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)

Avidity indices of antibody to hen egg-white lysozyme (HEWL) were measured by chaotropic ion (SCN-) elution enzyme-linked immunosorbent assay (ELISA) in pigs grouped as high, control or low for various immune and innate resistance-related traits. The avidity index was the molar concentration of SCN- required to reduce by 50% the ELISA optical density value for a given serum. The index was independent of the amount of antibody. Eight- to ten-week-old Yorkshire pigs were immunized with HEWL and serum antibody measured by ELISA as one of five traits used to assign them to high, low or control response groups. Serum antibody avidity for HEWL was evaluated on Day 14 and Day 30 after primary (Day 0) and secondary (Day 14) immunization. The effects of response group, gender, litter, serum IgG concentration and anti-HEWL antibody on avidity were determined using a linear model. Antibody avidity indices varied amongst individuals. Mean avidity indices for sera collected on Days 14 and 30 were 0.61 +/- 0.43 and 1.22 +/- 0.56, with maximum indices of 2.64 and 2.86 respectively. Avidity of secondary response antibody was significantly higher (P less than or equal to 0.05). Pigs of the high response group had significantly higher secondary antibody avidity than those of the control (P less than or equal to 0.08) and low groups (P less than or equal to 0.01). Avidity index was positively correlated with antibody to HEWL on Days 14 and 30 but not to preimmunization serum IgG concentration or to other measured traits.
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PMID:Antibody avidity in Yorkshire pigs of high and low immune response groups. 158 53

Effects of human lysozyme (HLZ) combined with thiocyanate (SCN-) ions on mutans streptococci, both in physiologic salivary concentrations, were studied. The bacteria were incubated for 75 min either in HLZ-supplemented sterilized human whole saliva (pH 5 and 7) or in neutral buffer in the presence or absence of HLZ (30 mg/l)-SCN- (1-5 mM) combinations. HLZ had no inhibitory effect on the viability of Streptococcus mutans, serotype c, either in saliva or in buffer, not even at pH 5, in the presence of salivary bicarbonate or in higher (up to 240 mg/l) concentrations of HLZ. In contrast, HLZ significantly decreased the viability of S. rattus in both media. HLZ also effectively blocked the lactic acid production of S. rattus but not that of S. mutans. Thiocyanate ions, which have been proposed to enhance the antimicrobial activity of lysozyme, did not affect the antibacterial activity of HLZ or HLZ-HCO3- combinations. It is concluded that the in vivo levels of SCN- ions, which constitute an integral part of the peroxidase antimicrobial system in saliva, may not be high enough to trigger the lysis of S. mutans by lysozyme in human saliva. The very low prevalence of S. rattus compared with S. mutans in human populations may be associated with their different susceptibility to lysozyme-mediated inhibition in saliva.
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PMID:Effects of lysozyme-thiocyanate combinations on the viability and lactic acid production of Streptococcus mutans and Streptococcus rattus. 188 53

The effects of timolol maleate on the secretion and composition of human saliva were studied in vivo. Eight healthy volunteers received orally 10 mg timolol maleate. Stimulated parotid saliva samples, resting whole saliva samples, and blood samples were collected immediately before and four times after the drug intake at intervals of 1 h. The levels of total protein, lysozyme, IgA, IgG and IgM, salivary peroxidase, myeloperoxidase, lactoferrin, amylase, thiocyanate (SCN-), and hypothiocyanite (OSCN-) were analyzed from saliva samples. Drug levels were measured both from parotid saliva and blood samples. Results were compared to the analyses of the samples collected in a similar way but without administration of any drugs. Decreased levels of total protein, lactoferrin, amylase, and salivary peroxidase were observed in parotid saliva after a single oral dose of timolol maleate. No such decrease was found in lysozyme, myeloperoxidase, SCN-, OSCN-, or immunoglobulins. Salivary flow rate was not significantly changed after drug intake. The results suggest that the beta-blocking drug may cause qualitative changes in the composition of saliva by inhibiting the synthesis and/or release of acinar proteins.
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PMID:Effects of a beta-blocking agent, timolol maleate, on saliva in healthy volunteers. 245 Dec 71

Crystallization conditions for hen egg white lysozyme in the presence of various ions were determined at pH 4.5 and 18 degrees C. The corresponding solubility curves show that the main effects are due to anions in the following order: SCN- greater than NO3- greater than Cl- greater than citrate2- greater than CH3COO- approximately H2PO4- greater than SO4(2-). This is in the reverse order of the lyotropic series of Hofmeister. As a consequence, SCN- precipitates and crystallizes lysozyme at low concentration, whereas sulfate is ineffective even at high concentrations. Crystals obtained with each salt were characterized by x-ray diffraction. Lysozyme thiocyanate and nitrate crystals belong to the monoclinic system, whereas all the others have a tetragonal lattice.
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PMID:Relative effectiveness of various ions on the solubility and crystal growth of lysozyme. 291 Aug 63

