Understanding the role of H-bonds in the stability of molecular glue-induced ternary complexes

Protein-protein interaction (PPI) networks play a central role in many biological processes and thus the possibility of modulating them using small molecules offers several biomedical and biotechnological opportunities. Molecular glues (MGs) are small molecules that bind to a PPI interface and stabilize the complex. Oftentimes, MGs present no measurable affinity to at least one of the proteins involved in the ternary complex, and the molecular bases for their action are not completely understood. We previously reported a significant correlation between protein-protein hydrogen bond robustness and the stability of the lenalidomide–induced CRBN–CK1α complex. In this work, we demonstrate that this relationship is not unique for that system, but rather represents a reproducible physicochemical phenomenon underlying the mechanism of action of chemically diverse MGs, including additional IMiDs and Fusicoccin A. Our results shed light into a vaguely understood phenomenon and pave the way for the development of new computational methods that enable the rational design of molecular glues.