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 penetration barrier operating outside the periplasmic enzyme penicillinase was studied in an ampicillin-resistant mutant of Escherichia coli K-12. Growth in the presence of lysozyme and sublethal concentrations of ampicillin partially opened the barrier. This could be recorded as an increased penetration of penicillin G, sodium cholate, and rifampin to their respective targets. Brief treatments with tris(hydroxymethyl)aminomethane-ethylenediaminetetraacetic acid and sodium cholate effectively impaired the barrier against penicillin and also caused leakage of penicillinase. Wild-type E. coli K-12, Proteus mirabilis, and Pseudomonas aeruginosa also showed an increased sensitivity to cholate after treatment with penicillins. Electron micrographs showed that lysis by cholate was due to a distortion of the cytoplasmic membrane causing a leakage of protein and RNA from the cells to the medium. Physiological data indicated that the increased sensitivity to cholate induced by growth in the presence of ampicillin or lysozyme was due to effects upon the murein. This was supported by measurement of the incorporation of (3)H-diaminopimelic acid. These results indicate that the murein sacculus either is a part of the penetration barrier or is responsible for holding the structure of the outer membrane together.
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PMID:Murein and the outer penetration barrier of Escherichia coli K-12, Proteus mirabilis, and Pseudomonas aeruginosa. 462 57

In animals developing experimentally induced unilateral pyelonephritis, both the infected kidney (IK) and the contralateral noninfected kidney (NIK) showed an immediate increase in renal lysozyme activity of about 5 days' duration after the unilateral injection of viable Proteus mirabilis into the renal cortex. Lysozyme activities of the NIK were consistently higher than those of the IK. This initial increase was followed by a second increase which lasted throughout the period of observation (17 days), and enzyme activities of the NIK were consistently higher than those of the IK. In saline punctured kidneys of control animals, both the saline punctured kidney (SP) and the non-saline punctured kidney (NSP) showed only the immediate increase in renal lysozyme activity, which persisted until the SP was completely healed. These enzyme activities were less than those observed in the infected animals, but the response of the NSP was greater than that of the SP. Trauma not directed to the kidney does not produce a similar response of renal lysozyme. The elevated renal lysozyme of the NIK could not be shown to protect it from bacterial infection.
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PMID:Renal lysozyme levels in animals developing Proteus mirabilis-induced pyelonephritis. 554 3

Antiserum was prepared against the purified gamma-glutamyltranspeptidase (EC 2.3.2.2) of Proteus mirabilis. The antiserum inactivated the gamma-glutamyltranspeptidase activities of both purified enzyme and intact cells. Native cells were agglutinated with the antibody. Immunocytochemical studies with indirect immunofluorescence and electron microscopy analysis suggested that gamma-glutamyltranspeptidase is localized on the surface of the cell. Its distribution in the cell wall or periplasmic space or both was also confirmed by the treatment of cells with lysozyme-EDTA. The purified enzyme was activated by the addition of membrane phospholipids isolated from the same bacterium. The hydrolysis activity was stimulated more than the transpeptidation activity by several phospholipids.
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PMID:gamma-Glutamyltranspeptidase from Proteus mirabilis: localization and activation by phospholipids. 615 26

Gram positive bacteria, including lysozyme-resistant strains, and yeasts were killed in hen egg albumen with or without iron at 30 of 39.5 degrees C. The albumen was more toxic at 39.5 degrees C than at 30 degrees C for Gram negative bacteria. With the exceptions of Pseudomonas fluorescens, Acinetobacter sp. and Proteus vulgaris, iron caused the growth of Gram negative bacteria or protected them from being killed in hen albumen at 39.5 degrees C. At this temperature, however, maximal growth of and glucose utilization by Escherichia coli C20 only occurred in albumen supplemented with growth factors, trace metals, additional nitrogen and sufficient iron to quench ovotransferrin. The bactericidal properties of albumen could be negated by changing its pH from 9.0 or above to 7.5 or below. At 39.5 degrees C, enterochelin allowed growth of E. coli in albumen at pH 7.9, but not at 9.4, whereas iron allowed growth at both pH values.
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PMID:The influence of incubation temperature and pH on the antimicrobial properties of hen egg albumen. 670 88

Bacteroides thetaiotaomicron, a gram-negative anaerobe found in human colons, could utilize chondroitin sulfate, a tissue mucopolysaccharide, as its sole source of carbohydrate. The enzymes responsible for the breakdown of chondroitin sulfate by B. thetaiotaomicron were similar to those produced by Proteus vulgaris and Flavobacterium heparinum and included a lyase (EC 4.2.2.4), which degraded chondroitin sulfate into sulfated disaccharides, sulfatases (EC 3.1.6.4), which removed the sulfate residues, and a glucuronidase, which broke the unsulfated disaccharides into monosaccharide components. Chondroitin sulfate lyase, the first enzyme in the breakdown sequence, was not extracellular. It appeared to be located in the periplasmic space since lyase activity was released by treatment with ethylenediaminetetraacetate and lysozyme. Moreover, sodium polyanethole sulfonate, a high-molecular-weight inhibitor of chondroitin lyase, did not inhibit breakdown of chondroitin sulfate by intact bacteria. The sulfatase and glucuronidase appeared to be intracellular. None of these enzymes was strongly bound to membranes, and none of the steps in the breakdown of chondroitin sulfate was sensitive to oxygen.
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PMID:Cellular location of enzymes involved in chondroitin sulfate breakdown by Bacteroides thetaiotaomicron. 678 76

