Urokinase (Abbokinase), also called urokinase-type Plasminogen Activator (uPA), is a serine protease (EC 3.4.21.73). Urokinase is a two-chain glycoprotein containing 411aa with 12 dissulfide bonds. Its molecular weight is 54kD. Urokinase is synthesized as a zymogen form (prourokinase or single chain urokinase), and is activated by proteolytic cleavage between L158 and I159. The two resulting chains are kept together by a disulfide bond. Urokinase is a secreted protein. Expressed in the prostate gland and prostate cancers. Post-translational modification Phosphorylation of Ser-158 and Ser-323 abolishes proadhesive ability but does not interfere with receptor binding. Urokinase was originally isolated from human urine, but is present in several physiological locations, such as blood stream and the extracellular matrix. The primary physiological substrate is plasminogen, which is an inactive zymogen form of the serine protease plasmin. Activation of plasmin triggers a proteolysis cascade which, depending on the physiological environment participates in thrombolysis or extracellular matrix degradation. This links urokinase to vascular diseases and cancer. The most important inhibitors of urokinase are the serpins plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2), which inhibits the protease activity irreversibly. In the extracellular matrix urokinase is tethered to the cell membrane by its interaction to the urokinase receptor.
Elevated expression levels of urokinase and several other components of the plasminogen activation system are found to be correlated with tumor malignancy. It is believed that the tissue degradation following plasminogen activation, facilitates tissue invasion and thus contributes to metastasis. This makes urokinase an attractive drug target and inhibitors have been sought to be used as anticancer agents. However incompatibilities between the human and mouse system hampers clinical evaluation of these agents. Through its interaction with the urokinase receptor, urokinase affects several other aspects of cancer biology such as cells adhesion, migration and cellular mitotic pathways.
Source:Urokinase, from human urine
Activity:~1nM UK will cause a change in absorbance of 0.001 at 405nm in 1 minute at RT in 100ul 0.05M Tris-HCl, 0.1M NaCl, pH 7.4, using S2444 (0.6mM) as the substrate.
Specific Activity:~68,000 IU/mg
Contaminants:Free of: Hepatitis B surface antigen, Hepatitis C antibody and HIV I and II.
Storage and Stability:Lyophilized powder may be stored at -20°C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
仕様
Size：100ug
Source Antigen：Human urine
Grade：Highly Purified
Purity：Highly Purified (~95%)
Form：Supplied as a lyophilized powder. No preservative added. Reconstitute with sterile ddH2O >100ug/ml.
