Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Polyphosphates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed2000

Molecular analysis of polyphosphate accumulation in bacteria.

The dynamic behavior of inorganic polyphosphate (polyP), its accumulation and disappearance, is the most striking aspect of polyP metabolism in bacteria. Imbalance between polyP synthesis and degradation results in fluctuations of polyP by 100- to 1000-fold. We here review recent results with respect to this polyP metabolism in bacteria. PolyP accumulation in response to amino acid starvation, accompanied by increased levels of stringent factors, has been observed in Escherichia coli. Inhibition by stringent factors of polyphosphatase interrupts the dynamic balance between the synthesis and degradation of polyP, accounting for polyP accumulation. Polyphosphate kinase is required for activation of intracellular protein degradation, which is required for adaptation at the onset of amino acid starvation. The adaptation to amino acid starvation is mediated by the network of stringent response and polyP metabolism. PolyP accumulation independent of stringent response has also been observed. Novobiocin, an inhibitor for DNA gyrase, stimulated accumulation of polyP but not that of stringent factors. However, a temperature-sensitive DNA gyrase mutant did not exhibit polyP accumulation at the non-permissive temperature. Antagonistic relationship of polyP to nucleic acid synthesis, explored by Harold, appears to be more complicated. We discuss relationship of Pi regulation to polyP accumulation in E. coli and Klebsiella aerogenes. A function of polyP as an in vivo phosphagen affecting polyP accumulation is also discussed.

Adaptation, Physiological↗
PubMed2000

Microbial selection of polyphosphate-accumulating bacteria in activated sludge wastewater treatment processes for enhanced biological phosphate removal.

Activated sludge processes with alternating anaerobic and aerobic conditions (the anaerobic-aerobic process) have been successfully used for enhanced biological phosphate removal (EBPR) from wastewater. It is known that polyphosphate-accumulating bacteria (PAB) play an essential role for EBPR in the anaerobic-aerobic process. The present paper reviews limited information available on the metabolism and the microbial community structure of EBPR, highlighting the microbial ecological selection of PAB in EBPR processes. Exposure of microorganisms to alternate carbon-rich anaerobic environments and carbon-poor aerobic environments in the anaerobic-aerobic process induces the key metabolic characteristics of PAB, which include organic substrate uptake followed by its conversion to stored polyhydroxyalkanoate (PHA) and hydrolysis of intracellular polyphosphate accompanied by subsequent Pi release under anaerobic conditions. Intracellular glycogen is assumed to function as a regulator of the redox balance in the cell. Storage of glycogen is a key strategy for PAB to maintain the redox balance in the anaerobic uptake of various organic substrates, and hence to win in the microbial selection. Acinetobacter spp., Microlunatus phosphovorus, Lampropedia spp., and the Rhodocyclus group have been reported as candidates of PAB. PAB may not be composed of a few limited genospecies, but involve phylogenetically and taxonomically diverse groups of bacteria. To define microbial community structure of EBPR processes, it is needed to look more closely into the occurrence and behavior of each species of PAB in various EBPR processes mainly by molecular methods because many of PAB seem to be impossible to culture.

Acinetobacter↗
PubMed2000

Effect of ethanol on structural transitions of DNA and polyphosphates under Ca2+ ions action in mixed solutions.

In the present work using the IR spectroscopy method the effect of ethanol on structural transitions of DNA and polyphosphates under the action of Ca2+ ions in mixed solutions containing ethanol (0-25 vol.%) was studied. It was shown that, on its interaction with Ca2+ ions, in aqueous and mixed solutions DNA becomes transformed into compact form. With the increase of concentration of ethanol the degree of Ca2+-induced DNA compactisation rises. It was found that, in mixed solutions containing ethanol, Ca2+-induced DNA compactisation depends not only on the solution's dielectric permeability but also on the solution structure. On stabilisation of the water structure in the presence of low ethanol concentrations a stabilisation of the DNA macromolecule occurs that leads to the increase of the Ca2+ ion concentration necessary for DNA compactisation. Comparison of the effects of ethanol on Ca2+-induced structural transitions in DNA and polyphosphates in mixed solvents permits to suppose that at alcohol concentrations in solution resulting in disruption of the water spatial structure, some peculiarities are observed in the behavior of those molecules whose hydrophobic interactions are essential.

Calcium↗
PubMed2001

Quantitative analysis of the elemental composition and the mass of bacterial polyphosphate bodies using STEM EDX.

