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

---

Query: EC:3.1.21.1 (DNase)
7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The enzymatic potential of 54 clinical and 22 environmental isolates of Pseudomonas aeruginosa from soil and water were evaluated by substrate plate assays. Clinical isolates produced substantial levels of 9 of the 11 enzymes assayed, whereas strains recovered from soil or water were relatively inert enzymatically. Elastase, deoxyribonuclease, and elevated protease activities were associated preferentially with clinical isolates of systemic origin; these activities were found twice as frequently in clinical isolates as in strains derived from sputum or the urogenital tract. Our data suggest that these factors may play an important role in the dissemination of P. aeruginosa from local or superficial sites. A comparison of the enzyme profiles of the environmental and clinical isolates indicated that colonization or infection by environmental strains of P. aeruginosa is a rare event and that environmental and clinical strains comprise separate biovars. Epidemiologically, enzyme profiles permitted the fingerprinting and differentiation of clinical strains from various sources.
...
PMID:Pseudomonas aeruginosa enzyme profiling: predictor of potential invasiveness and use as an epidemiological tool. 679 May 69

The thermostability of adenovirus 5 increases when the ionic strength is decreased before heating by dilution in distilled water (1 : 100, heating at 50 degrees C). A predilution in Eagle's MEM before heating or a previous dialysis against water had no effect on thermostability. The stabilizing effect was found likewise in crude and purified virus, in heating at 50 degrees C up to 320 min, from 50 degrees C to 56 degrees C, and in dilution from 10(-2) to 10(-5). The degree of stabilization was similar to cationic stabilization in 2M NaCl. The infectivity of heated adenovirus 5 was not sensitivity to DNase digestion. Other adenovirus types were stabilized in a similar manner.
...
PMID:Stabilization of adenovirus infectivity against thermoinactivation by lowered ionic strength. 730 Aug 2

The most widely used methods for the extraction of glycosphingolipids from animal tissues are based on the use of chloroform/methanol mixtures. These methods, although suitable for a great majority of lipids, fail to remove highly complex glycosphingolipids. Reported here is a method for the isolation of the entire population of glycosphingolipids by means of a gradual degradation of tissue components and enrichment in carbohydrate conjugates resistant to alkali and proteases. Fresh gastric mucosa was homogenized and treated with alkali (beta-elimination) and RNAase and DNAase to decrease the viscosity of the homogenate, followed by pronase digestion. Each treatment was completed by exhaustive dialysis against distilled water. The resultant tissue digest was partitioned with chloroform/methanol (2:1) to remove simple glycosphingolipids. The aqueous portion of the system was adjusted to 1.0% with Zwittergent TM- 314 and solubilized for 24 h by mixing. Thus, prepared sample subjected to Bio-Gel P60 column chromatography afforded five fractions. Of these, three were free of protein and contained carbohydrates, fatty acids and sphingosine. Further fractionation on Bio-Gel P 10 and P6 columns followed by thin-layer chromatography afforded homogeneous components with all the characteristics of highly complex glycosphingolipids.
...
PMID:A new method for the isolation of the simple and highly complex glycosphingolipids from animal tissue. 731 45

Four aspartic acid residues (Asp126, Asp156, Asp233 and Asp295) of Bacillus cereus sphingomyelinase (SMase) in the conservative regions were changed to glycine by in vitro mutagenesis, and the mutant SMases [D126G (Asp126-->Gly etc.), D156G, D233G and D295G] were produced in Bacillus brevis 47, a protein-producing strain. The sphingomyelin (SM)-hydrolysing activity of D295G was completely abolished and those of D126G and D156G were reduced by more than 80%, whereas that of D233G was not so profoundly affected. Two mutant enzymes (D126G and D156G) were purified and characterized further. The hydrolytic activities of D126G and D156G toward four phosphocholine-containing substrates with different hydrophobicities, SM, 2-hexadecanoylamino-4-nitrophenylphosphocholine(HNP), lysophosphatidylcholine (lysoPC) and p-nitro-phenylphosphocholine (p-NPPC), were compared with those of the wild-type. The activity of D126G toward water-soluble p-NPPC was comparable with that of the wild-type. On the other hand, D156G catalysed the hydrolysis of hydrophilic substrates such as HNP and p-NPPC more efficiently (> 4-fold) than the wild-type. These results suggested that Asp126 and Asp156, located in the highly conserved region, may well be involved in a substrate recognition process rather than catalytic action. Haemolytic activities of the mutant enzymes were found to be parallel with their SM-hydrolysing activities. Two regions, including the C-terminal region containing Asp295, were found to show considerable sequence identity with the corresponding regions of bovine pancreatic DNase I. Structural predictions indicated structural similarity between SMase and DNase I. An evolutionary relationship based on the catalytic function was suggested between the structures of these two phosphodiesterases.
...
PMID:Mutation in aspartic acid residues modifies catalytic and haemolytic activities of Bacillus cereus sphingomyelinase. 763 90

