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Dai Z, Ben-Younis A, Vlachaki A, Raleigh D, Thalassinos K. Understanding the structural dynamics of human islet amyloid polypeptide: Advancements in and applications of ion-mobility mass spectrometry. Biophys Chem 2024; 312:107285. [PMID: 38941872 PMCID: PMC11260546 DOI: 10.1016/j.bpc.2024.107285] [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: 01/19/2024] [Revised: 05/30/2024] [Accepted: 06/23/2024] [Indexed: 06/30/2024]
Abstract
Human islet amyloid polypeptide (hIAPP) forms amyloid deposits that contribute to β-cell death in pancreatic islets and are considered a hallmark of Type II diabetes Mellitus (T2DM). Evidence suggests that the early oligomers of hIAPP formed during the aggregation process are the primary pathological agent in islet amyloid induced β-cell death. The self-assembly mechanism of hIAPP, however, remains elusive, largely due to limitations in conventional biophysical techniques for probing the distribution or capturing detailed structures of the early, structurally dynamic oligomers. The advent of Ion-mobility Mass Spectrometry (IM-MS) has enabled the characterisation of hIAPP early oligomers in the gas phase, paving the way towards a deeper understanding of the oligomerisation mechanism and the correlation of structural information with the cytotoxicity of the oligomers. The sensitivity and the rapid structural characterisation provided by IM-MS also show promise in screening hIAPP inhibitors, categorising their modes of inhibition through "spectral fingerprints". This review delves into the application of IM-MS to the dissection of the complex steps of hIAPP oligomerisation, examining the inhibitory influence of metal ions, and exploring the characterisation of hetero-oligomerisation with different hIAPP variants. We highlight the potential of IM-MS as a tool for the high-throughput screening of hIAPP inhibitors, and for providing insights into their modes of action. Finally, we discuss advances afforded by recent advancements in tandem IM-MS and the combination of gas phase spectroscopy with IM-MS, which promise to deliver a more sensitive and higher-resolution structural portrait of hIAPP oligomers. Such information may help facilitate a new era of targeted therapeutic strategies for islet amyloidosis in T2DM.
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Affiliation(s)
- Zijie Dai
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK
| | - Aisha Ben-Younis
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK
| | - Anna Vlachaki
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge CB2 0PY, UK
| | - Daniel Raleigh
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK; Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States.
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK; Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, UK.
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2
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Feng RR, Wang M, Zhang W, Gai F. Unnatural Amino Acids for Biological Spectroscopy and Microscopy. Chem Rev 2024; 124:6501-6542. [PMID: 38722769 DOI: 10.1021/acs.chemrev.3c00944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Due to advances in methods for site-specific incorporation of unnatural amino acids (UAAs) into proteins, a large number of UAAs with tailored chemical and/or physical properties have been developed and used in a wide array of biological applications. In particular, UAAs with specific spectroscopic characteristics can be used as external reporters to produce additional signals, hence increasing the information content obtainable in protein spectroscopic and/or imaging measurements. In this Review, we summarize the progress in the past two decades in the development of such UAAs and their applications in biological spectroscopy and microscopy, with a focus on UAAs that can be used as site-specific vibrational, fluorescence, electron paramagnetic resonance (EPR), or nuclear magnetic resonance (NMR) probes. Wherever applicable, we also discuss future directions.
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Affiliation(s)
- Ran-Ran Feng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Manxi Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wenkai Zhang
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Feng Gai
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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3
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Hunt NT. Using 2D-IR Spectroscopy to Measure the Structure, Dynamics, and Intermolecular Interactions of Proteins in H 2O. Acc Chem Res 2024; 57:685-692. [PMID: 38364823 PMCID: PMC10918835 DOI: 10.1021/acs.accounts.3c00682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/30/2024] [Accepted: 01/30/2024] [Indexed: 02/18/2024]
Abstract
Infrared (IR) spectroscopy probes molecular structure at the level of the chemical bond or functional group. In the case of proteins, the most informative band in the IR spectrum is the amide I band, which arises predominantly from the C═O stretching vibration of the peptide link. The folding of proteins into secondary and tertiary structures leads to vibrational coupling between peptide units, generating specific amide I spectral signatures that provide a fingerprint of the macromolecular conformation. Ultrafast two-dimensional IR (2D-IR) spectroscopy allows the amide I band of a protein to be spread over a second frequency dimension in a way that mirrors 2D-NMR methods. This means that amide I 2D-IR spectroscopy produces a spectral map that is exquisitely sensitive to protein structure and dynamics and so provides detailed insights that cannot be matched by IR absorption spectroscopy. As a result, 2D-IR spectroscopy has emerged as a powerful tool for probing protein structure and dynamics over a broad range of time and length scales in the solution phase at room temperature. However, the protein amide I band coincides with an IR absorption from the bending vibration of water (δHOH), the natural biological solvent. To circumvent this problem, protein IR studies are routinely performed in D2O solutions because H/D substitution shifts the solvent bending mode (δDOD) to a lower frequency, revealing the amide I band. While effective, this method raises fundamental questions regarding the impact of the change in solvent mass on the structural or solvation dynamics of the protein and the removal of the energetic resonance between solvent and solute.In this Account, a series of studies applying 2D-IR to study the spectroscopy and dynamics of proteins in H2O-rich solvents is reviewed. A comparison of IR absorption spectroscopy and 2D-IR spectroscopy of protein-containing fluids is used to demonstrate the basis of the approach before a series of applications is presented. These range from measurements of fundamental protein biophysics to recent applications of machine learning to gain insight into protein-drug binding in complex mixtures. An outlook is presented, considering the potential for 2D-IR measurements to contribute to our understanding of protein behavior under near-physiological conditions, along with an evaluation of the obstacles that still need to be overcome.
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Affiliation(s)
- Neil T. Hunt
- Department of Chemistry and York Biomedical
Research Institute, University of York, Heslington, York, YO10
5DD, U.K.
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4
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Hunt NT. Biomolecular infrared spectroscopy: making time for dynamics. Chem Sci 2024; 15:414-430. [PMID: 38179520 PMCID: PMC10763549 DOI: 10.1039/d3sc05223k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/24/2023] [Indexed: 01/06/2024] Open
Abstract
Time resolved infrared spectroscopy of biological molecules has provided a wealth of information relating to structural dynamics, conformational changes, solvation and intermolecular interactions. Challenges still exist however arising from the wide range of timescales over which biological processes occur, stretching from picoseconds to minutes or hours. Experimental methods are often limited by vibrational lifetimes of probe groups, which are typically on the order of picoseconds, while measuring an evolving system continuously over some 18 orders of magnitude in time presents a raft of technological hurdles. In this Perspective, a series of recent advances which allow biological molecules and processes to be studied over an increasing range of timescales, while maintaining ultrafast time resolution, will be reviewed, showing that the potential for real-time observation of biomolecular function draws ever closer, while offering a new set of challenges to be overcome.
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Affiliation(s)
- Neil T Hunt
- Department of Chemistry and York Biomedical Research Institute, University of York Heslington York YO10 5DD UK
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5
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Farrell KM, Fields CR, Dicke SS, Zanni MT. Simultaneously Measured Kinetics of Two Amyloid Polymorphs Using Cross Peak Specific 2D IR Spectroscopy. J Phys Chem Lett 2023; 14:11750-11757. [PMID: 38117179 PMCID: PMC11163371 DOI: 10.1021/acs.jpclett.3c02698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The origin of in vitro amyloid fibril polymorphs is debated, in part, because few techniques can simultaneously monitor the formation kinetics of multiple amyloid polymorphs. Using a cross-peak specific polarization scheme, ⟨0°,0°,60°,-60°⟩, we resolve 22 previously unseen cross peaks in the 2D IR spectra of amyloid fibrils formed by the human islet amyloid polypeptide (hIAPP). Those cross peaks include a subset assigned to a second fibril polymorph, which forms on a slower time scale. We simulated the data with three different kinetic models for polymorph formation. Only a model based on secondary nucleation reproduces the cross peak kinetics. These experiments are evidence that fibrils formed by secondary nucleation have a different polymorphic structure than the parent fibrils and illustrate the enhanced structural resolution of this new cross peak specific polarization scheme.
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Affiliation(s)
- Kieran M Farrell
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Caitlyn R Fields
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Sidney S Dicke
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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6
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Bai Y, Zhang S, Dong H, Liu Y, Liu C, Zhang X. Advanced Techniques for Detecting Protein Misfolding and Aggregation in Cellular Environments. Chem Rev 2023; 123:12254-12311. [PMID: 37874548 DOI: 10.1021/acs.chemrev.3c00494] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Protein misfolding and aggregation, a key contributor to the progression of numerous neurodegenerative diseases, results in functional deficiencies and the creation of harmful intermediates. Detailed visualization of this misfolding process is of paramount importance for improving our understanding of disease mechanisms and for the development of potential therapeutic strategies. While in vitro studies using purified proteins have been instrumental in delivering significant insights into protein misfolding, the behavior of these proteins in the complex milieu of living cells often diverges significantly from such simplified environments. Biomedical imaging performed in cell provides cellular-level information with high physiological and pathological relevance, often surpassing the depth of information attainable through in vitro methods. This review highlights a variety of methodologies used to scrutinize protein misfolding within biological systems. This includes optical-based methods, strategies leaning on mass spectrometry, in-cell nuclear magnetic resonance, and cryo-electron microscopy. Recent advancements in these techniques have notably deepened our understanding of protein misfolding processes and the features of the resulting misfolded species within living cells. The progression in these fields promises to catalyze further breakthroughs in our comprehension of neurodegenerative disease mechanisms and potential therapeutic interventions.
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Affiliation(s)
- Yulong Bai
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Shengnan Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Hui Dong
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yu Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Xin Zhang
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
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7
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Zhang Z, Huang G, Song Z, Gatch AJ, Ding F. Amyloid Aggregation and Liquid-Liquid Phase Separation from the Perspective of Phase Transitions. J Phys Chem B 2023; 127:6241-6250. [PMID: 37414583 PMCID: PMC10404378 DOI: 10.1021/acs.jpcb.3c01426] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Amyloid aggregation describes the aberrant self-assembly of peptides into ordered fibrils characterized by cross-β spine cores and is associated with many neurodegenerative diseases and Type 2 diabetes. Oligomers, populated during the early stage of aggregation, are found to be more cytotoxic than mature fibrils. Recently, many amyloidogenic peptides have been reported to undergo liquid-liquid phase separation (LLPS)─a biological process important for the compartmentalization of biomolecules in living cells─prior to fibril formation. Understanding the relationship between LLPS and amyloid aggregation, especially the formation of oligomers, is essential for uncovering disease mechanisms and mitigating amyloid toxicity. In this Perspective, available theories and models of amyloid aggregation and LLPS are first briefly reviewed. By drawing analogies to gas, liquid, and solid phases in thermodynamics, a phase diagram of protein monomer, droplet, and fibril states separated by coexistence lines can be inferred. Due to the high free energy barrier of fibrillization kinetically delaying the formation of fibril seeds out of the droplets, a "hidden" monomer-droplet coexistence line extends into the fibril phase. Amyloid aggregation can then be described as the equilibration process from the initial "out-of-equilibrium" state of a homogeneous solution of monomers to the final equilibrium state of stable amyloid fibrils coexisting with monomers and/or droplets via the formation of metastable or stable droplets as the intermediates. The relationship between droplets and oligomers is also discussed. We suggest that the droplet formation of LLPS should be considered in future studies of amyloid aggregation, which may help to better understand the aggregation process and develop therapeutic strategies to mitigate amyloid toxicity.
