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)

The precursor of matrix metalloproteinase 9 (proMMP-9), also known as '92 kDa progelatinase/type IV procollagenase', was purified from the conditioned medium of U937 monocytic leukaemia and HT1080 fibrosarcoma cell lines stimulated with phorbol 12-myristate 13-acetate. ProMMP-9 in these culture media is non-covalently complexed with the 29 kDa tissue inhibitor of metalloproteinases (TIMP), but free proMMP-9 was separated from the TIMP-proMMP-9 complex by chromatography on Green A Dyematrex gel. The final product was homogeneous on SDS/PAGE, with a molecular mass of 88 kDa without reduction and 92 kDa with reduction. Treatment of proMMP-9 with 4-aminophenylmercuric acetate converted the 88 kDa precursor into 80 kDa and 68 kDa forms. Gelatin-containing zymographic analysis showed zones of lysis associated with all three species. However, only the 68 kDa species was shown to be catalytically active by its ability to bind to alpha 2-macroglobulin. In the presence of an equimolar amount of TIMP, only the 80 kDa species was generated by treatment with 4-aminophenylmercuric acetate, but no enzyme activity was detected. This indicates that TIMP binds to the 80 kDa intermediate and inhibits the generation of the active 68 kDa species. Eight endopeptidases (trypsin, chymotrypsin, plasmin, plasma kallikrein, thrombin, cathepsin G, neutrophil elastase and thermolysin) were tested for their ability to activate proMMP-9. Of them, trypsin was the most effective activator of proMMP-9. Only partial activation (10-30%) was observed with plasmin, cathepsin G and chymotrypsin. The active forms generated by trypsin were identified as 80 kDa, 74 kDa and 66 kDa by their abilities to bind to alpha 2-macroglobulin. In the presence of an equimolar amount of TIMP, proMMP-9 was also converted into the same molecular-mass species by trypsin, but they were not proteolytically active. This suggests activated MMP-9 is inhibited by TIMP. Activated MMP-9 digested gelatin, type-V collagen, reduced carboxymethylated transferrin and, to a lesser extent, type-IV collagen and laminin A chain. The specific activity against gelatin was estimated to be 15,000 units/mg (1 unit = 1 microgram of gelatin degraded/min at 37 degrees C) by titration with alpha 2-macroglobulin. Comparative studies on digestion of gelatin and collagen types IV and V by MMP-9 and MMP-2 indicated that both enzymes degrade these substrates into similar fragments. However, the susceptibilities of laminin, fibronectin and reduced carboxymethylated transferrin to these two MMPs were sufficiently different to indicate differences in substrate specificities between these two closely related proteinases.
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PMID:Purification and characterization of matrix metalloproteinase 9 from U937 monocytic leukaemia and HT1080 fibrosarcoma cells. 137 48

In vivo most extracellular iron is bound to transferrin or lactoferrin in such a way as to be unable to catalyze the formation of hydroxyl radical from superoxide (.O2-) and hydrogen peroxide (H2O2). At sites of Pseudomonas aeruginosa infection bacterial and neutrophil products could possibly modify transferrin and/or lactoferrin forming catalytic iron complexes. To examine this possibility, diferrictransferrin and diferriclactoferrin which had been incubated with pseudomonas elastase, pseudomonas alkaline protease, human neutrophil elastase, trypsin, or the myeloperoxidase product HOCl were added to a hypoxanthine/xanthine oxidase .O2-/H2O2 generating system. Hydroxyl radical formation was only detected with pseudomonas elastase treated diferrictransferrin and, to a much lesser extent, diferriclactoferrin. This effect was enhanced by the combination of pseudomonas elastase with other proteases, most prominently neutrophil elastase. Addition of pseudomonas elastase-treated diferrictransferrin to stimulated neutrophils also resulted in hydroxyl radical generation. Incubation of pseudomonas elastase with transferrin which had been selectively iron loaded at either the NH2- or COOH-terminal binding site yielded iron chelates with similar efficacy for hydroxyl radical catalysis. Pseudomonas elastase and HOCl treatment also decreased the ability of apotransferrin to inhibit hydroxyl radical formation by a Fe-NTA supplemented hypoxanthine/xanthine oxidase system. However, apotransferrin could be protected from the effects of HOCl if bicarbonate anion was present during the incubation. Apolactoferrin inhibition of hydroxyl radical generation was unaffected by any of the four proteases or HOCl. Alteration of transferrin by enzymes and oxidants present at sites of pseudomonas and other bacterial infections may increase the potential for local hydroxyl radical generation thereby contributing to tissue injury.
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PMID:Pseudomonas and neutrophil products modify transferrin and lactoferrin to create conditions that favor hydroxyl radical formation. 165 25

