Diprotin A is widely used in biochemical research as a selective inhibitor of dipeptidyl peptidase IV (DPP-IV). This enzyme plays a crucial role in the regulation of peptide hormones, including incretins, which are involved in glucose metabolism. By inhibiting DPP-IV, Diprotin A helps in studying the mechanisms of glucose homeostasis and the potential treatment of type 2 diabetes. Additionally, it is utilized in the development of assays to screen for new DPP-IV inhibitors, which are of significant interest in pharmaceutical research for diabetes management. Its application extends to the investigation of immune system modulation, as DPP-IV is also implicated in T-cell activation and immune response.