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)

One hundred and fifty lactic acid bacteria (LAB) isolated from vacuum-packaged processed meats were screened for antagonistic activity against various food spoilage microorganisms and foodborne pathogens. Nineteen strains produced bacteriocins active against closely related LAB and Listeria strains. Leuconostoc carnosum (LA54a and TA26b) and Leuconostoc mesenteroides subspecies dextranicum (TA33a) produced bacteriocins that were susceptible to proteolytic enzymes, but not to catalase, lysozyme or chloroform. They were heat stable up to 100 degrees C for thirty minutes at pH 2 to 7, and exerted a bacteriolytic effect. Bacteriocin production by all Leuconostoc strains was growth associated, occurring at incubation temperatures of 0 degrees C to 30 degrees C and initial medium pH 4.5 to 7.5. Probing of plasmid DNA from the three Leuconostoc strains with an oligonucleotide probe homologous to the nucleotide sequence of leucocin A-UAL 187 indicated plasmid-mediated bacteriocin production. Homology of the three Leuconostoc bacteriocin-coding genes to the amino-terminal end of the leucocin A-UAL 187 gene from Leuconostoc gelidum UAL 187 is therefore suggested. This evidence implies that all three Leuconostoc strains produce type 2, Listeria active bacteriocins.
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PMID:Antibacterial activity of three Leuconostoc strains isolated from vacuum-packaged processed meats. 807 4

One hundred strains of lactic acid bacteria isolated from dry cured sausages were tested for antagonistic activity against a set of test strains. Nine of 52 strains of Lactobacillus casei and three of 48 strains of Lact. plantarun produced inhibition zones against the indicator species. The substance excreted by Lact. casei CRL 705 was active against Lact. plantarum, Listeria monocytogenes, Staphylococcus aureus and a wide range of Gram-negative bacteria. The activity of the antibacterial compound from Lact. casei CRL 705 was destroyed by papain, trypsin and pepsin, but was resistant to heat (100 degrees C for 20 min), lysozyme and catalase. The agent was produced during the growth cycle and when the concentrated and neutralized supernatant fluid was added to a fresh culture of sensitive cells it produced a rapid inactivation. A decrease in optical density (O.D.) over time, indicative of cell lysis, was also observed. These characteristics allowed us to identify the inhibitory compound as a bacteriocin which we termed Lactocin 705.
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PMID:Antibacterial activity of Lactobacillus strains isolated from dry fermented sausages. 822 91

51Chromium-labeled rat pulmonary artery endothelial cells (EC) cultivated in MEM medium were killed, in a synergistic manner, by mixtures of subtoxic amounts of glucose oxidase-generated H2O2 and subtoxic amounts of the following agents: the cationic substances, nuclear histone, defensins, lysozyme, poly-L-arginine, spermine, pancreatic ribonuclease, polymyxin B, chlorhexidine, cetyltrimethyl ammonium bromide, as well as by the membrane-damaging agents phospholipases A2 (PLA2) and C (PLC), lysolecithin (LL), and by streptolysin S (SLS) of group A streptococci. Cytotoxicity induced by such mixtures was further enhanced by subtoxic amounts either of trypsin or of elastase. Glucose-oxidase cationized by complexing to poly-L-histidine proved an excellent deliverer of membrane-directed H2O2 capable of enhancing EC killing by other agonists. EC treated with rabbit anti-streptococcal IgG were also killed, in a synergistic manner, by H2O2, suggesting the presence in the IgG preparation of cross-reactive antibodies. Killing of EC by the various mixtures of agonists was strongly inhibited by scavengers of hydrogen peroxide (catalase, dimethylthiourea, MnCl2), by soybean trypsin inhibitor, by polyanions, as well as by putative inhibitors of phospholipases. Strong inhibition of cell killing was also observed with tannic acid and by extracts of tea, but less so by serum. On the other hand, neither deferoxamine, HClO, TNF, nor GTP gamma S had any modulating effects on the synergistic cell killing. EC exposed either to 6-deoxyglucose, puromycin, or triflupromazin became highly susceptible to killing by mixtures of hydrogen peroxide with several of the membrane-damaging agents. While maximal synergistic EC killing was achieved by mixtures of H2O2 with either PLA2, PLC, LL, or with SLS, a very substantial release of [3H]arachidonic acid (AA), PGE2, and 6-keto-PGF occurred only if a proteinase was also added to the mixture of agonists. The release of AA from EC was markedly inhibited either by scavengers of H2O2, by proteinase inhibitors, by cationic agents, by HClO, by tannic acid, and by quinacrin. We suggest that cellular injury induced in inflammatory and infectious sites might be the result of synergistic effects among leukocyte-derived oxidants, lysosomal hydrolases, cytotoxic cationic polypeptides, proteinases, and microbial toxins, which might be present in exudates. These "cocktails" not only kill cells, but also solubilize AA and several of its metabolites. However, AA release by the various agonists can be also achieved following attack by leukocyte-derived agonists on dead cells. It is proposed that treatment by "cocktails" of adequate antagonists might be beneficial to protect against cellular injury in vivo.
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PMID:Killing of endothelial cells and release of arachidonic acid. Synergistic effects among hydrogen peroxide, membrane-damaging agents, cationic substances, and proteinases and their modulation by inhibitors. 833 Sep 29

