Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thermal damage to the outer membrane of Escherichia coli W3110 was studied. When E. coli cells were heated at 55 degrees C in 50 mM Tris-hydrochloride buffer at pH 8.0, surface blebs were formed on the cell envelope, mainly at the septa of dividing cells. Membrane lipids were released from the cells during the heating period, and part of the released lipids formed vesicle-like structures from the membrane. This vesicle fraction had a lipopolysaccharide to phospholipid ratio similar to that of the outer membrane of intact cells, whereas it had a lower content of protein than the isolated outer membrane. After heating bacterial cells at 55 degrees C for 30 min, the resulting leakage from the cells of a periplasmic enzyme, alkaline phosphatase, amounted to 52% of the total activity, whereas no release of a cytoplasmic enzyme, glucose-6-phosphate dehydrogenase, was detected. The results obtained suggest that surface blebs formed by heat treatment almost completely consist of the outer membrane and that the blebs may be gradually released from the cell surface into the heating menstruum to partially form vesicles.
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PMID:Heat-induced blebbing and vesiculation of the outer membrane of Escherichia coli. 705 91

The lipopolysaccharide of the recombinant strain Salmonella minnesota r595-207 expressing the genus-specific epitope of Chlamydia lipopolysaccharide [Holst, O., Brade, L., Kosma, P. and Brade, H. (1991) J. Bacteriol, 173, 1862-1866] was sequentially de-O- and de-N-acylated by mild hydrazinolysis and treatment with 4 M KOH, respectively. The resulting mixture of compounds was separated by high-performance anion-exchange chromatography and gel-permeation chromatography, yielding four oligosaccharide phosphates two of which were readily identified by their 1H-NMR- and 13C-NMR spectra as alpha-Kdo-(2-4)-alpha-Kdo-(2-6)-beta-D-GlcpN-(1-6)-alpha-D-Glcp N 1,4'-bisphosphate (tetrasaccharide bisphosphate; Kdo = 3-deoxy-D-manno-octulopyranosonic acid) and alpha-Kdo-(2-8)-alpha-Kdo-(2-4)-alpha-Kdo-(2-6)-beta-D-GlcpN-(1-6) -alpha-D- GlcpN 1,4'-bisphosphate (pentasaccharide bisphosphate) [Holst, O., Broer, W., Thomas-Oates, J.E., Mamat, U. and Brade, H. (1993) Eur. J. Biochem. 214, 703-710]. The structures of the other two compounds were established by chemical analysis, NMR spectroscopy, and fast-atom-bombardment mass spectrometry as alpha-Kdo- (2-4)-alpha-Kdo-(2-6)-beta-D-GlcpN-(1-6)-alpha-D-GlcpN 1-phosphate (tetrasaccharide 1-phosphate) and alpha-Kdo-(2-8)-alpha-Kdo-(2-4)-alpha-Kdo-(2-6)-beta-D-GlcpN-(1-6) -alpha-D- GlcpN 1-phosphate (pentasaccharide 1-phosphate). alpha-Kdo-(2-4)-alpha-Kdo-(2-6)-beta-D-GlcpN-(1-6)-alpha/beta- D-GlcpN 4'-phosphate (tetrasaccharide 4'-phosphate) and alpha-Kdo-(2-8)-alpha-Kdo-(2-4)-alpha-Kdo-(2-6)-beta-D-GlcpN-(1-6) -alpha/beta-D-GlcpN 4'-phosphate (pentasaccharide 4'-phosphate) were prepared from the 1,4'-bisphosphates isolated from the recombinant strain Escherichia coli F515-207 by treatment with alkaline phosphatase and purification by high-performance anion-exchange chromatography and gel-permeation chromatography. Their structures were characterised by chemical analysis, NMR spectroscopy, and fast-bombardment mass spectrometry.
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PMID:Preparation and structural analysis of oligosaccharide monophosphates obtained from the lipopolysaccharide of recombinant strains of Salmonella minnesota and Escherichia coli expressing the genus-specific epitope of Chlamydia lipopolysaccharide. 751 46

Human dental pulp cells were treated with 1, 10, and 100 micrograms/ml of lipopolysaccharide (LPS). The effects of treatment were examined by measurement of the DNA content, protein content, and alkaline phosphatase activity of the cells. LPS samples were purified from Porphyromonas gingivalis, Porphyromonas endodontalis, and Fusobacterium nucleatum isolated from root canals, and Escherichia coli 0111:B4 LPS was used as a positive control. At a concentration of 1 microgram/ml, none of the LPSs caused any change in the production of DNA or protein, whereas the amount of DNA was increased at 10 micrograms/ml and inhibited at 100 micrograms/ml. Protein synthesis was decreased by LPSs at both 10 and 100 micrograms/ml. Alkaline phosphatase activity was not changed at any concentration of LPS tested.
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PMID:Effects of lipopolysaccharides on human dental pulp cells. 756 54

