Sawaya
- Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, University of California, 611 Charles Young Drive East, Los Angeles, California
| | - Steven K Buratto
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California
| | - David S Eisenberg
- Departments of Chemistry and Biochemistry and Biological Chemistry, Howard Hughes Medical Institute, UCLA-DOE Institute for Genomics and Proteomics, University of California, 611 Charles Young Drive East, Los Angeles, California
| | - Michael T Bowers
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California
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61
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Selivanova OM, Surin AK, Ryzhykau YL, Glyakina AV, Suvorina MY, Kuklin AI, Rogachevsky VV, Galzitskaya OV. To Be Fibrils or To Be Nanofilms? Oligomers Are Building Blocks for Fibril and Nanofilm Formation of Fragments of Aβ Peptide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:2332-2343. [PMID: 29338255 DOI: 10.1021/acs.langmuir.7b03393] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
To identify the key stages in the amyloid fibril formation we studied the aggregation of amyloidogenic fragments of Aβ peptide, Aβ(16-25), Aβ(31-40), and Aβ(33-42), using the methods of electron microscopy, X-ray analysis, mass spectrometry, and structural modeling. We have found that fragments Aβ(31-40) and Aβ(33-42) form amyloid fibrils in the shape of bundles and ribbons, while fragment Aβ(16-25) forms only nanofilms. We are the first who performed 2D reconstruction of amyloid fibrils by the Markham rotation technique on electron micrographs of negatively stained fragments of Aβ peptide. Combined analysis of the data allows us to speculate that both the fibrils and the films are formed via association of ring-shaped oligomers with the external diameter of about 6 to 7 nm, the internal diameter of 2 to 3 nm, and the height of ∼3 nm. We conclude that such oligomers are the main building blocks in fibrils of any morphology. The interaction of ring oligomers with each other in different ways makes it possible to explain their polymorphism. The new mechanism of polymerization of amyloidogenic proteins and peptides, described here, could stimulate new approaches in the development of future therapeutics for the treatment of amyloid-related diseases.
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Affiliation(s)
- Olga M Selivanova
- Institute of Protein Research, Russian Academy of Sciences , Pushchino 142290, Russia
| | - Alexey K Surin
- Institute of Protein Research, Russian Academy of Sciences , Pushchino 142290, Russia
- State Research Center for Applied Microbiology & Biotechnology , Obolensk 142279, Russia
| | - Yury L Ryzhykau
- Moscow Institute of Physics and Technology , Dolgoprudny 141701, Russian Federation
| | - Anna V Glyakina
- Institute of Protein Research, Russian Academy of Sciences , Pushchino 142290, Russia
- Institute of Mathematical Problems of Biology RAS, Keldysh Institute of Applied Mathematics of Russian Academy of Sciences , Pushchino 142290, Russia
| | - Mariya Yu Suvorina
- Institute of Protein Research, Russian Academy of Sciences , Pushchino 142290, Russia
| | - Alexander I Kuklin
- Moscow Institute of Physics and Technology , Dolgoprudny 141701, Russian Federation
- Joint Institute for Nuclear Research , Dubna 141980, Russian Federation
| | - Vadim V Rogachevsky
- Institute of Cell Biophysics, Russian Academy of Sciences , Pushchino 142290, Russia
| | - Oxana V Galzitskaya
- Institute of Protein Research, Russian Academy of Sciences , Pushchino 142290, Russia
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62
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Xi W, Vanderford EK, Hansmann UHE. Out-of-Register Aβ 42 Assemblies as Models for Neurotoxic Oligomers and Fibrils. J Chem Theory Comput 2018; 14:1099-1110. [PMID: 29357242 DOI: 10.1021/acs.jctc.7b01106] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We propose a variant of the recently found S-shaped Aβ1-42-motif that is characterized by out-of-register C-terminal β-strands. We show that chains with this structure can form not only fibrils that are compatible with the NMR signals but also barrel-shaped oligomers that resemble the ones formed by the much smaller cylindrin peptides. By running long all-atom molecular dynamics simulations at physiological temperatures with an explicit solvent, we study the stability of these constructs and show that they are plausible models for neurotoxic oligomers. After analyzing the transitions between different assemblies, we suggest a mechanism for amyloid formation in Alzheimer's disease.
