1
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Sarma S, Sudarshan TR, Nguyen V, Robang AS, Xiao X, Le JV, Helmicki ME, Paravastu AK, Hall CK. Design of parallel 𝛽-sheet nanofibrils using Monte Carlo search, coarse-grained simulations, and experimental testing. Protein Sci 2024; 33:e5102. [PMID: 39037281 PMCID: PMC11261811 DOI: 10.1002/pro.5102] [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: 11/10/2023] [Revised: 06/20/2024] [Accepted: 06/22/2024] [Indexed: 07/23/2024]
Abstract
Peptide self-assembly into amyloid fibrils provides numerous applications in drug delivery and biomedical engineering applications. We augment our previously-established computational screening technique along with experimental biophysical characterization to discover 7-mer peptides that self-assemble into "parallel β-sheets", that is, β-sheets with N-terminus-to-C-terminus 𝛽-strand vectors oriented in parallel. To accomplish the desired β-strand organization, we applied the PepAD amino acid sequence design software to the Class-1 cross-β spine defined by Sawaya et al. This molecular configuration includes two layers of parallel β-sheets stacked such that N-terminus-to-C-terminus vectors are oriented antiparallel for molecules on adjacent β-sheets. The first cohort of PepAD identified peptides were examined for their fibrillation behavior in DMD/PRIME20 simulations, and the top performing sequence was selected as a prototype for a subsequent round of sequence refinement. The two rounds of design resulted in a library of eight 7-mer peptides. In DMD/PRIME20 simulations, five of these peptides spontaneously formed fibril-like structures with a predominantly parallel 𝛽-sheet arrangement, two formed fibril-like structure with <50% in parallel 𝛽-sheet arrangement and one remained a random coil. Among the eight candidate peptides produced by PepAD and DMD/PRIME20, five were synthesized and purified. All five assembled into amyloid fibrils composed of parallel β-sheets based on Fourier transform infrared spectroscopy, circular dichroism, electron microscopy, and thioflavin-T fluorescence spectroscopy measurements.
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Affiliation(s)
- Sudeep Sarma
- Department of Chemical and Biomolecular EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Tarunya Rao Sudarshan
- Department of Chemical and Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Van Nguyen
- Department of Chemical and Biomolecular EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Alicia S. Robang
- Department of Chemical and Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Xingqing Xiao
- Department of Chemical and Biomolecular EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA
- Present address:
Department of Chemistry, School of Chemistry and Chemical EngineeringHainan UniversityHaikou CityHainan ProvincePeople's Republic of China
| | - Justin V. Le
- Department of Chemical and Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Michael E. Helmicki
- Department of Chemical and Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Anant K. Paravastu
- Department of Chemical and Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Carol K. Hall
- Department of Chemical and Biomolecular EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA
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2
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Robang A, Wong KM, Leisen J, Liu R, Radford WL, Rao Sudarshan T, Hudalla GA, Paravastu AK. Parallel β-Sheet Structure and Structural Heterogeneity Detected within Q11 Self-Assembling Peptide Nanofibers. J Phys Chem B 2024; 128:5387-5396. [PMID: 38787393 PMCID: PMC11163420 DOI: 10.1021/acs.jpcb.4c00825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 04/26/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024]
Abstract
Q11 peptide nanofibers are used as a biomaterial for applications such as antigen presentation and tissue engineering, yet detailed knowledge of molecular-level structure has not been reported. The Q11 peptide sequence was designed using heuristics-based patterning of hydrophobic and polar amino acids with oppositely charged amino acids placed at opposite ends of the sequence to promote antiparallel β-sheet formation. In this work, we employed solid-state nuclear magnetic resonance spectroscopy (NMR) to evaluate whether the molecular organization within Q11 self-assembled peptide nanofibers is consistent with the expectations of the peptide designers. We discovered that Q11 forms a distribution of molecular structures. NMR data from two-dimensional (2D) 13C-13C dipolar-assisted rotational resonance indicate that the K3 and E9 residues between Q11 β-strands are spatially proximate (within ∼0.6 nm). Frequency-selective rotational echo double resonance (fsREDOR) on K3 Nζ and E9 Cδ-labeled sites showed that approximately 9% of the sites are close enough for salt bridge formation to occur. Surprisingly, dipolar recoupling measurements revealed that Q11 peptides do not assemble into antiparallel β-sheets as expected, and structural analysis using Fourier-transform infrared spectroscopy and 2D NMR alone can be misleading. 13C PITHIRDS-CT dipolar recoupling measurements showed that the most abundant structure consists of parallel β-sheets, in contrast to the expected antiparallel β-sheet structure. Structural heterogeneity was detected from 15N{13C} REDOR measurements, with approximately 22% of β-strands having antiparallel nearest neighbors. We cannot propose a complete structural model of Q11 nanofibers because of the complexity involved when examining structurally heterogeneous samples using NMR. Altogether, our results show that while heuristics-based patterning is effective in promoting β-sheet formation, designing a peptide sequence to form a targeted β-strand arrangement remains challenging.
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Affiliation(s)
- Alicia
S. Robang
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Kong M. Wong
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Johannes Leisen
- School
of Chemistry & Biochemistry, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Renjie Liu
- J. Crayton
Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - Walker L. Radford
- School
of Chemistry & Biochemistry, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Tarunya Rao Sudarshan
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Gregory A. Hudalla
- J. Crayton
Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - Anant K. Paravastu
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Parker
H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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3
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Paul S, Jeništová A, Vosough F, Berntsson E, Mörman C, Jarvet J, Gräslund A, Wärmländer SKTS, Barth A. 13C- and 15N-labeling of amyloid-β and inhibitory peptides to study their interaction via nanoscale infrared spectroscopy. Commun Chem 2023; 6:163. [PMID: 37537303 PMCID: PMC10400569 DOI: 10.1038/s42004-023-00955-w] [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: 11/22/2022] [Accepted: 07/06/2023] [Indexed: 08/05/2023] Open
Abstract
Interactions between molecules are fundamental in biology. They occur also between amyloidogenic peptides or proteins that are associated with different amyloid diseases, which makes it important to study the mutual influence of two polypeptides on each other's properties in mixed samples. However, addressing this research question with imaging techniques faces the challenge to distinguish different polypeptides without adding artificial probes for detection. Here, we show that nanoscale infrared spectroscopy in combination with 13C, 15N-labeling solves this problem. We studied aggregated amyloid-β peptide (Aβ) and its interaction with an inhibitory peptide (NCAM1-PrP) using scattering-type scanning near-field optical microscopy. Although having similar secondary structure, labeled and unlabeled peptides could be distinguished by comparing optical phase images taken at wavenumbers characteristic for either the labeled or the unlabeled peptide. NCAM1-PrP seems to be able to associate with or to dissolve existing Aβ fibrils because pure Aβ fibrils were not detected after mixing.
