1
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Tian Y, Shang Q, Liang R, Viles JH. Copper(II) Can Kinetically Trap Arctic and Italian Amyloid-β 40 as Toxic Oligomers, Mimicking Cu(II) Binding to Wild-Type Amyloid-β 42: Implications for Familial Alzheimer's Disease. JACS AU 2024; 4:578-591. [PMID: 38425915 PMCID: PMC10900208 DOI: 10.1021/jacsau.3c00687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 03/02/2024]
Abstract
The self-association of amyloid-β (Aβ) peptide into neurotoxic oligomers is believed to be central to Alzheimer's disease (AD). Copper is known to impact Aβ assembly, while disrupted copper homeostasis impacts phenotype in Alzheimer's models. Here we show the presence of substoichiometric Cu(II) has very different impacts on the assembly of Aβ40 and Aβ42 isoforms. Globally fitting microscopic rate constants for fibril assembly indicates copper will accelerate fibril formation of Aβ40 by increasing primary nucleation, while seeding experiments confirm that elongation and secondary nucleation rates are unaffected by Cu(II). In marked contrast, Cu(II) traps Aβ42 as prefibrillar oligomers and curvilinear protofibrils. Remarkably, the Cu(II) addition to preformed Aβ42 fibrils causes the disassembly of fibrils back to protofibrils and oligomers. The very different behaviors of the two Aβ isoforms are centered around differences in their fibril structures, as highlighted by studies of C-terminally amidated Aβ42. Arctic and Italian familiar mutations also support a key role for fibril structure in the interplay of Cu(II) with Aβ40/42 isoforms. The Cu(II) dependent switch in behavior between nonpathogenic Aβ40 wild-type and Aβ40 Arctic or Italian mutants suggests heightened neurotoxicity may be linked to the impact of physiological Cu(II), which traps these familial mutants as oligomers and curvilinear protofibrils, which cause membrane permeability and Ca(II) cellular influx.
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Affiliation(s)
- Yao Tian
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
| | - Qi Shang
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
| | - Ruina Liang
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
| | - John H. Viles
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
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2
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Kuhn AJ, Chan K, Sajimon M, Yoo S, Balasco Serrão VH, Lee J, Abrams B, Nowick JS, Uversky VN, Wheeler C, Raskatov JA. Amyloid-α Peptide Formed through Alternative Processing of the Amyloid Precursor Protein Attenuates Alzheimer's Amyloid-β Toxicity via Cross-Chaperoning. J Am Chem Soc 2024; 146:2634-2645. [PMID: 38236059 DOI: 10.1021/jacs.3c11511] [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: 01/19/2024]
Abstract
Amyloid aggregation is a key feature of Alzheimer's disease (AD) and a primary target for past and present therapeutic efforts. Recent research is making it increasingly clear that the heterogeneity of amyloid deposits, extending past the commonly targeted amyloid-β (Aβ), must be considered for successful therapy. We recently demonstrated that amyloid-α (Aα or p3), a C-terminal peptidic fragment of Aβ, aggregates rapidly to form amyloids and can expedite the aggregation of Aβ through seeding. Here, we advance the understanding of Aα biophysics and biology in several important ways. We report the first cryogenic electron microscopy (cryo-EM) structure of an Aα amyloid fibril, proving unambiguously that the peptide is fibrillogenic. We demonstrate that Aα induces Aβ to form amyloid aggregates that are less toxic than pure Aβ aggregates and use nuclear magnetic resonance spectroscopy (NMR) to provide insights into specific interactions between Aα and Aβ in solution. This is the first evidence that Aα can coassemble with Aβ and alter its biological effects at relatively low concentrations. Based on the above, we urge researchers in the field to re-examine the significance of Aα in AD.
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Affiliation(s)
- Ariel J Kuhn
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Ka Chan
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Maria Sajimon
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Stan Yoo
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Vitor Hugo Balasco Serrão
- Biomolecular Cryoelectron Microscopy Facility, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Jack Lee
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Benjamin Abrams
- Department of Biomolecular Engineering, Life Sciences Microscopy Center, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - James S Nowick
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Boulevard, MDC07, Tampa, Florida 33612, United States
| | - Christopher Wheeler
- World Brain Mapping Foundation, Society for Brain Mapping & Therapeutics, 860 Via De La Paz, Suite E-1, Pacific Palisades, California 90272-3668, United States
- StemVax Therapeutics (Subsidiary of NovAccess Global), 8584 E. Washington Street #127, Chagrin Falls, Ohio 44023, United States
- StemVax Therapeutics (Subsidiary of NovAccess Global), 2265 E. Foothill Boulevard, Pasadena, California 91107, United States
- T-Neuro Pharma, 1451 Innovation Parkway SE, Suite 600, Albuquerque, New Mexico 87123, United States
- T-Neuro Pharma, P.O. Box 781, Aptos, California 95003, United States
| | - Jevgenij A Raskatov
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
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3
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Klawa SJ, Lee M, Riker KD, Jian T, Wang Q, Gao Y, Daly ML, Bhonge S, Childers WS, Omosun TO, Mehta AK, Lynn DG, Freeman R. Uncovering supramolecular chirality codes for the design of tunable biomaterials. Nat Commun 2024; 15:788. [PMID: 38278785 PMCID: PMC10817930 DOI: 10.1038/s41467-024-45019-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/12/2024] [Indexed: 01/28/2024] Open
Abstract
In neurodegenerative diseases, polymorphism and supramolecular assembly of β-sheet amyloids are implicated in many different etiologies and may adopt either a left- or right-handed supramolecular chirality. Yet, the underlying principles of how sequence regulates supramolecular chirality remains unknown. Here, we characterize the sequence specificity of the central core of amyloid-β 42 and design derivatives which enable chirality inversion at biologically relevant temperatures. We further find that C-terminal modifications can tune the energy barrier of a left-to-right chiral inversion. Leveraging this design principle, we demonstrate how temperature-triggered chiral inversion of peptides hosting therapeutic payloads modulates the dosed release of an anticancer drug. These results suggest a generalizable approach for fine-tuning supramolecular chirality that can be applied in developing treatments to regulate amyloid morphology in neurodegeneration as well as in other disease states.
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Affiliation(s)
- Stephen J Klawa
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Michelle Lee
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
| | - Kyle D Riker
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Tengyue Jian
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Broad Pharm, San Diego, California, 92121, USA
| | - Qunzhao Wang
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Yuan Gao
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Margaret L Daly
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Shreeya Bhonge
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - W Seth Childers
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Tolulope O Omosun
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
- U.S. Department of Justice, Chicago, IL, 60603, USA
| | - Anil K Mehta
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
- The National High Magnetic Field Laboratory, University of Florida, Gainesville, FL, 32611, USA
| | - David G Lynn
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA.
- Department of Biology, Emory University, Atlanta, GA, 30322, USA.
| | - Ronit Freeman
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA.
