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:3.1.21.3 (deoxyribonuclease)
1,528 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An extract made from the supernatant of Neisseria gonorrhoeae Gc2 strain 1291 degraded the Gc2 polysaccharide antigen. Chemical analysis of this polysaccharide indicated it contains glucose, galactose, glucosamine, galactosamine, glucosamine-6-phosphate, heptose, 2-keto-3-deoxyotonate, and ethanolamine and is the polysaccharide component of gonococcal lipopolysaccharide. Degradation of the polysaccharide by sonic extracts resulted either in complete loss of antigenicity and immunogenicity or in partial degradation to subunits that could inhibit the Gc2-specific hemagglutination inhibition. The factors responsible for degradation were destroyed by heating at 100 degrees C for 5 min or by Pronase digestion, but were unaffected by ribonuclease, deoxyribonuclease, Mg2+, Ca2+, or ethylenediaminetetraacetic acid. The process was pH dependent, with optimal activity occurring at pH 7. Sonic extract supernatants from group B and C meningococcal strains contained degrading properties, whereas similar extracts produced from Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Streptococcus pneumoniae type II failed to degrade the Gc2 polysaccharide.
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PMID:Degradation of the polysaccharide component of gonococcal lipopolysaccharide by gonococcal and meningococcal sonic extracts. 7 94

Dipolid human fibroblast-rich tissues contain a macromolecule with a molecular weight between 30,000 and 50,000 daltons which will inhibit the proliferation of fibroblasts in the G1 phase of the cell cycle (i.e., inhibit both 3H-thymidine uptake as well as the normal increase in cell number). The inhibitor is destroyed by trypsin but not by ribonuclease or deoxyribonuclease, and it is thermolabile. It has an acid IEP. It is not cytotoxic, and its inhibitory activity appears to be completely reversible. This fibroblast endogenous inhibitor does not interfere with the proliferation of DNA synthesis by human lymphocytes, bronchial carcinoma cells, or HeLa cells. The activity does not appear to be species specific. Therefore, we suggest that it is quite possible that the control of fibroblast proliferation resides in a fibroblast chalone. Diploid human fibroblasts, in contrast to chicken or mouse fibroblasts or heteroploid fibroblasts in general, stringently require serum for their proliferation. All of this mitogenic activity of calf serum can be concentrated in a molecular weight range around 100,000 daltons by ultrafiltration. All of the mitogenic activity within this molecular weight class can be concentrated at a pH of 5.2 via isoelectric focusing, and all of the activity at this isoelectric point can be concentrated in one peak on preparative polyacrylamide gel electrophoresis. This latter material is homogeneous at three different pH's in analytical gel electrophoresis as well as in SDS electrophoresis. This purified serum mitogen for diploid human fibroblasts in vitro also works in vivo and represents as much as 0.5% of calf serum protein, albeit there is much less of this protein in adult cow or horse. It is composed of two equal subunits weighing about 60,000 daltons each and contains about 2 moles of sialic acid, one S-S bond, and 6 moles of hexose per subunit. There is a reciprocal relationship between the biological activity of fibroblast inhibitor and serum mitogen, but there is no apparent direct interaction between these two proteins. Addition of pure serum mitogen to diploid human fibroblasts in vitro results in the release of commensurable chalone activity into the medium and a reciprocal loss of mitogen from the medium. Therefore, we propose that serum contains a single macromolecule which competes with endogenous chalone on the surface of diploid human fibroblasts and that this functions as an anti-chalone for the fibroblast.
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PMID:Circulating factors controlling cell proliferation. 13 64

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

A simplified, concise scheme was developed for the identification of nonfermentative, gram-negative bacteria which have most frequently been reported in the literature as definite or possible agents of human disease. These organisms included apyocyanogenic Pseudomonas aeruginosa, P. fluorescens, P. putida, P. stutzeri, P. maltophilia, P. putrefaciens, P. cepacia, P. alcaligenes, FLAVOBACTERIUM SPECIES, Bordetella bronchiseptica, Acinetobacter anitratum (Herellea vaginicola), A. Iwoffi (Mima polymorpha), Moraxella species, Alcaligenes odorans and Alcaligenes species. The tests used for identification included production of cytochrome oxidase, amylase, deoxyribonuclease, gelatinase, urease and Beta-galactosidase; motility; oxidation of one per cent glucose and ten per cent lactose; fluorescence; indole, hydrogen sulfide and nitrogen gas production; denitrification of nitrites; growth at 42C; penicillin sensitivity and production of an aromatic odor and greenish discoloration on blood agar. Using this scheme, 85 per cent of 243 isolates (unknowns and reference strains) were identified to genus and species. Of the 15 per cent remaining, 11 per cent were identified as alkaline organisms and four per cent were unidentifiable.
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PMID:Identification of nonfermentative gram-negative bacteria in the clinical laboratory. 16 60

