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Smallest Secondary Nucleation Competent Aβ Aggregates Probed by an ATP-Independent Molecular Chaperone Domain
[Image: see text] Protein oligomerization is a commonly encountered strategy by which the functional repertoire of proteins is increased. This, however, is a double-edged sword strategy because protein oligomerization is notoriously difficult to control. Living organisms have therefore developed a n...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American
Chemical Society
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8028046/ https://www.ncbi.nlm.nih.gov/pubmed/33621049 http://dx.doi.org/10.1021/acs.biochem.1c00003 |
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author | Leppert, Axel Tiiman, Ann Kronqvist, Nina Landreh, Michael Abelein, Axel Vukojević, Vladana Johansson, Jan |
author_facet | Leppert, Axel Tiiman, Ann Kronqvist, Nina Landreh, Michael Abelein, Axel Vukojević, Vladana Johansson, Jan |
author_sort | Leppert, Axel |
collection | PubMed |
description | [Image: see text] Protein oligomerization is a commonly encountered strategy by which the functional repertoire of proteins is increased. This, however, is a double-edged sword strategy because protein oligomerization is notoriously difficult to control. Living organisms have therefore developed a number of chaperones that prevent protein aggregation. The small ATP-independent molecular chaperone domain proSP-C BRICHOS, which is mainly trimeric, specifically inhibits fibril surface-catalyzed nucleation reactions that give rise to toxic oligomers during the aggregation of the Alzheimer’s disease-related amyloid-β peptide (Aβ42). Here, we have created a stable proSP-C BRICHOS monomer mutant and show that it does not bind to monomeric Aβ42 but has a high affinity for Aβ42 fibrils, using surface plasmon resonance. Kinetic analysis of Aβ42 aggregation profiles, measured by thioflavin T fluorescence, reveals that the proSP-C BRICHOS monomer mutant strongly inhibits secondary nucleation reactions and thereby reduces the level of catalytic formation of toxic Aβ42 oligomers. To study binding between the proSP-C BRICHOS monomer mutant and small soluble Aβ42 aggregates, we analyzed fluorescence cross-correlation spectroscopy measurements with the maximum entropy method for fluorescence correlation spectroscopy. We found that the proSP-C BRICHOS monomer mutant binds to the smallest emerging Aβ42 aggregates that are comprised of eight or fewer Aβ42 molecules, which are already secondary nucleation competent. Our approach can be used to provide molecular-level insights into the mechanisms of action of substances that interfere with protein aggregation. |
format | Online Article Text |
id | pubmed-8028046 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | American
Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-80280462021-04-08 Smallest Secondary Nucleation Competent Aβ Aggregates Probed by an ATP-Independent Molecular Chaperone Domain Leppert, Axel Tiiman, Ann Kronqvist, Nina Landreh, Michael Abelein, Axel Vukojević, Vladana Johansson, Jan Biochemistry [Image: see text] Protein oligomerization is a commonly encountered strategy by which the functional repertoire of proteins is increased. This, however, is a double-edged sword strategy because protein oligomerization is notoriously difficult to control. Living organisms have therefore developed a number of chaperones that prevent protein aggregation. The small ATP-independent molecular chaperone domain proSP-C BRICHOS, which is mainly trimeric, specifically inhibits fibril surface-catalyzed nucleation reactions that give rise to toxic oligomers during the aggregation of the Alzheimer’s disease-related amyloid-β peptide (Aβ42). Here, we have created a stable proSP-C BRICHOS monomer mutant and show that it does not bind to monomeric Aβ42 but has a high affinity for Aβ42 fibrils, using surface plasmon resonance. Kinetic analysis of Aβ42 aggregation profiles, measured by thioflavin T fluorescence, reveals that the proSP-C BRICHOS monomer mutant strongly inhibits secondary nucleation reactions and thereby reduces the level of catalytic formation of toxic Aβ42 oligomers. To study binding between the proSP-C BRICHOS monomer mutant and small soluble Aβ42 aggregates, we analyzed fluorescence cross-correlation spectroscopy measurements with the maximum entropy method for fluorescence correlation spectroscopy. We found that the proSP-C BRICHOS monomer mutant binds to the smallest emerging Aβ42 aggregates that are comprised of eight or fewer Aβ42 molecules, which are already secondary nucleation competent. Our approach can be used to provide molecular-level insights into the mechanisms of action of substances that interfere with protein aggregation. American Chemical Society 2021-02-23 2021-03-09 /pmc/articles/PMC8028046/ /pubmed/33621049 http://dx.doi.org/10.1021/acs.biochem.1c00003 Text en © 2021 The Authors. Published by American Chemical Society Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Leppert, Axel Tiiman, Ann Kronqvist, Nina Landreh, Michael Abelein, Axel Vukojević, Vladana Johansson, Jan Smallest Secondary Nucleation Competent Aβ Aggregates Probed by an ATP-Independent Molecular Chaperone Domain |
title | Smallest Secondary Nucleation Competent Aβ Aggregates
Probed by an ATP-Independent Molecular Chaperone Domain |
title_full | Smallest Secondary Nucleation Competent Aβ Aggregates
Probed by an ATP-Independent Molecular Chaperone Domain |
title_fullStr | Smallest Secondary Nucleation Competent Aβ Aggregates
Probed by an ATP-Independent Molecular Chaperone Domain |
title_full_unstemmed | Smallest Secondary Nucleation Competent Aβ Aggregates
Probed by an ATP-Independent Molecular Chaperone Domain |
title_short | Smallest Secondary Nucleation Competent Aβ Aggregates
Probed by an ATP-Independent Molecular Chaperone Domain |
title_sort | smallest secondary nucleation competent aβ aggregates
probed by an atp-independent molecular chaperone domain |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8028046/ https://www.ncbi.nlm.nih.gov/pubmed/33621049 http://dx.doi.org/10.1021/acs.biochem.1c00003 |
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