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:3.4.21.37 (neutrophil elastase)
4,078 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human factor IX circulates as a single-chain glycoprotein. Upon activation in vitro, it is cleaved into disulfide-linked light and heavy chains and an activation peptide. After reduction of activated 125I-factor IX, the heavy and light chains are readily identified by gel electrophoresis. A direct, immunoradiometric assay for factor IXa was developed to assess activation of factor IX for proteases that cleaved it. The assay utilized radiolabeled antithrombin III with heparin to identify the active site and antibodies to distinguish factor IX. After cleavage of factor IX by factor XIa, factor VIIa-tissue thromboplastin complex, or the factor X-activating enzyme from Russell's viper venom, antithrombin III bound readily to factor IXa. Cleavage of 125I-factor IX by trypsin, chymotrypsin, and granulocyte elastase in the presence of calcium yielded major polypeptide fragments of the sizes of the factor XIa-generated light and heavy chains. Kallikrein did not cleave the zymogen. Nonactivation cleavage was noted by thrombin, but only in the absence of calcium. When the immunoradiometric assay was used to assess trypsin-cleaved factor IX, the product bound antithrombin III, but not maximally. After digesting with insolubilized trypsin, clotting activity confirmed activation. In contrast, incubation of factor IX with elastase (Takaki A et al, J Clin Invest 71:1706, 1983) or chymotrypsin did not lead to generation of an antithrombin III-binding site, despite their digestion of 125I-factor IX into heavy and light chain-sized fragments. In evaluating activation of factor IX, physical evidence of activation cleavages does not necessarily correlate with generation of an active site.
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PMID:Cleavage and activation of human factor IX by serine proteases. 638 97

We have investigated the ability of neutral and lysosomal enzymes of mouse macrophages to degrade the insoluble extracellular matrices secreted by smooth muscle cells, endothelial cells, and fibroblasts. Matrices produced by smooth muscle cells contained glycoproteins, elastin, and collagens, but matrices of endothelial cells and fibroblasts contained no elastin. Sequential enzyme digestion of residual matrix revealed that plasmin, a product of macrophage plasminogen activation, degraded 50-70% of the glycoprotein in the matrices but did not degrade the elastin or the collagens. Purified macrophage elastase degraded glycoprotein and elastin components but had no effect on the collagens. The rate of elastin degradation by macrophage elastase was decreased in the presence of the glycoproteins. In contrast, human granulocyte elastase effectively degraded the matrix glycoproteins, elastin, and, to a lesser extent, collagens, Mammalian collagenase degraded only collagens. Conditioned medium from resident and inflammatory macrophages, containing mixtures of the secreted proteinases, degraded the glycoprotein and elastin components of the matrices. However, conditioned medium was less effective in degrading matrix than comparable amounts of purified macrophage elastase because > 90% of the elastase in the medium was in a latent form. Inclusion of plasminogen in the assays accelerated degradation. In the presence of plasminogen, glycoproteins were degraded readily by medium from P388D1, pyran copolymer-, thioglycollate-, and periodate-elicited macrophages and, to a lesser extent, by medium from endotoxin-elicited and resident macrophages; medium from P388D1, thioglycollate-, and periodate-elicited macrophages was most effective in elastin degradation, and resident, endotoxin-elicited and pyran copolymer-elicited macrophages degraded almost no elastin. The macrophage cathepsins D and B degraded all the matrix components at an optimum pH of 5.5 and acted with the secreted neutral proteinases to degrade the connective tissue macromolecules to amino acids and oligopeptides. These data indicate that macrophages at inflammatory sites contain and secrete proteolytic enzymes that could degrade the extracellular matrix.
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PMID:Degradation of connective tissue matrices by macrophages. I. Proteolysis of elastin, glycoproteins, and collagen by proteinases isolated from macrophages. 700 Sep 66

