1
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Miura Y, Namioka S, Iwai A, Yoshida N, Konno H, Sohma Y, Kanai M, Makabe K. Redesign of a thioflavin-T-binding protein with a flat β-sheet to evaluate a thioflavin-T-derived photocatalyst with enhanced affinity. Int J Biol Macromol 2024; 269:131992. [PMID: 38697433 DOI: 10.1016/j.ijbiomac.2024.131992] [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: 02/26/2024] [Revised: 04/24/2024] [Accepted: 04/28/2024] [Indexed: 05/05/2024]
Abstract
Amyloids, proteinous aggregates with β-sheet-rich fibrils, are involved in several neurodegenerative diseases such as Alzheimer's disease; thus, their detection is critically important. The most common fluorescent dye for amyloid detection is thioflavin-T (ThT), which shows on/off fluorescence upon amyloid binding. We previously reported that an engineered globular protein with a flat β-sheet, peptide self-assembly mimic (PSAM), can be used as an amyloid binding model. In this study, we further explored the residue-specific properties of ThT-binding to the flat β-sheet by introducing systematic mutations. We found that site-specific mutations at the ThT-binding channel enhanced affinity. We also evaluated the binding of a ThT-based photocatalyst, which showed the photooxygenation activity on the amyloid fibril upon light radiation. Upon binding of the photocatalyst to the PSAM variant, singlet oxygen-generating activity was observed. The results of this study expand our understanding of the detailed binding mechanism of amyloid-specific molecules.
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Affiliation(s)
- Yuina Miura
- Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jyonan, Yonezawa, Yamagata 992-8510, Japan
| | - Sae Namioka
- Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jyonan, Yonezawa, Yamagata 992-8510, Japan
| | - Atsushi Iwai
- Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Norio Yoshida
- Department of Complex Systems Science, Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-Ward, Nagoya 464-8601, Japan
| | - Hiroyuki Konno
- Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jyonan, Yonezawa, Yamagata 992-8510, Japan
| | - Youhei Sohma
- Graduate School of Medical and Pharmaceutical Sciences, Wakayama Medical University, 25-1 Shichiban-cho, Wakayama 640-8156, Japan
| | - Motomu Kanai
- Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koki Makabe
- Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jyonan, Yonezawa, Yamagata 992-8510, Japan.
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2
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Koroleva ON, Kuzmina NV, Dubrovin EV, Drutsa VL. Atomic force microscopy of spherical intermediates on the pathway to fibril formation of influenza A virus nuclear export protein. Microsc Res Tech 2024; 87:1131-1145. [PMID: 38270267 DOI: 10.1002/jemt.24499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 01/02/2024] [Accepted: 01/07/2024] [Indexed: 01/26/2024]
Abstract
The nuclear export protein of the influenza A virus (NEP) is involved in many important processes of the virus life cycle. This makes it an attractive target for the treatment of a disease caused by a virus. Previously it has been shown, that recombinant variants of NEP are highly prone to aggregation in solution under various conditions with the formation of amyloid-like aggregates. In the present work, the amyloid nature of NEP aggregates was evidenced by Congo red binding assays. Atomic force microscopy has shown that NEP can form two types of spherical nanoparticles, which provide an alternative pathway for the formation of amyloid-like fibrils. Type I of these "fibrillogenic" spheres, formed under physiological conditions, represents the micelle-like particles with height 10-60 nm, which can generate worm-like flexible fibrils with the diameter 2.5-4.0 nm, length 20-500 nm and the Young's modulus ~73 MPa. Type II spherical aggregates with size of about 400-1000 nm, formed at elevated temperatures, includes fractions of drop-like and vesicle-like particles, generating more rigid amyloid-like fibrils with height of ~8 nm, and length of up to 2 μm. The hypothetical mechanism of fibril formation via nanospherical structures was suggested. RESEARCH HIGHLIGHTS: AFM has revealed two types of the influenza A virus nuclear export protein spherical aggregates. They provide an alternative pathway for the formation of amyloid-like fibrils. The mechanism of fibril formation via spherical structures is suggested.
