title: Rational design of helical nanotubes from self-assembly of coiled-coil lock washers.
abstract: Design of a structurally defined helical assembly is described that involves recoding of the amino acid sequence of peptide GCN4-pAA. In solution and the crystalline state, GCN4-pAA adopts a 7-helix bundle structure that resembles a supramolecular lock washer. Structurally informed mutagenesis of the sequence of GCN4-pAA afforded peptide 7HSAP1, which undergoes self-association into a nanotube via noncovalent interactions between complementary interfaces of the coiled-coil lock-washer structures. Biophysical measurements conducted in solution and the solid state over multiple length scales of structural hierarchy are consistent with self-assembly of nanotube structures derived from 7-helix bundle subunits. The dimensions of the supramolecular assemblies are similar to those observed in the crystal structure of GCN4-pAA. Fluorescence studies of the interaction of 7HSAP1 with the solvatochromic fluorophore PRODAN indicated that the nanotubes could encapsulate shape-appropriate small molecules with high binding affinity.
authors.affiliation: Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30322, United States.
authors.forename: Chunfu
authors.initials: C
authors.lastname: Xu
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.forename: Anil K
authors.initials: AK
authors.lastname: Mehta
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Guerrero-Ferreira
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Wright
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Dunin-Horkawicz
authors.forename: Kyle
authors.initials: K
authors.lastname: Morris
authors.forename: Louise C
authors.initials: LC
authors.lastname: Serpell
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zuo
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Wall
authors.forename: Vincent P
authors.initials: VP
authors.lastname: Conticello
mesh_terms: D008958:Models, Molecular; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000235:genetics; D013499:Surface Properties
chemical_list: D010455:Peptides