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 type of plasminogen activator (PA) secreted by bovine embryos was identified. Day 12-14 embryos were collected from estrus-synchronized, superovulated, and naturally mated crossbred beef cows. Embryos were left intact (E) or microdissected into component embryonic discs (ED) and trophoblastic vesicles (TV). Intact embryos, ED, and TV were pre-cultured for 2 days in Minimum Essential Medium Alpha (MEM alpha) with 10% heat-inactivated fetal calf serum, washed in serum-free MEM alpha, and cultured individually for 5 days in 50 microliters microdrops of MEM alpha with 15 mg/ml bovine serum albumin. At 24 hr intervals, E, ED, and TV were observed for tissue morphology and transferred to fresh microdrops, and medium was recovered and frozen at -20 degrees C. At the end of culture, blastocoelic fluid (BF) and embryonic tissues were recovered and frozen at -20 degrees C. Plasminogen activator concentrations in medium, tissues, and BF were determined by using a caseinolytic assay. Antibodies to urokinase-type PA (anti-uPA) and tissue-type PA (anti-tPA), and the urokinase inhibitor, amiloride (AMR), were used to identify the type of PA produced by bovine embryonic tissues. Intact embryos and TV released more PA (P less than 0.05) than ED, and tissues exhibiting expanded blastocoels released less PA (P less than 0.05) than tissues with collapsed blastocoels. Blastocoelic fluid from TV exhibited more PA (P less than 0.05) activity than from ED. Treatment with anti-uPA decreased PA activity (P less than 0.05) in pooled medium and tissues from E compared to treatment with nonspecific immunoglobulins and anti-tPA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bovine embryos produce a urokinase-type plasminogen activator. 156 22

In the present study, methotrexate (MTX), was conjugated with a murine monoclonal antibody (79) to human common acute lymphoblastic leukemia antigen (CALLA), with human serum albumin (HSA) as an intermediary. The highest molar ratio of McAb 79:HSA:MTX in the conjugates was 1:2. 63:117. The conjugates obtained retained both antibody binding and drug activities. Although there was some loss of drug activity in binding to antibody, the toxicity of McAb79-HSA-MTX was entirely specific for the target cell, and the cytotoxicity of McAb79-HSA-MTX against CALLA+ cells was greater than that of control S13 (Anti-human urokinase)-HSA-MTX. The ratio of 79-HSA-MTX cytotoxicity to the target and non-target cells was 66:1, whereas there was no cytotoxicity to target cells when McAb79 was used only. There was no cytotoxic difference between 79-HSA-MTX and S13-HSA-MTX against CALLA- SB cells. These results suggest that the cytotoxicity of 79-HSA-MTX against CALLA leukemia cells is specific and this specificity is mediated by McAb79.
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PMID:[Preparation and cytotoxicity of McAb-HSA-MTX conjugates]. 217 64

A new continuous flow electrophoretic separator for cells and macromolecules was built and tested in laboratory experiments and in the microgravity environment of space flight. Buffer flows upward in a 120-cm long flow chamber, which is 6 cm wide X 1.5 mm thick in the laboratory version and 16 cm wide X 3.0 mm thick in the microgravity version. Electrophoretic subpopulations are collected in 197 fractions spanning 16 cm at the upper end of the chamber. The electrode buffer is recirculated through front and back cooling chambers, which are also electrode chambers. Ovalbumin and rat serum albumin were used as test proteins in resolution and throughout tests; resolution of these two proteins at 25% total w/v concentration in microgravity was the same as that found at 0.2% w/v concentration in the laboratory. Band spreading caused by Poiseuille flow and conductance gaps was evaluated using polystyrene microspheres in microgravity, and these phenomena were quantitatively the same in microgravity as in the laboratory. Rat anterior pituitary cells were separated into subpopulations enriched with cells that secrete specific hormones; growth-hormone-secreting cells were found to have high electrophoretic mobility, whereas prolactin-secreting cells were found to have low electrophoretic mobility. Cultured human embryonic kidney cells were separated into several electrophoretic subfractions that produced different plasminogen activators; a medium-high-mobility subpopulation and a medium-low-mobility subpopulation each produced a different molecular form of urokinase, whereas a high- and an intermediate-mobility subpopulation produced tissue plasminogen activator. Canine pancreatic islets of Langerhans cells were separated into subpopulations, which, after reaggregation into pseudoislets, were found to be enriched with cells that secrete specific hormones; insulin-secreting beta cells were found in lowest mobility fractions, whereas glucagon-secreting alpha cells were found in the highest mobility fractions. Results of particle electrophoresis experiments were comparable in microgravity and in the laboratory, since cell densities that overloaded the carrier buffer (resulting in zone sedimentation) were avoided, and a 500-fold increase in protein throughput was achieved without compromising resolution in microgravity.
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PMID:Continuous flow electrophoretic separation of proteins and cells from mammalian tissues. 244 May 79