Plasma levels of human leukocyte elastase, a serine proteinase stored in the azurophilic granules of polymorphonuclear granulocytes, increase in the early stages of several inflammatory diseases. We studied the intracellular enzyme activity by cytochemical quantitative image analysis and the amount of elastase released in plasma by an automatic immunoactivation immunoassay method in 66 patients with inflammatory diseases and in a control group. The patients were divided into two groups with infective disease (severe and moderate) and one group with non-infective inflammation. Intracellular activity and plasmatic levels of elastase were also compared with other inflammatory markers, i.e. erythrocyte sedimentation rate, C-reactive protein, alpha 1-antitrypsin, haptoglobin, alpha 1-acid glycoprotein and fibrinogen. Our studies suggest that plasma and leukocyte elastase are correlated both with etiology and with the severity of the inflammation.
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PMID:Quantitative cytochemistry of human leukocyte elastase compared with plasma elastase and acute phase proteins in inflammatory diseases. 758 91

A novel trypsin inhibitor, tentatively named countertrypin, was isolated from mouse plasma in an apparently homogeneous state. Countertrypin is a 53-kDa glycoprotein having about 30% carbohydrate, and did not cross-react immunologically with either mouse alpha 1-antiproteinase (also called alpha 1-proteinase inhibitor or alpha 1-antitrypsin) or contrapsin. Countertrypin had no inhibitory activity against chymotrypsin, pancreatic elastase, neutrophil elastase, thrombin, plasmin, plasma kallikrein, pancreatic kallikrein, clotting factor Xa, or papain. This inhibitory spectrum does not correspond to any of the known plasma proteinase inhibitors that have been well characterized in human or other mammals. NH2-terminal amino acid sequence analysis of the intact molecule and three peptides obtained by CNBr digestion revealed that a total of 93 amino acid residues could be aligned with stretches in human alpha 2-HS glycoprotein, bovine fetuin, and rat pp63 (rat fetuin). Human alpha 2-HS glycoprotein and bovine fetuin prepared without use of ethanol inhibited trypsin and pancreatic and neutrophil elastases. These results indicate that mouse countertrypin is a new member of the mammalian fetuin family, which possibly has the trypsin-inhibiting activity in common.
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PMID:Isolation and characterization of mouse countertrypin, a new trypsin inhibitor belonging to the mammalian fetuin family. 768 30

To infer possible mechanisms of acute airway inflammation and mucus hypersecretion in acute severe asthma, we performed cellular and biochemical analysis on sputum from 18 adults with acute severe asthma and compared the results with results of analysis of sputum from 12 adults with cystic fibrosis (CF). We found that in subjects with asthma neutrophils made up more than 75% of sputum cells in 10 samples whereas eosinophils made up more than 75% of cells in only three samples. Fifty percent of the subjects with asthma reported that their asthma exacerbation was precipitated by a respiratory tract infection, and these subjects had a significantly higher percentage of neutrophils in their sputum (85% +/- 6% vs 57% +/- 12%, p = 0.05). In the CF samples neutrophils made up more than 95% and eosinophils less than 1% of cells in all samples analyzed. Analysis of fluid phase chemicals in asthmatic and CF sputum samples showed that despite overall lower mean values of neutrophil elastase (27 +/- 11 micrograms/ml vs 466 +/- 121 micrograms/ml, p = 0.0001) and interleukin-8 (IL-8) (55 +/- 15 ng/ml vs 186 +/- 24 ng/ml, p = 0.0001), some of the asthmatic samples had values for these variables that overlapped those in the CF samples. In addition, the asthmatic samples were distinguished by the presence of higher tryptase (10 +/- 7 U/L vs 0.9 +/- 0.9 U/L, p = 0.0001) and interleukin-6 (1166 +/- 447 ng/ml vs 186 +/- 24 ng/ml; p = 0.0001) levels and by a higher ratio of albumin to mucin-like glycoprotein (0.8 +/- 0.5 vs 0.1 +/- 0.002, p = 0.02). DNA levels were lower in the asthmatic samples (0.5 +/- 0.3 mg/ml vs 3.5 +/- 1.2 mg/ml, p = 0.05). We conclude that neutrophils predominate more frequently than eosinophils as the major inflammatory cell in sputum from patients with asthma in acute exacerbation. We speculate that this may be because respiratory tract infections are a frequent precipitant of acute asthma. In addition, the high IL-8 levels and free neutrophil elastase activity observed in asthmatic sputum suggests that IL-8 may mediate airway neutrophilia in acute asthma and that neutrophil elastase may mediate mucin glycoprotein hypersecretion in acute asthma, as has been proposed for the mucin hypersecretion in CF.
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PMID:Prominent neutrophilic inflammation in sputum from subjects with asthma exacerbation. 772 65