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Affiliation(s)
- Suman Paul
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- attocube systems AG, Haar, Germany
| | - Adéla Jeništová
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Faraz Vosough
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Elina Berntsson
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Cecilia Mörman
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Jüri Jarvet
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | | | - Andreas Barth
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
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4
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Krzek M, Stroobants S, Gelin P, De Malsche W, Maes D. Influence of Centrifugation and Shaking on the Self-Assembly of Lysozyme Fibrils. Biomolecules 2022; 12:biom12121746. [PMID: 36551175 PMCID: PMC9775142 DOI: 10.3390/biom12121746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/15/2022] [Accepted: 11/19/2022] [Indexed: 11/25/2022] Open
Abstract
Protein self-assembly into fibrils and oligomers plays a key role in the etiology of degenerative diseases. Several pathways for this self-assembly process have been described and shown to result in different types and ratios of final assemblies, therewith defining the effective physiological response. Known factors that influence assembly pathways are chemical conditions and the presence or lack of agitation. However, in natural and industrial systems, proteins are exposed to a sequence of different and often complex mass transfers. In this paper, we compare the effect of two fundamentally different mass transfer processes on the fibrilization process. Aggregation-prone solutions of hen egg white lysozyme were subjected to predominantly non-advective mass transfer by employing centrifugation and to advective mass transport represented by orbital shaking. In both cases, fibrilization was triggered, while in quiescent only oligomers were formed. The fibrils obtained by shaking compared to fibrils obtained through centrifugation were shorter, thicker, and more rigid. They had rod-like protofibrils as building blocks and a significantly higher β-sheet content was observed. In contrast, fibrils from centrifugation were more flexible and braided. They consisted of intertwined filaments and had low β-sheet content at the expense of random coil. To the best of our knowledge, this is the first evidence of a fibrilization pathway selectivity, with the fibrilization route determined by the mass transfer and mixing configuration (shaking versus centrifugation). This selectivity can be potentially employed for directed protein fibrilization.
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Affiliation(s)
- Marzena Krzek
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Sander Stroobants
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Pierre Gelin
- μFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Wim De Malsche
- μFlow Group, Department of Chemical Engineering, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Dominique Maes
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium
- Correspondence:
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5
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Rajpoot J, Crooks EJ, Irizarry BA, Amundson A, Van Nostrand WE, Smith SO. Insights into Cerebral Amyloid Angiopathy Type 1 and Type 2 from Comparisons of the Fibrillar Assembly and Stability of the Aβ40-Iowa and Aβ40-Dutch Peptides. Biochemistry 2022; 61:1181-1198. [PMID: 35666749 PMCID: PMC9219409 DOI: 10.1021/acs.biochem.1c00781] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two distinct diseases are associated with the deposition of fibrillar amyloid-β (Aβ) peptides in the human brain in an age-dependent fashion. Alzheimer's disease is primarily associated with parenchymal plaque deposition of Aβ42, while cerebral amyloid angiopathy (CAA) is associated with amyloid formation of predominantly Aβ40 in the cerebral vasculature. In addition, familial mutations at positions 22 and 23 of the Aβ sequence can enhance vascular deposition in the two major subtypes of CAA. The E22Q (Dutch) mutation is associated with CAA type 2, while the D23N (Iowa) mutation is associated with CAA type 1. Here we investigate differences in the formation and structure of fibrils of these mutant Aβ peptides in vitro to gain insights into their biochemical and physiological differences in the brain. Using Fourier transform infrared and nuclear magnetic resonance spectroscopy, we measure the relative propensities of Aβ40-Dutch and Aβ40-Iowa to form antiparallel structure and compare these propensities to those of the wild-type Aβ40 and Aβ42 isoforms. We find that both Aβ40-Dutch and Aβ40-Iowa have strong propensities to form antiparallel β-hairpins in the first step of the fibrillization process. However, there is a marked difference in the ability of these peptides to form elongated antiparallel structures. Importantly, we find marked differences in the stability of the protofibril or fibril states formed by the four Aβ peptides. We discuss these differences with respect to the mechanisms of Aβ fibril formation in CAA.
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Affiliation(s)
- Jitika Rajpoot
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794-5215, United States
| | - Elliot J Crooks
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794-5215, United States
| | - Brandon A Irizarry
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794-5215, United States
| | - Ashley Amundson
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794-5215, United States
| | | | - Steven O Smith
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794-5215, United States
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6
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Liang R, Tian Y, Viles JH. Cross-seeding of WT amyloid-β with Arctic but not Italian familial mutants accelerates fibril formation in Alzheimer's disease. J Biol Chem 2022; 298:102071. [PMID: 35643314 PMCID: PMC9243174 DOI: 10.1016/j.jbc.2022.102071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 01/21/2023] Open
Abstract
Alzheimer’s disease (AD) involves the neurotoxic self-assembly of a 40 and 42 residue peptide, Amyloid-β (Aβ). Inherited early-onset AD can be caused by single point mutations within the Aβ sequence, including Arctic (E22G) and Italian (E22K) familial mutants. These mutations are heterozygous, resulting in an equal proportion of the WT and mutant Aβ isoform expression. It is therefore important to understand how these mixtures of Aβ isoforms interact with each other and influence the kinetics and morphology of their assembly into oligomers and fibrils. Using small amounts of nucleating fibril seeds, here, we systematically monitored the kinetics of fibril formation, comparing self-seeding with cross-seeding behavior of a range of isoform mixtures of Aβ42 and Aβ40. We confirm that Aβ40(WT) does not readily cross-seed Aβ42(WT) fibril formation. In contrast, fibril formation of Aβ40(Arctic) is hugely accelerated by Aβ42(WT) fibrils, causing an eight-fold reduction in the lag-time to fibrillization. We propose that cross-seeding between the more abundant Aβ40(Arctic) and Aβ42(WT) may be important for driving early-onset AD and will propagate fibril morphology as indicated by fibril twist periodicity. This kinetic behavior is not emulated by the Italian mutant, where minimal cross-seeding is observed. In addition, we studied the cross-seeding behavior of a C-terminal-amidated Aβ42 analog to probe the coulombic charge interplay between Glu22/Asp23/Lys28 and the C-terminal carboxylate. Overall, these studies highlight the role of cross-seeding between WT and mutant Aβ40/42 isoforms, which can impact the rate and structure of fibril assembly.
