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)

An insoluble fibrinolytic enzyme with a molecular weight of approximately 30,000, was purified from the human spleen. A single protein band possessing fibrinolytic activity was obtained on polyacrylamide gel disk electrophoresis at pH 4.5. The enzyme, tentatively termed spleen fibrinolytic proteinase (SFP), degraded fibrinogen at neutral pH following Michaelis-Menten kinetics. The fibrinogenolytic activity was not inhibited by t-AMCHA, a specific plasmin inhibitor. SFP barely degraded certain synthetic ester or polypeptide substrates for trypsin, chymotrypsin, plasma, Xa, elastase and collagenase. These results indicate a different nature for SFP compared to other enzymes examined. SFP was found to digest no elastin and its fibrinogenolytic activity was strongly inhibited by STI, indicating that it was not an elastase. SFP required neither Zn++ nor CA++ for its fibrinogenolytic activity, indicating that it differed from metal-dependent proteinases such as collagenase. SFP was inhibited by DFP but not by TLCK, suggesting that it contains an active serine residue, but no trypsin type histidine at its active center. These results appear to show that SFP is a unique proteinase in the spleen, which is capable of degrading fibrin and fibrinogen at neutral pH.
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PMID:Human spleen insoluble fibrinolytic proteinase acting at neutral pH: its partial purification and characterization. 626 69

Thirty-three strains of anaerobic bacteria isolated from human clinical specimens were examined for the presence of heparinase, hyaluronidase, chondroitin sulfatase, gelatinase, collagenase, fibrinolysin, lecithinase, and lipase activities. Pronounced heparinase activity was limited to species of the genus Bacteroides. A number of species of the genera Bacteroides and Clostridium produced hyaluronidase and chondroitin sulfatase. Gelatinase, collagenase, and fibrinolysin activities were encountered in isolates of the genera Bacteroides, Clostridium, and Peptostreptococcus. All strains capable of degrading collagen also hydrolyzed other protein substrates. Lipolytic activity was minimal among these anaerobic bacteria. No specific hydrolytic activity was consistently associated with the isolates.
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PMID:Hydrolytic enzymes of anaerobic bacteria isolated from human infections. 626 57

1. Rabbit bones in tissue culture synthesize an inhibitor of collagenase during the first 4 days of culture. 2. The inhibitor was purified by a combination of gel filtration, concanavalin A--Sepharose chromatography, ion-exchange chromatography and zinc-chelate affinity chromatography. 3. The purified inhibitor migrated as a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had a mol.wt. of 28000. 4. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase, neutral proteinase III (proteoglycanase), human leucocyte collagenase and gelatinase, but not thermolysin or bacterial collagenase. The serine proteinases plasmin and trypsin were not inhibited. 5. The inhibitor interacted with purified rabbit bone collagenase with 1:1 stoichiometry. 6. The inhibitory activity was lost after incubation for 1 h at 90 degrees C, after treatment with trypsin (250 micrograms/ml) at 37 degrees C for 30 min and after reduction and alkylation.
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PMID:Purification of rabbit bone inhibitor of collagenase. 627 44

A spontaneous mammary adenocarcinoma (AC) from an inbred female rat was investigated with regard to secretion of neutral proteases. Cultures of neoplastic epithelial cells derived from the tumour secreted an enzyme that fulfilled the criteria for a specific collagenase. In contrast to cultures of non-neoplastic cells, tumour collagenase was present as an active enzyme, since treatment with trypsin or p-aminophenylmercuric acetate (APMA) did not increase activity. The neoplastic cells were also prolific producers of plasminogen activator (PA). Dexamethasone (Dex) (10(-6)M) markedly reduced the levels of both enzymes. Addition of tranexamic acid (TA), an inhibitor of plasmin and of plasminogen activation, did not affect collagenase activity, even at 10(-1)M TA, nor did latent collagenase accumulate. Latent collagenase was secreted in culture by normal fibroblasts from neonatal rat lungs. This latent enzyme was activated by the addition of tumour cell medium plus plasminogen, but this effect was inhibited by the addition of TA. These results demonstrate that the neoplastic cells themselves secrete collagenase as an active enzyme. PA is also secreted, is not involved with tumour collagenase, but is capable, in the presence of plasminogen, of activating latent collagenase produced by the non-neoplastic cells within the tumour or in the surrounding tissue. This tumour possesses potent collagenolytic ability in vitro which may be partly responsible for its rapid invasion in vivo.
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PMID:Rat mammary carcinoma cells secrete active collagenase and activate latent enzyme in the stroma via plasminogen activator. 627 36

