Aggregation of Amyloidogenic Peptide Uperin-Molecular Dynamics Simulations

Uperin 3.5 is a remarkable natural peptide obtained from the skin of toadlets comprised of 17 amino acids which exhibits both antimicrobial and amyloidogenic properties. Molecular dynamics simulations were performed to study the beta-aggregation process of uperin 3.5 as well as two of its mutants, in which the positively charged residues Arg7 and Lys8 have been replaced by alanine. All three peptides rapidly underwent spontaneous aggregation and conformational transition from random coils to beta-rich structures. The simulations reveal that the initial and essential step of the aggregation process involves peptide dimerization and the formation of small beta-sheets. A decrease in positive charge and an increase in the number of hydrophobic residues in the mutant peptides lead to an increase in the rate of their aggregation.

Automated summary

Uperin 3.5, a natural peptide from the skin of toadlets, consisting of 17 amino acids, possesses antimicrobial and amyloidogenic properties. Molecular dynamics simulations reveal that Uperin 3.5 and its mutants undergo spontaneous aggregation, transitioning from random coils to β-rich structures. The initial and crucial step in the aggregation process involves peptide dimerization and the formation of small β-sheets. The mutant peptides exhibit increased aggregation rate due to decreased positive charge and increased hydrophobic residues.