R. Ghez, M.B. Small
JES
We have performed large-scale all-atom molecular dynamics (MD) simulations to study the aggregation behavior of four NFGAIL hexapeptides in the aqueous urea solution, with a urea concentration ranging from 0 to 5 M. We find that urea in general suppresses the peptide aggregation, but suppression slows down in the intermediation concentration regime around 3 M. Two competing mechanisms of urea are determined: urea molecules accumulated near the first solvation shell (FSS) tend to unfold the hexapeptide, which favors aggregation; on the other hand, the tight hydrogen bonds formed between urea and peptide mainchains hinder the association of peptides which disfavors the formation of the β-sheet. Furthermore, the different nonlinear urea concentration dependences of the urea-peptide and peptide-peptide hydrogen bonds lead to a nonmonotonic behavior, with a weak enhancement in the peptide aggregation around 3 M. © 2013 American Chemical Society.
R. Ghez, M.B. Small
JES
R.W. Gammon, E. Courtens, et al.
Physical Review B
C.M. Brown, L. Cristofolini, et al.
Chemistry of Materials
S.F. Fan, W.B. Yun, et al.
Proceedings of SPIE 1989