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: UMLS:C0034067 (emphysema)
11,506 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human leukocyte elastase (HLE) is a serine protease produced by neutrophils that has been implicated in diseases such as emphysema and cystic fibrosis. An HLE inhibitor may have therapeutic value in these diseases. An active site model of HLE bound to a tripeptidic trifluoromethyl ketone (TFMK) inhibitor, 2, was created from X-ray structures of HLE and porcine pancreatic elastase. Analysis of the model indicated a preferred binding conformation for the tripeptide and potentially important interactions between it and the enzyme. This information was used to aid in the design of a series of novel, pyridone-containing, non-peptidic HLE inhibitors such as 2-[3-[[(benzyloxy)carbonyl]amino]-2-oxo- 1,2-dihydro-1-pyridyl]-N-(3,3,3-trifluoro-1-isopropyl-2-oxopropyl)ace tam ide (5b) (Ki = 280 +/- 78 nM). Inspection of the active site model suggested that a benzyl substituent at the 5-position of the pyridone ring might improve potency by forming a lipophilic interaction with the enzyme S2 pocket. Synthesis and biological evaluation of a series of 5-benzylpyridone TFMKs provided evidence for this proposition. Further analysis of the model indicated that substitution on the 3-amino group of the pyridone ring with a hydrogen bond acceptor could potentially lead to interactions with the NH atoms of glycine-218 and/or -219. The oxalate derivative 2-[5-benzyl- 3-(carboxycarbonyl)-2-oxo-1,2-dihydro-1-pyridyl]-N-(3,3,3-trifl uor o-1- isopropyl-2-oxopropyl)acetamide (5v) was synthesized and found to have a Ki of 48 +/- 9 nM. Unfortunately, none of the compounds tested was active in an in vivo model of HLE-induced lung injury when dosed orally.
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PMID:Non-peptidic inhibitors of human leukocyte elastase. 1. The design and synthesis of pyridone-containing inhibitors. 793 32

The enzymatic breakdown of human lung elastin by leukocyte elastase precedes the development of pulmonary emphysema, and releases elastin-derived peptides (EDPs) into the circulation. While raised levels of EDPs measured by enzyme-linked immunosorbent assay (ELISA) have been proposed as a possible marker for early detection of emphysema, average normal values of EDPs measured by different investigators have differed by up to a factor of 1000. Standardisation of the methodology for elastin purification and EDP production in vitro is required to ensure the accuracy of EDP measurements in vivo, because antiserum used in the ELISA is raised against the EDPs produced in vitro. In the present study elastin was purified from human lung by sequential biochemical extraction, and solubilised by leukocyte elastase. Molecular weight distribution of EDPs produced by partial and complete elastin digestion were compared by gel exclusion chromatography. A method for successful separation of EDPs by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) is reported. The implications of these results for further immunological characterisation of these peptides are discussed with a view to standardisation of the techniques employed for the measurement of EDPs in vivo.
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PMID:Characterisation of human lung elastin-derived peptides. 848 61

Inhibitors of human leukocyte elastase (HLE) may exert potent therapeutic effects on pulmonary emphysema, adult respiratory distress syndrome and other diseases involving tissue degradation. 7-(4-Chlorophenylsulfonyl-L-glutanyl)amino-5-methyl-2-isopro pylamino-4H-3,1- benzoxazin-4-one (TEI-5624) and 7-(4-chlorophenylsulfonyl-L-lysyl)amino-5-methyl-2- isopropylamino-4H-3,1-benzoxazin-4-one (TEI-6344), two derivatives of 5-methyl-4H-3,1-benzoxazin-4-one, showed strong and highly specific inhibition of human sputum elastase (HSE), which is equivalent to HLE, with Ki values of 6.91 and 16.3 nM, respectively. The selectivity of TEI-5624 for HSE vs. several proteinases ranged from 300-fold to 45,000-fold in favor of HSE. TEI-5624 and TEI-6344 also efficiently prevented degradation of insoluble elastin by stimulated polymorphonuclear leukocytes. The elastase inhibitory capacity of these compounds was not affected by treatment with stimulated polymorphonuclear leukocytes or Pseudomonas aeruginosa-origin elastase. When administered intratracheally to hamsters. TEI-5624 and TEI-6344 were eliminated from the lung with half-times of 85 and 240 min, respectively. In acute injury induced by intratracheal administration of HSE in hamsters, these compounds significantly suppressed pulmonary hemorrhage when administered intratracheally (1 mg/kg) either 30 or 240 min before challenge with HSE (1 mg/kg). HSE-induced emphysema in hamsters was also prevented by TEI-5624 (1 mg/kg) administered intratracheally 7 hr after HSE administration (1 mg/kg). These results suggest that TEI-5624 and TEI-6344 may be useful therapeutic agents for the treatment of HLE-mediated diseases.
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PMID:5-Methyl-4H-3,1-benzoxazin-4-one derivatives: specific inhibitors of human leukocyte elastase. 849 3

