Molecular regulation of santalol biosynthesis in Santalum album L.

PubMed

Rani, Arti; Ravikumar, Puja; Reddy, Manjunatha Damodara; Kush, Anil

2013-09-25

Santalum album L. commonly known as East-Indian sandal or chandan is a hemiparasitic tree of family santalaceae. Santalol is a bioprospecting molecule present in sandalwood and any effort towards metabolic engineering of this important moiety would require knowledge on gene regulation. Santalol is a sesquiterpene synthesized through mevalonate or non-mevalonate pathways. First step of santalol biosynthesis involves head to tail condensation of isopentenyl pyrophosphate (IPP) with its allylic co-substrate dimethyl allyl pyrophosphate (DMAPP) to produce geranyl pyrophosphate (GPP; C10 - a monoterpene). GPP upon one additional condensation with IPP produces farnesyl pyrophosphate (FPP; C15 - an open chain sesquiterpene). Both the reactions are catalyzed by farnesyl diphosphate synthase (FDS). Santalene synthase (SS), a terpene cyclase catalyzes cyclization of open ring FPP into a mixture of cyclic sesquiterpenes such as α-santalene, epi-β-santalene, β-santalene and exo bergamotene, the main constituents of sandal oil. The objective of the present work was to generate a comprehensive knowledge on the genes involved in santalol production and study their molecular regulation. To achieve this, sequences encoding farnesyl diphosphate synthase and santalene synthase were isolated from sandalwood using suppression subtraction hybridization and 2D gel electrophoresis technology. Functional characterization of both the genes was done through enzyme assays and tissue-specific expression of both the genes was studied. To our knowledge, this is the first report on studies on molecular regulation, and tissue-specific expression of the genes involved in santalol biosynthesis. © 2013.

Heterologous expression of the mevalonic acid pathway in cyanobacteria enhances endogenous carbon partitioning to isoprene.

PubMed

Bentley, Fiona K; Zurbriggen, Andreas; Melis, Anastasios

2014-01-01

Heterologous expression of the isoprene synthase gene in the cyanobacterium Synechocystis PCC 6803 conferred upon these microorganisms the property of photosynthetic isoprene (C₅H₈) hydrocarbons production. Continuous production of isoprene from CO₂ and H₂O was achieved in the light, occurring via the endogenous methylerythritol-phosphate (MEP) pathway, in tandem with the growth of Synechocystis. This work addressed the issue of photosynthetic carbon partitioning between isoprene and biomass in Synechocystis. Evidence is presented to show heterologous genomic integration and cellular expression of the mevalonic acid (MVA) pathway genes in Synechocystis endowing a non-native pathway for carbon flux amplification to isopentenyl-diphosphate (IPP) and dimethylallyl-diphosphate (DMAPP) precursors of isoprene. Heterologous expression of the isoprene synthase in combination with the MVA pathway enzymes resulted in photosynthetic isoprene yield improvement by approximately 2.5-fold, compared with that measured in cyanobacteria transformed with the isoprene synthase gene only. These results suggest that the MVA pathway introduces a bypass in the flux of endogenous cellular substrate in Synechocystis to IPP and DMAPP, overcoming flux limitations of the native MEP pathway. The work employed a novel chromosomal integration and expression of synthetic gene operons in Synechocystis, comprising up to four genes under the control of a single promoter, and expressing three operons simultaneously. This is the first time an entire biosynthetic pathway with seven recombinant enzymes has been heterologously expressed in a photosynthetic microorganism. It constitutes contribution to the genetic engineering toolkit of photosynthetic microorganisms and a paradigm in the pursuit of photosynthetic approaches for the renewable generation of high-impact products.

Dynamics of Monoterpene Formation in Spike Lavender Plants

PubMed Central

Kutzner, Erika; Huber, Claudia; Segura, Juan; Arrillaga, Isabel

2017-01-01

The metabolic cross-talk between the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways was analyzed in spike lavender (Lavandula latifolia Med) on the basis of 13CO2-labelling experiments using wildtype and transgenic plants overexpressing the 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), the first and key enzyme of the MVA pathway. The plants were labelled in the presence of 13CO2 in a gas chamber for controlled pulse and chase periods of time. GC/MS and NMR analysis of 1,8-cineole and camphor, the major monoterpenes present in their essential oil, indicated that the C5-precursors, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) of both monoterpenes are predominantly biosynthesized via the MEP pathway. Surprisingly, overexpression of HMGR did not have significant impact upon the crosstalk between the MVA and MEP pathways indicating that the MEP route is the preferred pathway for the synthesis of C5 monoterpene precursors in spike lavender. PMID:29257083

Vγ9Vδ2 T cell activation by strongly agonistic nucleotidic phosphoantigens.

PubMed

Moulin, Morgane; Alguacil, Javier; Gu, Siyi; Mehtougui, Asmaa; Adams, Erin J; Peyrottes, Suzanne; Champagne, Eric

2017-12-01

Human Vγ9Vδ2 T cells can sense through their TCR tumor cells producing the weak endogenous phosphorylated antigen isopentenyl pyrophosphate (IPP), or bacterially infected cells producing the strong agonist hydroxyl dimethylallyl pyrophosphate (HDMAPP). The recognition of the phosphoantigen is dependent on its binding to the intracellular B30.2 domain of butyrophilin BTN3A1. Most studies have focused on pyrophosphate phosphoantigens. As triphosphate nucleotide derivatives are naturally co-produced with IPP and HDMAPP, we analyzed their specific properties using synthetic nucleotides derived from HDMAPP. The adenylated, thymidylated and uridylated triphosphate derivatives were found to activate directly Vγ9Vδ2 cell lines as efficiently as HDMAPP in the absence of accessory cells. These antigens were inherently resistant to terminal phosphatases, but apyrase, when added during a direct stimulation of Vγ9Vδ2 cells, abrogated their stimulating activity, indicating that their activity required transformation into strong pyrophosphate agonists by a nucleotide pyrophosphatase activity which is present in serum. Tumor cells can be sensitized with nucleotide phosphoantigens in the presence of apyrase to become stimulatory, showing that this can occur before their hydrolysis into pyrophosphates. Whereas tumors sensitized with HDMAPP rapidly lost their stimulatory activity, sensitization with nucleotide derivatives, in particular with the thymidine derivative, induced long-lasting stimulating ability. Using isothermal titration calorimetry, binding of some nucleotide derivatives to BTN3A1 intracellular domain was found to occur with an affinity similar to that of IPP, but much lower than that of HDMAPP. Thus, nucleotide phosphoantigens are precursors of pyrophosphate antigens which can deliver strong agonists intracellularly resulting in prolonged and strengthened activity.

A Whole-Cell Phenotypic Screening Platform for Identifying Methylerythritol Phosphate Pathway-Selective Inhibitors as Novel Antibacterial Agents

PubMed Central

Johnson, L. Jeffrey

2012-01-01

Isoprenoid biosynthesis is essential for survival of all living organisms. More than 50,000 unique isoprenoids occur naturally, with each constructed from two simple five-carbon precursors: isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Two pathways for the biosynthesis of IPP and DMAPP are found in nature. Humans exclusively use the mevalonate (MVA) pathway, while most bacteria, including all Gram-negative and many Gram-positive species, use the unrelated methylerythritol phosphate (MEP) pathway. Here we report the development of a novel, whole-cell phenotypic screening platform to identify compounds that selectively inhibit the MEP pathway. Strains of Salmonella enterica serovar Typhimurium were engineered to have separately inducible MEP (native) and MVA (nonnative) pathways. These strains, RMC26 and CT31-7d, were then used to differentiate MVA pathway- and MEP pathway-specific perturbation. Compounds that inhibit MEP pathway-dependent bacterial growth but leave MVA-dependent growth unaffected represent MEP pathway-selective antibacterials. This screening platform offers three significant results. First, the compound is antibacterial and is therefore cell permeant, enabling access to the intracellular target. Second, the compound inhibits one or more MEP pathway enzymes. Third, the MVA pathway is unaffected, suggesting selectivity for targeting the bacterial versus host pathway. The cell lines also display increased sensitivity to two reported MEP pathway-specific inhibitors, further biasing the platform toward inhibitors selective for the MEP pathway. We demonstrate development of a robust, high-throughput screening platform that combines phenotypic and target-based screening that can identify MEP pathway-selective antibacterials simply by monitoring optical density as the readout for cell growth/inhibition. PMID:22777049

Ethanol induced astaxanthin accumulation and transcriptional expression of carotenogenic genes in Haematococcus pluvialis.

PubMed

Wen, Zewen; Liu, Zhiyong; Hou, Yuyong; Liu, Chenfeng; Gao, Feng; Zheng, Yubin; Chen, Fangjian

2015-10-01

Haematococcus pluvialis is one of the most promising natural sources of astaxanthin. However, inducing the accumulation process has become one of the primary obstacles in astaxanthin production. In this study, the effect of ethanol on astaxanthin accumulation was investigated. The results demonstrated that astaxanthin accumulation occurred with ethanol addition even under low-light conditions. The astaxanthin productivity could reach 11.26 mg L(-1) d(-1) at 3% (v/v) ethanol, which was 2.03 times of that of the control. The transcriptional expression patterns of eight carotenogenic genes were evaluated using real-time PCR. The results showed that ethanol greatly enhanced transcription of the isopentenyl diphosphate (IPP) isomerase genes (ipi-1 and ipi-2), which were responsible for isomerization reaction of IPP and dimethylallyl diphosphate (DMAPP). This finding suggests that ethanol induced astaxanthin biosynthesis was up-regulated mainly by ipi-1 and ipi-2 at transcriptional level, promoting isoprenoid synthesis and substrate supply to carotenoid formation. Thus ethanol has the potential to be used as an effective reagent to induce astaxanthin accumulation in H. pluvialis. Copyright © 2015 Elsevier Inc. All rights reserved.

[Advances in isoprene synthase research].

PubMed

Gou, Yan; Liu, Zhongchuan; Wang, Ganggang

2017-11-25

Isoprene emission can lead to significant consequence for atmospheric chemistry. In addition, isoprene is a chemical compound for various industrial applications. In the organisms, isoprene is produced by isoprene synthase that eliminates the pyrophosphate from the dimethylallyl diphosphate. As a key enzyme of isoprene formation, isoprene synthase plays an important role in the process of natural emission and artificial synthesis of isoprene. So far, isoprene synthase has been found in various plants. Isoprene synthases from different sources are of conservative structural and similar biochemical properties. In this review, the biochemical and structural characteristics of isoprene synthases from different sources were compared, the catalytic mechanism of isoprene synthase was discussed, and the perspective application of the enzyme in bioengineering was proposed.

Two unexpected promiscuous activities of the iron-sulfur protein IspH in production of isoprene and isoamylene.

PubMed

Ge, Deyong; Xue, Yanfen; Ma, Yanhe

2016-05-11

Bacillus species, possessing the methylerythritol phosphate (MEP) pathway for the synthesis of isoprenoid feedstock, are the highest producers of isoprene among bacteria; however, the enzyme responsible for isoprene synthesis has not been identified. The iron-sulfur protein IspH is the final enzyme of the MEP pathway and catalyses the reductive dehydration of (E)-4-hydroxy-3-methyl-2-butenyl diphosphate (HMBPP) to form isopentenyl diphosphate and dimethylallyl diphosphate (DMAPP). In this study, we demonstrated two unexpected promiscuous activities of IspH from alkaliphilic Bacillus sp. N16-5, which can produce high levels of isoprene. Bacillus sp. N16-5 IspH could catalyse the formation of isoprene from HMBPP and the conversion of DMAPP into a mixture of 2-methyl-2-butene and 3-methyl-1-butene. Both reactions require an electron transfer system, such as that used for HMBPP dehydration. Isoprene and isoamylene synthesis in Bacillus sp. N16-5 was investigated and the reaction system was reconstituted in vitro, including IspH, ferredoxin and ferredoxin-NADP(+)-reductase proteins and NADPH. The roles of specific IspH protein residues were also investigated by site-directed mutagenesis experiments; two variants (H131N and E133Q) were found to have lost the HMBPP reductase activity but could still catalyse the formation of isoprene. Overexpression of IspH H131N in Bacillus sp. N16-5 resulted in a twofold enhancement of isoprene production, and the yield of isoprene from the strain expressing E133Q was increased 300% compared with the wild-type strain. IspH from Bacillus sp. N16-5 is a promiscuous enzyme that can catalyse formation of isoprene and isoamylene. This enzyme, especially the H131N and E133Q variants, could be used for the production of isoprene from HMBPP.

Functional characterization of a geraniol synthase-encoding gene from Camptotheca acuminata and its application in production of geraniol in Escherichia coli.

PubMed

Chen, Fei; Li, Wei; Jiang, Liangzhen; Pu, Xiang; Yang, Yun; Zhang, Guolin; Luo, Yinggang

2016-09-01

Geraniol synthase (GES) catalyzes the conversion of geranyl diphosphate (GPP) into geraniol, an acyclic monoterpene alcohol that has been widely used in many industries. Here we report the functional characterization of CaGES from Camptotheca acuminata, a camptothecin-producing plant, and its application in production of geraniol in Escherichia coli. The full-length cDNA of CaGES was obtained from overlap extension PCR amplification. The intact and N-terminus-truncated CaGESs were overexpressed in E. coli and purified to homogeneity. Recombinant CaGES showed the conversion activity from GPP to geraniol. To produce geraniol in E. coli using tCaGES, the biosynthetic precursor GPP should be supplied and transferred to the catalytic pocket of tCaGES. Thus, ispA(S80F), a mutant of farnesyl diphosphate (FPP) synthase, was prepared to produce GPP via the head-to-tail condensation of isoprenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). A slight increase of geraniol production was observed in the fermentation broth of the recombinant E. coli harboring tCaGES and ispA(S80F). To enhance the supply of IPP and DMAPP, the encoding genes involved in the whole mevalonic acid biosynthetic pathway were introduced to the E. coli harboring tCaGES and the ispA(S80F) and a significant increase of geraniol yield was observed. The geraniol production was enhanced to 5.85 ± 0.46 mg L(-1) when another copy of ispA(S80F) was introduced to the above recombinant strain. The following optimization of medium composition, fermentation time, and addition of metal ions led to the geraniol production of 48.5 ± 0.9 mg L(-1). The present study will be helpful to uncover the biosynthetic enigma of camptothecin and tCaGES will be an alternative to selectively produce geraniol in E. coli with other metabolic engineering approaches.

Clavine Alkaloids Gene Clusters of Penicillium and Related Fungi: Evolutionary Combination of Prenyltransferases, Monooxygenases and Dioxygenases

PubMed Central

Martín, Juan F.; Liras, Paloma

2017-01-01

The clavine alkaloids produced by the fungi of the Aspergillaceae and Arthrodermatacea families differ from the ergot alkaloids produced by Claviceps and Neotyphodium. The clavine alkaloids lack the extensive peptide chain modifications that occur in lysergic acid derived ergot alkaloids. Both clavine and ergot alkaloids arise from the condensation of tryptophan and dimethylallylpyrophosphate by the action of the dimethylallyltryptophan synthase. The first five steps of the biosynthetic pathway that convert tryptophan and dimethylallyl-pyrophosphate (DMA-PP) in chanoclavine-1-aldehyde are common to both clavine and ergot alkaloids. The biosynthesis of ergot alkaloids has been extensively studied and is not considered in this article. We focus this review on recent advances in the gene clusters for clavine alkaloids in the species of Penicillium, Aspergillus (Neosartorya), Arthroderma and Trychophyton and the enzymes encoded by them. The final products of the clavine alkaloids pathways derive from the tetracyclic ergoline ring, which is modified by late enzymes, including a reverse type prenyltransferase, P450 monooxygenases and acetyltransferases. In Aspergillus japonicus, a α-ketoglutarate and Fe2+-dependent dioxygenase is involved in the cyclization of a festuclavine-like unknown type intermediate into cycloclavine. Related dioxygenases occur in the biosynthetic gene clusters of ergot alkaloids in Claviceps purpurea and also in the clavine clusters in Penicillium species. The final products of the clavine alkaloid pathway in these fungi differ from each other depending on the late biosynthetic enzymes involved. An important difference between clavine and ergot alkaloid pathways is that clavine producers lack the enzyme CloA, a P450 monooxygenase, involved in one of the steps of the conversion of chanoclavine-1-aldehyde into lysergic acid. Bioinformatic analysis of the sequenced genomes of the Aspergillaceae and Arthrodermataceae fungi showed the presence of clavine gene clusters in Arthroderma species, Penicillium roqueforti, Penicillium commune, Penicillium camemberti, Penicillium expansum, Penicillium steckii and Penicillium griseofulvum. Analysis of the gene clusters in several clavine alkaloid producers indicates that there are gene gains, gene losses and gene rearrangements. These findings may be explained by a divergent evolution of the gene clusters of ergot and clavine alkaloids from a common ancestral progenitor six genes cluster although horizontal gene transfer of some specific genes may have occurred more recently. PMID:29186777

Optimization of the IPP Precursor Supply for the Production of Lycopene, Decaprenoxanthin and Astaxanthin by Corynebacterium glutamicum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heider, Sabine A. E.; Wolf, Natalie; Hofemeier, Arne

The biotechnologically relevant bacterium Corynebacterium glutamicum, currently used for the million ton-scale production of amino acids for the food and feed industries, is pigmented due to synthesis of the rare cyclic C50 carotenoid decaprenoxanthin and its glucosides. The precursors of carotenoid biosynthesis, isopenthenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate, are synthesized in this organism via the methylerythritol phosphate (MEP) or non-mevalonate pathway. Terminal pathway engineering in recombinant C. glutamicum permitted the production of various non-native C50 and C40 carotenoids. Here, the role of engineering isoprenoid precursor supply for lycopene production by C. glutamicum was characterized. Overexpression of dxs encodingmore » the enzyme that catalyzes the first committed step of the MEP-pathway by chromosomal promoter exchange in a prophage-cured, genome-reduced C. glutamicum strain improved lycopene formation. Similarly, an increased IPP supply was achieved by chromosomal integration of two artificial operons comprising MEP pathway genes under the control of a constitutive promoter. Combined overexpression of dxs and the other six MEP pathways genes in C. glutamicum strain LYC3-MEP was not synergistic with respect to improving lycopene accumulation. Based on C. glutamicum strain LYC3-MEP, astaxanthin could be produced in the milligrams per gram cell dry weight range when the endogenous genes crtE, crtB, and crtI for conversion of geranylgeranyl pyrophosphate to lycopene were coexpressed with the genes for lycopene cyclase and β-carotene hydroxylase from Pantoea ananatis and carotene C(4) oxygenase from Brevundimonas aurantiaca.« less

Synthetic Routes to Methylerythritol Phosphate Pathway Intermediates and Downstream Isoprenoids

PubMed Central

Jarchow-Choy, Sarah K; Koppisch, Andrew T; Fox, David T

2014-01-01

Isoprenoids constitute the largest class of natural products with greater than 55,000 identified members. They play essential roles in maintaining proper cellular function leading to maintenance of human health, plant defense mechanisms against predators, and are often exploited for their beneficial properties in the pharmaceutical and nutraceutical industries. Most impressively, all known isoprenoids are derived from one of two C5-precursors, isopentenyl diphosphate (IPP) or dimethylallyl diphosphate (DMAPP). In order to study the enzyme transformations leading to the extensive structural diversity found within this class of compounds there must be access to the substrates. Sometimes, intermediates within a biological pathway can be isolated and used directly to study enzyme/pathway function. However, the primary route to most of the isoprenoid intermediates is through chemical catalysis. As such, this review provides the first exhaustive examination of synthetic routes to isoprenoid and isoprenoid precursors with particular emphasis on the syntheses of intermediates found as part of the 2C-methylerythritol 4-phosphate (MEP) pathway. In addition, representative syntheses are presented for the monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), triterpenes (C30) and tetraterpenes (C40). Finally, in some instances, the synthetic routes to substrate analogs found both within the MEP pathway and downstream isoprenoids are examined. PMID:25009443

An Enzymatic Platform for the Synthesis of Isoprenoid Precursors

PubMed Central

Rodriguez, Sofia B.; Leyh, Thomas S.

2014-01-01

The isoprenoid family of compounds is estimated to contain ∼65,000 unique structures including medicines, fragrances, and biofuels. Due to their structural complexity, many isoprenoids can only be obtained by extraction from natural sources, an inherently risky and costly process. Consequently, the biotechnology industry is attempting to genetically engineer microorganisms that can produce isoprenoid-based drugs and fuels on a commercial scale. Isoprenoid backbones are constructed from two, five-carbon building blocks, isopentenyl 5-pyrophosphate and dimethylallyl 5-pyrophosphate, which are end-products of either the mevalonate or non-mevalonate pathways. By linking the HMG-CoA reductase pathway (which produces mevalonate) to the mevalonate pathway, these building block can be synthesized enzymatically from acetate, ATP, NAD(P)H and CoA. Here, the enzymes in these pathways are used to produce pathway intermediates and end-products in single-pot reactions and in remarkably high yield, ∼85%. A strategy for the regio-specific incorporation of isotopes into isoprenoid backbones is developed and used to synthesize a series of isotopomers of diphosphomevalonate, the immediate end-product of the mevalonate pathway. The enzymatic system is shown to be robust and capable of producing quantities of product in aqueous solutions that meet or exceed the highest levels achieved using genetically engineered organisms in high-density fermentation. PMID:25153179

Mechanistic insights into Mg2+-independent prenylation by CloQ from classical molecular mechanics and hybrid quantum mechanics/molecular mechanics molecular dynamics simulations.

PubMed

Bayse, Craig A; Merz, Kenneth M

2014-08-05

Understanding the mechanism of prenyltransferases is important to the design of engineered proteins capable of synthesizing derivatives of naturally occurring therapeutic agents. CloQ is a Mg(2+)-independent aromatic prenyltransferase (APTase) that transfers a dimethylallyl group to 4-hydroxyphenylpyruvate in the biosynthetic pathway for clorobiocin. APTases consist of a common ABBA fold that defines a β-barrel containing the reaction cavity. Positively charged basic residues line the inside of the β-barrel of CloQ to activate the pyrophosphate leaving group to replace the function of the Mg(2+) cofactor in other APTases. Classical molecular dynamics simulations of CloQ, its E281G and F68S mutants, and the related NovQ were used to explore the binding of the 4-hydroxyphenylpyruvate (4HPP) and dimethylallyl diphosphate substrates in the reactive cavity and the role of various conserved residues. Hybrid quantum mechanics/molecular mechanics potential of mean force (PMF) calculations show that the effect of the replacement of the Mg(2+) cofactor with basic residues yields a similar activation barrier for prenylation to Mg(2+)-dependent APTases like NphB. The topology of the binding pocket for 4HPP is important for selective prenylation at the ortho position of the ring. Methylation at this position alters the conformation of the substrate for O-prenylation at the phenol group. Further, a two-dimensional PMF scan shows that a "reverse" prenylation product may be a possible target for protein engineering.

Identification of Isopentenol Biosynthetic Genes from Bacillus subtilis by a Screening Method Based on Isoprenoid Precursor Toxicity▿

PubMed Central

Withers, Sydnor T.; Gottlieb, Shayin S.; Lieu, Bonny; Newman, Jack D.; Keasling, Jay D.

2007-01-01

We have developed a novel method to clone terpene synthase genes. This method relies on the inherent toxicity of the prenyl diphosphate precursors to terpenes, which resulted in a reduced-growth phenotype. When these precursors were consumed by a terpene synthase, normal growth was restored. We have demonstrated that this method is capable of enriching a population of engineered Escherichia coli for those clones that express the sesquiterpene-producing amorphadiene synthase. In addition, we enriched a library of genomic DNA from the isoprene-producing bacterium Bacillus subtilis strain 6051 in E. coli engineered to produce elevated levels of isopentenyl diphosphate and dimethylallyl diphosphate. The selection resulted in the discovery of two genes (yhfR and nudF) whose protein products acted directly on the prenyl diphosphate precursors and produced isopentenol. Expression of nudF in E. coli engineered with the mevalonate-based isopentenyl pyrophosphate biosynthetic pathway resulted in the production of isopentenol. PMID:17693564

Biosynthesis of isoprene in Escherichia coli via methylerythritol phosphate (MEP) pathway.

PubMed

Zhao, Yaru; Yang, Jianming; Qin, Bo; Li, Yonghao; Sun, Yuanzhang; Su, Sizheng; Xian, Mo

2011-06-01

Isoprene is an aviation fuel of high quality and an important polymer building block in the synthetic chemistry industry. In light of high oil prices, sustained availability, and environmental concerns, isoprene from renewable materials is contemplated as a substitute for petroleum-based product. Escherichia coli with advantages over other wild microorganisms, is considered as a powerful host for biofuels and chemicals. Here, we constructed a synthetic pathway of isoprene in E. coli by introducing an isoprene synthase (ispS) gene from Populus nigra, which catalyzes the conversion of dimethylallyl diphosphate (DMAPP) to isoprene. To improve the isoprene production, we overexpressed the native 1-deoxy-D: -xylulose-5-phosphate (DXP) synthase gene (dxs) and DXP reductoisomerase gene (dxr) in E. coli, which catalyzed the first step and the second step of MEP pathway, respectively. The fed-batch fermentation results showed that overexpression of DXS is helpful for the improvement of isoprene production. Surprisingly, heterologous expression of dxs and dxr from Bacillus subtilis in the E. coli expressing ispS resulted in a 2.3-fold enhancement of isoprene production (from 94 to 314 mg/L). The promising results showed that dxs and dxr from B. subtilis functioned more efficiently on the enhancement of isoprene production than native ones. This could be caused by the consequence of great difference in protein structures of the two original DXSs. It could be practical to produce isoprene in E. coli via MEP pathway through metabolic engineering. This work provides an alternative way for production of isoprene by engineered E. coli via MEP pathway through metabolic engineering.

Heteromeric and homomeric geranyl diphosphate synthases from Catharanthus roseus and their role in monoterpene indole alkaloid biosynthesis.

PubMed

Rai, Avanish; Smita, Shachi S; Singh, Anup Kumar; Shanker, Karuna; Nagegowda, Dinesh A

2013-09-01

Catharanthus roseus is the sole source of two most important monoterpene indole alkaloid (MIA) anti-cancer agents: vinblastine and vincristine. MIAs possess a terpene and an indole moiety derived from terpenoid and shikimate pathways, respectively. Geranyl diphosphate (GPP), the entry point to the formation of terpene moiety, is a product of the condensation of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) by GPP synthase (GPPS). Here, we report three genes encoding proteins with sequence similarity to large subunit (CrGPPS.LSU) and small subunit (CrGPPS.SSU) of heteromeric GPPSs, and a homomeric GPPSs. CrGPPS.LSU is a bifunctional enzyme producing both GPP and geranyl geranyl diphosphate (GGPP), CrGPPS.SSU is inactive, whereas CrGPPS is a homomeric enzyme forming GPP. Co-expression of both subunits in Escherichia coli resulted in heteromeric enzyme with enhanced activity producing only GPP. While CrGPPS.LSU and CrGPPS showed higher expression in older and younger leaves, respectively, CrGPPS.SSU showed an increasing trend and decreased gradually. Methyl jasmonate (MeJA) treatment of leaves significantly induced the expression of only CrGPPS.SSU. GFP localization indicated that CrGPPS.SSU is plastidial whereas CrGPPS is mitochondrial. Transient overexpression of AmGPPS.SSU in C. roseus leaves resulted in increased vindoline, immediate monomeric precursor of vinblastine and vincristine. Although C. roseus has both heteromeric and homomeric GPPS enzymes, our results implicate the involvement of only heteromeric GPPS with CrGPPS.SSU regulating the GPP flux for MIA biosynthesis.

Biotransformation of menadione to its prenylated derivative MK-3 using recombinant Pichia pastoris.

PubMed

Li, Zhemin; Zhao, Genhai; Liu, Hui; Guo, Yugang; Wu, Hefang; Sun, Xiaowen; Wu, Xihua; Zheng, Zhiming

2017-07-01

Prenylated quinones, especially menaquinones, have significant physiological activities, but are arduous to synthesize efficiently. Due to the relaxed aromatic substrate specificity and prenylation regiospecificity at the ortho- site of the phenolic hydroxyl group, the aromatic prenyltransferase NovQ from Streptomyces may be useful in menaquinone synthesis from menadione. In this study, NovQ was overexpressed in Pichia pastoris. After fermentation optimization, NovQ production increased by 1617%. Then the different effects of metal ions, detergents and pH on the activity of purified NovQ were investigated to optimize the prenylation reaction. Finally, purified NovQ and cells containing NovQ were used for menadione prenylation in vitro and in vivo, respectively. Menaquinone-1 (MK-1) was detected as the only product in vitro with γ,γ-dimethylallyl pyrophosphate and menadione hydroquinol substrates. MK-3 at a concentration of 90.53 mg/L was detected as the major product of whole cell catalysis with 3-methyl-2-buten-1-ol and menadione hydroquinol substrates. This study realized whole cell catalysis converting menadione to menaquinones.

An enzyme-coupled continuous fluorescence assay for farnesyl diphosphate synthases

PubMed Central

Dozier, Jonathan K; Distefano, Mark D

2012-01-01

Farnesyl diphosphate synthase (FDPS) catalyzes the conversion of isopentenyl diphosphate and dimethylallyl diphosphate to farnesyl diphosphate, a crucial metabolic intermediate in the synthesis of cholesterol, ubiquinone and prenylated proteins; consequently, much effort has gone into developing inhibitors that target FDPS. Currently most FDPS assays use either radiolabeled substrates and are discontinuous, or monitor pyrophosphate release and not farnesyl diphosphate (FPP) creation. Here we report the development of a continuous coupled enzyme assay for FDPS activity that involves the subsequent incorporation of the FPP product of that reaction into a peptide via the action of protein farnesyltransferase (PFTase). By using a dansylated peptide whose fluorescence quantum yield increases upon farnesylation, the rate of FDPS-catalyzed FPP production can be measured. We show that this assay is more sensitive than existing coupled assays, that it can be used to conveniently monitor FDPS activity in a 96-well plate format and that it can reproduce IC50 values for several previously reported FDPS inhibitors. This new method offers a simple, safe and continuous method to assay FDPS activity that should greatly facilitate the screening of inhibitors of this important target. PMID:22085443

Studies on chalcone derivatives: complex formation, thermal behavior, stability constant and antioxidant activity.

PubMed

El-Sayed, Yusif S; Gaber, M

2015-02-25

The chalcone 3-[4'-dimethylaminophenyl]-1-(2-pyridyl) prop-2-en-1-one (DMAPP) and 3-(4'-diethylaminophenyl)-1-(2-pyridinyl) prop-2-en-1-one abbreviated as DEAPP have been synthesized and characterized with IR, (1)H NMR, (13)C NMR spectroscopic techniques as described previously (El-Daly et al., 2008; Gaber et al., 2009; El-Sayed, 2013). By using UV visible spectroscopy method the mole fraction ratio for copper with DMAPP and DEAPP complexes were determined and it was found to be 1:1. The stability constants of this complex have been determined by Job's method. The stability constant (Kf) of copper with DMAPP and DEAPP complexes in universal buffer pH=3.2 was determined to be 9.9×10(4) and 5.2×10(4) respectively. The effect of Cu(II) ion on the emission spectrum of the free chalcone is also assigned. Adherence to Beer's law and Ringbom optimum concentration ranges are determined. The thermal decomposition of the metal complexes is studied by TGA technique. The kinetic parameters like activation energy, pre-exponential factor and entropy of activation are estimated. The structure of complexes was energetically optimized through molecular mechanics applying MM(+) force field coupled with molecular dynamics simulation. The bond lengths and bond angles have been calculated to confirm the geometry of the ligands and their Cu(II) complexes. The mode of interaction of the chalcone to copper nanoparticles was studied. The apparent association constants of the colloidal copper nanoparticles:chalcone complexes in solution were evaluated using the spectral method and compared with the formation constant of the Cu(II) chalcone complexes. Antioxidant activity of these chalcones was evaluated by using 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging method, which showed that the antioxidant activity of DMAPP has higher value than the DEAPP. Semi-empirical study results showed that DMAPP have higher dipole moment than DEAPP. Copyright © 2014 Elsevier B.V. All rights reserved.

Studies on chalcone derivatives: Complex formation, thermal behavior, stability constant and antioxidant activity

NASA Astrophysics Data System (ADS)

El-Sayed, Yusif S.; Gaber, M.

2015-02-01

The chalcone 3-[4‧-dimethylaminophenyl]-1-(2-pyridyl) prop-2-en-1-one (DMAPP) and 3-(4‧-diethylaminophenyl)-1-(2-pyridinyl) prop-2-en-1-one abbreviated as DEAPP have been synthesized and characterized with IR, 1H NMR, 13C NMR spectroscopic techniques as described previously (El-Daly et al., 2008; Gaber et al., 2009; El-Sayed, 2013). By using UV visible spectroscopy method the mole fraction ratio for copper with DMAPP and DEAPP complexes were determined and it was found to be 1:1. The stability constants of this complex have been determined by Job's method. The stability constant (Kf) of copper with DMAPP and DEAPP complexes in universal buffer pH = 3.2 was determined to be 9.9 × 104 and 5.2 × 104 respectively. The effect of Cu(II) ion on the emission spectrum of the free chalcone is also assigned. Adherence to Beer's law and Ringbom optimum concentration ranges are determined. The thermal decomposition of the metal complexes is studied by TGA technique. The kinetic parameters like activation energy, pre-exponential factor and entropy of activation are estimated. The structure of complexes was energetically optimized through molecular mechanics applying MM+ force field coupled with molecular dynamics simulation. The bond lengths and bond angles have been calculated to confirm the geometry of the ligands and their Cu(II) complexes. The mode of interaction of the chalcone to copper nanoparticles was studied. The apparent association constants of the colloidal copper nanoparticles:chalcone complexes in solution were evaluated using the spectral method and compared with the formation constant of the Cu(II) chalcone complexes. Antioxidant activity of these chalcones was evaluated by using 1,1‧-diphenyl-2-picrylhydrazyl (DPPHrad) radicals scavenging method, which showed that the antioxidant activity of DMAPP has higher value than the DEAPP. Semi-empirical study results showed that DMAPP have higher dipole moment than DEAPP [1].

Enhanced performance of the methylerythritol phosphate pathway by manipulation of redox reactions relevant to IspC, IspG, and IspH.

PubMed

Zhou, Jia; Yang, Liyang; Wang, Chonglong; Choi, Eui-Sung; Kim, Seon-Won

2017-04-20

The 2C-methyl-D-erythritol 4-phosphate (MEP) pathway is a carbon-efficient route for synthesis of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), the building blocks of isoprenoids. However, practical application of a native or recombinant MEP pathway for the mass production of isoprenoids in Escherichia coli has been unsatisfactory. In this study, the entire recombinant MEP pathway was established with plasmids and used for the production of an isoprenoid, protoilludene. E. coli harboring the recombinant MEP pathway plasmid (ME) and a protoilludene synthesis pathway plasmid (AO) produced 10.4mg/L of protoilludene after 48h of culture. To determine the rate-limiting gene on plasmid ME, each constituent gene of the MEP pathway was additionally overexpressed on the plasmid AO. The additional overexpression of IPP isomerase (IDI) enhanced protoilludene production to 67.4mg/L. Overexpression of the Fpr and FldA protein complex, which could mediate electron transfer from NADPH to Fe-S cluster proteins such as IspG and IspH of the MEP pathway, increased protoilludene production to 318.8mg/L. Given that it is required for IspC as well as IspG/H, the MEP pathway has high demand for NADPH. To increase the supply of NADPH, a NADH kinase from Saccharomyces cerevisiae (tPos5p) that converts NADH to NADPH was introduced along with the deletion of a promiscuous NADPH-dependent aldehyde reductase (YjgB) that consumes NADPH. This resulted in a protoilludene production of 512.7mg/L. The results indicate that IDI, Fpr-FldA redox proteins, and NADPH regenerators are key engineering points for boosting the metabolic flux toward a recombinant MEP pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

Formation of Diketopiperazines by Penicillium italicum Isolated from Oranges

PubMed Central

Scott, Peter M.; Kennedy, Barry P. C.; Harwig, Joost; Chen, Y-K.

1974-01-01

Prolyl-2-(1′,1′-dimethylallyl)tryptophyldiketopiperazine and 12,13-dehydroprolyl-2-(1′,1′-dimethylallyl)tryptophyldiketopiperazine, known metabolites of Aspergillus ustus, were produced in low yield by Penicillium italicum in liquid culture and on unsterilized orange peel. PMID:4441068

Circadian rhythm of anti-fungal prenylated chromene in leaves of Piper aduncum.

PubMed

Morandim, Andreia de A; Bergamo, Débora Cristina B; Kato, Massuo Jorge; Cavalheiro, Alberto José; Bolzani, Vanderlan da S; Furlan, Maysa

2005-01-01

Leaves of Piper aduncum accumulate the anti-fungal chromenes methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (1) and methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate (2). The enzymatic formation of 2 from dimethylallyl diphosphate and 1 was investigated using cell-free extracts of the title plant. An HPLC assay for the prenylation reaction was developed and the enzyme activity measured in the protein extracts. The prenyltransferase that catalyses the transfer of the dimethylallyl group to C-2' of 1 was soluble and required dimethylallyl diphosphate as the prenyl donor. In the leaves, the biosynthesis of the prenylated chromene 2 was time-regulated and prenyltransferase activity depended upon circadian variation. Preliminary characterisation and purification experiments on the prenyltransferase from P. aduncum have been performed.

Antimicrobial prenylated dihydrochalcones from Eriosema glomerata.

PubMed

Awouafack, Maurice D; Kouam, Simeon F; Hussain, Hidayat; Ngamga, Dieudonne; Tane, Pierre; Schulz, Barbara; Green, Ivan R; Krohn, Karsten

2008-01-01

Two new natural dihydrochalcones exhibiting antimicrobial properties together with six known compounds were isolated from the Cameroonian medicinal plant Eriosema glomerata. The structures of the new dihydrochalcones were elucidated as 2',4'-dihydroxy-4-methoxy-3'-( gamma, gamma-dimethylallyl)dihydrochalcone and 2',4'-dihydroxy-3'-( gamma, gamma-dimethylallyl)dihydrochalcone by detailed spectroscopic analysis. The two new dihydrochalcones, named erioschalcones A ( 1) and B ( 2), demonstrated significant inhibitory activity against the microbial strains Bacillus megaterium, Escherichia coli, Chlorella fusca and Microbotryum violaceum.

Characterization of Leachianone G 2″ -Dimethylallyltransferase, a Novel Prenyl Side-Chain Elongation Enzyme for the Formation of the Lavandulyl Group of Sophoraflavanone G in Sophora flavescens Ait. Cell Suspension Cultures

PubMed Central

Zhao, Ping; Inoue, Kenichiro; Kouno, Isao; Yamamoto, Hirobumi

2003-01-01

Leachianone G (LG) 2′′-dimethylallyltransferase, a novel prenyl side-chain elongation enzyme, was identified in Sophora flavescens Ait. cultured cells. The enzyme transfers a dimethylallyl group to the 2′′ position of another dimethylallyl group attached at position 8 of LG to form sophoraflavanone G, a branched monoterpenoid-conjugated flavanone characteristic to this plant. This membrane-bound dimethylallyltransferase required Mg2+ (optimum concentration was 10 mm) for the reaction and had an optimum pH of 8.8. It utilized dimethylallyl diphosphate as the sole prenyl donor, and the 2′-hydroxy function in LG was indispensable to the activity. The apparent Km values for dimethylallyl diphosphate and LG were 59 and 2.3 μm, respectively. Subcellular localization of three enzymes that participated in the formation of the lavandulyl group was also investigated by sucrose density gradient centrifugation. Two prenyltransferases, naringenin 8-dimethylallyltransferase and LG 2′′-dimethylallyltransferase, were localized in the plastids, whereas 8-dimethylallylnaringenin 2′-hydroxylase, which catalyzes the crucial step in the lavandulyl-group formation, was associated with the endoplasmic reticulum. These results suggest the close cooperation between the plastids and the endoplasmic reticulum in the formation of lavandulyl groups. PMID:14551337

Final Technical Report: Microbial Production of Isoprene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fall, Ray

2003-09-12

OAK B135 We have discovered that bacteria produce and emit the hydrocarbon isoprene (2-methyl-1,3-butadiene), and have suggested that if isoprene-producing enzymes and their genes can be harnessed, useful hydrocarbon-producing systems might be constructed. The main goal of the proposed work was to establish the biochemical mechanism and regulation of isoprene formation in the model bacterial system, Bacillus subtilis. In this 3-year project we (a) characterized the physiological regulation of isoprene formation in B. subtilis and its relationship to isoprene formation in plant chloroplasts; (b) analyzed genetic controls on isoprene formation in B. subtilis; and (c) developed models to explain themore » biochemical rationale for isoprene formation. We are also pursued (d) new methods for continuous measurement of isoprene release in bioreactors, and (e) determined the presence of isoprene-forming Bacillus on plant roots and used B. subtilis as a biocontrol agent for protection of plant roots from plant pathogenic bacteria. We have made significant advances in several areas. These include: (1) establishing the enzymatic basis of isoprene formation in B. subtilis, and demonstrating throughout growth in a bioreactor that isoprene synthase activity rises and falls with each of three peaks of isoprene release (i.e. it appears to be a regulated enzyme). (2) We have explored genetic aspects of isoprene formation, using gene disruption methods to greatly alter the patterns of isoprene formation in bioreactors. Analysis of these mutants and alteration of cellular levels of dimethylallyl diphosphate (DMAPP), the substrate for isoprene synthase, has led to the formulation of two models to explain why isoprene is formed: an isoprenoid overflow model and a signaling model. We have obtained compelling evidence that isoprene releases in bioreactors result from metabolic overflow. However, we have yet to determine the pattern of isoprene formation when these bacteria are grown in a more natural state (e.g. as biofilms on surfaces). (3) We successfully used on-line mass spectrometry methods to measure release of volatiles, including isoprene, from bioreactors during growth of B. subtilis. This methodology, still in its infancy, may provide a new means to assess physiological processes during industrial growth of Bacillus species, and use isoprene formation as a barometer of carbon flow in these bacteria. (4) We also addressed the question: is Bacillus isoprene formation analogous to chloroplast processes? This research was initiated because of the continuing interest in the puzzle of isoprene formation in leaf chloroplasts. In pursuit of linkages between bacterial and plant isoprene formation, we used our DMAPP assay to demonstrate that leaves of the isoprene-emitter (cottonwood) show a diurnal cycle, peaking at mid-day in parallel with isoprene release. Thus it appears that in two different biological systems isoprene formation is highly regulated, and linked to isoprenoid carbon availability. (5) We developed a new method to detect Bacillus species in plant root samples, and demonstrated that plant roots are a rich source of biofilm-forming B. subtilis. Furthermore, using cultured Arabidopsis roots as a test system, we were able to demonstrate the formation of stable, viable Bacillus biofilms on the roots. Such roots were protected from killing by a root pathogenic Pseudomonas syringae strain. We have now formulated a mechanism to explain how such biocontrol by B. subtilis occurs, and future work will explore the role of isoprene in signaling between different rhizobacteria and plant roots.« less

The structure of dimethylallyl tryptophan synthase reveals a common architecture of aromatic prenyltransferases in fungi and bacteria

PubMed Central

Metzger, Ute; Schall, Christoph; Zocher, Georg; Unsöld, Inge; Stec, Edyta; Li, Shu-Ming; Heide, Lutz; Stehle, Thilo

2009-01-01

Ergot alkaloids are toxins and important pharmaceuticals that are produced biotechnologically on an industrial scale. The first committed step of ergot alkaloid biosynthesis is catalyzed by dimethylallyl tryptophan synthase (DMATS; EC 2.5.1.34). Orthologs of DMATS are found in many fungal genomes. We report here the x-ray structure of DMATS, determined at a resolution of 1.76 Å. A complex of DMATS from Aspergillus fumigatus with its aromatic substrate L-tryptophan and with an analogue of its isoprenoid substrate dimethylallyl diphosphate reveals the structural basis of this enzyme-catalyzed Friedel-Crafts reaction, which shows strict regiospecificity for position 4 of the indole nucleus of tryptophan as well as unusual independence of the presence of Mg2+ ions. The 3D structure of DMATS belongs to a rare β/α barrel fold, called prenyltransferase barrel, that was recently discovered in a small group of bacterial enzymes with no sequence similarity to DMATS. These bacterial enzymes catalyze the prenylation of aromatic substrates in the biosynthesis of secondary metabolites (i.e., a reaction similar to that of DMATS). PMID:19706516

Effects of detergents on the properties of 4-hydroxybenzoate. Polyprenyl transferase and the specificity of the polyprenyl pyrophosphate synthetic system in mitochondria.

PubMed

Nishino, T; Rudney, H

1977-02-22

The properties of 4-hydroxybenzoate:polyprenyl transferase and the system synthesizing polyprenyl pyrophosphate have been studied in mitochondria from rat and guinea pig livers. With solanesyl pyrophosphate and 4-hydroxybenzoate as substrates the formation of 3-nonaprenyl-4-hydroxybenzoate was linear with time, concentration of protein, and concentration of solanesyl pyrophosphate. Solanesyl monophosphate is inactive as a substrate and is noninhibitory. Conversion of solanesyl monophosphate to the pyrophosphate could not be detected. Detergents such as Triton X-100, Tween-80, and sodium deoxycholate activated the enzyme in mitochondria which were aged by freezing at -20 degrees C for periods ranging from 1 h to several days. Maximum activation also required Mg2+. In agreement with previous observation the effect of Mg2+ and Triton X-100 on fresh mitochondria was quite variable; however, activation with aged preparations was very consistent. Treatment with TritonX-100 causes al alteration in the biosynthetic pattern of rat liver mitochondria so that rather than nonaprenyl, decaprenyl, pyrophosphate is preferentially made in the presence of solanesyl pyrophosphate and isopentenyl pyrophosphate. In the presence of Triton X-100 and added pool of solanesyl pyrophosphate appears to exert a feedback inhibition on the incorporation of isopentenyl pyrophosphate into solanesyl pyrophosphate. In the case of guinea pig liver mitochondria a different pattern is observed with Triton X-100 in contrast to the rat. The de novo formation of decaprenyl pyrophosphate from isopentenyl pyrophosphate appears to be inhibited by Triton X-100, but the synthesis of decaprenyl pyrophosphate from isopentenyl pyrophosphate and nonaprenyl pyrophosphate is not inhibited. The data also indicate that in guinea pig liver in a system synthesizing decaprenyl pyrophosphate from isopentenyl pyrophosphate, there does not appear to be a detectable pool of nonaprenyl pyrophosphate. These results show that detergents can affect the specificity of the mitochondrial system synthesizing polyprenyl pyrophosphates.

Immunomodulatory constituents from an ascomycete, Microascus tardifaciens.

PubMed

Fujimoto, H; Fujimaki, T; Okuyama, E; Yamazaki, M

1999-10-01

Fractionation guided by the immunosuppressive activity of the defatted AcOEt extract of an Ascomycete, Microascus tardifaciens, afforded eight constituents, questin (emodin 8-O-methylether) (1), rubrocristin (2), 5,7-dihydroxy-4-methylphthalide (3), cladosporin (asperentin) (4), cladosporin 8-O-methylether (5), tradioxopiperazine A [cyclo-L-alanyl-5-isopentenyl-2-(1',1'-dimethylallyl)-L-tryptophan] (6), tradioxopiperazine B [cyclo-L-alanyl-7-isopentenyl-2-(1',1'-dimethylallyl)-L-tryptophan] (7), and asperflavin (8), among which 6 and 7 were new compounds. Compounds 1 and 2 showed considerably high immunosuppressive activity, 6 was moderate and, 3, 4, 5, 7 and 8 showed low activity.

Molecular Characterization of Soybean Pterocarpan 2-Dimethylallyltransferase in Glyceollin Biosynthesis: Local Gene and Whole-Genome Duplications of Prenyltransferase Genes Led to the Structural Diversity of Soybean Prenylated Isoflavonoids

PubMed Central

Yoneyama, Keisuke; Akashi, Tomoyoshi; Aoki, Toshio

2016-01-01

Soybean (Glycine max) accumulates several prenylated isoflavonoid phytoalexins, collectively referred to as glyceollins. Glyceollins (I, II, III, IV and V) possess modified pterocarpan skeletons with C5 moieties from dimethylallyl diphosphate, and they are commonly produced from (6aS, 11aS)-3,9,6a-trihydroxypterocarpan [(−)-glycinol]. The metabolic fate of (−)-glycinol is determined by the enzymatic introduction of a dimethylallyl group into C-4 or C-2, which is reportedly catalyzed by regiospecific prenyltransferases (PTs). 4-Dimethylallyl (−)-glycinol and 2-dimethylallyl (−)-glycinol are precursors of glyceollin I and other glyceollins, respectively. Although multiple genes encoding (−)-glycinol biosynthetic enzymes have been identified, those involved in the later steps of glyceollin formation mostly remain unidentified, except for (−)-glycinol 4-dimethylallyltransferase (G4DT), which is involved in glyceollin I biosynthesis. In this study, we identified four genes that encode isoflavonoid PTs, including (−)-glycinol 2-dimethylallyltransferase (G2DT), using homology-based in silico screening and biochemical characterization in yeast expression systems. Transcript analyses illustrated that changes in G2DT gene expression were correlated with the induction of glyceollins II, III, IV and V in elicitor-treated soybean cells and leaves, suggesting its involvement in glyceollin biosynthesis. Moreover, the genomic signatures of these PT genes revealed that G4DT and G2DT are paralogs derived from whole-genome duplications of the soybean genome, whereas other PT genes [isoflavone dimethylallyltransferase 1 (IDT1) and IDT2] were derived via local gene duplication on soybean chromosome 11. PMID:27986914

Stimulation of inorganic pyrophosphate elaboration by cultured cartilage and chondrocytes.

PubMed

Ryan, L M; Kurup, I; Rosenthal, A K; McCarty, D J

1989-08-01

Inorganic pyrophosphate elaboration by articular cartilage may favor calcium pyrophosphate dihydrate crystal deposition. Frequently crystal deposits form in persons affected with metabolic diseases. The cartilage organ culture system was used to model these metabolic conditions while measuring the influence on extracellular pyrophosphate elaboration. Alterations of ambient pH, thyroid stimulating hormone levels, and parathyroid hormone levels did not change pyrophosphate accumulation in the media. However, subphysiologic ambient calcium concentrations (25, 100, 500 microM) increased pyrophosphate accumulation about chondrocytes 3- to 10-fold. Low calcium also induced release of [14C]adenine-labeled nucleotides from chondrocytes, potential substrates for generation of extracellular pyrophosphate by ectoenzymes. Exposing cartilage to 10% fetal bovine serum also enhanced by 50% the egress of inorganic pyrophosphate from the tissue.

