1
|
Semenyuk PI. Alpha-synuclein phosphorylation induces amyloid conversion via enhanced electrostatic bridging: Insights from molecular modeling of the full-length protein. Biophys Chem 2024; 307:107196. [PMID: 38335809 DOI: 10.1016/j.bpc.2024.107196] [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: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024]
Abstract
Fibril formation from alpha-synuclein is a key point in Parkinson's disease, multiple system atrophy, and other synucleinopathies. The mechanism of the amyloid-like conversion followed by the formation of pre-fibrillar soluble oligomers and fibrils is not completely clear; furthermore, it is unclear how the Parkinson's disease-related point mutations located in the pre-NAC region enhance fibrillation. In the present paper, atomistic replica exchange molecular dynamics simulations of the full-length alpha-synuclein and its two mutants, A53T and E46K, elucidated amyloid conversion intermediates. Both mutants demonstrated an enhanced tendency for the conversion but in different manners; the main intermediate conformations populated in the WT alpha-synuclein conformational ensemble disappeared due to mutations, indicating a different conversion pathway. Analysis of the preferable beta-hairpin positions and intermediate conformations seems to reflect a tendency to form a particular amyloid fibril polymorph. A strong elevation of amyloid transformation level was shown also for Ser129-phosphorylated alpha-synuclein. Altered intermediate conformations, the most preferable beta-hairpin positions in the NAC region, and prevalent salt bridges propose the formation of so-called polymorph 2 or even a novel type of fibrils. A better understanding of the detailed mechanism of the amyloid conversion sheds light on the effect of Lewy body-related phosphorylation and might help in the development of new therapeutics for synucleinopathies.
Collapse
Affiliation(s)
- Pavel I Semenyuk
- Belozersky Research Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Leninskie gory 1/40, Russia.
| |
Collapse
|
2
|
Huang J, Ahmed R, Akimoto M, Martinez Pomier K, Melacini G. Early-Onset Parkinson Mutation Remodels Monomer-Fibril Interactions to Allosterically Amplify Synuclein's Amyloid Cascade. JACS AU 2023; 3:3485-3493. [PMID: 38155658 PMCID: PMC10751762 DOI: 10.1021/jacsau.3c00655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 12/30/2023]
Abstract
Alpha synuclein (αS) aggregates are the main component of Lewy bodies (LBs) associated with Parkinson's disease (PD). A longstanding question about αS and PD pertains to the autosomal dominant E46K αS mutant, which leads to the early onset of PD and LB dementias. The E46K mutation not only promotes αS aggregation but also stabilizes αS monomers in "closed" conformers, which are compact and aggregation-incompetent. Hence, the mechanism of action of the E46K mutation is currently unclear. Here, we show that αS monomers harboring the E46K mutation exhibit more extensive interactions with fibrils compared to those of WT. Such monomer-fibril interactions are sufficient to allosterically drive transitions of αS monomers from closed to open conformations, enabling αS aggregation. We also show that E46K promotes head-to-tail monomer-monomer interactions in early self-association events. This multipronged mechanism provides a new framework to explain how the E46K mutation and possibly other αS variants trigger early-onset PD.
Collapse
Affiliation(s)
- Jinfeng Huang
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Rashik Ahmed
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Madoka Akimoto
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Karla Martinez Pomier
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Giuseppe Melacini
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, ON L8S 4M1, Canada
| |
Collapse
|
3
|
Cheung See Kit M, Cropley TC, Bleiholder C, Chouinard CD, Sobott F, Webb IK. The role of solvation on the conformational landscape of α-synuclein. Analyst 2023; 149:125-136. [PMID: 37982746 PMCID: PMC10760066 DOI: 10.1039/d3an01680c] [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] [Indexed: 11/21/2023]
Abstract
Native ion mobility mass spectrometry has been used extensively to characterize ensembles of intrinsically disordered protein (IDP) conformers, but the extent to which the gaseous measurements provide realistic pictures of the solution conformations for such flexible proteins remains unclear. Therefore, we systematically studied the relationship between the solution and gaseous structural ensembles by measuring electrospray charge state and collision cross section (CCS) distributions for cationic and anionic forms of α-synuclein (αSN), an anionic protein in solution, as well as directly probed gas phase residue to residue distances via ion/ion reactions between gaseous α-synuclein cations and disulfonic acid linkers that form strong electrostatic bonds. We also combined results from in-solution protein crosslinking identified from native tandem mass spectrometry (MS/MS) with an initial αSN ensemble generated computationally by IDPConformerGenerator to generate an experimentally restrained solution ensemble of αSN. CCS distributions were directly calculated for the solution ensembles determined by NMR and compared to predicted gaseous conformers. While charge state and collision cross section distributions are useful for qualitatively describing the relative structural dynamics of proteins and major conformational changes induced by changes to solution states, the predicted and measured gas phase conformers include subpopulations that are significantly different than those expected from completely "freezing" solution conformations and preserving them in the gas phase. However, insights were gained on the various roles of solvent in stabilizing various conformers for extremely dynamic proteins like α-synuclein.
Collapse
Affiliation(s)
- Melanie Cheung See Kit
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
| | - Tyler C Cropley
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Christian Bleiholder
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
| | | | - Frank Sobott
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Ian K Webb
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| |
Collapse
|
4
|
Sun W, Lebedenko OO, Salguero NG, Shannon MD, Zandian M, Poirier MG, Skrynnikov NR, Jaroniec CP. Conformational and Interaction Landscape of Histone H4 Tails in Nucleosomes Probed by Paramagnetic NMR Spectroscopy. J Am Chem Soc 2023; 145:25478-25485. [PMID: 37943892 PMCID: PMC10719895 DOI: 10.1021/jacs.3c10340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The fundamental repeat unit of chromatin, the nucleosome, consists of approximately 147 base pairs of double-stranded DNA and a histone protein octamer containing two copies each of histones H2A, H2B, H3, and H4. Each histone possesses a dynamically disordered N-terminal tail domain, and it is well-established that the tails of histones H3 and H4 play key roles in chromatin compaction and regulation. Here we investigate the conformational ensemble and interactions of the H4 tail in nucleosomes by means of solution NMR measurements of paramagnetic relaxation enhancements (PREs) in recombinant samples reconstituted with 15N-enriched H4 and nitroxide spin-label tagged H3. The experimental PREs, which report on the proximities of individual H4 tail residues to the different H3 spin-label sites, are interpreted by using microsecond time-scale molecular dynamics simulations of the nucleosome core particle. Collectively, these data enable improved localization of histone H4 tails in nucleosomes and support the notion that H4 tails engage in a fuzzy complex interaction with nucleosomal DNA.
Collapse
Affiliation(s)
- Wenjun Sun
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Olga O. Lebedenko
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
| | - Nicole Gonzalez Salguero
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Matthew D. Shannon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Mohamad Zandian
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Michael G. Poirier
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Nikolai R. Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
- Department of Chemistry, Purdue University, West Lafayette 47907, United States
| | - Christopher P. Jaroniec
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| |
Collapse
|
5
|
Chen SH, Weiss KL, Stanley C, Bhowmik D. Structural characterization of an intrinsically disordered protein complex using integrated small-angle neutron scattering and computing. Protein Sci 2023; 32:e4772. [PMID: 37646172 PMCID: PMC10503416 DOI: 10.1002/pro.4772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/22/2023] [Accepted: 08/27/2023] [Indexed: 09/01/2023]
Abstract
Characterizing structural ensembles of intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) of proteins is essential for studying structure-function relationships. Due to the different neutron scattering lengths of hydrogen and deuterium, selective labeling and contrast matching in small-angle neutron scattering (SANS) becomes an effective tool to study dynamic structures of disordered systems. However, experimental timescales typically capture measurements averaged over multiple conformations, leaving complex SANS data for disentanglement. We hereby demonstrate an integrated method to elucidate the structural ensemble of a complex formed by two IDRs. We use data from both full contrast and contrast matching with residue-specific deuterium labeling SANS experiments, microsecond all-atom molecular dynamics (MD) simulations with four molecular mechanics force fields, and an autoencoder-based deep learning (DL) algorithm. From our combined approach, we show that selective deuteration provides additional information that helps characterize structural ensembles. We find that among the four force fields, a99SB-disp and CHARMM36m show the strongest agreement with SANS and NMR experiments. In addition, our DL algorithm not only complements conventional structural analysis methods but also successfully differentiates NMR and MD structures which are indistinguishable on the free energy surface. Lastly, we present an ensemble that describes experimental SANS and NMR data better than MD ensembles generated by one single force field and reveal three clusters of distinct conformations. Our results demonstrate a new integrated approach for characterizing structural ensembles of IDPs.
Collapse
Affiliation(s)
- Serena H. Chen
- Computational Sciences and Engineering DivisionOak Ridge National LaboratoryOak RidgeTennesseeUSA
| | - Kevin L. Weiss
- Neutron Scattering DivisionOak Ridge National LaboratoryOak RidgeTennesseeUSA
| | - Christopher Stanley
- Computational Sciences and Engineering DivisionOak Ridge National LaboratoryOak RidgeTennesseeUSA
| | - Debsindhu Bhowmik
- Computational Sciences and Engineering DivisionOak Ridge National LaboratoryOak RidgeTennesseeUSA
| |
Collapse
|
6
|
Upadhyay A, Ekenna C. A New Tool to Study the Binding Behavior of Intrinsically Disordered Proteins. Int J Mol Sci 2023; 24:11785. [PMID: 37511544 PMCID: PMC10380747 DOI: 10.3390/ijms241411785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/07/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Understanding the binding behavior and conformational dynamics of intrinsically disordered proteins (IDPs) is crucial for unraveling their regulatory roles in biological processes. However, their lack of stable 3D structures poses challenges for analysis. To address this, we propose an algorithm that explores IDP binding behavior with protein complexes by extracting topological and geometric features from the protein surface model. Our algorithm identifies a geometrically favorable binding pose for the IDP and plans a feasible trajectory to evaluate its transition to the docking position. We focus on IDPs from Homo sapiens and Mus-musculus, investigating their interaction with the Plasmodium falciparum (PF) pathogen associated with malaria-related deaths. We compare our algorithm with HawkDock and HDOCK docking tools for quantitative (computation time) and qualitative (binding affinity) measures. Our results indicated that our method outperformed the compared methods in computation performance and binding affinity in experimental conformations.
