1
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Golota NC, Michael B, Saliba EP, Linse S, Griffin RG. Structural characterization of E22G Aβ 1-42 fibrils via1H detected MAS NMR. Phys Chem Chem Phys 2024; 26:14664-14674. [PMID: 38715538 PMCID: PMC11110645 DOI: 10.1039/d4cp00553h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/25/2024] [Indexed: 05/23/2024]
Abstract
Amyloid fibrils have been implicated in the pathogenesis of several neurodegenerative diseases, the most prevalent example being Alzheimer's disease (AD). Despite the prevalence of AD, relatively little is known about the structure of the associated amyloid fibrils. This has motivated our studies of fibril structures, extended here to the familial Arctic mutant of Aβ1-42, E22G-Aβ1-42. We found E22G-AβM0,1-42 is toxic to Escherichia coli, thus we expressed E22G-Aβ1-42 fused to the self-cleavable tag NPro in the form of its EDDIE mutant. Since the high surface activity of E22G-Aβ1-42 makes it difficult to obtain more than sparse quantities of fibrils, we employed 1H detected magic angle spinning (MAS) nuclear magnetic resonance (NMR) experiments to characterize the protein. The 1H detected 13C-13C methods were first validated by application to fully protonated amyloidogenic nanocrystals of GNNQQNY, and then applied to fibrils of the Arctic mutant of Aβ, E22G-Aβ1-42. The MAS NMR spectra indicate that the biosynthetic samples of E22G-Aβ1-42 fibrils comprise a single conformation with 13C chemical shifts extracted from hCH, hNH, and hCCH spectra that are very similar to those of wild type Aβ1-42 fibrils. These results suggest that E22G-Aβ1-42 fibrils have a structure similar to that of wild type Aβ1-42.
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Affiliation(s)
- Natalie C Golota
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Brian Michael
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Edward P Saliba
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Sara Linse
- Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, SE 22100, Sweden
| | - Robert G Griffin
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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2
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van der Wel PC. Solid-state nuclear magnetic resonance in the structural study of polyglutamine aggregation. Biochem Soc Trans 2024; 52:719-731. [PMID: 38563485 PMCID: PMC11088915 DOI: 10.1042/bst20230731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/06/2024] [Accepted: 03/19/2024] [Indexed: 04/04/2024]
Abstract
The aggregation of proteins into amyloid-like fibrils is seen in many neurodegenerative diseases. Recent years have seen much progress in our understanding of these misfolded protein inclusions, thanks to advances in techniques such as solid-state nuclear magnetic resonance (ssNMR) spectroscopy and cryogenic electron microscopy (cryo-EM). However, multiple repeat-expansion-related disorders have presented special challenges to structural elucidation. This review discusses the special role of ssNMR analysis in the study of protein aggregates associated with CAG repeat expansion disorders. In these diseases, the misfolding and aggregation affect mutant proteins with expanded polyglutamine segments. The most common disorder, Huntington's disease (HD), is connected to the mutation of the huntingtin protein. Since the discovery of the genetic causes for HD in the 1990s, steady progress in our understanding of the role of protein aggregation has depended on the integrative and interdisciplinary use of multiple types of structural techniques. The heterogeneous and dynamic features of polyQ protein fibrils, and in particular those formed by huntingtin N-terminal fragments, have made these aggregates into challenging targets for structural analysis. ssNMR has offered unique insights into many aspects of these amyloid-like aggregates. These include the atomic-level structure of the polyglutamine core, but also measurements of dynamics and solvent accessibility of the non-core flanking domains of these fibrils' fuzzy coats. The obtained structural insights shed new light on pathogenic mechanisms behind this and other protein misfolding diseases.
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3
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Yi X, Fritzsching KJ, Rogawski R, Xu Y, McDermott AE. Contribution of protein conformational heterogeneity to NMR lineshapes at cryogenic temperatures. Proc Natl Acad Sci U S A 2024; 121:e2301053120. [PMID: 38346186 PMCID: PMC10895356 DOI: 10.1073/pnas.2301053120] [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: 01/18/2023] [Accepted: 10/17/2023] [Indexed: 02/15/2024] Open
Abstract
While low-temperature Nuclear Magnetic Resonance (NMR) holds great promise for the analysis of unstable samples and for sensitizing NMR detection, spectral broadening in frozen protein samples is a common experimental challenge. One hypothesis explaining the additional linewidth is that a variety of conformations are in rapid equilibrium at room temperature and become frozen, creating an inhomogeneous distribution at cryogenic temperatures. Here, we investigate conformational heterogeneity by measuring the backbone torsion angle (Ψ) in Escherichia coli Dihydrofolate Reductase (DHFR) at 105 K. Motivated by the particularly broad N chemical shift distribution in this and other examples, we modified an established NCCN Ψ experiment to correlate the chemical shift of Ni+1 to Ψi. With selective 15N and 13C enrichment of Ile, only the unique I60-I61 pair was expected to be detected in 13C'-15N correlation spectrum. For this unique amide, we detected three different conformation basins based on dispersed chemical shifts. Backbone torsion angles Ψ were determined for each basin: 114 ± 7° for the major peak and 150 ± 8° and 164 ± 16° for the minor peaks as contrasted with 118° for the X-ray crystal structure (and 118° to 130° for various previously reported structures). These studies support the hypothesis that inhomogeneous distributions of protein backbone torsion angles contribute to the lineshape broadening in low-temperature NMR spectra.
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Affiliation(s)
- Xu Yi
- Department of Chemistry, Columbia University, New York, NY 1002
| | | | - Rivkah Rogawski
- Department of Chemistry, Columbia University, New York, NY 1002
| | - Yunyao Xu
- Department of Chemistry, Columbia University, New York, NY 1002
| | - Ann E McDermott
- Department of Chemistry, Columbia University, New York, NY 1002
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4
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Lyubchenko YL. Protein Self-Assembly at the Liquid-Surface Interface. Surface-Mediated Aggregation Catalysis. J Phys Chem B 2023; 127:1880-1889. [PMID: 36812408 DOI: 10.1021/acs.jpcb.2c09029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Protein self-assembly into aggregates of various morphologies is a ubiquitous phenomenon in physical chemistry and biophysics. The critical role of amyloid assemblies in the development of diseases, neurodegenerative diseases especially, highlights the importance of understanding the mechanistic picture of the self-assembly process. The translation of this knowledge to the development of efficient preventions and treatments for diseases requires designing experiments at conditions mimicking those in vivo. This Perspective reviews data satisfying two major requirements: membrane environment and physiologically low concentrations of proteins. Recent progress in experiments and computational modeling resulted in a novel model for the amyloid aggregation process at the membrane-liquid interface. The self-assembly under such conditions has a number of critical features, further understanding of which can lead to the development of efficient preventive means and treatments for Alzheimer's and other devastating neurodegenerative disorders.
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Affiliation(s)
- Yuri L Lyubchenko
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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5
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Yi X, Fritzsching KJ, Rogawski R, Xu Y, McDermott AE. Contribution of protein conformational heterogeneity to NMR lineshapes at cryogenic temperatures. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.24.525358. [PMID: 36747795 PMCID: PMC9900807 DOI: 10.1101/2023.01.24.525358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
While low temperature NMR holds great promise for the analysis of unstable samples and for sensitizing NMR detection, spectral broadening in frozen protein samples is a common experimental challenge. One hypothesis explaining the additional linewidth is that a variety of conformations are in rapid equilibrium at room temperature and become frozen, creating an inhomogeneous distribution at cryogenic temperatures. Here we investigate conformational heterogeneity by measuring the backbone torsion angle (Ψ) in E. coli DHFR at 105K. Motivated by the particularly broad N chemical shift distribution in this and other examples, we modified an established NCCN Ψ experiment to correlate the chemical shift of N i+1 to Ψ i . With selective 15 N and 13 C enrichment of Ile, only the unique I60-I61 pair was expected to be detected in 13 C'- 15 N correlation spectrum. For this unique amide we detected three different conformation basins based on dispersed chemical shifts. Backbone torsion angles Ψ were determined for each basin 114 ± 7 for the major peak, and 150 ± 8 and 164 ± 16° for the minor peak as contrasted with 118 for the X-ray crystal structure (and 118-130 for various previously reported structures). These studies support the hypothesis that inhomogeneous distributions of protein backbone torsion angles contribute to the lineshape broadening in low temperature NMR spectra. Significance Statement Understanding protein conformational flexibility is essential for insights into the molecular basis of protein function and the thermodynamics of proteins. Here we investigate the ensemble of protein backbone conformations in a frozen protein freezing, which is likely a close representation for the ensemble in rapid equilibrium at room temperature. Various conformers are spectrally resolved due to the exquisite sensitivity of NMR shifts to local conformations, and NMR methods allow us to directly probe the torsion angles corresponding to each band of chemical shifts.
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6
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Liang L, Ji Y, Chen K, Gao P, Zhao Z, Hou G. Solid-State NMR Dipolar and Chemical Shift Anisotropy Recoupling Techniques for Structural and Dynamical Studies in Biological Systems. Chem Rev 2022; 122:9880-9942. [PMID: 35006680 DOI: 10.1021/acs.chemrev.1c00779] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
With the development of NMR methodology and technology during the past decades, solid-state NMR (ssNMR) has become a particularly important tool for investigating structure and dynamics at atomic scale in biological systems, where the recoupling techniques play pivotal roles in modern high-resolution MAS NMR. In this review, following a brief introduction on the basic theory of recoupling in ssNMR, we highlight the recent advances in dipolar and chemical shift anisotropy recoupling methods, as well as their applications in structural determination and dynamical characterization at multiple time scales (i.e., fast-, intermediate-, and slow-motion). The performances of these prevalent recoupling techniques are compared and discussed in multiple aspects, together with the representative applications in biomolecules. Given the recent emerging advances in NMR technology, new challenges for recoupling methodology development and potential opportunities for biological systems are also discussed.
