1
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Goto Y, Nakajima K, Yamamoto S, Yamaguchi K. Supersaturation, a Critical Factor Underlying Proteostasis of Amyloid Fibril Formation. J Mol Biol 2024; 436:168475. [PMID: 38311232 DOI: 10.1016/j.jmb.2024.168475] [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: 10/03/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/10/2024]
Abstract
From a physicochemical viewpoint, amyloid fibril formation is a phase transition from soluble to crystal-like sates limited by supersaturation. It occurs only above solubility (i.e., the solubility limit) coupled with a breakdown of supersaturation. Although many studies have examined the role of molecular chaperones in the context of proteostasis, the role of supersaturation has not been addressed. Moreover, although molecular chaperone-dependent disaggregations have been reported for preformed amyloid fibrils, amyloid fibrils will not dissolve above the solubility of monomers, even if agitations fragment long fibrils to shorter amyloid particles. On the other hand, on considering a reversible and coupled equilibrium of interactions, folding/unfolding and amyloid formation/disaggregation, molecules stabilizing native states can work as a disaggregase reversing the amyloid fibrils to monomers. It is likely that the proteostasis network has various intra- and extracellular components which disaggregate preformed amyloid fibrils as well as prevent amyloid formation. Further studies with a view of solubility and supersaturation will be essential for comprehensive understanding of proteostasis.
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Affiliation(s)
- Yuji Goto
- Microsonochemistry Joint Research Chair, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Kichitaro Nakajima
- Microsonochemistry Joint Research Chair, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Suguru Yamamoto
- Division of Clinical Nephrology and Rheumatology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata 951-8510, Japan
| | - Keiichi Yamaguchi
- Microsonochemistry Joint Research Chair, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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2
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de Athayde Moncorvo Collado A, Socías SB, González-Lizárraga F, Ploper D, Vera Pingitore E, Chehín RN, Chaves S. Magnetic amyloid-based biocatalyst for the hydrolysis of urea. Food Chem 2024; 433:136830. [PMID: 37683486 DOI: 10.1016/j.foodchem.2023.136830] [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: 03/08/2023] [Revised: 06/19/2023] [Accepted: 07/05/2023] [Indexed: 09/10/2023]
Abstract
The presence of urea in wines and other alcoholic beverages represents a critical problem since it can chemically react with ethanol, which leads to the formation of ethyl carbamate, a carcinogenic agent according to the World Health Organization. Here we report the creation of a biocatalyst for the hydrolysis of urea, which could potentially be used before bottling alcoholic drinks. For this, the effective surface area of streptavidin-labeled magnetic microparticles was amplified by functionalization with biotin-labeled hen egg lysozyme amyloid fibers. Subsequently, by using copper and hydrogen peroxide induced cross-linking of unmodified proteins (CHICUP), soybean urease was immobilized to the fibers. This gave rise to a magnetic biocatalyst with remarkable urease activity, which was maintained even after 10 reuses. We propose that this strategy could be used as a platform for immobilizing other molecules to design and develop a myriad of biocatalysts for the food industry.
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Affiliation(s)
- A de Athayde Moncorvo Collado
- Instituto de Medicina Molecular y Celular Aplicada, Universidad Nacional de Tucumán-Consejo Nacional de Investigación Científicas y Técnicas- Sistema Provincial de Salud (UNT-CONICET-SIPROSA), Pasaje Manuel Dorrego, 1080. CP 4000. Tucumán, Argentina; Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT). Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Batalla de Chacabuco 461, CP 4000 Tucumán, Argentina.
| | - S B Socías
- Instituto de Medicina Molecular y Celular Aplicada, Universidad Nacional de Tucumán-Consejo Nacional de Investigación Científicas y Técnicas- Sistema Provincial de Salud (UNT-CONICET-SIPROSA), Pasaje Manuel Dorrego, 1080. CP 4000. Tucumán, Argentina.
| | - F González-Lizárraga
- Instituto de Medicina Molecular y Celular Aplicada, Universidad Nacional de Tucumán-Consejo Nacional de Investigación Científicas y Técnicas- Sistema Provincial de Salud (UNT-CONICET-SIPROSA), Pasaje Manuel Dorrego, 1080. CP 4000. Tucumán, Argentina.
| | - D Ploper
- Instituto de Medicina Molecular y Celular Aplicada, Universidad Nacional de Tucumán-Consejo Nacional de Investigación Científicas y Técnicas- Sistema Provincial de Salud (UNT-CONICET-SIPROSA), Pasaje Manuel Dorrego, 1080. CP 4000. Tucumán, Argentina.
| | - E Vera Pingitore
- Instituto de Medicina Molecular y Celular Aplicada, Universidad Nacional de Tucumán-Consejo Nacional de Investigación Científicas y Técnicas- Sistema Provincial de Salud (UNT-CONICET-SIPROSA), Pasaje Manuel Dorrego, 1080. CP 4000. Tucumán, Argentina.
| | - R N Chehín
- Instituto de Medicina Molecular y Celular Aplicada, Universidad Nacional de Tucumán-Consejo Nacional de Investigación Científicas y Técnicas- Sistema Provincial de Salud (UNT-CONICET-SIPROSA), Pasaje Manuel Dorrego, 1080. CP 4000. Tucumán, Argentina; Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT). Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Batalla de Chacabuco 461, CP 4000 Tucumán, Argentina.
| | - S Chaves
- Instituto de Medicina Molecular y Celular Aplicada, Universidad Nacional de Tucumán-Consejo Nacional de Investigación Científicas y Técnicas- Sistema Provincial de Salud (UNT-CONICET-SIPROSA), Pasaje Manuel Dorrego, 1080. CP 4000. Tucumán, Argentina.
