title: Targeting EphA2-Sam and Its Interactome: Design and Evaluation of Helical Peptides Enriched in Charged Residues.
abstract: The EphA2 receptor controls diverse physiological and pathological conditions and its levels are often upregulated in cancer. Targeting receptor overexpression, through modulation of endocytosis and consequent degradation, appears to be an appealing strategy for attacking tumor malignancy. In this scenario, the Sam domain of EphA2 plays a pivotal role because it is the site where protein regulators of endocytosis and stability are recruited by means of heterotypic Sam-Sam interactions. Because EphA2-Sam heterotypic complexes are largely based on electrostatic contacts, we have investigated the possibility of attacking these interactions with helical peptides enriched in charged residues. Several peptide sequences with high predicted helical propensities were designed, and detailed conformational analyses were conducted by diverse techniques including NMR, CD, and molecular dynamics (MD) simulations. Interaction studies were also performed by NMR, surface plasmon resonance (SPR), and microscale thermophoresis (MST) and led to the identification of two peptides capable of binding to the first Sam domain of Odin. These molecules represent early candidates for the generation of efficient Sam domain binders and antagonists of Sam-Sam interactions involving EphA2.
authors.affiliation: Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134, Naples, Italy.
authors.forename: Flavia A
authors.initials: FA
authors.lastname: Mercurio
authors.affiliation: Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134, Naples, Italy.|Department of Pharmacy, University of Naples "Federico II", Via Mezzocannone 16, 80134, Naples, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Marasco
authors.affiliation: Department of Biology, University of Naples "Federico II", Via Cinthia 4, 80126, Naples, Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: Di Natale
authors.affiliation: Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134, Naples, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Pirone
authors.affiliation: CROM, IRCCS-Istituto Nazionale Tumori "Fondazione G. Pascale", Via Mariano Semmola 52, 80131, Naples, Italy.
authors.forename: Susan
authors.initials: S
authors.lastname: Costantini
authors.affiliation: Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134, Naples, Italy.
authors.forename: Emilia M
authors.initials: EM
authors.lastname: Pedone
authors.affiliation: Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134, Naples, Italy.
authors.forename: Marilisa
authors.initials: M
authors.lastname: Leone
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D015195:Drug Design; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D036104:Receptor, EphA2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D060327:Solid-Phase Synthesis Techniques; D000071682:Sterile Alpha Motif; D020349:Surface Plasmon Resonance
chemical_list: D010455:Peptides; D011994:Recombinant Proteins; D036104:Receptor, EphA2
keywords: EphA2; Sam domain; cancer; conformational analysis; drug design; helical peptides