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)

Recent studies by DNA-DNA hybridization revealed that strains now designated as L. acidophilus, can be divided into several groups and only one group should be classified as L. acidophilus. We studied several phenotypic characteristics in representative strains from the six DNA-homology groups of L. acidophilus. No group specific pattern was observed among the strains for fermentation of eight carbohydrates, growth at 15 and 45 degrees C, resistance to 0.2% oxgall, lysis by lysozyme or sensitivity to 17 antibiotics. However, some differences among groups were observed in beta-galactosidase (beta-gal) activity and surface layer (s-layer) protein. Strains in B1 do not have a s-layer or beta-gal while B2 strains also lack a s-layer but do possess beta-gal. All strains in groups A1, A2, A3 and A4, capable of growing in lactose, have beta-gal activity and also have a s-layer composed of protein subunits of different molecular weights (MW). Strains in A1 homology group have a s-layer with 46 Kd protein subunits while strains in other A groups have s-layer protein subunits that varied in MW within each group. On the basis of these two traits several isolates of unknown homology groups have been tentatively placed in A1, B1 or B2 groups. L. acidophilus from A1 group showed strain variation in beta-gal specific activity and rate of acid production and growth. For use in dietary adjuncts, L. acidophilus strains should be selected for these three and other desirable traits. They should be maintained and grown in media containing lactose.
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PMID:Selection of Lactobacillus acidophilus strains for use in "acidophilus products". 311 4

The major whey proteins of the milks of the dolphin, manatee, and beagle were purified by gel filtration and ion exchange chromatography and characterized and identified by molecular weight determination, amino acid analysis, N-terminal sequencing, and activity measurements. The major whey protein components from all three species were found to be monomeric beta-lactoglobulins. These proteins were all active in binding retinol. Dolphin milk contained two beta-lactoglobulins (designated 1 and 2) which showed a slight difference in molecular weight and considerably divergent N-terminal sequences, whereas the other milks only contained a single form of beta-lactoglobulin. alpha-Lactalbumins were purified from dolphin and dog milks and were active in promoting lactose synthesis by bovine galactosyltransferase. The dolphin protein had an N-terminal sequence more similar to ruminant alpha-lactalbumins than to those known from other species. Although alpha-lactalbumin activity has been detected in manatee milk at low levels, the corresponding protein was not isolated. In addition, dog milk was found to contain high levels of lysozyme (greater than 1.0 mg/ml), which were identified by activity and sequencing. The functional and evolutionary implications of these results are discussed.
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PMID:Purification and characterization of the major whey proteins from the milks of the bottlenose dolphin (Tursiops truncatus), the Florida manatee (Trichechus manatus latirostris), and the beagle (Canis familiaris). 370 36

In food toxinfections caused by various microorganisms (Staphylococcus, Escherichia, Klebsiella, Proteus, Citrobacter, etc.) a decrease of lysozyme debit and an increase of pH of gastric juice were found. One third of patients exhibited lactose deficiency of the small intestine. Treatment with furazolidone contributed to the development of lactase deficit and delayed stools normalization. Crystalline lysozyme shortened duration of febrile reaction and diarrhea, its intake facilitated lactose hydrolysis.
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PMID:[Clinico-pathogenetic basis for using crystalline lysozyme in the combined therapy of food toxinfections]. 381 53

