1
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Mishra R, Gerlach GJ, Sahoo B, Camacho CJ, Wetzel R. A Targetable Self-association Surface of the Huntingtin exon1 Helical Tetramer Required for Assembly of Amyloid Pre-nucleation Oligomers. J Mol Biol 2024; 436:168607. [PMID: 38734203 DOI: 10.1016/j.jmb.2024.168607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 05/03/2024] [Accepted: 05/06/2024] [Indexed: 05/13/2024]
Abstract
Polyglutamine (polyQ) sequences undergo repeat-length dependent formation of disease-associated, amyloid-like cross-β core structures with kinetics and aggregate morphologies often influenced by the flanking sequences. In Huntington's disease (HD), the httNT segment on the polyQ's N-terminal flank enhances aggregation rates by changing amyloid nucleation from a classical homogeneous mechanism to a two-step process requiring an ɑ-helix-rich oligomeric intermediate. A folded, helix-rich httNT tetrameric structure suggested to be this critical intermediate was recently reported. Here we employ single alanine replacements along the httNT sequence to assess this proposed structure and refine the mechanistic model. We find that Ala replacement of hydrophobic residues within simple httNT peptides greatly suppresses helicity, supporting the tetramer model. These same helix-disruptive replacements in the httNT segment of an exon-1 analog greatly reduce aggregation kinetics, suggesting that an ɑ-helix rich multimer - either the tetramer or a larger multimer - plays an on-pathway role in nucleation. Surprisingly, several other Ala replacements actually enhance helicity and/or amyloid aggregation. The spatial localization of these residues on the tetramer surface suggests a self-association interface responsible for formation of the octomers and higher-order multimers most likely required for polyQ amyloid nucleation. Multimer docking of the tetramer, using the protein-protein docking algorithm ClusPro, predicts this symmetric surface to be a viable tetramer dimerization interface. Intriguingly, octomer formation brings the emerging polyQ chains into closer proximity at this tetramer-tetramer interface. Further supporting the potential importance of tetramer super-assembly, computational docking with a known exon-1 aggregation inhibitor predicts ligand contacts with residues at this interface.
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Affiliation(s)
- Rakesh Mishra
- Department Structural Biology, University of Pittsburgh School of Medicine Pittsburgh, PA 15260, USA.
| | - Gabriella J Gerlach
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine Pittsburgh, PA 15260, USA
| | - Bankanidhi Sahoo
- Department Structural Biology, University of Pittsburgh School of Medicine Pittsburgh, PA 15260, USA.
| | - Carlos J Camacho
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine Pittsburgh, PA 15260, USA.
| | - Ronald Wetzel
- Department Structural Biology, University of Pittsburgh School of Medicine Pittsburgh, PA 15260, USA.
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2
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Amado D, Chaves OA, Cruz PF, Loureiro RJS, Almeida ZL, Jesus CSH, Serpa C, Brito RMM. Folding Kinetics and Volume Variation of the β-Hairpin Peptide Chignolin upon Ultrafast pH-Jumps. J Phys Chem B 2024; 128:4898-4910. [PMID: 38733339 DOI: 10.1021/acs.jpcb.3c08271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2024]
Abstract
In-depth characterization of fundamental folding steps of small model peptides is crucial for a better understanding of the folding mechanisms of more complex biomacromolecules. We have previously reported on the folding/unfolding kinetics of a model α-helix. Here, we study folding transitions in chignolin (GYDPETGTWG), a short β-hairpin peptide previously used as a model to study conformational changes in β-sheet proteins. Although previously suggested, until now, the role of the Tyr2-Trp9 interaction in the folding mechanism of chignolin was not clear. In the present work, pH-dependent conformational changes of chignolin were characterized by circular dichroism (CD), nuclear magnetic resonance (NMR), ultrafast pH-jump coupled with time-resolved photoacoustic calorimetry (TR-PAC), and molecular dynamics (MD) simulations. Taken together, our results present a comprehensive view of chignolin's folding kinetics upon local pH changes and the role of the Tyr2-Trp9 interaction in the folding process. CD data show that chignolin's β-hairpin formation displays a pH-dependent skew bell-shaped curve, with a maximum close to pH 6, and a large decrease in β-sheet content at alkaline pH. The β-hairpin structure is mainly stabilized by aromatic interactions between Tyr2 and Trp9 and CH-π interactions between Tyr2 and Pro4. Unfolding of chignolin at high pH demonstrates that protonation of Tyr2 is essential for the stability of the β-hairpin. Refolding studies were triggered by laser-induced pH-jumps and detected by TR-PAC. The refolding of chignolin from high pH, mainly due to the protonation of Tyr2, is characterized by a volume expansion (10.4 mL mol-1), independent of peptide concentration, in the microsecond time range (lifetime of 1.15 μs). At high pH, the presence of the deprotonated hydroxyl (tyrosinate) hinders the formation of the aromatic interaction between Tyr2 and Trp9 resulting in a more disorganized and dynamic tridimensional structure of the peptide. This was also confirmed by comparing MD simulations of chignolin under conditions mimicking neutral and high pH.
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Affiliation(s)
- Daniela Amado
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Otávio A Chaves
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Pedro F Cruz
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Rui J S Loureiro
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Zaida L Almeida
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Catarina S H Jesus
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Carlos Serpa
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Rui M M Brito
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
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3
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Mohanty P, Phan TM, Mittal J. Transient interdomain interactions modulate the monomeric structural ensemble and oligomerization landscape of Huntingtin Exon 1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.03.592468. [PMID: 38766024 PMCID: PMC11100600 DOI: 10.1101/2024.05.03.592468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Polyglutamine expansion (≥ 36 residues) within the N-terminal exon-1 of Huntingtin (Httex1) leads to Huntington's disease, a neurogenerative condition marked by the presence of intranuclear Htt inclusions. Notably, the polyglutamine tract in Httex1 is flanked by an N-terminal coiled-coil domain - N17 (17 amino acids), which undergoes self-association to promote the formation of soluble Httex1 oligomers and brings the aggregation-prone polyQ tracts in close spatial proximity. However, the mechanisms underlying the subsequent conversion of soluble oligomers into insoluble β-rich aggregates with increasing polyQ length, remain unclear. Current knowledge suggests that expansion of the polyQ tract increases its helicity, and this favors its oligomerization and aggregation. In addition, studies utilizing conformation-specific antibodies and a stable coiled-coil heterotetrametric system fused to polyQ indicate that domain "cross-talk" (i.e., interdomain interactions) may be necessary to efficiently promote the emergence of toxic conformations (in monomers and oligomers) and fibrillar aggregation. Here, we performed extensive atomistic molecular dynamics (MD) simulations (aggregate time ∼ 0.7 ms) of N17-polyQ fragments to uncover the interplay between structural transformation and domain "cross-talk" on the monomeric structural ensemble and oligomerization landscape of Httex1. Our simulation ensembles of N17-polyQ monomers validated against 13 C NMR chemical shifts indicated that in addition to elevated α-helicity, polyQ expansion also favors transient, interdomain (N17-polyQ) interactions which result in the emergence of β-conformations. Further, interdomain interactions decreased the overall stability of N17-mediated dimers by counteracting the stabilizing effect of increased α-helicity and promoted a heterogenous oligomerization landscape on the sub-microsecond timescale. Overall, our study uncovers the significance of domain "cross-talk" in modulating the monomeric conformational ensemble and oligomerization landscape of Httex1 to favor the formation of amyloid aggregates.
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4
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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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5
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Sari L, Bali S, Joachimiak LA, Lin MM. Hairpin trimer transition state of amyloid fibril. Nat Commun 2024; 15:2756. [PMID: 38553453 PMCID: PMC10980705 DOI: 10.1038/s41467-024-46446-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 02/28/2024] [Indexed: 04/02/2024] Open
Abstract
Protein fibril self-assembly is a universal transition implicated in neurodegenerative diseases. Although fibril structure/growth are well characterized, fibril nucleation is poorly understood. Here, we use a computational-experimental approach to resolve fibril nucleation. We show that monomer hairpin content quantified from molecular dynamics simulations is predictive of experimental fibril formation kinetics across a tau motif mutant library. Hairpin trimers are predicted to be fibril transition states; one hairpin spontaneously converts into the cross-beta conformation, templating subsequent fibril growth. We designed a disulfide-linked dimer mimicking the transition state that catalyzes fibril formation, measured by ThT fluorescence and TEM, of wild-type motif - which does not normally fibrillize. A dimer compatible with extended conformations but not the transition-state fails to nucleate fibril at any concentration. Tau repeat domain simulations show how long-range interactions sequester this motif in a mutation-dependent manner. This work implies that different fibril morphologies could arise from disease-dependent hairpin seeding from different loci.
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Affiliation(s)
- Levent Sari
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sofia Bali
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Milo M Lin
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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6
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Parlato R, Volarić J, Lasorsa A, Bagherpoor Helabad M, Kobauri P, Jain G, Miettinen MS, Feringa BL, Szymanski W, van der Wel PCA. Photocontrol of the β-Hairpin Polypeptide Structure through an Optimized Azobenzene-Based Amino Acid Analogue. J Am Chem Soc 2024; 146:2062-2071. [PMID: 38226790 PMCID: PMC10811659 DOI: 10.1021/jacs.3c11155] [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: 10/09/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/17/2024]
Abstract
A family of neurodegenerative diseases, including Huntington's disease (HD) and spinocerebellar ataxias, are associated with an abnormal polyglutamine (polyQ) expansion in mutant proteins that become prone to form amyloid-like aggregates. Prior studies have suggested a key role for β-hairpin formation as a driver of nucleation and aggregation, but direct experimental studies have been challenging. Toward such research, we set out to enable spatiotemporal control over β-hairpin formation by the introduction of a photosensitive β-turn mimic in the polypeptide backbone, consisting of a newly designed azobenzene derivative. The reported derivative overcomes the limitations of prior approaches associated with poor photochemical properties and imperfect structural compatibility with the desired β-turn structure. A new azobenzene-based β-turn mimic was designed, synthesized, and found to display improved photochemical properties, both prior and after incorporation into the backbone of a polyQ polypeptide. The two isomers of the azobenzene-polyQ peptide showed different aggregate structures of the polyQ peptide fibrils, as demonstrated by electron microscopy and solid-state NMR (ssNMR). Notably, only peptides in which the β-turn structure was stabilized (azobenzene in the cis configuration) closely reproduced the spectral fingerprints of toxic, β-hairpin-containing fibrils formed by mutant huntingtin protein fragments implicated in HD. These approaches and findings will enable better deciphering of the roles of β-hairpin structures in protein aggregation processes in HD and other amyloid-related neurodegenerative diseases.