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4
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Ortigosa-Pascual L, Leiding T, Linse S, Pálmadóttir T. Photo-Induced Cross-Linking of Unmodified α-Synuclein Oligomers. ACS Chem Neurosci 2023; 14:3192-3205. [PMID: 37621159 PMCID: PMC10485903 DOI: 10.1021/acschemneuro.3c00326] [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: 05/12/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023] Open
Abstract
Photo-induced cross-linking of unmodified proteins (PICUP) has been used in the past to study size distributions of protein assemblies. PICUP may, for example, overcome the significant experimental challenges related to the transient nature, heterogeneity, and low concentration of amyloid protein oligomers relative to monomeric and fibrillar species. In the current study, a reaction chamber was designed, produced, and used for PICUP reaction optimization in terms of reaction conditions and lighting time from ms to s. These efforts make the method more reproducible and accessible and enable the use of shorter reaction times compared to previous studies. We applied the optimized method to an α-synuclein aggregation time course to monitor the relative concentration and size distribution of oligomers over time. The data are compared to the time evolution of the fibril mass concentration, as monitored by thioflavin T fluorescence. At all time points, the smaller the oligomer, the higher its concentration observed after PICUP. Moreover, the total oligomer concentration is highest at short aggregation times, and the decline over time follows the disappearance of monomers. We can therefore conclude that these oligomers form from monomers.
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Affiliation(s)
- Lei Ortigosa-Pascual
- Department of Biochemistry and Structural
Biology, Lund University, 221 00 Lund, Sweden
| | - Thom Leiding
- Department of Biochemistry and Structural
Biology, Lund University, 221 00 Lund, Sweden
| | - Sara Linse
- Department of Biochemistry and Structural
Biology, Lund University, 221 00 Lund, Sweden
| | - Tinna Pálmadóttir
- Department of Biochemistry and Structural
Biology, Lund University, 221 00 Lund, Sweden
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5
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Li G, Jeon CK, Ma M, Jia Y, Zheng Z, Delafield DG, Lu G, Romanova EV, Sweedler JV, Ruotolo BT, Li L. Site-specific chirality-conferred structural compaction differentially mediates the cytotoxicity of Aβ42. Chem Sci 2023; 14:5936-5944. [PMID: 37293657 PMCID: PMC10246695 DOI: 10.1039/d3sc00678f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/06/2023] [Indexed: 06/10/2023] Open
Abstract
Growing evidence supports the confident association between distinct amyloid beta (Aβ) isoforms and Alzheimer's Disease (AD) pathogenesis. As such, critical investigations seeking to uncover the translational factors contributing to Aβ toxicity represent a venture of significant value. Herein, we comprehensively assess full-length Aβ42 stereochemistry, with a specific focus on models that consider naturally-occurring isomerization of Asp and Ser residues. We customize various forms of d-isomerized Aβ as natural mimics, ranging from fragments containing a single d residue to full length Aβ42 that includes multiple isomerized residues, systematically evaluating their cytotoxicity against a neuronal cell line. Combining multidimensional ion mobility-mass spectrometry experimental data with replica exchange molecular dynamics simulations, we confirm that co-d-epimerization at Asp and Ser residues within Aβ42 in both N-terminal and core regions effectively reduces its cytotoxicity. We provide evidence that this rescuing effect is associated with the differential and domain-specific compaction and remodeling of Aβ42 secondary structure.
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Affiliation(s)
- Gongyu Li
- State Key Laboratory of Pharmaceutical Chemical Biology, Research Center for Analytical Science and Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University Tianjin 300071 China
- Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192 China
| | - Chae Kyung Jeon
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
| | - Min Ma
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison 777 Highland Ave. Madison WI 53705 USA
| | - Yifei Jia
- State Key Laboratory of Pharmaceutical Chemical Biology, Research Center for Analytical Science and Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University Tianjin 300071 China
| | - Zhen Zheng
- School of Pharmacy, Tianjin Medical University Tianjin 300070 China
| | - Daniel G Delafield
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison 777 Highland Ave. Madison WI 53705 USA
| | - Gaoyuan Lu
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison 777 Highland Ave. Madison WI 53705 USA
| | - Elena V Romanova
- Department of Chemistry and The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA
| | - Jonathan V Sweedler
- Department of Chemistry and The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
| | - Lingjun Li
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison 777 Highland Ave. Madison WI 53705 USA
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6
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Xu X, Han L, Zheng Z, Zhao R, Li L, Shao X, Li G. Composite Multidimensional Ion Mobility-Mass Spectrometry for Improved Differentiation of Stereochemical Modifications. Anal Chem 2023; 95:2221-2228. [PMID: 36635260 DOI: 10.1021/acs.analchem.2c03522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Stereochemical modifications (SCMs), mostly present in the form of d-amino acid substitution, have been increasingly identified from a wide range of neuropeptides and disease-associated biomarker proteins. Traditional mass spectrometry-based SCM identification has been effectively enhanced with technological and strategic advancements in ion mobility spectrometry. With the additional separation provided by ion mobility, SCM-induced structural changes can be probed both in theory and in practice, although the structural resolution for low-abundance SCMs still requires further improvement to enable accurate quantification or unambiguous identification of stereoisomers. Herein, we present a multi-component-enabled multidimensional ion mobility-mass spectrometry (3M-IM-MS) analytical workflow, based upon the metal-enhanced chiral amplification strategy we proposed previously (Nat. Commun., 2019, 5038). Notably, the 3M-IM-MS strategy comprises and features the powerful mathematical tools of continuous wavelet transform and Gaussian fitting-enabled peak splitting. Consequently, the resolving capability of ion mobility spectrometry for SCM analysis has been significantly enhanced, providing mobility profiles with baseline separation and more than fivefold improvement in resolving power and overall resolution. This study represents an alternative toward ultrahigh-resolution structural interrogation of mixtures with very small differences, featuring an important and long-lasting topic in chemical measurement.
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Affiliation(s)
- Xia Xu
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Li Han
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Zhen Zheng
- School of Pharmacy, Tianjin Medical University, Tianjin 300070, China
| | - Rui Zhao
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Lingjun Li
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Xueguang Shao
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, College of Chemistry, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Gongyu Li
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, College of Chemistry, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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7
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Uchino A, Irie Y, Tsukano C, Kawase T, Hirose K, Kageyama Y, Tooyama I, Yanagita RC, Irie K. Synthesis and Characterization of Propeller- and Parallel-Type Full-Length Amyloid β40 Trimer Models. ACS Chem Neurosci 2022; 13:2517-2528. [PMID: 35930616 DOI: 10.1021/acschemneuro.2c00363] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Oligomers of the amyloid β (Aβ) protein play a critical role in the pathogenesis of Alzheimer's disease. However, their heterogeneity and lability deter the identification of their tertiary structures and mechanisms of action. Aβ trimers and Aβ dimers may represent the smallest aggregation unit with cytotoxicity. Although propeller-type trimer models of E22P-Aβ40 tethered by an aromatic linker have recently been synthesized, they unexpectedly exhibited little cytotoxicity. To increase the flexibility of trimeric propeller-type models, we designed and synthesized trimer models with an alkyl linker, tert-butyltris-l-alanine (tButA), at position 36 or 38. In addition, we synthesized two parallel-type trimer models tethered at position 38 using alkyl linkers of different lengths, α,α-di-l-norvalyl-l-glycine (di-nV-Gly) and α,α-di-l-homonorleucyl-l-glycine (di-hnL-Gly), based on the previously reported toxic dimer model. The propeller-type E22P,V36tButA-Aβ40 trimer (4), which was designed to mimic the C-terminal anti-parallel β-sheet structures proposed by the structural analysis of 150 kDa oligomers of Aβ42, and the parallel-type E22P,G38di-nV-Gly-Aβ40 trimer (6) showed significant cytotoxicity against SH-SY5Y cells and aggregative ability to form protofibrillar species. In contrast, the E22P,G38tButA-Aβ40 trimer (5) and E22P,G38di-hnL-Gly-Aβ40 trimer (7) exhibited weak cytotoxicity, though they formed quasi-stable oligomers observed by ion mobility-mass spectrometry and native polyacrylamide gel electrophoresis. These results suggest that 4 and 6 could have some phase of the structure of toxic Aβ oligomers with a C-terminal hydrophobic core and that the conformation and/or aggregation process rather than the formation of stable oligomers contribute to the induction of cytotoxicity.