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Affiliation(s)
- Olga N Koroleva
- Faculty of Chemistry, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Natalia V Kuzmina
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russian Federation
| | - Evgeniy V Dubrovin
- Faculty of Physics, Lomonosov Moscow State University, Moscow, Russian Federation
- National University of Science and Technology, MISIS, Moscow, Russian Federation
| | - Valeriy L Drutsa
- A.N.Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
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3
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Bu F, Dee DR, Liu B. Structural insight into Escherichia coli CsgA amyloid fibril assembly. mBio 2024; 15:e0041924. [PMID: 38501920 PMCID: PMC11005368 DOI: 10.1128/mbio.00419-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/04/2024] [Indexed: 03/20/2024] Open
Abstract
The discovery of functional amyloids in bacteria dates back several decades, and our understanding of the Escherichia coli curli biogenesis system has gradually expanded over time. However, due to its high aggregation propensity and intrinsically disordered nature, CsgA, the main structural component of curli fibrils, has eluded comprehensive structural characterization. Recent advancements in cryo-electron microscopy (cryo-EM) offer a promising tool to achieve high-resolution structural insights into E. coli CsgA fibrils. In this study, we outline an approach to addressing the colloidal instability challenges associated with CsgA, achieved through engineering and electrostatic repulsion. Then, we present the cryo-EM structure of CsgA fibrils at 3.62 Å resolution. This structure provides new insights into the cross-β structure of E. coli CsgA. Additionally, our study identifies two distinct spatial arrangements within several CsgA fibrils, a 2-CsgA-fibril pair and a 3-CsgA-fibril bundle, shedding light on the intricate hierarchy of the biofilm extracellular matrix and laying the foundation for precise manipulation of CsgA-derived biomaterials.IMPORTANCEThe visualization of the architecture of Escherichia coli CsgA amyloid fibril has been a longstanding research question, for which a high-resolution structure is still unavailable. CsgA serves as a major subunit of curli, the primary component of the extracellular matrix generated by bacteria. The support provided by this extracellular matrix enables bacterial biofilms to resist antibiotic treatment, significantly impacting human health. CsgA has been identified in members of Enterobacteriaceae, with pathogenic E. coli being the most well-known model system. Our novel insights into the structure of E. coli CsgA protofilaments form the basis for drug design targeting diseases associated with biofilms. Additionally, CsgA is widely researched in biomaterials due to its self-assembly characteristics. The resolved spatial arrangements of CsgA amyloids revealed in our study will further enhance the precision design of functional biomaterials. Therefore, our study uniquely contributes to the understanding of CsgA amyloids for both microbiology and material science.
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Affiliation(s)
- Fan Bu
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Derek R. Dee
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Bin Liu
- The Hormel Institute, University of Minnesota, Austin, Minnesota, USA
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4
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Valli D, Ooi SA, Scattolini G, Chaudhary H, Tietze AA, Maj M. Improving cryo-EM grids for amyloid fibrils using interface-active solutions and spectator proteins. Biophys J 2024; 123:718-729. [PMID: 38368506 PMCID: PMC10995402 DOI: 10.1016/j.bpj.2024.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/28/2024] [Accepted: 02/13/2024] [Indexed: 02/19/2024] Open
Abstract
Preparation of cryoelectron microscopy (cryo-EM) grids for imaging of amyloid fibrils is notoriously challenging. The human islet amyloid polypeptide (hIAPP) serves as a notable example, as the majority of reported structures have relied on the use of nonphysiological pH buffers, N-terminal tags, and seeding. This highlights the need for more efficient, reproducible methodologies that can elucidate amyloid fibril structures formed under diverse conditions. In this work, we demonstrate that the distribution of fibrils on cryo-EM grids is predominantly determined by the solution composition, which is critical for the stability of thin vitreous ice films. We discover that, among physiological pH buffers, HEPES uniquely enhances the distribution of fibrils on cryo-EM grids and improves the stability of ice layers. This improvement is attributed to direct interactions between HEPES molecules and hIAPP, effectively minimizing the tendency of hIAPP to form dense clusters in solutions and preventing ice nucleation. Furthermore, we provide additional support for the idea that denatured protein monolayers forming at the interface are also capable of eliciting a surfactant-like effect, leading to improved particle coverage. This phenomenon is illustrated by the addition of nonamyloidogenic rat IAPP (rIAPP) to a solution of preaggregated hIAPP just before the freezing process. The resultant grids, supplemented with this "spectator protein", exhibit notably enhanced coverage and improved ice quality. Unlike conventional surfactants, rIAPP is additionally capable of disentangling the dense clusters formed by hIAPP. By applying the proposed strategies, we have resolved the structure of the dominant hIAPP polymorph, formed in vitro at pH 7.4, to a final resolution of 4 Å. The advances in grid preparation presented in this work hold significant promise for enabling structural determination of amyloid proteins which are particularly resistant to conventional grid preparation techniques.
