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Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Solid-state NMR reveals a close structural relationship between amyloid-β protofibrils and oligomers
Holger A Scheidt1, Isabel Morgado, Daniel Huster
1Institute of Medical Physics and Biophysics, University of Leipzig, D-04107 Leipzig, Germany.
The Journal of Biological Chemistry
|May 17, 2012
Summary
Amyloid-beta (Aβ) protofibrils share structural features with oligomers, not mature fibrils. This suggests a significant structural change occurs as Aβ transforms from protofibrils to mature fibrils.
Area of Science:
- Biochemistry
- Structural Biology
- Neuroscience
Background:
- Amyloid-beta (Aβ) peptides form various aggregates, including oligomers, protofibrils, and mature fibrils.
- These aggregates are implicated in neurodegenerative diseases like Alzheimer's disease.
- Understanding the structural transitions between Aβ species is crucial for disease mechanism elucidation.
Purpose of the Study:
- To investigate the tertiary contacts within amyloid-beta (Aβ) protofibrils and mature fibrils.
- To compare the structural relationship between Aβ protofibrils, oligomers, and mature fibrils.
- To provide insights into the structural conversion pathway of Aβ aggregates.
Main Methods:
- Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy was employed.
- Analysis focused on identifying intraresidue contacts, specifically between Glu-22 and Ile-31.
- Comparative structural analysis of Aβ protofibrils and mature fibrils.
Main Results:
- Intraresidue contacts between Glu-22 and Ile-31 were detected in Aβ protofibrils.
- These specific contacts were entirely absent in mature Aβ fibrils.
- The observed contacts in protofibrils resemble those found in Aβ oligomers.
Conclusions:
- Aβ protofibrils exhibit structural similarities to Aβ oligomers rather than mature fibrils.
- A significant structural transformation occurs during the conversion from protofibrils to mature fibrils.
- This transition may involve a shift from intramolecularly stabilized structures to intermolecularly stabilized fibrils.
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