Collapse
Affiliation(s)
- Aakriti Upadhyay
- Department of Computer Science, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Chinwe Ekenna
- Department of Computer Science, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA
| |
Collapse
|
7
|
Paladino A, Vitagliano L, Graziano G. The Action of Chemical Denaturants: From Globular to Intrinsically Disordered Proteins. BIOLOGY 2023; 12:biology12050754. [PMID: 37237566 DOI: 10.3390/biology12050754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023]
Abstract
Proteins perform their many functions by adopting either a minimal number of strictly similar conformations, the native state, or a vast ensemble of highly flexible conformations. In both cases, their structural features are highly influenced by the chemical environment. Even though a plethora of experimental studies have demonstrated the impact of chemical denaturants on protein structure, the molecular mechanism underlying their action is still debated. In the present review, after a brief recapitulation of the main experimental data on protein denaturants, we survey both classical and more recent interpretations of the molecular basis of their action. In particular, we highlight the differences and similarities of the impact that denaturants have on different structural classes of proteins, i.e., globular, intrinsically disordered (IDP), and amyloid-like assemblies. Particular attention has been given to the IDPs, as recent studies are unraveling their fundamental importance in many physiological processes. The role that computation techniques are expected to play in the near future is illustrated.
Collapse
Affiliation(s)
- Antonella Paladino
- Institute of Biostructures and Bioimaging, CNR, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, CNR, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Giuseppe Graziano
- Department of Science and Technology, University of Sannio, via Francesco de Sanctis snc, 82100 Benevento, Italy
| |
Collapse
|
8
|
Zhang O, Haghighatlari M, Li J, Liu ZH, Namini A, Teixeira JMC, Forman-Kay JD, Head-Gordon T. Learning to evolve structural ensembles of unfolded and disordered proteins using experimental solution data. J Chem Phys 2023; 158:174113. [PMID: 37144719 PMCID: PMC10163956 DOI: 10.1063/5.0141474] [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: 01/05/2023] [Accepted: 04/11/2023] [Indexed: 05/06/2023] Open
Abstract
The structural characterization of proteins with a disorder requires a computational approach backed by experiments to model their diverse and dynamic structural ensembles. The selection of conformational ensembles consistent with solution experiments of disordered proteins highly depends on the initial pool of conformers, with currently available tools limited by conformational sampling. We have developed a Generative Recurrent Neural Network (GRNN) that uses supervised learning to bias the probability distributions of torsions to take advantage of experimental data types such as nuclear magnetic resonance J-couplings, nuclear Overhauser effects, and paramagnetic resonance enhancements. We show that updating the generative model parameters according to the reward feedback on the basis of the agreement between experimental data and probabilistic selection of torsions from learned distributions provides an alternative to existing approaches that simply reweight conformers of a static structural pool for disordered proteins. Instead, the biased GRNN, DynamICE, learns to physically change the conformations of the underlying pool of the disordered protein to those that better agree with experiments.
Collapse
Affiliation(s)
- Oufan Zhang
- Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Mojtaba Haghighatlari
- Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Jie Li
- Kenneth S. Pitzer Theory Center and Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | - Ashley Namini
- Molecular Medicine Program, Hospital for Sick Children, Toronto, Ontario M5S 1A8, Canada
| | | | | | | |
Collapse
|
9
|
Menon S, Mondal J. Conformational Plasticity in α-Synuclein and How Crowded Environment Modulates It. J Phys Chem B 2023; 127:4032-4049. [PMID: 37114769 DOI: 10.1021/acs.jpcb.3c00982] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
A 140-residue intrinsically disordered protein (IDP), α-synuclein (αS), is known to adopt conformations that are vastly plastic and susceptible to environmental cues and crowders. However, the inherently heterogeneous nature of αS has precluded a clear demarcation of its monomeric precursor between aggregation-prone and functionally relevant aggregation-resistant states and how a crowded environment could modulate their mutual dynamic equilibrium. Here, we identify an optimal set of distinct metastable states of αS in aqueous media by dissecting a 73 μs-long molecular dynamics ensemble via building a comprehensive Markov state model (MSM). Notably, the most populated metastable state corroborates with the dimension obtained from PRE-NMR studies of αS monomer, and it undergoes kinetic transition at diverse time scales with a weakly populated random-coil-like ensemble and a globular protein-like state. However, subjecting αS to a crowded environment results in a nonmonotonic compaction of these metastable conformations, thereby skewing the ensemble by either introducing new tertiary contacts or by reinforcing the innate contacts. The early stage of dimerization process is found to be considerably expedited in the presence of crowders, albeit promoting nonspecific interactions. Together with this, using an extensively sampled ensemble of αS, this exposition demonstrates that crowded environments can potentially modulate the conformational preferences of IDP that can either promote or inhibit aggregation events.
Collapse
Affiliation(s)
- Sneha Menon
- Tata Institute of Fundamental Research Hyderabad, Telangana 500046, India
| | - Jagannath Mondal
- Tata Institute of Fundamental Research Hyderabad, Telangana 500046, India
| |
Collapse
|
10
|
Wu K, Sun W, Li D, Diao J, Xiu P. Inhibition of Amyloid Nucleation by Steric Hindrance. J Phys Chem B 2022; 126:10045-10054. [PMID: 36417323 DOI: 10.1021/acs.jpcb.2c06330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Despite recent experiments and simulations suggesting that small-molecule inhibitors and some post-translational modifications (e.g., glycosylation and ubiquitination) can suppress the pathogenic aggregation of proteins due to steric hindrance, the effect of steric hindrance on amyloid formation has not been systematically studied. Based on Monte Carlo simulations using a coarse-grained model for amyloidogenic proteins and a hard sphere acting as steric hindrance, we investigated how steric hindrance on proteins could affect amyloid formation, particularly two steps of primary nucleation, namely, oligomerization and conformational conversion into a β-sheet-enriched nucleus. We found that steric spheres played an inhibitory role in oligomerization with the effect proportional to the sphere radius RS, which we attributed to the decline in the nonspecific attractions between proteins. During the second step, small steric spheres facilitated the conformational conversion of proteins while large ones suppressed the conversion. The overall steric effect on amyloid nucleation was inhibitory regardless of RS. As RS increased, oligomeric assemblies changed from amorphous into sheet-like, structurally ordered species, reminiscent of the structure of amyloid fibrils. The oligomers with large RS were off-pathway with their ordered structures induced by the competition between steric hindrance and nonspecific attractions of soluble proteins. Interestingly, the equimolar mixture of proteins with and without steric hindrance amplified the sterically inhibitory effect by increasing the energy barrier of protein's conformational conversion. The physical mechanisms and biological implications of the above results are discussed. Our findings improve the current understanding of how nature regulates protein aggregation and amyloid formation by steric hindrance.
Collapse
Affiliation(s)
- Kai Wu
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China.,Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States of America
| | - Wuxuepeng Sun
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Dechang Li
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States of America
| | - Peng Xiu
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China
| |
Collapse
|
11
|
Förster D, Idier J, Liberti L, Mucherino A, Lin JH, Malliavin TE. Low-resolution description of the conformational space for intrinsically disordered proteins. Sci Rep 2022; 12:19057. [PMID: 36352011 PMCID: PMC9646904 DOI: 10.1038/s41598-022-21648-9] [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: 05/01/2022] [Accepted: 09/29/2022] [Indexed: 11/11/2022] Open
Abstract
Intrinsically disordered proteins (IDP) are at the center of numerous biological processes, and attract consequently extreme interest in structural biology. Numerous approaches have been developed for generating sets of IDP conformations verifying a given set of experimental measurements. We propose here to perform a systematic enumeration of protein conformations, carried out using the TAiBP approach based on distance geometry. This enumeration was performed on two proteins, Sic1 and pSic1, corresponding to unphosphorylated and phosphorylated states of an IDP. The relative populations of the obtained conformations were then obtained by fitting SAXS curves as well as Ramachandran probability maps, the original finite mixture approach RamaMix being developed for this second task. The similarity between profiles of local gyration radii provides to a certain extent a converged view of the Sic1 and pSic1 conformational space. Profiles and populations are thus proposed for describing IDP conformations. Different variations of the resulting gyration radius between phosphorylated and unphosphorylated states are observed, depending on the set of enumerated conformations as well as on the methods used for obtaining the populations.
Collapse
Affiliation(s)
- Daniel Förster
- grid.112485.b0000 0001 0217 6921UMR7374 Interfaces, Confinement, Matériaux et Nanostructures, Université d’Orléans, Orléans, France
| | - Jérôme Idier
- grid.503212.70000 0000 9563 6044UMR6004 Laboratoire des Sciences du Numérique de Nantes, Nantes, France
| | - Leo Liberti
- grid.508893.fLIX UMR 7161 CNRS École Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Antonio Mucherino
- grid.420225.30000 0001 2298 7270IRISA, University of Rennes 1, Rennes, France
| | - Jung-Hsin Lin
- grid.509455.8Biomedical Translation Research Center, Academia Sinica, Taipei, Taiwan
| | - Thérèse E. Malliavin
- grid.428999.70000 0001 2353 6535Institut Pasteur, Université Paris Cité, CNRS UMR3528, Unité de Bioinformatique Structurale, F-75015 Paris, France ,grid.29172.3f0000 0001 2194 6418Université de Lorraine, CNRS UMR7019, LPCT, F-54000 Nancy, France
| |
Collapse
|
12
|
REMD Simulations of Full-Length Alpha-Synuclein Together with Ligands Reveal Binding Region and Effect on Amyloid Conversion. Int J Mol Sci 2022; 23:ijms231911545. [PMID: 36232847 PMCID: PMC9569888 DOI: 10.3390/ijms231911545] [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: 08/22/2022] [Revised: 09/19/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022] Open
Abstract
Alpha-synuclein is a key protein involved in the development and progression of Parkinson’s disease and other synucleinopathies. The intrinsically disordered nature of alpha-synuclein hinders the computational screening of new drug candidates for the treatment of these neurodegenerative diseases. In the present work, replica exchange molecular dynamics simulations of the full-length alpha-synuclein together with low-molecular ligands were utilized to predict the binding site and effect on the amyloid-like conversion of the protein. This approach enabled an accurate prediction of the binding sites for three tested compounds (fasudil, phthalocyanine tetrasulfonate, and spermine), giving good agreement with data from experiments by other groups. Lots of information about the binding and protein conformational ensemble enabled the suggestion of a putative effect of the ligands on the amyloid-like conversion of alpha-synuclein and the mechanism of anti- and pro-amyloid activity of the tested compounds. Therefore, this approach looks promising for testing new drug candidates for binding with alpha-synuclein or other intrinsically disordered proteins and at the same time the estimation of the effect on protein behavior, including amyloid-like aggregation.
