The unique properties of dipeptidyl-peptidase IV (DPP IV/CD26) and the therapeutic potential of DPP IV inhibitors

This review deals with the properties and functions of dipeptidyl peptidase IV (DPP IV, EC 3.4.14.5). This membrane anchored ecto-protease has been id entified as the leukocyte antigen CD26. The following aspects of DPP IV/CD2 6 will be discussed : the structure of DPP IV and the new family of serine proteases to which it belongs, the substrate specificity, the distribution in the human body, specific DPP IV inhibitors and the role of CD26 in the i ntestinal and renal handling of proline containing peptides, in cell adhesi on, in peptide metabolism, in the immune system and in HIV infection. Espec ially the latest developments in the search for new inhibitors will be repo rted as well as the discovery of new natural substrates for DPP IV such as the glucagon-like peptides and the chemokines. Finally the therapeutical pe rspectives for DPP IV inhibitors will be discussed.