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:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The identity of glycoproteins in stimulated normal human tears was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of tears onto minigels, blotting, and subsequent incubation with different biotinylated lectins (concanavalin A [Con A], peanut agglutinin [PNA], glycine max agglutinin [SBA], Phaseolus vulgaris agglutinin, wheat germ agglutinin [WGA, native form], Artocarpus integrifolia agglutinin [Jacalin], and Pisum sativum agglutinin). Control proteins included purified secretory immunoglobulin A (sIgA) from human colostrum, human milk lactoferrin, and chicken-egg lysozyme. All samples were prepared in a denaturing (SDS) buffer under nonreducing and reducing conditions. The sIgA in tears and IgA (alpha) heavy chain fragments (reduced sample) were identified with most of the lectins tested. A particular high molecular weight (greater than 200 kD) protein fraction in tears that just entered the separation gel on SDS-PAGE was detected with WGA and Jacalin. This fraction stain poorly with silver. Tear lactoferrin was identified with all lectins used, although binding was low with SBA. Purified milk lactoferrin showed a poor reaction with Jacalin, but a protein in tears of similar mobility bound this lectin (nonreduced samples). Under both nonreducing and reducing conditions, tear-specific prealbumin in tears did not bind any of the lectins tested. Tear lysozyme only reacted with lectin after reduction. The techniques described may provide additional valuable information in addition to commonly used methods for tear protein analysis and further knowledge concerning the role of glycoproteins on the ocular surface.
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PMID:Identification of lectin binding proteins in human tears. 174 57

The phosphorescence properties of 6-bromo-2-naphthyl sulfate (BNS) in aqueous solution were studied. The phosphorescence lifetime is several hundred microseconds and is self-quenched. Although a fluorescent photoproduct is formed from BNS, it does not interfere with the decay properties of triplet-state BNS and its utility as a probe of the accessibility of the heme group in heme proteins. Quenching of BNS phosphorescence does not occur for the non-heme protein lysozyme and apomyoglobin but occurs by a dynamic mechanism with a quenching constant of 1-2 x 10(9) M-1 s-1 for cytochrome c and myoglobin and with a quenching constant of 6.2 x 10(9) M-1 s-1 for protoporphyrin IX. The phosphorescence of an inclusion complex of 1-bromonaphthalene and beta-cyclodextrin is not quenched by heme-containing proteins. The temperature and viscosity dependencies of the rate with which BNS phosphorescence is quenched by microperoxidase-11 are consistent with unit quenching efficiency. These results indicate that quenching of BNS phosphorescence occurs only upon contact with the quencher, and the quenching constant can be used to assess the degree of accessibility of the heme group.
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PMID:Demonstration that phosphorescent 6-bromo-2-naphthyl sulfate can be used to probe heme accessibility in heme proteins. 178 Mar 54

A rapid and simple procedure is described for cell lysis for preparation of nucleic acids and intact ribosomal RNA from Gram-positive bacteria. Commercial mutanolysin (purified from Streptomyces globisporus) was used for inducing lysis. Listeria, Lactobacillus and Lactococcus strains were very sensitive to mutanolysin when compared to lysozyme. Susceptibility to mutanolysin was improved by a preliminary treatment with acetone, and sodium dodecyl sulfate reduced the efficiency of lysis when used together with mutanolysin. The procedure was also effective for recovering plasmids from these bacteria.
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PMID:A rapid and efficient method of lysis of Listeria and other gram-positive bacteria using mutanolysin. 179 75

Low molecular weight proteins (LMWPs), such as lysozyme, may be suitable carriers to target drugs to the kidney. In this study the antiinflammatory drug naproxen was covalently bound to lysozyme (1:1). Pharmacokinetics of the conjugate, naproxen-lysozyme (nap-LYSO), were compared to that of an equimolar mixture of uncoupled naproxen with lysozyme in freely moving rats. Similar plasma kinetics and organ distribution for native lysozyme and the drug conjugate were observed (Clp = 1.2 and 1.1 ml/min; t1/2,beta = 85 and 75 min, respectively). In case of the uncoupled naproxen-lysozyme mixture, a monoexponential plasma disappearance of naproxen with a t1/2 of 2.8 hr was observed, coinciding with urinary excretion of naproxen metabolites (mainly 6-desmethylnaproxen sulfate; 6-DMN-S) between 2 and 8 hr after injection. Urinary recovery of total metabolites was 59% of the naproxen dose. In contrast, after injection of covalently bound naproxen, plasma levels of the parent drug were below the detection level, whereas naproxen was recovered as 6-DMN-S in urine over a period from 4 to 30 hr. However, only 8% of the administered dose was recovered as 6-DMN-S in urine, whereas 50% of the dose was recovered as naproxen metabolites in feces. Incubation experiments using purified renal tubular lysosomal lysates revealed that naproxen-lysozyme degradation ultimately results in a stable naproxen amino acid catabolite, naproxen-lysine (nap-lys). Hepatic uptake and biliary excretion of this catabolyte were demonstrated in isolated perfused rat livers. Further, an equipotent pharmacological activity relative to parent naproxen was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Low molecular weight proteins as carriers for renal drug targeting: naproxen-lysozyme. 179 38