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Affiliation(s)
- Zhenzhen Zhang
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Gangtong Huang
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Zhiyuan Song
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Adam J. Gatch
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, United States
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
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8
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Sanders HM, Chalyavi F, Fields CR, Kostelic MM, Li MH, Raleigh DP, Zanni MT, Marty MT. Interspecies Variation Affects Islet Amyloid Polypeptide Membrane Binding. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:986-990. [PMID: 37126782 PMCID: PMC10330443 DOI: 10.1021/jasms.3c00005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The aggregation of islet amyloid polypeptide (IAPP) is associated with β-cell dysfunction in type 2 diabetes (T2D) in humans. One possible mechanism of toxicity is the interaction of IAPP oligomers with lipid membranes to disrupt the bilayer integrity and/or homeostasis of the cell. Amino acid sequence variations of IAPPs between species can greatly decrease their propensity for aggregation. For example, human IAPP is toxic to β-cells, but rat and pig IAPP are not. However, it is not clear how these differences affect membrane association. Using native mass spectrometry with lipid nanodiscs, we explored the differences in the association of human, rat, and pig IAPP with lipid bilayers. We discovered that human and rat IAPP bound nanodiscs with anionic dipalmitoyl-phosphatidylglycerol (DPPG) lipids, but pig IAPP did not. Furthermore, human and rat IAPP interacted differently with the membrane. Human IAPP show potential tetramer complexes, but rat IAPP associated with the membrane sequentially. Thus, overall IAPP-bilayer interactions are not necessarily related to disease, but small differences in oligomeric behavior at the membrane may instead play a role.
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Affiliation(s)
- Henry M. Sanders
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721, USA
| | - Farzaneh Chalyavi
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Caitlyn R. Fields
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Marius M. Kostelic
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721, USA
| | - Ming-Hao Li
- Department of Chemistry and Laufer Center for Quantitative Biology, Stony Brook University, 100 Nicolls Rd., Stony Brook, New York 11794, USA
| | - Daniel P. Raleigh
- Department of Chemistry and Laufer Center for Quantitative Biology, Stony Brook University, 100 Nicolls Rd., Stony Brook, New York 11794, USA
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Michael T. Marty
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721, USA
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9
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Lin R, Tang G, Gao Z, Lei J, Ma B, Mo Y. Molecular Insights into the Self-Assembly of a Full-Length hIAPP Trimer: β-Protofibril Formed by β-Hairpin Lateral or Longitudinal Association. J Phys Chem B 2023. [PMID: 37262327 DOI: 10.1021/acs.jpcb.3c02633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The fibrillar protein deposits of the human islet amyloid polypeptide (hIAPP) in the pancreatic islet of Langerhans are pathological hallmark of type II diabetes. Extensive experimental studies have revealed that the oligomeric formations of the hIAPP are more toxic than the mature fibrils. Exploring the oligomeric conformations in the early aggregation state is valuable for effective therapeutics. In this work, using the all-atom explicit-solvent replica exchange molecular dynamic (REMD) simulations, we investigated the structural features and the assembly mechanisms of the full-length hIAPP trimer in solution. The hIAPP trimer adopted more β-sheets than a-helix conformations, and three types of ordered conformations including open β-barrel, single-layer, and double-layer U-shaped β-sheet structures with five β-strands were captured in our simulations. A representative single-layer β-sheet conformation with a CCS value of 1400 Å2 in our simulations matches exactly the experimentally ESI-IMS-MS-derived hIAPP trimer sample. These five β-strand conformations formed via the β-hairpin lateral and longitudinal association, respectively, showing two β-protofibril formation models. To the best of our knowledge, it is the first time to reveal two routes to β-sheet formation in the hIAPP trimers on the atomic level. The contact probabilities between pairs of the β-stranded residue show that the hydrophobic interactions between the residues F15 ∼ V17 and A25 ∼ L27 are responsible for the inter- and intra-peptide β-hairpin formations. All of these results indicate that the β-sheet formation is the first step in the conformational changes toward pathological aggregation and provides evidence of the β-sheet assembly mechanism into hIAPP aggregation.
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Affiliation(s)
- Rongmei Lin
- College of Physical Science and Technology, Guangxi Normal University, Guilin, Guangxi 541004, People's Republic of China
| | - Guoning Tang
- College of Physical Science and Technology, Guangxi Normal University, Guilin, Guangxi 541004, People's Republic of China
| | - Zhonggui Gao
- College of Physical Science and Technology, Guangxi Normal University, Guilin, Guangxi 541004, People's Republic of China
| | - Jiangtao Lei
- Institute of Space Science and Technology, Nanchang University, Nanchang, Jiangxi 330031, People's Republic of China
| | - Buyong Ma
- Engineering Research Center of Cell & Therapeutic Antibody, School of Pharmacy, Shanghai Jiaotong University, Shanghai 200240, People's Republic of China
| | - Yuxiang Mo
- College of Physical Science and Technology, Guangxi Normal University, Guilin, Guangxi 541004, People's Republic of China
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10
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Roy D, Maity NC, Kumar S, Maity A, Ratha BN, Biswas R, Maiti NC, Mandal AK, Bhunia A. Modulatory role of copper on hIAPP aggregation and toxicity in presence of insulin. Int J Biol Macromol 2023; 241:124470. [PMID: 37088193 DOI: 10.1016/j.ijbiomac.2023.124470] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/24/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023]
Abstract
Aggregation of the human islets amyloid polypeptide, or hIAPP, is linked to β-cell death in type II diabetes mellitus (T2DM). Different pancreatic β-cell environmental variables such as pH, insulin and metal ions play a key role in controlling the hIAPP aggregation. Since insulin and hIAPP are co-secreted, it is known from numerous studies that insulin suppresses hIAPP fibrillation by preventing the initial dimerization process. On the other hand, zinc and copper each have an inhibitory impact on hIAPP fibrillation, but copper promotes the production of toxic oligomers. Interestingly, the insulin oligomeric equilibrium is controlled by the concentration of zinc ions when the effect of insulin and zinc has been tested together. Lower zinc concentrations cause the equilibrium to shift towards the monomer and dimer states of insulin, which bind to monomeric hIAPP and stop it from developing into a fibril. On the other hand, the combined effects of copper and insulin have not yet been done. In this study, we have demonstrated how the presence of copper affects hIAPP aggregation and the toxicity of the resultant conformers with or without insulin. For this purpose, we have used a set of biophysical techniques, including NMR, fluorescence, CD etc., in combination with AFM and cell cytotoxicity assay. In the presence and/or absence of insulin, copper induces hIAPP to form structurally distinct stable toxic oligomers, deterring the fibrillation process. More specifically, the oligomers generated in the presence of insulin have slightly higher toxicity than those formed in the absence of insulin. This research will increase our understanding of the combined modulatory effect of two β-cell environmental factors on hIAPP aggregation.
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Affiliation(s)
- Dipanwita Roy
- Department of Biophysics, Bose Institute, Unified Academic Campus, Salt Lake, Sctor V, Kolkata 700091, India
| | - Narayan Chandra Maity
- Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Sector-III, Salt Lake, Kolkata 700106, India
| | - Sourav Kumar
- Department of Biophysics, Bose Institute, Unified Academic Campus, Salt Lake, Sctor V, Kolkata 700091, India
| | - Anupam Maity
- Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Bhisma N Ratha
- Department of Biophysics, Bose Institute, Unified Academic Campus, Salt Lake, Sctor V, Kolkata 700091, India
| | - Ranjit Biswas
- Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Sector-III, Salt Lake, Kolkata 700106, India
| | - Nakul Chandra Maiti
- Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Atin Kumar Mandal
- Division of Molecular Medicine, Bose Institute, Unified Academic Campus, Salt Lake, Sctor V, Kolkata, 700091, India
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, Unified Academic Campus, Salt Lake, Sctor V, Kolkata 700091, India.
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11
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Duan C, Wang R. Electrostatics-Induced Nucleated Conformational Transition of Protein Aggregation. PHYSICAL REVIEW LETTERS 2023; 130:158401. [PMID: 37115902 DOI: 10.1103/physrevlett.130.158401] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
Despite the wide existence of protein aggregation in nature and its intimate connection to many human diseases, the underlying mechanism remains unclear. Here, we develop a molecular theory by systematically incorporating the self-consistent field theory for charged macromolecules into the dilute solution thermodynamics. The kinetic pathway is tracked without any restriction on the morphology of the aggregates. We find that protein aggregation at low salt concentrations is via a two-step nucleated process involving a conformational transition from metastable spherical oligomer to elongated fibril. The scaling analysis elucidates the electrostatic origin of the conformational transition: the fibril enters the screening region much earlier than the spherical aggregate. As salt concentration increases, the classical mode of one-step nucleation corresponding to macroscopic liquid-liquid phase separation is recovered. Our results reveal that the screened electrostatic interaction is essential for the existence of the metastable oligomer and its subsequent conformational transition to fibril. The theoretical predictions of the kinetic pathway and the morphology of the aggregates are in good agreement with the experimental observations of real proteins.
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Affiliation(s)
- Chao Duan
- Department of Chemical and Biomolecular Engineering, University of California Berkeley, California 94720, USA
| | - Rui Wang
- Department of Chemical and Biomolecular Engineering, University of California Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Lab, Berkeley, California 94720, USA
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12
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Hamsici S, Gunay G, Acar H. Controllable membrane damage by tunable peptide aggregation with albumin. AIChE J 2022; 68:e17893. [PMID: 36816052 PMCID: PMC9937546 DOI: 10.1002/aic.17893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Aggregation of otherwise soluble proteins into amyloid structures is a hallmark of many disorders, such as Alzheimer's and Parkinson's disease. There is an increasing evidence that the small aggregations, instead of ordered fibrillar aggregates, are the main structures causing toxicity. However, the studies on the small aggregation phase are limited due to the variety of structures and the complexity of the physiological environment. Here, we showed an engineered co-assembling oppositely charged amyloid-like peptide pair ([II]) as a simple tool to establish methodologies to study the mechanism and kinetics of aggregation and relate its aggregation to toxicity. The toxicity mechanism of [II] is through cell membrane damage and stress, shown with YAP and eIF2α, as in the amyloid protein-initiated diseases. Albumin is demonstrated as an extrinsic and physiologically relevant molecule in controlling the aggregation lag time and toxicity of [II]. This study represents a molecular engineering strategy to create simplistic molecular tools for establishing methodologies to study the aggregation process and kinetics of amyloid-like proteins in various conditions. Understanding the nature of protein aggregation kinetics and linking them to their biological functions through engineered peptides paves the way for future designs and drug development applications.