Treatment with pyrophosphate inhibits uremic vascular calcification

PubMed Central

O’Neill, W. Charles; Lomashvili, Koba A.; Malluche, Hartmut H.; Faugere, Marie-Claude; Riser, Bruce L.

2011-01-01

Pyrophosphate, which may be deficient in advanced renal failure, is a potent inhibitor of vascular calcification. To explore its use as a potential therapeutic, we injected exogenous pyrophosphate subcutaneously or intraperitoneally in normal rats and found that their plasma pyrophosphate concentrations peaked within 15 min. There was a single exponential decay with a half-life of 33 min. The kinetics were indistinguishable between the two routes of administration or in anephric rats. The effect of daily intraperitoneal pyrophosphate injections on uremic vascular calcification was then tested in rats fed a high-phosphate diet containing adenine for 28 days to induce uremia. Although the incidence of aortic calcification varied and was not altered by pyrophosphate, the calcium content of calcified aortas was significantly reduced by 70%. Studies were repeated in uremic rats given calcitriol to produce more consistent aortic calcification and treated with sodium pyrophosphate delivered intraperitoneally in a larger volume of glucose-containing solution to prolong plasma pyrophosphate levels. This maneuver significantly reduced both the incidence and amount of calcification. Quantitative histomorphometry of bone samples after double-labeling with calcein indicated that there was no effect of pyrophosphate on the rates of bone formation or mineralization. Thus, exogenous pyrophosphate can inhibit uremic vascular calcification without producing adverse effects on bone. PMID:21124302

Treatment with pyrophosphate inhibits uremic vascular calcification.

PubMed

O'Neill, W Charles; Lomashvili, Koba A; Malluche, Hartmut H; Faugere, Marie-Claude; Riser, Bruce L

2011-03-01

Pyrophosphate, which may be deficient in advanced renal failure, is a potent inhibitor of vascular calcification. To explore its use as a potential therapeutic, we injected exogenous pyrophosphate subcutaneously or intraperitoneally in normal rats and found that their plasma pyrophosphate concentrations peaked within 15 min. There was a single exponential decay with a half-life of 33 min. The kinetics were indistinguishable between the two routes of administration or in anephric rats. The effect of daily intraperitoneal pyrophosphate injections on uremic vascular calcification was then tested in rats fed a high-phosphate diet containing adenine for 28 days to induce uremia. Although the incidence of aortic calcification varied and was not altered by pyrophosphate, the calcium content of calcified aortas was significantly reduced by 70%. Studies were repeated in uremic rats given calcitriol to produce more consistent aortic calcification and treated with sodium pyrophosphate delivered intraperitoneally in a larger volume of glucose-containing solution to prolong plasma pyrophosphate levels. This maneuver significantly reduced both the incidence and amount of calcification. Quantitative histomorphometry of bone samples after double-labeling with calcein indicated that there was no effect of pyrophosphate on the rates of bone formation or mineralization. Thus, exogenous pyrophosphate can inhibit uremic vascular calcification without producing adverse effects on bone.

21 CFR 182.8223 - Calcium pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium pyrophosphate. 182.8223 Section 182.8223... FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8223 Calcium pyrophosphate. (a) Product. Calcium pyrophosphate. (b) Conditions of use. This substance is generally recognized...

21 CFR 182.8223 - Calcium pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pyrophosphate. 182.8223 Section 182.8223... FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8223 Calcium pyrophosphate. (a) Product. Calcium pyrophosphate. (b) Conditions of use. This substance is generally recognized...

21 CFR 582.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium pyrophosphate. 582.6787 Section 582.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Condition of use. This substance is...

21 CFR 182.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium pyrophosphate. 182.6787 Section 182.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Conditions of use. This substance is...

21 CFR 582.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium pyrophosphate. 582.6787 Section 582.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Condition of use. This substance is...

21 CFR 182.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium pyrophosphate. 182.6787 Section 182.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Conditions of use. This substance is...

21 CFR 182.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium pyrophosphate. 182.6787 Section 182.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Conditions of use. This substance is...

21 CFR 182.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium pyrophosphate. 182.6787 Section 182.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Conditions of use. This substance is...

21 CFR 582.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium pyrophosphate. 582.6787 Section 582.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Condition of use. This substance is...

21 CFR 582.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium pyrophosphate. 582.6787 Section 582.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Condition of use. This substance is...

21 CFR 582.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium pyrophosphate. 582.6787 Section 582.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Sodium pyrophosphate. (a) Product. Sodium pyrophosphate. (b) Condition of use. This substance is...

21 CFR 182.6789 - Tetra sodium pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tetra sodium pyrophosphate. 182.6789 Section 182.6789 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6789 Tetra sodium pyrophosphate. (a) Product. Tetra sodium pyrophosphate. (b) Conditions of use. This...

21 CFR 182.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium acid pyrophosphate. 182.1087 Section 182.1087 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b...

21 CFR 182.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium acid pyrophosphate. 182.1087 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b) Conditions of use. This substance is generally...

21 CFR 582.6789 - Tetra sodium pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Tetra sodium pyrophosphate. 582.6789 Section 582.6789 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6789 Tetra sodium pyrophosphate. (a) Product. Tetra sodium pyrophosphate. (b) Conditions of use. This...

21 CFR 182.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium acid pyrophosphate. 182.1087 Section 182.1087 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b...

21 CFR 182.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium acid pyrophosphate. 182.1087 Section 182.1087 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b...

A non-synonymous SNP within the isopentenyl transferase 2 locus is associated with kernel weight in Chinese maize inbreds (Zea mays L.).

PubMed

Weng, Jianfeng; Li, Bo; Liu, Changlin; Yang, Xiaoyan; Wang, Hongwei; Hao, Zhuanfang; Li, Mingshun; Zhang, Degui; Ci, Xiaoke; Li, Xinhai; Zhang, Shihuang

2013-07-05

Kernel weight, controlled by quantitative trait loci (QTL), is an important component of grain yield in maize. Cytokinins (CKs) participate in determining grain morphology and final grain yield in crops. ZmIPT2, which is expressed mainly in the basal transfer cell layer, endosperm, and embryo during maize kernel development, encodes an isopentenyl transferase (IPT) that is involved in CK biosynthesis. The coding region of ZmIPT2 was sequenced across a panel of 175 maize inbred lines that are currently used in Chinese maize breeding programs. Only 16 single nucleotide polymorphisms (SNPs) and seven haplotypes were detected among these inbred lines. Nucleotide diversity (π) within the ZmIPT2 window and coding region were 0.347 and 0.0047, respectively, and they were significantly lower than the mean nucleotide diversity value of 0.372 for maize Chromosome 2 (P < 0.01). Association mapping revealed that a single nucleotide change from cytosine (C) to thymine (T) in the ZmIPT2 coding region, which converted a proline residue into a serine residue, was significantly associated with hundred kernel weight (HKW) in three environments (P <0.05), and explained 4.76% of the total phenotypic variation. In vitro characterization suggests that the dimethylallyl diphospate (DMAPP) IPT activity of ZmIPT2-T is higher than that of ZmIPT2-C, as the amounts of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) consumed by ZmIPT2-T were 5.48-, 2.70-, and 1.87-fold, respectively, greater than those consumed by ZmIPT2-C. The effects of artificial selection on the ZmIPT2 coding region were evaluated using Tajima's D tests across six subgroups of Chinese maize germplasm, with the most frequent favorable allele identified in subgroup PB (Partner B). These results showed that ZmIPT2, which is associated with kernel weight, was subjected to artificial selection during the maize breeding process. ZmIPT2-T had higher IPT activity than ZmIPT2-C, and this favorable allele for kernel weight could be used in molecular marker-assisted selection for improvement of grain yield components in Chinese maize breeding programs.

Controllable Fabrication of Amorphous Co-Ni Pyrophosphates for Tuning Electrochemical Performance in Supercapacitors.

PubMed

Chen, Chen; Zhang, Ning; He, Yulu; Liang, Bo; Ma, Renzhi; Liu, Xiaohe

2016-09-07

Incorporation of two transition metals offers an effective method to enhance the electrochemical performance in supercapacitors for transition metal compound based electrodes. However, such a configuration is seldom concerned in pyrophosphates. Here, amorphous phase Co-Ni pyrophosphates are fabricated as electrodes in supercapacitors. Through controllably adjusting the ratios of Co and Ni as well as the calcination temperature, the electrochemical performance can be tuned. An optimized amorphous Ni-Co pyrophosphate exhibits much higher specific capacitance than monometallic Ni and Co pyrophosphates and shows excellent cycling ability. When employing Ni-Co pyrophosphates as positive electrode and activated carbon as a negative electrode, the fabricated asymmetric supercapacitor cell exhibits favorable capacitance and cycling ability. This study provides facile methods to improve the transition metal pyrophosphate electrodes for efficient electrodes in electrochemical energy storage devices.

21 CFR 582.5306 - Ferric sodium pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ferric sodium pyrophosphate. 582.5306 Section 582.5306 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5306 Ferric sodium pyrophosphate. (a) Product. Ferric sodium pyrophosphate. (b...

21 CFR 182.6789 - Tetra sodium pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Tetra sodium pyrophosphate. 182.6789 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6789 Tetra sodium pyrophosphate. (a) Product. Tetra sodium pyrophosphate. (b) Conditions of use. This substance is generally recognized as safe when...

Investigating the pharmacodynamic and magnetic properties of pyrophosphate-bridged coordination complexes

NASA Astrophysics Data System (ADS)

Ikotun, Oluwatayo (Tayo) F.

The multidentate nature of pyrophosphate makes it an attractive ligand for complexation of metal cations. The participation of pyrophosphate in a variety of biological pathways and its metal catalyzed hydrolysis has driven our investigation into its coordination chemistry. We have successfully synthesized a library of binuclear pyrophosphate bridge coordination complexes. The problem of pyrophosphate hydrolysis to phosphate in the presence of divalent metal ions was overcome by incorporating capping ligands such as 1,10-phenanthroline and 2,2'-bipyridine prior to the addition of the pyrophosphate. The magnetic properties of these complexes was investigated and magneto-structural analysis was conducted. The biological abundance of pyrophosphate and the success of metal based drugs such as cisplatin, prompted our investigation of the cytotoxic properties of M(II) pyrophosphate dimeric complexes (where M(II) is CoII, CuII, and NiII) in adriamycin resistant human ovarian cancer cells. Thess compounds were found to exhibit toxicity in the nanomolar to picomolar range. We conducted in vitro stability studies and the mechanism of cytoxicity was elucidated by performing DNA mobility and binding assays, enzyme inhibition assays, and in vitro oxidative stress studies.

SEMICONDUCTOR TECHNOLOGY A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

NASA Astrophysics Data System (ADS)

Baohong, Gao; Yuling, Liu; Chenwei, Wang; Yadong, Zhu; Shengli, Wang; Qiang, Zhou; Baimei, Tan

2010-10-01

This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection.

Diprenylated chalcones and other constituents from the twigs of Dorstenia barteri var. subtriangularis.

PubMed

Ngameni, Barthelemy; Ngadjui, Bonaventure T; Folefoc, Gabriel N; Watchueng, Jean; Abegaz, Berhanu M

2004-02-01

The twigs of Dorstenia barteri var. subtriangularis yielded three diprenylated chalcones: (-)-3-(3,3-dimethylallyl)-5'-(2-hydroxy-3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone, (+)-3-(3,3-dimethylallyl)-4',5'-[2'''-(1-hydroxy-1-methylethyl)-dihydrofurano]-4,2'-dihydroxychalcone and 3,4-(6",6"-dimethyldihydropyrano)-4',5'-[2''',-(1-hydroxy-1-methylethyl)-dihydrofurano]-2'-hydroxychalcone for which the names bartericins A, B and C, respectively, are proposed. Stipulin, beta-sitosterol and its 3-beta-D-glucopyranosyl derivative were also isolated. The structures of these secondary metabolites were determined on the basis of spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC. The structural relationship of bartericins B and C was further established by the chemical cyclization of one to the other.

Formation of pyrophosphate on hydroxyapatite with thioesters as condensing agents

NASA Technical Reports Server (NTRS)

Weber, A. L.

1982-01-01

'Energy-rich' thioesters are shown to act as condensing agents in the formation of pyrophosphate on hydroxyapatite in the presence of water at ambient temperature. The yield of pyrophosphate based on thioester ranges from 2.5% to 11.4% and depends upon the pH and concentration of reactants. Reaction of 0.130 M hydroxyapatite suspended in a solution of 0.08 M sodium phosphate and 0.20 M imidazole hydrochloride (pH 7.0) with 0.10 M N,S-diacetylcysteamine for 6 days gives the highest yield of pyrophosphate (11.4%). Pyrophosphate formation requires the presence of hydroxyapatite, sodium phosphate and the thioester, N,S-diacetylcysteamine. The related thioester, N,S-diacetylcysteine, also yields pyrophosphate in reactions on hydroxyapatite.

21 CFR 582.5223 - Calcium pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5223 Calcium pyrophosphate. (a) Product. Calcium pyrophosphate. (b) Conditions of use...

21 CFR 582.5223 - Calcium pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5223 Calcium pyrophosphate. (a) Product. Calcium pyrophosphate. (b) Conditions of use...

21 CFR 582.5223 - Calcium pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5223 Calcium pyrophosphate. (a) Product. Calcium pyrophosphate. (b) Conditions of use...

21 CFR 582.5223 - Calcium pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5223 Calcium pyrophosphate. (a) Product. Calcium pyrophosphate. (b) Conditions of use...

21 CFR 582.5223 - Calcium pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5223 Calcium pyrophosphate. (a) Product. Calcium pyrophosphate. (b) Conditions of use...

21 CFR 582.5304 - Ferric pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5304 Ferric pyrophosphate. (a) Product. Ferric pyrophosphate. (b) Conditions of use. This...

21 CFR 582.5304 - Ferric pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5304 Ferric pyrophosphate. (a) Product. Ferric pyrophosphate. (b) Conditions of use. This...

21 CFR 582.5304 - Ferric pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5304 Ferric pyrophosphate. (a) Product. Ferric pyrophosphate. (b) Conditions of use. This...

21 CFR 582.5304 - Ferric pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5304 Ferric pyrophosphate. (a) Product. Ferric pyrophosphate. (b) Conditions of use. This...

21 CFR 582.5304 - Ferric pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5304 Ferric pyrophosphate. (a) Product. Ferric pyrophosphate. (b) Conditions of use. This...

21 CFR 582.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Additives § 582.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

21 CFR 582.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Additives § 582.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

21 CFR 582.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Additives § 582.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

21 CFR 582.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Additives § 582.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

21 CFR 582.1087 - Sodium acid pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Additives § 582.1087 Sodium acid pyrophosphate. (a) Product. Sodium acid pyrophosphate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

UbiX is a flavin prenyltransferase required for bacterial ubiquinone biosynthesis

PubMed Central

White, Mark D.; Payne, Karl A.P.; Fisher, Karl; Marshall, Stephen A.; Parker, David; Rattray, Nicholas J.W.; Trivedi, Drupad K.; Goodacre, Royston; Rigby, Stephen E.J.; Scrutton, Nigel S.; Hay, Sam; Leys, David

2016-01-01

Ubiquinone, or coenzyme Q, is a ubiquitous lipid-soluble redox cofactor that is an essential component of electron transfer chains1. Eleven genes have been implicated in bacterial ubiquinone biosynthesis, including ubiX and ubiD, which are responsible for decarboxylation of the 3-octaprenyl-4-hydroxybenzoate precursor2. Despite structural and biochemical characterization of UbiX as an FMN-binding protein, no decarboxylase activity has been detected3–4. We report here that UbiX produces a novel flavin-derived cofactor required for the decarboxylase activity of UbiD5. UbiX acts as a flavin prenyltransferase, linking a dimethylallyl moiety to the flavin N5 and C6 atoms. This adds a fourth non-aromatic ring to the flavin isoalloxazine group. In contrast to other prenyltransferases6–7, UbiX is metal-independent and requires dimethylallyl-monophosphate as substrate. Kinetic crystallography reveals that the prenyl transferase mechanism of UbiX resembles that of the terpene synthases8. The active site environment is dominated by π-systems, which assist phosphate-C1’ bond breakage following FMN reduction, leading to formation of the N5-C1’ bond. UbiX then acts as a chaperone for adduct reorientation, via transient carbocation species, leading ultimately to formation of the dimethylallyl C3’-C6 bond. The study establishes the mechanism for formation of a new flavin-derived cofactor, extending both flavin and terpenoid biochemical repertoire. PMID:26083743

The route of non-enzymic and enzymic breakdown of 5-phosphoribosyl 1-pyrophosphate to ribose 1-phosphate.

PubMed Central

Trembacz, H; Jezewska, M M

1990-01-01

Spontaneous decomposition of 5-phosphoribosyl 1-pyrophosphate at pH 5.5 was established to occur as follows: 5-Phosphoribosyl 1-pyrophosphate----5-phosphoribosyl 1,2-(cyclic)phosphate----ribose 1-phosphate----ribose Enzymic degradation of 5-phosphoribosyl 1-pyrophosphate by alkaline phosphatase from calf intestine and by acid phosphatases from potato and Aspergillus niger was found to proceed according to this pathway within the pH range 2.5-7.4 with accumulation of ribose 1-phosphate. In the case of alkaline phosphatase, Mg2+ ions inhibit the pyrophosphorolysis of 5-phosphoribosyl 1-pyrophosphate and stimulate the hydrolysis of ribose 1-phosphate. PMID:1700897

Sensor Function for Butyrophilin 3A1 in Prenyl Pyrophosphate Stimulation of Human Vγ2Vδ2 T Cells

PubMed Central

Wang, Hong; Morita, Craig T.

2016-01-01

Vγ2Vδ2 T cells play important roles in human immunity to pathogens and in cancer immunotherapy by responding to isoprenoid metabolites, such as (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate and isopentenyl pyrophosphate. The Ig superfamily protein butyrophilin (BTN)3A1 was shown to be required for prenyl pyrophosphate stimulation. We proposed that the intracellular B30.2 domain of BTN3A1 binds prenyl pyrophosphates, resulting in a change in the extracellular BTN3A1 dimer that is detected by Vγ2Vδ2 TCRs. Such B30.2 binding was demonstrated recently. However, other investigators reported that the extracellular BTN3A1 IgV domain binds prenyl pyrophosphates, leading to the proposal that the Vγ2Vδ2 TCR recognizes the complex. To distinguish between these mechanisms, we mutagenized residues in the two binding sites and tested the mutant BTN3A1 proteins for their ability to mediate prenyl pyrophosphate stimulation of Vγ2Vδ2 T cells to proliferate and secrete TNF-α. Mutagenesis of residues in the IgV site had no effect on Vγ2Vδ2 T cell proliferation or secretion of TNF-α. In contrast, mutagenesis of residues within the basic pocket and surrounding V regions of the B30.2 domain abrogated prenyl pyrophosphate-induced proliferation. Mutations of residues making hydrogen bonds to the pyrophosphate moiety also abrogated TNF-α secretion, as did mutation of aromatic residues making contact with the alkenyl chain. Some mutations further from the B30.2 binding site also diminished stimulation, suggesting that the B30.2 domain may interact with a second protein. These findings support intracellular sensing of prenyl pyrophosphates by BTN3A1 rather than extracellular presentation. PMID:26475929

Enhanced Photolysis of Nucleic Acid Monomers by Pyrophosphate in the Simulated Primitive Soup

NASA Astrophysics Data System (ADS)

Kongjiang, Wang; Zhifang, Chai; Xianming, Pan

1999-05-01

In our simulation of the photochemistry of the primitive soup, it was found that yield of chromophore loss of some nucleic acid bases, nucleosides and nucleotides [NA] undergoing ultraviolet radiation by medium pressure mercury lamp [MPML] was enhanced by pyrophosphate and triphosphate whether O2 is present or not. The yield of chromophore loss of guanosine, uracil, 5' CMP, and the derivatives of adenine and thymine was observed to rise with the increase of molar concentration of pyrophosphate in N2-saturated systems. In air-saturated samples, increase in yield of chromophore loss was observed when the concentration of pyrophosphate reaches 5×10-4 M, relative yield of chromophore loss (CLrel) coming to maximum in the range from 0.01 to 0.1 M, followed by a slight decline with the further increase of pyrophosphate concentration. The enhancement of photolysis of NA by pyrophosphate was due to the interaction between NA and pyrophosphate radicals photoionized by UV quanta of wavelength less than about 210 nm in the emission spectrum of a MPML. The relevance of this phenomenon to the origin of life has been discussed as well.

Precise through-space control of an abiotic electrophilic aromatic substitution reaction

NASA Astrophysics Data System (ADS)

Murphy, Kyle E.; Bocanegra, Jessica L.; Liu, Xiaoxi; Chau, H.-Y. Katharine; Lee, Patrick C.; Li, Jianing; Schneebeli, Severin T.

2017-04-01

Nature has evolved selective enzymes for the efficient biosynthesis of complex products. This exceptional ability stems from adapted enzymatic pockets, which geometrically constrain reactants and stabilize specific reactive intermediates by placing electron-donating/accepting residues nearby. Here we perform an abiotic electrophilic aromatic substitution reaction, which is directed precisely through space. Ester arms--positioned above the planes of aromatic rings--enable it to distinguish between nearly identical, neighbouring reactive positions. Quantum mechanical calculations show that, in two competing reaction pathways, both [C-H...O]-hydrogen bonding and electrophile preorganization by coordination to a carbonyl group likely play a role in controlling the reaction. These through-space-directed mechanisms are inspired by dimethylallyl tryptophan synthases, which direct biological electrophilic aromatic substitutions by preorganizing dimethylallyl cations and by stabilizing reactive intermediates with [C-H...N]-hydrogen bonding. Our results demonstrate how the third dimension above and underneath aromatic rings can be exploited to precisely control electrophilic aromatic substitutions.

Two inositol hexakisphosphate kinases drive inositol pyrophosphate synthesis in plants

USDA-ARS?s Scientific Manuscript database

Inositol pyrophosphates are novel cellular signaling molecules with newly discovered roles in energy sensing and metabolic control. Studies in eukaryotes have revealed that these compounds turn over rapidly, and thus only small amounts accumulate. Inositol pyrophosphates have not been the subject of...

21 CFR 182.8223 - Calcium pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium pyrophosphate. 182.8223 Section 182.8223 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8223 Calcium pyrophosphate. (a) Product. Calcium...

21 CFR 182.6787 - Sodium pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium pyrophosphate. 182.6787 Section 182.6787 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 1 § 182.6787 Sodium pyrophosphate. (a) Product. Sodium...

A Novel Inositol Pyrophosphate Phosphatase in Saccharomyces cerevisiae: Siw14 PROTEIN SELECTIVELY CLEAVES THE β-PHOSPHATE FROM 5-DIPHOSPHOINOSITOL PENTAKISPHOSPHATE (5PP-IP5).

PubMed

Steidle, Elizabeth A; Chong, Lucy S; Wu, Mingxuan; Crooke, Elliott; Fiedler, Dorothea; Resnick, Adam C; Rolfes, Ronda J

2016-03-25

Inositol pyrophosphates are high energy signaling molecules involved in cellular processes, such as energetic metabolism, telomere maintenance, stress responses, and vesicle trafficking, and can mediate protein phosphorylation. Although the inositol kinases underlying inositol pyrophosphate biosynthesis are well characterized, the phosphatases that selectively regulate their cellular pools are not fully described. The diphosphoinositol phosphate phosphohydrolase enzymes of the Nudix protein family have been demonstrated to dephosphorylate inositol pyrophosphates; however, theSaccharomyces cerevisiaehomolog Ddp1 prefers inorganic polyphosphate over inositol pyrophosphates. We identified a novel phosphatase of the recently discovered atypical dual specificity phosphatase family as a physiological inositol pyrophosphate phosphatase. Purified recombinant Siw14 hydrolyzes the β-phosphate from 5-diphosphoinositol pentakisphosphate (5PP-IP5or IP7)in vitro. In vivo,siw14Δ yeast mutants possess increased IP7levels, whereas heterologousSIW14overexpression eliminates IP7from cells. IP7levels increased proportionately whensiw14Δ was combined withddp1Δ orvip1Δ, indicating independent activity by the enzymes encoded by these genes. We conclude that Siw14 is a physiological phosphatase that modulates inositol pyrophosphate metabolism by dephosphorylating the IP7isoform 5PP-IP5to IP6. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Dissolution behaviour of ferric pyrophosphate and its mixtures with soluble pyrophosphates: Potential strategy for increasing iron bioavailability.

PubMed

Tian, Tian; Blanco, Elena; Smoukov, Stoyan K; Velev, Orlin D; Velikov, Krassimir P

2016-10-01

Ferric pyrophosphate (FePP) is a widely used iron source in food fortification and in nutritional supplements, due to its white colour, that is very uncommon for insoluble Fe salts. Although its dissolution is an important determinant of Fe adsorption in human body, the solubility characteristics of FePP are complex and not well understood. This report is a study on the solubility of FePP as a function of pH and excess of pyrophosphate ions. FePP powder is sparingly soluble in the pH range of 3-6 but slightly soluble at pH<2 and pH>8. In the presence of pyrophosphate ions the solubility of FePP strongly increases at pH 5-8.5 due to formation a soluble complex between Fe(III) and pyrophosphate ions, which leads to an 8-10-fold increase in the total ionic iron concentration. This finding is beneficial for enhancing iron bioavailability, which important for the design of fortified food, beverages, and nutraceutical products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sensitivity of technetium-99m-pyrophosphate scintigraphy in diagnosing cardiac amyloidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Falk, R.H.; Lee, V.W.; Rubinow, A.

1983-03-01

To determine the value of technetium-99m-pyrophosphate myocardial scintigraphy in the diagnosis of amyloid heart disease this procedure was prospectively performed in 20 consecutive patients with biopsy-proven primary amyloidosis. Eleven patients had echocardiographic abnormalities compatible with amyloid cardiomyopathy, 9 of whom had congestive heart failure. Diffuse myocardial pyrophosphate uptake was of equal or greater intensity than that of the ribs in 9 of the 11 patients with echocardiograms suggestive of amyloidosis, but in only 2 of the 9 with normal echocardiograms, despite abnormal electrocardiograms (p less than 0.01). Increased wall thickness measured by M-mode echocardiography correlated with myocardial pyrophosphate uptake (rmore » . 0.68, p less than 0.01). None of 10 control patients with nonamyloid, nonischemic heart disease had a strongly positive myocardial pyrophosphate uptake. Thus, myocardial technetium-99m-pyrophosphate scanning is a sensitive and specific test for the diagnosis of cardiac amyloidosis in patients with congestive heart failure of obscure origin. It does not appear to be of value for the early detection of cardiac involvement in patients with known primary amyloidosis without echocardiographic abnormalities.« less

Conservation of the PTEN catalytic motif in the bacterial undecaprenyl pyrophosphate phosphatase, BacA/UppP.

PubMed

Bickford, Justin S; Nick, Harry S

2013-12-01

Isoprenoid lipid carriers are essential in protein glycosylation and bacterial cell envelope biosynthesis. The enzymes involved in their metabolism (synthases, kinases and phosphatases) are therefore critical to cell viability. In this review, we focus on two broad groups of isoprenoid pyrophosphate phosphatases. One group, containing phosphatidic acid phosphatase motifs, includes the eukaryotic dolichyl pyrophosphate phosphatases and proposed recycling bacterial undecaprenol pyrophosphate phosphatases, PgpB, YbjB and YeiU/LpxT. The second group comprises the bacterial undecaprenol pyrophosphate phosphatase, BacA/UppP, responsible for initial formation of undecaprenyl phosphate, which we predict contains a tyrosine phosphate phosphatase motif resembling that of the tumour suppressor, phosphatase and tensin homologue (PTEN). Based on protein sequence alignments across species and 2D structure predictions, we propose catalytic and lipid recognition motifs unique to BacA/UppP enzymes. The verification of our proposed active-site residues would provide new strategies for the development of substrate-specific inhibitors which mimic both the lipid and pyrophosphate moieties, leading to the development of novel antimicrobial agents.

Calcium pyrophosphate dihydrate gout and other crystal deposition diseases.

PubMed

Reginato, A J

1991-08-01

The number of crystal or birefringent particles associated with arthritis is increasing, and a uniform taxonomy is needed. The term gout has been proposed as a generic term for these diseases based on historical, clinical, and crystallographic reasons. Calcium pyrophosphate dihydrate gout follows monosodium urate gout in frequency, and its spectrum of clinical manifestations continues to grow. Familial calcium pyrophosphate dihydrate gout was described for the first time in kindreds studied in England and Tunisia; new Jewish and Spanish kindreds were also reported. Type I collagen was shown to nucleate nativelike calcium pyrophosphate dihydrate crystals, and pyrophosphate elaboration was explored in cartilage explants in an attempt to reproduce the in vivo metabolic or endocrine disorders associated with calcium pyrophosphate dihydrate gout. The effect of pyrophosphatase and different cofactors such as magnesium in dissolving calcium pyrophosphate dihydrate crystals was investigated. High-resolution electron microscopy was used to study the interrelation between apatite and other basic calcium phosphate crystals in apatite gout. Raman microscopy was applied for the first time to identify crystals in biologic specimens. A simple and specific technique for basic calcium phosphate crystal identification is necessary to understand the relationship between different calcium phosphate crystals and osteoarthritis. Several reports about children and young patients with primary oxalate gout described the effect of oxalate on eyes, periodontal tissues, and bone. Multicenter studies showed poor results of renal transplantation, but favored combined liver and renal transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

ALKYL PYROPHOSPHATE METAL SOLVENT EXTRACTANTS AND PROCESS

DOEpatents

Long, R.L.

1958-09-30

A process is presented for the recovery of uranium from aqueous mineral acidic solutions by solvent extraction. The extractant is a synmmetrical dialkyl pyrophosphate in which the alkyl substituents have a chain length of from 4 to 17 carbon atoms. Mentioned as a preferred extractant is dioctyl pyrophosphate. The uranium is precipitated irom the organic extractant phase with an agent such as HF, fluoride salts. alcohol, or ammonia.

Cyclopiazonic acid biosynthesis in Aspergillus sp.: characterization of a reductase-like R* domain in cyclopiazonate synthetase that forms and releases cyclo-acetoacetyl-L-tryptophan.

PubMed

Liu, Xinyu; Walsh, Christopher T

2009-09-15

The fungal neurotoxin alpha-cyclopiazonic acid (CPA), a nanomolar inhibitor of Ca2+-ATPase, has a pentacyclic indole tetramic acid scaffold that arises from one molecule of tryptophan, acetyl-CoA, malonyl-CoA, and dimethylallyl pyrophosphate by consecutive action of three enzymes, CpaS, CpaD, and CpaO. CpaS is a hybrid, two module polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) that makes and releases cyclo-acetoacetyl-L-tryptophan (cAATrp), the tetramic acid that serves as substrate for subsequent prenylation and oxidative cyclization to the five ring CPA scaffold. The NRPS module in CpaS has a predicted four-domain organization of condensation, adenylation, thiolation, and reductase* (C-A-T-R*), where R* lacks the critical Ser-Tyr-Lys catalytic triad of the short chain dehydrogenase/reductase (SDR) superfamily. By heterologous overproduction in Escherichia coli of the 56 kDa Aspergillus flavus CpaS TR* didomain and the single T and R* domains, we demonstrate that CpaS catalyzes a Dieckmann-type cyclization on the N-acetoacetyl-Trp intermediate bound in thioester linkage to the phosphopantetheinyl arm of the T domain to form and release cAATrp. This occurs without any participation of NAD(P)H, so R* does not function as a canonical SDR family member. Use of the T and R* domains in in trans assays enabled multiple turnovers and evaluation of specific mutants. Mutation of the D3803 residue in the R* domain, conserved in other fungal tetramate synthetases, abolished activity both in in trans and in cis (TR*) activity assays. It is likely that cyclization of beta-ketoacylaminoacyl-S-pantetheinyl intermediates to released tetramates represents a default cyclization/release route for redox-incompetent R* domains embedded in NRPS assembly lines.

Structural basis for an inositol pyrophosphate kinase surmounting phosphate crowding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Huanchen; Falck, J.R.; Hall, Traci M. Tanaka

2012-01-11

Inositol pyrophosphates (such as IP7 and IP8) are multifunctional signaling molecules that regulate diverse cellular activities. Inositol pyrophosphates have 'high-energy' phosphoanhydride bonds, so their enzymatic synthesis requires that a substantial energy barrier to the transition state be overcome. Additionally, inositol pyrophosphate kinases can show stringent ligand specificity, despite the need to accommodate the steric bulk and intense electronegativity of nature's most concentrated three-dimensional array of phosphate groups. Here we examine how these catalytic challenges are met by describing the structure and reaction cycle of an inositol pyrophosphate kinase at the atomic level. We obtained crystal structures of the kinase domainmore » of human PPIP5K2 complexed with nucleotide cofactors and either substrates, product or a MgF{sub 3}{sup -} transition-state mimic. We describe the enzyme's conformational dynamics, its unprecedented topological presentation of nucleotide and inositol phosphate, and the charge balance that facilitates partly associative in-line phosphoryl transfer.« less

Heightened Avidity for Trisodium Pyrophosphate in Mice Lacking Tas1r3

PubMed Central

Aleman, Tiffany R.; McCaughey, Stuart A.

2015-01-01

Laboratory rats and mice prefer some concentrations of tri- and tetrasodium pyrophosphate (Na3HP2O7 and Na4P2O7) to water, but how they detect pyrophosphates is unknown. Here, we assessed whether T1R3 is involved. We found that relative to wild-type littermate controls, Tas1r3 knockout mice had stronger preferences for 5.6–56mM Na3HP2O7 in 2-bottle choice tests, and they licked more 17.8–56mM Na3HP2O7 in brief-access tests. We hypothesize that pyrophosphate taste in the intact mouse involves 2 receptors: T1R3 to produce a hedonically negative signal and an unknown G protein-coupled receptor to produce a hedonically positive signal; in Tas1r3 knockout mice, the hedonically negative signal produced by T1R3 is absent, leading to a heightened avidity for pyrophosphate. PMID:25452580

Familial pyrophosphate arthropathy. Occurrence and Crystal Identification.

PubMed

Bjelle, A

1981-01-01

Hereditary pyrophosphate arthropathy has been observed in three Swedish families and in a few other caucasian populations. The inheritance is most probably autosomal dominant with a variable penetrance. The most severe cases have been found in homozygotes among isolates of immigrants in Slovakia and Chile. Studies on genetic and etio-pathogenetic factors in hereditary pyrophosphate arthropathy, and the utilization of new diagnostic techniques for crystal identification, are important approaches towards a further understanding of the disease.

Study of orthophosphate, pyrophosphate, and pyrophosphatase in saliva with reference to calculus formation and inhibition.

PubMed

Pradeep, A R; Agarwal, Esha; P, Arjun Raju; Rao, M S Narayana; Faizuddin, Mohamed

2011-03-01

A large amount of calculus may hamper the efficacy of daily oral hygiene and thereby accelerate plaque formation. Salivary concentrations of orthophosphate and pyrophosphate are important in preventing calculus formation. Activity of orthophosphate, pyrophosphate, and pyrophosphatase was studied in whole saliva in calculus-forming groups and plaque-forming groups. The material for this study consists of 60 healthy individuals (age range: 15 to 30 years; mean age: 22 years). Depending on calculus index score, individuals were divided into four groups, each of 15 patients: Group 1, calculus index score 0 to 0.6; Group 2, calculus index score 0.7 to 1.8; Group 3, calculus index score 1.9 to 3; and Group 4, plaque group where index varied from 0 to 3. The saliva was collected and biochemically analyzed for concentration of orthophosphate, pyrophosphate, and pyrophosphatase. The mean values of orthophosphate in Groups 1, 2, 3, and 4 were 0.2559, 1.3639, 1.7311, and 0.1868 mM, respectively. The mean values of pyrophosphate in Groups 1, 2, 3, and 4 were 0.3258, 0.1091, 0.0314, and 0.3860 mM, respectively. The mean values of pyrophosphatase in Groups 1, 2, 3, and 4 were 10.7937, 15.4249, 27.2900, and 7.5427 units/ml, respectively. A holistic approach toward the control of periodontal disease should include antiplaque and anticalculus agents. The results are conclusive that the components orthophosphate, pyrophosphate, and pyrophosphatase present in saliva have a very significant role to play in formation and inhibition of calculus. This study reinforces the idea of using pyrophosphate and newer bisphosphonates as potential anticalculus agents.

Determination of pyrophosphate and sulfate using polyhexamethylene guanidine hydrochloride-stabilized silver nanoparticles.

PubMed

Terenteva, E A; Apyari, V V; Dmitrienko, S G; Garshev, A V; Volkov, P A; Zolotov, Yu A

2018-04-01

Positively charged polyhexamethylene guanidine hydrochloride-stabilized silver nanoparticles (PHMG-AgNPs) were prepared and applied as a colorimetric probe for single-step determination of pyrophosphate and sulfate. The approach is based on the nanoparticles aggregation leading to change in their absorption spectra and color of the solution. Due to both electrostatic and steric stabilization these nanoparticles show decreased sensitivity relatively to many common anions, which allows for simple and rapid direct single-step determination of pyrophosphate and sulfate. Effects of different factors (time of interaction, pH, concentrations of anions and the nanoparticles) on aggregation of PHMG-AgNPs and analytical performance of the procedure were investigated. The method allows for the determination of pyrophosphate and sulfate in the range of 0.16-2μgmL -1 and 20-80μgmL -1 with RSD of 2-5%, respectively. The analysis can be performed using either spectrophotometry or naked-eye detection. Practical application of the method was shown by the example of pyrophosphate determination in baking powder sample. Copyright © 2017 Elsevier B.V. All rights reserved.

Heightened avidity for trisodium pyrophosphate in mice lacking Tas1r3.

PubMed

Tordoff, Michael G; Aleman, Tiffany R; McCaughey, Stuart A

2015-01-01

Laboratory rats and mice prefer some concentrations of tri- and tetrasodium pyrophosphate (Na3HP2O7 and Na4P2O7) to water, but how they detect pyrophosphates is unknown. Here, we assessed whether T1R3 is involved. We found that relative to wild-type littermate controls, Tas1r3 knockout mice had stronger preferences for 5.6-56mM Na3HP2O7 in 2-bottle choice tests, and they licked more 17.8-56mM Na3HP2O7 in brief-access tests. We hypothesize that pyrophosphate taste in the intact mouse involves 2 receptors: T1R3 to produce a hedonically negative signal and an unknown G protein-coupled receptor to produce a hedonically positive signal; in Tas1r3 knockout mice, the hedonically negative signal produced by T1R3 is absent, leading to a heightened avidity for pyrophosphate. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Isolation and characterization of farnesyl diphosphate synthase from the cotton boll weevil, Anthonomus grandis.

PubMed

Taban, A Huma; Tittiger, Claus; Blomquist, Gary J; Welch, William H

2009-06-01

Farnesyl diphosphate synthase (FPPS) catalyzes the consecutive condensation of two molecules of isopentenyl diphosphate with dimethylallyl diphosphate to form farnesyl diphosphate (FPP). In insects, FPP is used for the synthesis of ubiquinones, dolicols, protein prenyl groups, and juvenile hormone. A full-length cDNA of FPPS was cloned from the cotton boll weevil, Anthonomus grandis (AgFPPS). AgFPPS cDNA consists of 1,835 nucleotides and encodes a protein of 438 amino acids. The deduced amino acid sequence has high similarity to previously isolated insect FPPSs and other known FPPSs. Recombinant AgFPPS expressed in E. coli converted labeled isopentenyl diphosphate in the presence of dimethylallyl diphosphate to FPP. Southern blot analysis indicated the presence of a single copy gene. Using molecular modeling, the three-dimensional structure of coleopteran FPPS was determined and compared to the X-ray crystal structure of avian FPPS. The alpha-helical fold is conserved in AgFPPS and the size of the active site cavity is consistent with the enzyme being a FPPS. (c) 2009 Wiley Periodicals, Inc.

High-Affinity Binding of Silybin Derivatives to the Nucleotide-Binding Domain of a Leishmania tropica P-Glycoprotein-Like Transporter and Chemosensitization of a Multidrug-Resistant Parasite to Daunomycin

PubMed Central

Pérez-Victoria, José M.; Pérez-Victoria, F. Javier; Conseil, Gwenaëlle; Maitrejean, Mathias; Comte, Gilles; Barron, Denis; Di Pietro, Attilio; Castanys, Santiago; Gamarro, Francisco

2001-01-01

In order to overcome the multidrug resistance mediated by P-glycoprotein-like transporters in Leishmania spp., we have studied the effects produced by derivatives of the flavanolignan silybin and related compounds lacking the monolignol unit on (i) the affinity of binding to a recombinant C-terminal nucleotide-binding domain of the L. tropica P-glycoprotein-like transporter and (ii) the sensitization to daunomycin on promastigote forms of a multidrug-resistant L. tropica line overexpressing the transporter. Oxidation of the flavanonol silybin to the corresponding flavonol dehydrosilybin, the presence of the monolignol unit, and the addition of a hydrophobic substituent such as dimethylallyl, especially at position 8 of ring A, considerably increased the binding affinity. The in vitro binding affinity of these compounds for the recombinant cytosolic domain correlated with their modulation of drug resistance phenotype. In particular, 8-(3,3-dimethylallyl)-dehydrosilybin effectively sensitized multidrug-resistant Leishmania spp. to daunomycin. The cytosolic domains are therefore attractive targets for the rational design of inhibitors against P-glycoprotein-like transporters. PMID:11158738

Method of synthesis of proton conducting materials

DOEpatents

Garzon, Fernando Henry; Einsla, Melinda Lou; Mukundan, Rangachary

2010-06-15

A method of producing a proton conducting material, comprising adding a pyrophosphate salt to a solvent to produce a dissolved pyrophosphate salt; adding an inorganic acid salt to a solvent to produce a dissolved inorganic acid salt; adding the dissolved inorganic acid salt to the dissolved pyrophosphate salt to produce a mixture; substantially evaporating the solvent from the mixture to produce a precipitate; and calcining the precipitate at a temperature of from about 400.degree. C. to about 1200.degree. C.

SEPARATION OF PLUTONIUM IONS FROM SOLUTION BY ADSORPTION ON ZIRCONIUM PYROPHOSPHATE

DOEpatents

Stoughton, R.W.

1961-01-31

A method is given for separating plutonium in its reduced, phosphate- insoluble state from other substances. It involves contacting a solution containing the plutonium with granular zirconium pyrophosphate.

The selectivity of water-based pyrophosphate recognition is tuned by metal substitution in dimetallic receptors.

PubMed

Svane, Simon; Kjeldsen, Frank; McKee, Vickie; McKenzie, Christine J

2015-07-14

The three dimetallic compounds [Ga2(bpbp)(OH)2(H2O)2](ClO4)3, [In2(bpbp)(CH3CO2)2](ClO4)3 and [Zn2(bpbp)(HCO2)2](ClO4) (bpbp(-) = 2,6-bis((N,N'-bis(2-picolyl)amino)methyl)-4-tertbutylphenolate) were evaluated as stable solid state precursors for reactive solution state receptors to use for the recognition of the biologically important anion pyrophosphate in water at neutral pH. Indicator displacement assays using in situ generated complex-pyrocatechol violet adducts, {M2(bpbp)(HxPV)}(n+) M = Ga(3+), In(3+), Zn(2+), were tested for selectivity in their reactions with a series of common anions: pyrophosphate, phosphate, ATP, arsenate, nitrate, perchlorate, chloride, sulfate, formate, carbonate and acetate. The receptor employing Ga(3+) showed a slow but visually detectable response (blue to yellow) in the presence of one equivalent of pyrophosphate but no response to any other anion, even when they were present in much higher concentrations. The systems based on In(3+) or Zn(2+) show less selectivity in accord with visibly discernible responses to several of the anions. These results demonstrate a facile method for increasing anion selectivity without modification of an organic dinucleating ligand scaffold. The comfortable supramolecular recognition of pyrophosphate by the dimetallic complexes is demonstrated by the single crystal X-ray structure of [Ga2(bpbp)(HP2O7)](ClO4)2 in which the pyrophosphate is coordinated to the two gallium ions via four of its oxygen atoms.

LEFPS1, a Tomato Farnesyl Pyrophosphate Gene Highly Expressed during Early Fruit Development1

PubMed Central

Gaffe, Joel; Bru, Jean-Philippe; Causse, Mathilde; Vidal, Alain; Stamitti-Bert, Linda; Carde, Jean-Pierre; Gallusci, Philippe

2000-01-01

Farnesyl pyrophosphate synthase (FPS) catalyzes the synthesis of farnesyl pyrophosphate, a key intermediate in sterol and sesquiterpene biosynthesis. Using a polymerase chain reaction-based approach, we have characterized LeFPS1, a tomato (Lycoperscion esculentum cv Wva 106) fruit cDNA, which encodes a functional FPS. We demonstrate that tomato FPSs are encoded by a small multigenic family with genes located on chromosomes 10 and 12. Consistent with farnesyl pyrophosphate requirement in sterol biosynthesis, FPS genes are ubiquitously expressed in tomato plants. Using an LeFPS1 specific probe, we show that the corresponding gene can account for most of FPS mRNA in most plant organs, but not during young seedling development, indicating a differential regulation of FPS genes in tomato. FPS gene expression is also under strict developmental control: FPS mRNA was mainly abundant in young organs and decreased as organs matured with the exception of fruits that presented a biphasic accumulation pattern. In this latter case in situ hybridization studies have shown that FPS mRNA is similarly abundant in all tissues of young fruit. Taken together our results suggest that several FPS isoforms are involved in tomato farnesyl pyrophosphate metabolism and that FPS genes are mostly expressed in relation to cell division and enlargement. PMID:10938353

Site-directed Mutagenesis Switching a Dimethylallyl Tryptophan Synthase to a Specific Tyrosine C3-Prenylating Enzyme*

PubMed Central

Fan, Aili; Zocher, Georg; Stec, Edyta; Stehle, Thilo; Li, Shu-Ming

2015-01-01

The tryptophan prenyltransferases FgaPT2 and 7-DMATS (7-dimethylallyl tryptophan synthase) from Aspergillus fumigatus catalyze C4- and C7-prenylation of the indole ring, respectively. 7-DMATS was found to accept l-tyrosine as substrate as well and converted it to an O-prenylated derivative. An acceptance of l-tyrosine by FgaPT2 was also observed in this study. Interestingly, isolation and structure elucidation revealed the identification of a C3-prenylated l-tyrosine as enzyme product. Molecular modeling and site-directed mutagenesis led to creation of a mutant FgaPT2_K174F, which showed much higher specificity toward l-tyrosine than l-tryptophan. Its catalytic efficiency toward l-tyrosine was found to be 4.9-fold in comparison with that of non-mutated FgaPT2, whereas the activity toward l-tryptophan was less than 0.4% of that of the wild-type. To the best of our knowledge, this is the first report on an enzymatic C-prenylation of l-tyrosine as free amino acid and altering the substrate preference of a prenyltransferase by mutagenesis. PMID:25477507

Giant geode (subchondrial cyst) in calcium pyrophosphate deposition disease on the curist.

PubMed

Weinberg, S; Scott, R A

1981-09-01

It is important to be aware of the radiographic features of pyrophosphate arthropathy with or without associated chondrocalcinosis. Accordingly, when appropriate structural joint changes are present an extraordinarily large subchondral cyst should not prompt a misdiagnosis of cystic tumor.

Biochemically and histopathologically comparative review of thiamine’s and thiamine pyrophosphate’s oxidative stress effects generated with methotrexate in rat liver

PubMed Central

Demiryilmaz, Ismail; Sener, Ebru; Cetin, Nihal; Altuner, Durdu; Suleyman, Bahadir; Albayrak, Fatih; Akcay, Fatih; Suleyman, Halis

2012-01-01

Summary Background Oxidative liver injury occurring with methotrexate restricts its use in the desired dose. Therefore, whether or not thiamine and thiamine pyrophosphate, whose antioxidant activity is known, have protective effects on oxidative liver injury generated with methotrexate was comparatively researched in rats using biochemical and histopathological approaches. Material/Methods Thiamine pyrophosphate+methotrexate, thiamine+methotrexate, and methotrexate were injected intraperitoneally in rats for 7 days. After this period, all animals’ livers were excised, killing them with high-dose anesthesia, and histopathologic and biochemical investigations were made. Result Biochemical results demonstrated a significant elevation in level of oxidant parameters such as MDA and MPO, and a reduction in antioxidant parameters such as GSH and SOD in the liver tissue of the methotrexate group. Also, the quantity of 8-OHdG/dG, a DNA injury product, was higher in the methotrexate group with high oxidant levels and low antioxidant levels, and the quantity of 8-OHdG/dG was in the thiamine pyrophosphate group with low oxidant levels and high antioxidant levels. In the thiamine and control groups, the 8-OHdG/dG rate was 1.48±0.35 pmol/L (P>0.05) and 0.55±0.1 pmol/L (P<0.0001). Thiamine pyrophosphate significantly decreased blood AST, ALT and LDH, but methotrexate and thiamine did not decrease the blood levels of AST, ALT and LDH. Histopathologically, although centrilobular necrosis, apoptotic bodies and inflammation were monitored in the methotrexate group, the findings in the thiamine pyrophosphate group were almost the same as in the control group. Conclusions Thiamine pyrophosphate was found to be effective in methotrexate hepatotoxicity, but thiamine was ineffective. PMID:23197226

Magnesium affects rubber biosynthesis and particle stability in Ficus elastica, Hevea brasiliensis and Parthenium argentatum

USDA-ARS?s Scientific Manuscript database

Natural rubber biosynthesis occurs in laticifers of Ficus elastica and Hevea brasiliensis, and in parenchyma cells of Parthenium argentatum. Natural rubber is synthesized by rubber transferase using allylic pyrophosphates as initiators, isopentenyl pyrophosphate as monomeric substrate and magnesium ...

Structural Basis for Flip-Flop Action of Thiamin Pyrophosphate-dependent Enzymes Revealed by Human Pyruvate Dehydrogenase

NASA Technical Reports Server (NTRS)

Ciszak, Ewa M.; Korotchkina, Lioubov G.; Dominiak, Paulina M.; Sidhu, Sukdeep; Patel, Mulchand S.