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Affiliation(s)
- Wenhui Xi
- Department of Chemistry and Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Elliott K Vanderford
- Department of Chemistry and Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Ulrich H E Hansmann
- Department of Chemistry and Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
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63
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Hoffmann W, Folmert K, Moschner J, Huang X, von Berlepsch H, Koksch B, Bowers MT, von Helden G, Pagel K. NFGAIL Amyloid Oligomers: The Onset of Beta-Sheet Formation and the Mechanism for Fibril Formation. J Am Chem Soc 2017; 140:244-249. [PMID: 29235867 DOI: 10.1021/jacs.7b09510] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The hexapeptide NFGAIL is a highly amyloidogenic peptide, derived from the human islet amyloid polypeptide (hIAPP). Recent investigations indicate that presumably soluble hIAPP oligomers are one of the cytotoxic species in type II diabetes. Here we use thioflavin T staining, transmission electron microscopy, as well as ion mobility-mass spectrometry coupled to infrared (IR) spectroscopy to study the amyloid formation mechanism and the quaternary and secondary structure of soluble NFGAIL oligomers. Our data reveal that at neutral pH NFGAIL follows a nucleation dependent mechanism to form amyloid fibrils. During the lag phase, highly polydisperse, polymorph, and compact oligomers (oligomer number n = 2-13) as well as extended intermediates (n = 4-11) are present. IR secondary structural analysis reveals that compact conformations adopt turn-like structures, whereas extended oligomers exhibit a significant amount of β-sheet content. This agrees well with previous molecular dynamic simulations and provides direct experimental evidence that unordered off-pathway NFGAIL aggregates up to the size of at least the 13-mer as well as partially folded β-sheet containing oligomers are coexisting.
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Affiliation(s)
- Waldemar Hoffmann
- Freie Universität Berlin , Institute of Chemistry and Biochemistry - Organic Chemistry, Takustr. 3, 14195 Berlin, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, 14195 Berlin, Germany
| | - Kristin Folmert
- Freie Universität Berlin , Institute of Chemistry and Biochemistry - Organic Chemistry, Takustr. 3, 14195 Berlin, Germany
| | - Johann Moschner
- Freie Universität Berlin , Institute of Chemistry and Biochemistry - Organic Chemistry, Takustr. 3, 14195 Berlin, Germany
| | - Xing Huang
- Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, 14195 Berlin, Germany
| | - Hans von Berlepsch
- Freie Universität Berlin , Institute of Chemistry and Biochemistry - Organic Chemistry, Takustr. 3, 14195 Berlin, Germany
| | - Beate Koksch
- Freie Universität Berlin , Institute of Chemistry and Biochemistry - Organic Chemistry, Takustr. 3, 14195 Berlin, Germany
| | - Michael T Bowers
- Department of Chemistry and Biochemistry, University of California Santa Barbara , Santa Barbara, California 93106, United States
| | - Gert von Helden
- Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, 14195 Berlin, Germany
| | - Kevin Pagel
- Freie Universität Berlin , Institute of Chemistry and Biochemistry - Organic Chemistry, Takustr. 3, 14195 Berlin, Germany
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64
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Matthes D, Gapsys V, Griesinger C, de Groot BL. Resolving the Atomistic Modes of Anle138b Inhibitory Action on Peptide Oligomer Formation. ACS Chem Neurosci 2017; 8:2791-2808. [PMID: 28906103 DOI: 10.1021/acschemneuro.7b00325] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The diphenyl-pyrazole compound anle138b is a known inhibitor of oligomeric aggregate formation in vitro and in vivo. Therefore, anle138b is considered a promising drug candidate to beneficially interfere with neurodegenerative processes causing devastating pathologies in humans. The atomistic details of the aggregation inhibition mechanism, however, are to date unknown since the ensemble of small nonfibrillar aggregates is structurally heterogeneous and inaccessible to direct structural characterization. Here, we set out to elucidate anle138b's mode of action using all-atom molecular dynamics simulations on the multi-microsecond time scale. By comparing simulations of dimeric to tetrameric aggregates from fragments of four amyloidogenic proteins (Aβ, hTau40, hIAPP, and Sup35N) in the presence and absence of anle138b, we show that the compound reduces the overall number of intermolecular hydrogen bonds, disfavors the sampling of the aggregated state, and remodels the conformational distributions within the small oligomeric peptide aggregates. Most notably, anle138b preferentially interacts with the disordered structure ensemble via its pyrazole moiety, thereby effectively blocking interpeptide main chain interactions and impeding the spontaneous formation of ordered β-sheet structures, in particular those with out-of-register antiparallel β-strands. The structurally very similar compound anle234b was previously identified as inactive by in vitro experiments. Here, we show that anle234b has no significant effect on the aggregation process in terms of reducing the β-structure content. Moreover, we demonstrate that the hydrogen bonding capabilities are autoinhibited due to steric effects imposed by the molecular geometry of anle234b and thereby indirectly confirm the proposed inhibitory mechanism of anle138b. We anticipate that the prominent binding of anle138b to partially disordered and dynamical aggregate structures is a generic basis for anle138b's ability to suppress toxic oligomer formation in a wide range of amyloidogenic peptides and proteins.