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Affiliation(s)
- Ruina Liang
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom
| | - Yao Tian
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom
| | - John H Viles
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom.
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7
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McKnelly KJ, Kreutzer AG, Howitz WJ, Haduong K, Yoo S, Hart C, Nowick JS. Effects of Familial Alzheimer's Disease Mutations on the Assembly of a β-Hairpin Peptide Derived from Aβ 16-36. Biochemistry 2022; 61:446-454. [PMID: 35213141 PMCID: PMC9042424 DOI: 10.1021/acs.biochem.1c00664] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Familial Alzheimer's disease (FAD) is associated with mutations in the β-amyloid peptide (Aβ) or the amyloid precursor protein (APP). FAD mutations of Aβ were incorporated into a macrocyclic peptide that mimics a β-hairpin to study FAD point mutations K16N, A21G, E22Δ, E22G, E22Q, E22K, and L34V and their effect on assembly, membrane destabilization, and cytotoxicity. The X-ray crystallographic structures of the four E22 mutant peptides reveal that the peptides assemble to form the same compact hexamer. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) experiments reveal that the mutant FAD peptides assemble as trimers or hexamers, with peptides that have greater positive charge assembling as more stable hexamers. Mutations that increase the positive charge also increase the cytotoxicity of the peptides and their propensity to destabilize lipid membranes.
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Affiliation(s)
- Kate J McKnelly
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Adam G Kreutzer
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - William J Howitz
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Katelyn Haduong
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Stan Yoo
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - Candace Hart
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States
| | - James S Nowick
- Department of Chemistry, University of California Irvine, Irvine, California 92697, United States.,Department of Pharmaceutical Sciences, University of California Irvine, Irvine, California 92697, United States
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8
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Weeks WB, Tainter CJ, Buchanan LE. Investigating the effects of N-terminal acetylation on KFE8 self-assembly with 2D IR spectroscopy. Biophys J 2022; 121:1549-1559. [PMID: 35247339 PMCID: PMC9072574 DOI: 10.1016/j.bpj.2022.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/13/2021] [Accepted: 03/01/2022] [Indexed: 12/01/2022] Open
Abstract
Peptide self-assembly is an exciting and robust approach to create novel nanoscale materials for biomedical applications. However, the complex interplay between intra- and intermolecular interactions in peptide aggregation means that minor changes in peptide sequence can yield dramatic changes in supramolecular structure. Here, we use two-dimensional infrared (2D IR) spectroscopy to study a model amphiphilic peptide, KFE8, and its N-terminal acetylated counterpart, AcKFE8. 2D IR spectra of isotope-labeled peptides reveal that AcKFE8 aggregates comprise two distinct β-sheet structures while KFE8 aggregates comprise only one of these structures. Using an excitonic Hamiltonian to simulate the vibrational spectra of model β-sheets, we determine that the spectra are consistent with antiparallel β-sheets with different strand alignments, specifically a two-residue shift in the register of the β-strands. These findings bring forth new insights into how N-terminal acetylation may subtly impact secondary structure, leading to larger effects on overall aggregate morphology. Additionally, these results highlight the importance of understanding the residue-level structural differences that result from changes in peptide sequence in order to facilitate the rational design of peptide materials.
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Affiliation(s)
- William B Weeks
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Craig J Tainter
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
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9
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Illes-Toth E, Meisl G, Rempel DL, Knowles TPJ, Gross ML. Pulsed Hydrogen-Deuterium Exchange Reveals Altered Structures and Mechanisms in the Aggregation of Familial Alzheimer's Disease Mutants. ACS Chem Neurosci 2021; 12:1972-1982. [PMID: 33988976 DOI: 10.1021/acschemneuro.1c00072] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Mutations of the Amyloid Precursor Protein, from which the amyloid β peptide Aβ42 is cleaved, are associated with familial Alzheimer's disease. The disease-relevant familial mutations include the Arctic (E22G), Iowa (D23N), Italian (E22K), Dutch (E22Q), Japanese (D7N), English (D6R), and Flemish (A21G) variants. A detailed mechanistic understanding of the aggregation behavior of the mutant peptides at the residue level is, however, still lacking. We report here a study of the aggregation kinetics of these mutants in vitro by pulsed hydrogen-deuterium exchange mass spectrometry (HDX-MS) to obtain a temporally and sequence resolved picture of their self-assembly. For all variants, HDX occurs to give a bimodal distribution representing two soluble classes of aggregates, one protected and one solvent-exposed. There is no evidence of other classes of structural intermediates within the detection limits of the HDX approach. The fractional changes in the bimodal exchange profiles for several regions of Aβ42 reveal that the central and C-terminal peptides gain protection upon fibril formation, whereas the N-terminal regions remain largely solvent-accessible. For these mutants, all peptide fragments follow the same kinetics, acquiring solvent protection at the same time, further supporting that there are no significant populations of intermediate species under our experimental conditions. The results demonstrate the potential of pulsed HDX-MS for resolving the region-specific aggregation behavior of Aβ42 isoforms in solution where X-ray crystallography and solid-state NMR (ssNMR) are challenged.
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Affiliation(s)
- Eva Illes-Toth
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
| | - Georg Meisl
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
| | - Don L. Rempel
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
| | - Tuomas P. J. Knowles
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
| | - Michael L. Gross
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
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10
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Waeytens J, Mathurin J, Deniset-Besseau A, Arluison V, Bousset L, Rezaei H, Raussens V, Dazzi A. Probing amyloid fibril secondary structures by infrared nanospectroscopy: experimental and theoretical considerations. Analyst 2021; 146:132-145. [PMID: 33107501 DOI: 10.1039/d0an01545h] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Amyloid fibrils are composed of aggregated peptides or proteins in a fibrillary structure with a higher β-sheet content than their native structure. Attenuated total reflection Fourier transform infrared spectroscopy only provides bulk analysis of a sample therefore it is impossible to discriminate between different aggregated structures. To overcome this limitation, near-field techniques like AFM-IR have emerged in the last twenty years to allow infrared nanospectroscopy. This technique obtains IR spectra with a spatial resolution of ten nanometres, the size of isolated fibrils. Here, we present essential practical considerations to avoid misinterpretations and artefacts during these analyses. Effects of polarization of the incident IR laser, illumination configuration and coating of the AFM probes are discussed, including the advantages and drawbacks of their use. This approach will improve interpretation of AFM-IR spectra especially for the determination of secondary structures of species not accessible using classical ATR-FTIR.