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Affiliation(s)
- Raffaella Parlato
- Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Jana Volarić
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747
AG Groningen, The
Netherlands
| | - Alessia Lasorsa
- Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Mahdi Bagherpoor Helabad
- Department
of Theory and Bio-Systems, Max Planck Institute
of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Piermichele Kobauri
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747
AG Groningen, The
Netherlands
| | - Greeshma Jain
- Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Markus S. Miettinen
- Computational
Biology Unit, Departments of Chemistry and Informatics, University of Bergen, 5020 Bergen, Norway
| | - Ben L. Feringa
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747
AG Groningen, The
Netherlands
| | - Wiktor Szymanski
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747
AG Groningen, The
Netherlands
- Medical
Imaging Center, University Medical Center
Groningen, Hanzeplein
1, 9713 GZ Groningen, The Netherlands
| | - Patrick C. A. van der Wel
- Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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7
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Prajapati KP, Ansari M, Yadav DK, Mittal S, Anand BG, Kar K. A robust yet simple method to generate fluorescent amyloid nanofibers. J Mater Chem B 2023; 11:8765-8774. [PMID: 37661927 DOI: 10.1039/d3tb01203d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Covalent tagging of fluorophores is central to the mechanistic understanding of important biological processes including protein-protein interaction and protein aggregation. Hence, studies on fluorophore-tagged peptides help in elucidating the molecular mechanism of amyloidogenesis, its cellular internalization, and crosstalk potential. Despite the many advantages the covalently tagged proteins offer, difficulties such as expensive and tedious synthesis and purification protocols have become a matter of concern. Importantly, covalently tagged fluorophores could introduce structural constraints, which may influence the conformation of the monomeric and aggregated forms of proteins. Here, we describe a robust-yet-simple method to make fluorescent-amyloid nanofibers through a coassembly-reaction route that does not alter the aggregation kinetics and the characteristic β-sheet-conformers of resultant nanofibers. Fluorescent amyloid nanofibers derived from insulin, lysozyme, Aβ1-42, and metabolites were successfully fabricated in our study. Importantly, the incorporated fluorophores exhibited remarkable stability, remaining intact without leaching even after undergoing serial dilutions and prolonged storage periods. This method enables monitoring of cellular internalization of the fluorescent-amyloid-nanofibers and the detection of FRET-signals during interfibrillar interactions. This simple and affordable protocol may significantly help amyloid researchers working on both in vitro and animal models.
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Affiliation(s)
- Kailash Prasad Prajapati
- Biophysical and Biomaterials Research Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Masihuzzaman Ansari
- Biophysical and Biomaterials Research Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Deepak Kumar Yadav
- Biophysical and Biomaterials Research Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Shikha Mittal
- Biophysical and Biomaterials Research Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Bibin Gnanadhason Anand
- Biophysical and Biomaterials Research Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Karunakar Kar
- Biophysical and Biomaterials Research Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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8
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Khaled M, Strodel B, Sayyed-Ahmad A. Comparative molecular dynamics simulations of pathogenic and non-pathogenic huntingtin protein monomers and dimers. Front Mol Biosci 2023; 10:1143353. [PMID: 37101557 PMCID: PMC10123271 DOI: 10.3389/fmolb.2023.1143353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/29/2023] [Indexed: 04/28/2023] Open
Abstract
Polyglutamine expansion at the N-terminus of the huntingtin protein exon 1 (Htt-ex1) is closely associated with a number of neurodegenerative diseases, which result from the aggregation of the increased polyQ repeat. However, the underlying structures and aggregation mechanism are still poorly understood. We performed microsecond-long all-atom molecular dynamics simulations to study the folding and dimerization of Htt-ex1 (about 100 residues) with non-pathogenic and pathogenic polyQ lengths, and uncovered substantial differences. The non-pathogenic monomer adopts a long α-helix that includes most of the polyQ residues, which forms the interaction interface for dimerization, and a PPII-turn-PPII motif in the proline-rich region. In the pathogenic monomer, the polyQ region is disordered, leading to compact structures with many intra-protein interactions and the formation of short β-sheets. Dimerization can proceed via different modes, where those involving the N-terminal headpiece bury more hydrophobic residues and are thus more stable. Moreover, in the pathogenic Htt-ex1 dimers the proline-rich region interacts with the polyQ region, which slows the formation of β-sheets.
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Affiliation(s)
- Mohammed Khaled
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
| | - Birgit Strodel
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- *Correspondence: Birgit Strodel, ; Abdallah Sayyed-Ahmad,
| | - Abdallah Sayyed-Ahmad
- Department of Physics, Birzeit University, Birzeit, Palestine
- *Correspondence: Birgit Strodel, ; Abdallah Sayyed-Ahmad,
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9
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Böker A, Paul W. Thermodynamics and Conformations of Single Polyalanine, Polyserine, and Polyglutamine Chains within the PRIME20 Model. J Phys Chem B 2022; 126:7286-7297. [DOI: 10.1021/acs.jpcb.2c04360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Arne Böker
- Institut für Physik, Martin Luther-Universität Halle-Wittenberg, von Seckendorff Platz 1, 06120 Halle, Germany
| | - Wolfgang Paul
- Institut für Physik, Martin Luther-Universität Halle-Wittenberg, von Seckendorff Platz 1, 06120 Halle, Germany
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10
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Zhang L, Kang H, Perez-Aguilar JM, Zhou R. Possible Co-Evolution of Polyglutamine and Polyproline in Huntingtin Protein: Proline-Rich Domain as Transient Folding Chaperone. J Phys Chem Lett 2022; 13:6331-6341. [PMID: 35796410 DOI: 10.1021/acs.jpclett.2c01184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Huntington's disease is an inherited neurodegenerative disorder caused by the overduplication of CAG repeats in the Huntingtin gene. Recent findings revealed that among the orthologs, the expansion of CAG repeats (polyQ) in the Huntingtin gene occurs in tandem with the duplication of CCG repeats (polyP). However, the molecular mechanism of this possible co-evolution remains unknown. We examined the structures of Huntingtin exon 1 (HttEx1) from six species along with five designed mutants. We found that the polyP segments "chaperone" the rest of the HttEx1 by forming ad hoc polyP binding grooves. Such a process elongates the otherwise poorly solvated polyQ domain, while modulating its secondary structure propensity from β-strands to α-helices. This chaperoning effect is achieved mostly through transient hydrogen bond interactions between polyP and the rest of HttEx1, resulting in a striking golden ratio of ∼2:1 between the chain lengths of polyQ and polyP.
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Affiliation(s)
- Leili Zhang
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, United States
| | - Hongsuk Kang
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, United States
| | - Jose Manuel Perez-Aguilar
- School of Chemical Sciences, Meritorious Autonomous University of Puebla (BUAP), University City, Puebla 72570, Mexico
| | - Ruhong Zhou
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, United States
- Institute of Quantitative Biology, College of Life Sciences, Zhejiang University, Hangzhou 310027, China
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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11
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Sinnige T. Molecular mechanisms of amyloid formation in living systems. Chem Sci 2022; 13:7080-7097. [PMID: 35799826 PMCID: PMC9214716 DOI: 10.1039/d2sc01278b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/14/2022] [Indexed: 12/28/2022] Open
Abstract
Fibrillar protein aggregation is a hallmark of a variety of human diseases. Examples include the deposition of amyloid-β and tau in Alzheimer's disease, and that of α-synuclein in Parkinson's disease. The molecular mechanisms by which soluble proteins form amyloid fibrils have been extensively studied in the test tube. These investigations have revealed the microscopic steps underlying amyloid formation, and the role of factors such as chaperones that modulate these processes. This perspective explores the question to what extent the mechanisms of amyloid formation elucidated in vitro apply to human disease. The answer is not yet clear, and may differ depending on the protein and the associated disease. Nevertheless, there are striking qualitative similarities between the aggregation behaviour of proteins in vitro and the development of the related diseases. Limited quantitative data obtained in model organisms such as Caenorhabditis elegans support the notion that aggregation mechanisms in vivo can be interpreted using the same biophysical principles established in vitro. These results may however be biased by the high overexpression levels typically used in animal models of protein aggregation diseases. Molecular chaperones have been found to suppress protein aggregation in animal models, but their mechanisms of action have not yet been quantitatively analysed. Several mechanisms are proposed by which the decline of protein quality control with organismal age, but also the intrinsic nature of the aggregation process may contribute to the kinetics of protein aggregation observed in human disease.
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Affiliation(s)
- Tessa Sinnige
- Bijvoet Centre for Biomolecular Research, Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
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12
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Siu HW, Hauser K. Observation of Oligomeric States Indicates a High Structural Flexibility Required for the Onset of Polyglutamine Fibrillization. J Phys Chem Lett 2022; 13:4543-4548. [PMID: 35580015 DOI: 10.1021/acs.jpclett.2c00203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Polyglutamine (polyQ) diseases are caused by misfolding and aggregation of expanded polyQ tracts in the affected protein. PolyQ fibrils have been studied in detail; however, less is known about oligomeric precursor states. By a combination of time-resolved temperature-jump (T-jump) infrared (IR) spectroscopy and an appropriately tailored polyQ model peptide, we succeeded in disentangling conformational dynamics in the heterogeneous ensemble of states evolving during aggregation. Individual structural elements could be differentiated by IR-specific signatures, i.e., hairpin monomers, β-structured oligomers, and disordered structure. Submillisecond dynamics were observed for early oligomeric states in contrast to the slow dynamics of fibril growth. We propose that a high structural flexibility of oligomers is required to initiate fibril formation, but not after a fibrillar structure has consolidated and the fibril just grows. Our study reveals that structural flexibility changes at different stages in the aggregation process, from fibril initiation to fibril growth.
