IUBMB Enzyme Nomenclature


Accepted name: carboxypeptidase U

Reaction: Release of C-terminal Arg and Lys from a polypeptide

Other names: arginine carboxypeptidase; carboxypeptidase R; plasma carboxypeptidase B (misleading, since the term carboxypeptidase B is used for other enzymes); thrombin-activatable fibrinolysis inhibitor

Comments: Pro-carboxypeptidase U in (human) plasma is activated by thrombin or plasmin during clotting to form the unstable carboxypeptidase U, with activity similar to that of the more stable lysine carboxypeptidase, except that no preference is shown for Lys over Arg. A zinc enzyme, In peptidase family M14 (carboxypeptidase A family)

Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, CAS registry number: 156621-18-0


1. Eaton, D.L., Malloy, B.E., Tsai, S.P., Henzel, W. and Drayna, D. Isolation, molecular cloning, and partial characterization of a novel carboxypeptidase B from human plasma. J. Biol. Chem. 266 (1991) 21833-21838. [PMID: 1939207]

2. Shinohara, T., Sakurada, C., Suzuki, T., Takeuchi, O., Campbell, W., Ikeda, S., Okada, N. and Okada, H. Pro-carboxypeptidase R cleaves bradykinin following activation. Int. Arch. Allergy Immunol. 103 (1994) 400-404. [PMID: 8130654]

3. Wang, W., Hendriks, D.F. and Scharpé, S. Carboxypeptidase U, a plasma carboxypeptidase with high affinity for plasminogen. J. Biol. Chem. 269 (1994) 15937-15944. [PMID: 8195249]

4. Tan, A.K. and Eaton, D.L. Activation and characterization of procarboxypeptidase B from human plasma. Biochemistry 34 (1995) 5811-5816. [PMID: 7727441]

5. Broze, G.J., Jr. and Higuchi, D.A. Coagulation-dependent inhibition of fibrinolysis: Role of carboxypeptidase U and the premature lysis of clots from hemophilic plasma. Blood 88 (1996) 3815-3823. [PMID: 8916945]

[EC created 1997]

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