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:3.4.21.7 (plasmin)
9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastric juice from 15 normals, 20 patients with gastric ulcer and 14 patients with erosive haemorrhagic gastroduodenitis was investigated in respect of its activity on unheated and heated fibrin plates and its content of FDP and plasminogen or plasmin with immunochemical methods. Gastric juice from normals showed no activity on unheated and heated fibrin plates, and no FDP or plasminogen could be demonstrated. In the patients with gastric ulcer the gastric juice showed little or no fibrinolytic activity on fibrin plates except in 2, who had regurgitation of duodenal juice and neutral pH of the juice. These patients had equally high activity on heated as on unheated plates and no plasmin could be demonstrated. It was shown that this activity was not due to fibrinolysis, but to non-specific proteolytic activity (probably trypsin). The patients with erosive haemorrhage gastroduodenitis exhibited quite a different picture. The gastric juice from these patients showed extremely high activity on fibrin plates, the activity was higher on unheated than on heated plates. The activity was inhibited in vitro by addition of EACA and in vivo after administration of AMCA. The occurence of plasmic could be demonstrated directly immunologically in the gastric juice. By comparsion of plasmin and trypsin in various assays it could further be improved that the gastric juice in these cases contained plasminogen activator and plasmin. The patients with erosive haemorrhagic gastroduodenitis showed no increase in fibrinolysis in the blood, but low values for plasminogen and alpha2-M, and the serum contained FDP. These findings in the blood and gastric juice were interpreted as signs of local fibrinolysis in the stomach and duodenum. There is reason to assume that this gastric fibrinolysis contributes substantially to the bleeding tendency. The effect of administration of AMCA on fibrinolytic activity and the haemorrhage lends support to the assumption of such a mechanism.
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PMID:Gastric fibrinolysis. 0 Aug 7

A modification of the fibrin plate method is presented. Plasminogen-free human fibrinogen and plasminogen purified by affinity chromatography have been used. Fibrin plates without and with a constant amount of plasminogen and with agarose as stabilizing medium were used for the estimation of plasmin and plasminogen activator activity. Activator activity could be demonstrated in sterile bile and saliva. When plasmin activity was present, estimations of plasminogen activator were approximate. The method is sensitive, small volumes of reagents and samples are needed. The error of the method is comparatively low and the reproducibility is good.
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PMID:Fibrin plate method with reagents purified by affinity chromatography and its use for determination of fibrinolytic and other proteolytic activity in saliva, bile and plasma. 0 32

The extracts of granules of human polymorphonuclear leukocytes hydrolyzed a variety of proteins including human and bovine hemoglobin, human fibrinogen, human and bovine serum albumin, bovine elastin, and casein. The hydrolysis of all the proteins except fibrinogen and elastin was increased by addition of urea. Various inhibitors of trypsin, kallikrein, plasmin, Clr, Cls, and other proteolytic enzymes had no inhibitory effect. Slight inhibition was observed with polyanethol sulfonate and strong inhibition with normal human serum. Serum of patients with hereditary angioneurotic edema having no functional C1-esterase inhibitor was as effective in inhibiting the proteolysis as normal serum. The inhibitor was localized in 4S fractions of normal serum fractionated on Sephadex G-200. Fractionation of normal serum by ammonium sulfate precipitation, Sephadex G-200 filtration, and CM-Sephadex chromatography did not result in appearance of inhibitory activity in more than one protein peak, suggesting the possibility that only one inhibitor might be responsible. Since all fractions which contained the inhibitor of proteolysis also contained alpha1-antitrypsin, since sera of patients having low alpha1-antitrypsin levels contained less inhibitory activity, and since antibodies against alpha1-antitrypsin reversed the inhibition obtained from normal serum, the inhibition of proteolysis may be attributed to alpha1-antitrypsin.
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PMID:Some properties of proteolysis by polymorphonuclear leukocyte-granule extracts. 0 49