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Affiliation(s)
- Ayumi Uchino
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Yumi Irie
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Chihiro Tsukano
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | | | | | - Yusuke Kageyama
- Molecular Neuroscience Research Center, Shiga University of Medical Sciences, Shiga 520-2192, Japan
| | - Ikuo Tooyama
- Molecular Neuroscience Research Center, Shiga University of Medical Sciences, Shiga 520-2192, Japan
| | - Ryo C Yanagita
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Kagawa 761-0795, Japan
| | - Kazuhiro Irie
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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8
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Foley AR, Raskatov J. AN ENANTIOMERIC FRAGMENT PAIR (EFP) APPROACH FOR THE STUDY OF CELLULAR UPTAKE OF INTRINSICALLY DISORDERED PROTEINS. Chembiochem 2022; 23:e202200146. [PMID: 35417609 DOI: 10.1002/cbic.202200146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/10/2022] [Indexed: 11/10/2022]
Abstract
The study of intrinsically disordered and amyloidogenic proteins poses a major challenge to researchers: the propensity of the system to aggregate and to form amyloid fibrils and deposits . This intrinsic nature limits the way amyloids can be studied and increases the level of complexity of the techniques needed to study the system of interest. Recent reports suggest that cellular recognition and internalization of pre-fibrillary species of amyloidogenic peptides and proteins may initiate some of its toxic actions. Therefore, developing novels tools to facilitate the understanding and determination of the interactions between intrinsically disordered proteins and the cellular membrane is becoming increasingly valuable. Here, we present and propose an approach for the study of the interactions of intrinsically disordered proteins with the cellular surface based on the use of enantiomeric fragment pairs (EFPs). By following a stepwise methodology in which the amyloidogenic peptide or protein is fragmented into specific segments, we show how this approach can be exploited to differentiate between different types of cellular uptake, to determine the degree of receptor-mediated cellular internalization of intrinsically disordered peptides and proteins, and to pinpoint the specific regions within the amino acid sequence responsible for the cellular recognition. Adopting this approach overcomes aggregation-related challenges and offers a particularly well-suited platform for the elucidation of receptor-intermediated recognition, uptake, and toxicity.
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Affiliation(s)
| | - Jevgenij Raskatov
- UCSC, Chemistry and Biochemistry, 1156 High Street, 95064, Santa Cruz, UNITED STATES
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9
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Matsushima Y, Irie Y, Kageyama Y, Bellier JP, Tooyama I, Maki T, Kume T, Yanagita RC, Irie K. Structure optimization of the toxic conformation model of amyloid β42 by intramolecular disulfide bond formation. Chembiochem 2022; 23:e202200029. [PMID: 35165998 DOI: 10.1002/cbic.202200029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/14/2022] [Indexed: 11/07/2022]
Abstract
Amyloid β (Aβ) oligomers play a critical role in the pathology of Alzheimer's disease. Recently, we reported that a conformation-restricted Aβ42 with an intramolecular disulfide bond through cysteine residues at positions 17/28 formed stable oligomers with potent cytotoxicity. To further optimize this compound as a toxic conformer model, we synthesized three analogs with a combination of cysteine and homocysteine at positions 17/28. The analogs with Cys-Cys, Cys-homoCys, or homoCys-Cys, but not the homoCys-homoCys analog, exhibited potent cytotoxicity against SH-SY5Y and THP-1 cells even at 10 nM. In contrast, the cytotoxicity of conformation-restricted analogs at positions 16/29 or 18/27 was significantly weaker than that of wild-type Aβ42. Furthermore, a thioflavin-T assay, non-denaturing gel electrophoresis, and morphological study suggested that the majority of these conformation-restricted analogs existed in an oligomeric state in cell culture medium, indicating that the toxic conformation of Aβ42, rather than the oligomeric state, is essential to induce cytotoxicity.
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Affiliation(s)
- Yuka Matsushima
- Kyoto University Graduate School of Agriculture Faculty of Agriculture: Kyoto Daigaku Nogaku Kenkyuka Nogakubu, Division of Food Science and Biotechnology, JAPAN
| | - Yumi Irie
- Kyoto University Graduate School of Agriculture Faculty of Agriculture: Kyoto Daigaku Nogaku Kenkyuka Nogakubu, Division of Food Science and Biotechnology, JAPAN
| | - Yusuke Kageyama
- Shiga University of Medical Science: Shiga Ika Daigaku, Molecular Neuroscience Research Center, JAPAN
| | - Jean-Pierre Bellier
- Shiga University of Medical Science: Shiga Ika Daigaku, Molecular Neuroscience Research Center, JAPAN
| | - Ikuo Tooyama
- Shiga University of Medical Science: Shiga Ika Daigaku, Molecular Neuroscience Research Center, JAPAN
| | - Takahito Maki
- University of Toyama: Toyama Daigaku, Department of Applied Pharmacology, JAPAN
| | - Toshiaki Kume
- University of Toyama: Toyama Daigaku, Department of Applied Pharmacology, JAPAN
| | - Ryo C Yanagita
- Kagawa University Faculty of Agriculture Graduate School of Agriculture: Kagawa Daigaku Nogakubu Daigakuin Nogaku Kenkyuka, Department of Applied Biological Sciences, JAPAN
| | - Kazuhiro Irie
- Kyoto University Graduate School of Agriculture Faculty of Agriculture: Kyoto Daigaku Nogaku Kenkyuka Nogakubu, Division of Food Science and Biotechnology, Kitashirakawa Oiwake-cho, Sakyo-ku, 606-8502, Kyoto, JAPAN
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10
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Foley AR, Raskatov JA. Understanding and controlling amyloid aggregation with chirality. Curr Opin Chem Biol 2021; 64:1-9. [PMID: 33610939 PMCID: PMC8368077 DOI: 10.1016/j.cbpa.2021.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/11/2021] [Accepted: 01/16/2021] [Indexed: 12/22/2022]
Abstract
Amyloid aggregation and human disease are inextricably linked. Examples include Alzheimer disease, Parkinson disease, and type II diabetes. While seminal advances on the mechanistic understanding of these diseases have been made over the last decades, controlling amyloid fibril formation still represents a challenge, and it is a subject of active research. In this regard, chiral modifications have increasingly been proved to offer a particularly well-suited approach toward accessing to previously unknown aggregation pathways and to provide with novel insights on the biological mechanisms of action of amyloidogenic peptides and proteins. Here, we summarize recent advances on how the use of mirror-image peptides/proteins and d-amino acid incorporations have helped modulate amyloid aggregation, offered new mechanistic tools to study cellular interactions, and allowed us to identify key positions within the peptide/protein sequence that influence amyloid fibril growth and toxicity.
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Affiliation(s)
- Alejandro R Foley
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Jevgenij A Raskatov
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, 95064, USA.