The National Institute of Hygienic Sciences Standard for Urokinase (Control 881) was established in collaboration with five laboratories. This standard contains 1100 international units of urokinase and 1.17 mg of human serum albumin in each ampoule. Urokinase used for the standard is constituted of 1 part of high molecular weight species (M. W. 54000) and 4 parts of low molecular weight species (M. W. 33000).
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PMID:[Urokinase Reference Standard of National Institute of Hygienic Sciences (Control 881)]. 263 13

Low molecular weight urokinase (LMW-UK) was coupled to the heavy chain of plasmin to make it able to bind to fibrin. The purified conjugate (PHC-UK conjugate), which consisted of equimolar concentrations of each starting material had a molecular weight of 93,600, bound tightly to fibrin-monomer-Sepharose and was not washed off with 1 M NaCl, but was eluted specifically with epsilon-amino caproic acid. The conjugate showed higher fibrinolytic activity than HMW-UK. A control conjugate prepared by coupling human serum albumin to LMW-UK (HSA-UK conjugate) showed the same fibrinolytic activity as HMW-UK. The half-lives of these two conjugates in rabbits were about 3 times that of HMW-UK. In an experimental pulmonary embolism model in rabbits, the PHC-UK conjugate showed about 10 times higher thrombolytic activity than HMW-UK, while the HSA-UK conjugate showed similar thrombolytic activity as HMW-UK, and moreover caused severe systemic fibrinogen breakdown. Thus the significant increase in thrombolytic activity after injection of PHC-UK conjugate into rabbits may be due to its newly acquired fibrin binding activity, and not to increase in its half-life. It is concluded that the PHC-UK conjugate may be useful in treatment of thrombosis.
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PMID:The plasmin heavy chain-urokinase conjugate: a specific thrombolytic agent. 295 92

Acid stable trypsin inhibitor having the same antigenicity as urinary trypsin inhibitor was first identified in the bile of patients with malignant tumors (biliary tract carcinoma or pancreas head carcinoma) and gallstones. Bile trypsin inhibitor from malignant tumor patients was partially purified by DEAE cellulose ion exchange column chromatography. Two molecular forms of the inhibitor were identified. The main form had a molecular weight of about 86,000 and the minor one a molecular weight of 31,000 as determined by gel filtration. Using isoelectric focussing, the larger molecular form gave a pI value of 2.0 and the smaller form, a pI value of 5.1. The isolated larger form migrated on the slightly cationic side of human serum albumin by analytical polyacrylamide gel electrophoresis. The larger form reacted and fused with anti-urinary trypsin inhibitor serum and strongly inhibited trypsin, partially inhibited chymotrypsin and plasmin, but did not inhibit urokinase. The clinical significance of acid stable trypsin inhibitor is discussed.
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PMID:Acid stable trypsin inhibitor in bile. 374 18

Plasma and urine fibrinolysis were studied in 36 patients with glomerulonephritis and proteinuria. In 40% of these plasma fibrinolytic activator activity was moderately reduced and fibrinolytic inhibitors were increased. Globulins with antiplasmin effect were raised, particularly in the earlier months. Both the serum cholesterol and the plasma fibrinogen were related to the level of serum albumin, and those patients with high fibrinogen levels were also those with poor plasma fibrinolytic activator and those showing a steady deterioration. Urinary fibrinolysis was greatly reduced in most patients and bore no relation to plasma fibrinolysis levels. Hence urokinase is not derived from circulating plasminogen activator.
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PMID:Study of proteins and fibrinolysis in patients with glomerulonephritis. 424 92

