DPP-4 is a catalytic glycoprotein which releases a dipeptide from oligopeptides by cleaving the peptides between the second and the third amino acids from the N-terminal end provided that the second amino acid is alanine or proline. DPP-4 (or CD26 as it is also called) was later demonstrated to be expressed in several cell types, such as hepatocytes, glomerular cells, kidney tubular cells and endothelial cells as well as in islet endocrine cells. DPP-4 is a protein which consists of 766 amino acids. DPP-4 is a functional unit consisting of two identical DPP-4 proteins attached to each other forming a dimer. The organization of the dimer is such that the catalytic sites of the two DPP-4 molecules are located in close proximity to each other. Together the two catalytic sites form a pocket which has a high catalytic activity.


1.Ahrén B. Front Endocrinol (Lausanne). 2019 Jun 19;10:376.