title: Iterative Nonproteinogenic Residue Incorporation Yields α/β-Peptides with a Helix-Loop-Helix Tertiary Structure and High Affinity for VEGF.
abstract: Inhibition of specific protein-protein interactions is attractive for a range of therapeutic applications, but the large and irregularly shaped contact surfaces involved in many such interactions make it challenging to design synthetic antagonists. Here, we describe the development of backbone-modified peptides containing both α- and β-amino acid residues (α/β-peptides) that target the receptor-binding surface of vascular endothelial growth factor (VEGF). Our approach is based on the Z-domain, which adopts a three-helix bundle tertiary structure. We show how a two-helix "mini-Z-domain" can be modified to contain β and other nonproteinogenic residues while retaining the target-binding epitope by using iterative unnatural residue incorporation. The resulting α/β-peptides are less susceptible to proteolysis than is their parent α-peptide, and some of these α/β-peptides match the full-length Z-domain in terms of affinity for receptor-recognition surfaces on the VEGF homodimer.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, USA.
authors.forename: James W
authors.identifier: 0000-0003-1165-6163
authors.initials: JW
authors.lastname: Checco
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, USA.
authors.forename: Samuel H
authors.identifier: 0000-0001-5617-0058
authors.initials: SH
authors.lastname: Gellman
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D005454:Fluorescence Polarization; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010455:Peptides; D042461:Vascular Endothelial Growth Factor A
keywords: alpha/beta-peptides; foldamers; inhibitors; vascular endothelial growth factor