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Jeacock K, Chappard A, Gallagher KJ, Mackay CL, Kilgour DPA, Horrocks MH, Kunath T, Clarke DJ. Determining the Location of the α-Synuclein Dimer Interface Using Native Top-Down Fragmentation and Isotope Depletion-Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:847-856. [PMID: 36976861 PMCID: PMC10161212 DOI: 10.1021/jasms.2c00339] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
α-Synuclein (αSyn), a 140-residue intrinsically disordered protein, comprises the primary proteinaceous component of pathology-associated Lewy body inclusions in Parkinson's disease (PD). Due to its association with PD, αSyn is studied extensively; however, the endogenous structure and physiological roles of this protein are yet to be fully understood. Here, ion mobility-mass spectrometry and native top-down electron capture dissociation fragmentation have been used to elucidate the structural properties associated with a stable, naturally occurring dimeric species of αSyn. This stable dimer appears in both wild-type (WT) αSyn and the PD-associated variant A53E. Furthermore, we integrated a novel method for generating isotopically depleted protein into our native top-down workflow. Isotope depletion increases signal-to-noise ratio and reduces the spectral complexity of fragmentation data, enabling the monoisotopic peak of low abundant fragment ions to be observed. This enables the accurate and confident assignment of fragments unique to the αSyn dimer to be assigned and structural information about this species to be inferred. Using this approach, we were able to identify fragments unique to the dimer, which demonstrates a C-terminal to C-terminal interaction between the monomer subunits. The approach in this study holds promise for further investigation into the structural properties of endogenous multimeric species of αSyn.
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Affiliation(s)
- Kiani Jeacock
- The EastCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Alexandre Chappard
- The EastCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Kelly J Gallagher
- The EastCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - C Logan Mackay
- The EastCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - David P A Kilgour
- Chemistry and Forensics, Nottingham Trent University, Nottingham NG11 8NS, U.K
| | - Mathew H Horrocks
- The EastCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Tilo Kunath
- Centre for Regenerative Medicine, Institute for Stem Cell Research, University of Edinburgh, Edinburgh EH16 4UU, U.K
| | - David J Clarke
- The EastCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
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2
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Mankoo OK, Kaur A, Goyal D, Goyal B. Unravelling the destabilization potential of ellagic acid on α-synuclein fibrils using molecular dynamics simulations. Phys Chem Chem Phys 2023; 25:8128-8143. [PMID: 36877087 DOI: 10.1039/d2cp06006j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The aberrant deposition of α-synuclein (α-Syn) protein into the intracellular neuronal aggregates termed Lewy bodies and Lewy neurites characterizes the devastating neurodegenerative condition known as Parkinson's disease (PD). The disruption of pre-existing disease-relevant α-Syn fibrils is recognized as a viable therapeutic approach for PD. Ellagic acid (EA), a natural polyphenolic compound, is experimentally proven as a potential candidate that prevents or reverses the α-Syn fibrillization process. However, the detailed inhibitory mechanism of EA against the destabilization of α-Syn fibril remains largely unclear. In this work, the influence of EA on α-Syn fibril and its putative binding mechanism were explored using molecular dynamics (MD) simulations. EA interacted primarily with the non-amyloid-β component (NAC) of α-Syn fibril, disrupting its β-sheet content and thereby increasing the coil content. The E46-K80 salt bridge, critical for the stability of Greek-key-like α-Syn fibril, was disrupted in the presence of EA. The binding free energy analysis using the MM-PBSA method demonstrates the favourable binding of EA to α-Syn fibril (ΔGbinding = -34.62 ± 11.33 kcal mol-1). Interestingly, the binding affinity between chains H and J of the α-Syn fibril was significantly reduced on the incorporation of EA, which highlights the disruptive ability of EA towards α-Syn fibril. The MD simulations provide mechanistic insights into the α-Syn fibril disruption by EA, which gives a valuable direction for the development of potential inhibitors of α-Syn fibrillization and its associated cytotoxicity.