Arthritis was induced by injecting cationic amidated bovine serum albumin (aBSA) (pI approximately 9.2) into the knee joint of immunized guinea pigs and the mechanisms of articular cartilage destruction were studied morphologically and biochemically. Marked synovitis associated with polymorphonuclear leukocyte (PML) infiltration occurred within 1 day of the challenge. Articular cartilage infiltrated by PMLs was almost completely destroyed after 2 weeks. During the initial destructive process, proteoglycans were depleted from the cartilage and later collagen fibers disappeared. Granulation tissue growing in the inflamed synovium and bone marrow replaced the destroyed cartilage and joint cavity and formed fibrous scar tissue (fibrous ankylosis) by 8 weeks. Subsequently, the knee joints developed cartilagenous ankylosis by 12 weeks and finally bony ankylosis at 28 weeks. Autoradiography using 125I-aBSA and immunofluorescence studies for immunoglobulin (IgG) and complement (C3) demonstrated that the antigen is trapped in all zones of the articular cartilage and serves as a trigger for immune complex formation. Significantly increased neutral proteinase activities against substrates of proteoglycan subunits, [3H]carboxymethylated transferrin and L-pyroglutamyl-L-prolyl-L-valine-paranitroanilide were detected in homogenates of the synovium and cartilage from arthritic knee joints 1 and 2 weeks after induction. Inhibitor studies and pH curves suggested that the proteinase is leukocyte elastase. Measurable amounts of gelatinolytic activity, detected by activation with 4-aminophenylmercuric acetate and inhibited with EDTA, were also present in the same samples, but there was no detectable collagenase activity. The data on SDS-gelatin substrate gel showed that the proteinase is gelatinase derived from PMLs. These results suggest that in aBSA-induced arthritis, elastase and gelatinase from PMLs invading articular cartilage may play important roles in cartilage destruction.
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PMID:Arthritis induced immunologically with cationic amidated bovine serum albumin in the guinea pig. A morphological and biochemical study on the destruction of articular cartilage. 167 78

In nine subjects undergoing oesophagectomy a transient but significant increase in pulmonary vascular permeability to transferrin was detected in both lungs 8 h after surgery. It coincided with a significant increase in plasma lactoferrin, evidence of intravascular and intra-alveolar neutrophil elastase release and with arterial hypoxaemia. The postoperative state in these patients had intravascular and pulmonary features often associated with the adult respiratory distress syndrome, and might be a useful model for the study of the early inflammatory events underlying lung injury in man.
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PMID:Neutrophil degranulation and increased pulmonary capillary permeability following oesophagectomy: a model of early lung injury in man. 317 65

In this study, we evaluated the in vitro and in vivo potency of human leukocyte elastase (HLE) and human cathepsin G (HCG) as proteoglycanases. In vitro evaluation was done using bovine nasal septum aggrecan and aggrecan/hyaluronan aggregate as substrates. Enzyme activity was assessed by the ability of the proteinases to abrogate the ability of aggrecan to aggregate with hyaluronan. In vivo activity of the proteinases was tested by injecting purified HLE and HCG intra-articularly into rabbit stifle joints and quantifying the levels of proteoglycan released into synovial fluids. On a molar basis, HCG was at least tenfold more potent than HLE as a proteoglycanase in vitro. Moreover, HCG was twofold more potent as a proteoglycanase in vivo. In contrast, HLE hydrolyzed elastin approximately 22-fold faster than HCG, but was only slightly more rapid than HCG when [3H]-transferrin was used as substrate. These data indicate that HCG is more potent than HLE as a proteoglycanase both in vitro and in vivo. Thus, HCG could be more important in the pathogenesis of rheumatoid arthritis than previously suspected.
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PMID:Comparison of the proteoglycanolytic activities of human leukocyte elastase and human cathepsin G in vitro and in vivo. 814 41

