General description

C-terminal histidine-tagged. Soluble form (residues 29-766) MW 105 kDa

Other Notes

View more information on Dipeptidyl Peptidase IV at www.sigma-aldrich.com/enzymeexplorer.

Unit Definition

One unit will produce 1.0 μmole of p-nitroaniline from Gly- L -Pro p-nitroanilide per min in 100 mM Tris-HCl at pH 7.6 at 37 °C.

Physical form

Supplied as a solution in 10 mM Tris-HCl, pH 7.6, 200 mM NaCl, 1 mM EDTA and 10% glycerol.

Application

Human dipeptidyl peptidase IV has been used to study interactive hemodynamic effects of its inhibition and angiotensin-converting enzyme inhibition in humans. Human dipeptidyl peptidase IV has also been used in a study that informed the understanding of Hymenoptera venom allergies.

The enzyme from Sigma has been used to study the LC-MS (liquid chromatography-mass spectrometry) based assay method for DPP-IV inhibitor screening and substrate discovery.

Biochem/physiol Actions

DPPIV has a post-proline dipeptidyl aminopeptidase activity that hydrolyzes N-terminal dipeptides from the unsubstituted N-terminus of peptides with the sequence of X-Pro-Z and X-Ala-Z. The optimum pH is found to be 7.4-8.7. DPPIV is involved in the regulation of several important physiological processes such as immune functions, inflammation, CNS, endocrine functions, bone marrow mobilization, cancer growth, cell adhesion, glucose hemostasis and sepsis/severe infection.

Native DPPIV is a ubiquitous type II transmembrane glycoprotein and a serine protease of the S9 prolyl-oligopeptidase family. In vivo, it is synthesized with a signal peptide, which functions as the membrane anchoring domain. There is an 88% sequence homology between the human and porcine kidney enzymes. Both exist as homodimers with a subunit molecular weight of ~30 kDa. The high mannose 100 kDa DPPIV precursor is processed in the Golgi to yield a 124 kDa heavily N-and O-linked mature glycoprotein. It is then sorted to the apical membrane through the concerted action of both N- and O-linked glycans and its association with lipid microdomains. The porcine enzyme contains 18.3% carbohydrates, which the glycan composition is 0.9% fucose, 3.4% mannose, 5.1% galactose, 8.2% glucosamine, and 0.7% sialic acid. DPPIV is highly expressed on endothelial cells, epithelial cells, and lymphocytes. It is also present in plasma in its soluble form.