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Affiliation(s)
- Dylan Valli
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Saik Ann Ooi
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Giorgio Scattolini
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Himanshu Chaudhary
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Alesia A Tietze
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Michał Maj
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden.
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Ragonis-Bachar P, Axel G, Blau S, Ben-Tal N, Kolodny R, Landau M. What can AlphaFold do for antimicrobial amyloids? Proteins 2024; 92:265-281. [PMID: 37855235 DOI: 10.1002/prot.26618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/05/2023] [Accepted: 10/05/2023] [Indexed: 10/20/2023]
Abstract
Amyloids, protein, and peptide assemblies in various organisms are crucial in physiological and pathological processes. Their intricate structures, however, present significant challenges, limiting our understanding of their functions, regulatory mechanisms, and potential applications in biomedicine and technology. This study evaluated the AlphaFold2 ColabFold method's structure predictions for antimicrobial amyloids, using eight antimicrobial peptides (AMPs), including those with experimentally determined structures and AMPs known for their distinct amyloidogenic morphological features. Additionally, two well-known human amyloids, amyloid-β and islet amyloid polypeptide, were included in the analysis due to their disease relevance, short sequences, and antimicrobial properties. Amyloids typically exhibit tightly mated β-strand sheets forming a cross-β configuration. However, certain amphipathic α-helical subunits can also form amyloid fibrils adopting a cross-α structure. Some AMPs in the study exhibited a combination of cross-α and cross-β amyloid fibrils, adding complexity to structure prediction. The results showed that the AlphaFold2 ColabFold models favored α-helical structures in the tested amyloids, successfully predicting the presence of α-helical mated sheets and a hydrophobic core resembling the cross-α configuration. This implies that the AI-based algorithms prefer assemblies of the monomeric state, which was frequently predicted as helical, or capture an α-helical membrane-active form of toxic peptides, which is triggered upon interaction with lipid membranes.
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Affiliation(s)
| | - Gabriel Axel
- George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Blau
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Nir Ben-Tal
- George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Rachel Kolodny
- Department of Computer Science, University of Haifa, Haifa, Israel
| | - Meytal Landau
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
- CSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- The Center for Experimental Medicine, Universitätsklinikum Hamburg-Eppendorf (UKE), Hamburg, Germany
- European Molecular Biology Laboratory (EMBL), Hamburg, Germany
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6
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Asarnow D, Becker VA, Bobe D, Dubbledam C, Johnston JD, Kopylov M, Lavoie NR, Li Q, Mattingly JM, Mendez JH, Paraan M, Turner J, Upadhye V, Walsh RM, Gupta M, Eng ET. Recent advances in infectious disease research using cryo-electron tomography. Front Mol Biosci 2024; 10:1296941. [PMID: 38288336 PMCID: PMC10822977 DOI: 10.3389/fmolb.2023.1296941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/07/2023] [Indexed: 01/31/2024] Open
Abstract
With the increasing spread of infectious diseases worldwide, there is an urgent need for novel strategies to combat them. Cryogenic sample electron microscopy (cryo-EM) techniques, particularly electron tomography (cryo-ET), have revolutionized the field of infectious disease research by enabling multiscale observation of biological structures in a near-native state. This review highlights the recent advances in infectious disease research using cryo-ET and discusses the potential of this structural biology technique to help discover mechanisms of infection in native environments and guiding in the right direction for future drug discovery.
