title: Self-Assembly of an α-Helical Peptide into a Crystalline Two-Dimensional Nanoporous Framework.
abstract: Sequence-specific peptides have been demonstrated to self-assemble into structurally defined nanoscale objects including nanofibers, nanotubes, and nanosheets. The latter structures display significant promise for the construction of hybrid materials for functional devices due to their extended planar geometry. Realization of this objective necessitates the ability to control the structural features of the resultant assemblies through the peptide sequence. The design of a amphiphilic peptide, 3FD-IL, is described that comprises two repeats of a canonical 18 amino acid sequence associated with straight α-helical structures. Peptide 3FD-IL displays 3-fold screw symmetry in a helical conformation and self-assembles into nanosheets based on hexagonal packing of helices. Biophysical evidence from TEM, cryo-TEM, SAXS, AFM, and STEM measurements on the 3FD-IL nanosheets support a structural model based on a honeycomb lattice, in which the length of the peptide determines the thickness of the nanosheet and the packing of helices defines the presence of nanoscale channels that permeate the sheet. The honeycomb structure can be rationalized on the basis of geometrical packing frustration in which the channels occupy defect sites that define a periodic superlattice. The resultant 2D materials may have potential as materials for nanoscale transport and controlled release applications.
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Magnotti
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Spencer A
authors.initials: SA
authors.lastname: Hughes
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta , Atlanta, Georgia 30322, United States.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Dillard
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Shengyuan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Lillian
authors.initials: L
authors.lastname: Hough
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Arshad
authors.initials: A
authors.lastname: Karumbamkandathil
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Tianquan
authors.identifier: 0000-0002-8351-3690
authors.initials: T
authors.lastname: Lian
authors.affiliation: Brookhaven National Laboratory , P.O. Box 5000, Upton, New York 11973, United States.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Wall
authors.affiliation: X-ray Science Division, Argonne National Laboratory , 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zuo
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta , Atlanta, Georgia 30322, United States.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Wright
authors.affiliation: Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Vincent P
authors.initials: VP
authors.lastname: Conticello
mesh_terms: D008958:Models, Molecular; D058608:Nanopores; D010455:Peptides / Q000737:chemistry*; D000072756:Protein Conformation, alpha-Helical
chemical_list: D010455:Peptides