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)

A complex comparative study of the characteristics of nonspecific resistance in different species of laboratory animals immunized with vaccine STI against anthrax has revealed the existence of marked interspecific differences between noninbred white mice, guinea pigs, rabbits and noninbred white rats in such characteristics as phagocytic activity, oxygen-dependent function of polymorphonuclear blood leukocytes, serum beta-lysin and lysozyme.
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PMID:[The nonspecific resistance indices of different species of laboratory animals immunized with STI anthrax vaccine]. 805 81

The developmental mechanisms of anthrax immunity were studied. Immunization was found to generally generate specific antibodies and lysozyme. Collectively, all the factors are responsible for suppressing the development of spores in the body. This proves the fact that the immunity is directed not only towards the exotoxin of B. anthracis, but it affects mainly the formation of vegetative cells. On entering the immuned body, vegetative cells may cause B. anthracis infection because antitoxic antibodies have no effect on encapsulated cells. The findings indicate that any anti-anthrax vaccine strain must show a complete immunological response in the body, as well as constitute immunity to all pathogenetic factors of B anthracis.
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PMID:[Molecular mechanisms underlying bacillus anthracis infection at early stages and search for novel vaccines]. 928 72

Puziss, Milton (Fort Detrick, Frederick, Md.) and Mary B. Howard. Studies on immunity in anthrax. XI. Control of cellular permeability by bicarbonate ion in relation to protective antigen elaboration. J. Bacteriol. 85:237-243. 1963.-No elaboration of Bacillus anthracis protective antigen was demonstrated after addition of bicarbonate to cultures incubated 42 hr in a bicarbonate-free medium. Antigen accumulation in culture filtrates was greater if the bicarbonate was added to these cultures early in the growth period. Cell-free extracts of washed cell suspensions, prepared by hand grinding or lysozyme treatment, had no demonstrable intracellular protective antigen. Sonic treatment released antigen in measurable amounts, but tended to destroy or degrade the labile antigen. Freezing and thawing disrupted the cells and liberated the antigen; protective antigen was shown to be of internal rather than of extracellular origin. Maximal intracellular antigen concentration occurred before the peak concentration was reached in the culture filtrates. Antigen also was found in cell extracts from bicarbonate-free culture media when none was present in the corresponding culture filtrates. A high level of internal protective antigen was present in cells grown in a bicarbonate-free medium maintained at a constantly alkaline pH; only a trace of antigen was present in the corresponding pH-adjusted culture filtrate. The hypothesis is presented that bicarbonate functions to control cellular permeability and release of antigen from the cells into the ambient medium.
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PMID:Studies on immunity in anthrax. XI. Control of cellular permeability by bicarbonate ion in relation to protective antigen elaboration. 1397 33

Bacillus anthracis causes anthrax, a lethal disease affecting humans that has attracted attention due to its bioterrorism potential. PlyG is a lysin of gamma-phage, which specifically infects B. anthracis and lyses its cell wall. PlyG contains a T7 lysozyme-like amidase domain, which appears to be the catalytic domain, in the N-terminal region and has a high degree of sequence similarity with PlyL, which is an N-acetylmuramoyl-l-alanine amidase encoded by the B. anthracis genome. Here, we demonstrated that two amino acid residues of PlyG, H29 and E90, are necessary for its catalytic activity in B. anthracis. These residues are structurally analogous to residues whose mutation in T7 lysozyme abolished its catalytic activity. A C-terminal deletion mutant of PlyG lacking the core sequence for binding to B. anthracis showed completely abolished binding activity, unlike PlyL, despite high sequence similarity with PlyL in the N-terminal region. This suggests that the C-terminal binding domain, as well as the N-terminal catalytic domain, is essential for the catalytic activity of PlyG. Our observations provide new insights into the mechanism of specific catalysis of PlyG in B. anthracis and may contribute to the establishment of new methods for anthrax therapy.
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PMID:Characterization of the catalytic activity of the gamma-phage lysin, PlyG, specific for Bacillus anthracis. 1866 16

