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

---

Query: EC:3.4.21.7 (plasmin)
9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Limulus amebocyte lysate was fractionated by heparin-Sepharose chromatography into four components (fractions A, B, C and D). Major coagulation factors, i.e., proclotting enzyme, coagulogen, and proclotting enzyme activating factor precursor (proactivator) in the lysate were eluted, respectively, in fraction A, fraction B and fraction C. Clotting enzyme activity was detected only following recombination of fraction A and fraction C in the presence of endotoxin. The conversion of proactivator to its active form (activator) was an endotoxin-dependent reaction and was inhibited by polymyxin B. Either proactivator is an endotoxin-sensitive factor or another endotoxin-sensitive factor, which activates proactivator, is present in fraction C. Optimal pH for proclotting enzyme activation by activator was broad and ranged from pH 6.0 to 8.0, while that for the endotoxin-mediated activation of proactivator was pH 7.0. No initial latent period was observed during activation of the proactivator or proenzyme. The activator was inhibited by benzamidine, leupeptin, soybean trypsin inhibitor and diisopropyl fluorophosphate, suggesting that the activator is a trypsin-type serine protease. Trypsin, but not thrombin, urokinase, plasmin, papain or alpha-chymotrypsin activated the proclotting enzyme. Therefore, limited proteolysis, i.e., of an arginyl- or lysyl-X bond(s), of the proenzyme molecule is probably involved in its activation.
...
PMID:Fractionation of Limulus amebocyte lysate. Characterization of activation of the proclotting enzyme by an endotoxin-mediated activator. 713 84

A rapid breakdown of collagen was found in granulation tissue induced by carrageenin in rats; the half-life of collagen in both growing and resorbing tissues was about 3.5 days, whereas that in non-resorbing tissue was about 7 days. On the other hand, the half-life of noncollagen protein in the growing, resorbing and non-resorbing tissues was about 2-3 days. epsilon-Amino-n-caproic acid n-hexyl ester, an inhibitor of plasmin and trypsin, selectively inhibited collagen breakdown in vivo without affecting the degradation of noncollagen protein or the syntheses of collagen and noncollagen protein in granulation tissues. A similar selective inhibition of collagen breakdown was also found upon treatment with soybean trypsin inhibitor. Collagenase activity was assayed directly in the insoluble 6,000 X g pellet of granulation tissue homogenates. epsilon-Amino-n-caproic acid n-hexyl ester and soybean trypsin inhibitor markedly inhibited the collagen breakdown in granulation tissue pellets in vitro. The results are consistent with those from in vivo experiments and suggest that both the inhibitors indirectly inhibit the collagen breakdown in granulation tissue through the inhibition of a latent collagenase-activating proteinase(s), because none of the inhibitors directly inhibit collagenase. It may be argued, therefore, that a proteinase(s) which activates a latent collagenase plays an important role in the rapid breakdown of collagen in granulation tissues.
...
PMID:Selective inhibition of collagen breakdown by proteinase inhibitors in granulation tissue in rats. 725 73

The primary amino acid sequence of the carboxyl-terminal portion of the alpha 3 chain of chicken type VI collagen (K-VI) presents a 58-residue motif with a high degree of homology with members of the Kunitz serine-proteinase inhibitors family. This module was cloned, expressed in E. coli, purified and compared to the bovine pancreatic trypsin inhibitor (BPTI) in an inhibition profile assay of two serine proteases, trypsin and plasmin. We found that recombinant K-VI is not endowed with inhibitory activity but it slightly activates both plasmin and trypsin, differently from other members of the family. Moreover, the ability to inhibit the serine protease activity is also lacking in the intact type VI collagen molecule.
...
PMID:Expression, purification and functional characterisation of a Kunitz-type module from chicken type VI collagen. 748 30

