Optimization of galectin-3 binding agents by in situ multiple compound synthesis and native mass spectrometry.

Developing high-affinity drug lead critically depends on the efficient structural optimization of a lead compound. However, the dynamic nature of the process by which drugs bind to target molecules often complicates the rational design of effective substituents, even if their three-dimensional structure is available. Herein, we report a streamlined strategy for the optimization of a galectin-3 binder through the integration of in situ chemistry and native mass spectrometry. This method involves the simultaneous synthesis of multiple analogues in a single reaction vessel, followed by the direct identification of high-affinity derivatives using native mass spectrometry. This approach enables the detection of ligand-protein complexes under native conditions. Through the further structural modification of the identified hit compound, we finally identified high-affinity galectin-3 binders. The results demonstrated that our strategy would reduce the time and effort required for the structural optimization stage of a lead compound.