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)

Addition of glucose oxidase (GO) increased H2O2 concentrations and decreased antielastolytic activities of beta-D-glucose containing perfusates of isolated rat lungs. Pretreatment with GO also caused acute edematous injury (increased lung weight gains, increased recovery of Ficoll in lung lavages, and increased pulmonary arterial pressures) in isolated lungs perfused with purified human neutrophil elastase (NE). Acute edematous injury in isolated lungs pretreated with GO and then NE exceeded levels found in lungs following addition of GO or NE alone or NE before GO. Simultaneous addition of catalase (an H2O2 scavenger) or methoxy-succinyl-L-alanyl-L-alanyl-prolyl-L-valine-chloromethyl ketone (an NE inhibitor, but not aminotriazole-inactivated catalase, N-tosyl-L-phenyl-alanine chloromethyl ketone (a chymotrypsin inhibitor) or N-alpha-p-tosyl-L-lysine chloromethyl ketone (a trypsin inhibitor), prevented acute edematous injury in isolated lungs perfused with both GO and NE. This observation indicated that injury was dependent on both H2O2 and NE, especially since the relative inactivating specificities of the inhibitors for H2O2 or NE, respectively, were confirmed under similar conditions in vitro. The synergistic nature of the interaction between H2O2 and NE-mediated injury was further clarified when GO- and NE-induced lung injury was prevented by addition of an oxidant-resistant NE inhibitor (Eglin-C), but not an oxidant-sensitive NE inhibitor (human alpha 1-protease inhibitor, alpha 1PI). Moreover, treatment with H2O2 also decreased the ability of alpha 1PI but not Eglin-C to decrease NE activity in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:O2 metabolites and neutrophil elastase synergistically cause edematous injury in isolated rat lungs. 364 11

A human urinary trypsin inhibitor preparation, MR-20, strongly inhibited granulocyte elastase activity. The concentration of MR-20 causing 50% inhibition of the hydrolysis of Suc(Ala) 3pNA by granulocyte elastase was estimated to be 6.4 X 10(-8) M (11 U/ml).
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PMID:Effect of human urinary trypsin inhibitor on granulocyte elastase activity. 364 71

We have determined the effect of altering assay conditions on the observed neutrophil elastase inhibitory capacity in lung secretions from emphysematous patients with normal serum alpha 1 PI. alpha 1 PI, ALP and alpha 2-macroglobulin were detected in all samples. Measurement at low enzyme concentration (less than 33.6 nmol/l) caused a 43% reduction in observed neutrophil elastase inhibitory capacity of sputum sol-phase, while inhibition by secretions in buffer without added NaCl was 20% greater than in the presence of 0.2 mol/l NaCl. Increasing the concentration of the synthetic substrate Suc-[Ala]3-pNA in the assay from 0.45 mmol/l to 7.2 mmol/l reduced the observed inhibitory capacity by 53% and the use of elastin-fluorescein gave lower results for inhibitory capacity than the Suc-[Ala]3-pNA (median 0.26 mol neutrophil elastase/mol measured inhibitors (range 0-0.72) with elastin; 1.40 mol neutrophil elastase/mol measured inhibitors (0.80-3.21) with Suc-[Ala]3-pNA). Assay conditions therefore greatly influence the results. In addition these findings suggest the presence of an additional inhibitor of neutrophil elastase in these secretions.
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PMID:The effect of assay conditions on the measurement of anti-elastase function in lung secretions. 364 4

Steady-state kinetic parameters were determined for the human leukocyte elastase catalyzed hydrolysis of a series of peptide-based thiobenzyl esters and p-nitroanilides. The peptide units are MeOSuc-Val, MeOSuc-Alan-Pro-Val (n = 0-2), and MeOSuc-Alan-Pro-Ala (n = 1 or 2). The results of this study suggest five important mechanistic features for HLE. Few important remote subsite contacts are established in the Michaelis complex. Full recognition and tight binding of the substrate occurs in the transition state for acylation. The P3-S3 interaction is critical during acylation. Subsite contacts are unimportant in deacylation. P1 specificity is regulated by peptide length. An important steady-state kinetic consequence of this specificity is that the rate-limiting step of kc for p-nitroanilide hydrolysis changes from acylation to deacylation as the peptide chain is lengthened.
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PMID:Catalysis by human leukocyte elastase: mechanistic insights into specificity requirements. 364 70

