Dipeptidyl Peptidase

Dipeptidyl Peptidases are widely distributed exopeptidases that possess central role in proteolysis. The dipeptidyl peptidase family, including DPP-IV DPP7, DPP8, DPP9, fibroblast activation protein and others, cleave the peptide bond after the penultimate proline residue and are drug target rich.

DPP-IV (DPP4 or CD26) is a serine protease detected on several immune cells and on epithelial cells of various organs. Besides the membrane-bound enzyme, a catalytically active soluble form is detected in several body fluids. Both variants cleave off dipeptides from the N-termini of various chemokines, neuropeptides, and hormones. DPP IV plays a key role in immune-regulation, inflammation, oxidative stress, cell adhesion, and apoptosis by targeting different substrates. DPP IV inhibitors are commonly used as hypoglycemic agents.

DPP8 and DPP9 show DPPIV-like activity and share a very high-sequence similarity to each other. DPP8 and DPP9 are intracellular N-terminal dipeptidyl peptidases (preferentially postproline) associated with pathophysiological roles in immune response and cancer biology.