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 presence of the enzymatically active allergens equivalent to Der p I (cysteine protease), Der p III (serine protease) and amylase in extracts of Dermatophagoides pteronyssinus, D. farinae and Euroglyphus maynei was determined using appropriate enzymatic techniques. Biochemical equivalents of all three allergens were present in each extract studied. Studies also showed that the mite extracts contained a variety of other biochemically active enzymes including trypsin, chymotrypsin, carboxypeptidase A and B, glucoamylase and lysozyme. Marked differences in the relative concentrations of some of these enzymes in different mite extracts were observed, particularly trypsin and carboxypeptidase A. The enzymes were physicochemically similar to equivalent enzymes from vertebrate and invertebrate sources. Chromatofocusing studies of faecal extracts derived from D. pteronyssinus and D. farinae showed that several isoforms of each enzyme were present. The data indicated that there were more trypsin isoforms, with pI over a wider range, in extracts prepared from D. pteronyssinus. Proteases and carbohydrases were also found in extracts prepared from faecally enriched material suggesting that they were endoperitrophic and associated with mite digestion. The data suggest that not only are the group I, III and amylase allergens a consistent feature of most pyroglyphid dust mites but also that other proteases and carbohydrases present in mite faeces are allergenic.
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PMID:A comparative study of allergenic and potentially allergenic enzymes from Dermatophagoides pteronyssinus, D. farinae and Euroglyphus maynei. 128 68

The previous findings that the group I and III mite allergens, and amylase present in mite faeces are hydrolytic enzymes has prompted a study to determine whether this material contains other enzymes which could be allergenic. Thus, spent growth medium devoid of whole Dermatophagoides pteronyssinus mites was shown to contain glucoamylase, lipase and lysozyme in addition to the cysteine protease, serine protease and amylase activities associated with the above allergens, respectively. All of these enzymes are probably associated with mite digestive processes. They were rapidly solubilised, heterogeneous with regard to charge (pI in the range 4-8) and demonstrated maximum biochemical activity in the neutral pH range. Three serine proteases were detected and comprised a chymotrypsin-like, a trypsin-like and an unclassified enzyme with pI of 4.1 and 5.3, 8.5 and 7.1, respectively. Only one cysteine protease was observed, which paralleled immunochemically identified Der p I in a variety of assays. It was shown to cleave at lysyl residues and could be inhibited by the specific cysteine protease inhibitor, E-64. The remaining serine proteases, glucoamylase, lipase and lysozyme represent potential allergens.
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PMID:Faecally derived hydrolytic enzymes from Dermatophagoides pteronyssinus: physicochemical characterisation of potential allergens. 171 11

The physiologic substrates of cytotoxic T lymphocyte granule-associated serine esterases (referred to hereafter as proteases or "granzymes"), and the role of these enzymes in cell-mediated activity remain unclear. We have developed an assay for possible ligands of the trypsin-like dimeric serine protease granzyme A based on Western immunoblotting techniques. This protein-binding assay demonstrates the selective binding of granzyme A to several proteins present in the target cell P815. The binding specificity is preserved when enzyme binding is performed in the presence of excess competing proteins, including such cationic species as lysozyme and RNase. Enzyme binding is inhibited, however, by heat or detergent inactivation of granzyme A. Subcellular fractionation of target cells shows that the nuclear fraction contains most granzyme A binding reactivity, which is recovered in the nuclear salt wash fraction. A protein with Mr = 100,000 and two closely migrating proteins with Mr = 35,000 and 38,000 are the predominant reactive moieties, and the N-terminal sequence of the 100-kDa protein confirmed that this protein was murine nucleolin. Incubation of granzyme A with nucleolin generates a discrete proteolytic cleavage product of Mr = 88,000. Since nucleolin is known to shuttle between nucleus and cytoplasm, the interaction of granzyme A and nucleolin may be important in the process of apoptosis which accompanies cytotoxic T lymphocyte-mediated lysis of target cells.
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PMID:Granzyme A binding to target cell proteins. Granzyme A binds to and cleaves nucleolin in vitro. 186 Aug 69

