Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

In search of the target protease for the tumor-associated trypsin inhibitor TATI we recently identified a trypsin-like protease in cyst fluid of mucinous ovarian tumors (Stenman, U.-H., Koivunen, E., and Vuento, M. (1988) Biol. Chem. Hoppe-Seyler 369, 9-14). We have now purified this protease and demonstrate that it represents isoenzyme forms of trypsinogen, here called tumor-associated trypsin(ogen)s (TAT). The purification procedure comprised batchwise anion exchange chromatography, immunoaffinity chromatography with antibodies to trypsin, and separation of the two isoenzymes by reverse phase chromatography. In sodium dodecyl sulfate (SDS)-gel electrophoresis, the TAT-1 and TAT-2 isoenzymes have relative molecular weights (Mr) of 25,000 and 28,000, respectively, TAT-2 being the major component. The amino-terminal amino acid sequences correspond to those of pancreatic trypsinogen-1 and -2, respectively, and activation of the zymogens results in cleavage of a NH2-terminal activation peptide of 8 residues characteristic of trypsinogen. Isoelectric focusing in the presence of urea gives pI values of about 5 and 4 for TAT-1 and -2, respectively. The substrate specificities of the two TAT isoenzymes are very similar to, but not identical with, those of trypsin-1 and trypsin-2, respectively, suggesting slight differences in substrate binding site. TAT was found to be an efficient activator of pro-urokinase. Hence, TAT could take part in the protease cascade associated with tumor invasion.
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PMID:Human ovarian tumor-associated trypsin. Its purification and characterization from mucinous cyst fluid and identification as an activator of pro-urokinase. 250 10

The fibrinolytic (fibrin dissolving) properties of several anionic, cationic, nonionic and zwitterionic detergents were assessed in an in vitro fibrin agarose assay. Of the 4 anionic detergents tested, only sodium dodecyl sulfate (SDS) was found to be fibrinolytic. SDS was fibrinolytic either in the absence or presence of factor XIII. Four other cationic detergents were found to possess similar fibrinolytic properties. These cationic detergents were cetyltrimethylammonium bromide (CTAB), mix alkyltrimethyl ammonium bromide (MTAB), hexadecyltrimethylammonium bromide (HTAB) and cetylpyridium chloride (CPC). The nonionic (digitonin, triton X-100/tween 20) and zeitterionic (CHAPS, zeittergent 3-08) detergents were not fibrinolytic. Detergents mediated fibrinolysis, unlike that of tissue type plasminogen activator and urokinase, was independent of the presence of plasminogen. Non-detergents such as polyethylene glycol and highly charged compounds such as poly-1-lysine and poly-1-glutamic acid were not fibrinolytic. Fibrinolytic activity was observed for SDS and the cationic detergents at concentrations ranging from 0.1-10 percent. The effects of these fibrinolytic detergents (SDS, CTAB, MTAB, HTAB and CPC) on clot formation and on pre-formed clots were then assessed, using freshly drawn human venous blood. Incorporation of these detergents into blood inhibited the formation of clots in a concentration dependent manner. The detergents were also able to dissolve pre-formed clots in a similar fashion. SDS was found to be most potent in these properties.
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PMID:Fibrin solubilizing properties of certain anionic and cationic detergents. 251 Mar 56

The fibrinolytic enzyme profile of SMS-KAN human neuroblastoma cells was found to vary dramatically during the differentiation process. Five maturational agents--retinoic acid, dibutyryl cAMP, 5-bromodeoxyuridine, sodium butyrate and phorbol myristate acetate were tested for their effects on cellular morphology, DNA synthesis, plasminogen activator (PA) and PA inhibitor (PAI) activity. SMS-KAN cells secrete urokinase (UK) and tissue PA (tPA) as well as a possibly unique PAI. Treatment of cells with 1 microM RA resulted in an inhibition of proliferation, extension of neurite-like processes indicative of differentiation, as well as a switch from secretion of UK to tPA and a reduction in PAI secretion. Other agents which caused neural process formation and decreased cell proliferation also induced alterations in PA/PAI while agents which had no detectable effect on cell growth induced little change in the fibrinolytic enzyme profile.
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PMID:Alterations in plasminogen activator and inhibitor activity during the differentiation of a human neuroblastoma cell line, SMS-KAN. 253 81