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Affiliation(s)
- Lixin Liang
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Ji
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kuizhi Chen
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
| | - Pan Gao
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
| | - Zhenchao Zhao
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
| | - Guangjin Hou
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023, China
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7
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van der Wel PCA. Dihedral Angle Measurements for Structure Determination by Biomolecular Solid-State NMR Spectroscopy. Front Mol Biosci 2021; 8:791090. [PMID: 34938776 PMCID: PMC8685456 DOI: 10.3389/fmolb.2021.791090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
In structural studies of immobilized, aggregated and self-assembled biomolecules, solid-state NMR (ssNMR) spectroscopy can provide valuable high-resolution structural information. Among the structural restraints provided by magic angle spinning (MAS) ssNMR the canonical focus is on inter-atomic distance measurements. In the current review, we examine the utility of ssNMR measurements of angular constraints, as a complement to distance-based structure determination. The focus is on direct measurements of angular restraints via the judicious recoupling of multiple anisotropic ssNMR parameters, such as dipolar couplings and chemical shift anisotropies. Recent applications are highlighted, with a focus on studies of nanocrystalline polypeptides, aggregated peptides and proteins, receptor-substrate interactions, and small molecule interactions with amyloid protein fibrils. The review also examines considerations of when and where ssNMR torsion angle experiments are (most) effective, and discusses challenges and opportunities for future applications.
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Affiliation(s)
- Patrick C. A. van der Wel
- Solid-state NMR Group, Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
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8
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Willbold D, Strodel B, Schröder GF, Hoyer W, Heise H. Amyloid-type Protein Aggregation and Prion-like Properties of Amyloids. Chem Rev 2021; 121:8285-8307. [PMID: 34137605 DOI: 10.1021/acs.chemrev.1c00196] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review will focus on the process of amyloid-type protein aggregation. Amyloid fibrils are an important hallmark of protein misfolding diseases and therefore have been investigated for decades. Only recently, however, atomic or near-atomic resolution structures have been elucidated from various in vitro and ex vivo obtained fibrils. In parallel, the process of fibril formation has been studied in vitro under highly artificial but comparatively reproducible conditions. The review starts with a summary of what is known and speculated from artificial in vitro amyloid-type protein aggregation experiments. A partially hypothetic fibril selection model will be described that may be suitable to explain why amyloid fibrils look the way they do, in particular, why at least all so far reported high resolution cryo-electron microscopy obtained fibril structures are in register, parallel, cross-β-sheet fibrils that mostly consist of two protofilaments twisted around each other. An intrinsic feature of the model is the prion-like nature of all amyloid assemblies. Transferring the model from the in vitro point of view to the in vivo situation is not straightforward, highly hypothetic, and leaves many open questions that need to be addressed in the future.
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Affiliation(s)
- Dieter Willbold
- Institute of Biological Information Processing, Structural Biochemistry, IBI-7, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.,Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.,Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (State University), 141700 Dolgoprudny, Russia
| | - Birgit Strodel
- Institute of Biological Information Processing, Structural Biochemistry, IBI-7, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.,Institute of Theoretical and Computational Chemistry, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Gunnar F Schröder
- Institute of Biological Information Processing, Structural Biochemistry, IBI-7, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.,Physics Department, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Wolfgang Hoyer
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Henrike Heise
- Institute of Biological Information Processing, Structural Biochemistry, IBI-7, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.,Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
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9
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Gao Y, Saccuzzo EG, Hill SE, Huard DJE, Robang AS, Lieberman RL, Paravastu AK. Structural Arrangement within a Peptide Fibril Derived from the Glaucoma-Associated Myocilin Olfactomedin Domain. J Phys Chem B 2021; 125:2886-2897. [PMID: 33683890 DOI: 10.1021/acs.jpcb.0c11460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Myocilin-associated glaucoma is a new addition to the list of diseases linked to protein misfolding and amyloid formation. Single point variants of the ∼257-residue myocilin olfactomedin domain (mOLF) lead to mutant myocilin aggregation. Here, we analyze the 12-residue peptide P1 (GAVVYSGSLYFQ), corresponding to residues 326-337 of mOLF, previously shown to form amyloid fibrils in vitro and in silico. We applied solid-state NMR structural measurements to test the hypothesis that P1 fibrils adopt one of three predicted structures. Our data are consistent with a U-shaped fibril arrangement for P1, one that is related to the U-shape predicted previously in silico. Our data are also consistent with an antiparallel fibril arrangement, likely driven by terminal electrostatics. Our proposed structural model is reminiscent of fibrils formed by the Aβ(1-40) Iowa mutant peptide, but with a different arrangement of molecular turn regions. Taken together, our results strengthen the connection between mOLF fibrils and the broader amylome and contribute to our understanding of the fundamental molecular interactions governing fibril architecture and stability.
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10
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Zhang Y, Zhang M, Liu Y, Zhang D, Tang Y, Ren B, Zheng J. Dual amyloid cross-seeding reveals steric zipper-facilitated fibrillization and pathological links between protein misfolding diseases. J Mater Chem B 2021; 9:3300-3316. [PMID: 33651875 DOI: 10.1039/d0tb02958k] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Amyloid cross-seeding, as a result of direct interaction and co-aggregation between different disease-causative peptides, is considered as a main mechanism for the spread of the overlapping pathology across different cells and tissues between different protein-misfolding diseases (PMDs). Despite the biomedical significance of amyloid cross-seeding in amyloidogenesis, it remains a great challenge to discover amyloid cross-seeding systems and reveal their cross-seeding structures and mechanisms. Herein, we are the first to report that GNNQQNY - a short fragment from yeast prion protein Sup35 - can cross-seed with both amyloid-β (Aβ, associated with Alzheimer's disease) and human islet amyloid polypeptide (hIAPP, associated with type II diabetes) to form β-structure-rich assemblies and to accelerate amyloid fibrillization. Dry, steric β-zippers, formed by the two β-sheets of different amyloid peptides, provide generally interactive and structural motifs to facilitate amyloid cross-seeding. The presence of different steric β-zippers in a variety of GNNQQNY-Aβ and GNNQQNY-hIAPP assemblies also explains amyloid polymorphism. In addition, alteration of steric zipper formation by single-point mutations of GNNQQNY and interactions of GNNQQNY with different Aβ and hIAPP seeds leads to different amyloid cross-seeding efficiencies, further confirming the existence of cross-seeding barriers. This work offers a better structural-based understanding of amyloid cross-seeding mechanisms linked to different PMDs.
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Affiliation(s)
- Yanxian Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering The University of Akron, Ohio, USA.
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11
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Szała-Mendyk B, Molski A. Clustering and Fibril Formation during GNNQQNY Aggregation: A Molecular Dynamics Study. Biomolecules 2020; 10:biom10101362. [PMID: 32987720 PMCID: PMC7598727 DOI: 10.3390/biom10101362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 12/02/2022] Open
Abstract
The precise kinetic pathways of peptide clustering and fibril formation are not fully understood. Here we study the initial clustering kinetics and transient cluster morphologies during aggregation of the heptapeptide fragment GNNQQNY from the yeast prion protein Sup35. We use a mid-resolution coarse-grained molecular dynamics model of Bereau and Deserno to explore the aggregation pathways from the initial random distribution of free monomers to the formation of large clusters. By increasing the system size to 72 peptides we could follow directly the molecular events leading to the formation of stable fibril-like structures. To quantify those structures we developed a new cluster helicity parameter. We found that the formation of fibril-like structures is a cooperative processes that requires a critical number of monomers, M⋆≈25, in a cluster. The terminal tyrosine residue is the structural determinant in the formation of helical fibril-like structures. This work supports and quantifies the two-step aggregation model where the initially formed amorphous clusters grow and, when they are large enough, rearrange into mature twisted structures. However, in addition to the nucleated fibrillation, growing aggregates undergo further internal reorganization, which leads to more compact structures of large aggregates.
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12
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Ghosh S, T D, Baul U, Vemparala S. Aggregation dynamics of charged peptides in water: Effect of salt concentration. J Chem Phys 2019; 151:074901. [DOI: 10.1063/1.5100890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Susmita Ghosh
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Devanand T
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Upayan Baul
- Institue of Physics, Albert-Ludwigs-University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Satyavani Vemparala
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
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13
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Wu H, Saltzberg DJ, Kratochvil HT, Jo H, Sali A, DeGrado WF. Glutamine Side Chain 13C═ 18O as a Nonperturbative IR Probe of Amyloid Fibril Hydration and Assembly. J Am Chem Soc 2019; 141:7320-7326. [PMID: 30998340 DOI: 10.1021/jacs.9b00577] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Infrared (IR) spectroscopy has provided considerable insight into the structures, dynamics, and formation mechanisms of amyloid fibrils. IR probes, such as main chain 13C═18O, have been widely employed to obtain site-specific structural information, yet only secondary structures and strand-to-strand arrangements can be probed. Very few nonperturbative IR probes are available to report on the side-chain conformation and environments, which are critical to determining sheet-to-sheet arrangements in steric zippers within amyloids. Polar residues, such as glutamine, contribute significantly to the stability of amyloids and thus are frequently found in core regions of amyloid peptides/proteins. Furthermore, polyglutamine (polyQ) repeats form toxic aggregates in several neurodegenerative diseases. Here we report the synthesis and application of a new nonperturbative IR probe-glutamine side chain 13C═18O. We use side chain 13C═18O labeling and isotope dilution to detect the presence of intermolecularly hydrogen-bonded arrays of glutamine side chains (Gln ladders) in amyloid-forming peptides. Moreover, the line width of the 13C═18O peak is highly sensitive to its local hydration environment. The IR data from side chain labeling allows us to unambiguously determine the sheet-to-sheet arrangement in a short amyloid-forming peptide, GNNQQNY, providing insight that was otherwise inaccessible through main chain labeling. With several different fibril samples, we also show the versatility of this IR probe in studying the structures and aggregation kinetics of amyloids. Finally, we demonstrate the capability of modeling amyloid structures with IR data using the integrative modeling platform (IMP) and the potential of integrating IR with other biophysical methods for more accurate structural modeling. Together, we believe that side chain 13C═18O will complement main chain isotope labeling in future IR studies of amyloids and integrative modeling using IR data will significantly expand the power of IR spectroscopy to elucidate amyloid assemblies.
