A PDE6 delta-KRas Inhibitor Chemotype with up to Seven H-Bonds and Picomolar Affinity that Prevents Efficient Inhibitor Release by Arl2.Martin-Gago, P., Fansa, E.K., Klein, C.H., Murarka, S., Janning, P., Schurmann, M., Metz, M., Ismail, S., Schultz-Fademrecht, C., Baumann, M., Bastiaens, P.I., Wittinghofer, A., Waldmann, H.
(2017) Angew Chem Int Ed Engl 56: 2423-2428
- PubMed: 28106325
- DOI: https://doi.org/10.1002/anie.201610957
- Primary Citation of Related Structures:
5ML2, 5ML3, 5ML4, 5ML6, 5ML8
- PubMed Abstract:
Small-molecule inhibition of the interaction between the KRas oncoprotein and the chaperone PDE6δ impairs KRas spatial organization and signaling in cells. However, despite potent binding in vitro (K D <10 nm), interference with Ras signaling and growth inhibition require 5-20 μm compound concentrations. We demonstrate that these findings can be explained by fast release of high-affinity inhibitors from PDE6δ by the release factor Arl2. This limitation is overcome by novel highly selective inhibitors that bind to PDE6δ with up to 7 hydrogen bonds, resulting in picomolar affinity. Their release by Arl2 is greatly decreased, and representative compounds selectively inhibit growth of KRas mutated and -dependent cells with the highest activity recorded yet. Our findings indicate that very potent inhibitors of the KRas-PDE6δ interaction may impair the growth of tumors driven by oncogenic KRas.
TU Dortmund, Faculty of Chemistry and Chemical Biology, 44227, Dortmund, Germany.