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)

Site-specific mutagenesis techniques have been used to construct active site variants of the Kunitz-type protease inhibitor domain present in the Alzheimer's beta-amyloid precursor protein (APP-KD). Striking alteration of its protease inhibitory properties were obtained when the putative P1 residue, arginine, was replaced with the small hydrophobic residue valine. The altered protein was no longer inhibitory toward bovine pancreatic trypsin, human Factor XIa, mouse epidermal growth factor-binding protein, or bovine chymotrypsin, all of which are strongly inhibited by the unaltered APP-KD (Sinha, S., Dovey, H. F., Seubert, P., Ward, P. J., Blacher, R. W., Blaber, M., Bradshaw, R. A., Arici, M., Mobley, W. C., and Lieberburg, I. (1990) J. Biol. Chem. 265, 8983-8985). Instead, the P1-Val-APP-KD was a potent inhibitor of human neutrophil elastase, with a Ki = 0.8 nM, as estimated by the inhibition of the activity of human neutrophil elastase measured using a chromogenic substrate. It also inhibited the degradation of insoluble elastin by the enzyme virtually stoichiometrically. Replacement of the P1' (Ala) and P2' (Met) residues of P1-Val-MKD with the corresponding residues (Ser, Ile) from alpha 1-proteinase inhibitor resulted in an inactive protein, underscoring the mechanistic differences between the serpins from the Kunitz-type protease inhibitor family. These results confirm the importance of the P1 arginine residue of APP-KD in determining inhibitory specificity, and are also the first time that a single amino acid replacement has been shown to generate a specific potent human neutrophil elastase inhibitor from a human KD sequence.
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PMID:Conversion of the Alzheimer's beta-amyloid precursor protein (APP) Kunitz domain into a potent human neutrophil elastase inhibitor. 193 50

Peptidyl derivatives of diphenyl (alpha-aminoalkyl)phosphonates have been synthesized and are effective and specific inhibitors of serine proteases at low concentrations. Z-PheP(OPh)2 irreversibly reacts with chymotrypsin (kobsd/[I] = 1200 M-1 s-1) and does not react with two elastases. The best inhibitor for most chymotrypsin-like enzymes including bovine chymotrypsin, cathepsin G, and rat mast cell protease II is the tripeptide Suc-Val-Pro-PheP(OPh)2 which corresponds to the sequence of an excellent p-nitroanilide substrate for several chymases. The valine derivative Z-ValP(OPh)2 is specific for elastases and reacts with human leukocyte elastase (HLE, 280 M-1 s-1) but not with chymotrypsin. The tripeptide Boc-Val-Pro-ValP(OPh)2, which has a sequence found in a good trifluoromethyl ketone inhibitor of HLE, is the best inhibitor for HLE (kobsd/[I] = 27,000 M-1 s-1) and porcine pancreatic elastase (PPE, kobsd/[I] = 11,000 M-1 s-1). The rates of inactivation of chymotrypsin by MeO-Suc-Ala-Ala-Pro-PheP(OPh)2 and PPE and HLE by MeO-Suc-Ala-Ala-Pro-ValP(OPh)2 were decreased 2-5-fold in the presence of the corresponding substrate, which demonstrates active site involvement. Only one of two diastereomers of Suc-Val-Pro-PheP(OPh)2 reacts with chymotrypsin (146,000 M-1 s-1), and the enzyme-inhibitor complex had one broad signal at 25.98 ppm in the 31P NMR spectrum corresponding to the Ser-195 phosphonate ester. Phosphonylated serine proteases are extremely stable since the half-time for reactivation was greater than 48 h for the inhibited elastases and 7.5-26 h for chymotrypsin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Irreversible inhibition of serine proteases by peptide derivatives of (alpha-aminoalkyl)phosphonate diphenyl esters. 198 40

