Polyphosphate
Mostrando 37-48 de 240 artigos, teses e dissertações.
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37. Purification and characterization of polyphosphate kinase from Neisseria meningitidis.
The important human pathogens Neisseria meningitidis and Neisseria gonorrhoeae accumulate phosphate in the form of polyphosphate (A. Noegel and E. C. Gotschlich, J. Exp. Med. 157:2049-2060, 1983), and the localization of more than half of this long-chain polymer on the exterior of the cells suggests a function as a protective, capsule-like coating. To enable
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38. Inorganic polyphosphate kinase and adenylate kinase participate in the polyphosphate:AMP phosphotransferase activity of Escherichia coli
Polyphosphate kinase (PPK), responsible for the processive synthesis of inorganic polyphosphate (polyP) from ATP in Escherichia coli, can transfer in reverse the terminal phosphate residue of polyP to ADP to yield ATP. PolyP also serves as a donor in a polyP:AMP phosphotransferase (PAP) activity observed in extracts of Acinetobacter johnsonii and Myxoc
The National Academy of Sciences.
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39. Presence of polyphosphate of low molecular weight in zygomycetes.
Polyphosphate of average chain length corresponding to 10 phosphate units was detected in the mycelial extract of zygomycetes. Gel electrophoresis techniques commonly used for the separation and characterization of acidic mucopolysaccharides were successfully used for the detection, purification, and characterization of the polyphosphate.
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40. Cloning and characterization of the meningococcal polyphosphate kinase gene: production of polyphosphate synthesis mutants.
The pathogenic Neisseria species accumulate polyphosphate to levels between 10 and 20% of their total phosphate content. However, the significance of this compound for the growth and pathogenicity of these species is not understood. A previous report (C.R. Tinsley, B.N. Manjula, and E.C. Gotschlich, Infect. Immun. 61:3703-3710, 1993) describes the purificati
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41. Polyphosphate levels in nongrowing cells of Saccharomyces mellis as determined by magnesium ion and the phenomenon of "Uberkompensation".
Magnesium ion enhances the maximum amount of polyphosphate that resting phosphate-starved cells of Saccharomyces mellis can store by increasing the length of time the cells will continue assimilating phosphate. The divalent cation has no effect on the rate of formation of polymer. As much as 12 times more polyphosphate is formed in cells incubated in reactio
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42. Thermotoga maritima Phosphofructokinases: Expression and Characterization of Two Unique Enzymes
A pyrophosphate-dependent phosphofructokinase (PPi-PFK) and an ATP-dependent phosphofructokinase (ATP-PFK) from Thermotoga maritima have been cloned and characterized. The PPi-PFK is unique in that the Km and Vmax values indicate that polyphosphate is the preferred substrate over pyrophosphate; the enzyme in reality is a polyphosphate-dependent PFK. The ATP-
American Society for Microbiology.
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43. Nuclear Magnetic Resonance Studies of Poly(3-Hydroxybutyrate) and Polyphosphate Metabolism in Alcaligenes eutrophus
The metabolic pathways of poly(3-hydroxybutyrate) (PHB) and polyphosphate in the microorganism Alcaligenes eutrophus H16 were studied by 1H, 13C, and 31P nuclear magnetic resonance (NMR) spectroscopy and by conventional analytical techniques. A. eutrophus cells accumulated two storage polymers of PHB and polyphosphate in the presence of carbon and phosphate
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44. Utilization by Escherichia coli of a high-molecular-weight, linear polyphosphate: roles of phosphatases and pore proteins.
We observed that wild-type Escherichia coli utilized a linear polyphosphate with a chain length of 100 phosphate residues (poly-P100) as the sole source of phosphate in growth medium. A mutation in the gene phoA of alkaline phosphatase or phoB, the positive regulatory gene, prevented growth in this medium. Since no alkaline phosphatase activity was detected
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45. Polyphosphates in Intraradical and Extraradical Hyphae of an Arbuscular Mycorrhizal Fungus, Gigaspora margarita
The amount of polyphosphate in the intraradical and extraradical hyphae of Gigaspora margarita was estimated from successive extractions with trichloroacetic acid (TCA), EDTA, and phenol-chloroform (PC). In the intraradical hyphae, most of the polyphosphate was present in TCA- and EDTA-soluble (short-chain and long-chain) fractions, whereas most of the polyp
American Society for Microbiology.
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46. Putative structure and functions of a poly-beta-hydroxybutyrate/calcium polyphosphate channel in bacterial plasma membranes.
A poly-beta-hydroxybutyrate complex extracted from the plasma membranes of genetically competent Escherichia coli contained polyhydroxybutyrate:polyphosphate:calcium in molar ratios approximating 1:1:0.5. The chain length of the polyhydroxybutyrate was estimated as 120-200 subunits, and that of the polyphosphate was estimated as 130-170 subunits. The extract
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47. Cloning, heterologous expression, and chromosomal localization of human inositol polyphosphate 1-phosphatase.
Inositol polyphosphate 1-phosphatase, an enzyme in the phosphatidylinositol signaling pathway, catalyzes the hydrolysis of the 1 position phosphate from inositol 1,3,4-trisphosphate and inositol 1,4-bisphosphate. We used a cDNA that encodes bovine inositol polyphosphate 1-phosphatase as a probe to isolate the human counterpart by low-stringency hybridization
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48. Transcription of ppk from Acinetobacter sp. Strain ADP1, Encoding a Putative Polyphosphate Kinase, Is Induced by Phosphate Starvation
Polyphosphate kinase (Ppk) catalyzes the formation of polyphosphate from ATP. We cloned the ppk gene (2,073 bp) from Acinetobacter sp. strain ADP1; this gene encodes a putative polypeptide of 78.6 kDa with extensive homology to polyphosphate kinase from Escherichia coli and other bacteria. Chromosomal disruption of ppk by inserting a transcriptionally fused
American Society for Microbiology.