The quantitative analysis of laboratory grown organisms (Plectonema boryanum and Staphylococcus aureus) revealed that a typical in vivo polyphosphate body (PPB) contains O (4.3 x 10(-8) microg), C (1.2 x 10(-8) microg), P (6.7 x 10(-9) microg), Mg (1.3 x 10(-9) microg), Ca (6.7 x 10(-10) microg), K (6.7 x 10(-10) microg), Fe (6.0 x 10(-10) microg), S (5.4 x 10(-10) microg) and Al (5.9 x 10(-10) microg). Quantitative X-ray analysis of samples from nature showed PPB contain O (1.63 x 10(-8) microg), C (4.75 x 10(-9) microg), P (2.50 x 10(-9) microg), Mg (5.0 x 10(-10) microg), Ca (2.50 x 10(-10) microg), K (2.50 x 10(-10) microg), Fe (2.25 x 10(-10) microg) and S (2.0 x 10(-10) microg). The mass of an average polyphosphate body was 6.7 x 10(-8) microg for P. boryanum, 2.5 x 10(-8) microg for S. aureus and for microbes from the natural environment 6.3 x 10(-8) microg. The results indicate that the PPB may have other unknown functions in addition to essential element storage, acting as a detoxification method by sequestering heavy metals and providing a homeostasis system in the cell.

Bacteria↗
PubMed1992

The soybean vegetative storage proteins VSP alpha and VSP beta are acid phosphatases active on polyphosphates.

The soybean vegetative storage protein genes (vspA, and vspB) are regulated in a complex manner developmentally and in response to external stimuli such as wounding and water deficit. The proteins accumulate to almost one-half the amount of soluble leaf protein when soybean plants are continually depodded and have been identified as storage proteins because of their abundance and pattern of expression in plant tissues. We have shown that purified VSP homodimers (VSP alpha and VSP beta) and heterodimers (VSP alpha/beta) possess acid phosphatase activity (alpha = 0.3-0.4 units/mg; beta = 2-4 units/mg; alpha/beta = 7-10 units/mg). Specific activities were determined by monitoring o-carboxyphenyl phosphate (0.7 mM) cleavage at pH 5.5 (VSP alpha) or pH 5.0 (VSP alpha/beta and VSP beta) in 0.15 M sodium acetate buffer at 25 degrees C. These enzymes are active over a broad pH range, maintaining greater than 40% of maximal activity from pH 4.0 to 6.5 and having maximal activity at pH 5.0-5.5. They are inactivated by sodium fluoride, sodium molybdate, and heating at 70 degrees C for 10 min. These phosphatases can liberate Pi from several different substrates, including napthyl acid phosphate, carboxyphenyl phosphate, sugar-phosphates, glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, phosphoenolpyruvate, ATP, ADP, PPi, and short chain polyphosphates. VSP alpha/beta cleaved phosphoenolpyruvate, ATP, ADP, PPi, and polyphosphates most efficiently. Apparent Km and Vmax values at 25 degrees C and pH 5.0 were 42 microM and 2.0 mumol/min/mg, 150 microM and 4.2 mumol/min/mg, and 420 microM and 4.1 mumol/min/mg, for tetrapolyphosphate, pyrophosphate, and phosphoenolpyruvate, respectively.

Acid Phosphatase↗
PubMed2006

The effect of polyphosphates on streptococci isolated from mastitis cases.

The effect of 0.01, 0.02, 0.03, 0.05, 0.6, 0.8 and 0.9% of polyphosphate mixture on 5 strains of Streptococcus agalactiae, 2 strains of Streptococcus dysgalactiae and 3 strains of Steptococcus uberis in blood agar in vitro and in milk was examined. It was found that the growth of all strains of the above mentioned bacteria was completely inhibited by 0.03% phosphate mixture in blood agar. In milk, however, the amount of polyphosphate mixture necessary for total inhibition was, from 0.6 to 0.9%, depending on the strain.

Animals↗
PubMed1989

One single lysine residue is responsible for the special interaction between polyphosphate and the outer membrane porin PhoE of Escherichia coli.

Site-directed mutagenesis was performed with the phosphate starvation-inducible outer membrane porin PhoE of Escherichia coli K-12 to study the molecular basis of its anion selectivity. Lysines 18, 29, 64, and 125 were replaced by glutamic acids, and the properties of the mutant porins were investigated in in vivo and in vitro experiments. Lipid bilayer experiments showed that all these mutations had no influence on the pore structure because PhoE and the mutants had the same single channel conductance in KCl solution. Selectivity measurements revealed that the mutations changed the ionic selectivity of PhoE, but the change was dependent on the location of the lysine. Replacement of Lys18 and Lys29 by glutamic acid had a relatively small influence. The effect of the Lys64 substitution was somewhat larger, and the effect of the replacement of Lys125 resulted in the most drastic change in selectivity and in the loss of the interaction of PhoE with polyphosphate, whereas the replacement of the other lysines had no effect on the polyphosphate interaction behavior. The results are consistent with the assumption that the charge spot in PhoE consists of only 1 lysine per monomer, located in position 125 of the primary sequence and probably close to the pore interior.