2003-01-01

The derivative of vitamin B1, thiamin pyrophosphate, is a cofactor of enzymes performing catalysis in pathways of energy production. In alpha (sub 2) beta (sub 2)-heterotetrameric human pyruvate dehydrogenase, this cofactor is used to cleave the C(sup alpha) -C(=O) bond of pyruvate followed by reductive acetyl transfer to lipoyl-dihydrolipoamide acetyltransferase. The dynamic nonequivalence of two, otherwise chemically equivalent, catalytic sites has not yet been understood. To understand the mechanism of action of this enzyme, we determined the crystal structure of the holo-form of human pyruvate dehydrogenase at 1.95-Angstrom resolution. We propose a model for the flip-flop action of this enzyme through a concerted approximately 2-Angstrom shuttle-like motion of its heterodimers. Similarity of thiamin pyrophosphate binding in human pyruvate dehydrogenase with functionally related enzymes suggests that this newly defined shuttle-like motion of domains is common to the family of thiamin pyrophosphate-dependent enzymes.

The characteristics of pyrophosphate: D-fructose-6-phosphate 1-phosphotransferases from Sansevieria trifasciata leaves and Phaseolus coccineus stems.

PubMed

Kowalczyk, S

1987-01-01

Three different molecular forms of pyrophosphate-dependent phosphofructokinase have been isolated: one from Sansevieria trifasciata leaves and two from Phaseolus coccineus stems. The form isolated from S. trifasciata has the molecular weight of about 115,000. The apparent molecular weights for the two forms from mung bean were approximately 220,000 and 450,000. All three forms have the same pH optima, an absolute requirement for Mg2+ ions both in the forward and reverse reaction, but differ in their sensitivity toward fructose 2,6-bisphosphate. Kinetic properties of the partially purified enzymes have been investigated in the presence and absence of fructose 2,6-bisphosphate. Pyrophosphate-dependent phosphofructokinase from S. trifasciata exhibited hyperbolic kinetics with all substrates tested. The saturation curves of the enzyme (form A) from mung bean for pyrophosphate, fructose 6-phosphate and fructose 1,6-bisphosphate were sigmoidal in the absence of fructose 2,6-bisphosphate. In the presence of fructose 2,6-bisphosphate these kinetics became hyperbolic.

Determination of phosphorus fertilizer soil reactions by Raman and synchrotron infrared microspectroscopy.

PubMed

Vogel, Christian; Adam, Christian; Sekine, Ryo; Schiller, Tara; Lipiec, Ewelina; McNaughton, Don

2013-10-01

The reaction mechanisms of phosphate-bearing mineral phases from sewage sludge ash-based fertilizers in soil were determined by Raman and synchrotron infrared microspectroscopy. Different reaction mechanisms in wet soil were found for calcium and magnesium (pyro-) phosphates. Calcium orthophosphates were converted over time to hydroxyapatite. Conversely, different magnesium phosphates were transformed to trimagnesium phosphate. Since the magnesium phosphates are unable to form an apatite structure, the plant-available phosphorus remains in the soil, leading to better growth results observed in agricultural pot experiments. The pyrophosphates also reacted very differently. Calcium pyrophosphate is unreactive in soil. In contrast, magnesium pyrophosphate quickly formed plant-available dimagnesium phosphate.

21 CFR 182.8223 - Calcium pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium pyrophosphate. 182.8223 Section 182.8223 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8223 Calcium...

21 CFR 582.5306 - Ferric sodium pyrophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ferric sodium pyrophosphate. 582.5306 Section 582.5306 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

21 CFR 182.8223 - Calcium pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium pyrophosphate. 182.8223 Section 182.8223 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8223 Calcium...

21 CFR 582.5306 - Ferric sodium pyrophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ferric sodium pyrophosphate. 582.5306 Section 582.5306 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

21 CFR 582.5306 - Ferric sodium pyrophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ferric sodium pyrophosphate. 582.5306 Section 582.5306 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

21 CFR 582.5306 - Ferric sodium pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ferric sodium pyrophosphate. 582.5306 Section 582.5306 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

Microbial Production of Isoprene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ray Fall

2007-07-29

Isoprene is a volatile hydrocarbon of unknown function, produced by certain bacteria, plants and animals, sometimes in huge amounts—the Earth’s forests are estimated to emit >500 x 106 tons of isoprene per year. With funding from this program we explored the biochemistry and regulation of isoprene formation in the model bacterial system, Bacillus subtilis, with the goals of explaining the biological rationale for isoprene biogenesis and constructing an isoprene-overproducing microbial system. Although the role for isoprene formation in B. subtilis is still uncertain, our current model for regulation of this hydrocarbon’s synthesis is that isoprene production in B. subtilis ismore » controlled by a combination of i) rapid regulation of isoprene synthase activity and ii) supply of the substrate for isoprene synthase, dimethyallyl diphosphate (DMAPP). This model parallels our current thinking about the control of isoprene formation in plant chloroplasts. In this reporting period we have been working to test part ii) of this model; this work has produced new results using genetic and analytical approaches. For examples, we have developed an analytical method to resolve DMAPP and its isomer, isopentenyl diphosphate, from each other in bacteria and plants. We have also shown that the IPP isomerase (type 2) of B. subtilis is not the source of “isoprene synthase” activity, and discovered that B. subtilis releases C5 isoprenoid alcohols to the medium, suggesting that isoprene plus other C5 isoprenoids may be common by-products of metabolism. In addition, we have continued to work on our discovery that wild type B. subtilis strains form prolific biofilms, are normal components of plant root microflora, and are testing the idea that B. subtilis growing in biofilms uses isoprene to induce plant root exudation.« less

Crystallization and preliminary X-ray diffraction study of phosphoribosyl pyrophosphate synthetase from E. Coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timofeev, V. I., E-mail: inna@ns.crys.ras.ru; Abramchik, Yu. A., E-mail: tostars@mail.ru; Zhukhlistova, N. E., E-mail: ugama@yandex.ru

2015-09-15

Enzymes of the phosphoribosyl pyrophosphate synthetase family (PRPPS, EC 2.7.6.1) catalyze the formation of 5-phosphoribosyl pyrophosphate (5-PRPP) from adenosine triphosphate and ribose 5-phosphate. 5-Phosphoribosyl pyrophosphate is an important intermediate in the synthesis of purine, pyrimidine, and pyridine nucleotides, as well as of the amino acids histidine and tryptophan. The crystallization conditions for E. coli PRPPS were found by the vapor-diffusion technique and were optimized to apply the capillary counter-diffusion technique. The X-ray diffraction data set was collected from the crystals grown by the counter-diffusion technique using a synchrotron radiation source to 3.1-Å resolution. The crystals of PRPPS belong to sp.more » gr. P6{sub 3}22 and have the following unit-cell parameters: a = b = 104.44 Å, c = 124.98 Å, α = β = 90°, γ = 120°. The collected X-ray diffraction data set is suitable for the solution of the three-dimensional structure of PRPPS at 3.1-Å resolution.« less

Evaluation of a dental floss containing soluble pyrophosphate on calculus formation using a short-term clinical model.

PubMed

Kleber, C J; Putt, M S; Milleman, J L; Harris, M

1998-01-01

This clinical study compared the effect of a dental floss containing 0.25 mg tetrasodium pyrophosphate per cm and a placebo floss on supragingival calculus formation using a 6-week, partial-mouth toothshield model. The six lower anterior teeth were scaled and polished before each 2-week period (i.e., pre-trial, washout, trial). During both the pre-trial and trial periods, subjects brushed twice daily with a non-tartar control dentifrice, while a toothshield protected the six test teeth from brushing. After rinsing with water and removing the shield, they flossed the test teeth. All subjects used placebo floss during the pre-trial period in order to determine the baseline Volpe-Manhold Index (VMI) calculus formation scores, which were used to balance groups for the trial period. During the trial period, one group used the placebo floss, while the second group used the pyrophosphate floss. The final results demonstrated that the pyrophosphate floss significantly inhibited calculus formation between teeth (mesial-distal scores) by 21%, and on labial surfaces by 37% relative to the placebo floss.

Monoamine oxidase inhibitors from Gentiana lutea.

PubMed

Haraguchi, Hiroyuki; Tanaka, Yasumasa; Kabbash, Amal; Fujioka, Toshihiro; Ishizu, Takashi; Yagi, Akira

2004-08-01

Three monoamine oxidase (MAO) inhibitors were isolated from Gentiana lutea. Their structures were elucidated to be 3-3''linked-(2'-hydroxy-4-O-isoprenylchalcone)-(2'''-hydroxy-4''-O-isoprenyldihydrochalcone) (1), 2-methoxy-3-(1,1'-dimethylallyl)-6a,10a-dihydrobenzo(1,2-c)chroman-6-one and 5-hydroxyflavanone. These compounds, and the hydrolysis product of 1, displayed competitive inhibitory properties against MAO-B which was more effective than MAO-A.

Inositol pyrophosphates promote tumor growth and metastasis by antagonizing liver kinase B1

PubMed Central

Rao, Feng; Xu, Jing; Fu, Chenglai; Cha, Jiyoung Y.; Gadalla, Moataz M.; Xu, Risheng; Barrow, James C.; Snyder, Solomon H.

2015-01-01

The inositol pyrophosphates, molecular messengers containing an energetic pyrophosphate bond, impact a wide range of biologic processes. They are generated primarily by a family of three inositol hexakisphosphate kinases (IP6Ks), the principal product of which is diphosphoinositol pentakisphosphate (IP7). We report that IP6K2, via IP7 synthesis, is a major mediator of cancer cell migration and tumor metastasis in cell culture and in intact mice. IP6K2 acts by enhancing cell-matrix adhesion and decreasing cell–cell adhesion. This action is mediated by IP7-elicited nuclear sequestration and inactivation of the tumor suppressor liver kinase B1 (LKB1). Accordingly, inhibitors of IP6K2 offer promise in cancer therapy. PMID:25617365

Three-dimensional structure of phosphoribosyl pyrophosphate synthetase from E. coli at 2.71 Å resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timofeev, V. I., E-mail: inna@ns.crys.ras.ru, E-mail: tostars@mail.ru, E-mail: ugama@yandex.ru; Abramchik, Yu. A.; Zhukhlistova, N. E.

2016-01-15

Phosphoribosyl pyrophosphate synthetase from Escherichia coli was cloned, purified, and crystallized. Single crystals of the enzyme were grown under microgravity. The X-ray diffraction data set was collected at the Spring-8 synchrotron facility and used to determine the three-dimensional structure of the enzyme by the molecular-replacement method at 2.71 Å resolution. The active and regulatory sites in the molecule of E. coli phosphoribosyl pyrophosphate synthetase were revealed by comparison with the homologous protein from Bacillus subtilis, the structure of which was determined in a complex with functional ligands. The conformations of polypeptide-chain fragments surrounding and composing the active and regulatory sitesmore » were shown to be identical in both proteins.« less

Retinoid production using metabolically engineered Escherichia coli with a two-phase culture system.

PubMed

Jang, Hui-Jeong; Yoon, Sang-Hwal; Ryu, Hee-Kyung; Kim, Jung-Hun; Wang, Chong-Long; Kim, Jae-Yean; Oh, Deok-Kun; Kim, Seon-Won

2011-07-29

Retinoids are lipophilic isoprenoids composed of a cyclic group and a linear chain with a hydrophilic end group. These compounds include retinol, retinal, retinoic acid, retinyl esters, and various derivatives of these structures. Retinoids are used as cosmetic agents and effective pharmaceuticals for skin diseases. Retinal, an immediate precursor of retinoids, is derived by β-carotene 15,15'-mono(di)oxygenase (BCM(D)O) from β-carotene, which is synthesized from the isoprenoid building blocks isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Retinoids are chemically unstable and biologically degraded via retinoic acid. Although extensive studies have been performed on the microbial production of carotenoids, retinoid production using microbial metabolic engineering has not been reported. Here, we report retinoid production using engineered Escherichia coli that express exogenous BCM(D)O and the mevalonate (MVA) pathway for the building blocks synthesis in combination with a two-phase culture system using a dodecane overlay. Among the BCM(D)O tested in E. coli, the synthetic retinoid synthesis protein (SR), based on bacteriorhodopsin-related protein-like homolog (Blh) of the uncultured marine bacteria 66A03, showed the highest β-carotene cleavage activity with no residual intracellular β-carotene. By introducing the exogenous MVA pathway, 8.7 mg/L of retinal was produced, which is 4-fold higher production than that of augmenting the MEP pathway (dxs overexpression). There was a large gap between retinal production and β-carotene consumption using the exogenous MVA pathway; therefore, the retinal derivatives were analyzed. The derivatives, except for retinoic acid, that formed were identified, and the levels of retinal, retinol, and retinyl acetate were measured. Amounts as high as 95 mg/L retinoids were obtained from engineered E. coli DH5α harboring the synthetic SR gene and the exogenous MVA pathway in addition to dxs overexpression, which were cultured at 29°C for 72 hours with 2YT medium containing 2.0% (w/v) glycerol as the main carbon source. However, a significant level of intracellular degradation of the retinoids was also observed in the culture. To prevent degradation of the intracellular retinoids through in situ extraction from the cells, a two-phase culture system with dodecane was used. The highest level of retinoid production (136 mg/L) was obtained after 72 hours with 5 mL of dodecane overlaid on a 5 mL culture. In this study, we successfully produced 136 mg/L retinoids, which were composed of 67 mg/L retinal, 54 mg/L retinol, and 15 mg/L retinyl acetate, using a two-phase culture system with dodecane, which produced 68-fold more retinoids than the initial level of production (2.2 mg/L). Our results demonstrate the potential use of E. coli as a promising microbial cell factory for retinoid production.

Hyaline cartilage involvement in patients with gout and calcium pyrophosphate deposition disease. An ultrasound study.

PubMed

Filippucci, E; Riveros, M Gutierrez; Georgescu, D; Salaffi, F; Grassi, W

2009-02-01

The main aim of the present study was to determine the sensitivity, specificity and accuracy of ultrasonography (US) in detecting monosodium urate and calcium pyrophosphate dihydrate crystals deposits at knee cartilage level using clinical definite diagnosis as standard reference. A total of 32 patients with a diagnosis of gout and 48 patients with pyrophosphate arthropathy were included in the study. Fifty-two patients with rheumatoid arthritis (RA), psoriatic arthritis or osteoarthritis (OA) were recruited as disease controls. All diagnoses were made using an international clinical criterion. US examinations were performed by an experienced sonographer, blind to clinical and laboratory data. Hyaline cartilage was assessed to detect two US findings recently indicated as indicative of crystal deposits: hyperechoic enhancement of the superficial margin of the hyaline cartilage and hyperechoic spots within the cartilage layer not generating a posterior acoustic shadow. Hyperechoic enhancement of the chondrosynovial margin was found in at least one knee of 14 out of 32 (43.7%) patients with gout and in a single knee of only one patient affected by pyrophosphate arthropathy (specificity=99%). Intra-cartilaginous hyperechoic spots were detected in at least one knee of 33 out of 48 (68.7%) patients with pyrophosphate arthropathy and in two disease controls one with OA and the second with RA (specificity=97.6%). The results of the present study indicate that US may play a relevant role in distinguishing cartilage involvement in patients with crystal-related arthropathy. The selected US findings were found to be highly specific.

Predictive model for growth of Clostridium perfringens during cooling of cooked beef supplemented with NaCl, sodium nitrite and sodium pyrophosphate

USDA-ARS?s Scientific Manuscript database

This paper presents a model for predicting relative growth of C. perfringens in ground beef products at different percentages of salt (0%, 1%, 2% and 3%) and nitrite (0 and 200 ppm). Included in the experiments were different levels of sodium pyrophosphate (SPP). The results of the experiments indic...

The role of technetium-99m stannous pyrophosphate in myocardial imaging to recognize, localize and identify extension of acute myocardial infarction in patients

NASA Technical Reports Server (NTRS)

Willerson, J. T.; Parkey, R. W.; Bonte, F. J.; Stokely, E. M.; Buja, E. M.

1975-01-01

The ability of technetium-99m stannous pyrophosphate myocardial scintigrams to aid diagnostically in recognizing, localizing, and identifying extension of acute myocardial infarction in patients was evaluated. The present study is an extension of previous animal and patient evaluations that were recently performed utilizing this myocardial imaging agent.

A pyrophosphate-responsive gadolinium(III) MRI contrast agent.

PubMed

Surman, Andrew J; Bonnet, Célia S; Lowe, Mark P; Kenny, Gavin D; Bell, Jimmy D; Tóth, Eva; Vilar, Ramon

2011-01-03

This study shows that the relaxivity and optical properties of functionalised lanthanide-DTPA-bis-amide complexes (lanthanide=Gd(3+) and Eu(3+) , DTPA=diethylene triamine pentaacetic acid) can be successfully modulated by addition of specific anions, without direct Ln(3+) /anion coordination. Zinc(II)-dipicolylamine moieties, which are known to bind strongly to phosphates, were introduced in the amide "arms" of these ligands, and the interaction of the resulting Gd-Zn(2) complexes with a range of anions was screened by using indicator displacement assays (IDAs). Considerable selectivity for polyphosphorylated species (such as pyrophosphate and adenosine-5'-triphosphate (ATP)) over a range of other anions (including monophosphorylated anions) was apparent. In addition, we show that pyrophosphate modulates the relaxivity of the gadolinium(III) complex, this modulation being sufficiently large to be observed in imaging experiments. To establish the binding mode of the pyrophosphate and gain insight into the origin of the relaxometric modulation, a series of studies including UV/Vis and emission spectroscopy, luminescence lifetime measurements in H(2) O and D(2) O, (17) O and (31) P NMR spectroscopy and nuclear magnetic resonance dispersion (NMRD) studies were carried out. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Label-free electrical detection of pyrophosphate generated from DNA polymerase reactions on field-effect devices.

PubMed

Credo, Grace M; Su, Xing; Wu, Kai; Elibol, Oguz H; Liu, David J; Reddy, Bobby; Tsai, Ta-Wei; Dorvel, Brian R; Daniels, Jonathan S; Bashir, Rashid; Varma, Madoo

2012-03-21

We introduce a label-free approach for sensing polymerase reactions on deoxyribonucleic acid (DNA) using a chelator-modified silicon-on-insulator field-effect transistor (SOI-FET) that exhibits selective and reversible electrical response to pyrophosphate anions. The chemical modification of the sensor surface was designed to include rolling-circle amplification (RCA) DNA colonies for locally enhanced pyrophosphate (PPi) signal generation and sensors with immobilized chelators for capture and surface-sensitive detection of diffusible reaction by-products. While detecting arrays of enzymatic base incorporation reactions is typically accomplished using optical fluorescence or chemiluminescence techniques, our results suggest that it is possible to develop scalable and portable PPi-specific sensors and platforms for broad biomedical applications such as DNA sequencing and microbe detection using surface-sensitive electrical readout techniques.

Effect of pH, sodium chloride and sodium pyrophosphate on the termal resistance of Escherichia coli O157:H7 in ground beef

USDA-ARS?s Scientific Manuscript database

Response to the Letter to the Editor: We have received with great satisfaction that our article “Modelling the effect of pH, sodium chloride and sodium pyrophosphate on the thermal resistance of Escherichia coli O157:H7 in ground beef” (Food Research International, 69:289-304; 2015) has awaken inte...

Magnetite nanoparticle-induced fluorescence quenching of adenosine triphosphate-BODIPY Conjugates: application to adenosine triphosphate and pyrophosphate sensing.

PubMed

Yu, Cheng-Ju; Wu, Su-Mei; Tseng, Wei-Lung

2013-09-17

We report that magnetite nanoparticles (Fe3O4 NPs) act as an efficient quencher for boron dipyrromethene-conjugated adenosine 5'-triphosphate (BODIPY-ATP) that is highly fluorescent in bulk solution. BODIPY-ATP molecules attached to the surface of Fe3O4 NPs through the coordination between the triphosphate group of BODIPY-ATP and Fe(3+)/Fe(2+) on the NP surface. The formed complexes induced an apparent reduction in the BODIPY-ATP fluorescence resulting from an oxidative-photoinduced electron transfer (PET) from the BODIPY-ATP excited state to an unfilled d shell of Fe(3+)/Fe(2+) on the NP surface. A comparison of the Stern-Volmer quenching constant between Fe(3+) and Fe(2+) suggests that Fe(3+) on the NP surface dominantly controls this quenching process. The efficiency for Fe3O4 NP-induced fluorescence quenching of the BODIPY-ATP was enhanced by increasing the concentration of Fe3O4 NPs and lowering the pH of the solution to below 6.0. We found that pyrophosphate and ATP compete with BODIPY-ATP for binding to Fe3O4 NPs. Thus, we amplified BODIPY-ATP fluorescence in the presence of increasing the pyrophosphate and ATP concentration; the detection limits at a signal-to-noise ratio of 3 for pyrophosphate and ATP were determined to be 7 and 30 nM, respectively. The Fe3O4 NP-based competitive binding assay detected ATP and pyrophosphate in only 5 min. The selectivity of this assay for ATP over metal ions, amino acids, and adenosine analogues is particularly high. The practicality of using the developed method to determine ATP in a single drop of blood is also validated.

Protein farnesyltransferase isoprenoid substrate discrimination is dependent on isoprene double bonds and branched methyl groups.

PubMed

Micali, E; Chehade, K A; Isaacs, R J; Andres, D A; Spielmann, H P

2001-10-16

Farnesylation is a posttranslational lipid modification in which a 15-carbon farnesyl isoprenoid is linked via a thioether bond to specific cysteine residues of proteins in a reaction catalyzed by protein farnesyltransferase (FTase). We synthesized the benzyloxyisoprenyl pyrophosphate (BnPP) series of transferable farnesyl pyrophosphate (FPP) analogues (1a-e) to test the length dependence of the isoprenoid substrate on the FTase-catalyzed transfer of lipid to protein substrate. Kinetic analyses show that pyrophosphates 1a-e and geranyl pyrophosphate (GPP) transfer with a lower efficiency than FPP whereas geranylgeranyl pyrophosphate (GGPP) does not transfer at all. While a correlation was found between K(m) and analogue hydrophobicity and length, there was no correlation between k(cat) and these properties. Potential binding geometries of FPP, GPP, GGPP, and analogues 1a-e were examined by modeling the molecules into the active site of the FTase crystal structure. We found that analogue 1d displaces approximately the same volume of the active site as does FPP, whereas GPP and analogues 1a-c occupy lesser volumes and 1e occupies a slightly larger volume. Modeling also indicated that GGPP adopts a different conformation than the farnesyl chain of FPP, partially occluding the space occupied by the Ca(1)a(2)X peptide in the ternary X-ray crystal structure. Within the confines of the FTase pocket, the double bonds and branched methyl groups of the geranylgeranyl chain significantly restrict the number of possible conformations relative to the more flexible lipid chain of analogues 1a-e. The modeling results also provide a molecular explanation for the observation that an aromatic ring is a good isostere for the terminal isoprene of FPP.

Bioactive calcium pyrophosphate glasses and glass-ceramics.

PubMed

Kasuga, Toshihiro

2005-01-01

Calcium phosphate glass-based materials in the pyrophosphate region are briefly reviewed. Calcium pyrophosphate glasses can be prepared by including a small amount of TiO(2) (

Radioisotope scanning in osseous sarcoidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rohatgi, P.K.

1980-01-01

Technetium-99m (/sup 99m/Tc)-labeled pyrophosphate or diphosphonate compounds and gallium-67 citrate (/sup 67/Ga) are two radionuclide scanning agents that are in widespread use in clinical practice. Technetium-99m pyrophosphate is used extensively for bone scanning to detect metastatic bone disease, benign bone tumors, osteomyelitis, benign hypertrophic osteoarthropathy, and Paget's disease. Only two reports describe abnormal /sup 99m/Tc/ pyrophosphate bone scans in four patients with osseous sarcoidosis. Gallium-67 scans are used primarily to localize neoplastic or inflammatory lesions anywhere in the body. In recent years /sup 67/Ga scans have also been used to detect the presence of both pulmonary and extrapulmonary sarcoidosis, butmore » there are no reports describing abnormal uptake of gallium in patients with osseous sarcoidosis. This report describes experience with radioisotope scanning in two patients with osseous sarcoidosis.« less

The effects of salt, sodium pyrophosphate and sodium lactate on the probability of growth of Escherichia coli O157:H7 in ground beef

USDA-ARS?s Scientific Manuscript database

Ground beef products are susceptible contamination with Escherichia coli O157:H7. The objective of this study was to examine the effect of salt, sodium pyrophosphate (SPP) and sodium lactate on the probability of growth of E. coli O157:H7 in ground beef after storage for 15 days at 10 degree centig...

Tc-99m pyrophosphate myocardial scanning in Chagas' disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

da Rocha, A.F.; Meguerian, B.A.; Harbert, J.C.

1981-04-01

Chagas' disease is a serious protozoan infection affecting up to 20% of populations in some endemic areas. Myocarditis and cardiomyopathy occur in 50% of patients who go on to develop chronic Chagas' disease. We have studied a patient with no overt cardiac symptoms who revealed intense myocardial uptake of Tc-99m pyrophosphate. The significance of this finding in relation to early detection and progress of therapy is explored.

Tc-99m pyrophosphate myocardial scanning in Chagas' disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goncalves da Rocha, A.F.; Meguerian, B.A.; Harbert, J.C.

1981-04-01

Chagas' disease is a serious protozoan infection affecting up to 20% of populations in some endemic areas. Myocarditis and cardiomyopathy occur in 50% of patients who go on to develop chronic Chagas's disease. We have studied a patient with no overt cardiac symptoms who revealed intense myocardial uptake of Tc-99m pyrophosphate. The significance of this finding in relation to early detection and progress of therapy is explored.

Soft-tissue sarcoma: imaged with technetium-99m pyrophosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blatt, C.J.; Hayt, D.B.; Desai, M.

1977-11-01

A liposarcoma showed intense concentration of technetium-99m pyrophosphate. An angiogram demonstrated a highly vascular lesion, and it is suggested that blood flow played a major role in allowing the tumor to be demonstrated on scintiphotography. There was some histologic evidence of calcification which probably also contributed to bone-tracer disposition. Quantitative analysis of the specimen demonstrated that this calcification was located primarily in the areas of hemorrhage and necrosis.

Radionuclide imaging in myocardial sarcoidosis. Demonstration of myocardial uptake of /sup 99m/Tc pyrophosphate and gallium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forman, M.B.; Sandler, M.P.; Sacks, G.A.

1983-03-01

A patient had severe congestive cardiomyopathy secondary to myocardial sarcoidosis. The clinical diagnosis was confirmed by radionuclide ventriculography, /sup 201/Tl, /sup 67/Ga, and /sup 99m/Tc pyrophosphate (TcPYP) scintigraphy. Myocardial TcPYP uptake has not been reported previously in sarcoidosis. In this patient, TcPYP was as useful as gallium scanning and thallium imaging in documenting the myocardial process.

An Evaluative History of Bisphosphonate Drugs: Dual Physiologic Effects of Pyrophosphate as Inspiration for a Novel Pharmaceutical Class.

PubMed

Hinshaw, W Banks; DeLong, Allyn F

2016-01-01

The documented history of the development of the bisphosphonate drugs is reviewed in sufficient detail to permit independent evaluation of the consistency of the conclusions reached from the available data. The evidence developed during the early interval of these studies 1960-1975 was sufficient to establish that pyrophosphate shares the subsequently established dual bisphosphonate characteristics of bone resorption inhibition and prevention of tissue mineralization.

The Thiamin Pyrophosphate-Motif

NASA Technical Reports Server (NTRS)

Dominiak, P.; Ciszak, E.

2003-01-01

Using databases the authors have identified a common thiamin pyrophosphate (TPP)-motif in the family of functionally diverse TPP-dependent enzymes. This common motif consists of multimeric organization of subunits and two catalytic centers. Each catalytic center (PP:PYR) is formed at the interface of the PP-domain binding the magnesium ion, pyrophosphate and amhopyrimidine ring of TPP, and the PYR-domain binding the aminopyrimidine ring of that cofactor. A pair of these catalytic centers constitutes the catalytic core (PP:PYR)(sub 2) within these enzymes. Analysis of the structural elements of this catalytic core reveals novel definition of the common amino acid sequences, which are GXPhiX(sub 4)(G)PhiXXGQ and GDGX(sub 25-30)NN in the PP-domain, and the EX(sub 4)(G)PhiXXGPhi in the PYR-domain, where Phi corresponds to a hydrophobic amino acid. This TPP-motif provides a novel tool for annotation of TPP-dependent enzymes useful in advancing functional proteomics.

Escherichia coli DnaE Polymerase Couples Pyrophosphatase Activity to DNA Replication

PubMed Central

Lapenta, Fabio; Montón Silva, Alejandro; Brandimarti, Renato; Lanzi, Massimiliano; Gratani, Fabio Lino; Vellosillo Gonzalez, Perceval; Perticarari, Sofia; Hochkoeppler, Alejandro

2016-01-01

DNA Polymerases generate pyrophosphate every time they catalyze a step of DNA elongation. This elongation reaction is generally believed as thermodynamically favoured by the hydrolysis of pyrophosphate, catalyzed by inorganic pyrophosphatases. However, the specific action of inorganic pyrophosphatases coupled to DNA replication in vivo was never demonstrated. Here we show that the Polymerase-Histidinol-Phosphatase (PHP) domain of Escherichia coli DNA Polymerase III α subunit features pyrophosphatase activity. We also show that this activity is inhibited by fluoride, as commonly observed for inorganic pyrophosphatases, and we identified 3 amino acids of the PHP active site. Remarkably, E. coli cells expressing variants of these catalytic residues of α subunit feature aberrant phenotypes, poor viability, and are subject to high mutation frequencies. Our findings indicate that DNA Polymerases can couple DNA elongation and pyrophosphate hydrolysis, providing a mechanism for the control of DNA extension rate, and suggest a promising target for novel antibiotics. PMID:27050298

A Pyrophosphate Based Energy Generating Module

DTIC Science & Technology

2008-12-01

OMB control number. 1. REPORT DATE DEC 2008 2 . REPORT TYPE N/A 3 . DATES COVERED - 4. TITLE AND SUBTITLE A Pyrophosphate Based Energy...for each substrate (PPi, PEP, and AMP) using double reciprocal Lineweaver-Burk plots of saturation data. 10| 2 10| 3 10|4 10|5 10|6 10|7 10-11 10- 10...Partitioning 1 2 3 4 Bilayer - + + + α-Hemolysin - - + + Upper Reservoir +PPi, +PEP +PPi, +PEP +PPi, +PEP +PPi, +PEP, +Luc Lower Reservoir +AMP

Simple tools for assembling and searching high-density picolitre pyrophosphate sequence data.

PubMed

Parker, Nicolas J; Parker, Andrew G

2008-04-18

The advent of pyrophosphate sequencing makes large volumes of sequencing data available at a lower cost than previously possible. However, the short read lengths are difficult to assemble and the large dataset is difficult to handle. During the sequencing of a virus from the tsetse fly, Glossina pallidipes, we found the need for tools to search quickly a set of reads for near exact text matches. A set of tools is provided to search a large data set of pyrophosphate sequence reads under a "live" CD version of Linux on a standard PC that can be used by anyone without prior knowledge of Linux and without having to install a Linux setup on the computer. The tools permit short lengths of de novo assembly, checking of existing assembled sequences, selection and display of reads from the data set and gathering counts of sequences in the reads. Demonstrations are given of the use of the tools to help with checking an assembly against the fragment data set; investigating homopolymer lengths, repeat regions and polymorphisms; and resolving inserted bases caused by incomplete chain extension. The additional information contained in a pyrophosphate sequencing data set beyond a basic assembly is difficult to access due to a lack of tools. The set of simple tools presented here would allow anyone with basic computer skills and a standard PC to access this information.

Enhanced triterpene accumulation in Panax ginseng hairy roots overexpressing mevalonate-5-pyrophosphate decarboxylase and farnesyl pyrophosphate synthase.

PubMed

Kim, Yong-Kyoung; Kim, Yeon Bok; Uddin, Md Romij; Lee, Sanghyun; Kim, Soo-Un; Park, Sang Un

2014-10-17

To elucidate the function of mevalonate-5-pyrophosphate decarboxylase (MVD) and farnesyl pyrophosphate synthase (FPS) in triterpene biosynthesis, the genes governing the expression of these enzymes were transformed into Panax ginseng hairy roots. All the transgenic lines showed higher expression levels of PgMVD and PgFPS than that by the wild-type control. Among the hairy root lines transformed with PgMVD, M18 showed the highest level of transcription compared to the control (14.5-fold higher). Transcriptions of F11 and F20 transformed with PgFPS showed 11.1-fold higher level compared with control. In triterpene analysis, M25 of PgMVD produced 4.4-fold higher stigmasterol content (138.95 μg/100 mg, dry weight [DW]) than that by the control; F17 of PgFPS showed the highest total ginsenoside (36.42 mg/g DW) content, which was 2.4-fold higher compared with control. Our results indicate that metabolic engineering in P. ginseng was successfully achieved through Agrobacterium rhizogenes-mediated transformation and that the accumulation of phytosterols and ginsenosides was enhanced by introducing the PgMVD and PgFPS genes into the hairy roots of the plant. Our results suggest that PgMVD and PgFPS play an important role in the triterpene biosynthesis of P. ginseng.

Site-specific transition metal occupation in multicomponent pyrophosphate for improved electrochemical and thermal properties in lithium battery cathodes: a combined experimental and theoretical study.

PubMed

Shakoor, Rana A; Kim, Heejin; Cho, Woosuk; Lim, Soo Yeon; Song, Hannah; Lee, Jung Woo; Kang, Jeung Ku; Kim, Yong-Tae; Jung, Yousung; Choi, Jang Wook

2012-07-18

As an attempt to develop lithium ion batteries with excellent performance, which is desirable for a variety of applications including mobile electronics, electrical vehicles, and utility grids, the battery community has continuously pursued cathode materials that function at higher potentials with efficient kinetics for lithium insertion and extraction. By employing both experimental and theoretical tools, herein we report multicomponent pyrophosphate (Li(2)MP(2)O(7), M = Fe(1/3)Mn(1/3)Co(1/3)) cathode materials with novel and advantageous properties as compared to the single-component analogues and other multicomponent polyanions. Li(2)Fe(1/3)Mn(1/3)Co(1/3)P(2)O(7) is formed on the basis of a solid solution among the three individual transition-metal-based pyrophosphates. The unique crystal structure of pyrophosphate and the first principles calculations show that different transition metals have a tendency to preferentially occupy either octahedral or pyramidal sites, and this site-specific transition metal occupation leads to significant improvements in various battery properties: a single-phase mode for Li insertion/extraction, improved cell potentials for Fe(2+)/Fe(3+) (raised by 0.18 eV) and Co(2+)/Co(3+) (lowered by 0.26 eV), and increased activity for Mn(2+)/Mn(3+) with significantly reduced overpotential. We reveal that the favorable energy of transition metal mixing and the sequential redox reaction for each TM element with a sufficient redox gap is the underlying physical reason for the preferential single-phase mode of Li intercalation/deintercalation reaction in pyrophosphate, a general concept that can be applied to other multicomponent systems. Furthermore, an extremely small volume change of ~0.7% between the fully charged and discharged states and the significantly enhanced thermal stability are observed for the present material, the effects unseen in previous multicomponent battery materials.

Structure of Leishmania major Methionyl-tRNA Synthetase in Complex with Intermediate Products Methionyladenylate and Pyrophosphate

PubMed Central

Larson, Eric T.; Kim, Jessica E.; Zucker, Frank H.; Kelley, Angela; Mueller, Natascha; Napuli, Alberto J.; Verlinde, Christophe L.M.J.; Fan, Erkang; Buckner, Frederick S.; Van Voorhis, Wesley C.; Merritt, Ethan A.; Hol, Wim G.J.

2011-01-01

Leishmania parasites cause two million new cases of leishmaniasis each year with several hundreds of millions people at risk. Due to the paucity and shortcomings of available drugs, we have undertaken the crystal structure determination of a key enzyme from Leishmania major in hopes of creating a platform for the rational design of new therapeutics. Crystals of the catalytic core of methionyl-tRNA synthetase from L. major (LmMetRS) were obtained with the substrates MgATP and methionine present in the crystallization medium. These crystals yielded the 2.0 Å resolution structure of LmMetRS in complex with two products, methionyladenylate and pyrophosphate, along with a Mg2+ ion that bridges them. This is the first class I aminoacyl-tRNA synthetase (aaRS) structure with pyrophosphate bound. The residues of the class I aaRS signature sequence motifs, KISKS and HIGH, make numerous contacts with the pyrophosphate. Substantial differences between the LmMetRS structure and previously reported complexes of E. coli MetRS (EcMetRS) with analogs of the methionyladenylate intermediate product are observed, even though one of these analogs only differs by one atom from the intermediate. The source of these structural differences is attributed to the presence of the product pyrophosphate in LmMetRS. Analysis of the LmMetRS structure in light of the Aquifex aeolicus MetRS-tRNAMet complex shows that major rearrangements of multiple structural elements of enzyme and/or tRNA are required to allow the CCA acceptor triplet to reach the methionyladenylate intermediate in the active site. Comparison with sequences of human cytosolic and mitochondrial MetRS reveals interesting differences near the ATP- and methionine-binding regions of LmMetRS, suggesting that it should be possible to obtain compounds that selectively inhibit the parasite enzyme. PMID:21144880

Metabolic Flux Analysis of Plastidic Isoprenoid Biosynthesis in Poplar Leaves Emitting and Nonemitting Isoprene1[W

PubMed Central

Ghirardo, Andrea; Wright, Louwrance Peter; Bi, Zhen; Rosenkranz, Maaria; Pulido, Pablo; Rodríguez-Concepción, Manuel; Niinemets, Ülo; Brüggemann, Nicolas; Gershenzon, Jonathan; Schnitzler, Jörg-Peter

2014-01-01

The plastidic 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway is one of the most important pathways in plants and produces a large variety of essential isoprenoids. Its regulation, however, is still not well understood. Using the stable isotope 13C-labeling technique, we analyzed the carbon fluxes through the MEP pathway and into the major plastidic isoprenoid products in isoprene-emitting and transgenic isoprene-nonemitting (NE) gray poplar (Populus × canescens). We assessed the dependence on temperature, light intensity, and atmospheric [CO2]. Isoprene biosynthesis was by far (99%) the main carbon sink of MEP pathway intermediates in mature gray poplar leaves, and its production required severalfold higher carbon fluxes compared with NE leaves with almost zero isoprene emission. To compensate for the much lower demand for carbon, NE leaves drastically reduced the overall carbon flux within the MEP pathway. Feedback inhibition of 1-deoxy-d-xylulose-5-phosphate synthase activity by accumulated plastidic dimethylallyl diphosphate almost completely explained this reduction in carbon flux. Our data demonstrate that short-term biochemical feedback regulation of 1-deoxy-d-xylulose-5-phosphate synthase activity by plastidic dimethylallyl diphosphate is an important regulatory mechanism of the MEP pathway. Despite being relieved from the large carbon demand of isoprene biosynthesis, NE plants redirected only approximately 0.5% of this saved carbon toward essential nonvolatile isoprenoids, i.e. β-carotene and lutein, most probably to compensate for the absence of isoprene and its antioxidant properties. PMID:24590857

Metabolic flux analysis of plastidic isoprenoid biosynthesis in poplar leaves emitting and nonemitting isoprene.

PubMed

Ghirardo, Andrea; Wright, Louwrance Peter; Bi, Zhen; Rosenkranz, Maaria; Pulido, Pablo; Rodríguez-Concepción, Manuel; Niinemets, Ülo; Brüggemann, Nicolas; Gershenzon, Jonathan; Schnitzler, Jörg-Peter

2014-05-01

The plastidic 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway is one of the most important pathways in plants and produces a large variety of essential isoprenoids. Its regulation, however, is still not well understood. Using the stable isotope 13C-labeling technique, we analyzed the carbon fluxes through the MEP pathway and into the major plastidic isoprenoid products in isoprene-emitting and transgenic isoprene-nonemitting (NE) gray poplar (Populus×canescens). We assessed the dependence on temperature, light intensity, and atmospheric [CO2]. Isoprene biosynthesis was by far (99%) the main carbon sink of MEP pathway intermediates in mature gray poplar leaves, and its production required severalfold higher carbon fluxes compared with NE leaves with almost zero isoprene emission. To compensate for the much lower demand for carbon, NE leaves drastically reduced the overall carbon flux within the MEP pathway. Feedback inhibition of 1-deoxy-D-xylulose-5-phosphate synthase activity by accumulated plastidic dimethylallyl diphosphate almost completely explained this reduction in carbon flux. Our data demonstrate that short-term biochemical feedback regulation of 1-deoxy-d-xylulose-5-phosphate synthase activity by plastidic dimethylallyl diphosphate is an important regulatory mechanism of the MEP pathway. Despite being relieved from the large carbon demand of isoprene biosynthesis, NE plants redirected only approximately 0.5% of this saved carbon toward essential nonvolatile isoprenoids, i.e. β-carotene and lutein, most probably to compensate for the absence of isoprene and its antioxidant properties.

Modelling the effect of pH, sodium chloride and sodium pyrophosphate on the thermal resistance of Escherichia coli O157:H7 in ground beef

USDA-ARS?s Scientific Manuscript database

A fractional factorial design was used to assess the combined effects of four internal temperatures (55.0, 57.5, 60.0 and 62.5C) and five concentrations of sodium chloride (NaCl) (0.0, 1.5, 3.0, 4.5 and 6.0 wt/wt%) and sodium pyrophosphate (SPP) (0.0, 0.1, 0.15, 0.2 and 0.3 wt/wt%) on the heat resis...

Effect of dinucleoside pyrophosphates on the oligomerization of activated mononucleotides on Na(+)-montmorillonite: reaction of 5'-phosphoro-4-(dimethylamino)pyridinium [4-(CH3)2NpypA] with A5'ppA

NASA Technical Reports Server (NTRS)

Prabahar, K. J.; Ferris, J. P.

1997-01-01

The oligomerization of adenosine 5'-phosphoro-4-(dimethylamino)pyridinium (4-(CH3)2-NpypA) and diadenosine 5',5'-pyrophosphate (A5'ppA) (9:1) on Na(+)-montmorillonite was studied. The oligomers were isolated and analyzed by selective enzymatic hydrolyses and the oligomeric composition and the percent of 3',5'-phosphodiester linkages present in each fraction was determined. The longest oligomers formed (11-mers) are slightly shorter than those produced in the absence of A5'ppA (12-mers). Smaller amounts of A5'ppA are incorporated into the oligomers than in the ImpA/A5'ppA reaction. The regioselectivity of 3',5'-phosphodiester bond formation is comparable to that of the oligomerization of 4-(CH3)2NpypA alone. An explanation of these data is proposed and the possible effect of dinucleoside pyrophosphate on prebiotic RNA formation is discussed.

Value of positive myocardial technetium-99m-pyrophosphate scintigraphy in the noninvasive diagnosis of cardiac amyloidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wizenberg, T.A.; Muz, J.; Sohn, Y.H.

1982-04-01

Ten consecutive patients with tissue-proven amyloidosis, seven of whom presented with congestive heart failure, were found to exhibit intense diffuse uptake of technetium-99m-pyrophosphate (Tc-99m-PYP) on cardiac radionuclide imaging. The patients exhibited echocardiographic and systolic time interval abnormalities suggesting combined restrictive and congestive cardiomyopathic changes. On M-mode echocardiograms, there was symmetrically increased thickness of the interventricular septum and left ventricular (LV) posterior wall in diastole (10 of 10), decreased fractional shortening of the LV minor axis diameter in systole (eight of nine), and decreased percent thickening of the LV minor axis diameter in systole (eight of nine) and LV posterior wallmore » (10 of 10) in systole. Three patients demonstrated enlarged LV end-diastolic diameter. All 10 patients had abnormal PEP/LVET and eight had shortened LVETI. When combined with noninvasive tests of LV performance, positive myocardial pyrophosphate (PYP) scanning provides a new and useful adjunct in the diagnosis of amyloid heart disease.« less

PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

DOEpatents

Levine, C.A.; Skiens, W.E.; Moore, G.R.

1960-08-01

A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

The Thiamin Pyrophosphate-Motif

NASA Technical Reports Server (NTRS)

Dominiak, Paulina M.; Ciszak, Ewa M.

2003-01-01

Using databases the authors have identified a common thiamin pyrophosphate (TPP)-motif in the family of functionally diverse TPP-dependent enzymes. This common motif consists of multimeric organization of subunits, two catalytic centers, common amino acid sequence, and specific contacts to provide a flip-flop, or alternate site, mechanism of action. Each catalytic center [PP:PYR] is formed at the interface of the PP-domain binding the magnesium ion, pyrophosphate and aminopyrimidine ring of TPP, and the PYR-domain binding the aminopyrimidine ring of that cofactor. A pair of these catalytic centers constitutes the catalytic core [PP:PYR]* within these enzymes. Analysis of the structural elements of this catalytic core reveals novel definition of the common amino acid sequences, which are GX@&(G)@XXGQ, and GDGX25-30 within the PP- domain, and the E&(G)@XXG@ within the PYR-domain, where Q, corresponds to a hydrophobic amino acid. This TPP-motif provides a novel tool for annotation of TPP-dependent enzymes useful in advancing functional proteomics.

An experimental-computer modeling study of inorganic phosphates surface adsorption on hydroxyapatite particles.

PubMed

Rivas, Manuel; Casanovas, Jordi; del Valle, Luis J; Bertran, Oscar; Revilla-López, Guillermo; Turon, Pau; Puiggalí, Jordi; Alemán, Carlos

2015-06-07

The adsorption of orthophosphate, pyrophosphate, triphosphate and a trisphosphonate onto hydroxyapatite has been examined using experiments and quantum mechanical calculations. Adsorption studies with FTIR and X-ray photoelectron spectroscopies have been performed considering both crystalline hydroxyapatite (HAp) and amorphous calcium phosphate particles, which were specifically prepared and characterized for this purpose. Density functional theory (DFT) calculations have been carried out considering the (100) and (001) surfaces of HAp, which were represented using 1 × 2 × 2 and 3 × 3 × 1 slab models, respectively. The adsorption of phosphate onto the two crystallographic surfaces is very much favored from an energetic point of view, which is fully consistent with current interpretations of the HAp growing process. The structures calculated for the adsorption of pyrophosphate and triphosphate evidence that this process is easier for the latter than for the former. Thus, the adsorption of pyrophosphate is severely limited by the surface geometry while the flexibility of triphosphate allows transforming repulsive electrostatic interactions into molecular strain. On the other hand, calculations predict that the trisphosphonate only adsorbs onto the (001) surface of HAp. Theoretical predictions are fully consistent with experimental data. Thus, comparison of DFT results and spectroscopic data suggests that the experimental conditions used to prepare HAp particles promote the predominance of the (100) surface. Accordingly, experimental identification of the adsorption of trisphosphonate onto such crystalline particles is unclear while the adsorption of pyrophosphate and triphosphate is clearly observed.

CRYSTALLINE INORGANIC PYROPHOSPHATASE ISOLATED FROM BAKER'S YEAST

PubMed Central

Kunitz, M.

1952-01-01

Crystalline inorganic pyrophosphatase has been isolated from baker's yeast. The crystalline enzyme is a protein of the albumin type with an isoelectric point near pH 4.8. Its molecular weight is of the order of 100,000. It contains about 5 per cent tyrosine and 3.5 per cent tryptophane. It is most stable at pH 6.8. The new crystalline protein acts as a specific catalyst for the hydrolysis of inorganic pyrophosphate into orthophosphate ions. It does not catalyze the hydrolysis of the pyrophosphate radical of such organic esters as adenosine di- and triphosphate, or thiamine pyrophosphate. Crystalline pyrophosphatase requires the presence of Mg, Co, or Mn ions as activators. These ions are antagonized by calcium ions. Mg is also antagonized by Co or Mn ions. The rate of the enzymatic hydrolysis of inorganic pyrophosphate is proportional to the concentration of enzyme and is a function of pH, temperature, concentration of substrate, and concentration of activating ion. The approximate conditions for optimum rate are: 40°C. and pH 7.0 at a concentration of 3 to 4 x 10–3 M Na4P2O7 and an equivalent concentration of magnesium salt. The enzymatic hydrolysis of Na4P2O7 or K4P2O7 proceeds to completion and is irreversible under the conditions at which hydrolysis is occurring. Details are given of the method of isolation of the crystalline enzyme. PMID:14898026

A new isocoumarin from Cajanus cajan (Fabaceae).

PubMed

Rodrigues, Virginia F; Oliveira, Rodrigo R; Vega, Maria Raquel G

2014-04-01

A new isocoumarin, 3-phenyl-8-hydroxy-6-methoxy-5-gamma,gamma-dimethylallyl-isocoumarin, named cajavilmina (1) and eight known compounds: a-amirenone (2), beta-amirenone (3), lupenone (4), 5-hydroxy-7-methoxydihydroflavone (5), longistilin C (6), 3-hydroxy-5-methoxystilbene (7), beta-sitosterol (8) and stigmasterol (9) were identified in a dichloromethane fraction from Cajanus cajan leaves. Structures were elucidated by analysis of spectral data, mainly those afforded by 1H, NOEDIFF and 13C NMR (1D and 2D NMR HMQC, HMBC and COSY) and mass spectra.

Acute and 3-month effects of calcium carbonate on the calcification propensity of serum and regulators of vascular calcification: secondary analysis of a randomized controlled trial.

PubMed

Bristow, S M; Gamble, G D; Pasch, A; O'Neill, W C; Stewart, A; Horne, A M; Reid, I R

2016-03-01

Calcium supplements have been associated with increased cardiovascular risk, but the mechanism is unknown. We investigated the effects of calcium supplements on the propensity of serum to calcify, based on the transition time of primary to secondary calciprotein particles (T50). Changes in serum calcium were related to changes in T50. Calcium supplements have been associated with increased cardiovascular risk; however, it is unknown whether this is related to an increase in vascular calcification. We investigated the acute and 3-month effects of calcium supplements on the propensity of serum to calcify, based on the transition time of primary to secondary calciprotein particles (T50), and on three possible regulators of calcification: fetuin-A, pyrophosphate and fibroblast growth factor-23 (FGF23). We randomized 41 postmenopausal women to 1 g/day of calcium as carbonate, or to a placebo containing no calcium. Measurements were performed at baseline and then 4 and 8 h after their first dose, and after 3 months of supplementation. Fetuin-A, pyrophosphate and FGF23 were measured in the first 10 participants allocated to calcium carbonate and placebo who completed the study. T50 declined in both groups, the changes tending to be greater in the calcium group. Pyrophosphate declined from baseline in the placebo group at 4 h and was different from the calcium group at this time point (p = 0.04). There were no other significant between-groups differences. The changes in serum total calcium from baseline were significantly related to changes in T50 at 4 h (r = -0.32, p = 0.05) and 8 h (r = -0.39, p = 0.01), to fetuin-A at 3 months (r = 0.57, p = 0.01) and to pyrophosphate at 4 h (r = 0.61, p = 0.02). These correlative findings suggest that serum calcium concentrations modulate the propensity of serum to calcify (T50), and possibly produce counter-regulatory changes in pyrophosphate and fetuin-A. This provides a possible mechanism by which calcium supplements might influence vascular calcification.