Catalytic activity of tissue-type plasminogen activator (t-PA) in plasma is regulated in part by formation of complexes with specific inhibitors as well as by hepatic clearance. Potential interaction of these two regulatory mechanisms was examined in the human hepatoma cell line Hep G2. These cells secrete plasminogen activator inhibitor type-1 (PAI-1) and initiate catabolism of exogenous t-PA by receptor-mediated endocytosis. Specific binding of 125I-t-PA to cells at 4 degrees C results in dose-dependent formation of a 95-kDa species recognized by monospecific anti-PAI-1 and anti-t-PA antibodies and stable in the presence of low (0.2%) concentrations of sodium dodecyl sulfate (SDS). Specific binding of 125I-t-PA and formation of the 95-kDa SDS-stable species are inhibited in a concentration-dependent manner following preincubation of cells with anti-PAI-1 antibodies. High and low molecular weight forms of urokinase plasminogen activator (u-PA) capable of forming specific complexes with PAI-1 complete for 125I-t-PA binding sites. However, the proenzyme form of u-PA (scu-PA), incapable of forming complexes with PAI-1, does not compete for 125I-t-PA binding sites. The role of the serine protease active site of t-PA in mediating both interaction with PAI-1 and specific binding was examined using 125I-t-PA that had been functionally inactivated with D-phenylalanyl-L-propyl-L-arginyl-chloromethyl ketone (PPACK). 125I-t-PA-PPACK, despite a 6-fold lower affinity than active 125I-t-PA, exhibited specific binding to cells without detectable formation of SDS-stable complexes with PAI-1. Both surface-bound 125I-t-PA and 125I-t-PA-PPACK are internalized and degraded by cells at 37 degrees C. 125I-t-PA is internalized as a stable complex with PAI-1, whereas 125I-t-PA-PPACK is internalized with similar kinetics but without the presence of an SDS-stable complex. Thus, PAI-1 appears capable of modulating t-PA catabolism in the human hepatocyte.
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PMID:Catabolism of tissue-type plasminogen activator by the human hepatoma cell line Hep G2. Modulation by plasminogen activator inhibitor type 1. 254 Jan 81

Human blood monocytes in culture differentiate to macrophagelike cells within 1 week. Coinciding with this morphological transition the cells started releasing increasing amounts of the serine proteinase plasminogen activator (PA; Mr 56,000) of the urokinase (u-PA) type and the proteinase inhibitor alpha-2-macroglobulin (alpha 2M). Unlike the cell-associated PA activity, which was also readily detected in fresh monocytes, the activity secreted into the serum-free culture medium could be measured only after treatment of the samples with sodium dodecyl sulphate. Heat or acid treatment of the medium was not sufficient to reveal the PA activity, suggesting that, apart from alpha 2M, another PA-inhibiting substance was present in the culture medium. The inhibitor (Mr 65,000) was found to be synthesized by macrophages and specifically inhibited u-PA activity but not tissue-type PA (t-PA) or plasmin activity. Dexamethasone decreased the secretion of PA by differentiated macrophages without affecting the production of alpha 2M or the PA inhibitor. Dexamethasone also inhibited the morphological differentiation of the cells when added to the monocyte-phase cells.
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PMID:Urokinase-type plasminogen activator and its inhibitor secreted by cultured human monocyte-macrophages. 257 31