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Affiliation(s)
- Daniel Asarnow
- Department of Biochemistry, University of Washington, Seattle, WA, United States
| | - Vada A. Becker
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, United States
| | - Daija Bobe
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, United States
| | - Charlie Dubbledam
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, United States
| | - Jake D. Johnston
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, United States
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, United States
| | - Mykhailo Kopylov
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, United States
| | - Nathalie R. Lavoie
- Department of Molecular Biology and Microbiology, School of Medicine, Tufts University, Boston, MA, United States
| | - Qiuye Li
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Jacob M. Mattingly
- Department of Chemistry, College of Arts and Sciences, Emory University, Atlanta, GA, United States
| | - Joshua H. Mendez
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, United States
| | - Mohammadreza Paraan
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, United States
| | - Jack Turner
- European Bioinformatics Institute (EMBL-EBI), Cambridge, United Kingdom
| | - Viraj Upadhye
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Richard M. Walsh
- Harvard Cryo-Electron Microscopy Center for Structural Biology and Harvard Medical School, Boston, MA, United States
| | - Meghna Gupta
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, United States
| | - Edward T. Eng
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, United States
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7
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Sengupta U, Kayed R. Tau Oligomers as Pathogenic Seeds: Preparation, Characterization, and Propagation In Vitro and In Vivo. Methods Mol Biol 2024; 2754:147-183. [PMID: 38512666 DOI: 10.1007/978-1-0716-3629-9_9] [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: 03/23/2024]
Abstract
Tau oligomers have been shown to be the main toxic tau species in several neurodegenerative disorders. To study tau oligomers, we have developed reagents and established methods for the reliable preparation, isolation, and detection of tau oligomers as well as their seeding and propagation both in vitro and in vivo. Detailed below are methods for isolation of tau oligomers from brain tissues and detection of tau oligomers using tau oligomer-specific antibodies by biochemical, immunohistochemical, and biophysical methods. Further, methods for evaluating the biological activity of the tau oligomers including their effects on synaptic function, seeding, and propagation in cell models and in vivo are also described.
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Affiliation(s)
- Urmi Sengupta
- George P. and Cynthia Woods Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, USA
- Departments of Neurology, and Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Rakez Kayed
- George P. and Cynthia Woods Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX, USA.
- Departments of Neurology, and Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, USA.
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8
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Upadhyay A, Chhangani D, Rao NR, Kofler J, Vassar R, Rincon-Limas DE, Savas JN. Amyloid fibril proteomics of AD brains reveals modifiers of aggregation and toxicity. Mol Neurodegener 2023; 18:61. [PMID: 37710351 PMCID: PMC10503190 DOI: 10.1186/s13024-023-00654-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 09/07/2023] [Indexed: 09/16/2023] Open
Abstract
BACKGROUND The accumulation of amyloid beta (Aβ) peptides in fibrils is prerequisite for Alzheimer's disease (AD). Our understanding of the proteins that promote Aβ fibril formation and mediate neurotoxicity has been limited due to technical challenges in isolating pure amyloid fibrils from brain extracts. METHODS To investigate how amyloid fibrils form and cause neurotoxicity in AD brain, we developed a robust biochemical strategy. We benchmarked the success of our purifications using electron microscopy, amyloid dyes, and a large panel of Aβ immunoassays. Tandem mass-spectrometry based proteomic analysis workflows provided quantitative measures of the amyloid fibril proteome. These methods allowed us to compare amyloid fibril composition from human AD brains, three amyloid mouse models, transgenic Aβ42 flies, and Aβ42 seeded cultured neurons. RESULTS Amyloid fibrils are primarily composed by Aβ42 and unexpectedly harbor Aβ38 but generally lack Aβ40 peptides. Multidimensional quantitative proteomics allowed us to redefine the fibril proteome by identifying 20 new amyloid-associated proteins. Notably, we confirmed 57 previously reported plaque-associated proteins. We validated a panel of these proteins as bona fide amyloid-interacting proteins using antibodies and orthogonal proteomic analysis. One metal-binding chaperone metallothionein-3 is tightly associated with amyloid fibrils and modulates fibril formation in vitro. Lastly, we used a transgenic Aβ42 fly model to test if knock down or over-expression of fibril-interacting gene homologues modifies neurotoxicity. Here, we could functionally validate 20 genes as modifiers of Aβ42 toxicity in vivo. CONCLUSIONS These discoveries and subsequent confirmation indicate that fibril-associated proteins play a key role in amyloid formation and AD pathology.