Collapse
|
13
|
Galamba N. Aggregation of a Parkinson's Disease-Related Peptide: When Does Urea Weaken Hydrophobic Interactions? ACS Chem Neurosci 2022; 13:1769-1781. [PMID: 35616516 PMCID: PMC9775218 DOI: 10.1021/acschemneuro.2c00169] [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] [Indexed: 12/25/2022] Open
Abstract
While the exact cause of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease is not completely understood, compelling evidence implicates the aggregation of specific proteins and peptides. Co-solvents can provide molecular insight into protein aggregation mechanisms and the chemical nature of potential aggregation inhibitors. Here, we study, through molecular simulations, the hydration and binding free energies of an amphiphilic peptide from the nonamyloid-β component (NAC), a key aggregation-prone domain of α-synuclein, in water and an 8 M aqueous urea solution. Isoleucine, glycine, and serine peptides of the same length are also studied to unravel the role of urea in the hydration and aggregation of hydrophobic and hydrophilic domains. A strong impact of urea in hindering the aggregation of the NAC subdomain is observed. A slightly weaker aggregation inhibition is observed for the Gly and Ser peptides, whereas a much lower aggregation inhibitory activity is found for the Ile peptide, seemingly contrasting with urea's protein unfolding mechanism. This behavior is shown to derive from a lower profusion of urea next to the hydrophobic side chains and the backbone of the Ile's peptide in the dimeric form. As a consequence, β-sheets, formed upon aggregation, remain nearly intact. Hydrophilic neighbor groups in the amphiphilic NAC subdomain, however, are shown to anchor enough urea to weaken hydrophobic interactions and disrupt β-sheet structures. Our results indicate that urea's activity is potentiated in amphiphilic domains and that potential drugs could disrupt hydrophobic β-sheet-rich regions while not binding primarily to hydrophobic amino acids.
Collapse
|
14
|
Mondal S, Ghanta KP, Bandyopadhyay S. Dynamic Heterogeneity at the Interface of an Intrinsically Disordered Peptide. J Chem Inf Model 2022; 62:1942-1955. [PMID: 35384652 DOI: 10.1021/acs.jcim.2c00019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
It is believed that water around an intrinsically disordered protein or peptide (IDP) in an aqueous environment plays an important role in guiding its conformational properties and aggregation behavior. However, despite its importance, only a handful of studies exploring the correlation between the conformational motions of an IDP and the microscopic properties of water at its surface are reported. Attempts have been made in this work to study the dynamic properties of water present in the vicinity of α-synuclein, an IDP associated with Parkinson's disease (PD). Room temperature molecular dynamics (MD) simulations of eight α-synuclein1-95 peptides with a wide range of initial conformations have been carried out in aqueous media. The calculations revealed that due to solid-like caging motions, the translational and rotational mobility of water molecules near the surfaces of the peptide repeat unit segments R1 to R7 are significantly restricted. A small degree of dynamic heterogeneity in the hydration environment around the repeat units has been observed with water near the hydrophobic R6 unit exhibiting relatively more restricted diffusivity. The time scales involving the overall structural relaxations of peptide-water and water-water hydrogen bonds near the peptide have been found to be correlated with the time scale of diffusion of the interfacial water molecules. We believe that the relatively more hindered dynamic environment near R6 can help create water-mediated contacts centered around R6 between peptide monomers at a higher concentration, thereby enhancing the early stages of peptide aggregation.
Collapse
Affiliation(s)
- Souvik Mondal
- Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| | - Krishna Prasad Ghanta
- Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| | - Sanjoy Bandyopadhyay
- Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| |
Collapse
|
15
|
Molecular Dynamics Simulation Studies on the Aggregation of Amyloid-β Peptides and Their Disaggregation by Ultrasonic Wave and Infrared Laser Irradiation. Molecules 2022; 27:molecules27082483. [PMID: 35458686 PMCID: PMC9030874 DOI: 10.3390/molecules27082483] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 03/29/2022] [Accepted: 04/07/2022] [Indexed: 01/02/2023] Open
Abstract
Alzheimer’s disease is understood to be caused by amyloid fibrils and oligomers formed by aggregated amyloid-β (Aβ) peptides. This review article presents molecular dynamics (MD) simulation studies of Aβ peptides and Aβ fragments on their aggregation, aggregation inhibition, amyloid fibril conformations in equilibrium, and disruption of the amyloid fibril by ultrasonic wave and infrared laser irradiation. In the aggregation of Aβ, a β-hairpin structure promotes the formation of intermolecular β-sheet structures. Aβ peptides tend to exist at hydrophilic/hydrophobic interfaces and form more β-hairpin structures than in bulk water. These facts are the reasons why the aggregation is accelerated at the interface. We also explain how polyphenols, which are attracting attention as aggregation inhibitors of Aβ peptides, interact with Aβ. An MD simulation study of the Aβ amyloid fibrils in equilibrium is also presented: the Aβ amyloid fibril has a different structure at one end from that at the other end. The amyloid fibrils can be destroyed by ultrasonic wave and infrared laser irradiation. The molecular mechanisms of these amyloid fibril disruptions are also explained, particularly focusing on the function of water molecules. Finally, we discuss the prospects for developing treatments for Alzheimer’s disease using MD simulations.
Collapse
|
16
|
Karamanos TK, Kalverda AP, Radford SE. Generating Ensembles of Dynamic Misfolding Proteins. Front Neurosci 2022; 16:881534. [PMID: 35431773 PMCID: PMC9008329 DOI: 10.3389/fnins.2022.881534] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 03/08/2022] [Indexed: 01/09/2023] Open
Abstract
The early stages of protein misfolding and aggregation involve disordered and partially folded protein conformers that contain a high degree of dynamic disorder. These dynamic species may undergo large-scale intra-molecular motions of intrinsically disordered protein (IDP) precursors, or flexible, low affinity inter-molecular binding in oligomeric assemblies. In both cases, generating atomic level visualization of the interconverting species that captures the conformations explored and their physico-chemical properties remains hugely challenging. How specific sub-ensembles of conformers that are on-pathway to aggregation into amyloid can be identified from their aggregation-resilient counterparts within these large heterogenous pools of rapidly moving molecules represents an additional level of complexity. Here, we describe current experimental and computational approaches designed to capture the dynamic nature of the early stages of protein misfolding and aggregation, and discuss potential challenges in describing these species because of the ensemble averaging of experimental restraints that arise from motions on the millisecond timescale. We give a perspective of how machine learning methods can be used to extract aggregation-relevant sub-ensembles and provide two examples of such an approach in which specific interactions of defined species within the dynamic ensembles of α-synuclein (αSyn) and β2-microgloblulin (β2m) can be captured and investigated.
Collapse
Affiliation(s)
- Theodoros K. Karamanos
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| | | | - Sheena E. Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
17
|
Holec SAM, Liu SL, Woerman AL. Consequences of variability in α-synuclein fibril structure on strain biology. Acta Neuropathol 2022; 143:311-330. [PMID: 35122113 DOI: 10.1007/s00401-022-02403-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 12/15/2022]
Abstract
Synucleinopathies are a group of clinically and neuropathologically distinct protein misfolding diseases caused by unique α-synuclein conformations, or strains. While multiple atomic resolution cryo-electron microscopy structures of α-synuclein fibrils are now deposited in Protein Data Bank, significant gaps in the biological consequences arising from each conformation have yet to be unraveled. Mutations in the α-synuclein gene (SNCA), cofactors, and the solvation environment contribute to the formation and maintenance of each disease-causing strain. This review highlights the impact of each of these factors on α-synuclein misfolding and discusses the implications of the resulting structural variability on therapeutic development.
Collapse
Affiliation(s)
- Sara A M Holec
- Department of Biology, Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, MA, USA
| | - Samantha L Liu
- Department of Biology, Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, MA, USA
- Molecular and Cellular Biology Program, Dartmouth College, Hanover, NH, USA
| | - Amanda L Woerman
- Department of Biology, Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, MA, USA.
| |
Collapse
|
18
|
Fukuhara D, Itoh SG, Okumura H. Replica permutation with solute tempering for molecular dynamics simulation and its application to the dimerization of amyloid-β fragments. J Chem Phys 2022; 156:084109. [DOI: 10.1063/5.0081686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We propose the replica permutation with solute tempering (RPST) by combining the replica-permutation method (RPM) and the replica exchange with solute tempering (REST). Temperature permutations are performed among more than two replicas in RPM, whereas temperature exchanges are performed between two replicas in the replica-exchange method (REM). The temperature transition in RPM occurs more efficiently than in REM. In REST, only the temperatures of the solute region, the solute temperatures, are exchanged to reduce the number of replicas compared to REM. Therefore, RPST is expected to be an improved method taking advantage of these methods. For comparison, we applied RPST, REST, RPM, and REM to two amyloid-β(16–22) peptides in explicit water. We calculated the transition ratio and the number of tunneling events in the temperature space and the number of dimerization events of amyloid-β(16–22) peptides. The results indicate that, in RPST, the number of replicas necessary for frequent random walks in the temperature and conformational spaces is reduced compared to the other three methods. In addition, we focused on the dimerization process of amyloid-β(16–22) peptides. The RPST simulation with a relatively small number of replicas shows that the two amyloid-β(16–22) peptides form the intermolecular antiparallel β-bridges due to the hydrophilic side-chain contact between Lys and Glu and hydrophobic side-chain contact between Leu, Val, and Phe, which stabilizes the dimer of the peptides.
Collapse
Affiliation(s)
- Daiki Fukuhara
- Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan
- Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Satoru G. Itoh
- Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan
- Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Hisashi Okumura
- Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan
- Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| |
Collapse
|
19
|
Tachi Y, Itoh SG, Okumura H. Molecular dynamics simulations of amyloid-β peptides in heterogeneous environments. Biophys Physicobiol 2022; 19:1-18. [PMID: 35666692 PMCID: PMC9135617 DOI: 10.2142/biophysico.bppb-v19.0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 03/31/2022] [Indexed: 12/01/2022] Open
Affiliation(s)
- Yuhei Tachi
- Department of Physics, Graduate school of Science, Nagoya University
| | - Satoru G. Itoh
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences
| | - Hisashi Okumura
- Institute for Molecular Science, National Institutes of Natural Sciences
| |
Collapse
|
20
|
Shahzadi S, Yasir M, Aftab B, Babar S, Hassan M. Exploration of Protein Aggregations in Parkinson's Disease Through Computational Approaches and Big Data Analytics. Methods Mol Biol 2022; 2340:449-467. [PMID: 35167085 DOI: 10.1007/978-1-0716-1546-1_19] [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
Protein aggregation has been implicated in numerous neurodegenerative disorders whose etiologies are poorly understood, and for which there are no effective treatments. Here we show that the computational approaches may help us to better understand the basics of Parkinson's disease (PD). The high-resolution structural, dynamical, and mechanistic insights delivered by computational studies of protein aggregation have a unique potential to enable the rational manipulation of oligomer formation. Additionally, big data and machine learning methods may provide valuable insights to better understand the nature of proteins involved in PD and their aggregative behavior for the betterment of PD treatment.
Collapse
Affiliation(s)
- Saba Shahzadi
- Institute of Molecular Sciences and Bioinformatics, Lahore, Pakistan
| | - Muhammad Yasir
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Bisma Aftab
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Sumbal Babar
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Mubashir Hassan
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan.
- Battelle Center for Mathematical Medicine, Nationwide Children Hospital & Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA.
| |
Collapse
|
21
|
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.