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Affiliation(s)
- Opinder Kaur Mankoo
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Anupamjeet Kaur
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Deepti Goyal
- Department of Chemistry, DAV College, Sector 10, Chandigarh 160011, India.
| | - Bhupesh Goyal
- School of Chemistry & Biochemistry, Thapar Institute of Engineering & Technology, Patiala 147004, Punjab, India.
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3
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Galzitskaya OV, Grishin SY, Glyakina AV, Dovidchenko NV, Konstantinova AV, Kravchenko SV, Surin AK. The Strategies of Development of New Non-Toxic Inhibitors of Amyloid Formation. Int J Mol Sci 2023; 24:ijms24043781. [PMID: 36835194 PMCID: PMC9964835 DOI: 10.3390/ijms24043781] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
In recent years, due to the aging of the population and the development of diagnostic medicine, the number of identified diseases associated with the accumulation of amyloid proteins has increased. Some of these proteins are known to cause a number of degenerative diseases in humans, such as amyloid-beta (Aβ) in Alzheimer's disease (AD), α-synuclein in Parkinson's disease (PD), and insulin and its analogues in insulin-derived amyloidosis. In this regard, it is important to develop strategies for the search and development of effective inhibitors of amyloid formation. Many studies have been carried out aimed at elucidating the mechanisms of amyloid aggregation of proteins and peptides. This review focuses on three amyloidogenic peptides and proteins-Aβ, α-synuclein, and insulin-for which we will consider amyloid fibril formation mechanisms and analyze existing and prospective strategies for the development of effective and non-toxic inhibitors of amyloid formation. The development of non-toxic inhibitors of amyloid will allow them to be used more effectively for the treatment of diseases associated with amyloid.
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Affiliation(s)
- Oxana V. Galzitskaya
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290 Pushchino, Russia
- Correspondence:
| | - Sergei Y. Grishin
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia
- Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia
| | - Anna V. Glyakina
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia
- Institute of Mathematical Problems of Biology RAS, The Branch of Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Nikita V. Dovidchenko
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Anastasiia V. Konstantinova
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia
- Faculty of Biotechnology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sergey V. Kravchenko
- Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia
| | - Alexey K. Surin
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia
- The Branch of the Institute of Bioorganic Chemistry, Russian Academy of Sciences, 142290 Pushchino, Russia
- State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Russia
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4
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Rational Generation of Monoclonal Antibodies Selective for Pathogenic Forms of Alpha-Synuclein. Biomedicines 2022; 10:biomedicines10092168. [PMID: 36140270 PMCID: PMC9496384 DOI: 10.3390/biomedicines10092168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/30/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Misfolded toxic forms of alpha-synuclein (α-Syn) have been implicated in the pathogenesis of synucleinopathies, including Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). The α-Syn oligomers and soluble fibrils have been shown to mediate neurotoxicity and cell-to-cell propagation of pathology. To generate antibodies capable of selectively targeting pathogenic forms of α-Syn, computational modeling was used to predict conformational epitopes likely to become exposed on oligomers and small soluble fibrils, but not on monomers or fully formed insoluble fibrils. Cyclic peptide scaffolds reproducing these conformational epitopes exhibited neurotoxicity and seeding activity, indicating their biological relevance. Immunization with the conformational epitopes gave rise to monoclonal antibodies (mAbs) with the desired binding profile showing selectivity for toxic α-Syn oligomers and soluble fibrils, with little or no reactivity with monomers, physiologic tetramers, or Lewy bodies. Recognition of naturally occurring soluble α-Syn aggregates in brain extracts from DLB and MSA patients was confirmed by surface plasmon resonance (SPR). In addition, the mAbs inhibited the seeding activity of sonicated pre-formed fibrils (PFFs) in a thioflavin-T fluorescence-based aggregation assay. In neuronal cultures, the mAbs protected primary rat neurons from toxic α-Syn oligomers, reduced the uptake of PFFs, and inhibited the induction of pathogenic phosphorylated aggregates of endogenous α-Syn. Protective antibodies selective for pathogenic species of α-Syn, as opposed to pan α-Syn reactivity, are expected to provide enhanced safety and therapeutic potency by preserving normal α-Syn function and minimizing the diversion of active antibody from the target by the more abundant non-toxic forms of α-Syn in the circulation and central nervous system.