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Affiliation(s)
- Seren Hamsici
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma, USA
| | - Gokhan Gunay
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma, USA
| | - Handan Acar
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma, USA,Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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13
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Miller ME, Li MH, Baghai A, Peetz VH, Zhyvoloup A, Raleigh DP. Analysis of Sheep and Goat IAPP Provides Insight into IAPP Amyloidogenicity and Cytotoxicity. Biochemistry 2022; 61:2531-2545. [PMID: 36286531 PMCID: PMC11132794 DOI: 10.1021/acs.biochem.2c00470] [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] [Indexed: 11/29/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) plays a role in glucose regulation but forms pancreatic amyloid deposits in type 2 diabetes, and that process contributes to β-cell dysfunction. Not all species develop diabetes, and not all secrete an IAPP that is amyloidogenic in vitro under normal conditions, a perfect correlation currently exists between both. Studies of IAPPs from such organisms can provide clues about the high amyloidogenicity of hIAPP and can inform the design of soluble analogues of hIAPP. Sheep and goat IAPP are among the most divergent from hIAPP, with 13 and 11 substitutions, respectively, including an unusual Tyr to His substitution at the C-terminus. The properties of sheep and goat IAPP were examined in solution and in the presence of anionic vesicles, resulting in no observed amyloid formation, even at increased concentrations. Furthermore, both peptides are considerably less toxic to cultured β-cells than hIAPP. The effect of the Y37H replacements was studied in the context of hIAPP, as was a Y37R substitution. Buffer- and salt-dependent effects were observed. There was little impact on the time to form amyloid in phosphate-buffered saline; however, a significant deceleration was observed in Tris buffer, and amyloid formation was slower in the absence of added salt. The Y37H substitution had little impact on toxicity, while the Y37R replacement led to a 30% decrease in toxicity compared with that of hIAPP. The implications for the amyloidogenicity of hIAPP and the design of soluble analogues of the human peptide are discussed.
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Affiliation(s)
- Matthew E.T. Miller
- Department of Chemistry, Stony Brook University, Nicolls Road, Stony Brook, New York 11790, United States
| | - Ming-Hao Li
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, New York 11790, United States
| | - Aria Baghai
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Vincent H. Peetz
- Department of Chemistry, Stony Brook University, Nicolls Road, Stony Brook, New York 11790, United States
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Daniel P. Raleigh
- Department of Chemistry, Stony Brook University, Nicolls Road, Stony Brook, New York 11790, United States
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, New York 11790, United States
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
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14
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Sun S, GrandPre T, Limmer DT, Groves JT. Kinetic frustration by limited bond availability controls the LAT protein condensation phase transition on membranes. SCIENCE ADVANCES 2022; 8:eabo5295. [PMID: 36322659 PMCID: PMC9629719 DOI: 10.1126/sciadv.abo5295] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
LAT is a membrane-linked scaffold protein that undergoes a phase transition to form a two-dimensional protein condensate on the membrane during T cell activation. Governed by tyrosine phosphorylation, LAT recruits various proteins that ultimately enable condensation through a percolation network of discrete and selective protein-protein interactions. Here, we describe detailed kinetic measurements of the phase transition, along with coarse-grained model simulations, that reveal that LAT condensation is kinetically frustrated by the availability of bonds to form the network. Unlike typical miscibility transitions in which compact domains may coexist at equilibrium, the LAT condensates are dynamically arrested in extended states, kinetically trapped out of equilibrium. Modeling identifies the structural basis for this kinetic arrest as the formation of spindle arrangements, favored by limited multivalent binding interactions along the flexible, intrinsically disordered LAT protein. These results reveal how local factors controlling the kinetics of LAT condensation enable formation of different, stable condensates, which may ultimately coexist within the cell.
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Affiliation(s)
- Simou Sun
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
- Institute for Digital Molecular Analytics and Science, Nanyang Technological University, 639798 Singapore
| | - Trevor GrandPre
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - David T. Limmer
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jay T. Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
- Institute for Digital Molecular Analytics and Science, Nanyang Technological University, 639798 Singapore
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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15
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Manathunga L, Zhyvoloup A, Baghai A, Raleigh DP. Differential Effects of Aromatic Residues on Amyloid Formation and Cytotoxicity of Human IAPP. Biochemistry 2022; 61:2334-2343. [PMID: 36215164 PMCID: PMC11132793 DOI: 10.1021/acs.biochem.2c00267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Islet amyloid polypeptide (IAPP) is a 37-residue polypeptide hormone secreted by the pancreatic β-cells. IAPP plays a role in glycemic regulation, but in the pre-type-2 diabetic state, it aggregates to form an islet amyloid. The process of islet amyloid formation contributes to β-cell dysfunction and disease progression. The features of the IAPP sequence that modulate amyloid formation are still not understood. Human IAPP contains three aromatic residues, F15, F23, and Y37. F15 and Y37 are highly conserved, while F23 is more commonly a Leu or Ile in other species. The role of the aromatic residues in modulating the time course of amyloid formation and the cytotoxicity was examined using aromatic to Leu mutations. All three single and double mutants and the triple mutant were studied. F23 plays a dominant role in both amyloid formation and toxicity. An F15L mutant accelerated amyloid formation, a Y37L mutant had little effect, while an F23L replacement slowed amyloid formation by a factor of 2.6. Double mutants, which contained an F23L replacement, had a larger effect than those that did not, and there are non-additive effects between pairs of aromatic residues. F23 also plays a key role in toxicity. Single or multiple mutants that contain the F23L replacement were noticeably less toxic than the wild-type or mutants which did not include the F23L substitution. In contrast, the F15L mutant was more toxic than the wild-type one. The implications for IAPP amyloid formation and for the design of non-aggregating analogues of IAPP are discussed.
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Affiliation(s)
- Lakshan Manathunga
- Deartment of Chemistry, Stony Brook University, Nicolls Road, Stony Brook, New York 11790, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Aria Baghai
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Daniel P. Raleigh
- Deartment of Chemistry, Stony Brook University, Nicolls Road, Stony Brook, New York 11790, United States
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
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16
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Xing Y, Andrikopoulos N, Zhang Z, Sun Y, Ke PC, Ding F. Modulating Nanodroplet Formation En Route to Fibrillization of Amyloid Peptides with Designed Flanking Sequences. Biomacromolecules 2022; 23:4179-4191. [PMID: 36137260 PMCID: PMC9618360 DOI: 10.1021/acs.biomac.2c00642] [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] [Indexed: 11/28/2022]
Abstract
Soluble oligomers populating early amyloid aggregation can be regarded as nanodroplets of liquid-liquid phase separation (LLPS). Amyloid peptides typically contain hydrophobic aggregation-prone regions connected by hydrophilic linkers and flanking sequences, and such a sequence hydropathy pattern drives the formation of supramolecular structures in the nanodroplets and modulates subsequent fibrillization. Here, we studied LLPS and fibrillization of coarse-grained amyloid peptides with increasing flanking sequences. Nanodroplets assumed lamellar, cylindrical micellar, and spherical micellar structures with increasing peptide hydrophilic/hydrophobic ratios, and such morphologies governed subsequent fibrillization processes. Adding glycine-serine repeats as flanking sequences to Aβ16-22, the amyloidogenic core of amyloid-β, our computational predictions of morphological transitions were corroborated experimentally. The uncovered inter-relationships between the peptide sequence pattern, oligomer/nanodroplet morphology, and fibrillization pathway, kinetics, and structure may contribute to our understanding of pathogenic amyloidosis in aging, facilitate future efforts ameliorating amyloidosis through peptide engineering, and aid in the design of novel amyloid-based functional nanobiomaterials and nanocomposites.
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Affiliation(s)
- Yanting Xing
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Nicholas Andrikopoulos
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Zhenzhen Zhang
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Yunxiang Sun
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
- Department of Physics, Ningbo University, Ningbo 315211, China
| | - Pu Chun Ke
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Nanomedicine Center, The GBA National Institute for Nanotechnology Innovation, 136 Kaiyuan Avenue, Guangzhou, 510700, China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
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17
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Dicke SS, Maj M, Fields CR, Zanni MT. Metastable intermediate during hIAPP aggregation catalyzed by membranes as detected with 2D IR spectroscopy. RSC Chem Biol 2022; 3:931-940. [PMID: 35866164 PMCID: PMC9257649 DOI: 10.1039/d2cb00028h] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
Abstract
The aggregation of human islet amyloid polypeptide (hIAPP) into amyloid fibrils involves formation of oligomeric intermediates that are thought to be the cytotoxic species responsible for β-cell dysfunction in type 2 diabetes. hIAPP oligomers permeating or disrupting the cellular membrane may be one mechanism of toxicity and so measuring the structural kinetics of aggregation in the presence of membranes is of much interest. In this study, we use 2D IR spectroscopy and 13C18O isotope labeling to study the secondary structure of the oligomeric intermediates formed in solution and in the presence of phospholipid vesicles at sites L12A13, L16V17, G24A25 and V32G33. Pairs of labels monitor the couplings between associated polypeptides and the dihedral angles between adjacent residues. In solution, the L12A13 residues form an oligomeric β-sheet in addition to an α-helix whereas with the phospholipid vesicles they are α-helical throughout the aggregation process. In both solution and with DOPC vesicles, L16V17 and V32G33 have disordered structures until fibrils are formed. Similarly, under both conditions, G24A25 exhibits 3-state kinetics, created by an oligomeric intermediate with a well-defined β-sheet structure. Amyloid fibril formation is often thought to involve intermediates with exceedingly low populations that are difficult to detect experimentally. These experiments establish that amyloid fibril formation of hIAPP when catalyzed by membranes includes a metastable intermediate and that this intermediate has a similar structure at G24A25 in the FGAIL region as the corresponding intermediate in solution, thought to be the toxic species. 2D IR and 13C18O isotope labeling establish that amyloid formation of hIAPP catalyzed by membranes includes a metastable intermediate with a similar structure at G24A25 in the FGAIL region as the corresponding intermediate in solution.![]()
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Affiliation(s)
- Sidney S Dicke
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Michał Maj
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA .,Formally at Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Caitlyn R Fields
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
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18
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Linking hIAPP misfolding and aggregation with type 2 diabetes mellitus: a structural perspective. Biosci Rep 2022; 42:231205. [PMID: 35475576 PMCID: PMC9118370 DOI: 10.1042/bsr20211297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/12/2022] [Accepted: 04/26/2022] [Indexed: 11/17/2022] Open
Abstract
There are over 40 identified human disorders that involve certain proteins folding incorrectly, accumulating in the body causing damage to cells and organs and causing disease. Type 2 Diabetes Mellitus (T2DM) is one of these protein misfolding disorders (PMDs) and involves human islet amyloid polypeptide (hIAPP) misfolding and accumulating in parts of the body, primarily in the pancreas, causing damage to islet cells and affecting glucose regulation. In this review, we have summarised our current understanding of what causes hIAPP to misfold, what conformations are found in different parts of the body with a particular focus on what is known about the structure of hIAPP and how this links to T2DM. Understanding the molecular basis behind these misfolding events is essential for understanding the role of hIAPP to develop better therapeutics since type 2 diabetes currently affects over 4.9 million people in the United Kingdom alone and is predicted to increase as our population ages.
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19
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Fan J, Lan H, Ning W, Zhong R, Chen F, Yan G, Cai K. Modeling amide-I vibrations of alanine dipeptide in solution by using neural network protocol. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 268:120675. [PMID: 34890871 DOI: 10.1016/j.saa.2021.120675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/27/2021] [Accepted: 11/26/2021] [Indexed: 06/13/2023]
Abstract
Infrared spectroscopy is a powerful tool for the understanding of molecular structure and function of polypeptides. Theoretical interpretation of IR spectra relies on ab initio calculations may be very costly in computational resources. Herein, we developed a neural network (NN) modeling protocol to evaluate a model dipeptide's backbone amide-I spectra. DFT calculations were performed for the amide-I vibrational motions and structural parameters of alanine dipeptide (ALAD) conformers in different micro-environments ranging from polar to non-polar ones. The obtained backbone dihedrals, C = O bond lengths and amide-I frequencies of ALAD were gather together for NN architecture. The applications of built NN protocols for the prediction of amide-I frequencies of ALAD in other solvation conditions are quite satisfactory with much less computational cost comparing with electronic structure calculations. The results show that this cost-effective way enables us to decipher the polypeptide's dynamic secondary structures and biological functions with their backbone vibrational probes.