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Affiliation(s)
- Dirk Matthes
- Computational
Biomolecular Dynamics Group, Department of Theoretical and Computational
Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg
11, 37077 Göttingen, Germany
| | - Vytautas Gapsys
- Computational
Biomolecular Dynamics Group, Department of Theoretical and Computational
Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg
11, 37077 Göttingen, Germany
| | - Christian Griesinger
- Department
of Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Bert L. de Groot
- Computational
Biomolecular Dynamics Group, Department of Theoretical and Computational
Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg
11, 37077 Göttingen, Germany
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65
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Qian Z, Zhang Q, Liu Y, Chen P. Assemblies of amyloid-β30-36 hexamer and its G33V/L34T mutants by replica-exchange molecular dynamics simulation. PLoS One 2017; 12:e0188794. [PMID: 29186195 PMCID: PMC5706729 DOI: 10.1371/journal.pone.0188794] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/13/2017] [Indexed: 02/02/2023] Open
Abstract
The aggregation of amyloid-β peptides is associated with the pathogenesis of Alzheimer’s disease, in which the 30–36 fragments play an important part as a fiber-forming hydrophobic region. The fibrillar structure of Aβ30–36 has been detected by means of X-ray diffraction, but its oligomeric structural determination, biophysical characterization, and pathological mechanism remain elusive. In this study, we have investigated the structures of Aβ30–36 hexamer as well as its G33V and L34T mutants in explicit water environment using replica-exchange molecular dynamics (REMD) simulations. Our results show that the wild-type (WT) Aβ30–36 hexamer has a preference to form β-barrel and bilayer β-sheet conformations, while the G33V or L34T mutation disrupts the β-barrel structures: the G33V mutant is homogenized to adopt β-sheet-rich bilayers, and the structures of L34T mutant on the contrary get more diverse. The hydrophobic interaction plays a critical role in the formation and stability of oligomeric assemblies among all the three systems. In addition, the substitution of G33 by V reduces the β-sheet content in the most populated conformations of Aβ30–36 oligomers through a steric effect. The L34T mutation disturbs the interpeptide hydrogen bonding network, and results in the increased coil content and morphological diversity. Our REMD runs provide structural details of WT and G33V/L34T mutant Aβ30–36 oligomers, and molecular insight into the aggregation mechanism, which will be helpful for designing novel inhibitors or amyloid-based materials.
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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, China
- * E-mail: (ZQ); (PC)
| | - Qingwen Zhang
- College of Physical Education and Training, Shanghai University of Sport, Shanghai, China
| | - Yu Liu
- Key Laboratory of Exercise and Health Sciences (Ministry of Education) and School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Peijie Chen
- Key Laboratory of Exercise and Health Sciences (Ministry of Education) and School of Kinesiology, Shanghai University of Sport, Shanghai, China
- * E-mail: (ZQ); (PC)
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66
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Kandel N, Zheng T, Huo Q, Tatulian SA. Membrane Binding and Pore Formation by a Cytotoxic Fragment of Amyloid β Peptide. J Phys Chem B 2017; 121:10293-10305. [PMID: 29039658 DOI: 10.1021/acs.jpcb.7b07002] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amyloid β (Aβ) peptide contributes to Alzheimer's disease by a yet unidentified mechanism. In the brain tissue, Aβ occurs in various forms, including an undecapeptide Aβ25-35, which exerts a neurotoxic effect through the mitochondrial dysfunction and/or Ca2+-permeable pore formation in cell membranes. This work was aimed at the biophysical characterization of membrane binding and pore formation by Aβ25-35. Interaction of Aβ25-35 with anionic and zwitterionic membranes was analyzed by microelectrophoresis. In pore formation experiments, Aβ25-35 was incubated in aqueous buffer to form oligomers and added to Quin-2-loaded vesicles. Gradual increase in Quin-2 fluorescence was interpreted in terms of membrane pore formation by the peptide, Ca2+ influx, and binding to intravesicular Quin-2. The kinetics and magnitude of this process were used to evaluate the rate constant of pore formation, peptide-peptide association constants, and the oligomeric state of the pores. Decrease in membrane anionic charge and high ionic strength conditions significantly suppressed membrane binding and pore formation, indicating the importance of electrostatic interactions in these events. Circular dichroism spectroscopy showed that Aβ25-35 forms the most efficient pores in β-sheet conformation. The data are consistent with an oligo-oligomeric pore model composed of up to eight peptide units, each containing 6-8 monomers.
