DPP4/CD26 Polyclonal antibody

DPP4 (also known as CD26) is a serine exopeptidase that cleaves X-proline dipeptides from the N terminus of polypeptides. It is an intrinsic membrane glycoprotein anchored into the cell membrane by its N-terminal end. High levels of the enzyme are found in the brush-border membranes of the kidney proximal tubule and of the small intestine, but several other tissues also express the enzyme. The enzyme is present in the fetal colon but disappears at birth. It is ectopically expressed in some human colon adenocarcinomas and human colon cancer cell lines(PMID:1977364).The dimeric 150- 220 kDa DPPIV has been reported to be active and accessible to DFP labeling, but the 110 kDa monomeric DPPIV is not(PMID:9065413). Sometimes traces of the 290 kDa active dimeric form of DPP IV as well as a 55-60 kDa protein appeared in the immunopurified DPP IV preparation. N-terminal amino acid sequence analysis revealed that the 55-60 kDa protein represents a fragment of DPP IV starting at amino acid 28.(PMID:9654125).