In the present investigation alterations in the free radical generating and scavenging enzymes in platelets, neutrophils (PMNLs), heart and lung homogenates following rat pulmonary thromboembolism have been studied. Thrombosis was induced by intravenous infusion of collagen and adrenaline. Levels of malonaldehyde (MDA) were elevated in the PMNLs after thrombosis. Activities of superoxide dismutase (SOD) and catalase (CAT) were found to increase in platelets and PMNLs respectively. However, there was no significant alteration in the lactate dehydrogenase (LDH), lysozyme (LYS), ratio of xanthine oxidase to dehydrogenase (XO/XH) and PMNLs O2- generation before and after thrombosis. Migration of PMNLs following thrombosis was indicated by increased activity of myeloperoxidase (MPO) in the heart. In addition, pretreatment with allopurinol, a xanthine oxidase inhibitor and indomethacin, a cyclooxygenase inhibitor offered protection against thromboembolism induced death/paralysis. Results suggest the involvement of free radicals in thrombosis.
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PMID:Free radical scavenging mechanisms during pulmonary thromboembolism in rats. 846 69

A novel peptide bacteriocin produced by the lactic acid bacterium Carnobacterium piscicola JG126 isolated from spoiled ham was purified and characterized. This bacteriocin, designated piscicolin 126, inhibited the growth of several gram-positive bacteria, especially the food-borne pathogen Listeria monocytogenes, but had no effect on the growth of a number of yeasts and gram-negative bacteria. Bactericidal activity was not destroyed by exposure to elevated temperatures at low pH values; however, bactericidal activity was lost at high pH values, especially when high pH values were combined with an elevated temperature. Piscicolin 126 activity was not affected by catalase, lipase, or lysozyme but was destroyed by exposure to a range of proteolytic enzymes. Piscicolin 126 was purified to homogeneity and was found to be a peptide having a molecular weight of 4,416.6 +/- 1.9. A sequence analysis revealed that this compound is a cystibiotic (class IIa) bacteriocin containing 44 amino acid residues and one intrapeptide disulfide ring. Piscicolin 126 has regions of homology with some other bacteriocins obtained from lactic acid bacteria and is most closely related to sakacin P and pediocin PA-1 (levels of identity, 75 and 55%, respectively). Addition of piscicolin 126 to a devilled ham paste test food system inhibited the growth of L. monocytogenes for at least 14 days. Piscicolin 126 was more effective than two commercially available bacteriocin preparations tested in the same system.
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PMID:Characterization of the chemical and antimicrobial properties of piscicolin 126, a bacteriocin produced by Carnobacterium piscicola JG126. 870 82