Major outer membrane antigens, proteins, and lipopolysaccharides (LPSs), from nontypable Haemophilus influenzae were characterized and examined as targets for complement-dependent human bactericidal antibodies. Outer membranes from two nontypable H. influenzae isolates that caused otitis media and pneumonia (middle ear and transtracheal aspirates) were prepared by shearing organisms in EDTA. These membranes were compared with membranes prepared independently by spheroplasting and lysozyme treatment of whole cells and found to have: similar sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of the proteins; identical densities (rho = 1.22 g/cm3); and minimal d-lactose dehydrogenase activity indicating purity from cytoplasmic membranes. Outer membranes were solubilized in an LPS-disaggregating buffer and proteins were separated from LPS by molecular sieve chromatography. The SDS-PAGE patterns of outer membrane proteins (OMPs) from the two strains differed in the major band although other prominent bands appeared similar in molecular weight. LPS prepared by hot phenol water extraction of each of the strains contained 45% (pneumonia isolate) and 60% (otitis isolate) lipid (wt/wt), 49% and 50% carbohydrate (wt/wt), respectively, and less than 1%, 3-deoxy-manno octulosonic acid. Immunoglobulin M (IgM) purified from normal human serum (NHS) plus complement was bactericidal for both strains. Purified immunoglobulin G (IgG) from NHS killed the middle ear isolate and immune convalescent IgM from the serum of the patient with pneumonia killed his isolate. NHS or convalescent serum were absorbed with OMPs and LPS (0.6-110 micrograms) from each of the strains and immune specific inhibition of bactericidal antibody activity by each antigen was determined. OMPs from the pulmonary isolate inhibited bactericidal antibody activity directed against the isolate in both NHS (1.5 microgram of antigen) and immune serum (0.75 microgram of antigen). OMPs (60 micrograms) from the ear isolate also inhibited bactericidal activity in the respective immune serum. LPSs exhibited minimal inhibition (greater than 110 micrograms). Three human sera (two normal, one immune) were selectively depleted of 80% of antibody activity against OMPs (measured by enzyme-linked immunosorbent assay) by affinity chromatography using OMPs from the pulmonary isolate coupled to a solid phase. These OMP antibody-depleted sera also showed an 88% reduction of bactericidal activity against this strain. Immunopurified antibody against OMPs eluted from the solid phase was bactericidal.
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PMID:Characterization of antigens from nontypable Haemophilus influenzae recognized by human bactericidal antibodies. Role of Haemophilus outer membrane proteins. 387 75

The effects of Mg2+ and Ca2+ ions on the efficiency of the plasmid transformation of lysozyme-treated Streptococcus lactis protoplasts were compared. A 33-megadalton plasmid, pLP712, coding for lactose fermentation and a 6.5-megadalton plasmid, pGB301, coding for erythromycin and chloramphenicol resistance were used as model plasmids, and S. lactis MG1614 was the recipient. Replacing Mg2+ with Ca2+ in the transformation buffer was found to increase transformant frequency more than 10-fold with both plasmids.
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PMID:Effect of Ca2+ ions on plasmid transformation of Streptococcus lactis protoplasts. 393 17

Mastitis was found to be a sizeable clinical problem in a group of lactating Gambian mothers. The mean monthly incidence was 2.6% and repeated episodes of mastitis were common. The role of milk antimicrobial factors in the local defence of the breast against mastitis was investigated by analysis of IgA, IgG, IgM, C3, C4, lactoferrin and lysozyme in the breast milk of 10 mastitis patients. Acute inflammation of the breast was accompanied by the rapid appearance of high concentrations of serum-derived immunoproteins in mastitic milk. Changes in the milk levels of lactose, sodium and transferrin indicated that this was due to a temporary opening of the paracellular pathway. Concentrations of secretory immunoproteins (IgA, lactoferrin and lysozyme) exhibited a delayed response, being elevated one week after the attack of mastitis. The normal milk of mastitis sufferers was significantly deficient in IgA, C3 and lactoferrin when compared with other lactating women suggesting that the former were predisposed to mastitis.
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PMID:Mastitis in rural Gambian mothers and the protection of the breast by milk antimicrobial factors. 403 82

The deoxyribonucleic acid (DNA) of Streptococcus lactis C2, S. cremoris B(1), and S. diacetilactis 18-16 was labeled by growing cells in Trypticase soy broth containing (3)H-labeled thymine. The cells were gently lysed with lysozyme, ethylenediaminetetraacetic acid, and sodium lauryl sulfate. The chromosomal DNA was separated from plasmid DNA by precipitation with 1.0 M sodium chloride. The existence of covalently closed circular DNA in the three organisms was shown by cesium chloride-ethidium bromide equilibrium density gradient centrifugation of the cleared lysate material. In an attempt to correlate the loss of lactose metabolism with the loss of plasmid DNA, lactose-negative mutants of these organisms were examined for the presence of extrachromosomal particles. Covalently closed circular DNA was detected in the lactose-negative mutants of S. lactis C2 and S. diacetilactis 18-16. In S. cremoris B(1), however, no covalently closed circular DNA was observed by using cesium chloride-ethidium bromide gradients. Electron micrographs of the satellite band material from S. lactis C2 and its lactose-negative mutant confirmed the presence of plasmid DNA. Three distinct plasmids having approximate molecular weights of 1.3 x 10(6), 2.1 x 10(6), and 5.1 x 10(6) were observed in both organisms.
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PMID:Extrachromosomal elements in group N streptococci. 420 91

