Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Strains of Escherichia coli can inhibit the in vitro growth of Neisseria gonorrhoeae. One E. coli strain released a potent agar-diffusible gonococcal growth inhibitor which was extracted and assayed in an agar well assay system. The culture conditions necessary to produce the inhibitor were determined. The inhibitor was bacteriostatic, in most cases, for N. gonorrhoeae. Based on ultrafiltration and column chromatography, the inhibitor appeared to have a molecular weight in the range of 1200 to 2000. Evidence that the molecule contained charged sites was obtained by membrane binding and column chromatography. The inhibitor was stable to extremes of heat, cold and pH. It was not volatile or susceptible to proteolytic enzymes, lysozyme, lipase, DNAase, RNAase or certain chelating agents. Its activity was completely blocked by ferric ammonium citrate. This inhibitor is dissimilar to previously reported gonococcal inhibitors of bacterial origin.
J Gen Microbiol 1979 Dec
PMID:Properties of a gonococcal inhibitor produced by Escherichia coli. 4 57

Under experimental conditions of genetic transformation, protamine and total histone were bactericidal for Bacillus subtilis cells. The abilities to cause lethality were very similar for both, either protamine or histone, with no antagonistic effects amongst these natural polycations. With both basic proteins acting simultaneously the enhancement was higher than a summation of the separate lethal effects. Sublethal concentration of protamine added at the beginning of transformation time, produced a strong inhibition of transforming efficiency. The same concentration added later than 10 min from the start of transformation had no inhibitory effect. These facts together with the absence of inhibition by simple pretreatment of DNA alone as well as the cell protection by protamine against lytic activity of lysozyme, suggest a protamine-cell surface interaction which impedes DNA uptake events.
Mol Gen Genet 1979 Mar 05
PMID:Lethal effect of protamine and histone on competent Bacillus subtilis cells. Inhibition of genetic transformation by protamine in sublethal concentration. 11 Oct 2

Bacillus cereus 569 is known to be resistant to lysis by lysozyme because of the presence of deacetylated glucosamine residues in its peptidoglycan, and cultures continued to grow even in the presence of lysozyme at 200 microgram ml-1. However, lysozyme caused rupture of the chains of bacteria and promoted the rate of autolysis in a non-growing cell suspension, causing a doubling of the rate of release of radioactively labelled wall material. Heat-inactivated cells did not autolyse and were not lysed by lysozyme unless they were supplemented by unheated cells or cell-free autolysate. Enhancement of autolysin activity could also be effected by pre-treatment of heated cells with lysozyme. The action of lysozyme on isolated cell walls released some free reducing groups, indicating limited breakage of the polysaccharide chains of peptidoglycan, and it was concluded that lysozyme modified the peptidoglycan and made it more susceptible to autolysin(s). Lysozyme also enhanced the rate of septum separation and the probable significance of the results in relation to the control of cell separation is discussed.
J Gen Microbiol 1979 Nov
PMID:Effects of lysozyme on Bacillus cereus 569: rupture of chains of bacteria and enhancement of sensitivity to autolysins. 11 28

Cell wall-deficient forms of Mycobacterium smegmatis were produced in growth medium containing D-cycloserine and horse serum. These cells were transformed into protoplasts with EDTA and lysozyme. Subsequent lysis by nucleases followed by osmotic shock produced membrane vesicles (whole cell ghosts).
J Gen Microbiol 1979 Dec
PMID:Preparation of protoplasts and whole cell ghosts from Mycobacterium smegmatis. 11 34

The DNA homology relationships of 25 micrococci (15 strains of Micrococcus, eight strains of Sarcina and two strains of Staphylococcus) were studied by the deoxyribonucleic acid hybridization method using nuclease S1, an endonuclease specific for single-stranded DNA molecules. Nineteen of the strains were classified into three groups. Group I contained Micrococcus lysodeikticus IAMI056, M. luteus IAMI1010, M. flavus IAMI2005 and IAMI2006, Sarcina flava IAMI2007 and IAMI1006. S. subflava IAMI2009, S. lutea ATCC381, and ATCC382, and M. luteus IAMI1006. Group II contained M. roseus IAMI315, ATCC412, ATCC185 and IAMI295. Group III contained S. lutea IAMI099, IFO3232 and ATCC383, M. varians ATCC399 and Staphylococcus lactis ATCC15306. Micrococcus luteus IAMI097, M. varians ATCC19099 and ATCC19100, M. conglomeratus IAMI459 and IAMI470, and St. aureus IAMI011 could not be assigned to any of the three groups. The grouping corresponds to that derived from the results of differential lysis by lysozyme, 'lytic enzyme 2' from Cytophaga sp., or Streptomyces albus G enzyme; and to types of peptidoglycan in the cell walls and genetic transformation. The usefulness of classification based on sensitivity to various lytic enzymes was demonstrated. Group I probably coincides with M. luteus of Bergey's Manual of Determinative Bacteriology (1974), and groups II and III with M. roseus and M. varians respectively.
J Gen Microbiol 1976 May
PMID:Classification of micrococci on the basis of deoxyribonucleic acid homology. 18 Feb 38