Urinary trypsin inhibitor is a glycoprotein which has an inhibitory effect on many enzymes, especially neutrophil elastase. The concentration of urinary trypsin inhibitor in serum (maternal and fetal), urine and amniotic fluid was measured in 20 cases of preeclampsia and compared with levels in normal pregnancy. Urinary trypsin inhibitor levels were significantly increased in the maternal and fetal serum of preeclamptic patients compared to normal pregnancy (p < 0.0001), as well as in urine and amniotic fluid of the same patients. Relative fluorescence release of a calcium chelating agent (fura-2) from human umbilical vein endothelial cell cultures was significantly increased by preeclamptic serum compared to serum of normal pregnant women (p < 0.03). After incubation of urinary trypsin inhibitor with the cultures, significant decrease of fura-2 release was observed (p < 0.03). Urinary trypsin inhibitor has an effect on suppression of activated neutrophils, elastase production and may have a protective effect on endothelial cells.
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PMID:Urinary trypsin inhibitor may have a protective effect on endothelial cells in preeclampsia. 781 24

A number of structurally diverse polyanions have been found to inhibit human leukocyte elastase (HLE) activity. The purpose of this study was to examine the effects of mucus glycoprotein (mucin), one of the most plentiful high molecular weight polyanions in the respiratory tracts, on HLE activity. Human airway mucin and bovine submaxillary mucin at concentrations of 0.4 to 2.8 mg/ml both markedly inhibited the elastolytic activity of 50 nM HLE, with maximum inhibition approaching 90%. The degree of inhibition was the same regardless of whether the mucin, elastase, and elastin were simultaneously combined or whether the mucin was added to elastase 20 min prior to adding elastin, indicating that mucin is a rapid-acting inhibitor. The shape of the inhibition curve resembled that of curves obtained using heparin and HLE. Mucin had little inhibitory effect on pancreatic elastase, which is structurally related to but less cationic than HLE. The inhibition of HLE by mucin was blocked by 1 M NaCl. Removal of sulfate esters by acid-catalyzed solvolysis markedly reduced the inhibitory effect of bovine submaxillary mucin. These results indicate that inhibition of HLE by mucin involves binding of the positively charged HLE molecules to the negatively charged sulfated carbohydrates in the mucin. Mucin was also found to substantially reduce the antiprotease activity of secretory leukocyte protease inhibitor, a low molecular weight cationic protein known to bind to mucin.
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PMID:Inhibition of neutrophil elastase by mucus glycoprotein. 791 11

Urinary trypsin inhibitor is a glycoprotein with a structure in which two Kunitz-type inhibitory domains are linked in a row. We isolated two genes encoding the 70 amino acid sequence from the 78th amino acid (Thr) to the C-terminal and the 68 amino acid sequence from the 80th (Ala) to the C-terminal of human urinary trypsin inhibitor, both which correspond to the second Kunitz-type inhibitory domain, and then constructed expression plasmids by ligating it to the E. coli alkaline phosphatase signal peptide gene. These plasmids under the control of the tryptophan promoter expressed the second domain in E. coli strain JE5505 which lacks the membrane lipoprotein. The recombinant second domain purified from the culture supernatant of the transformant inhibited trypsin, plasmin, leukocyte elastase and chymotrypsin which are known to be inhibited by urinary trypsin inhibitor. In addition it inhibited blood coagulation factor Xa and plasma kallikrein in a concentration dependent and competitive manner, and significantly prolonged the plasma-based activated partial thromboplastin time (APTT). The truncated natural counterpart obtained by a limited degradation of human urinary trypsin inhibitor also revealed the identical inhibitory activities.
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PMID:Novel factor Xa and plasma kallikrein inhibitory-activities of the second Kunitz-type inhibitory domain of urinary trypsin inhibitor. 819 13