The relationship between plasminogen activator (PA)/plasminogen activator inhibitor (PAI) activity and morphological differentiation was investigated in human neuroblastoma (NB) cells treated with retinoic acid (RA). Conditioned medium from nine NB cell lines and one closely related neuroepithelioma line was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and zymography. All NB cell lines were shown to secrete urokinase (UK)-type PA (mol. wt., 52 kDa), and all except two produced tissue PA (mol. wt., 65 kDa). Identification of the PAs was made based on molecular weight and sensitivity to inhibition by anti-UK and anti-tPA antibodies. Several cell lines expressed PA inhibitory molecules; two molecular-weight forms were observed (35 and 40 kDa) in different cell lines. Complex formation with [125]I-labelled proteases revealed specific binding with UK and trypsin but not thrombin, plasmin, or kallikrein. After treatment for 6 days with 1 microM RA, six of the cell lines exhibited an increase in cell-associated and/or secreted tPA activity, corresponding to morphological differentiation of the cells as manifested by extensive neurite outgrowth. A decrease in UK and UK-complex secretion was observed in several of these cell lines. Three cell lines exhibiting no detectable morphological alterations with RA treatment also showed no dramatic changes in PA/PAI activity. These results suggest that morphological differentiation of NB cells may be associated with alterations in the regulation of PA activity.
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PMID:Effect of retinoic acid on human neuroblastoma: correlation between morphological differentiation and changes in plasminogen activator and inhibitor activity. 259 Sep 98

Human fetal plasminogen was isolated from fetal cord blood obtained from full-term normal newborns. Two fetal plasminogen preparations were characterized by physical analyses and compared to adult human Glu-plasminogen. The protein concentration of plasminogen in each full-term fetal plasma was approximately 50% of the concentration found in adult plasma. The specific activity of the isolated plasminogen from both full-term fetal plasmas was 28.8 +/- 1.5 IU/mg protein, approximately the same as that of adult Glu-plasminogen. No significant difference was observed in the rate at which plasmin was generated from the normal fetal plasminogen and the adult Glu-plasminogen using streptokinase, urokinase, and tissue plasminogen activator. Electrophoretic analyses in an acrylamide gel/sodium dodecyl sulfate dissociating system showed that the fetal plasminogens and the adult Glu-plasminogen were the same molecular size. Analyses in an acrylamide gel isoelectric focusing system indicated that fetal and adult plasminogen both contained the same twelve isoelectric forms, however, there was a slight difference in the distribution of the isoelectric forms. The fetal and adult plasminogens both contained 792 +/- 1 amino acid residues, and there were no significant differences in amino acid composition between the fetal and adult preparations. These comparisons indicate that normal, full-term, fetal and adult Glu-plasminogen are identical.
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PMID:Comparison of human normal, full-term, fetal and adult plasminogen by physical and chemical analyses. 277 39

We studied the direct effects of glucocorticoids on plasminogen activator (PA) production by rat granulosa cells. PA production was assayed by culturing rat granulosa cells on [125I]fibrin plates and determining the extent of fibrinolysis after addition of the specific substrate plasminogen. In granulosa cells from preantral follicles of immature rats, treatment with FSH caused dose-dependent increases in PA production whereas glucocorticoids by itself was without effect. Increasing concentrations (10(-10) to 10(-6) M) of both natural and synthetic glucocorticoids potentiated the stimulating effect of FSH on PA production by 120 to 170%. The stimulatory potencies of the natural corticosteroids correlated with the glucocorticoid potencies (cortisol/corticosterone greater than aldosterone/11-deoxycorticosterone). In granulosa cells from Graafian follicles of mature rats, glucocorticoids on its own had direct stimulating effect on PA production. The stimulatory action of glucocorticoids on FSH-dependent PA production was completely blocked by simultaneous treatment with antiglucocorticoid RU 486. Antiserum directed against tissue-type PA (tPA) neutralized the increased fibrinolytic actions of glucocorticoids. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fibrin autography techniques, we showed that the increase in fibrinolytic activity in response to glucocorticoids resulted from increased production of tPA rather than urokinase-like PA. The effect of glucocorticoids on the production of PA inhibitors (PAI) was examined by 1) neutralization of urokinase activity by increasing amounts of culture media from granulosa cells treated with glucocorticoids, 2) reverse fibrin autography, and 3) Western blot analysis with a specific PAI antiserum. All these methods failed to detect a stimulatory action of glucocorticoids, with or without FSH, on PAI production by rat granulosa cells in the culture media. Our data showed that glucocorticoids have a direct stimulating effect on tPA production, but unlike its action on other in vitro systems, they have no significant effect on PAI production by rat granulosa cells in vitro.
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PMID:Glucocorticoids stimulate plasminogen activator production by rat granulosa cells. 278 80