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Synhaivska O, Bhattacharya S, Campioni S, Thompson D, Nirmalraj PN. Single-Particle Resolution of Copper-Associated Annular α-Synuclein Oligomers Reveals Potential Therapeutic Targets of Neurodegeneration. ACS Chem Neurosci 2022; 13:1410-1421. [PMID: 35414168 PMCID: PMC9073932 DOI: 10.1021/acschemneuro.2c00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
![]()
Metal ions stabilize
protein–protein interactions and can
modulate protein aggregation. Here, using liquid-based atomic force
microscopy and molecular dynamics simulations, we study the concentration-dependent
effect of Cu2+ ions on the aggregation pathway of α-synuclein
(α-Syn) proteins, which play a key role in the pathology of
Parkinson’s disease. The full spectrum of α-Syn aggregates
in the presence and absence of Cu2+ ions from monomers
to mature fibrils was resolved and quantified at the gold–water
interface. Raman spectroscopy confirmed the atomic force microscopy
(AFM) findings on the heterogeneity in aggregated states of α-Syn.
The formation of annular oligomers was exclusively detected upon incubating
α-Syn with Cu2+ ions. Our findings emphasize the
importance of targeting annular α-Syn protein oligomers for
therapeutic intervention and their potential role as biomarkers for
early detection and monitoring progression of neurodegeneration.
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Affiliation(s)
- Olena Synhaivska
- Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf CH-8600, Switzerland
| | - Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94T9PX, Ireland
| | - Silvia Campioni
- Functional Materials Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf CH-8600, Switzerland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94T9PX, Ireland
| | - Peter Niraj Nirmalraj
- Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf CH-8600, Switzerland
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Brain region-specific susceptibility of Lewy body pathology in synucleinopathies is governed by α-synuclein conformations. Acta Neuropathol 2022; 143:453-469. [PMID: 35141810 PMCID: PMC8960659 DOI: 10.1007/s00401-022-02406-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/12/2022] [Accepted: 02/01/2022] [Indexed: 12/29/2022]
Abstract
The protein α-synuclein, a key player in Parkinson’s disease (PD) and other synucleinopathies, exists in different physiological conformations: cytosolic unfolded aggregation-prone monomers and helical aggregation-resistant multimers. It has been shown that familial PD-associated missense mutations within the α-synuclein gene destabilize the conformer equilibrium of physiologic α-synuclein in favor of unfolded monomers. Here, we characterized the relative levels of unfolded and helical forms of cytosolic α-synuclein in post-mortem human brain tissue and showed that the equilibrium of α-synuclein conformations is destabilized in sporadic PD and DLB patients. This disturbed equilibrium is decreased in a brain region-specific manner in patient samples pointing toward a possible “prion-like” propagation of the underlying pathology and forms distinct disease-specific patterns in the two different synucleinopathies. We are also able to show that a destabilization of multimers mechanistically leads to increased levels of insoluble, pathological α-synuclein, while pharmacological stabilization of multimers leads to a “prion-like” aggregation resistance. Together, our findings suggest that these disease-specific patterns of α-synuclein multimer destabilization in sporadic PD and DLB are caused by both regional neuronal vulnerability and “prion-like” aggregation transmission enabled by the destabilization of local endogenous α-synuclein protein.
