The modulation of protein–protein interactions (PPIs) is emerging as a highly promising tool to fight diseases. However, whereas an increasing number of compounds are able to disrupt peptide-mediated PPIs efficiently, the inhibition of domain–domain PPIs appears to be much more challenging. Herein, we report our results related to the interaction between vascular endothelial growth factor (VEGF) and its receptor (VEGFR). The VEGF–VEGFR interaction is a typical domain–domain PPI that is highly relevant for the treatment of cancer and some retinopathies. Our final goal was to identify ligands able to bind VEGF at the region used by the growth factor to interact with its receptor. We undertook an extensive study, combining a variety of experimental approaches, including NMR-spectroscopy-based screening of small organic fragments, peptide libraries, and medicinal plant extracts. The key feature of the successful ligands that emerged from this study was their capacity to expose hydrophobic functional groups able to interact with the hydrophobic hot spots at the interacting VEGF surface patch.

This work was supported by the Ministry of Economy and Competitiveness and the European Fund for Regional Development (MINECO-FEDER) (Bio2013-40716-R) and the Generalitat de Catalunya (XRB and 2014-SGR-521). We also thank the NMR facility at the Scientific and Technological Centre of the University of Barcelona (CCiT UB) for their technical support.

Peer Reviewed