title: Effect of urea concentration on aggregation of amyloidogenic hexapeptides (NFGAIL).
abstract: 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.
authors: Department of Physics, Zhejiang University , Hangzhou, 310027, China.
authors: Zhuowei
authors: Z
authors: Cai
authors: Jingqiang
authors: J
authors: Li
authors: Chunji
authors: C
authors: Yin
authors: Zaixing
authors: Z
authors: Yang
authors: Jianlan
authors: J
authors: Wu
authors: Ruhong
authors: R
authors: Zhou
mesh_terms: D000682:Amyloid / Q000737:chemistry*; D006860:Hydrogen Bonding / Q000187:drug effects; D056004:Molecular Dynamics Simulation; D009842:Oligopeptides / Q000737:chemistry*; D014508:Urea / Q000032:analysis* / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000682:Amyloid; D009842:Oligopeptides; D014508:Urea