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Affiliation(s)
- Arun Upadhyay
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Deepak Chhangani
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, 32611, USA
| | - Nalini R Rao
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Julia Kofler
- Department of Pathology, Division of Neuropathology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Robert Vassar
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Diego E Rincon-Limas
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, 32611, USA
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, 32611, USA
- Genetics Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Jeffrey N Savas
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
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9
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Avni A, Joshi A, Mukhopadhyay S. Hydrogen-Deuterium Exchange Vibrational Raman Spectroscopy Distinguishes Distinct Amyloid Polymorphs Comprising Altered Core Architecture. J Phys Chem Lett 2023:5592-5601. [PMID: 37307286 DOI: 10.1021/acs.jpclett.3c01086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Amyloid fibrils are ordered protein aggregates comprising a hydrogen-bonded central cross-β core displaying a structural diversity in their supramolecular packing arrangements within the core. Such an altered packing results in amyloid polymorphism that gives rise to morphological and biological strain diversities. Here, we show that vibrational Raman spectroscopy coupled with hydrogen/deuterium (H/D) exchange discerns the key structural features that are responsible for yielding diverse amyloid polymorphs. Such a noninvasive and label-free methodology allows us to structurally distinguish distinct amyloid polymorphs displaying altered hydrogen bonding and supramolecular packing within the cross-β structural motif. By using quantitative molecular fingerprinting and multivariate statistical analysis, we analyze key Raman bands for the protein backbone and side chains that allow us to capture the conformational heterogeneity and structural distributions within distinct amyloid polymorphs. Our results delineate the key molecular factors governing the structural diversity in amyloid polymorphs and can potentially simplify studying amyloid remodeling by small molecules.
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10
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Pils M, Dybala A, Rehn F, Blömeke L, Bujnicki T, Kraemer-Schulien V, Hoyer W, Riesner D, Willbold D, Bannach O. Development and Implementation of an Internal Quality Control Sample to Standardize Oligomer-Based Diagnostics of Alzheimer's Disease. Diagnostics (Basel) 2023; 13:diagnostics13101702. [PMID: 37238187 DOI: 10.3390/diagnostics13101702] [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: 03/30/2023] [Revised: 05/05/2023] [Accepted: 05/07/2023] [Indexed: 05/28/2023] Open
Abstract
Protein misfolding and aggregation are pathological hallmarks of various neurodegenerative diseases. In Alzheimer's disease (AD), soluble and toxic amyloid-β (Aβ) oligomers are biomarker candidates for diagnostics and drug development. However, accurate quantification of Aβ oligomers in bodily fluids is challenging because extreme sensitivity and specificity are required. We previously introduced surface-based fluorescence intensity distribution analysis (sFIDA) with single-particle sensitivity. In this report, a preparation protocol for a synthetic Aβ oligomer sample was developed. This sample was used for internal quality control (IQC) to improve standardization, quality assurance, and routine application of oligomer-based diagnostic methods. We established an aggregation protocol for Aβ1-42, characterized the oligomers by atomic force microscopy (AFM), and assessed their application in sFIDA. Globular-shaped oligomers with a median size of 2.67 nm were detected by AFM, and sFIDA analysis of the Aβ1-42 oligomers yielded a femtomolar detection limit with high assay selectivity and dilution linearity over 5 log units. Lastly, we implemented a Shewhart chart for monitoring IQC performance over time, which is another important step toward quality assurance of oligomer-based diagnostic methods.