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3
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Malik A, Khan JM, Al-Amri AM, Altwaijry N, Sharma P, Alhomida A, Sen P. Hexametaphosphate, a Common Food Additive, Aggregated the Hen Egg White Lysozyme. ACS OMEGA 2023; 8:44086-44092. [PMID: 38027328 PMCID: PMC10666150 DOI: 10.1021/acsomega.3c06210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 09/25/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023]
Abstract
Polyphosphate polymers are chains of phosphate monomers chemically bonded together via phosphoanhydride bonds. They are found in all prokaryotic and eukaryotic organisms and are among the earliest, most anionic, and most mysterious molecules known. They are everywhere, from small cellular components to additives in our food. There is a strong association between hyperphosphatemia and mortality. That is why it is crucial to assess how polyphosphates, as food additives, affect the quality of edible proteins. This study investigated the effect of inexpensive and widely used food additives (hexametaphosphate labeled as E452) on bakery items, meat products, fish, and soft drinks. Using various spectroscopic and microscopic techniques, we examined how hexametaphosphate affected the aggregation propensity, structure, and stability of a commonly used food protein: hen egg white lysozyme (HEWL). The solubility of HEWL is affected in a bimodal fashion by the concentration of hexametaphosphate. The bimodal concentration-dependent effect was also observed in the tertiary and secondary structural changes. Hexametaphosphate-induced HEWL aggregates were amorphous, as evidenced by ThT fluorescence, far-UV CD, and TEM imaging. This study showed that the food additive (hexametaphosphate) may denature and aggregate proteins and may lead to undesirable health issues.
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Affiliation(s)
- Ajamaluddin Malik
- Department
of Biochemistry, College of Science, King
Saud University, Riyadh 11451, Saudi Arabia
| | - Javed Masood Khan
- Department
of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia
| | - Abdulaziz M. Al-Amri
- Department
of Biochemistry, College of Science, King
Saud University, Riyadh 11451, Saudi Arabia
| | - Nojood Altwaijry
- Department
of Biochemistry, College of Science, King
Saud University, Riyadh 11451, Saudi Arabia
| | - Prerna Sharma
- Geisinger
Commonwealth School of Medicine Scranton, Scranton, Pennsylvania 18509-3240, United States
| | - Abdullah Alhomida
- Department
of Biochemistry, College of Science, King
Saud University, Riyadh 11451, Saudi Arabia
| | - Priyankar Sen
- Centre
for Bioseparation Technology, VIT University, Vellore 632014, India
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4
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Sinha A, Kummer N, Wu T, De France KJ, Pinotsi D, Thoma JL, Fischer P, Campioni S, Nyström G. Nanocellulose aerogels as 3D amyloid templates. NANOSCALE 2023; 15:17785-17792. [PMID: 37909800 PMCID: PMC10653027 DOI: 10.1039/d3nr02109b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 08/23/2023] [Indexed: 11/03/2023]
Abstract
Proteins in solution tend to coat solid surfaces upon exposure. Depending on the nature of the surface, the environmental conditions, and the nature of the protein these adsorbed proteins may self-assemble into ordered, fibre-like structures called amyloids. Nanoparticulate surfaces, with their high surface to volume ratio, are particularly favourable to amyloid formation. Most prior research has focussed on either inorganic or organic nanoparticles in solution. In this research, we instead focus on aerogels created from TEMPO-oxidized cellulose nanofibers (TO-CNF) to serve as bio-based, three-dimensional amyloid templates with a tuneable surface chemistry. Previous research on the use of cellulose as a protein adsorption template has shown no evidence of a change in the secondary protein structure. Herein, however, with the aid of the reducing agent TCEP, we were able to induce the formation of amyloid-like 'worms' on the surface of TO-CNF aerogels. Furthermore, we demonstrate that the addition of the TO-CNF aerogel can also induce bulk aggregation under conditions where it previously did not exist. Finally, we show that the addition of the aerogel increases the rate of 'worm' formation in conditions where previous research has found a long lag-phase. Therefore, TO-CNF aerogels are shown to be excellent templates for inducing ordered protein aggregation.
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Affiliation(s)
- Ashutosh Sinha
- Laboratory for Cellulose and Wood Materials, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
- Institute of Food Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Nico Kummer
- Laboratory for Cellulose and Wood Materials, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
- Institute of Food Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Tingting Wu
- Laboratory for Cellulose and Wood Materials, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
| | - Kevin J De France
- Laboratory for Cellulose and Wood Materials, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
| | - Dorothea Pinotsi
- Scientific Centre for Optical and Electron Microscopy, ETH Zurich, 8093, Zurich, Switzerland
| | - Janine L Thoma
- Laboratory for Cellulose and Wood Materials, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
| | - Peter Fischer
- Institute of Food Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Silvia Campioni
- Laboratory for Cellulose and Wood Materials, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
| | - Gustav Nyström
- Laboratory for Cellulose and Wood Materials, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
- Institute of Food Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
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5
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Bhardwaj T, Giri R. Potential of ADAM 17 Signal Peptide To Form Amyloid Aggregates in Vitro. ACS Chem Neurosci 2023; 14:3818-3825. [PMID: 37802503 DOI: 10.1021/acschemneuro.3c00424] [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: 10/10/2023] Open
Abstract
ADAM 17, a disintegrin and metalloproteinase 17 belonging to the adamalysin protein family, is a Zn2+-dependent type-I transmembrane α-secretase protein. As a major sheddase, ADAM 17 acts as an indispensable regulator of chief cellular events and controls diverse cytokines, adhesion molecules, and growth factors. The signal peptide (residues 1-17) of ADAM 17 targets the protein to the secretory pathway and gets cleaved off afterward. No other function is documented for the ADAM 17 signal peptide (ADAM 17-SP) inside the cells. Here, we have taken a reductionist approach to understand the biophysical properties of ADAM 17-SP. Aiming to understand the possibility of aggregation, we found several aggregation-prone segments in the signal peptide. We performed in vitro experiments to show that the signal peptide forms amyloid-like aggregates in buffered conditions. We also studied its aggregation in the presence of sodium tripolyphosphate and heparin to correlate with the cellular conditions, as these biomolecules are naturally present inside cells. Further, we performed seeding experiments to observe the possibility of ADAM 17-SP aggregate interaction with the Aβ42 peptide. The results suggest that its seeds escalate the aggregation kinetics of the Aβ42 peptide and form heteromeric aggregates with it. We believe this finding could further intensify the aggregation studies on other signal peptides and shed light on the potential role of these segments other than signaling.