Bacterial Outer Membrane Proteins↗
PubMed1989

ATP- and polyphosphate-mediated stimulation of pp60c-src kinase activity in extracts from vascular smooth muscle.

Recently, we reported that pp60c-src kinase activity was present in adult bovine coronary arterial smooth muscle and showed that the activity of the enzyme in in vitro immunoprecipitation assays was stimulated 20-60-fold by ATP (Di Salvo, J., Gifford, D., and Kokkinakis, A. (1988) Biochem. Biophys. Res. Commun. 153, 388-394). In the present study, ATP-mediated stimulation of activity was also demonstrated in extracts from aortic vascular smooth muscle. In contrast, no stimulation was apparent in extracts from brain. Stimulation of activity in vascular preparations was also induced with beta,gamma-imidoadenosine 5'-triphosphate (AMP.PNP), a nonmetabolizable analog of ATP, and with several other polyphosphates including ADP and sodium pyrophosphate. No stimulation occurred in response to monophosphates such as AMP or KH2PO4. As expected, the specific activity of pp60c-src in brain extracts did not change when the amount of extracted protein included in immunoprecipitation mixtures was increased. Unexpectedly, however, the specific activity of the vascular enzyme decreased markedly as the amount of extracted protein subjected to immunoprecipitation was increased. Following stimulation of pp60c-src in vascular extracts with ATP, the enzyme behaved in a fashion similar to pp60c-src extracted from brain. That is, the enhanced specific activity of the stimulated vascular enzyme did not decrease with increasing amounts of extracted protein. Moreover, mixing experiments in which vascular smooth muscle extracts were added to brain extracts showed that the muscle extracts contained a factor which inhibited pp60c-src kinase activity. This inhibition was blocked when the mixed extracts were immunoprecipitated in the presence of ATP, or when inhibitory extract was treated with trypsin. Taken together, these data suggest that pp60c-src kinase activity in vascular tissue may be subject to a novel regulatory mechanism involving an inhibitory protein factor which can be nullified by polyphosphates.

Adenosine Diphosphate↗
PubMed1985

[Metabolic characteristics of polyphosphates and other macroergic phosphorus compounds in relation to the degree of penicillin production and growth conditions of Penicillium chrysogenum].

Metabolism of macroergic phosphorus compounds was studied in high- and low-productive isogenic strains of Penicillium chrysogenum. It was shown that the levels of the high-polymer polyphosphates (fractions PP1, PP2 and PP3) in the strain intensively producing penicillin were 2-3 times higher than those in the low-productive strain by the 2nd day of the fermentation process (the period of penicillin production). The levels of pyrophosphate and ATP in the mycelium during the fermentation process did not significantly differ in the strains. The study on the relation between metabolism of the high-molecular polyphosphates and conditions of the culture growth and antibiotic production revealed that their accumulation was connected with biosynthetic processes giving rise to the growth of P. chrysogenum, while their consumption with penicillin production. The dynamics of the pyrophosphatase and polyphosphatase activity in the mycelium of the strains was studied.

Adenosine Triphosphate↗
PubMed1983

Changes of ATP, polyphosphate and K+ contents in Saccharomyces carlsbergensis during uptake of Mn2+ and glucose.

The process of prolonged Mn2+ uptake by the yeast Saccharomyces carlsbergensis in the presence of 100 mM glucose and in the absence of phosphate can be divided into two steps. The first step (0-20 min) of Mn2+ uptake (4.3 mumol/g of wet cells) is characterized by an intense K+ efflux (23.8 mumol/g), synthesis of high molecular weight polyphosphate (HPP) (8.1 mumol/g) and decrease of ATP content (0.06 mumol/g). Simultaneously about 0.6 mumol of glucose is taken up and the level of low molecular weight polyphosphate (LPP) remains practically unchanged. The second step (20-120 min) of Mn2+ uptake (15.6 mumol/g) is characterized by a drop in HPP (16.6 mumol/g) and the synthesis of LPP (19.0 mumol/g). The ATP content decreases by 0.87 mumol/g as compared to the control, while that of K+ increases (5.7 mumol/g). During the first step of Mn2+ uptake the energy of the K+ concentration gradient may be used both for Mn2+ influx (2K+: 1Mn2+) and synthesis of HPP (1P:1.9K+). During the second step the Mn2+ accumulation is apparently driven by HPP conversion into LPP (1:1) and by ATPases serving the Mn2+/H+ exchange.