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Affiliation(s)
- Ho-Wah Siu
- Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - Karin Hauser
- Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
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13
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PolyQ aggregation studied by model peptides with intrinsic tryptophan fluorophores. Biophys Chem 2022; 284:106782. [DOI: 10.1016/j.bpc.2022.106782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/15/2022] [Accepted: 02/15/2022] [Indexed: 11/02/2022]
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14
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Kolkwitz PE, Mohrlüder J, Willbold D. Inhibition of Polyglutamine Misfolding with D-Enantiomeric Peptides Identified by Mirror Image Phage Display Selection. Biomolecules 2022; 12:biom12020157. [PMID: 35204656 PMCID: PMC8961585 DOI: 10.3390/biom12020157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 02/04/2023] Open
Abstract
Nine heritable diseases are known that are caused by unphysiologically elongated polyglutamine tracts in human proteins leading to misfolding, aggregation and neurodegeneration. Current therapeutic strategies include efforts to inhibit the expression of the respective gene coding for the polyglutamine-containing proteins. There are, however, concerns that this may interfere with the physiological function of the respective protein. We aim to stabilize the protein’s native conformation by D-enantiomeric peptide ligands to prevent misfolding and aggregation, shift the equilibrium between aggregates and monomers towards monomers and dissolve already existing aggregates into non-toxic and functional monomers. Here, we performed a mirror image phage display selection on the polyglutamine containing a fragment of the androgen receptor. An elongated polyglutamine tract in the androgen receptor causes spinal and bulbar muscular atrophy (SBMA). The selected D-enantiomeric peptides were tested for their ability to inhibit polyglutamine-induced androgen receptor aggregation. We identified D-enantiomeric peptide QF2D-2 (sqsqwstpqGkwshwprrr) as the most promising candidate. It binds to an androgen receptor fragment with 46 consecutive glutamine residues and decelerates its aggregation, even in seeded experiments. Therefore, QF2D-2 may be a promising drug candidate for SBMA treatment or even for all nine heritable polyglutamine diseases, since its aggregation-inhibiting property was shown also for a more general polyglutamine target.
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Affiliation(s)
- Pauline Elisabeth Kolkwitz
- Institute of Biological Information Processing (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (P.E.K.); (J.M.)
| | - Jeannine Mohrlüder
- Institute of Biological Information Processing (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (P.E.K.); (J.M.)
| | - Dieter Willbold
- Institute of Biological Information Processing (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (P.E.K.); (J.M.)
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
- Correspondence:
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15
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N-alpha-acetylation of Huntingtin protein increases its propensity to aggregate. J Biol Chem 2021; 297:101363. [PMID: 34732320 PMCID: PMC8640455 DOI: 10.1016/j.jbc.2021.101363] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/23/2021] [Accepted: 10/25/2021] [Indexed: 11/22/2022] Open
Abstract
Huntington’s disease (HD) is a neurodegenerative disorder caused by a poly-CAG expansion in the first exon of the HTT gene, resulting in an extended poly-glutamine tract in the N-terminal domain of the Huntingtin (Htt) protein product. Proteolytic fragments of the poly-glutamine–containing N-terminal domain form intranuclear aggregates that are correlated with HD. Post-translational modification of Htt has been shown to alter its function and aggregation properties. However, the effect of N-terminal Htt acetylation has not yet been considered. Here, we developed a bacterial system to produce unmodified or N-terminally acetylated and aggregation-inducible Htt protein. We used this system together with biochemical, biophysical, and imaging studies to confirm that the Htt N-terminus is an in vitro substrate for the NatA N-terminal acetyltransferase and show that N-terminal acetylation promotes aggregation. These studies represent the first link between N-terminal acetylation and the promotion of a neurodegenerative disease and implicates NatA-mediated Htt acetylation as a new potential therapeutic target in HD.
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16
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Li X, Sabol AL, Wierzbicki M, Salveson PJ, Nowick JS. An Improved Turn Structure for Inducing β‐Hairpin Formation in Peptides. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202105559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Xingyue Li
- Department of Chemistry University of California Irvine 4126 Natural Sciences I Irvine CA 92697-2025 USA
| | - Andrew L. Sabol
- Department of Chemistry University of California Irvine 4126 Natural Sciences I Irvine CA 92697-2025 USA
| | - Michał Wierzbicki
- Department of Chemistry University of California Irvine 4126 Natural Sciences I Irvine CA 92697-2025 USA
| | - Patrick J. Salveson
- Department of Chemistry University of California Irvine 4126 Natural Sciences I Irvine CA 92697-2025 USA
| | - James S. Nowick
- Department of Chemistry University of California Irvine 4126 Natural Sciences I Irvine CA 92697-2025 USA
- Department of Pharmaceutical Sciences University of California Irvine 4126 Natural Sciences I Irvine CA 92697-2025 USA
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17
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Li X, Sabol AL, Wierzbicki M, Salveson PJ, Nowick JS. An Improved Turn Structure for Inducing β-Hairpin Formation in Peptides. Angew Chem Int Ed Engl 2021; 60:22776-22782. [PMID: 34258835 DOI: 10.1002/anie.202105559] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/14/2021] [Indexed: 11/05/2022]
Abstract
Although β-hairpins are widespread in proteins, there is no tool to coax any small peptide to adopt a β-hairpin conformation, regardless of sequence. Here, we report that δ-linked γ(R)-methyl-ornithine (δ MeOrn) provides an improved β-turn template for inducing a β-hairpin conformation in peptides. We developed a synthesis of protected δ MeOrn as a building block suitable for use in Fmoc-based solid-phase peptide synthesis. The synthesis begins with l-leucine and affords gram quantities of the Nα -Boc-Nδ -Fmoc-γ(R)-methyl-ornithine building block. X-ray crystallography confirms that the δ MeOrn turn unit adopts a folded structure in a macrocyclic β-hairpin peptide. CD and NMR spectroscopy allow comparison of the δ MeOrn turn template to the δ-linked ornithine (δ Orn) turn template that we previously introduced and to the popular d-Pro-Gly turn template. These studies show that the folding of the δ MeOrn turn template is substantially better than that of δ Orn and is comparable to d-Pro-Gly.
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Affiliation(s)
- Xingyue Li
- Department of Chemistry, University of California Irvine, 4126 Natural Sciences I, Irvine, CA, 92697-2025, USA
| | - Andrew L Sabol
- Department of Chemistry, University of California Irvine, 4126 Natural Sciences I, Irvine, CA, 92697-2025, USA
| | - Michał Wierzbicki
- Department of Chemistry, University of California Irvine, 4126 Natural Sciences I, Irvine, CA, 92697-2025, USA
| | - Patrick J Salveson
- Department of Chemistry, University of California Irvine, 4126 Natural Sciences I, Irvine, CA, 92697-2025, USA
| | - James S Nowick
- Department of Chemistry, University of California Irvine, 4126 Natural Sciences I, Irvine, CA, 92697-2025, USA.,Department of Pharmaceutical Sciences, University of California Irvine, 4126 Natural Sciences I, Irvine, CA, 92697-2025, USA
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18
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Diociaiuti M, Bonanni R, Cariati I, Frank C, D’Arcangelo G. Amyloid Prefibrillar Oligomers: The Surprising Commonalities in Their Structure and Activity. Int J Mol Sci 2021; 22:ijms22126435. [PMID: 34208561 PMCID: PMC8235680 DOI: 10.3390/ijms22126435] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/10/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
It has been proposed that a “common core” of pathologic pathways exists for the large family of amyloid-associated neurodegenerations, including Alzheimer’s, Parkinson’s, type II diabetes and Creutzfeldt–Jacob’s Disease. Aggregates of the involved proteins, independently from their primary sequence, induced neuron membrane permeabilization able to trigger an abnormal Ca2+ influx leading to synaptotoxicity, resulting in reduced expression of synaptic proteins and impaired synaptic transmission. Emerging evidence is now focusing on low-molecular-weight prefibrillar oligomers (PFOs), which mimic bacterial pore-forming toxins that form well-ordered oligomeric membrane-spanning pores. At the same time, the neuron membrane composition and its chemical microenvironment seem to play a pivotal role. In fact, the brain of AD patients contains increased fractions of anionic lipids able to favor cationic influx. However, up to now the existence of a specific “common structure” of the toxic aggregate, and a “common mechanism” by which it induces neuronal damage, synaptotoxicity and impaired synaptic transmission, is still an open hypothesis. In this review, we gathered information concerning this hypothesis, focusing on the proteins linked to several amyloid diseases. We noted commonalities in their structure and membrane activity, and their ability to induce Ca2+ influx, neurotoxicity, synaptotoxicity and impaired synaptic transmission.
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Affiliation(s)
- Marco Diociaiuti
- Centro Nazionale Malattie Rare, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
- Correspondence:
| | - Roberto Bonanni
- Department of Systems Medicine, “Tor Vergata” University of Rome, Via Montpellier 1, 00133 Rome, Italy; (R.B.); (G.D.)
| | - Ida Cariati
- PhD in Medical-Surgical Biotechnologies and Translational Medicine, Department of Clinical Sciences and Translational Medicine, “Tor Vergata” University of Rome, Via Montpellier 1, 00133 Rome, Italy;
| | - Claudio Frank
- UniCamillus-Saint Camillus International University of Health Sciences, Via di Sant’Alessandro 8, 00131 Rome, Italy;
| | - Giovanna D’Arcangelo
- Department of Systems Medicine, “Tor Vergata” University of Rome, Via Montpellier 1, 00133 Rome, Italy; (R.B.); (G.D.)
