Abstract

Most drugs act by binding to one or more target proteins. It is a challenge to directly monitor this target engagement in situ with the currently available methods. This limitation has contributed to the relatively poor success rates in clinical drug development. We have developed a generic method, CETSA i.e. Cellular Thermal Shift Assay to monitor direct biophysical interaction of a drug with the target protein/s in cells and tissues. CETSA is based on the biophysical principle of ligand-induced thermal stabilization of proteins. By coupling CETSA with quantitative Mass Spectrometry, proteome-wide CETSA (MS-CETSA) has been established, which allows off-target effects as well as downstream effects to be discovered. We have used MS-CETSA for target deconvolution of several drugs in different stages of drug discovery. These include some FDA approved drugs as well as some phenotypic screening hits. In addition to being able to quickly confirm known targets for some of these drugs (which initially took years to discover), we also uncovered some interesting novel binding partners for others. The presentation will give an overview of these studies emphasizing that CETSA is a valuable tool for biomedical research and drug development.