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Affiliation(s)
- Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, Bruxelles, Belgique.
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11
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Devitt G, Crisford A, Rice W, Weismiller HA, Fan Z, Commins C, Hyman BT, Margittai M, Mahajan S, Mudher A. Conformational fingerprinting of tau variants and strains by Raman spectroscopy. RSC Adv 2021; 11:8899-8915. [PMID: 34381596 PMCID: PMC8330415 DOI: 10.1039/d1ra00870f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 02/18/2021] [Indexed: 12/11/2022] Open
Abstract
Tauopathies are a group of disorders in which the deposition of abnormally folded tau protein accompanies neurodegeneration. The development of methods for detection and classification of pathological changes in protein conformation are desirable for understanding the factors that influence the structural polymorphism of aggregates in tauopathies. We have previously demonstrated the utility of Raman spectroscopy for the characterization and discrimination of different protein aggregates, including tau, based on their unique conformational signatures. Building on this, in the present study, we assess the utility of Raman spectroscopy for characterizing and distinguishing different conformers of the same protein which in the case of tau are unique tau strains generated in vitro. We now investigate the impact of aggregation environment, cofactors, post-translational modification and primary sequence on the Raman fingerprint of tau fibrils. Using quantitative conformational fingerprinting and multivariate statistical analysis, we found that the aggregation of tau in different buffer conditions resulted in the formation of distinct fibril strains. Unique spectral markers were identified for tau fibrils generated using heparin or RNA cofactors, as well as for phosphorylated tau. We also determined that the primary sequence of the tau monomer influenced the conformational signature of the resulting tau fibril, including 2N4R, 0N3R, K18 and P301S tau variants. These results highlight the conformational polymorphism of tau fibrils, which is reflected in the wide range of associated neurological disorders. Furthermore, the analyses presented in this study provide a benchmark for the Raman spectroscopic characterization of tau strains, which may shed light on how the aggregation environment, cofactors and post-translational modifications influence tau conformation in vivo in future studies.
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Affiliation(s)
- George Devitt
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK .,School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK.,Institute for Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Anna Crisford
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK .,School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - William Rice
- School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Hilary A Weismiller
- Department of Chemistry and Biochemistry, University of Denver 2190 E. Iliff Ave. Denver CO 80208 USA
| | - Zhanyun Fan
- Department of Neurology, Harvard Medical School, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Charlestown MA 02129 USA
| | - Caitlin Commins
- Department of Neurology, Harvard Medical School, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Charlestown MA 02129 USA
| | - Bradley T Hyman
- Department of Neurology, Harvard Medical School, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Charlestown MA 02129 USA
| | - Martin Margittai
- Department of Chemistry and Biochemistry, University of Denver 2190 E. Iliff Ave. Denver CO 80208 USA
| | - Sumeet Mahajan
- School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK.,Institute for Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Amrit Mudher
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK .,Institute for Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
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12
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Vosough F, Barth A. Characterization of Homogeneous and Heterogeneous Amyloid-β42 Oligomer Preparations with Biochemical Methods and Infrared Spectroscopy Reveals a Correlation between Infrared Spectrum and Oligomer Size. ACS Chem Neurosci 2021; 12:473-488. [PMID: 33455165 PMCID: PMC8023574 DOI: 10.1021/acschemneuro.0c00642] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
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Soluble oligomers of the amyloid-β(1-42)
(Aβ42) peptide,
widely considered to be among the relevant neurotoxic species involved
in Alzheimer’s disease, were characterized with a combination
of biochemical and biophysical methods. Homogeneous and stable Aβ42
oligomers were prepared by treating monomeric solutions of the peptide
with detergents. The prepared oligomeric solutions were analyzed with
blue native and sodium dodecyl sulfate polyacrylamide gel electrophoresis,
as well as with infrared (IR) spectroscopy. The IR spectra indicated
a well-defined β-sheet structure of the prepared oligomers.
We also found a relationship between the size/molecular weight of
the Aβ42 oligomers and their IR spectra: The position of the
main amide I′ band of the peptide backbone correlated with
oligomer size, with larger oligomers being associated with lower wavenumbers.
This relationship explained the time-dependent band shift observed
in time-resolved IR studies of Aβ42 aggregation in the absence
of detergents, during which the oligomer size increased. In addition,
the bandwidth of the main IR band in the amide I′ region was
found to become narrower with time in our time-resolved aggregation
experiments, indicating a more homogeneous absorption of the β-sheets
of the oligomers after several hours of aggregation. This is predominantly
due to the consumption of smaller oligomers in the aggregation process.
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Affiliation(s)
- Faraz Vosough
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm SE-106 91, Sweden
| | - Andreas Barth
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm SE-106 91, Sweden
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13
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Single Point Mutation from E22-to-K in A β Initiates Early-Onset Alzheimer's Disease by Binding with Catalase. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2020:4981204. [PMID: 33425208 PMCID: PMC7775154 DOI: 10.1155/2020/4981204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 08/31/2020] [Accepted: 12/05/2020] [Indexed: 11/18/2022]
Abstract
Amyloid-beta (Aβ) is a critical etiological factor for late-onset familial Alzheimer's disease (AD). However, an early-onset AD has been found to be related with an Aβ mutation in glutamic acid 22-to-lysine (Italian type E22K). Why only one single point mutation at E22 residue induces AD remains unclear. Here, we report that a Chinese familial AD pedigree with E22K mutation was associated with higher levels of serum hydrogen peroxide (H2O2) and lower activity of catalase (a H2O2 degrading enzyme) than controls. Further, we found that E22K binding with catalase caused more severe H2O2 accumulation in the brains of E22K-injected rats than Aβ-injected rats. Unexpectedly, H2O2 bound with the mutation site 22K residue of E22K and elicited more rapid aggregation of E22K than Aβ in vitro. Moreover, H2O2 acted with E22K synergistically to induce higher cellular toxicity than with Aβ. Notably, intrahippocampal infusion of E22K led to more severe plaque deposition, neuron death, and more rapid memory decline than Aβ-injected rats. However, L-cysteine, a H2O2 scavenger, not only prevented self-aggregation of E22K but also reduced H2O2-promoted E22K assembly in vitro; subsequently, it alleviated Alzheimer-related phenotypes. Hence, E22K binding with catalase promotes the early onset of familial AD, and L-cys may reverse this disease.