- Centre of Space Bio-Medicine, “Tor Vergata” University of Rome, Via Montpellier 1, 00133 Rome, Italy
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19
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Siu HW, Heck B, Kovermann M, Hauser K. Template-assisted design of monomeric polyQ models to unravel the unique role of glutamine side chains in disease-related aggregation. Chem Sci 2020; 12:412-426. [PMID: 33552461 PMCID: PMC7863018 DOI: 10.1039/d0sc05299j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/28/2020] [Indexed: 01/28/2023] Open
Abstract
PolyQ model peptides reveal the effect of individual glutamine side chains on fibril formation.
Expanded polyglutamine (polyQ) sequences cause numerous neurodegenerative diseases which are accompanied by the formation of polyQ fibrils. The unique role of glutamines in the aggregation onset is undoubtedly accepted and a lot structural data of the fibrils have been acquired, however side-chain specific structural dynamics inducing oligomerization are not well understood yet. To analyze spectroscopically the nucleation process, we designed various template-assisted glutamine-rich β-hairpin monomers mimicking the structural motif of a polyQ fibril. In a top-down strategy, we use a template which forms a well-defined stable hairpin in solution, insert polyQ-rich sequences into each strand and monitor the effects of individual glutamines by NMR, CD and IR spectroscopic approaches. The design was further advanced by alternating glutamines with other amino acids (T, W, E, K), thereby enhancing the solubility and increasing the number of cross-strand interacting glutamine side chains. Our spectroscopic studies reveal a decreasing hairpin stability with increased glutamine content and demonstrate the enormous impact of only a few glutamines – far below the disease threshold – to destabilize structure. Furthermore, we could access sub-ms conformational dynamics of monomeric polyQ-rich peptides by laser-excited temperature-jump IR spectroscopy. Both, the increased number of interacting glutamines and higher concentrations are key parameters to induce oligomerization. Concentration-dependent time-resolved IR measurements indicate an additional slower kinetic phase upon oligomer formation. The here presented peptide models enable spectroscopic molecular analyses to distinguish between monomer and oligomer dynamics in the early steps of polyQ fibril formation and in a side-chain specific manner.
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Affiliation(s)
- Ho-Wah Siu
- Department of Chemistry , University of Konstanz , 78457 Konstanz , Germany . ;
| | - Benjamin Heck
- Department of Chemistry , University of Konstanz , 78457 Konstanz , Germany . ;
| | - Michael Kovermann
- Department of Chemistry , University of Konstanz , 78457 Konstanz , Germany . ;
| | - Karin Hauser
- Department of Chemistry , University of Konstanz , 78457 Konstanz , Germany . ;
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20
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Wetzel R. Exploding the Repeat Length Paradigm while Exploring Amyloid Toxicity in Huntington's Disease. Acc Chem Res 2020; 53:2347-2357. [PMID: 32975927 DOI: 10.1021/acs.accounts.0c00450] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Huntington's disease (HD) is a progressive, familial neurodegenerative disease triggered by the expansion of a polyglutamine (polyQ) track in the protein huntingtin (htt). PolyQ sequences up to Q36 in htt are not known to be toxic, while polyQ lengths above Q36 almost invariably lead to increased disease risk and decreased ages of onset. The large number of physical states (monomers, dimers, tetramers, non-β oligomers, nanofibrils, and clustered amyloid fibrils) on the self-association landscape, with their overlapping kinetics of formation, have greatly complicated identification of the molecular species responsible for HD toxicity, drawing attention to the need for innovative approaches.After reports of HD-associated intraneuronal htt inclusions in 1997, we elucidated aggregation mechanisms of both simple polyQ sequences and the more complex polyQ-containing "exon1" fragment of htt (htt-ex1). Grounded in this work, the more recent results described here were made possible by breakthroughs in the molecular design of diagnostic polyQ derivatives and in fluorescence applications for characterizing amyloid assembly intermediates. Thus, insertion of β-turn-promoting mutations into relatively short, disordered polyQ sequences created "pro-β-hairpin" polyQs (βHPs) that exhibit amyloid formation rates comparable to the enhanced rates seen with expanded polyQ peptides. Introduction of "β-breaker" mutations into these βHP polyQ sequences created molecules that are blocked from aggregating into amyloid and also can inhibit amyloid formation by other polyQ proteins. These mutational effects were then successfully transferred into more complex htt-ex1 sequence backgrounds. Insights into the aggregation properties of htt-ex1 derivatives-as well as into the nucleation process itself-were obtained using fluorescence correlation spectroscopy (FCS) and a novel thioflavin-T (ThT) protocol that allows quantitation of htt-ex1 assembly intermediates.Using these tools, we quantified physical states of htt-ex1 at different growth times in mammalian PC12 cells engineered for inducible expression of both normal and expanded polyQ repeat length versions of htt-ex1. For expanded polyQ versions, we found tetramers, oligomers, and fibrils (but no monomers) all populated in these cells at a time when the first indication of toxicity (nuclear DNA damage) was observed. These experiments provided a strong hint that monomeric forms of htt-ex1 are not involved in toxicity, but we were otherwise unable to implicate a specific toxic self-assembled state because of the overlapping kinetics of formation. To gain a more intimate focus and control over the timelines of htt-ex1 self-assembly and the resulting toxic response, we engineered various htt-ex1-βHP molecules-with and without added β-breaker mutations-that could be expressed in rat neuronal and Drosophila models of HD. In both models, novel htt-ex1-βHP analogues exhibiting strong aggregation in spite of their very short polyQ repeat lengths proved to be toxic, dramatically breaking the "repeat length paradigm" and strongly suggesting that the toxic species must be some kind of aggregate. In both models, β-breaker analogues of htt-ex1-βHP that are slow to make amyloid-instead favoring accumulation of non-β oligomers-were nontoxic. In contrast, htt-ex1-βHP analogues that rapidly progress to amyloid states were toxic, suggesting that an aggregate possessing the fundamental amyloid folding motif is very likely the major toxic species in HD.
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Affiliation(s)
- Ronald Wetzel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Sciences Tower 3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
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21
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Boatz JC, Piretra T, Lasorsa A, Matlahov I, Conway JF, van der Wel PCA. Protofilament Structure and Supramolecular Polymorphism of Aggregated Mutant Huntingtin Exon 1. J Mol Biol 2020; 432:4722-4744. [PMID: 32598938 DOI: 10.1016/j.jmb.2020.06.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 06/01/2020] [Accepted: 06/18/2020] [Indexed: 12/11/2022]
Abstract
Huntington's disease is a progressive neurodegenerative disease caused by expansion of the polyglutamine domain in the first exon of huntingtin (HttEx1). The extent of expansion correlates with disease progression and formation of amyloid-like protein deposits within the brain. The latter display polymorphism at the microscopic level, both in cerebral tissue and in vitro. Such polymorphism can dramatically influence cytotoxicity, leading to much interest in the conditions and mechanisms that dictate the formation of polymorphs. We examine conditions that govern HttEx1 polymorphism in vitro, including concentration and the role of the non-polyglutamine flanking domains. Using electron microscopy, we observe polymorphs that differ in width and tendency for higher-order bundling. Strikingly, aggregation yields different polymorphs at low and high concentrations. Narrow filaments dominate at low concentrations that may be more relevant in vivo. We dissect the role of N- and C-terminal flanking domains using protein with the former (httNT or N17) largely removed. The truncated protein is generated by trypsin cleavage of soluble HttEx1 fusion protein, which we analyze in some detail. Dye binding and solid-state NMR studies reveal changes in fibril surface characteristics and flanking domain mobility. Higher-order interactions appear facilitated by the C-terminal tail, while the polyglutamine forms an amyloid core resembling those of other polyglutamine deposits. Fibril-surface-mediated branching, previously attributed to secondary nucleation, is reduced in absence of httNT. A new model for the architecture of the HttEx1 filaments is presented and discussed in context of the assembly mechanism and biological activity.
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Affiliation(s)
- Jennifer C Boatz
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Talia Piretra
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Alessia Lasorsa
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - Irina Matlahov
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
| | - James F Conway
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA.
| | - Patrick C A van der Wel
- Department of Structural Biology, School of Medicine, University of Pittsburgh, 3501 5th Ave, Biomedical Science Tower 3, Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747, AG, Groningen, the Netherlands.
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22
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Horne WS, Grossmann TN. Proteomimetics as protein-inspired scaffolds with defined tertiary folding patterns. Nat Chem 2020; 12:331-337. [PMID: 32029906 DOI: 10.1038/s41557-020-0420-9] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 01/09/2020] [Indexed: 12/29/2022]
Abstract
Proteins have evolved as a variable platform that provides access to molecules with diverse shapes, sizes and functions. These features have inspired chemists for decades to seek artificial mimetics of proteins with improved or novel properties. Such work has focused primarily on small protein fragments, often isolated secondary structures; however, there has lately been a growing interest in the design of artificial molecules that mimic larger, more complex tertiary folds. In this Perspective, we define these agents as 'proteomimetics' and discuss the recent advances in the field. Proteomimetics can be divided into three categories: protein domains with side-chain functionality that alters the native linear-chain topology; protein domains in which the chemical composition of the polypeptide backbone has been partially altered; and protein-like folded architectures that are composed entirely of non-natural monomer units. We give an overview of these proteomimetic approaches and outline remaining challenges facing the field.
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Affiliation(s)
- W Seth Horne
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Tom N Grossmann
- Department of Chemistry and Pharmaceutical Sciences, VU University Amsterdam, Amsterdam, the Netherlands.
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23
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Role of physical nucleation theory in understanding conformational conversion between pathogenic and nonpathogenic aggregates of low-complexity amyloid peptides. RESEARCH ON CHEMICAL INTERMEDIATES 2019. [DOI: 10.1007/s11164-019-03974-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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24
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The growth of amyloid fibrils: rates and mechanisms. Biochem J 2019; 476:2677-2703. [DOI: 10.1042/bcj20160868] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/08/2019] [Accepted: 09/10/2019] [Indexed: 12/19/2022]
Abstract
AbstractAmyloid fibrils are β-sheet-rich linear protein polymers that can be formed by a large variety of different proteins. These assemblies have received much interest in recent decades, due to their role in a range of human disorders. However, amyloid fibrils are also found in a functional context, whereby their structural, mechanical and thermodynamic properties are exploited by biological systems. Amyloid fibrils form through a nucleated polymerisation mechanism with secondary processes acting in many cases to amplify the number of fibrils. The filamentous nature of amyloid fibrils implies that the fibril growth rate is, by several orders of magnitude, the fastest step of the overall aggregation reaction. This article focusses specifically on in vitro experimental studies of the process of amyloid fibril growth, or elongation, and summarises the state of knowledge of its kinetics and mechanisms. This work attempts to provide the most comprehensive summary, to date, of the available experimental data on amyloid fibril elongation rate constants and the temperature and concentration dependence of amyloid fibril elongation rates. These data are compared with those from other types of protein polymers. This comparison with data from other polymerising proteins is interesting and relevant because many of the basic ideas and concepts discussed here were first introduced for non-amyloid protein polymers, most notably by the Japanese school of Oosawa and co-workers for cytoskeletal filaments.