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14
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Zhao X, Liao C, Ma YT, Ferrell JB, Schneebeli ST, Li J. Top-down Multiscale Approach To Simulate Peptide Self-Assembly from Monomers. J Chem Theory Comput 2019; 15:1514-1522. [PMID: 30677300 DOI: 10.1021/acs.jctc.8b01025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Modeling peptide assembly from monomers on large time and length scales is often intractable at the atomistic resolution. To address this challenge, we present a new approach which integrates coarse-grained (CG), mixed-resolution, and all-atom (AA) modeling in a single simulation. We simulate the initial encounter stage with the CG model, while the further assembly and reorganization stages are simulated with the mixed-resolution and AA models. We have implemented this top-down approach with new tools to automate model transformations and to monitor oligomer formations. Further, a theory was developed to estimate the optimal simulation length for each stage using a model peptide, melittin. The assembly level, the oligomer distribution, and the secondary structures of melittin simulated by the optimal protocol show good agreement with prior experiments and AA simulations. Finally, our approach and theory have been successfully validated with three amyloid peptides (β-amyloid 16-22, GNNQQNY fragment from the yeast prion protein SUP35, and α-synuclein fibril 35-55), which highlight the synergy from modeling at multiple resolutions. This work not only serves as proof of concept for multiresolution simulation studies but also presents practical guidelines for further self-assembly simulations at more physically and chemically relevant scales.
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Affiliation(s)
- Xiaochuan Zhao
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Chenyi Liao
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Yong-Tao Ma
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Jonathon B Ferrell
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Severin T Schneebeli
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Jianing Li
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
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15
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Erskine E, MacPhee CE, Stanley-Wall NR. Functional Amyloid and Other Protein Fibers in the Biofilm Matrix. J Mol Biol 2018; 430:3642-3656. [PMID: 30098341 PMCID: PMC6173796 DOI: 10.1016/j.jmb.2018.07.026] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/17/2018] [Accepted: 07/24/2018] [Indexed: 02/06/2023]
Abstract
Biofilms are ubiquitous in the natural and man-made environment. They are defined as microbes that are encapsulated in an extracellular, self-produced, biofilm matrix. Growing evidence from the genetic and biochemical analysis of single species biofilms has linked the presence of fibrous proteins to a functional biofilm matrix. Some of these fibers have been described as functional amyloid or amyloid-like fibers. Here we provide an overview of the biophysical and biological data for a wide range of protein fibers found in the biofilm matrix of Gram-positive and Gram-negative bacteria.
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Affiliation(s)
- Elliot Erskine
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Cait E MacPhee
- James Clerk Maxwell Building, School of Physics, University of Edinburgh, The Kings Buildings, Mayfield Road, Edinburgh, EH9 3JZ, UK.
| | - Nicola R Stanley-Wall
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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16
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Martial B, Lefèvre T, Auger M. Understanding amyloid fibril formation using protein fragments: structural investigations via vibrational spectroscopy and solid-state NMR. Biophys Rev 2018; 10:1133-1149. [PMID: 29855812 PMCID: PMC6082320 DOI: 10.1007/s12551-018-0427-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 05/17/2018] [Indexed: 12/11/2022] Open
Abstract
It is well established that amyloid proteins play a primary role in neurodegenerative diseases. Alzheimer's, Parkinson's, type II diabetes, and Creutzfeldt-Jakob's diseases are part of a wider family encompassing more than 50 human pathologies related to aggregation of proteins. Although this field of research is thoroughly investigated, several aspects of fibrillization remain misunderstood, which in turn slows down, or even impedes, advances in treating and curing amyloidoses. To solve this problem, several research groups have chosen to focus on short fragments of amyloid proteins, sequences that have been found to be of great importance for the amyloid formation process. Studying short peptides allows bypassing the complexity of working with full-length proteins and may provide important information relative to critical segments of amyloid proteins. To this end, efficient biophysical tools are required. In this review, we focus on two essential types of spectroscopic techniques, i.e., vibrational spectroscopy and its derivatives (conventional Raman scattering, deep-UV resonance Raman (DUVRR), Raman optical activity (ROA), surface-enhanced Raman spectroscopy (SERS), tip-enhanced Raman spectroscopy (TERS), infrared (IR) absorption spectroscopy, vibrational circular dichroism (VCD)) and solid-state nuclear magnetic resonance (ssNMR). These techniques revealed powerful to provide a better atomic and molecular comprehension of the amyloidogenic process and fibril structure. This review aims at underlining the information that these techniques can provide and at highlighting their strengths and weaknesses when studying amyloid fragments. Meaningful examples from the literature are provided for each technique, and their complementarity is stressed for the kinetic and structural characterization of amyloid fibril formation.
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Affiliation(s)
- Benjamin Martial
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, G1V 0A6, Canada
| | - Thierry Lefèvre
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, G1V 0A6, Canada
| | - Michèle Auger
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, G1V 0A6, Canada.
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17
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Katyal N, Deep S. Inhibition of GNNQQNY prion peptide aggregation by trehalose: a mechanistic view. Phys Chem Chem Phys 2018; 19:19120-19138. [PMID: 28702592 DOI: 10.1039/c7cp02912h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Deposition of amyloid fibrils is the seminal event in the pathogenesis of numerous neurodegenerative diseases. The formation of this amyloid assembly is the manifestation of a cascade of structural transitions including toxic oligomer formation in the early stages of aggregation. Thus a viable therapeutic strategy involves the use of small molecular ligands to interfere with this assembly. In this perspective, we have explored the kinetics of aggregate formation of the fibril forming GNNQQNY peptide fragment from the yeast prion protein SUP35 using multiple all atom MD simulations with explicit solvent and provided mechanistic insights into the way trehalose, an experimentally known aggregation inhibitor, modulates the aggregation pathway. The results suggest that the assimilation process is impeded by different barriers at smaller and larger oligomeric sizes: the initial one being easily surpassed at higher temperatures and peptide concentrations. The kinetic profile demonstrates that trehalose delays the aggregation process by increasing both these activation barriers, specifically the latter one. It increases the sampling of small-sized aggregates that lack the beta sheet conformation. Analysis reveals that the barrier in the growth of larger stable oligomers causes the formation of multiple stable small oligomers which then fuse together bimolecularly. The PCA of 26 properties was carried out to deconvolute the events within the temporary lag phases, which suggested dynamism in lags involving an increase in interchain contacts and burial of SASA. The predominant growth route is monomer addition, which changes to condensation on account of a large number of depolymerisation events in the presence of trehalose. The favourable interaction of trehalose specifically with the sidechain of the peptide promotes crowding of trehalose molecules in its vicinity - the combination of both these factors imparts the observed behaviour. Furthermore, increasing trehalose concentration leads to faster expulsion of water molecules than interpeptide interactions. These expelled water molecules have larger translational movement, suggesting an entropy factor to favor the assembly process. Different conformations observed under this condition suggest the role of water molecules in guiding the morphology of the aggregates as well. A similar scenario exists on increasing peptide concentration.
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Affiliation(s)
- Nidhi Katyal
- Department of Chemistry, Indian Institute of Technology, Delhi, Hauzkhas, New Delhi, India.
| | - Shashank Deep
- Department of Chemistry, Indian Institute of Technology, Delhi, Hauzkhas, New Delhi, India.
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18
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Periole X, Huber T, Bonito-Oliva A, Aberg KC, van der Wel PCA, Sakmar TP, Marrink SJ. Energetics Underlying Twist Polymorphisms in Amyloid Fibrils. J Phys Chem B 2018; 122:1081-1091. [PMID: 29254334 PMCID: PMC5857390 DOI: 10.1021/acs.jpcb.7b10233] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Amyloid fibrils are highly ordered protein aggregates associated with more than 40 human diseases. The exact conditions under which the fibrils are grown determine many types of reported fibril polymorphism, including different twist patterns. Twist-based polymorphs display unique mechanical properties in vitro, and the relevance of twist polymorphism in amyloid diseases has been suggested. We present transmission electron microscopy images of Aβ42-derived (amyloid β) fibrils, which are associated with Alzheimer's disease, demonstrating the presence of twist variability even within a single long fibril. To better understand the molecular underpinnings of twist polymorphism, we present a structural and thermodynamics analysis of molecular dynamics simulations of the twisting of β-sheet protofilaments of a well-characterized cross-β model: the GNNQQNY peptide from the yeast prion Sup35. The results show that a protofilament model of GNNQQNY is able to adopt twist angles from -11° on the left-hand side to +8° on the right-hand side in response to various external conditions, keeping an unchanged peptide structure. The potential of mean force (PMF) of this cross-β structure upon twisting revealed that only ∼2kBT per peptide are needed to stabilize a straight conformation with respect to the left-handed free-energy minimum. The PMF also shows that the canonical structural core of β-sheets, i.e., the hydrogen-bonded backbone β-strands, favors the straight conformation. However, the concerted effects of the side chains contribute to twisting, which provides a rationale to correlate polypeptide sequence, environmental growth conditions and number of protofilaments in a fibril with twist polymorphisms.
