Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.25.1 (deoxyribonuclease)
 1,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lysogenization of nonlysogenic strains of Staphylococcus aureus was performed with two different bacteriophages, LS1 and LS2, that were unable to plaque on any of the strains of S. aureus tested. Infection of recipient strains was achieved when protoplasts were inoculated with LS1 or LS2 or when bacterial cultures were simultaneously inoculated with a virulent phage together with LS1 or LS2. Lysogenization was demonstrated by changes in phenotypic characters of the host strain and by liberation of bacteriophages from the modified strains as shown by electron microscopic examination. The lysogenic strains differed from the host strains by the following characters: they were coagulase, deoxyribonuclease, and lipase negative; they were untypable by the basic set of phages; they did not ferment mannitol under anaerobic conditions; and they produced only l-(+)-lactic acid by glucose fermentation. Their cell walls contained less glycine and concomitantly more serine than those of the host strains. Furthermore, they were devoid of protein A. Conversely, some antigenic factors as well as the presence of ribitol in the cell wall teichoic acid, indicated a parental relationship between the host strains and the derived lysogenic ones. Phages LS1 and LS2 could be excluded from the lysogenic strains by invading phages, and the revertant nonlysogenic strains recovered all of the characteristics of the initial host strains. It was thus concluded that the phenomenon described was due to lysogenic conversion. The origin of phages LS1 and LS2 is discussed.
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PMID:Lysogenic conversion for multiple characters in a strain of Staphylococcus aureus. 14 Aug 62

Optimal conditions for detecting staphylokinase, phosphatase, protease, lipase, esterase, egg yolk factor, lysozyme, deoxyribonuclease, hyaluronidase, penicillinase, and alpha-, beta-, and delta-hemolysins in cell-free filtrates of selected strains of staphylococci by agar plate methods were established by studying the effect of factors such as buffer composition, pH, ionic strength, type of agar, nature and concentration of substrate, and certain metal ions. The final tests that evolved from this study are simple to perform, require only 6 mul of the sample per test, and are capable of detecting microgram and, in some cases, nanogram quantities of the product. The zones of reaction can also be quantitatively related to the amount of material present. The test may also be useful for the detection of extracellular products of other microorganisms.
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PMID:Agar plate tests of enhanced sensitivity for detecting biologically active products of staphylococcal filtrates. 18 61

The extracellular production of hyaluronidase and chondroitin sulfatase was demonstrated in all of the subspecies of Bacteroides fragilis tested with the exception of B. fragilis subsp. vulgatus. Elastase was found only in one strain of B. coagulans tested. This appears to be the first report of these enzyme activities in this genus. Additional enzymes found to be produced by certain members othis genus were fibrinolysin, penicillinase, lysozyme, lecithinase, deoxyribonuclease, phosphatase, protease, and lipase.
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PMID:Extracellular enzymes of the genus Bacteroides. 18 84

Three methods at present available for the purification of staphylococcal delta-haemolysin were compared as to the purity and identify of the product obtained. None yielded a pure preparation of delta-haemolysin; one of the three preparations did not contain demonstrable delta-haemolysin when tested electrophoretically, but it contained deoxyribonuclease, penicillinase, phosphatase and alpha-haemolysin. The second preparation had delta-haemolysin activity and was free of alpha-haemolysin, but it contained lipase, egg-yolk factor, esterase, deoxyribonuclease, penicillinase, phosphatase and hyaluronidase. The third preparation contained all of the products mentioned above, except phosphatase, and it also contained alpha-haemolysin, staphylokinase, lysozyme and caseinase. These findings are discussed with special reference to the requirement for criteria of purity in work with staphylococcal products.
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PMID:Purity of staphylococcal delta-haemolysin obtained by three different procedures. 18 51

The production of enterotoxins, lipase and total extracellular protein by four strains of Staphylococcus aureus grown in batch culture at a controlled pH of 6.5 in a completely defined medium was markedly reduced by glucose or glycerol constantly maintained at 0.I M. A concomitant increase in the production of deoxyribonuclease, up to 13-fold, showed however that not all extracellular proteins are under the same control mechanism. The presence of glucose and glycerol in the medium also resulted in a rapid increase in the specific growth rate. However, growth of S. aureus s6 in Mgilimited continuous culture showed that glucose repression of enterotoxin B when the growth rate was held constant was more than twice that in batch culture. Therefore glucose repression can occur independently of an increase in growth rate. The specific rate of production of enterotoxin B, lipase, deoxyribonuclease, beta-haemolysin and total extracellular protein by S. aureus s6 increased as the growth rate increased from 0.07 to 0.24 h-1. Non-replicating cells grown in the absence of glucose produced considerable amounts of enterotoxin, and production was not repressed by the presence of glucose in the resuspension medium. In contrast, no enterotoxin B or C was obtained from nonreplicating cells grown in the presence of glucose. Chloramphenicol completely inhibited enterotoxin production by non-replicating cells, indicating that synthesis of new protein was required.
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PMID:Glucose repression of enterotoxins A, B and C and other extracellular proteins in staphlyococci in batch and continuous culture. 23 6