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Affiliation(s)
- Taniya Bhardwaj
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, VPO Kamand, Mandi, Himachal Pradesh 175075, India
| | - Rajanish Giri
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, VPO Kamand, Mandi, Himachal Pradesh 175075, India
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6
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Zein HF, Sutthibutpong T. Roles of Tryptophan and Charged Residues on the Polymorphisms of Amyloids Formed by K-Peptides of Hen Egg White Lysozyme Investigated through Molecular Dynamics Simulations. Int J Mol Sci 2023; 24:ijms24032626. [PMID: 36768943 PMCID: PMC9916845 DOI: 10.3390/ijms24032626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/15/2022] [Accepted: 12/19/2022] [Indexed: 01/31/2023] Open
Abstract
Atomistic molecular dynamics simulations of amyloid models, consisting of the previously reported STDY-K-peptides and K-peptides from the hen egg white lysozyme (HEWL), were performed to address the effects of charged residues and pH observed in an in vitro study. Simulation results showed that amyloid models with antiparallel configurations possessed greater stability and compactness than those with parallel configurations. Then, peptide chain stretching and ordering were measured through the end-to-end distance and the order parameter, for which the amyloid models consisting of K-peptides and the STDY-K-peptides at pH 2 displayed a higher level of chain stretching and ordering. After that, the molecular mechanics energy decomposition and the radial distribution function (RDF) clearly displayed the importance of Trp62 to the K-peptide and the STDY-K-peptide models at pH 2. Moreover, the results also displayed how the negatively charged Asp52 disrupted the interaction networks and prevented the amyloid formation from STDY-K-peptide at pH 7. Finally, this study provided an insight into the interplay between pH conditions and molecular interactions underlying the formation of amyloid fibrils from short peptides contained within the HEWL. This served as a basis of understanding towards the design of other amyloids for biomaterial applications.
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Affiliation(s)
- Husnul Fuad Zein
- Nanoscience and Nanotechnology Program, Faculty of Science, King Mongkut’s University of Technology Thonburi (KMUTT), 126 Pracha Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140, Thailand
- Department of Physics, King Mongkut’s University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand
| | - Thana Sutthibutpong
- Nanoscience and Nanotechnology Program, Faculty of Science, King Mongkut’s University of Technology Thonburi (KMUTT), 126 Pracha Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140, Thailand
- Department of Physics, King Mongkut’s University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand
- Center of Excellence in Theoretical and Computational Science (TaCS-CoE), Faculty of Science, King Mongkut’s University of Technology Thonburi (KMUTT), 126 Pracha Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140, Thailand
- Correspondence:
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7
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Pillai VS, Kumari P, Kolagatla S, Garcia Sakai V, Rudić S, Rodriguez BJ, Rubini M, Tych KM, Benedetto A. Controlling Amyloid Fibril Properties Via Ionic Liquids: The Representative Case of Ethylammonium Nitrate and Tetramethylguanidinium Acetate on the Amyloidogenesis of Lysozyme. J Phys Chem Lett 2022; 13:7058-7064. [PMID: 35900133 PMCID: PMC9358703 DOI: 10.1021/acs.jpclett.2c01505] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein aggregation into amyloid fibrils has been observed in several pathological conditions and exploited in nanotechnology. It is also key in several biochemical processes. In this work, we show that ionic liquids (ILs), a vast class of organic electrolytes, can finely tune amyloid properties, opening a new landscape in basic science and applications. The representative case of ethylammonium nitrate (EAN) and tetramethyl-guanidinium acetate (TMGA) ILs on lysozyme is considered. First, atomic force microscopy has shown that the addition of EAN and TMGA leads to thicker and thinner amyloid fibrils of greater and lower electric potential, respectively, with diameters finely tunable by IL concentration. Optical tweezers and neutron scattering have shed light on their mechanism of action. TMGA interacts with the protein hydration layer only, making the relaxation dynamics of these water molecules faster. EAN interacts directly with the protein instead, making it mechanically unstable and slowing down its relaxation dynamics.
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Affiliation(s)
- Visakh
V. S. Pillai
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Pallavi Kumari
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Srikanth Kolagatla
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Victoria Garcia Sakai
- ISIS
Neutron and Muon Source, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot OX11 0QX, U.K.
| | - Svemir Rudić
- ISIS
Neutron and Muon Source, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot OX11 0QX, U.K.
| | - Brian J. Rodriguez
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
| | - Marina Rubini
- School
of Chemistry, University College Dublin, Dublin D04 N2E5, Ireland
| | - Katarzyna M. Tych
- Groningen
Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Antonio Benedetto
- School
of Physics, University College Dublin, Dublin D04 N2E5, Ireland
- Conway
Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin D04 N2E5, Ireland
- Department
of Science, University of Roma Tre, 00146 Rome, Italy
- Laboratory
for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
- , ,
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8
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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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9
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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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10
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Najarzadeh Z, Zaman M, Sereikaite V, Strømgaard K, Andreasen M, Otzen DE. Heparin promotes fibrillation of most phenol-soluble modulin virulence peptides from Staphylococcus aureus. J Biol Chem 2021; 297:100953. [PMID: 34270957 PMCID: PMC8363829 DOI: 10.1016/j.jbc.2021.100953] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/29/2021] [Accepted: 07/08/2021] [Indexed: 10/26/2022] Open
Abstract
Phenol-soluble modulins (PSMs), such as α-PSMs, β-PSMs, and δ-toxin, are virulence peptides secreted by different Staphylococcus aureus strains. PSMs are able to form amyloid fibrils, which may strengthen the biofilm matrix that promotes bacterial colonization of and extended growth on surfaces (e.g., cell tissue) and increases antibiotic resistance. Many components contribute to biofilm formation, including the human-produced highly sulfated glycosaminoglycan heparin. Although heparin promotes S. aureus infection, the molecular basis for this is unclear. Given that heparin is known to induce fibrillation of a wide range of proteins, we hypothesized that heparin aids bacterial colonization by promoting PSM fibrillation. Here, we address this hypothesis using a combination of thioflavin T-fluorescence kinetic studies, CD, FTIR, electron microscopy, and peptide microarrays to investigate the mechanism of aggregation, the structure of the fibrils, and identify possible binding regions. We found that heparin accelerates fibrillation of all α-PSMs (except PSMα2) and δ-toxin but inhibits β-PSM fibrillation by blocking nucleation or reducing fibrillation levels. Given that S. aureus secretes higher levels of α-PSM than β-PSM peptides, heparin is therefore likely to promote fibrillation overall. Heparin binding is driven by multiple positively charged lysine residues in α-PSMs and δ-toxins, the removal of which strongly reduced binding affinity. Binding of heparin did not affect the structure of the resulting fibrils, that is, the outcome of the aggregation process. Rather, heparin provided a scaffold to catalyze or inhibit fibrillation. Based on our findings, we speculate that heparin may strengthen the bacterial biofilm and therefore enhance colonization via increased PSM fibrillation.