A small amount of antitryptic activity is detectable in the supernatant of deproteinized human serum. Preincubation of serum with trypsin causes an increase in acid-stable antitryptic activity. This rise in activity depends on the inter alpha-trypsin inhibitor concentration. The native inhibitor present in normal sera, and in higher concentrations in sera of patients with nephropathies, and the trypsin-liberated inhibitor show immunological cross reaction with antibodies to the serum inter-alpha-trypsin inhibitor. The two inhibitors differ in molecular weight and electrophoretic mobility. The physiological inhibitor (I-34), with a molecular weight of 34 000 and a high carbohydrate content, can be transformed by trypsin into an inhibitor (I-17) with a molecular weight of 17 000. This inhibitor is identical with the inhibitors liberated by trypsin from serum or from purified inter-alpha-trypsin inhibitor. The acid-stable inhibitor from urine is identical with the physiological serum inhibitor. Analogously, this inhibitor is transformed by trypsin into the inhibitor with a molecular weight of 17 000. We conclude that the inter-alpha-trypsin inhibitor is the precursor of both the physiological and the trypsin-liberated inhibitor. By a mechanism as yet unknown, but most likely a limited proteolysis, the secreted inhibitor is liberated from the high molecular weight precursor. In contrast to the monospecific trypsin-inhibiting precursor, the physiological and artificially liberated inhibitors are trypsin/chymotrypsin/plasmin inhibitors.
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PMID:[The inter-alpha-trypsin inhibitor as precursor of the acid-stable proteinase inhibitors in human serum and urine]. 0 63

Further evidence is presented that the acrosomal proteinase acrosin exists as a zymogen precursor in freshly ejaculated boar spermatozoa. Autoactivation of proacrosin to acrosin takes place optimally at slightly alkaline pH and in the presence of calcium ions. Activation is considerably accelerated by catalytic amounts of trypsin or highly purified acrosin. A significant acceleration of the activation is also achieved by porcine pancreatic and urinary kallikrein, whereas chymotrypsin, plasmin, thrombin or urokinase showed no effect. Activation can be inhibited by p-amino-benzamidine and p-nitrophenyl p'-guanidino-benzoate. Electrophoretic analysis at different stages of activation revealed that during this process various molecular forms of acrosin are produced, apparently by limited proteolysis.
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PMID:Multiple forms of boar acrosin and their relationship to proenzyme activation. 0 66

The esterase activity of thrombin and plasmin on artificial substrates was used to study the kinetics of these enzymes by Lineweaver and Burk's method. In the plasma of new-born infants, plasmin obtained from streptokinase has an avidity comparable with that in adults. Thrombin is obtained by the action of staphylocoagulase and taipan venom. Its avidity has important individual variations and is different from that in adults. An inhibitor is present both in the plasma and in the serum of the new-born. Fibrinogen was studied by variations in absorption of light during coagulation by thrombin. The abnormalities observed depend on the physical and clinical conditions of the medium (ph, osmolality). These characteristics depend on the age of the infant, but also seem to depend on the conditions of the sample and, in particular, on fibrinolytic reactions. The existence of foetal fibrinogen is discussed.
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PMID:[The state of prothrombin, plasminogen and fibrinogen in the newborn infant]. 0 59

Catalytic amounts of bovine beta-trypsin, bovine alpha-chymotrypsin and porcine plasmin establish a true thermodynamic equilibrium between virgin (I) (reactive site Lys15-Ala16 peptide bond intact) and modified (I) (this bond hydrolyzed) bovine trypsin/kallikrein inhibitor (Kunitz). The very slow reaction rates for attaining equilibrium are pH-dependent and differ for different enzymes. Optimal rates are for beta-trypsin at pH 3.75, for alpha-chymotrypsin at pH 5.5, and for plasmin at pH 5.0. Under conditions of optimum pH the equilibrium is reached with the highest rate by plasmin. In 10(-5)M inhibitor solutions the equilibrium concentrations of virgin and modified inhibitor are established by plasmin after almost 300 days starting from either pure virgin or pure modified inhibitor. Thus, the hydrolysis constant KHyd = [I]/[I] is determined to be 0.33 at pH 5.0. In spite of many unsuccessful attempts, this demonstrates that the reactive site peptide bond Lys15-Ala16 in the bovine trypsin inhibitor (Kunitz) can be hydrolyzed by catalytic amounts of endopeptidase. It further confirms that the hydrolyzed Lys15-Ala16 peptide bond in modified inhibitor is subject to thermodynamic control resynthesis.
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PMID:Hydrolysis-resynthesis equilibrium of the lysine-15--alanine-16 peptide bond in bovine trypsin inhibitor (Kunitz). 0 70

