Influence of the shape of nanostructured metal surfaces on adsorption of single peptide molecules in aqueous solution.
Self-assembly and function of biologically modified metal nanostructures depend on surface-selective adsorption; however, the influence of the shape of metal surfaces on peptide adsorption mechanisms has been poorly understood. The adsorption of single peptide molecules in aqueous solution (Tyr(12) , Ser(12) , A3, Flg-Na(3) ) is investigated on even {111} surfaces, stepped surfaces, and a 2 nm cuboctahedral nanoparticle of gold using molecular dynamics simulation with the CHARMM-METAL force field. Strong and selective adsorption is found on even surfaces and the inner edges of stepped surfaces (-20 to -60 kcal/mol peptide) in contrast to weaker and less selective adsorption on small nanoparticles (-15 to -25 kcal/mol peptide). Binding and selectivity appear to be controlled by the size of surface features and the extent of co-ordination of epitaxial sites by polarizable atoms (N, O, C) along the peptide chain. The adsorption energy of a single peptide equals a fraction of the sum of the adsorption energies of individual amino acids that is characteristic of surface shape, epitaxial pattern, and conformation constraints (often β-strand and random coil). The proposed adsorption mechanism is supported and critically evaluated by earlier sequence data from phage display, dissociation constants of small proteins as a function of nanoparticle size, and observed shapes of peptide-stabilized nanoparticles. Understanding the interaction of single peptides with shaped metal surfaces is a key step towards control over self-organization of multiple peptides on shaped metal surfaces and the assembly of superstructures from nanostructures.
Department of Polymer Engineering, University of Akron, Akron, OH 44325-0301, USA.
Jie
J
Feng
Joseph M
JM
Slocik
Mehmet
M
Sarikaya
Rajesh R
RR
Naik
Barry L
BL
Farmer
Hendrik
H
Heinz
D000327:Adsorption; D053768:Metal Nanoparticles / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010455:Peptides / Q000737:chemistry*
D010455:Peptides