Adenosine Triphosphate↗
PubMed1994

Genetically altered levels of inorganic polyphosphate in Escherichia coli.

The ppk gene encoding polyphosphate kinase (PPK), the enzyme in Escherichia coli that makes long chains of polyphosphate (polyP) reversibly from ATP, was disrupted by insertion of a kanamycin resistance gene. Expression of the exopolyphosphatase gene (ppx) immediately downstream of ppk in the operon was likewise disrupted. Cells were also transformed with a high-copy-number plasmid bearing ppk. Genetically altered polyP levels were estimated in cell extracts by the PPK conversion of ADP to ATP. PolyP levels (microgram/10(11) cells) near 2.0 were reduced in the ppk(-)-ppx- mutants to 0.16 and increased more than 100-fold (e.g. 220) in cells transformed with multiple copies of ppk. Mutant cells, lacking the long polyP chains, showed a growth lag following dilution of a stationary-phase culture. PolyP-deficient cells exhibit a striking phenotype in their failure to survive in stationary phase and loss of resistance to heat (55 degrees C) and to oxidants (42 mM H2O2). High polyP levels are also associated with reduced survival.

Adenosine Triphosphate↗
PubMed1993

An exopolyphosphatase of Escherichia coli. The enzyme and its ppx gene in a polyphosphate operon.

A gene, ppx, that encodes a novel exopolyphosphatase of 513 amino acids (58,133 Da) was found downstream of the gene for polyphosphate kinase, ppk. Transcription of the ppx gene depends on the ppk promoters, indicating a polyphosphate (polyP) operon of ppk and ppx. Exopolyphosphatase, purified to homogeneity from overproducing cells, is judged to be a dimer of 58-kDa subunits. Orthophosphate is released processively from the ends of polyP approximately 500 residues long, but chains of approximately 15 residues compete poorly with polyP as substrate; ATP is not a substrate. Mg2+ (1 mM) and a high concentration of K+ (175 mM) support optimal activity.

Acid Anhydride Hydrolases↗
PubMed1997

The function of inositol high polyphosphate binding proteins.

The inositol phosphate metabolism network has been found to be much more complex than previously thought, as more and more inositol phosphates and their metabolizing enzymes have been discovered. Some of the inositol phosphates have been shown to have biological activities, but little is known about their signal transduction mechanisms except for that of inositol 1,4,5-trisphosphate. The recent discovery, however, of a number of binding proteins for inositol high polyphosphate [inositol 1,3,4,5-tetrakisphosphate (IP4), inositol 1,3,4,5,6-pentakisphosphate, or inositol hexakisphosphate] enables us to speculate on the physiological function of these compounds. In this article we focus on two major issues: (1) the roles of inositol high polyphosphates in vesicular trafficking, especially exocytosis, and (2) pleckstrin homology domain-containing IP4 binding proteins involved in the Ras signaling pathway.

Amino Acid Sequence↗
PubMed1983

[Nucleoside polyphosphates: occurrence, metabolism and function].

Procaryotes have regulatory systems allowing to vary the metabolism in response to nutritional variations, to reduce the growth, and to start development. Nucleoside polyphosphates are mediators of coordinated alterations of metabolism. In this review, after a brief recall of the characteristics of the stringent response, the occurrence, determinations, and the metabolism of the nucleoside polyphosphates are presented. The representation of the pleiotropic effects includes the regulation of the protein synthesis and of the protein synthesis apparatus, of the protein turnover, of the N- and carbohydrate metabolism, of the formation of cell membranes and cell walls as well as the possible function of the development.

Adenine Nucleotides↗
PubMed2000

Selective degradation of 2'-adenylated diadenosine tri- and tetraphosphates, Ap(3)A and Ap(4)A, by two specific human dinucleoside polyphosphate hydrolases.

