Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The function and several of the structural features of the C1 inactivator protein isolated from the plasma of a mother and daughter with the variant form of hereditary angioneurotic edema have been examined. These abnormal inhibitors shared immunologic identity with the normal C1 inactivator protein; however, they were inactive in inhibiting the functional activity of C1s. Analysis of the abnormal inhibitors by sodium dodecyl sulfate (SDS) acrylamide gel electrophoresis suggested that each consisted of a single polypeptide chain, the mobility of which was slower than that of the normal C1 inactivator. The apparent molecular weight of the patients' inhibitors was 109,000 daltons as contrasted to 105,000 daltons, that of the normal C1 inactivator. The abnormal inhibitors failed to form a complex with C1s or plasmin as analyzed by SDS-acrylamide gels. The large proteolytic derivatives resulting from the plasmin- and trypsin-induced degradation of the abnormal inhibitors were approximately 3,000 daltons heavier than the corresponding products derived from normal C1 inactivator. Thus, the structural abnormality identified appeared to be a property of the core molecule. Treatment of the inhibitors with neuraminidase failed to demonstrate a difference between the normal and patient-derived C1 inactivator molecule. Neither were major differences found between the amino acid composition of the defective and normal inhibitors; however, the acidic amino acids tended to be higher in the patients' inhibitors, and the phenylalanine content lower. Thus, these studies have identified both structural and functional abnormalities in the C1 inactivator protein isolated from two related patients with hereditary angioneurotic edema. Examination of the interaction between endopeptidases and the inhibitors has further delineated the abnormal structural features.
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PMID:Studies on human plasma C1 inactivator-enzyme interactions. II. Structural features of an abnormal C1 inactivator from a kindred with hereditary angioneurotic edema. 12 52

We have asked whether treatment of normal cultured cells with proteases, other hydrolytic enzymes, or serum can convert them into transient phenocopies of transformed cells with respect to the very high rate of hexose transport characteristic of transformed cells. Treatment of density-inhibited cultures of normal chick embryo fibroblasts with trypsin, plasmin, neuraminidase, or hyaluronidase stimulated their rate of 2-deoxyglucose uptake to a level only marginally higher than that seen in normal exponentially growing cultures, and only 35-45% of that seen in transformed cultures. Addition of the hydrolytic enzymes to growing cell cultures had little effect on 2-deoxyglucose uptake. Serum, however, could stimulate 2-deoxyglucose uptake all the way up to the transformed level. Even though the hydrolases and serum differed in their ability to stimulate 2-deoxyglucose uptake, both reagents were capable of stimulating cell division equally well. Evidence is presented suggesting that the hexose transport rate is controlled by serum factors, and that proteolysis can affect the response of the cells of these factors.
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PMID:Hydrolase and serum treatment of normal chick embryo cells: effects on hexose transport. 12 53

During digestion of highly purified bovine factor VIII or neuraminidase-treated human factor VIII by plasmin the procoagulant activity is destroyed more rapidly than the aggregating activity. At an intermediate stage, fragments are transiently formed, which inhibit platelet aggregation by the respective undigested materials, but without corssed inhibition. During proteolysis by plasmin, human factor VIII retains antigenic and restocetin cofactor properties. Contrary to previous observations obtained with less purified preparations, plasmin digest of human or bovine factor VIII do not inhibit ADP-induced platelet aggregation. Thrombin and reptilase do not modify the aggragating activities of bovine and neuraminidase-treated human factor VIII.
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PMID:Factor VIII and human platelet aggregation. IV. Effect of proteolytic enzymes on platelet aggregation by factor VIII. 13 76