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Affiliation(s)
| | | | | | - Suren A Tatulian
- Department of Physics, University of Central Florida , Physical Sciences Bldg., Room 456, 4111 Libra Drive, Orlando, Florida 32816, United States
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67
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Ion mobility-mass spectrometry and orthogonal gas-phase techniques to study amyloid formation and inhibition. Curr Opin Struct Biol 2017; 46:7-15. [DOI: 10.1016/j.sbi.2017.03.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/28/2017] [Accepted: 03/03/2017] [Indexed: 11/24/2022]
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68
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Atomic structure of a toxic, oligomeric segment of SOD1 linked to amyotrophic lateral sclerosis (ALS). Proc Natl Acad Sci U S A 2017; 114:8770-8775. [PMID: 28760994 DOI: 10.1073/pnas.1705091114] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Fibrils and oligomers are the aggregated protein agents of neuronal dysfunction in ALS diseases. Whereas we now know much about fibril architecture, atomic structures of disease-related oligomers have eluded determination. Here, we determine the corkscrew-like structure of a cytotoxic segment of superoxide dismutase 1 (SOD1) in its oligomeric state. Mutations that prevent formation of this structure eliminate cytotoxicity of the segment in isolation as well as cytotoxicity of the ALS-linked mutants of SOD1 in primary motor neurons and in a Danio rerio (zebrafish) model of ALS. Cytotoxicity assays suggest that toxicity is a property of soluble oligomers, and not large insoluble aggregates. Our work adds to evidence that the toxic oligomeric entities in protein aggregation diseases contain antiparallel, out-of-register β-sheet structures and identifies a target for structure-based therapeutics in ALS.
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69
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Abstract
When assembling as fibrils Aβ40 peptides can only assume U-shaped conformations while Aβ42 can also arrange as S-shaped three-stranded chains. We show that this allows Aβ42 peptides to assemble pore-like structures that may explain their higher toxicity. For this purpose, we develop a scalable model of ring-like assemblies of S-shaped Aβ1-42 chains and study the stability and structural properties of these assemblies through atomistic molecular dynamics simulations. We find that the proposed arrangements are in size and symmetry compatible with experimentally observed Aβ assemblies. We further show that the interior pore in our models allows for water leakage as a possible mechanism of cell toxicity of Aβ42 amyloids.
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Affiliation(s)
- Wenhui Xi
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Ulrich H E Hansmann
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, 73019, USA.
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70
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Dorosh L, Stepanova M. Probing oligomerization of amyloid beta peptide in silico. MOLECULAR BIOSYSTEMS 2017; 13:165-182. [PMID: 27844078 DOI: 10.1039/c6mb00441e] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Aggregation of amyloid β (Aβ) peptide is implicated in fatal Alzheimer's disease, for which no cure is available. Understanding the mechanisms responsible for this aggregation is required in order for therapies to be developed. In an effort to better understand the molecular mechanisms involved in spontaneous aggregation of Aβ peptide, extensive molecular dynamics simulations are reported, and the results are analyzed through a combination of structural biology tools and a novel essential collective dynamics method. Several model systems composed of ten or twelve Aβ17-42 chains in water are investigated, and the influence of metal ions is probed. The results suggest that Aβ monomers tend to aggregate into stable globular-like oligomers with 13-23% of β-sheet content. Two stages of oligomer formation have been identified: quick collapse within the first 40 ns of the simulation, characterized by a decrease in inter-chain separation and build-up of β-sheets, and the subsequent slow relaxation of the oligomer structure. The resulting oligomers comprise a stable, coherently moving sub-aggregate of 6-9 strongly inter-correlated chains. Cu2+ and Fe2+ ions have been found to develop coordination bonds with carboxylate groups of E22, D23 and A42, which remain stable during 200 ns simulations. The presence of Fe2+, and particularly Cu2+ ions, in negatively charged cavities has been found to cause significant changes in the structure and dynamics of the oligomers. The results indicate, in particular, that formation of non-fibrillar oligomers might be involved in early template-free aggregation of Aβ17-42 monomers, with charged species such as Cu2+ or Fe2+ ions playing an important role.
