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)

A method was developed for obtaining a homogeneous silkworm hemolymph protein (peptidoglycan recognition protein, PGRP) which has affinity for peptidoglycan and the ability to trigger the prophenoloxidase cascade upon its binding to peptidoglycan. The purified PGRP had a molecular mass of about 19 kDa and is composed of a single polypeptide with an isoelectric point of 6.5. It bound to peptidoglycan in the absence of divalent cation, whereas its binding to beta1,3-glucan and chitin was not detected. N-Acetyl-D-glucosaminyl-(beta1-4)-N-acetylmuramyl-L-alanyl-D-isogluta mine did not inhibit purified PGRP to bind insoluble peptidoglycan, but fragmented soluble peptidoglycan did. PGRP seemed to require peptidoglycan as a possible ligand to keep its glycan portion consisting of at least two or more of the repeating unit. PGRP did not have any detectable lysozyme activity, and its amino acid composition and amino-terminal sequence of 20 amino acid residues were shown to be different from those of silkworm lysozyme. PGRP seems to be a hitherto unknown protein. In the absence of PGRP, the prophenoloxidase cascade in the plasma fraction of hemolymph could not be triggered by peptidoglycan, indicating that some type of activity, capable of activating the cascade, is generated upon their binding. However, the exact nature of this activity is not yet known. The purified PGRP bound to peptidoglycan did not hydrolyze significantly any of the 26 commercially available peptidyl-7-amino-4-methylcoumarins, substrates for various proteases.
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PMID:Purification of a peptidoglycan recognition protein from hemolymph of the silkworm, Bombyx mori. 866 62

The objectives of the studies were to evaluate the effect of levamisole and 1,3/1,6 glucan applied in pregnant mares on parameters of non-specific cellular and humoral immunity of foals. Eighteen mares in three experimental groups (six animals in each) and their progeny were examined. Multiparous mares, crossbreed of Polish, full-blood and Hannover lines (400-500 kg), 4-9 years old, originated from four different farms. They were kept under identical zoohygienic and nutritional conditions. The animals were randomly chosen in experimental groups. None of mares had been previously vaccinated. In group I, levamisole was injected three times at 7-day intervals at a dose of 2.5 mg/kg of body weight. Group II was injected at the same periods of time and manner with 1,3/1,6 glucan at a dose of 0.19 mg/kg of body weight, whereas mares in group III served as controls. Injection of the immunostimulators started in mares 4-6 weeks before expected parturition. Blood was taken from foals before the first dose of colostrum, then 18 and 36 h after the first dose of colostrum and on Days 7, 14, 21, 28, 35, 42, 49 and 56 of life. The parameters determined in blood were reduction of NBT by PMNs, phagocytic activity, phagocytic index, test of intracellular killing and in blood sera were total protein, gamma-globulin fraction, lysozyme activity, level of IgG, IgG(T), IgM and IgA. In the first dose of colostrum taken just after parturition, specific gravity, total protein, gamma-globulin complex, lysozyme activity, level of IgG, IgG(T), IgM, IgA were determined. Colostrum of mares immunostimulated with levamisole or 1,3/1,6 glucan were characterized by a high content of IgG and IgG(T) compared to the colostrum of nonstimulated mares. The level of immunity was higher in foals from dams immunostimulated with levamisole or 1,3/1,6 glucan. Clinical examinations in neonatal and postnatal period did not show any abnormalities in these foals.
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PMID:The effect of nonspecific immunostimulation of pregnant mares with 1,3/1,6 glucan and levamisole on the immunoglobulins levels in colostrum, selected indices of nonspecific cellular and humoral immunity in foals in neonatal and postnatal period. 1023 47

1,3-beta-D-glucans (glucans) are structural elements in the cell walls of yeast and fungi with immunomodulatory properties, mediated through their ability to activate macrophages. This study assessed the activation of cells of the peritoneal cavity between 3 and 90 days after i.p. injection of particulate yeast glucan differing in molecular weight (MW) and degree of (1,6)-linkages. Female QS mice, 7-9 weeks of age, were injected, i.p., with varying doses of low (< 5 x 10(5)), medium (1-2 x 10(6)) or high (> 3 x 10(6)) MW glucans, all with low (< 5%) beta-(1,6)-linkages, or high MW (> 3 x 10(6)) glucan with high 1,6-linkages (> 20%). All glucans induced a transient increase in the proportion of neutrophils and eosinophils and a reduction in mast cell numbers in the peritoneal cavity. Peritoneal macrophages showed an altered morphology, increased intracellular acid phosphatase, increased LPS-stimulated NO production and increased PMA-stimulated superoxide production. There were no significant changes in serum lysozyme levels. Most macrophage activities returned to control levels by 28 days post injection of 1, 3-beta-D-glucan. There was a trend for higher MW or (1,6)-linked, (1, 3)-beta-D-glucans to be more stimulatory. It was concluded that particulate yeast (1,3)-beta-D-glucan is an effective stimulator of immune function, the efficiency of which may be influenced by the MW and degree of (1,6)-linkages.
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PMID:The effect of molecular weight and beta-1,6-linkages on priming of macrophage function in mice by (1,3)-beta-D-glucan. 1054 Feb 5

