Inactivation of C3a and C5a octapeptides by carboxypeptidase R and carboxypeptidase N

Microbiol Immunol. 2002;46(2):131-4. doi: 10.1111/j.1348-0421.2002.tb02669.x.


Pro-carboxypeptidase R (proCPR), also known as thrombin-activatable fibrinolysis inhibitor (TAFI), precursor of carboxypeptidase U and plasma carboxypeptidase B is present in plasma and following activation by thrombin/thrombomodulin and/or plasmin can remove arginine from the carboxyterminal of C3a and C5a. We have shown that this enzyme can remove terminal arginine from the C5a octapeptide much more efficiently than the classical anaphylatoxin inactivator, carboxypeptidase N (CPN). Since we have previously demonstrated that proCPR is significantly upregulated in the inflammatory state, this enzyme would appear to significantly contribute to the inactivation of C5a, the most potent of the complement derived anaphylatoxins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carboxypeptidase B2 / blood
  • Carboxypeptidase B2 / pharmacology*
  • Complement C3a / antagonists & inhibitors*
  • Complement C5a / antagonists & inhibitors*
  • Humans
  • Hydrolysis
  • Lysine Carboxypeptidase / blood
  • Lysine Carboxypeptidase / pharmacology*
  • Time Factors


  • Complement C3a
  • Complement C5a
  • Carboxypeptidase B2
  • Lysine Carboxypeptidase