Acyl-enzymes of human leukocyte elastase (HLE) were generated in situ during the hydrolysis of peptide thiobenzyl esters and served as substrates for aminolysis by a variety of amino acid amides and short peptide nucleophiles. For amino acid amides, there is a positive correlation between nucleophilic reactivity toward N-methoxysuccinyl (MeOSuc)-Ala-Ala-Pro-Val-HLE and the hydrophobicity of the side chain. For peptides, nucleophilicity toward MeOSuc-Ala-Ala-Pro-Val-HLE decreases dramatically with increasing chain length. Combined, these results suggest that substrate specificity for the P1' residue may be more dependent on side chain hydrophobicity than on specific, structural features of the side chain and there may be no important binding interactions available past S1'. Kinetic parameters were also determined for the nucleophilic reactions of PheNH2 and TyrNH2 with MeOSuc-Pro-Val-HLE, MeOSuc-Ala-Pro-Val-HLE, MeOSuc-Ala-Ala-Pro-Val-HLE, and MeOSuc-Ala-Ala-Pro-Ala-HLE. Reactivity of these acyl-enzymes toward nucleophilic attack displays no dependence on peptide chain length but does increase significantly for the substrate with Ala at P1. This same correlation between reactivity and acyl-enzyme structure is also seen for nucleophilic attack by water.
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PMID:Catalysis by human leukocyte elastase. Aminolysis of acyl-enzymes by amino acid amides and peptides. 365 Jan 9

Human neutrophil elastase was inactivated by methoxysuccinyl-L-Ala-L-Ala-L-Pro-L-Ala-chloromethane. The modified enzyme was crystallized from 40 mM ammonium phosphate, pH 7.0 in the hexagonal space group P6(3) with unit cell parameters a = 74.53 A, b = 74.53 A, c = 70.88 A, alpha = beta = 90 degrees, gamma = 120 degrees. These crystals were resistant to radiation damage and diffracted beyond 1.84-A resolution. The asymmetric unit contained one 25,000-dalton monomer of human neutrophil elastase. Crystals were also grown from the enzyme modified with the analogous iodinated inactivator, p-iodoanilinosuccinyl-L-Ala-L-Ala-L-Pro-L-Ala-chloromethane. These crystals proved to be isomorphous with those of methoxysuccinyl-L-Ala-L-Ala-L-Pro-L-Ala-chloromethane-modified human neutrophil elastase, and served as a single-site, heavy atom derivative for solving the tertiary structure of the enzyme.
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PMID:Crystallization of human neutrophil elastase. 368 Feb 95

Low-molecular inhibitors of pancreatic and leukocyte elastase were synthesized of the general formula X-[Ala]n-A [X = Suc and Glt, A = ethylamide, n = 1, 2, 3 and 4; for n = 2 X = H and A = (2-phenylethyl)amide] and of the formula X-[Ala]3-A (X = H, Suc and Glt, A = methyl-, ethyl-, propyl-, isopropyl-, butyl-, isobutyl-, (2-phenylethyl)- and diethylamide; for A = ethylamide, X = maleyl or acetyl). Inhibition constants Ki of these pancreatic and leukocyte elastase inhibitors were determined using the chromogenic substrates Suc-[Ala]4-Nan or Glt-[Ala]4-Nan and Glt-[Ala]3-Val-Nan, respectively. The series of anionic inhibitors containing three alanine residues has the best inhibitory properties. Of the acyl groups, 4-carboxybutyryl appears most advantageous, propylamide is the most suitable of alkylamides for pancreatic elastase, and isobutylamide for leukocyte elastase. Peptides containing a free amino group show an inhibition for pancreatic elastase lower by one order than that of the corresponding acylated derivatives. Glt-[Ala]3-NH-Pr is the best inhibitor of pancreatic elastase with Ki = 0.003mM and Suc-[Ala]3-NH-iBu is the best inhibitor of leukocyte elastase with Ki = 0.7mM.
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PMID:Anionic inhibitors of pancreatic and leukocyte elastase. Alkylamides of 3-carboxypropionyl- and 4-carboxybutyrylalanine peptides. 384 9

