Direct and allosteric inhibition of the FGF2/HSPGs/FGFR1 ternary complex formation by an antiangiogenic, thrombospondin-1-mimic small molecule

• Published in: PloS one 2012-05, Vol.7 (5), p.e36990-e36990
• Main Authors: Pagano, Katiuscia, Torella, Rubben, Foglieni, Chiara, Bugatti, Antonella, Tomaselli, Simona, Zetta, Lucia, Presta, Marco, Rusnati, Marco, Taraboletti, Giulia, Colombo, Giorgio, Ragona, Laura
• Format: Article
• Language: English
• Subjects: Allosteric properties; Allosteric Regulation - drug effects; Analysis; Angiogenesis; Angiogenesis Inhibitors - chemistry; Angiogenesis Inhibitors - pharmacology; Antiangiogenics; Anticoagulants; Antineoplastic agents; Bacillus; Binding sites; Biology; Biotechnology; Cancer; Cell adhesion & migration; Cell growth; Cell surface; Chemistry; Complex formation; E coli; Escherichia coli; Fibroblast growth factor 2; Fibroblast Growth Factor 2 - antagonists & inhibitors; Fibroblast Growth Factor 2 - chemistry; Fibroblast growth factor receptor 1; Fibroblast growth factors; Fibroblasts; Growth factors; Heparan sulfate; Heparan Sulfate Proteoglycans - antagonists & inhibitors; Heparan Sulfate Proteoglycans - chemistry; Heparin; Humans; In Vitro Techniques; Inhibition; Inhibitors; Kinases; Ligands; Magnetic resonance; Metabolism; Mimicry; Models, Molecular; Molecular dynamics; Molecular Dynamics Simulation; Molecular Mimicry; Multiprotein Complexes - antagonists & inhibitors; Multiprotein Complexes - chemistry; Naphthalenesulfonates - chemistry; Naphthalenesulfonates - pharmacology; NMR; Nuclear magnetic resonance; Nuclear Magnetic Resonance, Biomolecular; Protein Interaction Mapping; Protein-tyrosine kinase; Proteoglycans; Receptor, Fibroblast Growth Factor, Type 1 - antagonists & inhibitors; Receptor, Fibroblast Growth Factor, Type 1 - chemistry; Receptors; Resonance; Surface Plasmon Resonance; Target recognition; Thrombospondin; Thrombospondin 1 - chemistry; Thrombospondin 1 - pharmacology; Tyrosine
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0036990

Fibroblast growth factors (FGFs) are recognized targets for the development of therapies against angiogenesis-driven diseases, including cancer. The formation of a ternary complex with the transmembrane tyrosine kinase receptors (FGFRs), and heparan sulphate proteoglycans (HSPGs) is required for FGF2 pro-angiogenic activity. Here by using a combination of techniques including Nuclear Magnetic Resonance, Molecular Dynamics, Surface Plasmon Resonance and cell-based binding assays we clarify the molecular mechanism of inhibition of an angiostatic small molecule, sm27, mimicking the endogenous inhibitor of angiogenesis, thrombospondin-1. NMR and MD data demonstrate that sm27 engages the heparin-binding site of FGF2 and induces long-range dynamics perturbations along FGF2/FGFR1 interface regions. The functional consequence of the inhibitor binding is an impaired FGF2 interaction with both its receptors, as demonstrated by SPR and cell-based binding assays. We propose that sm27 antiangiogenic activity is based on a twofold-direct and allosteric-mechanism, inhibiting FGF2 binding to both its receptors.