Spheroplasts of Providence alcalifaciens strain P29 auxotrophs were prepared by combined treatment with glycine and lysozyme-EDTA. About 15% of spheroplasts had areas of cytoplasmic membrane exposed where cell wall was absent. The spheroplasts of different auxotrophs were mixed pairwise and fusion was attempted with polyethylene glycol or nascent calcium phosphate. After spheroplasts had regenerated to bacterial forms selection was made for recombinants. Recombinants arose at frequencies of 3.8 X 10(-6) to 1.7 X 10(-7) per spheroplast initially present, by both methods of fusion. The frequency was strongly dependent on the number of chromosomal loci used in selection. The possible order of five loci was determined and this corresponded to that on the closely related Proteus mirabilis chromosome. Control experiments excluded possibilities of auxotrophic reversion, conjugation, transformation, transfection or transduction as explanations of the results. Analysis of prototrophic clones yielded stable prototrophs or mixtures of stable prototrophs and stable recombinants. Parental types were not encountered. Unselected markers segregated among recombinants. It was concluded that the formation of recombinant bacteria was due to spheroplast fusion and that only stable products of the very temporary heteroploid state were haploid recombinants. The low frequency of recombination was ascribed to the limited number of spheroplasts with areas of exposed cytoplasmic membrane.
J Gen Microbiol 1979 Oct
PMID:Genetic recombination in fused spheroplasts of Providence alcalifaciens. 29 58

Conditions for highly efficient genetic recombination in Streptomyces by protoplast fusion are described. Protoplasts of S. fradiae and S. griseofuscus were formed by a modification of the glycine-lysozyme-lytic enzyme method (Okanishi, Suzuki & Umezawa, 1974). Regeneration of cells from protoplasts was monitored throughout the growth cycle and was most efficient when cells of either S. fradiae or S. griseofuscus were taken from the transition phase between the exponential and stationary growth phases. Fusion of protoplasts carrying different auxotrophic or chromosomal drug-resistance markers was achieved by treatment with polyethylene glycol, and high frequencies of stable genetic recombinants were obtained.
J Gen Microbiol 1978 Jul
PMID:Genetic recombination in Streptomyces fradiae by protoplast fusion and cell regeneration. 73 Dec 5

Mutants of Escherichia coli K12, deficient in up to three major outer membrane proteins b, c and d have been constructed. Mutants that lack the lipopolysaccharide sugar heptose are deficient in protein b. All heptose-deficient strains are supersensitive to lysozyme, various antibiotics and detergents. They excrete the periplasmic enzyme ribonuclease I. Mutants deficient in proteins c and/or d have the same sensitivity towards these compounds as the parent strain. Cells of single, double and triple mutants are all rod-shaped. Electrophoretic analysis of cell envelope proteins indicates that in some mutants the protein deficiency is partially compensated for by increased amounts of one or two of the other major outer membrane proteins. Heptose-deficient strains have an increased amount of 2-keto-3-deoxyoctonate.
Mol Gen Genet 1976 Sep 23
PMID:Heptose-deficient mutants of Escherichia coli K12 deficient in up to three major outer membrane proteins. 78 63

The effect of chlorine on the germination, outgrowth, colony formation and structure of spores of Clostridium bifermentans, Bacillus subtilis var. niger and Bacillus cereus was examined. Chlorine decreased heat resistance and slowed or prevented germination and swelling, but spores that did swell were usualy able to elongate to form vegetative cells. Chlorine removed protein from spores, apparently from the coat, and allowed lysozyme to initiate germination. Treatment with other agents that remove spore-coat protein increased the lethal effect of chlorine by as much as 4000-fold, suggesting that coat protein protects spores against chlorine.
J Gen Microbiol 1975 Aug
PMID:The effect of chlorine on spores of Clostridium bifermentans, Bacillus subtilis and Bacillus cereus. 80 41

Variations in suppression efficiency were observed among nonsense mutations at different locations within the lysozyme gene (e) of T4 phage. The present experiments using three amber mutants in lysozyme gene indicate such variations presumably depend upon the base sequences neighboring to the nonsense mutations.
Mol Gen Genet 1976 Nov 24
PMID:Effect of neighboring nucleotide sequences on suppression efficiency in amber mutants of T4 phage lysozyme. 101 65


1 2 3 4 5 6 7 8 9 10 Next >>