It is known that the interferon-inducible 2',5'-oligoadenylate synthetase can catalyze the 2'-adenylation of various diadenosine polyphosphates. However, catabolism of those 2'-adenylated compounds has not been investigated so far. This study shows that the mono- and bis-adenylated (or mono- and bis-deoxyadenylated) diadenosine triphosphates are not substrates of the human Fhit (fragile histidine triad) protein, which acts as a typical dinucleoside triphosphate hydrolase (EC 3.6.1.29). In contrast, the diadenosine tetraphosphate counterparts are substrates for the human (asymmetrical) Ap(4)A hydrolase (EC 3.6.1.17). The relative rates of the hydrolysis of 0.15 mM AppppA, (2'-pdA)AppppA, and (2'-pdA)AppppA(2"'-pdA) catalyzed by the latter enzyme were determined as 100:232:38, respectively. The asymmetrical substrate was hydrolyzed to ATP + (2'-pdA)AMP (80%) and to (2'-pdA)ATP + AMP (20%). The human Fhit protein, for which Ap(4)A is a poor substrate, did not degrade the 2'-adenylated diadenosine tetraphosphates either. The preference of the interferon-inducible 2'-5' oligoadenylate synthetase to use Ap(3)A over Ap(4)A as a primer for 2'-adenylation and the difference in the recognition of the 2'-adenylated diadenosine triphosphates versus the 2'-adenylated diadenosine tetraphosphates by the dinucleoside polyphosphate hydrolases described here provide a mechanism by which the ratio of the 2'-adenylated forms of the signalling molecules, Ap(3)A and Ap(4)A, could be regulated in vivo.

Acid Anhydride Hydrolases↗
PubMed1994

Priming of the respiratory burst of human neutrophils by the diadenosine polyphosphates, AP4A and AP3A: role of intracellular calcium.

The diadenosine polyphosphates, Ap3A and Ap4A, prime the respiratory burst of human neutrophils after stimulation with fMet-Leu-Phe. Maximal priming of oxidase activity occurred at 600-800 microM Ap3A and Ap4A, compared with maximal priming observed at 200 microM ATP. The time course of priming of the oxidase by all 3 nucleotides was very rapid, being detectable if added within 10 s of fMet-Leu-Phe. All 3 nucleotides also elicited increases in intracellular Ca2+ levels and there was a close concentration-dependency between the extent of priming and the increase in intracellular Ca2+. However, at low concentrations of nucleotides (< 50 microM Ap3A and Ap4A and < 0.1 microM ATP) priming of the oxidase was observed without detectable increases in intracellular Ca2+. These observations indicate that diadenosine polyphosphates may be novel regulators of neutrophil function and that priming of oxidase activity may occur via mechanisms that are either dependent or independent of increases in intracellular Ca2+.

Adenosine Triphosphate↗
PubMed1999

The IalA invasion gene of Bartonella bacilliformis encodes a (de)nucleoside polyphosphate hydrolase of the MutT motif family and has homologs in other invasive bacteria.

The product of the ialA invasion gene of Bartonella bacilliformis has been expressed as a thioredoxin fusion protein. It is a (di)nucleoside polyphosphate hydrolase of the MutT motif protein family with strong sequence similarity to plant diadenosine tetraphosphate hydrolases. It hydrolyses nucleoside and dinucleoside polyphosphates with four or more phosphate groups, always producing an NTP as one product. Diadenosine tetraphosphate (Ap4A) is the preferred substrate with a Km of 10 microM and a kcat of 3.0 s-1. It is inhibited by Ca2+ and F- (Ki = 30 microM). Hydrolysis of Ap4A in H218O yielded [18O]AMP as the only labelled product. In terms of sequence, reaction mechanism and properties, IalA is very similar to eukaryotic Ap4A hydrolases and unlike previously described bacterial Ap4A hydrolases. Homologs are present in the genomes of other invasive pathogens. They may function to reduce stress-induced dinucleotide levels during invasion and so enhance pathogen survival.

Acid Anhydride Hydrolases↗
PubMed1995

Identification and chromosomal mapping of the mouse inositol polyphosphate 1-phosphatase gene.

A mouse inositol polyphosphate 1-phosphatase (Inpp1) cDNA fragment (348 bp) was amplified by means of the polymerase chain reaction using a mouse cDNA library as template with primers designed from published human and bovine cDNA sequences. We isolated a 1623-bp full-length Inpp1 cDNA from a mouse brain cDNA library using this amplified cDNA fragment as probe. Amino acid sequences of mouse, human, and bovine inositol polyphosphate 1-phosphatase are highly conserved. Northern blot analysis shows a major transcript of 1.65-kb mRNA and several higher molecular weight mRNAs that are expressed in a variety of mouse tissues. Utilizing the Jackson Lab backcross DNA panel map service, we mapped Inpp1 to chromosome 1, 1.06 cM proximal to Ctla4.

Amino Acid Sequence↗