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Affiliation(s)
- Xavier Periole
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen , Groningen 9747 AG, The Netherlands
| | - Thomas Huber
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University , 1230 York Avenue, New York, New York 10065, United States
| | - Alessandra Bonito-Oliva
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University , 1230 York Avenue, New York, New York 10065, United States
| | - Karina C Aberg
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University , 1230 York Avenue, New York, New York 10065, United States
| | - Patrick C A van der Wel
- Department of Structural Biology and Center for Protein Conformational Diseases, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15260, United States
| | - Thomas P Sakmar
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University , 1230 York Avenue, New York, New York 10065, United States
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet , 141 57 Huddinge, Sweden
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen , Groningen 9747 AG, The Netherlands
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19
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van der Wel PCA. Insights into protein misfolding and aggregation enabled by solid-state NMR spectroscopy. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 88:1-14. [PMID: 29035839 PMCID: PMC5705391 DOI: 10.1016/j.ssnmr.2017.10.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 05/17/2023]
Abstract
The aggregation of proteins and peptides into a variety of insoluble, and often non-native, aggregated states plays a central role in many devastating diseases. Analogous processes undermine the efficacy of polypeptide-based biological pharmaceuticals, but are also being leveraged in the design of biologically inspired self-assembling materials. This Trends article surveys the essential contributions made by recent solid-state NMR (ssNMR) studies to our understanding of the structural features of polypeptide aggregates, and how such findings are informing our thinking about the molecular mechanisms of misfolding and aggregation. A central focus is on disease-related amyloid fibrils and oligomers involved in neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's disease. SSNMR-enabled structural and dynamics-based findings are surveyed, along with a number of resulting emerging themes that appear common to different amyloidogenic proteins, such as their compact alternating short-β-strand/β-arc amyloid core architecture. Concepts, methods, future prospects and challenges are discussed.
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Affiliation(s)
- Patrick C A van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA.
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20
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Combining DNP NMR with segmental and specific labeling to study a yeast prion protein strain that is not parallel in-register. Proc Natl Acad Sci U S A 2017; 114:3642-3647. [PMID: 28330994 DOI: 10.1073/pnas.1619051114] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The yeast prion protein Sup35NM is a self-propagating amyloid. Despite intense study, there is no consensus on the organization of monomers within Sup35NM fibrils. Some studies point to a β-helical arrangement, whereas others suggest a parallel in-register organization. Intermolecular contacts are often determined by experiments that probe long-range heteronuclear contacts for fibrils templated from a 1:1 mixture of 13C- and 15N-labeled monomers. However, for Sup35NM, like many large proteins, chemical shift degeneracy limits the usefulness of this approach. Segmental and specific isotopic labeling reduce degeneracy, but experiments to measure long-range interactions are often too insensitive. To limit degeneracy and increase experimental sensitivity, we combined specific and segmental isotopic labeling schemes with dynamic nuclear polarization (DNP) NMR. Using this combination, we examined an amyloid form of Sup35NM that does not have a parallel in-register structure. The combination of a small number of specific labels with DNP NMR enables determination of architectural information about polymeric protein systems.
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21
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Mandal A, Boatz JC, Wheeler TB, van der Wel PCA. On the use of ultracentrifugal devices for routine sample preparation in biomolecular magic-angle-spinning NMR. JOURNAL OF BIOMOLECULAR NMR 2017; 67:165-178. [PMID: 28229262 PMCID: PMC5445385 DOI: 10.1007/s10858-017-0089-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/19/2017] [Indexed: 05/07/2023]
Abstract
A number of recent advances in the field of magic-angle-spinning (MAS) solid-state NMR have enabled its application to a range of biological systems of ever increasing complexity. To retain biological relevance, these samples are increasingly studied in a hydrated state. At the same time, experimental feasibility requires the sample preparation process to attain a high sample concentration within the final MAS rotor. We discuss these considerations, and how they have led to a number of different approaches to MAS NMR sample preparation. We describe our experience of how custom-made (or commercially available) ultracentrifugal devices can facilitate a simple, fast and reliable sample preparation process. A number of groups have since adopted such tools, in some cases to prepare samples for sedimentation-style MAS NMR experiments. Here we argue for a more widespread adoption of their use for routine MAS NMR sample preparation.
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Affiliation(s)
- Abhishek Mandal
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA
| | - Jennifer C Boatz
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA
| | - Travis B Wheeler
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, 15260, USA
| | - Patrick C A van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA.
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22
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Lei J, Qi R, Xie L, Xi W, Wei G. Inhibitory effect of hydrophobic fullerenes on the β-sheet-rich oligomers of a hydrophilic GNNQQNY peptide revealed by atomistic simulations. RSC Adv 2017. [DOI: 10.1039/c6ra27608c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Fullerenes suppress fibril-like β-sheet oligomers by interacting strongly with the nonpolar aliphatic groups of polar residues of GNNQQNY peptide, thus inhibit peptide aggregation.
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Affiliation(s)
- Jiangtao Lei
- State Key Laboratory of Surface Physics
- Key Laboratory for Computational Physical Sciences (Ministry of Education)
- Department of Physics
- Fudan University
- Shanghai
| | - Ruxi Qi
- State Key Laboratory of Surface Physics
- Key Laboratory for Computational Physical Sciences (Ministry of Education)
- Department of Physics
- Fudan University
- Shanghai
| | - Luogang Xie
- State Key Laboratory of Surface Physics
- Key Laboratory for Computational Physical Sciences (Ministry of Education)
- Department of Physics
- Fudan University
- Shanghai
| | - Wenhui Xi
- State Key Laboratory of Surface Physics
- Key Laboratory for Computational Physical Sciences (Ministry of Education)
- Department of Physics
- Fudan University
- Shanghai
| | - Guanghong Wei
- State Key Laboratory of Surface Physics
- Key Laboratory for Computational Physical Sciences (Ministry of Education)
- Department of Physics
- Fudan University
- Shanghai
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23
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Amyloid formation characteristics of GNNQQNY from yeast prion protein Sup35 and its seeding with heterogeneous polypeptides. Colloids Surf B Biointerfaces 2017; 149:72-79. [DOI: 10.1016/j.colsurfb.2016.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/03/2016] [Accepted: 10/06/2016] [Indexed: 11/19/2022]
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24
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Quinn CM, Polenova T. Structural biology of supramolecular assemblies by magic-angle spinning NMR spectroscopy. Q Rev Biophys 2017; 50:e1. [PMID: 28093096 PMCID: PMC5483179 DOI: 10.1017/s0033583516000159] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In recent years, exciting developments in instrument technology and experimental methodology have advanced the field of magic-angle spinning (MAS) nuclear magnetic resonance (NMR) to new heights. Contemporary MAS NMR yields atomic-level insights into structure and dynamics of an astounding range of biological systems, many of which cannot be studied by other methods. With the advent of fast MAS, proton detection, and novel pulse sequences, large supramolecular assemblies, such as cytoskeletal proteins and intact viruses, are now accessible for detailed analysis. In this review, we will discuss the current MAS NMR methodologies that enable characterization of complex biomolecular systems and will present examples of applications to several classes of assemblies comprising bacterial and mammalian cytoskeleton as well as human immunodeficiency virus 1 and bacteriophage viruses. The body of work reviewed herein is representative of the recent advancements in the field, with respect to the complexity of the systems studied, the quality of the data, and the significance to the biology.
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Affiliation(s)
- Caitlin M. Quinn
- University of Delaware, Department of Chemistry and Biochemistry, Newark, DE 19711; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA 15306
| | - Tatyana Polenova
- University of Delaware, Department of Chemistry and Biochemistry, Newark, DE 19711; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA 15306
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25
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Huntingtin exon 1 fibrils feature an interdigitated β-hairpin-based polyglutamine core. Proc Natl Acad Sci U S A 2016; 113:1546-51. [PMID: 26831073 DOI: 10.1073/pnas.1521933113] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Polyglutamine expansion within the exon1 of huntingtin leads to protein misfolding, aggregation, and cytotoxicity in Huntington's disease. This incurable neurodegenerative disease is the most prevalent member of a family of CAG repeat expansion disorders. Although mature exon1 fibrils are viable candidates for the toxic species, their molecular structure and how they form have remained poorly understood. Using advanced magic angle spinning solid-state NMR, we directly probe the structure of the rigid core that is at the heart of huntingtin exon1 fibrils and other polyglutamine aggregates, via measurements of long-range intramolecular and intermolecular contacts, backbone and side-chain torsion angles, relaxation measurements, and calculations of chemical shifts. These experiments reveal the presence of β-hairpin-containing β-sheets that are connected through interdigitating extended side chains. Despite dramatic differences in aggregation behavior, huntingtin exon1 fibrils and other polyglutamine-based aggregates contain identical β-strand-based cores. Prior structural models, derived from X-ray fiber diffraction and computational analyses, are shown to be inconsistent with the solid-state NMR results. Internally, the polyglutamine amyloid fibrils are coassembled from differently structured monomers, which we describe as a type of "intrinsic" polymorphism. A stochastic polyglutamine-specific aggregation mechanism is introduced to explain this phenomenon. We show that the aggregation of mutant huntingtin exon1 proceeds via an intramolecular collapse of the expanded polyglutamine domain and discuss the implications of this observation for our understanding of its misfolding and aggregation mechanisms.