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Affiliation(s)
- Marlene Pils
- attyloid GmbH, Merowingerplatz 1a, 40225 Düsseldorf, Germany
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Alexandra Dybala
- attyloid GmbH, Merowingerplatz 1a, 40225 Düsseldorf, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Fabian Rehn
- attyloid GmbH, Merowingerplatz 1a, 40225 Düsseldorf, Germany
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Lara Blömeke
- attyloid GmbH, Merowingerplatz 1a, 40225 Düsseldorf, Germany
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Tuyen Bujnicki
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Victoria Kraemer-Schulien
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Wolfgang Hoyer
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Detlev Riesner
- attyloid GmbH, Merowingerplatz 1a, 40225 Düsseldorf, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Dieter Willbold
- attyloid GmbH, Merowingerplatz 1a, 40225 Düsseldorf, Germany
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Oliver Bannach
- attyloid GmbH, Merowingerplatz 1a, 40225 Düsseldorf, Germany
- Institute of Biological Information Processing (Structural Biochemistry: IBI-7), Forschungszentrum Jülich, 52428 Jülich, Germany
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11
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Nirmalraj PN, Schneider T, Lüder L, Felbecker A. Protein fibril length in cerebrospinal fluid is increased in Alzheimer's disease. Commun Biol 2023; 6:251. [PMID: 36890343 PMCID: PMC9995532 DOI: 10.1038/s42003-023-04606-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/16/2023] [Indexed: 03/10/2023] Open
Abstract
Alzheimer's disease (AD) associated proteins exist in cerebrospinal fluid (CSF). This paper evidences that protein aggregate morphology distinctly differs in CSF of patients with AD dementia (ADD), mild cognitive impairment due to AD (MCI AD), with subjective cognitive decline without amyloid pathology (SCD) and with non-AD MCI using liquid-based atomic force microscopy (AFM). Spherical-shaped particles and nodular-shaped protofibrils were present in the CSF of SCD patients, whereas CSF of ADD patients abundantly contained elongated mature fibrils. Quantitative analysis of AFM topographs confirms fibril length is higher in CSF of ADD than in MCI AD and lowest in SCD and non-AD dementia patients. CSF fibril length is inversely correlated with CSF amyloid beta (Aβ) 42/40 ratio and CSF p-tau protein levels (obtained from biochemical assays) to predict amyloid and tau pathology with an accuracy of 94% and 82%, respectively, thus identifying ultralong protein fibrils in CSF as a possible signature of AD pathology.
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Affiliation(s)
- Peter Niraj Nirmalraj
- Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, CH-8600, Switzerland.
| | - Thomas Schneider
- Department of Neurology, Cantonal Hospital St. Gallen, St. Gallen, CH-9007, Switzerland
| | - Lars Lüder
- Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, CH-8600, Switzerland
| | - Ansgar Felbecker
- Department of Neurology, Cantonal Hospital St. Gallen, St. Gallen, CH-9007, Switzerland.
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12
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A new polymorphism of human amylin fibrils with similar protofilaments and a conserved core. iScience 2022; 25:105705. [PMID: 36567711 PMCID: PMC9772857 DOI: 10.1016/j.isci.2022.105705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/07/2022] [Accepted: 11/29/2022] [Indexed: 12/04/2022] Open
Abstract
Pancreatic amyloid deposits composed of a fibrillar form of the human islet amyloid polypeptide (hIAPP) are the pathological hallmark of type 2 diabetes (T2D). Although various cryo-EM structures of polymorphic hIAPP fibrils were reported, the underlying polymorphic mechanism of hIAPP remains elusive. Meanwhile, the structure of hIAPP fibrils with all residues visible in the fibril core is not available. Here, we report the full-length structures of two different polymorphs of hIAPP fibrils, namely slim form (SF, dimer) and thick form (TF, tetramer), formed in a salt-free environment, which share a similar ζ-shaped protofilament but differ in inter-protofilament interfaces. In the absence of salt, electrostatic interactions were found to play a dominant role in stabilizing the fibril structure, suggesting an antagonistic effect between electrostatic and hydrophobic interactions in different salt concentrations environments. Our results shed light on understanding the mechanism of amyloid fibril polymorphism.