In a previous study we have shown that monoclonal antibody F1 (MoAb F1), directed against an epitope on the heavy chain of factor XII distinct from the binding site for anionic surfaces, is able to activate factor XII in plasma (Nuijens JH, et al: J Biol Chem 264; 12941, 1989). Here, we studied in detail the mechanism underlying the activation of factor XII by MoAb F1 using purified proteins. Formation of factor XIIa was assessed by measuring its amidolytic activity towards the chromogenic substrate H-D-Pro-Phe-Arg-pNA (S-2302) in the presence of soybean trypsin inhibitor and by assessing cleavage on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Upon incubation with MoAb F1 alone, factor XII was auto-activated in a time-dependent fashion, activation being maximal after 30 hours. Factor XII incubated in the absence of MoAb F1 was hardly activated by kallikrein, whereas in the presence of MoAb F1, but not in that of a control MoAb, the rate of factor XII activation by kallikrein was promoted at least 60-fold. Maximal activation of factor XII with kallikrein in the presence of MoAb F1 was reached within 1 hour. This effect of kallikrein on the cleavage of factor XII bound to MoAb F1 was specific because the fibrinolytic enzymes plasmin, urokinase, and tissue-type plasminogen activator could not substitute for kallikrein. Also, trypsin could easily activate factor XII, but in contrast to kallikrein, this activation was independent of MoAb F1. SDS-PAGE analysis showed that the appearance of amidolytic activity correlated well with cleavage of factor XII. MoAb F1-induced activation of factor XII in this purified system was not dependent on the presence of high-molecular-weight kininogen (HK), in contrast to the activation of the contact system in plasma by MoAb F1. Experiments with deletion mutants revealed that the epitopic region for MoAb F1 on factor XII is located on the kringle domain. Thus, this study shows that binding of ligands to the kringle domain, which does not contribute to the proposed binding site for negatively charged surfaces, may induce activation of factor XII. Therefore, these findings point to the existence of multiple mechanisms of activation of factor XII.
...
PMID:Monoclonal antibody F1 binds to the kringle domain of factor XII and induces enhanced susceptibility for cleavage by kallikrein. 749 70

Previously we have shown that the measurable soluble sialyltransferase (STase) activity released into the medium during the incubation of rat jejunal slices was dependent upon the presence of a heparin-binding fraction (HBF) from heat-inactivated serum or a trypsin-binding protein (TBP) isolated from HBF. Both HBF and TBP were able to inhibit trypsin and plasmin. The measurement of galactosyltransferase (GTase) activity which was also released in incubations was not dependent on HBF or TBP. The present study is directed towards further exploring the relationship between STase activity and protease inhibitory activity. Heat-inactivated serum from turpentine-treated rats (HTS), had higher plasmin-trypsin-inhibitory (HTS) activities compared to heat-inactivated serum from control rats (HCS). When HTS was used to supplement jejunal incubations, there was a 25-40% increase in the measurable STase activity in the incubation medium compared to similar incubations carried out in buffer alone. In contrast, with HCS the increase was 10-15%. During incubations with hepatocytes, STase activity detected in the incubation medium was increased with the incubation buffer was supplemented with HTS compared to incubations supplemented with HCS. Serum antiproteolytic activity was higher in turpentine rats compared to controls. Incubation of serum at 37 degrees C led to a progressive decrease in plasmin-trypsin-inhibitory and STase activities. TBP a plasmin and trypsin inhibitor was able to prevent the decrease in STase activity. Overall, serum STase activity was higher in the turpentine treated rats. In contrast, GTPase activity in serum as well as that detected in the medium during jejunal and hepatocyte incubations was not dependent on protease inhibitory activity.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Relationship between plasmin-trypsin-inhibitory and sialyltransferase activities. 755 56

Human pregnancy-associated plasma protein A (PAPP-A) inhibited significantly the proteolytic activity of bovine trypsin and human plasmin. Trypsin or plasmin treatment of PAPP-A resulted in the generation of a major 85 kDa component and the rapid cleavage of internal thiol esters. The results indicated that both of these serine proteinases bound in a 1:1 stoichiometry to PAPP-A. The PAPP-A-bound enzymes were found to be enzymatically active towards small synthetic substrates and inaccessible to inactivation by soybean trypsin inhibitor and alpha 1-proteinase inhibitor. The mechanism of proteinase inhibition was likely to be entrapment, as described for alpha 2-macroglobulin.
...
PMID:Interaction of human pregnancy-associated plasma protein-A with serine proteinases. 758 86

A purified human urinary trypsin inhibitor (UTI) and its related synthetic peptides were examined to determine whether they could inhibit production of experimental and spontaneous lung metastases by murine Lewis lung carcinoma (3LL) cells. Three peptides, peptide I, peptide 2 and peptide 3, representing the amino acid sequences within the UTI molecule, were synthesized. UTI and peptide 2 inhibited human leukocyte elastase (HLE). UTI and peptide 3 specifically inhibited human and murine plasmin activity. Peptide I had essentially no inhibitory activity. In an in vivo spontaneous metastasis model, multiple s.c. injections of UTI or peptide 3 for 7 days immediately after s.c. tumor cell inoculation significantly inhibited the formation of lung metastasis in C57BL/6 mice in a dose-dependent manner. UTI reduced lung tumor colonization more effectively than peptide 3. Peptides 1 and 2, however, did not affect the formation of lung metastasis. Inhibition of lung metastasis was not due to direct anti-tumor effects of UTI and peptide 3. In an in vivo experimental metastasis assay, multiple s.c. injections of UTI for 7 days after i.v. tumor cell inoculation inhibited metastatic lung tumor colonization, while peptide 3 did not affect metastasis. Peptides 1 and 2 did not affect the formation of lung metastasis. When examined with an in vitro assay system using a modified Boyden chamber, UTI and peptide 3 suppressed the invasion of tumor cells through Matrigel. UTI and peptide 3 inhibited neither cell proliferation nor the binding of tumor cells to Matrigel and showed no significant suppression of chemotactic migration of tumor cells to fibronectin. Our results suggest that UTI efficiently regulates the mechanism involved in not only the entry into vascular circulation of tumor cells (intravasation, though, at least in part, inhibition of the proteolytic enzyme plasmin) but also the extravasation step of the metastatic process.
...
PMID:Inhibition of metastasis of Lewis lung carcinoma by urinary trypsin inhibitor in experimental and spontaneous metastasis models. 759 Dec 48