A mutant of Escherichia coli has been found to have an increased sensitivity to actinomycin D and to sodium deoxycholate and an unusual morphology which accompanies an abnormality in cellular division. All of these characteristics are suppressed when the strain is grown in the presence of d-alanine. This strain, called MAD-1, for murein altered division mutant, exhibits its pleiotropic phenotype only when certain carbon compounds are used as energy sources in minimal medium. Nonpermissive carbon sources, which elicit the disturbed phenotype, include glucose, mannitol, fructose, maltose, and lactose; permissive carbon sources include galactose, glycerol, lactate, and succinate. The mutant is able to transport nonpermissive carbon compounds; 3 mM 3',5'-cyclic adenosine monophosphate included in the medium does not alter the phenotype seen with growth on glucose. Deoxyribonucleic acid and protein synthesis are normal with respect to cellular mass increase. d-Alanine specifically suppresses the pleiotropic phenotype at a concentration six times lower than l-alanine, the only other compound found to be effective. There is no abnormality in the K(m) or V(max) of l-alanine racemase or d-alanine-d-alanine synthetase of MAD-1 compared to its parent, CR34. MAD-1 is more susceptible to growth inhibition by penicillin or cycloserine than its parent, and is exquisitely sensitive to lysis in the presence of sodium deoxycholate or lysozyme. When cell wall biosynthesis is inhibited, MAD-1 lyses much more rapidly than CR34, even after it has been phenotypically suppressed by growth on d-alanine. The incorporation of l-alanine and diaminopimelic acid into the peptidoglycan of the mutant and wild type is identical; d-alanine is incorporated 1.5 times more rapidly into MAD-1 cells grown under nonpermissive conditions. The peptidoglycan fragments seen after digestion with lysozyme were similar for MAD-1 and the wild type. The results are interpreted as being compatible with an increased autolytic rate in MAD-1, caused either by an increase in the quantity or activity of an autolysin, or by an abnormal cell wall which is especially susceptible to autolysis, but which was not detected by analysis of peptidoglycan fragments.
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PMID:Relationship between permeability, cell division, and murein metabolism in a mutant of Escherichia coli. 426 3

A procedure has been devised to isolate mutants of Bacillus subtilis with structurally defective membranes. The procedure used to screen for the mutants involved comparison of the stability of protoplasts of the mutant with those of the wild type in a medium of sufficient osmotic strength to stabilize wild-type protoplasts. Mutagenized cells were grown as clones on agar plates, and then replicated onto plates containing 0.5 m lactose, which is sufficient to stabilize wild-type protoplasts. The colonies on the lactose-containing plates were then treated with lysozyme to convert the cells to protoplasts. Colonies of wild-type protoplasts remained opaque; however, colonies of mutant protoplasts lysed and became clear. Twenty-nine osmotically fragile mutants were isolated in this manner; the membranes of several mutants were found to contain alterations in the composition of their proteins or lipids.
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PMID:Procedure for the isolation of mutants of Bacillus subtilis with defective cytoplasmic membranes. 463 25

The sensitivity to sodium lauryl sulfate (SLS) of Shigella flexneri and Escherichia coli is determined by at least three genes. One site is located near the lactose operon, and two loci are cotransducible with the arabinose operon. Calcium ions protect against SLS lysis. One gene is concerned with the relative ability of the bacterium to retain calcium against such chelating agents as ethylenediaminetetraacetic acid or phosphate buffer. This was first observed in a mutation from virulence to avirulence in S. flexneri with a concomitant loss of ability to penetrate the intestinal epithelium. The avirulent strain is far less sensitive to lysis by SLS in the presence of phosphate buffer than its virulent parent. The avirulent strain is also less sensitive to lysozyme and ethylenediaminetetraacetic acid. E. coli K-12 is much more sensitive to SLS than both of these Shigella strains. An E. coli-S. flexneri hybrid, which is unable to survive well in the gut and thus only produces an abortive infection, has inherited this extreme sensitivity to SLS.
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PMID:Mechanisms and genetics of resistance to sodium lauryl sulfate in strains of Shigella and Escherichia coli. 500 97


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