Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Human plasma contains a variety of proteins that are capable of inhibiting plasmin activity. Whole plasma possesses 'rapid' and 'progressive' plasmin-neutralizing activity: this study assesses the contribution of individual protease inhibitors to this plasmin-neutralizing property of plasma. 2. Rapid and progressive antiplasmin activities of human plasma correlate with alpha2-macroglobulin and alpha1-antitrypsin concentrations respectively. 3. Fluctuations in the amounts of the other measured inhibitors (antithrombin III, Cl in activator and inter-alpha-tryspin inhibitor) did not influence the measured antiplasmin activity.
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PMID:The contribution of plasma protease inhibitors to antiplasmin activity in man. 6 Jan 90

"Hemorrhage in the newborn" has long been recognized as merely a result of vitamin K deficiency. However, it is also recognized that fibrinolysis, especially the correlation between the plasminogen-activator and plasmin-inhibitors, play an important role in this disease during the neonatal period. With this in mind, we compared thromboelastograms (TEG) from samples with and without urokinase (plasminogen-activator). In 13 out of 15 newborn infant blood-samples (prior to and after addition of urokinase) the thromboelastogram showed the pattern of a consumption coagulopathy. The change in the concentration of plasmin-inhibitor during the neonatal period was also measured using alpha2-macroglobulin, alpha1-antitrypsin and antithrombin III with M-partigen-plates. The value of alpha2-macroglobulin showed normal adult levels but the value of alpha1-antitrypsin and antithrombin III did not even reach half of the adult level. During the newborn period, the plasmin-inhibitor shows a remarkable lowering tendency and it may be surmised that with such a lowering tendency plasmin-inhibitor may constitute an exceptionally large handicap when the activator is working. This is especially true in the case of lung hemorrhage since the activator arises from a severe pathological state in the lungs and in addition because this is complicated by the lowering of plasmin-inhibitor. These results indicate that the low level of plasmin-inhibitors work synergistically with the high value of activator. The low level of antithrombin III could be the reason for coagulation disorders such as disseminated intravascular coagulation, (DIC).
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PMID:New neonatal problems of blood coagulation and fibrinolysis. I. The change of plasmin inhibitor levels in the newborn infant. 6 4

Pig plasmin (Lysofibrin) was given to 11 patients with phlebographically verified venous thrombosis, 2 of whom were treated two and three times, respectively. The effect on coagulation and fibrinolytic parameters was studied. The platelet count, Owren's P&P (prothrombin plus factors VII and X), plasminogen, factor XIII, and antithrombin III did not change during the treatment. All patients developed a proteolytic activity demonstrable on both unheated and heated fibrin plates. The fibrinogen decreased successively to very low levels, and parallel to this an increase in fibrin/fibrinogen degradation products was found. The factor VIII and factor V activities decreased immediately after each Lysofibrin infusion but normalized rapidly again. The factor VIII molecule, however, retained its reactivity to rabbit antiserum against factor VIII. Immediately after the plasmin infusion a decrease of both alpha2-macroglobulin (alpha2-M) and the rapidly reacting alpha2-antiplasmin was observed. alpha2-M decreased successively and in several of the patients values were unmeasurable for a period of some days. A complex formation between pig plasmin and the alpha2-antiplasmin was demonstrated in crossed immunoelectrophoresis. The complexes were rapidly cleared from the circulation. No interaction between the pig plasmin and the inhibitor of the plasminogen activation, alpha1-antitrypsin or inter-alpha-inhibitor, was found.
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PMID:Effects of porcine plasmin on the coagulation and fibrinolytic systems in humans. 7 91

