PLoS ONE (Jan 2012)

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

  • Katiuscia Pagano,
  • Rubben Torella,
  • Chiara Foglieni,
  • Antonella Bugatti,
  • Simona Tomaselli,
  • Lucia Zetta,
  • Marco Presta,
  • Marco Rusnati,
  • Giulia Taraboletti,
  • Giorgio Colombo,
  • Laura Ragona

DOI
https://doi.org/10.1371/journal.pone.0036990
Journal volume & issue
Vol. 7, no. 5
p. e36990

Abstract

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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.