title: Pathway selection in peptide amphiphile assembly.
abstract: The nature of supramolecular structures could be strongly affected by the pathways followed during their formation just as mechanisms and final outcomes in chemical reactions vary with the conditions selected. So far this is a largely unexplored area of supramolecular chemistry. We demonstrate here how different preparation protocols to self-assemble peptide amphiphiles in water can result in the formation of different supramolecular morphologies, either long filaments containing β-sheets or smaller aggregrates containing peptide segments in random coil conformation. We found that the assembly rate into β-sheets decreases in the presence of a destabilizing "good" solvent like hexafluoroisopropanol (HFIP) and is affected by transient conditions in solution. Also the peptide amphiphile investigated spontaneously nucleates the β-sheet-containing filaments at a critical fraction of HFIP in water below 21%. Furthermore, β-sheet assemblies have a high kinetic stability and, once formed, do not disassemble rapidly. We foresee that insights into the characteristic dynamics of a supramolecular system provide an efficient approach to select the optimum assembly pathway necessary for function.
authors.affiliation: Institute for Complex Molecular Systems and Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Korevaar
authors.forename: Christina J
authors.initials: CJ
authors.lastname: Newcomb
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
authors.forename: Samuel I
authors.initials: SI
authors.lastname: Stupp
mesh_terms: D007700:Kinetics; D008968:Molecular Conformation; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D013501:Surface-Active Agents / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D010455:Peptides; D013501:Surface-Active Agents