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25
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Matlahov I, van der Wel PC. Conformational studies of pathogenic expanded polyglutamine protein deposits from Huntington's disease. Exp Biol Med (Maywood) 2019; 244:1584-1595. [PMID: 31203656 PMCID: PMC6920524 DOI: 10.1177/1535370219856620] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Huntington’s disease, like other neurodegenerative diseases, continues to lack an
effective cure. Current treatments that address early symptoms ultimately fail
Huntington’s disease patients and their families, with the disease typically
being fatal within 10–15 years from onset. Huntington’s disease is an inherited
disorder with motor and mental impairment, and is associated with the genetic
expansion of a CAG codon repeat encoding a polyglutamine-segment-containing
protein called huntingtin. These Huntington’s disease mutations cause misfolding
and aggregation of fragments of the mutant huntingtin protein, thereby likely
contributing to disease toxicity through a combination of gain-of-toxic-function
for the misfolded aggregates and a loss of function from sequestration of
huntingtin and other proteins. As with other amyloid diseases, the mutant
protein forms non-native fibrillar structures, which in Huntington’s disease are
found within patients’ neurons. The intracellular deposits are associated with
dysregulation of vital processes, and inter-neuronal transport of aggregates may
contribute to disease progression. However, a molecular understanding of these
aggregates and their detrimental effects has been frustrated by insufficient
structural data on the misfolded protein state. In this review, we examine
recent developments in the structural biology of polyglutamine-expanded
huntingtin fragments, and especially the contributions enabled by advances in
solid-state nuclear magnetic resonance spectroscopy. We summarize and discuss
our current structural understanding of the huntingtin deposits and how this
information furthers our understanding of the misfolding mechanism and disease
toxicity mechanisms.
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Affiliation(s)
- Irina Matlahov
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Patrick Ca van der Wel
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands
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26
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Anand BG, Prajapati KP, Dubey K, Ahamad N, Shekhawat DS, Rath PC, Joseph GK, Kar K. Self-Assembly of Artificial Sweetener Aspartame Yields Amyloid-like Cytotoxic Nanostructures. ACS NANO 2019; 13:6033-6049. [PMID: 31021591 DOI: 10.1021/acsnano.9b02284] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Recent reports have revealed the intrinsic propensity of single aromatic metabolites to undergo self-assembly and form nanostructures of amyloid nature. Hence, identifying whether aspartame, a universally consumed artificial sweetener, is inherently aggregation prone becomes an important area of investigation. Although the reports on aspartame-linked side effects describe a multitude of metabolic disorders, the mechanistic understanding of such destructive effects is largely mysterious. Since aromaticity, an aggregation-promoting factor, is intrinsic to aspartame's chemistry, it is important to know whether aspartame can undergo self-association and if such a property can predispose any cytotoxicity to biological systems. Our study finds that aspartame molecules, under mimicked physiological conditions, undergo a spontaneous self-assembly process yielding regular β-sheet-like cytotoxic nanofibrils of amyloid nature. The resultant aspartame fibrils were found to trigger amyloid cross-seeding and become a toxic aggregation trap for globular proteins, Aβ peptides, and aromatic metabolites that convert native structures to β-sheet-like fibrils. Aspartame fibrils were also found to induce hemolysis, causing DNA damage resulting in both apoptosis and necrosis-mediated cell death. Specific spatial arrangement between aspartame molecules is predicted to form a regular amyloid-like architecture with a sticky exterior that is capable of promoting viable H-bonds, electrostatic interactions, and hydrophobic contacts with biomolecules, leading to the onset of protein aggregation and cell death. Results reveal that the aspartame molecule is inherently amyloidogenic, and the self-assembly of aspartame becomes a toxic trap for proteins and cells, exposing the bitter side of such a ubiquitously used artificial sweetener.
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Affiliation(s)
- Bibin Gnanadhason Anand
- Department of Bioscience and Bioengineering , Indian Institute of Technology Jodhpur , Jodhpur 342037 , India
| | | | - Kriti Dubey
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
| | - Naseem Ahamad
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
| | - Dolat Singh Shekhawat
- Department of Bioscience and Bioengineering , Indian Institute of Technology Jodhpur , Jodhpur 342037 , India
| | - Pramod Chandra Rath
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
| | - George Kodimattam Joseph
- Department of Bioscience and Bioengineering , Indian Institute of Technology Jodhpur , Jodhpur 342037 , India
| | - Karunakar Kar
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
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27
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Wu D, Vonk JJ, Salles F, Vonk D, Haslbeck M, Melki R, Bergink S, Kampinga HH. The N terminus of the small heat shock protein HSPB7 drives its polyQ aggregation-suppressing activity. J Biol Chem 2019; 294:9985-9994. [PMID: 31097540 DOI: 10.1074/jbc.ra118.007117] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 05/09/2019] [Indexed: 11/06/2022] Open
Abstract
Heat shock protein family B (small) member 7 (HSPB7) is a unique, relatively unexplored member within the family of human small heat shock proteins (HSPBs). Unlike most HSPB family members, HSPB7 does not oligomerize and so far has not been shown to associate with any other member of the HSPB family. Intriguingly, it was found to be the most potent member within the HSPB family to prevent aggregation of proteins with expanded polyglutamine (polyQ) stretches. How HSPB7 suppresses polyQ aggregation has remained elusive so far. Here, using several experimental strategies, including in vitro aggregation assay, immunoblotting and fluorescence approaches, we show that the polyQ aggregation-inhibiting activity of HSPB7 is fully dependent on its flexible N-terminal domain (NTD). We observed that the NTD of HSPB7 is both required for association with and inhibition of polyQ aggregation. Remarkably, replacing the NTD of HSPB1, which itself cannot suppress polyQ aggregation, with the NTD of HSPB7 resulted in a hybrid protein that gained anti-polyQ aggregation activity. The hybrid NTDHSPB7-HSPB1 protein displayed a reduction in oligomer size and, unlike WT HSPB1, associated with polyQ. However, experiments with phospho-mimicking HSPB1 mutants revealed that de-oligomerization of HSPB1 alone does not suffice to gain polyQ aggregation-inhibiting activity. Together, our results reveal that the NTD of HSPB7 is both necessary and sufficient to bind to and suppress the aggregation of polyQ-containing proteins.
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Affiliation(s)
- Di Wu
- From the Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.,the College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China, the Department Chemie
| | - Jan J Vonk
- From the Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Felix Salles
- From the Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Danara Vonk
- From the Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Martin Haslbeck
- Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and
| | - Ronald Melki
- the Institut Francois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, 92265 Fontenay-Aux-Roses cedex, France
| | - Steven Bergink
- From the Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Harm H Kampinga
- From the Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands,
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28
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Priya SB, Gromiha MM. Structural insights into the aggregation mechanism of huntingtin exon 1 protein fragment with different polyQ-lengths. J Cell Biochem 2019; 120:10519-10529. [PMID: 30672003 DOI: 10.1002/jcb.28338] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 11/29/2018] [Indexed: 12/19/2022]
Abstract
Huntington disease is a neurodegenerative disorder caused by the expansion of polyglutamine (polyQ) at the N-terminal of the huntingtin exon 1 protein. The detailed structure and the mechanism behind this aggregation remain unclear and it is assumed that the polyQ undergoes a conformational transition to the β-sheet structure when it aggregates. Investigating the misfolding of polyQ facilitates the determination of the molecular mechanism of aggregation and can potentially help in developing a novel approach to inhibit polyQ aggregation. Moreover, the flanking sequences of the polyQ region play a vital role in structural changes and the aggregation mechanism. We performed all-atom molecular dynamics simulations to gain structural insights into the aggregation mechanism using eight different models with glutamine repeat lengths Q27 , Q27 P11 , Q34 , Q35 , Q36 , Q40 , Q50 , and Q50 P11 . In the models without flanking polyPs, we noticed that the transformation of a random coil to β-sheet occurs when the number of Q increases. We also found that the flanking polyPs prevent aggregation by decreasing the probability of forming a β-sheet structure. When polyQ length increases, the 17 N-terminal flanking residues are more likely to adopt a β-sheet conformation from α-helix and coil. From our simulations, we suggest that at least 34 glutamines are required for initiating aggregation and 40 residues length is critical for the aggregation of huntingtin exon 1 protein for disease onset. This study provides structural insights into misfolding and the role of flanking sequences in huntingtin aggregation which will further help in developing therapeutic strategies for Huntington's disease.
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Affiliation(s)
- S Binny Priya
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - M Michael Gromiha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India.,Advanced Computational Drug Discovery Unit (ACDD), Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
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29
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Mason TO, Shimanovich U. Fibrous Protein Self-Assembly in Biomimetic Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1706462. [PMID: 29883013 DOI: 10.1002/adma.201706462] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/28/2018] [Indexed: 05/22/2023]
Abstract
Protein self-assembly processes, by which polypeptides interact and independently form multimeric structures, lead to a wide array of different endpoints. Structures formed range from highly ordered molecular crystals to amorphous aggregates. Order arises in the system from a balance between many low-energy processes occurring due to a set of interactions between residues in a chain, between residues in different chains, and between solute and solvent. In Nature, self-assembling protein systems have evolved over millions of years to organize into supramolecular structures, optimized for specific functions, with this propensity determined by the sequence of their constituent amino acids, of which only 20 are encoded in DNA. The structural materials that arise from biological self-assembly can display remarkable mechanical properties, often as a result of hierarchical structure on the nano- and microscales, and much research has been devoted to mimicking and exploiting these properties for a variety of end uses. This work presents a review of a range of studies in which biological functions are effectively reproduced through the design of self-assembling fibrous protein systems.
