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

The role of proteolytic enzymes in the hCG-induced increase in testicular vasopermeability and neutrophil extravasation was studied using protease inhibitors. An intra-testicular injection of hCG together with incubation medium conditioned by polymorphonuclear leucocytes (PMNs) caused a significant increase in vasopermeability and a coincident extravasation of PMN's from the postcapillary venules in the rat testis. When p-aminobenzamidine, a serine protease inhibitor which inhibits urokinase-type plasminogen activator, was administered together with hCG in the incubation medium, both the permeability increase and PMN extravasation were prevented. Aprotinin, another serine protease inhibitor, and Eglin C, a specific neutrophil elastase and cathepsin G inhibitor were, however, without effect. None of these inhibitors caused any non-specific vascular effects in the testis at the concentrations used. These results support the concept that the hCG-induced increase in vasopermeability in the rat testis is related to extravasation of PMNs and suggest that urokinase-type plasminogen activator is involved in migration of these cells through the postcapillary venular walls.
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PMID:Plasminogen activator is involved in the hCG-induced neutrophil extravasation and vasopermeability increase in the rat testis. 169 41

Leukocyte elastase and leukocyte cathepsin G degrade porcine plasminogen primarily by hydrolysis of the A447-I448 bond between kringle4 and kringle5. The rate of formation of des-kringle1-4-plasminogen is faster with elastase (k"obs greater than 10(5) mol-1 s-1) than with cathepsin G (kobs less than 300 mol-1 s-1). In contrast to elastase, leukocyte cathepsin G does not inactivate alpha 2-antiplasmin. Consequently, plasminogen activation by urokinase in the presence of alpha 2-antiplasmin is elastase-dependent, but cathepsin G does not overcome the action of alpha 2-antiplasmin. The rate-enhancing effect of fibrin(ogen) fragments in plasminogen activation by tissue-type plasminogen activator is also disabled efficiently by these proteases. It is concluded that enhancement of plasmin expression by neutrophil proteases is accounted for primarily by the action of elastase.
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PMID:Neutrophil proteases in plasminogen activation. 171 63

The [Arg15,Glu52]aprotinin gene has been constructed from a synthetic [Glu52]-aprotinin gene via an exchange of the appropriate DNA cassette. The gene has been fused to the N-terminal part of the bacteriophage MS-2 polymerase and expressed in a temperature inducible E. coli expression system. The produced fusion protein is deposited as inclusion bodies. Pure and functionally active [Arg15,Glu52]aprotinin has been obtained after cleavage of the purified fusion protein and renaturation of the aprotinin homologue. Recombinant [Arg15,Glu52]aprotinin shows good inhibition of human anionic and cationic trypsin (Ki less than or equal to 10(-11)M) and of human plasma kallikrein (Ki = 3.2 x 10(-10)M). The inhibition constants for human plasmin are Ki = 1.3 x 10(-10)M and for human urinary kallikrein Ki = 10(-11)M. No inhibition was found with the human proteinases thrombin, coagulation factor Xa, urokinase, tissue plasminogen activator, cathepsin G, leukocyte elastase and pancreatic elastase.
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PMID:Expression, isolation and characterization of recombinant [Arg15,Glu52]aprotinin. 246 33

Human lumbar disc tissue when extracted with 4M GuHCl and subjected to dissociative CsCl density gradient ultracentrifugation yielded trypsin inhibitor activity in the low bouyant density fractions (rho less than or equal to 1.38 g/ml). Disc proteoglycans sedimented in the high bouyant density fractions (rho greater than or equal to 1.5 g/ml). Sephadex G75F gel filtration of the low bouyant density protein fractions afforded a major low molecular weight (Kav = 0.5) trypsin inhibitor pool which was further purified by trypsin affinity chromatography. This latter step facilitated separation of the trypsin inhibitors from neutral proteinase activity also present. The trypsin inhibitor fraction so isolated was shown to possess potent inhibitory activity against a range of human serine proteinases including leukocyte elastase and cathepsin G, urokinase, kallikrein, plasmin and thrombin. Significantly this serine proteinase inhibitor preparation effectively prevented degradation of proteoglycans by a neutral proteinase also isolated from the human intervertebral disc.
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PMID:Low molecular weight serine proteinase inhibitors of the human intervertebral disc. 348 24