Thrombospondin 1 is a multidomain trimeric glycoprotein from platelets and a variety of normal and transformed cells of both mesenchymal and epithelial origin, which functions in cell adhesion and cell-cell interactions. We have recently shown that human thrombospondin 1 binds and inhibits the neutrophil enzymes, neutrophil elastase [Hogg, P.J., Owensby, D.A., Mosher, D.F., Misenheimer, T.M., & Chesterman, C.N. (1993a) J. Biol. Chem. 268, 7139-7146] and cathepsin G [Hogg, P.J., Owensby, D.A., & Chesterman, C.N. (1993b) J. Biol. Chem. 268, 21811-21818]. One mole of thrombospondin 1 trimer binds 3 mol of neutrophil elastase or up to 6 mol of cathepsin G, with site-binding dissociation constants around the nanomolar range, and the enzymes have been shown to interact with thrombospondin 1 in the vicinity of the calcium-binding type 3 repeats. None of the protein modules in this region, or within the whole thrombospondin 1 molecule, have previously been implicated in the inhibition of proteinases. We noted that there are two stretches of eight amino acids each in the human thrombospondin 1 type 3 repeats, residues 735-742 and 794-801, that have striking similarity to a reactive-site consensus sequence derived from selected members of the Kazal and Streptomyces subtilisin inhibitor families. Synthetic peptides corresponding to the putative P5 through P4' residues of both proposed reactive centers interacted efficiently with the active site of cathepsin G and were competitive inhibitors of the fibronectin-degrading and platelet-activating activities of this enzyme, while only the peptide corresponding to residues 793-801 efficiently interacted with the active site of neutrophil elastase and competitively inhibited its fibronectin-degrading activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of possible inhibitory reactive centers in thrombospondin 1 that may bind cathepsin G and neutrophil elastase. 820 88

The primary objective of this study was to test the hypothesis that human neutrophil elastase (HNE) affects neutrophil infiltration (adhesion and emigration) into inflamed vessels. To determine whether HNE contributes to neutrophil adhesion in vivo, intravital microscopy was used to study neutrophil-endothelial cell interactions in single inflamed postcapillary venules. Superfusion of platelet-activating factor (PAF) (100 nmol/L) onto the mesentery caused an increase in neutrophil-neutrophil interactions, neutrophil adhesion to postcapillary venules, and cellular emigration out of the vasculature. Both L658 758 (an elastase-specific inhibitor), and Eglin C (an elastase and cathepsin G inhibitor) significantly attenuated all of these parameters in vivo. To further characterize the mechanism(s) involved, various in vitro parameters were assessed. HNE, but not trypsin, caused a dose-dependent (0.01 to 1.0 microgram/mL) increase in the expression of the beta subunit (CD18) of the CD11/CD18 adhesive glycoprotein complex on neutrophils. An HNE-dependent increase in CD11b expression was also observed; however, HNE did not affect the expression of other neutrophil adhesion molecules (L-selectin), superoxide production, or degranulation. PAF-enhanced CD18 expression on neutrophils and neutrophil migration were both abolished by L658 758 but PAF-induced neutrophil adhesion to endothelial monolayers was not affected by the antiproteinase. The in vitro data suggest that the antiproteinases do not directly prevent neutrophil adhesion in vivo but may be important in other CD18-dependent events such as neutrophil-neutrophil interaction or neutrophil infiltration (chemotaxis). These results translate into an important, rate-limiting role for elastase in the process of leukocyte infiltration and accumulation in inflamed microvessels.
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PMID:Effects of human neutrophil elastase (HNE) on neutrophil function in vitro and in inflamed microvessels. 840 Feb 69


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