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)

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

To elucidate the mechanism of synovial damage in rheumatoid arthritis, we studied the activation of latent collagenases released from adherent rheumatoid synovial cells in culture. Latent enzyme was not complexed with alpha2 macroglobulin, the prinicpal proteinase inhibitor in serum, and could be activated by trypsin in the presence of alpha2 macroglobulin if sufficient proteinase was added to saturate inhibitor. Latent collagenase bound half as effectively to collagen fibrils as active enzyme. Plasmin was a threefold better activator of latent enzyme than trypsin and could be generated by addition of plasminogen to synovial-cell cultures. Production of both collagenase and plasminogen activator was inhibited by dexamethasone (10(-9) M). These studies emphasize in importance of control of activation in regulation collagenase activity, It is likely that rheumatoid synovium produces both latent collagenase and plasminogen activator; plasmin is activated from its zymogen, plasminogen, present in inflamed tissues, and in turn activates collagenase.
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PMID:Endogenous activation of latent collagenase by rheumatoid synovial cells. Evidence for a role of plasminogen activator. 6 27

In untreated patients with inoperable lung cancer, serum levels of alpha1-antitrypsin were found significantly increased in comparison to patients with non malignant diseases of the lung, alpha2-macroglobulin levels were unchanged in both groups of patients. There was also no difference in alpha2-macroglobulins in cancer patients reacting with DNCB and in non-reactors. Thus alpha2-macroglobulin levels do not seem to correlate with the immunestatus of cancer patients. Proteinase inhibitors are involved in a variety of biological processes including blood, clotting, digestion, and sperm capacitation. alpha1-antitrypsin, a alpha-globulin with a molecular weight of about 60,000 has been found to be decreased in patients' serum under several pathological conditions. A clear correlation exists between alpha1-antitrypsin deficiency and hereditary pulmonary emphysema (1, 2), respiratory distress syndrome (3), and juvenile cirrhoses of the liver (4). Elevated serum levels of alpha1-antitrypsin have also been found in some cancer cases. Thirty years ago a cancer test was developed on the basis of differences in the antiproteolytic activity in cancer patients' sera and in patients with other non-neoplastic diseases (5, 6). Several authors have tried to confirm these early data regarding specifity and sensitivity with respect to a screening test for cancer (7, 8). Methods of these authors were based mainly on enzyme substrate inhibition assays by addition of the patients' sera. Recently a commercially available test, based on immune-precipitation according to Mancini (9), has been developed (Behring-Werke, Partigen). By using this standardized method for determinating alpha1-antitrypsin, Harris et al. have recently demonstrated that patients with inoperable lung cancer have significantly elevated levels of this antiprotease in their sera (10), in comparison to patients with non malignant diseases of the lung. alpha2-macroglobulin is a serum protein with a molecular weight of 800,000 and with known antiprotease activity and can therefore bind trypsin, plasmin, elastase, and collagenase and it is known that alpha2-macroglobulin decreases with increasing of age. Changes of alpha-macroglobulin have also been observed in several pathological conditions (11). James et al. 4ave found decreases in serum of myeloma patients (12). An association between the development and function of lymphocytes and alpha2-macroglobulin has been suggested by several authors (13, 14). This alpha2-globulin has also been demonstrated on the surface of peripheral blood lymphocytes (15) and there is evidence that it is synthesized by lymphocytes (16). The purpose of the present study was to determine serum alpha1-antitrypsin levels in patients with inoperable lung cancer and to determine whether there is also an inverse correlation to alpha2-macroglobulin. It was further attempted to correlate alpha2-macroglobulin with general immunological parameters, as it is known that patients with lung cancer show a decreased general immune-reactivity (17).
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PMID:Serum levels of alpha1-antitrypsin and alpha2-macroglobulin in lung cancer. 6 86

