Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ability of highly purified human leukocytic pyrogen (LP) to induce neutrophil lysosomal protein release is described. Human peripheral blood neutrophils isolated by Ficoll-Hypaque and dextran sedimentation were exposed to purified human LP. The specific granule-associated proteins, lysozyme and lactoferrin were selectively released, whereas primary granule (beta-glucuronidase) and cytoplasmic (lactic dehydrogenase) enzyme markers were not. Optimum release was observed after 45 min in the presence of Ca++ and Mg++. Cytochalasin B (5 microgram/ml) had no effect on LP-induced lysosomal enzyme release. Since the pyrogenicity of LP is dependent on prostaglandin synthesis, the effect of two potent inhibitors of prostaglandin synthesis on lysozyme release was studied. Both indomethacin and naproxen failed to inhibit specific granule protein release. These observations suggest that the concommitance of fever, elevated serum or urine lysozyme and hypoferremia may, in part, be explained by the interaction of LP and peripheral blood neutrophils.
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PMID:Human leukocytic pyrogen induces release of specific granule contents from human neutrophils. 65 95

Human blood neutrophilic leukocytes were separated and purified by modifications of the Hypaque/Ficoll and dextran separation methods, resulting in a suspension which was greater than 96% neutrophils. Neutrophils were prepared in 0.34 M sucrose containing heparin and were clarified of nongranular debris by sequential passage through polycarbonate filters of pore size 5 mu and 2 mu. Isopycnic sucrose gradients of such filtrates revealed three major bands. The gradient separated fractions were studied by electron microscopy including peroxidase cytochemistry and by enzyme assay for myeloperoxidase (MPO), beta-glucuronidase, muramidase alkaline phosphatase and acid phosphatase utilizing both p-nitrophenylphosphate (pnp) and beta-glycerophosphate as substrates. Peroxidase-positive granules were observed at both density 1.22 (band A) and density 1.20 (band B). Three peroxidase-negative granules were identified: the round or oval peroxidase-negative granule of density 1.22 (band A) and two smaller granules, distinguishable by size and shape at density 1.18 (band C). Band C granules contain crystalloid inclusions. Peaks of muramidase activity coincided with bands A and C, suggesting the presence of muramidase in the peroxidase-negative granules of density 1.22 and in one or both of the peroxidase-negative granules at density 1.18. beta-Glucuronidase was distributed like MPO, with a major peak in band B and a minor peak in band A. Acid beta-glycerophosphatase was largely in band A. Acid pnp phosphatase was nonspecifically associated with soluble nongranular protein which always remained at the origin of sucrose gradients. Alkaline phosphatase was not granule associated and sedimented alone to density 1.145, which is highly suggestive of a cytoplasmic membrane localization for this enzyme.
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PMID:Separation and characterization of human neutrophil granules. 444 23

Chemotactic factors decrease the negative surface charge of neutrophils (polymorphonuclear leukocytes [PMN]) and this has been speculated to be important in PMN margination and aggregation in vivo. PMN adherence and aggregation are also enhanced by degranulation of lysosomal enzymes. To further assess the possible relationship between degranulation, surface charge, adherence, and aggregation, human peripheral blood PMN (isolated by Hypaque-Ficoll and dextran sedimentation) were exposed to the secretagogues ionophore A23187, phorbol myristate acetate, concanavalin A, and chemotactic factors (partially purified C5a or the synthetic peptide f-met-leu-phe) plus cytochalasin B. Surface charge was measured in a cytopherometer. After incubation of PMN with secretagogues, PMN surface charge was decreased to a greater extent than incubation of PMN with chemotactic factors. The decreased surface charge induced by f-met-leu-phe plus cytochalasin B required both extracellular calcium and magnesium. The ionophore A23187-induced surface charge changes were dependent on extracellular calcium but not magnesium whereas the phorbol myristate acetate effect was only partially dependent on Ca(++) and Mg(++). The surface charge changes induced by secretagogues were related to both the amount of lysozyme released and to the increased adhesiveness of cells to plastic surfaces. These observations indicate exocytosis of lysosomal granule contents is associated with decreases in neutrophil surface charge, and there appears to be a correlation between decreases in surface charge and facilitation of neutrophil aggregation and adhesiveness. However, a causal relationship between these events has not been established, and the relationship may be simply temporal.
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PMID:Degranulating stimuli decrease the neagative surface charge and increase the adhesiveness of human neutrophils. 624 7