An assay of human antiplasmins has been developed utilizing radial diffusion of plasma from wells cut in plasmin-enriched, fibrinogen-agarose plates. After diffusion the fibrinogen is clotted. Zones of fibrin protected from background fibrinolysis develop as the result of plasma antiplasmin activity. A pooled plasma standard was taken to contain 100% antiplasmin activity. Antiplasmin activity of 52 normal subjects varied from 64 to 132%. Washed platelets contained 1-5% antiplasmin activity. Using antisera to precipitate individual inhibitors, physical methods of separation, and electrophoresis of plasma in agarose, several different proteins were found to have antiplasmin activity in this assay. Thus, alpha2-macroglobulin contributed 56%, alpha1-antitrypsin 20%, antithrombin III 2%, and other proteins 22% of the total antiplasmin activity. 1 ml of whole plasma neutralized 7.0 CTA units of plasmin.
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PMID:The measurement of human plasma antiplasmin activity by radial diffusion assay. 7 30

This study attempted to determine whether fibrin monomer complexes, or other alterations of coagulation factor activities that might predispose to thrombosis, were present in 30 vasectomized Rhesus monkeys that had had bilateral vasectomies 1-11 years earlier. Blood coagulation factors, prothrombin, factors V and VIII, fibrogen, and antithrombin III, are consumed when blood coagulation occurs. If consumption of these factors is in excess of the individual's ability to synthesize them, a decreased concentration results. No significant decreases in activities of any consumable clotting factors were found. If intravascular coagulation is present, certain products of coagulation may be present in the blood even though consumable factors remain normal. Products of intravascular coagulation include fibrin monomer and plasmin digestion products of fibrin. No significant differences in average values of fibrin monomer and fibrin digestion products in control and vasectomized animals were found. 1 animal had increased fibrin monomer, but on postmortem examination, no evidence of intravascular thrombosis was seen.
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PMID:Coagulation changes following vasectomy: a study in primates. 9 98

Fresh plasma was seeded with trace amounts of highly purified biologically intact iodine-labelled plasminogen and the plasmin-inhibitor complexes formed after activation with streptokinase or urokinase separated by gel filtration. Two radioactive peaks were observed, the first one eluted in the void volume and the second one just before the 7-S globulin peak. In incompletely activated samples, the second peak was always predominant over the first one. Both components were purified with high yield by a combination of affinity chromatography on lysine-agarose and gel filtration, and investigated by dodecylsulphate-polyacrylamide gel electrophoresis and immunoelectrophoresis. Neither component reacted with antisera against alpha1-antitrypsin, antithrombin III, C1-esterase inhibitor, inter-alpha-trypsin inhibitor or alpha1-antichymotrypsin. The component of the first peak appeared to be a complex between plasmin and alpha2-macroglobulin which reacted with antisera against human plasminogen and against alpha2-macroglobulin. The component of the second peak had a molecular weight (Mr) of 120000-140000 by dodecyl-sulphate-polyacrylamide gel electrophoresis and lpon reduction displayed a doublet band with an Mr of 65000-70000 and a band with Mr 11000. It reacted with antisera against plasminogen and with antisera raised against this complex and absorbed with purified plasminogen. The latter antisera reacted with a single component in plasma which is different from the above-mentioned plasma protease inhibitors. Specific removal of this component from plasma by immuno-absorption resulted in disappearance of the fast-reacting antiplasmin activity whereas alpha2-macroglobulin was found to represent the slower-reacting plasmin-neutralizing activity. In the presence of normal plasma levels of these proteins, the specific removal or absence of alpha1-antitrypsin, antithrombin III or C1-esterase inhibitor did not alter the inactivation rate of plasmin when added to plasma in quimolar amounts to that of plasminogen. It is concluded that only two plasma proteins are important in the binding of plasmin generated by activation of the plasma plasminogen, namely a fast-reacting inhibitor which is different from the known plasma protease inhibitors and which we have provisionally named antiplasmin, and alpha2-macroglobulin, which reacts more slowly.
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PMID:Identification and some properties of a new fast-reacting plasmin inhibitor in human plasma. 13 45