Between August 1983 and December 1987, 23 patients received a 30-minute intraoperative, intraarterial infusion of streptokinase (seven patients) or urokinase (16 patients) because of residual thrombus or persistent ischemia or both after thromboembolectomy. Ages ranged from 21 to 77 years (mean, 58 years). In 15 patients intraoperative lytic therapy was part of the initial operation, whereas in eight patients intraoperative lytic therapy was performed during a secondary operation to treat thrombosis of a recently placed graft. Seven patients in the latter group had hypercoagulable conditions (five had heparin-induced thrombosis; one had protein C deficiency; one had polycythemia with thrombocytosis). Improvement after intraoperative lytic therapy was seen on angiography performed after infusion in 13 of 17 (76%) patients in whom angiography was performed both before and after intraoperative lytic therapy. Grafts in 12 of these patients remained patent without additional intervention, and in one graft thrombus formed again. In contrast, among four patients without angiographic evidence of improvement, thrombus formed again in four grafts (p less than 0.004). Intraoperative lytic therapy was considered successful in 74% of instances (17/23), including four of seven patients with hypercoagulable states. Three of six patients whose grafts failed had major amputations, whereas there were no amputations after successful infusions. Twelve patients were heparinized after intraoperative lytic therapy. Ten patients in this group were considered treatment successes, and two were considered treatment failures. Three of 11 patients not heparinized after intraoperative lytic therapy were considered treatment failures. Four hematomas occurred in the former group and none in the latter (p less than 0.03). No hematomas occurred in the heparin-induced thrombosis group in spite of anticoagulation with sodium warfarin (Coumadin). Only one hematoma occurred within 6 hours of intraoperative lytic therapy, and thus it was attributable to the infusion. We conclude that intraoperative lytic therapy is an effective adjunct to manage residual thrombus or persistent ischemia or both after lower extremity revascularization. Postinfusion angiography is of prognostic value. Heparinization after intraoperative lytic therapy seems beneficial but significantly increases the risk of bleeding complications.
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PMID:Intraoperative infusion of lytic drugs for thrombotic complications of revascularization. 279 66

The iodinated Mr approximately equal to 15,000 amino-terminal fragment (ATF) of the urokinase-type plasminogen activator (u-PA) molecule bound specifically to the cell surface of all of seven cultured human tumor cell lines studied. Cross-linking of iodinated ATF to the cell surface using a bifunctional amino-reactive reagent followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography revealed with the four cell lines studied the occurrence of a single band migrating with an Mr of 70,000-75,000, indicating complex formation with an Mr of 55,000-60,000 u-PA receptor protein (u-PA-R). In the human monocyte cell line U937 cultivated in the presence of phorbol ester, the amount of complex was strongly increased, and a fraction of the complex had a slower electrophoretic mobility. Comparison between autoradiograms of reduced and unreduced samples suggests that u-PA-R consists of one polypeptide chain. Two forms of u-PA-R, which differed with respect to affinity to concanavalin A, were identified. u-PA-R retained its ability to bind to ATF after cell lysis, and it was purified approximately 2,200-fold from biosynthetically labeled U937 cells by affinity chromatography with proenzyme u-PA coupled to Sepharose. The purified Mr 55,000-60,000 protein was specifically bound and cross-linked to u-PA, proenzyme u-PA, and ATF, but not to tissue-type plasminogen activator or other unrelated proteins.
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PMID:A 55,000-60,000 Mr receptor protein for urokinase-type plasminogen activator. Identification in human tumor cell lines and partial purification. 282 65


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