1
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Kumari K, Singh AK, Mandal P, Rakshit S. Crowder Chain Length Variability and Excluded Volume Effect on the Phase Separation Behavior of Mucin. J Phys Chem Lett 2024:10505-10513. [PMID: 39393020 DOI: 10.1021/acs.jpclett.4c01524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2024]
Abstract
Phase separation within cellular membranes, a critical process underpinning diverse cellular functions, is significantly influenced by transmembrane proteins. Therefore, elucidating the behavior of a transmembrane protein in its phase-separated state is of utmost importance. Our study explores mucin behavior in the cellular milieu, aiming to determine the role of crowder chain length and excluded volume in phase separation. Confocal microscopy images demonstrate the strong partitioning of mucin into the condensed phase influenced by hydrophobic and electrostatic interactions. Fluorescence recovery after photobleaching analysis revealed increased mobility in the presence of shorter chain length crowders, indicating the dynamic behavior of protein within condensed phases. Excluded volume calculation using the theoretical model emphasizes its importance in mucin phase separation under crowded conditions. Our findings underscore the ability of mucin to phase-separate under crowded conditions, highlighting the crucial role of excluded volume and enhancing our understanding of its involvement in cancer progression.
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Affiliation(s)
- Komal Kumari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Anant Kumar Singh
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Priyankar Mandal
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Surajit Rakshit
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
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2
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Renawala HK, Chandrababu KB, Smith KJ, D'Addio SM, Topp EM. A Model Study to Assess Fibrillation and Product Stability to Support Peptide Drug Design. Mol Pharm 2024; 21:2223-2237. [PMID: 38552144 DOI: 10.1021/acs.molpharmaceut.3c00996] [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: 05/07/2024]
Abstract
The fibrillation of therapeutic peptides can present significant quality concerns and poses challenges for manufacturing and storage. A fundamental understanding of the mechanisms of fibrillation is critical for the rational design of fibrillation-resistant peptide drugs and can accelerate product development by guiding the selection of solution-stable candidates and formulations. The studies reported here investigated the effects of structural modifications on the fibrillation of a 29-residue peptide (PepA) and two sequence modified variants (PepB, PepC). The C-terminus of PepA was amidated, whereas both PepB and PepC retained the carboxylate, and Ser16 in PepA and PepB was substituted with a helix-stabilizing residue, α-aminoisobutyric acid (Aib), in PepC. In thermal denaturation studies by far-UV CD spectroscopy and fibrillation kinetic studies by fluorescence and turbidity measurements, PepA and PepB showed heat-induced conformational changes and were found to form fibrils, whereas PepC did not fibrillate and showed only minor changes in the CD signal. Pulsed hydrogen-deuterium exchange mass spectrometry (HDX-MS) showed a high degree of protection from HD exchange in mature PepA fibrils and its proteolytic fragments, indicating that most of the sequence had been incorporated into the fibril structure and occurred nearly simultaneously throughout the sequence. The effects of the net peptide charge and formulation pH on fibrillation kinetics were investigated. In real-time stability studies of two formulations of PepA at pH's 7.4 and 8.0, analytical methods detected significant changes in the stability of the formulations at different time points during the study, which were not observed during accelerated studies. Additionally, PepA samples were withdrawn from real-time stability and subjected to additional stress (40 °C, continuous shaking) to induce fibrillation; an approach that successfully amplified oligomers or prefibrillar species previously undetected in a thioflavin T assay. Taken together, these studies present an approach to differentiate and characterize fibrillation risk in structurally related peptides under accelerated and real-time conditions, providing a model for rapid, iterative structural design to optimize the stability of therapeutic peptides.