The susceptibility od Proteus, Providencia, and Morganella strains to bactericidal action of human serum was examined. The percentage of survival was determined after one and three hours incubation with 50% human serum. The susceptible strains were treated by serum preparations with blocked classical or alternative complement activation pathways as well as with lysozyme removed. Following mechanisms of the bactericidal action of serum were found: complement activated by the classical or alternative pathway with participation of lysozyme, complement activated simultaneously via both pathways-while the participation of lysozyme was necessary for killing some strains and superfluos for others and complement activated only via the classical pathway without lysozyme.
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PMID:Bactericidal activity of normal human serum against Morganella, Proteus, and Providencia strains. 766 Aug 59

A potent, humoral, bactericidal activity against Micrococcus luteus was discovered in pseudocoelomic fluid of the pig roundworm, Ascaris suum. The activity, which was not bacteriolytic, was not due to lysozyme or to a dietary antibiotic. It was not inactivated by exposure to 100 degrees C, to low or high pH, or to ethanol. Dialysis, electrophoresis and agar-diffusion experiments suggested that the main antibacterial activity in the fluid was associated with a basic substance of molecular weight somewhat less than 14,000 Da. Two other Gram-positive organisms, Bacillus megaterium and Staphylococcus aureus, were also killed by the Ascaris fluid, but the Gram-negative Escherichia coli, Proteus vulgaris and Bordetella bronchiseptica were insensitive.
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PMID:Bactericidal activity in the pig roundworm Ascaris suum. 814 3

The percentage of bacteriocin-producing and phage-producing Klebsiella strains was as follows: K. pneumoniae-10%, K. ozaenae-7%, K. rhinoscleromatis-9%. The antimicrobial spectrum of the studied inducible particler was broad and was not limited by the frames of the genus and family. Bacteriocins and bacteriophages from Klebsiella were active to Klebsiella, Enterobacter, Escherichia, Shigella and Proteus representatives significant in medicine. Klebocins and Klebsiella phages exhibited antagonistic effects to phytopathogenic bacteria. Some strains of Erwinia and Pseudomonas were sensitive to phages or bacteriocins from Klebsiella. Bacteriocins protected corn and tomato seeds from contamination by erwinioses agents. All cultures of Agrobacterium, Corynebacterium, Micrococcus, Staphylococcus, Streptococcus were resistant to action of phages and klebocins. Bacteriocins from Klebsiella were assayed for their sensitivity to trypsin, chymotrypsin, lysozyme, ribonuclease, deoxyribonuclease. Action of klebocins was associated with a protein component. Proceeding from data of diffusion through the disc ultrafiltration membranes molecular weight of klebocins was in the range of 30,000 and 50,000 Da.
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PMID:[The antimicrobial spectrum of the action of bacteriocins and bacteriophages from Klebsiella strains]. 816 98

The degree of peptidoglycan O acetylation in 18 strains of the different genera of the tribe Proteeae (Proteus, Providencia, and Morganella) has been determined by high-performance liquid chromatography-based organic acid analysis of mild-base-released acetic acid and quantitation of peptidoglycan concentrations by simultaneous amino sugar-amino acid analysis using high-performance anion-exchange chromatography with pulsed amperometric detection. The N,O-diacetylmuramyl content of all isolated and purified peptidoglycans was greater than 29% and ranged up to 57% relative to total muramic acid concentration. Each of the O-acetylated peptidoglycans was found to be resistant to solubilization by hen egg white lysozyme.
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PMID:Extent of peptidoglycan O acetylation in the tribe Proteeae. 833 Oct 84

This study investigated the antibacterial activity of human pleural fluid (HPF) and its interaction with gentamicin (GM), meropenem (MRPM), ciprofloxacin (CPFX) and clarithromycin (CLTM) against Escherichia coli K-12, Proteus rettgeri (Sanelli) and Staphylococcus aureus. Minimal inhibitory concentrations or volumes, expressed as MIC or volume percentage (MIV, V/V%), were measured using a micro-dilution technique in microtiter plates. The antimicrobial activity of HPF combinations with antimicrobial drugs was evaluated by the chequerboard method calculating the fractional inhibitory concentration index (FIC) values. HPF MIVs (%) were: 37.54; 19.85; 1.74 for E. coli, P. rettgeri and S. aureus, respectively. FIC values indicated a synergistic effect with GM, MRPM and CPFX against E. coli and P. rettgeri and an additive effect for the combination HPF plus CLTM or indifference with HPF plus GM and CPFX against S. aureus. The presence of antibodies, complement factors, lysozyme, alpha-defensins and enzymes could explain the antimicrobial activity of HPF and its synergistic effect with certain antibiotics.
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PMID:Antibacterial activity of human pleural fluid: alone and in combination with antibiotics. 991 8


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