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)

Single-chain urokinase-type plasminogen activator scu-PA is the precursor of double-chain urokinase tcu-PA , which has a much higher intrinsic catalytic activity than other zymogens of the serine protease family. To restore the "zymogen triad" of Asp-His-Ser in the serine protease family, the mutant gene of scu-PA mscu-PA, Ala(175)right curved arrow Ser(175), Tyr(187)right curved arrow His(187) was constructed by the method of oligonucleotide-directed, site-specific mutagenesis in order to reduce its intrinsic catalytic activity. mscu-PA was expressed in E. coli BL21. After denaturation and renaturation in vitro, the mscu-PA was purified to homogeneity by SP-Sepharose ion-exchange chromatography, Sephacryl S-200 chromatography and Benzamidine-Sepharose affinity adsorption. mscu-PA had the same activity to plasmin as scu-PA. The catalytic efficiency measured by k(cat)/K(m) to synthetic substrate S(2444) was 2.5-fold lower than that of scu-PA, and the activity against Glu-plasminogen was also reduced. After activation by plasmin, mtcu-PA and tcu-PA had similar catalytic efficiency against S(2444) and Glu-plasminogen. The results suggest that the intrinsic catalytic activity of mscu-PA be really reduced after restoring the "zymogen triad".
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2000
PMID:Construction and Characterization of a Mutant of Single-chain Urokinase-type Plasminogen Activator Ser(175)-His(187)-mscu-PA 1211 Sep 8

The recombinant single chain urokinase-type plasminogen activator (rscu-PA) and a mutant constructed by in vitro site-specific mutagenesis of Argl54 in rscu-PA to Glul54 (Glul54-mscu-PA) were both expressed in E. coli. The expressed products were both purified to homogeneity by in vitro denaturation and renaturation, followed by Zn(2+) selective precipitation and immuno-affinity chromatography. The plasmin sensitivity assay indicated that the activation of this single chain Glul54-mscu-PA by plasmin was essentially identical to that of rscu-PA. After activation by plasmin, the kinetic constants against synthetic substrate S2444 of the resulted two chain form of Glul54-mscu-PA (Glul54-mtcu-PA) and that of rscu-PA (rtcu-PA) were 87 &mgr;M and 80 &mgr;M, respectively, which indicated that the catalytic active site of the Glul54-mtcu-PA was not changed by the mutation. Whereas, both (125)I-fibrin plasma-clot lysis and fibrinogenolysis in plasma showed that the Glul54-mtcu-PA possessed a better affinity and selectivity for fibrin than rtcu-PA, even better than rscu-PA.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1997
PMID:Construction of Urokinase Mutant Glu154-mtcu-PA and Characterization of Its Properties. 1221 67

The fibrinolytic enzyme eFE-D was isolated and purified from earthworm Elsenia folelide by gel-filtration on Sephacryle S-200, ion-exchange chromatography on DEAE-Sepharose Fast Flow and hydrophobic chromatography on Phenyle-Sepharose Fast Flow as detected by the fibrinolytic activity with a standard fibrin plate method. The most strong fibrinolytic component eFE-D not only hydrolyzed fibrin directly, but also activated the plasminogen to plasmin. Its apparent fibrinolytic value was equal to 2,800 UK IU per mg. Its molecular weight as estimated by SDS-PAGE and MS analysis was 29 kD and 24.849 kD respectively and its isoelectric point (pI) was 4.O. Fibrinolytic enzyme eFE-D was very thermostable with a single polypeptide chain. Studies with protease inhibitors indicated that eFE-D was a kind of serine protease. Its N-terminal amino acid sequence is M-I-G-G-T-N-A-S-P-G-E-F-P-W-Q-L-S-Q-Q-R. The result of amino acid composition analysis showed that the enzyme contained abundant amino acids of low molecular weight, but few aromatic and alkaline amino acids.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1997
PMID:Purification and Characterization of the Fibrinolytic Enzyme(eFE-D) from Earthworm Eisenia folelide. 1221 77

HPA of 85.5% purity was synthesized by the solid phase method on HPLC. The data obtained from amino acid analysis and fast atom bombardment were in good agreement with the theoretical values. The studies on the biological activity demonstrated the peptide inhibited efficiently the in vitro ADP-induced human platelet aggregation. In vivo, the peptide increased evidently the activity of plasmin and inhibited experimental thrombosis in the rabbit.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1996
PMID:Studies on the synthesis and Antithrombosis Activity of the Analogue of Fibrin Decomposed Product-Related Peptide. 1223 97

TSG-6 protein (the secreted product of the tumor necrosis factor-stimulated gene-6), a hyaluronan-binding protein comprised mainly of a Link and CUB module arranged in a contiguous fashion, has been shown previously to be a potent inhibitor of neutrophil migration in an in vivo model of acute inflammation (Wisniewski, H. G., Hua, J. C., Poppers, D. M., Naime, D., Vilcek, J., and Cronstein, B. N. (1996) J. Immunol. 156, 1609-1615). It was hypothesized that this activity of TSG-6 was likely to be mediated by its potentiation of inter-alpha-inhibitor anti-plasmin activity (causing a down-regulation of the protease network), which was reliant on these proteins forming a stable, probably covalent approximately 120-kDa complex. Here we have shown that the recombinant Link module from human TSG-6 (Link_TSG6; expressed in Escherichia coli) has an inhibitory effect on neutrophil influx into zymosan A-stimulated murine air pouches, equivalent to that of full-length protein (which we produced in a Drosophila expression system). The active dose of 1 microg of Link_TSG6 per mouse (administered intravenously) also resulted in a significant reduction in the concentrations of various inflammatory mediators (i.e. tumor necrosis factor-alpha, KC, and prostaglandin E(2)) in air pouch exudates. Link_TSG6, although unable to form a stable complex with inter-alpha-inhibitor (under conditions that promote maximum complex formation with the full-length protein), could potentiate its anti-plasmin activity. This demonstrates that formation of an approximately 120-kDa TSG-6.inter-alpha-inhibitor complex is not required for TSG-6 to enhance the serine protease inhibitory activity of inter-alpha-inhibitor. Six single-site Link_TSG6 mutants (with wild-type folds) were compared for their abilities to inhibit neutrophil migration in vivo, bind hyaluronan, and potentiate inter-alpha-inhibitor. These experiments indicate that all of the inhibitory activity of TSG-6 resides within the Link module domain, and that this anti-inflammatory property is not related to either its hyaluronan binding function or its potentiation of the anti-plasmin activity of inter-alpha-inhibitor.
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PMID:The link module from human TSG-6 inhibits neutrophil migration in a hyaluronan- and inter-alpha -inhibitor-independent manner. 1240 3