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Affiliation(s)
- Thomas O Mason
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Ulyana Shimanovich
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 7610001, Israel
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30
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Drombosky KW, Rode S, Kodali R, Jacob TC, Palladino MJ, Wetzel R. Mutational analysis implicates the amyloid fibril as the toxic entity in Huntington's disease. Neurobiol Dis 2018; 120:126-138. [PMID: 30171891 DOI: 10.1016/j.nbd.2018.08.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 08/22/2018] [Accepted: 08/28/2018] [Indexed: 10/28/2022] Open
Abstract
In Huntington disease (HD), an expanded polyglutamine (polyQ > 37) sequence within huntingtin (htt) exon1 leads to enhanced disease risk. It has proved difficult, however, to determine whether the toxic form generated by polyQ expansion is a misfolded or avid-binding monomer, an α-helix-rich oligomer, or a β-sheet-rich amyloid fibril. Here we describe an engineered htt exon1 analog featuring a short polyQ sequence that nonetheless quickly forms amyloid fibrils and causes HD-like toxicity in rat neurons and Drosophila. Additional modifications within the polyQ segment produce htt exon1 analogs that populate only spherical oligomers and are non-toxic in cells and flies. Furthermore, in mixture with expanded-polyQ htt exon1, the latter analogs in vitro suppress amyloid formation and promote oligomer formation, and in vivo rescue neurons and flies expressing mhtt exon1 from dysfunction and death. Thus, in our experiments, while htt exon1 toxicity tracks with aggregation propensity, it does so in spite of the toxic construct's possessing polyQ tracts well below those normally considered to be disease-associated. That is, aggregation propensity proves to be a more accurate surrogate for toxicity than is polyQ repeat length itself, strongly supporting a major toxic role for htt exon1 aggregation in HD. In addition, the results suggest that the aggregates that are most toxic in these model systems are amyloid-related. These engineered analogs are novel tools for mapping properties of polyQ self-assembly intermediates and products that should similarly be useful in the analysis of other expanded polyQ diseases. Small molecules with similar amyloid inhibitory properties might be developed into effective therapeutic agents.
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Affiliation(s)
- Kenneth W Drombosky
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sascha Rode
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ravi Kodali
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Tija C Jacob
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Michael J Palladino
- Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ronald Wetzel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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31
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Anand BG, Prajapati KP, Shekhawat DS, Kar K. Tyrosine-Generated Nanostructures Initiate Amyloid Cross-Seeding in Proteins Leading to a Lethal Aggregation Trap. Biochemistry 2018; 57:5202-5209. [DOI: 10.1021/acs.biochem.8b00472] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Bibin G. Anand
- Biophysical and Biomaterials Research Laboratory, Room 310, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Kailash P. Prajapati
- Biophysical and Biomaterials Research Laboratory, Room 310, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Dolat S. Shekhawat
- Biophysical and Biomaterials Research Laboratory, Room 310, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Karunakar Kar
- Biophysical and Biomaterials Research Laboratory, Room 310, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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32
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Matlahov I, van der Wel PCA. Hidden motions and motion-induced invisibility: Dynamics-based spectral editing in solid-state NMR. Methods 2018; 148:123-135. [PMID: 29702226 DOI: 10.1016/j.ymeth.2018.04.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/05/2018] [Accepted: 04/16/2018] [Indexed: 10/17/2022] Open
Abstract
Solid-state nuclear magnetic resonance (ssNMR) spectroscopy enables the structural characterization of a diverse array of biological assemblies that include amyloid fibrils, non-amyloid aggregates, membrane-associated proteins and viral capsids. Such biological samples feature functionally relevant molecular dynamics, which often affect different parts of the sample in different ways. Solid-state NMR experiments' sensitivity to dynamics represents a double-edged sword. On the one hand, it offers a chance to measure dynamics in great detail. On the other hand, certain types of motion lead to signal loss and experimental inefficiencies that at first glance interfere with the application of ssNMR to overly dynamic proteins. Dynamics-based spectral editing (DYSE) ssNMR methods leverage motion-dependent signal losses to simplify spectra and enable the study of sub-structures with particular motional properties.
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Affiliation(s)
- Irina Matlahov
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA 15213, USA
| | - Patrick C A van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA 15213, USA; Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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33
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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: 44] [Impact Index Per Article: 6.3] [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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34
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Pan F, Man VH, Roland C, Sagui C. Structure and Dynamics of DNA and RNA Double Helices of CAG and GAC Trinucleotide Repeats. Biophys J 2017; 113:19-36. [PMID: 28700917 DOI: 10.1016/j.bpj.2017.05.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/19/2017] [Accepted: 05/26/2017] [Indexed: 12/13/2022] Open
Abstract
CAG trinucleotide repeats are known to cause 10 late-onset progressive neurodegenerative disorders as the repeats expand beyond a threshold, whereas GAC repeats are associated with skeletal dysplasias and expand from the normal five to a maximum of seven repeats. The TR secondary structure is believed to play a role in CAG expansions. We have carried out free energy and molecular dynamics studies to determine the preferred conformations of the A-A noncanonical pairs in (CAG)n and (GAC)n trinucleotide repeats (n = 1, 4) and the consequent changes in the overall structure of the RNA and DNA duplexes. We find that the global free energy minimum corresponds to A-A pairs stacked inside the core of the helix with anti-anti conformations in RNA and (high-anti)-(high-anti) conformations in DNA. The next minimum corresponds to anti-syn conformations, whereas syn-syn conformations are higher in energy. Transition rates of the A-A conformations are higher for RNA than DNA. Mechanisms for these various transitions are identified. Additional structural and dynamical aspects of the helical conformations are explored, with a focus on contrasting CAG and GAC duplexes. The neutralizing ion distribution around the noncanonical pairs is described.
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Affiliation(s)
- Feng Pan
- Department of Physics, North Carolina State University, Raleigh, North Carolina
| | - Viet Hoang Man
- Department of Physics, North Carolina State University, Raleigh, North Carolina
| | - Christopher Roland
- Department of Physics, North Carolina State University, Raleigh, North Carolina
| | - Celeste Sagui
- Department of Physics, North Carolina State University, Raleigh, North Carolina.
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35
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Kang H, Vázquez FX, Zhang L, Das P, Toledo-Sherman L, Luan B, Levitt M, Zhou R. Emerging β-Sheet Rich Conformations in Supercompact Huntingtin Exon-1 Mutant Structures. J Am Chem Soc 2017; 139:8820-8827. [PMID: 28609090 PMCID: PMC5835228 DOI: 10.1021/jacs.7b00838] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
There exists strong correlation between the extended polyglutamines (polyQ) within exon-1 of Huntingtin protein (Htt) and age onset of Huntington's disease (HD); however, the underlying molecular mechanism is still poorly understood. Here we apply extensive molecular dynamics simulations to study the folding of Htt-exon-1 across five different polyQ-lengths. We find an increase in secondary structure motifs at longer Q-lengths, including β-sheet content that seems to contribute to the formation of increasingly compact structures. More strikingly, these longer Q-lengths adopt supercompact structures as evidenced by a surprisingly small power-law scaling exponent (0.22) between the radius-of-gyration and Q-length that is substantially below expected values for compact globule structures (∼0.33) and unstructured proteins (∼0.50). Hydrogen bond analyses further revealed that the supercompact behavior of polyQ is mainly due to the "glue-like" behavior of glutamine's side chains with significantly more side chain-side chain H-bonds than regular proteins in the Protein Data Bank (PDB). The orientation of the glutamine side chains also tend to be "buried" inside, explaining why polyQ domains are insoluble on their own.
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Affiliation(s)
- Hongsuk Kang
- Computational Biology Center, IBM Thomas J. Watson Research Center , Yorktown Heights, New York 10598, United States
| | - Francisco X Vázquez
- Computational Biology Center, IBM Thomas J. Watson Research Center , Yorktown Heights, New York 10598, United States
| | - Leili Zhang
- Computational Biology Center, IBM Thomas J. Watson Research Center , Yorktown Heights, New York 10598, United States
| | - Payel Das
- Computational Biology Center, IBM Thomas J. Watson Research Center , Yorktown Heights, New York 10598, United States
| | | | - Binquan Luan
- Computational Biology Center, IBM Thomas J. Watson Research Center , Yorktown Heights, New York 10598, United States
| | - Michael Levitt
- Department of Structural Biology, Stanford University School of Medicine , Stanford, California 94305, United States
| | - Ruhong Zhou
- Computational Biology Center, IBM Thomas J. Watson Research Center , Yorktown Heights, New York 10598, United States
- Department of Chemistry, Columbia University , New York, New York 10027, United States
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36
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Punihaole D, Jakubek RS, Workman RJ, Marbella LE, Campbell P, Madura JD, Asher SA. Monomeric Polyglutamine Structures That Evolve into Fibrils. J Phys Chem B 2017; 121:5953-5967. [DOI: 10.1021/acs.jpcb.7b04060] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- David Punihaole
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Ryan S. Jakubek
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Riley J. Workman
- Department
of Chemistry and Biochemistry, Center for Computational Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
| | - Lauren E. Marbella
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Patricia Campbell
- Department
of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, United States
| | - Jeffry D. Madura
- Department
of Chemistry and Biochemistry, Center for Computational Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
| | - Sanford A. Asher
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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37
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Abstract
Protein aggregation is a hallmark of neurodegenerative disorders. In this group of brain-related disorders, a disease-specific "host" protein or fragment misfolds and adopts a metastatic, aggregate-prone conformation. Often, this misfolded conformation is structurally and thermodynamically different from its native state. Intermolecular contacts, which arise in this non-native state, promote aggregation. In this regard, understanding the molecular principles and mechanisms that lead to the formation of such a non-native state and further promote the formation of the critical nucleus for fiber growth is essential. In this study, the authors analyze the aggregation propensity of Huntingtin headpiece (httNT), which is known to facilitate the polyQ aggregation, in relation to the helix mediated aggregation mechanism proposed by the Wetzel group. The authors demonstrate that even though httNT displays a degenerate conformational spectrum on its own, interfaces of macroscopic or molecular origin can promote the α-helix conformation, eliminating all other alternatives in the conformational phase space. Our findings indicate that httNT molecules do not have a strong orientational preference for parallel or antiparallel orientation of the helices within the aggregate. However, a parallel packed bundle of helices would support the idea of increased polyglutamine concentration, to pave the way for cross-β structures.