Collapse
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.
| |
Collapse
|
22
|
Guzzo A, Delarue P, Rojas A, Nicolaï A, Maisuradze GG, Senet P. Missense Mutations Modify the Conformational Ensemble of the α-Synuclein Monomer Which Exhibits a Two-Phase Characteristic. Front Mol Biosci 2021; 8:786123. [PMID: 34912851 PMCID: PMC8667727 DOI: 10.3389/fmolb.2021.786123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/25/2021] [Indexed: 12/15/2022] Open
Abstract
α-Synuclein is an intrinsically disordered protein occurring in different conformations and prone to aggregate in β-sheet structures, which are the hallmark of the Parkinson disease. Missense mutations are associated with familial forms of this neuropathy. How these single amino-acid substitutions modify the conformations of wild-type α-synuclein is unclear. Here, using coarse-grained molecular dynamics simulations, we sampled the conformational space of the wild type and mutants (A30P, A53P, and E46K) of α-synuclein monomers for an effective time scale of 29.7 ms. To characterize the structures, we developed an algorithm, CUTABI (CUrvature and Torsion based of Alpha-helix and Beta-sheet Identification), to identify residues in the α-helix and β-sheet from Cα-coordinates. CUTABI was built from the results of the analysis of 14,652 selected protein structures using the Dictionary of Secondary Structure of Proteins (DSSP) algorithm. DSSP results are reproduced with 93% of success for 10 times lower computational cost. A two-dimensional probability density map of α-synuclein as a function of the number of residues in the α-helix and β-sheet is computed for wild-type and mutated proteins from molecular dynamics trajectories. The density of conformational states reveals a two-phase characteristic with a homogeneous phase (state B, β-sheets) and a heterogeneous phase (state HB, mixture of α-helices and β-sheets). The B state represents 40% of the conformations for the wild-type, A30P, and E46K and only 25% for A53T. The density of conformational states of the B state for A53T and A30P mutants differs from the wild-type one. In addition, the mutant A53T has a larger propensity to form helices than the others. These findings indicate that the equilibrium between the different conformations of the α-synuclein monomer is modified by the missense mutations in a subtle way. The α-helix and β-sheet contents are promising order parameters for intrinsically disordered proteins, whereas other structural properties such as average gyration radius, Rg, or probability distribution of Rg cannot discriminate significantly the conformational ensembles of the wild type and mutants. When separated in states B and HB, the distributions of Rg are more significantly different, indicating that global structural parameters alone are insufficient to characterize the conformational ensembles of the α-synuclein monomer.
Collapse
Affiliation(s)
- Adrien Guzzo
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne Franche-Comté, Dijon, France
| | - Patrice Delarue
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne Franche-Comté, Dijon, France
| | - Ana Rojas
- Schrödinger, Inc., New York, NY, United States
| | - Adrien Nicolaï
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne Franche-Comté, Dijon, France
| | - Gia G Maisuradze
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States
| | - Patrick Senet
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne Franche-Comté, Dijon, France.,Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, United States
| |
Collapse
|
23
|
Mondal S, Mondal S, Bandyopadhyay S. Importance of Solvent in Guiding the Conformational Properties of an Intrinsically Disordered Peptide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14429-14442. [PMID: 34817184 DOI: 10.1021/acs.langmuir.1c02401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Aggregated form of α-synuclein in the brain has been found to be the major component of Lewy bodies that are hallmarks of Parkinson's disease (PD), the second most devastating neurodegenerative disorder. We have carried out room-temperature all-atom molecular dynamics (MD) simulations of an ensemble of widely different α-synuclein1-95 peptide monomer conformations in aqueous solution. Attempts have been made to obtain a generic understanding of the local conformational motions of different repeat unit segments, namely R1-R7, of the peptide and the correlated properties of the solvent at the interface. The analyses revealed relatively greater rigidity of the hydrophobic R6 unit as compared to the other repeat units of the peptide. Besides, water molecules around R6 have been found to be less structured and weakly interacting with the peptide. These are important observations as the R6 unit with reduced conformational motions can act as the nucleation site for the aggregation process, while less structured weakly interacting water around it can become displaced easily, thereby facilitating the hydrophobic collapse of the peptide monomers and their association during the nucleation phase at higher concentrations. In addition, we demonstrated presence of doubly coordinated highly ordered as well as triply coordinated relatively disordered water molecules at the interface. We believe that while the ordered water molecules can favor water-mediated interactions between different peptide monomers, the randomly ordered ones on the other hand are likely to be expelled easily from the interface, thereby facilitating direct peptide-peptide interactions during the aggregation process.
Collapse
Affiliation(s)
- Souvik Mondal
- Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| | - Sandip Mondal
- Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| | - Sanjoy Bandyopadhyay
- Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| |
Collapse
|
24
|
Bogaerts J, Aerts R, Vermeyen T, Johannessen C, Herrebout W, Batista JM. Tackling Stereochemistry in Drug Molecules with Vibrational Optical Activity. Pharmaceuticals (Basel) 2021; 14:877. [PMID: 34577577 PMCID: PMC8468215 DOI: 10.3390/ph14090877] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 12/29/2022] Open
Abstract
Chirality plays a crucial role in drug discovery and development. As a result, a significant number of commercially available drugs are structurally dissymmetric and enantiomerically pure. The determination of the exact 3D structure of drug candidates is, consequently, of paramount importance for the pharmaceutical industry in different stages of the discovery pipeline. Traditionally the assignment of the absolute configuration of druggable molecules has been carried out by means of X-ray crystallography. Nevertheless, not all molecules are suitable for single-crystal growing. Additionally, valuable information about the conformational dynamics of drug candidates is lost in the solid state. As an alternative, vibrational optical activity (VOA) methods have emerged as powerful tools to assess the stereochemistry of drug molecules directly in solution. These methods include vibrational circular dichroism (VCD) and Raman optical activity (ROA). Despite their potential, VCD and ROA are still unheard of to many organic and medicinal chemists. Therefore, the present review aims at highlighting the recent use of VOA methods for the assignment of the absolute configuration of chiral small-molecule drugs, as well as for the structural analysis of biologics of pharmaceutical interest. A brief introduction on VCD and ROA theory and the best experimental practices for using these methods will be provided along with selected representative examples over the last five years. As VCD and ROA are commonly used in combination with quantum calculations, some guidelines will also be presented for the reliable simulation of chiroptical spectra. Special attention will be paid to the complementarity of VCD and ROA to unambiguously assess the stereochemical properties of pharmaceuticals.
Collapse
Affiliation(s)
- Jonathan Bogaerts
- Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium; (J.B.); (R.A.); (T.V.); (C.J.); (W.H.)
| | - Roy Aerts
- Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium; (J.B.); (R.A.); (T.V.); (C.J.); (W.H.)
| | - Tom Vermeyen
- Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium; (J.B.); (R.A.); (T.V.); (C.J.); (W.H.)
- Department of Chemistry, Ghent University, 9000 Ghent, Belgium
| | - Christian Johannessen
- Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium; (J.B.); (R.A.); (T.V.); (C.J.); (W.H.)
| | - Wouter Herrebout
- Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium; (J.B.); (R.A.); (T.V.); (C.J.); (W.H.)
| | - Joao M. Batista
- Institute of Science and Technology, Federal University of Sao Paulo, Sao Jose dos Campos 12231-280, SP, Brazil
| |
Collapse
|
25
|
Morgan JL, Yeager A, Estelle AB, Gsponer J, Barbar E. Transient Tertiary Structures of Disordered Dynein Intermediate Chain Regulate its Interactions with Multiple Partners. J Mol Biol 2021; 433:167152. [PMID: 34273400 DOI: 10.1016/j.jmb.2021.167152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 07/06/2021] [Accepted: 07/06/2021] [Indexed: 11/24/2022]
Abstract
The N-terminal domain of dynein intermediate chain (N-IC) is central to the cytoplasmic dynein 'cargo attachment subcomplex' and regulation of motor activity. It is a prototypical intrinsically disordered protein (IDP), serving as a primarily disordered polybivalent molecular scaffold for numerous binding partners, including three dimeric dynein light chains and coiled coil domains of dynein partners dynactin p150Glued and NudE. At the very N-terminus, a 40 amino acid single alpha helix (SAH) forms the major binding site for both p150Glued and NudE, while a shorter nascent helix (H2) separated from SAH by a disordered linker, is necessary for tight binding to dynactin p150Glued but not to NudE. Here we demonstrate that transient tertiary interactions in this highly dynamic protein underlie the differences in its interactions with p150Glued and NudE. NMR paramagnetic relaxation enhancement experiments and restrained molecular dynamics simulations identify interactions between the two non-contiguous SAH and H2 helical regions, the extent of which correlates with the length and stability of H2, showing clearly that tertiary and secondary structure formation are coupled in IDPs. These interactions are significantly attenuated when N-IC is bound to NudE, suggesting that NudE binding shifts the conformational ensemble to one that is more extended and with less structure in H2. While the intrinsic disorder and flexibility in N-IC modulate its ability to serve as a binding platform for numerous partners, deviations of this protein from random-coil behavior provide a process for regulating these binding interactions and potentially the dynein motor.
Collapse
Affiliation(s)
- Jessica L Morgan
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, United States
| | - Andrew Yeager
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Aidan B Estelle
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, United States
| | - Jörg Gsponer
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Elisar Barbar
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, United States.
| |
Collapse
|
26
|
Bisi N, Feni L, Peqini K, Pérez-Peña H, Ongeri S, Pieraccini S, Pellegrino S. α-Synuclein: An All-Inclusive Trip Around its Structure, Influencing Factors and Applied Techniques. Front Chem 2021; 9:666585. [PMID: 34307295 PMCID: PMC8292672 DOI: 10.3389/fchem.2021.666585] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 06/02/2021] [Indexed: 12/15/2022] Open
Abstract
Alpha-synuclein (αSyn) is a highly expressed and conserved protein, typically found in the presynaptic terminals of neurons. The misfolding and aggregation of αSyn into amyloid fibrils is a pathogenic hallmark of several neurodegenerative diseases called synucleinopathies, such as Parkinson’s disease. Since αSyn is an Intrinsically Disordered Protein, the characterization of its structure remains very challenging. Moreover, the mechanisms by which the structural conversion of monomeric αSyn into oligomers and finally into fibrils takes place is still far to be completely understood. Over the years, various studies have provided insights into the possible pathways that αSyn could follow to misfold and acquire oligomeric and fibrillar forms. In addition, it has been observed that αSyn structure can be influenced by different parameters, such as mutations in its sequence, the biological environment (e.g., lipids, endogenous small molecules and proteins), the interaction with exogenous compounds (e.g., drugs, diet components, heavy metals). Herein, we review the structural features of αSyn (wild-type and disease-mutated) that have been elucidated up to present by both experimental and computational techniques in different environmental and biological conditions. We believe that this gathering of current knowledge will further facilitate studies on αSyn, helping the planning of future experiments on the interactions of this protein with targeting molecules especially taking into consideration the environmental conditions.
