Carboxypeptidase U | |||||||||
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Identifiers | |||||||||
EC no. | 3.4.17.20 | ||||||||
CAS no. | 156621-18-0 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
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Carboxypeptidase U (EC 3.4.17.20, arginine carboxypeptidase, carboxypeptidase R, plasma carboxypeptidase B, thrombin-activatable fibrinolysis inhibitor) is an enzyme. [1] [2] [3] [4] [5] This enzyme catalyses the following chemical reaction
Pro-carboxypeptidase U in (human) plasma is activated by thrombin or plasmin during clotting to form the unstable carboxypeptidase U.
Thrombin is a serine protease, an enzyme that, in humans, is encoded by the F2 gene. Prothrombin is proteolytically cleaved to form thrombin in the clotting process. Thrombin in turn acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, as well as catalyzing many other coagulation-related reactions.
Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. Primary fibrinolysis is a normal body process, while secondary fibrinolysis is the breakdown of clots due to a medicine, a medical disorder, or some other cause.
Coagulation factor XII, also known as Hageman factor, is a plasma protein. It is the zymogen form of factor XIIa, an enzyme of the serine protease class. In humans, factor XII is encoded by the F12 gene.
Plasmin is an important enzyme present in blood that degrades many blood plasma proteins, including fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein is encoded by the PLG gene.
Protein C, also known as autoprothrombin IIA and blood coagulation factor XIX, is a zymogen, that is, an inactive enzyme. The activated form plays an important role in regulating anticoagulation, inflammation, and cell death and maintaining the permeability of blood vessel walls in humans and other animals. Activated protein C (APC) performs these operations primarily by proteolytically inactivating proteins Factor Va and Factor VIIIa. APC is classified as a serine protease since it contains a residue of serine in its active site. In humans, protein C is encoded by the PROC gene, which is found on chromosome 2.
Alpha 2-antiplasmin is a serine protease inhibitor (serpin) responsible for inactivating plasmin. Plasmin is an important enzyme that participates in fibrinolysis and degradation of various other proteins. This protein is encoded by the SERPINF2 gene.
Factor X, also known by the eponym Stuart–Prower factor, is an enzyme of the coagulation cascade. It is a serine endopeptidase. Factor X is synthesized in the liver and requires vitamin K for its synthesis.
Factor V is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor. Deficiency leads to predisposition for hemorrhage, while some mutations predispose for thrombosis.
Factor XI or plasma thromboplastin antecedent is the zymogen form of factor XIa, one of the enzymes of the coagulation cascade. Like many other coagulation factors, it is a serine protease. In humans, Factor XI is encoded by the F11 gene.
Plasminogen activator inhibitor-1 (PAI-1) also known as endothelial plasminogen activator inhibitor is a protein that in humans is encoded by the SERPINE1 gene. Elevated PAI-1 is a risk factor for thrombosis and atherosclerosis.
Plasminogen activators are serine proteases that catalyze the activation of plasmin via proteolytic cleavage of its zymogen form plasminogen. Plasmin is an important factor in fibrinolysis, the breakdown of fibrin polymers formed during blood clotting. There are two main plasminogen activators: urokinase (uPA) and tissue plasminogen activator (tPA). Tissue plasminogen activators are used to treat medical conditions related to blood clotting including embolic or thrombotic stroke, myocardial infarction, and pulmonary embolism.
Thrombomodulin (TM), CD141 or BDCA-3 is an integral membrane protein expressed on the surface of endothelial cells and serves as a cofactor for thrombin. It reduces blood coagulation by converting thrombin to an anticoagulant enzyme from a procoagulant enzyme. Thrombomodulin is also expressed on human mesothelial cell, monocyte and a dendritic cell subset.
A carboxypeptidase is a protease enzyme that hydrolyzes (cleaves) a peptide bond at the carboxy-terminal (C-terminal) end of a protein or peptide. This is in contrast to an aminopeptidases, which cleave peptide bonds at the N-terminus of proteins. Humans, animals, bacteria and plants contain several types of carboxypeptidases that have diverse functions ranging from catabolism to protein maturation. At least two mechanisms have been discussed.
Plasma kallikrein is an enzyme. This enzyme catalyses the following chemical reaction
Kininogens are precursor proteins for kinins, biologically active polypeptides involved in blood coagulation, vasodilation, smooth muscle contraction, inflammatory regulation, and the regulation of the cardiovascular and renal systems.
Protein C inhibitor is a serine protease inhibitor (serpin) that limits the activity of protein C.
Carboxypeptidase B2 (CPB2), also known as carboxypeptidase U (CPU), plasma carboxypeptidase B (pCPB) or thrombin-activatable fibrinolysis inhibitor (TAFI), is an enzyme that, in humans, is encoded by the gene CPB2.
Potato carboxypeptidase inhibitor (PCI) is a naturally occurring protease inhibitor peptide in potatoes that can form complexes with several metallo-carboxypeptidases, inhibiting them in a strong competitive way with a Ki in the nanomolar range.
PCI consists of 39 amino acids forming a 27-residue globular core stabilized by three disulfide bridges and a C-terminal tail with residues 35–39. PCI contains a small cysteine-rich module, called a T-knot scaffold, that is shared by several different protein families, including the EGF family.
Carboxypeptidase A6 (CPA6) is a metallocarboxypeptidase enzyme that in humans is encoded by the CPA6 gene. It is highly expressed in the adult mouse olfactory bulb and is broadly expressed in the embryonic brain and other tissues.
Aureolysin is an extracellular metalloprotease expressed by Staphylococcus aureus. This protease is a major contributor to the bacterium's virulence, or ability to cause disease, by cleaving host factors of the innate immune system as well as regulating S. aureus secreted toxins and cell wall proteins. To catalyze its enzymatic activities, aureolysin requires zinc and calcium which it obtains from the extracellular environment within the host.