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Alzheimer's disease (AD) has been consistently related to the formation of senile amyloid plaques mainly composed of amyloid β (Aβ) peptides. The toxicity of Aβ aggregates has been indicated to be responsible for AD pathology. One scenario to decrease Aβ toxicity is the development of effective inhibitors against Aβ amyloid formation. In this study, we investigate the effect of gallium nitride nanoparticles (GaN NPs) as inhibitors of Aβ40 amyloid formation using a combination of biophysical approaches. Our results show that the lag phase of Aβ40 aggregation kinetics is significantly retarded by GaN NPs in a concentration dependent manner, implying the activity of GaN NPs in interfering with the formation of the crucial nucleus during Aβ aggregation. Our results also show that GaN NPs can reduce the amyloid fibril elongation rate in the course of the aggregation kinetics. It is speculated that the high polarization characteristics of GaN NPs may provoke a strong interaction between the particles and Aβ40 peptide and in this way decrease self-association of the peptide monomers to form amyloids.
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This content will become publicly available on August 1, 2026
Optimized Purification of Human Amyloid‐beta (Aβ) 40 and Aβ42 Using an E. coli Expression System
Abstract Amyloid‐beta (Aβ) peptides, primarily Aβ40 and Aβ42, are central to the formation of amyloid plaques, a pathological hallmark of Alzheimer's disease (AD). These peptides, derived from the amyloid precursor protein (APP), are aggregation prone and neurotoxic. Experimental studies aimed at understanding Aβ aggregation and interaction require pure, monomeric peptides with the native sequences, including the absence of an N‐terminal methionine. We present an optimized protocol for producing recombinant human Aβ40 and Aβ42 using a SUMO fusion system inEscherichia coli. Cleavage of the SUMO tag enables recovery of native‐sequence peptides, producing physiologically relevant monomers with high yield and purity. This method eliminates the need for chemical synthesis and offers a reliable and cost‐effective approach to producing recombinant Aβ suitable for aggregation studies, structural analyses, and interaction assays. The resulting peptides closely mimic endogenous Aβ, facilitating accurate models of Alzheimer's disease pathogenesis and supporting future therapeutics development. © 2025 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Expression and purification of Aβ40 and Aβ42 fromEscherichia coli
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- Award ID(s):
- 2024964
- PAR ID:
- 10634549
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Current Protocols
- Volume:
- 5
- Issue:
- 8
- ISSN:
- 2691-1299
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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