During augmented synthesis of periplasmic alkaline phosphatase by various strains of Escherichia coli, the outer membrane of bacterial cells becomes permeable for both the enzyme and ethidium ions which do not generally penetrate inside the cells of gram-negative bacteria. In the absence of the lipoprotein in the outer membrane, its permeability for these compounds as well as its sensitivity to membranotropic agents increases, thus testifying to the influence of the lipoprotein upon certain properties of the outer membrane. A competitive interaction was found between the lipoprotein and lipopolysaccharide content in the outer membrane and their content and alkaline phosphatase secretion into the external medium. It is suggested that increased permeability of the E. coli outer membrane during augmented synthesis of the secreted protein is due to impaired biogenesis of membrane components.
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PMID:[Permeability of the Escherichia coli outer membrane for ethidium ions and periplasmic alkaline phosphatase during increased synthesis of it]. 757 70

Recent evidence suggests that the production of nitric oxide (NO) may have important roles in the regulation of osteoblast and osteoclast metabolism. The present study was performed to investigate the effects of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) on the expression of inducible NO-synthase (iNOS) and to measure high-output production of NO by primary rat osteoblasts and osteoblastic cell lines ROS 17/2.8, MC3T3-E1 and MG-63. In addition, we have investigated if NO may mediate some of the effects of these cytokines on osteoblast metabolism. Northern blots and immunocytochemistry revealed time-dependent iNOS messenger RNA and protein expression in primary rat osteoblasts in response to cytokine treatment. Reverse transcription polymerase chain reaction amplified an 807-base pair (bp) product from ROS 17/2.8 cells, which had a size and restriction enzyme-cut pattern identical to that predicted for authentic rat iNOS. Nitrite accumulation in culture medium was induced by IFN-gamma in a time- and dose-dependent manner and inhibited by cotreatment with inhibitors of NOS activity and by dexamethasone. IL-1 beta, TNF-alpha, and bacterial lipopolysaccharide were found to have weak stimulatory effects on nitrite production on their own. However, IL-1 beta and TNF-alpha showed strong synergy with IFN-gamma, but, surprisingly, lipopolysaccharide was found to exert potent inhibitory effects on IFN-gamma-induced nitrite synthesis. Basal production of nitrite and induction of its synthesis was similarly observed with primary rat osteoblasts as well as ROS 17/2.8, MC3T3-E1, and MG-63 cell lines. Cytokine-induced NO production significantly reduced osteoblast activity, as was evidenced by inhibition of DNA synthesis, cell proliferation, alkaline phosphatase activity, and osteocalcin production. The results provide evidence for a basal expression of iNOS activity and show that the iNOS messenger RNA, protein, and enzyme activity are all induced by cytokines across the species. The data further suggest that osteoblast-derived NO may have an important role in mediation of localized bone destruction associated with inflammatory bone diseases such as rheumatoid arthritis.
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PMID:Cytokine-stimulated expression of inducible nitric oxide synthase by mouse, rat, and human osteoblast-like cells and its functional role in osteoblast metabolic activity. 758 94

Pseudomonas aeruginosa blebs-off membrane vesicles (MVs) into culture medium during normal growth. Release of these vesicles increased approximately threefold after exposure of the organism to four times the MIC of gentamicin. Natural and gentamicin-induced membrane vesicles (n-MVs and g-MVs and g-MVs, respectively) were isolated by filtration and differential centrifugation, and several of their biological activities were characterized. Electron microscopy of both n-MVs and g-MVs revealed that they were spherical bilayer MVs with a diameter of 50 to 150 nm. Immunoelectron microscopy and Western blot (immunoblot) analysis of the vesicles demonstrated the presence of B-band lipopolysaccharide (LPS), with a slightly higher proportion of B-band LPS in g-MVs than in n-MVs. A-band LPS was occasionally detected in g-MVs but not in n-MVs. In addition to LPS, several enzymes, such as phospholipase C, protease, hemolysin, and alkaline phosphatase, which are known to contribute to the pathogenicity of Pseudomonas infections were found to be present in both vesicle types. Both types of vesicles contained DNA, with a significantly higher content in g-MVs. These vesicles could thus play an important role in genetic transformation and disease by serving as a transport vehicle for DNA and virulence factors and are presumably involved in septic shock.
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PMID:Virulence factors are released from Pseudomonas aeruginosa in association with membrane vesicles during normal growth and exposure to gentamicin: a novel mechanism of enzyme secretion. 760 73

