1
|
Salaikumaran M, Gopal PP. Rational Design of TDP-43 Derived α-Helical Peptide Inhibitors: An In Silico Strategy to Prevent TDP-43 Aggregation in Neurodegenerative Disorders. ACS Chem Neurosci 2024; 15:1096-1109. [PMID: 38466778 PMCID: PMC10959110 DOI: 10.1021/acschemneuro.3c00659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 01/21/2024] [Accepted: 02/19/2024] [Indexed: 03/13/2024] Open
Abstract
TDP-43, an essential RNA/DNA-binding protein, is central to the pathology of neurodegenerative diseases, such as amyotrophic lateral sclerosis and frontotemporal dementia. Pathological mislocalization and aggregation of TDP-43 disrupt RNA splicing, mRNA stability, and mRNA transport, thereby impairing neuronal function and survival. The formation of amyloid-like TDP-43 filaments is largely facilitated by the destabilization of an α-helical segment within the disordered C-terminal region. In this study, we hypothesized that preventing the destabilization of the α-helical domain could potentially halt the growth of these pathological filaments. To explore this, we utilized a range of in silico techniques to design and evaluate peptide-based therapeutics that bind to pathological TDP-43 amyloid-like filament crystal structures and resist β sheet conversion. Our computational approaches, including biophysical and secondary structure property prediction, molecular docking, 3D structure prediction, and molecular dynamics simulations, were used to assess the structure, stability, and binding affinity of these peptides in relation to pathological TDP-43 filaments. The results of our in silico analyses identified a selection of promising peptides which displayed a stable α-helical structure, exhibited an increased number of intramolecular hydrogen bonds within the helical domain, and demonstrated high binding affinities for pathological TDP-43 amyloid-like filaments. Molecular dynamics simulations provided further support for the structural and thermodynamic stability of these peptides, as they exhibited lower root-mean-square deviation and more favorable free energy landscapes over 300 ns. These findings establish α-helical propensity peptides as potential lead molecules for the development of novel therapeutics against TDP-43 aggregation. This structure-based computational approach for the rational design of peptide inhibitors opens a new direction in the search for effective interventions for ALS, FTD, and other related neurodegenerative diseases. The peptides identified as the most promising candidates in this study are currently subject to further testing and validation through both in vitro and in vivo experiments.
Collapse
Affiliation(s)
- Muthu
Raj Salaikumaran
- Department
of Pathology, Yale School of Medicine, New Haven, Connecticut 06520, United States
| | - Pallavi P. Gopal
- Department
of Pathology, Yale School of Medicine, New Haven, Connecticut 06520, United States
- Program
in Cellular Neuroscience, Neurodegeneration, and Repair, Yale School of Medicine, New Haven, Connecticut 06520-8055, United States
| |
Collapse
|
2
|
Singh BP, Morris RJ, Kunath T, MacPhee CE, Horrocks MH. Lipid-induced polymorphic amyloid fibril formation by α-synuclein. Protein Sci 2023; 32:e4736. [PMID: 37515406 PMCID: PMC10521247 DOI: 10.1002/pro.4736] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 06/27/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023]
Abstract
Many proteins that self-assemble into amyloid and amyloid-like fibers can adopt diverse polymorphic forms. These forms have been observed both in vitro and in vivo and can arise through variations in the steric-zipper interactions between β-sheets, variations in the arrangements between protofilaments, and differences in the number of protofilaments that make up a given fiber class. Different polymorphs arising from the same precursor molecule not only exhibit different levels of toxicity, but importantly can contribute to different disease conditions. However, the factors which contribute to formation of polymorphic forms of amyloid fibrils are not known. In this work, we show that in the presence of 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine, a highly abundant lipid in the plasma membrane of neurons, the aggregation of α-synuclein is markedly accelerated and yields a diversity of polymorphic forms under identical experimental conditions. This morphological diversity includes thin and curly fibrils, helical ribbons, twisted ribbons, nanotubes, and flat sheets. Furthermore, the amyloid fibrils formed incorporate lipids into their structures, which corroborates the previous report of the presence of α-synuclein fibrils with high lipid content in Lewy bodies. Thus, the present study demonstrates that an interface, such as that provided by a lipid membrane, can not only modulate the kinetics of α-synuclein amyloid aggregation but also plays an important role in the formation of morphological variants by incorporating lipid molecules in the process of amyloid fibril formation.
Collapse
Affiliation(s)
- Bhanu P. Singh
- School of Physics and Astronomy, The University of EdinburghEdinburghUK
- EaStCHEM School of Chemistry, The University of EdinburghEdinburghUK
| | - Ryan J. Morris
- School of Physics and Astronomy, The University of EdinburghEdinburghUK
| | - Tilo Kunath
- Centre for Regenerative Medicine, School of Biological Sciences, The University of EdinburghEdinburghUK
| | - Cait E. MacPhee
- School of Physics and Astronomy, The University of EdinburghEdinburghUK
| | - Mathew H. Horrocks
- EaStCHEM School of Chemistry, The University of EdinburghEdinburghUK
- IRR Chemistry Hub, Institute for Regeneration and Repair, The University of EdinburghEdinburghUK
| |
Collapse
|
3
|
New Insights into the Molecular Interplay between Human Herpesviruses and Alzheimer’s Disease—A Narrative Review. Brain Sci 2022; 12:brainsci12081010. [PMID: 36009073 PMCID: PMC9406069 DOI: 10.3390/brainsci12081010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/24/2022] [Accepted: 07/28/2022] [Indexed: 12/15/2022] Open
Abstract
Human herpesviruses (HHVs) have been implicated as possible risk factors in Alzheimer’s disease (AD) pathogenesis. Persistent lifelong HHVs infections may directly or indirectly contribute to the generation of AD hallmarks: amyloid beta (Aβ) plaques, neurofibrillary tangles composed of hyperphosphorylated tau proteins, and synaptic loss. The present review focuses on summarizing current knowledge on the molecular mechanistic links between HHVs and AD that include processes involved in Aβ accumulation, tau protein hyperphosphorylation, autophagy, oxidative stress, and neuroinflammation. A PubMed search was performed to collect all the available research data regarding the above mentioned mechanistic links between HHVs and AD pathology. The vast majority of research articles referred to the different pathways exploited by Herpes Simplex Virus 1 that could lead to AD pathology, while a few studies highlighted the emerging role of HHV 6, cytomegalovirus, and Epstein–Barr Virus. The elucidation of such potential links may guide the development of novel diagnostics and therapeutics to counter this devastating neurological disorder that until now remains incurable.
Collapse
|
4
|
Puławski W, Dzwolak W. Virtual Quasi-2D Intermediates as Building Blocks for Plausible Structural Models of Amyloid Fibrils from Proteins with Complex Topologies: A Case Study of Insulin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7024-7034. [PMID: 35617668 PMCID: PMC9178918 DOI: 10.1021/acs.langmuir.2c00699] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/08/2022] [Indexed: 06/15/2023]
Abstract
Conformational transitions of globular proteins into amyloid fibrils are complex multistage processes exceedingly challenging to simulate using molecular dynamics (MD). Slow monomer diffusion rates and rugged free energy landscapes disfavor swift self-assembly of orderly amyloid architectures within timescales accessible to all-atom MD. Here, we conduct a multiscale MD study of the amyloidogenic self-assembly of insulin: a small protein with a complex topology defined by two polypeptide chains interlinked by three disulfide bonds. To avoid kinetic traps, unconventional preplanarized insulin conformations are used as amyloid building blocks. These starting conformers generated through uniaxial compression of the native monomer in various spatial directions represent 6 distinct (out of 16 conceivable) two-dimensional (2D) topological classes varying in N-/C-terminal segments of insulin's A- and B-chains being placed inside or outside of the central loop constituted by the middle sections of both chains and Cys7A-Cys7B/Cys19B-Cys20A disulfide bonds. Simulations of the fibrillar self-assembly are initiated through a biased in-register alignment of two, three, or four layers of flat conformers belonging to a single topological class. The various starting topologies are conserved throughout the self-assembly process resulting in polymorphic amyloid fibrils varying in structural features such as helical twist, presence of cavities, and overall stability. Some of the protofilament structures obtained in this work are highly compatible with the earlier biophysical studies on insulin amyloid and high-resolution studies on insulin-derived amyloidogenic peptide models postulating the presence of steric zippers. Our approach provides in silico means to study amyloidogenic tendencies and viable amyloid architectures of larger disulfide-constrained proteins with complex topologies.