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Affiliation(s)
- Jianping Fan
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China; Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
| | - Huaying Lan
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China
| | - Wenfeng Ning
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China
| | - Rongzhen Zhong
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China
| | - Feng Chen
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
| | - Guiyang Yan
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
| | - Kaicong Cai
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China; Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
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20
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Saxena V, Steendam R, Jansen TLC. Distinguishing islet amyloid polypeptide fibril structures with infrared isotope-label spectroscopy. J Chem Phys 2022; 156:055101. [DOI: 10.1063/5.0082322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Vishesh Saxena
- University of Groningen, Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ruben Steendam
- University of Groningen, Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Thomas L. C. Jansen
- University of Groningen, Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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21
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Abioye RO, Okagu OD, Udenigwe CC. Inhibition of Islet Amyloid Polypeptide Fibrillation by Structurally Diverse Phenolic Compounds and Fibril Disaggregation Potential of Rutin and Quercetin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:392-402. [PMID: 34964624 DOI: 10.1021/acs.jafc.1c06918] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The influence of 12 food-derived phenolic compounds on islet amyloid polypeptide (IAPP) fibrillation was investigated. Results from thioflavin T assay demonstrated that gallic acid, caffeic acid, and rutin and its aglycone, quercetin, inhibited IAPP fibrillation at 1:0.5, 1:1, and 1:2 IAPP-phenolic molar ratios. Circular dichroism and dynamic light scattering at the 1:1 IAPP-phenolic ratio confirmed the inhibition of fibril formation. Rutin and quercetin increased the lag time by 90 and 6%, and the relative α-helix content by 63 and 48%, respectively. Gallic acid decreased the elongation rate by 30%, whereas caffeic acid decreased the maximum fluorescence intensity by 65%. Furthermore, fluorescence microscopy and transmission electron microscopy (TEM) showed IAPP fibril morphologies indicative of fibrillation reduction by the compounds. Molecular docking and TEM showed that rutin and quercetin disaggregated preformed IAPP fibrils potentially through fibrillar-monomeric equilibrium shifts. These findings demonstrate important structural features of phenolic compounds for disaggregating IAPP fibrils or inhibiting their formation.
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Affiliation(s)
- Raliat O Abioye
- Department of Chemistry and Biomolecular Sciences, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Ogadimma D Okagu
- Department of Chemistry and Biomolecular Sciences, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Chibuike C Udenigwe
- Department of Chemistry and Biomolecular Sciences, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
- School of Nutrition Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa K1H 8M5, Canada
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22
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Dissection of the amyloid formation pathway in AL amyloidosis. Nat Commun 2021; 12:6516. [PMID: 34764275 PMCID: PMC8585945 DOI: 10.1038/s41467-021-26845-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 10/25/2021] [Indexed: 11/18/2022] Open
Abstract
In antibody light chain (AL) amyloidosis, overproduced light chain (LC) fragments accumulate as fibrils in organs and tissues of patients. In vitro, AL fibril formation is a slow process, characterized by a pronounced lag phase. The events occurring during this lag phase are largely unknown. We have dissected the lag phase of a patient-derived LC truncation and identified structural transitions that precede fibril formation. The process starts with partial unfolding of the VL domain and the formation of small amounts of dimers. This is a prerequisite for the formation of an ensemble of oligomers, which are the precursors of fibrils. During oligomerization, the hydrophobic core of the LC domain rearranges which leads to changes in solvent accessibility and rigidity. Structural transitions from an anti-parallel to a parallel β-sheet secondary structure occur in the oligomers prior to amyloid formation. Together, our results reveal a rate-limiting multi-step mechanism of structural transitions prior to fibril formation in AL amyloidosis, which offers, in the long run, opportunities for therapeutic intervention. AL amyloidosis is caused by the accumulation of overproduced light chain (LC) fragments as fibrils in patient organs and it is the most prevalent systemic amyloidosis. Here, the authors combine biochemical and biophysical experiments to characterise the lag phase of a patient-derived truncated LC and they identify structural transitions that precede fibril formation.
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23
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Identification of transmissible proteotoxic oligomer-like fibrils that expand conformational diversity of amyloid assemblies. Commun Biol 2021; 4:939. [PMID: 34354242 PMCID: PMC8342456 DOI: 10.1038/s42003-021-02466-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 07/19/2021] [Indexed: 11/08/2022] Open
Abstract
Protein misfolding and amyloid deposition are associated with numerous diseases. The detailed characterization of the proteospecies mediating cell death remains elusive owing to the (supra)structural polymorphism and transient nature of the assemblies populating the amyloid pathway. Here we describe the identification of toxic amyloid fibrils with oligomer-like characteristics, which were assembled from an islet amyloid polypeptide (IAPP) derivative containing an Asn-to-Gln substitution (N21Q). While N21Q filaments share structural properties with cytocompatible fibrils, including the 4.7 Å inter-strand distance and β-sheet-rich conformation, they concurrently display characteristics of oligomers, such as low thioflavin-T binding, high surface hydrophobicity and recognition by the A11 antibody, leading to high potency to disrupt membranes and cause cellular dysfunction. The toxic oligomer-like conformation of N21Q fibrils, which is preserved upon elongation, is transmissible to naïve IAPP. These stable fibrils expanding the conformational diversity of amyloid assemblies represent an opportunity to elucidate the structural basis of amyloid disorders. Nguyen et al identified cytotoxic amyloid fibrils with oligomer-like characteristics, which were assembled from an islet amyloid polypeptide (IAPP) derivative containing an Asn-to-Gln substitution (N21Q). They presented evidence to show that these stable fibrils expand the conformational diversity of amyloid assemblies, which represents an opportunity to elucidate the structural basis of amyloid disorders.
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24
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Valentine ML, Al-Mualem ZA, Baiz CR. Pump Slice Amplitudes: A Simple and Robust Method for Connecting Two-Dimensional Infrared and Fourier Transform Infrared Spectra. J Phys Chem A 2021; 125:6498-6504. [PMID: 34259508 DOI: 10.1021/acs.jpca.1c04558] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ultrafast two-dimensional infrared (2D IR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy are often performed in tandem, with FTIR typically used to interpret and provide hypotheses for 2D IR experiments. Comparisons between 2D IR and FTIR spectra can also be used to examine the structure and orientation in systems of coupled vibrational chromophores. The most common method for comparing 2D IR and FTIR lineshapes, the diagonal slice method, contains significant artifacts when applied to oscillators with low anharmonicities. Here, we introduce a new technique, the pump slice amplitude (PSA) method, for relating 2D IR lineshapes to FTIR lineshapes and compare PSAs against diagonal slices using theoretical and experimental spectra. We find that PSAs are significantly more similar to FTIR lineshapes than diagonal slices in systems with low anharmonicity.
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Affiliation(s)
- Mason L Valentine
- Department of Chemistry, University of Texas at Austin, Austin 78712, United States
| | - Ziareena A Al-Mualem
- Department of Chemistry, University of Texas at Austin, Austin 78712, United States
| | - Carlos R Baiz
- Department of Chemistry, University of Texas at Austin, Austin 78712, United States
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25
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Watson MD, Lee JC. Coupling chemical biology and vibrational spectroscopy for studies of amyloids in vitro and in cells. Curr Opin Chem Biol 2021; 64:90-97. [PMID: 34186291 DOI: 10.1016/j.cbpa.2021.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/04/2021] [Accepted: 05/18/2021] [Indexed: 01/21/2023]
Abstract
Amyloid diseases are characterized by the aggregation of various proteins to form insoluble β-sheet-rich fibrils leading to cell death. Vibrational spectroscopies have emerged as attractive methods to study this process because of the rich structural information that can be extracted without large, perturbative probes. Importantly, specific vibrations such as the amide-I band directly report on secondary structure changes, which are key features of amyloid formation. Beyond intrinsic vibrations, the incorporation of unnatural vibrational probes can improve sensitivity for secondary structure determination (e.g. isotopic labeling), can provide residue-specific information of the surrounding polarity (e.g. unnatural amino acid), and are translatable into cellular studies. Here, we review the latest studies that have leveraged tools from chemical biology for the incorporation of novel vibrational probes into amyloidogenic proteins for both mechanistic and cellular studies.
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Affiliation(s)
- Matthew D Watson
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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26
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Niu H, Hou X, Zhang Y, Wu X, Deng F, Huang F, Shi L, Ma R. Self-Assembled Nanochaperones Inhibit the Aggregation of Human Islet Amyloid Polypeptide Associated with Type 2 Diabetes. ACS Macro Lett 2021; 10:662-670. [PMID: 35549098 DOI: 10.1021/acsmacrolett.1c00200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) aggregation is closely associated with dysfunction and apoptosis of pancreatic β-cells in type 2 diabetes (T2D). Accordingly, hIAPP amyloid inhibitors have shown promise against T2D. Here, by mimicking the function of natural molecular chaperones, nanochaperones (nChaps) based on self-assembled polymeric micelles with tunable surface microdomains for T2D treatment are reported. By capturing the aggregation-prone species of hIAPP onto the hydrophobic microdomains and segregating them by hydrophilic PEG chains, this kind of nChaps could effectively prevent hIAPP aggregation, block cell adhesion of hIAPP, facilitate hIAPP aggregates degradation and reduce hIAPP-related cytotoxicity. Therefore, our work will provide useful insights to develop a biomimetic strategy for the treatment of T2D.
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Affiliation(s)
- Haihong Niu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xiaoxue Hou
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China
| | - Yanli Zhang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xiaohui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Fei Deng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Fan Huang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China
| | - Linqi Shi
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Rujiang Ma
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials of Ministry of Education, College of Chemistry, Nankai University, Tianjin 300071, China
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Sun Y, Kakinen A, Wan X, Moriarty N, Hunt CP, Li Y, Andrikopoulos N, Nandakumar A, Davis TP, Parish CL, Song Y, Ke PC, Ding F. Spontaneous Formation of β-sheet Nano-barrels during the Early Aggregation of Alzheimer's Amyloid Beta. NANO TODAY 2021; 38:101125. [PMID: 33936250 PMCID: PMC8081394 DOI: 10.1016/j.nantod.2021.101125] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Soluble low-molecular-weight oligomers formed during the early aggregation of amyloid peptides have been hypothesized as a major toxic species of amyloidogenesis. Herein, we performed the first synergic in silico, in vitro and in vivo validations of the structure, dynamics and toxicity of Aβ42 oligomers. Aβ peptides readily assembled into β-rich oligomers comprised of extended β-hairpins and β-strands. Nanosized β-barrels were observed with certainty with simulations, transmission electron microscopy and Fourier transform infrared spectroscopy, corroborated by immunohistochemistry, cell viability, apoptosis, inflammation, autophagy and animal behavior assays. Secondary and tertiary structural proprieties of these oligomers, such as the sequence regions with high β-sheet propensities and inter-residue contact frequency patterns, were similar to the properties known for Aβ fibrils. The unambiguous spontaneous formation of β-barrels in the early aggregation of Aβ42 supports their roles as the common toxic intermediates in Alzheimer's pathobiology and a target for Alzheimer's therapeutics.