Taste and acceptance of pyrophosphates by rats and mice.

PubMed

McCaughey, Stuart A; Giza, Barbara K; Tordoff, Michael G

2007-06-01

The palatability and taste quality of pyrophosphates were evaluated in a series of behavioral and electrophysiological experiments. In two-bottle choice tests with water, rats strongly preferred some concentrations of Na3HP2O7 and Na4P2O7, moderately preferred some concentrations of K4P2O7 and Fe4(P2O7)3, and were indifferent to or avoided all concentrations of Ca2P2O7 and Na2H2P2O7. The contribution of sodium to the preference for sodium pyrophosphates was ascertained: 1) Rats with a choice between Na4P2O7 and NaCl preferred 1 mM Na4P2O7 to 4 mM NaCl but preferred 40 or 150 mM NaCl to 10 mM Na4P2O7, 2) blocking salt taste transduction by mixing Na4P2O7 with amiloride reduced preferences but did not eliminate them, and 3) three mouse strains (FVB/J, C57BL/6J, and CBA/J) known to differ in sodium preference had the same rank order of preferences for Na3HP2O7 and NaCl, but peak preferences were higher for Na3HP2O7 than for NaCl. The taste qualities of pyrophosphates were determined by measuring taste-evoked responses of neurons in the nucleus of the solitary tract of rats. Across-neuron patterns of activity for sodium pyrophosphates were similar to that of NaCl but the pattern of Na3HP2O7 plus amiloride was unique from those of sweet, salty, sour, bitter, and umami stimuli. Taken together, the results indicate that the high palatability of some concentrations of Na3HP2O7 and Na4P2O7 is due partially to their salty taste, but there must also be another cause, which may include a novel orosensory component distinct from the five major taste qualities.

Aromatic Prenylation in Phenazine Biosynthesis

PubMed Central

Saleh, Orwah; Gust, Bertolt; Boll, Björn; Fiedler, Hans-Peter; Heide, Lutz

2009-01-01

The bacterium Streptomyces anulatus 9663, isolated from the intestine of different arthropods, produces prenylated derivatives of phenazine 1-carboxylic acid. From this organism, we have identified the prenyltransferase gene ppzP. ppzP resides in a gene cluster containing orthologs of all genes known to be involved in phenazine 1-carboxylic acid biosynthesis in Pseudomonas strains as well as genes for the six enzymes required to generate dimethylallyl diphosphate via the mevalonate pathway. This is the first complete gene cluster of a phenazine natural compound from streptomycetes. Heterologous expression of this cluster in Streptomyces coelicolor M512 resulted in the formation of prenylated derivatives of phenazine 1-carboxylic acid. After inactivation of ppzP, only nonprenylated phenazine 1-carboxylic acid was formed. Cloning, overexpression, and purification of PpzP resulted in a 37-kDa soluble protein, which was identified as a 5,10-dihydrophenazine 1-carboxylate dimethylallyltransferase, forming a C–C bond between C-1 of the isoprenoid substrate and C-9 of the aromatic substrate. In contrast to many other prenyltransferases, the reaction of PpzP is independent of the presence of magnesium or other divalent cations. The Km value for dimethylallyl diphosphate was determined as 116 μm. For dihydro-PCA, half-maximal velocity was observed at 35 μm. Kcat was calculated as 0.435 s-1. PpzP shows obvious sequence similarity to a recently discovered family of prenyltransferases with aromatic substrates, the ABBA prenyltransferases. The present finding extends the substrate range of this family, previously limited to phenolic compounds, to include also phenazine derivatives. PMID:19339241

FGF2 Stimulation of the Pyrophosphate-Generating Enzyme, PC-1, in Pre-Osteoblast Cells Is Mediated by RUNX2

PubMed Central

Hatch, Nan E; Li, Yan; Franceschi, Renny T

2009-01-01

Pyrophosphate is an established inhibitor of hydroxyapatite deposition and crystal growth, yet when hydrolyzed into phosphate, it becomes a substrate for hydroxyapatite deposition. Pyrophosphate-generating enzyme (PC-1), Ank, and tissue nonspecific alkaline phosphatase (Tnap) are three factors that regulate extracellular pyrophosphate levels through its generation, transport, and hydrolysis. We previously showed that fibroblast growth factor 2 (FGF2) induces PC-1 and Ank while inhibiting Tnap expression and mineralization in MC3T3E1(C4) calvarial pre-osteoblast cells. In this study, we showed similar FGF2 regulation of these genes in primary pre-osteoblast cultures. In contrast to Ank and Tnap that are regulated by FGF2 in multiple cell types, we found regulation of PC-1 to be selective to pre-osteoblastic cells and to require the osteoblast-related transcription factor, Runx2. Specifically, FGF2 was unable to induce PC-1 expression in Runx2-negative nonbone cells or in calvarial cells from Runx2-deficient mice. Transfection of these cells with a Runx2 expression vector restored FGF2 responsiveness. FGF2 was also shown to stimulate recruitment of Runx2 to the endogenous PC-1 promoter in MC3T3E1(C4) cells, as measured by chromatin immunoprecipitation. Taken together, our results establish that FGF2 is a specific inducer of PC-1 in pre-osteoblast cells and that FGF2 induces PC-1 expression through a mechanism involving Runx2. PMID:19049325

Effects of regular and whitening dentifrices on remineralization of bovine enamel in vitro.

PubMed

Kielbassa, Andrej M; Tschoppe, Peter; Hellwig, Elmar; Wrbas, Karl-Thomas

2009-02-01

To compare in vitro the remineralizing effects of different regular dentifrices and whitening dentifrices (containing pyrophosphates) on predemineralized enamel. Specimens from 84 bovine incisors were embedded in epoxy resin, partly covered with nail varnish, and demineralized in a lactic acid solution (37 degrees C, pH 5.0, 8 days). Parts of the demineralized areas were covered with nail varnish, and specimens were randomly assigned to 6 groups. Subsequently, specimens were exposed to a remineralizing solution (37 degrees C, pH 7.0, 60 days) and brushed 3 times a day (1:3 slurry with remineralizing solution) with 1 of 3 regular dentifrices designed for anticaries (group 1, amine; group 2, sodium fluoride) or periodontal (group 3, amine/stannous fluoride) purposes or whitening dentifrice containing pyrophosphates (group 4, sodium fluoride). An experimental dentifrice (group 5, without pyrophosphates/fluorides) and a whitening dentifrice (group 6, monofluorophosphate) served as controls. Mineral loss and lesion depths were evaluated from contact microradiographs, and intergroup comparisons were performed using the closed-test procedure (alpha =.05). Compared to baseline, specimens brushed with the dentifrices containing stannous/amine fluorides revealed significant mineral gains and lesion depth reductions (P < .05). Concerning the reacquired mineral, the whitening dentifrice performed worse than the regular dentifrices (P > .05), while mineral gain, as well as lesion depth, reduction was negligible with the control groups. Dentifrices containing pyrophosphates perform worse than regular dentifrices but do not necessarily affect remineralization. Unless remineralizing efficacy is proven, whitening dentifrices should be recommended only after deliberate consideration in caries-prone patients.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gertz, M.A.; Brown, M.L.; Hauser, M.F.

Thirty-four patients with amyloidosis proved by biopsy specimen were studied using technetium Tc 99m pyrophosphate scintigraphy to assess its utility in the diagnosis of amyloid heart involvement. Of 14 patients studied retrospectively, only three had intense uptake judged to be diagnostic of cardiac amyloidosis. In a prospective analysis of 20 patients with amyloidosis, all of whom had evidence of cardiac involvement by two-dimensional echocardiography, 17 had abnormal scans. Fourteen of the 17 scans had only 1+ or 2+ uptake, a finding that also was present in 15 of the 20 control patients (without amyloid heart disease). Only three of themore » 20 patients with cardiac amyloidosis had intense uptake that was considered unequivocal and diagnostic of amyloidosis. Of the five patients with biopsy specimen proof of endomyocardial amyloidosis, only one had intense uptake and one had no uptake. When intense uptake of technetium Tc 99m pyrophosphate is found in the heart of a patient, amyloidosis is highly likely. The technique, however, is not sufficiently sensitive to warrant routine screening of patients with amyloidosis or cardiomyopathies. Cross-sectional echocardiography is superior to pyrophosphate scintigraphy for recognition of cardiac amyloidosis.« less

Label-Free Pyrophosphate Recognition with Functionalized Asymmetric Nanopores.

PubMed

Ali, Mubarak; Ahmed, Ishtiaq; Ramirez, Patricio; Nasir, Saima; Niemeyer, Christof M; Mafe, Salvador; Ensinger, Wolfgang

2016-04-01

The label-free detection of pyrophosphate (PPi) anions with a nanofluidic sensing device based on asymmetric nanopores is demonstrated. The pore surface is functionalized with zinc complexes based on two di(2-picolyl)amine [bis(DPA)] moieties using carbodiimide coupling chemistry. The complexation of zinc (Zn(2+) ) ion is achieved by exposing the modified pore to a solution of zinc chloride to form bis(Zn(2+) -DPA) complexes. The chemical functionalization is demonstrated by recording the changes in the observed current-voltage (I-V) curves before and after pore modification. The bis(Zn(2+) -DPA) complexes on the pore walls serve as recognition sites for pyrophosphate anion. The experimental results show that the proposed nanofluidic sensor has the ability to sense picomolar concentrations of PPi anion in the surrounding environment. On the contrary, it does not respond to other phosphate anions, including monohydrogen phosphate, dihydrogen phosphate, adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate. The experimental results are described theoretically by using a model based on the Poisson-Nernst-Planck equations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural genes for thiamine biosynthetic enzymes (thiCEFGH) in Escherichia coli K-12.

PubMed Central

Vander Horn, P B; Backstrom, A D; Stewart, V; Begley, T P

1993-01-01

Escherichia coli K-12 synthesizes thiamine pyrophosphate (vitamin B1) de novo. Two precursors [4-methyl-5-(beta-hydroxyethyl)thiazole monophosphate and 4-amino-5-hydroxymethyl-2-methylpyrimidine pyrophosphate] are coupled to form thiamine monophosphate, which is then phosphorylated to make thiamine pyrophosphate. Previous studies have identified two classes of thi mutations, clustered at 90 min on the genetic map, which result in requirements for the thiazole or the hydroxymethylpryimidine. We report here our initial molecular genetic analysis of the thi cluster. We cloned the thi cluster genes and examined their organization, structure, and function by a combination of phenotypic testing, complementation analysis, polypeptide expression, and DNA sequencing. We found five tightly linked genes, designated thiCEFGH. The thiC gene product is required for the synthesis of the hydroxymethylpyrimidine. The thiE, thiF, thiG, and thiH gene products are required for synthesis of the thiazole. These mutants did not respond to 1-deoxy-D-threo-2-pentulose, indicating that they are blocked in the conversion of this precursor compound to the thiazole itself. Images PMID:8432721

Combined experimental and theoretical studies on selective sensing of zinc and pyrophosphate ions by rational design of compartmental chemosensor probe: Dual sensing behaviour via secondary recognition approach and cell imaging studies.

PubMed

Mawai, Kiran; Nathani, Sandip; Roy, Partha; Singh, U P; Ghosh, Kaushik

2018-05-08

A compartmental chemosensor probe HL has been designed and synthesized for the selective recognition of zinc ions over other transition metal ions via fluorescence "ON" strategy. The chemosensing behaviour of HL was demonstrated through fluorescence, absorption and NMR spectroscopic techniques. The molecular structure of the zinc complex derived from HL was determined by X-ray crystallography. A probable mechanism of this selective sensing behavior was described on the basis of spectroscopic results and theoretical studies by density functional theory (DFT). The biological applicability of the chemosensor HL was examined via cell imaging on HeLa cells. The HL-zinc complex served as a secondary fluorescent probe responding to the pyrophosphate anion specifically over other anions. The fluorescence enhancement of HL in association with Zn2+ ions was quenched in the presence of pyrophosphate (PPi). Thus, a dual response was established based on "OFF-ON-OFF" strategy for detection of both cation and anion. This phenomenon was utilized in the construction of a "INHIBIT" logic gate.

Technetium-99m Pyrophosphate: Comparison of ED50 for Tetany and Acidosis with Acute LD500

DTIC Science & Technology

electrocardiogram and chemical analysis revealed that the hypocalcemic effect occurs at a much lower dosage than for the LD50. Polyphosphate was found to be more...toxic by the LD50 analysis than pyrophosphate. It is emphasized that the hypocalcemic toxic effects should be the determining factor in deciding what...to 1 with regard to the first signs of hypocalcemia by electrocardiographic measurements (i.e., 2 mg/kg). On this basis an injection of no more than 1 mg/kg is recommended to maintain a safety factor of around 10 to 1.

Pyrophosphate as substrate for alkaline phosphatase activity: A convenient flow-injection chemiluminescence assay.

PubMed

Zhang, Qingfeng; Zhang, Cuiyun; Yang, Meiding; Yu, Donghong; Yu, Cong

2017-11-01

A sensitive and convenient flow-injection chemiluminescence (FI-CL) turn-on assay for alkaline phosphatase (ALP) activity without any label and synthesis is developed. Cu 2+ can catalyze the luminol-H 2 O 2 CL reaction. Pyrophosphate (PPi) can chelate Cu 2+ and therefore the Cu 2+ -mediated luminol-H 2 O 2 CL reaction is inhibited. The addition of ALP can catalyze the hydrolysis of PPi into phosphate ions, Cu 2+ is released and the chemiluminescence recovers. A detection limit of 1 mU/mL ALP is obtained. Copyright © 2017 John Wiley & Sons, Ltd.

D-lysergic acid-activating enzyme from the ergot fungus Claviceps purpurea.

PubMed Central

Keller, U; Zocher, R; Krengel, U; Kleinkauf, H

1984-01-01

A D-lysergic acid-activating enzyme from the ergot fungus Claviceps purpurea was purified about 145-fold. The enzyme was able to catalyse both the D-lysergic acid-dependent ATP-pyrophosphate exchange and the formation of ATP from D-lysergic acid adenylate and pyrophosphate. Both reactions were also catalysed to a decreased but significant extent with respect to dihydrolysergic acid. The molecular mass of the enzyme was estimated to lie between 135 and 140 kDa. The involvement of the enzyme in the biosynthesis of ergot peptide alkaloids is discussed. Images Fig. 4. PMID:6326747

Selective detection of pyrophosphate anion by a simple Cd(II) based terpyridine complex

NASA Astrophysics Data System (ADS)

Purohit, Aditya Kumar; Ghosh, Biswa Nath; Kar, Pravin Kumar

2018-01-01

A simple ratiometric terpyridine-Cd(ll) complex was synthesized by the treatment of CdCl2 with terpyridine ligand 4‧-(4-N,N‧-dimethylaminophenyl)-2,2‧:6‧,2″-terpyridine. The synthesized complex was found to act as a selective fluorescent chemosensor for pyrophosphate P2O74 - (PPi) over other anions like F-, Cl-, Br-, CO32 -, SO32 -, AcO-, NO2-, and H2PO4-. Furthermore, the receptor probe was also successfully employed in HeLa cell for PPi detection, which indicates this can be used as a chemosensor for cells.

Cyclic peptide unguisin A is an anion receptor with high affinity for phosphate and pyrophosphate.

PubMed

Daryl Ariawan, A; Webb, James E A; Howe, Ethan N W; Gale, Philip A; Thordarson, Pall; Hunter, Luke

2017-04-05

Unguisin A (1) is a marine-derived, GABA-containing cyclic heptapeptide. The biological function of this flexible macrocycle is obscure. Here we show that compound 1 lacks any detectable activity in antimicrobial growth inhibition assays, a result that runs contrary to a previous report. However, we find that 1 functions as a promiscuous host molecule in a variety of anion-binding interactions, with high affinity particularly for phosphate and pyrophosphate. We also show that a series of rigidified, backbone-fluorinated analogues of 1 displays altered affinity for chloride ions.

Sodium pyrophosphate enhances iron bioavailability from bouillon cubes fortified with ferric pyrophosphate.

PubMed

Cercamondi, Colin I; Duchateau, Guus S M J E; Harika, Rajwinder K; van den Berg, Robin; Murray, Peter; Koppenol, Wieneke P; Zeder, Christophe; Zimmermann, Michael B; Moretti, Diego

2016-08-01

Fe fortification of centrally manufactured and frequently consumed condiments such as bouillon cubes could help prevent Fe deficiency in developing countries. However, Fe compounds that do not cause sensory changes in the fortified product, such as ferric pyrophosphate (FePP), exhibit low absorption in humans. Tetra sodium pyrophosphate (NaPP) can form soluble complexes with Fe, which could increase Fe bioavailability. Therefore, the aim of this study was to investigate Fe bioavailability from bouillon cubes fortified with either FePP only, FePP+NaPP, ferrous sulphate (FeSO4) only, or FeSO4+NaPP. We first conducted in vitro studies using a protocol of simulated digestion to assess the dialysable and ionic Fe, and the cellular ferritin response in a Caco-2 cell model. Second, Fe absorption from bouillon prepared from intrinsically labelled cubes (2·5 mg stable Fe isotopes/cube) was assessed in twenty-four Fe-deficient women, by measuring Fe incorporation into erythrocytes 2 weeks after consumption. Fe bioavailability in humans increased by 46 % (P<0·005) when comparing bouillons fortified with FePP only (4·4 %) and bouillons fortified with FePP+NaPP (6·4 %). Fe absorption from bouillons fortified with FeSO4 only and with FeSO4+NaPP was 33·8 and 27·8 %, respectively (NS). The outcome from the human study is in agreement with the dialysable Fe from the in vitro experiments. Our findings suggest that the addition of NaPP could be a promising strategy to increase Fe absorption from FePP-fortified bouillon cubes, and if confirmed by further research, for other fortified foods with complex food matrices as well.

Redox Additive-Improved Electrochemically and Structurally Robust Binder-Free Nickel Pyrophosphate Nanorods as Superior Cathode for Hybrid Supercapacitors.

PubMed

Sankar, Kalimuthu Vijaya; Seo, Youngho; Lee, Su Chan; Chan Jun, Seong

2018-03-07

For several decades, one of the great challenges for constructing a high-energy supercapacitor has been designing electrode materials with high performance. Herein, we report for the first time to our knowledge a novel hybrid supercapacitor composed of battery-type nickel pyrophosphate one-dimensional (1D) nanorods and capacitive-type N-doped reduced graphene oxide as the cathode and anode, respectively, in an aqueous redox-added electrolyte. More importantly, ex situ microscopic images of the nickel pyrophosphate 1D nanorods revealed that the presence of the battery-type redox additive enhanced the charge storage capacity and cycling life as a result of the microstructure stability. The nickel pyrophosphate 1D nanorods exhibited their maximum specific capacitance (8120 mF cm -2 at 5 mV s -1 ) and energy density (0.22 mWh cm -2 at a power density of 1.375 mW cm -2 ) in 1 M KOH + 75 mg K 3 [Fe(CN) 6 ] electrolyte. On the other side, the N-doped reduced graphene oxide delivered an excellent electrochemical performance, demonstrating that it was an appropriate anode. A hybrid supercapacitor showed a high specific capacitance (224 F g -1 at a current density of 1 A g -1 ) and high energy density (70 Wh kg -1 at a power density of 750 W kg -1 ), as well as a long cycle life (a Coulombic efficiency of 96% over 5000 cycles), which was a higher performance than most of those in recent reports. Our results suggested that the materials and redox additive in this novel design hold great promise for potential applications in a next-generation hybrid supercapacitor.

Zn2+-dependent surface behavior of diacylglycerol pyrophosphate and its mixtures with phosphatidic acid at different pHs

PubMed Central

Villasuso, Ana L.; Wilke, Natalia; Maggio, Bruno; Machado, Estela

2014-01-01

Diacylglycerol pyrophosphate (DGPP) is a minor lipid that attenuates the phosphatidic acid (PA) signal, and also DGPP itself would be a signaling lipid. Diacylglycerol pyrophosphate is an anionic phospholipid with a pyrophosphate group attached to diacylglycerol that was shown to respond to changes of pH, thus affecting the surface organization of DGPP and their interaction with PA. In this work, we have investigated how the presence of Zn2+ modulates the surface organization of DGPP and its interaction with PA at acidic and basic pHs. Both lipids formed expanded monolayers at pHs 5 and 8. At pH 5, monolayers formed by DGPP became stiffer when Zn2+was added to the subphase, while the surface potential decreased. At this pH, Zn2+ induced a phase transition from an expanded to a condensed-phase state in monolayers formed by PA. Conversely, at pH 8 the effects induced by the presence of Zn2+ on the surface behaviors of the pure lipids were smaller. Thus, the interaction of the bivalent cation with both lipids was modulated by pH and by the ionization state of the polar head groups. Mixed monolayers of PA and DGPP showed a non-ideal behavior and were not affected by the presence of Zn2+ at pH 8. This could be explained considering that when mixed, the lipids formed a closely packed monolayer that could not be further modified by the cation. Our results indicate that DGPP and PA exhibit expanded- and condensed-phase states depending on pH, on the proportion of each lipid in the film and on the presence of Zn2+. This may have implications for a possible role of DGPP as a signaling lipid molecule. PMID:25120554

From crystalline to amorphous calcium pyrophosphates: A solid state Nuclear Magnetic Resonance perspective.

PubMed

Gras, Pierre; Baker, Annabelle; Combes, Christèle; Rey, Christian; Sarda, Stéphanie; Wright, Adrian J; Smith, Mark E; Hanna, John V; Gervais, Christel; Laurencin, Danielle; Bonhomme, Christian

2016-02-01

Hydrated calcium pyrophosphates (CPP, Ca2P2O7·nH2O) are a fundamental family of materials among osteoarticular pathologic calcifications. In this contribution, a comprehensive multinuclear NMR (Nuclear Magnetic Resonance) study of four crystalline and two amorphous phases of this family is presented. (1)H, (31)P and (43)Ca MAS (Magic Angle Spinning) NMR spectra were recorded, leading to informative fingerprints characterizing each compound. In particular, different (1)H and (43)Ca solid state NMR signatures were observed for the amorphous phases, depending on the synthetic procedure used. The NMR parameters of the crystalline phases were determined using the GIPAW (Gauge Including Projected Augmented Wave) DFT approach, based on first-principles calculations. In some cases, relaxed structures were found to improve the agreement between experimental and calculated values, demonstrating the importance of proton positions and pyrophosphate local geometry in this particular NMR crystallography approach. Such calculations serve as a basis for the future ab initio modeling of the amorphous CPP phases. The general concept of NMR crystallography is applied to the detailed study of calcium pyrophosphates (CPP), whether hydrated or not, and whether crystalline or amorphous. CPP are a fundamental family of materials among osteoarticular pathologic calcifications. Their prevalence increases with age, impacting on 17.5% of the population after the age of 80. They are frequently involved or associated with acute articular arthritis such as pseudogout. Current treatments are mainly directed at relieving the symptoms of joint inflammation but not at inhibiting CPP formation nor at dissolving these crystals. The combination of advanced NMR techniques, modeling and DFT based calculation of NMR parameters allows new original insights in the detailed structural description of this important class of biomaterials. Copyright © 2016. Published by Elsevier Ltd.

Influence of naturally-occurring 5′-pyrophosphate-linked substituents on the binding of adenylic inhibitors to ribonuclease a: An X-ray crystallographic study

PubMed Central

Holloway, Daniel E; Chavali, Gayatri B; Leonidas, Demetres D; Baker, Matthew D; Acharya, K Ravi

2009-01-01

Ribonuclease A is the archetype of a functionally diverse superfamily of vertebrate-specific ribonucleases. Inhibitors of its action have potential use in the elucidation of the in vivo roles of these enzymes and in the treatment of pathologies associated therewith. Derivatives of adenosine 5′-pyrophosphate are the most potent nucleotide-based inhibitors known. Here, we use X-ray crystallography to visualize the binding of four naturally-occurring derivatives that contain 5′-pyrophosphate-linked extensions. 5′-ATP binds with the adenine occupying the B2 subsite in the manner of an RNA substrate but with the γ-phosphate at the P1 subsite. Diadenosine triphosphate (Ap3A) binds with the adenine in syn conformation, the β-phosphate as the principal P1 subsite ligand and without order beyond the γ-phosphate. NADPH and NADP+ bind with the adenine stacked against an alternative rotamer of His119, the 2′-phosphate at the P1 subsite, and without order beyond the 5′-α-phosphate. We also present the structure of the complex formed with pyrophosphate ion. The structural data enable existing kinetic data on the binding of these compounds to a variety of ribonucleases to be rationalized and suggest that as the complexity of the 5′-linked extension increases, the need to avoid unfavorable contacts places limitations on the number of possible binding modes. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 995–1008, 2009. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com PMID:19191310

Distinguishing erosive osteoarthritis and calcium pyrophosphate deposition disease.

PubMed

Rothschild, Bruce M

2013-04-18

Erosive osteoarthritis is a term utilized to describe a specific inflammatory condition of the interphalangeal and first carpal metacarpal joints of the hands. The term has become a part of medical philosophical semantics and paradigms, but the issue is actually more complicated. Even the term osteoarthritis (non-erosive) has been controversial, with some suggesting osteoarthrosis to be more appropriate in view of the perspective that it is a non-inflammatory process undeserving of the "itis" suffix. The term "erosion" has also been a source of confusion in osteoarthritis, as it has been used to describe cartilage, not bone lesions. Inflammation in individuals with osteoarthritis actually appears to be related to complicating phenomena, such as calcium pyrophosphate and hydroxyapatite crystal deposition producing arthritis. Erosive osteoarthritis is the contentious term. It is used to describe a specific form of joint damage to specific joints. The damage has been termed erosions and the distribution of the damage is to the interphalangeal joints of the hand and first carpal metacarpal joint. Inflammation is recognized by joint redness and warmth, while X-rays reveal alteration of the articular surfaces, producing a smudged appearance. This ill-defined, joint damage has a crumbling appearance and is quite distinct from the sharply defined erosions of rheumatoid arthritis and spondyloarthropathy. The appearance is identical to those found with calcium pyrophosphate deposition disease, both in character and their unique responsiveness to hydroxychloroquine treatment. Low doses of the latter often resolve symptoms within weeks, in contrast to higher doses and the months required for response in other forms of inflammatory arthritis. Reconsidering erosive osteoarthritis as a form of calcium pyrophosphate deposition disease guides physicians to more effective therapeutic intervention.

Distinguishing erosive osteoarthritis and calcium pyrophosphate deposition disease

PubMed Central

Rothschild, Bruce M

2013-01-01

Erosive osteoarthritis is a term utilized to describe a specific inflammatory condition of the interphalangeal and first carpal metacarpal joints of the hands. The term has become a part of medical philosophical semantics and paradigms, but the issue is actually more complicated. Even the term osteoarthritis (non-erosive) has been controversial, with some suggesting osteoarthrosis to be more appropriate in view of the perspective that it is a non-inflammatory process undeserving of the “itis” suffix. The term “erosion” has also been a source of confusion in osteoarthritis, as it has been used to describe cartilage, not bone lesions. Inflammation in individuals with osteoarthritis actually appears to be related to complicating phenomena, such as calcium pyrophosphate and hydroxyapatite crystal deposition producing arthritis. Erosive osteoarthritis is the contentious term. It is used to describe a specific form of joint damage to specific joints. The damage has been termed erosions and the distribution of the damage is to the interphalangeal joints of the hand and first carpal metacarpal joint. Inflammation is recognized by joint redness and warmth, while X-rays reveal alteration of the articular surfaces, producing a smudged appearance. This ill-defined, joint damage has a crumbling appearance and is quite distinct from the sharply defined erosions of rheumatoid arthritis and spondyloarthropathy. The appearance is identical to those found with calcium pyrophosphate deposition disease, both in character and their unique responsiveness to hydroxychloroquine treatment. Low doses of the latter often resolve symptoms within weeks, in contrast to higher doses and the months required for response in other forms of inflammatory arthritis. Reconsidering erosive osteoarthritis as a form of calcium pyrophosphate deposition disease guides physicians to more effective therapeutic intervention. PMID:23610748

Fluorenone based fluorescent probe for selective "turn-on" detection of pyrophosphate and alanine

NASA Astrophysics Data System (ADS)

Daniel Thangadurai, T.; Nithya, I.; Manjubaashini, N.; Bhuvanesh, N.; Bharathi, G.; Nandhakumar, R.; Nataraj, D.

2018-06-01

To sense biologically important entities with different size and dimensions, a fluorenone based fluorescent receptor was designed and synthesized. Probe 1 displayed a distinct fluorescence enhancement emission at 565 nm for pyrophosphate and 530 nm for alanine in polar solvent. The fluorescence titration experiments confirm 1:1 stoichiometric ratio with high-binding constant and very low limit of detection (LoD) values. Receptor 1 showed a highly selective and sensitive recognition to HP2O73 - and to alanine over other competitive anions and amino acids. In addition, the fluorescence lifetime measurement and reversible binding study results support the practical importance of 1.

ELECTRO-DEPOSITION OF NICKEL ALLOYS FROM THE PYROPHOSPHATE BATH: NICKEL- ZINC AND NICKEL-MOLYBDENUM ALLOYS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panikkar, S.K.; Char, T.L.R.

1958-02-01

Results of studies on the electrodeposition of nickel-zinc and nickel-- molybdenum alloys in a pyrophosphate bath using platinium electrodes are presented. The fects of varying current density and metal contents of the electrolyte on alloy deposit composition, cathode efficiency, and cathode potential are presented in tabular form. (J.R.D.) l2432 A study was made of the effect of homogenization on the mechanical properties of solution-treated and aged aluminum and the quantitative effects of several variables on hardness. The effect of alloying elements on the increase in hardness of aluminum is shown. (J.E.D.)

Expression and characterization of recombinant pyruvate phosphate dikinase from Entamoeba histolytica.

PubMed

Saavedra-Lira, E; Ramirez-Silva, L; Perez-Montfort, R

1998-01-15

The parasite Entamoeba histolytica is an organism whose main energetic source comes from glycolysis. It has the singularity that several of its glycolytic enzymes use pyrophosphate as an alternative phosphate donor. Thus, pyruvate phosphate dikinase (PPDK), an inorganic pyrophosphate (PPi)-dependent enzyme, substitutes pyruvate kinase present in humans. We previously cloned and sequenced the gene that codifies for PPDK in E. histolytica. We now report its expression in a bacterial system and its purification to 98% homogeneity. We determined its K(m) for phosphoenolpyruvate, AMP and PPi (21, < 5 and 100 microM, respectively). Unlike PPDK from maize and bacteria and pyruvate kinase from other cells, EhPPDk is dependent on divalent cations but does not require monovalent cations for activity. The enzyme has an optimum pH of 6.0, it is labile to low temperatures and has a tetrameric structure. Since EhPPDK is a PPi-dependent enzyme, we also tested the effect of some pyrophosphate analogs as inhibitors of activity. Studies on the function and structure of this enzyme may be important for therapeutic research in several parasitic diseases, since it has no counterpart in humans.

Structural Basis for Flip-Flop Action of Thiamin-Dependent Enzymes Revealed by Crystal Structure of Human Pyruvate Dehydrogenase

NASA Technical Reports Server (NTRS)

Ciszak, Ewa; Korotchkina, Lioubov G.; Dominiak, Paulina M.; Sidhu, Sukdeep; Patel, Mulchand S.

2003-01-01

The biologically active derivative of vitamin B1; thiamin pyrophosphate; is used as cofactor by many enzymes that perform a wide range of catalytic functions in the pathways of energy production. In alpha2beta2-heterotetrameric human pyruvate dehydrogenase, the first catalytic component enzyme of human pyruvate dehydrogenase complex, this cofactor is used to cleave the C(sup alpha)-C(=0) bond of pyruvate followed by reductive acetyl transfer to lipoyl-dihydrolipoamide acetyltransferase, the second catalytic component of the complex. The dynamic nonequivalence of two, otherwise chemically equivalent, catalytic sites have puzzled researchers from earlier functional studies of this enzyme. In order to gain insight into the mechanism of action of this enzyme, we determined the crystal structure of the holoform of human pyruvate dehydrogenase at 1.958, resolution. We propose a kinetic model for the flip-flop action of this enzyme through the concerted approx. 2A, shuttle-like motion of the heterodimers. The similarity of thiamin pyrophosphate binding in human pyruvate dehydrogenase and other functionally related enzymes suggests this newly defined mechanism of shuttle-like motion of domains to be common for the family of thiamin pyrophosphate-dependent enzymes.

Titanium Pyrophosphate for Removal of Trivalent Heavy Metals and Actinides Simulated by Retention of Europium

PubMed Central

Flores-Espinosa, Rosa María; Ordoñez-Regil, Eduardo; Fernández-Valverde, Suilma Marisela

2017-01-01

This work addresses the synthesis of titanium pyrophosphate, as well as the characterization and evaluation of the sorption process of europium, for removal of trivalent heavy metals and actinides simulate. The evaluation of the surface properties of titanium pyrophosphate was carried out determining the surface roughness and surface acidity constants. The values obtained from the determination of the surface roughness of the synthesized solid indicate that the surface of the material presents itself as slightly smooth. The FITEQL program was used to fit the experimental titration curves to obtain the surface acidity constants: log⁡K+ = 3.59 ± 0.06 and log⁡K− = −3.90 ± 0.05. The results of sorption kinetics evidenced that the pseudo-order model explains the retention process of europium, in which the initial sorption velocity was 8.3 × 10−4 mg g−1 min−1 and kinetic constant was 1.8 × 10−3 g mg min−1. The maximum sorption capacity was 0.6 mg g−1. The results obtained from sorption edge showed the existence of two bidentate complexes on the surface. PMID:28785720

Cloning and Characterization of Naringenin 8-Prenyltransferase, a Flavonoid-Specific Prenyltransferase of Sophora flavescens1[W

PubMed Central

Sasaki, Kanako; Mito, Kouji; Ohara, Kazuaki; Yamamoto, Hirobumi; Yazaki, Kazufumi

2008-01-01

Prenylated flavonoids are natural compounds that often represent the active components in various medicinal plants and exhibit beneficial effects on human health. Prenylated flavonoids are hybrid products composed of a flavonoid core mainly attached to either 5-carbon (dimethylallyl) or 10-carbon (geranyl) prenyl groups derived from isoprenoid (terpenoid) metabolism, and the prenyl groups are crucial for their biological activity. Prenylation reactions in vivo are crucial coupling processes of two major metabolic pathways, the shikimate-acetate and isoprenoid pathways, in which these reactions are also known as a rate-limiting step. However, none of the genes responsible for the prenylation of flavonoids has been identified despite more than 30 years of research in this field. We have isolated a prenyltransferase gene from Sophora flavescens, SfN8DT-1, responsible for the prenylation of the flavonoid naringenin at the 8-position, which is specific for flavanones and dimethylallyl diphosphate as substrates. Phylogenetic analysis shows that SfN8DT-1 has the same evolutionary origin as prenyltransferases for vitamin E and plastoquinone. The gene expression of SfN8DT-1 is strictly limited to the root bark where prenylated flavonoids are solely accumulated in planta. The ectopic expression of SfN8DT-1 in Arabidopsis thaliana resulted in the formation of prenylated apigenin, quercetin, and kaempferol, as well as 8-prenylnaringenin. SfN8DT-1 represents the first flavonoid-specific prenyltransferase identified in plants and paves the way for the identification and characterization of further genes responsible for the production of this large and important class of secondary metabolites. PMID:18218974

Antiproliferative effect of isopentenylated coumarins on several cancer cell lines.

PubMed

Kawaii, S; Tomono, Y; Ogawa, K; Sugiura, M; Yano, M; Yoshizawa, Y; Ito, C; Furukawa, H

2001-01-01

33 coumarins, mainly the simple isopentenylated coumarins and derived pyrano- and furanocoumarins, were examined for their antiproliferative activity towards several cancer and normal human cell lines. The pyrano- and furanocoumarins showed strong activity against the cancer cell lines, whereas they had weak antiproliferative activity against the normal human cell lines. The decreasing rank order of potency was osthenone (10), clausarin (25), clausenidin (26), dentatin (24), nordentatin (23), imperatorin (29), seselin (27), xanthyletin (21), suberosin (17), phebalosin (8) and osthol (12). The structure-activity relationship established from the results revealed that the 1,1-dimethylallyl and isopentenyl groups have an important role for antiproliferative activity.

Technetium-99m stannous pyrophosphate myocardial scintigraphy after cardiopulmonary resuscitation with cardioversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davison, R.; Spies, S.M.; Przybylek, J.

1979-08-01

Thirty consecutive patients underwent technetium-99m stannous pyrophosphate myocardial scintigraphy 48 to 72 h after successful cardiopulmonary resuscitation and direct current cardioversion. Five patients with transmural myocardial infarctions by ECG and enzyme determinations were correctly identified by scintigraphy. Myocardial scans were positive in five of nine patients with nontransmural infarction. Of 16 patients without evidence of myocardial infarction, only two (13%) had false-positive myocardial scans. The overall accuracy of imaging in this series was 80%. We conclude that false-positive scans after cardiopulmonary resuscitation with electrical cardioversion are infrequent, and do not significantly detract from the value of myocardial scintigraphy in themore » diagnosis of myocardial infarction.« less

Cd(II)-terpyridine-based complex as a ratiometric fluorescent probe for pyrophosphate detection in solution and as an imaging agent in living cells.

PubMed

Jiao, Shu-Yan; Li, Kun; Zhang, Wei; Liu, Yan-Hong; Huang, Zeng; Yu, Xiao-Qi

2015-01-21

The terpyridine anthracene ligand was synthesized and characterized. is a ratiometric fluorescent probe for Cd(2+) with a recognition mechanism based on intramolecular charge transfer (ICT). An complex was isolated, and its structure was established using single-crystal XRD. The complex was able to serve as a novel reversible chemosensing ensemble to allow ratiometric response to pyrophosphate (PPi) in aqueous media. Moreover, the fluorescence imaging in living cells from these two emission channels suggested that was a ratiometric probe for Cd(2+), and the in situ generated complex was also a ratiometric ensemble for PPi detection in living cells.

Preparation of titanium phosphates with additives in hydrothermal process and their powder properties for cosmetics.

PubMed

Onoda, Hiroaki; Yamaguchi, Taisuke

2013-04-01

In this study, titanium phosphates were prepared from titanium chloride and phosphoric acid, sodium pyrophosphate and sodium triphosphate solutions with water retention compounds in hydrothermal process as a novel white pigment for cosmetics. Their chemical composition, powder properties, photo catalytic activity, water retention and smoothness were studied. The addition of glycerin in the preparation from sodium pyrophosphate has the useful method to obtain homogenized spherical particles of titanium phosphate pigments for the cosmetics. These titanium phosphates had less photo catalytic activity to protect the sebum on the skin. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Conventional Radiology in Crystal Arthritis: Gout, Calcium Pyrophosphate Deposition, and Basic Calcium Phosphate Crystals.

PubMed

Jacques, Thibaut; Michelin, Paul; Badr, Sammy; Nasuto, Michelangelo; Lefebvre, Guillaume; Larkman, Neal; Cotten, Anne

2017-09-01

This article reviews the main radiographic features of crystal deposition diseases. Gout is linked to monosodium urate crystals. Classic radiographic features include subcutaneous tophi, large and well-circumscribed paraarticular bone erosions, and exuberant bone hyperostosis. Calcium pyrophosphate deposition (CPPD) can involve numerous structures, such as hyaline cartilages, fibrocartilages, or tendons. CPPD arthropathy involves joints usually spared by osteoarthritis. Basic calcium phosphate deposits are periarticular or intraarticular. Periarticular calcifications are amorphous, dense, and round or oval with well-limited borders, and most are asymptomatic. When resorbing, they become cloudy and less dense with an ill-defined shape and can migrate into adjacent structures. Copyright © 2017 Elsevier Inc. All rights reserved.

Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, V.W.; Caldarone, A.G.; Falk, R.H.

1983-07-01

A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidois. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of tc PYP scannning as a screening test for soft-tissue amyloidosis is discussed.

Overexpression of Plastid Transketolase in Tobacco Results in a Thiamine Auxotrophic Phenotype[OPEN

PubMed Central

Khozaei, Mahdi; Fisk, Stuart; Lawson, Tracy; Gibon, Yves; Sulpice, Ronan; Stitt, Mark; Lefebvre, Stephane C.; Raines, Christine A.

2015-01-01

To investigate the effect of increased plastid transketolase on photosynthetic capacity and growth, tobacco (Nicotiana tabacum) plants with increased levels of transketolase protein were produced. This was achieved using a cassette composed of a full-length Arabidopsis thaliana transketolase cDNA under the control of the cauliflower mosaic virus 35S promoter. The results revealed a major and unexpected effect of plastid transketolase overexpression as the transgenic tobacco plants exhibited a slow-growth phenotype and chlorotic phenotype. These phenotypes were complemented by germinating the seeds of transketolase-overexpressing lines in media containing either thiamine pyrophosphate or thiamine. Thiamine levels in the seeds and cotyledons were lower in transketolase-overexpressing lines than in wild-type plants. When transketolase-overexpressing plants were supplemented with thiamine or thiamine pyrophosphate throughout the life cycle, they grew normally and the seed produced from these plants generated plants that did not have a growth or chlorotic phenotype. Our results reveal the crucial importance of the level of transketolase activity to provide the precursor for synthesis of intermediates and to enable plants to produce thiamine and thiamine pyrophosphate for growth and development. The mechanism determining transketolase protein levels remains to be elucidated, but the data presented provide evidence that this may contribute to the complex regulatory mechanisms maintaining thiamine homeostasis in plants. PMID:25670766

Enhancement of the Rate of Pyrophosphate Hydrolysis by Nonenzymatic Catalysts and by Inorganic Pyrophosphatase*

PubMed Central

Stockbridge, Randy B.; Wolfenden, Richard

2011-01-01

To estimate the proficiency of inorganic pyrophosphatase as a catalyst, 31P NMR was used to determine rate constants and thermodynamics of activation for the spontaneous hydrolysis of inorganic pyrophosphate (PPi) in the presence and absence of Mg2+ at elevated temperatures. These values were compared with rate constants and activation parameters determined for the reaction catalyzed by Escherichia coli inorganic pyrophosphatase using isothermal titration calorimetry. At 25 °C and pH 8.5, the hydrolysis of MgPPi2− proceeds with a rate constant of 2.8 × 10−10 s−1, whereas E. coli pyrophosphatase was found to have a turnover number of 570 s−1 under the same conditions. The resulting rate enhancement (2 × 1012-fold) is achieved entirely by reducing the enthalpy of activation (ΔΔH‡ = −16.6 kcal/mol). The presence of Mg2+ ions or the transfer of the substrate from bulk water to dimethyl sulfoxide was found to increase the rate of pyrophosphate hydrolysis by as much as ∼106-fold. Transfer to dimethyl sulfoxide accelerated PPi hydrolysis by reducing the enthalpy of activation. Mg2+ increased the rate of PPi hydrolysis by both increasing the entropy of activation and reducing the enthalpy of activation. PMID:21460215

Cloning and characterization of farnesyl pyrophosphate synthase from the highly branched isoprenoid producing diatom Rhizosolenia setigera.

PubMed

Ferriols, Victor Marco Emmanuel N; Yaginuma, Ryoko; Adachi, Masao; Takada, Kentaro; Matsunaga, Shigeki; Okada, Shigeru

2015-05-21

The diatom Rhizosolenia setigera Brightwell produces highly branched isoprenoid (HBI) hydrocarbons that are ubiquitously present in marine environments. The hydrocarbon composition of R. setigera varies between C25 and C30 HBIs depending on the life cycle stage with regard to auxosporulation. To better understand how these hydrocarbons are biosynthesized, we characterized the farnesyl pyrophosphate (FPP) synthase (FPPS) enzyme of R. setigera. An isolated 1465-bp cDNA clone contained an open reading frame spanning 1299-bp encoding a protein with 432 amino acid residues. Expression of the RsFPPS cDNA coding region in Escherichia coli produced a protein that exhibited FPPS activity in vitro. A reduction in HBI content from diatoms treated with an FPPS inhibitor, risedronate, suggested that RsFPPS supplies precursors for HBI biosynthesis. Product analysis by gas chromatography-mass spectrometry also revealed that RsFPPS produced small amounts of the cis-isomers of geranyl pyrophosphate and FPP, candidate precursors for the cis-isomers of HBIs previously characterized. Furthermore, RsFPPS gene expression at various life stages of R. setigera in relation to auxosporulation were also analyzed. Herein, we present data on the possible role of RsFPPS in HBI biosynthesis, and it is to our knowledge the first instance that an FPPS was cloned and characterized from a diatom.

Enhancing of catalytic properties of vanadia via surface doping with phosphorus using atomic layer deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strempel, Verena E.; Naumann d'Alnoncourt, Raoul, E-mail: r.naumann@bascat.tu-berlin.de; Löffler, Daniel

2016-01-15

Atomic layer deposition is mainly used to deposit thin films on flat substrates. Here, the authors deposit a submonolayer of phosphorus on V{sub 2}O{sub 5} in the form of catalyst powder. The goal is to prepare a model catalyst related to the vanadyl pyrophosphate catalyst (VO){sub 2}P{sub 2}O{sub 7} industrially used for the oxidation of n-butane to maleic anhydride. The oxidation state of vanadium in vanadyl pyrophosphate is 4+. In literature, it was shown that the surface of vanadyl pyrophosphate contains V{sup 5+} and is enriched in phosphorus under reaction conditions. On account of this, V{sub 2}O{sub 5} with themore » oxidation state of 5+ for vanadium partially covered with phosphorus can be regarded as a suitable model catalyst. The catalytic performance of the model catalyst prepared via atomic layer deposition was measured and compared to the performance of catalysts prepared via incipient wetness impregnation and the original V{sub 2}O{sub 5} substrate. It could be clearly shown that the dedicated deposition of phosphorus by atomic layer deposition enhances the catalytic performance of V{sub 2}O{sub 5} by suppression of total oxidation reactions, thereby increasing the selectivity to maleic anhydride.« less

Molecular cloning and expression of Hedychium coronarium farnesyl pyrophosphate synthase gene and its possible involvement in the biosynthesis of floral and wounding/herbivory induced leaf volatile sesquiterpenoids.

PubMed

Lan, Jian-bin; Yu, Rang-cai; Yu, Yun-yi; Fan, Yan-ping

2013-04-15

Farnesyl pyrophosphate synthase (FPPS EC 2.5.1.10) catalyzes the production of farnesyl pyrophosphate (FPP), which is a key precursor for many sesquiterpenoids such as floral scent and defense volatiles against herbivore attack. Here we report a new full-length cDNA encoding farnesyl diphosphate synthase from Hedychium coronarium. The open reading frame for full-length HcFPPS encodes a protein of 356 amino acids, which is 1068 nucleotides long with calculated molecular mass of 40.7 kDa. Phylogenetic tree analysis indicates that HcFPPS belongs to the plant FPPS super-family and has strong relationship with FPPS from Musa acuminata. Expression of the HcFPPS gene in Escherichia coli yielded FPPS activity. Tissue-specific and developmental analyses of the HcFPPS mRNA and corresponding volatile sesquiterpenoid levels in H. coronarium flowers revealed that the HcFPPS might play a regulatory role in floral volatile sesquiterpenoid biosynthesis. The emission of the FPP-derived volatile terpenoid correlates with strong expression of HcFPPS induced by mechanical wounding and Udaspes folus-damage in leaves, which suggests that HcFPPS may have an important ecological function in H. coronarium vegetative organ. Copyright © 2013 Elsevier B.V. All rights reserved.

A novel pyrophosphate BaCr2(P2O7)2 as green pigment with high NIR solar reflectance and durable chemical stability

NASA Astrophysics Data System (ADS)

Tao, Zhengxu; Zhang, Wanqi; Huang, Yanlin; Wei, Donglei; Seo, Hyo Jin

2014-08-01

A novel pyrophosphate BaCr2(P2O7)2 was synthesized by the conventional solid-state reaction. The X-ray diffraction (XRD), FTIR spectrum, scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) near infrared (NIR) reflectance spectra were applied to characterize the powders. The refractive indexes and nature of the VB and CB were determined. The structure, color properties and application were investigated. The results reveal that the anomalist bodies with smooth surfaces were obtained at 1200 °C with a mean size of 3 μm. A high reflectance peak at 535 nm was observed in the visible region, which is associated with the brilliant and deep green color of this pigment. With all the acids, alkali and deionized water treatment, the polycrystalline pigment BaCr2(P2O7)2 was found to be durable in chemical stability. The significantly high NIR solar reflectance of BaCr2(P2O7)2 is 90.0%, a higher cooling ability, so it has been selected to be tested as cool green pigment in ceramics. Moreover, this novel pyrophosphate pigment has great potential as cool pigment for surface coating applications.

Early identification of amyloid heart disease by technetium-99m-pyrophosphate scintigraphy: a study with familial amyloid polyneuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hongo, M.; Hirayama, J.; Fujii, T.

1987-03-01

To determine whether technetium-99m-pyrophosphate (Tc-99m-PYP) scanning or two-dimensional echocardiography can detect amyloid heart disease in an earlier stage of familial amyloid polyneuropathy, 15 patients were examined. Although 10 of the 15 patients had no clinical evidence of congestive heart failure, as well as normal ventricular wall thickness and normal values for left ventricular systolic function, five (50%) of them showed mild or moderate myocardial uptake. On the other hand, none had characteristic highly refractile myocardial echoes on the two-dimensional echocardiographic images (p less than 0.01), and values for diastolic function were reduced in four of the five and normal inmore » the remaining one. In 85 control subjects, diffuse positive pyrophosphate scans of the heart were found in four (5%) of them (three with dilated cardiomyopathy and one with sarcoidosis), and highly refractile granular sparkling echoes were observed in nine (11%) (five with hypertrophic cardiomyopathy, three with aortic stenosis, and one with hypereosinophilic syndrome). We conclude that Tc-99m-PYP scanning is a more sensitive and specific method and may have the potential ability to detect amyloid heart disease in the earlier stage of familial amyloid polyneuropathy than two-dimensional echocardiography.« less

Prevention of lingual calculus formation with daily use of 6% H2O2/2% pyrophosphate whitening strips.