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

The release of beta-lysin, which followed the intravenous injection of antigen-antibody complexes, did not take place when these complexes were added to citrated whole blood but did occur in heparinized blood. beta-Lysin release in heparinized blood was inhibited by citrate but were reversed by the addition of calcium ions that implicated complement reactions. Fourteen different enzymes were added to platelet-rich plasma (PRP). Streptokinase, neuraminidase, papain, phospholipase C, sulfatase, and trypsin caused platelets to release significant quantities of beta-lysin, whereas elastase, phosphatase, protease, ribonuclease A, hyaluronidase, lipase, and pepsin caused little or no increase in the plasma beta-lysin concentration. One enzyme, fibrinolysin, inactivated beta-lysin faster than it was released. The enzyme-induced release of beta-lysin from PRP was often accompanied by a reduction in the number of platelets. The intravenous injection of streptokinase, neuraminidase, and sulfatase caused in vivo releases of beta-lysin into the plasma. The platelet-aggregating substances collagen, arachidonic acid, and adenosine 5'-diphosphate caused beta-lysin to be released from PRP. The platelet-aggregating substances L-epinephrine, zymosan, fibrinogen, reserpine, and serotonin caused little or no release of beta-lysin from platelets. The results of this study indicate that the release of beta-lysin during antigen-antibody-complement reactions, blood coagulation, phagocytosis, and inflammation could be enzyme mediated.
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PMID:Release of beta-lysin from platelets caused by antigen-antibody complexes, purified enzymes, and platelet-aggregating substances. 84 4

Transforming growth factor-beta (TGF-beta), a regulator of cell growth and differentiation, is secreted by most cultured cells in latent form (L-TGF-beta). Activation of L-TGF-beta can be achieved by various physico-chemical treatments, including acidification, alkalinization, heating and chaotropic agents. Proposed physiological activators include proteinases and glycosidases, which, however, only lead to limited activation (15-20% of the total TGF-beta activity after acidic activation). In the present study L-TGF-beta 1 partially purified from human platelets was not activated by treatment with neuraminidase or the proteinases plasmin, endoproteinase Arg-C, elastase and chymotrypsin. The mechanism of activation of L-TGF-beta was further assessed by using the human glioblastoma cell line 308, which releases biologically active TGF-beta 2. Factor(s) secreted by 308 glioblastoma cells were found to be able to activate partially purified L-TGF-beta 1 from human platelets. Our finding may prove to constitute a physiologically relevant mechanism for the activation of latent forms of TGF-beta in vivo.
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PMID:Activation of human platelet-derived latent transforming growth factor-beta 1 by human glioblastoma cells. Comparison with proteolytic and glycosidic enzymes. 183 Feb 5

Bovine plasma protein C inhibitor was purified; it was then characterized in comparison with human protein C inhibitor. The specific inhibitory activity of the purified inhibitor for bovine activated protein C was 8,500 times that of the inhibitor in plasma. The purified inhibitor showed a single band with Mr 56,000 by SDS-PAGE at pH 7.0, and two bands at pH 8.8, a major one with Mr 56,000 and a minor one with Mr 105,000, under both unreduced and reduced conditions. The pI range of the inhibitor was between 4.4 and 6.1. The Mr of the inhibitor was reduced by treatment with neuraminidase, O-glycanase, and also with glycopeptidase-A, suggesting that the inhibitor has both Asn-linked and Ser/Thr-linked carbohydrate chains. Twenty-seven of the NH2-terminal 49 amino acid residues of the bovine inhibitor, which lacks the first 4 residues from the NH2-terminal amino acid sequence of human inhibitor, were identical to those of the human inhibitor. The bovine inhibitor inhibited bovine and human activated protein C, human thrombin, Factor Xa, Factor XIa, and plasma kallikrein with Ki = 1.0, 5.2, 2.6, 3.0, 1.3 X 10(-8) M, and 4.5 X 10(-9) M, respectively. The inhibitory rates for activated protein C and thrombin were accelerated significantly in the presence of heparin or negatively charged dextran sulfate. However, the acceleration by heparin or dextran sulfate for the inhibition of Factor Xa, Factor XIa, and plasma kallikrein was not significant. The bovine inhibitor did not inhibit human Factor XIIa or plasmin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bovine plasma protein C inhibitor with structural and functional homologous properties to human plasma protein C inhibitor. 216 Apr 49