Collapse
Affiliation(s)
- Nicolò Bisi
- BioCIS, CNRS, Université Paris Saclay, Châtenay-Malabry Cedex, France
| | - Lucia Feni
- DISFARM-Dipartimento di Scienze Farmaceutiche, Sezione Chimica Generale e Organica "A. Marchesini", Università degli Studi di Milano, Milan, Italy
| | - Kaliroi Peqini
- DISFARM-Dipartimento di Scienze Farmaceutiche, Sezione Chimica Generale e Organica "A. Marchesini", Università degli Studi di Milano, Milan, Italy
| | - Helena Pérez-Peña
- Dipartimento di Chimica, Università degli Studi di Milano, Milan, Italy
| | - Sandrine Ongeri
- BioCIS, CNRS, Université Paris Saclay, Châtenay-Malabry Cedex, France
| | | | - Sara Pellegrino
- DISFARM-Dipartimento di Scienze Farmaceutiche, Sezione Chimica Generale e Organica "A. Marchesini", Università degli Studi di Milano, Milan, Italy
| |
Collapse
|
27
|
Shapiro DM, Ney M, Eghtesadi SA, Chilkoti A. Protein Phase Separation Arising from Intrinsic Disorder: First-Principles to Bespoke Applications. J Phys Chem B 2021; 125:6740-6759. [PMID: 34143622 DOI: 10.1021/acs.jpcb.1c01146] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The phase separation of biomolecules has become the focus of intense research in the past decade, with a growing body of research implicating this phenomenon in essentially all biological functions, including but not limited to homeostasis, stress responses, gene regulation, cell differentiation, and disease. Excellent reviews have been published previously on the underlying physical basis of liquid-liquid phase separation (LLPS) of biological molecules (Nat. Phys. 2015, 11, 899-904) and LLPS as it occurs natively in physiology and disease (Science 2017, 357, eaaf4382; Biochemistry 2018, 57, 2479-2487; Chem. Rev. 2014, 114, 6844-6879). Here, we review how the theoretical physical basis of LLPS has been used to better understand the behavior of biomolecules that undergo LLPS in natural systems and how this understanding has also led to the development of novel synthetic systems that exhibit biomolecular phase separation, and technologies that exploit these phenomena. In part 1 of this Review, we explore the theory behind the phase separation of biomolecules and synthetic macromolecules and introduce a few notable phase-separating biomolecules. In part 2, we cover experimental and computational methods used to study phase-separating proteins and how these techniques have uncovered the mechanisms underlying phase separation in physiology and disease. Finally, in part 3, we cover the development and applications of engineered phase-separating polypeptides, ranging from control of their self-assembly to create defined supramolecular architectures to reprogramming biological processes using engineered IDPs that exhibit LLPS.
Collapse
Affiliation(s)
- Daniel Mark Shapiro
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Max Ney
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Seyed Ali Eghtesadi
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Ashutosh Chilkoti
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| |
Collapse
|
28
|
Okumura H, Itoh SG, Nakamura K, Kawasaki T. Role of Water Molecules and Helix Structure Stabilization in the Laser-Induced Disruption of Amyloid Fibrils Observed by Nonequilibrium Molecular Dynamics Simulations. J Phys Chem B 2021; 125:4964-4976. [PMID: 33961416 DOI: 10.1021/acs.jpcb.0c11491] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Water plays a crucial role in the formation and destruction of biomolecular structures. The mechanism for destroying biomolecular structures was thought to be an active breaking of hydrogen bonds by water molecules. However, using nonequilibrium molecular dynamics simulations, in which an amyloid-β amyloid fibril was destroyed via infrared free-electron laser (IR-FEL) irradiation, we discovered a new mechanism, in which water molecules disrupt protein aggregates. The intermolecular hydrogen bonds formed by C═O and N-H in the fibril are broken at each pulse of laser irradiation. These bonds spontaneously re-form after the irradiation in many cases. However, when a water molecule happens to enter the gap between C═O and N-H, it inhibits the re-formation of the hydrogen bonds. Such sites become defects in the regularly aligned hydrogen bonds, from which all hydrogen bonds in the intermolecular β-sheet are broken as the fraying spreads. This role of water molecules is entirely different from other known mechanisms. This new mechanism can explain the recent experiments showing that the amyloid fibrils are not destroyed by laser irradiation under dry conditions. Additionally, we found that helix structures form more after the amyloid disruption; this is because the resonance frequency is different in a helix structure. Our findings provide a theoretical basis for the application of IR-FEL to the future treatment of amyloidosis.
Collapse
Affiliation(s)
- Hisashi Okumura
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan.,Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan.,Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan
| | - Satoru G Itoh
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan.,Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan.,Department of Structural Molecular Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan
| | - Kazuhiro Nakamura
- Department of Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma 371-8514, Japan
| | - Takayasu Kawasaki
- IR Free Electron Laser Research Center, Research Institute for Science and Technology, Organization for Research Advancement, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| |
Collapse
|
29
|
NMR unveils an N-terminal interaction interface on acetylated-α-synuclein monomers for recruitment to fibrils. Proc Natl Acad Sci U S A 2021; 118:2017452118. [PMID: 33903234 DOI: 10.1073/pnas.2017452118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Amyloid fibril formation of α-synuclein (αS) is associated with multiple neurodegenerative diseases, including Parkinson's disease (PD). Growing evidence suggests that progression of PD is linked to cell-to-cell propagation of αS fibrils, which leads to seeding of endogenous intrinsically disordered monomer via templated elongation and secondary nucleation. A molecular understanding of the seeding mechanism and driving interactions is crucial to inhibit progression of amyloid formation. Here, using relaxation-based solution NMR experiments designed to probe large complexes, we probe weak interactions of intrinsically disordered acetylated-αS (Ac-αS) monomers with seeding-competent Ac-αS fibrils and seeding-incompetent off-pathway oligomers to identify Ac-αS monomer residues at the binding interface. Under conditions that favor fibril elongation, we determine that the first 11 N-terminal residues on the monomer form a common binding site for both fibrils and off-pathway oligomers. Additionally, the presence of off-pathway oligomers within a fibril seeding environment suppresses seeded amyloid formation, as observed through thioflavin-T fluorescence experiments. This highlights that off-pathway αS oligomers can act as an auto-inhibitor against αS fibril elongation. Based on these data taken together with previous results, we propose a model in which Ac-αS monomer recruitment to the fibril is driven by interactions between the intrinsically disordered monomer N terminus and the intrinsically disordered flanking regions (IDR) on the fibril surface. We suggest that this monomer recruitment may play a role in the elongation of amyloid fibrils and highlight the potential of the IDRs of the fibril as important therapeutic targets against seeded amyloid formation.
Collapse
|
30
|
Amos SBA, Schwarz TC, Shi J, Cossins BP, Baker TS, Taylor RJ, Konrat R, Sansom MSP. Membrane Interactions of α-Synuclein Revealed by Multiscale Molecular Dynamics Simulations, Markov State Models, and NMR. J Phys Chem B 2021; 125:2929-2941. [PMID: 33719460 PMCID: PMC8006134 DOI: 10.1021/acs.jpcb.1c01281] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/01/2021] [Indexed: 01/30/2023]
Abstract
α-Synuclein (αS) is a presynaptic protein that binds to cell membranes and is linked to Parkinson's disease (PD). Binding of αS to membranes is a likely first step in the molecular pathophysiology of PD. The αS molecule can adopt multiple conformations, being largely disordered in water, adopting a β-sheet conformation when present in amyloid fibrils, and forming a dynamic multiplicity of α-helical conformations when bound to lipid bilayers and related membrane-mimetic surfaces. Multiscale molecular dynamics simulations in conjunction with nuclear magnetic resonance (NMR) and cross-linking mass spectrometry (XLMS) measurements are used to explore the interactions of αS with an anionic lipid bilayer. The simulations and NMR measurements together reveal a break in the helical structure of the central non-amyloid-β component (NAC) region of αS in the vicinity of residues 65-70, which may facilitate subsequent oligomer formation. Coarse-grained simulations of αS starting from the structure of αS when bound to a detergent micelle reveal the overall pattern of protein contacts to anionic lipid bilayers, while subsequent all-atom simulations provide details of conformational changes upon membrane binding. In particular, simulations and NMR data for liposome-bound αS indicate incipient β-strand formation in the NAC region, which is supported by intramolecular contacts seen via XLMS and simulations. Markov state models based on the all-atom simulations suggest a mechanism of conformational change of membrane-bound αS via a dynamic helix break in the region of residue 65 in the NAC region. The emergent dynamic model of membrane-interacting αS advances our understanding of the mechanism of PD, potentially aiding the design of novel therapeutic approaches.
Collapse
Affiliation(s)
- Sarah-Beth
T. A. Amos
- Department
of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Thomas C. Schwarz
- Department
of Structural and Computational
Biology, Max Perutz Laboratories, University
of Vienna, Campus Vienna
Biocenter 5, Vienna A-1030, Austria
| | - Jiye Shi
- UCB
Pharma, 208 Bath Road, Slough SL1 3WE, U.K.
| | | | | | | | - Robert Konrat
- Department
of Structural and Computational
Biology, Max Perutz Laboratories, University
of Vienna, Campus Vienna
Biocenter 5, Vienna A-1030, Austria
| | - Mark S. P. Sansom
- Department
of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| |
Collapse
|
31
|
Promotion and Inhibition of Amyloid-β Peptide Aggregation: Molecular Dynamics Studies. Int J Mol Sci 2021; 22:ijms22041859. [PMID: 33668406 PMCID: PMC7918115 DOI: 10.3390/ijms22041859] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 01/06/2023] Open
Abstract
Aggregates of amyloid-β (Aβ) peptides are known to be related to Alzheimer’s disease. Their aggregation is enhanced at hydrophilic–hydrophobic interfaces, such as a cell membrane surface and air-water interface, and is inhibited by polyphenols, such as myricetin and rosmarinic acid. We review molecular dynamics (MD) simulation approaches of a full-length Aβ peptide, Aβ40, and Aβ(16–22) fragments in these environments. Since these peptides have both hydrophilic and hydrophobic amino acid residues, they tend to exist at the interfaces. The high concentration of the peptides accelerates the aggregation there. In addition, Aβ40 forms a β-hairpin structure, and this structure accelerates the aggregation. We also describe the inhibition mechanism of the Aβ(16–22) aggregation by polyphenols. The aggregation of Aβ(16–22) fragments is caused mainly by the electrostatic attraction between charged amino acid residues known as Lys16 and Glu22. Since polyphenols form hydrogen bonds between their hydroxy and carboxyl groups and these charged amino acid residues, they inhibit the aggregation.
