title: Discovery of small peptide antagonists of PED/PEA15-D4α interaction from simplified combinatorial libraries.
abstract: Most biological processes involve permanent and temporary interactions between different proteins: protein complexes often play key roles in human diseases and, as a consequence, molecules that prevent protein-protein interactions can be potential new therapeutic agents to treat diseases. Here, we describe a simplified approach by which small synthetic peptide libraries were screened to identify the inhibitors of the complex between phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes15 (PED/PEA15) and D4α, a functional domain of the phospholipase D1, that is involved in the molecular mechanisms of insulin resistance occurring in type 2 diabetes. By using an enzyme-linked immunosorbent assay (ELISA)-based screening, performed on a fully automated platform, we analyzed two simplified peptide libraries in a positional scanning format. This screening led to the identification of small peptides able to inhibit PED/PEA15-D4α interaction. The selection of inhibitors was carried out employing combined competitive and direct experiments, through ELISA and surface plasmon resonance techniques, providing peptides with IC(50) values in the micromolar range. Our results showed that the protein complex PED/PEA15-D4α is susceptible to peptides having H-donor groups and aromatic rings on specific positions. These small sequences can be considered as promising scaffolds that could be converted into higher-affinity inhibitor compounds.
authors.affiliation: Department of Biological Sciences, School of Biotechnological Sciences, University of Naples Federico II, Via Mezzocannone, 16, 80134, Naples, Italy.
authors.forename: Pasqualina Liana
authors.initials: PL
authors.lastname: Scognamiglio
authors.forename: Nunzianna
authors.initials: N
authors.lastname: Doti
authors.forename: Paolo
authors.initials: P
authors.lastname: Grieco
authors.forename: Carlo
authors.initials: C
authors.lastname: Pedone
authors.forename: Menotti
authors.initials: M
authors.lastname: Ruvo
authors.forename: Daniela
authors.initials: D
authors.lastname: Marasco
mesh_terms: D051017:Apoptosis Regulatory Proteins; D057205:Automation, Laboratory; D001667:Binding, Competitive; D003001:Cloning, Molecular; D020650:Combinatorial Chemistry Techniques; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000503:physiopathology; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli; D057166:High-Throughput Screening Assays; D006801:Humans; D020128:Inhibitory Concentration 50; D007333:Insulin Resistance; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D019151:Peptide Library; D010455:Peptides / Q000494:pharmacology*; D010739:Phospholipase D / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects*; D017434:Protein Structure, Tertiary / Q000235:genetics; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D020349:Surface Plasmon Resonance
chemical_list: D051017:Apoptosis Regulatory Proteins; D047908:Intracellular Signaling Peptides and Proteins; C092039:PEA15 protein, human; D019151:Peptide Library; D010455:Peptides; D010750:Phosphoproteins; D011994:Recombinant Proteins; D010739:Phospholipase D; C106801:phospholipase D1