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26
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Srivastava A, Balaji PV. Molecular events during the early stages of aggregation of GNNQQNY: An all atom MD simulation study of randomly dispersed peptides. J Struct Biol 2015; 192:376-391. [DOI: 10.1016/j.jsb.2015.09.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 09/26/2015] [Accepted: 09/30/2015] [Indexed: 12/11/2022]
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27
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Ksenofontov AL, Parshina EY, Fedorova NV, Arutyunyan AM, Rumvolt R, Paalme V, Baratova LA, Järvekülg L, Dobrov EN. Heating-induced transition of Potyvirus Potato Virus A coat protein into β-structure. J Biomol Struct Dyn 2015; 34:250-8. [PMID: 25851284 DOI: 10.1080/07391102.2015.1022604] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In our previous communication, we have reported that virions of plant Potyvirus Potato Virus A (PVA) have a peculiar structure characterized by high content of disordered regions in intravirus coat protein (CP). In this report, we describe unusual properties of the PVA CP. With the help of a number of physicochemical methods, we have observed that the PVA CP just released from the virions by heating at 60-70 °C undergoes association into oligomers and transition to β- (and even cross-β-) conformation. Transition to β-structure on heating has been recently reported for a number of viral and non-viral proteins. The PVA CP isolated by LiCl method was also transformed into cross-β-structure on heating to 60 °C. Using the algorithms for protein aggregation prediction, we found that the aggregation-prone segments should be located in the central region of a PVA CP molecule. Possibly this transition mimics some functions of PVA CP in the virus life cycle in infected plants.
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Affiliation(s)
- Alexander L Ksenofontov
- a A.N. Belozersky Institute of Physico-Chemical Biology , Lomonosov Moscow State University , 1/40 Leninskie gory, Moscow 119991 , Russia
| | - Evgenia Yu Parshina
- b Department of Biophysics , Moscow State University , Moscow 119991 , Russia
| | - Natalia V Fedorova
- a A.N. Belozersky Institute of Physico-Chemical Biology , Lomonosov Moscow State University , 1/40 Leninskie gory, Moscow 119991 , Russia
| | - Alexander M Arutyunyan
- a A.N. Belozersky Institute of Physico-Chemical Biology , Lomonosov Moscow State University , 1/40 Leninskie gory, Moscow 119991 , Russia
| | - Reet Rumvolt
- c Department of Gene Technology , Tallinn University of Technology , Akadeemia tee 15, Tallinn 12618 , Estonia
| | - Viiu Paalme
- c Department of Gene Technology , Tallinn University of Technology , Akadeemia tee 15, Tallinn 12618 , Estonia
| | - Ludmila A Baratova
- a A.N. Belozersky Institute of Physico-Chemical Biology , Lomonosov Moscow State University , 1/40 Leninskie gory, Moscow 119991 , Russia
| | - Lilian Järvekülg
- c Department of Gene Technology , Tallinn University of Technology , Akadeemia tee 15, Tallinn 12618 , Estonia
| | - Eugeny N Dobrov
- a A.N. Belozersky Institute of Physico-Chemical Biology , Lomonosov Moscow State University , 1/40 Leninskie gory, Moscow 119991 , Russia
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28
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Langkilde AE, Morris KL, Serpell LC, Svergun DI, Vestergaard B. The architecture of amyloid-like peptide fibrils revealed by X-ray scattering, diffraction and electron microscopy. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:882-95. [PMID: 25849399 PMCID: PMC4388266 DOI: 10.1107/s1399004715001674] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 01/25/2015] [Indexed: 11/12/2022]
Abstract
Structural analysis of protein fibrillation is inherently challenging. Given the crucial role of fibrils in amyloid diseases, method advancement is urgently needed. A hybrid modelling approach is presented enabling detailed analysis of a highly ordered and hierarchically organized fibril of the GNNQQNY peptide fragment of a yeast prion protein. Data from small-angle X-ray solution scattering, fibre diffraction and electron microscopy are combined with existing high-resolution X-ray crystallographic structures to investigate the fibrillation process and the hierarchical fibril structure of the peptide fragment. The elongation of these fibrils proceeds without the accumulation of any detectable amount of intermediate oligomeric species, as is otherwise reported for, for example, glucagon, insulin and α-synuclein. Ribbons constituted of linearly arranged protofilaments are formed. An additional hierarchical layer is generated via the pairing of ribbons during fibril maturation. Based on the complementary data, a quasi-atomic resolution model of the protofilament peptide arrangement is suggested. The peptide structure appears in a β-sheet arrangement reminiscent of the β-zipper structures evident from high-resolution crystal structures, with specific differences in the relative peptide orientation. The complexity of protein fibrillation and structure emphasizes the need to use multiple complementary methods.
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Affiliation(s)
- Annette E. Langkilde
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Kyle L. Morris
- School of Life Sciences, University of Sussex, Falmer, Brighton, England
| | - Louise C. Serpell
- School of Life Sciences, University of Sussex, Falmer, Brighton, England
| | - Dmitri I. Svergun
- European Molecular Biology Laboratory, Hamburg Outstation, 22607 Hamburg, Germany
| | - Bente Vestergaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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29
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Schütz AK, Habenstein B, Luckgei N, Bousset L, Sourigues Y, Nielsen AB, Melki R, Böckmann A, Meier BH. Solid-state NMR sequential assignments of the amyloid core of full-length Sup35p. BIOMOLECULAR NMR ASSIGNMENTS 2014; 8:349-356. [PMID: 23943018 DOI: 10.1007/s12104-013-9515-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 08/01/2013] [Indexed: 06/02/2023]
Abstract
Sup35p is a yeast prion and is responsible for the [PSI(+)] trait in Saccharomyces cerevisiae. With 685 amino acids, full-length soluble and fibrillar Sup35p are challenging targets for structural biology as they cannot be investigated by X-ray crystallography or NMR in solution. We present solid-state NMR studies of fibrils formed by the full-length Sup35 protein. We detect an ordered and rigid core of the protein that gives rise to narrow and strong peaks, while large parts of the protein show either static disorder or dynamics on time scales which interfere with dipolar polarization transfer or shorten the coherence lifetime. Thus, only a small subset of resonances is observed in 3D spectra. Here we describe in detail the sequential assignments of the 22 residues for which resonances are observed in 3D spectra: their chemical shifts mostly corresponding to β-sheet secondary structure. We suspect that these residues form the amyloid core of the fibril.
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Affiliation(s)
- Anne K Schütz
- Physical Chemistry, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093, Zurich, Switzerland
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30
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Srivastava A, Balaji PV. Interplay of sequence, topology and termini charge in determining the stability of the aggregates of GNNQQNY mutants: a molecular dynamics study. PLoS One 2014; 9:e96660. [PMID: 24817093 PMCID: PMC4015988 DOI: 10.1371/journal.pone.0096660] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 04/11/2014] [Indexed: 01/16/2023] Open
Abstract
This study explores the stabilities of single sheet parallel systems of three sequence variants of 1GNNQQNY7, N2D, N2S and N6D, with variations in aggregate size (5–8) and termini charge (charged or neutral). The aggregates were simulated at 300 and 330 K. These mutations decrease amyloid formation in the yeast prion protein Sup35. The present study finds that these mutations cause instability even in the peptide context. The protonation status of termini is found to be a key determinant of stabilities; other determinants are sequence, position of mutation and aggregate size. All systems with charged termini are unstable, whereas both stable and unstable systems are found when the termini are neutral. When termini are charged, the largest stable aggregate for the N2S and N6D systems has 3 to 4 peptides whereas N2D mutation supports oligomers of larger size (5-and 6-mers) as well. Mutation at 2nd position (N2S and N2D) results in fewer H-bonds at the mutated as well as neighboring (Gly1/Gln4) positions. However, no such effect is found if mutation is at 6th position (N6D). The effect of Asn→Asp mutation depends on the position and termini charge: it is more destabilizing at the 2nd position than at the 6th in case of neutral termini, however, the opposite is true in case of charged termini. Appearance of twist in stable systems and in smaller aggregates formed in unstable systems suggests that twist is integral to amyloid arrangement. Disorder, dissociation or rearrangement of peptides, disintegration or collapse of aggregates and formation of amorphous aggregates observed in these simulations are likely to occur during the early stages of aggregation also. The smaller aggregates formed due to such events have a variety of arrangements of peptides. This suggests polymorphic nature of oligomers and presence of a heterogeneous mixture of oligomers during early stages of aggregation.
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Affiliation(s)
- Alka Srivastava
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Petety V. Balaji
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
- * E-mail:
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31
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Solid-state NMR studies of metal-free SOD1 fibrillar structures. J Biol Inorg Chem 2014; 19:659-66. [PMID: 24719206 DOI: 10.1007/s00775-014-1130-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 03/10/2014] [Indexed: 10/25/2022]
Abstract
Copper-zinc superoxide dismutase 1 (SOD1) is present in the protein aggregates deposited in motor neurons of amyotrophic lateral sclerosis (ALS) patients. ALS is a neurodegenerative disease that can be either sporadic (ca. 90%) or familial (fALS). The most widely studied forms of fALS are caused by mutations in the sequence of SOD1. Ex mortuo SOD1 aggregates are usually found to be amorphous. In vitro SOD1, in its immature reduced and apo state, forms fibrillar aggregates. Previous literature data have suggested that a monomeric SOD1 construct, lacking loops IV and VII, (apoSODΔIV-VII), shares the same fibrillization properties of apoSOD1, both proteins having the common structural feature of the central β-barrel. In this work, we show that structural information can be obtained at a site-specific level from solid-state NMR. The residues that are sequentially assignable are found to be located at the putative nucleation site for fibrillar species formation in apoSOD, as detected by other experimental techniques.
