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)

1. The elastase of human spleen was shown to exhibit endopeptidase activity against azo-casein and elastin. 2. Activity against several synthetic substrates was detected, and benzyloxycarbonyl-L-alanine 2-naphthyl ester was found to be a good substrate for routine use. 3. The enzyme showed a broad pH optimum in the range of 8.2-9.2 against azo-casein and the synthetic substrate. 4. The effect of inhibitors on the spleen elastase showed it to be a serine proteinase with a specificity similar to that of porcine pancreatic elastase. 5. Specific antisera were raised against the enzyme, and it was shown to be immunologically identical with the lysosomal elastase of human neutrophil leucocytes.
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PMID:Human lysosomal elastase. Catalytic and immunological properties. 93 78

Fragmentation of lung matrix fibronectin by proteases released from activated phagocytic cells has been implicated in lung vascular injury. We examined whether denatured collagen (gelatin)-bound fibronectin can be degraded by peritoneal exudate mononuclear phagocytes harvested from rats 96 h after intraperitoneal casein injection. Microtiter plates were pretreated with gelatin and then supplemented with purified 125I rat plasma fibronectin, which readily bound to the gelatin. Stimulated inflammatory exudate cells were added and proteolysis of the bound fibronectin was studied by the release of [125I]fibronectin fragments into the media. Following 2 h of incubation, peritoneal exudate mononuclear macrophages stimulated with opsonized zymosan released three times more radiolabeled fibronectin into the medium as compared to background controls, and 1.5 times more radiolabeled fibronectin as compared to cells not stimulated with zymosan. Western blot analysis and autoradiography confirmed the presence of fragments of fibronectin in the culture medium. Some of these fragments were clearly derived from the radiolabeled matrix, but others that were not labeled were potentially released directly from the added stimulated macrophages. The release of radiolabeled fibronectin was inhibited by N-p-tosyl-L-lysine chloromethyl ketone (TLCK), a trypsin specific inhibitor, but not by methoxysuccinyl-alanine-alanine-proline-valine-chloromethyl-ketone (AAPVCK), a leukocyte elastase-specific inhibitor. These results suggest that fibronectin bound to denatured collagen is susceptible to leukocyte elastase-independent enzymatic degradation by stimulated inflammatory exudate mononuclear phagocytic cells. Such proteolysis may mimic a pathological process associated with lung vascular injury during the sequestration of activated macrophages in the lung microcirculation and interstitium.
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PMID:Leukocyte elastase-independent proteolysis of gelatin-bound fibronectin by inflammatory macrophages. 175 31

IgG1 is cleaved in vitro by granulocyte elastase into Fc and Fab fragments. The elastase-specific Fc fragment has been previously detected in vivo. Biological activity of the fragments has been described in modulating neutrophil oxidative metabolism and enzyme release. To investigate further effects granulocyte chemotaxis (CT) was tested. The CT was assayed in Boyden chambers and the chemotactic index (CI) was calculated which represents the mean distance travelled by the activated cells. Stimulation of leucocyte CT by casein, activated serum and FMLP gives maximal values of delta CI = 46.7, 26.4 and 7.2 microns, respectively. Native IgG1 and the elastase-produced IgG fragments do not stimulate leucocyte CT. FMLP-stimulated CT is specifically inhibited by the elastase-produced Fc fragments. Addition of 7 nmol Fc to stimulus concentrations of 16 to 125 nM FMLP results in total inhibition of chemotaxis demonstrated by CI values which are lower than those for unstimulated cells. The inhibition of CT is concentration dependent in the range of 2 to 7 nmol Fc/10(6) PMN. Number and affinity of FMLP receptors are not influenced by Fc fragments, so Fc binds neither to FMLP nor the FMLP receptor. CT stimulated by casein shows a large portion of chemokinesis. Only at suboptimal casein concentrations do Fc and IgG have an inhibitory effect on CT (0.63 mg casein/ml, 10 nmol peptide/10(6) PMN). C5a-stimulated CT is not influenced by IgG or IgG fragments which indicates that the samples are not cytotoxic. So the FMLP and casein-stimulated CT is specifically inhibited by the elastase-produced Fc fragments in a low concentration range.
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PMID:Inhibition of neutrophil chemotaxis by elastase-generated IgG fragments. 188 90

