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:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathogenesis of middle ear inflammation caused by Streptococcus pneumoniae was explored in the chinchilla model with different pneumococcal cell wall (CW) preparations, including isolated native CW, M1 muramidase CW (M1-CW) digest, amidase CW digest, and M1 peptidoglycan (M1-PG) digest. Inflammatory cell and lysozyme concentrations in middle ear fluid (MEF) were measured between 6 and 72 h after the middle ears were inoculated with one of the preparations or sterile saline. Middle ear histopathology was measured quantitatively at 72 h. Native CW, M1-CW digest, and amidase-CW digest caused significantly more inflammatory cell influx and lysozyme accumulation in MEF than saline did. M1-PG digest also caused more inflammatory cell influx and lysozyme accumulation in MEF than saline did but caused less inflammation than native CW or either CW digest. Epithelial metaplasia was significantly greater in ears inoculated with native CW than in ears inoculated with the CW or PG digest or with saline. Pneumococcal CW is, therefore, the principal factor that initiates middle ear inflammation in acute pneumococcal otitis media, and CW teichoication seems to be important in initiating this response.
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PMID:Role of the bacterial cell wall in middle ear inflammation caused by Streptococcus pneumoniae. 161 50

Hydrolysis of Staphylococcus aureus 209 P cell wall peptidoglycan was accompanied by the liberation of 1.3 mol of C-terminal and 1.2 mol of N-terminal glycine per mole of Glu as well as of 0.5 mol of N-terminal and 0.3 mol of C-terminal alanine. Gel chromatography on Sephadex G-25, ion-exchange chromatography on QAE-Sephadex A-50 and paper electrophoresis of S. aureus peptidoglycan hydrolysates gave seven homogeneous fractions; these fractions were structurally defined. Lysoamidase hydrolyzed bonds Mur-Ala, Gly-Gly and Mur-GlcN in the peptidoglycan molecule. Hydrolysis of glycan chains was accompanied by the formation of large fragments, (GlcN-Mur)9 and (GlcN-Mur)28. The lytic effect of lysoamidase on S. aureus peptidoglycan is coupled with bacteriolytic enzymes of lysoamidase: acetmuramyl amidase, glycyl--glycine endopeptidase and acetyl--muramidase.
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PMID:[Hydrolysis of a Staphylococcus aureus cell wall peptidoglycan by 209 P lysoamidase]. 208 20

The length distribution of the glycan strands in the murein (peptidoglycan) sacculus of Escherichia coli has been analyzed after solubilization of the murein by complete digestion with human serum amidase. The glycan strands released were separated according to length by reversed-phase HPLC on wide-pore Nucleosil 300 C18 material at 50 degrees C, employing a convex gradient from 5 to 11% acetonitrile. The length of the fractionated glycan strands, which carry a nonreducing 1,6-anhydromuramic acid as a natural end group, was calculated from the ratio of total to nonreducing terminal muramic acid residues. This was possible after complete hydrolysis of the isolated glycan strands by muramidase followed by separation of the released nonreducing and reducing di- and tetrasaccharides by reversed-phase HPLC on Hypersil C18. The method established allows the separation of the glycan strands of murein, a poly-GlcNAc(beta 1-4)MurNAc-polysaccharide, up to a degree of polymerization of approximately 60. The predominant lengths of the glycan strands were 5 to 10 GlcNAc(beta 1-4)MurNAc disaccharide units.
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PMID:Isolation and separation of the glycan strands from murein of Escherichia coli by reversed-phase high-performance liquid chromatography. 228 38

The nucleotide sequences of genes cpl7 and cpl9 of the Streptococcus pneumoniae bacteriophages Cp-7 and Cp-9, encoding the muramidases CPL-7 and CPL-9, respectively, have been determined. The N-terminal domains of CPL-7 and CPL-9 were virtually identical to that previously reported for the CPL-1 muramidase. The C-terminal domain of the CPL-7 muramidase, however, was different from those of the host amidase and the phage Cp-1 and Cp-9 lysozymes. Whereas all enzymes studied are characterized by repeated sequences at their C termini, the repeat-unit lengths are 20 amino acids (aa) in CPL-1, CPL-9 and in the host amidase, but 48 aa in CPL-7. Six repeated sequences represent the C-terminal domains of CPL-1, CPL-9 and the host amidase, and 2.8 perfect tandem repetitions that of CPL-7. The peculiar characteristics of the structure of CPL-7 muramidase correlate with its biochemical and biological properties. Whereas CPL-1, CPL-9 and the pneumococcal amidase strictly depend on the presence of choline-containing cell walls for activity, CPL-7 is able to degrade cell walls containing either choline or ethanolamine. These results support the previously postulated role for the C-terminal domain of these lytic enzymes in substrate recognition and provide further experimental evidence supporting the notion that the proteins have evolved by an exchange of modular units.
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PMID:Modular organization of the lytic enzymes of Streptococcus pneumoniae and its bacteriophages. 231 37