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Affiliation(s)
- Yunxiang Sun
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
- Address correspondence to: Yunxiang Sun: ; Yang Song: ; Pu Chun Ke: ; Feng Ding:
| | - Aleksandr Kakinen
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane Qld 4072, Australia
| | - Xulin Wan
- Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, College of Food Science, Southwest University, 2 Tiansheng Rd, Beibei District, Chongqing, 400715, China
| | - Niamh Moriarty
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville VIC 3052, Australia
| | - Cameron P.J. Hunt
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville VIC 3052, Australia
| | - Yuhuan Li
- Zhongshan Hospital, Fudan University, 111 Yixueyuan Rd, Xuhui District, Shanghai, 200032, China
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Nicholas Andrikopoulos
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Aparna Nandakumar
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Thomas P. Davis
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane Qld 4072, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Clare L. Parish
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville VIC 3052, Australia
| | - Yang Song
- Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, 2 Tiansheng Rd, Beibei District, Chongqing, 400715, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- Address correspondence to: Yunxiang Sun: ; Yang Song: ; Pu Chun Ke: ; Feng Ding:
| | - Pu Chun Ke
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane Qld 4072, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Address correspondence to: Yunxiang Sun: ; Yang Song: ; Pu Chun Ke: ; Feng Ding:
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
- Address correspondence to: Yunxiang Sun: ; Yang Song: ; Pu Chun Ke: ; Feng Ding:
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28
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Potential of peptides and phytochemicals in attenuating different phases of islet amyloid polypeptide fibrillation for type 2 diabetes management. FOOD SCIENCE AND HUMAN WELLNESS 2021. [DOI: 10.1016/j.fshw.2021.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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29
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Lundqvist M, Rodriguez Camargo DC, Bernfur K, Chia S, Linse S. Expression, purification and characterisation of large quantities of recombinant human IAPP for mechanistic studies. Biophys Chem 2021; 269:106511. [PMID: 33360112 DOI: 10.1016/j.bpc.2020.106511] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 01/09/2023]
Abstract
Malfunction and amyloid formation of the Islet Amyloid Polypeptide (IAPP) are factors contributing to Type 2 diabetes. Unravelling the mechanism of IAPP aggregate formation may forward our understanding of this process and its effect on pancreatic β-islet cell. Such mechanistic studies require access to sequence homogeneous and highly pure IAPP. Here we present a new facile protocol for the production of pure recombinant human IAPP at relatively high yield. The protocol uses a His-tagged version of the Npro mutant EDDIE, which drives expression to inclusion bodies, from which the peptide is purified using sonication, refolding and auto-cleavage, removal of EDDIE using Ni-NTA chromatography and reverse-phase HPLC. The purified material is used at multiple concentrations in aggregation kinetics measurements monitored by thioflavin-T fluorescence. Global analysis of the data implies a double nucleation aggregation mechanism including both primary and secondary nucleation.
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Affiliation(s)
- Martin Lundqvist
- Department of Biophysical, Chemistry, Chemical Centre, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Diana C Rodriguez Camargo
- Department of Biophysical, Chemistry, Chemical Centre, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; Wren Therapeutics Limited, UK
| | - Katja Bernfur
- Department of Biophysical, Chemistry, Chemical Centre, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | | | - Sara Linse
- Department of Biophysical, Chemistry, Chemical Centre, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; Wren Therapeutics Limited, UK.
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30
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Xing Y, Nandakumar A, Kakinen A, Sun Y, Davis TP, Ke PC, Ding F. Amyloid Aggregation under the Lens of Liquid-Liquid Phase Separation. J Phys Chem Lett 2021; 12:368-378. [PMID: 33356290 PMCID: PMC7855599 DOI: 10.1021/acs.jpclett.0c02567] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Increasing experiments suggest that amyloid peptides can undergo liquid-liquid phase separation (LLPS) before the formation of amyloid fibrils. However, the exact role of LLPS in amyloid aggregation at the molecular level remains elusive. Here, we investigated the LLPS and amyloid fibrillization of a coarse-grained peptide, capable of capturing fundamental properties of amyloid aggregation over a wide range of concentrations in molecular dynamics simulations. On the basis of the Flory-Huggins theory of polymer solutions, we determined the binodal and spinodal concentrations of LLPS in the low-concentration regime, ϕBL and ϕSL, respectively. Only at concentrations above ϕBL, peptides formed metastable or stable oligomers corresponding to the high-density liquid phase (HDLP) in LLPS, out of which the nucleated conformational conversion to fibril seeds occurred. Below ϕSL, the HDLP was metastable and transient, and the subsequent fibrillization process followed the traditional nucleation and elongation mechanisms. Only above ϕSL, the HDLP became stable, and the initial fibril nucleation and growth were governed by the high local peptide concentrations. The predicted saturation of amyloid aggregation half-times with increasing peptide concentration to a constant, instead of the traditional power-law scaling to zero, was confirmed by simulations and by a thioflavin-T kinetic assay and the transmission electron microscopy of islet amyloid polypeptide (IAPP) aggregation. Our study provides a unified picture of amyloid aggregation for a wide range of concentrations within the framework of LLPS, which may help us better understand the etiology of amyloid diseases, where the amyloid protein concentration can vary by ∼9 orders of magnitude depending on the organ location and facilitate the engineering of novel amyloid-based functional materials.
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Affiliation(s)
- Yanting Xing
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Aparna Nandakumar
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Aleksandr Kakinen
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Yunxiang Sun
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Thomas P. Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Pu Chu Ke, ; Feng Ding,
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
- Pu Chu Ke, ; Feng Ding,
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31
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Milardi D, Gazit E, Radford SE, Xu Y, Gallardo RU, Caflisch A, Westermark GT, Westermark P, Rosa CL, Ramamoorthy A. Proteostasis of Islet Amyloid Polypeptide: A Molecular Perspective of Risk Factors and Protective Strategies for Type II Diabetes. Chem Rev 2021; 121:1845-1893. [PMID: 33427465 DOI: 10.1021/acs.chemrev.0c00981] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The possible link between hIAPP accumulation and β-cell death in diabetic patients has inspired numerous studies focusing on amyloid structures and aggregation pathways of this hormone. Recent studies have reported on the importance of early oligomeric intermediates, the many roles of their interactions with lipid membrane, pH, insulin, and zinc on the mechanism of aggregation of hIAPP. The challenges posed by the transient nature of amyloid oligomers, their structural heterogeneity, and the complex nature of their interaction with lipid membranes have resulted in the development of a wide range of biophysical and chemical approaches to characterize the aggregation process. While the cellular processes and factors activating hIAPP-mediated cytotoxicity are still not clear, it has recently been suggested that its impaired turnover and cellular processing by proteasome and autophagy may contribute significantly toward toxic hIAPP accumulation and, eventually, β-cell death. Therefore, studies focusing on the restoration of hIAPP proteostasis may represent a promising arena for the design of effective therapies. In this review we discuss the current knowledge of the structures and pathology associated with hIAPP self-assembly and point out the opportunities for therapy that a detailed biochemical, biophysical, and cellular understanding of its aggregation may unveil.
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Affiliation(s)
- Danilo Milardi
- Istituto di Cristallografia, Consiglio Nazionale delle Ricerche, Via P. Gaifami 18, 95126 Catania, Italy
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Yong Xu
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Rodrigo U Gallardo
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
| | - Gunilla T Westermark
- Department of Medical Cell Biology, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Per Westermark
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Ayyalusamy Ramamoorthy
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 41809-1055, United States
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32
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Saghir AE, Farrugia G, Vassallo N. The human islet amyloid polypeptide in protein misfolding disorders: Mechanisms of aggregation and interaction with biomembranes. Chem Phys Lipids 2020; 234:105010. [PMID: 33227292 DOI: 10.1016/j.chemphyslip.2020.105010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/06/2020] [Accepted: 11/09/2020] [Indexed: 02/09/2023]
Abstract
Human islet amyloid polypeptide (hIAPP), otherwise known as amylin, is a 37-residue peptide hormone which is reported to be a common factor in protein misfolding disorders such as type-2 diabetes mellitus, Alzheimer's disease and Parkinson's disease, due to deposition of insoluble hIAPP amyloid in the pancreas and brain. Multiple studies point to the importance of the peptide's interaction with biological membranes and the cytotoxicity of hIAPP species. Here, we discuss the aggregation pathways of hIAPP amyloid fibril formation and focus on the complex interplay between membrane-mediated assembly of hIAPP and the associated mechanisms of membrane damage caused by the peptide species. Mitochondrial membranes, which are unique in their lipid composition, are proposed as prime targets for the early intracellular formation of hIAPP toxic entities. We suggest that future studies should include more physiologically-relevant and in-cell studies to allow a more accurate model of in vivo interactions. Finally, we underscore an urgent need for developing effective therapeutic strategies aimed at hindering hIAPP-phospholipid interactions.
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Affiliation(s)
- Adam El Saghir
- Dept. of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Gianluca Farrugia
- Dept. of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta
| | - Neville Vassallo
- Dept. of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Centre for Molecular Medicine and Biobanking, University of Malta, Msida, Malta.
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33
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Farrell KM, Ostrander JS, Jones AC, Yakami BR, Dicke SS, Middleton CT, Hamm P, Zanni MT. Shot-to-shot 2D IR spectroscopy at 100 kHz using a Yb laser and custom-designed electronics. OPTICS EXPRESS 2020; 28:33584-33602. [PMID: 33115018 PMCID: PMC7679191 DOI: 10.1364/oe.409360] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 05/29/2023]
Abstract
The majority of 2D IR spectrometers operate at 1-10 kHz using Ti:Sapphire laser technology. We report a 2D IR spectrometer designed around Yb:KGW laser technology that operates shot-to-shot at 100 kHz. It includes a home-built OPA, a mid-IR pulse shaper, and custom-designed electronics with optional on-chip processing. We report a direct comparison between Yb:KGW and Ti:Sapphire based 2D IR spectrometers. Even though the mid-IR pulse energy is much lower for the Yb:KGW driven system, there is an 8x improvement in signal-to-noise over the 1 kHz Ti:Sapphire driven spectrometer to which it is compared. Experimental data is shown for sub-millimolar concentrations of amides. Advantages and disadvantages of the design are discussed, including thermal background that arises at high repetition rates. This fundamental spectrometer design takes advantage of newly available Yb laser technology in a new way, providing a straightforward means of enhancing sensitivity.
