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

PLoS One. 2012;7(5):e36990. doi: 10.1371/journal.pone.0036990. Epub 2012 May 14.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation / drug effects
  • Angiogenesis Inhibitors / chemistry
  • Angiogenesis Inhibitors / pharmacology*
  • Fibroblast Growth Factor 2 / antagonists & inhibitors*
  • Fibroblast Growth Factor 2 / chemistry*
  • Heparan Sulfate Proteoglycans / antagonists & inhibitors*
  • Heparan Sulfate Proteoglycans / chemistry*
  • Humans
  • In Vitro Techniques
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Molecular Mimicry
  • Multiprotein Complexes / antagonists & inhibitors
  • Multiprotein Complexes / chemistry
  • Naphthalenesulfonates / chemistry
  • Naphthalenesulfonates / pharmacology
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Interaction Mapping
  • Receptor, Fibroblast Growth Factor, Type 1 / antagonists & inhibitors*
  • Receptor, Fibroblast Growth Factor, Type 1 / chemistry*
  • Surface Plasmon Resonance
  • Thrombospondin 1 / chemistry
  • Thrombospondin 1 / pharmacology

Substances

  • Angiogenesis Inhibitors
  • Heparan Sulfate Proteoglycans
  • Multiprotein Complexes
  • Naphthalenesulfonates
  • Thrombospondin 1
  • Fibroblast Growth Factor 2
  • FGFR1 protein, human
  • Receptor, Fibroblast Growth Factor, Type 1