The protein profiles of various cell fractions of 180 strains of Streptococcus suis type 2, which were isolated from diseased pigs, from healthy pigs when they were slaughtered, and from human patients, were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The isolates from diseased pigs contained two proteins that were absent in most of the isolates from healthy pigs. One of these proteins was a 136-kDa protein that was previously identified as the muramidase-released protein (MRP). This protein was predominantly detected in protoplast supernatants and culture supernatants. The second protein was a 110-kDa protein that was detected only in culture supernatants and therefore was provisionally called extracellular factor (EF). Three phenotypes of S. suis type 2 strains were recognized. Isolates from organs of diseased pigs mainly belonged to the MRP+ EF+ phenotype (77%), while isolates from tonsils of healthy pigs mainly had the MRP- EF- phenotype (86%). Most of the isolates from human patients contained MRP (89%); 74% had the MRP+ EF- phenotype. These findings confirm the results of previous investigations which demonstrated that S. suis type 2 strains differ in virulence. Monoclonal antibodies raised against the 110-kDa EF recognized proteins with higher molecular weights in culture supernatants of all of the strains with the MRP+ EF- phenotype. However, none of the strains with the MRP+ EF+ phenotype produced these high-molecular-weight proteins. Our results demonstrate that MRP and EF are associated with virulence. This suggests that one or both of these proteins are virulence factors that play a role in the pathogenesis of S. suis type 2 infections in pigs and human patients.
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PMID:Identification of two proteins associated with virulence of Streptococcus suis type 2. 187 37

A metallo-endopeptidase, which appears to be an integral membrane protein of rat kidney, was purified to homogeneity by a series of standard chromatographic procedures. This enzyme significantly hydrolyzed human parathyroid hormone [hPTH(1-84)] and a synthetic substrate Suc-Leu-Leu-Val-Tyr-Mec (Suc = succinyl, Mec = 4-methyl-coumarinyl-7-amide). The purified enzyme had apparent molecular masses of 250 kDa on gel filtration, and 88 kDa and 245 kDa on sodium dodecyl sulfate/polyacrylamide gel electrophoresis under reducing and non-reducing conditions, respectively. Its pH optimum for activity was 8.0-8.5 and its isoelectric point was pH 4.9. Its activity was inhibited by EDTA, EGTA and o-phenanthroline, but not by phosphoramidon. The metal-depleted enzyme was reactivated by the addition of metal ions. The enzyme was also inhibited by chymostatin and eglin C, and by thiol compounds. Of the synthetic substrates examined, the enzyme hydrolyzed only Suc-Leu-Leu-Val-Tyr-Mec, one of the synthetic substrates for alpha-chymotrypsin. It did not hydrolyze synthetic substrates with less than four amino acid residues with tyrosine in the P1 position. The enzyme hydrolyzed hPTH and reduced hen egg lysozyme but did not hydrolyze azocasein or [3H]methyl-casein. NH2-terminal amino acid sequence analyses of the degradation products of hPTH(1-84) and reduced hen egg lysozyme by the purified enzyme revealed that the enzyme preferentially cleaved these peptides at peptide bonds flanked by hydrophilic amino acid residues. Amino acid analyses showed that the main degradation products of PTH were hPTH(17-29), hPTH(30-38) and hPTH(74-84). The ability of the enzyme to hydrolyze peptide bonds flanked by hydrophilic amino acid residues and its inability to degrade azocasein distinguish it from several other kidney endopeptidases reported, such as endopeptidase 24.11 and meprin.
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PMID:A membrane-bound metallo-endopeptidase from rat kidney hydrolyzing parathyroid hormone. Purification and characterization. 188 19