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Affiliation(s)
- L Dorosh
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada. and National Research Council of Canada, Edmonton, Alberta, Canada
| | - M Stepanova
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada. and National Research Council of Canada, Edmonton, Alberta, Canada and Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, MO, USA
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71
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Zhang H, Xi W, Hansmann UHE, Wei Y. Fibril-Barrel Transitions in Cylindrin Amyloids. J Chem Theory Comput 2017; 13:3936-3944. [PMID: 28671829 DOI: 10.1021/acs.jctc.7b00383] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We introduce Replica-Exchange-with-Tunneling (RET) simulations as a tool for studies of the conversion between polymorphic amyloids. For the 11-residue amyloid-forming cylindrin peptide we show that this technique allows for a more efficient sampling of the formation and interconversion between fibril-like and barrel-like assemblies. We describe a protocol for optimized analysis of RET simulations that allows us to propose a mechanism for formation and interconversion between various cylindrin assemblies. Especially, we show that an interchain salt bridge between residues K3 and D7 is crucial for formation of the barrel structure.
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Affiliation(s)
- Huiling Zhang
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China
| | - Wenhui Xi
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.,Department of Chemistry & Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Ulrich H E Hansmann
- Department of Chemistry & Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Yanjie Wei
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China
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72
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Abstract
Previously published experimental studies have suggested that when the 40-residue amyloid beta peptide is encapsulated in a reverse micelle, it folds into a structure that may nucleate amyloid fibril formation (Yeung, P. S.-W.; Axelsen, P. H. J. Am. Chem. Soc. 2012, 134, 6061 ). The factors that induce the formation of this structure have now been identified in a multi-microsecond simulation of the same reverse micelle system that was studied experimentally. Key features of the polypeptide-micelle interaction include the anchoring of a hydrophobic residue cluster into gaps in the reverse micelle surface, the formation of a beta turn at the anchor point that brings N- and C-terminal segments of the polypeptide into proximity, high ionic strength that promotes intramolecular hydrogen bond formation, and deformation of the reverse micelle surface to facilitate interactions with the surface along the entire length of the polypeptide. Together, these features cause the simulation-derived vibrational spectrum to red shift in a manner that reproduces the red-shift previously reported experimentally. On the basis of these findings, a new mechanism is proposed whereby membranes nucleate fibril formation and facilitate the in-register alignment of polypeptide strands that is characteristic of amyloid fibrils.
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Affiliation(s)
- Gözde Eskici
- Department of Biochemistry & Biophysics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104, United States
| | - Paul H Axelsen
- Departments of Pharmacology, Biochemistry and Biophysics, and Medicine, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
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73
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Hayward S, Milner-White EJ. Geometrical principles of homomeric β-barrels and β-helices: Application to modeling amyloid protofilaments. Proteins 2017. [PMID: 28646497 DOI: 10.1002/prot.25341] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Examples of homomeric β-helices and β-barrels have recently emerged. Here we generalize the theory for the shear number in β-barrels to encompass β-helices and homomeric structures. We introduce the concept of the "β-strip," the set of parallel or antiparallel neighboring strands, from which the whole helix can be generated giving it n-fold rotational symmetry. In this context, the shear number is interpreted as the sum around the helix of the fixed register shift between neighboring identical β-strips. Using this approach, we have derived relationships between helical width, pitch, angle between strand direction and helical axis, mass per length, register shift, and number of strands. The validity and unifying power of the method is demonstrated with known structures including α-hemolysin, T4 phage spike, cylindrin, and the HET-s(218-289) prion. From reported dimensions measured by X-ray fiber diffraction on amyloid fibrils, the relationships can be used to predict the register shift and the number of strands within amyloid protofilaments. This was used to construct models of transthyretin and Alzheimer β(40) amyloid protofilaments that comprise a single strip of in-register β-strands folded into a "β-strip helix." Results suggest both stabilization of an individual β-strip helix and growth by addition of further β-strip helices can involve the same pair of sequence segments associating with β-sheet hydrogen bonding at the same register shift. This process would be aided by a repeat sequence. Hence, understanding how the register shift (as the distance between repeat sequences) relates to helical dimensions will be useful for nanotube design.