Three human basement membranes, glomerular basement membrane (GBM) from renal cortex, alveolar basement membrane (ABM) from lung parenchyma and trophoblast basement membrane (TBM) from the terminal villi of placenta have been isolated by sieving and sonication techniques. Canine GBM and ABM were also prepared. There were marked differences among the membranes from human tissues. Compared to GBM, TBM had very little collagen but contained high concentrations of charged amino acids. ABM was intermediate in composition between GBM and TBM and contained desmosine and isodesmosine indicative of the presence of elastin. Canine ABM (c-ABM) did not contain desmosine or isodesmosine. In the canine system an antigen was detected in ABM which was not present in GBM. The membrane preparations were analyzed for fibronectin content using a specific antiserum to fibronectin. This glycoprotein could not be detected in GBM whereas it was present in ABM in amounts up to 0.8% and in TBM in amounts as high as 7.2%. All the membranes induced the formation of precipitating antibodies in rabbits. Soluble material obtained from the membranes by alkali extraction, reduction of disulfide bonds, enzymatic digestion with elastase, plasmin or collagenase provided immunologically reactive fragments. These soluble fragments gave reactions of identity among the three basement membranes in immunodiffusion reactions in gels with antisera raised to all three BMs. The finding that plasmin digests basement membranes suggests that it may play a role in connective tissue remodeling. The fact that elastase degrades basement membranes provides an endogenous system for injury which may be triggered by infections.
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PMID:Human basement membrane antigens from lung, placenta and kidney. 627 69

The relationship of a basement membrane collagen degrading enzyme (BM collagenase) and plasminogen activator (PA) was studied in a number of non-malignant and malignant human and murine cell lines. Several non-malignant cell lines secreted significant amounts of PA but not detectable BM collagenase activity whereas the malignant cell lines, with one exception, secreted both enzymes. Therefore, the secretion of BM collagenase appears to be a characteristic of many malignant cells whereas PA is synthesized also by normal cells. The BM collagenase needed proteolytic activation for maximal activity indicating that it is secreted in a latent form. The addition of plasminogen to the culture medium of human fibrosarcoma cells (HT-1080) resulted in maximal activation of the enzyme. Plasmin, but not plasminogen, increased the activity of partially purified enzyme protein. Accordingly, the activation of latent BM collagenase in vivo may be facilitated by PA through the conversion of plasminogen to plasmin. It is suggested that the secretion of BM collagenase concomitantly with PA is a prerequisite for metastasis.
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PMID:Secretion of basement membrane collagen degrading enzyme and plasminogen activator by transformed cells--role in metastasis. 629 70

Membranes removed during open-sky vitrectomy have been characterized by electron microscopy, reaction with anti-human fibrinogen, susceptibility to enzymatic digestion, amino acid analysis, and electrophoresis in sodium dodecyl sulfate. There were significant differences between longstanding and newly formed membranes. Longstanding membranes contained substantial amounts of hydroxyproline, glycine, and hydroxylysine, were capable of digestion by collagenase but not by plasmin, yielded faint positive results with anti-human fibrinogen, and showed fibrils characteristic of collagen by electron microscopy. After digestion with pepsin, electrophoresis revealed bands that migrated the same distance as vitreous collagen chains. This type of membrane is evidently collagenous in nature. A second type of membrane, which developed in the course of vitrectomy, contained no hydroxyproline, only traces of hydroxylysine, and relatively small amounts of glycine, was digested by plasmin, yielded strong positive results with anti-human fibrinogen, and showed fibers that were not characteristic of collagen by electron microscopy. Electrophoresis demonstrated bands similar to authentic fibrin in these newly formed membranes. These data suggest that this second type of membrane is composed largely of fibrin. Prevention of the formation of this second type of membrane during vitrectomy may require the addition of agents that inhibit fibrin formation.
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PMID:Characterization of membranes removed during open-sky vitrectomy. 635 52

