Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this report we present the first description of the isolation and partial characterization of the deoxyribonucleic acid (DNA) polymerase activity from two species of Mycoplasmatales, Mycoplasma orale type 1 and M. hyorhinis. We have identified only a single DNA polymerase species in the mycoplasma crude extracts, and the enzymes from the two organisms are very similar in their structural and enzymatic properties. The purified polymerase from each source has a specific activity of greater than 50,000 U/mg of protein, a sedimentation coefficient of 5.6s, and an estimated molecular weight by gel filtration of 130,000. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the most highly purified M. orale fraction contains a single major protein band of 130,000 daltons, which we believe may represent the polymerase protein. The enzymes are most reactive with gapped (activated) DNA and show a marked preference for this primer template over oligodeoxyribonucleotide-initiated homoribo- or homodeoxyribo-polymers. The most purified preparations are devoid of contaminating endonuclease activity and also appear to lack associated 5' leads to 3'- or 3' leads to 5'-exonuclease activities, as determined by highly sensitive assays. The absence of the 3' leads to 5'-exonuclease is particularly remarkable in that this activity is essentially ubiquitous among the DNA polymerases that have thus far been characterized from procaryotes.
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PMID:Purification and partial characterization of the principal deoxyribonucleic acid polymerase from Mycoplasmatales. 91 80

Pentoxifylline, a methylxanthine derivative and nonspecific type 4 phosphodiesterase inhibitor, has been used to improve survival of animals with sepsis and to attenuate lung injury in acute lung inflammation. The purpose of this study was to examine whether pentoxifylline would inhibit the expression of inflammatory cytokines, particularly tumor necrosis factor alpha (TNF), and thereby decrease the pathophysiology of acute porcine pleuropneumonia. E. coli lipopolysaccharide (LPS) and bacterial extracts of A. pleuropneumoniae--induced elevations in TNF mRNA which were fully abrogated by addition of pentoxifylline in both alveolar macrophage and neutrophil cultures. A 30% reduction in the level of LPS-induced interleukin (IL)-1beta mRNA levels also was achieved in macrophages. Pentoxifylline did not affect either IL-1alpha or IL-8 expression in vitro. Pentoxifylline therapy in vivo significantly reduced the number of band neutrophils in swine but did not reduce the pathology associated with pleuropneumonia, including changes in serum zinc, iron, or haptoglobin. Neither did it alter TNF, IL-1, IL-6, or IL-8 expression. Measurement of pentoxifylline and its metabolites in pig sera suggested that efficacious doses of pentoxifylline were probably not achieved in vivo. However, subcutaneous doses of pentoxifylline higher than 25 mg/kg produced transient diarrhea, vomiting, and tremors. These results suggest that pentoxifylline is an effective pharmacological tool for the dissection of cytokine regulation in vitro, but inhibitory concentrations may not be achievable for in vivo pharmacological use in swine.
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PMID:Effects of pentoxifylline on inflammatory cytokine expression and acute pleuropneumonia in swine. 1199 42

Contagious Bovine Pleuropneumonia caused by Mycoplasma mycoides subsp. mycoides small colony type is a respiratory disease of considerable economic importance in sub-Saharan Africa; control of the disease in Africa is hampered by diagnostic tests which are suited for herd-level but not for individual animal diagnostics. In the work presented we identified 22 potential immunogenic antigens of the Kenyan outbreak strain B237 by using phage display technology. We determined the relative strength of immunogenicity, the discriminatory capacity between bovine positive and negative sera, and the cross-reactivity with rabbit hyperimmune sera directed against 15 different mycoplasmal species. The three best-performing antigens, a conserved hypothetical protein (MSC_0636), a glycosyl transferase (MSC_0108), and an acyl carrier protein phosphodiesterase (MSC_0029) were considered candidate diagnostic proteins. They were expressed as GST-fusion proteins in Escherichia coli, purified, and used in an ELISA as solid phase antigens. The diagnostic potential of the recombinant antigens was tested using the sera of ten experimentally infected animals and six control animals. This prototype test resulted in 100% diagnostic sensitivity and specificity. In comparison, the complement fixation test and the competitive ELISA performed with a diagnostic sensitivity of 70% and 60%, respectively.
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PMID:Phage display-based identification and potential diagnostic application of novel antigens from Mycoplasma mycoides subsp. mycoides small colony type. 1990 Jul 69

Glycerophosphodiester phosphodiesterase (GlpQ) metabolizes glycerophosphorylcholine from the lung epithelium to produce free choline, which is transformed into phosphorylcholine and presented on the surfaces of many respiratory pathogens. Two orthologs of glpQ genes are found in Streptococcus pneumoniae: glpQ, with a membrane motif, is widespread in pneumococci, whereas glpQ2, which shares high similarity with glpQ in Haemophilus influenzae and Mycoplasma pneumoniae, is present only in S. pneumoniae serotype 3, 6B, 19A, and 19F strains. Recently, serotype 19A has emerged as an epidemiological etiology associated with invasive pneumococcal diseases. Thus, we investigated the pathophysiological role of glpQ2 in a serotype 19A sequence type 320 (19AST320) strain, which was the prevalent sequence type in 19A associated with severe pneumonia and invasive pneumococcal disease in pediatric patients. Mutations in glpQ2 reduced phosphorylcholine expression and the anchorage of choline-binding proteins to the pneumococcal surface during the exponential phase, where the mutants exhibited reduced autolysis and lower natural transformation abilities than the parent strain. The deletion of glpQ2 also decreased the adherence and cytotoxicity to human lung epithelial cell lines, whereas these functions were indistinguishable from those of the wild type in complementation strains. In a murine respiratory tract infection model, glpQ2 was important for nasopharynx and lung colonization. Furthermore, infection with a glpQ2 mutant decreased the severity of pneumonia compared with the parent strain, and glpQ2 gene complementation restored the inflammation level. Therefore, glpQ2 enhances surface phosphorylcholine expression in S. pneumoniae 19AST320 during the exponential phase, which contributes to the severity of pneumonia by promoting adherence and host cell cytotoxicity.
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PMID:Impact of the glpQ2 gene on virulence in a Streptococcus pneumoniae serotype 19A sequence type 320 strain. 2542 69