Three structurally related but functionally different serpins from horse plasma were isolated and characterized. In spite of their identical N-terminal sequences, which show some similarity to that of human alpha 1-proteinase inhibitor, the reactive-centre loops of each of these proteins show extensive variation. Only inhibitor I, with a P1 methionine residue, resembles human alpha 1-PI with regard to (a) similarity of amino acid sequence in the vicinity of the reactive-site peptide bond, (b) broad inhibitory specificity, (c) sensitivity to oxidative inactivation and (d) high rate of reactivity with neutrophil elastase(s). Inhibitor II, with a P1 arginine residue, is an exclusive trypsin inhibitor, and inhibitor III is an oxidation-resistant slow-reacting elastase inhibitor with a P1 alanine residue. Comparison of association rate constants for the inhibition of horse neutrophil elastases by the three inhibitors indicates that only inhibitor I is likely to be physiologically important in the regulation of these enzymes.
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PMID:Comparative properties of three functionally different but structurally related serpin variants from horse plasma. 200 10

Neutrophil-activating peptide 2 (NAP-2) is generated by cleavage of two inactive precursors, connective-tissue-activating peptide III (CTAP-III) and platelet basic protein (PBP), which are stored in the alpha-granules of blood platelets. Using highly purified CTAP-III as the substrate we studied the generation of NAP-2 by several neutral tissue proteinases. CTAP-III was rapidly cleaved by chymotrypsin, cathepsin G and trypsin, yielding products with neutrophil-stimulating activity. This activity remained unchanged for 24 h in the presence of chymotrypsin, decreased only slowly in the presence of cathepsin G, but was rapidly destroyed by trypsin. CTAP-III was also degraded by human neutrophil elastase and porcine pancreatic elastase, but no active fragments were obtained. By contrast, no degradation of CTAP-III was observed with thrombin, plasmin or 'granzymes' from cytolytic T-lymphocyte granules. Two active fragments of CTAP-III, generated by chymotrypsin or cathepsin G, were purified and partially sequenced, and were found to have the same N-terminal sequence as NAP-2. These results indicate that both proteinases cleave preferentially the bond between amino acids 15 (Tyr) and 16 (Ala) of CTAP-III. We conclude that chymotrypsin-like proteolytic activity in the vicinity of activated platelets may generate NAP-2 intravascularly. Due to its presence in the primary granules of neutrophils and monocytes cathepsin G is likely to be involved in this process.
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PMID:Formation of neutrophil-activating peptide 2 from platelet-derived connective-tissue-activating peptide III by different tissue proteinases. 203 37

A novel beta-lactam derivative, N-(2-chloromethylphenyl) 3,3-difluoroazetidin-2-one, which behaves as a time-dependent inactivator of leukocyte elastase, has been tested in biological models designed to detect its potential therapeutic value in the treatment of emphysema. Its effect on two types of leukocyte elastase, purified human leukocyte elastase and elastase freshly discharged upon stimulation of guinea pig polymorphonuclear neutrophils, was examined using three methods: the cleavage of a chromogenic peptide substrate, MeO-Suc-Ala-Ala-Pro-Val-NA, the lysis and solubilization of tritiated elastin and the microscopic examination of the damage to lung elastic network. The inhibitor was shown to be effective at preventing proteolysis due to leukocyte elastase. Besides its low cellular toxicity, no apparent hindrance of its efficiency was found in the above quasi in vivo environment. This suggests that this inhibitor may be of potential therapeutic value in elastase-related pathology.
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PMID:Biological evaluation of the inhibition of neutrophil elastase by a synthetic beta-lactam derivative. 208 24

Four stable hybridoma cell lines producing monoclonal antibodies specific for neutrophil proteinase 4 (NP4) were established and one monoclonal antibody was chosen to produce an immunoaffinity-resin for the purification of NP4. In a precipitation assay system these antibodies bound NP4 in a dose-dependent manner, but did so neither with neutrophil elastase nor with cathepsin G. NP4 was purified and electrophoresis of the affinity-purified enzyme in sodium dodecyl sulfate polyacrylamide gels resulted in a single Mr = 30,000 polypeptide. The purified enzyme digested fibrin but not elastin and it cleaved Boc-Ala-ONp readily (Km = 0.47mM) at neutral pH, but had no effect on Suc-[Ala]3 Nan and N-Suc-[Ala]2-Pro-Phe-pNA. The proteolytic activity was inhibited by DFP, alpha 1 PI and alpha 2 M with a Ki of 10(-9)M for the NP4-alpha 1 PI complex. The NH2-terminal sequence and the amino-acid composition of NP4 were distinct from those of elastase and cathepsin G. Neutrophils contain large amounts of NP4 as judged by the comparable amounts of elastase- and NP4-alpha 1 PI complexes present in inflammatory exudates.
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PMID:Monoclonal antibodies specific for neutrophil proteinase 4. Production and use for isolation of the enzyme. 212 Nov 62