Collapse
|
32
|
Kakeshpour T, Ramanujam V, Barnes CA, Shen Y, Ying J, Bax A. A lowly populated, transient β-sheet structure in monomeric Aβ 1-42 identified by multinuclear NMR of chemical denaturation. Biophys Chem 2020; 270:106531. [PMID: 33453683 DOI: 10.1016/j.bpc.2020.106531] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/08/2020] [Accepted: 12/13/2020] [Indexed: 02/07/2023]
Abstract
Chemical denaturation is a well-established approach for probing the equilibrium between folded and unfolded states of proteins. We demonstrate applicability of this method to the detection of a small population of a transiently folded structural element in a system that is often considered to be intrinsically fully disordered. The 1HN, 15N, 13Cα, and 13C' chemical shifts of Aβ1-40 and Aβ1-42 peptides and their M35-oxidized variants were monitored as a function of urea concentration and compared to analogous urea titrations of synthetic pentapeptides of homologous sequence. Fitting of the chemical shift titrations yields a 10 ± 1% population for a structured element at the C-terminus of Aβ1-42 that folds with a cooperativity of m = 0.06 kcal/mol·M. The fit also yields the chemical shifts of the folded state and, using a database search, for Aβ1-42 these shifts identified an antiparallel intramolecular β-sheet for residues I32-A42, linked by a type I' β-turn at G37 and G38. The structure is destabilized by oxidation of M35. Paramagnetic relaxation rates and two previously reported weak, medium-range NOE interactions are consistent with this transient β-sheet. Introduction of the requisite A42C mutation and tagging with MTSL resulted in a small stabilization of this β-sheet. Chemical shift analysis suggests a C-terminal β-sheet may be present in Aβ1-40 too, but the turn type at G37 is not type I'. The approach to derive Transient Structure from chemical Denaturation by NMR (TSD-NMR), demonstrated here for Aβ peptides, provides a sensitive tool for identifying the presence of lowly populated, transiently ordered elements in proteins that are considered to be intrinsically disordered, and permits extraction of structural data for such elements.
Collapse
Affiliation(s)
- Tayeb Kakeshpour
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Venkat Ramanujam
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - C Ashley Barnes
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Yang Shen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Jinfa Ying
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
| |
Collapse
|
33
|
Jain K, Ghribi O, Delhommelle J. Folding Free-Energy Landscape of α-Synuclein (35-97) Via Replica Exchange Molecular Dynamics. J Chem Inf Model 2020; 61:432-443. [PMID: 33350818 DOI: 10.1021/acs.jcim.0c01278] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The misfolding and aggregation of α-synuclein (α-syn) in Lewy bodies are implicated in the pathogenesis of various neurodegenerative disorders, such as Parkinson's disease and dementia. The formation of α-syn fibrils is a complex process, involving various intermediates and oligomeric forms. These intermediates establish at an early stage of aggregation and subsequently lead to fibrillation. Determining which conformations are accessible to monomeric α-syn and especially, as shown in a recent work, to the central amino acids from residue 35 to residue 97 (63 residues) is thus crucial to understand the formation of these oligomers. Here, we carry out extensive replica exchange molecular dynamics (total time-18 μs) with an all-atom model and explicit solvent to characterize the free-energy landscape of human α-syn (residue 35 to residue 97). The simulation results lead us to identify two free-energy basins. Clustering analysis for the deepest free-energy minimum reveals a compact structure, with a secondary structure predominantly α-helix, while the shallower minimum corresponds to an elongated conformation, also predominantly α-helix. Furthermore, at physiological temperature, we find that conformational rearrangements happen via helix breaks due to the presence of glycine. We also show that the most likely conformations are characterized by the α-helix structure rather than the β-hairpin structure (for residue 38 to residue 53), in contrast with prior simulation studies using coarse-grained models or an implicit solvent. For higher temperatures, we observe a shift in secondary structure with a decrease in the population of α-helix in favor of random coils, β-bend, and β-turns.
Collapse
Affiliation(s)
- Karnesh Jain
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Othman Ghribi
- Department of Biomedical Sciences, School of Medicine & Health Sciences, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Jerome Delhommelle
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| |
Collapse
|
34
|
Abstract
Self-assembly of proteins and peptides into the amyloid fold is a widespread phenomenon in the natural world. The structural hallmark of self-assembly into amyloid fibrillar assemblies is the cross-beta motif, which conveys distinct morphological and mechanical properties. The amyloid fibril formation has contrasting results depending on the organism, in the sense that it can bestow an organism with the advantages of mechanical strength and improved functionality or, on the contrary, could give rise to pathological states. In this chapter we review the existing information on amyloid-like peptide aggregates, which could either be derived from protein sequences, but also could be rationally or de novo designed in order to self-assemble into amyloid fibrils under physiological conditions. Moreover, the development of self-assembled fibrillar biomaterials that are tailored for the desired properties towards applications in biomedical or environmental areas is extensively analyzed. We also review computational studies predicting the amyloid propensity of the natural amino acid sequences and the structure of amyloids, as well as designing novel functional amyloid materials.
Collapse
Affiliation(s)
- C. Kokotidou
- University of Crete, Department of Materials Science and Technology Voutes Campus GR-70013 Heraklion Crete Greece
- FORTH, Institute for Electronic Structure and Laser N. Plastira 100 GR 70013 Heraklion Greece
| | - P. Tamamis
- Texas A&M University, Artie McFerrin Department of Chemical Engineering College Station Texas 77843-3122 USA
| | - A. Mitraki
- University of Crete, Department of Materials Science and Technology Voutes Campus GR-70013 Heraklion Crete Greece
- FORTH, Institute for Electronic Structure and Laser N. Plastira 100 GR 70013 Heraklion Greece
| |
Collapse
|
35
|
Capturing the Conformational Ensemble of the Mixed Folded Polyglutamine Protein Ataxin-3. Structure 2020; 29:70-81.e5. [PMID: 33065068 DOI: 10.1016/j.str.2020.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/22/2020] [Accepted: 09/24/2020] [Indexed: 01/31/2023]
Abstract
Ataxin-3 is a deubiquitinase involved in protein quality control and other essential cellular functions. It preferentially interacts with polyubiquitin chains of four or more units attached to proteins delivered to the ubiquitin-proteasome system. Ataxin-3 is composed of an N-terminal Josephin domain and a flexible C terminus that contains two or three ubiquitin-interacting motifs (UIMs) and a polyglutamine tract, which, when expanded beyond a threshold, leads to protein aggregation and misfolding and causes spinocerebellar ataxia type 3. The high-resolution structure of the Josephin domain is available, but the structural and dynamical heterogeneity of ataxin-3 has so far hindered the structural description of the full-length protein. Here, we characterize non-expanded and expanded variants of ataxin-3 in terms of conformational ensembles adopted by the proteins in solution by jointly using experimental data from nuclear magnetic resonance and small-angle X-ray scattering with coarse-grained simulations. Our results pave the way to a molecular understanding of polyubiquitin recognition.
Collapse
|
36
|
Kiechle M, Grozdanov V, Danzer KM. The Role of Lipids in the Initiation of α-Synuclein Misfolding. Front Cell Dev Biol 2020; 8:562241. [PMID: 33042996 PMCID: PMC7523214 DOI: 10.3389/fcell.2020.562241] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/26/2020] [Indexed: 01/06/2023] Open
Abstract
The aggregation of α-synuclein (α-syn) is inseparably connected to Parkinson’s disease (PD). It is now well-established that certain forms of α-syn aggregates, oligomers and fibrils, can exert neurotoxicity in synucleinopathies. With the exception of rare familial forms, the vast majority of PD cases are idiopathic. Understanding the earliest molecular mechanisms that cause initial α-syn misfolding could help to explain why PD affects only some individuals and others not. Factors that chaperone the transition of α-syn’s physiological to pathological function are of particular interest, since they offer opportunities for intervention. The relationship between α-syn and lipids represents one of those factors. Membrane interaction is crucial for normal cellular function, but lipids also induce the aggregation of α-syn, causing cell toxicity. Also, disease-causing or risk-factor mutations in genes related to lipid metabolism like PLA2G6, SCARB2 or GBA1 highlight the close connection between PD and lipids. Despite the clear link, the ambivalent interaction has not been studied sufficiently so far. In this review, we address how α-syn interacts with lipids and how they can act as key factor for orchestrating toxic conversion of α-syn. Furthermore, we will discuss a scenario in which initial α-syn aggregation is determined by shifts in lipid/α-syn ratio as well as by dyshomeostasis of membrane bound/unbound state of α-syn.
Collapse
|
37
|
Michaels TCT, Šarić A, Curk S, Bernfur K, Arosio P, Meisl G, Dear AJ, Cohen SIA, Dobson CM, Vendruscolo M, Linse S, Knowles TPJ. Dynamics of oligomer populations formed during the aggregation of Alzheimer's Aβ42 peptide. Nat Chem 2020; 12:445-451. [PMID: 32284577 DOI: 10.1038/s41557-020-0452-1] [Citation(s) in RCA: 179] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 03/02/2020] [Indexed: 01/10/2023]
Abstract
Oligomeric species populated during the aggregation of the Aβ42 peptide have been identified as potent cytotoxins linked to Alzheimer's disease, but the fundamental molecular pathways that control their dynamics have yet to be elucidated. By developing a general approach that combines theory, experiment and simulation, we reveal, in molecular detail, the mechanisms of Aβ42 oligomer dynamics during amyloid fibril formation. Even though all mature amyloid fibrils must originate as oligomers, we found that most Aβ42 oligomers dissociate into their monomeric precursors without forming new fibrils. Only a minority of oligomers converts into fibrillar structures. Moreover, the heterogeneous ensemble of oligomeric species interconverts on timescales comparable to those of aggregation. Our results identify fundamentally new steps that could be targeted by therapeutic interventions designed to combat protein misfolding diseases.
Collapse
Affiliation(s)
- Thomas C T Michaels
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK.,Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
| | - Andela Šarić
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London, UK.,MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Samo Curk
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London, UK.,MRC Laboratory for Molecular Cell Biology, University College London, London, UK.,Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Katja Bernfur
- Department of Chemistry, Division for Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | - Paolo Arosio
- Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Georg Meisl
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Alexander J Dear
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK.,Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
| | - Samuel I A Cohen
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Christopher M Dobson
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK.
| | - Sara Linse
- Department of Chemistry, Division for Biochemistry and Structural Biology, Lund University, Lund, Sweden.