This study aimed to determine physical and kinetic properties of glucosyltransferase (GTF) adsorbed onto hydroxyapatite (HA) surfaces. For development of a solid-phase enzyme assay, 4.0-mg samples of washed HA powder were exposed to centrifuged whole saliva (WSHA) or buffer, and subsequently exposed to a GTF solution. The activities of GTF adsorbed to HA and that remaining in solution were measured. WSHA was more effective in adsorbing GTF than was naked HA. Enzyme activity on the surface of WSHA was enhanced; more activity was detected on WSHA than was apparently removed from solution. A similar effect was observed when GTF was adsorbed to naked HA from a mixture with lysozyme or saliva; however, no enhancement was seen when GTF was adsorbed from a mixture with albumin. Compared with GTF in solution, adsorbed GTF displayed activity over a much wider range of pH values. Temperature-activity profiles indicated that GTF adsorbed to surfaces had a lower temperature optimum (40 degrees C) than did soluble enzyme (45 degrees C), and that the bound enzyme was more resistant to adverse effects of heat at elevated temperatures. The majority of glucan made by GTF adsorbed to parotid saliva-coated HA remained attached to the surface. The activity of lysozyme adsorbed to HA was reduced by adsorption of GTF to the same surface and was almost completely abolished by formation of glucans by the adsorbed GTF. These results suggest that soluble bacterial enzymes found in saliva can be incorporated into pellicle, interact with host-derived molecules on the surfaces of teeth, express enzymatic activity, and potentially influence the biological properties of pellicle.
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PMID:The activity of glucosyltransferase adsorbed onto saliva-coated hydroxyapatite. 1103 35

High molecular weight cyclic alpha-1,4-glucan (referred to as cycloamylose) exhibited an artificial chaperone property toward three enzymes in different categories. The inclusion properties of cycloamylose effectively accommodated detergents, which keep the chemically denatured enzymes from aggregation, and promoted proper protein folding. Chemically denatured citrate synthase was refolded and completely recovered it's enzymatic activity after dilution with polyoxyethylenesorbitan buffer followed by cycloamylose treatment. The refolding was completed within 2 h, and the activity of the refolded citrate synthase was quite stable. Cycloamylose also promoted the refolding of denatured carbonic anhydrase B and denatured lysozyme of a reduced form.
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PMID:Cycloamylose as an efficient artificial chaperone for protein refolding. 1111 53

Atlantic salmon head kidney macrophages grown in the presence of particulate yeast beta-glucan and bacterial lipopolysaccharide (LPS) showed increased production of lysozyme in the culture supernatants compared to non-treated controls. The increased lysozyme production started at day 3 and was five- to six-fold higher compared to controls at day 6 in culture. Beta-glucan showed an approximate linear dose-response curve between 1 and 250 microg x ml(-1) whereas LPS showed a dose-response curve with a well-defined optimum concentration (10 microg x ml(-1)). The increase in lysozyme activity was accompanied by an accumulation of lysozyme gene transcript in the stimulated cells. Recombinant human tumor necrosis factor alpha, known for its ability to stimulate lysozyme in human macrophages and to elevate respiratory burst activity of rainbow trout macrophages, failed to stimulate lysozyme production of Atlantic salmon macrophages. Macrophages isolated from fish suffering from a non-lethal Ichthyobodo necator infection displayed a highly increased ability to produce lysozyme in response to both beta-glucan and LPS. As in higher vertebrates, lysozyme production may reflect the differentiation stage of the Atlantic salmon macrophages as well as a direct activation of lysozyme gene transcription by biological response modifiers. The rather late increase in lysozyme production induced by beta-glucan and LPS may thus be explained by stimulation of differentiation of the macrophages in culture eventually combined with direct activation of transcription of the lysozyme gene.
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PMID:Enhanced lysozyme production in Atlantic salmon (Salmo salar L.) macrophages treated with yeast beta-glucan and bacterial lipopolysaccharide. 1127

