title: Self-assembly behavior of peptide amphiphiles (PAs) with different length of hydrophobic alkyl tails.
abstract: Amphiphilic peptide and their derivatives, with distinguished advantages over conventional materials, have received extensively research interesting recently. In this work, four peptide amphiphiles (PAs1-4) with different length of hydrophobic alkyl tails (C9 for PA1, C11 for PA2, C13 for PA3, and C15 for PA4) were fabricated and their self-assembly behaviors in aqueous medium at different pHs were investigated systematically. It was found that all the peptide amphiphiles can self-assemble in water at a neutral pH of 7 to form tightly packed nanofibers with a beta-sheet conformation. When altering the solution environment to basic medium (pH 11), due to the strong hydrophobic interaction of long alkyl tails in PA3 and PA4, the fibrous nanostructure self-assembled from PA3 and PA4 was not destroyed. However, the nanofibers self-assembled from PA1 in which the length of alkyl tail was relatively short converted into loose spherical micelles with a beta-sheet conformation. Due to the moderate length of alkyl tail in PA2, both nanofibers and micelles can be formed via the self-assembly of PA2 when increasing the pH of the self-assembling system.
authors.affiliation: Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
authors.forename: Xiao-Ding
authors.initials: XD
authors.lastname: Xu
authors.forename: Yue
authors.initials: Y
authors.lastname: Jin
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Xian-Zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Ren-Xi
authors.initials: RX
authors.lastname: Zhuo
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D000595:Amino Acid Sequence; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D013059:Spectrum Analysis, Raman; D014867:Water / Q000737:chemistry*
chemical_list: D000473:Alkanes; D008823:Micelles; D010455:Peptides; D014867:Water