Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Certain group A streptococci are known to possess a receptor for the human enzyme plasmin. Plasmin is a member of a super gene family that includes other serine proteases and kringle containing proteins. In this study we have examined the interaction of a group A streptococcus with structurally related proteins, including plasmin, glu-plasminogen, tissue plasminogen activator, kallikrein, factor XII, prothrombin, thrombin, trypsin, and urokinase. Our studies indicate that only the key fibrinolytic enzyme, plasmin, demonstrates significant binding activity to the group A streptococcus.
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PMID:Group A streptococci bind human plasmin but not other structurally related proteins. 255 Oct 62

The secretion of elevated levels of proteinases is considered to be a distinct property of most transformed cells. The cellular and secreted levels of plasminogen activators and collagenases have been examined in the nonmalignant human osteosarcoma (HOS), the malignant Kirsten murine sarcoma virus transformed (KHOS/NP), the temperature sensitive revertant of virus transformed HOS (KHOS-240S) and N-methyl-N'-nitro-N-nitrosoguanidine transformed HOS (MNNG/HOS) clones. Virus and MNNG transformed clones exhibit 100- and 7-fold higher cellular and and 270- and 30-fold higher extracellular plasminogen activator (PA) activity as compared with untransformed HOS controls. The cellular PA activity of the revertant clone is similar to but the secreted level is slightly higher than the HOS controls. SDS-PAGE in the presence of casein and plasminogen is consistent with the major PA species of urinary type (u-PA) and with the absence of PA inhibitor in the parent and revertant clones. The cellular levels of active collagenase are low in all the clones. However, on activation by trypsin, the two active collagenase bands of similar intensity are observed for all the lines in SDS-PAGE in the presence of gelatin. While there appears to be some elevation of secreted collagenase prior to trypsin activation, the activated collagenases appear to have the same size and activity in all of the clones.
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PMID:Synthesis and secretion of plasminogen activators and collagenases in human cells transformed by Kirsten murine sarcoma virus and N-methyl-N'-nitro-N-nitrosoguanidine. 256 62

Venous occlusion of the left arm in consenting men was induced for 10 or 20 min to stimulate local fibrinolytic and other proteases, thereby favouring the conversion of prorenin to renin. Using the two techniques cryoactivation and tryptic activation, we found that plasma active renin increased significantly after such occlusion (10 and 20 min) while prorenin rose more convincingly and progressively from 10 to 20 min. The renin increase can be partially attributed to hemoconcentration, but in vivo production and (or) local activation of prorenin to renin cannot be excluded. The prorenin rise can apparently be attributed to local extrarenal production, and not to hemoconcentration or influx, since it was progressive and neither prorenin nor renin levels were raised at all in blood circulating outside the occluded arm. Prekallikrein and plasminogen levels were elevated in occlusion plasmas, but responsibility of these enzyme systems for any enhanced activation of prorenin was not established. The trypsin inhibitory capacity was also elevated, increasing the requirement of trypsin to achieve optimal activation of prorenin, but not changing the prorenin estimate itself. Thus, prorenin appears to be released extrarenally, within the vasculature of an occluded arm, while in vitro evidence suggests that the mechanisms for its activation were stimulated. The importance of such extrarenal production and activation of prorenin for renin production under other physiological or pathophysiological conditions remains to be determined.
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PMID:Extrarenal production and activation of human plasma prorenin: the evidence after venous occlusion. 265 95

In vitro experiments have shown that proteases such as trypsin, kallikrein and plasmin may split plasma fibronectin, yielding changes in apparent mass concentration, i.e.: a decrease when using immunonephelometry (IN), and an increase when using electroimmunoassay (EIA). In the present in vivo study, plasma from 49 patients with severe infections was assayed for fibronectin by IN and EIA, and for prekallikrein, plasminogen and antithrombin. In patients with normal prekallikrein (n = 26) and plasminogen (n = 23), the agreement between the two fibronectin assay methods was good (ratio EIA/IN = 0.99 +/- 0.06); a similar good agreement was found in 45 healthy blood donors (ratio 0.97 +/- 0.02). In contrast, the 20 patients with low prekallikrein showed fibronectin values that were significantly higher by EIA than by nephelometry (ratio 1.27 +/- 0.10, p less than 0.01). Similarly, the 26 patients with low plasminogen had a significantly increased ratio (1.21 +/- 0.09, p less than 0.05). No such difference was seen, however, between patients with low or normal antithrombin. Thus, kallikrein and plasmin activation in vivo appear to increase the fibronectin concentration measured by EIA, possibly due to the formation of small fragments with increased electrophoretic motility.
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PMID:Influence of plasma protease activation on electroimmunoassay and nephelometry of plasma fibronectin in sepsis. 269 1

