Identification of Ligands for Ion Channels: TRPM2

Abstract

AbstractTransient receptor potential melastatin 2 (TRPM2) is a calcium‐permeable, nonselective cation channel with a widespread distribution throughout the body. It is involved in many pathological and physiological processes, making it a potential therapeutic target for various diseases, including Alzheimer's disease, Parkinson's disease, and cancers. New analytical techniques are beneficial for gaining a deeper understanding of its involvement in disease pathogenesis and for advancing the drug discovery for TRPM2‐related diseases. In this work, we present the application of collision‐induced affinity selection mass spectrometry (CIAS‐MS) for the direct identification of ligands binding to TRPM2. CIAS‐MS circumvents the need for high mass detection typically associated with mass spectrometry of large membrane proteins. Instead, it focuses on the detection of small molecules dissociated from the ligand‐protein‐detergent complexes. This affinity selection approach consolidates all affinity selection steps within the mass spectrometer, resulting in a streamlined process. We showed the direct identification of a known TRPM2 ligand dissociated from the protein‐ligand complex. We demonstrated that CIAS‐MS can identify binding ligands from complex mixtures of compounds and screened a compound library against TRPM2. We investigated the impact of voltage increments and ligand concentrations on the dissociation behavior of the binding ligand, revealing a dose‐dependent relationship.