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)

Solutions of chlorine-releasing agents (CRAs) show varying activity against Bacillus subtilis spores; sodium hypochlorite (NaOCl) shows higher activity than sodium dichloroisocyanurate (NaDCC) which is more active than chloramine-T. Investigations with coat- and cortex-extracted spores indicate that resistance to CRAs depends not only on the spore coat but also the cortex. Whereas extraction of alkali-soluble coat protein increased sensitivity to NaOCl and NaDCC, degradation of coat and cortex material was required to achieve significant activity with chloramine-T. NaOCl (in the presence and absence of NaOH) and NaDCC (in the presence of NaOH only) produced degradation of spore coat and cortex material which may be related to their rapid sporicidal action at low concentrations under these conditions. By contrast, chloramine-T produced no degradation of cortex peptidoglycan and was only effective against normal and alkali-treated spores at high concentrations, requiring extraction of peptidoglycan with urea/dithiothreitol/sodium lauryl sulphate (UDS) or UDS/lysozyme to achieve significant activity at low concentrations. Results suggest that the sporicidal action of CRAs is associated with spore coat and cortex degradation causing rehydration of the protoplast allowing diffusion to the site of action on the underlying protoplast.
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PMID:Interaction of Bacillus subtilis spores with sodium hypochlorite, sodium dichloroisocyanurate and chloramine-T. 155 40

This study investigated the interaction between neutrophil myeloperoxidase (MPO) and the C1q component of the complement system. Using a dot-spot assay, MPO was found to bind to C1q in a dose-dependent manner. The specificity of this reaction was proved by the inhibitory effect of F(ab')2 antibodies to C1q and by the inability of MPO to bind to C1r, C1s and IgG. The interaction between MPO and C1q did not influence the enzymatic activity of the peroxidase but resulted in a more stable C1q as assessed by hemolytic assay for C1q. The protective effect of MPO on C1q did not require the presence of H2O2 in the reaction mixture nor was it inhibited by sodium azide, whereas it was abolished by heating the peroxidase. Lactoferrin and lysozyme, unlike MPO, were ineffective in protecting C1q from functional decay. Addition of H2O2 and chloride to MPO and C1q led to a complete inactivation of C1q, which could not be induced by H2O2 alone. The hypochlorite, which is known to be generated during the reaction of MPO with H2O2 and chloride, exhibited a similar inactivating effect on C1q, which was prevented by an external source of methionine.
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PMID:Protective and inactivating effects of neutrophil myeloperoxidase on C1q activity. 215 59

Exposure for 20 min of stationary phase cells of Salmonella typhimurium to a combined triple stress system (TSS) treatment comprising hypochlorite derived 5 ppm free available chlorine in solution acidified with 1% succinate (pH 2.5) and at a chill shock temperature of 5 degrees C resulted in symptoms of injury. Cells became sensitive to 40 micrograms/ml lysozyme, 50 micrograms/ml actinomycin D and 100 micrograms/ml ribonuclease B, to which control cells were resistant. Metabolic injury was indicated by reduction in colony forming ability of stressed cells on minimal salts glucose agar M9 medium. There was no detectable leakage loss of 260-280 nm-absorbing materials. This was also confirmed by assay of the cellular RNA material components. Loss of alkaline phosphatase activity was observed in the stressed cells. The intensity of induced cellular damage as measured by lysozyme sensitivity was greatest in the cells exposed to the complete TSS, followed by those stressed in 1% succinate at 5 degrees C, then 5 ppm chlorine at 5 degrees C and the singular chill shock stress at 5 degrees C, respectively. The magnitudes of cellular damage, however, were suggestive of synergistic interactions among the component stress factors of the TSS. The findings obtained indicated impairment of the structural integrity and functional capabilities of the permeability barriers and the inactivation of certain periplasmic enzymes. The resultant cumulative cellular damage from the TSS exposure may therefore enhance greater sensitivity of treated cells to subsequent stress factors.
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PMID:Mechanisms of triple stress-mediated damage in stationary phase cells of Salmonella typhimurium exposed to succinate-acidified hypochlorite system at 5 degrees C. 242