The purpose of this study was to isolate distinct populations of canine neutrophil granules and to compare them with neutrophil granules from other species. Size, shape, density, and content of canine neutrophil granules were determined. Neutrophils obtained by Ficoll-Hypaque sedimentation were homogenized, and granule populations were separated by isopycnic centrifugation on a linear sucrose gradient (rho, 1.14 to 1.22 g/ml). The most dense granule population (rho, 1.197 g/ml) contained all of the myeloperoxidase, beta-glucuronidase, and elastase, more than half of the acid beta-glycerophosphatase, and most of the lysozyme. The population with intermediate density (rho, 1.179 g/ml) contained lactoferrin, vitamin B12-binding protein, and the remainder of the acid beta-glycerophosphatase and lysozyme. The least dense granule population did not contain a major peak of any of the enzymes or binding proteins tested but was distinguished by density and morphology. The size and shape of the granules were determined from scanning electron micrographs and assessment of shape was aided by transmission electron micrographs. By these methods three populations of canine neutrophil granules were characterized and named: myeloperoxidase granules, vitamin B12-binding protein granules, and low-density granules.
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PMID:Characterization of canine neutrophil granules. 629 95

Hydrolytic enzymes [acid phosphatase, beta-glucuronidase, beta-D-N-acetyl glucosaminidase (beta-D-NAGA), lysozyme and angiotensin-converting enzyme (ACE)] are the major constituents of alveolar macrophages (AM). These enzymes play a crucial role in the pathogenesis of interstitial lung diseases. Cell-associated activity of several enzymes in alveolar macrophages obtained from control subjects (n = 5) and patients suffering five representative types of interstitial pulmonary diseases [sarcoidosis (n = 10), extrinsic allergic alveolitis (n = 5), idiopathic pulmonary fibrosis (n = 5), neoplastic infiltration of the lung (n = 5) and Pneumocystis carinii pneumonia (n = 5)] were evaluated. Cells were obtained by bronchoalveolar lavage and isolated by Ficoll-Hypaque gradient. Enzymatic activity was assessed by standardized tests. Bronchoalveolar lavage (BAL) lymphocyte counts were significantly elevated in the patients with active sarcoidosis (median: 57%), allergic extrinsic alveolitis (median: 51%) and neoplastic infiltration (median: 31%) as compared with the other groups, whereas BAL neutrophil and eosinophil counts were significantly elevated in the patients with idiopathic pulmonary fibrosis (neutrophil median: 29%; eosinophil median: 3%). The highest alveolar macrophage enzymatic activities were obtained in the active sarcoidosis group (median ACE: 23.38 microKat 10(-6) AM; median lysozyme: 8.64 nKat 10(-6) AM; median beta-glucuronidase: 324.22 U 10(-6) AM; median acid phosphatase: 0.78 nKat 10(-6) AM; median beta-D-NAGA: 1.85 nKat 10(-6) AM) which was significantly greater than in the control group (median ACE: 6.69 microKat 10(-6) AM; median lysozyme: 1.95 nKat 10(-6) AM; median beta-glucuronidase: 39.88 U 10(-6) AM; median acid phosphatase: 0.38 nKat 10(-6) AM; median beta-D-NAGA: 0.44 nKat 10(-6) AM). However, intracellular lysosomal enzymatic activities of alveolar macrophages from patients with allergic extrinsic alveolitis, a disease in which the degree of alveolar macrophage activation is maximal, were similar to those of the control group. These findings demonstrated a different pattern of expression of alveolar macrophage's hydrolytic enzymes in lymphocytic diffuse pulmonary interstitial disease. In sarcoidotic patients, hydrolytic enzymes were increased whereas in allergic extrinsic alveolitis, hydrolytic enzyme activities were similar to control groups. Indirect data suggest that the release of lysosomal enzymes by alveolar macrophages during allergic extrinsic alveolitis may be a factor involved in the pulmonary lesions appearing in this disease.
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PMID:Hydrolytic enzyme of the alveolar macrophage in diffuse pulmonary interstitial disease. 873 8