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Bhattacharya S, Xu L, Thompson D. Characterization of Amyloidogenic Peptide Aggregability in Helical Subspace. Methods Mol Biol 2022; 2340:401-448. [PMID: 35167084 DOI: 10.1007/978-1-0716-1546-1_18] [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] [Indexed: 06/14/2023]
Abstract
Prototypical amyloidogenic peptides amyloid-β (Aβ) and α-synuclein (αS) can undergo helix-helix associations via partially folded helical conformers, which may influence pathological progression to Alzheimer's (AD) and Parkinson's disease (PD), respectively. At the other extreme, stable folded helical conformers have been reported to resist self-assembly and amyloid formation. Experimental characterisation of such disparities in aggregation profiles due to subtle differences in peptide stabilities is precluded by the conformational heterogeneity of helical subspace. The diverse physical models used in molecular simulations allow sampling distinct regions of the phase space and are extensive in capturing the ensemble of rich helical subspace. Robust and powerful computational predictive methods utilizing network theory and free energy mapping can model the origin of helical population shifts in amyloidogenic peptides, which highlight their inherent aggregability. In this chapter, we discuss computational models, methods, design rules, and strategies to identify the driving force behind helical self-assembly and the molecular origin of aggregation resistance in helical intermediates of Aβ42 and αS. By extensive multiscale mapping of intrapeptide interactions, we show that the computational models can capture features that are otherwise imperceptible to experiments. Our models predict that targeting terminal residues may allow modulation and control of initial pathogenic aggregability of amyloidogenic peptides.
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Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland.
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8
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Xu L, Bhattacharya S, Thompson D. Predictive Modeling of Neurotoxic α-Synuclein Polymorphs. Methods Mol Biol 2022; 2340:379-399. [PMID: 35167083 DOI: 10.1007/978-1-0716-1546-1_17] [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] [Indexed: 06/14/2023]
Abstract
Assembly of monomeric α-synuclein (αS) into aggregation-resistant helically folded tetramers and related multimers is a key target for Parkinson's disease (PD). Protein dynamics hampers experimental characterization of the polymorphism of these structures and so computational modeling and simulation is providing a complementary approach to obtain high-resolution structural information on the assembly of αS and interactions with biological surfaces. These computational techniques are particularly valuable for intrinsically disordered proteins (IDPs) and short-lived peptide and protein assemblies with as yet undetermined 3D structures. Experimental observables such as NMR J-coupling constants and chemical shifts can be predicted directly from simulation data, and compared with available experimental data to generate the most physically realistic atomic-resolution structure. For appropriately validated and benchmarked computational models, macroscopic aggregation properties can be related to the calculated thermodynamic properties at an atomic level. In this chapter, we describe a useful protocol for designing helical αS multimers, especially tetramers, and scanning the peptide-membrane interface for cell-bound αS tetramers. These computationally modeled structures are validated by comparison with the range of available known experimental parameters at time of writing in early 2020, and used to generate predictive design rules to motivate and guide experiments.
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Affiliation(s)
- Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland.
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9
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Evans SR, West C, Klein-Seetharaman J. Similarity of the non-amyloid-β component and C-terminal tail of monomeric and tetrameric alpha-synuclein with 14-3-3 sigma. Comput Struct Biotechnol J 2021; 19:5348-5359. [PMID: 34667532 PMCID: PMC8495038 DOI: 10.1016/j.csbj.2021.09.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 08/28/2021] [Accepted: 09/09/2021] [Indexed: 11/20/2022] Open
Abstract
Alpha-synuclein (αSyn) is often described as a predominantly disordered protein that has a propensity to self-assemble into toxic oligomers that are found in patients with Parkinson's and Alzheimer's diseases. αSyn's chaperone behavior and tetrameric structure are proposed to be protective against toxic oligomerization. In this paper, we extended the previously proposed similarity between αSyn and 14-3-3 proteins to the α-helical tetrameric species of αSyn in detail. 14-3-3 proteins are a family of well-folded proteins with seven human isoforms, and function in signal transduction and as molecular chaperones. We investigated protein homology, using sequence alignment, amyloid, and disorder prediction, as well as three-dimensional visualization and protein-interaction networks. Our results show sequence homology and structural similarity between the aggregation-prone non-amyloid-β component (NAC) residues Val-52 to Gly-111 in αSyn and 14-3-3 sigma residues Leu-12 to Gly-78. We identified an additional region of sequence homology in the C-terminal region of αSyn (residues Ser-129 to Asp-135) and a C-terminal loop of 14-3-3 between helix αH and αI (residues Ser-209 to Asp-215). This data indicates αSyn shares conserved domain architecture with small heat shock proteins. We show predicted regions of high amyloidogenic propensity and intrinsic structural disorder in αSyn coincide with amyloidogenic and disordered predictions for 14-3-3 proteins. The homology in the NAC region aligns with residues involved in dimer- and tetramerization of the non-amyloidogenic 14-3-3 proteins. Because 14-3-3 proteins are generally not prone to misfolding, our results lend further support to the hypothesis that the NAC region is critical to the assembly of αSyn into the non-toxic tetrameric state.
