Proteins undergo dynamic interactions with carbohydrates, lipids and nucleotides to form catalytic cores, fine-tuned for different cellular actions. The study of dynamic interactions between proteins and their cognate ligands is therefore fundamental to the understanding of biological systems. During the last two decades MS, and its associated techniques, has become accepted as a method for the study of protein-ligand interactions, not only for covalent complexes, where the use of MS is well ...