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Affiliation(s)
- Zahra Najarzadeh
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, Denmark
| | - Masihuz Zaman
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Vita Sereikaite
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Maria Andreasen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, Denmark.
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11
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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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12
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Abidi SMS, Dar AI, Acharya A. Multifunctional Gold Nanoparticle-Conjugated Cellulose Nanoonions Alleviate Aβ42 Fibrillation-Induced Toxicity via Regulation of Oxidative Stress and Ion Homeostasis. Biomacromolecules 2021; 22:2419-2435. [PMID: 33945268 DOI: 10.1021/acs.biomac.1c00228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Inhibition of hen egg white lysozyme (HEWL) and Aβ42 fibrillation have been established as the main models for the treatment of systemic lysozyme amyloidosis and Alzheimer's disease (AD), respectively. Several antiamyloidogenic nanomaterials have been developed over the period; however, their intracellular mechanism of action is still not well understood. In this context, plant-based, gold-conjugated, injectable, hydrophilic cellulose nanoonions (CNOs), viz., DH-CNO (∼60 ± 5 nm) and LC-CNO (∼55 ± 12 nm), were developed from their respective hydrophobic cellulose nanocrystals (DH-CNC and LC-CNC) using a single-step chemical template-mediated process. This unique nanocellulose architecture was chemically and morphologically characterized by various spectroscopic and microscopic techniques. Further, the different biophysical studies documented marked the inhibition/disintegration potential of gold-conjugated LC-CNO against HEWL and Aβ42 peptide aggregation. It was further observed that inhibition of protein fibrillation could be achieved within ∼10 min when the same materials were used under photoirradiation conditions. In vitro protein aggregation studies using HEK293 cells suggested that gold-conjugated LC-CNO could effectively reduce the cellular toxicity via regulation of oxidative stress and ion homeostasis. The outcome of the present study will help in designing cellulose-based novel functional nanochaperones against various neurodegenerative diseases.
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Affiliation(s)
- Syed M S Abidi
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India.,Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh201002, India
| | - Aqib Iqbal Dar
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India.,Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh201002, India
| | - Amitabha Acharya
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India.,Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh201002, India
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13
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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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14
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Zeng HJ, Wang SS, Sun LJ, Miao M, Yang R. Investigation on the effect of three isoflavones on the fibrillation of hen egg-white lysozyme. J Mol Recognit 2021; 34:e2889. [PMID: 33646596 DOI: 10.1002/jmr.2889] [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: 09/15/2020] [Revised: 12/02/2020] [Accepted: 12/21/2020] [Indexed: 11/10/2022]
Abstract
In this paper, the effects of three isoflavones including daidzein, genistein, and puerarin on fibrillation of hen egg-white lysozyme were investigated by various analytical methods. The results demonstrated that all isoflavones could effectively inhibit the fibrillogenesis of hen egg-white lysozyme and destabilized the preformed fibrils of hen egg-white lysozyme in a dose-dependent manner. To further understand the inhibition mechanism, molecular modeling was carried out. The docking results demonstrated that the isoflavones could bind to two key fibrogenic sites in hen egg-white lysozyme through van der Waals force, electrostatic forces, and hydrogen bonding, as well as σ-π stacking. By these means, isoflavones could not only obviously enhance the hydrophobicity of the binding sites, but also greatly stabilize the native state of HEWL, which was able to postpone the fibrosis process of hen egg-white lysozyme.
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Affiliation(s)
- Hua-Jin Zeng
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Sha-Sha Wang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Li-Jun Sun
- College of Chemistry, Green Catalysis center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and their Bioanalytical Applications, Zhengzhou University, Zhengzhou, China
| | - Min Miao
- College of Chemistry, Green Catalysis center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and their Bioanalytical Applications, Zhengzhou University, Zhengzhou, China
| | - Ran Yang
- College of Chemistry, Green Catalysis center, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and their Bioanalytical Applications, Zhengzhou University, Zhengzhou, China
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15
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Ahanger I, Parray ZA, Nasreen K, Ahmad F, Hassan MI, Islam A, Sharma A. Heparin Accelerates the Protein Aggregation via the Downhill Polymerization Mechanism: Multi-Spectroscopic Studies to Delineate the Implications on Proteinopathies. ACS OMEGA 2021; 6:2328-2339. [PMID: 33521471 PMCID: PMC7841943 DOI: 10.1021/acsomega.0c05638] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/04/2021] [Indexed: 06/12/2023]
Abstract
Heparin is one of the members of the glycosaminoglycan (GAG) family, which has been associated with protein aggregation diseases including Alzheimer's disease, Parkinson's disease, and prion diseases. Here, we investigate heparin-induced aggregation of bovine serum albumin (BSA) using different spectroscopic techniques [absorption, 8-anilino-1-naphthalene sulfonic acid (ANS) and thioflavin T (ThT) fluorescence binding, and far- and near-UV circular dichroism]. Kinetic measurements revealed that heparin is involved in the significant enhancement of aggregation of BSA. The outcomes showed dearth of the lag phase and a considerable change in rate constant, which provides conclusive evidence, that is, heparin-induced BSA aggregation involves the pathway of the downhill polymerization mechanism. Heparin also causes enhancement of fluorescence intensity of BSA significantly. Moreover, heparin was observed to form amyloids and amorphous aggregates of BSA which were confirmed by ThT and ANS fluorescence, respectively. Circular dichroism measurements exhibit a considerable change in the secondary and tertiary structure of the protein due to heparin. In addition, binding studies of heparin with BSA to know the cause of aggregation, isothermal titration calorimetry measurements were exploited, from which heparin was observed to promote the aggregation of BSA by virtue of electrostatic interactions between positively charged amino acid residues of protein and negatively charged groups of GAG. The nature of binding of heparin with BSA is very much apparent with an appreciable heat of interaction and is largely exothermic in nature. Moreover, the Gibbs free energy change (ΔG) is negative, which indicates spontaneous nature of binding, and the enthalpy change (ΔH) and entropy change (ΔS) are also largely negative, which suggest that the interaction is driven by hydrogen bonding.