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13
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Cell-free synthesis of amyloid fibrils with infectious properties and amenable to sub-milligram magic-angle spinning NMR analysis. Commun Biol 2022; 5:1202. [DOI: 10.1038/s42003-022-04175-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022] Open
Abstract
AbstractStructural investigations of amyloid fibrils often rely on heterologous bacterial overexpression of the protein of interest. Due to their inherent hydrophobicity and tendency to aggregate as inclusion bodies, many amyloid proteins are challenging to express in bacterial systems. Cell-free protein expression is a promising alternative to classical bacterial expression to produce hydrophobic proteins and introduce NMR-active isotopes that can improve and speed up the NMR analysis. Here we implement the cell-free synthesis of the functional amyloid prion HET-s(218-289). We present an interesting case where HET-s(218-289) directly assembles into infectious fibril in the cell-free expression mixture without the requirement of denaturation procedures and purification. By introducing tailored 13C and 15N isotopes or CF3 and 13CH2F labels at strategic amino-acid positions, we demonstrate that cell-free synthesized amyloid fibrils are readily amenable to high-resolution magic-angle spinning NMR at sub-milligram quantity.
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14
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Housmans JAJ, Houben B, Monge-Morera M, Asvestas D, Nguyen HH, Tsaka G, Louros N, Carpentier S, Delcour JA, Rousseau F, Schymkowitz J. Investigating the Sequence Determinants of the Curling of Amyloid Fibrils Using Ovalbumin as a Case Study. Biomacromolecules 2022; 23:3779-3797. [PMID: 36027608 DOI: 10.1021/acs.biomac.2c00660] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Highly ordered, straight amyloid fibrils readily lend themselves to structure determination techniques and have therefore been extensively characterized. However, the less ordered curly fibrils remain relatively understudied, and the structural organization underlying their specific characteristics remains poorly understood. We found that the exemplary curly fibril-forming protein ovalbumin contains multiple aggregation prone regions (APRs) that form straight fibrils when isolated as peptides or when excised from the full-length protein through hydrolysis. In the context of the intact full-length protein, however, the regions separating the APRs facilitate curly fibril formation. In fact, a meta-analysis of previously reported curly fibril-forming proteins shows that their inter-APRs are significantly longer and more hydrophobic when compared to straight fibril-forming proteins, suggesting that they may cause strain in the amyloid state. Hence, inter-APRs driving curly fibril formation may not only apply to our model protein but rather constitute a more general mechanism.
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Affiliation(s)
- Joëlle A J Housmans
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Bert Houben
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Margarita Monge-Morera
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium
| | - Diego Asvestas
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Hung Huy Nguyen
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Grigoria Tsaka
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Nikolaos Louros
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Sebastien Carpentier
- Facility for Systems Biology Based Mass Spectrometry, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Jan A Delcour
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium
| | - Frederic Rousseau
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium.,Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, box 802, 3000 Leuven, Belgium
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15
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Artikis E, Kraus A, Caughey B. Structural biology of ex vivo mammalian prions. J Biol Chem 2022; 298:102181. [PMID: 35752366 PMCID: PMC9293645 DOI: 10.1016/j.jbc.2022.102181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 01/13/2023] Open
Abstract
The structures of prion protein (PrP)–based mammalian prions have long been elusive. However, cryo-EM has begun to reveal the near-atomic resolution structures of fully infectious ex vivo mammalian prion fibrils as well as relatively innocuous synthetic PrP amyloids. Comparisons of these various types of PrP fibrils are now providing initial clues to structural features that correlate with pathogenicity. As first indicated by electron paramagnetic resonance and solid-state NMR studies of synthetic amyloids, all sufficiently resolved PrP fibrils of any sort (n > 10) have parallel in-register intermolecular β-stack architectures. Cryo-EM has shown that infectious brain-derived prion fibrils of the rodent-adapted 263K and RML scrapie strains have much larger ordered cores than the synthetic fibrils. These bona fide prion strains share major structural motifs, but the conformational details and the overall shape of the fibril cross sections differ markedly. Such motif variations, as well as differences in sequence within the ordered polypeptide cores, likely contribute to strain-dependent templating. When present, N-linked glycans and glycophosphatidylinositol (GPI) anchors project outward from the fibril surface. For the mouse RML strain, these posttranslational modifications have little effect on the core structure. In the GPI-anchored prion structures, a linear array of GPI anchors along the twisting fibril axis appears likely to bind membranes in vivo, and as such, may account for pathognomonic membrane distortions seen in prion diseases. In this review, we focus on these infectious prion structures and their implications regarding prion replication mechanisms, strains, transmission barriers, and molecular pathogenesis.