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Affiliation(s)
- Harshil K Renawala
- Department of Industrial and Molecular Pharmaceutics, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Karthik B Chandrababu
- Department of Industrial and Molecular Pharmaceutics, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Katelyn J Smith
- Pharmaceutical Sciences and Clinical Supply, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Suzanne M D'Addio
- Pharmaceutical Sciences and Clinical Supply, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Elizabeth M Topp
- Department of Industrial and Molecular Pharmaceutics, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
- Davidson School of Chemical Engineering, College of Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- National Institute for Bioprocessing Research and Training, Belfield, Blackrock, Co. Dublin A94 X099, Ireland
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3
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Horne RI, Andrzejewska EA, Alam P, Brotzakis ZF, Srivastava A, Aubert A, Nowinska M, Gregory RC, Staats R, Possenti A, Chia S, Sormanni P, Ghetti B, Caughey B, Knowles TPJ, Vendruscolo M. Discovery of potent inhibitors of α-synuclein aggregation using structure-based iterative learning. Nat Chem Biol 2024; 20:634-645. [PMID: 38632492 PMCID: PMC11062903 DOI: 10.1038/s41589-024-01580-x] [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: 01/17/2023] [Accepted: 02/12/2024] [Indexed: 04/19/2024]
Abstract
Machine learning methods hold the promise to reduce the costs and the failure rates of conventional drug discovery pipelines. This issue is especially pressing for neurodegenerative diseases, where the development of disease-modifying drugs has been particularly challenging. To address this problem, we describe here a machine learning approach to identify small molecule inhibitors of α-synuclein aggregation, a process implicated in Parkinson's disease and other synucleinopathies. Because the proliferation of α-synuclein aggregates takes place through autocatalytic secondary nucleation, we aim to identify compounds that bind the catalytic sites on the surface of the aggregates. To achieve this goal, we use structure-based machine learning in an iterative manner to first identify and then progressively optimize secondary nucleation inhibitors. Our results demonstrate that this approach leads to the facile identification of compounds two orders of magnitude more potent than previously reported ones.
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Affiliation(s)
- Robert I Horne
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Ewa A Andrzejewska
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Parvez Alam
- Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Z Faidon Brotzakis
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Ankit Srivastava
- Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Alice Aubert
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Magdalena Nowinska
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Rebecca C Gregory
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Roxine Staats
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Andrea Possenti
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Sean Chia
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Pietro Sormanni
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Byron Caughey
- Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
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4
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Tomioka Y, Akuta T, Tokunaga M, Arakawa T. Different behavior of Ferguson plot between agarose and polyacrylamide gels. Biophys Chem 2024; 307:107200. [PMID: 38367540 DOI: 10.1016/j.bpc.2024.107200] [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: 11/14/2023] [Revised: 02/04/2024] [Accepted: 02/12/2024] [Indexed: 02/19/2024]
Abstract
In this study, we conducted Ferguson plot analyses using both agarose and polyacrylamide gels in native electrophoresis and SDS-PAGE. The results revealed intriguing differences in the behavior of bovine serum albumin (BSA) and other model proteins. Specifically, BSA exhibited Ferguson plot slopes that were dependent on the oligomer size in agarose native gel electrophoresis, while such size-dependent behavior was not observed in native-PAGE or SDS-PAGE. These findings suggest that Ferguson plot analysis is a suitable approach when using agarose gel under the electrophoretic conditions employed in this study. Furthermore, our investigation extended to model proteins with acidic isoelectric points and larger molecular weights, namely Ferritin and caseinolytic peptidase B (ClpB). Notably, these proteins displayed distinct Ferguson plot slopes when subjected to agarose gel electrophoresis. Intriguingly, when polyacrylamide gel was employed, ClpB exhibited multiple bands, each with its unique Ferguson plot slope, deviating from the expected behavior based on molecular size. This divergence in Ferguson plot characteristics between agarose and polyacrylamide gels points to an interesting and complex interplay between protein properties and gel electrophoresis conditions.
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Affiliation(s)
- Yui Tomioka
- Product Development Division, Kyokuto Pharmaceutical Industrial Co., Ltd., 3333-26, Aza-Asayama, Kamitezuna Takahagi-shi, Ibaraki 318-0004, Japan.
| | - Teruo Akuta
- Product Development Division, Kyokuto Pharmaceutical Industrial Co., Ltd., 3333-26, Aza-Asayama, Kamitezuna Takahagi-shi, Ibaraki 318-0004, Japan.
| | - Masao Tokunaga
- Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University, Korimoto, Kagoshima-shi 890-0065, Japan
| | - Tsutomu Arakawa
- Alliance Protein Laboratories, 13380 Pantera Rd, San Diego, CA 92130, USA.