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11
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Kageyama Y, Irie Y, Matsushima Y, Segawa T, Bellier JP, Hidaka K, Sugiyama H, Kaneda D, Hashizume Y, Akatsu H, Miki K, Kita A, Walker DG, Irie K, Tooyama I. Characterization of a Conformation-Restricted Amyloid β Peptide and Immunoreactivity of Its Antibody in Human AD brain. ACS Chem Neurosci 2021; 12:3418-3432. [PMID: 34464082 DOI: 10.1021/acschemneuro.1c00416] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Characterization of amyloid β (Aβ) oligomers, the transition species present prior to the formation of Aβ fibrils and that have cytotoxicity, has become one of the major topics in the investigations of Alzheimer's disease (AD) pathogenesis. However, studying pathophysiological properties of Aβ oligomers is challenging due to the instability of these protein complexes in vitro. Here, we report that conformation-restricted Aβ42 with an intramolecular disulfide bond at positions 17 and 28 (SS-Aβ42) formed stable Aβ oligomers in vitro. Thioflavin T binding assays, nondenaturing gel electrophoresis, and morphological analyses revealed that SS-Aβ42 maintained oligomeric structure, whereas wild-type Aβ42 and the highly aggregative Aβ42 mutant with E22P substitution (E22P-Aβ42) formed Aβ fibrils. In agreement with these observations, SS-Aβ42 was more cytotoxic compared to the wild-type and E22P-Aβ42 in cell cultures. Furthermore, we developed a monoclonal antibody, designated TxCo-1, using the toxic conformation of SS-Aβ42 as immunogen. X-ray crystallography of the TxCo-1/SS-Aβ42 complex, enzyme immunoassay, and immunohistochemical studies confirmed the recognition site and specificity of TxCo-1 to SS-Aβ42. Immunohistochemistry with TxCo-1 antibody identified structures resembling senile plaques and vascular Aβ in brain samples of AD subjects. However, TxCo-1 immunoreactivity did not colocalize extensively with Aβ plaques identified with conventional Aβ antibodies. Together, these findings indicate that Aβ with a turn at positions 22 and 23, which is prone to form Aβ oligomers, could show strong cytotoxicity and accumulated in brains of AD subjects. The SS-Aβ42 and TxCo-1 antibody should facilitate understanding of the pathological role of Aβ with toxic conformation in AD.
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Affiliation(s)
- Yusuke Kageyama
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Yumi Irie
- Division of Food Science & Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Yuka Matsushima
- Division of Food Science & Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Tatsuya Segawa
- Immuno-Biological Laboratories Co., Ltd., Fujioka-Shi, Gunma 375-0005, Japan
| | - Jean-Pierre Bellier
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Kumi Hidaka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Daita Kaneda
- Choju Medical Institute, Fukushimura Hospital, 19-14 Noyoricho, Yamanaka, Aichi 441-8124, Japan
| | - Yoshio Hashizume
- Choju Medical Institute, Fukushimura Hospital, 19-14 Noyoricho, Yamanaka, Aichi 441-8124, Japan
| | - Hiroyasu Akatsu
- Choju Medical Institute, Fukushimura Hospital, 19-14 Noyoricho, Yamanaka, Aichi 441-8124, Japan
- Department of Community-Based Medical Education, Nagoya City University Graduate School of Medicine, Nagoya, Aichi 467-8601, Japan
| | - Kunio Miki
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Akiko Kita
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan, Osaka 590-0494, Japan
| | - Douglas G. Walker
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Kazuhiro Irie
- Division of Food Science & Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Ikuo Tooyama
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Shiga 520-2192, Japan
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12
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Mohammadi E, Tittl A, Tsakmakidis KL, Raziman TV, Curto AG. Dual Nanoresonators for Ultrasensitive Chiral Detection. ACS PHOTONICS 2021; 8:1754-1762. [PMID: 34164565 PMCID: PMC8213055 DOI: 10.1021/acsphotonics.1c00311] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Indexed: 05/19/2023]
Abstract
The discrimination of enantiomers is crucial in biochemistry. However, chiral sensing faces significant limitations due to inherently weak chiroptical signals. Nanophotonics is a promising solution to enhance sensitivity thanks to increased optical chirality maximized by strong electric and magnetic fields. Metallic and dielectric nanoparticles can separately provide electric and magnetic resonances. Here we propose their synergistic combination in hybrid metal-dielectric nanostructures to exploit their dual character for superchiral fields beyond the limits of single particles. For optimal optical chirality, in addition to maximization of the resonance strength, the resonances must spectrally coincide. Simultaneously, their electric and magnetic fields must be parallel and π/2 out of phase and spatially overlap. We demonstrate that the interplay between the strength of the resonances and these optimal conditions constrains the attainable optical chirality in resonant systems. Starting from a simple symmetric nanodimer, we derive closed-form expressions elucidating its fundamental limits of optical chirality. Building on the trade-offs of different classes of dimers, we then suggest an asymmetric dual dimer based on realistic materials. These dual nanoresonators provide strong and decoupled electric and magnetic resonances together with optimal conditions for chiral fields. Finally, we introduce more complex dual building blocks for a metasurface with a record 300-fold enhancement of local optical chirality in nanoscale gaps, enabling circular dichroism enhancement by a factor of 20. By combining analytical insight and practical designs, our results put forward hybrid resonators to increase chiral sensitivity, particularly for small molecular quantities.
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Affiliation(s)
- Ershad Mohammadi
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Andreas Tittl
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Kosmas L. Tsakmakidis
- Section
of Condensed Matter Physics, Department of Physics, National and Kapodistrian University of Athens, Panepistimioupolis, GR-157 84 Athens, Greece
| | - T. V. Raziman
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Alberto G. Curto
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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13
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Raskatov JA, Schneider JP, Nilsson BL. Defining the Landscape of the Pauling-Corey Rippled Sheet: An Orphaned Motif Finding New Homes. Acc Chem Res 2021; 54:2488-2501. [PMID: 33901396 PMCID: PMC8154201 DOI: 10.1021/acs.accounts.1c00084] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
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When peptides are mixed with their mirror images in an equimolar
ratio, two-dimensional periodic structural folds can form, in which
extended peptide strands are arrayed with alternating chirality. The
resultant topography class, termed the rippled β-sheet, was
introduced as a theoretical concept by Pauling and Corey in 1953.
Unlike other fundamental protein structural motifs identified around
that time, including the α-helix and the pleated β-sheet,
it took several decades before conclusive experimental data supporting
the proposed rippled β-sheet motif were gained. Much of the
key experimental evidence was provided over the course of the past
decade through the concurrent efforts of our three laboratories. Studies
that focused on developing new self-assembling hydrogel materials
have shown that certain amphiphilic peptides form fibrils and hydrogel
networks that are more rigid and have a higher thermodynamic stability
when made from racemic peptide mixtures as opposed to pure enantiomers.
Related interrogation of assemblies composed of mixtures of l- and d-amphiphilic peptides confirmed that the resulting
fibrils were composed of alternating l/d peptides
consistent with rippled β-sheets. It was also demonstrated that
mirror-image amyloid beta (Aβ) could act as a molecular chaperone
to promote oligomer-to-fibril conversion of the natural Aβ enantiomer,
which was found to reduce Aβ neurotoxicity against different
neuronal cell models. With a cross-disciplinary approach that combines
experiment and theory, our three laboratories have demonstrated the
unique biophysical, biochemical, and biological properties that arise
upon mixing of peptide enantiomers, in consequence of rippled β-sheet
formation. In this Account, we give an overview of the early history
of the rippled β-sheet and provide a detailed structural description/definition
of this motif relative to the pleated β-sheet. We then summarize
the key findings, obtained on three unique sets of aggregating mirror-image
peptide pairs through independent efforts of our three laboratories,
and use these results to delineate the landscape of the rippled β-sheet
structural motif to inspire future studies. Peptide sequence parameters
that favor rippled β-sheet assembly are described, along with
the accompanying kinetic and thermodynamic properties, as well as
the resulting emergent physical properties of the assemblies. The
Account then concludes with a brief overview of some key unresolved
challenges in this nascent field. There is much potential for future
applications of this unique supramolecular motif in the realm of materials
design and biomedical research. We hope this Account will stimulate
much-needed discussion of this fascinating structural class to eventually
produce a fully quantitative, rational framework for the molecular
engineering of rippled β-sheets in the future.