Removal of sialic acid from the von Willebrand factor (vWF) subunit exposes additional cleavage sites in the amino-terminal region that are associated with loss of large multimers. The extent of large multimer loss was evaluated by examining the sites of subunit cleavage of native and carbohydrate-modified vWF after treatment with trypsin, chymotrypsin, or plasmin. In the presence of proteinase inhibitors, purified vWF was treated with neuraminidase alone to remove 90% to 95% of the sialic acid or with neuraminidase and beta-galactosidase to remove the sialic acid and 45% to 50% of the D-galactose, with little or no loss of large multimers observed. Digestion of native vWF with trypsin produced the greatest loss of large multimers, while chymotrypsin produced less and plasmin produced the least. Large multimer loss was more extensive with each enzyme after carbohydrate modification of vWF. The extent and approximate location of subunit cleavage was determined by immunoblotting and monoclonal antibody epitope mapping. Trypsin, chymotrypsin, and plasmin were shown to produce both amino- and carboxyl-terminal fragments. The number, location, and relative quantities of carboxyl-terminal fragments produced were unchanged after carbohydrate modification. However, digestion of the amino-terminal region was considerably more extensive after carbohydrate modification as judged by a marked decrease or absence of the larger fragments seen when native vWF was digested, and by the appearance of new smaller molecular mass species. Therefore, the greater loss of large multimers that occurs after carbohydrate modification is likely to be the result of cleavages in the amino-terminal region of the molecule. By protecting the vWF subunit against amino-terminal cleavage, sialic acid inhibits the loss of large multimers.
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PMID:Sialic acid prevents loss of large von Willebrand factor multimers by protecting against amino-terminal proteolytic cleavage. 246 Jan 62

Human chromosomal DNA encoding single-chain urokinase-type Plasminogen Activator (scu-PA, or pro-urokinase) was inserted in an expression plasmid and transfected in human A431, mouse LB6 and CHO cells. LB6 cells were also transfected with a Bovine Papilloma Virus derivative containing the scu-PA gene. Human scu-PA was purified from cell supernatants of recombinant clones and characterized for structure and function. All recombinant scu-PAs are undistinguishable from human urine-derived scu-PA for peptide backbone, but possess a higher sugar content, as revealed by SDS-PAGE analysis after digestion with glycopeptidase F. This difference is partly due to an increased sialic acid content, as shown by analysis of neuraminidase-treated scu-PAs. No difference was found, however, among recombinant and natural scu-PAs in the kinetics of conversion into two-chain active forms (tcu-PAs) by human plasmin, and in the KM and kcat values of tcu-PA activity on the chromogenic substrate S-2444 and on human plasminogen. Also, recombinant and non-recombinant tcu-PAs displayed similar dose-response curves for binding to the endothelial inhibitor PAI-1. In conclusion, the glycosylation pattern of u-PA does not affect its interaction with the plasma proteins directly involved in its fibrinolytic function.
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PMID:The differential glycosylation of human pro-urokinase from various recombinant mammalian cell lines does not affect activity and binding to PAI-1. 251 81

The effects of a range of commercially available proteases and glycosidases on blastocyst development and hatching were examined on rabbit embryos cultured from the morula stage in a defined medium supplemented with charcoal-treated bovine serum albumin. The proteases tested were trypsin, alpha-chymotrypsin, thrombin, elastase, plasmin, papain, clostripain, collagenase, Streptomyces griseus protease and cathepsin C. The glycosidases tested were neuraminidase, alpha-mannosidase, beta-galactosidase and hyaluronidase. None of these enzymes appeared to stimulate blastocyst growth. The only enzymes which digested the embryonic investments, the zona and mucin coat, sufficiently to cause complete blastocyst hatching were trypsin and Streptomyces griseus protease at relatively low concentrations (250 ng/ml) and chymotrypsin and elastase at higher concentrations.
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PMID:A survey of the effects of proteases and glycosidases on culture of rabbit morulae to blastocysts. 353 6


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