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)

Some properties of protein inhibitor for trypsin (TI) from Act. janthinus 118 were studied. It was shown that TI has an antitrypsin activity within a wide pH range with a maximum at about 9,5. At 4 degrees and 20 degrees C TI is stable for 24 hours within the pH range of 6,0--11,0. At 100 degrees C TI is more stable in the slightly acid region of pH than at neutral or alkaline conditions. Trypsin and chymotrypsin inactivate the inhibitor for 8 hours. TI inhibits trypsin, fibrinolysin, subtilisin, pronase and terrilytin, but have no effect on chymotrypsin, thrombin, papain and pepsin. The dissociation constants for the trypsin-inhibitor complex were found to be 1,7.10-8 M, 4,1.10-9 M and 2,4.10-10 M, with casein, p-nitroanilide benzoylarginine and tosylarginine methyl ester used as substrates, respectively. The corresponding dissociation rate constants for the subtilisin-inhibitor complex were equal to 1.10-9 M and 4.10-10 M with casein and carbobenzoxy-L-alanyl-L-alanyl-L-leucin p-nitroanilide used as substrates, respectively.
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PMID:[Stability and specificity of extracellular protein inhibitor for trypsin from Actinomyces janthinus 118]. 3 28

Highly sensitive gelatin substrate films prepared according to a recent variant of the procedure are studied for their susceptibility to the action of various endopeptidases and exopeptidases. Trypsin, papain, elastase, and chymotrypsin are found to hydrolyze the gelatin films most easily, while higher enzyme concentrations are required in case of pepsin, plasmin and collagenase. The exopeptidases, i.e. leucine aminopeptidase, amino acid arylamidase and carboxypeptidases A and B do not cause lysis of gelatin substrate films. The example of a rabbit blastocyst protease involved in implantation is given to demonstrate the application of gelatin substrate film tests for studies of enzymes which have no or little activity against known synthetic substrates (like BANA or GPNA) but hydrolyze gelatin films. Studies of interactions of this blastocyst protease with various inhibitors of known specificity, however, show that the active center of this enzyme nevertheless has striking similarities to trypsin (and also to chymotrypsin). The enzyme is possibly related to elastase. It is emphasized that, besides this, there are a number of different protease type enzymes in rabbit blastocyst and uterine tissues, some of which can be demonstrated only with chromogenic substrates and some only by gelatin methods. Aspects of applicability of the two types of protease tests are briefly discussed.
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PMID:[The specificity and sensitivity of the gelatin base protease substrate film test ]. 4 23

Thrombin converts fibrinogen to fibrin monomer by cleaving fibrinopeptides A and B (FPA and FPB) from the amino terminal ends of the A (alpha) and B (beta) chains. A radioimmunoassay capable of measuring the A peptide in human blood as an index of thrombin action in vivo has been described previously. This paper describes the development of a radioimmunoassay for FPB and the use of both assays in the demonstration of distinctive patterns of cleavage of the amino terminal ends of the A (alha) and B (beta) chains of fibrinogen by various enzymes. Antisera were raised in rabbits to a synthetic analogue of FPB coupled to bovine serum albumin. FPB analogue was couple to desaminotyrosine and radiolabeled with 125I by the chloramine-T technique. The radiolabeled peptide was bound by the antiserum, and binding was inhibited by synthetic or native FPB. Unbound tracer was separated from bound tracer by charcoal adsorption. The senistivity of the assay was such that 50% inhibition of binding of the tracer was caused by 1.25 ng of the native FPB. Fibrinogen was treated with thrombin, plasmin, trypsin, Reptilase, and an extract of the venom from Ancistrodon contortrix contortrix (ACC). After ethanol precipitation and centrifugation, dialysates of enzymatically altered fibrinogen were assayed for FPA and FPB. The action of thrombin on fibrinogen resulted in a rapid release of FPA and a slower release of FPB. Plasmin cleaved a segment(s) of the B (beta) chain which included FPB but cleaved no detectable FPA-containing material for the first 2 h of incubation. In the case of plasmin-treated fibrinogen, the dialysates had been further treated with thrombin before being assayed for FPA and FPB. Trypsin rapidly cleaved both peptides, the B before the A. Reptilase cleaved only FPA in 24 h. ACC cleaved FPB at a rapid rate, with a slowere cleavage of FPA. The distinctive cleavage patterns produced by the serine proteases may be useful in interpreting the levels of FPA and FPB measured in human blood and in studying the generation of FPA and FPB in clinical blood samples.
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PMID:Radioimmunoassay of human fibrinopeptide B and kinetics of fibrinopeptide cleavage by different enzymes. 5 Mar 28

