Reversible Covalent Imine-Tethering for Selective Stabilization of 14-3‑3 Hub Protein Interactions

• Published in: Journal of the American Chemical Society Vol. 143; no. 22; pp. 8454 - 8464
• Main Authors: Cossar, Peter J, Wolter, Madita, van Dijck, Lars, Valenti, Dario, Levy, Laura M, Ottmann, Christian, Brunsveld, Luc
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 09.06.2021
• Subjects: 14-3-3 Proteins - chemistry; Humans; Imines - chemistry; Models, Molecular; Molecular Structure; NIMA-Interacting Peptidylprolyl Isomerase - chemistry; Protein Stability
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.1c03035

The stabilization of protein complexes has emerged as a promising modality, expanding the number of entry points for novel therapeutic intervention. Targeting proteins that mediate protein–protein interactions (PPIs), such as hub proteins, is equally challenging and rewarding as they offer an intervention platform for a variety of diseases, due to their large interactome. 14-3-3 hub proteins bind phosphorylated motifs of their interaction partners in a conserved binding channel. The 14-3-3 PPI interface is consequently only diversified by its different interaction partners. Therefore, it is essential to consider, additionally to the potency, also the selectivity of stabilizer molecules. Targeting a lysine residue at the interface of the composite 14-3-3 complex, which can be targeted explicitly via aldimine-forming fragments, we studied the de novo design of PPI stabilizers under consideration of potential selectivity. By applying cooperativity analysis of ternary complex formation, we developed a reversible covalent molecular glue for the 14-3-3/Pin1 interaction. This small fragment led to a more than 250-fold stabilization of the 14-3-3/Pin1 interaction by selective interfacing with a unique tryptophan in Pin1. This study illustrates how cooperative complex formation drives selective PPI stabilization. Further, it highlights how specific interactions within a hub proteins interactome can be stabilized over other interactions with a common binding motif.