title: Self-assembly of peptide-amphiphile nanofibers: the roles of hydrogen bonding and amphiphilic packing.
abstract: The role of hydrogen bonding and amphiphilic packing in the self-assembly of peptide-amphiphiles (PAs) was investigated using a series of 26 PA derivatives, including 19 N-methylated variants and 7 alanine mutants. These were studied by circular dichroism spectroscopy, a variety of Fourier transform infrared spectroscopies, rheology, and vitreous ice cryo-transmission electron microscopy. From these studies, we have been able to determine which amino acids are critical for the self-assembly of PAs into nanofibers, why the nanofiber is favored over other possible nanostructures, the orientation of hydrogen bonding with respect to the nanofiber axis, and the constraints placed upon the portion of the peptide most intimately associated with the biological environment. Furthermore, by selectively eliminating key hydrogen bonds, we are able to completely change the nanostructure resulting from self-assembly in addition to modifying the macroscopic mechanical properties associated with the assembled gel. This study helps to clarify the mechanism of self-assembly for peptide amphiphiles and will thereby help in the design of future generations of PAs.
authors.affiliation: Department of Chemistry, Rice University, 6100 Main Street, MS60, Houston, Texas 77005, USA.
authors.forename: Sergey E
authors.initials: SE
authors.lastname: Paramonov
authors.forename: Ho-Wook
authors.initials: HW
authors.lastname: Jun
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Hartgerink
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D006860:Hydrogen Bonding; D008422:Materials Testing; D019563:Mechanics; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D049329:Nanostructures / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013501:Surface-Active Agents / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D010455:Peptides; D013501:Surface-Active Agents