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Publication Abstract from PubMed

The stabilization of protein-protein interactions (PPIs) has emerged as a promising strategy in chemical biology and drug discovery. The identification of suitable starting points for stabilizing native PPIs and their subsequent elaboration into selective and potent molecular glues lacks structure-guided optimization strategies. We have previously identified a disulfide fragment that stabilized the hub protein 14-3-3sigma bound to several of its clients, including ERalpha and C-RAF. Here, we show the structure-based optimization of the nonselective fragment toward selective and highly potent small-molecule stabilizers of the 14-3-3sigma/ERalpha complex. The more elaborated molecular glues, for example, show no stabilization of 14-3-3sigma/C-RAF up to 150 muM compound. Orthogonal biophysical assays, including mass spectrometry and fluorescence anisotropy, were used to establish structure-activity relationships. The binding modes of 37 compounds were elucidated with X-ray crystallography, which further assisted the concomitant structure-guided optimization. By targeting specific amino acids in the 14-3-3sigma/ERalpha interface and locking the conformation with a spirocycle, the optimized covalent stabilizer 181 achieved potency, cooperativity, and selectivity similar to the natural product Fusicoccin-A. This case study showcases the value of addressing the structure, kinetics, and cooperativity for molecular glue development.

Structure-Based Optimization of Covalent, Small-Molecule Stabilizers of the 14-3-3sigma/ERalpha Protein-Protein Interaction from Nonselective Fragments.,Konstantinidou M, Visser EJ, Vandenboorn E, Chen S, Jaishankar P, Overmans M, Dutta S, Neitz RJ, Renslo AR, Ottmann C, Brunsveld L, Arkin MR J Am Chem Soc. 2023 Sep 20;145(37):20328-20343. doi: 10.1021/jacs.3c05161. Epub , 2023 Sep 7. PMID:37676236^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.