PubMed

Farrell, S; Barker, M L; Gerlach, R W; Putt, M S; Milleman, J L

2009-01-01

This randomized controlled clinical trial was conducted to evaluate whether daily use of a hydrogen peroxide/ pyrophosphate-containing antitartar whitening strip might safely yield clinical reductions in post-prophylaxis calculus accumulation. A three-month, randomized controlled trial was conducted to compare calculus accumulation with a daily 6% hydrogen peroxide/pyrophosphate strip versus regular brushing. After an eight-week run-in phase to identify calculus formers, a prophylaxis was administered, and 77 subjects were randomly assigned to daily strip or brushing only groups. All subjects received an anticavity dentifrice (Crest Cavity Protection) and manual brush for use throughout the three-month study; for subjects assigned to the experimental group, strip application was once daily for five minutes on the facial and lingual surfaces of the mandibular teeth. Efficacy was measured as mm calculus (VMI) before prophylaxis and after six and 12 weeks of treatment, while safety was assessed from examination and interview. Subjects ranged in age from 21-87 years, with groups balanced (p > 0.26) on pertinent demographic and behavioral parameters, and pre-prophylaxis calculus baseline mean scores (16.0 mm). At Week 6, calculus accumulation was lower in the strip group, with adjusted mean (SE) lingual VMI of 12.0 (0.87) for the strip group and 17.0 (0.88) for the brushing control. At Week 12, calculus accumulation was lower in the strip group, with adjusted mean (SE) lingual VMI of 14.3 (0.85) for the strip group and 17.2 (0.86) for the brushing control. Treatments differed significantly (p < 0.02) on calculus accumulation at both time points. A total of three subjects (8%) in the strip group and two subjects (5%) in the brushing control had mild oral irritation or tooth sensitivity during treatment; no one discontinued early due to an adverse event. Daily use of hydrogen peroxide whitening strips with pyrophosphate reduced calculus formation by up to 29% versus regular brushing, without meaningful adverse events.

Nanomolar pyrophosphate detection and nucleus staining in living cells with simple terpyridine-Zn(II) complexes.

PubMed

Chao, Duobin; Ni, Shitan

2016-05-20

Great efforts have been made to develop fluorescent probes for pyrophosphate (PPi) detection. Nucleus staining with fluorescence microscopy has been also widely investigated. But fluorescent probes for PPi detection with high sensitivity in water medium and nucleus staining with low-cost non-precious metal complexes in living cells are still challenging. Herein, we report simple terpyridine-Zn(II) complexes for selective nanomolar PPi detection over ATP and ADP in water based on aggregation induced emission (AIE) and intramolecular charge transfer (ICT). In addition, these terpyridine-Zn(II) complexes were successfully employed for nucleus staining in living cells. These results demonstrated simply obtained terpyridine-Zn(II) complexes are powerful tool for PPi detection and the development of PPi-related studies.

Subchondral cysts (geodes) in arthritic disorders: pathologic and radiographic appearance of the hip joint.

PubMed

Resnick, D; Niwayama, G; Coutts, R D

1977-05-01

A comprehensive study of femoral heads of patients and cadavers with osteoarthritis, rheumatoid arthritis, osteonecrosis, and calcium pyrophosphate dihydrate deposition disease allows insight into the radiographic and pathologic appearance of subchondral radiolucencies in these disorders. The term geode, rather than cyst or pseudocyst, may be a more appropriate decription of these lesions. In osteoarthritis, goedes occur on the pressure segment of the femoral head in association with loss of articular space; in rheumatoid arthritis, they are initially noted at the chondro-osseous junction and subsequently involve the entire femoral head. In osteonecrosis, geodes appear in the necrotic segment of the femoral head. In calcium pyrophosphate deposition disease, geodes resemble those in osteoarthritis but are larger, more numerous, and more widespread.

Directed evolution and expression tuning of geraniol synthase for efficient geraniol production in Escherichia coli.

PubMed

Tashiro, Miki; Fujii, Akira; Kawai-Noma, Shigeko; Saito, Kyoichi; Umeno, Daisuke

2017-11-17

To achieve an efficient production of geraniol and its derivatives in Escherichia coli, we aimed to improve the activity of geraniol synthase (GES) through a single round of mutagenesis and screening for higher substrate consumption. We isolated GES variants that outperform their parent in geraniol production. The analysis of GES variants indicated that the expression level of GES was the bottleneck for geraniol synthesis. Over-expression of the mutant GES M53 with a 5'-untranslated sequence designed for high translational efficiency, along with the additional expression of mevalonate pathway enzymes, isopentenyl pyrophosphate isomerase, and geranyl pyrophosphate synthase, yielded 300 mg/L/12 h geraniol and its derivatives (>1000 mg/L/42 h in total) in a shaking flask.

Electronic structure of lead pyrophosphate

NASA Astrophysics Data System (ADS)

Suewattana, Malliga; Singh, David

2007-03-01

Lead Pyrophosphate Pb2P2O7 is of interest for potential radiation detection applications and use in long term waste storage. It forms in triclinic P1 crystals and can also be grown as glasses. We performed electronic structure calculations using the crystal structure which determined by Mullica et. al (J. Solid State Chem (1986)) using x-ray diffraction and found large forces on atoms suggesting that the refined atomic positions were not fully correct. Here we report first principles structure relaxation and a revised crystal structure for this compound. We analyze the resulting structure using pair distribution functions and discuss the implications for the electronic properties. This work was supported by DOE NA22 and the Office of Naval Research.

Non-standard amino acid recognition by Escherichia coli leucyl-tRNA synthetase

NASA Technical Reports Server (NTRS)

Martinis, S. A.; Fox, G. E.

1997-01-01

Recombinant E. coli leucyl-tRNA synthetase was screened for amino acid-dependent pyrophosphate exchange activity using noncognate aliphatic amino acids including norvaline, homocysteine, norleucine, methionine, and homoserine. [32P]-labeled reaction products were separated by thin layer chromatography using a novel solvent system and then quantified by phosphorimaging. Norvaline which differs from leucine by only one methyl group stimulated pyrophosphate exchange activity as did both homocysteine and norleucine to a lesser extent. The KM parameters for leucine and norvaline were measured to be 10 micromoles and 1.5 mM, respectively. Experiments are in progress to determine if norvaline is transferred to tRNA(Leu) and/or edited by a pre- or post-transfer mechanism.

Bilateral symptomatic synovial cysts of the lumbar spine caused by calcium pyrophosphate deposition disease: a case report.

PubMed

Gadgil, Anirudh A; Eisenstein, Stephan M; Darby, Alan; Cassar Pullicino, Victor

2002-10-01

A case of bilateral symptomatic facet joint synovial cysts arising in association with calcium pyrophosphate deposition disease is reported. To present a previously unreported cause for symptomatic synovial cysts of the lumbar spine. Synovial cysts of the facet joints occur most commonly in association with degenerative disease of the spine in older individuals. The association of these cysts with trauma, rheumatoid arthritis, spondylolysis, and kissing spinous processes also has been reported. These cysts can cause symptoms and signs from direct compression of the dura. Chondrocalcinosis has not been previously reported to cause symptomatic synovial cysts. A 67-year-old woman presented with right lower limb sciatica caused by a right L4-L5 facet joint cyst, which resolved after surgical decompression. A year later, she presented with left lower limb sciatica caused by development of a new L4-L5 facet joint cyst, which also resolved after surgical decompression. Histopathologic examination of each cyst showed a cyst wall of fibrous tissue with synovial lining, inflammation, and granulation tissue. Examination of the tissue under polarized light showed positively birefringent, short blunt crystals of calcium pyrophosphate dihydrate. In patients with a history of gout or pseudogout, a rare possibility of a synovial cyst should be considered in the differential diagnosis during investigation for the cause of neural compression resulting in sciatic syndrome.

Thermodynamic limits on the size and size distribution of nucleic acids synthesized in vitro: the role of pyrophosphate hydrolysis.

PubMed

Peller, L

1977-02-08

The free-energy change of phosphodiester bond formation from nucleoside triphosphates is more favorable than with nucleoside diphosphates as substrates. Base-stacking interactions can make significant contributions to both delta G degrees ' values. Pyrophosphate hydrolysis when it accompanies the former reaction dominates all thermodynamic considerations. Three experimental situations are discussed in which high-molecular-weight polynucleotides are synthesized without a strong driving force for covalent bond formation. For one of these, a kinetic scheme is presented which encompasses an early narrow Poisson distribution of chain lengths with ultimate passage to a disperse equilibrium population of chain sizes. Hydrolytic removal of pyrophosphate expands the time scale for this undesirable process by a factor of 10(9), while it enormously elevates the thermodynamic ceiling for the average degrees of polymerization in the other two examples. The electron micrographically revealed broad size population from an early study of partial replication of a T7 DNA template is found to adhere (fortuitously) to a disperse most probable representation. Some possible origins are examined for the branched structures in this product, as well as in a later investigation of replication of this nucleic acid. The achievement of both very high molecular weights and sharply peaked size distributions in polynucleotides synthesized in vitro will require coupling to inorganic pyrophosphatase action as in vivo.

Cloning and characterization of farnesyl pyrophosphate synthase from the highly branched isoprenoid producing diatom Rhizosolenia setigera

PubMed Central

Ferriols, Victor Marco Emmanuel N.; Yaginuma, Ryoko; Adachi, Masao; Takada, Kentaro; Matsunaga, Shigeki; Okada, Shigeru

2015-01-01

The diatom Rhizosolenia setigera Brightwell produces highly branched isoprenoid (HBI) hydrocarbons that are ubiquitously present in marine environments. The hydrocarbon composition of R. setigera varies between C25 and C30 HBIs depending on the life cycle stage with regard to auxosporulation. To better understand how these hydrocarbons are biosynthesized, we characterized the farnesyl pyrophosphate (FPP) synthase (FPPS) enzyme of R. setigera. An isolated 1465-bp cDNA clone contained an open reading frame spanning 1299-bp encoding a protein with 432 amino acid residues. Expression of the RsFPPS cDNA coding region in Escherichia coli produced a protein that exhibited FPPS activity in vitro. A reduction in HBI content from diatoms treated with an FPPS inhibitor, risedronate, suggested that RsFPPS supplies precursors for HBI biosynthesis. Product analysis by gas chromatography-mass spectrometry also revealed that RsFPPS produced small amounts of the cis-isomers of geranyl pyrophosphate and FPP, candidate precursors for the cis-isomers of HBIs previously characterized. Furthermore, RsFPPS gene expression at various life stages of R. setigera in relation to auxosporulation were also analyzed. Herein, we present data on the possible role of RsFPPS in HBI biosynthesis, and it is to our knowledge the first instance that an FPPS was cloned and characterized from a diatom. PMID:25996801

Evaluating Mineral-Associated Soil Organic Matter Pools as Indicators of Forest Harvesting Disturbance

NASA Astrophysics Data System (ADS)

Kellman, L. M.; Gabriel, C. E.

2015-12-01

Soil organic matter (SOM) in northern forest soils is associated with a suite of minerals that can confer SOM stability, resulting in the potential for long-term storage of carbon. Increasingly, evidence is suggesting that SOM in certain mineral phases is dynamic and vulnerable to soil disturbance. The objective of this research was to investigate changes in a suite of mineral-associated pools of SOM through depth in a temperate forest soil to determine which mineral-associated carbon pools are most sensitive to forest harvesting disturbance. Sequential selective dissolutions representing increasingly stable SOM pools (soluble minerals (deionized water); humus-mineral complexes (Na-pyrophosphate); poorly crystalline minerals (HCl hydroxylamine); and crystalline secondary minerals (Na-dithionite + HCl)) of mineral soils through depth to 50 cm were carried out in podzolic soils sampled from temperate red spruce forests of contrasting stand age in Nova Scotia, Canada. Results of this analysis point to a loss of carbon from SOM within the B-horizon of the most recently harvested site from the pyrophosphate-extracted humus mineral complexed SOM, suggesting that it is this exchangeable pool that appears to be destabilized following clearcut harvesting at these study sites. This suggests that recovery from this landuse disturbance is dependent upon increasing storage of this SOM pool, and that mineral-associated pools, particularly pyrophosphate-extractable SOM, may be a useful indicator of changes to soil carbon storage following land use change.

Presence of a plant-like proton-pumping pyrophosphatase in acidocalcisomes of Trypanosoma cruzi.

PubMed

Scott, D A; de Souza, W; Benchimol, M; Zhong, L; Lu, H G; Moreno, S N; Docampo, R

1998-08-21

The vacuolar-type proton-translocating pyrophosphatase (V-H+-PPase) is an enzyme previously described in detail only in plants. This paper demonstrates its presence in the trypanosomatid Trypanosoma cruzi. Pyrophosphate promoted organellar acidification in permeabilized amastigotes, epimastigotes, and trypomastigotes of T. cruzi. This activity was stimulated by K+ ions and was inhibited by Na+ ions and pyrophosphate analogs, as is the plant activity. Separation of epimastigote extracts on Percoll gradients yielded a dense fraction that contained H+-PPase activity measured both by proton uptake and phosphate release but lacked markers for mitochondria, lysosomes, glycosomes, cytosol, and plasma membrane. Antiserum raised against specific sequences of the plant V-H+-PPase cross-reacted with a T. cruzi protein, which was also detectable in the dense Percoll fraction. The organelles in this fraction appeared by electron microscopy to consist mainly of acidocalcisomes (acidic calcium storage organelles). This identification was confirmed by x-ray microanalysis. Immunofluorescence and immunoelectron microscopy indicated that the V-H+-PPase was located in the plasma membrane and acidocalcisomes of the three different forms of the parasite. Pyrophosphate was able to drive calcium uptake in permeabilized T. cruzi. This uptake depended upon a proton gradient and was reversed by a specific V-H+-PPase inhibitor. Our results imply that the phylogenetic distribution of V-H+-PPases is much wider than previously perceived but that the enzyme has a unique subcellular location in trypanosomes.

Iron bioavailability in Wistar rats fed with fortified rice by Ultra Rice technology with or without addition of yacon flour (Smallanthus sonchifolius).

PubMed

Della Lucia, Ceres M; Vaz Tostes, Maria das Graças; Silveira, Carlos Mário M; Bordalo, Lívia A; Rodrigues, Fabiana C; Pinheiro-Sant'Ana, Helena Maria; Martino, Hércia S D; Costa, Neuza Maria B

2013-03-01

This study aimed to evaluate iron (Fe) bioavailability in Wistar rats fed with rice fortified with micronized ferric pyrophosphate (FP) by Ultra Rice (UR) technology with or without addition of yacon flour as a source of 7.5% of fructooligosaccharides (FOS). Diets were supplied with 12 mg iron/kg from the following sources: ferrous sulfate (FS - control diet), fortified rice with micronized ferric pyrophosphate (Ultra Rice) (UR diet), ferrous sulfate + yacon flour (FS + Y diet) or Ultra Rice + yacon flour (UR + Y diet). Blood samples were collected at the end of depletion and repletion stages for determination of hemoglobin concentration and calculation of the relative biological value (RBV). Also, the content of short chain fatty acids (SCFA) (acetic, propionic and butyric acids) from animals' stools and caecum weight were determined. The UR diet showed high iron bioavailability (RBV = 84.7%). However, the addition of yacon flour in the diet containing fortified rice (UR + Y diet) decreased RBV (63.1%) significantly below the other three groups (p < 0.05). Groups that received yacon flour showed higher acetic acid values compared to those who did not. In conclusion, fortified UR with micronized ferric pyrophosphate showed high iron bioavailability but the addition of yacon flour at 7.5% FOS reduced iron bioavailability despite increased caecum weight and SCFA concentration.

Effects of phosphates on shellfish and on calcium carbonate crystallization in vitro. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilbur, K.M.

1986-07-17

It has been known that inorganic phosphate inhibits the precipitation of calcium carbonate in artificial sea water. This work addresses the question of whether phosphate also affects the deposition of CaCO/sub 3/ in the exoskeletons of invertebrates. Tetrasodiumpyrophosphate and pentasodiumtripolyphosphate in concentrations of 15 ppM caused abnormality, mortality, and inhibition of shell deposition in trochophore larvae of the oyster Crassostrea. Inhibition of shell growth resulting from pollution at 15 ppM could be expected in Rangia with orthophosphate, tetrasodium pyrophosphate, and sodiumtripolyphosphate, in Helisoma with tetrasodium pyrophosphate, and pentasodium tripolyphosphate, and in larvae of Crassostea the relative inhibitory action of shellmore » growth was tetrasodiumpyrophosphate > sodiumtripolyphosphate > sodium orthophosphate greater than or equal to sodium hexametaphosphate. 4 refs.« less

Oligomerizations of deoxyadenosine bis-phosphates and of their 3-prime-5-prime, 3-prime-3-prime, and 5-prime-5-prime dimers - Effects of a pyrophosphate-linked, poly(T) analog

NASA Technical Reports Server (NTRS)

Visscher, J.; Bakker, C. G.; Schwartz, Alan W.

1990-01-01

The effect of a 3-prime-5-prime pyrophosphate-linked oligomer of pTp on oligomerizations of pdAp and of its 3-prime-5-prime, 3-prime-3-prime, and 5-prime-5-prime dimers was investigated, using HPLC to separate the reaction mixtures; peak detection was by absorbance monitoring at 254 nm. It was expected that the dimers would form stable complexes with the template, with the degree of stability depending upon the internal linkage of each dimer. It was found that, although the isomers differ substantially in their oligomerization behavior in the absence of template, the analog-template catalyzes the oligomerization to about the same extent in all three cases.

Calcium pyrophosphate arthritis

MedlinePlus

... disease that can cause attacks of arthritis. Like gout, crystals form in the joints. But in this ... CPPD arthritis can be confused with: Gouty arthritis (gout) Osteoarthritis Rheumatoid arthritis Exams and Tests Most arthritic ...

Calcium Pyrophosphate Deposition (CPPD)

MedlinePlus

... Keep me signed in Passwords are Case Sensitive. Ex. Enter smith as follows: Smith Forgot Username/Password? ... Erythematosus (Juvenile) Takayasu's Arteritis Tendinitis & Bursitis Tumor Necrosis Factor Receptor Associated Periodic Syndrome (Juvenile) Vasculitis Enfermedades y ...

21 CFR 161.190 - Canned tuna.

Code of Federal Regulations, 2014 CFR

2014-04-01

... section. For the purpose of inhibiting the development of struvite crystals, sodium acid pyrophosphate may... section. Beginning with the top sieve, lift and drop each sieve by its open edge three times. Each time...

21 CFR 161.190 - Canned tuna.

Code of Federal Regulations, 2013 CFR

2013-04-01

... section. For the purpose of inhibiting the development of struvite crystals, sodium acid pyrophosphate may... section. Beginning with the top sieve, lift and drop each sieve by its open edge three times. Each time...

Effect of Na4O7P2 on Cu powder preparation from Cu2O-water slurry system.

PubMed

Ahn, J G; Hoang, T H; Kim, D J; Kim, M S; Kim, C O; Chung, H S

2008-03-01

A unique approach is presented for preparing highly dispersed ultrafine copper particles from cuprous oxide slurry using a wet chemical reaction with hydrazine (N2H4) as a reductant along with an appropriate addition of sodium pyrophosphate (Na4O7P2) as a surfactant. It was found that very thin oxidized surfaces on the copper particles are formed during the reaction in the solution and subsequently sodium pyrophosphate plays an important role in the zeta potential of the particles, affecting their dispersion and growth significantly. The copper particles at low zeta potential easily aggregate and grow to bigger ones, whereas they at high zeta potential keep away each other and grew individually to ultrafine size. Additionally, a model for the copper particles growth in accordance with dispersion is proposed.

Influence of Humic Acids Extracted from Peat by Different Methods on Functional Activity of Macrophages in Vitro.

PubMed

Trofimova, E S; Zykova, M V; Ligacheva, A A; Sherstoboev, E Y; Zhdanov, V V; Belousov, M V; Yusubov, M S; Krivoshchekov, S V; Danilets, M G; Dygai, A M

2017-04-01

We studied activation of macrophages with humic acids extracted from peat of large deposits in the Tomsk region by two extraction methods: by hydroxide or sodium pyrophosphate. Humic acid of lowland peat types containing large amounts of aromatic carbon, phenolic and alcohol groups, carbohydrate residues and ethers, irrespectively of the extraction methods contained LPS admixture that probably determines their activating properties. Humic acid of upland peat types characterized by high content of carbonyl, carboxyl, and ester groups enhance NO production and reduce arginase expression, but these effects were minimized when sodium hydroxide was used as an extraction solvent. Pyrophosphate samples of the upland peat types were characterized by aromaticity and diversity of functional groups and have a significant advantage because of they induce specific endotoxin-independent stimulating action on antigen presenting cells.

Isolation and characterization of Chinese standard fulvic acid sub-fractions separated from forest soil by stepwise elution with pyrophosphate buffer.

PubMed

Bai, Yingchen; Wu, Fengchang; Xing, Baoshan; Meng, Wei; Shi, Guolan; Ma, Yan; Giesy, John P

2015-03-04

XAD-8 adsorption technique coupled with stepwise elution using pyrophosphate buffers with initial pH values of 3, 5, 7, 9, and 13 was developed to isolate Chinese standard fulvic acid (FA) and then separated the FA into five sub-fractions: FApH3, FApH5, FApH7, FApH9 and FApH13, respectively. Mass percentages of FApH3-FApH13 decreased from 42% to 2.5%, and the recovery ratios ranged from 99.0% to 99.5%. Earlier eluting sub-fractions contained greater proportions of carboxylic groups with greater polarity and molecular mass, and later eluting sub-fractions had greater phenolic and aliphatic content. Protein-like components, as well as amorphous and crystalline poly(methylene)-containing components were enriched using neutral and basic buffers. Three main mechanisms likely affect stepwise elution of humic components from XAD-8 resin with pyrophosphate buffers including: 1) the carboxylic-rich sub-fractions are deprotonated at lower pH values and eluted earlier, while phenolic-rich sub-fractions are deprotonated at greater pH values and eluted later. 2) protein or protein-like components can be desorbed and eluted by use of stepwise elution as progressively greater pH values exceed their isoelectric points. 3) size exclusion affects elution of FA sub-fractions. Successful isolation of FA sub-fractions will benefit exploration of the origin, structure, evolution and the investigation of interactions with environmental contaminants.

Stabilized-solubilized ferric pyrophosphate as a new iron source for food fortification. Bioavailability studies by means of the prophylactic-preventive method in rats.

PubMed

Salgueiro, M J; Arnoldi, S; Kaliski, M A; Torti, H; Messeri, E; Weill, R; Zubillaga, M; Boccio, J

2009-02-01

The purpose of the present work was to evaluate the iron bioavailability of a new ferric pyrophosphate salt stabilized and solubilized with glycine. The prophylactic-preventive test in rats, using ferrous sulfate as the reference standard, was applied as the evaluating methodology both using water and yogurt as vehicles. Fifty female Sprague-Dawley rats weaned were randomized into five different groups (group 1: FeSO(4); group 2: pyr; group 3: FeSO(4) + yogurt; group 4: pyr + yogurt and group 5: control). The iron bioavailability (BioFe) of each compound was calculated using the formula proposed by Dutra-de-Oliveira et al. where BioFe % = (HbFef - HbFei) x 100/ToFeIn. Finally, the iron bioavailability results of each iron source were also given as relative biological value (RBV) using ferrous sulfate as the reference standard. The results showed that both BioFe % and RBV % of the new iron source tested is similar to that of the reference standard independently of the vehicle employed for the fortification procedure (FeSO(4) 49.46 +/- 12.0% and 100%; Pyr 52.66 +/- 15.02% and 106%; FeSO(4) + yogurth 54.39 +/- 13.92% and 110%; Pyr + yogurt 61.97 +/- 13.54% and 125%; Control 25.30 +/- 6.60, p < 0.05). Therefore, the stabilized and soluble ferric pyrophosphate may be considered as an optimal iron source for food fortification.

Oximes of αω-diquaternary alkane salts as antidotes to organophosphate anticholinesterases

PubMed Central

Berry, W. K.; Davies, D. R.; Green, A. L.

1959-01-01

Sixteen compounds of the general structure {HON: CH.C5H4N+.[CH2]n.R+}2Br- have been synthesized in which the position of the oxime group in the pyridine ring, the second charged group R+ and the number of methylene groups between the charged atoms have been varied. The rate at which these compounds reactivate cholinesterase inhibited by ethyl pyrophosphate has been studied and a number have been found which are more active than 2-hydroxyiminomethyl-N-methylpyridinium methanesulphonate. Since considerable variation in structure was found among those compounds which are better reactivators than the latter, the concept that 2-hydroxyiminomethyl-N-methylpyridinium salts are unique in their ability to fit the surface of the inhibited enzyme is no longer tenable. The reactivating power of these oximes correlated well with their ability, when given in conjunction with atropine, to save the lives of mice poisoned by ethyl pyrophosphate. The most effective compounds, NN'-trimethylenebis-(4-hydroxyiminomethylpyridinium bromide) and NN'-hexamethylenebis(2-hydroxyiminomethylpyridinium bromide), contained a further oxime group in R+, but the second oxime group was not essential for high activity. These new oximes were also superior in saving the lives of mice poisoned with sarin (isopropyl methylphosphonofluoridate), but the improvement was not as dramatic as when the mice were poisoned with ethyl pyrophosphate. The toxicity of the compounds varied with both n and R+ and was unrelated to the therapeutic potency. PMID:13662572

Identifying Potential Therapeutics for Osteoporosis by Exploiting the Relationship between Mevalonate Pathway and Bone Metabolism.

PubMed

Wan Hasan, Wan Nuraini; Chin, Kok-Yong; Jolly, James Jam; Abd Ghafar, Norzana; Soelaiman, Ima Nirwana

2018-04-23

Osteoporosis is a silent skeletal disease characterized by low bone mass and destruction of skeletal microarchitecture, leading to an increased fracture risk. This occurs due to an imbalance in bone remodelling, whereby the rate of bone resorption is greater than bone formation. Mevalonate pathway, previously known to involve in cholesterol synthesis, is an important regulatory pathway for bone remodelling. This review aimed to provide an overview of the relationship between mevalonate pathway and bone metabolism, as well as agents which act through this pathway to achieve their therapeutic potential. Mevalonate pathway produces farnesyl pyrophosphate and geranylgeranyl pyrophosphate essential in protein prenylation. An increase in protein prenylation favours bone resorption over bone formation. Non-nitrogen containing bisphosphonates inhibit farnesyl diphosphate synthase which produces farnesyl pyrophosphate. They are used as the first line therapy for osteoporosis. Statins, a well-known class of cholesterol-lowering agents, inhibit 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, the rate-determining enzyme in the mevalonate pathway. It was shown to increase bone mineral density and prevent fracture in humans. Tocotrienol is a group of vitamin E commonly found in palm oil, rice bran and annatto bean. It causes degradation of HMG-CoA reductase. Many studies demonstrated that tocotrienol prevented bone loss in animal studies but its efficacy has not been tested in humans. mevalonate pathway can be exploited to develop effective antiosteoporosis agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Isolation and Characterization of Chinese Standard Fulvic Acid Sub-fractions Separated from Forest Soil by Stepwise Elution with Pyrophosphate Buffer

PubMed Central

Bai, Yingchen; Wu, Fengchang; Xing, Baoshan; Meng, Wei; Shi, Guolan; Ma, Yan; Giesy, John P.

2015-01-01

XAD-8 adsorption technique coupled with stepwise elution using pyrophosphate buffers with initial pH values of 3, 5, 7, 9, and 13 was developed to isolate Chinese standard fulvic acid (FA) and then separated the FA into five sub-fractions: FApH3, FApH5, FApH7, FApH9 and FApH13, respectively. Mass percentages of FApH3-FApH13 decreased from 42% to 2.5%, and the recovery ratios ranged from 99.0% to 99.5%. Earlier eluting sub-fractions contained greater proportions of carboxylic groups with greater polarity and molecular mass, and later eluting sub-fractions had greater phenolic and aliphatic content. Protein-like components, as well as amorphous and crystalline poly(methylene)-containing components were enriched using neutral and basic buffers. Three main mechanisms likely affect stepwise elution of humic components from XAD-8 resin with pyrophosphate buffers including: 1) the carboxylic-rich sub-fractions are deprotonated at lower pH values and eluted earlier, while phenolic-rich sub-fractions are deprotonated at greater pH values and eluted later. 2) protein or protein-like components can be desorbed and eluted by use of stepwise elution as progressively greater pH values exceed their isoelectric points. 3) size exclusion affects elution of FA sub-fractions. Successful isolation of FA sub-fractions will benefit exploration of the origin, structure, evolution and the investigation of interactions with environmental contaminants. PMID:25735451

21 CFR 161.190 - Canned tuna.

Code of Federal Regulations, 2011 CFR

2011-04-01

... section. For the purpose of inhibiting the development of struvite crystals, sodium acid pyrophosphate may... and drop each sieve by its open edge three times. Each time, the open edge of the sieve is lifted the...

21 CFR 161.190 - Canned tuna.

Code of Federal Regulations, 2012 CFR

2012-04-01

... section. For the purpose of inhibiting the development of struvite crystals, sodium acid pyrophosphate may... and drop each sieve by its open edge three times. Each time, the open edge of the sieve is lifted the...

Problem-Solving Test: Pyrosequencing

ERIC Educational Resources Information Center

Szeberenyi, Jozsef

2013-01-01

Terms to be familiar with before you start to solve the test: Maxam-Gilbert sequencing, Sanger sequencing, gel electrophoresis, DNA synthesis reaction, polymerase chain reaction, template, primer, DNA polymerase, deoxyribonucleoside triphosphates, orthophosphate, pyrophosphate, nucleoside monophosphates, luminescence, acid anhydride bond,…

A Molecular Vestige of the Origin of Life on Minerals: Phosphorybosyl-Disphosphate

NASA Astrophysics Data System (ADS)

Akouche, M.; Jaber, M.; Maurel, M.-C.; Lambert, J.-F.; Georgelin, T.

2017-07-01

Nucleotides were synthesized from Ribose, Adenine, and phosphates on silica surfaces in one pot process. A important molecular intermediate was enlightened, the phosphoribosyl pyrophosphate. This molecule is a molecular relic of early earth.

Redirection of the Reaction Specificity of a Thermophilic Acetolactate Synthase toward Acetaldehyde Formation

PubMed Central

Cheng, Maria; Yoshiyasu, Hayato; Okano, Kenji; Ohtake, Hisao; Honda, Kohsuke

2016-01-01

Acetolactate synthase and pyruvate decarboxylase are thiamine pyrophosphate-dependent enzymes that convert pyruvate into acetolactate and acetaldehyde, respectively. Although the former are encoded in the genomes of many thermophiles and hyperthermophiles, the latter has been found only in mesophilic organisms. In this study, the reaction specificity of acetolactate synthase from Thermus thermophilus was redirected to catalyze acetaldehyde formation to develop a thermophilic pyruvate decarboxylase. Error-prone PCR and mutant library screening led to the identification of a quadruple mutant with 3.1-fold higher acetaldehyde-forming activity than the wild-type. Site-directed mutagenesis experiments revealed that the increased activity of the mutant was due to H474R amino acid substitution, which likely generated two new hydrogen bonds near the thiamine pyrophosphate-binding site. These hydrogen bonds might result in the better accessibility of H+ to the substrate-cofactor-enzyme intermediate and a shift in the reaction specificity of the enzyme. PMID:26731734

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaba, D.M.; Metz, S.; Maze, M.

Transthoracic electric countershock can cause necrotic myocardial lesions in humans as well as experimental animals. The authors investigated the effect on postcountershock myocardial damage of pretreatment with prazosin, an alpha-1 antagonist; L-metoprolol, a beta-1 antagonist, and verapamil, a calcium channel-blocking agent. Twenty dogs were anesthetized with halothane and given two transthoracic countershocks of 295 delivered joules each after drug or vehicle treatment. Myocardial injury was quantitated 24 h following countershock by measuring the uptake of technetium-99m pyrophosphate in the myocardium. Elevated technetium-99m pyrophosphate uptake occurred in visible lesions in most dogs regardless of drug treatment. For each of four parametersmore » of myocardial damage there was no statistically significant difference between control animals and those treated with prazosin, metoprolol, or verapamil. These data suggest that adrenergic or calcium channel-mediated mechanisms are not involved in the pathogenesis of postcountershock myocardial damage.« less

Powder XRD and dielectric studies of gel grown calcium pyrophosphate crystals

NASA Astrophysics Data System (ADS)

Parekh, Bharat; Parikh, Ketan; Joshi, Mihir

2013-06-01

Formation of calcium pyrophosphate dihydrate (CPPD) crystals in soft tissues such as cartilage, meniscus and synovial tissue leads to CPPD deposition diseases. The appearance of these crystals in the synovial fluid can give rise to an acute arthritic attack with pain and inflammation of the joints, a condition called pseudo-gout. The growth of CPP crystals has been carried out, in the present study, using the single diffusion gel growth technique, which can broadly mimic in vitro the condition in soft tissues. The crystals were characterized by different techniques. The FTIR study revealed the presence of various functional groups. Powder XRD study was also carried out to verify the crystal structure. The dielectric study was carried out at room temperature by applying field of different frequency from 500 Hz to 1 MHz. The dielectric constant, dielectric loss and a.c. resistivity decreased as frequency increased, whereas the a.c. conductivity increased as frequency increased.

Limonene Arrests Parasite Development and Inhibits Isoprenylation of Proteins in Plasmodium falciparum

PubMed Central

Moura, Ivan Cruz; Wunderlich, Gerhard; Uhrig, Maria L.; Couto, Alicia S.; Peres, Valnice J.; Katzin, Alejandro M.; Kimura, Emília A.

2001-01-01

Isoprenylation is an essential protein modification in eukaryotic cells. Herein, we report that in Plasmodium falciparum, a number of proteins were labeled upon incubation of intraerythrocytic forms with either [3H]farnesyl pyrophosphate or [3H]geranylgeranyl pyrophosphate. By thin-layer chromatography, we showed that attached isoprenoids are partially modified to dolichol and other, uncharacterized, residues, confirming active isoprenoid metabolism in this parasite. Incubation of blood-stage P. falciparum treated with the isoprenylation inhibitor limonene significantly decreased the parasites' progression from the ring stage to the trophozoite stage and at 1.22 mM, 50% of the parasites died after the first cycle. Using Ras- and Rap-specific monoclonal antibodies, putative Rap and Ras proteins of P. falciparum were immunoprecipitated. Upon treatment with 0.5 mM limonene, isoprenylation of these proteins was significantly decreased, possibly explaining the observed arrest of parasite development. PMID:11502528

Abdominal and hepatic uptake of /sup 99m/Tc-pyrophosphate in neonatal necrotizing enterocolitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caride, V.J.; Touloukian, R.J.; Ablow, R.C.

1981-04-01

Abdominal /sup 99m/Tc-pyrophosphate (/sup 99m/Tc-PYP) scans were obtained in 15 neonates: 12 with neonatal necrotizing enterocolitis (NEC), two with osteomyelitis, and one with myocarditis. Ten of the babies with NEC had at least one positive scan; of these 10 studies, seven (Group A) showed both diffuse abdominal uptake and localized hepatic activity, two (Group B) showed abdominal uptake and questionable hepatic uptake, and one (Group C) demonstrated diffuse abdominal uptake only. The other two babies with NEC had normal scans (Group D). All NEC patients had normal scans. A patient with myocarditis had hepatic uptake of /sup 99m/Tc-PYP while themore » abdominal scan in the two infants with osteomyelitis was normal. These preliminary observations suggest that further study of a relationship between abdominal scan findings and the course of NEC is warranted.« less

Key structure-activity relationships in the vanadium phosphorus oxide catalyst system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, M.R.; Ebner, J.R.

1990-04-01

The crystal structure of vanadyl pyrophosphate has been redetermined using single crystals obtained from a near solidified melt of a microcrystalline catalyst sample. Crystals that index as vanadyl pyrophosphate obtained from this melt are variable in color. Crystallographic refinement of the single crystal x-ray diffraction data indicates that structural differences among these materials can be described in terms of crystal defects associated with linear disorder of the vanadium atoms. The importance of the disorder is outlined in the context of its effect on the proposed surface topology parallel to (1,0,0). Models of the surface topology simply and intuitively account formore » the non-stoichometric surface atomic P/V ratio exhibited by selective catalysts of this phase. These models also point to the possible role of the excess phosphorus in providing site isolation of reactive centers at the surface. 33 refs., 7 figs.« less

Analysis of uracil phosphoribosyltransferase expression in Mycobacterium tuberculosis and evaluation of upp knockout strain in infected mice.

PubMed

Villela, Anne Drumond; Pham, Ha; Jones, Victoria; Grzegorzewicz, Anna E; Rodrigues-Junior, Valnês da Silva; Campos, Maria Martha; Basso, Luiz Augusto; Jackson, Mary; Santos, Diógenes Santiago

2017-02-01

The upp (Rv3309c)-encoded uracil phosphoribosyltransferase from Mycobacterium tuberculosis (MtUPRT) converts uracil and 5-phosphoribosyl-α-1-pyrophosphate into pyrophosphate and uridine 5΄-monophosphate, the precursor of all pyrimidine nucleotides. A M. tuberculosis knockout strain for upp gene was generated by allelic replacement. Knockout and complemented strains were validated by a functional assay of uracil incorporation. A basal level of MtUPRT expression is shown to be independent of either growth medium used, addition of bases, or oxygen presence/absence. The upp disruption does not affect M. tuberculosis growth in Middlebrook 7H9 medium, and it is not required for M. tuberculosis virulence in a mouse model of infection. Thus, MtUPRT is unlikely to be a good target for drugs against M. tuberculosis. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Insight into the ionotropic gelation of chitosan using tripolyphosphate and pyrophosphate as cross-linkers.

PubMed

Sacco, Pasquale; Paoletti, Sergio; Cok, Michela; Asaro, Fioretta; Abrami, Michela; Grassi, Mario; Donati, Ivan

2016-11-01

Ionotropic gelation of chitosan by means of opposite charged ions represents an efficient alternative to covalent reticulation because of milder condition of use and, in general, higher biocompatibility of the resulting systems. In this work 90° light scattering (turbidimetry), circular dichroism (CD) and 1 H NMR measurements have been performed to study the interactions between the biopolymer and ionic cross-linkers tripolyphosphate (TPP) and pyrophosphate (PPi) in dilute solutions. Thereafter, a dialysis-based technique was exploited to fabricate tridimensional chitosan hydrogels based on both polyanions. Resulting matrices showed a different mechanical behavior because of their peculiar mesh-texture at micro/nano-scale: in the present contribution we demonstrate that TPP and PPi favor the formation of homogeneous and inhomogeneous systems, respectively. The different texture of networks could be exploited in future for the preparation of systems for the controlled release of molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of monoclinic calcium pyrophosphate dihydrate and hydroxyapatite in human sclera using Raman microspectroscopy.

PubMed

Chen, Ko-Hua; Li, Mei-Jane; Cheng, Wen-Ting; Balic-Zunic, Tonci; Lin, Shan-Yang

2009-02-01

Raman microspectroscopy was first used to determine the composition of a calcified plaque located at the pterygium-excision site of a 51-year-old female patient's left nasal sclera after surgery. It was unexpectedly found that the Raman spectrum of the calcified sample at 1149, 1108, 1049, 756, 517, 376 and 352/cm was similar to the Raman spectrum of monoclinic form of calcium pyrophosphate dihydrate (CPPD) crystal, but differed from the Raman spectrum of triclinic form of CPPD. An additional peak at 958/cm was also observed in the Raman spectrum of the calcified plaque, which was identical to the characteristic peak at 958/cm of hydroxyapatite (HA). This is the first study to report the spectral biodiagnosis of both monoclinic CPPD and HA co-deposited in the calcified plaque of a patient with sclera dystrophic calcification using Raman microspectroscopy.

Identification of monoclinic calcium pyrophosphate dihydrate and hydroxyapatite in human sclera using Raman microspectroscopy

PubMed Central

Chen, Ko-Hua; Li, Mei-Jane; Cheng, Wen-Ting; Balic-Zunic, Tonci; Lin, Shan-Yang

2009-01-01

Raman microspectroscopy was first used to determine the composition of a calcified plaque located at the pterygium-excision site of a 51-year-old female patient's left nasal sclera after surgery. It was unexpectedly found that the Raman spectrum of the calcified sample at 1149, 1108, 1049, 756, 517, 376 and 352/cm was similar to the Raman spectrum of monoclinic form of calcium pyrophosphate dihydrate (CPPD) crystal, but differed from the Raman spectrum of triclinic form of CPPD. An additional peak at 958/cm was also observed in the Raman spectrum of the calcified plaque, which was identical to the characteristic peak at 958/cm of hydroxyapatite (HA). This is the first study to report the spectral biodiagnosis of both monoclinic CPPD and HA co-deposited in the calcified plaque of a patient with sclera dystrophic calcification using Raman microspectroscopy. PMID:19200254

Live-Cell Pyrophosphate Imaging by in Situ Hot-Spot Generation.

PubMed

Li, Mingmin; Li, Jin; Di, Huixia; Liu, Huiqiao; Liu, Dingbin

2017-03-21

Controlling the electromagnetic hot-spot generation is essential for surface-enhanced Raman scattering (SERS) assays. Current hot-spot-based SERS assays have been extensively studied in solutions or on substrates. However, probing biospecies by controlling the hot-spot assembly in living systems has not been demonstrated thus far. Herein, we report a background-free SERS probe for imaging pyrophosphate (PPi), a biochemically significant anion, in living cells. Intracellular PPi is able to induce the nanoparticle dimerization, thus creating an intense electromagnetic hot spot and dramatically enhancing the signal of the Raman reporters residing in the hot spot. More impressively, the reporter we used in this study provides a strong and sharp single peak in the cellular Raman-silent region (1800-2800 cm -1 ), thus eliminating the possible background interference. This strategy could be readily extended to detect other biomarkers by only replacing the recognition ligands.

PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

DOEpatents

Grinstead, R.R.

1962-01-23

A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

The relative hydrolytic reactivities of pyrophosphites and pyrophosphates.

PubMed

Mistry, Dharmit; Powles, Nicholas

2013-09-14

The pH-rate profiles for the hydrolysis of pyrophosphate (PP(V)) and pyrophosphite (PP(III), pyro-di-H-phosphonate) are a complex function of pH, reflecting the different ionic species and their relative reactivities. PP(III) is more reactive than PP(V) at all pHs and only PP(III) shows a hydroxide-ion reaction at high pH, so it is 10(10)-fold more reactive than PP(V) in 0.1 M NaOH. The pK(a2) of PP(III) ~0.44, so the dominant species at pH's > 1 is the di-anion PP(III)(2-). Although there is no observable (NMR or ITC) binding of Mg(2+) to the PP(III) di-anion there is a modest increase in the rate of hydrolysis of PP(III) by Mg(2+). PP(III) is neither a substrate nor an inhibitor of pyrophosphatase, the enzyme that efficiently catalyses the hydrolysis of PP(V).

Bacterial Cell Wall Precursor Phosphatase Assays Using Thin-layer Chromatography (TLC) and High Pressure Liquid Chromatography (HPLC).

PubMed

Pazos, Manuel; Otten, Christian; Vollmer, Waldemar

2018-03-20

Peptidoglycan encases the bacterial cytoplasmic membrane to protect the cell from lysis due to the turgor. The final steps of peptidoglycan synthesis require a membrane-anchored substrate called lipid II, in which the peptidoglycan subunit is linked to the carrier lipid undecaprenol via a pyrophosphate moiety. Lipid II is the target of glycopeptide antibiotics and several antimicrobial peptides, and is degraded by 'attacking' enzymes involved in bacterial competition to induce lysis. Here we describe two protocols using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC), respectively, to assay the digestion of lipid II by phosphatases such as Colicin M or the LXG toxin protein TelC from Streptococcus intermedius . The TLC method can also monitor the digestion of undecaprenyl (pyro)phosphate, whereas the HPLC method allows to separate the di-, mono- or unphosphorylated disaccharide pentapeptide products of lipid II.

Bacterial Cell Wall Precursor Phosphatase Assays Using Thin-layer Chromatography (TLC) and High Pressure Liquid Chromatography (HPLC)

PubMed Central

Pazos, Manuel; Otten, Christian; Vollmer, Waldemar

2018-01-01

Peptidoglycan encases the bacterial cytoplasmic membrane to protect the cell from lysis due to the turgor. The final steps of peptidoglycan synthesis require a membrane-anchored substrate called lipid II, in which the peptidoglycan subunit is linked to the carrier lipid undecaprenol via a pyrophosphate moiety. Lipid II is the target of glycopeptide antibiotics and several antimicrobial peptides, and is degraded by ‘attacking’ enzymes involved in bacterial competition to induce lysis. Here we describe two protocols using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC), respectively, to assay the digestion of lipid II by phosphatases such as Colicin M or the LXG toxin protein TelC from Streptococcus intermedius. The TLC method can also monitor the digestion of undecaprenyl (pyro)phosphate, whereas the HPLC method allows to separate the di-, mono- or unphosphorylated disaccharide pentapeptide products of lipid II. PMID:29651453

Structural aspects of calcium iron phosphate glass containing neodymium oxide

NASA Astrophysics Data System (ADS)

Li, Haijian; Liang, Xiaofeng; Wang, Cuiling; Yu, Huijun; Li, Zhen; Yang, Shiyuan

2014-06-01

Homogeneous glasses of the xNd2O3sbnd (100 - x)(12CaOsbnd 20Fe2O3sbnd 68P2O5) system were obtained within the 0 ⩽ x ⩽ 10 mol% composition range. The density and molar volume measurements helped to understand the structural changes occurring in these glasses. Vickers-hardness results showed that addition of Nd2O3 strengthened the crosslinking of the glass network. Spectra analysis indicated that Nd2O3 enters in the structure of the phosphate glasses as a network modifier. The depolymerization of the glass network by the addition of Nd2O3 is characterized by the increase in the concentration of pyrophosphate. The decrease of the Q1 terminal oxygen with increasing Nd2O3 content indicated that Psbnd Osbnd Nd bonds participated in the pyrophosphate glass structure, determined from the Raman spectra.

Oxidation-reduction potentials of molybdenum, flavin and iron-sulphur centres in milk xanthine oxidase.

PubMed Central

Cammack, R; Barber, M J; Bray, R C

1976-01-01

1. The mid-point reduction potentials of the various groups in xanthine oxidase from bovine milk were determined by potentiometric titration with dithionite in the presence of dye mediators, removing samples for quantification of the reduced species by e.p.r. (electron-paramagnetic-resonance) spectroscopy. The values obtained for the functional enzyme in pyrophosphate buffer, pH8.2, are: Fe/S centre I, -343 +/- 15mV; Fe/S II, -303 +/- 15mV; FAD/FADH-; -351 +/- 20mV; FADH/FADH2, -236 +/-mV; Mo(VI)/Mo(V) (Rapid), -355 +/- 20mV; Mo(V) (Rapid)/Mo(IV), -355 +/- 20mV. 2. Behaviour of the functional enzyme is essentially ideal in Tris but less so in pyrophosphate. In Tris, the potential for Mo(VI)/Mo(V) (Rapid) is lowered relative to that in pyrophosphate, but the potential for Fe/S II is raised. The influence of buffer on the potentials was investigated by partial-reduction experiments with six other buffers. 3. Conversion of the enzyme with cyanide into the non-functional form, which gives the Slow molybdenum signal, or alkylation of FAD, has little effect on the mid-point potentials of the other centres. The potentials associated with the Slow signal are: Mo(VI)/Mo(V) (Slow), -440 +/- 25mV; Mo(V) (Slow)/Mo(IV), -480 +/- 25 mV. This signal exhibits very sluggish equilibration with the mediator system. 4. The deviations from ideal behaviour are discussed in terms of possible binding of buffer ions or anti-co-operative interactions amongst the redox centres. PMID:183752

A rapid and highly selective method for the estimation of pyro-, tri- and orthophosphates.

PubMed

Kamat, D R; Savant, V V; Sathyanarayana, D N

1995-03-01

A rapid, highly selective and simple method has been developed for the quantitative determination of pyro-, tri- and orthophosphates. The method is based on the formation of a solid complex of bis(ethylenediamine)cobalt(III) species with pyrophosphate at pH 4.2-4.3, with triphosphate at pH 2.0-2.1 and with orthophosphate at pH 8.2-8.6. The proposed method for pyro- and triphosphates differs from the available method, which is based on the formation of an adduct with tris(ethylenediamine)cobalt(III) species. The complexes have the composition [Co(en)(2)HP(2)O(7)]4H(2)O and [Co(en)(2)H(2)P(3)O(10)]2H(2)O, respectively. The precipitation is instantaneous and quantitative under the recommended optimum conditions giving 99.5% gravimetric yield in both cases. There is no interferences from orthophosphate, trimetaphosphate and pyrophosphate species in the triphosphate estimation up to 5% of each component. The efficacy of the method has been established by determining pyrophosphate and triphosphate contents in various matrices. In the case of orthophosphate, the proposed method differs from the available methods such as ammonium phosphomolybdate, vanadophosphomolybdate and quinoline phosphomolybdate, which are based on the formation of a precipitate, followed by either titrimetry or gravimetry. The precipitation is instantaneous and the method is simple. Under the recommended pH and other reaction conditions, gravimetric yields of 99.6-100% are obtainable. The method is applicable to orthophosphoric acid and a variety of phosphate salts.

Use of blood-pool imaging in evaluation of diffuse activity patterns in technetium-99m pyrophosphate myocardial scintigraphy.

PubMed

Cowley, M J; Mantle, J A; Rogers, W J; Russell, R O; Rackley, C E; Logic, J R

1979-06-01

It has been suggested that diffuse Tc-99m pyrophosphate precordial activity may be due to persistent blood-pool activity in routine delayed views during myocardial imaging. To answer this question, we reviewed myocardial scintigrams recorded 60--90 min following the injection of 12--15 mCi of Tc-99m pyrophosphate for the presence of diffuse precordial activity, and compared these with early images of the blood pool in 265 patients. Diffuse activity in the delayed images was identified in 48 patients: in 20 with acute myocardial infarction and in 28 with no evidence of it. Comparison of these routine delayed images with early views of the blood pool revealed two types of patterns. In patients with acute infarction, 95% had delayed images that were distinguishable from blood pool either because the activity was smaller than the early blood pool, or by the presence of localized activity superimposed on diffuse activity identical to blood pool. In those without infarction, 93% had activity distribution in routine delayed views matching that in the early blood-pool images. The usefulness of the diffuse TcPPi precordial activity in myocardial infarction is improved when early blood-pool imaging is used to exclude persistence of blood-pool activity as its cause. Moreover, it does not require additional amounts of radioactivity nor complex computer processing, a feature that may be of value in the community hospital using the technique to "rule out" infarction 24--72 hr after onset of suggestive symptoms.