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Affiliation(s)
- Ishfaq
Ahmad Ahanger
- Department
of Chemistry, Biochemistry and Forensic Science, Amity School of Applied
Sciences, Amity University Haryana, Gurugram 122 413, India
- Centre
for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Zahoor Ahmad Parray
- Centre
for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Khalida Nasreen
- Centre
for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Faizan Ahmad
- Centre
for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Md. Imtaiyaz Hassan
- Centre
for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Asimul Islam
- Centre
for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Anurag Sharma
- Department
of Chemistry, Biochemistry and Forensic Science, Amity School of Applied
Sciences, Amity University Haryana, Gurugram 122 413, India
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16
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Breakdown of supersaturation barrier links protein folding to amyloid formation. Commun Biol 2021; 4:120. [PMID: 33500517 PMCID: PMC7838177 DOI: 10.1038/s42003-020-01641-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/24/2020] [Indexed: 12/13/2022] Open
Abstract
The thermodynamic hypothesis of protein folding, known as the "Anfinsen's dogma" states that the native structure of a protein represents a free energy minimum determined by the amino acid sequence. However, inconsistent with the Anfinsen's dogma, globular proteins can misfold to form amyloid fibrils, which are ordered aggregates associated with diseases such as Alzheimer's and Parkinson's diseases. Here, we present a general concept for the link between folding and misfolding. We tested the accessibility of the amyloid state for various proteins upon heating and agitation. Many of them showed Anfinsen-like reversible unfolding upon heating, but formed amyloid fibrils upon agitation at high temperatures. We show that folding and amyloid formation are separated by the supersaturation barrier of a protein. Its breakdown is required to shift the protein to the amyloid pathway. Thus, the breakdown of supersaturation links the Anfinsen's intramolecular folding universe and the intermolecular misfolding universe.
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17
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Ghosh R, Raveendranath R, Kishore N. Unraveling diverse action of triton X-100 and methimazole on lysozyme fibrillation/aggregation: Physicochemical insights. Int J Biol Macromol 2020; 167:736-745. [PMID: 33278448 DOI: 10.1016/j.ijbiomac.2020.11.210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/19/2020] [Accepted: 11/30/2020] [Indexed: 01/18/2023]
Abstract
Identification of functionalities responsible for prevention of fibrillation in proteins is important to design effective drugs in addressing neurodegenerative diseases. We have used nonionic surfactant triton X-100 (TX-100) and antithyroid drug methimazole (MMI) to understand mechanistic aspects of action of these molecules having different functionalities on hen egg-white lysozyme at different stages of fibrillation. After establishing the nucleation, elongation and maturation stages of fibrillation of protein at 57 °C, energetics of interactions with these molecules have been determined by using isothermal titration calorimetry. Differential scanning calorimetry has permitted assessment of thermal stability of the protein at these stages, with or without these molecular entities. The enthalpies of interaction of TX-100 and MMI with protein fibrils suggest importance of hydrogen bonding and polar interactions in their effectiveness towards prevention of fibrils. TX-100, in spite of several polar centres, is unable to prevent fibrillation, rather it promotes. MMI is able to establish polar interactions with interacting strands of the protein and disintegrate fibrils. A rigorous comparison with inhibitors reported in literature highlights importance -OH and >CO functionalities in fibrillation prevention. Even though MMI has hydrogen bonding centres, its efficiency as inhibitor falls after the inhibited lysozyme fibrils further interact and form amorphous aggregates.
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Affiliation(s)
- Ritutama Ghosh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
| | - Revathy Raveendranath
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
| | - Nand Kishore
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
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18
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Hall D. A simple method for modeling amyloid kinetics featuring position biased fiber breakage. Biophys Physicobiol 2020; 17:30-35. [PMID: 33110736 PMCID: PMC7550252 DOI: 10.2142/biophysico.bsj-2020003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 03/12/2020] [Indexed: 12/01/2022] Open
Abstract
A mathematical model of amyloid fiber formation is described that is able to simply specify different rates of fiber breakage at internal versus end regions. This Note presents the derivation of the relevant equations and provides results showing the dramatic effects of position biased fiber breakage on the kinetics of amyloid growth.
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Affiliation(s)
- Damien Hall
- Laboratory of Biochemistry and Genetics, NIDDK, NIH, Bethesda, MD 20892-0830, USA.,Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.,Present address: International Center, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Aichi 466-8555, Japan
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19
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Townsend DJ, Middleton DA, Ashton L. Raman Spectroscopy with 2D Perturbation Correlation Moving Windows for the Characterization of Heparin-Amyloid Interactions. Anal Chem 2020; 92:13822-13828. [PMID: 32935978 DOI: 10.1021/acs.analchem.0c02390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It has been shown extensively that glycosaminoglycan (GAG)-protein interactions can induce, accelerate, and impede the clearance of amyloid fibrils associated with systemic and localized amyloidosis. Obtaining molecular details of these interactions is fundamental to our understanding of amyloid disease. Consequently, there is a need for analytical approaches that can identify protein conformational transitions and simultaneously characterize heparin interactions. By combining Raman spectroscopy with two-dimensional (2D) perturbation correlation moving window (2DPCMW) analysis, we have successfully identified changes in protein secondary structure during pH- and heparin-induced fibril formation of apolipoprotein A-I (apoA-I) associated with atherosclerosis. Furthermore, from the 2DPCMW, we have identified peak shifts and intensity variations in Raman peaks arising from different heparan sulfate moieties, indicating that protein-heparin interactions vary at different heparin concentrations. Raman spectroscopy thus reveals new mechanistic insights into the role of GAGs during amyloid fibril formation.