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5
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Louros N, Schymkowitz J, Rousseau F. Mechanisms and pathology of protein misfolding and aggregation. Nat Rev Mol Cell Biol 2023; 24:912-933. [PMID: 37684425 DOI: 10.1038/s41580-023-00647-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2023] [Indexed: 09/10/2023]
Abstract
Despite advances in machine learning-based protein structure prediction, we are still far from fully understanding how proteins fold into their native conformation. The conventional notion that polypeptides fold spontaneously to their biologically active states has gradually been replaced by our understanding that cellular protein folding often requires context-dependent guidance from molecular chaperones in order to avoid misfolding. Misfolded proteins can aggregate into larger structures, such as amyloid fibrils, which perpetuate the misfolding process, creating a self-reinforcing cascade. A surge in amyloid fibril structures has deepened our comprehension of how a single polypeptide sequence can exhibit multiple amyloid conformations, known as polymorphism. The assembly of these polymorphs is not a random process but is influenced by the specific conditions and tissues in which they originate. This observation suggests that, similar to the folding of native proteins, the kinetics of pathological amyloid assembly are modulated by interactions specific to cells and tissues. Here, we review the current understanding of how intrinsic protein conformational propensities are modulated by physiological and pathological interactions in the cell to shape protein misfolding and aggregation pathology.
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Affiliation(s)
- Nikolaos Louros
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
| | - Frederic Rousseau
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
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6
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Light, Water, and Melatonin: The Synergistic Regulation of Phase Separation in Dementia. Int J Mol Sci 2023; 24:ijms24065835. [PMID: 36982909 PMCID: PMC10054283 DOI: 10.3390/ijms24065835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 03/22/2023] Open
Abstract
The swift rise in acceptance of molecular principles defining phase separation by a broad array of scientific disciplines is shadowed by increasing discoveries linking phase separation to pathological aggregations associated with numerous neurodegenerative disorders, including Alzheimer’s disease, that contribute to dementia. Phase separation is powered by multivalent macromolecular interactions. Importantly, the release of water molecules from protein hydration shells into bulk creates entropic gains that promote phase separation and the subsequent generation of insoluble cytotoxic aggregates that drive healthy brain cells into diseased states. Higher viscosity in interfacial waters and limited hydration in interiors of biomolecular condensates facilitate phase separation. Light, water, and melatonin constitute an ancient synergy that ensures adequate protein hydration to prevent aberrant phase separation. The 670 nm visible red wavelength found in sunlight and employed in photobiomodulation reduces interfacial and mitochondrial matrix viscosity to enhance ATP production via increasing ATP synthase motor efficiency. Melatonin is a potent antioxidant that lowers viscosity to increase ATP by scavenging excess reactive oxygen species and free radicals. Reduced viscosity by light and melatonin elevates the availability of free water molecules that allow melatonin to adopt favorable conformations that enhance intrinsic features, including binding interactions with adenosine that reinforces the adenosine moiety effect of ATP responsible for preventing water removal that causes hydrophobic collapse and aggregation in phase separation. Precise recalibration of interspecies melatonin dosages that account for differences in metabolic rates and bioavailability will ensure the efficacious reinstatement of the once-powerful ancient synergy between light, water, and melatonin in a modern world.
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7
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Tian Y, Viles JH. pH Dependence of Amyloid-β Fibril Assembly Kinetics: Unravelling the Microscopic Molecular Processes. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202210675. [PMID: 38504922 PMCID: PMC10947324 DOI: 10.1002/ange.202210675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Indexed: 11/09/2022]
Abstract
Central to Alzheimer's disease (AD) is the assembly of the amyloid-beta peptide (Aβ) into fibrils. A reduction in pH accompanying inflammation or subcellular compartments, may accelerate fibril formation as the pH approaches Aβ's isoelectric point (pI). Using global fitting of fibril formation kinetics over a range of pHs, we identify the impact net charge has on individual fibril assembly microscopic rate constants. We show that the primary nucleation has a strong pH dependence. The titration behaviour exhibits a mid-point or pK a of 7.0, close to the pK a of Aβ histidine imidazoles. Surprisingly, both the secondary nucleation and elongation rate constants are pH independent. This indicates the charge of Aβ, in particular histidine protonation, has little impact on this stage of Aβ assembly. These fundamental processes are key to understanding the forces that drive the assembly of Aβ into toxic oligomers and fibrils.