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Kabani M, Redeker V, Melki R. A role for the proteasome in the turnover of Sup35p and in [PSI(+) ] prion propagation. Mol Microbiol 2014; 92:507-28. [PMID: 24589377 DOI: 10.1111/mmi.12572] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2014] [Indexed: 01/21/2023]
Abstract
Yeast prions are superb models for understanding the mechanisms of self-perpetuating protein aggregates formation. [PSI(+) ] stands among the most documented yeast prions and results from self-assembly of the translation termination factor Sup35p into protein fibrils. A plethora of cellular factors were shown to affect [PSI(+) ] formation and propagation. Clearance of Sup35p prion particles is however poorly understood and documented. Here, we investigated the role of the proteasome in the degradation of Sup35p and in [PSI(+) ] prion propagation. We found that cells lacking the RPN4 gene, which have reduced intracellular proteasome pools, accumulated Sup35p and have defects in [PSI(+) ] formation and propagation. Sup35p is degraded in vitro by the 26S and 20S proteasomes in a ubiquitin-independent manner, generating an array of amyloidogenic peptides derived from its prion-domain. We also demonstrate the formation of a proteasome-resistant fragment spanning residues 83-685 which is devoid of the prion-domain that is essential for [PSI(+) ] propagation. Most important was the finding that the 26S and 20S proteasomes degrade Sup35p fibrils in vitro and abolish their infectivity. Our results point to an overlooked role of the proteasome in clearing toxic protein aggregates, and have important implications for a better understanding of the life cycle of infectious protein assemblies.
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Affiliation(s)
- Mehdi Kabani
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Bât. 34, Avenue de la Terrasse, F-91190, Gif-sur-Yvette, France
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Gath J, Bousset L, Habenstein B, Melki R, Böckmann A, Meier BH. Unlike twins: an NMR comparison of two α-synuclein polymorphs featuring different toxicity. PLoS One 2014; 9:e90659. [PMID: 24599158 PMCID: PMC3944079 DOI: 10.1371/journal.pone.0090659] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 02/05/2014] [Indexed: 11/18/2022] Open
Abstract
We structurally compare, using solid-state NMR, two different polymorphs of α-synuclein which, as established recently, display contrasting biochemical properties, toxicity, and tropism for cells. We show that both forms, which can each be produced as a pure polymorph, are greatly different in secondary structure. While β-sheets are the dominating secondary structure elements for both polymorphs, they are markedly divergent in terms of number of elements, as well as their distribution. We demonstrate that all identified β-sheets feature an in-register parallel stacking for both polymorphs. The two forms show a different molecular arrangement in the unit cell and distinct dynamic features, while sharing a highly flexible C-terminal domain. The use of reproducible, well-identified conditions for sample preparation and the recording of identical NMR experiments allows for a direct comparison of the results.
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Affiliation(s)
- Julia Gath
- Physical Chemistry, ETH Zürich, Zurich, Switzerland
| | - Luc Bousset
- Laboratoire d′Enzymologie et Biochimie Structurales, UPR 3082 CNRS, Gif-sur-Yvette, France
| | - Birgit Habenstein
- Institut de Biologie et Chimie des Protéines, UMR 5086 CNRS/Université de Lyon 1, Lyon, France
| | - Ronald Melki
- Laboratoire d′Enzymologie et Biochimie Structurales, UPR 3082 CNRS, Gif-sur-Yvette, France
| | - Anja Böckmann
- Institut de Biologie et Chimie des Protéines, UMR 5086 CNRS/Université de Lyon 1, Lyon, France
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Gill AC. β-hairpin-mediated formation of structurally distinct multimers of neurotoxic prion peptides. PLoS One 2014; 9:e87354. [PMID: 24498083 PMCID: PMC3909104 DOI: 10.1371/journal.pone.0087354] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 12/19/2013] [Indexed: 01/09/2023] Open
Abstract
Protein misfolding disorders are associated with conformational changes in specific proteins, leading to the formation of potentially neurotoxic amyloid fibrils. During pathogenesis of prion disease, the prion protein misfolds into β-sheet rich, protease-resistant isoforms. A key, hydrophobic domain within the prion protein, comprising residues 109-122, recapitulates many properties of the full protein, such as helix-to-sheet structural transition, formation of fibrils and cytotoxicity of the misfolded isoform. Using all-atom, molecular simulations, it is demonstrated that the monomeric 109-122 peptide has a preference for α-helical conformations, but that this peptide can also form β-hairpin structures resulting from turns around specific glycine residues of the peptide. Altering a single amino acid within the 109-122 peptide (A117V, associated with familial prion disease) increases the prevalence of β-hairpin formation and these observations are replicated in a longer peptide, comprising residues 106-126. Multi-molecule simulations of aggregation yield different assemblies of peptide molecules composed of conformationally-distinct monomer units. Small molecular assemblies, consistent with oligomers, comprise peptide monomers in a β-hairpin-like conformation and in many simulations appear to exist only transiently. Conversely, larger assemblies are comprised of extended peptides in predominately antiparallel β-sheets and are stable relative to the length of the simulations. These larger assemblies are consistent with amyloid fibrils, show cross-β structure and can form through elongation of monomer units within pre-existing oligomers. In some simulations, assemblies containing both β-hairpin and linear peptides are evident. Thus, in this work oligomers are on pathway to fibril formation and a preference for β-hairpin structure should enhance oligomer formation whilst inhibiting maturation into fibrils. These simulations provide an important new atomic-level model for the formation of oligomers and fibrils of the prion protein and suggest that stabilization of β-hairpin structure may enhance cellular toxicity by altering the balance between oligomeric and fibrillar protein assemblies.
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Affiliation(s)
- Andrew C. Gill
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, Easter Bush Campus, University of Edinburgh, Roslin, Edinburgh, United Kingdom
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Matthes D, Daebel V, Meyenberg K, Riedel D, Heim G, Diederichsen U, Lange A, de Groot BL. Spontaneous Aggregation of the Insulin-Derived Steric Zipper Peptide VEALYL Results in Different Aggregation Forms with Common Features. J Mol Biol 2014; 426:362-76. [DOI: 10.1016/j.jmb.2013.10.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 10/09/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
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Debelouchina GT, Bayro MJ, Fitzpatrick AW, Ladizhansky V, Colvin MT, Caporini MA, Jaroniec CP, Bajaj VS, Rosay M, Macphee CE, Vendruscolo M, Maas WE, Dobson CM, Griffin RG. Higher order amyloid fibril structure by MAS NMR and DNP spectroscopy. J Am Chem Soc 2013; 135:19237-47. [PMID: 24304221 DOI: 10.1021/ja409050a] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Protein magic angle spinning (MAS) NMR spectroscopy has generated structural models of several amyloid fibril systems, thus providing valuable information regarding the forces and interactions that confer the extraordinary stability of the amyloid architecture. Despite these advances, however, obtaining atomic resolution information describing the higher levels of structural organization within the fibrils remains a significant challenge. Here, we detail MAS NMR experiments and sample labeling schemes designed specifically to probe such higher order amyloid structure, and we have applied them to the fibrils formed by an eleven-residue segment of the amyloidogenic protein transthyretin (TTR(105-115)). These experiments have allowed us to define unambiguously not only the arrangement of the peptide β-strands into β-sheets but also the β-sheet interfaces within each protofilament, and in addition to identify the nature of the protofilament-to-protofilament contacts that lead to the formation of the complete fibril. Our efforts have resulted in 111 quantitative distance and torsion angle restraints (10 per residue) that describe the various levels of structure organization. The experiments benefited extensively from the use of dynamic nuclear polarization (DNP), which in some cases allowed us to shorten the data acquisition time from days to hours and to improve significantly the signal-to-noise ratios of the spectra. The β-sheet interface and protofilament interactions identified here revealed local variations in the structure that result in multiple peaks for the exposed N- and C-termini of the peptide and in inhomogeneous line-broadening for the residues buried within the interior of the fibrils.
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Affiliation(s)
- Galia T Debelouchina
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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Cormier AR, Pang X, Zimmerman MI, Zhou HX, Paravastu AK. Molecular structure of RADA16-I designer self-assembling peptide nanofibers. ACS NANO 2013; 7:7562-72. [PMID: 23977885 PMCID: PMC3946435 DOI: 10.1021/nn401562f] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The designer self-assembling peptide RADA16-I forms nanofiber matrices which have shown great promise for regenerative medicine and three-dimensional cell culture. The RADA16-I amino acid sequence has a β-strand-promoting alternating hydrophobic/charged motif, but arrangement of β-strands into the nanofiber structure has not been previously determined. Here we present a structural model of RADA16-I nanofibers, based on solid-state NMR measurements on samples with different schemes for (13)C isotopic labeling. NMR peak positions and line widths indicate an ordered structure composed of β-strands. The NMR data show that the nanofibers are composed of two stacked β-sheets stabilized by a hydrophobic core formed by alanine side chains, consistent with previous proposals. However, the previously proposed antiparallel β-sheet structure is ruled out by measured (13)C-(13)C dipolar couplings. Instead, neighboring β-strands within β-sheets are parallel, with a registry shift that allows cross-strand staggering of oppositely charged arginine and aspartate side chains. The resulting structural model is compared to nanofiber dimensions observed via images taken by transmission electron microscopy and atomic force microscopy. Multiple NMR peaks for each alanine side chain were observed and could be attributed to multiple configurations of side chain packing within a single scheme for intermolecular packing.