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Affiliation(s)
- David J Townsend
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - David A Middleton
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Lorna Ashton
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom
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20
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Sawada M, Yamaguchi K, Hirano M, Noji M, So M, Otzen D, Kawata Y, Goto Y. Amyloid Formation of α-Synuclein Based on the Solubility- and Supersaturation-Dependent Mechanism. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4671-4681. [PMID: 32271585 DOI: 10.1021/acs.langmuir.0c00426] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Amyloid fibrils are formed by denatured proteins when the supersaturation of denatured proteins is broken by agitation, such as ultrasonication, or by seeding, although the detailed mechanism of how solubility and supersaturation regulate amyloid formation remains unclear. To further understand the mechanism of amyloid formation, we examined α-synuclein (α-syn) amyloid formation at varying concentrations of SDS, LPA, heparin, or NaCl at pH 7.5. Amyloid fibrils were formed below or around the critical micelle concentrations (CMCs) of SDS (2.75 mM) and LPA (0.24 mM), although no fibrils were formed above the CMCs. On the other hand, amyloid fibrils were formed with 0.01-2.5 mg/mL of heparin and 0.5-1.0 M NaCl, and amyloid formation was gradually suppressed at higher concentrations of heparin and NaCl. To reproduce these concentration-dependent effects of additives, we constructed two models: (i) the ligand-binding-dependent solubility-modulation model and (ii) the cosolute-dependent direct solubility-modulation model, both of which were used by Tanford and colleagues to analyze the additive-dependent conformational transitions of proteins. The solubility of α-syn was assumed to vary depending on the concentration of additives either by the decreased solubility of the additive-α-syn complex (model i) or by the direct regulation of α-syn solubility (model ii). Both models well reproduced additive-dependent bell-shaped profiles of acceleration and inhibition observed for SDS and LPA. As for heparin and NaCl, participation of amorphous aggregates at high concentrations of additives was suggested. The models confirmed that solubility and supersaturation play major roles in driving amyloid formation in vitro, furthering our understanding of the pathogenesis of amyloidosis in vivo.
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Affiliation(s)
- Maya Sawada
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Keiichi Yamaguchi
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Miki Hirano
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masahiro Noji
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masatomo So
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Daniel Otzen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
| | - Yasushi Kawata
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama Minami, Tottori 680-8552, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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21
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Al Adem K, Lukman S, Kim TY, Lee S. Inhibition of lysozyme aggregation and cellular toxicity by organic acids at acidic and physiological pH conditions. Int J Biol Macromol 2020; 149:921-930. [DOI: 10.1016/j.ijbiomac.2020.01.267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/26/2020] [Accepted: 01/27/2020] [Indexed: 12/16/2022]
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22
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Muta H, So M, Sakurai K, Kardos J, Naiki H, Goto Y. Amyloid Formation under Complicated Conditions in Which β 2-Microglobulin Coexists with Its Proteolytic Fragments. Biochemistry 2019; 58:4925-4934. [PMID: 31724398 DOI: 10.1021/acs.biochem.9b00917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amyloid formation in vivo occurs under complicated conditions in which various amyloidogenic and non-amyloidogenic components coexist, often under crowding. Controversy surrounds the role of additional components under complicated conditions. They have been suggested to accelerate amyloid formation because molecular crowding or interactions with additives increase effective concentrations and, thus, break the supersaturation of amyloidogenic proteins. On the other hand, cellular crowding conditions with various heterogeneous components may retard or prevent amyloid formation because they impede homologous amyloidogenic associations. To elucidate the roles of these additional components, we examined the amyloid formation of β2-microglobulin (β2m), a protein responsible for dialysis-related amyloidosis, with a simplified model system in which intact β2m and its proteolytic peptides coexist. Among the nine proteolytic peptides of β2m produced in vitro with lysyl endopeptidase, the 22-residue K3 peptide is highly amyloidogenic. The amyloid formation of the K3 peptide, which occurred with a lag time of 1 h at pH 2 and 37 °C, was significantly retarded by the coexistence of β2m or a mixture of the proteolytic digests. To identify the sites of inhibitory interactions, we performed paramagnetic relaxation enhancement measurements using spin-labeled K3 and uniformly 15N-labeled β2m with nuclear magnetic resonance detection. The results revealed that K3 interacted weakly with a broad cluster of the hydrophobic residues of β2m, which accommodated the residues located in some distant sequence, leading to competitive inhibition. The results showed that relatively weak and broad interactions formed a nonproductive complex, implying a role for heterogeneous interactions under complicated conditions.
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Affiliation(s)
- Hiroya Muta
- Institute for Protein Research , Osaka University , Yamadaoka 3-2 , Suita , Osaka 565-0871 , Japan
| | - Masatomo So
- Institute for Protein Research , Osaka University , Yamadaoka 3-2 , Suita , Osaka 565-0871 , Japan
| | - Kazumasa Sakurai
- Institute of Advanced Technology , Kindai University , Wakayama 649-6493 , Japan
| | - Jozsef Kardos
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry , Eötvös Loránd University , Pázmány P. sétány 1/C , Budapest 1117 , Hungary
| | - Hironobu Naiki
- Faculty of Medical Sciences , University of Fukui , Fukui 910-1193 , Japan
| | - Yuji Goto
- Institute for Protein Research , Osaka University , Yamadaoka 3-2 , Suita , Osaka 565-0871 , Japan
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23
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Hall D. On the nature of the optimal form of the holdase-type chaperone stress response. FEBS Lett 2019; 594:43-66. [PMID: 31432502 DOI: 10.1002/1873-3468.13580] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/12/2019] [Accepted: 08/14/2019] [Indexed: 11/08/2022]
Abstract
The holdase paradigm of chaperone action involves preferential binding by the chaperone to the unfolded protein state, thereby preventing it from either, associating with other unstable proteins (to form large dysfunctional aggregates), or being degraded by the proteolytic machinery of the cell/organism. In this paper, we examine the necessary physical constraints imposed upon the holdase chaperone response in a cell-like environment and use these limitations to comment on the likely nature of the optimal form of chaperone response in vivo.