In this study, we demonstrate that the synthesis and release of serine proteinases by hematopoietic cells affects the in vitro proliferation of hematopoietic progenitor cells (HPCs) in response to proteins, including hematopoietic growth factors (HGFs), transferrin, insulin, and albumin in serum-free cultures. In serum-free cultures, bone marrow mononuclear cells or the CD34- progeny of the CD34+ cells were shown to release the serine proteinases human neutrophil elastase (HNE), cathepsin G (Cath G), and proteinase 3 (Pr3). In the absence of serum, we showed that HNE, Cath G, and Pr3 rapidly and dose-dependently degraded HGF and other proteins present in the medium, resulting in decreased proliferation of HPCs. Addition of the serine proteinase inhibitors alpha1-proteinase inhibitor (alpha1-PI) or the secretory leukocyte proteinase inhibitor (SLPI), but not leupeptin, aprotinin, or AEBSF (4-[2-aminoethyl]-benzenesulfonylfluoride hydrochloride), could completely prevent the degradation of proteins relevant to the growth of hematopoietic cells. Thus, the addition of serine proteinase inhibitors like alpha1-PI or SLPI may be critical for the expansion of CD34+ cells or gene transfer into CD34+ cells or other hematopoietic cells in vitro using serum-free media under good manufacturing practice conditions.
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PMID:Cytokine-dependent proliferation of human CD34+ progenitor cells in the absence of serum is suppressed by their progeny's production of serine proteinases. 1672 57

Lactoferrin (Lf) is a member of the transferrin family of iron-binding anti-bacterial proteins, present in most exocrine secretions, such as saliva, and plays an important role in mucosal defense. In this study, we identified small Lf peptides with Con A low-affinity in the parotid saliva of chronic periodontitis patients by Con A two-dimensional immunoelectrophoresis, Con A affinity chromatography and Western blotting using anti-human Lf polyclonal Ab. N-terminal amino acid sequencing of the four Con A low-affinity Lf peptides confirmed them to be fragments of intact Lf. The detection ratio of the proteinase 3 (PR3)-like activity was elevated in the parotid saliva of periodontitis patients and was associated with the severity of clinical symptoms. PR3 protein was also detected in the parotid saliva of periodontitis patients, and PR3, but not human leukocyte elastase and cathepsin G, degraded intact Lf. Con A low-affinity saliva Lf peptides showed no anti-bacterial activity against Escherichia coli, and had a reduced iron-chelating capacity. Con A low-affinity saliva Lf peptides, PR3-treated Lf preparation and two of four synthetic polypeptides induced the production of interleukin IL-6, monocyte chemoattractant protein-1 and IL-8, and the activation of NF-kappaB in human oral epithelial HSC-2 cells. Furthermore, concentrations of the Lf peptides in the parotid saliva of periodontitis patients were increased with a correlation to the severity of clinical symptoms. These results suggest that Lf in the parotid saliva of periodontitis patients was degraded into small peptides by the PR3-like activity with the capability to induce inflammatory mediators.
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PMID:Cleaved inflammatory lactoferrin peptides in parotid saliva of periodontitis patients. 1703 Mar 85

Human neutrophil elastase (HNE) is a multifunctional serine protease, involved in infection defense, inflammatory process regulation, and physiopathological processes of several diseases. We developed aptamer-capture based assays for human neutrophil elastase with different substrates and solid supports to meet different demands, such as simplicity, sensitivity, and high throughput. Aptamers against HNE were immobilized on magnetic beads or microplates as affinity ligands to capture HNE, and then the enriched HNE catalyzed the conversion of chromogenic substrates or fluorogenic substrates to products. The measurement of the generated enzymatic products enabled the final detection of HNE. In the assay using chromogenic substrates and aptamer modified magnetic beads, 0.4 pM HNE could be successfully detected. The sensitivity of the assay was further improved by using fluorogenic substrates, and a detection limit of HNE at 20 fM was achieved. The use of aptamer-coated microplates instead of aptamer modified magnetic beads in the assays also allowed the sensitive detection of HNE, offering advantages in fast sample handling and measurement. The established assays for HNE displayed good specificity, and proteins including serum albumin, transferrin, immunoglobulin G, thrombin, porcine pancreatic elastase, trypsin, proteinase K, chymotrypsin, lysozyme, cathepsin G, and proteinase 3 did not cause interference in the detection of HNE.
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PMID:Aptamer-capture based assays for human neutrophil elastase. 2359 34