Inhibition of protein-protein interactions among tubulins in vitro and in cellulo using C-terminal-binding nanoparticles.

Protein-protein interactions (PPIs) are fundamental to cellular function, yet selectively inhibiting them remains a significant challenge. This difficulty arises because PPI interfaces involve surface areas (1000-5000 Å2) significantly larger than those involved in small-molecule ligand recognition. Here, we report the development of molecularly imprinted nanoparticles (MINPs) designed to target the disordered C-terminal tails (CTTs) of α- and β-tubulins. By modulating hydrogen-bonding functional monomers and cross-linkers, we tuned the MINP binding properties to achieve either dual α- and β-tubulin affinity or high selectivity for a single isoform. A nonselective MINP was found to outperform its more selective counterparts, likely by maximizing target occupancy and inducing steric clashes across the microtubule lattice. This dense molecular recognition leads to potent microtubule disruption, G2/M phase arrest, and apoptosis in MDA-MB-231 breast cancer cells. These findings demonstrate that intrinsically disordered protein regions like CTTs are viable targets for PPI regulation.