Mass spectrometry methods to study protein-metabolite interactions

To ​​​​understand and manipulate biochemical processes and signaling pathways, the knowledge of endogenous protein-metabolite interactions would be extremely helpful. Recent developments in precision mass spectrometry, high-throughput proteomics and sensitive metabolomic profiling are beginning to converge on a possible solution, heralding a new era of global metabolome-proteome 'interactome' studies that promise to change biomedical research and drug discovery. Areas covered: Here, we review innovative mass spectrometry-based methods and recent pioneering studies aimed at elucidating the physical associations of small molecule ligands with cellular proteins. The technologies covered belong to two main categories: tag-based and tag-free methods. We emphasize the latter in this review, and outline promising experimental workflows and key data analysis considerations involved. Expert opinion: Recent ground-breaking advances in chemical-proteomics technology and allied computational methods now make the global detection of protein-ligand engagement an increasingly attractive research problem. Despite ongoing challenges, rapid progress in the field is expected these coming next few years, leading to a refreshed systems biology research paradigm and much needed new opportunities for improving sparse drug discovery pipelines.