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK. .,Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| |
Collapse
|
38
|
Cholak E, Bugge K, Khondker A, Gauger K, Pedraz-Cuesta E, Pedersen ME, Bucciarelli S, Vestergaard B, Pedersen SF, Rheinstädter MC, Langkilde AE, Kragelund BB. Avidity within the N-terminal anchor drives α-synuclein membrane interaction and insertion. FASEB J 2020; 34:7462-7482. [PMID: 32277854 DOI: 10.1096/fj.202000107r] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/02/2020] [Accepted: 03/17/2020] [Indexed: 12/25/2022]
Abstract
In the brain, α-synuclein (aSN) partitions between free unbound cytosolic and membrane bound forms modulating both its physiological and pathological role and complicating its study due to structural heterogeneity. Here, we use an interdisciplinary, synergistic approach to characterize the properties of aSN:lipid mixtures, isolated aSN:lipid co-structures, and aSN in mammalian cells. Enabled by the isolation of the membrane-bound state, we show that within the previously described N-terminal membrane anchor, membrane interaction relies both on an N-terminal tail (NTT) head group layer insertion of 14 residues and a folded-upon-binding helix at the membrane surface. Both binding events must be present; if, for example, the NTT insertion is lost, the membrane affinity of aSN is severely compromised and formation of aSN:lipid co-structures hampered. In mammalian cells, compromised cooperativity results in lowered membrane association. Thus, avidity within the N-terminal anchor couples N-terminal insertion and helical surface binding, which is crucial for aSN membrane interaction and cellular localization, and may affect membrane fusion.
Collapse
Affiliation(s)
- Ersoy Cholak
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Bugge
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science and Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Kimmie Gauger
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Elena Pedraz-Cuesta
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Saskia Bucciarelli
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Bente Vestergaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Stine F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Annette Eva Langkilde
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science and Department of Biology, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
39
|
Mariño L, Ramis R, Casasnovas R, Ortega-Castro J, Vilanova B, Frau J, Adrover M. Unravelling the effect of N(ε)-(carboxyethyl)lysine on the conformation, dynamics and aggregation propensity of α-synuclein. Chem Sci 2020; 11:3332-3344. [PMID: 34122841 PMCID: PMC8157327 DOI: 10.1039/d0sc00906g] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
α-Synuclein (αS) aggregation is a hallmark in several neurodegenerative diseases. Among them, Parkinson's disease is highlighted, characterized by the intraneuronal deposition of Lewy bodies (LBs) which causes the loss of dopaminergic neurons. αS is the main component of LBs and in them, it usually contains post-translational modifications. One of them is the formation of advanced glycation end-products (mainly CEL and MOLD) arising from its reaction with methylglyoxal. Despite its biological relevance, there are no data available proving the effect of glycation on the conformation of αS, nor on its aggregation mechanism. This has been hampered by the formation of a heterogeneous set of compounds that precluded conformational studies. To overcome this issue, we have here produced αS homogeneously glycated with CEL. Its use, together with different biophysical techniques and molecular dynamics simulations, allowed us to study for the first time the effect of glycation on the conformation of a protein. CEL extended the conformation of the N-terminal domain as a result of the loss of transient N-/C-terminal long-range contacts while increasing the heterogeneity of the conformational population. CEL also inhibited the αS aggregation, but it was not able to disassemble preexisting amyloid fibrils, thus proving that CEL found on LBs must be formed in a later event after aggregation. We study the effect of an advanced glycation end product (N(ε)-(carboxyethyl)lysine), found on the Lewy bodies of people suffering from Parkinson’s disease, on the conformational and aggregation features of alpha-synuclein.![]()
Collapse
Affiliation(s)
- Laura Mariño
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut d'Investigació Sanitària Illes Balears (IdISBa), Departament de Química, Universitat de les Illes Balears Ctra. Valldemossa km 7.5 E-07122 Palma de Mallorca Spain +34 971 173426 +34 971 173491
| | - Rafael Ramis
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut d'Investigació Sanitària Illes Balears (IdISBa), Departament de Química, Universitat de les Illes Balears Ctra. Valldemossa km 7.5 E-07122 Palma de Mallorca Spain +34 971 173426 +34 971 173491
| | - Rodrigo Casasnovas
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut d'Investigació Sanitària Illes Balears (IdISBa), Departament de Química, Universitat de les Illes Balears Ctra. Valldemossa km 7.5 E-07122 Palma de Mallorca Spain +34 971 173426 +34 971 173491
| | - Joaquín Ortega-Castro
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut d'Investigació Sanitària Illes Balears (IdISBa), Departament de Química, Universitat de les Illes Balears Ctra. Valldemossa km 7.5 E-07122 Palma de Mallorca Spain +34 971 173426 +34 971 173491
| | - Bartolomé Vilanova
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut d'Investigació Sanitària Illes Balears (IdISBa), Departament de Química, Universitat de les Illes Balears Ctra. Valldemossa km 7.5 E-07122 Palma de Mallorca Spain +34 971 173426 +34 971 173491
| | - Juan Frau
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut d'Investigació Sanitària Illes Balears (IdISBa), Departament de Química, Universitat de les Illes Balears Ctra. Valldemossa km 7.5 E-07122 Palma de Mallorca Spain +34 971 173426 +34 971 173491
| | - Miquel Adrover
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut d'Investigació Sanitària Illes Balears (IdISBa), Departament de Química, Universitat de les Illes Balears Ctra. Valldemossa km 7.5 E-07122 Palma de Mallorca Spain +34 971 173426 +34 971 173491
| |
Collapse
|
40
|
Doherty CPA, Ulamec SM, Maya-Martinez R, Good SC, Makepeace J, Khan GN, van Oosten-Hawle P, Radford SE, Brockwell DJ. A short motif in the N-terminal region of α-synuclein is critical for both aggregation and function. Nat Struct Mol Biol 2020; 27:249-259. [PMID: 32157247 PMCID: PMC7100612 DOI: 10.1038/s41594-020-0384-x] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 01/22/2020] [Indexed: 02/04/2023]
Abstract
Aggregation of human α-synuclein (αSyn) is linked to Parkinson’s disease (PD) pathology. The central region of the αSyn sequence contains the non-amyloid β-component (NAC) crucial for aggregation. However, how NAC flanking regions modulate αSyn aggregation remains unclear. Using bioinformatics, mutation, and NMR we identify a 7-residue sequence, named P1 (residues 36-42), that controls αSyn aggregation. Deletion or substitution of this ‘master-controller’ prevents aggregation at pH 7.5 in vitro. At lower pH, P1 synergises with a sequence containing the PreNAC region (P2, residues 45-57) to prevent aggregation. Deleting P1 (ΔP1) or both P1 and P2 (ΔΔ) also prevents age-dependent αSyn aggregation and toxicity in C. elegans models and prevents αSyn-mediated vesicle fusion by altering the conformational properties of the protein when lipid-bound. The results highlight the importance of a master-controller sequence motif that controls both αSyn aggregation and function- a region that could be targeted to prevent aggregation in disease.
Collapse
Affiliation(s)
- Ciaran P A Doherty
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Sabine M Ulamec
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Roberto Maya-Martinez
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Sarah C Good
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Jemma Makepeace
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - G Nasir Khan
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Patricija van Oosten-Hawle
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom.
| | - David J Brockwell
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom.
| |
Collapse
|
41
|
Dynamic conformational flexibility and molecular interactions of intrinsically disordered proteins. J Biosci 2020. [DOI: 10.1007/s12038-020-0010-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
42
|
Entropy and Information within Intrinsically Disordered Protein Regions. ENTROPY 2019; 21:e21070662. [PMID: 33267376 PMCID: PMC7515160 DOI: 10.3390/e21070662] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 02/06/2023]
Abstract
Bioinformatics and biophysical studies of intrinsically disordered proteins and regions (IDRs) note the high entropy at individual sequence positions and in conformations sampled in solution. This prevents application of the canonical sequence-structure-function paradigm to IDRs and motivates the development of new methods to extract information from IDR sequences. We argue that the information in IDR sequences cannot be fully revealed through positional conservation, which largely measures stable structural contacts and interaction motifs. Instead, considerations of evolutionary conservation of molecular features can reveal the full extent of information in IDRs. Experimental quantification of the large conformational entropy of IDRs is challenging but can be approximated through the extent of conformational sampling measured by a combination of NMR spectroscopy and lower-resolution structural biology techniques, which can be further interpreted with simulations. Conformational entropy and other biophysical features can be modulated by post-translational modifications that provide functional advantages to IDRs by tuning their energy landscapes and enabling a variety of functional interactions and modes of regulation. The diverse mosaic of functional states of IDRs and their conformational features within complexes demands novel metrics of information, which will reflect the complicated sequence-conformational ensemble-function relationship of IDRs.
Collapse
|
43
|
Ferrie JJ, Haney CM, Yoon J, Pan B, Lin YC, Fakhraai Z, Rhoades E, Nath A, Petersson EJ. Using a FRET Library with Multiple Probe Pairs To Drive Monte Carlo Simulations of α-Synuclein. Biophys J 2019; 114:53-64. [PMID: 29320696 DOI: 10.1016/j.bpj.2017.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/21/2017] [Accepted: 11/06/2017] [Indexed: 01/24/2023] Open
Abstract
We describe a strategy for experimentally-constraining computational simulations of intrinsically disordered proteins (IDPs), using α-synuclein, an IDP with a central role in Parkinson's disease pathology, as an example. Previously, data from single-molecule Förster Resonance Energy Transfer (FRET) experiments have been effectively utilized to generate experimentally constrained computational models of IDPs. However, the fluorophores required for single-molecule FRET experiments are not amenable to the study of short-range (<30 Å) interactions. Using ensemble FRET measurements allows one to acquire data from probes with multiple distance ranges, which can be used to constrain Monte Carlo simulations in PyRosetta. To appropriately employ ensemble FRET data as constraints, we optimized the shape and weight of constraining potentials to afford ensembles of structures that are consistent with experimental data. We also used this approach to examine the structure of α-synuclein in the presence of the compacting osmolyte trimethylamine-N-oxide. Despite significant compaction imparted by 2 M trimethylamine-N-oxide, the underlying ensemble of α-synuclein remains largely disordered and capable of aggregation, also in agreement with experimental data. These proof-of-concept experiments demonstrate that our modeling protocol enables one to efficiently generate experimentally constrained models of IDPs that incorporate atomic-scale detail, allowing one to study an IDP under a variety of conditions.