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14
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Inyushin M, Zayas-Santiago A, Rojas L, Kucheryavykh L. On the Role of Platelet-Generated Amyloid Beta Peptides in Certain Amyloidosis Health Complications. Front Immunol 2020; 11:571083. [PMID: 33123145 PMCID: PMC7567018 DOI: 10.3389/fimmu.2020.571083] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/15/2020] [Indexed: 12/15/2022] Open
Abstract
As do many other immunity-related blood cells, platelets release antimicrobial peptides that kill bacteria, fungi, and even certain viruses. Here we review the literature suggesting that there is a similarity between the antimicrobials released by other blood cells and the amyloid-related Aβ peptide released by platelets. Analyzing the literature, we also propose that platelet-generated Aβ amyloidosis may be more common than currently recognized. This systemic Aβ from a platelet source may participate in various forms of amyloidosis in pathologies ranging from brain cancer, glaucoma, skin Aβ accumulation, and preeclampsia to Alzheimer’s disease and late-stage Parkinson’s disease. We also discuss the advantages and disadvantages of specific animal models for studying platelet-related Aβ. This field is undergoing rapid change, as it evaluates competing ideas in the light of new experimental observations. We summarized both in order to clarify the role of platelet-generated Aβ peptides in amyloidosis-related health disorders, which may be helpful to researchers interested in this growing area of investigation.
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Affiliation(s)
- Mikhail Inyushin
- Department of Physiology, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - Astrid Zayas-Santiago
- Department of Pathology & Laboratory Medicine, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - Legier Rojas
- Department of Physiology, Universidad Central del Caribe, Bayamon, Puerto Rico
| | - Lilia Kucheryavykh
- Department of Biochemistry, Universidad Central del Caribe, Bayamon, Puerto Rico
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15
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Biophysical characterization of p53 core domain aggregates. Biochem J 2020; 477:111-120. [PMID: 31841126 DOI: 10.1042/bcj20190778] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 12/16/2022]
Abstract
Aggregation is the cause of numerous protein conformation diseases. A common facet of these maladies is the transition of a protein from its functional native state into higher order forms, such as oligomers and amyloid fibrils. p53 is an essential tumor suppressor that is prone to such conformational transitions, resulting in its compromised ability to avert cancer. This work explores the biophysical properties of early-, mid-, and late-stage p53 core domain (p53C) aggregates. Atomistic and coarse-grained molecular dynamics (MD) simulations suggest that early- and mid-stage p53C aggregates have a polymorphic topology of antiparallel and parallel β-sheets that localize to the core amyloidogenic sequence. Both topologies involve similar extents of interstrand mainchain hydrogen bonding, while sidechain interactions could play a role in regulating strand orientation. The free energy difference between the antiparallel and parallel states was within statistical uncertainty. Negative stain electron microscopy of mature fibrils shows a wide distribution of fiber widths, indicating that polymorphism may extend to the quaternary structure level. Circular dichroism of the fibrils was indicative of β-sheet rich structures in atypical conformations. The Raman spectrum of aggregated p53C was consistent with a mixture of arranged β-sheets and heterogeneous structural elements, which is compatible with the MD findings of an ordered β-sheet nucleus flanked by disordered structure. Structural polymorphism is a common property of amyloids; however, because certain polymorphs of the same protein can be more harmful than others, going forward it will be pertinent to establish correlations between p53C aggregate structure and pathology.
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16
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Huang YR, Liu RT. The Toxicity and Polymorphism of β-Amyloid Oligomers. Int J Mol Sci 2020; 21:E4477. [PMID: 32599696 PMCID: PMC7352971 DOI: 10.3390/ijms21124477] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 12/26/2022] Open
Abstract
It is widely accepted that β-amyloid oligomers (Aβos) play a key role in the progression of Alzheimer's disease (AD) by inducing neuron damage and cognitive impairment, but Aβos are highly heterogeneous in their size, structure and cytotoxicity, making the corresponding studies tough to carry out. Nevertheless, a number of studies have recently made remarkable progress in the describing the characteristics and pathogenicity of Aβos. We here review the mechanisms by which Aβos exert their neuropathogenesis for AD progression, including receptor binding, cell membrane destruction, mitochondrial damage, Ca2+ homeostasis dysregulation and tau pathological induction. We also summarize the characteristics and pathogenicity such as the size, morphology and cytotoxicity of dimers, trimers, Aβ*56 and spherical oligomers, and suggest that Aβos may play a different role at different phases of AD pathogenesis, resulting in differential consequences on neuronal synaptotoxicity and survival. It is warranted to investigate the temporal sequence of Aβos in AD human brain and examine the relationship between different Aβos and cognitive impairment.
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Affiliation(s)
- Ya-ru Huang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui-tian Liu
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
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17
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Waeytens J, Van Hemelryck V, Deniset-Besseau A, Ruysschaert JM, Dazzi A, Raussens V. Characterization by Nano-Infrared Spectroscopy of Individual Aggregated Species of Amyloid Proteins. Molecules 2020; 25:molecules25122899. [PMID: 32599698 PMCID: PMC7356528 DOI: 10.3390/molecules25122899] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 12/30/2022] Open
Abstract
Amyloid fibrils are composed of aggregated peptides or proteins in a fibrillar structure with a higher β-sheet content than in their native structure. To characterize them, we used an innovative tool that coupled infrared spectroscopy with atomic force microscopy (AFM-IR). With this method, we show that we can detect different individual aggregated species from oligomers to fibrils and study their morphologies by AFM and their secondary structures based on their IR spectra. AFM-IR overcomes the weak spatial resolution of usual infrared spectroscopy and achieves a resolution of ten nanometers, the size of isolated fibrils. We characterized oligomers, amyloid fibrils of Aβ42 and fibrils of α-synuclein. To our surprise, we figured out that the nature of some surfaces (ZnSe) used to study the samples induces destructuring of amyloid samples, leading to amorphous aggregates. We strongly suggest taking this into consideration in future experiments with amyloid fibrils. More importantly, we demonstrate the advantages of AFM-IR, with a high spatial resolution (≤ 10 nm) allowing spectrum recording on individual aggregated supramolecular entities selected thanks to the AFM images or on thin layers of proteins.