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Affiliation(s)
- Ashley R. Cormier
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310-6046
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, FL 32310
| | - Xiaodong Pang
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Maxwell I. Zimmerman
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310-6046
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, FL 32310
| | - Huan-Xiang Zhou
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Anant K. Paravastu
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310-6046
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, FL 32310
- Address correspondence to
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Li J, van der Wel PCA. Spinning-rate encoded chemical shift correlations from rotational resonance solid-state NMR experiments. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 230:117-24. [PMID: 23475055 PMCID: PMC3635064 DOI: 10.1016/j.jmr.2013.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/22/2013] [Accepted: 02/04/2013] [Indexed: 05/23/2023]
Abstract
Structural measurements in magic-angle-spinning (MAS) solid-state NMR rely heavily on (13)C-(13)C distance measurements. Broadbanded recoupling methods are used to generate many cross-peaks, but have complex polarization transfer mechanisms that limit the precision of distance constraints and can suffer from weak intensities for distant peaks due to relaxation, the broad distribution of polarization, as well as dipolar truncation. Frequency-selective methods that feature narrow-banded recoupling can reduce these effects. Indeed, rotational resonance (R(2)) experiments have found application in many different biological systems, where they have afforded improved precision and accuracy. Unfortunately, a highly selective transfer mechanism also leads to few cross-peaks in the resulting spectra, which complicates the extraction of multiple constraints. R(2)-width (R(2)W) measurements that scan a range of MAS rates to probe the R(2) matching conditions of one or more sites can improve precision, and also permit multiple simultaneous distance measurements. However, multidimensional R(2)W can be very time-consuming. Here, we present an approach that facilitates the acquisition of 2D-like spectra based on a series of 1D R(2)W experiments, by taking advantage of the chemical shift information encoded in the MAS rates where matching occurs. This yields a more time-efficient experiment with many of the benefits of more conventional multidimensional R(2)W measurements. The obtained spectra reveal long-distance (13)C-(13)C cross-peaks resulting from R(2)-mediated polarization transfer. This experiment also enables the efficient setup and targeted implementation of traditional R(2) or R(2)W experiments. Analogous applications may extend to other variable-MAS and frequency-selective solid-state NMR experiments.
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Affiliation(s)
- Jun Li
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pennsylvania 15260, USA
| | - Patrick C. A. van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pennsylvania 15260, USA
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Kar K, Hoop CL, Drombosky KW, Baker MA, Kodali R, Arduini I, van der Wel PCA, Horne WS, Wetzel R. β-hairpin-mediated nucleation of polyglutamine amyloid formation. J Mol Biol 2013; 425:1183-97. [PMID: 23353826 PMCID: PMC3602386 DOI: 10.1016/j.jmb.2013.01.016] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/15/2013] [Accepted: 01/15/2013] [Indexed: 12/01/2022]
Abstract
The conformational preferences of polyglutamine (polyQ) sequences are of major interest because of their central importance in the expanded CAG repeat diseases that include Huntington's disease. Here, we explore the response of various biophysical parameters to the introduction of β-hairpin motifs within polyQ sequences. These motifs (tryptophan zipper, disulfide, d-Pro-Gly, Coulombic attraction, l-Pro-Gly) enhance formation rates and stabilities of amyloid fibrils with degrees of effectiveness well correlated with their known abilities to enhance β-hairpin formation in other peptides. These changes led to decreases in the critical nucleus for amyloid formation from a value of n=4 for a simple, unbroken Q23 sequence to approximate unitary n values for similar length polyQs containing β-hairpin motifs. At the same time, the morphologies, secondary structures, and bioactivities of the resulting fibrils were essentially unchanged from simple polyQ aggregates. In particular, the signature pattern of solid-state NMR (13)C Gln resonances that appears to be unique to polyQ amyloid is replicated exactly in fibrils from a β-hairpin polyQ. Importantly, while β-hairpin motifs do produce enhancements in the equilibrium constant for nucleation in aggregation reactions, these Kn values remain quite low (~10(-)(10)) and there is no evidence for significant enhancement of β-structure within the monomer ensemble. The results indicate an important role for β-turns in the nucleation mechanism and structure of polyQ amyloid and have implications for the nature of the toxic species in expanded CAG repeat diseases.
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Affiliation(s)
- Karunakar Kar
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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40
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Osborne KL, Bachmann M, Strodel B. Thermodynamic analysis of structural transitions during GNNQQNY aggregation. Proteins 2013; 81:1141-55. [DOI: 10.1002/prot.24263] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/16/2013] [Accepted: 01/17/2013] [Indexed: 01/10/2023]
Affiliation(s)
- Kenneth L. Osborne
- Institute of Complex Systems: Structural Biochemistry; Research Centre Jülich; 52425 Jülich; Germany
| | - Michael Bachmann
- Center for Simulational Physics; The University of Georgia; Athens; Georgia 30602; USA
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41
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Sgarbossa A, Monti S, Lenci F, Bramanti E, Bizzarri R, Barone V. The effects of ferulic acid on β-amyloid fibrillar structures investigated through experimental and computational techniques. Biochim Biophys Acta Gen Subj 2013; 1830:2924-37. [PMID: 23291428 DOI: 10.1016/j.bbagen.2012.12.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 11/29/2012] [Accepted: 12/21/2012] [Indexed: 01/01/2023]
Abstract
BACKGROUND Current research has indicated that small natural compounds could interfere with β-amyloid fibril growth and have the ability to disassemble preformed folded structures. Ferulic acid (FA), which possesses both hydrophilic and hydrophobic moieties and binds to peptides/proteins, is a potential candidate against amyloidogenesis. The molecular mechanisms connected to this action have not been elucidated in detail yet. METHODS Here the effects of FA on preformed fibrils are investigated by means of a concerted experimental-computational approach. Spectroscopic techniques, such as FTIR, fluorescence, size exclusion chromatography and confocal microscopy in combination with molecular dynamics simulations are used to identify those features which play a key role in the destabilization of the aggregates. RESULTS Experimental findings highlight that FA has disruptive effects on the fibrils. The computational analysis suggests that dissociation of peptides from the amyloid superstructures could take place along the fibril axis and be primarily determined by the cooperative rupture of the backbone hydrogen bonds and of the Asp-Lys salt bridges. CONCLUSION FA clusters could induce a sort of stabilization and tightening of the fibril structure in the short term and its disruption in the long term, inhibiting further fibril re-assembly through FA screening effects. GENERAL SIGNIFICANCE The combination of experimental and computational techniques could be successfully used to identify the disrupting action of FA on preformed Aβ fibrils in water solution.
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Affiliation(s)
- Antonella Sgarbossa
- Biophysics Institute, National Research Council, Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Italy
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42
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Kinetics of amyloid aggregation: a study of the GNNQQNY prion sequence. PLoS Comput Biol 2012; 8:e1002782. [PMID: 23209391 PMCID: PMC3510058 DOI: 10.1371/journal.pcbi.1002782] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 09/28/2012] [Indexed: 12/24/2022] Open
Abstract
The small amyloid-forming GNNQQNY fragment of the prion sequence has been the subject of extensive experimental and numerical studies over the last few years. Using unbiased molecular dynamics with the OPEP coarse-grained potential, we focus here on the onset of aggregation in a 20-mer system. With a total of 16.9 of simulations at 280 K and 300 K, we show that the GNNQQNY aggregation follows the classical nucleation theory (CNT) in that the number of monomers in the aggregate is a very reliable descriptor of aggregation. We find that the critical nucleus size in this finite-size system is between 4 and 5 monomers at 280 K and 5 and 6 at 300 K, in overall agreement with experiment. The kinetics of growth cannot be fully accounted for by the CNT, however. For example, we observe considerable rearrangements after the nucleus is formed, as the system attempts to optimize its organization. We also clearly identify two large families of structures that are selected at the onset of aggregation demonstrating the presence of well-defined polymorphism, a signature of amyloid growth, already in the 20-mer aggregate. Protein aggregation plays an important pathological role in numerous neurodegenerative diseases such as Alzheimer's, Parkinson's, Creutzfeldt-Jakob, the Prion disease and diabetes mellitus. In most cases, misfolded proteins are involved and aggregate irreversibly to form highly ordered insoluble macrostructures, called amyloid fibrils, which deposit in the brain. Studies have revealed that all proteins are capable of forming amyloid fibrils that all share common structural features and therefore aggregation mechanisms. The toxicity of amyloid aggregates is however not attributed to the fibrils themselves but rather to smaller more disordered aggregates, oligomers, forming parallel to or prior to fibrils. Understanding the assembly process of these amyloid oligomers is key to understanding their toxicity mechanism in order to devise a possible treatment strategy targeting these toxic aggregates. Our approach here is to computationally study the aggregation dynamics of a 20-mer of an amyloid peptide GNNQQNY from a prion protein. Our findings suggest that the assembly is a spontaneous process that can be described as a complex nucleation and growth mechanism and which can lead to two classes of morphologies for the aggregates, one of which resembles a protofibril-like structure. Such numerical studies are crucial to understanding the details of fast biological processes and complement well experimental studies.