Hypochlorite-treated Clostridium botulinum 12885A spores, but not buffer-treated spores, could be germinated with lysozyme, indicating that their coats are made permeable to lysozyme by hypochlorite treatment so that the cortex is accessible. Hypochlorite-treated spores and spores extracted with 8 M urea-2-mercaptoethanol (pH 3.0) were sensitive to certain components of recovery media, but spores sensitized to lysozyme by other treatments were not. These data indicate that hypochlorite does more than increase coat permeability to lysozyme. Scanning electron microscopy revealed a more open-appearing surface of hypochlorite-treated spores, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that a greater amount of protein was removed from hypochlorite-treated and other lysozyme-sensitized spores than from buffer-treated spores. The data suggest that spore coat proteins may be removed by hypochlorite treatment, and this may be responsible for the sensitivity of spores and for their observed ability to germinate in lysozyme.
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PMID:Proposed mechanism for sensitization by hypochlorite treatment of Clostridium botulinum spores. 630 69

Injury of bacterial spores is manifested in ways similar to those for vegetative cells, i.e. altered nutritional requirements, increased sensitivity to inhibitors and modified optimum temperatures. However, injury in spores may involve activation, germination and/or outgrowth systems, in addition to the vegetative growth processes. Food processes in the form of heat, acid, inhibitors, preservatives, low water activity and combinations of these factors can stress spores. Consequently, detection and enumeration methods designed to recover bacterial spores from processed foods must always consider the requirements of injured spores. Injury to germination systems has been circumvented through the addition of non-nutritive agents, such as lysozyme, to recovery media, or by incubation at an alternative temperature which favours a secondary germination system. A shift in temperature has also permitted repair of damaged outgrowth systems. Addition of materials such as starch and charcoal can reduce the sensitivity of injured spores to some inhibitors. Our current research on hypochlorite injury of Cl. botulinum, differing injury responses for B. cereus in rice and TSB, and injury of B. cereus earlier in the heating process at 85 degrees C than at 90 degrees C indicate a need for more information on the injury of spores in processed foods.
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PMID:Detection and enumeration of injured bacterial spores in processed foods. 638 33

The emergence and development of chemical and thermal resistance in spores of Bacillus subtilis was examined. The chemicals studied were of the disinfectant type: glutaraldehyde, hypochlorite, hypochlorite-methanol and povidone-iodine. Growth and sporulation were followed by electron microscopy and resistance assigned to specific stages in relation to 45Ca and DPA accumulation. A sequential development of resistance was observed with thermal resistance appearing first at early Stage V corresponding to maturation of cortex and deposition of rudimentary spore coat material. Chemical resistance coincided with middle to late Stage V dependent on the chemical concerned. A progressive development of resistance was observed on prolonged incubation in sporulation medium and was affected by inclusion of lysozyme in the spore washing sequence.
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PMID:Emergence and development of resistance to antimicrobial chemicals and heat in spores of Bacillus subtilis. 643 22

Spores of Bacillus subtilis NCTC 8236 were treated with glutaraldehyde, Lugol's iodine, polyvinylpyrrolidone-iodine (PVP-I), sodium hypochlorite or sodium dichloroisocyanurate (NaDCC). After exposure survivors were enumerated on nutrient agar containing potential revival agents (subtilisin, lysozyme, calcium dipicolinate, calcium lactate). Of these, only calcium lactate had any significant enhancing effect and then only with iodine-treated spores. Calcium lactate (9 mmol l-1) in nutrient broth enhanced the rate and extent of germination of iodine-treated spores but not of spores previously subjected to glutaraldehyde, hypochlorite or NaDCC.
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PMID:Revival of Bacillus subtilis spores from biocide-induced injury in the germination process. 839 79

