Download MendeleyNanomolar inhibitor of the galectin-8 N-terminal domain binds via a non-canonical cation-pi interaction.
Puric, E., Hassan, M., Sjovall, F., Tomasic, T., Pevec, M., Lah, J., Forteza, J.A., Sundin, A., Leffler, H., Nilsson, U.J., Logan, D.T., Anderluh, M.(2025) Commun Chem 8: 59-59
- PubMed: 39994474
- DOI: https://doi.org/10.1038/s42004-025-01458-6
- Primary Citation of Related Structures:
9FYJ - PubMed Abstract:
Galectin-8 is a tandem-repeat galectin consisting of two distinct carbohydrate recognition domains and is a potential drug target. We have developed a library of galectin-8N inhibitors that exhibit high nanomolar K d values as determined by a competitive fluorescence polarization assay. A detailed thermodynamic analysis of the binding of D-galactosides to galectin-8N by isothermal titration calorimetry reveals important differences in enthalpic and/or entropic contributions to binding. Contrary to expectations, the binding of 2-O-propargyl-D-galactoside was found to strongly increase the binding enthalpy, whereas the binding of 2-O-carboxymethylene-D-galactoside was surprisingly less enthalpy-driven. The results of our work suggest that the ethynyl group can successfully replace the carboxylate group when targeting the water-exposed guanidine moiety of a critical arginine residue. This results in only a minor loss of affinity and an adjusted enthalpic contribution to the overall binding due to non-canonical cation-π interactions, as evidenced by the obtained crystal structure of 2-O-propargyl-D-galactoside in complex with the N-terminal domain of galectin-8. Such an interaction has neither been identified nor discussed to date in a small-molecule ligand-protein complex.
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
Organizational Affiliation:
