Human CD26 (DDP4) Antibody from BIOLEGEND

Dipeptidyl peptidase IV (DPP4) is a multifunctional type II transmembrane serine peptidase. It is also known as a cell surface glycoprotein receptor, CD26, involved in the co-stimulatory signal essential for T-cell receptor (TCR)-mediated T-cell activation. It acts as a positive regulator of T-cell co-activation, by binding at least ADA, CAV1, IGF2R, and PTPRC. DPP4 is widely expressed in many specialized cell types and has distinct functions independently of its form, anchored to the membrane or in soluble form. The soluble form of DPP4 appears to be derived primarily from endothelial cells, epithelial cells, and leukocytes. It is upregulated in proinflammatory states including obesity, type-2 diabetes mellitus, and atherosclerosis. DPP4 is a serine aminopeptidase that cleaves preferentially Xaa–Pro dipeptides from oligopeptides with typical length of 30 amino acid, but tolerates other small residues at P1-position. Its biological substrates include many chemokines, mitogenic growth factors, neuropeptides and peptide hormones. Thus, it regulates various physiological processes by cleaving peptides in the circulation on the cell surface. It has been discovered that DPP4 may be a receptor for receptor binding domain (RBD) of spike entry glycoprotein in Middle East respiratory syndrome coronavirus (MERS-CoV).