Pure alpha2M is prepared with fresh plasma as starting material, to prevent the interaction of alpha2M from proteolytic enzymes of plasma such as thrombin, plasmin and kallikrein. During the purification steps, polybrene and aprotin are used as inhibitors and plasminogen is absorbed onto bentonite. When alpha 2M is submitted to polyacrylamide gel electrophoresis (PAA) containing 0.1% SDS, a complete dissociation in two half-molecules of MW 380,000 occurs. When alpha2M is incubated in 1% SDS and 1% beta-mercaptoethanol as reducing agent, only one component of MW 190,000 is observed in PAA-SDS. This experiments show that the alpha2M molecule consist of two symetric halves of same MW (380,000) linked by non covalent bonds. Each two-half-molecules is made of two polypeptides chains MW 190,000 linked by disulfide bonds. Thus alpha2M molecule contains four polypeptides chains having a same MW. The same techniques were applied to the study of alaph2M proteinases complexes. Three different proteinases (plasmin, trypsin and papain) were used in these experiments. Trypsin and papain are commercialy available. Plasminogen was obtained by affinity chromatography and activated into plasmin by insoluble streptokinase fixed on PAB cellulose.
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PMID:[Studies on human alpha-2 macroglobulin structure and its complexes with proteases, using polyacrylamide gel electrophoresis]. 5 41

Neither normal nor hemophilic factor VIII protein enters a 5% sosium dodecyl sulfate gel; on reduction, however, a single 195 000-molecular-weight peptide is observed. Hemophilic and normal factor VIII contain carbohydrate and appear identical in subunit molecular weight, electrical charge, and major antigenic determinants. Thrombin activation and inactivation of factor VIII does not detectably change the subunit molecular weight. Trypsin causes similar activity changes and obviously cleaves the factor VIII subunit. Human plasmin destroys factor VIII procoagulant activity and degrades the factor VIII subunit to 103 000-, 88 000-, and 17 000-molecular-weight peptides. Both normal and hemophilic factor VIII as well as thrombin-inactivated factor VIII support ristocetin-induced platelet aggregation. Purified factor VIII chromatographed on 4% agarose in 1.0 M sodium chloride shows no dissociation of the procoagulant activity from the void volume protein. Gel chromatography on 4% agarose in 0.25 M calcium chloride results in a procoagulant activity peak removed from the void volume protein; both peaks contain protein which does not enter a 5% SDS gel, but on reduction a 195 000-molecular-weight subunit band is observed for each. Both the void volume protein peak and the procoagulant activity peak from the 0.25 M calcium chloride-agarose gel column support ristocetin-induced platelet aggregation. After removal of calcium, a small amount of procoagulant activity is present only in the void volume peak. These data suggest that both the procoagulant and von Willebrand activities are on the same molecule. Thus our previous conclusion remains the same: human factor VIII is a large glycoprotein composed of identical 195 000-molecular-weight subunits jointed by disulfide bonds and is responsible for both antihemophilic and von Willebrand activities in human plasma.
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PMID:Molecular structural studies of human factor VIII. 12 89

This study has explored the nature of the molecular events which occur when C1 inactivator, a human plasma inhibitor of the complement, kinin-forming, coagulation, and fibrinolytic enzyme systems, interacts with C1s, plasmin, and trypsin. Purified inhibitor preparations demonstrated two bands, when examined by acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). The molecular weights of the major and minor bands were 105,000 and 96,000 daltons, respectively. The minor component appeared to be immunologically and functionally identical to the main C1 inactivator component. Loss of C1s and plasmin functional activity was associated with the formation of a 1:1 molar complex between the inhibitor and each enzyme. These complexes were stable in the presence of SDS and urea. The light chain of both these enzymes provided the binding site for C1 inactivator. Complex formation and enzyme inhibition occurred only with native and not with an inhibitor preparation denatured by acid treatment, thereby demonstrating the importance of conformational factors in the enzyme-inhibitor reaction. Although peptide bond cleavage of the C1 inactivator molecule by C1s was not documented, plasmin was found to degrade the inhibitor with the production of several characteristic derivatives. At least one of these products retained the ability to complex with C1s and plasmin. Trypsin, which failed to form a complex with C1 inactivator, degraded the inhibitor in a limited and sequential manner with the production of nonfunctional derivatives one of which appeared structurally similar to a plasmin-induced product. These studies therefore, provide new information concerning the molecular interactions between C1 inactivator and several of the proteases which it inhibits.
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PMID:Studies on human plasma C1 inactivator-enzyme interactions. I. Mechanisms of interaction with C1s, plasmin, and trypsin. 12 51