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Affiliation(s)
- Yao Tian
- Department of BiochemistrySchool of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
| | - John H. Viles
- Department of BiochemistrySchool of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
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8
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Tian Y, Viles JH. pH Dependence of Amyloid-β Fibril Assembly Kinetics: Unravelling the Microscopic Molecular Processes. Angew Chem Int Ed Engl 2022; 61:e202210675. [PMID: 36197009 PMCID: PMC9828734 DOI: 10.1002/anie.202210675] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Indexed: 11/05/2022]
Abstract
Central to Alzheimer's disease (AD) is the assembly of the amyloid-beta peptide (Aβ) into fibrils. A reduction in pH accompanying inflammation or subcellular compartments, may accelerate fibril formation as the pH approaches Aβ's isoelectric point (pI). Using global fitting of fibril formation kinetics over a range of pHs, we identify the impact net charge has on individual fibril assembly microscopic rate constants. We show that the primary nucleation has a strong pH dependence. The titration behaviour exhibits a mid-point or pKa of 7.0, close to the pKa of Aβ histidine imidazoles. Surprisingly, both the secondary nucleation and elongation rate constants are pH independent. This indicates the charge of Aβ, in particular histidine protonation, has little impact on this stage of Aβ assembly. These fundamental processes are key to understanding the forces that drive the assembly of Aβ into toxic oligomers and fibrils.
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Affiliation(s)
- Yao Tian
- Department of BiochemistrySchool of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
| | - John H. Viles
- Department of BiochemistrySchool of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
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9
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Lauth LM, Voigt B, Bhatia T, Machner L, Balbach J, Ott M. Heparin promotes rapid fibrillation of the basic Parathyroid Hormone at physiological pH. FEBS Lett 2022; 596:2928-2939. [PMID: 35903816 DOI: 10.1002/1873-3468.14455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 06/14/2022] [Accepted: 07/09/2022] [Indexed: 11/06/2022]
Abstract
In acidic secretory granules of mammalian cells, peptide hormones including the parathyroid hormone (PTH) are presumably stored in the form of functional amyloid fibrils. Mature PTH, however, is considerably positively charged in acidic environments, a condition known to impede unassisted self-aggregation into fibrils. Here, we studied the role of the polyanion heparin on promoting fibril formation of PTH. Employing ITC, CD spectroscopy, NMR, SAXS and fluorescence-based assays we could demonstrate that heparin binds PTH with submicromolar affinity and facilitates its conversion into fibrillar seeds, enabling rapid formation of amyloid fibrils under acidic conditions. In absence of heparin, PTH remained in a soluble monomeric state. We suspect that heparin-like surfaces are required in vivo to convert PTH efficiently into fibrillar deposits.
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Affiliation(s)
- Luca M Lauth
- Department of Biochemistry and Biotechnology, Martin-Luther-University, Halle-Wittenberg, Halle, Germany
| | - Bruno Voigt
- Department of Biophysics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Twinkle Bhatia
- Department of Biochemistry and Biotechnology, Martin-Luther-University, Halle-Wittenberg, Halle, Germany
| | - Lisa Machner
- Department of Molecular Medicine, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Jochen Balbach
- Department of Biophysics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Maria Ott
- Department of Biochemistry and Biotechnology, Martin-Luther-University, Halle-Wittenberg, Halle, Germany
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10
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Supersaturation-Dependent Formation of Amyloid Fibrils. Molecules 2022; 27:molecules27144588. [PMID: 35889461 PMCID: PMC9321232 DOI: 10.3390/molecules27144588] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 01/27/2023] Open
Abstract
The supersaturation of a solution refers to a non-equilibrium phase in which the solution is trapped in a soluble state, even though the solute’s concentration is greater than its thermodynamic solubility. Upon breaking supersaturation, crystals form and the concentration of the solute decreases to its thermodynamic solubility. Soon after the discovery of the prion phenomena, it was recognized that prion disease transmission and propagation share some similarities with the process of crystallization. Subsequent studies exploring the structural and functional association between amyloid fibrils and amyloidoses solidified this paradigm. However, recent studies have not necessarily focused on supersaturation, possibly because of marked advancements in structural studies clarifying the atomic structures of amyloid fibrils. On the other hand, there is increasing evidence that supersaturation plays a critical role in the formation of amyloid fibrils and the onset of amyloidosis. Here, we review the recent evidence that supersaturation plays a role in linking unfolding/folding and amyloid fibril formation. We also introduce the HANABI (HANdai Amyloid Burst Inducer) system, which enables high-throughput analysis of amyloid fibril formation by the ultrasonication-triggered breakdown of supersaturation. In addition to structural studies, studies based on solubility and supersaturation are essential both to developing a comprehensive understanding of amyloid fibrils and their roles in amyloidosis, and to developing therapeutic strategies.