Several samples of oversulfated chondroitin and dermatan were obtained by chemical sulfation and by SAX-HPLC enrichment. The starting products and oversulfated products were tested as potential inhibitors of human leukocyte elastase, an enzyme hypothesized to be involved in the etiology of diseases such as emphysema, atherosclerosis, and rheumatoid arthritis. Chemical oversulfation (SO3H/COOH 1.6-3.2), preferentially occurring at C-6 of galactosamine residues, was found generally to increase the inhibitory power on elastase. Chemically oversulfated galactosaminoglycans thus have potential as therapeutic agents, considering that they produce non-significant effects on the hemocoagulative system. Two naturally oversulfated dermatans sulfate (SO3H/COOH ca. 1.2), mainly oversulfated at C-2 of iduronic acid residues, showed comparatively higher anticoagulant activity (in the HC-II mediated thrombin inhibition test).
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PMID:Inhibition of human leukocyte elastase by chemically and naturally oversulfated galactosaminoglycans. 854 7

Macrophage elastase (ME) was originally named when metal-dependent elastolytic activity was detected in conditioned media of murine macrophages. Subsequent cDNA cloning of the mouse and human enzyme demonstrated that ME is a distinct member of the matrix metalloproteinase family. To date, the catalytic parameters that describe the hydrolysis of elastin by ME have not been quantified and its activity against other matrix proteins have not been described. In this report, we have examined the action of purified recombinant human ME (rHME), produced in Escherichia coli, on elastin and other extracellular matrix proteins. On a molar basis, rHME is approximately 30% as active as human leukocyte elastase in solubilizing elastin. rHME also efficiently degrades alpha1-antitrypsin (alpha1-AT), the primary physiological inhibitor of human leukocyte elastase. In addition, rHME efficiently degrades fibronectin, laminin, entactin, type IV collagen, chondroitan sulfate, and heparan sulfate. These results suggest that HME may be required for macrophages to penetrate basement membranes and remodel injured tissue during inflammation. Moreover, abnormal expression of HME may contribute to destructive processes such as pulmonary emphysema and vascular aneurysm formation. To further understand the specificity of HME, the initial cleavage sites in alpha1-AT have been determined. In addition, the hydrolysis of a series of synthetic peptides with different P'1 residues has been determined. rHME can accept large and small amino acids at the P'1 site, but has a preference for leucine.
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PMID:Hydrolysis of a broad spectrum of extracellular matrix proteins by human macrophage elastase. 911 92