The role of plasminogen activator in ovulation was investigated using the inhibitor, trans-aminomethylcyclohexane carboxylic acid (t-AMCHA). In the regular cycle rat, the plasminogen activator activity of the follicles increased from the diestrus to the estrus phase. In the latter phase, a proteolytic enzyme which was not inhibited by t-AMCHA appeared. After ovulation, the plasminogen activator activity decreased. When ovulation was induced in immature rats by pregnant mare serum gonadotrophin and human chorionic gonadotrophin, remarkable fibrinolytic activity appeared in the ovaries immediately before ovulation. When t-AMCHA was given in the ovulation-induced rats, the fibrinolytic activity of the ovaries was suppressed, the number of ovulated ova decreased and the timing of ovulation was delayed. When t-AMCHA solution was given to rats in the proestrus phase, ovulation was almost completely suppressed, but aprotinin solution exerted no effect on ovulation. These results suggest that plasminogen activator is a key enzyme in ovulation, and that the chain reaction from plasminogen activator to proteolytic enzyme (including collagenase) is of greater importance than that of plasminogen activator to plasmin.
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PMID:The role of plasminogen activator in ovulation. 642

The correlation between activation of macrophages and increased secretion of plasminogen activator suggests that macrophages are exposed to the protease plasmin. Incubation of 125I-labeled, caseinate-elicited guinea pig peritoneal macrophages with plasmin cleaves a surface protein, gp160, characterized previously by its sensitivity to trypsin. The gp160 fragments produced by plasmin (fr85 and fr71), which remain disulfide-bonded in the membrane, comigrate with the fragments produced by trypsin, indicating close or identical cleavage sites. No other detectable 125I-labeled surface component is cleaved by plasmin. Neither gp160 nor any other detectable 125I-labeled surface component was cleaved by a series of other proteases associated with inflammation including thrombin, collagenase, pancreatic elastase, leukocyte elastase, cathepsin G, and urokinase. Analysis with the use of homogeneous plasmin from guinea pig plasma shows that concentrations as low as 50 micrograms/ml cause measurable cleavage of gp160 in 30 min.
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PMID:Macrophage surface component gp160: sensitivity to plasmin and other proteases. 646 Aug 5

Activation of bovine plasma prekallikrein was investigated with several proteinases. Highly purified bovine plasma prekallikrein was rapidly activated to kallikrein [EC 3.4.21.8] by bovine activated Hageman factor, trypsin [EC 3.4.21.4] and Pronase P (proteinases from Streptomyces griseus) and more gradually by papain [EC 3.4.22.2] and ficin [EC 3.4.22.3]. Activation of prekallikrein was also observed with bovine plasmin [EC 3.4.21.7], but not with bovine clotting factors Xa (Stuart factor) [EC 3.4.21.6] and IXa (Christmas factor) or thrombin [EC 3.4.21.5]. Urokinase [EC 3.4.99.26], Reptilase, collagenase [EC 3.4.24.3], elastase [EC 3.4.21.11], alpha-chymotrypsin [EC 3.4.21.1], Nagarse [EC 3.4.21.14], and stem bromelain [EC 3.4.22 4] did not convert prekallikrein to kallikrein. Plasma kallikrein activated to Hageman factor released kinin rapidly from bovine high molecular weight (HMW) kininogen. However, from bovine low molecular weight (LMW) kininogen, liberation of kinin was extremely slow. The kallikrein activity was inhibited by soybean trypsin inhibitor (SBTI), Trasylol, diisopropylfluorophosphate (DFP), and N-alpha-tosyl-L-lysine chloromethylketone (TLCK), but not by egg-white trypsin inhibitor (EWTI), lima bean trypsin inhibitor (LBTI), heparin or hexadimethrine bromide (Polybrene). The kallikrein formed an enzyme-inhibitor complex with SBTI and Trasylol, but not with LBTI. Prekallikrein did not react with SBTI. Prekallikrein consists of a single polypeptide chain of molecular weight about 90,000, as estimated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Activation of prekallikrein by Hageman factor was found to involve cleavage of the single peptide bond on the disulfide-bridged polypeptide chain, and no change of molecular weight was observed during the activation. The peptide bond cleaved in prekallikrein by the activation was an Arg-X peptide bond on a disulfide-bridged polypeptide chain.
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PMID:Studies on prekallikrein of bovine plasma. II. Activation of prekallikrein with proteinases and properties of kallikrein activated by bovine Hageman factor. 676 24


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