The purpose of this study was to determine whether granule fractions of human neutrophils differentially kill Actinobacillus actinomycetemcomitans and Capnocytophaga spp. Granule extracts were subjected to gel filtration, and seven fractions (designated A through G) were obtained. Under aerobic conditions at pH 7.0, representative strains of A. actinomycetemcomitans were killed by fraction D and variably by fraction B. In contrast, the Capnocytophaga spp. were killed by fractions C, D, F, and G. Fractions A (containing lactoferrin and myeloperoxidase) and E (containing lysozyme) exerted little bactericidal activity under these conditions. Anaerobiosis had little effect on the bactericidal activity of fractions D and F but inhibited that of fractions B and C. Electrophoresis, zymography, determination of amino acid composition, and N-terminal sequence analysis revealed that fraction C contained elastase, proteinase 3, and azurocidin. Fraction D contained lysozyme, elastase, and cathepsin G. Subfractions of C and D containing elastase (subfraction C4), a mixture of elastase and azurocidin (subfraction C5), and cathepsin G (subfraction D9) were found to be bactericidal. The bactericidal effects of fraction D and subfraction D9 against A. actinomycetemcomitans was not inhibited by heat inactivation, phenylmethylsulfonyl fluoride, or N-benzyloxycarbonylglycylleucylphenylalanylchloromethyl ketone. We conclude that (i) A. actinomycetemcomitans and Capnocytophaga spp. were sensitive to the bactericidal effects of different neutrophil granule components, (ii) both were sensitive to the bactericidal effects of neutral serine proteases, and (iii) the killing of A. actinomycetemcomitans by cathepsin G-containing fractions was independent of oxygen and neutral serine protease activity.
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PMID:Differential killing of Actinobacillus actinomycetemcomitans and Capnocytophaga spp. by human neutrophil granule components. 189 75

The ultrastructural localization of a range of hydrolytic enzymes has been investigated in the granular haemocytes of the marine mussel Mytilus edulis. Arylsulphatase activity and immunocytochemical localization of beta-glucuronidase and elastase were demonstrated within the large granules of the haemocytes. Lysozyme and cathepsin B were both localized within all sizes of granule, however, at high dilutions the primary antibody against lysozyme was also restricted to the large granules. The labelling density for cathepsin B antibody tended to be very low. Antibodies for cathepsin G showed a clear, discrete labelling which was restricted to the granules of haemocytes containing small granules. The fact that antibodies raised against human proteinases recognize invertebrate enzymes suggests that there must be a certain degree of structural similarity between the human proteinases and the enzymes present in the mussel haemocytes indicating either convergence or conservation of the enzyme molecules. The presence of a range of hydrolytic enzymes including proteinases, glycosidases and sulphatases within the large granules shows that these granules are a form of lysosome. The reduction in activity of lysosomal enzymes in haemocytes following adhesion to glass is evidence for release of the enzymes from the granules (degranulation). The possibility of a serine protease being specifically associated with the small granules and its role as a cytolysin are discussed.
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PMID:Hydrolytic enzymes associated with the granular haemocytes of the marine mussel Mytilus edulis. 207 9

Freshly isolated human neutrophils were investigated for their ability to degrade heparan sulfate proteoglycans in the subendothelial extracellular matrix (ECM) produced by cultured corneal and vascular endothelial cells. The ECM was metabolically labeled with Na2(35S)O4 and labeled degradation products were analyzed by gel filtration over Sepharose 6B. More than 90% of the released radioactivity consisted of heparan sulfate fragments 5-6 times smaller than intact heparan sulfate side chains released from the ECM by either papain or alkaline borohydride. These fragments were sensitive to deamination with nitrous acid and were not produced in the presence of either heparin or serine protease inhibitors. In contrast, degradation of soluble high molecular weight heparan sulfate proteoglycan, which was first released from the ECM, was inhibited by heparin but there was no effect of protease inhibitors. These results indicate that interaction of human neutrophils with the subendothelial ECM is associated with degradation of its heparan sulfate by means of a specific, newly identified, heparanase activity and that this degradation is facilitated to a large extent by serine proteases. The neutrophil heparanase was readily and preferentially released (15-25% of the cellular content in 60 min) by simply incubating the cells at 4 degrees C in the absence of added stimuli. Under these conditions, less than 5% of the cellular content of lactate dehydrogenase, lysozyme, and globin degrading proteases was released. Further purification of the neutrophil heparanase was achieved by its binding to heparin-Sepharose and elution at 1 M NaCl. It is suggested that heparanase activity is involved in the early events of extravasation and diapedesis of neutrophils in response to a threshold signal from an extravascular inflamed organ.
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PMID:Degradation of heparan sulfate in the subendothelial extracellular matrix by a readily released heparanase from human neutrophils. Possible role in invasion through basement membranes. 299 75

