The effect of PC20:0 and di-C7-PC amphiphilic surfactants on the aggregation of Aβ1–40 and Aβ1–42 using molecular dynamics simulation.

At least 25 types of degenerative diseases are thought to be caused by amyloid-beta, including Alzheimer's. However, the exact mechanism of Alzheimer's is still unknown. It has been shown that amphiphilic surfactants with varying tail lengths, PC20:0 and di-C7-PC, have differing effects on the structures of Aβ (1–40) and Aβ (1–42). This paper examines the interaction between these surfactants and peptides. The calculations were performed at concentrations lower than the critical micelle concentration. Four and 12 peptides of beta-amyloid isomers regimens were used for each simulation. Direct and indirect behavioral effects were extensively investigated. A number of critical analyses, including RMSD, ∆RMSF, Pi, and the hydration network, were performed to examine these peptides in the absence and presence of ligands. There can be a negative ∆RMSF for each sequence as a result of ligand or surfactant binding to that sequence; otherwise, the structure is partially or locally folded. Demonstrated that PC20:0 and di-C7-PC amphiphilic surfactants affect the aggregation of Aβ1–40 and Aβ1–42. The results of our simulations showed that the negative values of ΔRMSF match with some Pi > 1 values for both the hydrophobic and hydrophilic sides of ligands. Therefore, potential interactions between residual peptides and ligands were identified. A negative ΔRMSF did not match the Pi > 1 value, indicating the folding behavior of peptide residues. [ABSTRACT FROM AUTHOR]