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Affiliation(s)
- Efrosini Artikis
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840 USA
| | - Allison Kraus
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| | - Byron Caughey
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840 USA.
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16
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Taylor AIP, Staniforth RA. General Principles Underpinning Amyloid Structure. Front Neurosci 2022; 16:878869. [PMID: 35720732 PMCID: PMC9201691 DOI: 10.3389/fnins.2022.878869] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/11/2022] [Indexed: 12/14/2022] Open
Abstract
Amyloid fibrils are a pathologically and functionally relevant state of protein folding, which is generally accessible to polypeptide chains and differs fundamentally from the globular state in terms of molecular symmetry, long-range conformational order, and supramolecular scale. Although amyloid structures are challenging to study, recent developments in techniques such as cryo-EM, solid-state NMR, and AFM have led to an explosion of information about the molecular and supramolecular organization of these assemblies. With these rapid advances, it is now possible to assess the prevalence and significance of proposed general structural features in the context of a diverse body of high-resolution models, and develop a unified view of the principles that control amyloid formation and give rise to their unique properties. Here, we show that, despite system-specific differences, there is a remarkable degree of commonality in both the structural motifs that amyloids adopt and the underlying principles responsible for them. We argue that the inherent geometric differences between amyloids and globular proteins shift the balance of stabilizing forces, predisposing amyloids to distinct molecular interaction motifs with a particular tendency for massive, lattice-like networks of mutually supporting interactions. This general property unites previously characterized structural features such as steric and polar zippers, and contributes to the long-range molecular order that gives amyloids many of their unique properties. The shared features of amyloid structures support the existence of shared structure-activity principles that explain their self-assembly, function, and pathogenesis, and instill hope in efforts to develop broad-spectrum modifiers of amyloid function and pathology.
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17
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Matiiv AB, Trubitsina NP, Matveenko AG, Barbitoff YA, Zhouravleva GA, Bondarev SA. Structure and Polymorphism of Amyloid and Amyloid-Like Aggregates. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:450-463. [PMID: 35790379 DOI: 10.1134/s0006297922050066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 04/08/2022] [Accepted: 04/09/2022] [Indexed: 06/15/2023]
Abstract
Amyloids are protein aggregates with the cross-β structure. The interest in amyloids is explained, on the one hand, by their role in the development of socially significant human neurodegenerative diseases, and on the other hand, by the discovery of functional amyloids, whose formation is an integral part of cellular processes. To date, more than a hundred proteins with the amyloid or amyloid-like properties have been identified. Studying the structure of amyloid aggregates has revealed a wide variety of protein conformations. In the review, we discuss the diversity of protein folds in the amyloid-like aggregates and the characteristic features of amyloid aggregates that determine their unusual properties, including stability and interaction with amyloid-specific dyes. The review also describes the diversity of amyloid aggregates and its significance for living organisms.
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Affiliation(s)
- Anton B Matiiv
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, 199034, Russia
| | - Nina P Trubitsina
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, 199034, Russia
| | - Andrew G Matveenko
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, 199034, Russia
| | - Yury A Barbitoff
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, 199034, Russia
- Bioinformatics Institute, Saint Petersburg, 197342, Russia
| | - Galina A Zhouravleva
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, 199034, Russia
- Laboratory of Amyloid Biology, Saint Petersburg State University, Saint Petersburg, 199034, Russia
| | - Stanislav A Bondarev
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, 199034, Russia.
- Laboratory of Amyloid Biology, Saint Petersburg State University, Saint Petersburg, 199034, Russia
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