Dipeptidyl peptidase

Function

Dipeptidyl peptidase (DPP) is an enzyme which cleaves dipeptides from polypeptides.

• DPP-I or cathepsin C is involved in inflammatory diseases.
  
• DPP-II is a serine protease.
  
• DPP-III acts similarly to DPP-IV.
  
• DPP-IV (or CD26) cleaves proline dipeptides from the N-termini and is associated with immune regulation. For details see: Dipeptidyl peptidase IV and Dipeptidyl Peptidase-4 Inhibitor Pharmacokinetics.

Relevance

DPP-IV level is alternating in certain malignancies.^[1] DPP-IV inhibitors control body glucose levels and provide potential advantages in diabetes type 2 therapies.^[2]

Disease

DPP-IV is involved in the development of various chronic liver disease like hepatitis C virus infection.^[3]

Structural highlights

Human DPP-I contains 3 chains. Light and heavy chains forming the catalytic site and a third chain including the exclusion domain which is responsible of the exopeptidase activity of DPP-I by partially blocking the active site cleft. The inhibitors binds to a Cys residue at the active site. ^[4]