Malignant cells have the ability to invade and metastasize in great part because they secrete proteolytic enzymes. In order to investigate if the abnormal proteinase/antiproteinase balance of cancer bearing patients changes when the malignant tumor is destroyed, we studied 50 patients with invasive carcinoma of the cervix and 33 healthy women as a control group. Patients with cancer were treated with radiation according to the protocols of our hospital. The following serum determinations were performed: plasminogen activators (PA), cathepsin B (CB), antiproteinase alpha-1-antitrypsin (A1AT), trypsin inhibitory capacity (TIC) and antiproteolitic activity ratio (AAR), all of them before and after treatment. Serum proteolytic activity was elevated manyfold in all patients with invasive tumor as well A1AT. The antiproteolytic activity however, was significantly reduced to about 50% of its normal value in the same group of patients. In patients with good response to radiotherapy (tumor necrosis) a great reduction of proteinase activity as well as a recovery to normal of the AAR was observed. Contrary, in those with a poor response after radiation, proteolytic activity remained elevated and AAR diminished. It is concluded that serum PA, CB, A1AT and AAR values can be precise indicators of the presence of malignancy. These tests might be also of help for improving follow-up studies and for better prognostic estimates.
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PMID:[Protease-antiprotease balance in patients with invasive carcinoma of the cervix and uterus before and after radiotherapy]. 278 98

Tumor cells from a murine fibrosarcoma (FSa) produce plasminogen activator (PA), a protease that converts the zymogen plasminogen into the trypsin-like enzyme plasmin. Several studies indicate that tumor cell invasion is accompanied by proteolysis and that PA, generated by highly malignant cells, is by far the most ubiquitous protease associated with malignant transformation. Subpopulations of FSa cells were isolated by using density gradient centrifugation and the ability of these populations to form lung colonies was compared with their associated levels of PA production. Five populations of cells from a murine fibrosarcoma were separated in continuous gradients of Renografin in the density range 1.05-1.18 g/cm2. The PA activities of an unseparated control cell lysate and cell lysates of the five separated populations were determined by using [125I]fibrin as a substrate in a reaction between cell lysate and plasminogen. The assay was based on the release of digested [125I]fibrin from the surface of Petri dishes into the supernatant solution, and the results were expressed as a percentage of the total radioactivity. The cell populations collected at densities of 1.05 and 1.09 (B1, B2) were the more clonogenic with relative clonogenic efficiencies of 2.6 and 3.3 times that of the unseparated tumor population, respectively. Analysis for PA demonstrated that enzyme formation was restricted mostly to these two populations. Cells from populations 4 and 5 did not secrete increased amounts of PA and had reduced clonogenic efficiencies compared with the unseparated FSa control population. These results are consistent with the hypothesis that PA activity is correlated with the clonogenicity of tumor subpopulations isolated from a heterogeneous and complex tumor system such as the FSa.
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PMID:Plasminogen activator activity in clonogenic cell populations separated from a murine fibrosarcoma. 292 Apr 77

The relationship between proteinase-like peptidase activities and oestrogen receptor levels and status in breast cancer tissue homogenates from 61 patients with breast cancer has been evaluated. With Spearman's rank-order correlation analysis, significant positive correlations were observed between receptor levels and the activities of cathepsin-(B + L)-like, cathepsin-H-like, trypsin-like, plasminogen-activator-like and elastase-like peptidases. In addition, the activities of all but the latter enzyme were significantly higher in patients with receptor-rich tumours than in receptor-poor tumours, and this may have implications for future treatment regimens for patients with oestrogen-receptor-rich tumours. The findings reported are consistent with the suggestion that in breast cancer there may be an association between steroid receptors and proteolytic enzymes such that the release of these enzymes may be under hormonal control.
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PMID:Proteinase-like peptidase activities and oestrogen receptor levels in breast cancer tissue. 292 Dec 76

