title: Structural characterization and 5'-mononucleotide binding of polyalanine beta-sheet complexes.
abstract: A study was initiated into the formation and stability of highly soluble beta-sheet macrostructures. Such beta-sheet macrostructures are useful model systems for the study of the biological function of the hydrophobic core of proteins and for the de novo design of novel catalytic mimics. In the current study, a 16-mer-alanine-based peptide (Ac-KA14K-NH2) that is highly water soluble and adopts an extremely stable macromolecular beta-sheet structure was synthesized. A tyrosine-containing analog (Ac-KYA13K-NH1) was used to study the tertiary structure of the complex by circular dichroism spectroscopy, while the influence of the charges on the complex formation and binding affinity was evaluated using a zwitterionic analog (Ac-KEA13KE-NH1). Both the secondary and tertiary structures of the beta-sheet complex were stable to denaturants, as demonstrated by far- and near-ultraviolet circular dichroism spectroscopy. Binding studies with mononucleotides have shown that the beta-sheet complex binds to molecules through both hydrophobic and electrostatic interactions. These intrinsic properties were found to be a prerequisite for the observed enhanced cleavage of phosphodiester bonds.
authors.affiliation: Torrey Pines Institute for Molecular Studies, San Diego, California 92121, USA.
authors.forename: E
authors.initials: E
authors.lastname: Pérez-Payá
authors.forename: B
authors.initials: B
authors.lastname: Forood
authors.forename: R A
authors.initials: RA
authors.lastname: Houghten
authors.forename: S E
authors.initials: SE
authors.lastname: Blondelle
mesh_terms: D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D002942:Circular Dichroism; D005456:Fluorescent Dyes / Q000737:chemistry; D009711:Nucleotides / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D000817:Anilino Naphthalenesulfonates; D005456:Fluorescent Dyes; D009711:Nucleotides; D009842:Oligopeptides; D010455:Peptides; C019529:polyalanine; D010727:Phosphoric Diester Hydrolases