Primary biliary cirrhosis (PBC) is a chronic, progressive, cholestatic liver disease. Interleukin-1 beta (IL-1 beta) may play a role in the pathogenesis of PBC by contributing to altered immune function and fibrosis. Colchicine or methotrexate has some beneficial effects in the treatment of PBC, and also affects interleukin-1 (IL-1). Therefore, we prospectively studied the synthesis of IL-1 beta by peripheral blood mononuclear cells (PBMC) from 42 patients with PBC entered into a randomized, double-blind, double-dummy controlled trial of colchicine and methotrexate. PBMC obtained at entry, 6, 12, 18, and 24 months were stimulated to produce IL-1 beta with phytohemagglutinin (PHA), lipopolysaccharide (LPS), Staphylococcus epidermidis, recombinant IL-2, or mitochondrial antigen. Patients in the two treatment groups did not differ at entry in biochemical measures or liver histological stage. Over 24 months in both groups, serum bilirubin and histologic stage remained stable and alkaline phosphatase decreased significantly. For all patients, synthesis of IL-1 beta increased constitutively and in response to immune-mediated stimulants (PHA, IL-2, and mitochondrial antigen) but not the bacterial stimulants LPS or S epidermidis. Compared with levels of IL-1 beta at entry, PHA induced increases for patients treated with methotrexate (12, 18, and 24 months) or colchicine (18 and 24 months). At 24 months, IL-2-induced IL-1 beta synthesis was increased in patients treated with methotrexate, whereas S epidermidis-induced IL-1 beta was enhanced in colchicine-treated patients. Before treatment, IL-1 beta production did not relate to severity of disease except in response to S epidermidis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Synthesis of interleukin-1 beta in primary biliary cirrhosis: relationship to treatment with methotrexate or colchicine and disease progression. 763 20

By using an in vitro bone-forming culture system, the chick periosteal osteogenesis (CPO) model, the direct effects on osteogenesis of sonicated extracts derived from oral bacteria were examined. Both extracts from bacterial species having strong associations with periodontal diseases (Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia, hereinafter referred to as suspected periodontopathogens) and extracts from species not correlated with periodontal disease (Streptococcus sanguis, Veillonella atypica, and Prevotella denticola, hereinafter referred to as nonpathogenic bacteria) were tested. All bacterial cultures were grown under standard anaerobic culture conditions. Sonicated bacterial extracts were prepared from the bacterial pellet. These were added in various proportions to the CPO cultures. Parameters of osteogenesis, including alkaline phosphatase activity, calcium and P(i) accumulation, and collagen synthesis, were measured in 6-day-old cultures. Compared with controls grown in the absence of bacterial products, osteogenesis was inhibited significantly in cultures treated with extracts derived from the suspected periodontopathogens. No osteogenic inhibition was observed in cultures treated with extracts from the nonpathogenic bacteria. These results suggest that the ability to inhibit osteogenesis in vitro may be a pathogenic property shared by a limited group of species. Further characterization of the P. gingivalis extracts revealed that both proteinaceous and nonproteinaceous products, including lipopolysaccharide, were able to inhibit osteogenesis. P. gingivalis extract-mediated inhibition of osteogenesis in CPO cultures was blocked by indomethacin, implicating prostaglandins in the regulation of the bacterial effects. The bacterial extracts had either reversible or irreversible inhibitory effects on osteogenesis when added after differentiation or before/during differentiation of bone cells, respectively.
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PMID:Characterization of inhibitory effects of suspected periodontopathogens on osteogenesis in vitro. 764 57

Attenuated Salmonella are useful oral vaccine vectors capable of carrying multiple heterologous antigen genes, but optimal expression of foreign antigens has not yet been achieved. We hypothesized that Salmonella phoP-activated genes, which are transcriptionally activated within antigen-processing macrophages, could prove useful for delivery of heterologous antigens to the immune system. We have created a suicide vector that allows the stable chromosomal insertion of heterologous antigen genes within the phoP-activated gene C (pagC) of Salmonella and permits the expression of heterologous antigens as fusion proteins between the first 84 amino acids of PagC and the chosen antigen. The Escherichia coli phoA gene encoding alkaline phosphatase was cloned into this vector; the resultant plasmid was used to construct Salmonella typhimurium strains that express PagC-alkaline phosphatase fusion proteins from a single chromosomal gene copy. Such strains were administered orally and i.p. as vaccines to BALB/c mice and compared with control strains expressing alkaline phosphatase constitutively. After 3 weeks, mouse sera were analyzed for IgG responses to S. typhimurium lipopolysaccharide and alkaline phosphatase. Remarkably, though all mice had comparable antibody responses to lipopolysaccharide, only mice immunized with strains bearing phoP-activated fusion genes had antibody responses to the heterologous antigen. We conclude that expression of a heterologous antigen from an S. typhimurium in vivo-induced promoter that is activated within macrophages markedly enhances the immunogenicity of a model antigen expressed from a single chromosomal gene copy.
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PMID:Macrophage-inducible expression of a model antigen in Salmonella typhimurium enhances immunogenicity. 770 46

Effect of dibutyryl cyclic adenosine monophosphate (dbt cAMP) on alkaline phosphatase (APase) of mitogen stimulated murine B lymphocytes was studied. Addition of dbtcAMP to lipopolysaccharide (LPS) stimulated B cells enhanced APase activity in a dose dependent and synergistic manner. dbtcAMP also stimulated the proliferative response of LPS treated B lymphocytes. On the other hand, when B lymphocytes stimulated with anti-immunoglobulin (anti-Ig) were treated with dbtcAMP neither DNA synthesis nor APase activity was enhanced. These results suggest that cAMP is a potent synergistic activator of APase in B lymphocytes committed to proliferation.
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PMID:Positive regulatory role of cAMP on alkaline phosphatase activity and proliferation of mitogen stimulated B lymphocytes. 777 90


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