Cleaves C-terminal arginine or lysine residues from biologically active peptides such as kinins or anaphylatoxins in the circulation thereby regulating their activities. Down-regulates fibrinolysis by removing C-terminal lysine residues from fibrin that has already been partially degraded by plasmin. Release of C-terminal Arg and Lys from a polypeptide. Binds 1 zinc ion per subunit. TAFI/CPB2 is unique among carboxypeptidases in that it spontaneously inactivates with a short half-life, a property that is crucial for its role in controlling blood clot lysis. The zymogen is stabilized by interactions with the activation peptide. Release of the activation peptide increases a dynamic flap mobility and in time this leads to conformational changes that disrupt the catalytic site and expose a cryptic thrombin-cleavage site present at Arg-324. Plasma; synthesized in the liver. N-glycosylated. N-glycan at Asn-108: Hex5HexNAc4. Belongs to the peptidase M14 family.