title: Tuning of peptide assembly through force balance adjustment.
abstract: Controlled self-assembly of amphiphilic tripeptides into distinct nanostructures is achieved via a controlled design of the molecular architecture. The tripeptide Ac-Phe-Phe-Lys-CONH2 (FFK), hardly soluble in water, forms long amyloid-like tubular structures with the aid of β-sheet hydrogen bonding and aromatic π-π stacking. Substitution of phenylalanine (F) with tyrosine (Y), that is, only a subtle structural variation in adding a hydroxyl group to the phenyl ring, results in great change in molecular self-assembly behavior. When one F is substituted with Y, the resulting molecules of FYK and YFK self-assemble into long thinner fibrils with high propensity for lateral association. When both Fs are substituted with Y, the resulting YYK molecule forms spherical aggregates. Introduction of hydroxyl groups into the molecule modifies aromatic interactions and introduces hydrogen bonding. Moreover, since the driving forces for peptide self-assembly including hydrogen bonding, electrostatic repulsion, and π-π stacking have high interdependence with each other, changes in aromatic interaction induce a Domino effect and cause a shift of force balance to a new state. This leads to significant variations in self-assembly behavior.
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao Economic Development Zone, Qingdao 266555, China. mwcao@upc.edu.cn
authors.forename: Meiwen
authors.initials: M
authors.lastname: Cao
authors.forename: Changhai
authors.initials: C
authors.lastname: Cao
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.forename: Daohong
authors.initials: D
authors.lastname: Xia
authors.forename: Hai
authors.initials: H
authors.lastname: Xu
mesh_terms: D002942:Circular Dichroism; D006860:Hydrogen Bonding; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D009842:Oligopeptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D009842:Oligopeptides
keywords: Aromatic interaction; Force balance; Phenylalanine; Self-assembly; Short peptides; β-Sheet