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Zhang S, Yoo S, Snyder DT, Katz BB, Henrickson A, Demeler B, Wysocki VH, Kreutzer AG, Nowick JS. A Disulfide-Stabilized Aβ that Forms Dimers but Does Not Form Fibrils. Biochemistry 2022; 61:252-264. [PMID: 35080857 PMCID: PMC9083094 DOI: 10.1021/acs.biochem.1c00739] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aβ dimers are a basic building block of many larger Aβ oligomers and are among the most neurotoxic and pathologically relevant species in Alzheimer's disease. Homogeneous Aβ dimers are difficult to prepare, characterize, and study because Aβ forms heterogeneous mixtures of oligomers that vary in size and can rapidly aggregate into more stable fibrils. This paper introduces AβC18C33 as a disulfide-stabilized analogue of Aβ42 that forms stable homogeneous dimers in lipid environments but does not aggregate to form insoluble fibrils. The AβC18C33 peptide is readily expressed in Escherichia coli and purified by reverse-phase HPLC to give ca. 8 mg of pure peptide per liter of bacterial culture. SDS-PAGE establishes that AβC18C33 forms homogeneous dimers in the membrane-like environment of SDS and that conformational stabilization of the peptide with a disulfide bond prevents the formation of heterogeneous mixtures of oligomers. Mass spectrometric (MS) studies in the presence of dodecyl maltoside (DDM) further confirm the formation of stable noncovalent dimers. Circular dichroism (CD) spectroscopy establishes that AβC18C33 adopts a β-sheet conformation in detergent solutions and supports a model in which the intramolecular disulfide bond induces β-hairpin folding and dimer formation in lipid environments. Thioflavin T (ThT) fluorescence assays and transmission electron microscopy (TEM) studies indicate that AβC18C33 does not undergo fibril formation in aqueous buffer solutions and demonstrate that the intramolecular disulfide bond prevents fibril formation. The recently published NMR structure of an Aβ42 tetramer (PDB: 6RHY) provides a working model for the AβC18C33 dimer, in which two β-hairpins assemble through hydrogen bonding to form a four-stranded antiparallel β-sheet. It is anticipated that AβC18C33 will serve as a stable, nonfibrilizing, and noncovalent Aβ dimer model for amyloid and Alzheimer's disease research.
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Affiliation(s)
- Sheng Zhang
- Department of Chemistry, University of California Irvine, Irvine, California 92697-2025, United States
| | - Stan Yoo
- Department of Chemistry, University of California Irvine, Irvine, California 92697-2025, United States
| | - Dalton T. Snyder
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Benjamin B. Katz
- Department of Chemistry, University of California Irvine, Irvine, California 92697-2025, United States
| | - Amy Henrickson
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Dr., Lethbridge, Alberta, Canada T1K 3M4
| | - Borries Demeler
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Dr., Lethbridge, Alberta, Canada T1K 3M4
| | - Vicki H. Wysocki
- Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Adam G. Kreutzer
- Department of Chemistry, University of California Irvine, Irvine, California 92697-2025, United States,Corresponding Authors: James S. Nowick – Department of Chemistry, University of California, Irvine, California 92697-2025, United States; Department of Pharmaceutical Sciences, University of California, Irvine, California 92697-2025, United States. , Adam G. Kreutzer – Department of Chemistry, University of California, Irvine, California 92697-2025, United States.
| | - James S. Nowick
- Department of Chemistry, University of California Irvine, Irvine, California 92697-2025, United States,Department of Pharmaceutical Sciences, University of California Irvine, Irvine, California 92697-2025, United States,Corresponding Authors: James S. Nowick – Department of Chemistry, University of California, Irvine, California 92697-2025, United States; Department of Pharmaceutical Sciences, University of California, Irvine, California 92697-2025, United States. , Adam G. Kreutzer – Department of Chemistry, University of California, Irvine, California 92697-2025, United States.
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Kasim JK, Kavianinia I, Ng J, Harris PWR, Birch NP, Brimble MA. Efficient synthesis and characterisation of the amyloid beta peptide, Aβ 1-42, using a double linker system. Org Biomol Chem 2019; 17:30-34. [PMID: 30500032 DOI: 10.1039/c8ob02929f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The amyloidogenic Aβ42 peptide was efficiently prepared using a double linker system, markedly improving solubility and chromatographic peak resolution, thus enabling full characterisation using standard techniques. The tag was readily cleaved with sodium hydroxide and removed by aqueous extraction, affording Aβ42 in high purity and yield for biophysical characterisation studies.
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Affiliation(s)
- Johanes K Kasim
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand.
| | - Iman Kavianinia
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand. and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds St, Auckland 1010, New Zealand and School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.
| | - Jin Ng
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand. and Brain Research New Zealand Rangahau Roro Aotearoa and Centre for Brain Research, Auckland 1010, New Zealand
| | - Paul W R Harris
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand. and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds St, Auckland 1010, New Zealand and School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.
| | - Nigel P Birch
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand. and Brain Research New Zealand Rangahau Roro Aotearoa and Centre for Brain Research, Auckland 1010, New Zealand
| | - Margaret A Brimble
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand. and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds St, Auckland 1010, New Zealand and School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.
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Yamamoto M, Shinoda K, Sasaki D, Kanai M, Sohma Y. Design and properties of [Met35(O)]Aβ42-lactam(Asp23/Lys28) possessing a lactam tether as a salt-bridge surrogate. Bioorg Med Chem 2019; 27:888-893. [DOI: 10.1016/j.bmc.2019.01.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 01/16/2019] [Accepted: 01/29/2019] [Indexed: 01/03/2023]
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