Collagenase released from rheumatoid synovial cells in culture is in a latent form. Subsequently, it may be activated by limited proteolysis. This study was designed to determine whether latent enzyme could bind to collagen fibrils and await activation. The data showed that latent collagenase bound to fibrils equally well at 24 degrees C and 37 degrees C, but that this represented little more than half the binding achieved by active enzyme at temperatures lower than that at which fibrils can be degraded. Binding was not inhibited by the presence of alpha2 macroglobulin, the principal proteinase inhibitor of plasma which cannot complex with inactive or latent collagenase but readily complexes with active species of enzyme. The data support the hypotheses that inactive forms of collagenase accumulate in tissues by binding to substrate, and that activation by proteases such as plasmin initiates collagen breakdown.
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PMID:Binding of latent rheumatoid synovial collagenase to collagen fibrils. 7 45

Because rheumatoid inflammation is associated with the presence of large numbers of leukocytes in joint effusions, the question of whether enzymatic splitting of collagen and fibrin can lead to generation of chemotactic factors was investigated. Fibrinogen was purified from the plasma of four different species, and the homogeneity of the preparations was established by physicochemical and immunologic techniques. Fibrin was prepared and then lysed with plasmin to obtain fibrin degradation products (FDP). Similarly, purified collagenase was used to lyse collagen in vitro, and the chemotactic activity of the reaction mixtures was analyzed. The experiments presented indicate that fibrinogen, fibrin, and plasmin do not possess any intrinsic chemotactic activity. However, when fibrin was split by plasmin, FDP of human, bovine, sheep, and equine origin all proved to be strong leukotactic agents for polymorphonuclear leukocytes (PMN). Purified collagenase per se was found to be a cell type-specific chemotactic agent for PMN. Not only were collagen degradation products not chemotactic, but they also inhibited the leukotactic activity of the purified collagenase. Furthermore, this inhibition of the chemotactic activity of collagenase was independent of its enzymatic activity. The results presented suggest that there is a direct correlation between the process of fibrinolysis and the chemotactic attraction of leukocytes and between the presence of collagenase and leukotaxis. This system may serve as a model to explain the mechanisms by which cells accumulate in inflamed joints.
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PMID:The chemotaxis of selected cell types to connective tissue degradation products. 16 19

The relationship between activation of resting chick embryo fibroblasts by proteases and proteolytic alteration of the cell surface has been investigated. Five different proteases were examined: trypsin, collagenase, plasmin, alpha-chymotrypsin, and thrombin. All of these proteases, when added to the culture medium at concentrations of 0.08-2.2 mug/ml, stimulated deoxyglucose uptake and induced cell division. The absolute levels of stimulation depended on the specific protease. Activation ranged from a doubling in cell number in 24 hr for trypsin and thrombin down to a 47% increase in cell number for alpha-chymotrypsin. Except in the case of thrombin, the stimulatory effects of these proteases correlated with breakdown of Z, a protein which is the major chick surface protein as revealed by lactoperoxidase-catalyzed iodination and which disappears upon transformation. In the case of thrombin, stimulatory concentrations brought about no detectable loss of surface components. Thus loss of Z is not a necessary condition for activation of chick fibroblasts; it may be a sufficient condition for activation of part of the cell population.
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PMID:Effect of proteases on activation of resting chick embryo fibroblasts and on cell surface proteins. 17 Oct 80

Complex formation in vitro between human alpha2-macroglobulin and the human proteases cationic trypsin, chymotrypsin, plasmin and granulocyte elastase and collagenase was clearly visualized by the use of thin-layer electrofocusing in polyacrylamide gel followed by electrophoresis in agarose gel containing antibodies against human alpha2-macroglobulin. The technique permits semi-quantitative determination of the amount of complex and can demonstrate the formation of complexes between alpha2-macroglobulin and protease in vivo in ascitic fluid in peritonitis.
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PMID:Demonstration and semiquantitative determination of complexes between various proteases and human alpha2-macroglobulin. 17 30