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11
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Saraiva MA, Florêncio MH. Buffering capacity is determinant for restoring early α-synuclein aggregation. Biophys Chem 2022; 282:106760. [DOI: 10.1016/j.bpc.2022.106760] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/28/2021] [Accepted: 01/10/2022] [Indexed: 11/02/2022]
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12
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Development of HANABI, an ultrasonication-forced amyloid fibril inducer. Neurochem Int 2021; 153:105270. [PMID: 34954259 DOI: 10.1016/j.neuint.2021.105270] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/16/2021] [Accepted: 12/21/2021] [Indexed: 12/20/2022]
Abstract
Amyloid fibrils involved in amyloidoses are crystal-like aggregates, which are formed by breaking supersaturation of denatured proteins. Ultrasonication is an efficient method of agitation for breaking supersaturation and thus inducing amyloid fibrils. By combining an ultrasonicator and a microplate reader, we developed the HANABI (HANdai Amyloid Burst Inducer) system that enables high-throughput analysis of amyloid fibril formation. Among high-throughput approaches of amyloid fibril assays, the HANABI system has advantages in accelerating and detecting spontaneous amyloid fibril formation. HANABI is also powerful for amplifying a tiny amount of preformed amyloid fibrils by seeding. Thus, HANABI will contribute to creating therapeutic strategies against amyloidoses by identifying their biomarkers.
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13
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Yamaguchi K, Hasuo K, So M, Ikenaka K, Mochizuki H, Goto Y. Strong acids induce amyloid fibril formation of β 2-microglobulin via an anion-binding mechanism. J Biol Chem 2021; 297:101286. [PMID: 34626645 PMCID: PMC8564678 DOI: 10.1016/j.jbc.2021.101286] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 11/28/2022] Open
Abstract
Amyloid fibrils, crystal-like fibrillar aggregates of proteins associated with various amyloidoses, have the potential to propagate via a prion-like mechanism. Among known methodologies to dissolve preformed amyloid fibrils, acid treatment has been used with the expectation that the acids will degrade amyloid fibrils similar to acid inactivation of protein functions. Contrary to our expectation, treatment with strong acids, such as HCl or H2SO4, of β2-microglobulin (β2m) or insulin actually promoted amyloid fibril formation, proportionally to the concentration of acid used. A similar promotion was observed at pH 2.0 upon the addition of salts, such as NaCl or Na2SO4. Although trichloroacetic acid, another strong acid, promoted amyloid fibril formation of β2m, formic acid, a weak acid, did not, suggesting the dominant role of anions in promoting fibril formation of this protein. Comparison of the effects of acids and salts confirmed the critical role of anions, indicating that strong acids likely induce amyloid fibril formation via an anion-binding mechanism. The results suggest that although the addition of strong acids decreases pH, it is not useful for degrading amyloid fibrils, but rather induces or stabilizes amyloid fibrils via an anion-binding mechanism.