A 2.9-kilobase Acc I fragment of the DNA of the pneumococcal bacteriophage Cp-1, containing the cpl gene, hybridizes with the lytA gene encoding the pneumococcal amidase. The nucleotide sequence of the cpl gene of Cp-1, encoding a muramidase (CPL), has been determined. The 3' regions of the cpl and lytA coding sequences show considerable nucleotide sequence homology and the carboxyl-terminal domains of the deduced amino acid sequences of these lysins are quite similar: 73 of the carboxyl-terminal 142 amino acid residues are identical, and of the 69 substitutions, 55 are conservative. Comparisons between CPL, the pneumococcal amidase, and the muramidase of the fungus Chalaropsis sp. (an enzyme that also degrades the pneumococcal cell wall) strongly suggest that the carboxyl-terminal domains of CPL and of the amidase might be responsible for the specific recognition of choline-containing cell walls, as well as for the noncompetitive inhibition of the catalytic activity of these enzymes by the pneumococcal lipoteichoic acid or by high concentrations of choline. In addition, the active center of these enzymes should be located in their amino-terminal domains. Our results suggest an evolutionary relationship between phage and host lysins.
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PMID:Molecular evolution of lytic enzymes of Streptococcus pneumoniae and its bacteriophages. 342 70

Pep 5 and nisin are cationic bactericidal peptides which were shown to induce autolysis in Staphylococcus cohnii 22. In contrast to nisin, Pep 5 induced lysis could be stimulated in the presence of glucose. Addition of lipoteichoic acids (LTA) (D-alanine:phosphorus = 0.475:1) inhibited all effects of Pep 5 on susceptible cells in a molar ratio LTA:Pep 5 of 10:1. Treatment of S. cohnii 22 with Pep 5 or nisin for 20 min and subsequent washing with 2.5 M NaCl released autolysin activity. Crude preparations of the hydrolyzing enzymes produced free amino groups as well as polysaccharide fragments from the murein backbone, suggesting the presence of a muramidase or glucosamidase, and endopeptidase or amidase. Both enzyme activities were inhibited by lipoteichoic acid; they could be fully reactivated by addition of Pep 5 in sufficient concentrations. The velocity of hydrolysis was not influenced by nisin, whereas it was doubled in presence of Pep 5. The results are discussed in view of a possible mechanism of induction of lysis by Pep 5 and nisin.
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PMID:Induction of autolysis of staphylococci by the basic peptide antibiotics Pep 5 and nisin and their influence on the activity of autolytic enzymes. 400 48

Autolysin-defective pneumococci continue to synthesize both peptidoglycan and teichoic acid polymers (Fischer and Tomasz, J. Bacteriol. 157:507-513, 1984). Most of these peptidoglycan polymers are released into the surrounding medium, and a smaller portion becomes attached to the preexisting cell wall. We report here studies on the degree of cross-linking, teichoic acid substitution, and chemical composition of these peptidoglycan polymers and compare them with normal cell walls. peptidoglycan chains released from the penicillin-treated pneumococci contained no attached teichoic acids. The released peptidoglycan was hydrolyzed by M1 muramidase; over 90% of this material adsorbed to vancomycin-Sepharose and behaved like disaccharide-peptide monomers during chromatography, indicating that the released peptidoglycan contained un-cross-linked stem peptides, most of which carried the carboxy-terminal D-alanyl-D-alanine. The N-terminal residue of the released peptidoglycan was alanine, with only a minor contribution from lysine. In addition to the usual stem peptide components of pneumococcal cell walls (alanine, lysine, and glutamic acid), chemical analysis revealed the presence of significant amounts of serine, aspartate, and glycine and a high amount of alanine and glutamate as well. We suggest that these latter amino acids and the excess alanine and glutamate are present as interpeptide bridges. Heterogeneity of these was suggested by the observation that digestion of the released peptidoglycan with the pneumococcal murein hydrolase (amidase) produced peptides that were resolved by ion-exchange chromatography into two distinct peaks; the more highly mobile of these was enriched with glycine and aspartate. The peptidoglycan chains that became attached to the preexisting cell wall in the presence of penicillin contained fewer peptide cross-links and proportionally fewer attached teichoic acids than did their normal counterparts. The normal cell wall was heavily cross-linked, and the cross-linked peptides were distributed equally between the teichoic acid-linked and teichoic acid-free fragments.
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PMID:Peptidoglycan cross-linking and teichoic acid attachment in Streptococcus pneumoniae. 400 47