Lactobacillus amylovorus LMG P-13139, isolated from corn steep liquor, produces two bactericidal peptides with respective estimated molecular masses of 4.5 and 6.0 kDa upon denaturing sodium dodecyl sulfatepolyacrylamide gel electrophoresis. The antimicrobial activity detected in the fermentation supernatant fraction of L. amylovorus LMG P-13139 was heat stable (20 min, 121 degrees C), displayed a narrow inhibitory spectrum, and was sensitive to proteinase K, trypsin, and alpha-chymotrypsin but insensitive to alpha-amylase, lysozyme, catalase, and lipase. The 4.5-kDa bacteriocin was purified and characterized and designated lactobin A. Lactobin A was isolated as a floating pellicle from culture supernatant brought to 35% saturation with ammonium sulfate. Upon this ammonium sulfate treatment, crude lactobin A was incorporated, together with Tween 80 as a major contaminant, in high-molecular-mass complexes sized at approximately 670 kDa by gel filtration chromatography. Contaminating fatty acids were removed from these micelles by a simple one-step methanol-chloroform extraction without loss of activity. Both inhibitory peptides were separated in an isocratic isopropanol gradient on a PepRPC 5/5 reversed-phase column, and both peptides retained activity towards Lactobacillus helveticus ATCC 15009 upon separation. Lactobin A has a molecular mass determined by electrospray mass spectrometry of 4,879 +/- 0.69 Da. Its peptide chain contains 50 unmodified amino acids, of which 26% are glycine residues and 40% are hydrophobic residues (A, V, L, I, and P). It displays the highest structural homology (42% identity and 28% similarity) with the lafX gene product, encoded by the second open reading frame of the lactacin F operon. These data strongly indicate that lactobin A belongs to the class IIb bacteriocins according to the classification of Klaenhammer.
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PMID:Isolation, purification, and amino acid sequence of lactobin A, one of the two bacteriocins produced by Lactobacillus amylovorus LMG P-13139. 897 34

Four bacteriocin producing lactic acid bacteria isolated from vegetables were identified as Lactococcus lactis strains on the basis of physiological and biochemical characteristics, carbohydrate fermentation patterns and analysis of total soluble protein pattern by SDS PAGE. The bacteriocins had a wide spectrum of activity as antagonism was detected not only towards a variety of lactic acid bacteria, but also to Staphylococcus aureus and Listeria monocytogenes. These bacteriocins were resistant to heating at 121 degree C for 15 minutes and showed highest activity at low pH (<5.0). They were inactivated by the proteolytic enzymes alpha-chymotrypsin and proteinase K, but not by lipase, alpha-amylase, catalase or lysozyme. These bacteriocinogenic Lactococcus strains were all immune to the bacteriocins produced as well as to commercial nisin. Bacteriocin producer culture supernatants showed a high degree (70 or 100%) of cross-reactivity in the nisin ELISA, suggesting similarity of the produced bacteriocins to nisin. The potential application of bacteriocin producing lactococci of vegetable origin for safety assurance of vegetable foods and controlling vegetable fermentations is discussed.
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PMID:Production of nisin-like bacteriocins by Lactococcus lactis strains isolated from vegetables. 926 41

Methods of making molecularly ordered protein films are reviewed with special reference to the recently developed technique of protein multilayer assembly by alternated adsorption of opposite-charge polyions. This method has been applied for linear and branched polyions, DNA, polynucleotides, proteins, viruses and clay nanoplates. This provides good prospects for biomolecular architecture. Quartz crystal microbalance, X-ray and neutron reflectivity, scanning electron microscopy, atomic force microscopy and UV-absorbance data are used to analyze the film structure. Multilayer buildup by alternation of polyions and 16 different charged proteins is discussed. In most cases, enzymes in the films retained their activity. Protein/ceramic nanoplates consisting of alternated montmorillonite clay and glucose oxidase layers electrostatically linked by polycations were also assembled. Protein layers can be arranged according to specific biological activity. Consecutive enzymic reactions were performed in anisotropic protein layers prepared with precise control of distances between the active layers (1-50 nm). Film superlattices containing ordered layers of more than one protein were constructed using myoglobin, lysozyme, peroxidase, glucoamylase, glucose oxidase and catalase. Glucoamylase, glucose oxidase/peroxidase catalyze the starch-glucose-H2020 reaction. The reaction products and nonreacting starch were separated by filtration when the substrate solution passed through the multienzyme films assembled on a filter. Formation of alternate outermost layers (of opposite charge or opposite specificity) at every adsorption cycle is the key point of the layer-by-layer assembly. Multilayers were obtained by alternated adsorption of concanavalin A and glycogen (or streptavidin and biotinylated polylysine) were designed using their biospecific interaction. Protein films are of extreme interest as novel biologically active materials.
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PMID:Protein architecture: assembly of ordered films by means of alternated adsorption of oppositely charged macromolecules. 946 49