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38
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Fibril polymorphism affects immobilized non-amyloid flanking domains of huntingtin exon1 rather than its polyglutamine core. Nat Commun 2017; 8:15462. [PMID: 28537272 PMCID: PMC5458082 DOI: 10.1038/ncomms15462] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/31/2017] [Indexed: 02/07/2023] Open
Abstract
Polyglutamine expansion in the huntingtin protein is the primary genetic cause of Huntington's disease (HD). Fragments coinciding with mutant huntingtin exon1 aggregate in vivo and induce HD-like pathology in mouse models. The resulting aggregates can have different structures that affect their biochemical behaviour and cytotoxic activity. Here we report our studies of the structure and functional characteristics of multiple mutant htt exon1 fibrils by complementary techniques, including infrared and solid-state NMR spectroscopies. Magic-angle-spinning NMR reveals that fibrillar exon1 has a partly mobile α-helix in its aggregation-accelerating N terminus, and semi-rigid polyproline II helices in the proline-rich flanking domain (PRD). The polyglutamine-proximal portions of these domains are immobilized and clustered, limiting access to aggregation-modulating antibodies. The polymorphic fibrils differ in their flanking domains rather than the polyglutamine amyloid structure. They are effective at seeding polyglutamine aggregation and exhibit cytotoxic effects when applied to neuronal cells. Huntington's disease is caused by a polyglutamine stretch expansion in the first exon of huntingtin. Here, the authors use infrared spectroscopy and solid-state NMR and show that polymorphic huntingtin exon1 fibres differ in their flanking regions but not their core polyglutamine amyloid structures.
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39
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Aggregation landscapes of Huntingtin exon 1 protein fragments and the critical repeat length for the onset of Huntington's disease. Proc Natl Acad Sci U S A 2017; 114:4406-4411. [PMID: 28400517 DOI: 10.1073/pnas.1702237114] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disease caused by an abnormal expansion in the polyglutamine (polyQ) track of the Huntingtin (HTT) protein. The severity of the disease depends on the polyQ repeat length, arising only in patients with proteins having 36 repeats or more. Previous studies have shown that the aggregation of N-terminal fragments (encoded by HTT exon 1) underlies the disease pathology in mouse models and that the HTT exon 1 gene product can self-assemble into amyloid structures. Here, we provide detailed structural mechanisms for aggregation of several protein fragments encoded by HTT exon 1 by using the associative memory, water-mediated, structure and energy model (AWSEM) to construct their free energy landscapes. We find that the addition of the N-terminal 17-residue sequence ([Formula: see text]) facilitates polyQ aggregation by encouraging the formation of prefibrillar oligomers, whereas adding the C-terminal polyproline sequence ([Formula: see text]) inhibits aggregation. The combination of both terminal additions in HTT exon 1 fragment leads to a complex aggregation mechanism with a basic core that resembles that found for the aggregation of pure polyQ repeats using AWSEM. At the extrapolated physiological concentration, although the grand canonical free energy profiles are uphill for HTT exon 1 fragments having 20 or 30 glutamines, the aggregation landscape for fragments with 40 repeats has become downhill. This computational prediction agrees with the critical length found for the onset of HD and suggests potential therapies based on blocking early binding events involving the terminal additions to the polyQ repeats.
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40
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DeBlase AF, Harrilal CP, Lawler JT, Burke NL, McLuckey SA, Zwier TS. Conformation-Specific Infrared and Ultraviolet Spectroscopy of Cold [YAPAA+H]+ and [YGPAA+H]+ Ions: A Stereochemical “Twist” on the β-Hairpin Turn. J Am Chem Soc 2017; 139:5481-5493. [PMID: 28353347 DOI: 10.1021/jacs.7b01315] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew F. DeBlase
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Christopher P. Harrilal
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - John T. Lawler
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Nicole L. Burke
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Scott A. McLuckey
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Timothy S. Zwier
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
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41
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Kuiper EFE, de Mattos EP, Jardim LB, Kampinga HH, Bergink S. Chaperones in Polyglutamine Aggregation: Beyond the Q-Stretch. Front Neurosci 2017; 11:145. [PMID: 28386214 PMCID: PMC5362620 DOI: 10.3389/fnins.2017.00145] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 03/08/2017] [Indexed: 01/12/2023] Open
Abstract
Expanded polyglutamine (polyQ) stretches in at least nine unrelated proteins lead to inherited neuronal dysfunction and degeneration. The expansion size in all diseases correlates with age at onset (AO) of disease and with polyQ protein aggregation, indicating that the expanded polyQ stretch is the main driving force for the disease onset. Interestingly, there is marked interpatient variability in expansion thresholds for a given disease. Between different polyQ diseases the repeat length vs. AO also indicates the existence of modulatory effects on aggregation of the upstream and downstream amino acid sequences flanking the Q expansion. This can be either due to intrinsic modulation of aggregation by the flanking regions, or due to differential interaction with other proteins, such as the components of the cellular protein quality control network. Indeed, several lines of evidence suggest that molecular chaperones have impact on the handling of different polyQ proteins. Here, we review factors differentially influencing polyQ aggregation: the Q-stretch itself, modulatory flanking sequences, interaction partners, cleavage of polyQ-containing proteins, and post-translational modifications, with a special focus on the role of molecular chaperones. By discussing typical examples of how these factors influence aggregation, we provide more insight on the variability of AO between different diseases as well as within the same polyQ disorder, on the molecular level.
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Affiliation(s)
- E F E Kuiper
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
| | - Eduardo P de Mattos
- Department of Cell Biology, University Medical Center Groningen, University of GroningenGroningen, Netherlands; Programa de Pós-Graduação em Genética e Biologia Molecular, Department of Genetics, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto AlegrePorto Alegre, Brazil
| | - Laura B Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Department of Genetics, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto AlegrePorto Alegre, Brazil; Departamento de Medicina Interna, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Harm H Kampinga
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
| | - Steven Bergink
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
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42
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Kashchiev D. Modeling the Effect of Monomer Conformational Change on the Early Stage of Protein Self-Assembly into Fibrils. J Phys Chem B 2016; 121:35-46. [PMID: 28029261 DOI: 10.1021/acs.jpcb.6b09302] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Filamentous self-assembly of proteins is an important process implicated in a plethora of human diseases and of interest for nanotechnology. Using rate equations, we analyze the early stage of the process in solutions that initially contain fibrillation-passive protein monomers and in which the nascent fibrils are practically insoluble. The analysis is based on a model accounting for the conformational and/or other changes the passive monomers experience to transform themselves into fibrillation-active monomers and thus become fibril nuclei. The model allows exact, comprehensive, and simple mathematical description of the early stage of fibrillation, which reveals the usually neglected role of the nucleation nonstationarity in this stage of fibrillation. We obtain exact and user-friendly expressions for experimentally accessible quantities such as the size distribution of fibrils, their number and mass concentrations, the rate and nonstationary period of fibril nucleation, and the delay time of fibril formation. Analyzing available experimental data, we find that the theory successfully describes the fibrillation time course of pathological and nonpathological ataxin-3, a protein involved in the neurodegenerative disorder spinocerebellar ataxia type-3. The analysis provides mechanistic insight into the reason for the higher fibril nucleation and elongation rates of the pathological ataxin-3.
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Affiliation(s)
- Dimo Kashchiev
- Institute of Physical Chemistry, Bulgarian Academy of Sciences , ul. Acad. G. Bonchev 11, Sofia 1113, Bulgaria
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43
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Kar K, Baker MA, Lengyel GA, Hoop CL, Kodali R, Byeon IJ, Horne WS, van der Wel PCA, Wetzel R. Backbone Engineering within a Latent β-Hairpin Structure to Design Inhibitors of Polyglutamine Amyloid Formation. J Mol Biol 2016; 429:308-323. [PMID: 27986569 DOI: 10.1016/j.jmb.2016.12.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/03/2016] [Accepted: 12/07/2016] [Indexed: 11/28/2022]
Abstract
Candidates for the toxic molecular species in the expanded polyglutamine (polyQ) repeat diseases range from various types of aggregates to "misfolded" monomers. One way to vet these candidates is to develop mutants that restrict conformational landscapes. Previously, we inserted two self-complementary β-hairpin enhancing motifs into a short polyQ sequence to generate a mutant, here called "βHP," that exhibits greatly improved amyloid nucleation without measurably enhancing β-structure in the monomer ensemble. We extend these studies here by introducing single-backbone H-bond impairing modifications αN-methyl Gln or l-Pro at key positions within βHP. Modifications predicted to allow formation of a fully H-bonded β-hairpin at the fibril edge while interfering with H-bonding to the next incoming monomer exhibit poor amyloid formation and act as potent inhibitors in trans of simple polyQ peptide aggregation. In contrast, a modification that disrupts intra-β-hairpin H-bonding within βHP, while also aggregating poorly, is ineffective at inhibiting amyloid formation in trans. The inhibitors constitute a dynamic version of the edge-protection negative design strategy used in protein evolution to limit unwanted protein aggregation. Our data support a model in which polyQ peptides containing strong β-hairpin encouraging motifs only rarely form β-hairpin conformations in the monomer ensemble, but nonetheless take on such conformations at key steps during amyloid formation. The results provide insights into polyQ solution structure and fibril formation while also suggesting an approach to the design of inhibitors of polyQ amyloid growth that focuses on conformational requirements for fibril and nucleus elongation.