A study was made of the effect of plasmin and trypsin on the phospholipase activation, and also of the action of phospholipase A (cobra venom) on the release reaction and the erythrocyte and thrombocyte aggregation. Trypsin and fibrinolysin proved to activate phospholipase, this being accompanied by the accumulation of nonesterified fatty acids in the blood serum. Phospholipase A caused a release of the thromboplastic factor from erythrocytes and thrombocytes and their aggregation. The later is inhibited by albumin and EDTA. It is suggested that the action of the proteolytic enzymes on the blood formed elements was realized through the phospholipase activation.
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PMID:[Effect of phospholipase A on erythrocyte and thrombocyte aggregation]. 13 79

Trypsin, thrombin, fibrinolysin, papain, chymothrypsin and urokinase were immobilized on aminopolystyrene resin by the reaction of diazocoupling. An activation of prothrombin and plasminogen and also hydrolysis of fibrin by immobilized enzymes were studied. The immobilized enzymes hydrolyzed N-benzoyl-1-arginine ethyl ester and L-tyrosine ethyl ester. The only preparation of immobilized thrombin possessed the coagulational activity. After the covalent binding trypsin and plasmin maintained the capacity to cause a fibrinolysis. Immobilized trypsin, plasmin, papain, chymotrypsin and urokinase exhibited the fibrinolytic effect due to convertion of plasminogen into plasmin.
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PMID:[Blood coagulating properties of immobilized proteases]. 14 May 25

In the presence of growth-limiting serum concentrations trypsin displays mitogenic activity on actively-growing but not quiescent BHK cells. These results suggest that BHK cells arrested in G1 (G0) are not sensitive to protease-induced growth stimulation. Previous work strongly suggested that the trypsin active-site is not directly involved in its mitogenic activity on BHK cells. Additional studies on denatured trypsin fragments further indicate that the molecular conformation and size of native trypsin may not be absolutely required for mitogenic activity. Cellular multiplication induced by the addition of fresh serum to quiescent BHK cultures is not inhibited by high concentrations of soybean trypsin inhibitor. Similar to our previous findings with trypsin, it has been further observed that plasmin is not sufficient to initiate the growth of BHK cells in soft agar. Trypsin also fails to enhance the growth of a thermosensitive polyoma-transformed BHK line in soft agar at the restrictive temperature. Finally, the growth of transformed BHK cells in soft agar does not display a requirement for plasminogen and is not inhibited by soybean trypsin inhibitor. These studies argue against the involvement of plasmin or other exogenous trypsin-like enzymes in the growth and transformation of BHK cells.
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PMID:Studies on the nature of protease-induced growth stimulation in normal and transformed BHK cells. 15 91

A series of substituted benzamidines has been examined for their inhibitory activity against the human serine proteases--trypsin, thrombin, plasmin, and C1s, a subunit of the first component of complement. The inhibition constants obtained for each enzyme were correlated with physical-chemical properties of the substituent group using the quantitative structure-activity relationship approach. This analysis indicated that plasmin and C1s are very similar in their interactions with substituted benzamidines. The binding of benzamidines in both enzymes was affected by electron donation from the substituent and its hydrophobicity. Thrombin-benzamidine interaction was affected only by the hydrophobicity of the substituent. Trypsin displayed a complex interaction with substituted benzamidines, and interaction was dependent on molar refractivity and molecular weight. Certain substituents deviated significantly from the interactions predicted by the analysis. These compounds, the (m- and p-amidinophenyl)pyruvic acids, when analyzed by computer modeling, suggested that direct interaction between the substituent and the enzyme surface is important in assessing the effect of substituent groups on inhibitory activity.
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PMID:Inhibition of four human serine proteases by substituted benzamidines. 15 12


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