Non-covalent Interactions: Studying RNA – Small Molecule Binding Using Automated Chip-based Nanoelectrospray Mass Spectrometry in Negative Ion Mode

Negative ion nanoelectrospray ionization mass spectrometry (nESI-MS) is notoriously challenging, even more so under the high aqueous conditions required for protein-ligand interactions at physiological conditions. However, we present a successful application of negative ion nESI-MS for the investigation of noncovalent interactions between Ψ-RNA and small molecule inhibitors.