We hypothesized that the peptidoglycan component of B. anthracis may play a critical role in morbidity and mortality associated with inhalation anthrax. To explore this issue, we purified the peptidoglycan component of the bacterial cell wall and studied the response of human peripheral blood cells. The purified B. anthracis peptidoglycan was free of non-covalently bound protein but contained a complex set of amino acids probably arising from the stem peptide. The peptidoglycan contained a polysaccharide that was removed by mild acid treatment, and the biological activity remained with the peptidoglycan and not the polysaccharide. The biological activity of the peptidoglycan was sensitive to lysozyme but not other hydrolytic enzymes, showing that the activity resides in the peptidoglycan component and not bacterial DNA, RNA or protein. B. anthracis peptidoglycan stimulated monocytes to produce primarily TNFalpha; neutrophils and lymphocytes did not respond. Peptidoglycan stimulated monocyte p38 mitogen-activated protein kinase and p38 activity was required for TNFalpha production by the cells. We conclude that peptidoglycan in B. anthracis is biologically active, that it stimulates a proinflammatory response in monocytes, and uses the p38 kinase signal transduction pathway to do so. Given the high bacterial burden in pulmonary anthrax, these findings suggest that the inflammatory events associated with peptidoglycan may play an important role in anthrax pathogenesis.
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PMID:Bacillus anthracis peptidoglycan stimulates an inflammatory response in monocytes through the p38 mitogen-activated protein kinase pathway. 1900 59

To prove linkage between an environmental sample and an anthrax case, there must be isolates obtained from both that can be compared. Although Bacillus anthracis is easily isolated from powder samples, isolating it from soil is difficult because of the high bacterial count in it. Formulations of PLET were prepared, inoculated with B. anthracis, B. cereus and B. thuringiensis and examined for growth. Two hundred eighty-three isolates including 23 B. anthracis were placed onto one formulation while MICs against trimethoprim-sulfamethoxazole were determined. The media supported B. anthracis growth at 30 degrees C and inhibited almost all other bacterial growth, including closely-related species. Sensitivity for B. anthracis and selectivity against other Bacillus and against non-Bacillus were 96.8%, 100% and 97.2% respectively. Isolates that grew had MICs >4 and >76 microg mL(-1) against trimethoprim and sulfamethoxazole, respectively. Soils spiked with 10(2)B. anthracis spores and suspended in PLET broth yielded a 6-7 log(10) increase in B. anthracis. Other growth was inhibited. PLET supplemented with sulfamethoxazole (38 microg mL(-1)), trimethoprim (2 microg mL(-1)), polymyxin B (15,000 U L(-1)), and lysozyme (150,000 U L(-1)) can successfully select for B. anthracis and will facilitate agricultural, environmental and forensic investigations of B. anthracis isolates.
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PMID:Improvement of a selective media for the isolation of B. anthracis from soils. 1980 58

Bacillus anthracis is a National Institute of Allergy and Infectious Diseases Category A priority pathogen and the causative agent of the deadly disease anthrax. We applied a transposon mutagenesis system to screen for novel chromosomally encoded B. anthracis virulence factors. This approach identified ClpX, the regulatory ATPase subunit of the ClpXP protease, as essential for both the hemolytic and proteolytic phenotypes surrounding colonies of B. anthracis grown on blood or casein agar media, respectively. Deletion of clpX attenuated lethality of B. anthracis Sterne in murine subcutaneous and inhalation infection models, and markedly reduced in vivo survival of the fully virulent B. anthracis Ames upon intraperitoneal challenge in guinea pigs. The extracellular proteolytic activity dependent upon ClpX function was linked to degradation of cathelicidin antimicrobial peptides, a front-line effector of innate host defense. B. anthracis lacking ClpX were rapidly killed by cathelicidin and alpha-defensin antimicrobial peptides and lysozyme in vitro. In turn, mice lacking cathelicidin proved hyper-susceptible to lethal infection with wild-type B. anthracis Sterne, confirming cathelicidin to be a critical element of innate defense against the pathogen. We conclude that ClpX is an important factor allowing B. anthracis to subvert host immune clearance mechanisms, and thus represents a novel therapeutic target for prevention or therapy of anthrax, a foremost biodefense concern.
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PMID:ClpX contributes to innate defense peptide resistance and virulence phenotypes of Bacillus anthracis. 2037 6

O-Acetylation of the MurNAc moiety of peptidoglycan is typically associated with bacterial resistance to lysozyme, a muramidase that serves as a central component of innate immunity. Here, we report that the peptidoglycan of Bacillus anthracis, the etiological agent of anthrax, is O-acetylated and that, unusually, this modification is produced by two unrelated families of O-acetyltransferases. Also, in contrast to other bacteria, O-acetylation of B. anthracis peptidoglycan is combined with N-deacetylation to confer resistance of cells to lysozyme. Activity of the Pat O-acetyltransferases is required for the separation of the daughter cells following bacterial division and for anchoring of one of the major S-layer proteins. Our results indicate that peptidoglycan O-acetylation modulates endogenous muramidase activity affecting the cell-surface properties and morphology of this important pathogen.
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PMID:O-Acetylation of peptidoglycan is required for proper cell separation and S-layer anchoring in Bacillus anthracis. 2113 5