title: Two-Dimensional Folding of Polypeptides into Molecular Nanostructures at Surfaces.
abstract: Herein we report the fabrication of molecular nanostructures on surfaces via two-dimensional (2D) folding of the nine amino acid peptide bradykinin. Soft-landing electrospray ion beam deposition in conjunction with high-resolution imaging by scanning tunneling microscopy is used to fabricate and investigate the molecular nanostructures. Subnanometer resolved images evidence the large conformational freedom of the molecules if thermal motion is inhibited and the formation of stable uniform dimers of only one specific conformation when diffusion can take place. Molecular dynamics modeling supported by density functional theory calculations give atomically precise insight into the induced-fit binding scheme when the folded dimer is formed. In the absence of solvent, we find a hierarchy of binding strength from polar to nonpolar, manifested in an inverted polar-nonpolar segregation which suppresses unspecific interactions at the rim of the nanostructure. The demonstrated 2D-folding scheme resembles many key properties of its native 3D counterpart and shows that functional, molecular nanostructures on surfaces fabricated by folding could be just as versatile and specific.
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstr. 1, Stuttgart DE-70569, Germany.
authors.forename: Stephan
authors.identifier: 0000-0002-7099-5424
authors.initials: S
authors.lastname: Rauschenbach
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstr. 1, Stuttgart DE-70569, Germany.
authors.forename: Gordon
authors.initials: G
authors.lastname: Rinke
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstr. 1, Stuttgart DE-70569, Germany.
authors.forename: Rico
authors.initials: R
authors.lastname: Gutzler
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstr. 1, Stuttgart DE-70569, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Abb
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstr. 1, Stuttgart DE-70569, Germany.
authors.forename: Alyazan
authors.initials: A
authors.lastname: Albarghash
authors.affiliation: University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Duy
authors.initials: D
authors.lastname: Le
authors.affiliation: University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Talat S
authors.initials: TS
authors.lastname: Rahman
authors.affiliation: Justus Liebig University Giessen, Institute of Applied Physics , Heinrich-Buff-Ring 16, Giessen DE-35392, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Dürr
authors.affiliation: University of Stuttgart , Bernhäuserstr. 75, Leinfelden-Echterdingen DE-70771, Germany.
authors.forename: Ludger
authors.initials: L
authors.lastname: Harnau
authors.affiliation: Max Planck Institute for Solid State Research , Heisenbergstr. 1, Stuttgart DE-70569, Germany.|Ecole Polytechnique Fédérale de Lausanne, Institut de Physique , Lausanne CH-1015, Switzerland.
authors.forename: Klaus
authors.initials: K
authors.lastname: Kern
mesh_terms: D001920:Bradykinin / Q000737:chemistry*; D004058:Diffusion; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry*; D017510:Protein Folding; D011789:Quantum Theory; D013499:Surface Properties
chemical_list: D001920:Bradykinin
keywords: electrospray ion beam deposition; folding; peptides; scanning tunneling microscopy; surfaces