Antiproliferative constituents in plants 14. Coumarins and acridone alkaloids from Boenninghausenia japonica NAKAI.

PubMed

Chaya, Norihito; Terauchi, Kazuko; Yamagata, Yuriko; Kinjo, Junei; Okabe, Hikaru

2004-08-01

The MeOH extracts of the ground part and the root of Boenninghausenia japonica NAKAI showed inhibitory activity against tumor cell growth. Fractionation of the extracts has resulted in isolation of 1,3-dihydroxy-4-(2'-hydroxy-3'-hydroxymethyl-3',4'-epoxy-butyl)-N-methylacridone, 1,3-dihydroxy-4-[(Z)-3'-hydroxy-3'-methyl-buten-1'-yl]-N-methylacridone, 3-(1',1'-dimethylallyl)-7-hydroxy-8-methoxy-2H-1-benzopyran-2-one, casegravol, cis-casegravol, and edgeworin in addition to 9 compounds reported from B. japonica and B. albiflora. The isolates from this plant and some related compounds were tested for antiproliferative activity against human gastric adenocarcinoma (MK-1), human uterus carcinoma (HeLa), and murine melanoma (B16F10) cells.

Symptomatic cardiac amyloidosis in an American family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruder, M.A.; Alpert, M.A.; Sanfelippo, J.F.

1984-07-01

This report describes an American family with a high incidence of symptomatic cardiac amyloidosis among four siblings, and explores the role of echocardiography and technetium pyrophosphate myocardial scintigraphy in the detection of this infiltrative cardiomyopathy within the involved family.

Steel test panel helps control additives in pyrophosphate copper plating

NASA Technical Reports Server (NTRS)

Hollar, W. T.

1967-01-01

Test panel helps control maximum tolerance level for plating solution contaminants. It provides low, medium, and high-current density areas such as exist in production plating, and plating is examined for uniformity of texture and ductility.

Pyrophosphate-Dependent ATP Formation from Acetyl Coenzyme A in Syntrophus aciditrophicus , a New Twist on ATP Formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

James, Kimberly L.; Ríos-Hernández, Luis A.; Wofford, Neil Q.

Syntrophus aciditrophicusis a model syntrophic bacterium that degrades key intermediates in anaerobic decomposition, such as benzoate, cyclohexane-1-carboxylate, and certain fatty acids, to acetate when grown with hydrogen-/formate-consuming microorganisms. ATP formation coupled to acetate production is the main source for energy conservation byS. aciditrophicus. However, the absence of homologs for phosphate acetyltransferase and acetate kinase in the genome ofS. aciditrophicusleaves it unclear as to how ATP is formed, as most fermentative bacteria rely on these two enzymes to synthesize ATP from acetyl coenzyme A (CoA) and phosphate. Here, we combine transcriptomic, proteomic, metabolite, and enzymatic approaches to show thatS. aciditrophicususes AMP-forming, acetyl-CoA synthetase (Acs1)more » for ATP synthesis from acetyl-CoA.acs1mRNA and Acs1 were abundant in transcriptomes and proteomes, respectively, ofS. aciditrophicusgrown in pure culture and coculture. Cell extracts ofS. aciditrophicushad low or undetectable acetate kinase and phosphate acetyltransferase activities but had high acetyl-CoA synthetase activity under all growth conditions tested. Both Acs1 purified fromS. aciditrophicusand recombinantly produced Acs1 catalyzed ATP and acetate formation from acetyl-CoA, AMP, and pyrophosphate. High pyrophosphate levels and a high AMP-to-ATP ratio (5.9 ± 1.4) inS. aciditrophicuscells support the operation of Acs1 in the acetate-forming direction. Thus,S. aciditrophicushas a unique approach to conserve energy involving pyrophosphate, AMP, acetyl-CoA, and an AMP-forming, acetyl-CoA synthetase. We find bacteria use two enzymes, phosphate acetyltransferase and acetate kinase, to make ATP from acetyl-CoA, while acetate-forming archaea use a single enzyme, an ADP-forming, acetyl-CoA synthetase, to synthesize ATP and acetate from acetyl-CoA.Syntrophus aciditrophicusapparently relies on a different approach to conserve energy during acetyl-CoA metabolism, as its genome does not have homologs to the genes for phosphate acetyltransferase and acetate kinase. Here, we show thatS. aciditrophicususes an alternative approach, an AMP-forming, acetyl-CoA synthetase, to make ATP from acetyl-CoA. AMP-forming, acetyl-CoA synthetases were previously thought to function only in the activation of acetate to acetyl-CoA.« less

Pyrophosphate-Dependent ATP Formation from Acetyl Coenzyme A in Syntrophus aciditrophicus , a New Twist on ATP Formation

DOE PAGES

James, Kimberly L.; Ríos-Hernández, Luis A.; Wofford, Neil Q.; ...

2016-08-16

Syntrophus aciditrophicusis a model syntrophic bacterium that degrades key intermediates in anaerobic decomposition, such as benzoate, cyclohexane-1-carboxylate, and certain fatty acids, to acetate when grown with hydrogen-/formate-consuming microorganisms. ATP formation coupled to acetate production is the main source for energy conservation byS. aciditrophicus. However, the absence of homologs for phosphate acetyltransferase and acetate kinase in the genome ofS. aciditrophicusleaves it unclear as to how ATP is formed, as most fermentative bacteria rely on these two enzymes to synthesize ATP from acetyl coenzyme A (CoA) and phosphate. Here, we combine transcriptomic, proteomic, metabolite, and enzymatic approaches to show thatS. aciditrophicususes AMP-forming, acetyl-CoA synthetase (Acs1)more » for ATP synthesis from acetyl-CoA.acs1mRNA and Acs1 were abundant in transcriptomes and proteomes, respectively, ofS. aciditrophicusgrown in pure culture and coculture. Cell extracts ofS. aciditrophicushad low or undetectable acetate kinase and phosphate acetyltransferase activities but had high acetyl-CoA synthetase activity under all growth conditions tested. Both Acs1 purified fromS. aciditrophicusand recombinantly produced Acs1 catalyzed ATP and acetate formation from acetyl-CoA, AMP, and pyrophosphate. High pyrophosphate levels and a high AMP-to-ATP ratio (5.9 ± 1.4) inS. aciditrophicuscells support the operation of Acs1 in the acetate-forming direction. Thus,S. aciditrophicushas a unique approach to conserve energy involving pyrophosphate, AMP, acetyl-CoA, and an AMP-forming, acetyl-CoA synthetase. We find bacteria use two enzymes, phosphate acetyltransferase and acetate kinase, to make ATP from acetyl-CoA, while acetate-forming archaea use a single enzyme, an ADP-forming, acetyl-CoA synthetase, to synthesize ATP and acetate from acetyl-CoA.Syntrophus aciditrophicusapparently relies on a different approach to conserve energy during acetyl-CoA metabolism, as its genome does not have homologs to the genes for phosphate acetyltransferase and acetate kinase. Here, we show thatS. aciditrophicususes an alternative approach, an AMP-forming, acetyl-CoA synthetase, to make ATP from acetyl-CoA. AMP-forming, acetyl-CoA synthetases were previously thought to function only in the activation of acetate to acetyl-CoA.« less

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper... pyrophosphate. Copper sulfate. Iodine Calcium iodate. Calcium iodobehenate. Cuprous iodide. 3,5-Diiodosalicylic.... Thymol iodide. Iron Iron ammonium citrate. Iron carbonate. Iron chloride. Iron gluconate. Iron oxide...

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper... pyrophosphate. Copper sulfate. Iodine Calcium iodate. Calcium iodobehenate. Cuprous iodide. 3,5-Diiodosalicylic.... Thymol iodide. Iron Iron ammonium citrate. Iron carbonate. Iron chloride. Iron gluconate. Iron oxide...

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper... pyrophosphate. Copper sulfate. Iodine Calcium iodate. Calcium iodobehenate. Cuprous iodide. 3,5-Diiodosalicylic.... Thymol iodide. Iron Iron ammonium citrate. Iron carbonate. Iron chloride. Iron gluconate. Iron oxide...

Charcot-like joints in calcium pyrophosphate dihydrate deposition disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Helms, C.A.; Chapman, G.S.; Wild, J.H.

1981-10-01

Two cases of Charcot-like joints in patients with pseudogout who were otherwise neurologically intact are presented. The arthropathy of pseudogout should include Charcot-like joints and it is emphasized that an apparent Charcot joint should raise the question of pseudogout.

Definition and Reliability Assessment of Elementary Ultrasonographic Findings in Calcium Pyrophosphate Deposition Disease: A Study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force.

PubMed

Filippou, Georgios; Scirè, Carlo A; Damjanov, Nemanja; Adinolfi, Antonella; Carrara, Greta; Picerno, Valentina; Toscano, Carmela; Bruyn, George A; D'Agostino, Maria Antonietta; Delle Sedie, Andrea; Filippucci, Emilio; Gutierrez, Marwin; Micu, Mihaela; Möller, Ingrid; Naredo, Esperanza; Pineda, Carlos; Porta, Francesco; Schmidt, Wolfgang A; Terslev, Lene; Vlad, Violeta; Zufferey, Pascal; Iagnocco, Annamaria

2017-11-01

To define the ultrasonographic characteristics of calcium pyrophosphate crystal (CPP) deposits in joints and periarticular tissues and to evaluate the intra- and interobserver reliability of expert ultrasonographers in the assessment of CPP deposition disease (CPPD) according to the new definitions. After a systematic literature review, a Delphi survey was circulated among a group of expert ultrasonographers, who were members of the CPPD Ultrasound (US) Outcome Measures in Rheumatology (OMERACT) subtask force, to obtain definitions of the US characteristics of CPPD at the level of fibrocartilage (FC), hyaline cartilage (HC), tendon, and synovial fluid (SF). Subsequently, the reliability of US in assessing CPPD at knee and wrist levels according to the agreed definitions was tested in static images and in patients with CPPD. Cohen's κ was used for statistical analysis. HC and FC of the knee yielded the highest interobserver κ values among all the structures examined, in both the Web-based (0.73 for HC and 0.58 for FC) and patient-based exercises (0.55 for the HC and 0.64 for the FC). Kappa values for the other structures were lower, ranging from 0.28 in tendons to 0.50 in SF in the static exercise and from 0.09 (proximal patellar tendon) to 0.27 (triangular FC of the wrist) in the patient-based exercise. The new OMERACT definitions for the US identification of CPPD proved to be reliable at the level of the HC and FC of the knee. Further studies are needed to better define the US characteristics of CPPD and optimize the scanning technique in other anatomical sites.

Quantitative estimation of infarct size by simultaneous dual radionuclide single photon emission computed tomography: comparison with peak serum creatine kinase activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawaguchi, K.; Sone, T.; Tsuboi, H.

1991-05-01

To test the hypothesis that simultaneous dual energy single photon emission computed tomography (SPECT) with technetium-99m (99mTc) pyrophosphate and thallium-201 (201TI) can provide an accurate estimate of the size of myocardial infarction and to assess the correlation between infarct size and peak serum creatine kinase activity, 165 patients with acute myocardial infarction underwent SPECT 3.2 +/- 1.3 (SD) days after the onset of acute myocardial infarction. In the present study, the difference in the intensity of 99mTc-pyrophosphate accumulation was assumed to be attributable to difference in the volume of infarcted myocardium, and the infarct volume was corrected by the ratiomore » of the myocardial activity to the osseous activity to quantify the intensity of 99mTc-pyrophosphate accumulation. The correlation of measured infarct volume with peak serum creatine kinase activity was significant (r = 0.60, p less than 0.01). There was also a significant linear correlation between the corrected infarct volume and peak serum creatine kinase activity (r = 0.71, p less than 0.01). Subgroup analysis showed a high correlation between corrected volume and peak creatine kinase activity in patients with anterior infarctions (r = 0.75, p less than 0.01) but a poor correlation in patients with inferior or posterior infarctions (r = 0.50, p less than 0.01). In both the early reperfusion and the no reperfusion groups, a good correlation was found between corrected infarct volume and peak serum creatine kinase activity (r = 0.76 and r = 0.76, respectively; p less than 0.01).« less

Purification, molecular cloning, and expression of 2-hydroxyphytanoyl-CoA lyase, a peroxisomal thiamine pyrophosphate-dependent enzyme that catalyzes the carbon–carbon bond cleavage during α-oxidation of 3-methyl-branched fatty acids

PubMed Central

Foulon, Veerle; Antonenkov, Vasily D.; Croes, Kathleen; Waelkens, Etienne; Mannaerts, Guy P.; Van Veldhoven, Paul P.; Casteels, Minne

1999-01-01

In the third step of the α-oxidation of 3-methyl-branched fatty acids such as phytanic acid, a 2-hydroxy-3-methylacyl-CoA is cleaved into formyl-CoA and a 2-methyl-branched fatty aldehyde. The cleavage enzyme was purified from the matrix protein fraction of rat liver peroxisomes and identified as a protein made up of four identical subunits of 63 kDa. Its activity proved to depend on Mg2+ and thiamine pyrophosphate, a hitherto unrecognized cofactor of α-oxidation. Formyl-CoA and 2-methylpentadecanal were identified as reaction products when the purified enzyme was incubated with 2-hydroxy-3-methylhexadecanoyl-CoA as the substrate. Hence the enzyme catalyzes a carbon–carbon cleavage, and we propose calling it 2-hydroxyphytanoyl-CoA lyase. Sequences derived from tryptic peptides of the purified rat protein were used as queries to recover human expressed sequence tags from the databases. The composite cDNA sequence of the human lyase contained an ORF of 1,734 bases that encodes a polypeptide with a calculated molecular mass of 63,732 Da. Recombinant human protein, expressed in mammalian cells, exhibited lyase activity. The lyase displayed homology to a putative Caenorhabditis elegans protein that resembles bacterial oxalyl-CoA decarboxylases. Similarly to the decarboxylases, a thiamine pyrophosphate-binding consensus domain was present in the C-terminal part of the lyase. Although no peroxisome targeting signal, neither 1 nor 2, was apparent, transfection experiments with constructs encoding green fluorescent protein fused to the full-length lyase or its C-terminal pentapeptide indicated that the C terminus of the lyase represents a peroxisome targeting signal 1 variant. PMID:10468558

The floral transcriptome of ylang ylang (Cananga odorata var. fruticosa) uncovers biosynthetic pathways for volatile organic compounds and a multifunctional and novel sesquiterpene synthase

PubMed Central

Jin, Jingjing; Kim, Mi Jung; Dhandapani, Savitha; Tjhang, Jessica Gambino; Yin, Jun-Lin; Wong, Limsoon; Sarojam, Rajani; Chua, Nam-Hai; Jang, In-Cheol

2015-01-01

The pleasant fragrance of ylang ylang varieties (Cananga odorata) is mainly due to volatile organic compounds (VOCs) produced by the flowers. Floral scents are a key factor in plant–insect interactions and are vital for successful pollination. C. odorata var. fruticosa, or dwarf ylang ylang, is a variety of ylang ylang that is popularly grown in Southeast Asia as a small shrub with aromatic flowers. Here, we describe the combined use of bioinformatics and chemical analysis to discover genes for the VOC biosynthesis pathways and related genes. The scented flowers of C. odorata var. fruticosa were analysed by gas chromatography/mass spectrometry and a total of 49 VOCs were identified at four different stages of flower development. The bulk of these VOCs were terpenes, mainly sesquiterpenes. To identify the various terpene synthases (TPSs) involved in the production of these essential oils, we performed RNA sequencing on mature flowers. From the RNA sequencing data, four full-length TPSs were functionally characterized. In vitro assays showed that two of these TPSs were mono-TPSs. CoTPS1 synthesized four products corresponding to β-thujene, sabinene, β-pinene, and α-terpinene from geranyl pyrophosphate and CoTPS4 produced geraniol from geranyl pyrophosphate. The other two TPSs were identified as sesqui-TPSs. CoTPS3 catalysed the conversion of farnesyl pyrophosphate to α-bergamotene, whereas CoTPS2 was found to be a multifunctional and novel TPS that could catalyse the synthesis of three sesquiterpenes, β-ylangene, β-copaene, and β-cubebene. Additionally, the activities of the two sesqui-TPSs were confirmed in planta by transient expression of these TPS genes in Nicotiana benthamiana leaves by Agrobacterium-mediated infiltration. PMID:25956881

Efficacy and mechanisms of non-antibacterial, chemical plaque control by dentifrices--an in vitro study.

PubMed

Busscher, Henk J; White, Don J; Atema-Smit, Jelly; van der Mei, Henny C

2007-04-01

The provision of antiplaque benefits to dentifrices assists patients in improving hygiene and reducing susceptibility to gingivitis and caries. Chemical plaque control involves different mechanisms and is mostly associated with antibacterial effects, but also includes effects on pellicle surface chemistry to improve cleansing or discourage renewed plaque formation. It is the aim of this paper to analyze in vitro detachment of co-aggregating oral actinomyces and streptococci from pellicle surfaces by dentifrice supernates and to study subsequent de novo streptococcal deposition. Detachment by dentifrices of a co-adhering bacterial pair was studied in the parallel plate flow chamber on a 16 h pellicle coated surface. After detachment by perfusing the chamber with a dentifrice, re-deposition was initiated by flowing with a fresh streptococcal suspension. The dentifrices included both a regular, SLS-fluoride based formulation as well a pyrophosphate, anticalculus and antimicrobial formulations. All dentifrice supernates containing SLS were effective in detaching co-adhering bacteria from pellicles surfaces, except in combination with SnF(2). When hexametaphosphate was added immediate detachment was relatively low, but continued even during re-deposition. The re-deposition of streptococci after detachment by other, NaF containing dentifrices involved relatively few large aggregates, presumably because fluoride was able to block bi-dentate calcium binding sites on the bacterial cell surfaces, mediating co-adhesion. When pyrophosphate was present in addition to NaF, re-deposition involved significantly more large aggregates, likely because pyrophosphate served as a bi-dentate bridge between calcium bound on the bacterial cell surfaces. Commercially available dentifrice formulations differ in their ability to stimulate bacterial detachment from pellicles and dependent on their composition yield the formation of large co-adhering aggregates of actinomyces and streptococci in de novo deposition.

Anthranilate phosphoribosyltransferase: Binding determinants for 5'-phospho-alpha-d-ribosyl-1'-pyrophosphate (PRPP) and the implications for inhibitor design.

PubMed

Evans, Genevieve L; Furkert, Daniel P; Abermil, Nacim; Kundu, Preeti; de Lange, Katrina M; Parker, Emily J; Brimble, Margaret A; Baker, Edward N; Lott, J Shaun

2018-02-01

Phosphoribosyltransferases (PRTs) bind 5'-phospho-α-d-ribosyl-1'-pyrophosphate (PRPP) and transfer its phosphoribosyl group (PRib) to specific nucleophiles. Anthranilate PRT (AnPRT) is a promiscuous PRT that can phosphoribosylate both anthranilate and alternative substrates, and is the only example of a type III PRT. Comparison of the PRPP binding mode in type I, II and III PRTs indicates that AnPRT does not bind PRPP, or nearby metals, in the same conformation as other PRTs. A structure with a stereoisomer of PRPP bound to AnPRT from Mycobacterium tuberculosis (Mtb) suggests a catalytic or post-catalytic state that links PRib movement to metal movement. Crystal structures of Mtb-AnPRT in complex with PRPP and with varying occupancies of the two metal binding sites, complemented by activity assay data, indicate that this type III PRT binds a single metal-coordinated species of PRPP, while an adjacent second metal site can be occupied due to a separate binding event. A series of compounds were synthesized that included a phosphonate group to probe PRPP binding site. Compounds containing a "bianthranilate"-like moiety are inhibitors with IC 50 values of 10-60μM, and K i values of 1.3-15μM. Structures of Mtb-AnPRT in complex with these compounds indicate that their phosphonate moieties are unable to mimic the binding modes of the PRib or pyrophosphate moieties of PRPP. The AnPRT structures presented herein indicated that PRPP binds a surface cleft and becomes enclosed due to re-positioning of two mobile loops. Copyright © 2017 Elsevier B.V. All rights reserved.

A method for quantifying bioavailable organic carbon in aquifer sediments

USGS Publications Warehouse

Rectanus, H.V.; Widdowson, M.; Novak, J.; Chapelle, F.

2005-01-01

The fact that naturally occurring microorganisms can biodegrade PCE and TCE allows the use of monitored natural attenuation (MNA) as a remediation strategy at chlorinated solvent-contaminated sites. Research at numerous chlorinated solvent sites indicates an active dechlorinating microbial population coupled with an ample supply of organic carbon are conditions needed to sustain reductive dechlorination. A series of extraction experiments was used to compare the ability of the different extractants to remove organic carbon from aquifer sediments. The different extractants included pyrophosphate, sodium hydroxide, and polished water. Pyrophosphate served as a mild extractant that minimally alters the organic structure of the extracted material. Three concentrations (0.1, 0.5, and 1%) of pyrophosphate extracted 18.8, 24.9, and 30.8% of sediment organic carbon, respectively. Under alkali conditions (0.5 N NaOH), which provided the harshest extractant, 30.7% of the sediment organic carbon was recovered. Amorphous organic carbon, measured by potassium persulfate oxidization, consisted of 44.6% of the sediment organic carbon and served as a baseline control for maximum carbon removal. Conversely, highly purified water provided a minimal extraction control and extracted 5.7% of the sediment organic carbon. The removal of organic carbon was quantified by aqueous TOC in the extract and residual sediment organic carbon content. Characterization of the organic carbon extracts by compositional analysis prior and after exposure to the mixed culture might indicate the type organic carbon and functional groups used and/or generated by the organisms. This is an abstract of a paper presented at the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

Magnetic Graphene Nanosheet-Based Microfluidic Device for Homogeneous Real-Time Electronic Monitoring of Pyrophosphatase Activity Using Enzymatic Hydrolysate-Induced Release of Copper Ion.

PubMed

Lin, Youxiu; Zhou, Qian; Li, Juan; Shu, Jian; Qiu, Zhenli; Lin, Yuping; Tang, Dianping

2016-01-05

A novel flow-through microfluidic device based on a magneto-controlled graphene sensing platform was designed for homogeneous electronic monitoring of pyrophosphatase (PPase) activity; enzymatic hydrolysate-induced release of inorganic copper ion (Cu(2+)) from the Cu(2+)-coordinated pyrophosphate ions (Cu(2+)-PPi) complex was assessed to determine enzyme activity. Magnetic graphene nanosheets (MGNS) functionalized with negatively charged Nafion were synthesized by using the wet-chemistry method. The Cu(2+)-PPi complexes were prepared on the basis of the coordination reaction between copper ion and inorganic pyrophosphate ions. Upon target PPase introduction into the detection system, the analyte initially hydrolyzed pyrophosphate ions into phosphate ions and released the electroactive copper ions from Cu(2+)-PPi complexes. The released copper ions could be readily captured through the negatively charged Nafion on the magnetic graphene nanosheets, which could be quantitatively monitored by using the stripping voltammetry on the flow-through detection cell with an external magnet. Under optimal conditions, the obtained electrochemical signal exhibited a high dependence on PPase activity within a dynamic range from 0.1 to 20 mU mL(-1) and allowed the detection at a concentration as low as 0.05 mU mL(-1). Coefficients of variation for reproducibility of the intra-assay and interassay were below 7.6 and 9.8%, respectively. The inhibition efficiency of sodium fluoride (NaF) also received good results in pyrophosphatase inhibitor screening research. In addition, the methodology afforded good specificity and selectivity, simplification, and low cost without the need of sample separations and multiple washing steps, thus representing a user-friendly protocol for practical utilization in a quantitative PPase activity.

The association of uranium with organic matter in Holocene peat: An experimental leaching study

USGS Publications Warehouse

Zielinski, R.A.; Meier, A.L.

1988-01-01

Uraniferous peat was sampled from surface layers of a Holocene U deposit in northeastern Washington State. Dried, sized, and homogenized peat that contained 5980 ??307 ppm U was subjected to a variety of leaching conditions to determine the nature and strength of U-organic bonding in recently accumulated organic matter. The results complement previous experimental studies of U uptake on peat and suggest some natural or anthropogenic disturbances that are favorable for remobilizing U. The fraction of U leached in 24 h experiments at 25??C ranged from 0 to 95%. The most effective leach solutions contained anions capable of forming stable dissolved complexes with uranyl (UO2+2) cation. These included H2SO4 (pH = 1.5) and concentrated (>0.01 M) solutions of sodium bicarbonate-carbonate (pH = 7.0-10.0), or sodium pyrophosphate (pH = 10). Effective leaching by carbonate and pyrophosphate in the absence of added oxidant, and the insignificant effect of added oxidant (as pressurized O2) strongly suggest that U is initially fixed on organic matter as an oxidized U(VI) species. Uranium is more strongly bound than some other polyvalent cations, based on its resistance to exchange in the presence of large excesses of dissolved Ca2+ and Cu2+. Measurements of the rate of U leaching indicate faster rates in acid solution compared to carbonate solution, and are consisten with simultaneous attack of sites with different affinities for U. Sulfuric acid appears a good choice for commercial extraction of U from mined peat. In situ disturbances such as overliming of peat soils, addition of fertilizers containing pyrophosphate, or incursions of natural carbonate-rich waters could produce significant remobilization of U, and possibly compromise the quality of local domestic water supplies. ?? 1988.

Effect of pyrophosphate ions on the conversion of calcium-lithium-borate glass to hydroxyapatite in aqueous phosphate solution.

PubMed

Fu, Hailuo; Rahaman, Mohamed N; Day, Delbert E; Huang, Wenhai

2010-10-01

The conversion of glass to a hydroxyapatite (HA) material in an aqueous phosphate solution is used as an indication of the bioactive potential of the glass, as well as a low temperature route for preparing biologically useful materials. In this work, the effect of varying concentrations of pyrophosphate ions in the phosphate solution on the conversion of a calcium-lithium-borate glass to HA was investigated. Particles of the glass (150-355 μm) were immersed for up to 28 days in 0.25 M K(2)HPO(4) solution containing 0-0.1 M K(4)P(2)O(7). The kinetics of degradation of the glass particles and their conversion to HA were monitored by measuring the weight loss of the particles and the ionic concentration of the solution. The structure and composition of the conversion products were analyzed using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. For K(4)P(2)O(7) concentrations of up to 0.01 M, the glass particles converted to HA, but the time for complete conversion increased from 2 days (no K(4)P(2)O(7)) to 10 days (0.01 M K(4)P(2)O(7)). When the K(4)P(2)O(7) concentration was increased to 0.1 M, the product consisted of an amorphous calcium phosphate material, which eventually crystallized to a pyrophosphate product (predominantly K(2)CaP(2)O(7) and Ca(2)P(2)O(7)). The consequences of the results for the formation of HA materials and devices by the glass conversion route are discussed.

Effect of pyrophosphate ions on the conversion of calcium–lithium–borate glass to hydroxyapatite in aqueous phosphate solution

PubMed Central

Fu, Hailuo; Day, Delbert E.; Huang, Wenhai

2010-01-01

The conversion of glass to a hydroxyapatite (HA) material in an aqueous phosphate solution is used as an indication of the bioactive potential of the glass, as well as a low temperature route for preparing biologically useful materials. In this work, the effect of varying concentrations of pyrophosphate ions in the phosphate solution on the conversion of a calcium–lithium–borate glass to HA was investigated. Particles of the glass (150–355 µm) were immersed for up to 28 days in 0.25 M K2HPO4 solution containing 0–0.1 M K4P2O7. The kinetics of degradation of the glass particles and their conversion to HA were monitored by measuring the weight loss of the particles and the ionic concentration of the solution. The structure and composition of the conversion products were analyzed using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. For K4P2O7 concentrations of up to 0.01 M, the glass particles converted to HA, but the time for complete conversion increased from 2 days (no K4P2O7) to 10 days (0.01 M K4P2O7). When the K4P2O7 concentration was increased to 0.1 M, the product consisted of an amorphous calcium phosphate material, which eventually crystallized to a pyrophosphate product (predominantly K2CaP2O7 and Ca2P2O7). The consequences of the results for the formation of HA materials and devices by the glass conversion route are discussed. PMID:20680413

Fluorometric determination of the activity of alkaline phosphatase based on the competitive binding of gold nanoparticles and pyrophosphate to CePO4:Tb nanorods.

PubMed

Xu, Ai-Zhen; Zhang, Li; Zeng, Hui-Hui; Liang, Ru-Ping; Qiu, Jian-Ding

2018-05-09

A fluorometric method is described for the determination of the activity of alkaline phosphatase (ALP). It relies on the competition between gold nanoparticles (AuNPs) and pyrophosphate (PPi) for the coordination sites on the surface of CePO 4 :Tb nanorods. The green fluorescence of the CePO 4 :Tb is reduced in the presence of AuNPs due to fluorescence resonance energy transfer (FRET), but can be restored on addition of PPi due to the stronger affinity of PPi to the CePO 4 :Tb. In the presence of ALP, PPi is hydrolyzed to form phosphate which has much weaker affinity for the CePO 4 :Tb. Hence, the AuNPs will reassemble on the CePO 4 :Tb, and fluorescence is reduced. Fluorescence drops linearly in the 0.2 to 100 U·L -1 activity range, and the detection limit is 60 mU·L -1 (at S/N = 3). The method does not require any modification of the surface of the CePO 4 :Tb and is highly sensitive and selective. The inhibition of ALP activity by Na 3 VO 4 was also studied. In our perception, the method may find application in the diagnosis of ALP-related diseases, in screening for inhibitors, and in studies on ALP-related functions in biological systems. Graphical abstract A assay for the detection of alkaline phosphatase is proposed based on the fluorescence resonance energy transfer between CePO 4 :Tb and AuNPs. It relies on the competitive binding of AuNPs and pyrophosphate (PPi) to CePO 4 :Tb and the hydrolysis of PPi by ALP.

Binding of uridine 5'-diphosphate in the "basic patch" of the zinc deacetylase LpxC and implications for substrate binding.

PubMed

Gennadios, Heather A; Christianson, David W

2006-12-26

LpxC is a zinc metalloenzyme that catalyzes the first committed step in the biosynthesis of lipid A, a vital component of the outer membrane of Gram-negative bacteria. Accordingly, the inhibition of LpxC is an attractive strategy for the treatment of Gram-negative bacterial infections. Here, we report the 2.7 A resolution X-ray crystal structure of LpxC from Aquifex aeolicus complexed with uridine 5'-diphosphate (UDP), and the 3.1 A resolution structure of LpxC complexed with pyrophosphate. The X-ray crystal structure of the LpxC-UDP complex provides the first view of interactions likely to be exploited by the substrate UDP group in the "basic patch" of the active site. The diphosphate group of UDP makes hydrogen bond interactions with strictly conserved residue K239 as well as solvent molecules. The ribose moiety of UDP interacts with partially conserved residue E197. The UDP uracil group hydrogen bonds with both the backbone NH group and the backbone carbonyl group of E160, and with the backbone NH group of K162 through an intervening water molecule. Finally, the alpha-phosphate and uracil groups of UDP interact with R143 and R262 through intervening water molecules. The structure of LpxC complexed with pyrophosphate reveals generally similar intermolecular interactions in the basic patch. Unexpectedly, diphosphate binding in both complexes is accompanied by coordination to an additional zinc ion, resulting in the identification of a new metal-binding site termed the E-site. The structures of the LpxC-UDP and LpxC-pyrophosphate complexes provide new insights with regard to substrate recognition in the basic patch and metal ion coordination in the active site of LpxC.

A bicistronic transgene system for genetic modification of Parthenium argentatum

USDA-ARS?s Scientific Manuscript database

Parthenium argentatum (guayule) was transformed with a bicistronic transgene containing a viral 2A cleavage sequence. The transgene includes the coding sequences of two key enzymes of the mevalonate pathway, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and farnesyl pyrophosphate synthase (FPPS), ...

Functions of maize genes encoding pyruvate phosphate dikinase in developing endosperm

USDA-ARS?s Scientific Manuscript database

Pyruvate phosphate dikinase reversibly converts AMP, pyrophosphate and phosphoenolpyruvate (PEP) to ATP, orthophosphate and pyruvate. Maize PPDK functions in mesophyll in C4 photosynthesis, yet also is highly abundant in starchy endosperm during grain fill where its function is unknown. To investiga...

21 CFR 137.180 - Self-rising flour.

Code of Federal Regulations, 2011 CFR

2011-04-01

... acid-reacting substances monocalcium phosphate, sodium acid pyrophosphate, and sodium aluminum... section not less than 0.5 percent of carbon dioxide is evolved. The acid-reacting substance is added in sufficient quantity to neutralize the sodium bicarbonate. The combined weight of such acid-reacting substance...

21 CFR 137.180 - Self-rising flour.

Code of Federal Regulations, 2014 CFR

2014-04-01

... acid-reacting substances monocalcium phosphate, sodium acid pyrophosphate, and sodium aluminum... section not less than 0.5 percent of carbon dioxide is evolved. The acid-reacting substance is added in sufficient quantity to neutralize the sodium bicarbonate. The combined weight of such acid-reacting substance...

21 CFR 137.180 - Self-rising flour.

Code of Federal Regulations, 2013 CFR

2013-04-01

... acid-reacting substances monocalcium phosphate, sodium acid pyrophosphate, and sodium aluminum... section not less than 0.5 percent of carbon dioxide is evolved. The acid-reacting substance is added in sufficient quantity to neutralize the sodium bicarbonate. The combined weight of such acid-reacting substance...

21 CFR 137.180 - Self-rising flour.

Code of Federal Regulations, 2012 CFR

2012-04-01

... acid-reacting substances monocalcium phosphate, sodium acid pyrophosphate, and sodium aluminum... section not less than 0.5 percent of carbon dioxide is evolved. The acid-reacting substance is added in sufficient quantity to neutralize the sodium bicarbonate. The combined weight of such acid-reacting substance...

Functional specialization of one copy of glutamine phosphoribosyl pyrophosphate amidotransferase in ureide production from symbiotically fixed nitrogen in Phaseolus vulgaris.

PubMed

Coleto, Inmaculada; Trenas, Almudena T; Erban, Alexander; Kopka, Joachim; Pineda, Manuel; Alamillo, Josefa M

2016-08-01

Purines are essential molecules formed in a highly regulated pathway in all organisms. In tropical legumes, the nitrogen fixed in the nodules is used to generate ureides through the oxidation of de novo synthesized purines. Glutamine phosphoribosyl pyrophosphate amidotransferase (PRAT) catalyses the first committed step of de novo purine synthesis. In Phaseolus vulgaris there are three genes coding for PRAT. The three full-length sequences, which are intron-less genes, were cloned, and their expression levels were determined under conditions that affect the synthesis of purines. One of the three genes, PvPRAT3, is highly expressed in nodules and protein amount and enzymatic activity in these tissues correlate with nitrogen fixation activity. Inhibition of PvPRAT3 gene expression by RNAi-silencing and subsequent metabolomic analysis of the transformed roots shows that PvPRAT3 is essential for the synthesis of ureides in P. vulgaris nodules. © 2016 John Wiley & Sons Ltd.

Inositol pyrophosphates mediate the DNA-PK/ATM-p53 cell death pathway by regulating CK2 phosphorylation of Tti1/Tel2

PubMed Central

Rao, Feng; Cha, Jiyoung; Xu, Jing; Xu, Risheng; Vandiver, M. Scott; Tyagi, Richa; Tokhunts, Robert; Koldobskiy, Michael A.; Fu, Chenglai; Barrow, Roxanne; Wu, Mingxuan; Fiedler, Dorothea; Barrow, James C.; Snyder, Solomon H.

2014-01-01

The apoptotic actions of p53 require its phosphorylation by a family of phosphoinositide-3-kinase-related-kinases (PIKKs), which include DNA-PKcs and ATM. These kinases are stabilized by the TTT (Tel2, Tti1, Tti2) co-chaperone family, whose actions are mediated by CK2 phosphorylation. The inositol pyrophosphates, such as 5-diphosphoinositol pentakisphosphate (IP7), are generated by a family of inositol hexakisphosphate kinases (IP6Ks) of which IP6K2 has been implicated in p53-associated cell death. In the present study we report a novel apoptotic signaling cascade linking CK2, TTT, the PIKKs, and p53. We demonstrate that IP7, formed by IP6K2, binds CK2 to enhance its phosphorylation of the TTT complex thereby stabilizing DNA-PKcs and ATM. This process stimulates p53 phosphorylation at serine-15 to activate the cell death program in human cancer cells and in murine B cells. PMID:24657168

The Conservation of Structure and Mechanism of Catalytic Action in a Family of Thiamin Pyrophosphate (TPP)-dependent Enzymes

NASA Technical Reports Server (NTRS)

Dominiak, P.; Ciszak, Ewa

2004-01-01

Thiamin pyrophosphate (TPP)-dependent enzymes are a divergent family of TPP and metal ion binding proteins that perform a wide range of functions with the common decarboxylation steps of a -(O=)C-C(OH)- fragment of alpha-ketoacids and alpha- hydroxyaldehydes. To determine how structure and catalytic action are conserved in the context of large sequence differences existing within this family of enzymes, we have carried out an analysis of TPP-dependent enzymes of known structures. The common structure of TPP-dependent enzymes is formed at the interface of four alpha/beta domains from at least two subunits, which provide for two metal and TPP-binding sites. Residues around these catalytic sites are conserved for functional purpose, while those further away from TPP are conserved for structural reasons. Together they provide a network of contacts required for flip-flop catalytic action within TPP-dependent enzymes. Thus our analysis defines a TPP-action motif that is proposed for annotating TPP-dependent enzymes for advancing functional proteomics.

Novel ANKH Amino Terminus Mutation (Pro5Ser) Associated With Early-Onset Calcium Pyrophosphate Disease With Associated Phosphaturia

PubMed Central

Gruber, Barry L.; Couto, Ana Rita; Armas, Jácome Bruges; Brown, Matthew A.; Finzel, Kathleen; Terkeltaub, Robert A.

2015-01-01

This report describes a 32-year-old woman presenting since childhood with progressive calcium pyrophosphate disease (CPPD), characterized by severe arthropathy and chondrocalcinosis involving multiple peripheral joints and intervertebral disks. Because ANKH mutations have been previously described in familial CPPD, the proband’s DNA was assessed at this locus by direct sequencing of promoter and coding regions and revealed 3 sequence variants in ANKH. Sequences of exon 1 revealed a novel isolated nonsynonymous mutation (c.13 C>T), altering amino acid in codon 5 from proline to serine (CCG>TCG). Sequencing of parental DNA revealed an identical mutation in the proband’s father but not the mother. Subsequent clinical evaluation demonstrated extensive chondrocalcinosis and degenerative arthropathy in the proband’s father. In summary, we report a novel mutation, not previously described, in ANKH exon 1, wherein serine replaces proline, in a case of early-onset severe CPPD associated with metabolic abnormalities, with similar findings in the proband’s father. PMID:22647861

Novel phosphate-activated macrophages prevent ectopic calcification by increasing extracellular ATP and pyrophosphate

PubMed Central

Villa-Bellosta, Ricardo; Hamczyk, Magda R.; Andrés, Vicente

2017-01-01

Purpose Phosphorus is an essential nutrient involved in many pathobiological processes. Less than 1% of phosphorus is found in extracellular fluids as inorganic phosphate ion (Pi) in solution. High serum Pi level promotes ectopic calcification in many tissues, including blood vessels. Here, we studied the effect of elevated Pi concentration on macrophage polarization and calcification. Macrophages, present in virtually all tissues, play key roles in health and disease and display remarkable plasticity, being able to change their physiology in response to environmental cues. Methods and results High-throughput transcriptomic analysis and functional studies demonstrated that Pi induces unpolarized macrophages to adopt a phenotype closely resembling that of alternatively-activated M2 macrophages, as revealed by arginine hydrolysis and energetic and antioxidant profiles. Pi-induced macrophages showed an anti-calcifying action mediated by increased availability of extracellular ATP and pyrophosphate. Conclusion We conclude that the ability of Pi-activated macrophages to prevent calcium-phosphate deposition is a compensatory mechanism protecting tissues from hyperphosphatemia-induced pathologic calcification. PMID:28362852

Cellular Cations Control Conformational Switching of Inositol Pyrophosphate Analogues

PubMed Central

Hager, Anastasia; Wu, Mingxuan; Wang, Huanchen; Brown, Nathaniel W.; Shears, Stephen B.

2016-01-01

The inositol pyrophosphate messengers (PP-InsPs) are emerging as an important class of cellular regulators. These molecules have been linked to numerous biological processes, including insulin secretion and cancer cell migration, but how they trigger such a wide range of cellular responses has remained unanswered in many cases. Here, we show that the PP-InsPs exhibit complex speciation behaviour and propose that a unique conformational switching mechanism could contribute to their multifunctional effects. We synthesised non-hydrolysable bisphosphonate analogues and crystallised the analogues in complex with mammalian PPIP5K2 kinase. Subsequently, the bisphosphonate analogues were used to investigate the protonation sequence, metal-coordination properties, and conformation in solution. Remarkably, the presence of potassium and magnesium ions enabled the analogues to adopt two different conformations near physiological pH. Understanding how the intrinsic chemical properties of the PP-InsPs can contribute to their complex signalling outputs will be essential to elucidate their regulatory functions. PMID:27460418

Iron and Manganese Pyrophosphates as Cathodes for Lithium-Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Hui; Upreti, Shailesh; Chernova, Natasha A.

2015-10-15

The mixed-metal phases, (Li{sub 2}Mn{sub 1-y}Fe{sub y}P{sub 2}O{sub 7}, 0 {le} y {le} 1), were synthesized using a 'wet method', and found to form a solid solution in the P2{sub 1}/a space group. Both thermogravimetric analysis and magnetic susceptibility measurements confirm the 2+ oxidation state for both the Mn and Fe. The electrochemical capacity improves as the Fe concentration increases, as do the intensities of the redox peaks of the cyclic voltammogram, indicating higher lithium-ion diffusivity in the iron phase. The two Li{sup +} ions in the three-dimensional tunnel structure of the pyrophosphate phase allows for the cycling of moremore » than one lithium per redox center. Cyclic voltammograms show a second oxidation peak at 5 V and 5.3 V, indicative of the extraction of the second lithium ion, in agreement with ab initio computation predictions. Thus, electrochemical capacities exceeding 200 Ah/kg may be achieved if a stable electrolyte is found.« less

Novel ANKH amino terminus mutation (Pro5Ser) associated with early-onset calcium pyrophosphate disease with associated phosphaturia.

PubMed

Gruber, Barry L; Couto, Ana Rita; Armas, Jácome Bruges; Brown, Matthew A; Finzel, Kathleen; Terkeltaub, Robert A

2012-06-01

This report describes a 32-year-old woman presenting since childhood with progressive calcium pyrophosphate disease (CPPD), characterized by severe arthropathy and chondrocalcinosis involving multiple peripheral joints and intervertebral disks. Because ANKH mutations have been previously described in familial CPPD, the proband's DNA was assessed at this locus by direct sequencing of promoter and coding regions and revealed 3 sequence variants in ANKH. Sequences of exon 1 revealed a novel isolated nonsynonymous mutation (c.13 C>T), altering amino acid in codon 5 from proline to serine (CCG>TCG). Sequencing of parental DNA revealed an identical mutation in the proband's father but not the mother. Subsequent clinical evaluation demonstrated extensive chondrocalcinosis and degenerative arthropathy in the proband's father. In summary, we report a novel mutation, not previously described, in ANKH exon 1, wherein serine replaces proline, in a case of early-onset severe CPPD associated with metabolic abnormalities, with similar findings in the proband's father.

Waffle production: influence of batter ingredients on sticking of waffles at baking plates-Part II: effect of fat, leavening agent, and water.

PubMed

Huber, Regina; Schoenlechner, Regine

2017-05-01

Fresh egg waffles are continuously baked in tunnel baking ovens in industrial scale. Waffles that partly or fully stick to the baking plates cause significant product loss and increased costs. The aim of this study was, therefore, to investigate the effect of different recipe ingredients on the sticking behavior of waffles. In this second part, ingredients investigated were different leavening agents (sodium acid pyrophosphate, ammonium bicarbonate, magnesium hydroxide carbonate, or monocalcium phosphate), different fat sources (rapeseed oil, cocos fat, butter, or margarine), and different water sources (tap water 12°dH and distilled water). Within the different types of fats, solid fats with high amount of short-chain fatty acids (cocos fat or butter) decreased the number of sticking waffles compared to liquid oils (rapeseed oil). Regarding leavening agents, magnesium hydroxide carbonate and ammonium bicarbonate were superior to sodium acid pyrophosphate or monocalcium phosphate. Between the two water sources, effects were small.

A Phosphoenzyme Mimic, Overlapping Catalytic Sites and Reaction Coordinate Motion for Human NAMPT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burgos, E.; Ho, M; Almo, S

2009-01-01

Nicotinamide phosphoribosyltransferase (NAMPT) is highly evolved to capture nicotinamide (NAM) and replenish the nicotinamide adenine dinucleotide (NAD+) pool during ADP-ribosylation and transferase reactions. ATP-phosphorylation of an active-site histidine causes catalytic activation, increasing NAM affinity by 160,000. Crystal structures of NAMPT with catalytic site ligands identify the phosphorylation site, establish its role in catalysis, demonstrate unique overlapping ATP and phosphoribosyltransferase sites, and establish reaction coordinate motion. NAMPT structures with beryllium fluoride indicate a covalent H247-BeF3- as the phosphohistidine mimic. Activation of NAMPT by H247-phosphorylation causes stabilization of the enzyme-phosphoribosylpyrophosphate complex, permitting efficient capture of NAM. Reactant and product structures establish reactionmore » coordinate motion for NAMPT to be migration of the ribosyl anomeric carbon from the pyrophosphate leaving group to the nicotinamide-N1 while the 5-phosphoryl group, the pyrophosphate moiety, and the nicotinamide ring remain fixed in the catalytic site.« less

Mechanism of Mg2+-Accompanied Product Release in Sugar Nucleotidyltransferases.

PubMed

Vithani, Neha; Ankush Jagtap, Pravin Kumar; Verma, Sunil Kumar; Tripathi, Ravi; Awasthi, Shalini; Nair, Nisanth N; Prakash, Balaji

2018-03-06

The nucleotidyl transfer reaction, catalyzed by sugar nucleotidyltransferases (SNTs), is assisted by two active site Mg 2+ ions. While studying this reaction using X-ray crystallography, we captured snapshots of the pyrophosphate (product) as it exits along a pocket. Surprisingly, one of the active site Mg 2+ ions remains coordinated to the exiting pyrophosphate. This hints at the participation of Mg 2+ in the process of product release, besides its role in catalyzing nucleotidyl transfer. These observations are further supported by enhanced sampling molecular dynamics simulations. Free energy computations suggest that the product release is likely to be rate limiting in SNTs, and the origin of the high free energy barrier for product release could be traced back to the "slow" conformational change of an Arg residue at the exit end of the pocket. These results establish a dual role for Mg 2+ , and propose a general mechanism of product release during the nucleotidyl transfer by SNTs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reversible changes in size of cell nuclei isolated from Amoeba proteus: role of the cytoskeleton.

PubMed

Pomorski, P; Grebecka, L; Grebecki, A; Makuch, R

2000-01-01

Micrurgically isolated interphasal nuclei of Amoeba proteus, which preserve F-actin cytoskeletal shells on their surface, shrink after perfusion with imidazole buffer without ATP, and expand to about 200% of their cross-sectional area upon addition of pyrophosphate. These changes in size may be reproduced several times with the same nucleus. The shrunken nuclei are insensitive to the osmotic effects of sugars and distilled water, whereas the expanded ones react only to the distilled water, showing further swelling. The shrinking-expansion cycles are partially inhibited by cytochalasins. They are attributed to the state of actomyosin complex in the perinuclear cytoskeleton, which is supposed to be in the rigor state in the imidazole buffer without ATP, and to dissociate in the presence of pyrophosphate. Inflow of external medium to the nuclei during dissociation of the myosin from the perinuclear F-actin may be due to colloidal osmosis depending on other macromolecular components of the karyoplasm.

Effects of Humic Acids Isolated from Peat of Various Origin on in Vitro Production of Nitric Oxide: a Screening Study.

PubMed

Trofimova, E S; Zykova, M V; Ligacheva, A A; Sherstoboev, E Yu; Zhdanov, V V; Belousov, M V; Yusubov, M S; Krivoshchekov, S V; Danilets, M G; Dygai, A M

2016-09-01

A screening study of biological activity of native humic acids isolated from peat was performed; several physical and chemical parameters of their structures were studied by UV- and infrared spectroscopy. Spectroscopy yielded similar shape of light absorption curves of humic acids of different origin, which can reflect similarity of general structural principles of these substances. Alkaline humic acids have more developed system of polyconjugation, while molecular structures of pyrophosphate humic acids were characterized by higher aromaticity and condensation indexes. Biological activity of the studied humic acids was assessed by NO-stimulating capacity during their culturing with murine peritoneal macrophages in a wide concentration range. It was shown that due to dose-dependent enhancement of NO production humic acids can change the functional state of macrophages towards development of pro-inflammatory properties. These changes were associated with high activity of humic acids isolated by pyrophosphate extraction, which allows considering effects of isolation method on biological activity.

High-resolution structures of Lactobacillus salivarius transketolase in the presence and absence of thiamine pyrophosphate.

PubMed

Lukacik, Petra; Lobley, Carina M C; Bumann, Mario; Arena de Souza, Victoria; Owens, Raymond J; O'Toole, Paul W; Walsh, Martin A

2015-10-01

Probiotic bacterial strains have been shown to enhance the health of the host through a range of mechanisms including colonization, resistance against pathogens, secretion of antimicrobial compounds and modulation of the activity of the innate immune system. Lactobacillus salivarius UCC118 is a well characterized probiotic strain which survives intestinal transit and has many desirable host-interaction properties. Probiotic bacteria display a wide range of catabolic activities, which determine their competitiveness in vivo. Some lactobacilli are heterofermentative and can metabolize pentoses, using a pathway in which transketolase and transaldolase are key enzymes. L. salivarius UCC118 is capable of pentose utilization because it encodes the key enzymes on a megaplasmid. The crystal structures of the megaplasmid-encoded transketolase with and without the enzyme cofactor thiamine pyrophosphate have been determined. Comparisons with other known transketolase structures reveal a high degree of structural conservation in both the catalytic site and the overall conformation. This work extends structural knowledge of the transketolases to the industrially and commercially important Lactobacillus genus.