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Key Words
- 14-3-3 proteins
- Alpha-synuclein
- BAD, BCL2 associated agonist of cell death gene name
- Homology
- IDP, Intrinsically disorder protein(s)
- MAPT, microtubule-associated protein tau gene name
- PPI, Protein-Protein interactions
- Prediction
- Protein structure
- SIP, shared interaction partner
- SNCA, alpha-synuclein gene name
- TH, tyrosine hydroxylase gene name
- Tetramer
- YWHAB, 14-3-3 protein beta isoform gene name
- YWHAE, 14-3-3 protein epsilon isoform gene name
- YWHAH, 14-3-3 protein eta isoform gene name
- pHSPB6, phosphorylated Heat Shock Protein beta-6
- sHSP, small heat shock protein
- αSyn, alpha-synuclein
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Affiliation(s)
- Sarah R. Evans
- Colorado School of Mines, Quantitative Biosciences and Engineering, 1012 14 St, Chemistry, Golden, CO 80401, USA
| | - Colista West
- Colorado School of Mines, Department of Chemistry, 1012 14 St, Chemistry, Golden, CO 80401, USA
| | - Judith Klein-Seetharaman
- Colorado School of Mines, Quantitative Biosciences and Engineering, 1012 14 St, Chemistry, Golden, CO 80401, USA
- Colorado School of Mines, Department of Chemistry, 1012 14 St, Chemistry, Golden, CO 80401, USA
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Chen J, Zaer S, Drori P, Zamel J, Joron K, Kalisman N, Lerner E, Dokholyan NV. The structural heterogeneity of α-synuclein is governed by several distinct subpopulations with interconversion times slower than milliseconds. Structure 2021; 29:1048-1064.e6. [PMID: 34015255 PMCID: PMC8419013 DOI: 10.1016/j.str.2021.05.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/12/2021] [Accepted: 04/30/2021] [Indexed: 11/22/2022]
Abstract
α-Synuclein plays an important role in synaptic functions by interacting with synaptic vesicle membrane, while its oligomers and fibrils are associated with several neurodegenerative diseases. The specific monomer structures that promote its membrane binding and self-association remain elusive due to its transient nature as an intrinsically disordered protein. Here, we use inter-dye distance distributions from bulk time-resolved Förster resonance energy transfer as restraints in discrete molecular dynamics simulations to map the conformational space of the α-synuclein monomer. We further confirm the generated conformational ensemble in orthogonal experiments utilizing far-UV circular dichroism and cross-linking mass spectrometry. Single-molecule protein-induced fluorescence enhancement measurements show that within this conformational ensemble, some of the conformations of α-synuclein are surprisingly stable, exhibiting conformational transitions slower than milliseconds. Our comprehensive analysis of the conformational ensemble reveals essential structural properties and potential conformations that promote its various functions in membrane interaction or oligomer and fibril formation.
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Affiliation(s)
- Jiaxing Chen
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Sofia Zaer
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Paz Drori
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Joanna Zamel
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Khalil Joron
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Nir Kalisman
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
| | - Nikolay V Dokholyan
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA; Department of Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, PA 17033, USA; Departments of Chemistry and Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA.