The presence of a peripheral zone of (presumed intracellular) plasminogen activator in the normal rabbit cornea has suggested that activator, once released, might regulate the permeability of limbal vessels and angiogenesis, by plasmin-dependent pathways. Plasminogen activator (urokinase [UK]) in rabbit serum albumin (RSA) was injected once (20 microliter, 3.7 CTA U) into the corneal stroma, 2 mm from the limbus. Sprouts arose from the engorged circumlimbal vessels (16 of 20 corneas) beginning on the third day and grew into the cornea over the next several days. Histologically, PMNs were observed in association with growing vessels. Contralateral corneas injected with UK (in RSA) previously inactivated by 99.7% with the specific active site inhibitor, Phe-Ala-Arg-chloromethyl ketone showed minimal vessel engorgement or stromal edema and no vascularization (0 to 20 corneas). Injuries to the so-called (plasminogen activator-containing)"critical zone" of the cornea which elicit neovascularization possibly do so by causing extracellular release of endogenous plasminogen activator. Thus, in addition to initiating the destructive events of ulceration, activator might initiate increases in vessel permeability and also neovascularization, which would result in the eventual arrest of ulceration.
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PMID:Plasminogen activator (urokinase) causes vascularization of the cornea. 617 46

alpha-Tocopherol (vitamin E) inhibited the activity of urokinase on fibrin plates and on the amidolytic substrate S-2444 in a concentration- and time-dependent manner. Inhibition was not removed by dialysis. In the presence of dilutions of plasma, protein-containing fractions of gel-filtered plasma, or bovine serum albumin, the inhibition of urokinase by alpha-tocopherol was abolished. Urokinase activity was not inhibited by phytol, menadione or hydroquinone.
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PMID:Inhibition of the plasminogen activator urokinase by alpha-tocopherol. 680 92

Addition of several arginine-specific serine proteases to culture medium conditioned by fibroblasts results in the proteases being taken into sodium dodecyl sulfate-stable complexes with a secreted factor termed protease nexin (PN) (Baker, J. B., Low, D. A., Simmer, R. L., and Cunningham, D. D. (1980) Cell 21, 37-45). PN not only inhibits these degradative enzymes but also mediates their binding, internalization, and degradation by the cells (Low, D. A., Baker, J. B., Koonce, W. C., and Cunningham, D. D. (1981) Proc. Natl. Acad. Sci. U. S. A. 78, 2340-2344). Here we describe a simple procedure for purifying milligram quantities of PN from serum-free medium conditioned by human foreskin cells. Accumulation of PN in the medium is increased by using high density microcarrier cultures supplemented with epidermal growth factor and bovine serum albumin. Application of ultrafiltration-concentrated medium to a heparin-Sepharose column followed by extensive washing of the column with buffer containing 0.2 M NaCl and elution with buffer containing 1.0 M NaCl results in the recovery of 60-90% of the input PN in a form that is 90-97% pure. This preparation can be further purified by hydrophobic chromatography on octyl-agarose. Purified PN has a molecular mass of approximately 51 kilodaltons. On nonequilibrium pH gradient electrophoresis it migrates as five bands with isoelectric points between 7.5 and 7.8. Purified PN exhibits all the properties attributed to PN in culture medium. These include: 1) formation of sodium dodecyl sulfate-stable complexes with thrombin, urokinase, and plasmin; 2) inhibition of protease activity; 3) heparin-enhanced inhibition of thrombin; and 4) cellular binding of protease-PN complexes in a heparin-sensitive reaction. When thrombin-PN complexes are dissociated with 1 M hydroxylamine a smaller form of PN (approximately 46 kilodaltons) is detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the complexed PN is proteolytically modified.
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PMID:Purification of human protease nexin. 688 87


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