The protease activities responsible for the cotranslational processing of the Semliki Forest virus structural polyprotein were investigated by using an in vitro transcription-translation system. Three cleavages released the individual chains from the nascent polyprotein in the order capsid, p62, 6K (a nonstructural peptide), and E1. We showed directly that the protease activity responsible for the release of the capsid protein resides in the capsid itself: by progressive truncation of the cDNA used for the SP6 transcription, we showed that a precursor containing as few as 38 residues of the p62 protein left at the C terminus of the capsid was still very efficiently cleaved in vitro. We further tested the possibility that serine-219 of the capsid is involved in autoproteolysis by site-directed in vitro mutagenesis. A change in the sequence Gly-Asp-Ser(219)-Gly, a tetrapeptide conserved among several animal serine proteases, to Gly-Asp-Arg-Ser-Thr was shown to completely abolish in vitro cleavage. This supports the notion that the capsid is a serine protease. The role of the capsid protease in the processing of the 6K junctions was then investigated by translations of a hybrid polyprotein in which the capsid and most of the p62 sequences are replaced by those of the secretory protein lysozyme. The cleavages and concomitant appearance of the 6K peptide occurred efficiently and were shown to require the presence of membranes. This demonstrates that the capsid protease is not required for those cleavages and suggests that a membrane-associated host protease is responsible for the cleavage.
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PMID:Processing of the Semliki Forest virus structural polyprotein: role of the capsid protease. 355 12

gamma-Seminoprotein (gamma-Sm) is a human prostate-specific antigen and a serine protease judging from the complete amino acid sequence which shows extensive homology with the kallikrein family. The enzymatic activity of gamma-Sm was defined as a chymotrypsin-like activity using reduced and S-3-(trimethylated amino)propylated lysozyme and insulin-oxidized A and B chains as substrates. The -Leu/Ser- peptide bond of lysozyme was rapidly hydrolyzed by gamma-Sm. gamma-Sm also hydrolyzed the -Phe/Glu- of lysozyme and the -Leu/Cys(SO3H)- of insulin B chain. Insulin A chain and arginyl- or lysyl-linkage of these proteins were not hydrolyzed by gamma-Sm at all.
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PMID:The chymotrypsin-like activity of human prostate-specific antigen, gamma-seminoprotein. 369

The injection of thioglycollate medium into the peritoneal cavity of the mouse induces high levels of macrophage fibrinolytic activity due to the production and secretion of a plasminogen activator, a trypsinlike serine protease, which is absent in unstimulated macrophages. Intraperitoneal injection of endotoxin or mineral oil can stimulate only a fraction (<10%) of the fibrinolytic activity of thioglycollate cells, similar to the partial stimulation (<10%) seen 1-2 days after phagocytosis of latex or SRBC by unstimulated macrophages. The endotoxin-stimulated macrophages contain and release relatively low levels of plasminogen activator, but these primed cells can be triggered to produce and secrete high levels of enzyme, by phagocytosis of latex. Under conditions where the plasminogen activator is induced and secreted, there are no effects on the production and/or release of lysozyme or intracellular acid hydrolases, Discovery of a two-stage procedure for inducing macrophage plasminogen activator made it possible to study the role of cell priming and phagocytosis separately. Endotoxin was a more effective priming agent, weight for weight, than lipid A:BSA complex. Secretion of the plasminogen activator was induced only by thioglycollate, or endotoxin and latex. In situ fibrinolysis was induced by these agents and mineral oil, BCG, and fetal calf serum, in decreasing order of effectiveness. Phagocytosis of latex in all cases except thioglycollate stimulation, increased fibrinolytic activity from three- to sixfold. Latex and a variety of other particles such as M. lysodeikticus, aggregated gamma-globulin and immune complexes showed dose-dependent stimulation of fibrinolysis by endotoxin-primed macrophages. Although the initial phagocytic trigger was not specific for the substance employed, the ability to induce a sustained response depended on the persistence of the phagocytized particle within the cell. Fibrinolysis and secretion of plasminogen activator continued at high levels for at least 9 days after uptake of latex, a nondigestible particle, whereas plasminogen activator was secreted only transiently after ingestion of rapidly digested M. lysodeikticus. The induction of plasminogen activator secretion provides a mechanism by which the activated macrophage can exert a selective effect on its extracellular environment.
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PMID:Induction of macrophage plasminogen activator by endotoxin stimulation and phagocytosis: evidence for a two-stage process. 442 92

Three sporulation mutants have been isolated which produce spores with an atypical resistance phenotype, i.e. they are sensitive to organic solvents and heat but resistant to lysozyme. All three mutants produced serine protease, alkaline phosphatase and glucose dehydrogenase which are biochemical marker events for stages I, II and III. Two of the three mutants produced dipicolinic acid, a late marker, but the third was defective in its production. Heat-resistance was not restored to any of the mutants by the provision of exogenous dipicolinate. Gel electrophoresis showed that the mutant spores had similar patterns of spore coat proteins to the wild-type and electron microscopy revealed no significant structural differences. The three mutations responsible for the phenotypes of the mutant spores lie in the phe-argA region of the Bacillus subtilis chromosome. Recombination index values indicate that the mutations are in three separate genes. They define at least two new sporulation loci, designated spoVH and spoVJ.
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PMID:SpoVH and spoVJ--new sporulation loci in Bacillus subtilis 168. 640 8


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