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Affiliation(s)
- Karunakar Kar
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Matthew A Baker
- Department of Chemistry, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - George A Lengyel
- Department of Chemistry, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Cody L Hoop
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Ravindra Kodali
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - In-Ja Byeon
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - W Seth Horne
- Department of Chemistry, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Patrick C A van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Ronald Wetzel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA.
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44
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Chen M, Tsai M, Zheng W, Wolynes PG. The Aggregation Free Energy Landscapes of Polyglutamine Repeats. J Am Chem Soc 2016; 138:15197-15203. [PMID: 27786478 DOI: 10.1021/jacs.6b08665] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Aggregates of proteins containing polyglutamine (polyQ) repeats are strongly associated with several neurodegenerative diseases. The length of the repeats correlates with the severity of the disease. Previous studies have shown that pure polyQ peptides aggregate by nucleated growth polymerization and that the size of the critical nucleus (n*) decreases from tetrameric to dimeric and monomeric as length increases from Q18 to Q26. Why the critical nucleus size changes with repeat-length has been unclear. Using the associative memory, water-mediated, structure and energy model, we construct the aggregation free energy landscapes for polyQ peptides of different repeat-lengths. These studies show that the monomer of the shorter repeat-length (Q20) prefers an extended conformation and that its aggregation indeed has a trimeric nucleus (n* ∼ 3), while a longer repeat-length monomer (Q30) prefers a β-hairpin conformation which then aggregates in a downhill fashion at 0.1 mM. For an intermediate length peptide (Q26), there is an equal preference for hairpin and extended forms in the monomer which leads to a mixed inhomogeneous nucleation mechanism for fibrils. The predicted changes of monomeric structure and nucleation mechanism are confirmed by studying the aggregation free energy profile for a polyglutamine repeat with site-specific PG mutations that favor the hairpin form, giving results in harmony with experiments on this system.
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Affiliation(s)
- Mingchen Chen
- Center for Theoretical Biological Physics, ‡Department of Bioengineering, and §Department of Chemistry, Rice University , Houston, Texas 77005, United States
| | - MinYeh Tsai
- Center for Theoretical Biological Physics, ‡Department of Bioengineering, and §Department of Chemistry, Rice University , Houston, Texas 77005, United States
| | - Weihua Zheng
- Center for Theoretical Biological Physics, ‡Department of Bioengineering, and §Department of Chemistry, Rice University , Houston, Texas 77005, United States
| | - Peter G Wolynes
- Center for Theoretical Biological Physics, ‡Department of Bioengineering, and §Department of Chemistry, Rice University , Houston, Texas 77005, United States
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45
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Walsh PS, Blodgett KN, McBurney C, Gellman SH, Zwier TS. Inherent Conformational Preferences of Ac-Gln-Gln-NHBn: Sidechain Hydrogen Bonding Supports a β-Turn in the Gas Phase. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201607842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Patrick S. Walsh
- Department of Chemistry; Purdue University; West Lafayette IN 47907 USA
| | - Karl N. Blodgett
- Department of Chemistry; Purdue University; West Lafayette IN 47907 USA
| | - Carl McBurney
- Department of Chemistry; University of Wisconsin-Madison; Madison WI 53706 USA
| | - Samuel H. Gellman
- Department of Chemistry; University of Wisconsin-Madison; Madison WI 53706 USA
| | - Timothy S. Zwier
- Department of Chemistry; Purdue University; West Lafayette IN 47907 USA
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46
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Walsh PS, Blodgett KN, McBurney C, Gellman SH, Zwier TS. Inherent Conformational Preferences of Ac‐Gln‐Gln‐NHBn: Sidechain Hydrogen Bonding Supports a β‐Turn in the Gas Phase. Angew Chem Int Ed Engl 2016; 55:14618-14622. [PMID: 27775204 DOI: 10.1002/anie.201607842] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/04/2016] [Indexed: 01/30/2023]
Affiliation(s)
- Patrick S. Walsh
- Department of Chemistry Purdue University West Lafayette IN 47907 USA
| | - Karl N. Blodgett
- Department of Chemistry Purdue University West Lafayette IN 47907 USA
| | - Carl McBurney
- Department of Chemistry University of Wisconsin-Madison Madison WI 53706 USA
| | - Samuel H. Gellman
- Department of Chemistry University of Wisconsin-Madison Madison WI 53706 USA
| | - Timothy S. Zwier
- Department of Chemistry Purdue University West Lafayette IN 47907 USA
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47
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Versatile members of the DNAJ family show Hsp70 dependent anti-aggregation activity on RING1 mutant parkin C289G. Sci Rep 2016; 6:34830. [PMID: 27713507 PMCID: PMC5054386 DOI: 10.1038/srep34830] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/21/2016] [Indexed: 02/06/2023] Open
Abstract
Parkinson’s disease is one of the most common neurodegenerative disorders and several mutations in different genes have been identified to contribute to the disease. A loss of function parkin RING1 domain mutant (C289G) is associated with autosomal-recessive juvenile-onset Parkinsonism (AR-JP) and displays altered solubility and sequesters into aggregates. Single overexpression of almost each individual member of the Hsp40 (DNAJ) family of chaperones efficiently reduces parkin C289G aggregation and requires interaction with and activity of endogenously expressed Hsp70 s. For DNAJB6 and DNAJB8, potent suppressors of aggregation of polyglutamine proteins for which they rely mainly on an S/T-rich region, it was found that the S/T-rich region was dispensable for suppression of parkin C289G aggregation. Our data implies that different disease-causing proteins pose different challenges to the protein homeostasis system and that DNAJB6 and DNAJB8 are highly versatile members of the DNAJ protein family with multiple partially non-overlapping modes of action with respect to handling disease-causing proteins, making them interesting potential therapeutic targets.
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48
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Goyal B, Srivastava KR, Patel K, Durani S. Modulation of β-Hairpin Peptide Self-Assembly: A Twenty-Residue Poly-lβ-Hairpin Modified Rationally as a Mixed-l,dHydrolase. ChemistrySelect 2016. [DOI: 10.1002/slct.201600078] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Bhupesh Goyal
- Department of Chemistry; Indian Institute of Technology Bombay; Powai Mumbai- 400076 India
- Department of Chemistry; School of Basic and Applied Sciences; Sri Guru Granth Sahib World University; Fatehgarh Sahib- 140406 Punjab India
| | - Kinshuk Raj Srivastava
- Department of Chemistry; Indian Institute of Technology Bombay; Powai Mumbai- 400076 India
- Department of Physics and Astronomy; Michigan State University; East Lansing USA
| | - Kirti Patel
- Department of Chemistry; Indian Institute of Technology Bombay; Powai Mumbai- 400076 India
- Department of Chemistry; N. B. Mehta Science College, Bordi, Dahanu; Dist. Thane Maharashtra India
| | - Susheel Durani
- Department of Chemistry; Indian Institute of Technology Bombay; Powai Mumbai- 400076 India
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49
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Zhang Y, Man VH, Roland C, Sagui C. Amyloid Properties of Asparagine and Glutamine in Prion-like Proteins. ACS Chem Neurosci 2016; 7:576-87. [PMID: 26911543 DOI: 10.1021/acschemneuro.5b00337] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Sequences rich in glutamine (Q) and asparagine (N) are intrinsically disordered in monomeric form, but can aggregate into highly ordered amyloids, as seen in Q/N-rich prion domains (PrDs). Amyloids are fibrillar protein aggregates rich in β-sheet structures that can self-propagate through protein-conformational chain reactions. Here, we present a comprehensive theoretical study of N/Q-rich peptides, including sequences found in the yeast Sup35 PrD, in parallel and antiparallel β-sheet aggregates, and probe via fully atomistic molecular dynamics simulations all their possible steric-zipper interfaces in order to determine their protofibril structure and their relative stability. Our results show that polyglutamine aggregates are more stable than polyasparagine aggregates. Enthalpic contributions to the free energy favor the formation of polyQ protofibrils, while entropic contributions favor the formation of polyN protofibrils. The considerably larger phase space that disordered polyQ must sample on its way to aggregation probably is at the root of the associated slower kinetics observed experimentally. When other amino acids are present, such as in the Sup35 PrD, their shorter side chains favor steric-zipper formation for N but not Q, as they preclude the in-register association of the long Q side chains.
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Affiliation(s)
- Yuan Zhang
- Department of Physics, and
Center for High Performance Simulations (CHiPS), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Viet Hoang Man
- Department of Physics, and
Center for High Performance Simulations (CHiPS), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Christopher Roland
- Department of Physics, and
Center for High Performance Simulations (CHiPS), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Celeste Sagui
- Department of Physics, and
Center for High Performance Simulations (CHiPS), North Carolina State University, Raleigh, North Carolina 27695, United States
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50
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Kampinga HH, Bergink S. Heat shock proteins as potential targets for protective strategies in neurodegeneration. Lancet Neurol 2016; 15:748-759. [PMID: 27106072 DOI: 10.1016/s1474-4422(16)00099-5] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/09/2016] [Accepted: 02/24/2016] [Indexed: 01/08/2023]
Abstract
Protein aggregates are hallmarks of nearly all age-related neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and several polyglutamine diseases such as Huntington's disease and different forms of spinocerebellar ataxias (SCA; SCA1-3, SCA6, and SCA7). The collapse of cellular protein homoeostasis can be both a cause and a consequence of this protein aggregation. Boosting components of the cellular protein quality control system has been widely investigated as a strategy to counteract protein aggregates or their toxic consequences. Heat shock proteins (HSPs) play a central part in regulating protein quality control and contribute to protein aggregation and disaggregation. Therefore, HSPs are viable targets for the development of drugs aimed at reducing pathogenic protein aggregates that are thought to contribute to the development of so many neurodegenerative disorders.
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Affiliation(s)
- Harm H Kampinga
- Department of Cell Biology, University Medical Center Groningen, Rijksuniversiteit Groningen, Groningen, Netherlands.
| | - Steven Bergink
- Department of Cell Biology, University Medical Center Groningen, Rijksuniversiteit Groningen, Groningen, Netherlands
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