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Affiliation(s)
- Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, B-1050 Bruxelles, Belgique; (J.W.); (J.-M.R.)
- Laboratoire de Chimie Physique d’Orsay, CNRS UMR8000, Université Paris-Sud, Université Paris-Saclay, F-91400 Orsay, France; (A.D.-B.); (A.D.)
| | | | - Ariane Deniset-Besseau
- Laboratoire de Chimie Physique d’Orsay, CNRS UMR8000, Université Paris-Sud, Université Paris-Saclay, F-91400 Orsay, France; (A.D.-B.); (A.D.)
| | - Jean-Marie Ruysschaert
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, B-1050 Bruxelles, Belgique; (J.W.); (J.-M.R.)
| | - Alexandre Dazzi
- Laboratoire de Chimie Physique d’Orsay, CNRS UMR8000, Université Paris-Sud, Université Paris-Saclay, F-91400 Orsay, France; (A.D.-B.); (A.D.)
| | - Vincent Raussens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, B-1050 Bruxelles, Belgique; (J.W.); (J.-M.R.)
- Correspondence:
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18
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Som Chaudhury S, Sannigrahi A, Nandi M, Mishra VK, De P, Chattopadhyay K, Mishra S, Sil J, Das Mukhopadhyay C. A Novel PEGylated Block Copolymer in New Age Therapeutics for Alzheimer’s Disease. Mol Neurobiol 2019; 56:6551-6565. [DOI: 10.1007/s12035-019-1542-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/27/2019] [Indexed: 12/15/2022]
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19
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Au DF, Ostrovsky D, Fu R, Vugmeyster L. Solid-state NMR reveals a comprehensive view of the dynamics of the flexible, disordered N-terminal domain of amyloid-β fibrils. J Biol Chem 2019; 294:5840-5853. [PMID: 30737281 DOI: 10.1074/jbc.ra118.006559] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 02/08/2019] [Indexed: 11/06/2022] Open
Abstract
Amyloid fibril deposits observed in Alzheimer's disease comprise amyloid-β (Aβ) protein possessing a structured hydrophobic core and a disordered N-terminal domain (residues 1-16). The internal flexibility of the disordered domain is likely essential for Aβ aggregation. Here, we used 2H static solid-state NMR methods to probe the dynamics of selected side chains of the N-terminal domain of Aβ1-40 fibrils. Line shape and relaxation data suggested a two-state model in which the domain's free state undergoes a diffusive motion that is quenched in the bound state, likely because of transient interactions with the structured C-terminal domain. At 37 °C, we observed freezing of the dynamics progressively along the Aβ sequence, with the fraction of the bound state increasing and the rate of diffusion decreasing. We also found that without solvation, the diffusive motion is quenched. The solvent acted as a plasticizer reminiscent of its role in the onset of global dynamics in globular proteins. As the temperature was lowered, the fraction of the bound state exhibited sigmoidal behavior. The midpoint of the freezing curve coincided with the bulk solvent freezing for the N-terminal residues and increased further along the sequence. Using 2H R 1ρ measurements, we determined the conformational exchange rate constant between the free and bound states under physiological conditions. Zinc-induced aggregation leads to the enhancement of the dynamics, manifested by the faster conformational exchange, faster diffusion, and lower freezing-curve midpoints.
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Affiliation(s)
- Dan Fai Au
- From the Department of Chemistry, University of Colorado, Denver, Colorado 80204
| | - Dmitry Ostrovsky
- Department of Mathematics, University of Colorado, Denver, Colorado 80204
| | - Riqiang Fu
- National High Field Magnetic Laboratory, Tallahassee, Florida 32310
| | - Liliya Vugmeyster
- From the Department of Chemistry, University of Colorado, Denver, Colorado 80204.
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20
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Recent Advances by In Silico and In Vitro Studies of Amyloid-β 1-42 Fibril Depicted a S-Shape Conformation. Int J Mol Sci 2018; 19:ijms19082415. [PMID: 30115846 PMCID: PMC6121414 DOI: 10.3390/ijms19082415] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 12/19/2022] Open
Abstract
The amyloid-β 1-42 (Aβ1-42) peptide is produced by proteolytic cleavage of the amyloid precursor protein (APP) by sequential reactions that are catalyzed by γ and β secretases. Aβ1-42, together with the Tau protein are two principal hallmarks of Alzheimer's disease (AD) that are related to disease genesis and progression. Aβ1-42 possesses a higher aggregation propensity, and it is able to form fibrils via nucleated fibril formation. To date, there are compounds available that prevent Aβ1-42 aggregation, but none have been successful in clinical trials, possibly because the Aβ1-42 structure and aggregation mechanisms are not thoroughly understood. New molecules have been designed, employing knowledge of the Aβ1-42 structure and are based on preventing or breaking the ionic interactions that have been proposed for formation of the Aβ1-42 fibril U-shaped structure. Recently, a new Aβ1-42 fibril S-shaped structure was reported that, together with its aggregation and catalytic properties, could be helpful in the design of new inhibitor molecules. Therefore, in silico and in vitro methods have been employed to analyze the Aβ1-42 fibril S-shaped structure and its aggregation to obtain more accurate Aβ1-42 oligomerization data for the design and evaluation of new molecules that can prevent the fibrillation process.
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21
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Xi W, Hansmann UHE. Conversion between parallel and antiparallel β-sheets in wild-type and Iowa mutant Aβ 40 fibrils. J Chem Phys 2018; 148:045103. [PMID: 29390821 DOI: 10.1063/1.5016166] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Using a variant of Hamilton-replica-exchange, we study for wild type and Iowa mutant Aβ40 the conversion between fibrils with antiparallel β-sheets and such with parallel β-sheets. We show that wild type and mutant form distinct salt bridges that in turn stabilize different fibril organizations. The conversion between the two fibril forms leads to the release of small aggregates that in the Iowa mutant may shift the equilibrium from fibrils to more toxic oligomers.