Rates of hydrolysis of the newly developed peptide chromogenic substrates S-2160 (N-Bz-Phe-Val-Arg-pNA, HCl), S-2238 (H-D-Phe-Pip-Arg-pNA, 2HCl), S-2222 (N-Bz-Ile-Glu-Gly-Arg-pNA, HCl), and S-2251 (H-D-Val-Leu-Lys-pNA, 2HCl) from AB Kabi Peptide Research and Chromozym TH (Z-Gly-Pro-Arg-pNA, HCl) from Pentapharm Limited were tested against highly purified preparations of human plasmin, bovine trypsin, human alpha thrombin, and bovine factor Xa. S-2160, S-2238, and Chromozym TH are sensitive to thrombin, Chromozym TH and S-2238 exhibiting a substantially greater sensitivity than S-2160. All 3 substrates are insensitive to factor Xa but hydrolyzed to varying degrees by plasmin and trypsin. In contrast, S-2222 is sensitive to Xa and insensitive to thrombin. S-2251 is relatively plasmin-specific, being resistant to the clotting enzymes thrombin and Xa. S-2251 exhibits even greater sensitivity to the SK-plasmin complex than to plasmin. In addition, the substrate Chromozym PK (N-Bz-Pro-Phe-Arg-pNA, HCl) was evaluated and found to be relatively specific for plasma kallikrein. Assays for antithrombin III and heparin using S-2222 as the substrate and factor Xa as the enzyme, plasma plasminogen and plasmin inhibitors using S-2251 as the substrate, and plasma prekallikrein and kallikrein inhibitors using Chromozym PK as the substrate have been developed. Synthetic peptides mimicking amino acid sequences adjacent to proteolytic activation cleavage of plasma serine protease precursors appear to be sensitive and relatively specific tools applicable to kinetical and clinical studies of these enzymes and their inhibitors.
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PMID:Serine protease specificity for peptide chromogenic substrates. 14 72

Rates of hydrolysis of the newly developed peptide chromogenic substrates S-2160, S-2238, S-2222 and S-2251 and Chromozym TH were tested against highly purified preparations of human plasmin, bovine trypsin, human alpha-thrombin, and bovine factor Xa. S-2160, S-2238, and chromozym TH are sensitive to thrombin, Chromozym TH and S-2238 exhibiting a substantially greater sensitivity than S-2160. All three substrates are insensitive to factor Xa but hydrolyzed to varying degrees by plasmin and trypsin. In contrast, S-2222 is sensitive to factor Xa and insensitive to thrombin. S-2251 is relatively plasmin-specific. In addition, the substrate Chromozym PK was evaluated and found to be relatively specific for plasma kallikrein. Clinically useful assays for antithrombin III and heparin using S-2222 as the substrate and factor Xa as the enzyme, plasma plasminogen and plasmin inhibitors using S-2251 as the substrate, and plasma prekallikrein and kallikrein inhibitors using Chromozym PK as the substrate have been developed.
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PMID:Sensitivity and specificity of plasma serine protease chromogenic substrates. 14 51

Human thrombin-antithrombin III and plasmin-antiplasmin, two enzyme-inhibitor complexes composed of four different molecules, contain antigenic structures not present in the parent molecules, which can be directly quantitated in plasma with the use of non-cross-reacting antisera. It is anticipated that this neonatigenic expression is a more general phenomenon, which could provide a simple means of measuring activation of enzyme systems in biological fluids.
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PMID:Neoantigenic expression in enzyme-inhibitor complexes. A means to demonstrate activation of enzyme systems. 15 Aug 60

To characterize the mode of action of heparin, the kinetics of inhibition of thrombin, factor Xa, and plasmin by antithrombin III was studied without and in the presence of heparin. Following the concentration dependence of inactivation a linear dependence was found between the apparent first-order inactivation rate constant and the anti-thrombin III concentration. This behaviour is typical of enzyme-activator interaction. Values of kinetic constants of the inactivation reaction could be determined. Thus, heparin acts obviously as an activator of the enzymes and enhances their affinity for antithrombin III.
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PMID:Role of heparin in the interaction of serine proteinases with antithrombin III. 15 69


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