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Affiliation(s)
- Jevgenij A. Raskatov
- Department of Chemistry and Biochemistry, UCSC, 1156 High Street, Santa Cruz, California 95064, United States
| | - Joel P. Schneider
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Bradley L. Nilsson
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, United States
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14
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Rationally designed peptide-based inhibitor of Aβ42 fibril formation and toxicity: a potential therapeutic strategy for Alzheimer's disease. Biochem J 2020; 477:2039-2054. [PMID: 32427336 PMCID: PMC7293109 DOI: 10.1042/bcj20200290] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 12/22/2022]
Abstract
Amyloid beta peptide (Aβ42) aggregation in the brain is thought to be responsible for the onset of Alzheimer's disease, an insidious condition without an effective treatment or cure. Hence, a strategy to prevent aggregation and subsequent toxicity is crucial. Bio-inspired peptide-based molecules are ideal candidates for the inhibition of Aβ42 aggregation, and are currently deemed to be a promising option for drug design. In this study, a hexapeptide containing a self-recognition component unique to Aβ42 was designed to mimic the β-strand hydrophobic core region of the Aβ peptide. The peptide is comprised exclusively of D-amino acids to enhance specificity towards Aβ42, in conjunction with a C-terminal disruption element to block the recruitment of Aβ42 monomers on to fibrils. The peptide was rationally designed to exploit the synergy between the recognition and disruption components, and incorporates features such as hydrophobicity, β-sheet propensity, and charge, that all play a critical role in the aggregation process. Fluorescence assays, native ion-mobility mass spectrometry (IM-MS) and cell viability assays were used to demonstrate that the peptide interacts with Aβ42 monomers and oligomers with high specificity, leading to almost complete inhibition of fibril formation, with essentially no cytotoxic effects. These data define the peptide-based inhibitor as a potentially potent anti-amyloid drug candidate for this hitherto incurable disease.
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15
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Matsushima Y, Yanagita RC, Irie K. Control of the toxic conformation of amyloid β42 by intramolecular disulfide bond formation. Chem Commun (Camb) 2020; 56:4118-4121. [PMID: 32163091 DOI: 10.1039/d0cc01053g] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a method to fix the conformation of Aβ42 to the toxic or non-toxic form by intramolecular disulfide bonds. We found that an Aβ42 analog crosslinked within the molecule at the 17th and 28th amino acid residues exhibited high aggregative ability and potent neurotoxicity comparable to those of E22P-Aβ42. This analog would be useful in the research of Aβ42 oligomers and to develop reliable antibodies for early diagnosis of Alzheimer's disease.
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Affiliation(s)
- Yuka Matsushima
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
| | - Ryo C Yanagita
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Kagawa 761-0795, Japan
| | - Kazuhiro Irie
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
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16
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Meng F, Lu T, Wang Y, Zhao Y, Li Z, Li F. Role of Chain Extension in the Ability of Peptide Oligomers to Damage the Lipid Membrane Studied by the l- to d-Amino Acid Substitutions of hIAPP 18-27. J Phys Chem B 2020; 124:10147-10156. [PMID: 33140962 DOI: 10.1021/acs.jpcb.0c07656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Exploration of the relation between the structural feature of oligomers and the ability of oligomers to damage the membrane has been an important subject in the study of the cytotoxic mechanism of amyloid proteins. In this work, we selected the hIAPP18-27 fragment as a model peptide and modified it by an alternating substitution of a d-amino acid for an l-amino acid in the hydrophilic N-terminal region, the hydrophobic C-terminal region, and the entire sequence. We prepared the oligomers using these peptides and investigated the effects of chain extension in different regions of the peptide on the ability of the oligomers to damage the membrane composed of POPC/POPG 4:1. We examined the morphology, structure, surface hydrophobicity, and packing compactness of the oligomers and monitored the changes in the structure and aggregation of the peptides upon interaction with the membrane. We found that the surface hydrophobicity and the disruptive ability of the oligomers are increased by an alternating l- and d-amino acid arrangement in the hydrophobic region of the peptide, while the packing compactness of the oligomers is increased and the disruptive ability of the oligomers decreased by an alternating l- and d-amino acid arrangement only in the hydrophilic region. The extension of the hydrophobic chain plays a significant role in the disruptive ability of the oligomers. Our results suggest that a positive relation between the surface hydrophobicity and the disruptive ability could be established only for the oligomers in which the peptide chains are flexible and loosely packed.
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Affiliation(s)
- Feihong Meng
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Avenue, Changchun, 130012, P. R. China
| | - Tong Lu
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Avenue, Changchun, 130012, P. R. China
| | - Yajie Wang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Avenue, Changchun, 130012, P. R. China
| | - Yanping Zhao
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, 2699 Qianjin Avenue, Changchun, 130012, P. R. China
| | - Zhengqiang Li
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, 2699 Qianjin Avenue, Changchun, 130012, P. R. China
| | - Fei Li
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Avenue, Changchun, 130012, P. R. China
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17
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Foley AR, Raskatov JA. Assessing Reproducibility in Amyloid β Research: Impact of Aβ Sources on Experimental Outcomes. Chembiochem 2020; 21:2425-2430. [PMID: 32249510 PMCID: PMC7647053 DOI: 10.1002/cbic.202000125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/04/2020] [Indexed: 12/16/2022]
Abstract
The difficulty of synthesizing and purifying the amyloid β (Aβ) peptide, combined with its high aggregation propensity and low solubility under physiological conditions, leads to a wide variety of experimental results from kinetic assays to biological activity. Thus, it becomes challenging to reproduce outcomes, and this limits our ability to rely on reported results as the foundation for new research. This article examines variability of the Aβ peptide from different sources, comparing purity, and oligomer and fibril formation propensity side by side. The results highlight the importance of performing rigorous controls so that meaningful biophysical, biochemical, and neurobiological results can be obtained to improve our understanding on Aβ.
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Affiliation(s)
- Alejandro R Foley
- Department of Chemistry and Biochemistry, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA, 95064, USA
| | - Jevgenij A Raskatov
- Department of Chemistry and Biochemistry, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA, 95064, USA
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18
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Limbocker R, Mannini B, Ruggeri FS, Cascella R, Xu CK, Perni M, Chia S, Chen SW, Habchi J, Bigi A, Kreiser RP, Wright AK, Albright JA, Kartanas T, Kumita JR, Cremades N, Zasloff M, Cecchi C, Knowles TPJ, Chiti F, Vendruscolo M, Dobson CM. Trodusquemine displaces protein misfolded oligomers from cell membranes and abrogates their cytotoxicity through a generic mechanism. Commun Biol 2020; 3:435. [PMID: 32792544 PMCID: PMC7426408 DOI: 10.1038/s42003-020-01140-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 07/07/2020] [Indexed: 12/21/2022] Open
Abstract
The onset and progression of numerous protein misfolding diseases are associated with the presence of oligomers formed during the aberrant aggregation of several different proteins, including amyloid-β (Aβ) in Alzheimer’s disease and α-synuclein (αS) in Parkinson’s disease. These small, soluble aggregates are currently major targets for drug discovery. In this study, we show that trodusquemine, a naturally-occurring aminosterol, markedly reduces the cytotoxicity of αS, Aβ and HypF-N oligomers to human neuroblastoma cells by displacing the oligomers from cell membranes in the absence of any substantial morphological and structural changes to the oligomers. These results indicate that the reduced toxicity results from a mechanism that is common to oligomers from different proteins, shed light on the origin of the toxicity of the most deleterious species associated with protein aggregation and suggest that aminosterols have the therapeutically-relevant potential to protect cells from the oligomer-induced cytotoxicity associated with numerous protein misfolding diseases. Limbocker et al. show that trodusquemine, an aminosterol, reduces the cytotoxicity of protein misfolded oligomers by displacing them from cell membranes in the absence of any overt structural/ morphological changes in them. This mechanism appears to be general, as they test it for oligomers of αS, Aβ and the model protein HypF-N to human neuroblastoma cells.