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Affiliation(s)
- Keiichi Yamaguchi
- Global Center for Medical Engineering and Informatics, Osaka University, Suita, Osaka, Japan; Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kenshiro Hasuo
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Masatomo So
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kensuke Ikenaka
- Department of Neurology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Hideki Mochizuki
- Department of Neurology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Yuji Goto
- Global Center for Medical Engineering and Informatics, Osaka University, Suita, Osaka, Japan; Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
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14
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Zadali R, Hassani V, Rafiei Y, Meratan AA, Mamashli F, Nemat-Gorgani M. A study on the interaction of the amyloid fibrils of α-synuclein and hen egg white lysozyme with biological membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1864:183776. [PMID: 34547253 DOI: 10.1016/j.bbamem.2021.183776] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 09/06/2021] [Accepted: 09/10/2021] [Indexed: 01/23/2023]
Abstract
Alpha-synuclein (α-syn) aggregation and mitochondrial dysfunction are considered as two of the main factors associated with Parkinson's disease (PD). In the present investigation, the effectiveness of the amyloid fibrils obtained from α-syn with those of hen egg white lysozyme (HEWL), as disease-related and-unrelated proteins, to damage rat brain and rat liver mitochondria have been investigated. This was extended by looking at SH-SY5Y human neuroblastoma cells and erythrocytes, thereby investigating the significance of structural characteristics of amyloid fibrils related to their interactions with biomembranes obtained from various sources. Results presented clearly demonstrate substantial differences in the response of tested biomembranes to toxicity induced by α-syn/HEWL amyloid fibrils, highlighting a structure-function relationship. We found that fibrillar aggregates of α-syn, but not HEWL, caused a significant increase in mitochondrial ROS, loss of membrane potential, and mitochondrial swelling, in a dose-dependent manner. Toxicity was found to be more pronounced in brain mitochondria, as compared to liver mitochondria. For SH-SY5Y cells and erythrocytes, however, both α-syn and HEWL amyloid fibrils showed the capacity to induce toxicity. Taken together, these results may suggest selective toxicity of α-syn amyloid fibrils to mitochondria mediated likely by their direct interaction with the outer mitochondrial membrane, indicating a correlation between specific structural characteristics of α-syn fibrils and an organelle strongly implicated in PD pathology.
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Affiliation(s)
- Ramin Zadali
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Vahid Hassani
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Yasin Rafiei
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Ali Akbar Meratan
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran.
| | - Fatemeh Mamashli
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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15
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So M, Kimura Y, Yamaguchi K, Sugiki T, Fujiwara T, Aguirre C, Ikenaka K, Mochizuki H, Kawata Y, Goto Y. Polyphenol-solubility alters amyloid fibril formation of α-synuclein. Protein Sci 2021; 30:1701-1713. [PMID: 34046949 DOI: 10.1002/pro.4130] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/10/2021] [Accepted: 05/18/2021] [Indexed: 12/18/2022]
Abstract
Amyloid fibril formation is associated with various amyloidoses, including neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Amyloid fibrils form above the solubility of amyloidogenic proteins or peptides upon breaking supersaturation, followed by a nucleation and elongation mechanism, which is similar to the crystallization of solutes. Many additives, including salts, detergents, and natural compounds, promote or inhibit amyloid formation. However, the underlying mechanisms of the opposing effects are unclear. We examined the effects of two polyphenols, that is, epigallocatechin gallate (EGCG) and kaempferol-7─O─glycoside (KG), with high and low solubilities, respectively, on the amyloid formation of α-synuclein (αSN). EGCG and KG inhibited and promoted amyloid formation of αSN, respectively, when monitored by thioflavin T (ThT) fluorescence or transmission electron microscopy (TEM). Nuclear magnetic resonance (NMR) analysis revealed that, although interactions of αSN with soluble EGCG increased the solubility of αSN, thus inhibiting amyloid formation, interactions of αSN with insoluble KG reduced the solubility of αSN, thereby promoting amyloid formation. Our study suggests that opposing effects of polyphenols on amyloid formation of proteins and peptides can be interpreted based on the solubility of polyphenols.
