title: Phage Selection of Chemically Stabilized α-Helical Peptide Ligands.
abstract: Short α-helical peptides stabilized by linkages between constituent amino acids offer an attractive format for ligand development. In recent years, a range of excellent ligands based on stabilized α-helices were generated by rational design using α-helical peptides of natural proteins as templates. Herein, we developed a method to engineer chemically stabilized α-helical ligands in a combinatorial fashion. In brief, peptides containing cysteines in position i and i + 4 are genetically encoded by phage display, the cysteines are modified with chemical bridges to impose α-helical conformations, and binders are isolated by affinity selection. We applied the strategy to affinity mature an α-helical peptide binding β-catenin. We succeeded in developing ligands with Kd's as low as 5.2 nM, having >200-fold improved affinity. The strategy is generally applicable for affinity maturation of any α-helical peptide. Compared to hydrocarbon stapled peptides, the herein evolved thioether-bridged peptide ligands can be synthesized more easily, as no unnatural amino acids are required and the cyclization reaction is more efficient and yields no stereoisomers. A further advantage of the thioether-bridged peptide ligands is that they can be expressed recombinantly as fusion proteins.
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Diderich
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.
authors.forename: Davide
authors.initials: D
authors.lastname: Bertoldo
authors.affiliation: Swiss Institute for Experimental Cancer Research (ISREC), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.
authors.forename: Pierre
authors.initials: P
authors.lastname: Dessen
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.
authors.forename: Maola M
authors.initials: MM
authors.lastname: Khan
authors.affiliation: Ludwig Center for Cancer Research, Department of Oncology, University of Lausanne , CH-1066 Epalinges, Switzerland.
authors.forename: Irene
authors.initials: I
authors.lastname: Pizzitola
authors.affiliation: Ludwig Center for Cancer Research, Department of Oncology, University of Lausanne , CH-1066 Epalinges, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Held
authors.affiliation: Swiss Institute for Experimental Cancer Research (ISREC), Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.
authors.forename: Joerg
authors.initials: J
authors.lastname: Huelsken
authors.affiliation: Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Heinis
mesh_terms: D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000378:metabolism*; D008024:Ligands; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry; D051176:beta Catenin / Q000378:metabolism
chemical_list: D008024:Ligands; D019151:Peptide Library; D010455:Peptides; D051176:beta Catenin