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)

S-mercuric-N-dansylcysteine was investigated as a potential probe of protein sulphydryl groups using bovine serum albumin, S-carboxymethyl-bovine serum albumin, lysozyme, and partially reduced lysozyme as test proteins. Criteria used to assess covalent binding through mercury-bridged mercaptide linkages include a finite reaction time (minutes to hours), abolition of the characteristic fluorescence spectrum following addition of a reducing agent, and failure to separate probe and protein after chromatography or electrophoresis. By these criteria, both Torpedo californica acetylcholinesterase and human serum cholinesterase (butyrylcholinesterase) contain four free sulphydryl groups per tetrameric enzyme molecule whereas Electrophorus electricus acetylcholinesterase has none. Labeled acetylcholinesterase and butyrylcholinesterase remain active and responsive to the inactivator Zn2+. Zn2+ promotes an increase in the fluorescence of bound S-mercuric-N-dansylcysteine, whereas activators such as Mg2+ or gallamine promote a decrease, suggesting that the label may be a useful probe of ligand-induced conformational changes. With T. californica acetylcholinesterase, but not with human serum cholinesterase, Zn2+ also promotes access to two additional groups that are reactive towards the sulphydryl reagent.
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PMID:The reaction of S-mercuric-N-dansylcysteine with acetylcholinesterase and butyrylcholinesterase. 278 87

Some human urine is bactericidal for the F-62 strain of Neisseria gonorrhoeae. Gonococci of three auxotypes (Pro-; Arg-, Hyx-, Ura-; and Pro-, Arg-. (Orn*), Ura-) were tested by in-vitro exposure to 31 samples of urine from 14 men. Nineteen of the urine specimens were bactericidal, and 12 were not. Except for one sample, all cidal urines came from five men. Cidal activity was associated with acidic, concentrated urines; it was unaffected by exposure to lowered pH, pronase, heat or cold, and was dialyzable with use of a dialysis membrane with a cut-off molecular weight of 1000. Neutralization of the acid urines removed the antigonococcal activity. Noncidal acid urines became cidal urines when concentrated by lyophilization. Zinc, lysozyme, fluoride ions, and fatty acids are substances that have antibacterial activity and are also present in urine. These substances were examined for antigonococcal activity. Neither zinc salts, fluoride ions, lysozyme, nor fatty acids in concentrations exceeding those found in urine were bactericidal for the gonococci. These results show that sufficiently concentrated, acidic urines kill gonococci by an unknown mechanism.
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PMID:Bactericidal properties of urine for Neisseria gonorrhoeae. 312 16

Monomeric zinc tetrasulphophthalocyanine in aqueous buffer is an effective sensitizer for the photo-oxidation of amino acids and nucleic acid bases and for the photodynamic inactivation of the enzyme, lysozyme; these reactions appear to be mediated by singlet oxygen.
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PMID:Zinc tetrasulphophthalocyanine as a photodynamic sensitizer for biomolecules. 348 23

The group B Streptococcus is one of the most virulent organisms causing perinatal infection. Human amniotic fluid from the second and third trimesters was pooled and analyzed for electrolytes, protein, albumin, zinc, inorganic phosphorus, ferritin, lysozyme, and immunoglobulins. We inoculated replicates of specimens with known virulent strains of group B streptococci (893, 891, and 878) and Escherichia coli (C5) with Todd-Hewitt broth and normal saline solution used as controls. Group B streptococci strains 893 and 891 proliferated rapidly at rates similar to their rates in Todd-Hewitt Broth. Strain 878 grew at a rate slower than that of strains 893 and 891. The amniotic fluid specimens were similar with respect to factors reported as inhibitory to bacterial proliferation. Second- and third-trimester amniotic fluid supports the growth of group B streptococci as well as a culture medium optimized for bacterial growth. Strain-specific variance in group B streptococci growth rates in amniotic fluid may have clinical significance for those at risk for group B streptococci infection.
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PMID:Proliferation of group B streptococci in human amniotic fluid in vitro. 354 26

Aggregation of bacteria by zinc and lysozyme was studied and compared with aggregation induced by a high-molecular-weight salivary agglutinin. Each ligand was found to exhibit a unique profile of properties when examined by both a microradiochemical centrifugation assay and a turbidimetric assay. Significant differences in rate of aggregation and bacterial species specificity were noted. Zinc- and lysozyme-mediated aggregations were shown to be calcium independent and to proceed rapidly at 0 degree C, in contrast to the salivary agglutinin. Zinc produced large, asymmetric aggregates, saliva produced intermediate-sized aggregates, and lysozyme produced the smallest aggregates. These size differences are consistent with many of the observed reaction properties.
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PMID:A comparison of bacterial aggregation induced by saliva, lysozyme, and zinc. 398 83