Collapse
Affiliation(s)
- Wojciech Puławski
- Institute
of High Pressure Physics, Polish Academy
of Sciences, 29/37 Sokołowska
Str., 01-142 Warsaw, Poland
| | - Wojciech Dzwolak
- Institute
of High Pressure Physics, Polish Academy
of Sciences, 29/37 Sokołowska
Str., 01-142 Warsaw, Poland
- Faculty
of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str., 02-093 Warsaw, Poland
| |
Collapse
|
5
|
Taylor AIP, Staniforth RA. General Principles Underpinning Amyloid Structure. Front Neurosci 2022; 16:878869. [PMID: 35720732 PMCID: PMC9201691 DOI: 10.3389/fnins.2022.878869] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/11/2022] [Indexed: 12/14/2022] Open
Abstract
Amyloid fibrils are a pathologically and functionally relevant state of protein folding, which is generally accessible to polypeptide chains and differs fundamentally from the globular state in terms of molecular symmetry, long-range conformational order, and supramolecular scale. Although amyloid structures are challenging to study, recent developments in techniques such as cryo-EM, solid-state NMR, and AFM have led to an explosion of information about the molecular and supramolecular organization of these assemblies. With these rapid advances, it is now possible to assess the prevalence and significance of proposed general structural features in the context of a diverse body of high-resolution models, and develop a unified view of the principles that control amyloid formation and give rise to their unique properties. Here, we show that, despite system-specific differences, there is a remarkable degree of commonality in both the structural motifs that amyloids adopt and the underlying principles responsible for them. We argue that the inherent geometric differences between amyloids and globular proteins shift the balance of stabilizing forces, predisposing amyloids to distinct molecular interaction motifs with a particular tendency for massive, lattice-like networks of mutually supporting interactions. This general property unites previously characterized structural features such as steric and polar zippers, and contributes to the long-range molecular order that gives amyloids many of their unique properties. The shared features of amyloid structures support the existence of shared structure-activity principles that explain their self-assembly, function, and pathogenesis, and instill hope in efforts to develop broad-spectrum modifiers of amyloid function and pathology.
Collapse
|
6
|
Lattanzi V, André I, Gasser U, Dubackic M, Olsson U, Linse S. Amyloid β 42 fibril structure based on small-angle scattering. Proc Natl Acad Sci U S A 2021; 118:e2112783118. [PMID: 34815346 PMCID: PMC8640717 DOI: 10.1073/pnas.2112783118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2021] [Indexed: 01/30/2023] Open
Abstract
Amyloid fibrils are associated with a number of neurodegenerative diseases, including fibrils of amyloid β42 peptide (Aβ42) in Alzheimer's disease. These fibrils are a source of toxicity to neuronal cells through surface-catalyzed generation of toxic oligomers. Detailed knowledge of the fibril structure may thus facilitate therapeutic development. We use small-angle scattering to provide information on the fibril cross-section dimension and shape for Aβ42 fibrils prepared in aqueous phosphate buffer at pH = 7.4 and pH 8.0 under quiescent conditions at 37 °C from pure recombinant Aβ42 peptide. Fitting the data using a continuum model reveals an elliptical cross-section and a peptide mass-per-unit length compatible with two filaments of two monomers, four monomers per plane. To provide a more detailed atomistic model, the data were fitted using as a starting state a high-resolution structure of the two-monomer arrangement in filaments from solid-state NMR (Protein Data Bank ID 5kk3). First, a twofold symmetric model including residues 11 to 42 of two monomers in the filament was optimized in terms of twist angle and local packing using Rosetta. A two-filament model was then built and optimized through fitting to the scattering data allowing the two N-termini in each filament to take different conformations, with the same conformation in each of the two filaments. This provides an atomistic model of the fibril with twofold rotation symmetry around the fibril axis. Intriguingly, no polydispersity as regards the number of filaments was observed in our system over separate samples, suggesting that the two-filament arrangement represents a free energy minimum for the Aβ42 fibril.
Collapse
Affiliation(s)
- Veronica Lattanzi
- Biochemistry and Structural Biology, Lund University, SE-22100 Lund, Sweden;
- Division of Physical Chemistry, Lund University, SE-22100 Lund, Sweden
| | - Ingemar André
- Biochemistry and Structural Biology, Lund University, SE-22100 Lund, Sweden
| | - Urs Gasser
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Marija Dubackic
- Biochemistry and Structural Biology, Lund University, SE-22100 Lund, Sweden
- Division of Physical Chemistry, Lund University, SE-22100 Lund, Sweden
| | - Ulf Olsson
- Division of Physical Chemistry, Lund University, SE-22100 Lund, Sweden
| | - Sara Linse
- Biochemistry and Structural Biology, Lund University, SE-22100 Lund, Sweden
| |
Collapse
|
7
|
Matuszyk MM, Garwood CJ, Ferraiuolo L, Simpson JE, Staniforth RA, Wharton SB. Biological and methodological complexities of beta-amyloid peptide: Implications for Alzheimer's disease research. J Neurochem 2021; 160:434-453. [PMID: 34767256 DOI: 10.1111/jnc.15538] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/29/2021] [Accepted: 11/09/2021] [Indexed: 01/01/2023]
Abstract
Although controversial, the amyloid cascade hypothesis remains central to the Alzheimer's disease (AD) field and posits amyloid-beta (Aβ) as the central factor initiating disease onset. In recent years, there has been an increase in emphasis on studying the role of low molecular weight aggregates, such as oligomers, which are suggested to be more neurotoxic than fibrillary Aβ. Other Aβ isoforms, such as truncated Aβ, have also been implicated in disease. However, developing a clear understanding of AD pathogenesis has been hampered by the complexity of Aβ biochemistry in vitro and in vivo. This review explores factors contributing to the lack of consistency in experimental approaches taken to model Aβ aggregation and toxicity and provides an overview of the different techniques available to analyse Aβ, such as electron and atomic force microscopy, nuclear magnetic resonance spectroscopy, dye-based assays, size exclusion chromatography, mass spectrometry and SDS-PAGE. The review also explores how different types of Aβ can influence Aβ aggregation and toxicity, leading to variation in experimental outcomes, further highlighting the need for standardisation in Aβ preparations and methods used in current research.
Collapse
Affiliation(s)
- Martyna M Matuszyk
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Claire J Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Laura Ferraiuolo
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | | | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| |
Collapse
|
8
|
Das A. Systematic Search for a Predictor for the Clinical Observables of Alzheimer's Disease. J Phys Chem B 2021; 125:12177-12186. [PMID: 34723517 DOI: 10.1021/acs.jpcb.1c06725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
One of the prevailing life-threatening incurable neurodegenerative diseases that are presently endangering human society as a whole, and hence, baffling the entire spectrum of the scientific and pharmaceutical world, is Alzheimer's disease (AD). AD is a manifestation of self-assembly of both wild-type (sporadic) and mutated (familial) forms of the amyloid-β peptide, a proteolytic product of the amyloid precursor protein, where the self-assembly results in the genesis of pathogenic fibrillar aggregates. Currently prevailing diagnostic and hence therapeutic challenges originate from the unavailability of a specific predictor for clinical observables. The continuous emergence of novel pathogenic mutants with unpredictable phenotypes adds immensely to the nonspecific nature of the problem. The current research reports a simple physical parameter, the binding affinity of a protofilament to its protofibril, which predicts the clinical observables of familial AD with astounding accuracy and more importantly, without any adjustable parameters.
