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)

Lysozyme-treated cells of a blue-green alga, Plectonema boryanum, had an internal pH of 7.3+/-0.2 under isotonic and hypotonic conditions. This value was similar to that of untreated cells. The CCCP-induced biphasic H+ change seen in the isotonic cells was not observed in the hypotonically treated cells. The biphasic time course remained in the hypotonic preparation if CaCl2 or MgCl2 was added prior to the osmotic shock. It is suggested that the cells have two compartments of H+ concentration. The outer region may be more acidic than the inner region. A light-induced H+ efflux was observed under isotonic conditions and an influx of H+ under hypotonic conditions. The H+ influx was not observed when lysozyme-treated cells were incubated with CaCl2 or MgCl2 prior to the hypotonic treatment. Two types of effects of divalent cations, one on the rigidity of the outer membrane and another on the permeability characteristics of the inner photosynthetic membrane, are indicated. Rearrangement of the photosynthetic membranes and an apparent inversion of the H+ pump by hypotonic shock are also suggested.
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PMID:H+ translocation in lysozyme-treated cells of the blue-green alga Plectonema boryanum. Difference between isotonically and hypotonically treated preparations and effects of divalent cations. 2 Nov 72

Protoplasts of Streptomyces hygroscopicus 155 producing nigericin, a polyether antibiotic, were prepared. Conditions for protoplasting and optimal concentrations of lysozyme and glycine, and the age of mycelium were studied. With the method of the experiment design, concentrations of four components: CaCl2, MgCl2, KH2PO4 and TES buffer in the regeneration medium were determined. The levels of CaCl2 and TES buffer proved to be the most important parameters.
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PMID:[Preparation and regeneration of protoplasts of the strain Streptomyces hygroscopicus 155]. 130 22

1. Binding of biotin-heparin to immobilized lactoferrin and lysozyme was optimum at pH 6.0, 100 mM NaCl. Complex interactions between NaCl and CaCl2 concentrations were observed for heparin binding to both proteins. 2. The metal ions Cu2+, Zn2+, Fe2+ and Fe3+ inhibited heparin binding, with half-maximal inhibition of binding to lactoferrin occurring between 600 microM and 1 mM and for lysozyme between 500 and 800 microM. 3. Binding of biotin-heparin to both proteins was inhibited to varying degrees by heparin, heparan sulfate, chondroitin sulfate A, dextran sulfate and DNA.
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PMID:Heparin-binding properties of lactoferrin and lysozyme. 147 67

Adsorption isotherms of BSA at the solid-water interfaces have been studied as a function of protein concentration, ionic strength of the medium, pH and temperature using silica, barium sulphate, carbon, alumina, chromium, ion-exchange resins and sephadex as solid interfaces. In most cases, isotherms for adsorption of BSA attained the state of adsorption saturation. In the presence of barium sulphate, carbon and alumina, two types in the isotherms are observed. Adsorption of BSA is affected by change in pH, ionic strength and temperature of the medium. In the presence of metallic chromium, adsorbed BSA molecules are either denatured or negatively adsorbed at the metallic interface. Due to the presence of pores in ion-exchange resins, adsorption of BSA is followed by preferential hydration on resin surfaces in some cases. Sometimes two steps of isotherms are also observed during adsorption of BSA on the solid resins in chloride form. Adsorption of BSA, beta-lactoglobulin, gelatin, myosin and lysozyme is negative on Sephadex surface due to the excess adsorption of water by Sephadex. The negative adsorption is significantly affected in the presence of CaCl2, KSCN, LiCl, Na2SO4, NaI, KCl and urea. The values of absolute amounts of water and protein, simultaneously adsorbed on the surface of different solids, have been evaluated in some cases on critical thermodynamic analysis. The standard free energies (delta G0) of excess positive and negative adsorption of the protein per square meter at the state of monolayer saturation have been calculated using proposed universal scale of thermodynamics. The free energy of adsorption with reference to this state is shown to be strictly comparable to each other. The magnitude of standard free energy of transfer (delta G0B) of one mole of protein or a protein mixture at any type of physiochemical condition and at any type of surface is observed to be 38.5 kJ/mole.
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PMID:Protein adsorption at solid-liquid interfaces: Part IV--Effects of different solid-liquid systems and various neutral salts. 175 29

Cells of Escherichia coli were efficiently transfected with Q beta phage RNA by electroporation. A single voltage shock at 6.25 kV/cm with a 25 microF capacitor resulted in an infectivity yield considerably higher than that attained by a lysozyme-EDTA spheroplast method or a CaCl2 procedure. A linear relationship was found between concentration of the input RNA and yield of the transfectants, over a wide range. Efficiency of the electroporation-mediated transfection (electrotransfection) was increased by addition of certain sodium salts but decreased by preincubation in a Tris buffer containing sucrose.
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PMID:RNA transfection of Escherichia coli by electroporation. 264 84

Ampicillin, fusidic acid, gentamicin, imipenem, mezlocillin, ofloxacin, penicillin G, piperacillin, and vancomycin were examined for inhibitory and bactericidal activity in various broth media against 7 clinical isolates of Streptococcus faecalis. On a weight-for-weight basis, ampicillin, imipenem, mezlocillin, and ofloxacin proved to be more efficacious. All enterococcal isolates were resistant against gentamicin; fusidic acid and vancomycin lacked bactericidal activity. The combinations of either ampicillin, imipenem, mezlocillin, ofloxacin, piperacillin, or vancomycin with a subinhibitory concentration (4 micrograms/ml) of gentamicin, with or without added 65% (v/v) fresh defibrinated human blood, respectively, yielded additive effects against all enterococcal isolates. The addition of fresh human blood failed to enhance the antienterococcal activity of 4 micrograms/ml of gentamicin; in contrast, addition of 65% (v/v) fresh or heat-inactivated (56 degrees C, 30 min) normal rabbit, bovine, and human sera augmented the activity of gentamicin, an effect that was ablated through the addition of either 0.005 M DTT or 0.01 M MgCl2 + 0.01 M EGTA + 0.01 M CaCl2, supplements known to antagonize human serum beta-lysin, but not lysozyme activity.
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PMID:Streptococcus faecalis: in vitro susceptibility to antimicrobial drugs, single and combined, with and without defibrinated human blood. 308 51