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Affiliation(s)
- Steven Hayward
- D'Arcy Thompson Centre for Computational Biology, School of Computing Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - E James Milner-White
- College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
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74
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Salveson PJ, Spencer RK, Kreutzer AG, Nowick JS. X-ray Crystallographic Structure of a Compact Dodecamer from a Peptide Derived from Aβ 16-36. Org Lett 2017; 19:3462-3465. [PMID: 28683555 DOI: 10.1021/acs.orglett.7b01445] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The assembly of the β-amyloid peptide, Aβ, into soluble oligomers is associated with neurodegeneration in Alzheimer's disease. The Aβ oligomers are thought to be composed of β-hairpins. Here, the effect of shifting the residue pairing of the β-hairpins on the structures of the oligomers that form is explored through X-ray crystallography. Three residue pairings were investigated using constrained macrocyclic β-hairpins in which Aβ30-36 is juxtaposed with Aβ17-23, Aβ16-22, and Aβ15-21. The Aβ16-22-Aβ30-36 pairing forms a compact ball-shaped dodecamer composed of fused triangular trimers. This dodecamer may help explain the structures of the trimers and dodecamers formed by full-length Aβ.
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Affiliation(s)
- Patrick J Salveson
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - Ryan K Spencer
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - Adam G Kreutzer
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - James S Nowick
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
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75
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76
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Bleiholder C, Bowers MT. The Solution Assembly of Biological Molecules Using Ion Mobility Methods: From Amino Acids to Amyloid β-Protein. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2017; 10:365-386. [PMID: 28375705 PMCID: PMC6287953 DOI: 10.1146/annurev-anchem-071114-040304] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Ion mobility spectrometry-mass spectrometry (IMS-MS) methods are increasingly used to study noncovalent assemblies of peptides and proteins. This review focuses on the noncovalent self-assembly of amino acids and peptides, systems at the heart of the amyloid process that play a central role in a number of devastating diseases. Three different systems are discussed in detail: the 42-residue peptide amyloid-β42 implicated in the etiology of Alzheimer's disease, several amyloid-forming peptides with 6-11 residues, and the assembly of individual amino acids. We also discuss from a more fundamental perspective the processes that determine how quickly proteins and their assemblies denature when the analyte ion has been stripped of its solvent in an IMS-MS measurement and how to soften the measurement so that biologically meaningful data can be recorded.
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Affiliation(s)
- Christian Bleiholder
- Department of Chemistry and Biochemistry, Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306;
| | - Michael T Bowers
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
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77
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Wang L, Ilitchev AI, Giammona MJ, Li F, Buratto SK, Bowers MT. Human Islet Amyloid Polypeptide Assembly: The Key Role of the 8–20 Fragment. J Phys Chem B 2016; 120:11905-11911. [DOI: 10.1021/acs.jpcb.6b09475] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Li Wang
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
- State
Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, P. R. China
| | - Alexandre I. Ilitchev
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Maxwell J. Giammona
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Fei Li
- State
Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, P. R. China
| | - Steven K. Buratto
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Michael T. Bowers
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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78
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Breydo L, Redington JM, Uversky VN. Effects of Intrinsic and Extrinsic Factors on Aggregation of Physiologically Important Intrinsically Disordered Proteins. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 329:145-185. [PMID: 28109327 DOI: 10.1016/bs.ircmb.2016.08.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Misfolding and aggregation of proteins and peptides play an important role in a number of diseases as well as in many physiological processes. Many of the proteins that misfold and aggregate in vivo are intrinsically disordered. Protein aggregation is a complex multistep process, and aggregates can significantly differ in morphology, structure, stability, cytotoxicity, and self-propagation ability. The aggregation process is influenced by both intrinsic (e.g., mutations and expression levels) and extrinsic (e.g., polypeptide chain truncation, macromolecular crowding, posttranslational modifications, as well as interaction with metal ions, other small molecules, lipid membranes, and chaperons) factors. This review examines the effect of a variety of these factors on aggregation of physiologically important intrinsically disordered proteins.
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Affiliation(s)
- L Breydo
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.
| | - J M Redington
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - V N Uversky
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States; Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.
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79
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Truex NL, Wang Y, Nowick JS. Assembly of Peptides Derived from β-Sheet Regions of β-Amyloid. J Am Chem Soc 2016; 138:13882-13890. [PMID: 27642651 PMCID: PMC5089065 DOI: 10.1021/jacs.6b06000] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
![]()
In
Alzheimer’s disease, aggregation of the β-amyloid
peptide (Aβ) results in the formation of oligomers and fibrils
that are associated with neurodegeneration. Aggregation of Aβ
occurs through interactions between different regions of the peptide.