125I-labeled heparin cofactor II (HCII) was mixed with plasma and coagulation was initiated by addition of CaCl2, phospholipids, and kaolin or tissue factor. In the presence of 67 micrograms/ml of dermatan sulfate, radioactivity was detected in a band which corresponded to the thrombin-HCII complex (Mr = 96,000) upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. No other complexes were observed. The thrombin-HCII complex was undetectable when 5 units/ml of heparin was present or when prothrombin-deficient plasma was used. In experiments with purified proteases, HCII did not significantly inhibit coagulation factors VIIa, IXa, Xa, XIa, XIIa, kallikrein, activated protein C, plasmin, urokinase, tissue plasminogen activator, leukocyte elastase, the gamma-subunit of nerve growth factor, and the epidermal growth factor-binding protein. HCII inhibited leukocyte cathepsin G slowly, with a rate constant of 8 X 10(4) M-1 min-1 in the presence of dermatan sulfate. These results indicate that the protease specificity of HCII is more restricted than that of other plasma protease inhibitors and suggest that the anticoagulant effect of dermatan sulfate is due solely to inhibition of thrombin by HCII.
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PMID:The protease specificity of heparin cofactor II. Inhibition of thrombin generated during coagulation. 383 15

The correlation between activation of macrophages and increased secretion of plasminogen activator suggests that macrophages are exposed to the protease plasmin. Incubation of 125I-labeled, caseinate-elicited guinea pig peritoneal macrophages with plasmin cleaves a surface protein, gp160, characterized previously by its sensitivity to trypsin. The gp160 fragments produced by plasmin (fr85 and fr71), which remain disulfide-bonded in the membrane, comigrate with the fragments produced by trypsin, indicating close or identical cleavage sites. No other detectable 125I-labeled surface component is cleaved by plasmin. Neither gp160 nor any other detectable 125I-labeled surface component was cleaved by a series of other proteases associated with inflammation including thrombin, collagenase, pancreatic elastase, leukocyte elastase, cathepsin G, and urokinase. Analysis with the use of homogeneous plasmin from guinea pig plasma shows that concentrations as low as 50 micrograms/ml cause measurable cleavage of gp160 in 30 min.
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PMID:Macrophage surface component gp160: sensitivity to plasmin and other proteases. 646 Aug 5

The human intracellular serine proteinase inhibitor, proteinase inhibitor 6 (PI-6), was expressed in the methylotropic yeast Pichia pastoris. The PI-6 cDNA was modified to encode six histidine residues immediately after the initiation codon, and was placed under the control of the P. pastoris alcohol oxidase promoter in the vector pHIL-D2. On the methanol induction, active recombinant PI-6 was produced within the yeast cells, and following cell lysis, was separated from yeast proteins by affinity chromatography using nickel nitrilo-tri-acetic acid (NTA) resin. The interaction of recombinant PI-6 with a range of serine proteinases was studied. Second order association rate constants (ka) were derived for the interaction with trypsin (1.8 x 10(6) M-1 s-1), thrombin (1.2 x 10(5) M-1 s-1), urokinase plasminogen activator (4.0 x 10(4) M-1 s-1), plasmin (1.3 x 10(6) M-1 s-1), and activated protein C (7.5 x 10(3) M-1 s-1). By monitoring complex formation, recombinant PI-6 was also shown to interact with factor Xa. No complex formation was observed with chymotrypsin, human leukocyte elastase, cathepsin G and tissue plasminogen activator, although PI-6 is apparently a substrate for chymotrypsin, leukocyte elastase and cathepsin G.
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PMID:Production and characterization of recombinant human proteinase inhibitor 6 expressed in Pichia pastoris. 754 63

