Fatty Acid Concentration and Phase Transitions Modulate Aβ Aggregation Pathways

Pratip Rana, Dexter N. Dean, Edward D. Steen, Ashuwin Vaidya, Vijayaraghavan Rangachari, Preetam Ghosh

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Aggregation of amyloid β (Aβ) peptides is a significant event that underpins Alzheimer disease (AD) pathology. Aβ aggregates, especially the low-molecular weight oligomers, are the primary toxic agents in AD and hence, there is increasing interest in understanding their formation and behavior. Aggregation is a nucleation-dependent process in which the pre-nucleation events are dominated by Aβ homotypic interactions. Dynamic flux and stochasticity during pre-nucleation renders the reactions susceptible to perturbations by other molecules. In this context, we investigate the heterotypic interactions between Aβ and fatty acids (FAs) by two independent tool-sets such as reduced order modelling (ROM) and ensemble kinetic simulation (EKS). We observe that FAs influence Aβ dynamics distinctively in three broadly-defined FA concentration regimes containing non-micellar, pseudo-micellar or micellar phases. While the non-micellar phase promotes on-pathway fibrils, pseudo-micellar and micellar phases promote predominantly off-pathway oligomers, albeit via subtly different mechanisms. Importantly off-pathway oligomers saturate within a limited molecular size, and likely with a different overall conformation than those formed along the on-pathway, suggesting the generation of distinct conformeric strains of Aβ, which may have profound phenotypic outcomes. Our results validate previous experimental observations and provide insights into potential influence of biological interfaces in modulating Aβ aggregation pathways.

Original languageEnglish
Article number10370
JournalScientific Reports
Volume7
Issue number1
DOIs
StatePublished - 1 Dec 2017

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phase transition
nucleation
fatty acid
stochasticity
pathology
peptide
perturbation
kinetics
modeling
simulation

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Rana, Pratip ; Dean, Dexter N. ; Steen, Edward D. ; Vaidya, Ashuwin ; Rangachari, Vijayaraghavan ; Ghosh, Preetam. / Fatty Acid Concentration and Phase Transitions Modulate Aβ Aggregation Pathways. In: Scientific Reports. 2017 ; Vol. 7, No. 1.
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Fatty Acid Concentration and Phase Transitions Modulate Aβ Aggregation Pathways. / Rana, Pratip; Dean, Dexter N.; Steen, Edward D.; Vaidya, Ashuwin; Rangachari, Vijayaraghavan; Ghosh, Preetam.

In: Scientific Reports, Vol. 7, No. 1, 10370, 01.12.2017.

Research output: Contribution to journalArticle

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