Collapse
Affiliation(s)
- Atanu Das
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra 411 008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
9
|
Saffari B, Amininasab M. Crocin Inhibits the Fibrillation of Human α-synuclein and Disassembles Mature Fibrils: Experimental Findings and Mechanistic Insights from Molecular Dynamics Simulation. ACS Chem Neurosci 2021; 12:4037-4057. [PMID: 34636232 DOI: 10.1021/acschemneuro.1c00379] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The aggregation of human alpha-synuclein (hαS) is pivotally implicated in the development of most types of synucleinopathies. Molecules that can inhibit or reverse the aggregation process of amyloidogenic proteins have potential therapeutic value. The anti-aggregating activity of multiple carotenoid compounds has been reported over the past decades against a growing list of amyloidogenic polypeptides. Here, we aimed to determine whether crocin, the main carotenoid glycoside component of saffron, would inhibit hαS aggregation or could disassemble its preformed fibrils. By employing a series of biochemical and biophysical techniques, crocin was exhibited to inhibit hαS fibrillation in a dose-dependent fashion by stabilizing very early aggregation intermediates in off-pathway non-toxic conformations with little β-sheet content. We also observed that crocin at high concentrations could efficiently destabilize mature fibrils and disassemble them into seeding-incompetent intermediates by altering their β-sheet conformation and reshaping their structure. Our atomistic molecular dynamics (MD) simulations demonstrated that crocin molecules bind to both the non amyloid-β component (NAC) region and C-terminal domain of hαS. These interactions could thereby stabilize the autoinhibitory conformation of the protein and prevent it from adopting aggregation-prone structures. MD simulations further suggested that ligand molecules prefer to reside longitudinally along the fibril axis onto the edges of the inter-protofilament interface where they establish hydrogen and hydrophobic bonds with steric zipper stabilizing residues. These interactions turned out to destabilize hαS fibrils by altering the interstrand twist angles, increasing the rigidity of the fibril core, and elevating its radius of gyration. Our findings suggest the potential pharmaceutical implication of crocin in synucleinopathies.
Collapse
Affiliation(s)
- Babak Saffari
- Department of Cell and Molecular Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6455, Iran
| | - Mehriar Amininasab
- Department of Cell and Molecular Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6455, Iran
| |
Collapse
|
10
|
Irizarry BA, Davis J, Zhu X, Boon BDC, Rozemuller AJM, Van Nostrand WE, Smith SO. Human cerebral vascular amyloid contains both antiparallel and parallel in-register Aβ40 fibrils. J Biol Chem 2021; 297:101259. [PMID: 34599967 PMCID: PMC8528725 DOI: 10.1016/j.jbc.2021.101259] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 09/19/2021] [Accepted: 09/27/2021] [Indexed: 01/02/2023] Open
Abstract
The accumulation of fibrillar amyloid-β (Aβ) peptides alongside or within the cerebral vasculature is the hallmark of cerebral amyloid angiopathy (CAA). This condition commonly co-occurs with Alzheimer's disease (AD) and leads to cerebral microbleeds, intracranial hemorrhages, and stroke. CAA also occurs sporadically in an age-dependent fashion and can be accelerated by the presence of familial Aβ mutant peptides. Recent studies using Fourier transform infrared (FTIR) spectroscopy of vascular Aβ fibrils derived from rodents containing the double E22Q/D23N mutations indicated the presence of a novel antiparallel β-sheet structure. To address whether this structure is associated solely with the familial mutations or is a common feature of CAA, we propagated Aβ fibrils from human brain vascular tissue of patients diagnosed with nonfamilial CAA. Aβ fibrils were isolated from cerebral blood vessels using laser capture microdissection in which specific amyloid deposits were removed from thin slices of the brain tissue. Transmission electron microscopy revealed that these deposits were organized into a tight meshwork of fibrils, which FTIR measurements showed could serve as seeds to propagate the growth of Aβ40 fibrils for structural studies. Solid-state NMR measurements of the fibrils propagated from vascular amyloid showed they contained a mixture of parallel, in-register, and antiparallel β-sheet structures. The presence of fibrils with antiparallel structure derived from vascular amyloid is distinct from the typical parallel, in-register β-sheet structure that appears in fibrils derived from parenchymal amyloid in AD. These observations reveal that different microenvironments influence the structures of Aβ fibrils in the human brain.
Collapse
Affiliation(s)
- Brandon A Irizarry
- Center for Structural Biology, Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, USA
| | - Judianne Davis
- George and Anne Ryan Institute for Neuroscience, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Xiaoyue Zhu
- George and Anne Ryan Institute for Neuroscience, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Baayla D C Boon
- Department of Neurology, Alzheimer Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - VUmc, Amsterdam, the Netherlands; Department of Pathology, Alzheimer Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - VUmc, Amsterdam, the Netherlands
| | - Annemieke J M Rozemuller
- Department of Pathology, Alzheimer Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - VUmc, Amsterdam, the Netherlands
| | - William E Van Nostrand
- George and Anne Ryan Institute for Neuroscience, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Steven O Smith
- Center for Structural Biology, Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, USA.
| |
Collapse
|
11
|
Peccati F, Sodupe M. Atomistic insights into the structure of heptapeptide nanofibers. J Chem Phys 2021; 155:055101. [PMID: 34364337 DOI: 10.1063/5.0048988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Artificial amyloid-like nanofibers formed from short peptides are emerging as new supramolecular structures for catalysis and advanced materials. In this work, we analyze, by means of computational approaches, the preferred atomistic fibrillar architectures that result from the self-assembly of polar NY7, NF7, SY7, SF7, and GY7 peptides into steric zippers formed by two β-sheets (describing an individual steric zipper) and by four β-sheets. For all heptapeptides, except GY7, parallel β-sheet organizations with polar residues packed at the steric zipper appear to be the preferred assemblies for the two β-sheets system due to the formation of a strong network of hydrogen bonds. For GY7, however, an antiparallel organization with glycine at the steric zipper is the most stable one. The preferred architecture is mostly conserved when enlarging our model from two to four β-sheets. The present work shows that the relative stability of different architectures results from a delicate balance between peptide composition, side chain hydrophobicity, and non-covalent interactions at the interface and provides the basis for a rational design of new improved artificial prion-inspired materials.
Collapse
Affiliation(s)
- Francesca Peccati
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
| | - Mariona Sodupe
- Departament de Química, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| |
Collapse
|
12
|
Ma YW, Lin TY, Tsai MY. Fibril Surface-Dependent Amyloid Precursors Revealed by Coarse-Grained Molecular Dynamics Simulation. Front Mol Biosci 2021; 8:719320. [PMID: 34422910 PMCID: PMC8378332 DOI: 10.3389/fmolb.2021.719320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/26/2021] [Indexed: 01/05/2023] Open
Abstract
Amyloid peptides are known to self-assemble into larger aggregates that are linked to the pathogenesis of many neurodegenerative disorders. In contrast to primary nucleation, recent experimental and theoretical studies have shown that many toxic oligomeric species are generated through secondary processes on a pre-existing fibrillar surface. Nucleation, for example, can also occur along the surface of a pre-existing fibril—secondary nucleation—as opposed to the primary one. However, explicit pathways are still not clear. In this study, we use molecular dynamics simulation to explore the free energy landscape of a free Abeta monomer binding to an existing fibrillar surface. We specifically look into several potential Abeta structural precursors that might precede some secondary events, including elongation and secondary nucleation. We find that the overall process of surface-dependent events can be described at least by the following three stages: 1. Free diffusion 2. Downhill guiding 3. Dock and lock. And we show that the outcome of adding a new monomer onto a pre-existing fibril is pathway-dependent, which leads to different secondary processes. To understand structural details, we have identified several monomeric amyloid precursors over the fibrillar surfaces and characterize their heterogeneity using a probability contact map analysis. Using the frustration analysis (a bioinformatics tool), we show that surface heterogeneity correlates with the energy frustration of specific local residues that form binding sites on the fibrillar structure. We further investigate the helical twisting of protofilaments of different sizes and observe a length dependence on the filament twisting. This work presents a comprehensive survey over the properties of fibril growth using a combination of several openMM-based platforms, including the GPU-enabled openAWSEM package for coarse-grained modeling, MDTraj for trajectory analysis, and pyEMMA for free energy calculation. This combined approach makes long-timescale simulation for aggregation systems as well as all-in-one analysis feasible. We show that this protocol allows us to explore fibril stability, surface binding affinity/heterogeneity, as well as fibrillar twisting. All these properties are important for understanding the molecular mechanism of surface-catalyzed secondary processes of fibril growth.