A series of potent and selective human leukocyte elastase (HLE) inhibitors of the Val-Pro-Val type has been developed. Initially, the central proline residue was replaced by nonnatural amino acids Phi ((2S,3aS,7aS)-perhydroindole-2-carboxylic acid) and Abo ((3S)-2-azabicyclo-[2.2.2]octane-3-carboxylic acid), and secondly several groups able to confer antioxidant properties to the molecule were introduced at the lipophilic N-terminal side chain. When compared to reference inhibitors, in vitro HLE inhibitory potency was maintained (10-100 nM) both with compounds containing the antioxidant moiety at the end of the N-terminal side chain and with compounds in which the N-terminal valine of the tripeptidic sequence had been replaced by a epsilon-substituted lysine. The lipidic peroxidation inhibitory potency of this series of inhibitors was found to be similar to that of the reference antioxidant compounds (around 1 microM). Moreover, HLE-induced hemorrhage in the hamster lung was effectively prevented (40-60% at 15 micrograms/kg) by most of the inhibitors tested when administered intratracheally 3 h before instillation of elastase. Among the most active analogs, compounds 11a,c,g were still active when administered 18 h before elastase. Interestingly, compound 14a was able to prevent HLE-mediated lung damage when administered 72 h prior to enzymatic challenge, indicating exceptional stability and retention in the lung. Finally, in a 14-day chronic model of emphysema in the hamster, 14a significantly conserved alveolar spaces, a marker of lung tissue destruction, and was more potent than reference inhibitor ICI 200 880. This indicates that addition of peroxidation inhibitory properties to an HLE inhibitor can provide a powerful in vivo inhibitor of pulmonary tissue destruction.
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PMID:Dual inhibition of human leukocyte elastase and lipid peroxidation: in vitro and in vivo activities of azabicyclo[2.2.2]octane and perhydroindole derivatives. 919 69

Human leukocyte elastase (HLE) is a serine protease that contributes to tissue destruction in various disease states-for example, in emphysema. FR901277 is a natural product isolated from the culture filtrate of Streptomyces resistomicificus and is a potent inhibitor of both HLE and porcine pancreatic elastase (PPE). FR901277 consists of four normal amino acids and three unusual amino acids, and is a unique bicyclic peptide compound. The crystal structure of PPE complexed with FR901277 has been determined at 1.6 A resolution. The Ogamma atom of Ser-195 in PPE did not form a covalent bond with FR901277, but formed a hydrogen bond with the Nvarepsilon atom of His-57. On the other hand, the portion from L-Orn(1) through dehydroxyThr(3) in FR901277 formed an antiparallel beta-sheet structure with the backbone of the active site in PPE. The S4 through S2' binding subsites in PPE were all occupied by the hydrophobic side chains of the inhibitor molecule. Especially, the ethylidene moiety of FR901277 occupied the S1 specific pocket, indicating a CH/pi interaction. In addition, the isopropyl side chain of L-Val(7) was located at the enzyme surface between the S2 and S1' pockets with several van der Waals contacts. However, the amino acid (4) residue was not involved in a significant interaction with PPE. Comparison of inhibitor structures in different environments showed that FR901277 has a highly rigid bicyclic framework; however, it can slightly change its conformation according to the circumstances. The binding mode of FR901277 at the active site of PPE was directly applicable to that in HLE, after consideration of induced fit. The structure of the PPE-FR901277 complex provided much information regarding potential sites for modification of the physicochemical properties of FR901277.
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PMID:Structure of porcine pancreatic elastase complexed with FR901277, a novel macrocyclic inhibitor of elastases, at 1.6 A resolution. 1073 4

Human neutrophil elastase (HNE, IEC 3. 4. 21. 37) is a causative factor of inflammatory diseases, including emphysema and rheumatoid arthritis. Enzymatic characterization is important for the development of new drugs involved in the regulation of this enzyme. In this study, we investigated the enzymatic and biochemical properties of five different elastolytic enzymes, with a molecular mass between 24 kDa and 72 kDa. Three elastases, molecular masses of 27, 29, 31 kDa, might be elastase isozymes that have the same NH2-terminal amino acid sequences of Ile-Val-Gly-Gly-Arg-Arg-Ala. The 24-kDa enzyme, which showed the identical NH2-terminal amino acid sequences to elastase, was a degraded fragment of native elastase. The elastolytic activity was conserved at the 6/7 domain of the NH2-terminal region. The inhibitory characteristics of PMSF, DipF were the same as those of native elastases. The 72-kDa molecule, which showed elastolytic activity, might be a trimer formed between native elastases (31 kDa and 29 kDa) and a cathepsin G-like enzyme, which did not show elastolytic activity but enhanced the elastolytic activity of neutrophil elastase. Although this cathepsin G-like enzyme showed weak cathepsin G activity, it has distinguishable NH2-terminal sequences of Ile-Val-Gly-Gly-Ser-Arg-Ala- from those of elastase or cathepsin G. The potentiation of elastolytic activity could be a result of the trimerization of native elastase with a cathepsin G-like enzyme, and was then weakly inhibited by serine protease inhibitors, such as PMSF, DipF. Therefore, we suggest the cathepsin G-like enzyme to be a novel enzyme, which has an important role in the development of inflammation.
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PMID:Enzymatic and molecular biochemical characterizations of human neutrophil elastases and a cathepsin G-like enzyme. 1110 Nov 39