A large amount of plasma low density lipoprotein is present in human aortic intima, and this can be removed and measured by electrophoresis directly from the minced tissue into an antibody-containing gel. We now find that, in addition to this electrophoretically mobile lipoprotein, there is an immobilized lipoprotein fraction than can be released from lesions by incubation of the tissue sample with plasmin or other proteolytic enzymes after the mobile lipoprotein has been removed. The concentration of immobilized lipoprotein is highly correlated with the concentration of the residual cholesterol (not mobile on electrophoresis) that has accumulated in the tissue (r = 0.702; P less than 0.001). Thus, in normal intima and early gelatinous lesions it is about 15% of the concentration of mobile lipoprotein, whereas in the atheroma lipid layers of fibrous or gelatinous plaques it may be 2 or 3 times greater than the concentration of mobile lipoprotein. This suggests that immobilization of plasma lipoprotein is an intermediate step in the irreversible deposition of extracellular cholesterol in atherosclerotic lesions. Incubation with plasmin allowed maximum release of lipoprotein: plasmin = crude collagenase greater than trypsin greater than "pure" collagenase greater than chondroitinase ABC in order of their relative effectiveness. The concentration of immobilized lipoprotein was significantly correlated (r = 0.793; P less than 0.001) with the concentration in the tissue of fibrin or other insoluble derivatives of fibrinogen ("fibrin"). In aliquots of lesions incubated with varying amounts of plasmin for varying times there was a constant relation between release of lipoprotein and release of fibrin-degradation products. Together, these findings suggest that the lipoprotein is associated with insoluble "fibrin". This appears to be of considerable clinical interest, suggesting a synergism between lipoprotein and fibrinogen in the accumulation of lipid in lesions.
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PMID:The release of an immobilized lipoprotein fraction from atherosclerotic lesions by incubation with plasmin. 18 79

1. Cathepsin B, a tissue (lysosomal) proteinase, and two humoral proteinases, plasmin and kallikrein, activate the latent collagenase ('procollagenase') which is released by mouse bone explants in culture. Other lysosomal proteinases (carboxypeptidase B, cathepsin C and D) and thrombin did not activate the procollagenase. Dialysis of the culture fluids against 3M-NaSCN at 4 degrees C and, for some culture fluids, prolonged preincubation at 25 degrees C also caused the activation of procollagenase. 2. In all these cases, activation of procollagenase involved at least two successive steps: the activation of an endogenous latent activator present in the culture fluids and the activation of procollagenase itself. 3. An assay method was developed for the endogenous activator. Human serum, bovine serum albumin, casein and cysteine inhibited the endogenous activator at concentrations that did not influence the collagenase activity. N-Ethylmaleimide and 4-hydroxy-mercuribenzoate stimulated the endogenous activator, but iodoacetate had no effect. 4. It is proposed that cathepsin B, kallikrein and plasmin may play a role in the physiological activation of latent collagenase and thus initiate degradation of collagen in vivo. This may occur whatever the molecular nature of procollagenase (zymogen or enzyme-inhibitor complex) might be.
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PMID:Further studies on the activation of procollagenase, the latent precursor of bone collagenase. Effects of lysosomal cathepsin B, plasmin and kallikrein, and spontaneous activation. 19 17

We have observed that treatment of rabbit synovial fibroblasts with proteolytic enzymes can induce secretion of collagenase (EC 3.4.24.7) and plasminogen activator (EC 3.4.21.-). Cells treated for 2-24 hr with plasmin, trypsin, chymotrypsin, pancreatic elastase, papain, bromelain, thermolysin, or alpha-protease but not with thrombin or neuraminidase secreted detectable amounts of collagenase within 16-48 hr. Treatment of fibroblasts with trypsin also induced secretion of plasminogen activator. Proteases initiated secretion of collagenase (up to 20 units per 10(6) cells per 24 hr) only when treatment produced decreased cell adhesion. Collagenase production did not depend on continued presence of proteolytic activity or on subsequent cell adhesion, spreading, or proliferation. Routine subculturing with crude trypsin also induced collagenase secretion by cells. Secretion of collagenase was prevented and normal spreading was obtained if the trypsinized cells were placed into medium containing fetal calf serum. Soybean trypsin inhibitor, alpha(1)-antitrypsin, bovine serum albumin, collagen, and fibronectin did not inhibit collagenase production. Although proteases that induced collagenase secretion also removed surface glycoprotein, the kinetics of induction of cell protease secretion were different from those for removal of fibronectin. Physiological inducers of secretion of collagenase and plasminogen activator by cells have not been identified. These results suggest that extracellular proteases in conjunction with plasma proteins may govern protease secretion by cells.
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PMID:Proteases induce secretion of collagenase and plasminogen activator by fibroblasts. 20 72


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