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11
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Molecular crowding accelerates aggregation of α-synuclein by altering its folding pathway. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2021; 50:59-67. [PMID: 33386904 DOI: 10.1007/s00249-020-01486-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/30/2020] [Accepted: 11/26/2020] [Indexed: 10/22/2022]
Abstract
Intracellular macromolecular crowding can lead to increased aggregation of proteins, especially those that lack a natively folded conformation. Crowding may also be mimicked by the addition of polymers like polyethylene glycol (PEG) in vitro. α-Synuclein is an intrinsically disordered protein that exhibits increased aggregation and amyloid fibril formation in a crowded environment. Two hypotheses have been proposed to explain this observation. One is the excluded volume effect positing that reduced water activity in a crowded environment leads to increased effective protein concentration, promoting aggregation. An alternate explanation is that increased crowding facilitates conversion to a non-native form increasing the rate of aggregation. In this work, we have segregated these two hypotheses to investigate which one is operating. We show that mere increase in concentration of α-synuclein is not enough to induce aggregation and consequent fibrillation. In vitro, we find a complex relationship between PEG concentrations and aggregation, in which smaller PEGs delay fibrillation; while, larger ones promote fibril nucleation. In turn, while PEG600 did not increase the rate of aggregation, PEG1000 did and PEG4000 and PEG12000 slowed it but led to a higher overall fibril burden in the latter to cases. In cells, PEG4000 reduces the aggregation of α-synuclein but in a way specific to the cellular environment/due to cellular factors. The aggregation of the similarly sized, globular lysozyme does not increase in vitro when at the same concentrations with either PEG8000 or PEG12000. Thus, natively disordered α-synuclein undergoes a conformational transition in specific types of crowded environment, forming an aggregation-prone conformer.
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12
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Lucas HR, Fernández RD. Navigating the dynamic landscape of alpha-synuclein morphology: a review of the physiologically relevant tetrameric conformation. Neural Regen Res 2020; 15:407-415. [PMID: 31571649 PMCID: PMC6921358 DOI: 10.4103/1673-5374.265792] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
N-acetylated α-synuclein (αSyn) has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson's disease. In recent years, a physiologically relevant, higher order conformation has been identified as a helical tetramer that is tailored by buried hydrophobic interactions and is distinctively aggregation resistant. The canonical mechanism by which the tetramer assembles remains elusive. As novel biochemical approaches, computational methods, pioneering purification platforms, and powerful imaging techniques continue to develop, puzzling information that once sparked debate as to the veracity of the tetramer has now shed light upon this new counterpart in αSyn neurobiology. Nuclear magnetic resonance and computational studies on multimeric αSyn structure have revealed that the protein folding propensity is controlled by small energy barriers that enable large scale reconfiguration. Alternatively, familial mutations ablate tetramerization and reconfigure polymorphic fibrillization. In this review, we will discuss the dynamic landscape of αSyn quaternary structure with a focus on the tetrameric conformation.
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Affiliation(s)
- Heather R Lucas
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Ricardo D Fernández
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA, USA
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13
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Zou Y, Qian Z, Gong Y, Tang Y, Wei G, Zhang Q. Critical nucleus of Greek-key-like core of α-synuclein protofibril and its disruption by dopamine and norepinephrine. Phys Chem Chem Phys 2020; 22:203-211. [DOI: 10.1039/c9cp04610k] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Protofibrillar trimer is the critical nucleus for the αS fibril formation, and the tetramer is the minimal stable nucleus. The interactions of DA/NE with αS trimer/tetramer disrupt the backbone H-bonds and destabilize the αS protofibrils.
