Insights of affinity-based probes for target identification in drug discovery

Identifying molecular targets of physiologically active organic compounds remains a major challenge in contemporary biomedical research and drug discovery. In recent years, the development of activity-based protein profiling (ABPP) techniques has proven to be superior to classical molecular target identification methods. ABPP can be classified into activity-based probes (AcBPs) and affinity-based probes (AfBPs). AfBPs bind to target proteins through reversible non-covalent interactions, thus minimizing the impact on the natural biological functions of the protein. The development of AfBPs has great potential for studying drug targets, optimizing drugs, and improving therapeutic efficacy. As a result, there has been a dramatic increase in research and development focused on affinity probes with the use of a wide range of AfBPs such as biotin probes, FITC probes, BRET probes, and radiolabeled probes. This tutorial describes the process of designing and synthesizing different types of AfBPs from biologically active compounds, and then utilizing the probes to identify the target proteins. It also provides insights for subsequent drug discovery and development.