Collapse
Affiliation(s)
- Yuan-Wei Ma
- Department of Chemistry, Tamkang University, New Taipei City, Taiwan
| | - Tong-You Lin
- Department of Chemistry, Tamkang University, New Taipei City, Taiwan
| | - Min-Yeh Tsai
- Department of Chemistry, Tamkang University, New Taipei City, Taiwan
| |
Collapse
|
13
|
Rice LJ, Ecroyd H, van Oijen AM. Illuminating amyloid fibrils: Fluorescence-based single-molecule approaches. Comput Struct Biotechnol J 2021; 19:4711-4724. [PMID: 34504664 PMCID: PMC8405898 DOI: 10.1016/j.csbj.2021.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/15/2022] Open
Abstract
The aggregation of proteins into insoluble filamentous amyloid fibrils is a pathological hallmark of neurodegenerative diseases that include Parkinson's disease and Alzheimer's disease. Since the identification of amyloid fibrils and their association with disease, there has been much work to describe the process by which fibrils form and interact with other proteins. However, due to the dynamic nature of fibril formation and the transient and heterogeneous nature of the intermediates produced, it can be challenging to examine these processes using techniques that rely on traditional ensemble-based measurements. Single-molecule approaches overcome these limitations as rare and short-lived species within a population can be individually studied. Fluorescence-based single-molecule methods have proven to be particularly useful for the study of amyloid fibril formation. In this review, we discuss the use of different experimental single-molecule fluorescence microscopy approaches to study amyloid fibrils and their interaction with other proteins, in particular molecular chaperones. We highlight the mechanistic insights these single-molecule techniques have already provided in our understanding of how fibrils form, and comment on their potential future use in studying amyloid fibrils and their intermediates.
Collapse
Affiliation(s)
- Lauren J. Rice
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health & Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Heath Ecroyd
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health & Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Antoine M. van Oijen
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health & Medical Research Institute, Wollongong, NSW 2522, Australia
| |
Collapse
|
14
|
Ghosh S, Verma S. Carvedilol inhibits Aβ 25-35 fibrillation by intervening the early stage helical intermediate formation: A biophysical investigation. Int J Biol Macromol 2021; 188:263-271. [PMID: 34371042 DOI: 10.1016/j.ijbiomac.2021.08.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/16/2021] [Accepted: 08/03/2021] [Indexed: 12/28/2022]
Abstract
Self-assembly of disordered amyloid-beta (Aβ) peptides results in highly ordered amyloid fibrils. The structural information of the early-stage events and also in the presence of inhibitors is of great significance. It is challenging to acquire due to the nature of the amyloids and experimental constraints. Here, we demonstrate the cascade of aggregation (early to late) of the Aβ25-35 peptide in the absence and presence of carvedilol, a nonselective β-adrenergic receptor blocker. The aggregation process of Aβ25-35 peptide is monitored using Thioflavin T (ThT) fluorescence, dynamic light scattering (DLS), circular dichroism (CD), Raman spectroscopic techniques, and imaging experiments. We find that the Aβ25-35 peptide undergoes an early-stage (3-6 h) helical intermediate formation across the fibrillation pathway using CD and Raman measurements. Carvedilol obstructs the helical intermediate formation of Aβ25-35 peptide resulting in inhibition. CD spectra and deconvolution of the Raman bands suggest the β-sheet formation (24-100 h) in the absence of carvedilol. Spectroscopic results indicate a disordered structure for the peptide in the presence of carvedilol (24-100 h). Electron microscopy (EM) shows the formation of polymorphic fibrils for the peptide alone and non-amyloidal aggregates in the presence of carvedilol. Molecular docking study suggests that the plausible mode of interaction with carvedilol involves the C-terminal residues of the peptide.
Collapse
Affiliation(s)
- Sudeshna Ghosh
- Department of Chemistry, Indian Institute of Technology Kanpur, UP 208016, India.
| | - Sandeep Verma
- Department of Chemistry, Indian Institute of Technology Kanpur, UP 208016, India.
| |
Collapse
|
15
|
Pradhan T, Annamalai K, Sarkar R, Hegenbart U, Schönland S, Fändrich M, Reif B. Solid state NMR assignments of a human λ-III immunoglobulin light chain amyloid fibril. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:9-16. [PMID: 32946005 PMCID: PMC7973639 DOI: 10.1007/s12104-020-09975-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/11/2020] [Indexed: 05/09/2023]
Abstract
The aggregation of antibody light chains is linked to systemic light chain (AL) amyloidosis, a disease where amyloid deposits frequently affect the heart and the kidney. We here investigate fibrils from the λ-III FOR005 light chain (LC), which is derived from an AL-patient with severe cardiac involvement. In FOR005, five residues are mutated with respect to its closest germline gene segment IGLV3-19 and IGLJ3. All mutations are located close to the complementarity determining regions (CDRs). The sequence segments responsible for the fibril formation are not yet known. We use fibrils extracted from the heart of this particular amyloidosis patient as seeds to prepare fibrils for solid-state NMR. We show that the seeds induce the formation of a specific fibril structure from the biochemically produced protein. We have assigned the fibril core region of the FOR005-derived fibrils and characterized the secondary structure propensity of the observed amino acids. As the primary structure of the aggregated patient protein is different for every AL patient, it is important to study, analyze and report a greater number of light chain sequences associated with AL amyloidosis.
Collapse
Affiliation(s)
- Tejaswini Pradhan
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit Und Umwelt, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
- Department of Chemistry, Munich Center for Integrated Protein Science (CIPS-M), Technische Universität München (TUM), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Karthikeyan Annamalai
- Institute of Protein Biochemistry, Ulm University, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Riddhiman Sarkar
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit Und Umwelt, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
- Department of Chemistry, Munich Center for Integrated Protein Science (CIPS-M), Technische Universität München (TUM), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Ute Hegenbart
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, 69120, Heidelberg, Germany
| | - Stefan Schönland
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, 69120, Heidelberg, Germany
| | - Marcus Fändrich
- Institute of Protein Biochemistry, Ulm University, Helmholtzstrasse 8/1, 89081, Ulm, Germany
| | - Bernd Reif
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit Und Umwelt, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
- Department of Chemistry, Munich Center for Integrated Protein Science (CIPS-M), Technische Universität München (TUM), Lichtenbergstr. 4, 85747, Garching, Germany.
| |
Collapse
|
16
|
Peccati F, Díaz-Caballero M, Navarro S, Rodríguez-Santiago L, Ventura S, Sodupe M. Atomistic fibrillar architectures of polar prion-inspired heptapeptides. Chem Sci 2020; 11:13143-13151. [PMID: 34094496 PMCID: PMC8163036 DOI: 10.1039/d0sc05638c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 10/20/2020] [Indexed: 12/15/2022] Open
Abstract
This article provides the computational prediction of the atomistic architectures resulting from self-assembly of the polar heptapeptide sequences NYNYNYN, SYSYSYS and GYGYGYG. Using a combination of molecular dynamics and a newly developed tool for non-covalent interaction analysis, we uncover the properties of a new class of bionanomaterials, including hydrogen-bonded polar zippers, and the relationship between peptide composition, fibril geometry and weak interaction networks. Our results, corroborated by experimental observations, provide the basis for the rational design of prion-inspired nanomaterials.
Collapse
Affiliation(s)
- Francesca Peccati
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA) Bizkaia Technology Park, Building 801A, 48160 Derio Spain +34 4469/946 572 538
| | - Marta Díaz-Caballero
- Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona 08193 Bellaterra Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona 08193 Bellaterra Spain
| | - Susanna Navarro
- Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona 08193 Bellaterra Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona 08193 Bellaterra Spain
| | | | - Salvador Ventura
- Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona 08193 Bellaterra Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona 08193 Bellaterra Spain
- ICREA, Passeig Lluís Companys 23 E-08010 Barcelona Spain
| | - Mariona Sodupe
- Departament de Química, Universitat Autònoma de Barcelona 08193 Bellaterra Spain
| |
Collapse
|
17
|
Crocus-derived compounds alter the aggregation pathway of Alzheimer's Disease: associated beta amyloid protein. Sci Rep 2020; 10:18150. [PMID: 33097779 PMCID: PMC7585429 DOI: 10.1038/s41598-020-74770-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 09/18/2020] [Indexed: 11/08/2022] Open
Abstract
Natural products have played a dominant role in the discovery of lead compounds for the development of drugs aimed at the treatment of human diseases. This electrospray ionization-ion mobility spectrometry-mass spectrometry (ESI-IMS-MS)-based study demonstrates that dietary antioxidants, isolated components from the stigmas of saffron (Crocus sativus L.) may be effective in inhibiting Aβ fibrillogenesis, a neuropathological hallmark of Alzheimer's Disease (AD). This study reveals a substantial alteration in the monomer/oligomer distribution of Aβ1-40, concomitant with re-direction of fibril formation, induced by the natural product interaction. These alterations on the Aβ1-40 aggregation pathway are most prominent for trans-crocin-4 (TC4). Use of ESI-IMS-MS, electron microscopy alongside Thioflavin-T kinetics, and the interpretation of 3-dimensional Driftscope plots indicate a correlation of these monomer/oligomer distribution changes with alterations to Aβ1-40 amyloid formation. The latter could prove instrumental in the development of novel aggregation inhibitors for the prevention, or treatment of AD.