The bacteriocin produced by Mycobacterium smegmatis ATCC 14468 was isolated, and a study was made of its chemical, physical, and biological properties. No appreciable bacteriocin activity was found in the culture supernatant fluids, but it was released in appreciable quantities after disruption of the cells. The material was purified 49-fold by means of chromatography on diethylaminoethyl-cellulose, ammonium sulfate fractionation, gel filtration on Sephadex G-200, and chromatography on diethylaminoethyl-Sephadex A-50. Its molecular weight was determined to be approximately 75,000 from the elution profile on Sephadex G-200 chromatography. The bacteriocin was resistant to deoxyribonuclease, ribonuclease, lipase, ultraviolet irradiation, and freeze-thawing, whereas it was relatively less thermostable and was sensitive to proteolytic enzymes. The lethal effect of the bacteriocin was demonstrated by the decrease in viable counts of the bacteriocin-sensitive indicator strain, M. diernhoferi ATCC 19340. The bacteriocin preparation inhibited the growth of HeLa-S3 cells.
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PMID:Purification, properties, and cytotoxic effect of a bacteriocin from Mycobacterium smegmatis. 46 82

About 60 characteristics have been investigated in 7 hemolyzing and 12 nonhemolyzing strains of L. monocytogenes. From these investigations resulted inter alia that the organism grows well under strictly anaerobic conditions, esculin is split at 45 degrees C,NH3 is produced from peptone, but not from arginin, and H2S can be traced by sufficiently sensitive methods. All strains possess a lipase, muramidase, and deoxyribonuclease, the hemolytic ones only also a lecithinase. Besides, the hemolytic strains only dispose of experimental virulence and of a CAMP factor-like agent. The experimental animal of choice seems to be the conjunctivally infected guinea pig in which a generalized infection develops.
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PMID:[Some properties of carrier strains of Listeria monocytogenes (author's transl)]. 81 65

A strain of Actinomyces odontolyticus, originally isolated from human dental plaque, produced a non-dialyzable, trypsin-sensitive substance that was bactericidal for certain strains of bifidobacteria at 42 degrees C but not at 37 degrees C. Detectable quantities of the bacteriocin were not produced in liquid media. Experimentally useful yields were obtained by extraction from pour plate cultures of producer cells. At 42 degrees C, exponential killing did not occur until indicator cells had doubled at least once. At 37 degrees C, the bacteriocin effected a transient bacteriostasis. Partially purified concentrates were obtained by diethylaminoethyl-cellulose chromatography, and such material was not inactivated by ribonuclease, deoxyribonuclease, or lipase. Pronase, trypsin, and exposure to 100 degrees C for 20 min completely abolished activity. Inhibitory activity was considerably reduced by exposure to a pH of either 3 or 11. Treatment of producer cells with curing agents did not induce a high frequency of non-bacteriocinogenic cells. The odontolyticin was adsorbed by susceptible, as well as resistant, bacteria.
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PMID:Bacteriocin from Actinomyces odontolyticus with temperature-dependent killing properties. 90 31

During bacteriophage studies on Haemophilus influenzer, it was observed that encapsulated type b and unencapsulated Rb strains released a bactericidal substance acitve against types a, c, d, e, and f H. influenzae, non-typable H. influenzae strains, other Haemophilus species, and certain members of the Enterobacteriaceae. The bactericidal activity was assayed by a plaque test utilizing an Rd strain as an indicator lawn and was also demonstrated in mixed broth cultures of a producer strain and an indicator strain. Immediately lysis of sensitive bacteria by the factor was not evident. The factor is sensitive to trypsin but resistant to deoxyribonuclease, treatment with 2-mercaptoethanol, lipase, alpha-amylase, and heating in a 100 degrees C water bath for 20 min. The activity is not dependent upon increased Ca2+ or Mg2+ concentration as is necessary for HP1C1 and S2 phage propagation. The bactericidal factor is not pelleted by high-speed centrifugation at 150,000 X g for 6 h. Treatment with ultraviolet light or mitomycin C does not result in observable phage, phage-like particles, or increased bactericidal activity. T-HE BACTERICIDAL FACTOR IS NOT A TYPICAL SMALL MOLECULAR WEIGHT "COLICIN-LIKE" BACTERiocin in that it is not inducible, has a wider range of activity, and does not kill by "single-hit" kinetics. On preliminary characterization, it is a thermostable protein toxic to certain bacterial strains.
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PMID:Bactericidal substance produced by Haemophilus influenzae b. 108 28

Strains from type culture collections and clinical isolates belonging to the Aeromonas and Pseudomonas genera were identified with conventional tests. Production of extra-cellular enzymes and haemolysins were detected by simple plate agar methods. The following enzymes were found to be of special value for a rapid and simple classification of certain species in both genera: potease (casein and gelatin agar), lecithinase (lecithin agar), and deoxyribonuclease (DNA agar). Elastase, staphylolytic enzyme, lipase, ribonuclease, amylase, and egg yolk reaction were other enzymes studied. However, these tests were not positive for more than 90% of any species. A. hydrophila, A. salmonicida, and P. aeruginosa were haemolytic on agar containing rabbit erythrocytes.
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PMID:Characterization of three Aeromonas and nine pseudomonas species by extracellular enzymes and haemolysins. 117 Apr 82


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