The conditions for the efficient polyethylene glycol (PEG)-induced spheroplast transformation of three strains of Streptococcus thermophilus have been established. This required the careful optimization of various experimental parameters, the most important being the choice of the lytic enzyme (lysozyme versus mutanolysin), the extent of cell wall digestion and the conditions for the PEG shock which were found to be strain-specific. The transfection assay we had previously developed for S. thermophilus represented a key step and powerful tool in our transformation studies. It allowed individual and stepwise adjustment of the above mentioned factors, but was also compulsory for the establishment of an effective regeneration medium for the strains we examined. Among various potential osmotic protectors tested, raffinose in combination with CaCl2 and MgCl2 was most efficient and routinely supported regeneration with up to 10% efficiency, after PEG treatment. With the spheroplast transformation procedure described in this paper, shuttle vectors and recombinant plasmids could be introduced into three industrial yogurt starters, with maximal efficiencies of 7.5 x 10(4) transformants/micrograms of liposome encapsulated, covalently closed circular DNA. A striking, yet unexplained, reduction in transformation rates was observed when erythromycin rather than chloramphenicol was used as the selecting agent.
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PMID:Development of an efficient spheroplast transformation procedure for S. thermophilus: the use of transfection to define a regeneration medium. 313 74

An L-form isolated from Escherichia coli K12 by sequential treatment with N-methyl-N'-nitro-N-nitrosoguanidine and lysozyme was adapted to grow in hyperosmolar liquid cultures. It was stable in the absence of antibiotic when cultured in brain heart infusion (BHI) broth containing NaCl and CaCl2, the optimal concentrations being 0.34 M and 1 mM, respectively. No growth of the L-form was observed when CaCl2 was not added to BHI medium containing 0.34 M-NaCl. On the other hand, when KCl replaced NaCl as the osmotic stabilizer, growth of the L-form was repressed in the presence of CaCl2. Electron microscopy of the L-form confirmed the absence of a cell wall. A revertant strain derived from the L-form grew as a stable bacillary form in BHI medium without osmotic stabilizer. The growth characteristics of the revertant strain resembled those of the parent strain. The revertant strain produced L-forms in the presence of NaCl.
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PMID:Morphology, growth and reversion in a stable L-form of Escherichia coli K12. 330 59

Lysozyme release from purified human polymorphonuclear leukocytes was found to be uniquely enhanced by 2.5-20 mM LiCl. This effect was dose dependent and was not detected when the media was supplemented with NaCl, KCl, MgCl2, or CaCl2. The purified isotopes of Li+, 6Li, and 7Li were equally effective in enhancing lysozyme release from the cells at 10 and 20 mM, but 6Li was more effective than 7Li at 5 mM. The enhancement of enzyme release in the presence of Li+ was comparable to the enhancement observed in the presence of N-formylmethionylleucylphenylalanine (fMLP). Addition of LiCl plus fMLP did not result in lysozyme release in excess of each stimulant alone, except when the cells were incubated with 20 mM 6Li + 10(-5) M fMLP. In addition, enzyme release induced by these two agents could be further enhanced to the same degree by addition of cytochalasin D to the incubation mixtures. While similarities between enzyme release induced by LiCl and fMLP were detected, optimal stimulation of enzyme release by Li+ was much more sensitive to inhibition by pertussis toxin than was maximal fMLP stimulation. Therefore, the intracellular events altered by Li+ and the peptide may share some metabolic steps, but they differ in their sensitivity to alterations in cAMP metabolism.
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PMID:Characterization of lithium-induced enzyme release from human polymorphonuclear leukocytes. 377 61

Permeabilization of human neutrophils has been accomplished by using saponin, a cholesterol complexing agent, permitting experimental manipulation of the intracellular milieu. Access of ordinarily impermeable solutes, such as [14C]-inulin or [14C]-sucrose, to the water space of the cells was considered the main criterion for permeabilization. Other criteria were substantial (50 to 80%) release of cytoplasmic lactate dehydrogenase and permeability to trypan blue. Successful permeabilization did not cause substantial release of the granule enzymes lysozyme or beta-glucuronidase. Washing the neutrophils, to remove soluble saponin and released cytoplasmic contents, and resuspension did not alter their permeabilized character. By supplementing the medium with CaCl2, thereby obtaining free Ca2+ concentrations of 1.5 X 10(-7) M to 10(-4) M, it was possible to stimulate lysozyme secretion from washed or unwashed permeabilized neutrophils. A total of 20 to 30% of the total cellular lysozyme was released during an incubation of 5 min at 37 degrees C. Secretion was inversely related to cell concentration. No beta-glucuronidase was secreted under these conditions and no response was obtained by using unpermeabilized cells. Thus, permeabilized neutrophils respond to increases in free Ca2+ alone, without resorting to conventional secretagogues. This system also permits the manipulation of intracellular constituents important for stimulus-response coupling.
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PMID:Micromolar concentrations of free calcium provoke secretion of lysozyme from human neutrophils permeabilized with saponin. 396 35


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