This paper and the accompanying paper constitute a two-part investigation
of two key regions of Aβ: the central region and the C-terminal
region. These two regions promote aggregation and adopt β-sheet
structure in the fibrils, and may also do so in the oligomers. In
this paper, we study the assembly of macrocyclic β-sheet peptides
that contain residues 17–23 (LVFFAED) from the central region
and residues 30–36 (AIIGLMV) from the C-terminal region. These
peptides assemble to form tetramers. Each tetramer consists of two
hydrogen-bonded dimers that pack through hydrophobic interactions
in a sandwich-like fashion. Incorporation of a single 15N isotopic label into each peptide provides a spectroscopic probe
with which to elucidate the β-sheet assembly and interaction: 1H,15N HSQC studies facilitate the identification
of the monomers and tetramers; 15N-edited NOESY studies
corroborate the pairing of the dimers within the tetramers. In the
following paper, J. Am. Chem. Soc.2016, DOI: 10.1021/jacs.6b06001, we will extend these studies to elucidate the coassembly of the
peptides to form heterotetramers.
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Affiliation(s)
- Nicholas L Truex
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - Yilin Wang
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - James S Nowick
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
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80
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Bonner JG, Hendricks NG, Julian RR. Structural Effects of Solvation by 18-Crown-6 on Gaseous Peptides and TrpCage after Electrospray Ionization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1661-1669. [PMID: 27506205 DOI: 10.1007/s13361-016-1456-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 06/28/2016] [Accepted: 06/30/2016] [Indexed: 06/06/2023]
Abstract
Significant effort is being employed to utilize the inherent speed and sensitivity of mass spectrometry for rapid structural determination of proteins; however, a thorough understanding of factors influencing the transition from solution to gas phase is critical for correct interpretation of the results from such experiments. It was previously shown that combined use of action excitation energy transfer (EET) and simulated annealing can reveal detailed structural information about gaseous peptide ions. Herein, we utilize this method to study microsolvation of charged groups by retention of 18-crown-6 (18C6) in the gas phase. In the case of GTP (CEGNVRVSRE LAGHTGY), solvation of the 2+ charge state leads to reduced EET, whereas the opposite result is obtained for the 3+ ion. For the mini-protein C-Trpcage, solvation by 18C6 leads to dramatic increase in EET for the 3+ ion. Examination of structural details probed by molecular dynamics calculations illustrate that solvation by 18C6 alleviates the tendency of charged side chains to seek intramolecular solvation, potentially preserving native-like structures in the gas phase. These results suggest that microsolvation may be an important tool for facilitating examination of native-like protein structures in gas phase experiments. Graphical Abstract ᅟ.
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Affiliation(s)
- James G Bonner
- Department of Chemistry, University of California, Riverside, CA, 92521, USA
| | - Nathan G Hendricks
- Department of Chemistry, University of California, Riverside, CA, 92521, USA
| | - Ryan R Julian
- Department of Chemistry, University of California, Riverside, CA, 92521, USA.
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81
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Breydo L, Kurouski D, Rasool S, Milton S, Wu JW, Uversky VN, Lednev IK, Glabe CG. Structural differences between amyloid beta oligomers. Biochem Biophys Res Commun 2016; 477:700-705. [PMID: 27363332 PMCID: PMC11247950 DOI: 10.1016/j.bbrc.2016.06.122] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 12/14/2022]
Abstract
In Alzheimer's disease, soluble Aβ oligomers are believed to play important roles in the disease pathogenesis, and their levels correlate with cognitive impairment. We have previously shown that Aβ oligomers can be categorized into multiple structural classes based on their reactivity with conformation-dependent antibodies. In this study, we analyzed the structures of Aβ40 oligomers belonging to two of these classes: fibrillar and prefibrillar oligomers. We found that fibrillar oligomers were similar in structure to fibrils but were less stable towards denaturation while prefibrillar oligomers were found to be partially disordered. These results are consistent with previously proposed structures for both oligomer classes while providing additional structural information.
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Affiliation(s)
- Leonid Breydo
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, United States; Department of Molecular Medicine and Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33612, United States.