Psoriatic scale proteases were found to be extracted effectively in salt solution (1 mol/l) containing Triton X-100 (5 g/l). The extraction in dilute buffer or sucrose yielded low activities. The acid (0.25 N H2SO4) and KSCN (2 mol/l) solutions effectively extracted plasminogen activator. Fibrinolysin was most active in salt (1 mol/l KCl) and in KSCN (2 mol/l) extracts. Psoriatic scale proteases were fractionated by Sephadex G-100 gel filtration and further by DEAE cellulose chromatography. Five different enzyme preparations were obtained. The first preparation, resembling cathepsin D, effectively hydrolysed hemoglobin at pH 3.5 and casein at pH 5.8 and was insensitive to protease modifiers. The second preparation effectively hydrolysed trypsin substrates (AGLME, TAME, BAEE and BANA) and also histone and casein at pH 7.2 and was inhibited by protease inhibitors, TLCK and E-600. The third preparation hydrolysed histone and casein at pH 10.2 and was effectively inhibited by E-600 and partially by protease inhibitors and TPCK. The fourth preparation, resembling cathepsin B1, hydrolysed BANA and BAEE at pH 5.8 and was activated by SH-reagents and EDTA. The fifth enzyme preparation hydrolysed ATEE and was inhibited by E-600 and TPCK. Plasminogen activator was found mainly in the second enzyme preparation and fibrinolysin activity in the third and fifth enzyme preparations. The second, third and fifth enzyme preparations were different from the enzymes found in healthy human skin. The proteases of psoriatic scale resemble those of tissue and cell cultures undergoing rapid cell division. The possible role of proteases in the increased cell division in psoriasis plaque is discussed.
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PMID:Human skin proteases. Fractionation of psoriasis scale proteases and separation of a plasminogen activator and a histone hydrolysing protease. 0 31

Two radiochemical esterolytic assays for urokinase are described. One assay is based on the urokinase-dependent hydrolysis of Nalpha-acetyl-glycyl-L-lysine [3H]methyl ester and the other on the urokinase-dependent activation of plasminogen and assay of generated plasmin with Nalpha-tosyl-L-arginine [3H]methyl ester. The assays are performed in tubes placed in liquid scintillation counting vials. At the end of the experiment generated [3H]methanol is extracted into the liquid scintillation cocktail and counted. Unhydrolyzed substrate largely remains in the aqueous phase and contributes only a small fraction of the counts. This facile separation of 3H-labeled alcohol from the ester substrate allows the simple and highly sensitive assay for urokinase. The assays give results in good agreement with the classical fibrin plate assay.
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PMID:Sensitive radiochemical esterolytic assays for urokinase. 0 14

The macromolecular breakdown products of fibrinogen are known mainly for their inhibitory effect on the clotting of fibrinogen by thrombin. This inhibitory effect is due to interference with both the proteolytic action of thrombin and the polymerization of the fibrin monomers. However, the action of these products is not limited to these effects. They can on the one hand inhibit the consumption of Factors II and XIII and promote the inactivation of Factor VIII by thrombin. On the other hand, they can potentiate the activation of prothrombin in purified systems via the intrinsic pathway. The incidental observation was also made that Factor IXa and or Factor Xa inactivate Factor VIII. As substrates of both thrombin and plasmin the large fragments protect these two enzymes from spontaneous inactivation, while at the same time they inhibit their respective proteolytic activities. Contradictory results were obtained regarding their effect on platelets. The micromolecular (dialyzable) breakdown products prolong the thrombin, prothrombin, and partial thromboplastin times of plasma and retard the generation of the intrinsic prothrombin activator. They can also potentiate the effects of biologically active peptides and amines on the smooth muscles and on vascular permeability.
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PMID:Physiological effects of the plasminolytic derivatives of fibrinogen. 0 46


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