Collapse
Affiliation(s)
- John J Ferrie
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Conor M Haney
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jimin Yoon
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Buyan Pan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yi-Chih Lin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zahra Fakhraai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth Rhoades
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Abhinav Nath
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, Washington
| | - E James Petersson
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania.
| |
Collapse
|
44
|
Arya S, Singh AK, Bhasne K, Dogra P, Datta A, Das P, Mukhopadhyay S. Femtosecond Hydration Map of Intrinsically Disordered α-Synuclein. Biophys J 2019; 114:2540-2551. [PMID: 29874605 DOI: 10.1016/j.bpj.2018.04.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 10/14/2022] Open
Abstract
Protein hydration water plays a fundamentally important role in protein folding, binding, assembly, and function. Little is known about the hydration water in intrinsically disordered proteins that challenge the conventional sequence-structure-function paradigm. Here, by combining experiments and simulations, we show the existence of dynamical heterogeneity of hydration water in an intrinsically disordered presynaptic protein, namely α-synuclein, implicated in Parkinson's disease. We took advantage of nonoccurrence of cysteine in the sequence and incorporated a number of cysteine residues at the N-terminal segment, the central amyloidogenic nonamyloid-β component (NAC) domain, and the C-terminal end of α-synuclein. We then labeled these cysteine variants using environment-sensitive thiol-active fluorophore and monitored the solvation dynamics using femtosecond time-resolved fluorescence. The site-specific femtosecond time-resolved experiments allowed us to construct the hydration map of α-synuclein. Our results show the presence of three dynamically distinct types of water: bulk, hydration, and confined water. The amyloidogenic NAC domain contains dynamically restrained water molecules that are strikingly different from the water molecules present in the other two domains. Atomistic molecular dynamics simulations revealed longer residence times for water molecules near the NAC domain and supported our experimental observations. Additionally, our simulations allowed us to decipher the molecular origin of the dynamical heterogeneity of water in α-synuclein. These simulations captured the quasi-bound water molecules within the NAC domain originating from a complex interplay between the local chain compaction and the sequence composition. Our findings from this synergistic experimental simulation approach suggest longer trapping of interfacial water molecules near the amyloidogenic hotspot that triggers the pathological conversion into amyloids via chain sequestration, chain desolvation, and entropic liberation of ordered water molecules.
Collapse
Affiliation(s)
- Shruti Arya
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India
| | - Avinash K Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Karishma Bhasne
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India
| | - Priyanka Dogra
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India
| | - Anindya Datta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India.
| | - Payel Das
- Data Science Department, IBM Thomas J. Watson Research Center, Yorktown Heights, New York.
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India.
| |
Collapse
|
45
|
Ilie IM, Caflisch A. Simulation Studies of Amyloidogenic Polypeptides and Their Aggregates. Chem Rev 2019; 119:6956-6993. [DOI: 10.1021/acs.chemrev.8b00731] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Ioana M. Ilie
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
| |
Collapse
|
46
|
Brodie NI, Popov KI, Petrotchenko EV, Dokholyan NV, Borchers CH. Conformational ensemble of native α-synuclein in solution as determined by short-distance crosslinking constraint-guided discrete molecular dynamics simulations. PLoS Comput Biol 2019; 15:e1006859. [PMID: 30917118 PMCID: PMC6453469 DOI: 10.1371/journal.pcbi.1006859] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 04/08/2019] [Accepted: 02/08/2019] [Indexed: 12/01/2022] Open
Abstract
Combining structural proteomics experimental data with computational methods is a powerful tool for protein structure prediction. Here, we apply a recently-developed approach for de novo protein structure determination based on the incorporation of short-distance crosslinking data as constraints in discrete molecular dynamics simulations (CL-DMD) for the determination of conformational ensemble of the intrinsically disordered protein α-synuclein in the solution. The predicted structures were in agreement with hydrogen-deuterium exchange, circular dichroism, surface modification, and long-distance crosslinking data. We found that α-synuclein is present in solution as an ensemble of rather compact globular conformations with distinct topology and inter-residue contacts, which is well-represented by movements of the large loops and formation of few transient secondary structure elements. Non-amyloid component and C-terminal regions were consistently found to contain β-structure elements and hairpins. As the population ages, neurodegenerative diseases such as Parkinson’s disease will become an increasing problem in many countries. Aggregation of the protein α-synuclein is the primary cause of Parkinson’s disease, but there is still a dearth of structural information pertaining to the native, non-aggregating form of this protein. A better understanding the structural state of the native protein may prove useful for the design of new therapeutics to combat this disease. In order to obtain more structural information on this protein, we have recently modelled the native α-synuclein protein. These models were generated using a novel approach which combines protein crosslinking and discrete molecular dynamics simulations. We have found that the α-synuclein protein can adopt several shapes, all with a similar topology, resembling a three fingered closed claw. A region of the protein important for aggregation was found to be protected from the surrounding biological environment in these conformations, and the stabilization of these structures may be a fruitful avenue for future drug research into mitigating the cause and effect of Parkinson’s disease.
Collapse
Affiliation(s)
- Nicholas I. Brodie
- University of Victoria -Genome British Columbia Proteomics Centre, Vancouver Island Technology Park, Victoria, British Columbia, Canada
| | - Konstantin I. Popov
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Evgeniy V. Petrotchenko
- University of Victoria -Genome British Columbia Proteomics Centre, Vancouver Island Technology Park, Victoria, British Columbia, Canada
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Quebec, Canada
| | - Nikolay V. Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Departments of Pharmacology, and Biochemistry and Molecular Biology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, United States of America
- * E-mail: (NVD); (CHB)
| | - Christoph H. Borchers
- University of Victoria -Genome British Columbia Proteomics Centre, Vancouver Island Technology Park, Victoria, British Columbia, Canada
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Quebec, Canada
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
- Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University, Montreal, Quebec, Canada
- * E-mail: (NVD); (CHB)
| |
Collapse
|
47
|
Maiti S, Acharya B, Boorla VS, Manna B, Ghosh A, De S. Dynamic Studies on Intrinsically Disordered Regions of Two Paralogous Transcription Factors Reveal Rigid Segments with Important Biological Functions. J Mol Biol 2019; 431:1353-1369. [PMID: 30802457 DOI: 10.1016/j.jmb.2019.02.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/31/2019] [Accepted: 02/15/2019] [Indexed: 10/27/2022]
Abstract
Long stretches of intrinsically disordered regions (IDRs) are abundantly present in eukaryotic transcription factors. Although their biological significance is well appreciated, the underlying structural and dynamic mechanisms of their function are still not clear. Using solution NMR spectroscopy, we have studied the structural and dynamic features of two paralogous HOX transcription factors, SCR and DFD, from Drosophila. Both proteins have a conserved DNA-binding homeodomain and a long stretch of functionally important IDR. Using NMR dynamics, we determined flexibility of each residue in these proteins. The flexibility of the residues in the disordered region is not uniform. In both proteins, the IDRs have short stretches of consecutive residues with relatively less flexibility, that is, higher rigidity. We show that one such rigid segment is specifically recognized by another co-transcription factor, thus highlighting the importance of these rigid segments in IDR-mediated protein-protein interactions. Using molecular dynamics simulation, we further show that the rigid segments sample less conformations compared to the rest of the residues in the disordered region. The restrained conformational sampling of these rigid residues should lower the loss in conformational entropy during their interactions with binding partners resulting in sequence specific binding. This work provides experimental evidence of a "rigid-segment" model of IDRs, where functionally important rigid segments are connected by highly flexible linkers. Furthermore, a comparative study of IDRs in paralogous proteins reveals that in spite of low-sequence conservation, the rigid and flexible segments are sequentially maintained to preserve related functions and regulations of these proteins.
Collapse
Affiliation(s)
- Snigdha Maiti
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Bidisha Acharya
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Veda Sheersh Boorla
- Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Bharat Manna
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Amit Ghosh
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Soumya De
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.
| |
Collapse
|
48
|
Sciolino N, Burz DS, Shekhtman A. In-Cell NMR Spectroscopy of Intrinsically Disordered Proteins. Proteomics 2019; 19:e1800055. [PMID: 30489014 DOI: 10.1002/pmic.201800055] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/29/2018] [Indexed: 01/14/2023]
Abstract
This review summarizes the results of in-cell Nuclear Magnetic Resonance, NMR, spectroscopic investigations of the eukaryotic and prokaryotic intrinsically disordered proteins, IDPs: α-synuclein, prokaryotic ubiquitin-like protein, Pup, tubulin-related neuronal protein, Tau, phenylalanyl-glycyl-repeat-rich nucleoporins, FG Nups, and the negative regulator of flagellin synthesis, FlgM. The results show that the cellular behavior of IDPs may differ significantly from that observed in the test tube.
Collapse
Affiliation(s)
- Nicholas Sciolino
- Department of Chemistry, University at Albany, State University of New York, Albany, NY, 12222, USA
| | - David S Burz
- Department of Chemistry, University at Albany, State University of New York, Albany, NY, 12222, USA
| | - Alexander Shekhtman
- Department of Chemistry, University at Albany, State University of New York, Albany, NY, 12222, USA
| |
Collapse
|
49
|
Wu H, Wolynes PG, Papoian GA. AWSEM-IDP: A Coarse-Grained Force Field for Intrinsically Disordered Proteins. J Phys Chem B 2018; 122:11115-11125. [PMID: 30091924 PMCID: PMC6713210 DOI: 10.1021/acs.jpcb.8b05791] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The associative memory, water-mediated, structure and energy model (AWSEM) has been successfully used to study protein folding, binding, and aggregation problems. In this work, we introduce AWSEM-IDP, a new AWSEM branch for simulating intrinsically disordered proteins (IDPs), where the weights of the potentials determining secondary structure formation have been finely tuned, and a novel potential is introduced that helps to precisely control both the average extent of protein chain collapse and the chain's fluctuations in size. AWSEM-IDP can efficiently sample large conformational spaces, while retaining sufficient molecular accuracy to realistically model proteins. We applied this new model to two IDPs, demonstrating that AWSEM-IDP can reasonably well reproduce higher-resolution reference data, thus providing the foundation for a transferable IDP force field. Finally, we used thermodynamic perturbation theory to show that, in general, the conformational ensembles of IDPs are highly sensitive to fine-tuning of force field parameters.
Collapse
Affiliation(s)
- Hao Wu
- Biophysics Program, Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, United States
| | - Peter G. Wolynes
- Departments of Chemistry and Physics and Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
| | - Garegin A. Papoian
- Biophysics Program, Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, United States
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| |
Collapse
|
50
|
Milles S, Salvi N, Blackledge M, Jensen MR. Characterization of intrinsically disordered proteins and their dynamic complexes: From in vitro to cell-like environments. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 109:79-100. [PMID: 30527137 DOI: 10.1016/j.pnmrs.2018.07.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/16/2018] [Accepted: 07/16/2018] [Indexed: 05/08/2023]
Abstract
Over the last two decades, it has become increasingly clear that a large fraction of the human proteome is intrinsically disordered or contains disordered segments of significant length. These intrinsically disordered proteins (IDPs) play important regulatory roles throughout biology, underlining the importance of understanding their conformational behavior and interaction mechanisms at the molecular level. Here we review recent progress in the NMR characterization of the structure and dynamics of IDPs in various functional states and environments. We describe the complementarity of different NMR parameters for quantifying the conformational propensities of IDPs in their isolated and phosphorylated states, and we discuss the challenges associated with obtaining structural models of dynamic protein-protein complexes involving IDPs. In addition, we review recent progress in understanding the conformational behavior of IDPs in cell-like environments such as in the presence of crowding agents, in membrane-less organelles and in the complex environment of the human cell.
Collapse
Affiliation(s)
- Sigrid Milles
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
| | - Nicola Salvi
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
| | | | | |
Collapse
|