Collapse
|
18
|
Aubrey LD, Blakeman BJF, Lutter L, Serpell CJ, Tuite MF, Serpell LC, Xue WF. Quantification of amyloid fibril polymorphism by nano-morphometry reveals the individuality of filament assembly. Commun Chem 2020; 3:125. [PMID: 36703355 PMCID: PMC9814634 DOI: 10.1038/s42004-020-00372-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 08/12/2020] [Indexed: 01/29/2023] Open
Abstract
Amyloid fibrils are highly polymorphic structures formed by many different proteins. They provide biological function but also abnormally accumulate in numerous human diseases. The physicochemical principles of amyloid polymorphism are not understood due to lack of structural insights at the single-fibril level. To identify and classify different fibril polymorphs and to quantify the level of heterogeneity is essential to decipher the precise links between amyloid structures and their functional and disease associated properties such as toxicity, strains, propagation and spreading. Employing gentle, force-distance curve-based AFM, we produce detailed images, from which the 3D reconstruction of individual filaments in heterogeneous amyloid samples is achieved. Distinctive fibril polymorphs are then classified by hierarchical clustering, and sample heterogeneity is objectively quantified. These data demonstrate the polymorphic nature of fibril populations, provide important information regarding the energy landscape of amyloid self-assembly, and offer quantitative insights into the structural basis of polymorphism in amyloid populations.
Collapse
Affiliation(s)
- Liam D. Aubrey
- grid.9759.20000 0001 2232 2818Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, CT2 7NJ UK
| | - Ben J. F. Blakeman
- grid.9759.20000 0001 2232 2818Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, CT2 7NJ UK
| | - Liisa Lutter
- grid.9759.20000 0001 2232 2818Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, CT2 7NJ UK
| | - Christopher J. Serpell
- grid.9759.20000 0001 2232 2818School of Physical Sciences, University of Kent, Canterbury, CT2 7NH UK
| | - Mick F. Tuite
- grid.9759.20000 0001 2232 2818Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, CT2 7NJ UK
| | - Louise C. Serpell
- grid.12082.390000 0004 1936 7590Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG UK
| | - Wei-Feng Xue
- grid.9759.20000 0001 2232 2818Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, CT2 7NJ UK
| |
Collapse
|
19
|
Feuillie C, Lambert E, Ewald M, Azouz M, Henry S, Marsaudon S, Cullin C, Lecomte S, Molinari M. High Speed AFM and NanoInfrared Spectroscopy Investigation of Aβ 1-42 Peptide Variants and Their Interaction With POPC/SM/Chol/GM1 Model Membranes. Front Mol Biosci 2020; 7:571696. [PMID: 33033718 PMCID: PMC7510551 DOI: 10.3389/fmolb.2020.571696] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022] Open
Abstract
Due to an aging population, neurodegenerative diseases such as Alzheimer's disease (AD) have become a major health issue. In the case of AD, Aβ1 - 42 peptides have been identified as one of the markers of the disease with the formation of senile plaques via their aggregation, and could play a role in memory impairment and other tragic syndromes associated with the disease. Many studies have shown that not only the morphology and structure of Aβ1 - 42 peptide assembly are playing an important role in the formation of amyloid plaques, but also the interactions between Aβ1 - 42 and the cellular membrane are crucial regarding the aggregation processes and toxicity of the amyloid peptides. Despite the increasing amount of information on AD associated amyloids and their toxicity, the molecular mechanisms involved still remain unclear and require in-depth investigation at the local scale to clearly decipher the role of the sequence of the amyloid peptides, of their secondary structures, of their oligomeric states, and of their interactions with lipid membranes. In this original study, through the use of Atomic Force Microscopy (AFM) related-techniques, high-speed AFM and nanoInfrared AFM, we tried to unravel at the nanoscale the link between aggregation state, structure and interaction with membranes in the amyloid/membrane interaction. Using three mutants of Aβ peptides, L34T, oG37C, and WT Aβ1 - 42 peptides, with differences in morphology, structure and assembly process, as well as model lipidic membranes whose composition and structure allow interactions with the peptides, our AFM study coupling high spatial and temporal resolution and nanoscale structure information clearly evidences a local correlation between the secondary structure of the peptides, their fibrillization kinetics and their interactions with model membranes. Membrane disruption is associated to small transient oligomeric entities in the early stages of aggregation that strongly interact with the membrane, and present an antiparallel β-sheet secondary structure. The strong effect on membrane integrity that exists when these oligomeric Aβ1 - 42 peptides interact with membranes of a particular composition could be a lead for therapeutic studies.
Collapse
Affiliation(s)
- Cecile Feuillie
- CBMN, CNRS UMR 5248, IPB, Université de Bordeaux, Pessac, France
| | - Eleonore Lambert
- LRN EA 4682, Université de Reims Champagne-Ardenne, Reims, France
| | - Maxime Ewald
- LRN EA 4682, Université de Reims Champagne-Ardenne, Reims, France
| | - Mehdi Azouz
- CBMN, CNRS UMR 5248, IPB, Université de Bordeaux, Pessac, France.,Department of Chemistry, Université de Montréal, Montreal, QC, Canada
| | - Sarah Henry
- CBMN, CNRS UMR 5248, IPB, Université de Bordeaux, Pessac, France
| | - Sophie Marsaudon
- CBMN, CNRS UMR 5248, IPB, Université de Bordeaux, Pessac, France
| | | | - Sophie Lecomte
- CBMN, CNRS UMR 5248, IPB, Université de Bordeaux, Pessac, France
| | - Michael Molinari
- CBMN, CNRS UMR 5248, IPB, Université de Bordeaux, Pessac, France
| |
Collapse
|
20
|
Lucas MJ, Pan HS, Verbeke EJ, Webb LJ, Taylor DW, Keitz BK. Functionalized Mesoporous Silicas Direct Structural Polymorphism of Amyloid-β Fibrils. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:7345-7355. [PMID: 32482072 DOI: 10.1021/acs.langmuir.0c00827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The aggregation of amyloid-β (Aβ) is associated with the onset of Alzheimer's disease (AD) and involves a complex kinetic pathway as monomers self-assemble into fibrils. A central feature of amyloid fibrils is the existence of multiple structural polymorphs, which complicates the development of disease-relevant structure-function relationships. Developing these relationships requires new methods to control fibril structure. In this work, we evaluated the effect that mesoporous silicas (SBA-15) functionalized with hydrophobic (SBA-PFDTS) and hydrophilic groups (SBA-PEG) have on the aggregation kinetics and resulting structure of Aβ1-40 fibrils. The hydrophilic SBA-PEG had little effect on amyloid kinetics, while as-synthesized and hydrophobic SBA-PFDTS accelerated aggregation kinetics. Subsequently, we quantified the relative population of fibril structures formed in the presence of each material using electron microscopy. Fibrils formed from Aβ1-40 exposed to SBA-PEG were structurally similar to control fibrils. In contrast, Aβ1-40 incubated with SBA-15 or SBA-PFDTS formed fibrils with shorter crossover distances that were more structurally representative of fibrils found in AD patient derived samples. Overall, our results suggest that mesoporous silicas and other exogenous materials are promising scaffolds for the de novo production of specific fibril polymorphs of Aβ1-40 and other amyloidogenic proteins.