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Affiliation(s)
- Kieran M. Farrell
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Josh S. Ostrander
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Currently with the Department of Chemistry, Indiana Wesleyan University, Marion, Indiana 46953, USA
| | - Andrew C. Jones
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Currently with the Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Albuquerque, New Mexico 87185, USA
| | - Baichhabi R. Yakami
- PhaseTech Spectroscopy, 2810 Crossroads Drive, Suite 4000 Madison, Wisconsin 53718, USA
| | - Sidney S. Dicke
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Chris T. Middleton
- PhaseTech Spectroscopy, 2810 Crossroads Drive, Suite 4000 Madison, Wisconsin 53718, USA
| | - Peter Hamm
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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34
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Bishoyi AK, Roham PH, Rachineni K, Save S, Hazari MA, Sharma S, Kumar A. Human islet amyloid polypeptide (hIAPP) - a curse in type II diabetes mellitus: insights from structure and toxicity studies. Biol Chem 2020; 402:133-153. [PMID: 33544470 DOI: 10.1515/hsz-2020-0174] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
Abstract
The human islet amyloid polypeptide (hIAPP) or amylin, a neuroendocrine peptide hormone, is known to misfold and form amyloidogenic aggregates that have been observed in the pancreas of 90% subjects with Type 2 Diabetes Mellitus (T2DM). Under normal physiological conditions, hIAPP is co-stored and co-secreted with insulin; however, under chronic hyperglycemic conditions associated with T2DM, the overexpression of hIAPP occurs that has been associated with the formation of amyloid deposits; as well as the death and dysfunction of pancreatic β-islets in T2DM. Hitherto, various biophysical and structural studies have shown that during this process of aggregation, the peptide conformation changes from random structure to helix, then to β-sheet, subsequently to cross β-sheets, which finally form left-handed helical aggregates. The intermediates, formed during this process, have been shown to induce higher cytotoxicity in the β-cells by inducing cell membrane disruption, endoplasmic reticulum stress, mitochondrial dysfunction, oxidative stress, islet inflammation, and DNA damage. As a result, several research groups have attempted to target both hIAPP aggregation phenomenon and the destabilization of preformed fibrils as a therapeutic intervention for T2DM management. In this review, we have summarized structural aspects of various forms of hIAPP viz. monomer, oligomers, proto-filaments, and fibrils of hIAPP. Subsequently, cellular toxicity caused by toxic conformations of hIAPP has been elaborated upon. Finally, the need for performing structural and toxicity studies in vivo to fill in the gap between the structural and cellular aspects has been discussed.
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Affiliation(s)
- Ajit Kumar Bishoyi
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Pratiksha H Roham
- Department of Biotechnology, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411007, Maharashtra, India
| | - Kavitha Rachineni
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Shreyada Save
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - M Asrafuddoza Hazari
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Shilpy Sharma
- Department of Biotechnology, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411007, Maharashtra, India
| | - Ashutosh Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
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35
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Wu MH, Chan AC, Tu LH. Role of lysine residue of islet amyloid polypeptide in fibril formation, membrane binding, and inhibitor binding. Biochimie 2020; 177:153-163. [PMID: 32860895 DOI: 10.1016/j.biochi.2020.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/31/2020] [Accepted: 08/18/2020] [Indexed: 12/27/2022]
Abstract
The aggregation of islet amyloid polypeptide (IAPP) is implicated in the pathogenesis of type 2 diabetes (T2D). In T2D, this peptide aggregates to form amyloid fibrils; the mechanism responsible for islet amyloid formation is unclear. However, it is known that the aggregation propensity of IAPP is highly related to its primary sequence. Several residues have been suggested to be critical in modulating IAPP amyloid formation, but role of the sole lysine residue at position 1 (Lys-1) in IAPP has not been discussed. In our previous study, we found that glycated IAPP can form amyloid faster than normal IAPP and induce normal IAPP to expedite the aggregation process. To gain more insight into the contribution of Lys-1 in the kinetics of fibril formation, we synthesized another two IAPP variants, K1E-IAPP and K1Nle-IAPP, in which the Lys residue was mutated to glutamate and norleucine, respectively. Interestingly, we observed that the negative or neutral charged side chain at this position was preferred for amyloid formation. The findings suggested this residue may take part in the inter- or intra-molecular interaction during IAPP aggregation, even though it was proposed not to be in part of fibril core structure. Our data also revealed that the inhibitory mechanism of some inhibitors for IAPP aggregation require reaction with Lys-1. Modifications of Lys-1, such as protein glycation, may affect the effectiveness of the inhibitory action of some potential drugs in the treatment of amyloidosis.
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Affiliation(s)
- Meng-Hsin Wu
- Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan
| | - Ai-Ci Chan
- Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan
| | - Ling-Hsien Tu
- Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan.
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36
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Baiz CR, Błasiak B, Bredenbeck J, Cho M, Choi JH, Corcelli SA, Dijkstra AG, Feng CJ, Garrett-Roe S, Ge NH, Hanson-Heine MWD, Hirst JD, Jansen TLC, Kwac K, Kubarych KJ, Londergan CH, Maekawa H, Reppert M, Saito S, Roy S, Skinner JL, Stock G, Straub JE, Thielges MC, Tominaga K, Tokmakoff A, Torii H, Wang L, Webb LJ, Zanni MT. Vibrational Spectroscopic Map, Vibrational Spectroscopy, and Intermolecular Interaction. Chem Rev 2020; 120:7152-7218. [PMID: 32598850 PMCID: PMC7710120 DOI: 10.1021/acs.chemrev.9b00813] [Citation(s) in RCA: 173] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Vibrational spectroscopy is an essential tool in chemical analyses, biological assays, and studies of functional materials. Over the past decade, various coherent nonlinear vibrational spectroscopic techniques have been developed and enabled researchers to study time-correlations of the fluctuating frequencies that are directly related to solute-solvent dynamics, dynamical changes in molecular conformations and local electrostatic environments, chemical and biochemical reactions, protein structural dynamics and functions, characteristic processes of functional materials, and so on. In order to gain incisive and quantitative information on the local electrostatic environment, molecular conformation, protein structure and interprotein contacts, ligand binding kinetics, and electric and optical properties of functional materials, a variety of vibrational probes have been developed and site-specifically incorporated into molecular, biological, and material systems for time-resolved vibrational spectroscopic investigation. However, still, an all-encompassing theory that describes the vibrational solvatochromism, electrochromism, and dynamic fluctuation of vibrational frequencies has not been completely established mainly due to the intrinsic complexity of intermolecular interactions in condensed phases. In particular, the amount of data obtained from the linear and nonlinear vibrational spectroscopic experiments has been rapidly increasing, but the lack of a quantitative method to interpret these measurements has been one major obstacle in broadening the applications of these methods. Among various theoretical models, one of the most successful approaches is a semiempirical model generally referred to as the vibrational spectroscopic map that is based on a rigorous theory of intermolecular interactions. Recently, genetic algorithm, neural network, and machine learning approaches have been applied to the development of vibrational solvatochromism theory. In this review, we provide comprehensive descriptions of the theoretical foundation and various examples showing its extraordinary successes in the interpretations of experimental observations. In addition, a brief introduction to a newly created repository Web site (http://frequencymap.org) for vibrational spectroscopic maps is presented. We anticipate that a combination of the vibrational frequency map approach and state-of-the-art multidimensional vibrational spectroscopy will be one of the most fruitful ways to study the structure and dynamics of chemical, biological, and functional molecular systems in the future.
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Affiliation(s)
- Carlos R. Baiz
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, U.S.A
| | - Bartosz Błasiak
- Department of Physical and Quantum Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Jens Bredenbeck
- Johann Wolfgang Goethe-University, Institute of Biophysics, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Seoul 02841, Republic of Korea
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
| | - Jun-Ho Choi
- Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Steven A. Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, U.S.A
| | - Arend G. Dijkstra
- School of Chemistry and School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Chi-Jui Feng
- Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, U.S.A
| | - Sean Garrett-Roe
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, U.S.A
| | - Nien-Hui Ge
- Department of Chemistry, University of California at Irvine, Irvine, CA 92697-2025, U.S.A
| | - Magnus W. D. Hanson-Heine
- School of Chemistry, University of Nottingham, Nottingham, University Park, Nottingham, NG7 2RD, U.K
| | - Jonathan D. Hirst
- School of Chemistry, University of Nottingham, Nottingham, University Park, Nottingham, NG7 2RD, U.K
| | - Thomas L. C. Jansen
- University of Groningen, Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Kijeong Kwac
- Center for Molecular Spectroscopy and Dynamics, Seoul 02841, Republic of Korea
| | - Kevin J. Kubarych
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109, U.S.A
| | - Casey H. Londergan
- Department of Chemistry, Haverford College, Haverford, Pennsylvania 19041, U.S.A
| | - Hiroaki Maekawa
- Department of Chemistry, University of California at Irvine, Irvine, CA 92697-2025, U.S.A
| | - Mike Reppert
- Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Shinji Saito
- Department of Theoretical and Computational Molecular Science, Institute for Molecular Science, Myodaiji, Okazaki, 444-8585, Japan
| | - Santanu Roy
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, U.S.A
| | - James L. Skinner
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, U.S.A
| | - Gerhard Stock
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - John E. Straub
- Department of Chemistry, Boston University, Boston, MA 02215, U.S.A
| | - Megan C. Thielges
- Department of Chemistry, Indiana University, 800 East Kirkwood, Bloomington, Indiana 47405, U.S.A
| | - Keisuke Tominaga
- Molecular Photoscience Research Center, Kobe University, Nada, Kobe 657-0013, Japan
| | - Andrei Tokmakoff
- Department of Chemistry, James Franck Institute and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, U.S.A
| | - Hajime Torii
- Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, and Department of Optoelectronics and Nanostructure Science, Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-Ku, Hamamatsu 432-8561, Japan
| | - Lu Wang
- Department of Chemistry and Chemical Biology, Institute for Quantitative Biomedicine, Rutgers University, 174 Frelinghuysen Road, Piscataway, NJ 08854, U.S.A
| | - Lauren J. Webb
- Department of Chemistry, The University of Texas at Austin, 105 E. 24th Street, STOP A5300, Austin, Texas 78712, U.S.A
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1396, U.S.A
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37
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Fields CR, Dicke SS, Petti MK, Zanni MT, Lomont JP. A Different hIAPP Polymorph Is Observed in Human Serum Than in Aqueous Buffer: Demonstration of a New Method for Studying Amyloid Fibril Structure Using Infrared Spectroscopy. J Phys Chem Lett 2020; 11:6382-6388. [PMID: 32706257 PMCID: PMC7968077 DOI: 10.1021/acs.jpclett.0c01345] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
There is enormous interest in measuring amyloid fibril structures, but most structural studies measure fibril formation in vitro using aqueous buffer. Ideally, one would like to measure fibril structure and mechanism under more physiological conditions. Toward this end, we have developed a method for studying amyloid fibril structure in human serum. Our approach uses isotope labeling, antibody depletion of the most abundant proteins (albumin and IgG), and infrared spectroscopy to measure aggregation in human serum with reduced protein content. Reducing the nonamyloid protein content enables the measurements by decreasing background signals but retains the full composition of salts, sugars, metal ions, etc. that are naturally present but usually missing from in vitro studies. We demonstrate the method by measuring the two-dimensional infrared (2D IR) spectra of isotopically labeled human islet amyloid polypeptide (hIAPP or amylin). We find that the fibril structure of hIAPP formed in serum differs from that formed via aggregation in aqueous buffer at residues Gly24 and Ala25, which reside in the putative "amyloidogenic core" or FGAIL region of the sequence. The spectra are consistent with extended parallel stacks of strands consistent with β-sheet-like structure, rather than a partially disordered loop that forms in aqueous buffer. These experiments provide a new method for using infrared spectroscopy to monitor the structure of proteins under physiological conditions and reveal the formation of a significantly different polymorph structure in the most important region of hIAPP.