Veillonella alcalescens subsp. dispar was grown in a synthetic medium containing either radiolabeled thymidine or uridine to monitor cell lysis by assay of the release of deoxyribonucleic acid or ribonucleic acid (RNA), respectively. Biochemical analyses demonstrated that, although human or hen egg white lysozymes alone did not release deoxyribonucleic acid or RNA, the nucleic acids were liberated in equal amounts from lysozyme-treated cells by the addition of low concentrations of the sodium salts of HCO-3, SCN-, Cl-, and F-, RNA release was dependent on enzyme and anion concentration. Human lysozyme was more potent than hen egg white lysozyme, and bicarbonate was the most effective anion in promoting bacteriolysis. Surprisingly, ultrastructural analyses differed from biochemical results. Lysozyme alone caused lysis in approximately 40% of the cell population. Detailed ultrastructural examination revealed aggregated cytoplasmic components which appeared as small clumps, explaining why nucleic acids were not measurable in the biochemical assays. In reaction mixtures containing lysozyme plus inorganic salts, electron microscopy results were compatible with biochemical data. Ultrastructural studies demonstrated that the addition of inorganic salts to lysozyme-treated cells resulted in the solubilization of the protoplasmic aggregates of lysed cells, presumably freeing the complexed RNA, and in the rapid lysis of the remaining cells (approximately 60%). These data suggest that electron microscopy must be used in conjunction with biochemical assays to assess lytic damage of bacterial cells.
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PMID:Bacteriolysis of Veillonella alcalescens by lysozyme and inorganic anions present in saliva. 616 67

All of the common cytochalasins activate superoxide anion release and exocytosis of beta-N-acetylglucosaminidase and lysozyme from guinea-pig polymorphonuclear leukocytes (neutrophils) incubated in a buffered sucrose medium. Half-maximal activation of both processes is produced by approx. 0.2 microM cytochalasin A, C greater than 2 microM cytochalasin B greater than or equal to 4-5 microM cytochalasin D, E. While maximal rates of O2- release and extents of exocytosis require extracellular calcium (1-2 mM), replacing sucrose with monovalent cation chlorides is inhibitory to neutrophil activation by cytochalasins. Na+, K+ or choline inhibit either cytochalasin B- or E-stimulated O2- production with IC50 values of 5-10 mM and inhibition occurs whether Cl-, NO3- or SCN- is the anion added with Na+ or K+. Release of beta-N-acetylglucosaminidase in control or cytochalasin B-stimulated cells is inhibited by NaCl(IC50 approximately 10 mM), while cytochalasin E-stimulated exocytosis is reduced less and K+ or choline chloride are ineffective in inhibiting either cytochalasin B- or E-stimulated exocytosis. Release of beta-glucuronidase, myeloperoxidase or acid phosphatase from neutrophils incubated in buffered sucrose is not stimulated by cytochalasin B. Stimulation of either O2- or beta-N-acetylglucosaminidase release by low concentrations of cytochalasin A is followed by inhibition of each at higher concentrations. It appears that all cytochalasins can activate both NAD(P)H oxidase and selective degranulation of neutrophils incubated in salt-restricted media and that differential inhibition of these two processes by monovalent cations and/or anions is produced at some step(s) subsequent to cytochalasin interaction with the cell.
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PMID:Activation of superoxide production and differential exocytosis in polymorphonuclear leukocytes by cytochalasins A, B, C, D and E. Effects of various ions. 627 16

Streptococcus mutans GS5 was grown in synthetic medium containing radioactive thymidine to monitor deoxyribonucleic acid release. At neutral pH, cell lysis of hen egg-white lysozyme- or lysozyme-protease-treated cells was dependent upon the nature and concentration of the additive inorganic anions, HCO-3, SCN-, Cl- or F-. At acidic pH, NaHCO3, but not NaSCN, NaCl or NaF, was effective in promoting cell lysis which was due not only to the change in pH but also to the new HCO-3 anion concentration at the new pH. In both pH 4 and 5.2 reaction mixtures, the lysozyme and trypsin acted synergistically with NaHCO3 and the amount of lysis produced was markedly greater than in reaction mixtures containing lysozyme and bicarbonate but no protease. At apparent sub-lytic concentrations of NaHCO3, lysis was achieved by adding an appropriate concentration of one of NaSCN, NaCl or NaF to the lysozyme-protease-damaged cells. Thiocyanate proved to be most effective among the anions requiring lower concentrations to elicit lysis compared to chloride or fluoride for a fixed sub-lytic concentration of bicarbonate. As the NaHCO3 concentration increased, the lysis in the presence of these other anions increased until maximum levels of released deoxyribonucleic acid (DNA) were attained. In addition, the higher the NaHCO3 concentration, the more marked was the change in the degree of cell lysis. At a selected concentration at which NaHCO3 was not effective with any one salt, lysis could be achieved by combining all four inorganic anions at this concentration. The results suggest that the various anions present in oral fluids may together be sufficient to trigger lysis of oral microorganisms.
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PMID:Synergism of lysozyme, proteases and inorganic monovalent anions in the bacteriolysis of oral Streptococcus mutans GS5. 631 51

