Thrombin-activable fibrinolysis inhibitor (TAFI) zymogen is an active carboxypeptidase

J Biol Chem. 2007 Feb 2;282(5):3066-76. doi: 10.1074/jbc.M606559200. Epub 2006 Nov 30.


Thrombin-activable fibrinolysis inhibitor (TAFI) is a carboxypeptidase found in human plasma, presumably as an inactive zymogen. The current dogma is that proteolytic activation by thrombin/thrombomodulin generates the active enzyme (TAFIa), which down-regulates fibrinolysis by removing C-terminal lysine residues from partially degraded fibrin. In this study, we have shown that the zymogen exhibits continuous and stable carboxypeptidase activity against large peptide substrates, and we suggest that the activity down-regulates fibrinolysis in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Carboxypeptidase B2 / blood
  • Carboxypeptidase B2 / isolation & purification
  • Carboxypeptidase B2 / metabolism*
  • Enzyme Activation
  • Enzyme Precursors / metabolism
  • Fibrinolysis
  • Homeostasis
  • Humans
  • Kinetics
  • Molecular Sequence Data
  • Peptide Fragments / chemical synthesis
  • Peptide Fragments / chemistry
  • Peptide Fragments / isolation & purification
  • Plasminogen / metabolism
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Substrate Specificity


  • Enzyme Precursors
  • Peptide Fragments
  • Plasminogen
  • Carboxypeptidase B2