Electrochemical Formation of Multilayer SnO2-Sb x O y Coating in Complex Electrolyte

NASA Astrophysics Data System (ADS)

Maizelis, Antonina; Bairachniy, Boris

2017-02-01

The multilayer antimony-doped tin dioxide coating was obtained by cathodic deposition of multilayer metal-hydroxide coating with near 100-nm thickness layers on the alloy underlayer accompanied by the anodic oxidation of this coating. The potential regions of deposition of tin, antimony, tin-antimony alloy, and mixture of this metals and their hydroxides in the pyrophosphate-tartrate electrolyte were revealed by the cyclic voltammetric method. The possibility of oxidation of cathodic deposit consisting of tin and Sn(II) hydroxide compounds to the hydrated tin dioxide in the same electrolyte was demonstrated. The operations of alloy underlayer deposition and oxidation of multilayer metal-hydroxide coating were proposed to carry out in the diluted pyrophosphate-tartrate electrolyte, similar to the main electrolyte. The accelerated tests showed higher service life of the titanium electrode with multilayer antimony-doped tin dioxide coating compared to both electrode with single-layer electrodeposited coating and the electrode with the coating obtained using prolonged heat treatment step.

Electrochemical Formation of Multilayer SnO2-Sb x O y Coating in Complex Electrolyte.

PubMed

Maizelis, Antonina; Bairachniy, Boris

2017-12-01

The multilayer antimony-doped tin dioxide coating was obtained by cathodic deposition of multilayer metal-hydroxide coating with near 100-nm thickness layers on the alloy underlayer accompanied by the anodic oxidation of this coating. The potential regions of deposition of tin, antimony, tin-antimony alloy, and mixture of this metals and their hydroxides in the pyrophosphate-tartrate electrolyte were revealed by the cyclic voltammetric method. The possibility of oxidation of cathodic deposit consisting of tin and Sn(II) hydroxide compounds to the hydrated tin dioxide in the same electrolyte was demonstrated.The operations of alloy underlayer deposition and oxidation of multilayer metal-hydroxide coating were proposed to carry out in the diluted pyrophosphate-tartrate electrolyte, similar to the main electrolyte.The accelerated tests showed higher service life of the titanium electrode with multilayer antimony-doped tin dioxide coating compared to both electrode with single-layer electrodeposited coating and the electrode with the coating obtained using prolonged heat treatment step.

The functional analyses of the cis-prenyltransferase and the rubber elongation factor in rubber biosynthesis

USDA-ARS?s Scientific Manuscript database

Natural rubber (cis-1,4-polyisoprene) is an essential plant derived commodity required for the manufacture of numerous industrial, medical and household items. Rubber is synthesized and sequestered on cytsolic vesicles known as rubber particles. When provided with farnesyl pyrophosphate (FPP) and is...

Fusion proteins useful for producing pinene

DOEpatents

Peralta-Yahya, Pamela P.; Keasling, Jay D

2016-06-28

The present invention provides for a modified host cell comprising a heterologous pinene synthase (PS), or enzymatically active fragment or variant thereof, and optionally a geranyl pyrophosphate synthase (GPPS), or enzymatically active fragment or variant thereof, or a fusion protein comprising: (a) a PS and (b) a GPPS linked by a linker.

[Regulation of terpene metabolism]. [Mentha piperita, Mentha spicata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croteau, R.

1989-01-01

Progress in understanding of the metabolism of monoterpenes by peppermint and spearmint is recorded including the actions of two key enzymes, geranyl pyrophosphate:limonene cyclase and a UDP-glucose dependent glucosyl transferase; concerning the ultrastructure of oil gland senescence; enzyme subcellular localization; regulation of metabolism; and tissue culture systems.

THE SYNTHESIS OF LEAD PYROPHOSPHATE, PB2P2O7, IN WATER

EPA Science Inventory

Polyphosphates are used in the drinking water to prevent the precipitation of cations such as calcium and iron. The possible negative impact of using polyphosphates is the undesirable complexation of lead which could result in elevated lead levels in consumer’s tap water. Altho...

Terpenoids and Their Biosynthesis in Cyanobacteria

PubMed Central

Pattanaik, Bagmi; Lindberg, Pia

2015-01-01

Terpenoids, or isoprenoids, are a family of compounds with great structural diversity which are essential for all living organisms. In cyanobacteria, they are synthesized from the methylerythritol-phosphate (MEP) pathway, using glyceraldehyde 3-phosphate and pyruvate produced by photosynthesis as substrates. The products of the MEP pathway are the isomeric five-carbon compounds isopentenyl diphosphate and dimethylallyl diphosphate, which in turn form the basic building blocks for formation of all terpenoids. Many terpenoid compounds have useful properties and are of interest in the fields of pharmaceuticals and nutrition, and even potentially as future biofuels. The MEP pathway, its function and regulation, and the subsequent formation of terpenoids have not been fully elucidated in cyanobacteria, despite its relevance for biotechnological applications. In this review, we summarize the present knowledge about cyanobacterial terpenoid biosynthesis, both regarding the native metabolism and regarding metabolic engineering of cyanobacteria for heterologous production of non-native terpenoids. PMID:25615610

Prenylated chalcones, flavone and other constituents of the twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis.

PubMed

Ngadjui, Bonaventure T; Watchueng, Jean; Keumedjio, Felix; Ngameni, Bathélémy; Simo, Ingrid K; Abegaz, Berhanu M

2005-03-01

The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,5'-di-(2-hydroxy-3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone, 3, 4-(2,2-dimethylpyrano)-3'-(2-hydroxy-3-methylbut-3-enyl)-2',4'-dihydroxychalcone and the known stipulin were isolated from both species. 3-(2-Hydroxy-3-methylbut-3-enyl)-5'-(3,3-dimethylallyl)-4,2',4'-trihydroxychalcone and the known compounds: 4-hydroxylonchocarpin, kanzonol B, bartericins A, B, C and 3'-(2-hydroxy -3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone were isolated from D. barteri while the known compounds: gancaonin Q, paratocarpins C, F, and lupeol were obtained from Dorstenia angusticornis. beta-Sitosterol and its beta-d-glucopyranoside were isolated from both species. Structures of these secondary metabolites were established using spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC.

Structural characterization of rubber from jackfruit and euphorbia as a model of natural rubber.

PubMed

Mekkriengkrai, Dararat; Ute, Koiichi; Swiezewska, Ewa; Chojnacki, Tadeusz; Tanaka, Yasuyuki; Sakdapipanich, Jitladda T

2004-01-01

A structural study of low molecular weight rubbers from Jackfruit (Artocarpus heterophyllus) and Painted spurge (Euphorbia heterophylla) was carried out as model compounds of natural rubber from Hevea brasiliensis. The rubber content of latex from Jackfruit was 0.4-0.7%, which is very low compared with that of 30-35% in the latex from Hevea tree. The rubber from Jackfruit latex was low molecular weight with narrow unimodal molecular weight distribution (MWD), whereas that obtained from E. heterophylla showed very broad MWD. The 1H and 13C NMR analyses showed that Jackfruit rubber consists of a dimethylallyl group and two trans-isoprene units connected to a long sequence of cis-isoprene units. The alpha-terminal group of Jackfruit rubber was presumed to be composed of a phosphate group based on the presence of 1H NMR signal at 4.08 ppm corresponding to the terminal =CH-CH2OP group.

21 CFR 184.1304 - Ferric pyrophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... reference. Copies are available from the National Academy Press, 2101 Constitution Ave. NW., Washington, DC.../federal_register/code_of_federal_regulations/ibr_locations.html. (c) In accordance with § 184.1(b)(1), the... in accordance with section 412(g) of the Federal Food, Drug, and Cosmetic Act (the act) (21 U.S.C...

21 CFR 184.1304 - Ferric pyrophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... reference. Copies are available from the National Academy Press, 2101 Constitution Ave. NW., Washington, DC.../federal_register/code_of_federal_regulations/ibr_locations.html. (c) In accordance with § 184.1(b)(1), the... in accordance with section 412(g) of the Federal Food, Drug, and Cosmetic Act (the act) (21 U.S.C...

The effect of Mg/2+/ and Ca/2+/ on urea-catalyzed phosphorylation reactions

NASA Technical Reports Server (NTRS)

Handschuk, G. J.; Lohrmann, R.; Orgel, L. E.

1973-01-01

The effect of Mg(2+) and Ca(2+) on phosphorylation reactions catalyzed by urea is investigated, showing that Mg(2+) improves markedly the yield of products containing pyrophosphate bonds. Yields of up to 25% of uridine diphosphate can be obtained with struvite at temperatures as low as 65 C.

Investigation of Tin as a Constituent of Inorganic Coatings for Magnesium Alloys

DTIC Science & Technology

1975-05-01

WORDS (Continue on revete side if neceeeary and identify by block number) Inorganic Coatings Coatings for Magnesium Tin Magnesium Corrosion PR suaJEC...stannous pyrophosphate 10 grams dextrine water to one (1) liter (1) White, E.L. and F.W. Fink Corrosion protection of Magnesium and Magnesium alloys

[Regulation of terpene metabolism]. Annual progress report, March 15, 1988--March 14, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croteau, R.

1989-12-31

Progress in understanding of the metabolism of monoterpenes by peppermint and spearmint is recorded including the actions of two key enzymes, geranyl pyrophosphate:limonene cyclase and a UDP-glucose dependent glucosyl transferase; concerning the ultrastructure of oil gland senescence; enzyme subcellular localization; regulation of metabolism; and tissue culture systems.

Investigation into the Physiological Significance of the Phytohormone Abscisic Acid in Perkinsus marinus, an Oyster Parasite Harboring a Nonphotosynthetic Plastid.

PubMed

Sakamoto, Hirokazu; Suzuki, Shigeo; Nagamune, Kisaburo; Kita, Kiyoshi; Matsuzaki, Motomichi

2017-07-01

Some organisms have retained plastids even after they have lost the ability to photosynthesize. Several studies of nonphotosynthetic plastids in apicomplexan parasites have shown that the isopentenyl pyrophosphate biosynthesis pathway in the organelle is essential for their survival. A phytohormone, abscisic acid, one of several compounds biosynthesized from isopentenyl pyrophosphate, regulates the parasite cell cycle. Thus, it is possible that the phytohormone is universally crucial, even in nonphotosynthetic plastids. Here, we examined this possibility using the oyster parasite Perkinsus marinus, which is a plastid-harboring cousin of apicomplexan parasites and has independently lost photosynthetic ability. Fluridone, an inhibitor of abscisic acid biosynthesis, blocked parasite growth and induced cell clustering. Nevertheless, abscisic acid and its intermediate carotenoids did not affect parasite growth or rescue the parasite from inhibition. Moreover, abscisic acid was not detected from the parasite using liquid chromatography mass spectrometry. Our findings show that abscisic acid does not play any significant roles in P. marinus. © 2016 The Authors. Journal of Eukaryotic Microbiology published by Wiley Periodicals, Inc. on behalf of International Society of Protistologists.

Control of plant phosphate homeostasis by inositol pyrophosphates and the SPX domain.

PubMed

Jung, Ji-Yul; Ried, Martina K; Hothorn, Michael; Poirier, Yves

2018-02-01

Proteins containing a SPX domain are involved in phosphate (Pi) homeostasis, including Pi transport and adaptation to Pi deficiency. The SPX domain harbors a basic surface binding Pi at low affinity and inositol pyrophosphates (PP-InsPs) at high affinity. Genetic and biochemical studies revealed that PP-InsPs serve as ligands for the SPX domain. Residues in the PHO1 SPX domain involved in PP-InsPs binding are critical for its Pi export activity, and the interaction between SPX proteins and the PHR1 transcription factor, which results in PHR1 inactivation, is promoted by PP-InsPs. Changes in PP-InsPs levels in response to Pi deficiency may thus contribute to the adaptation of plants to stress via the modulation of the activity of SPX-containing proteins and their interactors. Modulating PP-InsP levels or the affinity/specificity of the SPX domain for PP-InsP could potentially be used to engineer crops to maintain high yield under reduced Pi fertilizer input. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inosine-5'-monophosphate is a candidate agent to resolve rigor mortis of skeletal muscle.

PubMed

Matsuishi, Masanori; Tsuji, Mariko; Yamaguchi, Megumi; Kitamura, Natsumi; Tanaka, Sachi; Nakamura, Yukinobu; Okitani, Akihiro

2016-11-01

The object of the present study was to reveal the action of inosine-5'-monophosphate (IMP) toward myofibrils in postmortem muscles. IMP solubilized isolated actomyosin within a narrow range of KCl concentration, 0.19-0.20 mol/L, because of the dissociation of actomyosin into actin and myosin, but it did not solubilize the proteins in myofibrils with 0.2 mol/L KCl. However, IMP could solubilize both proteins in myofibrils with 0.2 mol/L KCl in the presence of 1 m mol/L pyrophosphate or 1.0-3.3 m mol/L adenosine-5'-diphosphate (ADP). Thus, we presumed that pyrophosphate and ADP released thin filaments composed of actin, and thick filaments composed of myosin from restraints of myofibrils, and then both filaments were solubilized through the IMP-induced dissociation of actomyosin. Thus, we concluded that IMP is a candidate agent to resolve rigor mortis because of its ability to break the association between thick and thin filaments. © 2016 Japanese Society of Animal Science.

Effects of calcium on hepatocyte iron uptake from transferrin, iron-pyrophosphate and iron-ascorbate.

PubMed

Nilsen, T

1991-10-16

Calcium stimulates hepatocyte iron uptake from transferrin, ferric-iron-pyrophosphate and ferrous-iron-ascorbate. Maximal stimulation of iron uptake is observed at 1-1.5 mM of extra-cellular calcium and the effect is reversible and immediate. Neither the receptor affinity for transferrin, nor the total amounts of transferrin associated with the cells or the rate of transferrin endocytosis are significantly affected by calcium. In the presence of calcium the rate of iron uptake of non-transferrin bound iron increases abruptly at approximate 17 degrees C and 27 degrees C and as assessed by Arrhenius plots, the activation energy is reduced in a calcium dependent manner at approx. 27 degrees C. At a similar temperature, i.e., between 25 degrees C and 28 degrees C, calcium increases the rates of cellular iron uptake from transferrin in a way that is not reflected in the rate of transferrin endocytosis. By the results of this study it is concluded that calcium increases iron transport across the plasma membrane by a mechanism dependent on membrane fluidity.

Single- and repeated-dose oral toxicity studies of citicoline free-base (choline cytidine 5'-pyrophosphate) in Sprague-Dawley rats.

PubMed

Schauss, A G; Somfai-Relle, S; Financsek, I; Glavits, R; Parent, S C; Endres, J R; Varga, T; Szücs, Z; Clewell, A

2009-01-01

The dietary supplement Citicoline free-base (choline cytidine 5'-pyrophosphate) was toxicologically evaluated in Sprague-Dawley rats using oral gavage. In an acute 14-day study, 2000 mg/kg was well tolerated. In a 90-day study, 100, 350, and 1000 mg/kg/day doses resulted in no mortality. In males, slight significant increases in serum creatinine (350 and 1000 mg/kg/day), and decreases in urine volume (all treated groups) were observed. In females, slight significant increases in total white blood cell and absolute lymphocyte counts (1000 mg/kg/day), and blood urea nitrogen (BUN) (100 and 350, but not 1000 mg/kg/day) were noted. A dose-related increase in renal tubular mineralization, without degenerative or inflammatory reaction, was found in females (all treated groups) and two males (1000 mg/kg/day). Renal mineralization in rats (especially females) is influenced by calcium:phosphorus ratios in the diet. A high level of citicoline consumption resulted in increased phosphorus intake in the rats, and likely explains this result.

The Thiamine-Pyrophosphate-Motif

NASA Technical Reports Server (NTRS)

Ciszak, Ewa; Dominiak, Paulina

2004-01-01

Thiamin pyrophosphate (TPP), a derivative of vitamin B1, is a cofactor for enzymes performing catalysis in pathways of energy production including the well known decarboxylation of a-keto acid dehydrogenases followed by transketolation. TPP-dependent enzymes constitute a structurally and functionally diverse group exhibiting multimeric subunit organization, multiple domains and two chemically equivalent catalytic centers. Annotation of functional TPP-dependcnt enzymes, therefore, has not been trivial due to low sequence similarity related to this complex organization. Our approach to analysis of structures of known TPP-dependent enzymes reveals for the first time features common to this group, which we have termed the TPP-motif. The TPP-motif consists of specific spatial arrangements of structural elements and their specific contacts to provide for a flip-flop, or alternate site, enzymatic mechanism of action. Analysis of structural elements entrained in the flip-flop action displayed by TPP-dependent enzymes reveals a novel definition of the common amino acid sequences. These sequences allow for annotation of TPP-dependent enzymes, thus advancing functional proteomics. Further details of three-dimensional structures of TPP-dependent enzymes will be discussed.

Passivation of Cu-Zn alloy on low carbon steel electrodeposited from a pyrophosphate medium

NASA Astrophysics Data System (ADS)

Yavuz, Abdulcabbar; Yakup Hacıibrahimoğlu, M.; Bedir, Metin

2018-01-01

The motivation of this study is to understand whether zinc-based alloy also has a passivation behaviour similar to zinc itself. Cu-Zn alloys were electrodeposited potentiostatically from a pyrophosphate medium on a carbon steel electrode and their corrosion behaviours were studied. Pt and carbon steel electrodes were used in order to examine the corrosion/passivation behaviour of bare Cu, bare Zn and Cu-Zn alloy coatings. The passivation behaviour of all brass-modified electrodes having Zn content between 10% and 100% was investigated. The growth potential affects the morphology and structure of crystals. The brass coatings are more porous than their pure components. The crystalline structure of Cu-Zn alloys can be obtained by changing the deposition potential. The zinc content in brass increases when the deposition voltage applied decreases. However, the growth potential and the ratio of zinc in brass do not affect the passivation behaviour of the resulting alloys. The coatings obtained by applying different growth potentials were immersed in tap water for 24 h to compare their corrosion behaviours with carbon steel having pitting formation.

Comparative analysis and validation of the malachite green assay for the high throughput biochemical characterization of terpene synthases

PubMed Central

Vardakou, Maria; Salmon, Melissa; Faraldos, Juan A.; O’Maille, Paul E.

2014-01-01

Terpenes are the largest group of natural products with important and diverse biological roles, while of tremendous economic value as fragrances, flavours and pharmaceutical agents. Class-I terpene synthases (TPSs), the dominant type of TPS enzymes, catalyze the conversion of prenyl diphosphates to often structurally diverse bioactive terpene hydrocarbons, and inorganic pyrophosphate (PPi). To measure their kinetic properties, current bio-analytical methods typically rely on the direct detection of hydrocarbon products by radioactivity measurements or gas chromatography–mass spectrometry (GC–MS). In this study we employed an established, rapid colorimetric assay, the pyrophosphate/malachite green assay (MG), as an alternative means for the biochemical characterization of class I TPSs activity.•We describe the adaptation of the MG assay for turnover and catalytic efficiency measurements of TPSs.•We validate the method by direct comparison with established assays. The agreement of kcat/KM among methods makes this adaptation optimal for rapid evaluation of TPSs.•We demonstrate the application of the MG assay for the high-throughput screening of TPS gene libraries. PMID:26150952

Comparative analysis and validation of the malachite green assay for the high throughput biochemical characterization of terpene synthases.

PubMed

Vardakou, Maria; Salmon, Melissa; Faraldos, Juan A; O'Maille, Paul E

2014-01-01

Terpenes are the largest group of natural products with important and diverse biological roles, while of tremendous economic value as fragrances, flavours and pharmaceutical agents. Class-I terpene synthases (TPSs), the dominant type of TPS enzymes, catalyze the conversion of prenyl diphosphates to often structurally diverse bioactive terpene hydrocarbons, and inorganic pyrophosphate (PPi). To measure their kinetic properties, current bio-analytical methods typically rely on the direct detection of hydrocarbon products by radioactivity measurements or gas chromatography-mass spectrometry (GC-MS). In this study we employed an established, rapid colorimetric assay, the pyrophosphate/malachite green assay (MG), as an alternative means for the biochemical characterization of class I TPSs activity.•We describe the adaptation of the MG assay for turnover and catalytic efficiency measurements of TPSs.•We validate the method by direct comparison with established assays. The agreement of k cat/K M among methods makes this adaptation optimal for rapid evaluation of TPSs.•We demonstrate the application of the MG assay for the high-throughput screening of TPS gene libraries.

Binding Modes of Teixobactin to Lipid II: Molecular Dynamics Study.

PubMed

Liu, Yang; Liu, Yaxin; Chan-Park, Mary B; Mu, Yuguang

2017-12-08

Teixobactin (TXB) is a newly discovered antibiotic targeting the bacterial cell wall precursor Lipid II (L II ). In the present work, four binding modes of TXB on L II were identified by a contact-map based clustering method. The highly flexible binary complex ensemble was generated by parallel tempering metadynamics simulation in a well-tempered ensemble (PTMetaD-WTE). In agreement with experimental findings, the pyrophosphate group and the attached first sugar subunit of L II are found to be the minimal motif for stable TXB binding. Three of the four binding modes involve the ring structure of TXB and have relatively higher binding affinities, indicating the importance of the ring motif of TXB in L II recognition. TXB-L II complexes with a ratio of 2:1 are also predicted with configurations such that the ring motif of two TXB molecules bound to the pyrophosphate-MurNAc moiety and the glutamic acid residue of one L II , respectively. Our findings disclose that the ring motif of TXB is critical to L II binding and novel antibiotics can be designed based on its mimetics.

Human Isoprenoid Synthase Enzymes as Therapeutic Targets

NASA Astrophysics Data System (ADS)

Park, Jaeok; Matralis, Alexios; Berghuis, Albert; Tsantrizos, Youla

2014-07-01

The complex biochemical network known as the mevalonate pathway is responsible for the biosynthesis of all isoprenoids in the human body, which consists of a vast array of metabolites that are vital for proper cellular functions. Two key isoprenoids, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) are responsible for the post-translational prenylation of small GTP-binding proteins, and serve as the biosynthetic precursors to numerous other biomolecules. The down-stream metabolite of FPP and GGPP is squalene, the precursor to steroids, bile acids, lipoproteins and vitamin D. In the past, interest in prenyl synthase inhibitors focused mainly on the role of the FPP in lytic bone diseases. More recently, pre-clinical and clinical studies have strongly implicated high levels of protein prenylation in a plethora of human diseases, including non-skeletal cancers, the progression of neurodegenerative diseases and cardiovascular diseases. In this review, we focus mainly on the potential therapeutic value of down-regulating the biosynthesis of FPP, GGPP and squalene. We summarize the most recent drug discovery efforts and the structural data available that support the current on-going studies.

Human isoprenoid synthase enzymes as therapeutic targets

PubMed Central

Park, Jaeok; Matralis, Alexios N.; Berghuis, Albert M.; Tsantrizos, Youla S.

2014-01-01

In the human body, the complex biochemical network known as the mevalonate pathway is responsible for the biosynthesis of all isoprenoids, which consists of a vast array of metabolites that are vital for proper cellular functions. Two key isoprenoids, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) are responsible for the post-translational prenylation of small GTP-binding proteins, and serve as the biosynthetic precursors to numerous other biomolecules. The down-stream metabolite of FPP and GGPP is squalene, the precursor to steroids, bile acids, lipoproteins, and vitamin D. In the past, interest in prenyl synthase inhibitors focused mainly on the role of the FPP in lytic bone diseases. More recently pre-clinical and clinical studies have strongly implicated high levels of protein prenylation in a plethora of human diseases, including non-skeletal cancers, the progression of neurodegenerative diseases and cardiovascular diseases. In this review, we focus mainly on the potential therapeutic value of down-regulating the biosynthesis of FPP, GGPP, and squalene. We summarize the most recent drug discovery efforts and the structural data available that support the current on-going studies. PMID:25101260

Synthesis of β-Calcium Pyrophosphate by sol-gel method

NASA Astrophysics Data System (ADS)

Windarti, T.; Taslimah; Haris, A.; Astuti, Y.; Darmawan, A.

2017-02-01

Beta calcium pyrophosphate [β-CPP, β-Ca2P2O7] can be used as bone graft extender in posterolateral lumbar fusion. In this research, β-CPP was synthesized by sol-gel method using phosphorus pentaoxide [P2O5] and calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] as phosphorus and calcium precursors. The reaction was carried out in ethanol medium with Ca/P ratio of 1.67. After 21 hours of reaction and 20 hours of drying at 80°C, white powder of amorphous calcium phosphate (ACP) was produced. Transformation of ACP to β-CPP was undertaken by firring at 400-800°C for 8 hours. Transformations of amorphous to microcrystalline, semicrystalline and crystalline structures occur at 400, 600 and 800°C, respectively. The β-CPP with the crystallite size of 61.71 nm, Ca/P ratio of 0.89 and Ca/O ratio of 0.21 was achieved by firing at 800°C. Morphology changes due to firing in which irregular shape of β-CPP at 400° changed to regular cuboid at 600 °C and above.

IMP improves water-holding capacity, physical and sensory properties of heat-induced gels from porcine meat.

PubMed

Nakamura, Yukinobu; Migita, Koshiro; Okitani, Akihiro; Matsuishi, Masanori

2014-05-01

Water-holding capacity (WHC) of heat-induced pork gels was examined. The heat-induced gels were obtained from meat homogenates prepared by adding nine volumes of 0.3-0.5 mol/L NaCl solutions containing 9-36 mmol/L disodium inosine-5'-monophosphate (IMP) or 9 mmol/L tetrapotassium pyrophosphate (KPP) to minced pork. IMP at 36 mmol/L enhanced the WHC to the same level as attained by KPP. Physical and sensory properties of heat-induced gels were also examined. The heat-induced gels were prepared from porcine meat homogenates containing 0.3 mol/L NaCl and 9-36 mmol/L IMP or 9 mmol/L KPP. IMP at 36 mmol/L enhanced the values of hardness, cohesiveness, gumminess and springiness, measured with a Tensipresser, and several organoleptic scores to the same level as the score attained by KPP. Thus, it is concluded that IMP is expected to be a practical substitute for pyrophosphates to improve the quality of sausages. © 2014 Japanese Society of Animal Science.

Technetium-99m(Sn2+)pyrophosphate in ischemic and infarcted dog myocardium in early stages of acute coronary occlusion: histochemical and tissue-counting comparisons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bianco, J.A.; Kemper, A.J.; Taylor, A.

1983-06-01

We have investigated the pattern of accumulation of Tc-99m(Sn2+)pyrophosphate (Tc-99m PPi) in myocardial tissue of dogs during the early stages of acute occlusion of the left anterior descending coronary artery. Three groups were studied after: (a) 40 min occlusion followed by 6 hr reperfusion (n . 6); (b) 6 hr occlusion followed by one hour reperfusion (n . 5); and (c) 7 hr occlusion with no reperfusion (n . 4). Areas of myocardial infarction were defined with triphenyl-tetrazolium chloride (TTC) staining, and blood flow was determined with 9-mu radioactive microspheres. In Group C uptake in infarcted and peri-infarct areas wasmore » not enhanced, most likely owing to low flow. In Group B, with late reperfusion, Tc-99m PPi sequestration was increased in both infarcted and peri-infarcted tissues. In Group A, areas ischemic during occlusion but with normal flow and viability by TTC after 6 hr of reperfusion showed significant uptake of Tc-99m PPi (twice the uptake of nonischemic regions).« less

Osteoblast response to zirconia-hybridized pyrophosphate-stabilized amorphous calcium phosphate

PubMed Central

Whited, Bryce M.; Skrtic, Drago; Love, Brian J.

2006-01-01

Calcium phosphate bioceramics, such as hydroxyapatite, have long been used as bone substitutes because of their proven biocompatibility and bone binding properties in vivo. Recently, a zirconia-hybridized pyrophosphate-stabilized amorphous calcium phosphate (Zr-ACP) has been synthesized, which is more soluble than hydroxyapatite and allows for controlled release of calcium and phosphate ions. These ions have been postulated to increase osteoblast differentiation and mineralization in vitro. The focus of this work is to elucidate the physicochemical properties of Zr-ACP and to measure cell response to Zr-ACP in vitro using a MC3T3-E1 mouse calvarial-derived osteoprogenitor cell line. Cells were cultured in osteogenic medium and mineral was added to culture at different stages in cell maturation. Culture in the presence of Zr-ACP showed significant increases in cell proliferation, alkaline phosphatase activity (ALP), and osteopontin (OPN) synthesis, whereas collagen synthesis was unaffected. In addition, calcium and phosphate ion concentrations and medium pH were found to transiently increase with the addition of Zr-ACP, and are hypothesized to be responsible for the osteogenic effect of Zr-ACP. PMID:16278876

A Genetic and Pharmacological Analysis of Isoprenoid Pathway by LC-MS/MS in Fission Yeast

PubMed Central

Takami, Tomonori; Fang, Yue; Zhou, Xin; Jaiseng, Wurentuya; Ma, Yan; Kuno, Takayoshi

2012-01-01

Currently, statins are the only drugs acting on the mammalian isoprenoid pathway. The mammalian genes in this pathway are not easily amenable to genetic manipulation. Thus, it is difficult to study the effects of the inhibition of various enzymes on the intermediate and final products in the isoprenoid pathway. In fission yeast, antifungal compounds such as azoles and terbinafine are available as inhibitors of the pathway in addition to statins, and various isoprenoid pathway mutants are also available. Here in these mutants, treated with statins or antifungals, we quantified the final and intermediate products of the fission yeast isoprenoid pathway using liquid chromatography-mass spectrometry/mass spectrometry. In hmg1-1, a mutant of the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), ergosterol (a final sterol product), and squalene (an intermediate pathway product), were decreased to approximately 80% and 10%, respectively, compared with that of wild-type cells. Consistently in wild-type cells, pravastatin, an HMGR inhibitor decreased ergosterol and squalene, and the effect was more pronounced on squalene. In hmg1-1 mutant and in wild-type cells treated with pravastatin, the decrease in the levels of farnesyl pyrophosphate and geranylgeranyl pyrophosphate respectively was larger than that of ergosterol but was smaller than that of squalene. In Δerg6 or Δsts1 cells, mutants of the genes involved in the last step of the pathway, ergosterol was not detected, and the changes of intermediate product levels were distinct from that of hmg1-1 mutant. Notably, in wild-type cells miconazole and terbinafine only slightly decreased ergosterol level. Altogether, these studies suggest that the pleiotropic phenotypes caused by the hmg1-1 mutation and pravastatin might be due to decreased levels of isoprenoid pyrophosphates or other isoprenoid pathway intermediate products rather than due to a decreased ergosterol level. PMID:23145048

Efficacy of a microencapsulated iron pyrophosphate-fortified fruit juice: a randomised, double-blind, placebo-controlled study in Spanish iron-deficient women.

PubMed

Blanco-Rojo, Ruth; Pérez-Granados, Ana M; Toxqui, Laura; González-Vizcayno, Carmen; Delgado, Marco A; Vaquero, M Pilar

2011-06-01

Fe-deficiency anaemia is a worldwide health problem. We studied the influence of consuming an Fe-fortified fruit juice on Fe status in menstruating women. A randomised, double-blind, placebo-controlled study of 16 weeks of duration was performed. Subjects were randomised into two groups: the P group (n 58) or the F group (n 64), and consumed, as a supplement to their usual diet, 500 ml/d of a placebo fruit juice or an Fe-fortified fruit juice, respectively. The Fe-fortified fruit juice, containing microencapsulated iron pyrophosphate, provided 18 mg Fe/d (100 % of the RDA). At baseline and monthly, dietary intake, body weight and Fe parameters were determined: total erythrocytes, haematocrit, mean corpuscular volume (MCV), red blood cell distribution width (RDW), Hb, serum Fe, serum ferritin, serum transferrin, transferrin saturation, soluble transferrin receptor (sTfR) and zinc protoporphyrin (ZnPP). The fruit juice consumption involved increased intake of carbohydrates and vitamin C, and increased BMI within normal limits. Ferritin was higher in the F group after week 4 (P < 0·05) and became 80 % higher than in the P group after week 16 (P < 0·001), and transferrin decreased in the F group compared with the P group after week 4 (P < 0·001). RDW was higher at weeks 4 and 8 in the F group compared with the P group (P < 0·05). Transferrin saturation increased after week 8, and haematocrit, MCV and Hb increased after week 12, in the F group compared with the P group. Serum Fe did not change. sTfR and ZnPP decreased in the F group at week 16 (P < 0·05). Iron pyrophosphate-fortified fruit juice improves Fe status and may be used to prevent Fe-deficiency anaemia.

Synthesis, characterization and properties of uridine 5'-( -D-apio-D-furanosyl pyrophosphate).

PubMed

Kindel, P K; Watson, R R

1973-06-01

1. A method was developed for synthesizing UDP-apiose [uridine 5'-(alpha-d-apio-d-furanosyl pyrophosphate)] from UDP-glucuronic acid [uridine 5'-(alpha-d-glucopyranosyluronic acid pyrophosphate)] in 62% yield with the enzyme UDP-glucuronic acid cyclase. 2. UDP-apiose had the same mobility as uridine 5'-(alpha-d-xylopyranosyl pyrophosphate) when chromatographed on paper and when subjected to paper electrophoresis at pH5.8. When [(3)H]UDP-[U-(14)C]glucuronic acid was used as the substrate for UDP-glucuronic acid cyclase, the (3)H/(14)C ratio in the reaction product was that expected if d-apiose remained attached to the uridine. In separate experiments doubly labelled reaction product was: (a) hydrolysed at pH2 and 100 degrees C for 15min; (b) degraded at pH8.0 and 100 degrees C for 3min; (c) used as a substrate in the enzymic synthesis of [(14)C]apiin. In each type of experiment the reaction products were isolated and identified and were found to be those expected if [(3)H]UDP-[U-(14)C]apiose was the starting compound. 3. Chemical characterization established that the product containing d-[U-(14)C]apiose and phosphate formed on alkaline degradation of UDP-[U-(14)C]apiose was alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate. 4. Chemical characterization also established that the product containing d-[U-(14)C]apiose and phosphate formed on acid hydrolysis of alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate was d-[U-(14)C]apiose 2-phosphate. 5. The half-life periods for the degradation of UDP-[U-(14)C]apiose to alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate and UMP at pH8.0 and 80 degrees C, at pH8.0 and 25 degrees C and at pH8.0 and 4 degrees C were 31.6s, 97.2min and 16.5h respectively. The half-life period for the hydrolysis of UDP-[U-(14)C]-apiose to d-[U-(14)C]apiose and UDP at pH3.0 and 40 degrees C was 4.67min. After 20 days at pH6.2-6.6 and 4 degrees C, 17% of the starting UDP-[U-(14)C]apiose was degraded to alpha-d-[U-(14)C]apio-d-furanosyl 1:2-cyclic phosphate and UMP and 23% was hydrolysed to d-[U-(14)C]apiose and UDP. After 120 days at pH6.4 and -20 degrees C 2% of the starting UDP-[U-(14)C]apiose was degraded and 4% was hydrolysed.

Electron transfer in biology

NASA Astrophysics Data System (ADS)

Williams, R. J. P.

Electron transfer is one of the key reactions of biology not just in catalysis of oxidation/reduction reactions but in the conversion of sources of energy such as light to usable form for chemical transformations. There are then two intriguing problems. What is the nature of the matrix in which electrons flow in a biological cell after the initial charge separation due for example to the absorption of light. Here we are examining biological structures similar to man's electronic wires and the construction must be of low resistance in what are apparently insulators - organic polymers. It has been found that the electronic conduction system is largely made from metallo-proteins associated with lipid membranes. We understand much about these biological wires today. The second problem concerns the conversion of the energy captured from the light into usable chemical form. The major synthetic step in the production of biological polymers, including proteins, DNA, RNA, polysaccharides and fats, is condensation, i.e. the removal of water in the formation of amides, esters and so on. Now these condensation reactions are driven in biology by using a drying agent in water, namely the anhydride, pyrophosphate, in a special compound ATP, adenosine triphosphate. The central problem is to discover exactly how the flow of electrons can be related to the synthesis of (bound) pyrophosphate. (In a thermodynamic sense pyrophosphate is a water soluble kinetically stable drying agent comparable with solid P2O5.) In the biological systems the connection between these different classes of reaction, electron transfer and condensation, is known to be via the production of an energized gradient of protons across the biological membrane which arises from the flow of electrons across the same membrane in the electron transport wires of biology. However we do not understand thoroughly the steps which lead from electron flow in a membrane to proton gradients in that membrane, i.e. electron/proton coupling. Again we do not understand thoroughly how subsequently the proton gradient across a membrane makes ATP, pyrophosphate. Today there is good experimental evidence as to the likely answers in principle. These analyse the coupling devices in mechanical terms. In this article I describe at first the 'wires' of biology, uncoupled simple electron flow, and then go on to the ways in which electron flow could be transduced by mechanical devices, also proteins, into proton gradients and then ATP. This will be termed coupled electron flow. The objective of the article is to stimulate participation by physical chemists in the further description of biological energy capture from light or the oxidation of hydrocarbons to a form suitable for driving chemical syntheses in a controlled manner.

Synthesis, characterization and properties of uridine 5′-(α-d-apio-d-furanosyl pyrophosphate)

PubMed Central

Kindel, Paul K.; Watson, Ronald R.

1973-01-01

1. A method was developed for synthesizing UDP-apiose [uridine 5′-(α-d-apio-d-furanosyl pyrophosphate)] from UDP-glucuronic acid [uridine 5′-(α-d-glucopyranosyluronic acid pyrophosphate)] in 62% yield with the enzyme UDP-glucuronic acid cyclase. 2. UDP-apiose had the same mobility as uridine 5′-(α-d-xylopyranosyl pyrophosphate) when chromatographed on paper and when subjected to paper electrophoresis at pH5.8. When [3H]UDP-[U-14C]glucuronic acid was used as the substrate for UDP-glucuronic acid cyclase, the 3H/14C ratio in the reaction product was that expected if d-apiose remained attached to the uridine. In separate experiments doubly labelled reaction product was: (a) hydrolysed at pH2 and 100°C for 15min; (b) degraded at pH8.0 and 100°C for 3min; (c) used as a substrate in the enzymic synthesis of [14C]apiin. In each type of experiment the reaction products were isolated and identified and were found to be those expected if [3H]UDP-[U-14C]apiose was the starting compound. 3. Chemical characterization established that the product containing d-[U-14C]apiose and phosphate formed on alkaline degradation of UDP-[U-14C]apiose was α-d-[U-14C]apio-d-furanosyl 1:2-cyclic phosphate. 4. Chemical characterization also established that the product containing d-[U-14C]apiose and phosphate formed on acid hydrolysis of α-d-[U-14C]apio-d-furanosyl 1:2-cyclic phosphate was d-[U-14C]apiose 2-phosphate. 5. The half-life periods for the degradation of UDP-[U-14C]apiose to α-d-[U-14C]apio-d-furanosyl 1:2-cyclic phosphate and UMP at pH8.0 and 80°C, at pH8.0 and 25°C and at pH8.0 and 4°C were 31.6s, 97.2min and 16.5h respectively. The half-life period for the hydrolysis of UDP-[U-14C]-apiose to d-[U-14C]apiose and UDP at pH3.0 and 40°C was 4.67min. After 20 days at pH6.2–6.6 and 4°C, 17% of the starting UDP-[U-14C]apiose was degraded to α-d-[U-14C]apio-d-furanosyl 1:2-cyclic phosphate and UMP and 23% was hydrolysed to d-[U-14C]apiose and UDP. After 120 days at pH6.4 and −20°C 2% of the starting UDP-[U-14C]apiose was degraded and 4% was hydrolysed. PMID:4723773

Expression of the cytoplasmic mevalonate pathway in chloroplasts to reduce substrate limitations for cytoplasmically-produced terpenoid secondary products

USDA-ARS?s Scientific Manuscript database

All products of isoprenoid metabolism originate with the C5 non-allylic substrate, isopentenyl pyrophosphate (IPP). IPP is produced in plants by two distinct pathways, the mevalonate pathway (MEV) in the cytosol and the 2 C methyl-D-erythritol 4 phosphate (MEP) pathway in plastids. A multi-gene a...

The effect of a fluoride dentifrice containing an anticalculus agent on dental caries in children.

PubMed

Lu, K H; Yen, D J; Zacherl, W A; Ruhlman, C D; Sturzenberger, O P; Lehnhoff, R W

1985-01-01

In this double-blind caries study, 1160 Taiwanese children (ages 8-15) completed a program using a test dentifrice containing 1.243 percent sodium fluoride and soluble pyrophosphates, or a control dentifrice without these agents. The average reduction of new carious tooth surfaces was 39 percent with the sodium fluoride dentifrice.

Vitamin B1 content in potato: effect of genotype, tuber enlargement, and storage, and estimation of stability and broad-sense heritability

USDA-ARS?s Scientific Manuscript database

Thiamine pyrophosphate (vitamin B1) is an essential nutrient in the human diet, and is often referred as the energy vitamin. Potato contains modest amounts of thiamine. However, genetic variation of thiamine concentrations in potato has never been investigated. In this study, we determined thiamine ...

METHOD OF RECOVERING TRANSURANIC ELEMENTS OF AN ATOMIC NUMBER BELOW 95

DOEpatents

Seaborg, G.T.; James, R.A.

1959-12-15

The concentration of neptanium or plutonium by two carrier precipitation steps with identical carriers but using (after dissolution of the first carrier in nitric acid) a reduced quantity of carrier for the second precipitation is discussed. Carriers suitable are uranium(IV) hypophosphate, uranium(IV) pyrophosphate, uranium(IV) oxalate, thorium oxalate, thorium citrate, thorium tartrate, thorium sulfide, and uranium(IV) sulfide.

Study of irradiated bone. III. Scintigraphic and radiographic detection of radiation-induced osteosarcomas. [/sup 99m/Tc-pyrophosphate; rabbits

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, M.A.; Casarett, G.W.; Weber, D.A.

1980-05-01

Within 1 yr after localized irradiation of a hind limb with single (1756 rads) or fractionated (4650 rads in 3 wk) x-ray doses, radiation-induced osteosarcomas were observed in four of nine single-dose rabbits and two of 11 fractionated-dose rabbits. Tumors were observed in the proximal tibia in five cases and the distal femur in one case. In terms of production of osteoid or osseous tissue, three tumors were well differentiated, one slightly differentiated, and two (spindle-cell tumors) undifferentiated. This report summarizes the Tc-99m pyrophosphate (TcPPi) imaging and autoradiographic, radiographic, and histologic studies of these osteosarcomas. The four differentiated osteosarcomas weremore » detected 1 to 2.5 mo earlier by TcPPi imaging than by radiography, whereas the two undifferentiated tumors were suspected 2 wk or 3.5 mo earlier radiographically. Autoradiograms showed TcPPi localization in bone produced by differentiated osteosarcomas, and in regions of reactive bone resorption and formation peripheral to tumors. The results support a recommendation for combined radiographic and scintigraphic techniques for the early detection of osteosarcomas.« less

Shining a light on LAMP assays--a comparison of LAMP visualization methods including the novel use of berberine.

PubMed

Fischbach, Jens; Xander, Nina Carolin; Frohme, Marcus; Glökler, Jörn Felix

2015-04-01

The need for simple and effective assays for detecting nucleic acids by isothermal amplification reactions has led to a great variety of end point and real-time monitoring methods. Here we tested direct and indirect methods to visualize the amplification of potato spindle tuber viroid (PSTVd) by loop-mediated isothermal amplification (LAMP) and compared features important for one-pot in-field applications. We compared the performance of magnesium pyrophosphate, hydroxynaphthol blue (HNB), calcein, SYBR Green I, EvaGreen, and berberine. All assays could be used to distinguish between positive and negative samples in visible or UV light. Precipitation of magnesium-pyrophosphate resulted in a turbid reaction solution. The use of HNB resulted in a color change from violet to blue, whereas calcein induced a change from orange to yellow-green. We also investigated berberine as a nucleic acid-specific dye that emits a fluorescence signal under UV light after a positive LAMP reaction. It has a comparable sensitivity to SYBR Green I and EvaGreen. Based on our results, an optimal detection method can be chosen easily for isothermal real-time or end point screening applications.

PLUTONIUM PURIFICATION PROCESS EMPLOYING THORIUM PYROPHOSPHATE CARRIER

DOEpatents

King, E.L.

1959-04-28

The separation and purification of plutonium from the radioactive elements of lower atomic weight is described. The process of this invention comprises forming a 0.5 to 2 M aqueous acidffc solution containing plutonium fons in the tetravalent state and elements with which it is normally contaminated in neutron irradiated uranium, treating the solution with a double thorium compound and a soluble pyrophosphate compound (Na/sub 4/P/sub 2/O/sub 7/) whereby a carrier precipitate of thorium A method is presented of reducing neptunium and - trite is advantageous since it destroys any hydrazine f so that they can be removed from solutions in which they are contained is described. In the carrier precipitation process for the separation of plutonium from uranium and fission products including zirconium and columbium, the precipitated blsmuth phosphate carries some zirconium, columbium, and uranium impurities. According to the invention such impurities can be complexed and removed by dissolving the contaminated carrier precipitate in 10M nitric acid, followed by addition of fluosilicic acid to about 1M, diluting the solution to about 1M in nitric acid, and then adding phosphoric acid to re-precipitate bismuth phosphate carrying plutonium.

RT-LAMP assay: an alternative approach for profiling of bovine heat shock protein 70 gene in PBMC cultured model.

PubMed

Sengar, Gyanendra Singh; Deb, Rajib; Raja, T V; Singh, Umesh; Kant, Rajiv; Bhanuprakash, V; Alyethodi, R R; Kumar, Sushil; Verma, Preetam; Chakraborty, Soumendu; Alex, Rani; Singh, Rani

2017-07-01

The purpose of this study is to develop a novel Reverse Transcriptase Loop-mediated isothermal amplification (RT-LAMP) based assay for in vitro profiling of heat shock protein 70 (Hsp70) in bovine peripheral blood mononuclear cell (PBMC) culture model utilizing the absorbance level of magnesium pyrophosphate-a by-product of LAMP reaction. A set of bovine Hsp70 specific RT-LAMP primers were designed to detect the differential absorbance level of magnesium pyrophosphate by-product which signifies the degree of Hsp70 amplification from cDNA of thermally induced cultured cells at different recovery periods. The study revealed significant (P < 0.05) correlation between absorbance level and the fold change of Hsp70 transcripts at different kinetic intervals of heat stress recovery in bovine PBMC cell culture models. RT-LAMP based absorbance assay can be used as an indicator to measure the degree of bovine Hsp70 transcripts produced during thermal stress and can be used as an alternative to the traditional Real time PCR assay. Developed RT-LAMP assay can be used as a cost-effective method for profiling of bovine HSP70 gene.

Isolation and functional expression of human COQ2, a gene encoding a polyprenyl transferase involved in the synthesis of CoQ.

PubMed

Forsgren, Margareta; Attersand, Anneli; Lake, Staffan; Grünler, Jacob; Swiezewska, Ewa; Dallner, Gustav; Climent, Isabel

2004-09-01

The COQ2 gene in Saccharomyces cerevisiae encodes a Coq2 (p-hydroxybenzoate:polyprenyl transferase), which is required in the biosynthetic pathway of CoQ (ubiquinone). This enzyme catalyses the prenylation of p-hydroxybenzoate with an all-trans polyprenyl group. We have isolated cDNA which we believe encodes the human homologue of COQ2 from a human muscle and liver cDNA library. The clone contained an open reading frame of length 1263 bp, which encodes a polypeptide that has sequence homology with the Coq2 homologues in yeast, bacteria and mammals. The human COQ2 gene, when expressed in yeast Coq2 null mutant cells, rescued the growth of this yeast strain in the absence of a non-fermentable carbon source and restored CoQ biosynthesis. However, the rate of CoQ biosynthesis in the rescued cells was lower when compared with that in cells rescued with the yeast COQ2 gene. CoQ formed when cells were incubated with labelled decaprenyl pyrophosphate and nonaprenyl pyrophosphate, showing that the human enzyme is active and that it participates in the biosynthesis of CoQ.

New Boron Analogues of Pyrophosphates and Deoxynucleoside Boranophosphates

PubMed Central

Vyakaranam, Kamesh; Rana, Geeta; Spielvogel, Bernard F.

2001-01-01

Tetraethyldicyanoborane pyrophosphate (2) and 3'-(diethylphosphite-cyanoborano)-5'-dimethoxytrityl.N4-benzoyl-deoxycytidine (3) have been synthesized in 70% and 76% yields, respectively. The compatibility of the substituted boranophosphates with common protecting groups is hereby demonstrated. Boron containing biologically active compounds, such as nucleosides and nucleotides 1-6 and amino acids 7-9 are important due to their potential therapeutic activity, research and diagnostic applications. Many boron containing compounds have shown promising activity as anticancer, 10. 11. 12 antiinflammatory,13 and antiosteoporotic 13agents. Oligonucleotdes in which a non-bridging oxygen atom is replaced by a borane(BH3) group are a very important class of modified nucleic acids. 1. 3. 14-16 The BH3 group is isoelectronic with oxygen in natural oligonucleotides and isoelectronic and isostructural with the oligonucleotide methyl phosphonates, which are nuclease resistant. On the other hand, the α-borano triphosphates are good substrates for DNA polymerases and incorporation of boranophosphates into DNA causes an increase in the resistance to exo- and endonucleases 2. 17a as compared to non-modified DNA. There are also notable applications of the α-borano triphosphates in PCR sequencing 17a and nucleic acid detection 17b. PMID:18475988

A Cascade of Thermophilic Enzymes As an Approach to the Synthesis of Modified Nucleotides.