Collapse
Affiliation(s)
- Michael J Lucas
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Henry S Pan
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Eric J Verbeke
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, United States
| | - Lauren J Webb
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - David W Taylor
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, United States
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712, United States
- LIVESTRONG Cancer Institutes, Dell Medical School, Austin, Texas 78712, United States
| | - Benjamin K Keitz
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
21
|
Boatz JC, Piretra T, Lasorsa A, Matlahov I, Conway JF, van der Wel PCA. Protofilament Structure and Supramolecular Polymorphism of Aggregated Mutant Huntingtin Exon 1. J Mol Biol 2020; 432:4722-4744. [PMID: 32598938 DOI: 10.1016/j.jmb.2020.06.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 06/01/2020] [Accepted: 06/18/2020] [Indexed: 12/11/2022]
Abstract
Huntington's disease is a progressive neurodegenerative disease caused by expansion of the polyglutamine domain in the first exon of huntingtin (HttEx1). The extent of expansion correlates with disease progression and formation of amyloid-like protein deposits within the brain. The latter display polymorphism at the microscopic level, both in cerebral tissue and in vitro. Such polymorphism can dramatically influence cytotoxicity, leading to much interest in the conditions and mechanisms that dictate the formation of polymorphs. We examine conditions that govern HttEx1 polymorphism in vitro, including concentration and the role of the non-polyglutamine flanking domains. Using electron microscopy, we observe polymorphs that differ in width and tendency for higher-order bundling. Strikingly, aggregation yields different polymorphs at low and high concentrations. Narrow filaments dominate at low concentrations that may be more relevant in vivo. We dissect the role of N- and C-terminal flanking domains using protein with the former (httNT or N17) largely removed. The truncated protein is generated by trypsin cleavage of soluble HttEx1 fusion protein, which we analyze in some detail. Dye binding and solid-state NMR studies reveal changes in fibril surface characteristics and flanking domain mobility. Higher-order interactions appear facilitated by the C-terminal tail, while the polyglutamine forms an amyloid core resembling those of other polyglutamine deposits. Fibril-surface-mediated branching, previously attributed to secondary nucleation, is reduced in absence of httNT. A new model for the architecture of the HttEx1 filaments is presented and discussed in context of the assembly mechanism and biological activity.
Collapse
Affiliation(s)
- Jennifer C Boatz
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Talia Piretra
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Alessia Lasorsa
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - Irina Matlahov
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - James F Conway
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Patrick C A van der Wel
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| |
Collapse
|
22
|
Szała B, Molski A. Chiral structure fluctuations predicted by a coarse-grained model of peptide aggregation. SOFT MATTER 2020; 16:5071-5080. [PMID: 32453328 DOI: 10.1039/d0sm00090f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This work reports on the chiral structure fluctuations of peptide clusters at the early stages of aggregation in a coarse-grained peptide model. Our model reproduces a variety of aggregate structures, from disordered to crystal-like, that are observed experimentally. Unexpectedly, our molecular dynamics simulations showed that the small peptide cluster undergoes chiral structure fluctuations although the underlying implicit solvent model does not assume the chirality of peptides. The chiral fluctuations are quantified through a cluster twist parameter. A simple model is presented where the twist parameter undergoes a stochastic diffusion on a 1D potential surface. The shape of the potential surface changes with the cluster size. The model shows semi-quantitative agreement with the simulations. We hypothesize that the chiral fluctuations at the early stages of peptide aggregation can contribute to the selection of the final fibril structures.
Collapse
Affiliation(s)
- Beata Szała
- Adam Mickiewicz University in Poznań, Faculty of Chemistry, Umultowska 89b, 61-614 Poznań, Poland.
| | | |
Collapse
|
23
|
Polymorphic Aβ42 fibrils adopt similar secondary structure but differ in cross-strand side chain stacking interactions within the same β-sheet. Sci Rep 2020; 10:5720. [PMID: 32235842 PMCID: PMC7109039 DOI: 10.1038/s41598-020-62181-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 03/10/2020] [Indexed: 12/20/2022] Open
Abstract
Formation of polymorphic amyloid fibrils is a common feature in neurodegenerative diseases involving protein aggregation. In Alzheimer’s disease, different fibril structures may be associated with different clinical sub-types. Structural basis of fibril polymorphism is thus important for understanding the role of amyloid fibrils in the pathogenesis and progression of these diseases. Here we studied two types of Aβ42 fibrils prepared under quiescent and agitated conditions. Quiescent Aβ42 fibrils adopt a long and twisted morphology, while agitated fibrils are short and straight, forming large bundles via lateral association. EPR studies of these two types of Aβ42 fibrils show that the secondary structure is similar in both fibril polymorphs. At the same time, agitated Aβ42 fibrils show stronger interactions between spin labels across the full range of the Aβ42 sequence, suggesting a more tightly packed structure. Our data suggest that cross-strand side chain packing interactions within the same β-sheet may play a critical role in the formation of polymorphic fibrils.
Collapse
|
24
|
Liu J, Tian M, Shen L. Surface effects on the degree of twist in amyloid fibril structures. Chem Commun (Camb) 2020; 56:3147-3150. [PMID: 32057047 DOI: 10.1039/c9cc10079b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Amyloid fibrils, implicated in health and diseases, commonly exhibit a periodic twist trait relevant to the structures and dynamics of the fibrils. However, the origins and modulations of fibril twist in complex in vivo environments are not yet fully understood. Here we highlight an important factor that causes twist variations in amyloid fibril structures-the presence of surrounding surfaces. Using cholesterol-containing lipid bilayers with varying cholesterol contents, we have demonstrated via atomic force microscopy that amyloid-β peptide fibrils initiated on membranes increase their average pitch size of twisting periodicity as the cholesterol content increases. These surface-induced twist variations arise from the enhanced hydrophobic interactions between the fibril and the surface distorting the torsional elastic energy of the fibril twisting as supported by a theory of an elastic model. These findings not only provide an important insight into fibril polymorphism phenomena resulting from the surface effects but also suggest a novel solution to modulate filament twisting on the nanoscale for biomaterials applications involving nanoscale features.
Collapse
Affiliation(s)
- Jingjing Liu
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430074, China.
| | - Mengting Tian
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430074, China.
| | - Lei Shen
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430074, China.
| |
Collapse
|
25
|
Liu J, Tian M, Shen L. Nanopatterned Polymer Surface Modulates Twist Polymorphism in a Single Amyloid Fibril. Macromol Rapid Commun 2020; 41:e1900619. [PMID: 32125062 DOI: 10.1002/marc.201900619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 01/30/2020] [Accepted: 02/20/2020] [Indexed: 01/02/2023]
Abstract
The periodic twist behaviors of amyloid fibrils initiated and formed on block copolymer films with nanoscale features are studied. The discovery of twist variations even in a single amyloid fibril is reported: the fibril can vary its twist extents in response to the underlying nanopatterned surfaces by keeping its neighboring crossover sections right above the periodic nanodomains and tuning the distance between neighboring crossover sections based on either the periodic nanodomain distance or the fibril contour direction. This nanopattern-induced twist polymorphism arises from the fibril's two edges, exhibiting different hydrophobic interactions with the periodic nanodomains, as demonstrated by simulation studies. This work contributes to the understanding of surface effects on twist polymorphism in amyloid fibril structures that may be important to fibril polymorphism in amyloid pathologies and bioapplications of amyloid fibrils.
Collapse
Affiliation(s)
- Jingjing Liu
- Wuhan University of Technology, Wuhan, 430074, China
| | - Mengting Tian
- Wuhan University of Technology, Wuhan, 430074, China
| | - Lei Shen
- Wuhan University of Technology, Wuhan, 430074, China
| |
Collapse
|
26
|
Jakubowski J, Orr AA, Le DA, Tamamis P. Interactions between Curcumin Derivatives and Amyloid-β Fibrils: Insights from Molecular Dynamics Simulations. J Chem Inf Model 2020; 60:289-305. [PMID: 31809572 PMCID: PMC7732148 DOI: 10.1021/acs.jcim.9b00561] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Indexed: 12/24/2022]
Abstract
The aggregation of amyloid-β (Aβ) peptides into senile plaques is a hallmark of Alzheimer's disease (AD) and is hypothesized to be the primary cause of AD related neurodegeneration. Previous studies have shown the ability of curcumin to both inhibit the aggregation of Aβ peptides into oligomers or fibrils and reduce amyloids in vivo. Despite the promise of curcumin and its derivatives to serve as diagnostic, preventative, and potentially therapeutic AD molecules, the mechanism by which curcumin and its derivatives bind to and inhibit Aβ fibrils' formation remains elusive. Here, we investigated curcumin and a set of curcumin derivatives in complex with a hexamer peptide model of the Aβ1-42 fibril using nearly exhaustive docking, followed by multi-ns molecular dynamics simulations, to provide atomistic-detail insights into the molecules' binding and inhibitory properties. In the vast majority of the simulations, curcumin and its derivatives remain firmly bound in complex with the fibril through primarily three different principle binding modes, in which the molecules interact with residue domain 17LVFFA21, in line with previous experiments. In a small subset of these simulations, the molecules partly dissociate the outermost peptide of the Aβ1-42 fibril by disrupting β-sheets within the residue domain 12VHHQKLVFF20. A comparison between binding modes leading or not leading to partial dissociation of the outermost peptide suggests that the latter is attributed to a few subtle key structural and energetic interaction-based differences. Interestingly, partial dissociation appears to be either an outcome of high affinity interactions or a cause leading to high affinity interactions between the molecules and the fibril, which could partly serve as a compensation for the energy loss in the fibril due to partial dissociation. In conjunction with this, we suggest a potential inhibition mechanism of Αβ1-42 aggregation by the molecules, where the partially dissociated 16KLVFF20 domain of the outermost peptide could either remain unstructured or wrap around to form intramolecular interactions with the same peptide's 29GAIIG33 domain, while the molecules could additionally act as a patch against the external edge of the second outermost peptide's 16KLVFF20 domain. Thereby, individually or concurrently, these could prohibit fibril elongation.