Neutrophils have been implicated in multiple models of end-organ injury. The purposes of this study were to determine whether (1) a sublethal septic insult promotes lung neutrophil accumulation, (2) this pulmonary neutrophil accumulation is reversible, (3) these accumulated neutrophils can be activated to injure lung, and (4) this pulmonary neutrophil accumulation obligates lung injury. Rats were administered low-dose endotoxin, 500 micrograms/kg, intraperitoneally, and at 6 or 12 hours, lungs were harvested and assayed for myeloperoxidase, a marker of neutrophil accumulation, and iodine 125-labeled albumin uptake, a marker of lung injury. A second set of rats were administered low-dose endotoxin and at 6 or 12 hours were given a neutrophil activator formyl-norleucyl-leucyl-phenylalanine (FNLP) 250 micrograms/kg, intravenously. At 8 or 14 hours, lungs were harvested and assayed for 125I-labeled albumin uptake. A third set of rats were administered low-dose endotoxin, and at 5 1/2 hours 30 minutes before FNLP administration, they were given a neutrophil elastase inhibitor, methyoxysuccinyl-L-alanine-L-alanine-L-proline-L-valine-chlorometh yl ketone, 2.5 mg/kg, intraperitoneally. At 6 hours rats were given FNLP, and at 8 hours lungs were harvested and assayed for 125I-labeled albumin uptake. The following results were obtained: (1) low-dose endotoxin caused a transient increase (p less than 0.05) in lung neutrophil accumulation at 6 hours, which was resolved by 12 hours; (2) lung 125I-labeled albumin uptake was unchanged both 6 and 12 hours after isolated low-dose endotoxin administration; (3) neutrophil activation increased (p less than 0.05) lung 125I-labeled albumin uptake when imposed 6 but not 12 hours after low-dose endotoxin administration; and (4) elastase inhibition decreased (p less than 0.05) the lung 125I-labeled albumin uptake promoted by endotoxin and FNLP. We conclude that sublethal endotoxemia causes a reversible lung neutrophil accumulation and that this lung neutrophil accumulation does not obligate lung injury; but activation of these accumulated neutrophils can promote lung injury, and this neutrophil-associated lung injury is mediated in part by neutrophil elastase.
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PMID:Reversible lung neutrophil accumulation can cause lung injury by elastase-mediated mechanisms. 216 56

Human rheumatoid synovial cells in culture secrete at least three related metalloproteinases that digest extracellular matrix macromolecules. One of them, termed matrix metalloproteinase 2 (MMP-2), has been purified as an inactive zymogen (proMMP-2). The final product is homogeneous on SDS/PAGE with Mr = 72,000 under reducing conditions. The NH2-terminal sequence of proMMP-2 is Ala-Pro-Ser-Pro-Ile-Ile-Lys-Phe-Pro-Gly-Asp-Val-Ala-Pro-Lys-Thr, which is identical to that of the so-called '72-kDa type IV collagenase/gelatinase'. The zymogen can be rapidly activated by 4-aminophenylmercuric acetate to an active form of MMP-2 with Mr = 67,000, and the new NH2-terminal generated is Tyr-Asn-Phe-Phe-Pro-Arg-Lys-Pro-Lys-Trp-Asp-Lys-Asn-Gln-Ile. However, following 4-aminophenylmercuric acetate activation, MMP-2 is gradually inactivated by autolysis. Nine endopeptidases (trypsin, chymotrypsin, plasmin, plasma kallikrein, thrombin, neutrophil elastase, cathepsin G, matrix metalloproteinase 3, and thermolysin) were tested for their abilities to activate proMMP-2, but none had this ability. This contrasts with the proteolytic activation of proMMP-1 (procollagenase) and proMMP-3 (prostromelysin). The optimal activity of MMP-2 against azocoll is around pH 8.5, but about 50% of activity is retained at pH 6.5. Enzymic activity is inhibited by EDTA, 1,10-phenanthroline or tissue inhibitor of metalloproteinases, but not by inhibitors of serine, cysteine or aspartic proteinases. MMP-2 digests gelatin, fibronectin, laminin, and collagen type V, and to a lesser extent type IV collagen, cartilage proteoglycan and elastin. Comparative studies on digestion of collagen types IV and V by MMP-2 and MMP-3 (stromelysin) indicate that MMP-3 degrades type IV collagen more readily than MMP-2, while MMP-2 digests type V collagen effectively. Biosynthetic studies of MMPs using cultured human rheumatoid synovial fibroblasts indicated that the production of both proMMP-1 and proMMP-3 is negligible but it is greatly enhanced by the treatment with rabbit-macrophage-conditioned medium, whereas the synthesis of proMMP-2 is constitutively expressed by these cells and is not significantly affected by the treatment. This suggests that the physiological and/or pathological role of MMP-2 and its site of action may be different from those of MMP-1 and MMP-3.
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PMID:Matrix metalloproteinase 2 from human rheumatoid synovial fibroblasts. Purification and activation of the precursor and enzymic properties. 226 96