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Parmar AS, Nunes AM, Baum J, Brodsky B. A peptide study of the relationship between the collagen triple-helix and amyloid. Biopolymers 2012; 97:795-806. [PMID: 22806499 DOI: 10.1002/bip.22070] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Type XXV collagen, or collagen-like amyloidogenic component, is a component of amyloid plaques, and recent studies suggest this collagen affects amyloid fibril elongation and has a genetic association with Alzheimer's disease. The relationship between the collagen triple helix and amyloid fibrils was investigated by studying peptide models, including a very stable triple helical peptide (Pro-Hyp-Gly)₁₀ , an amyloidogenic peptide GNNQQNY, and a hybrid peptide where the GNNQQNY sequence was incorporated between (GPO)(n) domains. Circular dichroism and nuclear magnetic resonance (NMR) spectroscopy showed the GNNQQNY peptide formed a random coil structure, whereas the hybrid peptide contained a central disordered GNNQQNY region transitioning to triple-helical ends. Light scattering confirmed the GNNQQNY peptide had a high propensity to form amyloid fibrils, whereas amyloidogenesis was delayed in the hybrid peptide. NMR data suggested the triple-helix constraints on the GNNQQNY sequence within the hybrid peptide may disfavor the conformational change necessary for aggregation. Independent addition of a triple-helical peptide to the GNNQQNY peptide under aggregating conditions delayed nucleation and amyloid fibril growth. The inhibition of amyloid nucleation depended on the Gly-Xaa-Yaa sequence and required the triple-helix conformation. The inhibitory effect of the collagen triple-helix on an amyloidogenic sequence, when in the same molecule or when added separately, suggests Type XXV collagen, and possibly other collagens, may play a role in regulating amyloid fibril formation.
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Affiliation(s)
- Avanish S Parmar
- Department of Biomedical Engineering, Tufts University, Medford, MA, USA
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44
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Yau J, Sharpe S. Structures of amyloid fibrils formed by the prion protein derived peptides PrP(244-249) and PrP(245-250). J Struct Biol 2012; 180:290-302. [PMID: 22929126 DOI: 10.1016/j.jsb.2012.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 10/28/2022]
Abstract
While the formation of amyloid fibrils from diverse peptide and protein sequences is well established, the molecular determinants of structure and assembly are not well understood. In particular, the relationship between amino acid sequence and the type of internal steric zipper packing adopted in amyloid fibrils has not been established. Here we report the structures of two cytotoxic amyloid peptides derived from the mammalian prion protein, PrP(244-249) and PrP(245-250), determined using solid state NMR. While the amino acid composition of these two hexapeptides is very similar (ISFLIF and SFLIFL), the intermolecular interactions that give rise to the intersheet packing within the fibrils differ significantly. PrP(245-250) adopts a class 1 steric zipper, with parallel sheets stacked in an antiparallel face to face arrangement, stabilized by N- to C-terminal salt bridges. PrP(244-249), by contrast, forms two different intersheet interfaces within amyloid fibrils, with parallel opposing sheets in either a face to face (class 3) or face to back (class 2) arrangement. The fibrils formed by this peptide are primarily stabilized by close packing of the hydrophobic side chains, with contributions from side-chain to backbone hydrogen bonding (class 2 only). Thus, the structures presented here provide new insight into the relationship between amino acid sequence and the types of interactions stabilizing amyloid fibrils.
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Affiliation(s)
- Jason Yau
- Molecular Structure and Function Programme, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada
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45
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Abstract
For several different proteins an apparent correlation has been observed between the propensity for dimerization by domain-swapping and the ability to aggregate into amyloid-like fibrils. Examples include the disease-related proteins β 2-microglobulin and transthyretin. This has led to proposals that the amyloid-formation pathway may feature extensive domain swapping. One possible consequence of such an aggregation pathway is that the resulting fibrils would incorporate structural elements that resemble the domain-swapped forms of the protein and, thus, reflect certain native-like structures or domain-interactions. In magic angle spinning solid-state NMR-based and other structural studies of such amyloid fibrils, it appears that many of these proteins form fibrils that are not native-like. Several fibrils, instead, have an in-register, parallel conformation, which is a common amyloid structural motif and is seen, for instance, in various prion fibrils. Such a lack of native structure in the fibrils suggests that the apparent connection between domain-swapping ability and amyloid-formation may be more subtle or complex than may be presumed at first glance.
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Affiliation(s)
- Patrick C A van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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46
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Giffard M, Hediger S, Lewandowski JR, Bardet M, Simorre JP, Griffin RG, De Paëpe G. Compensated second-order recoupling: application to third spin assisted recoupling. Phys Chem Chem Phys 2012; 14:7246-55. [PMID: 22513727 PMCID: PMC4440590 DOI: 10.1039/c2cp40406k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We consider the effect of phase shifts in the context of second-order recoupling techniques in solid-state NMR. Notably we highlight conditions leading to significant improvements for the Third Spin Assisted Recoupling (TSAR) mechanism and demonstrate the benefits of resulting techniques for detecting long-distance transfer in biomolecular systems. The modified pulse sequences of PAR and PAIN-CP, Phase-Shifted Proton Assisted Recoupling (AH-PS-PAR) and Phase-Shifted Proton-Assisted Insensitive Nuclei Cross Polarization (ABH-PS-PAIN-CP), still rely on cross terms between heteronuclear dipolar couplings involving assisting protons that mediate zero-quantum polarization transfer between low-γ nuclei ((13)C-(13)C, (15)N-(15)N, (15)N-(13)C polarization transfer). Using Average Hamiltonian Theory we show that phase inversion compensates off-resonance contributions and yields improved polarization transfer as well as substantial broadening of the matching conditions. PS-TSAR greatly improves on the standard TSAR based methods because it alleviates their sensitivity to precise RF settings which significantly enhances robustness of the experiments. We demonstrate these new methods on a 19.6 kDa protein (U-[(15)N, (13)C]-YajG) at high magnetic fields (up to 900 MHz (1)H frequency) and fast sample spinning (up to 65 kHz MAS frequency).
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Affiliation(s)
- Mathilde Giffard
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
| | - Sabine Hediger
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
| | | | - Michel Bardet
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
| | - Jean-Pierre Simorre
- Institut de Biologie Structurale, UMR 5075 (CEA/CNRS/UJF), 38027 Grenoble, France
| | - Robert G. Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Gaël De Paëpe
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
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Lopez del Amo JM, Schmidt M, Fink U, Dasari M, Fändrich M, Reif B. An asymmetric dimer as the basic subunit in Alzheimer's disease amyloid β fibrils. Angew Chem Int Ed Engl 2012; 51:6136-9. [PMID: 22565601 DOI: 10.1002/anie.201200965] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Juan Miguel Lopez del Amo
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und Umwelt, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
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48
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Lopez del Amo JM, Schmidt M, Fink U, Dasari M, Fändrich M, Reif B. An Asymmetric Dimer as the Basic Subunit in Alzheimer’s Disease Amyloid β Fibrils. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201200965] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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49
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Lamley JM, Lewandowski JR. Simultaneous acquisition of homonuclear and heteronuclear long-distance contacts with time-shared third spin assisted recoupling. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 218:30-34. [PMID: 22578552 DOI: 10.1016/j.jmr.2012.03.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 03/13/2012] [Accepted: 03/17/2012] [Indexed: 05/31/2023]
Abstract
We present a time-shared Third Spin Assisted Recoupling (TSTSAR) experiment that allows for simultaneous acquisition of homonuclear ((13)C-(13)C) and heteronuclear ((15)N-(13)C) long-distance contacts in biomolecular solids under magic angle spinning. TSTSAR leads to substantial time savings and increases the information content of 2D correlation spectra.
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Affiliation(s)
- Jonathan M Lamley
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
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50
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Matthes D, Gapsys V, de Groot BL. Driving forces and structural determinants of steric zipper peptide oligomer formation elucidated by atomistic simulations. J Mol Biol 2012; 421:390-416. [PMID: 22326493 DOI: 10.1016/j.jmb.2012.02.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 01/27/2012] [Accepted: 02/01/2012] [Indexed: 12/20/2022]
Abstract
Understanding the structural and energetic requirements of non-fibrillar oligomer formation harbors the potential to decipher an important yet still elusive part of amyloidogenic peptide and protein aggregation. Low-molecular-weight oligomers are described to be transient and polymorphic intermediates in the nucleated self-assembly process to highly ordered amyloid fibers and were additionally found to exhibit a profound cytotoxicity. However, detailed structural information on the oligomeric species involved in the nucleation cannot be readily inferred from experiments. Here, we study the spontaneous assembly of steric zipper peptides from the tau protein, insulin and α-synuclein with atomistic molecular dynamics simulations on the microsecond timescale. Detailed analysis of the forces driving the oligomerization reveals a common two-step process akin to a general condensation-ordering mechanism and thus provides a rational understanding of the molecular basis of peptide self-assembly. Our results suggest that the initial formation of partially ordered peptide oligomers is governed by the solvation free energy, whereas the dynamical ordering and emergence of β-sheets are mainly driven by optimized inter-peptide interactions in the collapsed state. A novel mapping technique based on collective coordinates is employed to highlight similarities and differences in the conformational ensemble of small oligomer structures. Elucidating the dynamical and polymorphic β-sheet oligomer conformations at atomistic detail furthermore suggests complementary sheet packing characteristics similar to steric zipper structures, but with a larger heterogeneity in the strand alignment pattern and sheet-to-sheet arrangements compared to the cross-β motif found in the fibrillar or crystalline states.
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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
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