The macrophage elastase enzyme (MMP-12) expressed mainly in alveolar macrophages has been identified in the mouse lung as the main destructive agent associated with cigarette smoking, which gives rise to emphysema, both directly via elastin degradation and indirectly by disturbing the proteinase/antiproteinase balance via inactivation of the alpha1-proteinase inhibitor (alpha1-PI), the antagonist of the leukocyte elastase. The catalytic domain of human recombinant MMP-12 has been crystallized in complex with the broad-specificity inhibitor batimastat (BB-94). The crystal structure analysis of this complex, determined using X-ray data to 1.1 A and refined to an R-value of 0.165, reveals an overall fold similar to that of other MMPs. However, the S-shaped double loop connecting strands III and IV is fixed closer to the beta-sheet and projects its His172 side-chain further into the rather hydrophobic active-site cleft, defining the S3 and the S1-pockets and separating them from each other to a larger extent than is observed in other MMPs. The S2-site is planar, while the characteristic S1'-subsite is a continuous tube rather than a pocket, in which the MMP-12-specific Thr215 replaces a Val residue otherwise highly conserved in almost all other MMPs. This alteration might allow MMP-12 to accept P1' Arg residues, making it unique among MMPs. The active-site cleft of MMP-12 is well equipped to bind and efficiently cleave the AlaMetPhe-LeuGluAla sequence in the reactive-site loop of alpha1-PI, as occurs experimentally. Similarities in contouring and particularly a common surface hydrophobicity both inside and distant from the active-site cleft explain why MMP-12 shares many substrates with matrilysin (MMP-7). The MMP-12 structure is an excellent template for the structure-based design of specific inhibitors for emphysema therapy and for the construction of mutants to clarify the role of this MMP.
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PMID:Substrate specificity determinants of human macrophage elastase (MMP-12) based on the 1.1 A crystal structure. 1157 28

We report a case of Pneumocystis carinii pneumonia (PCP) in which acute lung tissue destruction progressed within a few days to form multiple bullae in a patient with no HIV-1 infection. A 59-year-old man with mild pulmonary emphysema had been followed for two years. He had smoked 40 cigarettes per day for forty years. Six months before, bronchogenic carcinoma had been diagnosed in the lower right lung. After chemotherapy and radiotherapy, he had a sudden onset of high fever with respiratory failure. PCP was diagnosed by examination of the bronchoalveolar lavage fluid (BALF), and the patient was treated with intravenously administered trimethoprim-sulphamethoxazole (TMP-SMX) and methylprednisolone. His chest radiograph was not typical for PCP, and showed no diffuse ground-grass or fine granular opacities. A high-resolution CT of the chest revealed a low attenuation area consistent with severe emphysematous alterations and progressively enlarging bullae. A few cases have been reported of progressive pulmonary cystic disease associated with PCP pneumonia in patients with AIDS, in which the cause of bulla formation was thought to be lung parenchyma destruction induced by HIV itself, or increased elastase release from HIV-infected macrophages. The present case demonstrated that HIV infection was not an essential factor in the development of bullous changes. In a patient with a long history of smoking and emphysema, PCP may trigger-macrophage activation and an excessive release of leukocyte elastase, leading to elastin destruction in the alveoli.
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PMID:[A case of acute progressive pulmonary cystic disease associated with Pneumocystis carinii pneumonia in a non-HIV-infected patient]. 1157 32


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