Discovery of Small-Molecule Stabilizers of 14-3-3 Protein–Protein Interactions via Dynamic Combinatorial Chemistry

Protein–protein interactions (PPIs) play an important role in numerous biological processes such as cell-cycle regulation and multiple diseases. The family of 14-3-3 proteins is an attractive target as they serve as binding partner to various proteins and are therefore capable of regulating their biological activities. Discovering small-molecule modulators, in particular stabilizers, of such complexes via traditional screening approaches is a challenging task. Herein, we pioneered the first application of dynamic combinatorial chemistry (DCC) to a PPI target, to find modulators of 14-3-3 proteins. Evaluation of the amplified hits from the DCC experiments for their binding affinity via surface plasmon resonance (SPR), revealed that the low-micromolar (K_D 15–16 μM) acylhydrazones are 14-3-3/synaptopodin PPI stabilizers. Thus, DCC appears to be ideally suited for the discovery of not only modulators but even the more elusive stabilizers of notoriously challenging PPIs.