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)

The lyc gene, encoding an autolytic lysozyme from Clostridium acetobutylicum ATCC824, has been cloned. The nucleotide sequence of the lyc gene has been determined and found to encode a protein of 324 amino acids (aa) with a deduced Mr of 34,939. The lyc gene is preceded by two open reading frames with unknown functions, suggesting that this gene is part of an operon. Comparison between the deduced aa sequence of the lyc gene and the directly determined N-terminal sequence of the extracellular clostridial lysozyme suggests that the enzyme is synthesized without a cleavable signal peptide. Moreover, the comparative analyses between the clostridial lysozyme and other known cell-wall lytic enzymes revealed a significant similarity with the N-terminal portion of the lysozymes of Streptomyces globisporus, the fungus Chalaropsis, the Lactobacillus bulgaricus bacteriophage mv1, and the Streptococcus pneumoniae bacteriophages of the Cp family (CPL lysozymes). In addition, the analyses showed that the C-terminal half of the clostridial lysozyme was homologous to the N-terminal domain of the muramoyl-pentapeptide-carboxypeptidase of Streptomyces albus, suggesting a role in substrate binding. The existence of five putative repeated motifs in the C-terminal region of the autolytic lysozyme suggests that this region could play a role in the recognition of the polymeric substrate.
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PMID:Sequence of the lyc gene encoding the autolytic lysozyme of Clostridium acetobutylicum ATCC824: comparison with other lytic enzymes. 191 74

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

The CPL-1 lysozyme coded by the pneumococcal phage Cp-1 has been overproduced in Escherichia coli under the control of a modified lipoprotein lactose promoter. This result has provided the conditions to analyse the CPL-1 secondary structure by circular dichroism (CD). The CD spectra recorded in the far-ultraviolet region showed, at neutral pH, two minima at 210 nm and 230 nm and a shoulder at 217 nm, whereas two bands at 260 nm and 295 nm were observed in the near-ultraviolet region. It has been estimated, by using the CDPROT program, that the protein is composed of 19% alpha-helix, 32% beta-sheet, 28% beta-turn and 21% random coil. Minor changes in the CD spectra were detected either when the pH was varied over 6-10 or when the ionic strength was increased to 1 M NaCl. Choline, a well known modulator of the enzyme activity that is present in the pneumococcal cell wall, induced remarkable changes in the intensities of the bands at 210, 230 and 295 nm, with the appearance of an unusual positive band at 225 nm. The conformational change was reversible and correlated with the competitive inhibitory effect of choline on the lysozyme activity, supporting, by a new and direct experimental approach, the basic role of choline in the recognition of the cell wall substrate. The analyses of the secondary structure prediction and the CD data reported here are compatible with the two-domain structure of CPL-1 reinforce our hypothesis that the C-terminal region is directly involved in the binding of the enzyme to the pneumococcal teichoic and lipoteichoic acids.
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PMID:Structural studies of the lysozyme coded by the pneumococcal phage Cp-1. Conformational changes induced by choline. 240 66

In autumn and spring a group of 132 ten-year-old school children (54.5% from families of smokers) were examined for blood content of immunoglobulins (IgG, IgA, (gM, in autumn including also IgE), lysozyme (LYS) and the so called acute reactants (alpha-1-antitrypsin = A1AT; alpha-2-macroglobulin = A2M; transferrin = TRF; ceruloplasmin = CPL); and for saliva sIgA and sLYS. Autumn examination detected significantly higher mean values of IgE in children from families of smokers, while other mean differences remained insignificant. Spring examination revealed significant differences in the means of IgA levels children from families of smokers (FS) had significantly lower levels of IgA while their saliva sIgA values were significantly higher. Mean spring CPL levels in FS were significantly higher. Analysis of distribution curves of autumn examination showed a significant shift of A1AT towards higher values in boys from FS. Girls from FS exhibited a shift of LYS towards lower values. Spring examination in boys FS evidenced a shift of CPL and sIgA values towards higher values; the curve of serum IgA levels split distinctly into two subgroups. In girls from FS the only change observed during the spring examination was a shift of A2M levels towards higher values with an indication of a split. To conclude, passive smoking in school children is responsible for a number of significant changes, the latter being more frequent and marked in spring when the children's organism is weakened by many other unfavourable circumstances. More significant changes were seen in boys.
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PMID:Humoral defending mechanisms in children of smoking parents. 244 22

Cp-1, a small virulent bacteriophage infecting Streptococcus pneumoniae, encodes its own lytic enzyme (CPL). A fragment of Cp-1 DNA containing the gene cpl coding for CPL was cloned and expressed in high amounts in Escherichia coli. CPL was purified to electrophoretic homogeneity by using affinity chromatography on choline-Sepharose (T. Briese and R. Hakenbeck, Eur. J. Biochem. 146:417-427, 1985), and the enzyme showing a Mr of 39,000 was characterized as a muramidase. This muramidase required for in vivo and in vitro activity the presence of choline in the teichoic acids of the pneumococcal cell walls. Free choline or lipoteichoic acid noncompetitively inhibited the activity of CPL.
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PMID:Cloning, purification, and biochemical characterization of the pneumococcal bacteriophage Cp-1 lysin. 329 86

The prevalence of respiratory diseases was followed in a group of 80 children (39 boys and 41 girls) of mean age 12.4 +/- 0.9 years during the part of school year (November - May incl.). The specimen of blood was taken from all studied children before the study started and the values of nine serum proteins were measured (IgG, IgA, IgM, IgE, alfa 1-antitrypsin = A 1-AT, transferrin = TRF, ceruloplasmin = CPL, alpha 2-macroglobulin = A 2M, lysozyme = LYS), as well as levels of two secretory proteins in saliva (sIgA and sLYS). The difference between the subgroup of boys, who fall into some respiratory illness during the observation time, and those who remain healthy, did not reach the level of significance. In contrast, the girls subgroup revealed significantly higher respiratory morbidity. With those girls, who remained healthy, the levels of serum IgE were highly increased and A 1-AT level weakly increased compared to ill girls. The level of TRF and CPL were significantly decreased with the healthy girls.
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PMID:The interrelations of some humoral factors of resistance with the prevalence of respiratory diseases in children. I. The differences among the protein levels in healthy and ill children. 617 77