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Affiliation(s)
- Wenhui Xi
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Ulrich H E Hansmann
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, USA
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22
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Young LJ, Kaminski Schierle GS, Kaminski CF. Imaging Aβ(1-42) fibril elongation reveals strongly polarised growth and growth incompetent states. Phys Chem Chem Phys 2017; 19:27987-27996. [PMID: 29026905 PMCID: PMC7612976 DOI: 10.1039/c7cp03412a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The major hallmark of Alzheimer's disease is the deposition of plaques of amyloid fibrils formed from amyloid-β (Aβ) peptides. Kinetic studies have contributed significantly towards a mechanistic understanding of amyloid fibril self-assembly, however dynamic features of the aggregation process cannot be captured using ensemble methods. Here we present an assay for imaging Aβ42 aggregation dynamics at the single fibril level, allowing for the quantitative extraction of concentration and temperature dependent kinetic parameters. From direct observation of elongation using TIRF and super-resolution optical microscopy, we find that Aβ42 fibril growth is strongly polarized, with fast and slow growing ends arising from different elongation rates, but also from a growth incompetent state, which dominates the process at the slow growing end. Our findings reveal the surprising complexity of the Aβ42 fibril elongation reaction at the microscopic level.
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Affiliation(s)
- Laurence J Young
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS, UK.
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23
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Cieplak AS. Protein folding, misfolding and aggregation: The importance of two-electron stabilizing interactions. PLoS One 2017; 12:e0180905. [PMID: 28922400 PMCID: PMC5603215 DOI: 10.1371/journal.pone.0180905] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 06/22/2017] [Indexed: 12/17/2022] Open
Abstract
Proteins associated with neurodegenerative diseases are highly pleiomorphic and may adopt an all-α-helical fold in one environment, assemble into all-β-sheet or collapse into a coil in another, and rapidly polymerize in yet another one via divergent aggregation pathways that yield broad diversity of aggregates’ morphology. A thorough understanding of this behaviour may be necessary to develop a treatment for Alzheimer’s and related disorders. Unfortunately, our present comprehension of folding and misfolding is limited for want of a physicochemical theory of protein secondary and tertiary structure. Here we demonstrate that electronic configuration and hyperconjugation of the peptide amide bonds ought to be taken into account to advance such a theory. To capture the effect of polarization of peptide linkages on conformational and H-bonding propensity of the polypeptide backbone, we introduce a function of shielding tensors of the Cα atoms. Carrying no information about side chain-side chain interactions, this function nonetheless identifies basic features of the secondary and tertiary structure, establishes sequence correlates of the metamorphic and pH-driven equilibria, relates binding affinities and folding rate constants to secondary structure preferences, and manifests common patterns of backbone density distribution in amyloidogenic regions of Alzheimer’s amyloid β and tau, Parkinson’s α-synuclein and prions. Based on those findings, a split-intein like mechanism of molecular recognition is proposed to underlie dimerization of Aβ, tau, αS and PrPC, and divergent pathways for subsequent association of dimers are outlined; a related mechanism is proposed to underlie formation of PrPSc fibrils. The model does account for: (i) structural features of paranuclei, off-pathway oligomers, non-fibrillar aggregates and fibrils; (ii) effects of incubation conditions, point mutations, isoform lengths, small-molecule assembly modulators and chirality of solid-liquid interface on the rate and morphology of aggregation; (iii) fibril-surface catalysis of secondary nucleation; and (iv) self-propagation of infectious strains of mammalian prions.
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Affiliation(s)
- Andrzej Stanisław Cieplak
- Department of Chemistry, Bilkent University, Ankara, Turkey
- Department of Chemistry, Yale University, New Haven, Connecticut, United States of America
- Department of Chemistry, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
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24
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Abdolvahabi A, Shi Y, Rasouli S, Croom CM, Aliyan A, Martí AA, Shaw BF. Kaplan-Meier Meets Chemical Kinetics: Intrinsic Rate of SOD1 Amyloidogenesis Decreased by Subset of ALS Mutations and Cannot Fully Explain Age of Disease Onset. ACS Chem Neurosci 2017; 8:1378-1389. [PMID: 28290665 DOI: 10.1021/acschemneuro.7b00029] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Over 150 mutations in SOD1 (superoxide dismutase-1) cause amyotrophic lateral sclerosis (ALS), presumably by accelerating SOD1 amyloidogenesis. Like many nucleation processes, SOD1 fibrillization is stochastic (in vitro), which inhibits the determination of aggregation rates (and obscures whether rates correlate with patient phenotypes). Here, we diverged from classical chemical kinetics and used Kaplan-Meier estimators to quantify the probability of apo-SOD1 fibrillization (in vitro) from ∼103 replicate amyloid assays of wild-type (WT) SOD1 and nine ALS variants. The probability of apo-SOD1 fibrillization (expressed as a Hazard ratio) is increased by certain ALS-linked SOD1 mutations but is decreased or remains unchanged by other mutations. Despite this diversity, Hazard ratios of fibrillization correlated linearly with (and for three mutants, approximately equaled) Hazard ratios of patient survival (R2 = 0.67; Pearson's r = 0.82). No correlation exists between Hazard ratios of fibrillization and age of initial onset of ALS (R2 = 0.09). Thus, Hazard ratios of fibrillization might explain rates of disease progression but not onset. Classical kinetic metrics of fibrillization, i.e., mean lag time and propagation rate, did not correlate as strongly with phenotype (and ALS mutations did not uniformly accelerate mean rate of nucleation or propagation). A strong correlation was found, however, between mean ThT fluorescence at lag time and patient survival (R2 = 0.93); oligomers of SOD1 with weaker fluorescence correlated with shorter survival. This study suggests that SOD1 mutations trigger ALS by altering a property of SOD1 or its oligomers other than the intrinsic rate of amyloid nucleation (e.g., oligomer stability; rates of intercellular propagation; affinity for membrane surfaces; and maturation rate).