We developed a non-radioactive method of ligand western blotting for specific detection of active forms of serine proteases. The method consists of three steps: (i) separation of proteins by electrophoresis in sodium dodecyl sulfate-polyacrylamide gel, followed by blotting of proteins to nitrocellulose membrane; (ii) binding of a specific ligand, such as soybean trypsin inhibitor labeled with biotin, to protease on the membrane; and (iii) detection of the protease-inhibitor complex by color reaction (or chemiluminescence) developed by streptavidin-conjugated peroxidase (or alkaline phosphatase). By using this method, plasmin and trypsin (serine proteases) were detected, but papain (thiol protease) or pepsin (acidic protease) was not. Plasmin was detectable up to less than 4 ng. Inactive precursors of serine protease, i.e. plasminogen and trypsinogen, did not exhibit visible bands until they were activated by treatment with streptokinase or trypsin, respectively. We applied this method to clinical samples, and succeeded in detecting plasminogen, after conversion to plasmin with streptokinase treatment, in as little as 5 microliters of serum or trypsin, as it was in 10 microliters of pancreatic juice.
...
PMID:Ligand western blotting for specific detection of active forms of proteases. 766 77

Porcine stomach mucosa was found to contain a 740-kDa protein having endopeptidase activity toward peptide 4-methylcoumaryl-7-amide substrates and low molecular mass peptides. This protein was purified to an apparent homogeneity by a series of chromatographic steps on DEAE-cellulose, Sepharose CL-4B, hydroxylapatite, and fast protein liquid chromatography Mono Q columns. The protein was shown to be a complex of the plasma proteinase inhibitor alpha 2-macroglobulin and a 25-kDa endopeptidase. The enzyme activity was completely inhibited by diisopropyl fluorophosphate, p-amidinophenylmethanesulfonyl fluoride, leupeptin, antipain, bovine pancreatic trypsin inhibitor, soybean trypsin inhibitor, and ovomucoid, indicating that the entrapped enzyme is a serine proteinase. The proteinase could be released from alpha 2-macroglobulin by mild acid treatment and the released enzyme showed activity toward protein substrates. Substrate specificity studies using synthetic and peptide substrates indicated that the enzyme preferentially hydrolyzes Arg-X bonds and, to a much lesser extent, Lys-X bonds, and is apparently distinct from thrombin, kallikrein, plasmin, and other trypsin-like proteinases so far reported including tryptase. Thus, the present enzyme is thought to be a novel type of serine proteinase. The proteinase associated with alpha 2-macroglobulin was also found in porcine intestinal mucosa, but not in plasma.
...
PMID:Isolation and characterization of a novel serine proteinase complexed with alpha 2-macroglobulin from porcine gastric mucosa. 767 2

The three-dimensional structure of the basic pancreatic trypsin inhibitor (BPTI) contains four internal water molecules, which form a total of nine intermolecular hydrogen bonds with the BPTI polypeptide chain. To investigate the effect of such internal hydration on protein structure and stability, we displaced one of the internal water molecules in a recombinant BPTI analogue, BPTI(G36S), in which Gly 36 is replaced by serine. The replacement of a water molecule by the seryl side chain was established by the absence of the protein-water nuclear Overhauser effects (NOE) that had been attributed to the water molecule near Gly 36 in wild-type BPTI and by the presence of new, intramolecular NOEs to the hydroxyl proton of Ser 36. BPTI(G36S) has slightly reduced thermal stability compared to BPTI, corresponding to a destabilization by delta (delta G) approximately 0.7 kcal/M in 6 M guanidinium hydrochloride solution. Additionally, the stabilities of the complexes formed between BPTI(G36S) and trypsin, plasmin, or kallikrein are significantly reduced when compared to the corresponding complexes with wild-type BPTI.
...
PMID:Designed replacement of an internal hydration water molecule in BPTI: structural and functional implications of a glycine-to-serine mutation. 768 91


<< Previous 1 2 3 4 5 6 7 8 9 10

---