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Affiliation(s)
- Ryan Limbocker
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK.,Department of Chemistry and Life Science, United States Military Academy, West Point, NY, 10996, USA
| | - Benedetta Mannini
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Francesco S Ruggeri
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Roberta Cascella
- Department of Experimental and Clinical Biomedical Science, University of Florence, 50134, Florence, Italy
| | - Catherine K Xu
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Michele Perni
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Sean Chia
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Serene W Chen
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Johnny Habchi
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Alessandra Bigi
- Department of Experimental and Clinical Biomedical Science, University of Florence, 50134, Florence, Italy
| | - Ryan P Kreiser
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY, 10996, USA
| | - Aidan K Wright
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY, 10996, USA
| | - J Alex Albright
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY, 10996, USA
| | - Tadas Kartanas
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Janet R Kumita
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Nunilo Cremades
- Institute for Biocomputation and Physics of Complex Systems (BIFI)-Joint Unit BIFI-IQFR (CSIC), University of Zaragoza, 50018, Zaragoza, Spain
| | - Michael Zasloff
- MedStar-Georgetown Transplant Institute, Georgetown University School of Medicine, Washington, DC, 20010, USA
| | - Cristina Cecchi
- Department of Experimental and Clinical Biomedical Science, University of Florence, 50134, Florence, Italy
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK.,Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Fabrizio Chiti
- Department of Experimental and Clinical Biomedical Science, University of Florence, 50134, Florence, Italy.
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK.
| | - Christopher M Dobson
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
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19
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Kuhn AJ, Abrams BS, Knowlton S, Raskatov JA. Alzheimer's Disease "Non-amyloidogenic" p3 Peptide Revisited: A Case for Amyloid-α. ACS Chem Neurosci 2020; 11:1539-1544. [PMID: 32412731 DOI: 10.1021/acschemneuro.0c00160] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Amyloid-β (Aβ) is an intrinsically disordered peptide thought to play an important role in Alzheimer's disease (AD). It has been the target of most AD therapeutic efforts, which have repeatedly failed in clinical trials. A more predominant peptidic fragment, formed through alternative processing of the amyloid precursor protein, is the p3 peptide. p3 has received little attention, which is possibly due to the prevailing view in the AD field that it is "non-amyloidogenic." By probing the self-assembly of this peptide, we found that p3 aggregates to form oligomers and fibrils and, when compared with Aβ, displays enhanced aggregation rates. Our findings highlight the solubilizing effect of the N-terminus of Aβ and the favorable formation of structures formed through C-terminal hydrophobic peptide interfaces. Based on our findings, we suggest a reevaluation of the current therapeutic approaches targeting only the β-secretase pathway of AD, given that the α- secretase pathway is also amyloidogenic.
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Affiliation(s)
- Ariel J. Kuhn
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Benjamin S. Abrams
- Department of Biomolecular Engineering, Life Sciences Microscopy Center, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Stella Knowlton
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Jevgenij A. Raskatov
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
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20
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Foley AR, Lee HW, Raskatov JA. A Focused Chiral Mutant Library of the Amyloid β 42 Central Electrostatic Cluster as a Tool To Stabilize Aggregation Intermediates. J Org Chem 2020; 85:1385-1391. [PMID: 31875394 DOI: 10.1021/acs.joc.9b02312] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Amyloidogenic peptides and proteins aggregate into fibrillary structures that are usually deposited in tissues and organs and are often involved in the development of diseases. In contrast to native structured proteins, amyloids do not follow a defined energy landscape toward the fibrillary state and often generate a vast population of aggregation intermediates that are transient and exceedingly difficult to study. Here, we employ chiral editing as a tool to study the aggregation mechanism of the Amyloid β (Aβ) 42 peptide, whose aggregation intermediates are thought to be one of the main driving forces in Alzheimer's disease (AD). Through the design of a focused chiral mutant library (FCML) of 16 chiral Aβ42 variants, we identified several point D-substitutions that allowed us to modulate the aggregation propensity and the biological activity of the peptide. Surprisingly, the reduced propensity toward aggregation and the stabilization of oligomeric intermediates did not always correlate with an increase in toxicity. In the present study, we show how chiral editing can be a powerful tool to trap and stabilize Aβ42 conformers that might otherwise be too transient and dynamic to study, and we identify sites within the Aβ42 sequence that could be potential targets for therapeutic intervention.
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Affiliation(s)
- Alejandro R Foley
- Department of Chemistry and Biochemistry , University of California Santa Cruz , Santa Cruz , California 95064 , United States
| | - Hsiau-Wei Lee
- Department of Chemistry and Biochemistry , University of California Santa Cruz , Santa Cruz , California 95064 , United States
| | - Jevgenij A Raskatov
- Department of Chemistry and Biochemistry , University of California Santa Cruz , Santa Cruz , California 95064 , United States
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21
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Molecular basis for chirality-regulated Aβ self-assembly and receptor recognition revealed by ion mobility-mass spectrometry. Nat Commun 2019; 10:5038. [PMID: 31695027 PMCID: PMC6834639 DOI: 10.1038/s41467-019-12346-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 09/02/2019] [Indexed: 12/22/2022] Open
Abstract
Despite extensive efforts on probing the mechanism of Alzheimer’s disease (AD) and enormous investments into AD drug development, the lack of effective disease-modifying therapeutics and the complexity of the AD pathogenesis process suggest a great need for further insights into alternative AD drug targets. Herein, we focus on the chiral effects of truncated amyloid beta (Aβ) and offer further structural and molecular evidence for epitope region-specific, chirality-regulated Aβ fragment self-assembly and its potential impact on receptor-recognition. A multidimensional ion mobility-mass spectrometry (IM-MS) analytical platform and in-solution kinetics analysis reveal the comprehensive structural and molecular basis for differential Aβ fragment chiral chemistry, including the differential and cooperative roles of chiral Aβ N-terminal and C-terminal fragments in receptor recognition. Our method is applicable to many other systems and the results may shed light on the potential development of novel AD therapeutic strategies based on targeting the D-isomerized Aβ, rather than natural L-Aβ. Chiral inversion of amino acids is thought to modulate the structure and function of amyloid beta (Aβ) but these processes are poorly understood. Here, the authors develop an ion mobility-mass spectrometry based approach to study chirality-regulated structural features of Aβ fragments and their influence on receptor recognition.