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Affiliation(s)
- Masatomo So
- Institute for Protein Research, Osaka University, Osaka, Japan.,Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Yuto Kimura
- Institute for Protein Research, Osaka University, Osaka, Japan
| | - Keiichi Yamaguchi
- Institute for Protein Research, Osaka University, Osaka, Japan.,Global Center for Medical Engineering and Informatics, Osaka University, Osaka, Japan
| | | | | | - Cesar Aguirre
- Institute for Protein Research, Osaka University, Osaka, Japan.,Department of Neurology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Kensuke Ikenaka
- Department of Neurology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hideki Mochizuki
- Department of Neurology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yasushi Kawata
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University, Osaka, Japan.,Global Center for Medical Engineering and Informatics, Osaka University, Osaka, Japan
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16
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Yamaguchi K, So M, Aguirre C, Ikenaka K, Mochizuki H, Kawata Y, Goto Y. Polyphosphates induce amyloid fibril formation of α-synuclein in concentration-dependent distinct manners. J Biol Chem 2021; 296:100510. [PMID: 33676889 PMCID: PMC8059054 DOI: 10.1016/j.jbc.2021.100510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 11/17/2022] Open
Abstract
Polyphosphates (polyPs), chains of phosphate residues found in species across nature from bacteria to mammals, were recently reported to accelerate the amyloid fibril formation of many proteins. How polyPs facilitate this process, however, remains unknown. To gain insight into their mechanisms, we used various physicochemical approaches to examine the effects of polyPs of varying chain lengths on ultrasonication-dependent α-synuclein (α-syn) amyloid formation. Although orthophosphate and diphosphate exhibited a single optimal concentration of amyloid formation, triphosphate and longer-chain phosphates exhibited two optima, with the second at a concentration lower than that of orthophosphate or diphosphate. The second optimum decreased markedly as the polyP length increased. This suggested that although the optima at lower polyP concentrations were caused by interactions between negatively charged phosphate groups and the positive charges of α-syn, the optima at higher polyP concentrations were caused by the Hofmeister salting-out effects of phosphate groups, where the effects do not depend on the net charge. NMR titration experiments of α-syn with tetraphosphate combined with principal component analysis revealed that, at low tetraphosphate concentrations, negatively charged tetraphosphates interacted with positively charged "KTK" segments in four KTKEGV repeats located at the N-terminal region. At high concentrations, hydrated tetraphosphates affected the surface-exposed hydrophilic groups of compact α-syn. Taken together, our results suggest that long-chain polyPs consisting of 60 to 70 phosphates induce amyloid formation at sub-μM concentrations, which are comparable with the concentrations of polyPs in the blood or tissues. Thus, these findings may identify a role for polyPs in the pathogenesis of amyloid-related diseases.
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Affiliation(s)
- Keiichi Yamaguchi
- Global Center for Medical Engineering and Informatics, Osaka University, Osaka, Japan; Institute for Protein Research, Osaka University, Osaka, Japan
| | - Masatomo So
- Institute for Protein Research, Osaka University, Osaka, Japan
| | - César Aguirre
- Institute for Protein Research, Osaka University, Osaka, Japan; Department of Neurology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Kensuke Ikenaka
- Department of Neurology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hideki Mochizuki
- Department of Neurology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yasushi Kawata
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Yuji Goto
- Global Center for Medical Engineering and Informatics, Osaka University, Osaka, Japan; Institute for Protein Research, Osaka University, Osaka, Japan.
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17
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Dhembla C, Arya R, Kumar A, Kundu S, Sundd M. L. major apo-acyl carrier protein forms ordered aggregates due to an exposed phenylalanine, while phosphopantetheine inhibits aggregation in the holo-form. Int J Biol Macromol 2021; 179:144-153. [PMID: 33667556 DOI: 10.1016/j.ijbiomac.2021.02.215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/23/2021] [Accepted: 02/27/2021] [Indexed: 11/25/2022]
Abstract
L. major acyl carrier protein (ACP) is a mitochondrial protein, involved in fatty acid biosynthesis. The protein is expressed as an apo-protein, and post-translationally modified at Ser 37 by a 4'-Phosphopantetheinyl transferase. Crystal structure of the apo-form of the protein at pH 5.5 suggests a four helix bundle fold, typical of ACP's. However, upon lowering the pH to 5.0, it undergoes a conformational transition from α-helix to β-sheet, and displays amyloid like properties. When left for a few days at room temperature at this pH, the protein forms fibrils, visible under Transmission electron microscopy (TEM). Using an approach combining NMR, biophysical techniques, and mutagenesis, we have identified a Phe residue present on helix II of ACP, liable for this change. Phosphopantetheinylation of LmACP, or mutation of Phe 45 to the corresponding residue in E. coli ACP (methionine), slows down the conformational change. Conversely, substitution of methionine 44 of E. coli ACP with a phenylalanine, causes enhanced ThT binding. Thus, we demonstrate the unique property of an exposed Phe in inducing, and phophopantetheine in inhibiting amyloidogenesis. Taken together, our study adds L. major acyl carrier protein to the list of ACPs that act as pH sensors.
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Affiliation(s)
- Chetna Dhembla
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Richa Arya
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Ambrish Kumar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Monica Sundd
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India.
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