ATP Controls the Aggregation of Aβ16-22 Peptides

The oligomerization of A beta(16-22) peptide, which is the hydrophobic core region of full-length A beta(1-42), causes Alzheimer's disease (AD). This progressive neurodegenerative disease affects over 44 million people worldwide. However, very few synthesized drug molecules are available to inhibit the aggregation of A beta. Recently, experimental studies have shown that the biological ATP molecule prevents A beta fibrillation at the millimolar scale; however, the significance of ATP molecules on A beta fibrillation and the mechanism behind it remain elusive. We have carried out a total of 7.5 mu s extensive all-atom molecular dynamics and 8.82 mu s of umbrella sampling in explicit water using AMBER14SB, AMBER99SB-ILDN, and AMBER-FB15 force fields for A beta(16-22) peptide, to investigate the role of ATP on the disruption of A beta(16-22) prefibrils. From various analyses, such as secondary structure analysis, residue-wise contact map, SASA, and interaction energies, we have observed that, in the presence of ATP, the aggregation of A beta(16-22) peptide is very unfavorable. Moreover, the biological molecule ATP interacts with the A beta(16-22) peptide via hydrogen bonding, pi-pi stacking, and NH-pi interactions which, ultimately, prevent the aggregation of A beta(16-22) peptide. Hence, we assume that the deficiency of ATP may cause Alzheimer's disease (AD).