title: Design of metal-binding sites onto self-assembled peptide fibrils.
abstract: The ability to develop a rational basis for the binding of inorganic materials to specific binding sites within self-assembling biological scaffolds has important applications in nanobiotechnology. Amyloid-forming peptides are a class of such scaffolds and show enormous potential as templates for the fabrication of low resistance, conducting nanowires. Here we report the use of a self-assembling peptide building block as scaffold for the systematic introduction of metal-binding residues at specific locations within the structure. The octapeptide NSGAITIG (Asparagine-Serine-Glycine-Alanine-Isoleucine-Threonine-Isoleucine-Glycine) from the fiber protein of adenovirus has been identified in previous structural studies as an elementary fibril-forming building block. Using this building block as a scaffold, we have designed three new cysteine-containing octa-peptides to study their eventual fibril-forming ability and potential templating of metal nanoparticles. We find that the cysteine substitutions do not alter the fibril-forming potential of the peptides, and that the fibrils formed bind efficiently to silver, gold, and platinum nanoparticles; furthermore, we report unexpected behavior of serine in nucleating gold and platinum nanoparticles. We find that combination of cysteine and serine residues projecting from adjacent sites on a peptide scaffold represents a potentially useful strategy in nucleating inorganic materials. The ability to reliably produce metal-coated fibrils is a vital first step towards the exploitation of these fibrils as conducting nanowires with applications in nano-circuitry. Short, biologically inspired self-assembling peptide scaffolds derived from natural fibrous proteins with known three-dimensional structure may provide a viable approach towards the rational design of inorganic nanowires.
authors.affiliation: Department of Materials Science and Technology, University of Crete, Vassilika Vouton, 710 03 Heraklion, Crete, Greece.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Kasotakis
authors.forename: Estelle
authors.initials: E
authors.lastname: Mossou
authors.forename: Lihi
authors.initials: L
authors.lastname: Adler-Abramovich
authors.forename: Edward P
authors.initials: EP
authors.lastname: Mitchell
authors.forename: V Trevor
authors.initials: VT
authors.lastname: Forsyth
authors.forename: Ehud
authors.initials: E
authors.lastname: Gazit
authors.forename: Anna
authors.initials: A
authors.lastname: Mitraki
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D001665:Binding Sites; D015195:Drug Design; D006046:Gold / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D012834:Silver / Q000737:chemistry
chemical_list: D016229:Amyloid beta-Peptides; D010455:Peptides; D012834:Silver; D010984:Platinum; D006046:Gold