1
|
Piccirilli F, Vondracek H, Silvestrini L, Parisse P, Spinozzi F, Vaccari L, Toma A, Aglieri V, Casalis L, Piccionello AP, Mariani P, Birarda G, Ortore MG. Dimeric and monomeric conformation of SARS-CoV-2 main protease: New technical approaches based on IR radiation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 322:124772. [PMID: 39003826 DOI: 10.1016/j.saa.2024.124772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 06/11/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024]
Abstract
The main proteases Mpro are a group of highly conserved cysteine hydrolases in β-coronaviruses. They have been demonstrated to play an unavoidable role in viral replication, and consequently they have been suggested as key targets for treating coronavirus-caused infectious diseases, mainly from the COVID-19 epidemic. Since the most functional form for Mpro enzymatic activity is associated to its homodimer, compounds inhibiting dimerization should also inhibit catalytic activity. We show how PIR-SEIRA (Plasmonic Internal Reflection-Surface Enhanced InfraRed Absorption) spectroscopy can be a noteworthy technique to study proteins subtle structural variations associated to inhibitor binding. Nanoantennas arrays can selectively confine and enhance electromagnetic field via localized plasmonic resonances, thus promoting ultrasensitive detection of biomolecules in close proximity of nanoantenna arrays and enabling the effective investigation of protein monolayers. By adopting this approach, reflection measurements conducted under back illumination of nanoantennas allow to probe anchored protein monolayers, with minimum contribution of environmental buffer molecules. PIR-SEIRA spectroscopy on Mpro was carried out by ad hoc designed devices, resonating in the spectral region of Amide I and Amide II bands. We evaluated here the structure of anchored monomers and dimers in different buffered environment and in presence of a newly designed Mpro inhibitor. Experimental results show that dimerization is not associated to relevant backbone rearrangements of the protein at secondary structure level, and even if the compound inhibits the dimerization, it is not effective at breaking preformed dimers.
Collapse
Affiliation(s)
| | - Hendrik Vondracek
- Elettra-Synchrotron Trieste S.C.p.A., Strada Statale 14, Basovizza, Trieste, I-34149, Italy
| | - Lucia Silvestrini
- Department of Life and Environmental Sciences, Marche Polytechnic University, via brecce bianche, Ancona, I-60131, Italy
| | - Pietro Parisse
- Elettra-Synchrotron Trieste S.C.p.A., Strada Statale 14, Basovizza, Trieste, I-34149, Italy; CNR - Istituto Officina dei Materiali, s.s. 14 km 163.5 in Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Francesco Spinozzi
- Department of Life and Environmental Sciences, Marche Polytechnic University, via brecce bianche, Ancona, I-60131, Italy
| | - Lisa Vaccari
- Elettra-Synchrotron Trieste S.C.p.A., Strada Statale 14, Basovizza, Trieste, I-34149, Italy
| | - Andrea Toma
- Fondazione Istituto Italiano di Tecnologia, via Morego 30, Genova, I- 16163, Italy
| | - Vincenzo Aglieri
- Fondazione Istituto Italiano di Tecnologia, via Morego 30, Genova, I- 16163, Italy
| | - Loredana Casalis
- Elettra-Synchrotron Trieste S.C.p.A., Strada Statale 14, Basovizza, Trieste, I-34149, Italy
| | - Antonio Palumbo Piccionello
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, viale delle scienze, Palermo, I-90133, Italy
| | - Paolo Mariani
- Department of Life and Environmental Sciences, Marche Polytechnic University, via brecce bianche, Ancona, I-60131, Italy
| | - Giovanni Birarda
- Elettra-Synchrotron Trieste S.C.p.A., Strada Statale 14, Basovizza, Trieste, I-34149, Italy.
| | - Maria Grazia Ortore
- Department of Life and Environmental Sciences, Marche Polytechnic University, via brecce bianche, Ancona, I-60131, Italy.
| |
Collapse
|
2
|
Rezaei-Ghaleh N, Amininasab M, Giller K, Becker S. Familial Alzheimer's Disease-Related Mutations Differentially Alter Stability of Amyloid-Beta Aggregates. J Phys Chem Lett 2023; 14:1427-1435. [PMID: 36734539 PMCID: PMC9940190 DOI: 10.1021/acs.jpclett.2c03729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Amyloid-beta (Aβ) deposition as senile plaques is a pathological hallmark of Alzheimer's disease (AD). AD is characterized by a large level of heterogeneity in amyloid pathology, whose molecular origin is poorly understood. Here, we employ NMR spectroscopy and MD simulation at ambient and high pressures and investigate how AD-related mutations in Aβ peptide influence the stability of Aβ aggregates. The pressure-induced monomer dissociation from Aβ aggregates monitored by NMR demonstrated that the Iowa (D23N), Arctic (E22G), and Osaka (ΔE22) mutations altered the pressure stability of Aβ40 aggregates in distinct manners. While the NMR data of monomeric Aβ40 showed only small localized effects of mutations, the MD simulation of mutated Aβ fibrils revealed their distinct susceptibility to elevated pressure. Our data propose a structural basis for the distinct stability of various Aβ fibrils and highlights "stability" as a molecular property potentially contributing to the large heterogeneity of amyloid pathology in AD.
