2,5-Pyridinedicarboxylic acid is a bioactive and highly selective inhibitor of D-dopachrome tautomerase.
Parkins, A., Das, P., Prahaladan, V., Rangel, V.M., Xue, L., Sankaran, B., Bhandari, V., Pantouris, G.(2023) Structure 31: 355
- PubMed: 36805127 
- DOI: https://doi.org/10.1016/j.str.2023.01.008
- Primary Citation of Related Structures:  
8DBB - PubMed Abstract: 
Macrophage migration inhibitory factor (MIF) and D-dopachrome tautomerase (D-DT) are two pleotropic cytokines, which are coexpressed in various cell types to activate the cell surface receptor CD74. Via the MIF/CD74 and D-DT/CD74 axes, the two proteins exhibit either beneficial or deleterious effect on human diseases. In this study, we report the identification of 2,5-pyridinedicarboxylic acid (a.k.a. 1) that effectively blocks the D-DT-induced activation of CD74 and demonstrates an impressive 79-fold selectivity for D-DT over MIF. Crystallographic characterization of D-DT-1 elucidates the binding features of 1 and reveals previously unrecognized differences between the MIF and D-DT active sites that explain the ligand's functional selectivity. The commercial availability, low cost, and high selectivity make 1 the ideal tool for studying the pathophysiological functionality of D-DT in disease models. At the same time, our comprehensive biochemical, computational, and crystallographic analyses serve as a guide for generating highly potent and selective D-DT inhibitors.
Organizational Affiliation: 
Department of Chemistry, University of the Pacific, Stockton, CA 95211, USA.