title: Unfolding a molecular trefoil derived from a zwitterionic metallopeptide to form self-assembled nanostructures.
abstract: While used extensively by nature to control the geometry of protein structures, and dynamics of proteins, such as self-organization, hydration forces and ionic interactions received less attention for controlling the behaviour of small molecules. Here we describe the synthesis and characterization of a novel zwitterionic metallopeptide consisting of a cationic core and three distal anionic groups linked by self-assembling peptide motifs. 2D NMR spectra, total correlated spectroscopy and nuclear Overhauser effect spectroscopy, show that the molecule exhibits a three-fold rotational symmetry and adopts a folded conformation in dimethyl sulfoxide due to Coulombic forces. When hydrated in water, the molecule unfolds to act as a self-assembling building block of supramolecular nanostructures. By combining ionic interactions with the unique geometry from metal complex and hydrophobic interactions from simple peptides, we demonstrate a new and effective way to design molecules for smart materials through mimicking a sophisticated biofunctional system using a conformational switch.
authors.affiliation: Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Shi
authors.affiliation: Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Susan Sondej
authors.initials: SS
authors.lastname: Pochapsky
authors.affiliation: Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Pochapsky
authors.affiliation: Nano-fabrication, Imaging &Characterization Core Lab, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Bei
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Nano-fabrication, Imaging &Characterization Core Lab, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Xixiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Xu
mesh_terms: D017666:Deuterium Oxide / Q000737:chemistry; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry*; D058767:Protein Unfolding
chemical_list: D007477:Ions; D010455:Peptides; D017666:Deuterium Oxide; D004121:Dimethyl Sulfoxide