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22
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Foley AR, Finn TS, Kung T, Hatami A, Lee HW, Jia M, Rolandi M, Raskatov JA. Trapping and Characterization of Nontoxic Aβ42 Aggregation Intermediates. ACS Chem Neurosci 2019; 10:3880-3887. [PMID: 31319029 DOI: 10.1021/acschemneuro.9b00340] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Amyloid β (Aβ) 42 is an aggregation-prone peptide and the believed seminal etiological agent of Alzheimer's disease (AD). Intermediates of Aβ42 aggregation, commonly referred to as diffusible oligomers, are considered to be among the most toxic forms of the peptide. Here, we studied the effect of the age-related epimerization of Ser26 (i.e., S26s chiral edit) in Aβ42 and discovered that this subtle molecular change led to reduced fibril formation propensity. Surprisingly, the resultant soluble aggregates were nontoxic. To gain insight into the structural changes that occurred in the peptide upon S26s substitution, the system was probed using an array of biophysical and biochemical methods. These experiments consistently pointed to the stabilization of aggregation intermediates in the Aβ42-S26s system. To better understand the changes arising as a consequence of the S26s substitution, molecular level structural studies were performed. Using a combined nuclear magnetic resonance (NMR)- and density functional theory (DFT)-computational approach, we found that the S26s chiral edit induced only local structural changes in the Gly25-Ser26-Asn27 region. Interestingly, these subtle changes enabled the formation of an intramolecular Ser26-Asn27 H-bond, which disrupted the ability of Asn27 to engage in the fibrillogenic side chain-to-side chain H-bonding pattern. This reveals that intermolecular stabilizing interactions between Asn27 side chains are a key element controlling Aβ42 aggregation and toxicity.
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Affiliation(s)
- Alejandro R. Foley
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Thomas S. Finn
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Timothy Kung
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Asa Hatami
- Sangamo Therapeutics, Richmond, California 94804, United States
| | - Hsiau-Wei Lee
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Manping Jia
- Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Marco Rolandi
- Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Jevgenij A. Raskatov
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
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23
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Kuhn AJ, Raskatov JA. Using mirror-image peptides to enhance robustness and reproducibility in studying the amyloid β-protein. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 168:57-67. [PMID: 31699327 DOI: 10.1016/bs.pmbts.2019.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Alzheimer's disease, the most common form of dementia, is a devastating disease that affects over 44 million people worldwide. One etiological agent of Alzheimer's, the amyloid β-protein (Aβ), is an aggregation-prone, intrinsically disordered peptide that can form a wide variety of aggregates. The pathways by which Aβ aggregates in order to exert its toxicity, referred to as the Amyloid Cascade, remains largely elusive despite substantial deconvolution efforts. Preparing high-quality material that exhibits reproducible biophysical characteristics has proven challenging. Herein, we propose that mirror-image peptides can be used to rigorously control Aβ preparation quality.
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Affiliation(s)
- Ariel J Kuhn
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA, United States
| | - Jevgenij A Raskatov
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA, United States.
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24
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Moro ML, Phillips AS, Gaimster K, Paul C, Mudher A, Nicoll JAR, Boche D. Pyroglutamate and Isoaspartate modified Amyloid-Beta in ageing and Alzheimer's disease. Acta Neuropathol Commun 2018; 6:3. [PMID: 29298722 PMCID: PMC5753481 DOI: 10.1186/s40478-017-0505-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 12/16/2017] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia among older adults. Accumulation of amyloid-β (Aβ) in the brain is considered central in AD pathogenesis and its understanding crucial for developing new diagnostic and therapeutic approaches. Recent literature suggests that ageing may induce post translational modifications in Aβ, in the form of spontaneous amino acid modifications, which enhance its pathogenic properties, contributing to its aggregation.In this study, we have investigated whether the isoaspartate (IsoD-Aβ) and pyroglutamate (pE3-Aβ) modified forms of Aβ are significantly associated with AD pathology or represent markers of ageing. Cerebral neocortex of 27 AD cases, 32 old controls (OC) and 11 young controls (YC) was immunostained for pE3-Aβ and IsoD-Aβ, quantified as protein load and correlated with other Aβ forms and p-TAU. IsoD-Aβ and pE3-Aβ were detected at low levels in non-demented controls, and significantly increased in AD (p ≤ 0.001), with a characteristic deposition of IsoD-Aβ in blood vessel walls and pE3-Aβ within neurons. Both AD and OC showed positive associations between IsoD-Aβ and Aβ (p = 0.003 in AD and p = 0.001 in OC) and between IsoD-Aβ and pE3-Aβ (p = 0.001 in AD and OC). This last association was the only significant pE3-Aβ correlation identified in AD, whereas in the control cohorts pE3-Aβ also correlated with Aβ and AβPP (p = 0.001 in OC and p = 0.010 in YC).Our analyses suggest that IsoD-Aβ accumulation starts with ageing; whereas pE3-Aβ deposition is more closely linked to AD. Our findings support the importance of age-related modifications of Aβ in AD pathogenesis.
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25
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Hayden EY, Hoi KK, Lopez J, Inayathullah M, Condron MM, Teplow DB. Identification of key regions and residues controlling Aβ folding and assembly. Sci Rep 2017; 7:12434. [PMID: 28974765 PMCID: PMC5626695 DOI: 10.1038/s41598-017-10845-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/15/2017] [Indexed: 12/11/2022] Open
Abstract
Amyloid β-protein (Aβ) assembly is hypothesized to be a seminal neuropathologic event in Alzheimer’s disease (AD). We used an unbiased D-amino acid substitution strategy to determine structure-assembly relationships of 76 different Aβ40 and Aβ42 peptides. We determined the effects of the substitutions on peptide oligomerization, secondary structure dynamics, fibril assembly dynamics, and fibril morphology. Our experiments revealed that the assembly of Aβ42 was more sensitive to chiral substitutions than was Aβ40 assembly. Substitutions at identical positions in the two peptides often, but not always, produced the same effects on assembly. Sites causing substantial effects in both Aβ40 and Aβ42 include His14, Gln15, Ala30, Ile31, Met35, and Val36. Sites whose effects were unique to Aβ40 include Lys16, Leu17, and Asn 27, whereas sites unique to Aβ42 include Phe20 and Ala21. These sites may be appropriate targets for therapeutic agents that inhibit or potentiate, respectively, these effects.
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Affiliation(s)
- Eric Y Hayden
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Kimberly K Hoi
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.,Department of Pediatrics and Department of Neurology, UCSF, San Francisco, CA, 94158, USA
| | - Jasmine Lopez
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Mohammed Inayathullah
- Biomaterials and Advanced Drug Delivery Laboratory, School of Medicine, Stanford University, Palo Alto, CA, 94304, USA
| | - Margaret M Condron
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - David B Teplow
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA. .,Molecular Biology Institute and Brain Research Institute; UCLA, Los Angeles, CA, 90095, USA.
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26
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Using chirality to probe the conformational dynamics and assembly of intrinsically disordered amyloid proteins. Sci Rep 2017; 7:12433. [PMID: 28970487 PMCID: PMC5624888 DOI: 10.1038/s41598-017-10525-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/09/2017] [Indexed: 12/22/2022] Open
Abstract
Intrinsically disordered protein (IDP) conformers occupy large regions of conformational space and display relatively flat energy surfaces. Amyloid-forming IDPs, unlike natively folded proteins, have folding trajectories that frequently involve movements up shallow energy gradients prior to the “downhill” folding leading to fibril formation. We suggest that structural perturbations caused by chiral inversions of amino acid side-chains may be especially valuable in elucidating these pathways of IDP folding. Chiral inversions are subtle in that they do not change side-chain size, flexibility, hydropathy, charge, or polarizability. They allow focus to be placed solely on the question of how changes in amino acid side-chain orientation, and the resultant alterations in peptide backbone structure, affect a peptide’s conformational landscape (Ramachandran space). If specific inversions affect folding and assembly, then the sites involved likely are important in mediating these processes. We suggest here a “focused chiral mutant library” approach for the unbiased study of amyloid-forming IDPs.
