Discovery of Noninhibitory Macrocyclic Ligands for Protein Tyrosine Phosphatase 1B Using a Function-Based, Iterative Screening Strategy

substrate for the phosphatase, allowing ligand-dependent recruitment of the enzyme to the bead surface to be coupled to dephosphorylation of the co-displayed substrate. This is detected by staining with a labeled anti-phosphotyrosine antibody. Finally, we demonstrate that the same general approach can be applied to proteins lacking enzymatic activity by screening against biotin ligase-target protein fusions and employing a proximity labeling-like assay to register screening hits.