Collapse
Affiliation(s)
- Nasrollah Rezaei-Ghaleh
- Institute
of Physical Biology, Heinrich Heine University
Düsseldorf, D-40225 Düsseldorf, Germany
- Institute
of Biological Information Processing, IBI-7: Structural Biochemistry, Forschungszentrum Jülich, D-52428 Jülich, Germany
- Department
of NMR-based Structural Biology, Max Planck
Institute for Multidisciplinary Sciences, D-37077 Göttingen, Germany
| | - Mehriar Amininasab
- Department
of Cell and Molecular Biology, School of Biology, College of Science, University of Tehran, 1417466191 Tehran, Iran
| | - Karin Giller
- Department
of NMR-based Structural Biology, Max Planck
Institute for Multidisciplinary Sciences, D-37077 Göttingen, Germany
| | - Stefan Becker
- Department
of NMR-based Structural Biology, Max Planck
Institute for Multidisciplinary Sciences, D-37077 Göttingen, Germany
| |
Collapse
|
3
|
Diaz-Espinoza R. Catalytically Active Amyloids as Future Bionanomaterials. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3802. [PMID: 36364578 PMCID: PMC9656882 DOI: 10.3390/nano12213802] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/14/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Peptides and proteins can aggregate into highly ordered and structured conformations called amyloids. These supramolecular structures generally have convergent features, such as the formation of intermolecular beta sheets, that lead to fibrillary architectures. The resulting fibrils have unique mechanical properties that can be exploited to develop novel nanomaterials. In recent years, sequences of small peptides have been rationally designed to self-assemble into amyloids that catalyze several chemical reactions. These amyloids exhibit reactive surfaces that can mimic the active sites of enzymes. In this review, I provide a state-of-the-art summary of the development of catalytically active amyloids. I will focus especially on catalytic activities mediated by hydrolysis, which are the most studied examples to date, as well as novel types of recently reported activities that promise to expand the possible repertoires. The combination of mechanical properties with catalytic activity in an amyloid scaffold has great potential for the development of future bionanomaterials aimed at specific applications.
Collapse
Affiliation(s)
- Rodrigo Diaz-Espinoza
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 3363, Chile
| |
Collapse
|
4
|
Takekiyo T, Yamada N, Amo T, Asano A, Yoshimura Y. Triiodide ion-induced inhibition of amyloid aggregate formation: A case study of α-synuclein. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
5
|
Moretti P, Mariani P, Ortore MG, Plotegher N, Bubacco L, Beltramini M, Spinozzi F. Comprehensive Structural and Thermodynamic Analysis of Prefibrillar WT α-Synuclein and Its G51D, E46K, and A53T Mutants by a Combination of Small-Angle X-ray Scattering and Variational Bayesian Weighting. J Chem Inf Model 2020; 60:5265-5281. [PMID: 32866007 PMCID: PMC8154249 DOI: 10.1021/acs.jcim.0c00807] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Indexed: 12/13/2022]
Abstract
The in solution synchrotron small-angle X-ray scattering SAXS technique has been used to investigate an intrinsically disordered protein (IDP) related to Parkinson's disease, the α-synuclein (α-syn), in prefibrillar diluted conditions. SAXS experiments have been performed as a function of temperature and concentration on the wild type (WT) and on the three pathogenic mutants G51D, E46K, and A53T. To identify the conformers that populate WT α-syn and the pathogenic mutants in prefibrillar conditions, scattering data have been analyzed by a new variational bayesian weighting method (VBWSAS) based on an ensemble of conformers, which includes unfolded monomers, trimers, and tetramers, both in helical-rich and strand-rich forms. The developed VBWSAS method uses a thermodynamic scheme to account for temperature and concentration effects and considers long-range protein-protein interactions in the framework of the random phase approximation. The global analysis of the whole set of data indicates that WT α-syn is mostly present as unfolded monomers and trimers (helical-rich trimers at low T and strand-rich trimers at high T), but not tetramers, as previously derived by several studies. On the contrary, different conformer combinations characterize mutants. In the α-syn G51D mutant, the most abundant aggregates at all the temperatures are strand-rich tetramers. Strand-rich tetramers are also the predominant forms in the A53T mutant, but their weight decreases with temperature. Only monomeric conformers, with a preference for the ones with the smallest sizes, are present in the E46K mutant. The derived conformational behavior then suggests a different availability of species prone to aggregate, depending on mutation, temperature, and concentration and accounting for the different neurotoxicity of α-syn variants. Indeed, this approach may be of pivotal importance to describe conformational and aggregational properties of other IDPs.