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Affiliation(s)
- Damien Hall
- Laboratory of Biochemistry and Genetics, NIDDK, NIH, Bethesda, MD, USA.,Institute for Protein Research, Osaka University, Suita, Osaka, Japan
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24
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Noji M, Sasahara K, Yamaguchi K, So M, Sakurai K, Kardos J, Naiki H, Goto Y. Heating during agitation of β 2-microglobulin reveals that supersaturation breakdown is required for amyloid fibril formation at neutral pH. J Biol Chem 2019; 294:15826-15835. [PMID: 31495783 DOI: 10.1074/jbc.ra119.009971] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/19/2019] [Indexed: 12/27/2022] Open
Abstract
Amyloidosis-associated amyloid fibrils are formed by denatured proteins when supersaturation of denatured proteins is broken. β2-Microglobulin (β2m) forms amyloid fibrils and causes dialysis-related amyloidosis in patients receiving long-term hemodialysis. Although amyloid fibrils of β2m in patients are observed at neutral pH, formation of β2m amyloids in vitro has been difficult to discern at neutral pH because of the amyloid-resistant native structure. Here, to further understand the mechanism underlying in vivo amyloid formation, we investigated the relationship between protein folding/unfolding and misfolding leading to amyloid formation. Using thioflavin T assays, CD spectroscopy, and transmission EM analyses, we found that β2m efficiently forms amyloid fibrils even at neutral pH by heating with agitation at high-salt conditions. We constructed temperature- and NaCl concentration-dependent conformational phase diagrams in the presence or absence of agitation, revealing how amyloid formation under neutral pH conditions is related to thermal unfolding and breakdown of supersaturation. Of note, after supersaturation breakdown and following the law of mass action, the β2m monomer equilibrium shifted to the unfolded state, destabilizing the native state and thereby enabling amyloid formation even under physiological conditions with a low amount of unfolded precursor. The amyloid fibrils depolymerized at both lower and higher temperatures, resembling cold- or heat-induced denaturation of globular proteins. Our results suggest an important role for heating in the onset of dialysis-related amyloidosis and related amyloidoses.
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Affiliation(s)
- Masahiro Noji
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Kenji Sasahara
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Keiichi Yamaguchi
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Masatomo So
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Kazumasa Sakurai
- Institute of Advanced Technology, Kindai University, Wakayama 649-6493, Japan
| | - József Kardos
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. Sétány 1/C, Budapest, 1117, Hungary
| | - Hironobu Naiki
- Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
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25
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Sasahara K, Yamaguchi K, So M, Goto Y. Polyphosphates diminish solubility of a globular protein and thereby promote amyloid aggregation. J Biol Chem 2019; 294:15318-15329. [PMID: 31439662 DOI: 10.1074/jbc.ra119.008662] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 08/21/2019] [Indexed: 01/08/2023] Open
Abstract
Structural changes of globular proteins and their resultant amyloid aggregation have been associated with various human diseases, such as lysozyme amyloidosis and light-chain amyloidosis. Because many globular proteins can convert into amyloid fibrils in vitro, the mechanisms of amyloid fibril formation have been studied in various experimental systems, but several questions remain unresolved. Here, using several approaches, such as turbidimetry, fluorescence and CD spectroscopy, EM, and isothermal titration calorimetry, we examined the binding of polyphosphates to hen egg-white lysozyme under acidic conditions and observed polyphosphate-induced structural changes of the protein promoting its aggregation. Our data indicate that negatively charged polyphosphates bind to protein molecules with a net positive charge. The polyphosphate-bound, structurally destabilized protein molecules then start assembling into insoluble amorphous aggregates once they pass the solubility limit. We further show that the polyphosphates decrease the solubility limit of the protein and near this limit, the protein molecules are in a labile state and highly prone to converting into amyloid fibrils. Our results explain how polyphosphates affect amorphous aggregation of proteins, how amyloid formation is induced in the presence of polyphosphates, and how polyphosphate chain length is an important factor in amyloid formation.
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Affiliation(s)
- Kenji Sasahara
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Keiichi Yamaguchi
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masatomo So
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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26
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Possible mechanisms of polyphosphate-induced amyloid fibril formation of β 2-microglobulin. Proc Natl Acad Sci U S A 2019; 116:12833-12838. [PMID: 31182591 DOI: 10.1073/pnas.1819813116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Polyphosphate (polyP), which is found in various microorganisms and human cells, is an anionic biopolymer consisting of inorganic phosphates linked by high-energy phosphate bonds. Previous studies revealed that polyPs strongly promoted the amyloid formation of several amyloidogenic proteins; however, the mechanism of polyP-induced amyloid formation remains unclear. In the present study using β2-microglobulin (β2m), a protein responsible for dialysis-related amyloidosis, we investigated amyloid formation in the presence of various chain lengths of polyPs at different concentrations under both acidic (pH 2.0 to 2.5) and neutral pH (pH 7.0 to 7.5) conditions. We found that the amyloid formation of β2m at acidic pH was significantly accelerated by the addition of polyPs at an optimal polyP concentration, which decreased with an increase in chain length. The results obtained indicated that electrostatic interactions between positively charged β2m and negatively charged polyPs play a major role in amyloid formation. Under neutral pH conditions, long polyP with 60 to 70 phosphates induced the amyloid formation of β2m at several micromoles per liter, a similar concentration range to that in vivo. Since β2m with an isoelectric point of 6.4 has a slightly negative net charge at pH 7, polyPs were unlikely to interact with β2m electrostatically. PolyPs appear to dehydrate water molecules around β2m under the unfolded conformation, leading to the preferential stabilization of less water-exposed amyloid fibrils. These results not only revealed the pH-dependent mechanism of the amyloid formation of β2m but also suggested that polyPs play an important role in the development of dialysis-related amyloidosis.