Both PAF (10 microM) and bradykinin (0.1-10 microM) increased lysozyme (from submucosal gland serous cells (+138 and +45% for PAF, 10 microM, and bradykinin, 1 microM, respectively) and albumin (mainly active epithelial transport; +387 and +108%) outputs into the ferret tracheal lumen in vitro and reduced the negativity of the potential difference (PD: -33 and -17%) across the trachea. Since PAF can cause bronchial smooth muscle hyperresponsiveness, we tested whether these effects were interactive, and if PAF would increase the actions of bradykinin. The bradykinin-induced lysozyme and albumin outputs were more than trebled and the PD change was enhanced by PAF, after the immediate secretory effects of the latter had returned to baseline. The secretory and PD responses to PAF were all prevented by the PAF-antagonist WEB 2086 and by a combination of the free-radical scavengers catalase and SOD, indicating that PAF may act on specific receptors to release free-radicals. Nedocromil sodium inhibited the increase in lysozyme and albumin outputs produced by PAF, but had no effect on the PD response. None of the tracheal responses to bradykinin was modified by WEB 2086, catalase and SOD, or nedocromil sodium. The secretory and PD hyperresponsiveness to bradykinin caused by PAF was prevented by WEB 2086 and by catalase and SOD. Nedocromil sodium greatly inhibited the lysozyme and albumin hyperresponsiveness but had no effect on the PD response. Thus PAF may release more than one type of radical which have differential effects on serous cells and albumin transport compared with PD; nedocromil sodium may act only against the radical causing the secretory effects.
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PMID:PAF-induced secretory hyperresponsiveness in the ferret trachea to bradykinin and its pharmacological inhibition. 951 26

Bacteria isolated from radish were identified as Lactococcus lactis subsp. cremoris R and their bacteriocin was designated lactococcin R. Lactococcin R was sensitive to some proteolytic enzymes (proteinase-K, pronase-E, proteases, pepsin, alpha-chymotrypsin) but was resistant to trypsin, papain, catalase, lysozyme and lipase, organic solvents, or heating at 90 degrees C for 15, 30 and 60 min, or 121 degrees C for 15 min. Lactococcin R remained active after storage at -20 and -70 degrees C for 3 months and after exposure to a pH of 2-9. The molecular weight of lactococcin R was about 2.5 kDa. Lactococcin R was active against many food-borne pathogenic and food spoilage bacteria such as Clostridium, Staphylococcus, Listeria, Bacillus, Micrococcus, Enterococcus, Lactobacillus, Leuconostoc, Streptococcus and Pediococcus spp., but was not active against any Gram-negative bacteria. Lactococcin R was produced during log phase and reached a maximum activity (1600 AU ml-1) at early stationary phase. The highest lactococcin R production was obtained in MRS broth with 0.5% glucose, at 6.5-7.0 initial pH values, 30 degrees C temperature and 18-24-h incubation times. Lactococcin R adsorbed maximally to its heat-killed producing cells at pH 6-7 (95%). Crude lactococcin R at 1280 AU ml-1 was bactericidal, reducing colony counts of Listeria monocytogenes by 99.98% in 3 h. Lactococcin R should be useful as a biopreservative to prevent growth of food-borne pathogenic and food spoilage bacteria in ready-to-eat, dairy, meat, poultry and other food products. Lactococcin R differs from nisin in having a lower molecular weight, 2.5 kDa vs 3.4 kDa, and in being sensitive to pepsin and alpha-chymotrypsin to which nisin is resistant.
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PMID:Detection and characterization of a bacteriocin produced by Lactococcus lactis subsp. cremoris R isolated from radish. 1020 54


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