The aim of this work was to study the influence of bacterial cell concentrations and inorganic anions on lysis of Streptococcus mutans BHT by human salivary lysozyme (HSL). HSL was partly purified from saliva by ion exchange chromatography. The bacteria were grown in a synthetic medium containing 3H-thymidine to monitor DNA release. The experiments demonstrated that release of 3H-thymidine was dependent on the bacterial cell concentration and an apparent Km-value corresponding to approximately 2.9 X 10(8) cells/ml was calculated. The influence of I-, Br-, Cl-, F-, HCO3- and SCN- on bacteriolysis was studied. All anions tested were slightly inhibitory on the action of HSL. The inhibition varied from 7 to 76% depending on the ion and ionic strength. The order of addition of HSL and sodium chloride caused different lytic responses. This was reflected by the amount of HSL adsorbed by the bacteria.
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PMID:Influence of bacterial cell concentration and inorganic anions on lysis of Streptococcus mutans BHT by salivary lysozyme. 659 37

Streptococcus mutans BHT was grown in a synthetic medium containing radioactive thymidine to monitor deoxyribonucleic acid release. Kinetic experiments demonstrated that although lysozyme alone could not liberate deoxyribonucleic acid, cellular deoxyribonucleic acid was liberated from lysozyme-treated cells by addition of low concentrations of inorganic sodium salts. When the salts were tested for their ability to dislodge cell-bound tritiated lysozyme, the extent of the initial release of enzyme by individual anions correlated with the anion potency for deoxyribonucleic acid liberation (SCN- greater than ClO4- greater than I- greater than Br- greater than NO3- greater than Cl- greater than F-), although the total amount of lysozyme dislodged did not correspond directly with cell lysis. Differences in the effectiveness of anions (SCN-, HCO3-, Cl- and F-) in potentiating cell lysis could be enhanced or minimized by varying the lysozyme, anion, and bacterial cell concentrations. As the anion concentration was increased for each enzyme concentration and cell concentration, the lysis increased, in some cases markedly, until maximum levels of released deoxyribonucleic acid were attained. The maximum levels of lysis of SCN- and HCO3- were similar and were greater than those for Cl- and F-. In addition, the maximum levels were observed to increase for each of the anions as the concentration of lysozyme increased.
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PMID:Lysis of Streptococcus mutans by hen egg white lysozyme and inorganic sodium salts. 721 17

Samples of whole saliva and dental plaque were collected from initially 10-year old subjects who participated in a 40-month cohort study investigating the effect of chewing gum usage on caries rates. The subjects represented nine cohorts of which one did not receive gum, while in eight cohorts the subjects received gum containing either xylitol, sorbitol, their mixtures, or sucrose as bulk sweeteners, the maximum sweetener consumption in the form of gums being up to 10.7 g/day, used in 3-5 daily chewing episodes. Gum usage had no significant effect on the levels of salivary protein, IgA, alpha-amylase, peroxidase, lysozyme, SCN and buffer capacity. At the endpoint, the group that received 100% xylitol pellet-shaped gum five times/day, had significantly lower levels of sucrase (p <0.05) and free sialic acid (p < 0.001) in whole saliva than at baseline. This group showed significantly (p <0.05) smaller plaque index scores at two cross-sectional measurements, and exhibited the lowest log(10) counts of salivary lactobacilli at endpoint than most other groups. The salivary levels of peptidase(s) (oligopeptidase B-like enzymes) hydrolyzing N-alpha-benzoyl-DL-arginyl-p-nitroaniline were significantly (p<0.05) or almost significantly lower in groups which received 100% xylitol pellet gums. All groups exhibited obviously an aging-related increase of salivary mutans streptococcus scores, except the above xylitol group in which the mean scores did not change.
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PMID:Properties of whole saliva and dental plaque in relation to 40-month consumption of chewing gums containing xylitol, sorbitol of sucrose. 886 27


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