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Affiliation(s)
- Alireza Abdolvahabi
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, United States
| | - Yunhua Shi
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, United States
| | - Sanaz Rasouli
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, United States
- Institute of Biomedical Studies, Baylor University, Waco, Texas 76706, United States
| | - Corbin M. Croom
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, United States
| | - Amir Aliyan
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Angel A. Martí
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Bryan F. Shaw
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76706, United States
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25
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Matías-Guiu JA, Guerrero-Márquez C, Cabrera-Martín MN, Gómez-Pinedo U, Romeral M, Mayo D, Porta-Etessam J, Moreno-Ramos T, Carreras JL, Matías-Guiu J. Amyloid- and FDG-PET in sporadic Creutzfeldt-Jakob disease: Correlation with pathological prion protein in neuropathology. Prion 2017; 11:205-213. [PMID: 28509609 DOI: 10.1080/19336896.2017.1314427] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION The role of positron emission tomography (PET) in Creutzfeldt-Jakob disease is less defined than in other neurodegenerative diseases. We studied the correlation between the uptake of 18F-florbetaben and 18F-fluorodeoxyglucose with pathological prion protein deposition in histopathology in a case. METHODS A patient with 80 y old with a rapid neurological deterioration with a confirmed diagnosis of CJD was studied. PET and MRI studies were performed between 13-20 d before the death. A region of interest analysis was performed using Statistical Parametric Mapping. RESULTS MRI showed atrophy with no other alterations. FDG-PET showed extensive areas of hypometabolism including left frontoparietal lobes as well as bilateral thalamus. Correlation between uptake of 18F-florbetaben and pathological prion protein deposition was r = 0.786 (p < 0.05). Otherwise, correlation between uptake of 18F-FDG and pathological prion protein was r = 0.357 (p = 0.385). Immunohistochemistry with β-amyloid did not show amyloid deposition or neuritic plaques. CONCLUSIONS Our study supports the use of FDG-PET in the assessment of CJD. FDG-PET may be especially useful in cases of suspected CJD and negative MRI. Furthermore, this case report provides more evidence about the behavioral of amyloid tracers, and the possibility of a low-affinity binding to other non-amyloid proteins, such as the pathological prion protein, is discussed.
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Affiliation(s)
- Jordi A Matías-Guiu
- a Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - Carmen Guerrero-Márquez
- b Laboratory of Neuropathology, Brain Bank, Department of Pathology , Hospital Universitario Fundación Alcorcón , Madrid , Spain
| | - María Nieves Cabrera-Martín
- c Department of Nuclear Medicine, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - Ulises Gómez-Pinedo
- a Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain.,d Laboratory of Regenerative Medicine, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - María Romeral
- a Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - Diego Mayo
- a Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - Jesús Porta-Etessam
- a Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - Teresa Moreno-Ramos
- a Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - José Luis Carreras
- c Department of Nuclear Medicine, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
| | - Jorge Matías-Guiu
- a Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC) , Universidad Complutense , Madrid , Spain
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Abdolvahabi A, Shi Y, Rasouli S, Croom CM, Chuprin A, Shaw BF. How Do Gyrating Beads Accelerate Amyloid Fibrillization? Biophys J 2017; 112:250-264. [PMID: 28122213 PMCID: PMC5266089 DOI: 10.1016/j.bpj.2016.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 11/22/2016] [Accepted: 12/05/2016] [Indexed: 01/21/2023] Open
Abstract
The chemical and physical mechanisms by which gyrating beads accelerate amyloid fibrillization in microtiter plate assays are unclear. Identifying these mechanisms will help optimize high-throughput screening assays for molecules and mutations that modulate aggregation and might explain why different research groups report different rates of aggregation for identical proteins. This article investigates how the rate of superoxide dismutase-1 (SOD1) fibrillization is affected by 12 different beads with a wide range of hydrophobicity, mass, stiffness, and topology but identical diameter. All assays were performed on D90A apo-SOD1, which is a stable and wild-type-like variant of SOD1. The most significant and uniform correlation between any material property of each bead and that bead's effect on SOD1 fibrillization rate was with regard to bead mass. A linear correlation existed between bead mass and rate of fibril elongation (R2 = 0.7): heavier beads produced faster rates and shorter fibrils. Nucleation rates (lag time) also correlated with bead mass, but only for non-polymeric beads (i.e., glass, ceramic, metallic). The effect of bead mass on fibrillization correlated (R2 = 0.96) with variations in buoyant forces and contact forces (between bead and microplate well), and was not an artifact of residual momentum during intermittent gyration. Hydrophobic effects were observed, but only for polymeric beads: lag times correlated negatively with contact angle of water and degree of protein adhesion (surface adhesion and hydrophobic effects were negligible for non-polymeric beads). These results demonstrate that contact forces (alone) explain kinetic variation among non-polymeric beads, whereas surface hydrophobicity and contact forces explain kinetic variation among polymeric beads. This study also establishes conditions for high-throughput amyloid assays of SOD1 that enable the control over fibril morphologies and produce eightfold faster lag times and fourfold less stochasticity than in previous studies.
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Affiliation(s)
| | - Yunhua Shi
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas
| | - Sanaz Rasouli
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas; Institute of Biomedical Studies, Baylor University, Waco, Texas
| | - Corbin M Croom
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas
| | - Aleksandra Chuprin
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas
| | - Bryan F Shaw
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas.
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Laine RF, Kaminski Schierle GS, van de Linde S, Kaminski CF. From single-molecule spectroscopy to super-resolution imaging of the neuron: a review. Methods Appl Fluoresc 2016; 4:022004. [PMID: 28809165 PMCID: PMC5390958 DOI: 10.1088/2050-6120/4/2/022004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/09/2016] [Accepted: 05/19/2016] [Indexed: 12/03/2022]
Abstract
For more than 20 years, single-molecule spectroscopy has been providing invaluable insights into nature at the molecular level. The field has received a powerful boost with the development of the technique into super-resolution imaging methods, ca. 10 years ago, which overcome the limitations imposed by optical diffraction. Today, single molecule super-resolution imaging is routinely used in the study of macromolecular function and structure in the cell. Concomitantly, computational methods have been developed that provide information on numbers and positions of molecules at the nanometer-scale. In this overview, we outline the technical developments that have led to the emergence of localization microscopy techniques from single-molecule spectroscopy. We then provide a comprehensive review on the application of the technique in the field of neuroscience research.
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Affiliation(s)
- Romain F Laine
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, Cambridge University, Pembroke Street, Cambridge, CB2 3RA, UK
| | - Gabriele S Kaminski Schierle
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, Cambridge University, Pembroke Street, Cambridge, CB2 3RA, UK
| | - Sebastian van de Linde
- Department of Biotechnology and Biophysics, Julius-Maximilians-University, Am Hubland, D-97074 Würzburg, Germany
| | - Clemens F Kaminski
- Laser Analytics Group, Department of Chemical Engineering and Biotechnology, Cambridge University, Pembroke Street, Cambridge, CB2 3RA, UK
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