Escherichia coli endotoxin (0.1 to 1000 micrograms/ml) stimulated the release of neutrophil chemotactic activity (P < 0.001) and induced bronchial epithelial cell (BEC) cytotoxicity assessed by lactate dehydrogenase release (P < 0.001). Endotoxin (100 micrograms/ml) inhibited BEC accumulation (P < 0.001). In the present study, we investigated the role of proteolytic activity of BECs per se in response to endotoxin. Several structurally and functionally different antiproteases, alpha 1 protease inhibitor, soybean trypsin inhibitor, two chloromethyl ketone derivatives (N-tosyl-L-lysine chloromethyl ketone and methoxysuccinyl-Ala-Ala-Pro-Val chloromethyl ketone), and L-658,758, a neutrophil elastase inhibitor, attenuated the release of neutrophil chemotactic activity and lactate dehydrogenase (P < 0.01). alpha 1-Protease inhibitor and N-tosyl-L-lysine chloromethyl ketone attenuated the inhibition of BEC accumulation by endotoxin (P < 0.001). The proteolytic enzyme activity measured by synthetic substrates revealed that endotoxin significantly augmented the serine proteolytic activity in the cell layers. Culture supernatant fluids and cell lysates of BECs in the presence of endotoxin solubilized 14C-labeled casein. These data suggest that responses of BECs to endotoxin may involve activation of cellular proteolytic activity.
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PMID:Antiproteases modulate bronchial epithelial cell responses to endotoxin. 774 15

Neutrophil (PMN) recruitment into the peritoneum during acute bacterial peritonitis is an important part of the host defense barrier in CAPD patients. However, the subsequent phagocytosis of bacteria may also lead to PMN degranulation and the release of lysosomal enzymes. We determined the concentration of neutrophil elastase, both in complex with its natural inhibitor alpha 1Pi (E alpha 1Pi), and in uncomplexed, free form, in infected and normal CAPD peritoneal fluid by ELISA. In addition elastase activity was estimated in a casein degradation assay. Infected fluid contained a median (range) of 1.4 nM (0 to 9.2) free elastase by ELISA and 1.2 nM (0 to 11.9) activity. There were strong correlations between the peritoneal leukocyte count and both immunoreactive elastase and activity (r = 0.816, P < 0.001, 0.687, P < 0.01, respectively). In contrast, normal fluid contained 0.0 nM (0 to 0.32) immunoreactive elastase (P < 0.01) and 0.0 nM (0 to 0.6) elastase activity (P < 0.001). E alpha 1Pi complexes were raised significantly during peritonitis at 6.2 nM (0 to 34.3) and were barely detectable in normal fluid 0.0 nM (0 to 0.17; P < 0.005). The study shows that small but significant quantities of uninhibited elastase can be detected in the peritoneal fluid of CAPD patients with acute bacterial peritonitis. This observation may have important implications for the pathogenesis of peritoneal membrane damage and the phlogistic response to infection.
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PMID:Intra-peritoneal free elastase in CAPD peritonitis. 835 70

Wound fluid contains several proteinases that are important in the repair process. In this study, we analyzed caseinolytic activity in wound fluid obtained from acute (burn) wounds. Caseinolytic activity in wound fluid increased markedly 2 d after injury and appeared on casein zymographs as a series of bands or a smear ranging from 30 to 100 kDa. Most of the enzyme activity was inhibited by the synthetic human neutrophil elastase inhibitor MDL 27,367 but not by the naturally occurring inhibitor of elastase, human secretory leukoproteinase inhibitor. Fractionation of wound fluid indicated that a single enzyme accounted for approximately 80% of the caseinolytic activity. This enzyme degraded the elastase substrate methoxysuccinyl-ala-ala-pro-val-p-nitroanilide at a slow rate. The above findings suggested that the enzyme responsible for caseinolytic activity might be proteinase 3, an elastase-related enzyme whose physiologic functions are poorly understood. Consistent with the above possibility, we found that monoclonal antibodies against proteinase 3 removed caseinolytic activity from wound fluid, and that purified proteinase 3 had a similar caseinolytic profile and inhibitor sensitivity to burn fluid.
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PMID:Identification of proteinase 3 as the major caseinolytic activity in acute human wound fluid. 942 90

Ulcerative keratitis is a common and potentially blinding ocular disease of horses, capable of progressing to corneal perforation in as little as 24 h. This rapid stromal degeneration is mediated in part by exogenous and endogenous proteinases. We measured and compared the concentrations of two matrix metalloproteinases (MMP-2 and MMP-9) and a serine proteinase (neutrophil elastase) present in the precorneal tear film of normal horses and horses with rapidly progressing ulcerative keratitis. Precorneal tear film samples were collected from 23 ulcerated and 21 unaffected eyes of 23 horses with unilateral ulcerative keratitis, and from 33 normal eyes of 17 control horses. MMP-2, MMP-9, and neutrophil elastase were identified by casein and gelatin zymography and quantified by computerized image analysis. Median MMP-9 levels were significantly higher in the precorneal tear film of young control horses vs. older control horses (P = 0.005). Median MMP-2, MMP-9, and neutrophil elastase levels were significantly higher in the precorneal tear film of ulcerated eyes when compared to age-matched normal controls (P = 0.004, P = 0.001, and P = 0.012, respectively). Median MMP-2 levels were also significantly higher in the precorneal tear film of contralateral eyes of affected horses when compared to age-matched normal controls (P = 0.004). No significant differences in median proteinase levels were detected between 'sterile' ulcers and those from which bacteria or mixed infections (bacteria and fungi) were isolated. However, median MMP-2 and neutrophil elastase levels were significantly higher in the precorneal tear film of eyes with 'sterile' ulcers when compared with ulcerated eyes from which fungi were isolated (P < 0.05). The results of this study support the use of topical antiproteinase therapy which targets both MMPs and serine proteinases in progressive equine ulcerative keratitis.
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PMID:Evaluation of tear film proteinases in horses with ulcerative keratitis. 1139 92