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Affiliation(s)
- Yu Zou
- Department of Sport and Exercise Science
- College of Education
- Zhejiang University
- Hangzhou 310007
- People's Republic of China
| | - Zhenyu Qian
- Key Laboratory of Exercise and Health Sciences (Ministry of Education) and School of Kinesiology
- Shanghai University of Sport
- Shanghai 200438
- People's Republic of China
| | - Yehong Gong
- College of Physical Education and Training
- Shanghai University of Sport
- Shanghai 200438
- People's Republic of China
| | - Yiming Tang
- State Key Laboratory of Surface Physics
- Key Laboratory for Computational Physical Science (Ministry of Education), and Department of Physics, Fudan University
- 220 Handan Road
- Shanghai 200433
- People's Republic of China
| | - Guanghong Wei
- State Key Laboratory of Surface Physics
- Key Laboratory for Computational Physical Science (Ministry of Education), and Department of Physics, Fudan University
- 220 Handan Road
- Shanghai 200433
- People's Republic of China
| | - Qingwen Zhang
- College of Physical Education and Training
- Shanghai University of Sport
- Shanghai 200438
- People's Republic of China
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14
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Chwastyk M, Cieplak M. Conformational Biases of α-Synuclein and Formation of Transient Knots. J Phys Chem B 2019; 124:11-19. [DOI: 10.1021/acs.jpcb.9b08481] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Mateusz Chwastyk
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Marek Cieplak
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
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15
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Caminati G, Martina MR, Menichetti S, Procacci P. Blocking the FKBP12 induced dendrimeric burst in aberrant aggregation of α-synuclein by using the ElteN378 synthetic inhibitor. J Enzyme Inhib Med Chem 2019; 34:1711-1715. [PMID: 31547734 PMCID: PMC6764402 DOI: 10.1080/14756366.2019.1667342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
α-Synuclein (α-syn), a disordered cytoplasmatic protein, plays a fundamental role in the pathogenesis of Parkinson’s disease (PD). Here, we have shown, using photophysical measurements, that addition of FKBP12 to α-syn solutions, dramatically accelerates protein aggregation, leading to an explosion of dendritic structures revealed by fluorescence and phase-contrast microscopy. We have further demonstrated that this aberrant α-syn aggregation can be blocked using a recently discovered non-immunosuppressive synthetic inhibitor of FKBP12, ElteN378. The role of FKBP12 and of ElteN378 in the α-syn aggregation mechanism has been elucidated using molecular dynamics simulations based on an effective coarse-grained model. The reported data not only reveal a new potent synthetic drug as a candidate for early stage treatment of α-syn dependent neurodegenerations but also pave the way to a deeper understanding of the mechanism of action of FKBP12 on α-syn oligomeric aggregation, a topic which is still controversial.
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Affiliation(s)
- Gabriella Caminati
- Department of Chemistry "Ugo Schiff", University of Florence , Sesto Fiorentino , Italy.,Center for Colloid and Surface Science (CSGI), University of Florence , Sesto Fiorentino , Italy
| | - Maria Raffaella Martina
- Department of Chemistry "Ugo Schiff", University of Florence , Sesto Fiorentino , Italy.,Center for Colloid and Surface Science (CSGI), University of Florence , Sesto Fiorentino , Italy
| | - Stefano Menichetti
- Center for Colloid and Surface Science (CSGI), University of Florence , Sesto Fiorentino , Italy
| | - Piero Procacci
- Center for Colloid and Surface Science (CSGI), University of Florence , Sesto Fiorentino , Italy
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16
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Female Sex and Brain-Selective Estrogen Benefit α-Synuclein Tetramerization and the PD-like Motor Syndrome in 3K Transgenic Mice. J Neurosci 2019; 39:7628-7640. [PMID: 31405930 DOI: 10.1523/jneurosci.0313-19.2019] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 07/12/2019] [Accepted: 07/23/2019] [Indexed: 12/14/2022] Open
Abstract