| | - Dmitry Kurouski
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, Albany, NY 12222, United States
| | - Suhail Rasool
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, United States
| | - Saskia Milton
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, United States
| | - Jessica W Wu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, United States
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33612, United States; Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Igor K Lednev
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, Albany, NY 12222, United States
| | - Charles G Glabe
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, United States; Biochemistry Department, Faculty of Science and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
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82
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Chiricotto M, Tran TT, Nguyen PH, Melchionna S, Sterpone F, Derreumaux P. Coarse-grained and All-atom Simulations towards the Early and Late Steps of Amyloid Fibril Formation. Isr J Chem 2016. [DOI: 10.1002/ijch.201600048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Mara Chiricotto
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Thanh Thuy Tran
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Phuong H. Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Simone Melchionna
- Istituto Sistemi Complessi; Consiglio Nazionale delle Ricerche; P. le A. Moro 2 00185 Rome Italy
| | - Fabio Sterpone
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
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83
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Abedini A, Plesner A, Cao P, Ridgway Z, Zhang J, Tu LH, Middleton CT, Chao B, Sartori DJ, Meng F, Wang H, Wong AG, Zanni MT, Verchere CB, Raleigh DP, Schmidt AM. Time-resolved studies define the nature of toxic IAPP intermediates, providing insight for anti-amyloidosis therapeutics. eLife 2016; 5. [PMID: 27213520 PMCID: PMC4940161 DOI: 10.7554/elife.12977] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 05/20/2016] [Indexed: 01/04/2023] Open
Abstract
Islet amyloidosis by IAPP contributes to pancreatic β-cell death in diabetes, but the nature of toxic IAPP species remains elusive. Using concurrent time-resolved biophysical and biological measurements, we define the toxic species produced during IAPP amyloid formation and link their properties to induction of rat INS-1 β-cell and murine islet toxicity. These globally flexible, low order oligomers upregulate pro-inflammatory markers and induce reactive oxygen species. They do not bind 1-anilnonaphthalene-8-sulphonic acid and lack extensive β-sheet structure. Aromatic interactions modulate, but are not required for toxicity. Not all IAPP oligomers are toxic; toxicity depends on their partially structured conformational states. Some anti-amyloid agents paradoxically prolong cytotoxicity by prolonging the lifetime of the toxic species. The data highlight the distinguishing properties of toxic IAPP oligomers and the common features that they share with toxic species reported for other amyloidogenic polypeptides, providing information for rational drug design to treat IAPP induced β-cell death. DOI:http://dx.doi.org/10.7554/eLife.12977.001
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Affiliation(s)
- Andisheh Abedini
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Annette Plesner
- Child and Family Research Institute, Department of Pathology and Laboratory Medicine and Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Ping Cao
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Zachary Ridgway
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Jinghua Zhang
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Ling-Hsien Tu
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Chris T Middleton
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | - Brian Chao
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Daniel J Sartori
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Fanling Meng
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Hui Wang
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Amy G Wong
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | - C Bruce Verchere
- Child and Family Research Institute, Department of Pathology and Laboratory Medicine and Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Daniel P Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Ann Marie Schmidt
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
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84
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Salveson PJ, Spencer RK, Nowick JS. X-ray Crystallographic Structure of Oligomers Formed by a Toxic β-Hairpin Derived from α-Synuclein: Trimers and Higher-Order Oligomers. J Am Chem Soc 2016; 138:4458-67. [PMID: 26926877 PMCID: PMC4825732 DOI: 10.1021/jacs.5b13261] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
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Oligomeric
assemblies of the protein α-synuclein are thought
to cause neurodegeneration in Parkinson’s disease and related
synucleinopathies. Characterization of α-synuclein oligomers
at high resolution is an outstanding challenge in the field of structural
biology. The absence of high-resolution structures of oligomers formed
by α-synuclein impedes understanding the synucleinopathies at
the molecular level. This paper reports the X-ray crystallographic
structure of oligomers formed by a peptide derived from residues 36–55
of α-synuclein. The peptide 1a adopts a β-hairpin
structure, which assembles in a hierarchical fashion. Three β-hairpins
assemble to form a triangular trimer. Three copies of the triangular
trimer assemble to form a basket-shaped nonamer. Two nonamers pack
to form an octadecamer. Molecular modeling suggests that full-length
α-synuclein may also be able to assemble in this fashion. Circular
dichroism spectroscopy demonstrates that peptide 1a interacts
with anionic lipid bilayer membranes, like oligomers of full-length
α-synuclein. LDH and MTT assays demonstrate that peptide 1a is toxic toward SH-SY5Y cells. Comparison of peptide 1a to homologues suggests that this toxicity results from
nonspecific interactions with the cell membrane. The oligomers formed
by peptide 1a are fundamentally different than the proposed
models of the fibrils formed by α-synuclein and suggest that
α-Syn36–55, rather than the NAC, may nucleate
oligomer formation.
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Affiliation(s)
- Patrick J Salveson
- Department of Chemistry, University of California Irvine , Irvine, California 92697-2025, United States
| | - Ryan K Spencer
- Department of Chemistry, University of California Irvine , Irvine, California 92697-2025, United States
| | - James S Nowick
- Department of Chemistry, University of California Irvine , Irvine, California 92697-2025, United States
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