RESUMO
On the basis of the knowledge that the proline-rich hot spot PPPRPP region of P(151)PSNPPPRPP(160), an oligopeptide derived from the cytosolic portion of p22phox (p22), binds to the single functional bis-SH3 domain of the regulatory protein p47phox (p47), we designed a mimetic of the tripeptide PPP based on NMR and X-ray crystallographic data for the p22(151-161) peptide PPSNPPPRPPA with a peptide construct. Incorporation of the synthetic pseudo-triproline mimetic Pro-Pro-Cyp in a molecule derived from molecular modeling studies led to only a 7-fold diminution in activity in a surface plasmon resonance assay relative to the same molecule containing the natural Pro-Pro-Pro tripeptide. The alternative sequence corresponding to a Pro-Cyp-Pro insertion was inactive. This is a first example of the use of a triproline mimetic to interfere with the formation of the p47-p22 complex, which is critical for the activation of NOX, leading to the production of reactive oxygen species as superoxide anions.
RESUMO
The kinase DYRK1A is an attractive target for drug discovery programs due to its implication in multiple diseases. Through a fragment screen, we identified a simple biaryl compound that is bound to the DYRK1A ATP site with very high efficiency, although with limited selectivity. Structure-guided optimization cycles enabled us to convert this fragment hit into potent and selective DYRK1A inhibitors. Exploiting the structural differences in DYRK1A and its close homologue DYRK2, we were able to fine-tune the selectivity of our inhibitors. Our best compounds potently inhibited DYRK1A in the cell culture and in vivo and demonstrated drug-like properties. The inhibition of DYRK1A in vivo translated into dose-dependent tumor growth inhibition in a model of ovarian carcinoma.