Many studies report a higher risk for Parkinson's disease (PD) and younger age of onset in men. This, and the fact that the neuropathological process underlying PD symptoms may begin before menopause, suggests that estrogen-based hormone therapy could modify this higher risk in males. However, the effects of female sex or estrogen on α-synuclein (αS) homeostasis and related PD neuropathology remain unknown. Here, we used an αS tetramer-abrogating mouse model of PD (3K) that amplifies the familial E46K PD mutation to investigate the effects of female sex and brain-selective estrogen treatment on αS tetramerization and solubility, formation of vesicle-rich αS+ aggregates, dopaminergic and cortical fiber integrity, and associated motor deficits. In male 3K mice, the motor phenotype became apparent at ∼10 weeks and increased to age 6 months, paralleled by PD-like neuropathology, whereas 3K females showed a significant delay in onset. At 6 months, this beneficial phenotypic effect in 3K females was associated with a higher αS tetramer-to-monomer ratio and less decrease in dopaminergic and cortical fiber length and quantity. Brain-selective estrogen treatment in symptomatic 3K mice significantly increased the tetramer-to-monomer ratio, turnover by autophagy of aggregate-prone monomers, and neurite complexity of surviving DAergic and cortical neurons, in parallel with benefits in motor performance. Our findings support an upstream role for αS tetramer loss in PD phenotypes and a role for estrogen in mitigating PD-like neuropathology in vivo Brain-selective estrogen therapy may be useful in delaying or reducing PD symptoms in men and postmenopausal women.SIGNIFICANCE STATEMENT The mechanisms responsible for the male-to-female preponderance in Parkinson's disease (PD) are not well understood yet important for treatment efficacy. We previously showed that abrogating native α-synuclein (αS) tetramers produces a close PD model, including dopaminergic and cortical fiber loss and a progressive motor disorder responsive to l-DOPA. Here, we analyzed sex and use 10b-17β-dihydroxyestra-1,4-dien-3-one treatment of symptomatic 3K males, and demonstrate that the beneficial effects of female sex on PD-like neuropathology can be reinstated by elevating estrogen in the male brain. The study provides evidence that 17β-estradiol restores the tetramer-to-monomer ratio by autophagy turnover of excess αS monomers, vesicle and fiber integrity in brain regions critically involved in motor behavior. These data provide the basis for understanding sex differences in αS homeostasis and the development of therapeutic approaches to treating men and postmenopausal women with PD.
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17
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Bhattacharya S, Xu L, Thompson D. Molecular Simulations Reveal Terminal Group Mediated Stabilization of Helical Conformers in Both Amyloid-β42 and α-Synuclein. ACS Chem Neurosci 2019; 10:2830-2842. [PMID: 30917651 DOI: 10.1021/acschemneuro.9b00053] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The presence of partially structured helices in natively unfolded amyloid-β42 (Aβ42) and α-synuclein (αS) has been shown to accelerate fibrillation in the onset of Alzheimer's and Parkinson's disease, respectively. At the other extreme, folded stable helical conformers have also been reported to resist amyloid formation. Recent studies indicate that amyloidogenic aggregation can be impeded using small molecules that stabilize the α-helical monomers and switch off the neurotoxic pathway. We predict a common intrapeptide route to stabilization based on the plasticity of helical conformations of Aβ42 and αS as assessed through extensive atomistic molecular dynamics (MD) computer simulations (∼36 μs) across ten distinct protein force field and water model combinations. Computed free energies and interaction maps (not obtainable from experiments alone) show that flexible terminal groups (N-terminus of Aβ42 and C-terminus of αS) show a tendency to stabilize folded helical conformations in both peptides via primary hydrophobic interactions with central hydrophobic domains, and secondary salt bridges with other domains. These interactions confer aggregation resistance by decreasing the population of partially structured helices and are absent in control simulations of complete unfolding. Computed helical stability is also significantly reduced in terminal-deleted variants. The models suggest new strategies to tackle neurodegeneration by rationally re-engineering terminal groups to optimize their predicted ability to deactivate helical monomers.
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Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
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18
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Xu L, Bhattacharya S, Thompson D. On the ubiquity of helical α-synuclein tetramers. Phys Chem Chem Phys 2019; 21:12036-12043. [DOI: 10.1039/c9cp02464f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The stability of oligomers linearly increases from dimers to octamers, but assembly of oligomers larger than tetramers requires high activation energies.
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Affiliation(s)
- Liang Xu
- Department of Physics
- Bernal Institute
- University of Limerick
- V94 T9PX
- Ireland
| | | | - Damien Thompson
- Department of Physics
- Bernal Institute
- University of Limerick
- V94 T9PX
- Ireland
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