Plasmin, free of an activator, was obtained after activation of the highly purified human plasminogen by means of trypsin immobilized on Sepharose 4B and after removal of the enzyme from the system. Plasmin was acylated at the active centre using p-amidinophenyl ester of p'-anisic acid to produce the fibrinolytic agent causing a long-term effect. Inactive acyl plasmin was deacylated with the constant rate k3 = 3.10(-4) c-1 (r1/2 = 40 min) at pH 7.4 and 37 degrees. Preliminary studies of the anisoyl-plasmin effect on the system of fibrinolysis in rats showed that in the absence of fibrin clot the fibrinolytic activity was not increased immediately in the euglobulin fraction of blood but after 30 min in result of deacylation of the acyl-enzyme administered into circulation.
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PMID:[Isolation and properties of acylplasmin]. 293

Incubation of HTC rat hepatoma cells with the synthetic glucocorticoid dexamethasone rapidly inhibits plasminogen activator (PA) activity secondary to the induction of a specific acid-stable inhibitor of plasminogen activation (Cwikel, B. J., Barouski-Miller, P.A., Coleman, P.L., and Gelehrter, T.D. (1984) J. Biol. Chem. 259, 6847-6851). We have further characterized this inhibitor with respect to its interaction with both urokinase and tissue plasminogen activator, and its protease specificity. The HTC PA inhibitor rapidly inhibits urokinase and tissue plasminogen activator with an apparent second-order rate constant of 3-5 x 10(7) M-1 X s-1. The inhibitor forms stable covalent complexes with both urokinase and tissue plasminogen activator, with which plasmin, trypsin, and factor Xa apparently do not compete. Complex formation is saturable and requires the active site of the PA. The mass of the inhibitor-PA complex is 50,000 daltons greater than that of PA alone, consistent with an Mr for the PA inhibitor of 50,000 as demonstrated directly by reverse fibrin autography. The HTC PA inhibitor does not inhibit thrombin and differs in its kinetic and biochemical properties from protease nexin.
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PMID:Characterization of the dexamethasone-induced inhibitor of plasminogen activator in HTC hepatoma cells. 293 42

Mice were induced to superovulate and 2-cell embryos were cultured in Whitten's medium with 10 mg bovine serum albumin/ml (WM) as control, Medium WM with 2.3, 4.6, 23.1 or 46.2 micrograms plasmin/ml, Medium WM with 14.6, 29.1 or 145.7 micrograms plasminogen/ml, Medium WM with 0.1, 0.2, 1.1 or 2.2 micrograms trypsin/ml; Medium WM with 0.2, 0.3, 1.6 or 3.3 micrograms pronase/ml and Medium WM with 10% heat-treated bovine serum (HTBS). Proteolytic activities in the culture media were evaluated at the start of the culture period and 10 days later. Blastocyst formation was significantly reduced in cultures supplemented with pronase and in the two higher levels of trypsin when compared to that in Medium WM. More embryos developed to the blastocyst stage in Medium WM + 2.3 or 23.1 micrograms plasmin/ml and Medium WM + 14.6 micrograms plasminogen/ml than in Medium WM (P less than 0.05). The incidence of hatching was significantly greater in Medium WM than in all plasminogen- and plasmin-supplemented media except for Medium WM + 29.1 micrograms plasminogen/ml. Although not significantly different, hatching was lower in Medium WM and Medium WM + 0.1 microgram trypsin/ml when compared to Medium WM + HTBS. Similar numbers of embryos completed the hatching process in Media WM, WM + 0.1 or 0.2 micrograms trypsin/ml and WM + 0.3 micrograms pronase/ml. Since dissolution of the zona pellucida occurred within 96 h for embryos cultured in Media WM + 1.6 or 3.3 micrograms pronase/ml and WM + 1.1 or 2.2 micrograms trypsin/ml, hatching could not be evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enhancement of hatching and trophoblastic outgrowth by mouse embryos cultured in Whitten's medium containing plasmin and plasminogen. 294 70


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