The present study was undertaken to compare the effects of intraperitoneally injected bacterial lipopolysaccharide (LPS) and yeast beta-glucan on lysozyme activity in Atlantic salmon, and to explore what organ(s) are responsible for the increase in plasma lysozyme activity induced by the compounds. The results indicated that LPS stimulates plasma lysozyme activity at least as efficiently as beta-glucan. The lysozyme gene was shown to be transcribed in head kidney, spleen, liver and intestine, and accumulation of transcript was demonstrated in response to both beta-glucan and LPS in all of these organs. Intracellular lysozyme activity was detected in the same organs and in isolated blood polymorphonuclear cells (PMN) and lymphocytes. Increased lysozyme activity in response to both beta-glucan and LPS was demonstrated in blood PMN and cells isolated from head kidney and intestine. In spleen and liver on the other hand, there was no increase in lysozyme activity in response to the stimulants. Based on previous work and the present results it is suggested that plasma lysozyme induced by LPS and beta-glucan originate from macrophages in the different organs. The head kidney is likely to be the main supplier of plasma lysozyme considering its high contents of macrophages. This work supports the notion that microbial compounds containing phylogenetically conserved structures (beta-glucan and LPS) are able to stimulate the non-specific defence of animals against infection by enhancing the lysozyme expression.
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PMID:In vivo effects of beta-glucan and LPS on regulation of lysozyme activity and mRNA expression in Atlantic salmon (Salmo salar L.). 1254 25

Culture medium affected the virulence of a strain of Candida albicans toward Galleria mellonella larvae, but the yeast growth rates in yeast extract - peptone - dextrose broth and synthetic Galleria serum were not correlated with yeast virulence. Virulent C. albicans grew rapidly in larval serum, whereas, it limited nodulation and continued development in vivo, producing toxins that damaged the hemocytes and fat body. Nonpathogenic yeast-phase cells grew slowly in larval serum but induced extensively melanized nodules in vivo and developed no further. There was no discernible relationship in 14 exo-enzymes between the virulent and avirulent yeast strains and virulence. The avirulent myosin-I-defective yeast cells were rapidly removed from the hemolymph in vivo because of lysozyme-mediated yeast agglutination and the possible binding of the yeast cells by lysozyme and apolipophorin-III. Both lysozyme and apolipophorin-III are proteins that bind beta-1,3-glucan. Finally, insects with nonpathogenic C. albicans exhibited induced immunity and were more resistant to candidiasis from the wild-type yeast cells than were noninduced insects.
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PMID:Virulence of Candida albicans mutants toward larval Galleria mellonella (Insecta, Lepidoptera, Galleridae). 1460 87

Previous studies have demonstrated that beta-glucans stimulate Atlantic salmon, Salmo salar L., head kidney macrophages both in vitro and in vivo and increase protection against various pathogens. Based on our previous work that showed potent immunostimulatory CpG motif-containing oligodeoxynucleotides increased resistance to amoebic gill disease (AGD), the present study investigated the immunostimulatory effects of three commercial beta-glucan-containing feeds and their ability to increase resistance to AGD. All three commercial beta-glucans were able to stimulate the respiratory burst activity of Atlantic salmon head kidney macrophages in vitro, albeit at different times and concentrations. However, dietary incorporation of the beta-glucans was unable to stimulate the in vivo respiratory burst activity of head kidney macrophages, or serum lysozyme production, and did not increase resistance against AGD. However, this trial showed for the first time that a small subpopulation of Atlantic salmon subjected to a severe AGD infection was able to resist becoming heavily infected and furthermore survive the challenge.
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PMID:The effect of beta-glucan administration on macrophage respiratory burst activity and Atlantic salmon, Salmo salar L., challenged with amoebic gill disease--evidence of inherent resistance. 1596 Jun 58

The purpose of this study was to determine if multiple injections of different dosages of beta-glucan derived from barley would enhance the immune response and disease resistance against infections due to opportunistic pathogens Aeromonas hydrophila and Edwardsiella tarda in Labeo rohita fingerlings. Hence, four different dosages of beta-glucan suspension in phosphate-buffered saline at the rate of 0, 5, 10, 15 mg kg(-1) body weight of fish were injected intraperitoneally to the fingerlings of Labeo rohita at two-week intervals for four times. After every two-week interval different serum biochemical, haematological and immunological parameters of fish were evaluated. At the end of immunostimulation trial of 56 days, fish were divided into four subgroups under each major treatment group for challenge through i.p injection and bath immersion with two pathogens, A. hydrophila and E. tarda. The mortality (%) and agglutinating antibody titre was recoded on 28th day post challenge. Most of the immune parameters such as leucocyte count, phagocytic ratio, phagocytic index, lysozyme activity, complement activity, serum bactericidal activity were significantly (P < 0.05) enhanced on 42 days after three i.p injections of 10 mg of beta-glucan kg(-1) body wt. Challenge study indicated least mortality in the group of fishes injected with medium dose of 10 mg of beta-glucan kg(-1) body wt. four times. Multiple injections of beta-glucan might have maintained the activation of phagocytic cells for a long period which in turn would lead to long-term protection in fishes. Thus, injections of 10 mg of beta-glucan kg(-1) body wt. for three times can be advocated to enhance the immune response of fish species under aquaculture.
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PMID:Effect of multiple injections of beta-glucan on non-specific immune response and disease resistance in Labeo rohita fingerlings. 1603 42


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