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Affiliation(s)
- Caitlyn R Fields
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Sidney S Dicke
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Megan K Petti
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Justin P Lomont
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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38
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Cai K, Liu J, Liu Y, Chen F, Yan G, Lin H. Application of a transparent window vibrational probe (azido probe) to the structural dynamics of model dipeptides and amyloid β-peptide. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 227:117681. [PMID: 31685425 DOI: 10.1016/j.saa.2019.117681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/02/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
The azido asymmetric stretching motion is widely used for the elucidation of the intrinsic conformational preference and folding mechanism of protein since it has strong vibrational absorbance in the spectral transparent windows. However, the possible secondary structural disturbance induced by the insertion of azido group in the side chain of polypeptides should be carefully evaluated. Here, DFT calculation and enhanced sampling method were employed for model dipeptides with or without azido substitution, and the outcome results show that the lower potential energy basins of isolated model dipeptides are consistent with the preferred structural distributions of model dipeptides in aqueous solution. The azido asymmetric stretching frequency shows its sensitivity to the backbone configurations just like amide-I vibration does, and the azido vibration exhibits great potential as a structural reporter in the transparent window. For the evaluation of the application of azido group in biologically related system, the structural dynamics of Aβ37-42 and N3-Aβ37-42 fragments and the self-assemble process of their protofiliments in aqueous solution were demonstrated. The outcome results show that the structural fluctuations of Aβ37-42 and its protofilament in aqueous solution are quite similar with or without azido substitution, and the dewetting transitions of Aβ37-42 and N3-Aβ37-42 β-sheet layers are both complete within 30 ns and assemble into stable protofilaments. Therefore, the azido asymmetric vibrational motion is a minimally invasive structural probe and would not introduce much disturbance to the structural dynamics of polypeptides.
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Affiliation(s)
- Kaicong Cai
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, 361005, Fujian, PR China.
| | - Jia Liu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, 361005, Fujian, PR China
| | - Ya'nan Liu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, 361005, Fujian, PR China
| | - Feng Chen
- Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Ningde, 352100, PR China
| | - Guiyang Yan
- Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Ningde, 352100, PR China
| | - Huiqiu Lin
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China
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39
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Ridgway Z, Eldrid C, Zhyvoloup A, Ben-Younis A, Noh D, Thalassinos K, Raleigh DP. Analysis of Proline Substitutions Reveals the Plasticity and Sequence Sensitivity of Human IAPP Amyloidogenicity and Toxicity. Biochemistry 2020; 59:742-754. [PMID: 31922743 DOI: 10.1021/acs.biochem.9b01109] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pancreatic amyloid formation by the polypeptide IAPP contributes to β-cell dysfunction in type 2 diabetes. There is a 1:1 correspondence between the ability of IAPP from different species to form amyloid in vitro and the susceptibility of the organism to develop diabetes. Rat IAPP is non-amyloidogenic and differs from human IAPP at six positions, including three proline replacements: A25P, S28P, and S29P. Incorporation of these proline residues into human IAPP leads to a non-amyloidogenic analogue that is used clinically. The role of the individual proline residues is not understood. We examine the three single and three double proline substitutions in the context of human IAPP. An S28P substitution significantly decreases amyloidogenicity and toxicity, while an S29P substitution has very modest effects despite being an identical replacement just one residue away. The consequences of the A25P substitution are between those of the two Ser to Pro substitutions. Double analogues containing an S28P replacement are less amyloidogenic and less toxic than the IAPPA25P S29P double analogue. Ion mobility mass spectrometry reveals that there is no correlation between the monomer or dimer conformation as reported by collision cross section measurements and the time to form amyloid. The work reveals both the plasticity of IAPP amyloid formation and the exquisite sequence sensitivity of IAPP amyloidogenicity and toxicity. The study highlights the key role of the S28P substitution and provides information that will aid in the rational design of soluble variants of IAPP. The variants studied here offer a system for further exploring features that control IAPP toxicity.
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Affiliation(s)
- Zachary Ridgway
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Charles Eldrid
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Aisha Ben-Younis
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Daeun Noh
- Graduate Program in Biochemistry and Structural Biology , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Daniel P Raleigh
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States.,Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
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40
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Saravanan MS, Ryazanov S, Leonov A, Nicolai J, Praest P, Giese A, Winter R, Khemtemourian L, Griesinger C, Killian JA. The small molecule inhibitor anle145c thermodynamically traps human islet amyloid peptide in the form of non-cytotoxic oligomers. Sci Rep 2019; 9:19023. [PMID: 31836748 PMCID: PMC6911113 DOI: 10.1038/s41598-019-54919-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/15/2019] [Indexed: 01/09/2023] Open
Abstract
Type 2 diabetes (T2DM) is associated with aggregation of the human islet amyloid polypeptide (hIAPP) into cytotoxic amyloid species. Here we tested the effect of a diphenylpyrazole (DPP)-derived small molecule inhibitor, anle145c, on cytotoxicity and on aggregation properties of hIAPP. We demonstrate that incubation of hIAPP with the inhibitor yields ~10 nm-sized non-toxic oligomers, independent of the initial aggregation state of hIAPP. This suggests that anle145c has a special mode of action in which anle145c-stabilized oligomers act as a thermodynamic sink for the preferred aggregation state of hIAPP and anle145c. We also demonstrate that the inhibitor acts in a very efficient manner, with sub-stoichiometric concentrations of anle145c being sufficient to (i) inhibit hIAPP-induced death of INS-1E cells, (ii) prevent hIAPP fibril formation in solution, and (iii) convert preformed hIAPP fibrils into non-toxic oligomers. Together, these results indicate that anle145c is a promising candidate for inhibition of amyloid formation in T2DM.
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Affiliation(s)
- Manikam S Saravanan
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Sergey Ryazanov
- NMR based structural biology, MPI for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
- DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Andrei Leonov
- NMR based structural biology, MPI for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
- DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Janine Nicolai
- Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, Faculty of Chemistry and Chemical Biology, Otto Hahn Str. 4a, D-44221, Dortmund, Germany
| | - Patrique Praest
- Medical Microbiology, University Medical Center Utrecht, 3684CX, Utrecht, The Netherlands
| | - Armin Giese
- Zentrum für Neuropathologie und Prionforschung, Ludwig-Maximilians - University München, München, Germany
| | - Roland Winter
- Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, Faculty of Chemistry and Chemical Biology, Otto Hahn Str. 4a, D-44221, Dortmund, Germany
| | - Lucie Khemtemourian
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 4 place Jussieu, F-75005, Paris, France.
- Institute of Chemistry & Biology of Membranes & Nanoobjects (CBMN), CNRS UMR5248, University of Bordeaux, Bordeaux INP, allée Geoffroy St-Hilaire, 33600, Pessac, France.
| | - Christian Griesinger
- NMR based structural biology, MPI for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
- DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany.
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
| | - J Antoinette Killian
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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41
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Ostrander JS, Lomont JP, Rich KL, Saraswat V, Feingold BR, Petti MK, Birdsall ER, Arnold MS, Zanni MT. Monolayer Sensitivity Enables a 2D IR Spectroscopic Immuno-biosensor for Studying Protein Structures: Application to Amyloid Polymorphs. J Phys Chem Lett 2019; 10:3836-3842. [PMID: 31246039 PMCID: PMC6823637 DOI: 10.1021/acs.jpclett.9b01267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Immunosensors use antibodies to detect and quantify biomarkers of disease, though the sensors often lack structural information. We create a surface-sensitive two-dimensional infrared (2D IR) spectroscopic immunosensor for studying protein structures. We tether antibodies to a plasmonic surface, flow over a solution of amyloid proteins, and measure the 2D IR spectra. The 2D IR spectra provide a global assessment of antigen structure, and isotopically labeled proteins give residue-specific structural information. We report the 2D IR spectra of fibrils and monomers using a polyclonal antibody that targets human islet amyloid polypeptide (hIAPP). We observe two fibrillar polymorphs differing in their structure at the G24 residue, which supports the hypothesis that hIAPP polymorphs form from a common oligomeric intermediate. This work provides insight into the structure of hIAPP, establishes a new method for studying protein structures using 2D IR spectroscopy, and creates a spectroscopic immunoassay applicable for studying a wide range of biomarkers.
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Affiliation(s)
- Joshua S. Ostrander
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Justin P. Lomont
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Kacie L. Rich
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Vivek Saraswat
- Department of Materials Science and Engineering, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Benjamin R. Feingold
- Department of Materials Science and Engineering, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Megan K. Petti
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Erin R. Birdsall
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Michael S. Arnold
- Department of Materials Science and Engineering, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
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42
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Hsu YH, Chen YW, Wu MH, Tu LH. Protein Glycation by Glyoxal Promotes Amyloid Formation by Islet Amyloid Polypeptide. Biophys J 2019; 116:2304-2313. [PMID: 31155148 DOI: 10.1016/j.bpj.2019.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/16/2019] [Accepted: 05/14/2019] [Indexed: 01/01/2023] Open
Abstract
Protein glycation, also known as nonenzymatic glycosylation, is a spontaneous post-translational modification that would change the structure and stability of proteins or hormone peptides. Recent studies have indicated that glycation plays a role in type 2 diabetes (T2D) and neurodegenerative diseases. Over the last two decades, many types of advanced glycation end products (AGEs), formed through the reactions of an amino group of proteins with reducing sugars, have been identified and detected in vivo. However, the effect of glycation on protein aggregation has not been fully investigated. In this study, we aim to elucidate the impact of protein glycation on islet amyloid polypeptide (IAPP, also known as amylin) aggregation, which was strongly associated with T2D. We chemically synthesized glycated IAPP (AGE-IAPP) to mimic the consequence of this hormone peptide in a hyperglycemia (high blood sugar) environment. Our data revealed that AGE-IAPP formed amyloid faster than normal IAPP, and higher-molecular-weight AGE-IAPP oligomers were also observed in the early stage of aggregation. Circular dichroism spectra also indicated that AGE-IAPP exhibited faster conformational changes from random coil to its β-sheet fibrillar states. Moreover, AGE-IAPP can induce normal IAPP to expedite its aggregation process, and its fibrils can also act as templates to promote IAPP aggregation. AGE-IAPP, like normal IAPP, is capable of interacting with synthetic membranes and also exhibits cytotoxicity. Our studies demonstrated that glycation modification of IAPP promotes the amyloidogenic properties of IAPP, and it may play a role in accumulating additional amyloid during T2D progression.
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Affiliation(s)
- Yi-Hsuan Hsu
- Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan
| | - Yun-Wen Chen
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Meng-Hsin Wu
- Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan
| | - Ling-Hsien Tu
- Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan.
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43
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Godin E, Nguyen PT, Zottig X, Bourgault S. Identification of a hinge residue controlling islet amyloid polypeptide self-assembly and cytotoxicity. J Biol Chem 2019; 294:8452-8463. [PMID: 30975901 DOI: 10.1074/jbc.ra118.006454] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 04/04/2019] [Indexed: 11/06/2022] Open
Abstract
The islet amyloid polypeptide (IAPP) is a 37-residue peptide hormone whose deposition as amyloid fibrils in the pancreatic islets is associated with type 2 diabetes. Previous studies have suggested that residue Asn-21 plays a critical role in the in vitro self-assembly of IAPP. Herein, we studied structure-self-assembly relationships focusing on position 21 to gain detailed insights into the molecular mechanisms of IAPP self-assembly and to probe the conformational nature of the toxic assemblies associated with β-cell death. Thioflavin T (ThT) fluorescence, CD spectroscopy, and transmission EM analysis revealed that the Asn-21 amide side chain is not required for IAPP nucleation and amyloid elongation, as N21A and N21G variants assembled into prototypical fibrils. In contrast, Asn-21 substitution with the conformationally constrained and turn-inducing residue Pro accelerated IAPP self-assembly. Successive substitutions with hydrophobic residues led to the formation of ThT-negative β-sheet-rich aggregates having high surface hydrophobicity. Cell-based assays revealed no direct correlation between the in vitro amyloidogenicity of these variants and their toxicity. In contrast, leakage of anionic lipid vesicles disclosed that membrane disruption is closely associated with cytotoxicity. We observed that the N21F variant self-assembles into worm-like aggregates, causing loss of lipid membrane structural integrity and inducing β-cell apoptosis. These results indicate that specific intra- and intermolecular interactions involving Asn-21 promote IAPP primary nucleation events by modulating the conformational conversion of the oligomeric intermediates into amyloid fibrils. Our study identifies position 21 as a hinge residue that modulates IAPP amyloidogenicity and cytotoxicity.