Changes in biological properties of serum albumin, egg white lysozyme, human serum alpha-1 antiproteinase and human leukocyte ribonuclease in effect of interaction with the enzyme system composed of myeloperoxidase from human neutrophilic polymorphonuclear leukocytes, Cl- and H2O2 were investigated. All the studied proteins lost their biological functions and were denaturated, but the amounts of hydrogen peroxide necessary to produce these effects differed remarkably for each individual protein. The alpha-1 antiproteinase ability of binding to trypsin was abolished upon employing 1.2 mols of H2O2 per mol of alpha-1 antiproteinase. The lysozyme enzymatic activity was abolished when 1.4 mols of H2O2 per mol of lysozyme were employed. Albumin decreased its binding to specific antialbumin antibodies and entirely lost the binding properties when 2 mols and about 10 mols of H2O2 per mol of albumin were employed, respectively. On the other hand 18 mols of H2O2 per mol of human leukocyte ribonuclease were necessary to inactivate this enzyme. All the mentioned proteins were protected from losing their biological functions by excess of specific amino acids with affinity to hypochlorite: Alpha-1 antiproteinase by excess of N-acetylmethionine, lysozyme by N-acetylmethionine and N-acetyl glycyltryptophane, albumin by N-acetyl derivatives of methionine, cysteine, tryptophane and lysine, whereas ribonuclease was protected from denaturation by all above mentioned amino acid derivatives. None of the studied proteins was protected from denaturation by N-acetyl tyrosine, or phenylalanine.
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PMID:Inactivation and denaturation of some proteins by enzyme system: myeloperoxidase, chloride and hydrogen peroxide. 840 71

Hypochlorite-oxidized low-density lipoprotein ((-)OCl-LDL) has been shown to stimulate various functions of human polymorphonuclear leukocytes (PMNLs). Incubation of PMNLs with (-)OCl-LDL (produced by incubation of 0.4 mM LDL cholesterol with 1 mM NaOCl for 40 min at 37 degrees C) but not native or copper-oxidized LDL induced a substantial generation of reactive oxygen species (ROS) as measured by means of chemiluminescence with one peak at 10-12 min. Upon stimulation with (-)OCl-LDL about 70% of ROS (hydrogen peroxide and superoxide anion) were released from the cells into the extracellular environment. The (-)OCl-LDL-induced increase of the respiratory burst was dependent upon the dose, exposure time, and extent of LDL oxidation. Cytochalasin B, an inhibitor of phagocytosis, markedly diminished the LDL-induced ROS generation to nearly 40% of control values. (-)OCl-LDL enhanced the adhesion of PMNLs to human umbilical venous endothelial cells 2.5-fold as compared to native LDL and promoted the secretion of the active granule enzymes lysozyme and beta-glucuronidase. Together, the results suggest a potential role of LDL-activated PMNLs in initiating and/or maintaining the inflammatory process during the early phase of atherosclerotic lesion development. Alternatively, PMNLs may also play a protective role by phagocytosing oxidized LDL and, thus, preventing further detrimental atherogenic effects of oxidized LDL.
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PMID:Hypochlorite-modified low-density lipoprotein stimulates human polymorphonuclear leukocytes for enhanced production of reactive oxygen metabolites, enzyme secretion, and adhesion to endothelial cells. 954 3

A major Bacillus anthracis spore coat protein of 13.4 kDa, designated Cot alpha, was found only in the Bacillus cereus group. A stable ca. 30-kDa dimer of this protein was also present in spore coat extracts. Cot alpha, which is encoded by a monocistronic gene, was first detected late in sporulation, consistent with a sigma(K)-regulated gene. On the basis of immunogold labeling, the protein is in the outer spore coat and absent from the exosporium. In addition, disruption of the gene encoding Cot alpha resulted in spores lacking a dark-staining outer spore coat in thin-section electron micrographs. The mutant spores were stable upon heating or storage, germinated at the same rate as the wild type, and were resistant to lysozyme. They were, however, more sensitive than the wild type to phenol, chloroform, and hypochlorite but more resistant to diethylpyrocarbonate. In all cases, resistance or sensitivity to these reagents was restored by introducing a clone of the cot alpha gene into the mutant. Since Cot alpha is an abundant outer spore coat protein of the B. cereus group with a prominent role in spore resistance and sensitivity, it is a promising target for the inactivation of B. anthracis spores.
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PMID:Characterization of a major Bacillus anthracis spore coat protein and its role in spore inactivation. 1506 44


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