Aggregation and Fibril Structure of AβM01–42 and Aβ1–42
A mechanistic understanding of Aβ aggregation and high-resolution structures of Aβ fibrils and oligomers are vital to elucidating relevant details of neurodegeneration in Alzheimer’s disease, which will facilitate the rational design of diagnostic and therapeutic protocols. The most detailed and rep...
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| Format: | Article |
| Language: | en_US |
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American Chemical Society (ACS)
2018
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| Online Access: | http://hdl.handle.net/1721.1/117211 https://orcid.org/0000-0003-0710-0429 https://orcid.org/0000-0003-1307-882X https://orcid.org/0000-0003-1589-832X |
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| author | Frederick, Kendra K. Linse, Sara Silvers, Robert Paul Georg Colvin, Michael Thomas Jacavone, Angela Lindquist, Susan Griffin, Robert Guy |
| author2 | Massachusetts Institute of Technology. Department of Biology |
| author_facet | Massachusetts Institute of Technology. Department of Biology Frederick, Kendra K. Linse, Sara Silvers, Robert Paul Georg Colvin, Michael Thomas Jacavone, Angela Lindquist, Susan Griffin, Robert Guy |
| author_sort | Frederick, Kendra K. |
| collection | MIT |
| description | A mechanistic understanding of Aβ aggregation and high-resolution structures of Aβ fibrils and oligomers are vital to elucidating relevant details of neurodegeneration in Alzheimer’s disease, which will facilitate the rational design of diagnostic and therapeutic protocols. The most detailed and reproducible insights into structure and kinetics have been achieved using Aβ peptides produced by recombinant expression, which results in an additional methionine at the N-terminus. While the length of the C-terminus is well established to have a profound impact on the peptide’s aggregation propensity, structure, and neurotoxicity, the impact of the N-terminal methionine on the aggregation pathways and structure is unclear. For this reason, we have developed a protocol to produce recombinant Aβ1–42, sans the N-terminal methionine, using an N-terminal small ubiquitin-like modifier–Aβ1–42 fusion protein in reasonable yield, with which we compared aggregation kinetics with AβM01–42 containing the additional methionine residue. The data revealed that Aβ1–42 and AβM01–42 aggregate with similar rates and by the same mechanism, in which the generation of new aggregates is dominated by secondary nucleation of monomers on the surface of fibrils. We also recorded magic angle spinning nuclear magnetic resonance spectra that demonstrated that excellent spectral resolution is maintained with both AβM01–42 and Aβ1–42 and that the chemical shifts are virtually identical in dipolar recoupling experiments that provide information about rigid residues. Collectively, these results indicate that the structure of the fibril core is unaffected by N-terminal methionine. This is consistent with the recent structures of AβM01–42 in which M0 is located at the terminus of a disordered 14-amino acid N-terminal tail. |
| first_indexed | 2024-09-23T08:02:26Z |
| format | Article |
| id | mit-1721.1/117211 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:02:26Z |
| publishDate | 2018 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1172112022-09-23T10:31:02Z Aggregation and Fibril Structure of AβM01–42 and Aβ1–42 Frederick, Kendra K. Linse, Sara Silvers, Robert Paul Georg Colvin, Michael Thomas Jacavone, Angela Lindquist, Susan Griffin, Robert Guy Massachusetts Institute of Technology. Department of Biology Massachusetts Institute of Technology. Department of Chemistry Massachusetts Institute of Technology. Plasma Science and Fusion Center Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) Griffin, Robert G. Silvers, Robert Paul Georg Colvin, Michael Thomas Jacavone, Angela Lindquist, Susan Griffin, Robert Guy A mechanistic understanding of Aβ aggregation and high-resolution structures of Aβ fibrils and oligomers are vital to elucidating relevant details of neurodegeneration in Alzheimer’s disease, which will facilitate the rational design of diagnostic and therapeutic protocols. The most detailed and reproducible insights into structure and kinetics have been achieved using Aβ peptides produced by recombinant expression, which results in an additional methionine at the N-terminus. While the length of the C-terminus is well established to have a profound impact on the peptide’s aggregation propensity, structure, and neurotoxicity, the impact of the N-terminal methionine on the aggregation pathways and structure is unclear. For this reason, we have developed a protocol to produce recombinant Aβ1–42, sans the N-terminal methionine, using an N-terminal small ubiquitin-like modifier–Aβ1–42 fusion protein in reasonable yield, with which we compared aggregation kinetics with AβM01–42 containing the additional methionine residue. The data revealed that Aβ1–42 and AβM01–42 aggregate with similar rates and by the same mechanism, in which the generation of new aggregates is dominated by secondary nucleation of monomers on the surface of fibrils. We also recorded magic angle spinning nuclear magnetic resonance spectra that demonstrated that excellent spectral resolution is maintained with both AβM01–42 and Aβ1–42 and that the chemical shifts are virtually identical in dipolar recoupling experiments that provide information about rigid residues. Collectively, these results indicate that the structure of the fibril core is unaffected by N-terminal methionine. This is consistent with the recent structures of AβM01–42 in which M0 is located at the terminus of a disordered 14-amino acid N-terminal tail. National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant EB-001960) National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant B-002026) Swedish Research Council European Research Council (Advanced Grant) German Research Foundation (research fellowship SI2105/1-1) 2018-07-31T13:17:54Z 2018-07-31T13:17:54Z 2017-08 Article http://purl.org/eprint/type/JournalArticle 0006-2960 1520-4995 http://hdl.handle.net/1721.1/117211 Silvers, Robert, Michael T. Colvin, Kendra K. Frederick, Angela C. Jacavone, Susan Lindquist, Sara Linse, and Robert G. Griffin. “Aggregation and Fibril Structure of AβM01–42 and Aβ1–42.” Biochemistry 56, no. 36 (August 30, 2017): 4850–4859. https://orcid.org/0000-0003-0710-0429 https://orcid.org/0000-0003-1307-882X https://orcid.org/0000-0003-1589-832X en_US http://dx.doi.org/10.1021/acs.biochem.7b00729 Biochemistry Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society (ACS) Prof. Griffin via Erja Kajosalo |
| spellingShingle | Frederick, Kendra K. Linse, Sara Silvers, Robert Paul Georg Colvin, Michael Thomas Jacavone, Angela Lindquist, Susan Griffin, Robert Guy Aggregation and Fibril Structure of AβM01–42 and Aβ1–42 |
| title | Aggregation and Fibril Structure of AβM01–42 and Aβ1–42 |
| title_full | Aggregation and Fibril Structure of AβM01–42 and Aβ1–42 |
| title_fullStr | Aggregation and Fibril Structure of AβM01–42 and Aβ1–42 |
| title_full_unstemmed | Aggregation and Fibril Structure of AβM01–42 and Aβ1–42 |
| title_short | Aggregation and Fibril Structure of AβM01–42 and Aβ1–42 |
| title_sort | aggregation and fibril structure of aβm01 42 and aβ1 42 |
| url | http://hdl.handle.net/1721.1/117211 https://orcid.org/0000-0003-0710-0429 https://orcid.org/0000-0003-1307-882X https://orcid.org/0000-0003-1589-832X |
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