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Dimerization of the Aβ42 under the Influence of the Gold Nanoparticle: A REMD Study
Quynh Mai Thai1,2, Nguyen Thanh Tung3,4, Dung Do Thi Mai5
1Laboratory of Biophysics, Institute for Advanced Study in Technology, Ton Duc Thang University, Ho Chi Minh City 72915, Vietnam.
Abstract:
Advances in Alzheimer's disease (AD) are related to the oligomerization of Amyloid β (Aβ) peptides. Therefore, alteration of the process can prevent AD. We investigated the Aβ42 dimerization under the effects of gold nanoparticles using temperature replica-exchange molecular dynamics (REMD) simulations. The structural change of dimers in the presence and absence of the gold nanoparticle, Au55, was monitored over stable intervals. Physical insights into the oligomerization of Aβ were thus clarified. The computed metrics indicate that Au55 affects the progress of oligomerization. Specifically, the presence of the gold nanoparticle significantly modifies the structure of dimeric Aβ42. The β-content experienced a substantial decrease with the induction of Au55. The turn and coil-contents are also decreased under the effects of the gold nanoparticle. However, the α-content of the dimer exhibited a rigid increase. The influence of gold nanoparticles on the dimeric Aβ42 differs significantly from that of silver nanoparticles, which reduce β-content but increase coil-, turn-, and α-contents. The nature of inhibition will be discussed, in which the vdW interaction plays a driving force for the interaction between the Aβ42 dimer and the gold nanoparticle.
Insights
Gold nanoparticles alter Alzheimer's-linked Amyloid β (Aβ) dimerization. This research clarifies Aβ oligomerization, showing gold nanoparticles significantly change Aβ42 dimer structure, potentially preventing Alzheimer's disease (AD).
Area of Science:
- Biophysics and Computational Chemistry
- Neurodegenerative Disease Research
Background:
- Alzheimer's disease (AD) progression is linked to Amyloid β (Aβ) peptide oligomerization.
- Modulating Aβ oligomerization is a key strategy for AD prevention.
- Understanding Aβ dimerization is crucial for developing therapeutic interventions.
Purpose of the Study:
- To investigate the structural changes in Aβ42 dimers induced by gold nanoparticles (Au55).
- To elucidate the physical mechanisms governing Aβ oligomerization in the presence of gold nanoparticles.
- To compare the effects of gold nanoparticles with those of silver nanoparticles on Aβ42 dimer structure.
Main Methods:
- Utilized temperature replica-exchange molecular dynamics (REMD) simulations.
- Monitored structural changes of Aβ42 dimers in the presence and absence of Au55 nanoparticles.
- Analyzed secondary structure content (β-content, α-content, turn, and coil) of Aβ42 dimers.
Main Results:
- Au55 significantly alters the structure of dimeric Aβ42, affecting oligomerization progress.
- The presence of Au55 led to a substantial decrease in β-content, turn, and coil, alongside a notable increase in α-content.
- The interaction between Aβ42 dimer and Au55 is driven by van der Waals (vdW) forces.
Conclusions:
- Gold nanoparticles demonstrably modify Aβ42 dimer structure, influencing oligomerization pathways.
- The observed structural changes induced by Au55 differ significantly from those induced by silver nanoparticles.
- Van der Waals interactions are identified as a primary driving force in the Aβ42 dimer-gold nanoparticle interaction, suggesting a potential inhibition mechanism.