Cells of Bacillus thuringiensis containing refractile spores autolyzed readily when suspended in buffer. The autolysate contained enzymes which lysed vegetative cell walls of the organism. Three enzymes were isolated from the autolysate, and each was purified approximately 30-fold. One enzyme, most active near pH 4.0, was found to be an N-acetylmuramidase. The other two enzymes exhibited pH optima at 8.5. One was stimulated by cobalt ions and the other was not. The cobalt-stimulated enzyme was shown to be an N-acetylmuramyl-l-alanine amidase. The cobalt insensitive enzyme exhibited both N-acetylmuramyl-l-alanine amidase and endopeptidase activity. The amidase activity may reflect incomplete separation of the cobalt-stimulated enzyme. The endopeptidase cleaved the peptide bond between l-alanine d-glutamic acid. A cell wall lytic endopeptidase with this specificity has not been previously reported. All three enzymes were extremely limited in the range of bacterial cell walls which they attacked. Except for cell walls of Micrococcus lysodeikticus, which were lysed by the muramidase, only cell walls of members of the genus Bacillus were attacked.
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PMID:Isolation and characterization of three autolytic enzymes associated with sporulation of Bacillus thuringiensis var. thuringiensis. 573

beta-N-Acetylglucosaminidase has been purified from the walls of Bacillus subtilis 168 and compared with the other known autolysin, N-acetylmuramyl-L-alanine amidase (amidase). The beta-N-acetylglucosaminidase was a dimer in LiCl buffers with a sub-unit molecular weight of 90000 and a pH optimum of about 5.0. It was very sensitive to proteolytic enzymes and was critically activated by 0.1 to 0.2 M-LiCl. It was insoluble in concentrations of LiCl lower than 0.05 to 0.1 M. It was less strongly bound to walls than was the amidase, which was a monomer of molecular weight 30000 to 40000 in LiCl buffers. The beta-N-acetylglucosaminidase is an endo-enzyme and showed no exo-activity. Lysozyme-like enzyme (muramidase) activity was undetectable in the wall extracts examined.
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PMID:Purification and properties of autolytic endo-beta-N-acetylglucosaminidase and the N-acetylmuramyl-L-alanine amidase from Bacillus subtilis strain 168. 615 66

Two naturally occurring forms of gonococcal peptidoglycan (PG) were tested for their susceptibility to human PG hydrolases. Purified 3H-labeled PG substituted extensively with O-acetyl derivatives (O-PG; from Neisseria gonorrhoeae FA19) and 14C-labeled O-acetyl-deficient PG (non-O-PG; from N. gonorrhoeae RD5) were mixed together and treated with either normal human sera (NHS) or with lysozyme purified from human polymorphonuclear leukocytes (PMN-LZ). The initial rate of hydrolysis of O-PG by NHS or by PMN-LZ was two- to fourfold less than that of its non-O-PG counterpart in the same tube. When the reactions were allowed to go to completion. NHS solubilized both PGs completely, whereas PMN-LZ solubilized all of the non-O-PG and left ca. 60% of the O-PG insoluble. The PMN-LZ-soluble fraction of O-PG consisted largely of glycosidically linked fragments with molecular weights greater than ca. 10(4), whereas the corresponding non-O-PG was degraded to lower-molecular-weight fragments, exclusively. At completion, NHS hydrolyzed both PGs to fragments whose size was equal to or smaller than that of the free disaccharide unit of PG, suggesting that human sera contain a peptide-splitting (amidase) activity and a glycosidase activity, in addition to that of the well-known muramidase. NHS also promoted the release of high-molecular-weight PG fragments from intact gonococci. The persistence of human hydrolase-resistant PG in the form of soluble macromolecular fragments may potentiate the biological effects of gonococcal PG in vivo.
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PMID:Resistance of O-acetylated gonococcal peptidoglycan to human peptidoglycan-degrading enzymes. 640 67


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