We investigated the ability of free fatty acids to inhibit the activity of Clostridium histolyticum collagenase (EC 3.4.24.3) and human neutrophil elastase (EC 3.4.21.37). We determined the activity of collagenase by degradation of resorufin-labeled casein fluorimetrically. The determination of the elastase activity was performed by a spectrophotometric method using a 4-nitroanilide peptide substrate. We found that most of the tested fatty acids inhibited collagenase at concentrations between 50 microM and 500 microM. For elastase we found an inhibition of the activity at concentrations between 500 nM and 50 microM. The most potent inhibitory fatty acids of both enzymes differed. Thus, as a result for collagenase we can assume that the saturated fatty acids with C(16)-C(19) were the most potent ones. For elastase the inhibition rate of unsaturated acids was much higher than the rate of the saturated ones. The highly active erucic acid with an IC(50) value of 450 nM (elastase) is remarkable.
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PMID:Free fatty acids inhibit the activity of Clostridium histolyticum collagenase and human neutrophil elastase. 1235 83

To explore possible mechanisms responsible for the absence of cell re-colonization of mural thrombi in aneurysms, we analyzed the release and storage of leukocyte proteases in the most luminal layer versus intermediate and abluminal layers of 10 mural thrombi of human abdominal aortic aneurysms. The luminal layer contained many polymorphonuclear leukocytes (PMNs), which released pro-matrix metalloproteinase (MMP)-9 and MMP-8. Leukocyte elastase was also stored and released by the luminal layer (immunohistochemistry, activity on synthetic substrates, and casein zymography). Acid buffer allowed extraction of leukocyte elastase from the luminal layer, which was inhibited by elastase inhibitors. Casein zymography of luminal extracts and conditioned medium from formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMNs exhibited a similar lysis pattern, corresponding to elastase activity. Smooth muscle cell (SMC) seeding resulted in colonization of the intermediate thrombus layer ex vivo but not of the luminal layer. Extracts of the luminal layer induced loss of anchorage of both cultured human smooth muscle cells and stromal cells of bone marrow origin (anoikis). This anoikis was prevented by preincubation of the extracts with serine protease inhibitors. Moreover, adhesion of human SMCs and stromal bone marrow cells on fibrin gels was strongly inhibited when the gel was preincubated with pure elastase, medium of fMLP-stimulated PMNs, or extracts of luminal layers of mural thrombi. This loss of cell anchorage was prevented by the preincubation of the medium or extracts with alpha(1)-antitrypsin, but not when alpha(1)-antitrypsin was added after binding of elastase to the fibrin gel. In conclusion, elastase released by PMNs trapped within the mural thrombus impairs the spontaneous anchorage of mesenchymal cells to a fibrin matrix. This phenomenon could be one mechanism by which cellular healing of the mural thrombus in aneurysms is prevented.
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PMID:Role of leukocyte elastase in preventing cellular re-colonization of the mural thrombus. 1516 42

Cardiopulmonary bypass induces a systemic inflammatory response (SIR), characterized by the activation of cellular and humoral elements, with concomitant release of neutrophil elastase and matrix-metallo proteinases. In the present study, the protease release during extracorporeal circulation in 28 patients undergoing cardiac surgical operations was monitored using casein zymography. A peak in protease activity was found in all patients at the end of cardiopulmonary bypass. Plasma samples of patients were allowed to interact with different traps obtained by immobilizing different protease inhibitors on specific carriers. alpha1-Antitrypsin, Bovine Pancreatic Trypsin Inhibitor, Elastatinal or Leupeptin were used as inhibitors and were covalently immobilized by diazotization or by condensation. A reduction in the proteolytic activity of the plasma samples was observed after interaction with the different traps. The most efficient traps, i.e. the ones displaying greatest power to inhibit protease activity, were those obtained by immobilizing Bovine Pancreatic Trypsin Inhibitor and Leupeptin. The biocompatibility of traps was also tested. Results show that protease activity in blood can be decreased by our protease traps.
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PMID:Biotechnological traps for the reduction of inflammation due to cardiopulmonary bypass operations. 1653 21


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