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Affiliation(s)
- Elizabeth Godin
- Department of Chemistry, Pharmaqam, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications, PROTEO, Quebec G1V 0A6, Canada
| | - Phuong Trang Nguyen
- Department of Chemistry, Pharmaqam, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications, PROTEO, Quebec G1V 0A6, Canada
| | - Ximena Zottig
- Department of Chemistry, Pharmaqam, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications, PROTEO, Quebec G1V 0A6, Canada
| | - Steve Bourgault
- Department of Chemistry, Pharmaqam, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada; Quebec Network for Research on Protein Function, Engineering, and Applications, PROTEO, Quebec G1V 0A6, Canada.
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44
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Vibrational Approach to the Dynamics and Structure of Protein Amyloids. Molecules 2019; 24:molecules24010186. [PMID: 30621325 PMCID: PMC6337179 DOI: 10.3390/molecules24010186] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 12/31/2018] [Accepted: 01/02/2019] [Indexed: 02/06/2023] Open
Abstract
Amyloid diseases, including neurodegenerative diseases such as Alzheimer’s and Parkinson’s, are linked to a poorly understood progression of protein misfolding and aggregation events that culminate in tissue-selective deposition and human pathology. Elucidation of the mechanistic details of protein aggregation and the structural features of the aggregates is critical for a comprehensive understanding of the mechanisms of protein oligomerization and fibrillization. Vibrational spectroscopies, such as Fourier transform infrared (FTIR) and Raman, are powerful tools that are sensitive to the secondary structure of proteins and have been widely used to investigate protein misfolding and aggregation. We address the application of the vibrational approaches in recent studies of conformational dynamics and structural characteristics of protein oligomers and amyloid fibrils. In particular, introduction of isotope labelled carbonyl into a peptide backbone, and incorporation of the extrinsic unnatural amino acids with vibrational moieties on the side chain, have greatly expanded the ability of vibrational spectroscopy to obtain site-specific structural and dynamic information. The applications of these methods in recent studies of protein aggregation are also reviewed.
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45
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Bai C, Lin D, Mo Y, Lei J, Sun Y, Xie L, Yang X, Wei G. Influence of fullerenol on hIAPP aggregation: amyloid inhibition and mechanistic aspects. Phys Chem Chem Phys 2019; 21:4022-4031. [DOI: 10.1039/c8cp07501h] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
C60(OH)24inhibits hIAPP aggregation by suppressing the fibril-prone structure and destabilizes hIAPP protofibrils by binding to the amyloid core region.
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Affiliation(s)
- Cuiqin Bai
- Department of Physics
- State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Science (Ministry of Education)
- Fudan University
- Shanghai 200433
- People's Republic of China
| | - Dongdong Lin
- Department of Microelectronic Science and Engineering Science Faculty of Science
- Ningbo University
- Ningbo 315211
- P. R. China
| | - Yuxiang Mo
- College of Physical Science and Technology
- Guangxi Normal University
- 15 Yucai Road
- Guilin
- China
| | - Jiangtao Lei
- Department of Physics
- State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Science (Ministry of Education)
- Fudan University
- Shanghai 200433
- People's Republic of China
| | - Yunxiang Sun
- Department of Physics
- State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Science (Ministry of Education)
- Fudan University
- Shanghai 200433
- People's Republic of China
| | - Luogang Xie
- College of Physics and Electronic Engineering
- Zhengzhou University of Light Industry
- Zhengzhou 453002
- People's Republic of China
| | - Xinju Yang
- Department of Physics
- State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Science (Ministry of Education)
- Fudan University
- Shanghai 200433
- People's Republic of China
| | - Guanghong Wei
- Department of Physics
- State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Science (Ministry of Education)
- Fudan University
- Shanghai 200433
- People's Republic of China
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46
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Khatua DK, Halder M. Distinctively complete inhibition of fibrillation of serum albumins by methotrexate in vitro: experimental and modelling studies to understand the tuning of protein misfolding-related aggregations. NEW J CHEM 2019. [DOI: 10.1039/c9nj05128g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Formation of amyloid fibril and non-fibril agglomerations of BSA in the absence and presence of FA and MTX, respectively.
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Affiliation(s)
- Deb Kumar Khatua
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur-721302
- India
| | - Mintu Halder
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur-721302
- India
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47
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Sun Y, Kakinen A, Xing Y, Pilkington EH, Davis TP, Ke PC, Ding F. Nucleation of β-rich oligomers and β-barrels in the early aggregation of human islet amyloid polypeptide. Biochim Biophys Acta Mol Basis Dis 2018; 1865:434-444. [PMID: 30502402 DOI: 10.1016/j.bbadis.2018.11.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/10/2018] [Accepted: 11/26/2018] [Indexed: 10/27/2022]
Abstract
The self-assembly of human islet amyloid polypeptide (hIAPP) into β-sheet rich amyloid aggregates is associated with pancreatic β-cell death in type 2 diabetes (T2D). Prior experimental studies of hIAPP aggregation reported the early accumulation of α-helical intermediates before the rapid conversion into β-sheet rich amyloid fibrils, as also corroborated by our experimental characterizations with transmission electron microscopy and Fourier transform infrared spectroscopy. Although increasing evidence suggests that small oligomers populating early hIAPP aggregation play crucial roles in cytotoxicity, structures of these oligomer intermediates and their conformational conversions remain unknown, hindering our understanding of T2D disease mechanism and therapeutic design targeting these early aggregation species. We further applied large-scale discrete molecule dynamics simulations to investigate the oligomerization of full-length hIAPP, employing multiple molecular systems of increasing number of peptides. We found that the oligomerization process was dynamic, involving frequent inter-oligomeric exchanges. On average, oligomers had more α-helices than β-sheets, consistent with ensemble-based experimental measurements. However, in ~4-6% independent simulations, β-rich oligomers expected as the fibrillization intermediates were observed, especially in the pentamer and hexamer simulations. These β-rich oligomers could adopt β-barrel conformations, recently postulated to be the toxic oligomer species but only observed computationally in the aggregates of short amyloid protein fragments. Free-energy analysis revealed high energies of these β-rich oligomers, supporting the nucleated conformational changes of oligomers in amyloid aggregation. β-barrel oligomers of full-length hIAPP with well-defined three-dimensional structures may play an important pathological role in T2D etiology and may be a therapeutic target for the disease.
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Affiliation(s)
- Yunxiang Sun
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Aleksandr Kakinen
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Yanting Xing
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Emily H Pilkington
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Thomas P Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
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48
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Buchanan LE, Maj M, Dunkelberger EB, Cheng PN, Nowick JS, Zanni MT. Structural Polymorphs Suggest Competing Pathways for the Formation of Amyloid Fibrils That Diverge from a Common Intermediate Species. Biochemistry 2018; 57:6470-6478. [PMID: 30375231 DOI: 10.1021/acs.biochem.8b00997] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
It is now recognized that many amyloid-forming proteins can associate into multiple fibril structures. Here, we use two-dimensional infrared spectroscopy to study two fibril polymorphs formed by human islet amyloid polypeptide (hIAPP or amylin), which is associated with type 2 diabetes. The polymorphs exhibit different degrees of structural organization near the loop region of hIAPP fibrils. The relative populations of these polymorphs are systematically altered by the presence of macrocyclic peptides which template β-sheet formation at specific sections of the hIAPP sequence. These experiments are consistent with polymorphs that result from competing pathways for fibril formation and that the macrocycles bias hIAPP aggregation toward one pathway or the other. Another macrocyclic peptide that matches the loop region but extends the lag time leaves the relative populations of the polymorphs unaltered, suggesting that the branching point for structural divergence occurs after the lag phase, when the oligomers convert into seeds that template fibril formation. Thus, we conclude that the structures of the polymorphs stem from restricting oligomers along diverging folding pathways, which has implications for drug inhibition, cytotoxicity, and the free energy landscape of hIAPP aggregation.
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Affiliation(s)
- Lauren E Buchanan
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706-1396 , United States
| | - Michał Maj
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706-1396 , United States
| | - Emily B Dunkelberger
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706-1396 , United States
| | - Pin-Nan Cheng
- Department of Chemistry , University of California-Irvine , Irvine , California 92697-2025 , United States
| | - James S Nowick
- Department of Chemistry , University of California-Irvine , Irvine , California 92697-2025 , United States
| | - Martin T Zanni
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706-1396 , United States
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49
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Silva A, Sárkány Z, Fraga JS, Taboada P, Macedo-Ribeiro S, Martins PM. Probing the Occurrence of Soluble Oligomers through Amyloid Aggregation Scaling Laws. Biomolecules 2018; 8:biom8040108. [PMID: 30287796 PMCID: PMC6316134 DOI: 10.3390/biom8040108] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 09/29/2018] [Accepted: 10/01/2018] [Indexed: 12/24/2022] Open
Abstract
Drug discovery frequently relies on the kinetic analysis of physicochemical reactions that are at the origin of the disease state. Amyloid fibril formation has been extensively investigated in relation to prevalent and rare neurodegenerative diseases, but thus far no therapeutic solution has directly arisen from this knowledge. Other aggregation pathways producing smaller, hard-to-detect soluble oligomers are increasingly appointed as the main reason for cell toxicity and cell-to-cell transmissibility. Here we show that amyloid fibrillation kinetics can be used to unveil the protein oligomerization state. This is illustrated for human insulin and ataxin-3, two model proteins for which the amyloidogenic and oligomeric pathways are well characterized. Aggregation curves measured by the standard thioflavin-T (ThT) fluorescence assay are shown to reflect the relative composition of protein monomers and soluble oligomers measured by nuclear magnetic resonance (NMR) for human insulin, and by dynamic light scattering (DLS) for ataxin-3. Unconventional scaling laws of kinetic measurables were explained using a single set of model parameters consisting of two rate constants, and in the case of ataxin-3, an additional order-of-reaction. The same fitted parameters were used in a discretized population balance that adequately describes time-course measurements of fibril size distributions. Our results provide the opportunity to study oligomeric targets using simple, high-throughput compatible, biophysical assays.
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Affiliation(s)
- Alexandra Silva
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
| | - Zsuzsa Sárkány
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
| | - Joana S Fraga
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal.
| | - Pablo Taboada
- Área de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
- Instituto de Investigación Sanitaria (IDIS), 15706 de Santiago de Compostela, Spain.
| | - Sandra Macedo-Ribeiro
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
| | - Pedro M Martins
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal.
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50
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Guo AZ, Fluitt AM, de Pablo JJ. Early-stage human islet amyloid polypeptide aggregation: Mechanisms behind dimer formation. J Chem Phys 2018; 149:025101. [DOI: 10.1063/1.5033458] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Ashley Z. Guo
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Aaron M. Fluitt
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Juan J. de Pablo
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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