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27
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Dutta S, Foley AR, Warner CJA, Zhang X, Rolandi M, Abrams B, Raskatov JA. Suppression of Oligomer Formation and Formation of Non‐Toxic Fibrils upon Addition of Mirror‐Image Aβ42 to the Natural
l
‐Enantiomer. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201706279] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Subrata Dutta
- Dept. of Chemistry and Biochemistry UCSC 1156 High Street Santa Cruz CA USA
| | - Alejandro R. Foley
- Dept. of Chemistry and Biochemistry UCSC 1156 High Street Santa Cruz CA USA
| | | | - Xiaolin Zhang
- Dept. of Electrical Engineering UCSC 1156 High Street Santa Cruz CA USA
- Dept. of Materials Science and Engineering University of Washington Seattle WA USA
| | - Marco Rolandi
- Dept. of Electrical Engineering UCSC 1156 High Street Santa Cruz CA USA
| | - Benjamin Abrams
- Dept. of Biomolecular Engineering Life Sciences Microscopy Center UCSC 1156 High Street Santa Cruz 95064 CA USA
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28
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Dutta S, Foley AR, Warner CJA, Zhang X, Rolandi M, Abrams B, Raskatov JA. Suppression of Oligomer Formation and Formation of Non-Toxic Fibrils upon Addition of Mirror-Image Aβ42 to the Natural l-Enantiomer. Angew Chem Int Ed Engl 2017; 56:11506-11510. [PMID: 28682473 DOI: 10.1002/anie.201706279] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Indexed: 11/11/2022]
Abstract
Racemates often have lower solubility than enantiopure compounds, and the mixing of enantiomers can enhance the aggregation propensity of peptides. Amyloid beta (Aβ) 42 is an aggregation-prone peptide that is believed to play a key role in Alzheimer's disease. Soluble Aβ42 aggregation intermediates (oligomers) have emerged as being particularly neurotoxic. We hypothesized that the addition of mirror-image d-Aβ42 should reduce the concentration of toxic oligomers formed from natural l-Aβ42. We synthesized l- and D-Aβ42 and found their equimolar mixing to lead to accelerated fibril formation. Confocal microscopy with fluorescently labeled analogues of the enantiomers showed their colocalization in racemic fibrils. Owing to the enhanced fibril formation propensity, racemic Aβ42 was less prone to form soluble oligomers. This resulted in the protection of cells from the toxicity of l-Aβ42 at concentrations up to 50 μm. The mixing of Aβ42 enantiomers thus accelerates the formation of non-toxic fibrils.
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Affiliation(s)
- Subrata Dutta
- Dept. of Chemistry and Biochemistry, UCSC, 1156 High Street, Santa Cruz, CA, USA
| | - Alejandro R Foley
- Dept. of Chemistry and Biochemistry, UCSC, 1156 High Street, Santa Cruz, CA, USA
| | | | - Xiaolin Zhang
- Dept. of Electrical Engineering, UCSC, 1156 High Street, Santa Cruz, CA, USA.,Dept. of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Marco Rolandi
- Dept. of Electrical Engineering, UCSC, 1156 High Street, Santa Cruz, CA, USA
| | - Benjamin Abrams
- Dept. of Biomolecular Engineering, Life Sciences Microscopy Center, UCSC, 1156 High Street, Santa Cruz, 95064, CA, USA
| | - Jevgenij A Raskatov
- Dept. of Chemistry and Biochemistry, UCSC, 1156 High Street, Santa Cruz, CA, USA
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29
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Warner CJA, Dutta S, Foley AR, Raskatov JA. A Tailored HPLC Purification Protocol That Yields High-purity Amyloid Beta 42 and Amyloid Beta 40 Peptides, Capable of Oligomer Formation. J Vis Exp 2017. [PMID: 28448032 DOI: 10.3791/55482] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Amyloidogenic peptides such as the Alzheimer's disease-implicated Amyloid beta (Aβ), can present a significant challenge when trying to obtain high purity material. Here we present a tailored HPLC purification protocol to produce high-purity amyloid beta 42 (Aβ42) and amyloid beta 40 (Aβ40) peptides. We have found that the combination of commercially available hydrophobic poly(styrene/divinylbenzene) stationary phase, polymer laboratory reverse phase - styrenedivinylbenzene (PLRP-S) under high pH conditions, enables the attainment of high purity (>95%) Aβ42 in a single chromatographic run. The purification is highly reproducible and can be amended to both semi-preparative and analytical conditions depending upon the amount of material wished to be purified. The protocol can also be applied to the Aβ40 peptide with identical success and without the need to alter the method.
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Affiliation(s)
| | - Subrata Dutta
- Department of Chemistry, University of California, Santa Cruz
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30
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Warner CJ, Dutta S, Foley AR, Chen E, Kliger DS, Raskatov JA. Using chiral peptide substitutions to probe the structure function relationship of a key residue of Aβ42. Chirality 2016; 29:5-9. [DOI: 10.1002/chir.22667] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 11/10/2022]
Affiliation(s)
| | - Subrata Dutta
- Department of Chemistry and Biochemistry; University of California, Santa Cruz; CA USA
| | - Alejandro R. Foley
- Department of Chemistry and Biochemistry; University of California, Santa Cruz; CA USA
| | - Eefei Chen
- Department of Chemistry and Biochemistry; University of California, Santa Cruz; CA USA
| | - David S. Kliger
- Department of Chemistry and Biochemistry; University of California, Santa Cruz; CA USA
| | - Jevgenij A. Raskatov
- Department of Chemistry and Biochemistry; University of California, Santa Cruz; CA USA
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31
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Warner CJA, Dutta S, Foley AR, Raskatov JA. Introduction of d-Glutamate at a Critical Residue of Aβ42 Stabilizes a Prefibrillary Aggregate with Enhanced Toxicity. Chemistry 2016; 22:11967-70. [PMID: 27272258 PMCID: PMC5096037 DOI: 10.1002/chem.201601763] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Indexed: 01/09/2023]
Abstract
The amyloid beta peptide 42 (Aβ42) is an aggregation-prone peptide that plays a pivotal role in Alzheimer's disease. We report that a subtle perturbation to the peptide through a single chirality change at glutamate 22 leads to a pronounced delay in the β-sheet adoption of the peptide. This was accompanied by an attenuated propensity of the peptide to form fibrils, which was correlated with changes at the level of the fibrillary architecture. Strikingly, the incorporation of d-glutamate was found to stabilize a soluble, ordered macromolecular assembly with enhanced cytotoxicity to PC12 cells, highlighting the importance of advanced prefibrillary Aβ aggregates in neurotoxicity.
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Affiliation(s)
- Christopher J A Warner
- Department of Chemistry and Biochemistry, Physical Science Building, University of California, 1156 High Street, Santa Cruz, USA
| | - Subrata Dutta
- Department of Chemistry and Biochemistry, Physical Science Building, University of California, 1156 High Street, Santa Cruz, USA
| | - Alejandro R Foley
- Department of Chemistry and Biochemistry, Physical Science Building, University of California, 1156 High Street, Santa Cruz, USA
| | - Jevgenij A Raskatov
- Department of Chemistry and Biochemistry, Physical Science Building, University of California, 1156 High Street, Santa Cruz, USA.
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