The airway secretions which line the respiratory tract form a biphasic layer composed of an aqueous 'sol' layer and a more superficial 'gel' layer. In the sol layer, also described as the 'periciliary' layer or 'airway surface fluid', the cilia beat and relax. The lubricant sol layer enables the gel mucus present at the tips of the cilia to be transported by the ciliary beating of the ciliated cells. Due to difficulties with sampling, little is known about the physical and biochemical properties of the sol layer. The gel layer is composed of high molecular weight glycoproteins (mucins) linked with proteins and lipids. They form a gel network with a high water content (95%) and rheologic and physical properties (viscoelasticity, adhesivity) adapted in normal conditions to protect the airway mucosa, particularly through mucociliary transport. The adhesive properties of mucus, which are influenced by its lipid composition and degree of hydration, are very important in controlling the efficacy of mucus transport through ciliary activity and coughing. An intermediate viscosity and elasticity is required for optimal mucociliary transport. In obstructive airway diseases, either of genetic origin, such as cystic fibrosis (CF), or acquired (acute or chronic bronchitis), and particularly during inflammatory and infectious episodes, mucus dehydration is associated with an increase in secreted or transudated molecules and with marked augmentation of DNA content. These abnormalities contribute to the increased viscosity and adhesivity of the airway secretions and are responsible for their abnormally low transport rate by ciliary activity and for inefficient cough clearance. In view of these alterations in the physical and functional properties of CF airway secretions, pharmacologic approaches should aim to rehydrate the mucus and to restore normal mucociliary or cough transport by stimulating chloride ion secretion (i.e. using UTP or ATP associated with amiloride in order to block sodium ion and water reabsorption). During acute episodes of infection, recombinant human DNase (rhDNase) may rapidly prevent mucus stasis by improving its rheologic properties. Lubrication of the mucus at the sol phase interface by 'surfactant' therapy may also represent a very promising therapeutic perspective to reduce the hyperviscosity and hyperadhesivity of airway secretions.
...
PMID:Physical and functional properties of airway secretions in cystic fibrosis--therapeutic approaches. 779 36

In murine lens extracts a Mg(2+)-dependent DNase activity was found and characterized with respect to its ionic conditions. The lenticular DNase can be clearly distinguished from DNaseII. Only a moderate DNase activity is detectable in intact nuclei of lens cells from 1-day-old mice, but DNase is obviously present with high activity in lens cell nuclei from 7-day-old mice. During this time, when murine eyes are not yet open, and the fiber cell nuclei including the nuclear membrane remain to be completely digested, only weak activity can be detected in cytosolic lens extracts. In three allelic dominant mice mutants exhibiting hereditary cataracts the DNase activity is inhibited. The decrease of DNase activity follows the same directionality (Cat-2ns > Cat-2no > Cat-2t) as the decrease in the relative content of water soluble lens proteins, which might be used as a rough indicator for the severity of cataractogenesis. Both trends are highly significant (P < 0.0001).
...
PMID:DNase activity in murine lenses: implications for cataractogenesis. 833 53

Identification of Na+ binding sites in protein crystals is complicated by comparable electron density of this monovalent cation and water. Valence calculations can predict the location of metal ion binding sites in proteins with high precision. These calculations were used to screen 332,242 water molecules in 2742 protein structures reported in the Protein Data Bank (PDB), searching for molecules with Na+/- specific valence values V(Na+) > or = 1.0 v.u., as expected for a bound Na ion. Thirty-three water molecules (<0.01% of the total) were found be have V(Na+) > or = 1.0 v.u. and to be located within 3.5 A from at least two protein oxygen atoms. These water molecules, with a high Na+ -specific valence, do not have valences specific for other cations, like Li+, K+, Mg2+ or Ca2+. They belong to nine different proteins (deoxyribonuclease I, enolase, hen egg-white lysozyme, human lysozyme, phospholipase A2, proteinase A, rubredoxin, thrombin and phage T4 lysozyme) and appear with similar coordination geometry, typically octahedral, in the same place in multiple crystal structure determinations of the same protein. In the case of thrombin, the water molecule singled out by valence calculations is, in fact, a bound Na ion as demonstrated by molecular replacement with Rb+. Valence calculations provide an accurate screening of water in protein crystals and may help identify Na+ binding sites of functional importance.
...
PMID:Valence screening of water in protein crystals reveals potential Na+ binding sites. 859 92

