title: Stimuli induced structural changes of gold nanoparticle assemblies having sequential alternating amphiphilic peptides at the surface.
abstract: Gold nanoparticles having sequential alternating amphiphilic peptide chains, Phe-(Leu-Glu)8, on the surface have been prepared. We describe structural control of the amphiphilic peptide coated gold nanoparticle assembly by a conformational transition of the surface peptides. Under the acidic condition, the conformation of the surface amphiphilic peptide was converted to a beta-sheet structure from an aggregated alpha-helix by incubation. Under this condition, the amphiphilic peptide coated gold nanoparticles formed a nanosheet assembly. The plasmon absorption maximum of the gold nanoparticles shifted to a shorter wavelength with the formation of the beta-sheet assembly of the surface peptide. This suggests that the structure of the peptide coated gold nanoparticle assembly could be controlled by the conformational transition of the surface peptide. Furthermore, the core gold nanoparticle could be fixed in the beta-sheet assembly in the state that stood alone. This system may be useful for novel molecular devices that exhibit quantized properties.
authors.affiliation: Department of Materials Science and Technology, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-5888, Japan. higuchi.masahiro@nitech.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Higuchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Nagata
authors.forename: Sohei
authors.initials: S
authors.lastname: Abiko
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D000595:Amino Acid Sequence; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D010316:Particle Size; D011487:Protein Conformation; D013499:Surface Properties
chemical_list: D009842:Oligopeptides; D006046:Gold