Collapse
Affiliation(s)
| | | | - Doan A. Le
- Artie McFerrin Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843-3122, United States
| | - Phanourios Tamamis
- Artie McFerrin Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843-3122, United States
| |
Collapse
|
27
|
Choi H, Lee W, Lee G, Yoon DS, Na S. The Formation Mechanism of Segmented Ring-Shaped Aβ Oligomers and Protofibrils. ACS Chem Neurosci 2019; 10:3830-3838. [PMID: 31313912 DOI: 10.1021/acschemneuro.9b00324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A clear understanding of amyloid formation with diverse morphologies is critical to overcoming the fatal disease amyloidosis. Studies have revealed that monomer concentration is a crucial factor for determining amyloid morphologies, such as protofibrils, annular, or spherical oligomers. However, gaining a complete understanding of the mechanism of formation of the various amyloid morphologies has been limited by the lack of experimental devices and insufficient knowledge. In this study, we demonstrate that the monomer concentration is an essential factor in determining the morphology of beta-amyloid (Aβ) oligomers or protofibrils. By computational and experimental approaches, we investigated the strategies for structural stabilization of amyloid protein, the morphological changes, and amyloid aggregation. In particular, we found unprecedented conformations, e.g., single bent oligomers and segmented ring-shaped protofibrils, the formation of which was explained by the computational analysis. Our findings provide insight into the structural features of amyloid molecules formed at low concentrations of monomer, which will help determine the clinical targets (in therapy) to effectively inhibit amyloid formation in the early stages of the amyloid growth phase.
Collapse
Affiliation(s)
| | - Wonseok Lee
- Department of Control and Instrumentation Engineering , Korea University , Sejong 30019 , Republic of Korea
| | | | | | | |
Collapse
|
28
|
Karimi H, Heydari Dokoohaki M, Zolghadr AR, Ghatee MH. The interactions of an Aβ protofibril with a cholesterol-enriched membrane and involvement of neuroprotective carbazolium-based substances. Phys Chem Chem Phys 2019; 21:11066-11078. [PMID: 31090756 DOI: 10.1039/c9cp00859d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Recent studies have shown that the aggregation of the amyloid-beta peptide (Aβ) in the brain cell membrane is responsible for the emergence of Alzheimer's disease (AD); the exploration of effective factors involved in the extension of the aggregation process and alternatively the examination of an effective inhibitor via theoretical and experimental tools are among the main research topics in the field of AD treatment. Therefore, in this study, we used all-atom molecular dynamics (MD) simulations to clarify the impact of cell membrane cholesterol on the interaction of Aβ with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) as a membrane model. Moreover, the effect of the P7C3-S243 molecule on the abovementioned process was investigated. The simulation results disclosed the neuroprotective property of the P7C3-S243 molecule. The MD simulation results indicate that the interaction of cholesterol molecules with the Aβ oligomer is negligible and cannot enhance membrane rupture. However, strong hydrogen bonding between the POPC molecules and the oligomers led to membrane perturbation. According to our modellings, the P7C3-S243 molecular layer can protect the cell membrane by inhibiting the direct interaction between the bilayer and Aβ. In addition, free-energy calculations were conducted to determine the possible penetration of Aβ fibrils into the cholesterol-enriched membrane.
Collapse
Affiliation(s)
- Hedayat Karimi
- Department of Chemistry, Shiraz University, Shiraz, 71946-84795, Iran.
| | | | | | | |
Collapse
|
29
|
Abstract
AbstractThe aggregation of the 11 residue long NACore peptide segment of α-synuclein (68-GAVVTGVTAVA-78) has been investigated using a combination of cryogenic transmission electron microscopy (cryo-TEM), small- and wide-angle X-ray scattering, and spectroscopy techniques. The aqueous peptide solubility is pH dependent, and aggregation was triggered by a pH quench from pH 11.3 to approximately pH 8 or 6, where the average peptide net charge is weakly negative (pH 8), or essentially zero (pH 6). Cryo-TEM shows the presence of long and stiff fibrillar aggregates at both pH, that are built up from β-sheets, as demonstrated by circular dichroism spectroscopy and thioflavin T fluorescence. The fibrils are crystalline, with a wide angle X-ray diffraction pattern that is consistent with a previously determined crystal structure of NACore. Of particular note is the cryo-TEM observation of small globular shaped aggregates, of the order of a few nanometers in size, adsorbed onto the surface of already formed fibrils at pH 6. The fibrillation kinetics is slow, and occurs on the time scale of days. Similarly slow kinetics is observed at both pH, but slightly slower at pH 6, even though the peptide solubility is here expected to be lower. The observation of the small globular shaped aggregates, together with the associated kinetics, could be highly relevant in relation to mechanisms of secondary nucleation and oligomer formation in amyloid systems.
Collapse
|
30
|
Chen M, Schafer NP, Wolynes PG. Surveying the Energy Landscapes of Aβ Fibril Polymorphism. J Phys Chem B 2018; 122:11414-11430. [PMID: 30215519 DOI: 10.1021/acs.jpcb.8b07364] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Many unrelated proteins and peptides have been found spontaneously to form amyloid fibers above a critical concentration. Even for a single sequence, however, the amyloid fold is not a single well-defined structure. Although the cross-β hydrogen bonding pattern is common to all amyloids, all other aspects of amyloid fiber structures are sensitive to both the sequence of the aggregating peptides and the solvent conditions under which the aggregation occurs. Amyloid fibers are easy to identify and grossly characterize using microscopy, but their insolubility and aperiodicity along the dimensions transverse to the fiber axis have complicated detailed experimental structural characterization. In this paper, we explore the landscape of possibilities for amyloid protofilament structures that are made up of a single stack of peptides associated in a parallel in-register manner. We view this landscape as a two-dimensional version of the usual three-dimensional protein folding problem: the survey of the two-dimensional folds of protein ribbons. Adopting this view leads to a practical method of predicting stable protofilament structures of arbitrary sequences. We apply this scheme to variants of Aβ, the amyloid forming peptide that is characteristically associated with Alzheimer's disease. Consistent with what is known from experiment, we find that Aβ protofibrils are polymorphic. To our surprise, however, the ribbon-folding landscape of Aβ turned out to be strikingly simple. We confirm that, at the level of the monomeric protofilament, the landscape for the Aβ sequence is reasonably well funneled toward structures that are similar to those that have been determined by experiment. The landscape has more distinct minima than does a typical globular protein landscape but fewer and deeper minima than the landscape of a randomly shuffled sequence having the same overall composition. It is tempting to consider the possibility that the significant degree of funneling of Aβ's ribbon-folding landscape has arisen as a result of natural selection. More likely, however, the intermediate complexity of Aβ's ribbon-folding landscape has come from the post facto selection of the Aβ sequence as an object of study by researchers because only by having a landscape with some degree of funneling can ordered aggregation of such a peptide occur at in vivo concentrations. In addition to predicting polymorph structures, we show that predicted solubilities of polymorphs correlate with experiment and with their elongation free energies computed by coarse-grained molecular dynamics.