Collapse
Affiliation(s)
- Paolo Moretti
- Department
of Life and Environmental Sciences, Polytechnic
University of Marche, 60131 Ancona, Marche, Italy
| | - Paolo Mariani
- Department
of Life and Environmental Sciences, Polytechnic
University of Marche, 60131 Ancona, Marche, Italy
| | - Maria Grazia Ortore
- Department
of Life and Environmental Sciences, Polytechnic
University of Marche, 60131 Ancona, Marche, Italy
| | | | - Luigi Bubacco
- Department
of Biology, University of Padova, 35121 Padova, Veneto, Italy
| | - Mariano Beltramini
- Department
of Biology, University of Padova, 35121 Padova, Veneto, Italy
| | - Francesco Spinozzi
- Department
of Life and Environmental Sciences, Polytechnic
University of Marche, 60131 Ancona, Marche, Italy
| |
Collapse
|
6
|
Trehalose Effect on the Aggregation of Model Proteins into Amyloid Fibrils. Life (Basel) 2020; 10:life10050060. [PMID: 32414105 PMCID: PMC7281244 DOI: 10.3390/life10050060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022] Open
Abstract
Protein aggregation into amyloid fibrils is a phenomenon that attracts attention from a wide and composite part of the scientific community. Indeed, the presence of mature fibrils is associated with several neurodegenerative diseases, and in addition these supramolecular aggregates are considered promising self-assembling nanomaterials. In this framework, investigation on the effect of cosolutes on protein propensity to aggregate into fibrils is receiving growing interest, and new insights on this aspect might represent valuable steps towards comprehension of highly complex biological processes. In this work we studied the influence exerted by the osmolyte trehalose on fibrillation of two model proteins, that is, lysozyme and insulin, investigated during concomitant variation of the solution ionic strength due to NaCl. In order to monitor both secondary structures and the overall tridimensional conformations, we have performed UV spectroscopy measurements with Congo Red, Circular Dichroism, and synchrotron Small Angle X-ray Scattering. For both proteins we describe the effect of trehalose in changing the fibrillation pattern and, as main result, we observe that ionic strength in solution is a key factor in determining trehalose efficiency in slowing down or blocking protein fibrillation. Ionic strength reveals to be a competitive element with respect to trehalose, being able to counteract its inhibiting effects toward amyloidogenesis. Reported data highlight the importance of combining studies carried out on cosolutes with valuation of other physiological parameters that may affect the aggregation process. Also, the obtained experimental results allow to hypothesize a plausible mechanism adopted by the osmolyte to preserve protein surface and prevent protein fibrillation.
Collapse
|
7
|
Baldassarri EJ, Ortore MG, Spinozzi F, Round A, Ferrero C, Mariani P. K vs. Na Effects on the Self-Assembly of Guanosine 5'-Monophosphate: A Solution SAXS Structural Study +. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E629. [PMID: 32231081 PMCID: PMC7221663 DOI: 10.3390/nano10040629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 12/18/2022]
Abstract
The hierarchical process of guanosine (G) self-assembly, leading in aqueous solution and in the presence of metal cations to the formation of G-quadruplexes, represents an intriguing topic both for the biological correlation with telomerase activity and for the nano-technological applications, as demonstrated by the current measured in a quadruplex wire 100 nm long. Similar to G-rich DNA sequences and G-oligonucleotides, the guanosine 5'-monophosphate (GMP) self-aggregates in water to form quadruplexes. However, due to the absence of a covalent axial backbone, this system can be very useful to understand the chemical-physical conditions that govern the guanosine supramolecular aggregation. We have then investigated by in-solution Synchrotron Small Angle X-ray Scattering technique the role of different cations in promoting the quadruplex formation as a function of concentration and temperature. Results show how potassium, with its peculiar biological traits, favours the G-quadruplex elongation process in respect to other cations (Na + , but also NH 4 + and Li + ), determining the longest particles in solution. Moreover, the formation and the elongation of G-quadruplexes have been demonstrated to be controlled by both GMP concentration and excess cation content, even if they specifically contribute to these processes in different ways. The occurrence of condensed liquid crystalline phases was also detected, proving that excess cations play also unspecific effects on the effective charges on the G-quadruplex surface.