The particulate hydrogenase of Vibrio succinogenes is solubilized during treatment of cell envelopes at pH 11.0. Alkali-solubilized enzyme requires sulfhydryl compounds for activity. At neutral pH, soluble enzyme is reincorporated into alkalitreated cell envelopes and no longer requires an additional activator. In the present study, cell envelopes prepared by lysing cells with ethylenediaminetetraacetic acid plus lysozyme (EDTA-lysozyme) were used to determine the chemical composition of cell envelopes and derived pH 11.0 soluble and insoluble fractions and to investigate some properties of the binding and activation of alkali-solubilized hydrogenase. Lysis with EDTA-lysozyme resulted in the formation of spheroplast ghosts. The derived cell envelopes contained 61% protein, 3% ash, 23% lipid, and 1% phosphorus. The alkali-treated cell envelopes contained 50% protein, 2% ash, 24% lipid, and 1% phosphorus. The ash from cell envelopes and alkali-treated cell envelopes was rich in iron and phosphorus and also contained calcium, copper, magnesium, sodium, and zinc. Virtually all of the weight of the ashed samples was accounted for by the oxides of these metals. Since the reconstitution of particulate hydrogenase was achieved with pH 11.0 supernatant solution and precipitate, intact mucopeptide is not essential for hydrogenase binding. Release of hydrogenase during EDTA-lysozyme lysis was found to depend upon an apparent structural change which occurs in the membranes during extended storage at -20 C.
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PMID:Chemical constituents and hydrogenase binding in cell envelopes of Vibrio succinogenes. 497 63

The antimicrobial factors in amniotic fluid (AF) were analyzed in 81 women during various periods of gestation. The AF inhibited the growth of E. coli 026 when the phosphate/zinc ratio was less than 200 or iron less than or equal to 1.2 microgram/ml and unbound transferrin was greater than 40%. A heat-stable non-lysozymal phosphate insensitive cationic protein with molecular weight higher than transferrin was also found in inhibitory AF. The antimicrobial properties of AF did not correlate with absolute zinc or lysozyme levels. The AF was non-inhibitory when it contained greater than 60 +/- 5 micrograms/ml of phosphate with phosphate/zinc ratio greater than 200, iron greater than 1.2 microgram/ml and unbound transferrin was less than 40%. Amongst all criteria described, iron (P = 0.002) and unbound transferrin levels (P = 0.0005) were the most reliable and consistent all through pregnancy but others were highly reliable only during the 36th-40th week of gestation. The clinical application of these factors are being investigated.
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PMID:Amniotic fluid analysis for antimicrobial factors. 612 10

The portal of entry for most pathogens is at the mucosal surface, and mucosal defences afford the host the earliest opportunity to ward off infection. The vagina is exposed to considerable trauma, and harbours a complex microflora, but only a small number of microorganisms are associated with disease. It seems likely that mucosal defenses are important in this process. Mucosal secretions contain mucus, lysozyme, lactoferrin, zinc, fibronectin, and complement, all of which afford non-specific protection. In addition, secretory immunoglobulin A (IgA) concentration in these secretions increases in response to specific pathogens. Blood leukocytes migrate onto mucosal surfaces during infection with some microorganisms, and the interaction between phagocytic cells and genital pathogens has been the focus of intense investigation. Improved understanding of mucosal defences is crucial for prevention of infection.
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PMID:Host defences and the vaginal mucosa. A re-evaluation. 639 5

Lysates of induced E. coli (lambda) lysogens contain two enzymes acting on murein: endopeptidase and murein transglycosylase. The transglycosylase was separated from the endopeptidase and purified to homogeneity. Its bacteriolytic activity was 200-fold higher than of hen egg lysozyme. The bacteriolytic activity of the lysate depends on the presence of the enzyme. The endopeptidase alone not lyse the cells, but it enhances the extent of lysis. The properties of the transglycosylase (molecular weight 17 500, pH optimum at 6.6, inactivation by Zn2+), show that it is entirely different from the bacterial enzyme of the same specificity described by others. Data are presented, which suggest that this enzyme is the phage lambda R-gene product.
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PMID:Murein transglycosylase from phage lambda lysate. Purification and properties. 644 76

Lysozyme levels were determined in the mucosa of gut in 80 children with chronic inflammatory bowel disease, malabsorption and acrodermatitis enteropathica.l Levels of lysozyme in the mucosa of colon were found to be significantly higher in cases with chronic inflammatory bowel disease, whereas in children with malabsorption (celiac disease) concentration of lysozyme in the mucosa of small intestine were significantly lower compared to a control group. In a 4 months old boy with acrodermatitis enteropathica there was a low level of lysozyme in the mucosa of the small intestine. After therapy with zinc for one year concentration of lysozyme was normalized.
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PMID:[Lysozyme concentrations in the intestinal mucosa in malabsorption syndromes and chronic inflammatory intestinal diseases]. 669 40


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