Collapse
Affiliation(s)
- Mingchen Chen
- Center for Theoretical Biological Physics , Rice University , Houston , Texas 77005 , United States.,Department of Bioengineering , Rice University , Houston , Texas 77005 , United States
| | - Nicholas P Schafer
- Center for Theoretical Biological Physics , Rice University , Houston , Texas 77005 , United States.,Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Peter G Wolynes
- Center for Theoretical Biological Physics , Rice University , Houston , Texas 77005 , United States.,Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| |
Collapse
|
31
|
Lu L, Deng Y, Li X, Li H, Karniadakis GE. Understanding the Twisted Structure of Amyloid Fibrils via Molecular Simulations. J Phys Chem B 2018; 122:11302-11310. [PMID: 30106299 DOI: 10.1021/acs.jpcb.8b07255] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Accumulation and aggregation of amyloid are associated with the pathogenesis of many human diseases, such as Alzheimer's disease and Type 2 diabetes mellitus. Therefore, a quantitative understanding of the molecular mechanisms causing different aggregated structures and biomechanical properties of amyloid fibrils could shed some light into the progression of these diseases. In this work, we develop coarse-grained molecular dynamics (CGMD) models to simulate the dynamic self-assembly of two types of amyloids (amylin and amyloid β (Aβ)). We investigate the structural and mechanical properties of different types of aggregated amyloid fibrils. Our simulations demonstrate that amyloid fibrils could result from longitudinal growth of protofilament bundles, confirming one of the hypotheses on the fibril formation. In addition, we find that the persistence length of amylin fibrils increases concurrently with their pitch length, suggesting that the bending stiffness of amylin fibrils becomes larger when the amylin fibrils are less twisted. Similar results are observed for Aβ fibrils. These findings quantify the connection between the structural and the biomechanical properties of the fibrils. The CGMD models developed in this work can be potentially used to examine efficacy of anti-aggregation drugs, which could help in developing new treatments.
Collapse
Affiliation(s)
- Lu Lu
- Division of Applied Mathematics , Brown University , Providence , Rhode Island 02912 , United States
| | - Yixiang Deng
- School of Engineering , Brown University , Providence , Rhode Island 02912 , United States
| | - Xuejin Li
- Division of Applied Mathematics , Brown University , Providence , Rhode Island 02912 , United States
| | - He Li
- Division of Applied Mathematics , Brown University , Providence , Rhode Island 02912 , United States
| | - George Em Karniadakis
- Division of Applied Mathematics , Brown University , Providence , Rhode Island 02912 , United States
| |
Collapse
|
32
|
Recent Advances by In Silico and In Vitro Studies of Amyloid-β 1-42 Fibril Depicted a S-Shape Conformation. Int J Mol Sci 2018; 19:ijms19082415. [PMID: 30115846 PMCID: PMC6121414 DOI: 10.3390/ijms19082415] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 12/19/2022] Open
Abstract
The amyloid-β 1-42 (Aβ1-42) peptide is produced by proteolytic cleavage of the amyloid precursor protein (APP) by sequential reactions that are catalyzed by γ and β secretases. Aβ1-42, together with the Tau protein are two principal hallmarks of Alzheimer's disease (AD) that are related to disease genesis and progression. Aβ1-42 possesses a higher aggregation propensity, and it is able to form fibrils via nucleated fibril formation. To date, there are compounds available that prevent Aβ1-42 aggregation, but none have been successful in clinical trials, possibly because the Aβ1-42 structure and aggregation mechanisms are not thoroughly understood. New molecules have been designed, employing knowledge of the Aβ1-42 structure and are based on preventing or breaking the ionic interactions that have been proposed for formation of the Aβ1-42 fibril U-shaped structure. Recently, a new Aβ1-42 fibril S-shaped structure was reported that, together with its aggregation and catalytic properties, could be helpful in the design of new inhibitor molecules. Therefore, in silico and in vitro methods have been employed to analyze the Aβ1-42 fibril S-shaped structure and its aggregation to obtain more accurate Aβ1-42 oligomerization data for the design and evaluation of new molecules that can prevent the fibrillation process.
Collapse
|
33
|
Ilie IM, Caflisch A. Disorder at the Tips of a Disease-Relevant Aβ42 Amyloid Fibril: A Molecular Dynamics Study. J Phys Chem B 2018; 122:11072-11082. [PMID: 29965774 DOI: 10.1021/acs.jpcb.8b05236] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
We present a simulation study of the early events of peptide dissociation from a fibril of the Alzheimer's Aβ42 peptide. The fibril consists of layers of two adjacent Aβ42 peptides each folded in an S-shaped structure which has been determined by solid state NMR spectroscopy of a monomorphic disease-relevant species. Multiple molecular dynamics runs (16 at 310 K and 15 at 370 K) were carried out starting from an 18-peptide protofibril for a cumulative sampling of about 15 μs. The simulations show structural stability of the fibrillar core and an overall increase in the twist to about 3 degrees. The N-terminal segment 1-14 is disordered in all peptides. At both ends of the fibril, the central segment 21-29, which includes part of the β2 strand, dissociates in some of the simulations. The β1 and β3 strands, residues 15-20 and 35-41, respectively, are structurally stable. The transient binding of the N-terminal stretch to the β3 strand of the adjacent peptide at the tip is likely to contribute to the arrest phase of the stop-and-go mechanism.
Collapse
Affiliation(s)
- Ioana M Ilie
- Department of Biochemistry , University of Zürich , 8057 Zürich , Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry , University of Zürich , 8057 Zürich , Switzerland
| |
Collapse
|
34
|
Frederix PWJM, Patmanidis I, Marrink SJ. Molecular simulations of self-assembling bio-inspired supramolecular systems and their connection to experiments. Chem Soc Rev 2018; 47:3470-3489. [PMID: 29688238 PMCID: PMC5961611 DOI: 10.1039/c8cs00040a] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Indexed: 01/01/2023]
Abstract
In bionanotechnology, the field of creating functional materials consisting of bio-inspired molecules, the function and shape of a nanostructure only appear through the assembly of many small molecules together. The large number of building blocks required to define a nanostructure combined with the many degrees of freedom in packing small molecules has long precluded molecular simulations, but recent advances in computational hardware as well as software have made classical simulations available to this strongly expanding field. Here, we review the state of the art in simulations of self-assembling bio-inspired supramolecular systems. We will first discuss progress in force fields, simulation protocols and enhanced sampling techniques using recent examples. Secondly, we will focus on efforts to enable the comparison of experimentally accessible observables and computational results. Experimental quantities that can be measured by microscopy, spectroscopy and scattering can be linked to simulation output either directly or indirectly, via quantum mechanical or semi-empirical techniques. Overall, we aim to provide an overview of the various computational approaches to understand not only the molecular architecture of nanostructures, but also the mechanism of their formation.
Collapse
Affiliation(s)
- Pim W. J. M. Frederix
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials , University of Groningen , Groningen , The Netherlands . ;
| | - Ilias Patmanidis
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials , University of Groningen , Groningen , The Netherlands . ;
| | - Siewert J. Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials , University of Groningen , Groningen , The Netherlands . ;
| |
Collapse
|
35
|
Abstract
Various recent developments in solid-state nuclear magnetic resonance (ssNMR) spectroscopy have enabled an array of new insights regarding the structure, dynamics, and interactions of biomolecules. In the ever more integrated world of structural biology, ssNMR studies provide structural and dynamic information that is complementary to the data accessible by other means. ssNMR enables the study of samples lacking a crystalline lattice, featuring static as well as dynamic disorder, and does so independent of higher-order symmetry. The present study surveys recent applications of biomolecular ssNMR and examines how this technique is increasingly integrated with other structural biology techniques, such as (cryo) electron microscopy, solution-state NMR, and X-ray crystallography. Traditional ssNMR targets include lipid bilayer membranes and membrane proteins in a lipid bilayer environment. Another classic application has been in the area of protein misfolding and aggregation disorders, where ssNMR has provided essential structural data on oligomers and amyloid fibril aggregates. More recently, the application of ssNMR has expanded to a growing array of biological assemblies, ranging from non-amyloid protein aggregates, protein–protein complexes, viral capsids, and many others. Across these areas, multidimensional magic angle spinning (MAS) ssNMR has, in the last decade, revealed three-dimensional structures, including many that had been inaccessible by other structural biology techniques. Equally important insights in structural and molecular biology derive from the ability of MAS ssNMR to probe information beyond comprehensive protein structures, such as dynamics, solvent exposure, protein–protein interfaces, and substrate–enzyme interactions.
Collapse
|