Low molecular weight, water-soluble saccharide complexes of oxovanadium(IV) have been synthesized and characterized by analytical, spectroscopic and electrochemical techniques. All the complexes were found to be mononuclear, possessing the VO2+ moiety. These are shown to be hydrolytically and oxidatively stable over a wide range of pH (1-12) and have been extensively characterized by absorption and EPR spectroscopy and by electrochemistry. Several correlations have been drawn from the data generated. Some of these complexes have been demonstrated to possess in vitro RNase inhibition activity with no effect on DNase. This suggests that these molecules closely mimic the substrate portion of the RNase-catalysed RNA hydrolysis and can act as transition-state analogues to RNase.
...
PMID:Transition metal saccharide chemistry and biology: synthesis, characterization, electrochemistry and EPR studies of oxovanadium (IV) complexes of saccharides and their derivatives and in vitro interaction of some of these with ribonuclease and deoxyribonuclease. 880 75

Molecular dynamics simulations have been performed on solvated G-actin bound to ADP and ATP, starting with the crystal structure of the actin-DNase 1 complex, including a Ca2+ or Mg2+ ion at the high-affinity divalent cation-binding site. Water molecules have been found to enter the nucleotide-binding site (phosphate vicinity) along two pathways, from the side where the nucleotide base is exposed to water, as well as from the opposite side. The water channels suggest a "back-door" mechanism for ATP hydrolysis in which the phosphate is released to a side opposite that of nucleotide binding and unbinding. The simulations also reveal a propensity of G-actin to alter its crystallographic structure toward the filamentous structure. Domain movement closes the nucleotide cleft, the movement being more pronounced for bound Mg2+. The conformational change is interpreted as a response of the system to missing water molecules in the crystal structure. The structures arising in the simulations, classified according to nucleotide cleft separation and radius of gyration of the protein, fall into two distinct clusters: a cluster of states that are similar to the G-actin crystal structure, and a cluster of states with small cleft separation and with the subdomain 3/4 loop 264-273 detached from the protein. The latter states resemble the putative filamentous structure of actin, in which the loop connects the two strands of the actin filament.
...
PMID:Stability and dynamics of G-actin: back-door water diffusion and behavior of a subdomain 3/4 loop. 925 82

We examined the taxonomic position of seven Aeromonas isolates, recovered from Flemish and Scottish drinking water production plants and reservoirs, which were previously recognized by numerical analysis of genomic AFLP fingerprints as members of an unknown Aeromonas taxon that most closely resembled the species Aeromonas bestiarum (DNA hybridization group [HG] 2). The new phenotypic and DNA-DNA hybridization data obtained in this study show that the A. bestiarum-like strains constitute a separate Aeromonas species, for which the name Aeromonas popoffii sp. nov. is being proposed. The new species exhibited an internal DNA relatedness ranging from 79 to 100% and was 22 to 63% related to the type or reference strains of other Aeromonas spp. The highest DNA binding values were determined with A. bestiarum (51 to 63%), followed by Aeromonas hydrophila sensu stricto (HG1; 50 to 60%) and Aeromonas salmonicida (HG3; 39 to 55%). Although fingerprints generated by ribotyping and cellular fatty acid analysis often were highly similar, minor differences between the respective fingerprints were of significance for the differentiation of A. popoffii from its closest taxonomic neighbors, HG1, HG2, and HG3. Phenotypically, all seven strains of A. popoffii were positive for acid and gas production from D-glucose and glycerol, growth in KCN broth, arginine dihydrolase, DNase, Voges-Proskauer reaction, and resistance to vibriostatic agent O/129 and ampicillin but displayed negative reactions for production of urease, tryptophan deaminase, ornithine decarboxylase, and lysine decarboxylase (LDC). None of the strains displayed strong hemolytic activity. The lack of D-sucrose fermentation and LDC production and the ability to utilize DL-lactate as the sole energy and carbon source were useful characteristics for the biochemical separation of A. popoffii from A. bestiarum. Other Aeromonas spp. could be differentiated phenotypically from the new species by at least two features. The chromosomal G+C content of A. popoffii ranges from 57.7 to 59.6 mol%. Strain LMG 17541 is proposed as the type strain.
...
PMID:Aeromonas popoffii sp. nov., a mesophilic bacterium isolated from drinking water production plants and reservoirs. 933 24


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---