High-Throughput\nScreening of DPPIV Inhibitors Antagonizing\nGLP‑1 Degradation Using an Enzymatic Activated Fluorescent\nProbe

Dipeptidyl peptidase IV (DPPIV, EC 3.4.14.5) is an exopeptidase\nwidely expressed on various cell surfaces that selectively cleaves\nN-terminal dipeptides from diverse substrates. In recent years, DPPIV\ninhibitors have been extensively utilized in the treatment of hepatitis\nmellitus (DM). In this study, we designed a far-red fluorescent probe, <b>DBX-AP</b>, through molecular docking simulations and by leveraging\nthe functional characteristics of DPPIV. This probe enables rapid,\nhighly selective, and real-time monitoring of DPPIV activity both\nin vitro and in vivo. Using <b>DBX-AP</b>, we developed a visual\nhigh-throughput screening technique for the detection of DPPIV inhibitors.\nFrom a library of 4828 compounds, three inhibitors (K784-2660, 6484-0066,\nand E699-0153) were identified for their strong inhibitory effects\non DPPIV. These inhibitors not only suppressed DPPIV activity in the\nileum of mice, thereby reducing GLP-1 degradation, but also effectively\ninhibited DPPIV activity in gut microbiota. The successful application\nof <b>DBX-AP</b> in visual detection technology highlights its\npotential for evaluating DPPIV activity and identifying novel DPPIV\ninhibitors for diabetes mellitus treatment.