Collapse
Affiliation(s)
- Enrico Junior Baldassarri
- Marche Structural Biology Center, Department of Life and Environmental Sciences, Università Politecnica delle Marche, 60131 Ancona, Italy
| | - Maria Grazia Ortore
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, 60131 Ancona, Italy
| | - Francesco Spinozzi
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, 60131 Ancona, Italy
| | - Adam Round
- European XFEL, SPB/SFX Instrument, 22869 Schenefeld, Germany
| | - Claudio Ferrero
- European Synchrotron Radiation Facility-E.S.R.F., 38043 Grenoble, France
| | - Paolo Mariani
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, 60131 Ancona, Italy
| |
Collapse
|
8
|
Takekiyo T, Yamada N, Nakazawa CT, Amo T, Asano A, Yoshimura Y. Formation of α-synuclein aggregates in aqueous ethylammonium nitrate solutions. Biopolymers 2020; 111:e23352. [PMID: 32203628 DOI: 10.1002/bip.23352] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/04/2023]
Abstract
The effect of adding ethylammonium nitrate (EAN), which is an ionic liquid (IL), on the aggregate formation of α-synuclein (α-Syn) in aqueous solution has been investigated. FTIR and Raman spectroscopy were used to investigate changes in the secondary structure of α-Syn and in the states of water molecules and EAN. The results presented here show that the addition of EAN to α-Syn causes the formation of an intermolecular β-sheet structure in the following manner: native disordered state → polyproline II (PPII)-helix → intermolecular β-sheet (α-Syn amyloid-like aggregates: α-SynA). Although cations and anions of EAN play roles in masking the charged side chains and PPII-helix-forming ability involved in the formation of α-SynA, water molecules are not directly related to its formation. We conclude that EAN-induced α-Syn amyloid-like aggregates form at hydrophobic associations in the middle of the molecules after masking the charged side chains at the N- and C-terminals of α-Syn.
Collapse
Affiliation(s)
- Takahiro Takekiyo
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Natsuki Yamada
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Chikako T Nakazawa
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Taku Amo
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Atsushi Asano
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| | - Yukihiro Yoshimura
- Department of Applied Chemistry, National Defense Academy, Yokosuka, Kanagawa, Japan
| |
Collapse
|
9
|
Plamitzer L, Bouř P. Pressure dependence of vibrational optical activity of model biomolecules. A computational study. Chirality 2020; 32:710-721. [PMID: 32150771 DOI: 10.1002/chir.23216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 11/07/2022]
Abstract
Change of molecular properties with pressure is an attracting means to regulate molecular reactivity or biological activity. However, the effect is usually small and so far explored rather scarcely. To obtain a deeper insight and estimate the sensitivity of vibrational optical activity spectra to pressure-induced conformational changes, we investigate small model molecules. The Ala-Ala dipeptide, isomaltose disaccharide and adenine-uracil dinucleotide were chosen to represent three different biomolecular classes. The pressure effects were modeled by molecular dynamics and density functional theory simulations. The dinucleotide was found to be the most sensitive to the pressure, whereas for the disaccharide the smallest changes are predicted. Pressure-induced relative intensity changes in vibrational circular dichroism and Raman optical activity spectra are predicted to be 2-3-times larger than for non-polarized IR and Raman techniques.