Inhibitors of neutrophil proteases may have therapeutic effects in inflammatory diseases. MDL 27,324 (Dansyl-Ala-Ala-Pro-Val-CF3), inhibits human neutrophil elastase and MDL 27,399 (MeOSucc-Ala-Ala-Pro-Phe-COOCH3), inhibits human neutrophil cathepsin G. These compounds individually or in combination, partially inhibited the hydrolysis of fluoresceinated bovine serum albumin and fluoresceinated immune complexes by rat and human neutrophil granule lysate. In contrast, the combination of inhibitors completely prevented the breakdown of a complex connective tissue substrate, azure hide powder. Rat neutrophils phagocytosed and hydrolyzed fluoresceinated immune complexes, a process which was inhibited by cytochalasin B (15 micrograms/ml, 65% inhibition) and chloroquine (200 microM, 80% inhibition). Although MDL 27,324 was taken up by the cells, it had only a modest inhibitory effect on the proteolysis of ingested fluoresceinated immune complexes (200 microM, 20% inhibition); MDL 27,399 had similar limited efficacy. Therefore, these compounds may be effective inhibitors of neutrophil serine proteases secreted into the extracellular space during inflammation without interfering with the normal process of intracellular degradation of phagocytosed material.
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PMID:Novel inhibitors of polymorphonuclear neutrophil (PMN) elastase and cathepsin G: evaluation in vitro of their potential for the treatment of inflammatory connective tissue damage. 229 60

Comparison of MeO-Suc-Val-Pro-Phe-CO2Me (29) and MeO-Suc-Ala-Ala-Pro-Phe- CO2Me (25) with their corresponding trifluoromethyl ketones 9a and 9b, respectively, in rat and human neutrophil cathepsin G assays showed the alpha-keto esters to be more potent inhibitors. Likewise, Ac-Pro-Ala-Pro-Ala-CO2Me (21) was more potent than its corresponding trifluoromethyl ketone (9c) in both porcine pancreatic elastase and human neutrophil elastase assays. Within a set of Ala-Ala-Pro-Val-CF3 elastase inhibitors, the carbobenzyloxy (Cbz) N-protecting group conferred greater potency as a P5 site recognition unit for elastase than did dansyl, methoxysuccinyl, or tert-butyloxycarbonyl. Initial inhibition of elastase was greater when trifluoromethyl ketone 9f was added from a stock solution of dimethyl sulfoxide than when it had been buffer-equilibrated prior to assay, which suggests that the nonhydrated ketone is the more effective form of the inhibitor. The most potent elastase inhibitor we report is Na-(Ad-SO2)-N epsilon-(MeO-Suc)Lys-Pro-Val-CF3 (16) which has a Ki of 0.58 nM.
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PMID:Synthesis of peptidyl fluoromethyl ketones and peptidyl alpha-keto esters as inhibitors of porcine pancreatic elastase, human neutrophil elastase, and rat and human neutrophil cathepsin G. 229 31


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