The lipopeptide antibiotic surfactin is a potent extracellular biosurfactant produced by various Bacillus subtilis strains. Biosynthesis of surfactin was studied in a cell-free system prepared from B. subtilis ATCC 21332 and OKB 105, which is a transformant producing surfactin in high yield [Nakano, M. M., Marahiel, M. A., & Zuber, P. (1988) J. Bacteriol. 170, 5662-5668]. Cell material was disintegrated by treatment with lysozyme and French press. A cell-free extract was prepared by ammonium sulfate fractionation, which catalyzed the formation of surfactin at the expense of ATP. Lipopeptide biosynthesis required the L-amino acid components of surfactin and D-3-hydroxytetradecanoyl-coenzyme A thioester. D-Leucine which is present in surfactin was not utilized but inhibited the biosynthetic process. The structure of surfactin, synthesized enzymatically in vitro, was confirmed by chromatographic comparison with the authentic compound and by amino acid analyses. An enzyme fraction was prepared by gel permeation chromatography which catalyzed ATP/pyrophosphate exchange reactions dependent on the component amino acids of surfactin. This enzyme fraction was capable of binding substrate amino acids covalently, probably via thioester linkages. The formation of these intermediates was inhibited by various thiol blocking reagents and phenylmethanesulfonyl fluoride. De novo synthesis of the lipopeptide was not observed with this partially purified enzyme fraction most likely due to the lack of an acyltransferase activity required for linking the beta-hydroxy fatty acid to the peptide moiety.
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PMID:Cell-free biosynthesis of surfactin, a cyclic lipopeptide produced by Bacillus subtilis. 190 54

Adult human articular cartilage contains a component with an apparent molecular weight of 16 kd, which is extractable with high ionic strength buffers. This protein, which, in addition to lysozyme, is one of the most prominent components in salt extracts of adult cartilage, is not detectable in cartilage from newborns. We performed N-terminal sequence analysis to identify the protein. The amino acid sequence obtained for the first 20 residues was identical to that reported for phospholipase A2 (PLA2) from human placenta and human synovial cells. The extractable PLA2 was found to be active. The lack of PLA2 in salt extracts from newborn cartilage observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis was confirmed by the very low levels of PLA2 activity detectable in these preparations. PLA2 was clearly present in cartilage extracts from an 18-year-old subject and a 19-year-old subject, suggesting that its accumulation begins at some stage during the adolescent growth period. The enzyme does not appear to be released from cartilage matrix under normal physiologic conditions, and it is possible that the accumulation of PLA2 in maturing cartilage is a result of the decreased matrix turnover associated with the termination of skeletal growth. Whether PLA2 is active in the cartilage matrix, its precise localization, and its effects on the resident chondrocytes remain to be determined.
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PMID:Phospholipase A2 is a major component of the salt-extractable pool of matrix proteins in adult human articular cartilage. 193 Mar 29

The binding of lysozyme (LZM) to bacterial lipopolysaccharide (LPS) inhibited the biological activities of LPS as well as the enzymic activity of LZM. The mode of binding has been characterized by using dansylated LZM and enzyme inhibition. The binding of LPS to LZM significantly increased the fluorescence intensity (Fl-intensity) of the danyl group and was found to be time-dependent; the complex was produced gradually and became stabilized within 20 min at 37 degrees, 10 min at 50 degrees, and 1 min at 70 degrees. The maximum level of binding was also dependent on the reaction temperature, and more complex was formed at higher temperatures. Complexation was strongly dependent on the salt concentration and was not observed at greater than 0.5M NaCl. From collected evidence of the Fl-intensities of various dansyl derivatives and amphiphiles, it is concluded that LZM interacts with LPS by multiple binding-modes, the first being strongly related to the enzyme inhibition, the second being close to the Fl-intensity, and the third being dependent on the inhibition of immunopharmacological activities. For the amphiphiles used in this study, sodium dodecyl sulfate (SDS), 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-propanesulfonate (CHAPSO), decansulfonic acid, and cardiolipin have binding modes similar to that of LPS.
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PMID:Characterization of complex formation between lipopolysaccharide and lysozyme. 195 26

A 42-kDa bovine protein that binds bovine angiogenin [angiogenin binding protein (AngBP)] has been identified as a dissociable cell-surface component of calf pulmonary artery endothelial cells and a transformed bovine endothelial cell line, GM7373. Binding of 125I-labeled bovine angiogenin (125I-Ang) to AngBP occurs with an apparent Kd approximately 5 x 10(-10) M and is specific, saturable, and inhibited by excess unlabeled angiogenin. 125I-Ang can be crosslinked efficiently to AngBP by a water-soluble carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbo-diimide. Bovine ribonuclease A competes with the binding of 125I-Ang to AngBP, but lysozyme does not. Direct binding to AngBP of 125I-labeled bovine ribonuclease A is, however, much weaker than that of 125I-Ang. Two enzymatically active derivatives of angiogenin cleaved at residues 60-61 and 67-68, respectively, fail to induce angiogenesis and also bind to AngBP only weakly. AngBP has been isolated by treatment of cells with heparan sulfate, affinity chromatography on angiogenin-Sepharose of the material dissociated from the cell surface, and gel filtration HPLC. The results suggest that AngBP has the characteristics of a receptor that may likely function in angiogenesis.
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PMID:An angiogenin-binding protein from endothelial cells. 200 62


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