Collapse
Affiliation(s)
- Luboš Plamitzer
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 542/2, Prague 6, 166 10, Czech Republic.,Faculty of Mathematics and Physics, Charles University, Ke Karlovu 2027/3, Prague 2, 121 16, Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo náměstí 542/2, Prague 6, 166 10, Czech Republic
| |
Collapse
|
10
|
Neira JL, Palomino-Schätzlein M, Ricci C, Ortore MG, Rizzuti B, Iovanna JL. Dynamics of the intrinsically disordered protein NUPR1 in isolation and in its fuzzy complexes with DNA and prothymosin α. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1867:140252. [PMID: 31325636 DOI: 10.1016/j.bbapap.2019.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 12/17/2022]
Abstract
Intrinsically disordered proteins (IDPs) explore diverse conformations in their free states and, a few of them, also in their molecular complexes. This functional plasticity is essential for the function of IDPs, although their dynamics in both free and bound states is poorly understood. NUPR1 is a protumoral multifunctional IDP, activated during the acute phases of pancreatitis. It interacts with DNA and other IDPs, such as prothymosin α (ProTα), with dissociation constants of ~0.5 μM, and a 1:1 stoichiometry. We studied the structure and picosecond-to-nanosecond (ps-ns) dynamics by using both NMR and SAXS in: (i) isolated NUPR1; (ii) the NUPR1/ProTα complex; and (iii) the NUPR1/double stranded (ds) GGGCGCGCCC complex. Our SAXS findings show that NUPR1 remained disordered when bound to either partner, adopting a worm-like conformation; the fuzziness of bound NUPR1 was also pinpointed by NMR. Residues with the largest values of the relaxation rates (R1, R1ρ, R2 and ηxy), in the free and bound species, were mainly clustered around the 30s region of the sequence, which agree with one of the protein hot-spots already identified by site-directed mutagenesis. Not only residues in this region had larger relaxation rates, but they also moved slower than the rest of the molecule, as indicated by the reduced spectral density approach (RSDA). Upon binding, the energy landscape of NUPR1 was not funneled down to a specific, well-folded conformation, but rather its backbone flexibility was kept, with distinct motions occurring at the hot-spot region.
Collapse
Affiliation(s)
- José L Neira
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche (Alicante), Spain; Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, Zaragoza, Spain.
| | | | - Caterina Ricci
- Department of Life and Environmental Sciences, Marche Polytechnic University, via Brecce Bianche, 60131 Ancona, Italy
| | - Maria Grazia Ortore
- Department of Life and Environmental Sciences, Marche Polytechnic University, via Brecce Bianche, 60131 Ancona, Italy
| | - Bruno Rizzuti
- CNR-NANOTEC, Licryl-UOS Cosenza and CEMIF.Cal, Department of Physics, University of Calabria, Via P. Bucci, Cubo 31 C, 87036 Arcavacata di Rende, Cosenza, Italy
| | - Juan L Iovanna
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM U1068, CNRS UMR 7258, Aix-Marseille Université and Institut Paoli-Calmettes, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13288 Marseille, France
| |
Collapse
|
11
|
Piccirilli F, Plotegher N, Ortore MG, Tessari I, Brucale M, Spinozzi F, Beltramini M, Mariani P, Militello V, Lupi S, Perucchi A, Bubacco L. High-Pressure-Driven Reversible Dissociation of α-Synuclein Fibrils Reveals Structural Hierarchy. Biophys J 2017; 113:1685-1696. [PMID: 29045863 DOI: 10.1016/j.bpj.2017.08.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/20/2017] [Accepted: 08/04/2017] [Indexed: 01/02/2023] Open
Abstract
The analysis of the α-synuclein (aS) aggregation process, which is involved in Parkinson's disease etiopathogenesis, and of the structural feature of the resulting amyloid fibrils may shed light on the relationship between the structure of aS aggregates and their toxicity. This may be considered a paradigm of the ground work needed to tackle the molecular basis of all the protein-aggregation-related diseases. With this aim, we used chemical and physical dissociation methods to explore the structural organization of wild-type aS fibrils. High pressure (in the kbar range) and alkaline pH were used to disassemble fibrils to collect information on the hierarchic pathway by which distinct β-sheets sequentially unfold using the unique possibility offered by high-pressure Fourier transform infrared spectroscopy. The results point toward the formation of kinetic traps in the energy landscape of aS fibril disassembly and the presence of transient partially folded species during the process. Since we found that the dissociation of wild-type aS fibrils by high pressure is reversible upon pressure release, the disassembled molecules likely retain structural information that favors fibril reformation. To deconstruct the role of the different regions of aS sequence in this process, we measured the high-pressure dissociation of amyloids formed by covalent chimeric dimers of aS (syn-syn) and by the aS deletion mutant that lacks the C-terminus, i.e., aS (1-99). The results allowed us to single out the role of dimerization and that of the C-terminus in the complete maturation of fibrillar aS.
Collapse
Affiliation(s)
- Federica Piccirilli
- CNR-IOM, University of Trieste, Trieste, Italy; Physics Department, University of Trieste, Trieste, Italy
| | - Nicoletta Plotegher
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Maria Grazia Ortore
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | | | | | - Francesco Spinozzi
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Ancona, Italy
| | | | - Paolo Mariani
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Valeria Militello
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
| | - Stefano Lupi
- Physics Department, University of Trieste, Trieste, Italy; Dipartimento di Fisica Università di Roma "La Sapienza", Rome, Italy
| | | | - Luigi Bubacco
- Department of Biology, University of Padova, Padova, Italy.
| |
Collapse
|