Binding of urokinase to the glycolipid-anchored urokinase receptor (uPAR) has been implicated in macrophage differentiation. However, no biochemical markers of differentiation have yet been directly linked to uPAR occupancy. As extensive changes in proteolytic profile characterize monocytic differentiation, we have examined the role of uPAR occupancy on protease expression by differentiating phagocytes. Antibodies to either urokinase or to uPAR that prevent receptor binding inhibited induction of cathepsin B in cultured monocytes and both cathepsin B and 92-kD gelatinase mRNA and protein in phorbol diester-stimulated myeloid cells. Mannosamine, an inhibitor of glycolipid anchor assembly, also blocked protease expression. Anti-catalytic urokinase antibodies, excess inactive urokinase, or aprotinin had no effect, indicating that receptor occupancy per se regulated protease expression. Antibodies to the integrins CD11a and CD29 or to the glycolipid-anchored proteins CD14 and CD55 also had no effect. Protease induction was independent of matrix attachment. Antibodies to urokinase or uPAR affected neither the decrease in cathepsin G nor the increase in tumor necrosis factor-alpha in phorbol ester-stimulated cells. These data establish that uPAR is a multifunctional receptor, not only promoting pericellular proteolysis and matrix attachment, but also effecting cysteine- and metallo-protease expression during macrophage differentiation.
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PMID:Urokinase receptor is a multifunctional protein: influence of receptor occupancy on macrophage gene expression. 761 19

Human monocyte/neutrophil elastase inhibitor (HEI) is a serpin superfamily protein that rapidly and irreversibly inhibits neutrophil and pancreatic elastase. We generated a recombinant baculovirus that supports production of HEI in insect cells at approximately 400 times the level in monocytes. Recombinant HEI was found to be indistinguishable from monocyte HEI in its physicochemical properties and ability to inhibit neutrophil elastase and pancreatic elastase. The recombinant protein was used to test for additional functions. HEI was shown to inhibit proteinase 3, an important neutrophil inflammatory protease, by the classical serpin mechanism of forming a covalent protease-protease inhibitor complex. Preliminary evidence suggests that HEI also inhibits neutrophil cathepsin G. On the other hand, HEI does not inhibit u-plasminogen activator (urokinase). These findings suggest that HEI functions as a class-specific regulator of the neutrophil serine proteases characteristically found at inflammatory sites.
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PMID:Inhibitory properties of recombinant human monocyte/neutrophil elastase inhibitor. 765 87

Z-D-Phe-Pro-boroMpg-OPin (9a)1,2 has been shown previously to be a highly specific inhibitor of thrombin in spite of lacking an arginine-like guanidino group at the P1 site. A range of compounds have been synthesized based upon this lead compound, varying the neutral side chain at the P1 site. Of the 20 examples based upon the structures at P2 and P3 of Z-D-X-Pro (X being Phe or beta,beta-diphenylalanine), all were found to be effective inhibitors of thrombin (Ki's between 10 and 100 nM). Furthermore all exhibited a high specificity toward thrombin having values for a Ki(trypsin)/Ki(thrombin) ratio of between 10- and 100-fold. High ratio values were found for a number of the compounds tested against a range of serine proteinases (plasmin, factor Xa, kallikrein, urokinase, protein Ca, chymotrypsin, elastase, and cathepsin G). As far as potency toward thrombin, compounds containing the methoxypropyl group at P1 were favored over those with a methoxy grouping on a shorter alkyl chain (8) or without the methoxy group (1-5). The compounds display potent anticoagulant activity with values for 18 in thrombin time of 0.63 microM and in activated partial thromboplastin time of 2.0 microM. 11B NMR has been used to confirm interaction of the boron atom with the active site. From the high specificity shown with all the compounds we propose that the compounds, constitute a new class of thrombin inhibitors.
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PMID:Characterization of a class of peptide boronates with neutral P1 side chains as highly selective inhibitors of thrombin. 773 10


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