Peptide sequences which fit the extended binding sites of porcine pancreatic elastase and human leukocyte elastase were covalently coupled to oleic acid. These compounds behave as competitive inhibitors towards both elastases. The coupling of fatty acid moiety to the peptide greatly decreases its inhibitor constant (Ki) vs human leukocyte elastase (Ki for Oleoyl(Ala)2ProValine: 3.0 (10(-6)M). It is less active on porcine pancreatic elastase (Ki for Oleoyl(Ala)2ProAlanine: 3.8 10(-4)M). The modifications of the carboxylic end group of the peptide to an aldehyde further greatly enhanced the inhibition capacity of the compound towards leukocyte elastase (Ki for Oleoyl(Ala)2ProAlaninal: 0.7 microM). Oleoyl peptide derivatives were seen to bind in a saturable fashion to purified insoluble elastin, and decreased the susceptibility of the macromolecule to hydrolysis by both pancreatic and leukocyte elastases. As stoichiometric quantities of elastase (vs inhibitor) could not desorb 3H-oleoyl(Ala)2Pro-Val bound to insoluble elastin, it is postulated that oleoyl peptide derivatives may act as bifunctional agents. This contention was further strengthened by the comparison of the adsorption curves of elastase to untreated insoluble elastin and elastin saturated with oleoyl peptide derivatives respectively. It was shown finally that Oleoyl(Ala)2Pro-Valine was also capable of inhibiting elastases in their adsorbed form to insoluble elastin.
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PMID:Fatty acid peptide derivatives as model compounds to protect elastin against degradation by elastases. 384 69

Porcine leukocyte elastase was purified from granulocytes by chelating chromatography on copper chelate Sepharose and by ion exchange chromatography on CM-Sepharose. Thus an enzyme preparation with a specific activity (substrate: MeOSuc(Ala)2ProValNan) of 89.3 U/mg protein was obtained. Dodecyl sulphate gel electrophoresis revealed one protein band corresponding to a molecular mass of 27 kDa. The amino acid composition was determined and isoleucine was identified as the only N-terminal amino acid residue. The bimolecular velocity constant for the inhibition by diisopropyl fluorophosphate was determined as 2000 1 . mol-1 . min-1. The dissociation constants, Ki, of the complexes of porcine leukocyte elastase with various inhibitors were calculated. The kinetic constants for the elastase-catalysed hydrolysis of MeOSuc(Ala)2ProValNan, Suc(Ala)2ValNan and Suc(Ala)3Nan were determined, as well as the kinetic constants of the inactivation of leukocyte elastase by active site mapping reagents. Detergents such as Triton X-100, Tween 20 and Brij 35, as well as porcine serum albumin, activated the porcine leukocyte elastase preparation.
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PMID:Isolation and characterization of porcine leukocyte elastase. Leukocyte elastase-inhibitor complexes in porcine blood, II. 385 25

The authors wished to determine whether secretory cell metaplasia (SCM) induced in the bronchi of hamsters by human neutrophil elastase (HNE) was enzymatically mediated. We also wished to determine whether SCM could be induced by a proteolytic enzyme devoid of elastolytic activity. Accordingly, groups of weight-matched hamsters were given a single intratracheal instillation of 0.5 ml of saline solution containing one of the following: 300 micrograms of HNE purified from blood neutrophils, n = 14; 300 micrograms of HNE inactivated with Suc-Ala-Ala-Pro-Val chloromethyl ketone (CMK), n = 10; 500 micrograms of porcine pancreatic trypsin treated with CMK to eliminate residual active elastase, n = 10; 500 micrograms of trypsin inactivated by tosyl lysine chloromethyl ketone, n = 10; 2 micrograms CMK, n = 10; and saline alone, n = 10. Seven untreated animals served as additional controls. Twenty-one days post treatment, 5-6 micron paraffin-embedded sections, from the left lung hilar region, stained by Alcian blue and periodic acid-Schiff reaction were graded on a five-point scale for determination of the secretory cell index, which reflects SCM. Both elastase and trypsin produced severe SCM: mean +/- SEM secretory cell indices were 2.96 +/- 0.11 and 2.72 +/- 0.19, respectively, compared with values of 0.90 +/- 0.35 for the untreated group and 0.93 +/- 0.46 for the saline group (p less than .05). The secretory cell indices of the groups treated with inactivated elastase or trypsin were comparable to those of the saline-treated and untreated groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Proteolytic activity of human neutrophil elastase and porcine pancreatic trypsin causes bronchial secretory cell metaplasia in hamsters. 390 65


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