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

A rapid and simplified system for the differentiation of nonfermentative Gram-negative bacilli, encountered frequently in clinical specimens, is presented for use in the clinical laboratory. Nonfermentative bacteria can be grouped initially by the motility, oxidase and OF glucose reactions. This grouping simplifies the choice of additional tests for further identification. The additional tests included Gram stain, acid production from 10% lactose agar, nitrate reduction, arginine dihydrolase activity, fluorescein production, deoxyribonuclease activity, hydrolysis of aesculin, growth at 42 degrees C, gelatinase activity and susceptibility to antibiotics.
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PMID:Differentiation of nonfermentative gram-negative bacilli in the clinical laboratory. 32 28

A total of 520 clinical and environmental isolates of the family Micrococcaceae that fermented glucose anaerobically were tested for their ability to produce coagulase, thermostable nuclease, and deoxyribonuclease. Of these, 450 isolates coagulated rabbit plasma, produced thermostable nuclease, and were identified as Staphylococcus aureus, 447 of which produced a 3+ to 4+ clot. The remaining three isolates produced a 2+ clot, deoxyribonuclease, and thermostable nuclease. It was found that three of the S. aureus isolates failed to produce deoxyribonuclease. A total of 70 isolates which did not coagulate rabbit plasma and which were thermostable nuclease negative were identified as S. epidermidis. Three of them produced deoxyribonuclease. It is suggested that the thermostable nuclease test be performed on all isolates producing a 2+ (or 1+) clot in the coagulase test before identifying them as S. aureus.
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PMID:Evaluation of three test procedures for identification of Staphylococcus aureus from clinical sources. 34 34

Thirty-nine strains of gram-positive microaerophilic cocci isolated from cases of heifer and dry-cow mastitis were biochemically characterized with the API 50E and API-ZYM test kit systems, gas-liquid chromatography for analysis of end products of glucose metabolism, and anaerobic biochemical tests (L. V. Holdeman, E. P. Cato, and W. E. C. Moore, Anaerobe Laboratory Manual, Virginia Polytechnic Institute, Blacksburg, 1977). Strains were screened for production of a variety of extracellular enzymes on substrate-containing agar plates and for hemolysin and coagulase production. Antibiotic susceptibility and sensitivity tests were also performed. The microaerophilic cocci displayed homogeneity with respect to the majority of the biochemical tests used; i.e., greater than or equal to 90% of the strains were consistently positive or negative in any one test and probably represent one species. All produced deoxyribonuclease, ribonuclease, and hyaluronidase, and 92% were positive for chondroitin sulfatase. Catalase and coagulase tests were negative. Greening was observed on bovine blood agar. Acetic and succinic acids were produced by all strains as the only detectable products of glucose metabolism. The strains were susceptible to penicillin G, cefoxitin, doxycycline, and chloramphenicol and were resistant to clindamycin, novobiocin, and metronidazole. Their taxonomic position remains unclear.
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PMID:Biochemical characterization of unidentified microaerophilic cocci isolated from heifer and dry-cow mastitis. 39 19

A considerable amount of Mn2+-stimulated DNAase (deoxyribonuclease) activity is released by Bacillus subtilis 168 during sporulation in a glucose-deficient medium; much smaller amounts are released during starvation for phosphate or nitrogen. Protein synthesis is required. Two forms of evidence are presented that production of the DNAase is associated with events late in stage II of sporulation. 19 Thymidine starvation, which inhibits the biochemical events associated with sporulation, also inhibits release of the DNAase. 2. Several asporogenous mutants blocked at stage II or earlier and unable to produce alkaline phosphatase (a stage-II event) do not produce the enzyme. Mutants blocked towards the end of stage II or later produce both enzymes. During sporulation of the wild-type strain, the DNAase appears about 1 h after alkaline phosphatase. The results suggest that production of the DNAase is controlled by a still-undiscovered stage-II genetic locus.
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PMID:Extracellular manganese-stimulated deoxyribonuclease as a marker event in sporulation of Bacillus subtilis. 41 78

Whole sheets of plasma membrane, each with their attached flagellum, were purified from Trypanosoma brucei. The method devised for their isolation included a new technique of cell breakage that used a combination of osmotic stress followed by mechanical sheer and avoided the problem of extreme vesiculation as well as the trapping of organelles in cell 'ghosts'. The purified membranes all contained the pellicular microtubular array. The antigenic surface coat was completely released from the plasma membrane during the isolation procedure. The membranes had a very high cholesterol/phospholipid ratio (1.54). A large proportion (42%) of the cellular DNA was recovered in the plasma-membrane fraction unless a step involving deoxyribonuclease treatment, which decreased the DNA content to less than 13%, was included before secrose-density gradient centrifugation. This step also aided the separation of plasma membranes from other cellular components. The ouabain-sensitive Na+ + K+-stimulated adenosine triphosphatase and adenylate cyclase co-purified with the plasma membranes. Although 5'-nucleotidase was thought to be a plasma-membrane component, it was easily detached from the membrane. The purified membranes were essentially free of L-alanine-alpha-oxoglutarate aminotransferase, L-asparte-alpha-oxoglutarate aminotransferase, malate dehydrogenase, oligomycin-sensitive adenosine triphosphatase, glucose 6-phosphatase, Mg2+-stimulated p-nitrophenyl phosphatase and catalase.
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PMID:The isolation and partial characterization of the plasma membrane from Trypanosoma brucei. 48 94


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