Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We isolated a novel protease that converts plasminogen to angiostatin-like fragments (BL-angiostatins) from a culture of Bacillus megaterium A9542 through a single-step chromatography on CM-cellulose. The protease, designated bacillolysin MA (BL-MA), belongs to a family of neutral metalloproteinases based on the nucleotide sequence of its gene. At an enzyme:substrate ratio of 1:540, BL-MA cleaved human plasminogen mainly at Ser441-Val442 to form BL-angiostatin and miniplasminogen with a K(m) of 3.0 +/- 0.8 microM and a k(cat) of 0.70 +/- 0.09 s(-1). The resulting BL-angiostatins inhibited the proliferation, migration, and tube formation of vascular endothelial cells at concentrations of 1-10 microg/ml. Although BL-MA failed to activate plasminogen, it increased urokinase-catalyzed activation of plasminogen caused by production of miniplasminogen, which is highly susceptible to activation. In addition, BL-MA was active in converting prourokinase, prothrombin, coagulation factor X, and protein C to their active forms. BL-MA enhanced both the clotting of human plasma and clot dissolution in the presence of prourokinase. Thus, BL-MA affects blood coagulation and fibrinolysis systems and can be used to produce angiostatin-like plasminogen fragments and active serine proteases of human plasma.
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PMID:Bacillolysin MA, a novel bacterial metalloproteinase that produces angiostatin-like fragments from plasminogen and activates protease zymogens in the coagulation and fibrinolysis systems. 1567 46

Modification of the tumor microenvironment by inflammatory cells represents a newly recognized driving force in cancer with critical roles in tumor invasion, growth, angiogenesis, and metastasis. Increased thrombolytic cascade serine proteases, specifically urokinase-type plasminogen activator and its receptor, correlate with inflammatory cell migration, pancreatic cancer growth, invasion and unfavorable outcomes. Inflammation in pancreatic cancer is linked with myeloid-derived suppressor cell (MDSC) activity and cancer progression. Myxomavirus is a complex DNA virus encoding highly potent immune modulators. Serp-1 and M-T7 are two such secreted anti-inflammatory myxomaviral proteins. Serp-1 inhibits uPA, plasmin and coagulation factor X while M-T7 inhibits C, CC, and CXC chemokines. We have explored the potential use of these viral proteins for treatment of a range of human cancer isolates engrafted in severe combined immunodeficient (SCID) mice. Engrafted tumors were treated with either Serp-1, neuroserpin, a related mammalian serpin that inhibits thrombolytic proteases, or M-T7. Serp-1 and neuroserpin inhibited growth of the pancreatic cancer cell line Hs766t (P=0.03 and P=0.01, respectively) at 4 weeks after implantation. Serp-1 also inhibited growth of a second pancreatic cancer cell line MIA PaCa-2 in mice (P=0.02). Growth of the human breast cancer line MDA231 was not inhibited by Serp-1. M-T7, in contrast, did not alter growth of any of the cancer cell lines tested after implant into SCID mice. Serpin inhibition of pancreatic tumor growth was associated with a significant decrease in splenocyte MDSC counts by flow cytometry (P=0.009), without detected change in other splenocyte subpopulations. Serp-1 and NSP treatment also significantly reduced macrophage infiltration in tumors (P=0.001). In summary two anti-inflammatory serpins reduced inflammatory macrophage invasion and pancreatic tumor cell growth, suggesting potential therapeutic efficacy.
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PMID:Myxomaviral Anti-Inflammatory Serpin Reduces Myeloid-Derived Suppressor Cells and Human Pancreatic Cancer Cell Growth in Mice. 2579 14