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27
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Ramshini H, Moghaddasi AS, Mollania N, Khodarahmi R. Diverse antithetical effects of the bio-compatible Ag-NPs on the hen egg lysozyme amyloid aggregation: from an efficient inhibitor to obscure inducer. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2018. [DOI: 10.1007/s13738-018-1478-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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Noji M, So M, Yamaguchi K, Hojo H, Onda M, Akazawa-Ogawa Y, Hagihara Y, Goto Y. Heat-Induced Aggregation of Hen Ovalbumin Suggests a Key Factor Responsible for Serpin Polymerization. Biochemistry 2018; 57:5415-5426. [DOI: 10.1021/acs.biochem.8b00619] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Masahiro Noji
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Masatomo So
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Keiichi Yamaguchi
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Hironobu Hojo
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
| | - Maki Onda
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Naka Ku, Sakai, Osaka 599-8570, Japan
| | - Yoko Akazawa-Ogawa
- National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Yoshihisa Hagihara
- National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Yuji Goto
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan
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29
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Adachi M, Noji M, So M, Sasahara K, Kardos J, Naiki H, Goto Y. Aggregation-phase diagrams of β 2-microglobulin reveal temperature and salt effects on competitive formation of amyloids versus amorphous aggregates. J Biol Chem 2018; 293:14775-14785. [PMID: 30077972 DOI: 10.1074/jbc.ra118.004683] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 07/28/2018] [Indexed: 11/06/2022] Open
Abstract
Several serious diseases are associated with crystal-like amyloid fibrils or glass-like amorphous aggregates of denatured proteins. However, protein aggregation involving both types of aggregates has not yet been elucidated in much detail. Using a protein associated with dialysis-related amyloidosis, β2-microglobulin (β2m), we previously demonstrated that amyloid fibrils and amorphous aggregates form competitively depending on salt (NaCl) concentration. To examine the generality of the underlying competitive mechanisms, we herein investigated the effects of heat on acid-denatured β2m at pH 2. Using thioflavin fluorescence, CD, and light scattering analysis along with atomic force microscopy imaging, we found that the temperature-dependent aggregation of β2m markedly depends on NaCl concentration. Stepwise transitions from monomers to amyloids and then back to monomers were observed at low NaCl concentrations. Amorphous aggregates formed rapidly at ambient temperatures at high NaCl concentrations, but the transition from amorphous aggregates to amyloids occurred only as the temperature increased. Combining the data from the temperature- and NaCl-dependent transitions, we constructed a unified phase diagram of conformational states, indicating a parabolic solubility curve with a minimum NaCl concentration at ambient temperatures. Although amyloid fibrils formed above this solubility boundary, amorphous aggregates dominated in regions distant from this boundary. Kinetic competition between supersaturation-limited slow amyloid fibrillation and supersaturation-unlimited fast amorphous aggregation deformed the phase diagram, with amyloid regions disappearing with fast titration rates. We conclude that phase diagrams combining thermodynamics and kinetics data provide a comprehensive view of β2m aggregation exhibiting severe hysteresis depending on the heat- or salt-titration rates.
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Affiliation(s)
- Masayuki Adachi
- From the Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Masahiro Noji
- From the Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Masatomo So
- From the Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Kenji Sasahara
- From the Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - József Kardos
- the ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest 1117, Hungary, and
| | - Hironobu Naiki
- Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Yuji Goto
- From the Institute for Protein Research, Osaka University, Osaka 565-0871, Japan,
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30
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Yamaguchi KI, Kuwata K. Formation and properties of amyloid fibrils of prion protein. Biophys Rev 2018; 10:517-525. [PMID: 29204880 PMCID: PMC5899736 DOI: 10.1007/s12551-017-0377-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/23/2017] [Indexed: 02/06/2023] Open
Abstract
Amyloid fibrils formed from prion protein (PrP) are associated with prion diseases. In this review we discuss a number of extrinsic and intrinsic experimental factors related to the formation of PrP amyloid fibrils in vitro. We first examined the effects of ultrasonic power on the induction of amyloid fibrillation from PrP. The most important conclusion drawn from the results is that an applied ultrasonic power of approximately 2 W enhanced the nucleation of amyloid fibrils efficiently but that more powerful ultrasonication led to retardation of growth. We also reviewed evidence on the amyloidogenic regions of PrP based on peptide screening throughout the polypeptide sequence. These results showed that helix 2 (H2) peptides of PrP were capable of both the fibrillation and propagation of straight, long fibrils. Moreover, the conformation of preformed H2 fibrils changed reversibly depending on the pH of the solution, implying that interactions between side-chains modulated the conformation of amyloid fibrils. The evidence discussed in this review relates specifically to PrP but may be relevant to other amyloidogenic proteins.
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Affiliation(s)
- Kei-ichi Yamaguchi
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871 Japan
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Yanagido 1-1, Gifu, 501-1193 Japan
| | - Kazuo Kuwata
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Yanagido 1-1, Gifu, 501-1193 Japan
- Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu, 501-1193 Japan
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31
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Goto Y, Adachi M, Muta H, So M. Salt-induced formations of partially folded intermediates and amyloid fibrils suggests a common underlying mechanism. Biophys Rev 2017; 10:493-502. [PMID: 29256120 DOI: 10.1007/s12551-017-0370-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 11/19/2017] [Indexed: 12/26/2022] Open
Abstract
Amyloid fibrils are misfolded forms of proteins and are involved in various diseases. They have been studied extensively with the aim to obtain a comprehensive understanding of protein folding and misfolding and to use this knowledge to develop therapeutic strategies against the associated diseases. Salt conditions are important factors determining the formation and stability of amyloid fibrils. In the 1990s, salt effects were studied extensively to understand the conformational stability of acid-denatured proteins, and the results of these studies revealed the role of electrostatic repulsion in forming the compact intermediate states. In this review, we compare the effects of salts on the compact intermediate states with those on the formation of amyloid fibrils under acidic conditions. The results argue that both protein folding and misfolding are driven by the same forces, although the resultant conformations are distinct because they are monomeric and multimeric reactions, respectively.
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Affiliation(s)
- Yuji Goto
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka, 565-0871, Japan.
| | - Masayuki Adachi
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka, 565-0871, Japan
| | - Hiroya Muta
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka, 565-0871, Japan
| | - Masatomo So
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka, 565-0871, Japan
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