PubMed

Esipov, R S; Abramchik, Yu A; Fateev, I V; Konstantinova, I D; Kostromina, M A; Muravyova, T I; Artemova, K G; Miroshnikov, A I

2016-01-01

We propose a new approach for the synthesis of biologically important nucleotides which includes a multi-enzymatic cascade conversion of D -pentoses into purine nucleotides. The approach exploits nucleic acid exchange enzymes from thermophilic microorganisms: ribokinase, phosphoribosylpyrophosphate synthetase, and adenine phosphoribosyltransferase. We cloned the ribokinase gene from Thermus sp . 2.9, as well as two different genes of phosphoribosylpyrophosphate synthetase (PRPP-synthetase) and the adenine phosphoribosyltransferase (APR-transferase) gene from Thermus thermophilus HB27 into the expression vectors, generated high-yield E. coli producer strains, developed methods for the purification of the enzymes, and investigated enzyme substrate specificity. The enzymes were used for the conversion of D -pentoses into 5-phosphates that were further converted into 5-phospho-α- D -pentofuranose 1-pyrophosphates by means of ribokinase and PRPP-synthetases. Target nucleotides were obtained through the condensation of the pyrophosphates with adenine and its derivatives in a reaction catalyzed by APR-transferase. 2-Chloro- and 2-fluoroadenosine monophosphates were synthesized from D -ribose and appropriate heterobases in one pot using a system of thermophilic enzymes in the presence of ATP, ribokinase, PRPP-synthetase, and APR-transferase.

Development of inhibitors of the 2C-methyl-D-erythritol 4-phosphate (MEP) pathway enzymes as potential anti-infective agents.

PubMed

Masini, Tiziana; Hirsch, Anna K H

2014-12-11

Important pathogens such as Mycobacterium tuberculosis and Plasmodium falciparum, the causative agents of tuberculosis and malaria, respectively, and plants, utilize the 2C-methyl-D-erythritol 4-phosphate (MEP, 5) pathway for the biosynthesis of isopentenyl diphosphate (1) and dimethylallyl diphosphate (2), the universal precursors of isoprenoids, while humans exclusively utilize the alternative mevalonate pathway for the synthesis of 1 and 2. This distinct distribution, together with the fact that the MEP pathway is essential in numerous organisms, makes the enzymes of the MEP pathway attractive drug targets for the development of anti-infective agents and herbicides. Herein, we review the inhibitors reported over the past 2 years, in the context of the most important older developments and with a particular focus on the results obtained against enzymes of pathogenic organisms. We will also discuss new discoveries in terms of structural and mechanistic features, which can help to guide a rational development of inhibitors.

δ-Deuterium Isotope Effects as Probes for Transition-State Structures of Isoprenoid Substrates

PubMed Central

2015-01-01

The biosynthetic pathways to isoprenoid compounds involve transfer of the prenyl moiety in allylic diphosphates to electron-rich (nucleophilic) acceptors. The acceptors can be many types of nucleophiles, while the allylic diphosphates only differ in the number of isoprene units and stereochemistry of the double bonds in the hydrocarbon moieties. Because of the wide range of nucleophilicities of naturally occurring acceptors, the mechanism for prenyltransfer reactions may be dissociative or associative with early to late transition states. We have measured δ-secondary kinetic isotope effects operating through four bonds for substitution reactions with dimethylallyl derivatives bearing deuterated methyl groups at the distal (C3) carbon atom in the double bond under dissociative and associative conditions. Computational studies with density functional theory indicate that the magnitudes of the isotope effects correlate with the extent of bond formation between the allylic moiety and the electron-rich acceptor in the transition state for alkylation and provide insights into the structures of the transition states for associative and dissociative alkylation reactions. PMID:24665882

Utilizing a Dynamical Description of IspH to Aid in the Development of Novel Antimicrobial Drugs

PubMed Central

Blachly, Patrick G.; de Oliveira, César A. F.; Williams, Sarah L.; McCammon, J. Andrew

2013-01-01

The nonmevalonate pathway is responsible for isoprenoid production in microbes, including H. pylori, M. tuberculosis and P. falciparum, but is nonexistent in humans, thus providing a desirable route for antibacterial and antimalarial drug discovery. We coordinate a structural study of IspH, a [4Fe-4S] protein responsible for converting HMBPP to IPP and DMAPP in the ultimate step in the nonmevalonate pathway. By performing accelerated molecular dynamics simulations on both substrate-free and HMBPP-bound [Fe4S4]2+ IspH, we elucidate how substrate binding alters the dynamics of the protein. Using principal component analysis, we note that while substrate-free IspH samples various open and closed conformations, the closed conformation observed experimentally for HMBPP-bound IspH is inaccessible in the absence of HMBPP. In contrast, simulations with HMBPP bound are restricted from accessing the open states sampled by the substrate-free simulations. Further investigation of the substrate-free simulations reveals large fluctuations in the HMBPP binding pocket, as well as allosteric pocket openings – both of which are achieved through the hinge motions of the individual domains in IspH. Coupling these findings with solvent mapping and various structural analyses reveals alternative druggable sites that may be exploited in future drug design efforts. PMID:24367248

Farnesol is utilized for isoprenoid biosynthesis in plant cells via farnesyl pyrophosphate formed by successive monophosphorylation reactions

PubMed Central

Thai, Long; Rush, Jeffrey S.; Maul, Jude E.; Devarenne, Timothy; Rodgers, Dana L.; Chappell, Joseph; Waechter, Charles J.

1999-01-01

The ability of Nicotiana tabacum cell cultures to utilize farnesol (F-OH) for sterol and sesquiterpene biosynthesis was investigated. [3H]F-OH was readily incorporated into sterols by rapidly growing cell cultures. However, the incorporation rate into sterols was reduced by greater than 70% in elicitor-treated cell cultures whereas a substantial proportion of the radioactivity was redirected into capsidiol, an extracellular sesquiterpene phytoalexin. The incorporation of [3H]F-OH into sterols was inhibited by squalestatin 1, suggesting that [3H]F-OH was incorporated via farnesyl pyrophosphate (F-P-P). Consistent with this possibility, N. tabacum proteins were metabolically labeled with [3H]F-OH or [3H]geranylgeraniol ([3H]GG-OH). Kinase activities converting F-OH to farnesyl monophosphate (F-P) and, subsequently, F-P-P were demonstrated directly by in vitro enzymatic studies. [3H]F-P and [3H]F-P-P were synthesized when exogenous [3H]F-OH was incubated with microsomal fractions and CTP. The kinetics of formation suggested a precursor–product relationship between [3H]F-P and [3H]F-P-P. In agreement with this kinetic pattern of labeling, [32P]F-P and [32P]F-P-P were synthesized when microsomal fractions were incubated with F-OH and F-P, respectively, with [γ-32P]CTP serving as the phosphoryl donor. Under similar conditions, the microsomal fractions catalyzed the enzymatic conversion of [3H]GG-OH to [3H]geranylgeranyl monophosphate and [3H]geranylgeranyl pyrophosphate ([3H]GG-P-P) in CTP-dependent reactions. A novel biosynthetic mechanism involving two successive monophosphorylation reactions was supported by the observation that [3H]CTP was formed when microsomes were incubated with [3H]CDP and either F-P-P or GG-P-P, but not F-P. These results document the presence of at least two CTP-mediated kinases that provide a mechanism for the utilization of F-OH and GG-OH for the biosynthesis of isoprenoid lipids and protein isoprenylation. PMID:10557276

Farnesol is utilized for isoprenoid biosynthesis in plant cells via farnesyl pyrophosphate formed by successive monophosphorylation reactions.

PubMed

Thai, L; Rush, J S; Maul, J E; Devarenne, T; Rodgers, D L; Chappell, J; Waechter, C J

1999-11-09

The ability of Nicotiana tabacum cell cultures to utilize farnesol (F-OH) for sterol and sesquiterpene biosynthesis was investigated. [(3)H]F-OH was readily incorporated into sterols by rapidly growing cell cultures. However, the incorporation rate into sterols was reduced by greater than 70% in elicitor-treated cell cultures whereas a substantial proportion of the radioactivity was redirected into capsidiol, an extracellular sesquiterpene phytoalexin. The incorporation of [(3)H]F-OH into sterols was inhibited by squalestatin 1, suggesting that [(3)H]F-OH was incorporated via farnesyl pyrophosphate (F-P-P). Consistent with this possibility, N. tabacum proteins were metabolically labeled with [(3)H]F-OH or [(3)H]geranylgeraniol ([(3)H]GG-OH). Kinase activities converting F-OH to farnesyl monophosphate (F-P) and, subsequently, F-P-P were demonstrated directly by in vitro enzymatic studies. [(3)H]F-P and [(3)H]F-P-P were synthesized when exogenous [(3)H]F-OH was incubated with microsomal fractions and CTP. The kinetics of formation suggested a precursor-product relationship between [(3)H]F-P and [(3)H]F-P-P. In agreement with this kinetic pattern of labeling, [(32)P]F-P and [(32)P]F-P-P were synthesized when microsomal fractions were incubated with F-OH and F-P, respectively, with [gamma-(32)P]CTP serving as the phosphoryl donor. Under similar conditions, the microsomal fractions catalyzed the enzymatic conversion of [(3)H]GG-OH to [(3)H]geranylgeranyl monophosphate and [(3)H]geranylgeranyl pyrophosphate ([(3)H]GG-P-P) in CTP-dependent reactions. A novel biosynthetic mechanism involving two successive monophosphorylation reactions was supported by the observation that [(3)H]CTP was formed when microsomes were incubated with [(3)H]CDP and either F-P-P or GG-P-P, but not F-P. These results document the presence of at least two CTP-mediated kinases that provide a mechanism for the utilization of F-OH and GG-OH for the biosynthesis of isoprenoid lipids and protein isoprenylation.

Reactive formulations for a neutralization of toxic industrial chemicals

DOEpatents

Tucker, Mark D [Albuqueruqe, NM; Betty, Rita G [Rio Rancho, NM

2006-10-24

Decontamination formulations for neutralization of toxic industrial chemicals, and methods of making and using same. The formulations are effective for neutralizing malathion, hydrogen cyanide, sodium cyanide, butyl isocyanate, carbon disulfide, phosgene gas, capsaicin in commercial pepper spray, chlorine gas, anhydrous ammonia gas; and may be effective at neutralizing hydrogen sulfide, sulfur dioxide, formaldehyde, ethylene oxide, methyl bromide, boron trichloride, fluorine, tetraethyl pyrophosphate, phosphorous trichloride, arsine, and tungsten hexafluoride.

Studying the Role for CD4+ T Cell Subsets in Human Lupus

DTIC Science & Technology

2013-07-01

heterogeneous, ranging from self- originating uric acid , calcium pyrophosphate crystals, choles- terol crystals, ATP, and glucose to environment-derived...Tardivel, and J. Tschopp. 2006. Gout- associated uric acid crystals activate the NALP3 inflammasome. Nature 440: 237–241. 44. Napirei, M., H. Karsunky, B...patterns (PAMPs) commonly found in microorganisms (1, 2). Different classes of PRRs have been identified. These receptors include TLRs, retinoic acid

The role of guanosine-3',5'-bis-pyrophosphate in mediating antimicrobial activity of the antibiotic 3,5-dihydroxy-4-ethyl-trans-stilbene.

PubMed Central

Sundar, L; Chang, F N

1992-01-01

The mode of action of 3,5-dihydroxy-4-ethyl-trans-stilbene (ES), an antibiotic produced by Xenorhabdus luminescens symbiotically associated with an entomopathogenic nematode, was investigated. ES was active against gram-positive and a number of gram-negative bacteria. In susceptible bacteria this antibiotic caused the inhibition of total RNA synthesis and, to a lesser extent, protein synthesis. At or above MICs, ES triggered a substantial accumulation of an intracellular regulatory compound, guanosine-3',5'-bis-pyrophosphate (ppGpp). This response was also noticed in species of bacteria which have previously not been shown to use ppGpp as a regulatory molecule. The involvement of ppGpp in antibiotic action was confirmed by using an isogenic stringent and a relaxed pair of Escherichia coli strains. The fact that the accumulation of ppGpp was correlated with the susceptibility of various gram-positive and gram-negative bacteria to ES suggests that this nucleotide is involved in the regulation of RNA synthesis and growth in all these microorganisms. Thus, inhibition of RNA synthesis via an increase in ppGpp concentrations may represent a mechanism that is prevalent among most bacteria and one that could be exploited for achieving a rapid inhibition of bacterial growth. Images PMID:1282791

Thiamine pyrophosphate requirement for o-succinylbenzoic acid synthesis in Escherichia coli and evidence for an intermediate.

PubMed Central

Meganathan, R; Bentley, R

1983-01-01

Cell-free extracts of various strains of Escherichia coli synthesize the menaquinone biosynthetic intermediate o-succinylbenzoic acid (OSB) when supplied with chorismic acid, 2-ketoglutaric acid, and thiamine pyrophosphate (TPP). To assay for OSB synthesis, 2-[U-14C]ketoglutaric acid was used as substrate, and the synthesized OSB was examined by radiogas chromatography (as the dimethyl ester). [U-14C]Shikimic acid also gave rise to radioactive OSB if the cofactors necessary for enzymatic conversion to chorismic acid were added. Use of 2-[1-14C]ketoglutaric acid does not give rise to labeled OSB. In the absence of TPP during the incubations, OSB synthesis was much reduced; these observations are consistent with the proposed role for the succinic semialdehyde-TPP anion as the reagent adding to chorismic acid. Extracts of cells from menC and menD mutants did not form OSB separately, but did so in combination. There was evidence for formation of a product, X, by extracts of a menC mutant incubated with chorismic acid, TPP, and 2-ketoglutaric acid; X was converted to OSB by extracts of a menD mutant. It appears that the intermediate, X, is formed by one gene product and converted to OSB by the second gene product. PMID:6337125

Turnover of cyclic 2,3-diphosphoglycerate in Methanobacterium thermoautotrophicum. Phosphate flux in P1- and H2-limited chemostat cultures.

PubMed

Krueger, R D; Campbell, J W; Fahrney, D E

1986-09-15

The archaebacterium Methanobacterium thermoautotrophicum was grown at 65 degrees C in H2- and Pi-limited chemostat cultures at dilution rates corresponding to 3- and 4-h doubling times, respectively. Under these conditions the steady state concentration of cyclic 2,3-diphosphoglycerate was 44 mM in the H2-limited cells and 13 mM in the cells grown under Pi limitation. Flux of Pi into the cyclic pyrophosphate pool was estimated by two 32P-labeling procedures: approach to isotopic equilibrium and replacement of prelabeled cyclic diphosphoglycerate with unlabeled compound. The results unequivocally demonstrate turnover of the phosphoryl groups; either both phosphoryl groups of the cyclic pyrophosphate leave together or the second leaves at a faster rate. The half-life of the rate-determining step for loss of the phosphoryl groups was approximately equal to the culture doubling time. The Pi flowing into the cyclic diphosphoglycerate pool accounted for 19% of the total Pi flux into Pi-limited cells and 43% of the total for H2-limited cells. The high phosphate flux through the large cyclic diphosphoglycerate pool suggests that this molecule plays an important role in the phosphorus metabolism of this methanogen.

Kinetic study of the thermal decomposition of uranium metaphosphate, U(PO3)4, into uranium pyrophosphate, UP2O7

NASA Astrophysics Data System (ADS)

Yang, Hee-Chul; Kim, Hyung-Ju; Lee, Si-Young; Yang, In-Hwan; Chung, Dong-Yong

2017-06-01

The thermochemical properties of uranium compounds have attracted much interest in relation to thermochemical treatments and the safe disposal of radioactive waste bearing uranium compounds. The characteristics of the thermal decomposition of uranium metaphosphate, U(PO3)4, into uranium pyrophosphate, UP2O7, have been studied from the view point of reaction kinetics and acting mechanisms. A mixture of U(PO3)4 and UP2O7 was prepared from the pyrolysis residue of uranium-bearing spent TBP. A kinetic analysis of the reaction of U(PO3)4 into UP2O7 was conducted using an isoconversional method and a master plot method on the basis of data from a non-isothermal thermogravimetric analysis. The thermal decomposition of U(PO3)4 into UP2O7 followed a single-step reaction with an activation energy of 175.29 ± 1.58 kJ mol-1. The most probable kinetic model was determined as a type of nucleation and nuclei-growth models, the Avrami-Erofeev model (A3), which describes that there are certain restrictions on nuclei growth of UP2O7 during the solid-state decomposition of U(PO3)4.

Integrated analysis of isopentenyl pyrophosphate (IPP) toxicity in isoprenoid-producing Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

George, Kevin W.; Thompson, Mitchell; Kim, Joonhoon

Isopentenyl pyrophosphate (IPP) toxicity presents a challenge in engineered microbial systems since its formation is unavoidable in terpene biosynthesis. Here in this work, we develop an experimental platform to study IPP toxicity in isoprenol-producing Escherichia coli. We first characterize the physiological response to IPP accumulation, demonstrating that elevated IPP levels are linked to growth inhibition, reduced cell viability, and plasmid instability. We show that IPP toxicity selects for pathway “breakage”, using proteomics to identify a reduction in phosphomevalonate kinase (PMK) as a probable recovery mechanism. Next, using multi-omics data, we demonstrate that endogenous E. coli metabolism is globally impacted bymore » IPP accumulation, which slows nutrient uptake, decreases ATP levels, and perturbs nucleotide metabolism. We also observe the extracellular accumulation of IPP and present preliminary evidence that IPP can be transported by E. coli, findings that might be broadly relevant for the study of isoprenoid biosynthesis. Finally, we discover that IPP accumulation leads to the formation of ApppI, a nucleotide analog of IPP that may contribute to observed toxicity phenotypes. This comprehensive assessment of IPP stress suggests potential strategies for the alleviation of prenyl diphosphate toxicity and highlights possible engineering targets for improved IPP flux and high titer isoprenoid production.« less

Pyrophosphate-Dependent Fructose-6-Phosphate 1-Phosphotransferase Induction and Attenuation of Hsp Gene Expression during Endosperm Modification in Quality Protein Maize1[C][W][OA

PubMed Central

Guo, Xiaomei; Ronhovde, Kyla; Yuan, Lingling; Yao, Bo; Soundararajan, Madhavan P.; Elthon, Thomas; Zhang, Chi; Holding, David R.

2012-01-01

Quality Protein Maize (QPM) is a hard-endosperm version of the high-lysine opaque2 (o2) maize (Zea mays) mutant, but the genes involved in modification of the soft o2 endosperm are largely unknown. Pyrophosphate-dependent fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the ATP-independent conversion of fructose-6-phosphate to fructose-1,6-bisphosphate in glycolysis. We found a large increase in transcript and protein levels of the α-regulatory subunit of PFP (PFPα) in QPM endosperm. In vitro enzyme assays showed a significant increase in forward PFP activity in developing endosperm extracts of QPM relative to the wild type and o2. An expressed retrogene version of PFPα of unknown function that was not up-regulated in QPM was also identified. The elevated expression levels of a number of ATP-requiring heat shock proteins (Hsps) in o2 endosperm are ameliorated in QPM. PFPα is also coinduced with Hsps in maize roots in response to heat, cold, and the unfolded protein response stresses. We propose that reduced ATP availability resulting from the generalized Hsp response in addition to the reduction of pyruvate, orthophosphate dikinase activity in o2 endosperm is compensated in part by increased PFP activity in QPM. PMID:22158678

Approved Antiviral Drugs over the Past 50 Years

PubMed Central

2016-01-01

SUMMARY Since the first antiviral drug, idoxuridine, was approved in 1963, 90 antiviral drugs categorized into 13 functional groups have been formally approved for the treatment of the following 9 human infectious diseases: (i) HIV infections (protease inhibitors, integrase inhibitors, entry inhibitors, nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and acyclic nucleoside phosphonate analogues), (ii) hepatitis B virus (HBV) infections (lamivudine, interferons, nucleoside analogues, and acyclic nucleoside phosphonate analogues), (iii) hepatitis C virus (HCV) infections (ribavirin, interferons, NS3/4A protease inhibitors, NS5A inhibitors, and NS5B polymerase inhibitors), (iv) herpesvirus infections (5-substituted 2′-deoxyuridine analogues, entry inhibitors, nucleoside analogues, pyrophosphate analogues, and acyclic guanosine analogues), (v) influenza virus infections (ribavirin, matrix 2 protein inhibitors, RNA polymerase inhibitors, and neuraminidase inhibitors), (vi) human cytomegalovirus infections (acyclic guanosine analogues, acyclic nucleoside phosphonate analogues, pyrophosphate analogues, and oligonucleotides), (vii) varicella-zoster virus infections (acyclic guanosine analogues, nucleoside analogues, 5-substituted 2′-deoxyuridine analogues, and antibodies), (viii) respiratory syncytial virus infections (ribavirin and antibodies), and (ix) external anogenital warts caused by human papillomavirus infections (imiquimod, sinecatechins, and podofilox). Here, we present for the first time a comprehensive overview of antiviral drugs approved over the past 50 years, shedding light on the development of effective antiviral treatments against current and emerging infectious diseases worldwide. PMID:27281742

Effect of chelators and nisin produced in situ on inhibition and inactivation of gram negatives.

PubMed

Boziaris, I S; Adams, M R

1999-12-15

The ability of chelators and nisin generated in situ to inhibit and inactivate E. coli and other gram negatives in a model substrate was investigated. The effect of various chelators and different concentrations of exogenous nisin on inhibition of E. coli in broth medium showed that only EDTA and pyrophosphates were able to cause appreciable inhibition of E. coli by nisin. In a broth where L. lactis NCFB 497 produced nisin in a concentration of 250-300 IU/ml, pyrophosphates were unable to inactivate E. coli. Under the same conditions, addition of EDTA led to inactivation of E. coli at neutral and slightly acidic pH only. A cocktail of strains of E. coli was less sensitive than E. coli ATCC 25922 alone. Pseudomonas aeruginosa was more sensitive and salmonellae more resistant. EDTA also caused a slight reduction in the L. lactis population and its biochemical activity as regards pH drop and acid production. Some of the inhibition of E. coli could be ascribed to the physical presence of Lactococcus cells rather than their metabolites excreted into the medium. Failure to observe any inhibition in fermented broths at their natural pH (4.0) was ascribed to the poor chelating power of EDTA under acid conditions.

Integrated analysis of isopentenyl pyrophosphate (IPP) toxicity in isoprenoid-producing Escherichia coli

DOE PAGES

George, Kevin W.; Thompson, Mitchell; Kim, Joonhoon; ...

2018-03-09

Isopentenyl pyrophosphate (IPP) toxicity presents a challenge in engineered microbial systems since its formation is unavoidable in terpene biosynthesis. Here in this work, we develop an experimental platform to study IPP toxicity in isoprenol-producing Escherichia coli. We first characterize the physiological response to IPP accumulation, demonstrating that elevated IPP levels are linked to growth inhibition, reduced cell viability, and plasmid instability. We show that IPP toxicity selects for pathway “breakage”, using proteomics to identify a reduction in phosphomevalonate kinase (PMK) as a probable recovery mechanism. Next, using multi-omics data, we demonstrate that endogenous E. coli metabolism is globally impacted bymore » IPP accumulation, which slows nutrient uptake, decreases ATP levels, and perturbs nucleotide metabolism. We also observe the extracellular accumulation of IPP and present preliminary evidence that IPP can be transported by E. coli, findings that might be broadly relevant for the study of isoprenoid biosynthesis. Finally, we discover that IPP accumulation leads to the formation of ApppI, a nucleotide analog of IPP that may contribute to observed toxicity phenotypes. This comprehensive assessment of IPP stress suggests potential strategies for the alleviation of prenyl diphosphate toxicity and highlights possible engineering targets for improved IPP flux and high titer isoprenoid production.« less

Acute neck pain caused by pseudogout attack of calcified cervical yellow ligament: a case report.

PubMed

Kobayashi, Takashi; Miyakoshi, Naohisa; Abe, Toshiki; Abe, Eiji; Kikuchi, Kazuma; Noguchi, Hideaki; Konno, Norikazu; Shimada, Yoichi

2016-05-30

Calcification of the yellow ligament sometimes compresses the spinal cord and can induce myelopathy. Usually, the calcification does not induce acute neck pain. We report a case of a patient with acute neck pain caused by calcium pyrophosphate dihydrate in a calcified cervical yellow ligament. A 70-year-old Japanese woman presented with acute neck pain. She had a moderately high fever (37.5 °C), and her neck pain was so severe that she could not move her neck in any direction. Computed tomography showed a high-density area between the C5 and C6 laminae suspicious for calcification of the yellow ligament. Magnetic resonance imaging showed intermediate-signal intensity on T1-weighted imaging and high-signal intensity on T2-weighted imaging surrounding a low-signal region on both T1- and T2-weighted imaging with cord compression. There was a turbid, yellow fluid collection in the yellow ligament at the time of operation. Histologically, calcium pyrophosphate dihydrate crystals were found in the fluid, and she was diagnosed as having a pseudogout attack of the yellow ligament. Pseudogout attack of the cervical yellow ligament is rare, but this clinical entity should be added to the differential diagnosis of acute neck pain, especially when calcification of the yellow ligament exists.

Discovery, clinical development, and therapeutic uses of bisphosphonates.

PubMed

Licata, Angelo A

2005-04-01

To review the literature concerning the history, development, and therapeutic uses of bisphosphonates. English-language articles were identified through a search of MEDLINE (through December 2004) using the key word bisphosphonate. Reference lists of pivotal studies, reviews, and full prescribing information for the approved agents were also examined. Selected studies included those that discussed the discovery and initial applications of bisphosphonates, as well as their historical development, pharmacokinetic and pharmacodynamic properties, and current therapeutic uses. Bisphosphonates structurally resemble pyrophosphates (naturally occurring polyphosphates) and have demonstrated similar physicochemical effects to pyrophosphates. In addition, bisphosphonates reduce bone turnover and resist hydrolysis when administered orally. The information gained from initial work with etidronate generated a considerable scientific effort to design new and more effective bisphosphonates. The PCP moiety in the general bisphosphonate structure is essential for binding to hydroxyapatite and allows for a number of chemical variations by changing the 2 lateral side chains (designated R(1) and R(2)). The R(1) side chain determines binding affinity to hydroxyapatite, and the R(2) side chain determines antiresorptive potency. Accordingly, each bisphosphonate has its own characteristic profile of activity. The bisphosphonates reduce bone turnover, increase bone mass, and decrease fracture risk and therefore have a significant place in the management of skeletal disorders including osteoporosis, Paget's disease, bone metastases, osteogenesis imperfecta, and heterotopic ossification.

Developmental accumulation of inorganic polyphosphate affects germination and energetic metabolism in Dictyostelium discoideum

PubMed Central

Livermore, Thomas Miles; Chubb, Jonathan Robert; Saiardi, Adolfo

2016-01-01

Inorganic polyphosphate (polyP) is composed of linear chains of phosphate groups linked by high-energy phosphoanhydride bonds. However, this simple, ubiquitous molecule remains poorly understood. The use of nonstandardized analytical methods has contributed to this lack of clarity. By using improved polyacrylamide gel electrophoresis we were able to visualize polyP extracted from Dictyostelium discoideum. We established that polyP is undetectable in cells lacking the polyphosphate kinase (DdPpk1). Generation of this ppk1 null strain revealed that polyP is important for the general fitness of the amoebae with the mutant strain displaying a substantial growth defect. We discovered an unprecedented accumulation of polyP during the developmental program, with polyP increasing more than 100-fold. The failure of ppk1 spores to accumulate polyP results in a germination defect. These phenotypes are underpinned by the ability of polyP to regulate basic energetic metabolism, demonstrated by a 2.5-fold decrease in the level of ATP in vegetative ppk1. Finally, the lack of polyP during the development of ppk1 mutant cells is partially offset by an increase of both ATP and inositol pyrophosphates, evidence for a model in which there is a functional interplay between inositol pyrophosphates, ATP, and polyP. PMID:26755590

Insoluble zinc, cupric and tin pyrophosphates inhibit the formation of volatile sulphur compounds.

PubMed

Jonski, G; Young, A; Wåler, S M; Rölla, G

2004-10-01

Oral malodour is mainly a result of the production of volatile sulphur compounds (VSC). The present study was concerned with investigating the anti-VSC effect of insoluble pyrophosphates (PP) of zinc, copper(II) and tin(II). The hypothesis to be tested was that the sulphide anions produced when VSC are solubilized in water have a higher affinity for the respective metal ions than the PP anion. The anti-VSC effects of insoluble PP were compared with the corresponding soluble metal salts using three in vitro methods: saliva putrefaction; dialysis of a suspension of PP and saliva against water; and analysis of water containing hydrogen sulphide and methyl mercaptan gases, and gases in the headspace. The levels of VSC were analysed by gas chromatography in the first and third methods, and released metal ions were analysed by atomic absorption spectroscopy in the second. The results showed that: the insoluble metal PP inhibited VSC formation in saliva by 99-100%; under dialysis, only minute amounts of metal ions are released from the combination of PP and saliva; and the PP lost their metal cations in water containing dissolved gases and inhibited VSC formation. Hence, the results support the experimental hypothesis. Sulphide ions are obviously very strong ligands for these metal ions.

Nucleosides and nucleotides. 192. Toward the total synthesis of cyclic ADP-carbocyclic-ribose. Formation of the intramolecular pyrophosphate linkage by a conformation-restriction strategy in a syn-form using a halogen substitution at the 8-position of the adenine ring.

PubMed

Sumita, Y; Shirato, M; Ueno, Y; Matsuda, A; Shuto, S

2000-01-01

The synthesis of cyclic ADP-carbocyclic-ribose (2), as a stable mimic for cyclic ADP-ribose, was investigated. Construction of the 18-membered backbone structure was successfully achieved by condensation of the two phosphate groups of 19, possibly due to restriction of the conformation of the substrate in a syn-form using an 8-chloro substituent at the adenine moiety. SN2 reactions between an optically active carbocyclic unit 8, which was constructed by a previously developed method, and 8-bromo-N6-trichloroacetyl-2',3'-O-isopropylideneadenosine 9c gave N-1-carbocyclic derivative, which was deprotected to give 5'-5"-diol derivatives 18. When 18 was treated with POCl3 in PO(OEt)3, the bromo group at the 8-position was replaced to give N-1-carbocyclic-8-chloroadenosine 5',5"-diphosphate derivative 19 in 43% yield. Treatment of 19 with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride gave the desired intramolecular condensation product 20 in 10% yield. This is the first chemical construction of the 18-membered backbone structure containing an intramolecular pyrophosphate linkage of a cADPR-related compound with an adenine base.

Human recombinant soluble guanylyl cyclase: expression, purification, and regulation

NASA Technical Reports Server (NTRS)

Lee, Y. C.; Martin, E.; Murad, F.

2000-01-01

The alpha1- and beta1-subunits of human soluble guanylate cyclase (sGC) were coexpressed in the Sf9 cells/baculovirus system. In addition to the native enzyme, constructs with hexahistidine tag at the amino and carboxyl termini of each subunit were coexpressed. This permitted the rapid and efficient purification of active recombinant enzyme on a nickel-affinity column. The enzyme has one heme per heterodimer and was readily activated with the NO donor sodium nitroprusside or 3-(5'-hydroxymethyl-2'furyl)-1-benzyl-indazole (YC-1). Sodium nitroprusside and YC-1 treatment potentiated each other in combination and demonstrated a remarkable 2,200-fold stimulation of the human recombinant sGC. The effects were inhibited with 1H-(1,2, 4)oxadiazole(4,3-a)quinoxalin-1one (ODQ). The kinetics of the recombinant enzyme with respect to GTP was examined. The products of the reaction, cGMP and pyrophosphate, inhibited the enzyme. The extent of inhibition by cGMP depended on the activation state of the enzyme, whereas inhibition by pyrophosphate was not affected by the enzyme state. Both reaction products displayed independent binding and cooperativity with respect to enzyme inhibition. The expression of large quantities of active enzyme will facilitate structural characterization of the protein.

Nucleoside pyrophosphatase activity associated with pig kidney alkaline phosphatase

PubMed Central

Wass, Milica; Butterworth, P. J.

1971-01-01

1. A study was made of the hydrolysis, at pH9.0, of ATP and ADP catalysed by pig kidney alkaline phosphatase. Both of these nucleoside pyrophosphates are substrates for the enzyme; Km values are 4×10−5m for ATP and 6.3×10−5m for ADP. Vmax. for ADP is approximately double that of ATP. 2. Above 0.1mm approximately, both ATP and ADP are inhibitory, but the inhibition is reversible by the addition of Mg2+ ions to form MgATP2− or MgADP− complexes. The complexes, besides being non-inhibitory, are also substrates for the enzyme with Km values identical with those of the respective free nucleotides. 3. Mg2+ ions are inhibitory when present in excess of ATP or ADP. The degree of inhibition is greater with ATP as substrate, but with both ATP and ADP a mixed competitive–non-competitive type of inhibition is observed. 4. It is suggested that under normal conditions the enzyme is inhibited by cellular concentrations of ATP plus ADP but that an increase in the concentration of Mg2+ ions stimulates activity by relieving nucleoside pyrophosphate inhibition. The properties may be of importance in the regulation of the transport of bivalent cations. PMID:4331861

Development of petri net-based dynamic model for improved production of farnesyl pyrophosphate by integrating mevalonate and methylerythritol phosphate pathways in yeast.

PubMed

Baadhe, Rama Raju; Mekala, Naveen Kumar; Palagiri, Satwik Reddy; Parcha, Sreenivasa Rao

2012-07-01

In this case study, we designed a farnesyl pyrophosphate (FPP) biosynthetic network using hybrid functional Petri net with extension (HFPNe) which is derived from traditional Petri net theory and allows easy modeling with graphical approach of various types of entities in the networks together. Our main objective is to improve the production of FPP in yeast, which is further converted to amorphadiene (AD), a precursor of artemisinin (antimalarial drug). Natively, mevalonate (MEV) pathway is present in yeast. Methyl erythritol phosphate pathways (MEP) are present only in higher plant plastids and eubacteria, but not present in yeast. IPP and DAMP are common isomeric intermediate in these two pathways, which immediately yields FPP. By integrating these two pathways in yeast, we augmented the FPP synthesis approximately two folds higher (431.16 U/pt) than in MEV pathway alone (259.91 U/pt) by using HFPNe technique. Further enhanced FPP levels converted to AD by amorphadiene synthase gene yielding 436.5 U/pt of AD which approximately two folds higher compared to the AD (258.5 U/pt) synthesized by MEV pathway exclusively. Simulation and validation processes performed using these models are reliable with identified biological information and data.

Changes in expression of soluble inorganic pyrophosphatases of Phaseolus vulgaris under phosphate starvation.

PubMed

Hernández-Domíguez, Eric E; Valencia-Turcotte, Lilián G; Rodríguez-Sotres, Rogelio

2012-05-01

Phosphorus is an essential element for all living cells, but its availability is often limiting in the soil. Plants have adapted to such limitation and respond to phosphorus deficiency. The soluble inorganic pyrophosphatases (PPase; EC 3.6.1.1) recycle the pyrophosphate produced by many biosynthetic reactions, and may play a role in the plant adaptation to phosphorus deficiency. In this work, three PPase mRNAs were identified from the Phaseolus vulgaris EST international database and their sequences were corroborated and completed using 3'RACE. After design and validation of the appropriate oligonucleotide primers, the PPase mRNA expression was measured by qRT-PCR in leaves, stems, and roots of bean plants grown with 1mM phosphate or under phosphate starvation. The plant tissues were classified according to their position on the plant, and some physiological signs of stress were recorded. qRT-PCR revealed changes in mRNA expression, but not for all isozymes under analysis, and not for all tissues. In addition, changes in the activity of some PPases were observed in zymograms. Our data are consistent with an important role for pyrophosphate in the adaptation of the plant to phosphate starvation. © 2012 Elsevier Ireland Ltd. All rights reserved.

Identification of New Drug Targets in Multi-Drug Resistant Bacterial Infections

DTIC Science & Technology

2013-10-01

observation allowed us to improve the substrate specificity assay and identify that threonine serves as an optimal substrate in the pyrophosphate exchange...activity was obtained, and the activity now seems to be optimal with the small hydroxyl containing amino acids threonine and serine. These... diabetic ulcers are favored sites of infection (6, 7). A. baumannii has also been shown to cause infections outside the health care setting, namely, severe

A mixed iron-manganese based pyrophosphate cathode, Na2Fe0.5Mn0.5P2O7, for rechargeable sodium ion batteries.

PubMed

Shakoor, Rana A; Park, Chan Sun; Raja, Arsalan A; Shin, Jaeho; Kahraman, Ramazan

2016-02-07

The development of secondary batteries based on abundant and cheap elements is vital. Among various alternatives to conventional lithium-ion batteries, sodium-ion batteries (SIBs) are promising due to the abundant resources and low cost of sodium. While there are many challenges associated with the SIB system, cathode is an important factor in determining the electrochemical performance of this battery system. Accordingly, ongoing research in the field of SIBs is inclined towards the development of safe, cost effective cathode materials having improved performance. In particular, pyrophosphate cathodes have recently demonstrated decent electrochemical performance and thermal stability. Herein, we report the synthesis, electrochemical properties, and thermal behavior of a novel Na2Fe0.5Mn0.5P2O7 cathode for SIBs. The material was synthesized through a solid state process. The structural analysis reveals that the mixed substitution of manganese and iron has resulted in a triclinic crystal structure (P1[combining macron] space group). Galvanostatic charge/discharge measurements indicate that Na2Fe0.5Mn0.5P2O7 is electrochemically active with a reversible capacity of ∼80 mA h g(-1) at a C/20 rate with an average redox potential of 3.2 V. (vs. Na/Na(+)). It is noticed that 84% of initial capacity is preserved over 90 cycles showing promising cyclability. It is also noticed that the rate capability of Na2Fe0.5Mn0.5P2O7 is better than Na2MnP2O7. Ex situ and CV analyses indicate that Na2Fe0.5Mn0.5P2O7 undergoes a single phase reaction rather than a biphasic reaction due to different Na coordination environment and different Na site occupancy when compared to other pyrophosphate materials (Na2FeP2O7 and Na2MnP2O7). Thermogravimetric analysis (25-550 °C) confirms good thermal stability of Na2Fe0.5Mn0.5P2O7 with only 2% weight loss. Owing to promising electrochemical properties and decent thermal stability, Na2Fe0.5Mn0.5P2O7, can be an attractive cathode for SIBs.

Cofortification of ferric pyrophosphate and citric acid/trisodium citrate into extruded rice grains doubles iron bioavailability through in situ generation of soluble ferric pyrophosphate citrate complexes.

PubMed

Hackl, Laura; Cercamondi, Colin I; Zeder, Christophe; Wild, Daniela; Adelmann, Horst; Zimmermann, Michael B; Moretti, Diego

2016-05-01

Iron fortification of rice is a promising strategy for improving iron nutrition. However, it is technically challenging because rice is consumed as intact grains, and ferric pyrophosphate (FePP), which is usually used for rice fortification, has low bioavailability. We investigated whether the addition of a citric acid/trisodium citrate (CA/TSC) mixture before extrusion increases iron absorption in humans from FePP-fortified extruded rice grains. We conducted an iron absorption study in iron-sufficient young women (n = 20), in which each participant consumed 4 different meals (4 mg Fe/meal): 1) extruded FePP-fortified rice (No CA/TSC); 2) extruded FePP-fortified rice with CA/TSC added before extrusion (CA/TSC extruded); 3) extruded FePP-fortified rice with CA/TSC solution added after cooking and before consumption (CA/TSC solution); and 4) nonextruded rice fortified with a FeSO4 solution added after cooking and before consumption (reference). Iron absorption was calculated from erythrocyte incorporation of stable iron isotopes 14 d after administration. In in vitro experiments, we assessed the soluble and dialyzable iron from rice meals in which CA/TSC was added at different preparation stages and from meals with different iron:CA:TSC ratios. Fractional iron absorption was significantly higher from CA/TSC-extruded meals (3.2%) than from No CA/TSC (1.7%) and CA/TSC solution (1.7%; all P < 0.05) and was not different from the FeSO4 reference meal (3.4%). In vitro solubility and dialyzability were higher in CA/TSC-extruded rice than in rice with No CA/TSC and CA/TSC solution, and solubility increased with higher amounts of added CA and TSC in extruded rice. Iron bioavailability nearly doubled when CA/TSC was extruded with FePP into fortified rice, resulting in iron bioavailability comparable to that of FeSO4 We attribute this effect to an in situ generation of soluble FePP citrate moieties during extrusion and/or cooking because of the close physical proximity of FePP and CA/TSC in the extruded rice matrix. This trial was registered at clinicaltrials.gov as NCT02176759. © 2016 American Society for Nutrition.

Origin of Blue-Green Emission in α-Zn2P2O7 and Local Structure of Ln3+ Ion in α-Zn2P2O7:Ln3+ (Ln = Sm, Eu): Time-Resolved Photoluminescence, EXAFS, and DFT Measurements.

PubMed

Gupta, Santosh Kumar; Ghosh, Partha Sarathi; Yadav, Ashok Kumar; Jha, Shambhu Nath; Bhattacharyya, Dibyendu; Kadam, Ramakant Mahadeo

2017-01-03

Considering the fact that pyrophosphate-based hosts are in high demand for making highly efficient luminescence materials, we doped two visible lanthanide ions, viz. Sm 3+ and Eu 3+ , in Zn 2 P 2 O 7 . Interestingly, it was oberved that pure Zn 2 P 2 O 7 displayed blue-green dual emission on irradiation with ultraviolet light. Emission and lifetime spectroscopy shows the presence of defects in pyrophosphate samples which are responsible for such emission. DFT calculations clearly pinpointed that the electronic transitions between defect states located at just below the conduction band minimum (arises due to V O 1+ and V O 2+ defects) and valence band maximum, as well as impurity states situated in the band gap, can lead to dual emission in the blue-green region, as is also indicated by emission and lifetime spectra. X-ray absorption near edge spectroscopy (XANES) shows the stabilization of europium as well as samarium ion in the +3 oxidation state in α-Zn 2 P 2 O 7 . The fact that α-Zn 2 P 2 O 7 has two different coordination numbers for zinc ions, i.e. five- and six-coordinate, the study of dopant ion distribution in this particular matrix will be an important step in realizing a highly efficient europium- and samarium-based red-emitting phosphor. Time resolved photoluminescence (TRPL) shows that both of these ions are heterogeneously distributed between five- and six-coordinated Zn 2+ sites and it is the six-coordinated Zn 2+ site which is the most favorable for lanthanide ion doping. Extended X-ray absorption fine structure (EXAFS) measurements also suggested that a six-coordinated zinc ion is the preferred site occupied by trivalent lanthanide ions, which is in complete agreement with TRPL results. It was observed that there is almost complete transfer of photon energy from Zn 2 P 2 O 7 to Eu 3+ , whereas this transfer is inefficient and almost incomplete in case of Sm 3+ , which is indeed important information for the realization of pyrophosphate-based tunable phosphors.

Kinetics of template-directed pyrophosphate-linked dideoxyguanylate synthesis as a function of 2-MeImpdG and poly(C) concentration: insights into the mechanism

NASA Technical Reports Server (NTRS)

Kanavarioti, A.; Gangopadhyay, S.

1999-01-01

Aqueous solutions of deoxyguanosine 5'-monophosphate 2-methylimidazolide, 2-MeImpdG, yield primarily deoxyguanosine 5'-monophosphate, 5'dGMP, and pyrophosphate-linked dideoxyguanylate, dG5'ppdG, abbreviated G2p (see Chart 1). The initial rate of G2p formation, d[G2p]/dt in M h-1, determined at 23 degrees C, pH 7.8, 1.0 M NaCl and 0.2 M Mg2+ by timed high-performance liquid chromatography (HPLC) analysis, exhibits a second-order dependence on 2-MeImpdG concentration, [G]o, indicating a bimolecular mechanism of dimerization in the range 0.02 M < or = [G]o < or = 0.09 M. In the presence of polycytidylate, poly(C), G2p synthesis is accelerated and oligodeoxyguanylate products are formed by incorporation of 2-MeImpdG molecules. The kinetics of G2p formation as a function of both monomer and polymer concentration, expressed in C equivalents, were also determined under the above conditions and exhibited a complex behavior. Specifically, at a constant [poly(C)], values of d[G2p]/dt typically increased with [G]o with a parabolic upward curvature. At a constant [G]o, values of d[G2p]/dt increase with [poly(C)], but level off at the higher poly(C) concentrations. As [G]o increases this saturation occurs at a higher poly(C) concentration, a result opposite to expectation for a simple complexation of two reacting monomers with the catalyst prior to reaction. Nevertheless, these results are shown to be quantitatively consistent with a template-directed (TD) mechanism of dimerization where poly(C) acts as the template to bind 2-MeImpdG in a cooperative manner and lead, for the first time, to the formulation of principles that govern template-directed chemistry. Analysis of the kinetic data via a proposed TD cooperative model provides association constants for the affinity between polymer and monomer and the intrinsic reactivity of 2-MeImpdG toward pyrophosphate synthesis. To the best of our knowledge, poly(C)/2-MeImpdG is the first system that could serve as a textbook example of a TD reaction under conditions such that the template is fully saturated by monomers and under conditions that it is not.

Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate.

PubMed

Schilmiller, Anthony L; Schauvinhold, Ines; Larson, Matthew; Xu, Richard; Charbonneau, Amanda L; Schmidt, Adam; Wilkerson, Curtis; Last, Robert L; Pichersky, Eran

2009-06-30

We identified a cis-prenyltransferase gene, neryl diphosphate synthase 1 (NDPS1), that is expressed in cultivated tomato (Solanum lycopersicum) cultivar M82 type VI glandular trichomes and encodes an enzyme that catalyzes the formation of neryl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. mRNA for a terpene synthase gene, phellandrene synthase 1 (PHS1), was also identified in these glands. It encodes an enzyme that uses neryl diphosphate to produce beta-phellandrene as the major product as well as a variety of other monoterpenes. The profile of monoterpenes produced by PHS1 is identical with the monoterpenes found in type VI glands. PHS1 and NDPS1 map to chromosome 8, and the presence of a segment of chromosome 8 derived from Solanum pennellii LA0716 causes conversion from the M82 gland monoterpene pattern to that characteristic of LA0716 plants. The data indicate that, contrary to the textbook view of geranyl diphosphate as the "universal" substrate of monoterpene synthases, in tomato glands neryl diphosphate serves as a precursor for the synthesis of monoterpenes.

Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate

PubMed Central

Schilmiller, Anthony L.; Schauvinhold, Ines; Larson, Matthew; Xu, Richard; Charbonneau, Amanda L.; Schmidt, Adam; Wilkerson, Curtis; Last, Robert L.; Pichersky, Eran

2009-01-01

We identified a cis-prenyltransferase gene, neryl diphosphate synthase 1 (NDPS1), that is expressed in cultivated tomato (Solanum lycopersicum) cultivar M82 type VI glandular trichomes and encodes an enzyme that catalyzes the formation of neryl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. mRNA for a terpene synthase gene, phellandrene synthase 1 (PHS1), was also identified in these glands. It encodes an enzyme that uses neryl diphosphate to produce β-phellandrene as the major product as well as a variety of other monoterpenes. The profile of monoterpenes produced by PHS1 is identical with the monoterpenes found in type VI glands. PHS1 and NDPS1 map to chromosome 8, and the presence of a segment of chromosome 8 derived from Solanum pennellii LA0716 causes conversion from the M82 gland monoterpene pattern to that characteristic of LA0716 plants. The data indicate that, contrary to the textbook view of geranyl diphosphate as the “universal” substrate of monoterpene synthases, in tomato glands neryl diphosphate serves as a precursor for the synthesis of monoterpenes. PMID:19487664

Genetic structure and regulation of isoprene synthase in Poplar (Populus spp.).

PubMed

Vickers, Claudia E; Possell, Malcolm; Nicholas Hewitt, C; Mullineaux, Philip M

2010-07-01

Isoprene is a volatile 5-carbon hydrocarbon derived from the chloroplastic methylerythritol 2-C-methyl-D: -erythritol 4-phosphate isoprenoid pathway. In plants, isoprene emission is controlled by the enzyme isoprene synthase; however, there is still relatively little known about the genetics and regulation of this enzyme. Isoprene synthase gene structure was analysed in three poplar species. It was found that genes encoding stromal isoprene synthase exist as a small gene family, the members of which encode virtually identical proteins and are differentially regulated. Accumulation of isoprene synthase protein is developmentally regulated, but does not differ between sun and shade leaves and does not increase when heat stress is applied. Our data suggest that, in mature leaves, isoprene emission rates are primarily determined by substrate (dimethylallyl diphosphate, DMADP) availability. In immature leaves, where isoprene synthase levels are variable, emission levels are also influenced by the amount of isoprene synthase protein. No thylakoid isoforms could be identified in Populus alba or in Salix babylonica. Together, these data show that control of isoprene emission at the genetic level is far more complicated than previously assumed.

A cis-prenyltransferase from Methanosarcina acetivorans catalyzes both head-to-tail and nonhead-to-tail prenyl condensation.

PubMed

Ogawa, Takuya; Emi, Koh-Ichi; Koga, Kazushi; Yoshimura, Tohru; Hemmi, Hisashi

2016-06-01

Cis-prenyltransferase usually consecutively catalyzes the head-to-tail condensation reactions of isopentenyl diphosphate to allylic prenyl diphosphate in the production of (E,Z-mixed) polyprenyl diphosphate, which is the precursor of glycosyl carrier lipids. Some recently discovered homologs of the enzyme, however, catalyze the nonhead-to-tail condensation reactions between allylic prenyl diphosphates. In this study, we characterize a cis-prenyltransferase homolog from a methanogenic archaeon, Methanosarcina acetivorans, to obtain information on the biosynthesis of the glycosyl carrier lipids within it. This enzyme catalyzes both head-to-tail and nonhead-to-tail condensation reactions. The kinetic analysis shows that the main reaction of the enzyme is consecutive head-to-tail prenyl condensation reactions yielding polyprenyl diphosphates, while the chain lengths of the major products seem shorter than expected for the precursor of glycosyl carrier lipids. On the other hand, a subsidiary reaction of the enzyme, i.e., nonhead-to-tail condensation between dimethylallyl diphosphate and farnesyl diphosphate, gives a novel diterpenoid compound, geranyllavandulyl diphosphate. © 2016 Federation of European Biochemical Societies.

Use of cyclodextrins in biotransformation reactions with cell cultures of Morus nigra: biosynthesis of prenylated chalcone isocordoin.

PubMed

Bolasco, Adriana; Fioravanti, Rossella; Rossi, Francesca; Rossi, Paola; Vitali, Alberto

2010-06-16

In vivo biotransformation experiments were performed by using a cell suspension culture of Morus nigra expressing a high PT (prenyltransferase) activity, fed with the target substrate 2',4'-dihydroxychalcone. In order to improve the reaction yields by enhancing the chalcone solubility, three different cyclodextrins have been used to host the substrate. The respective complexes have been studied by means of both spectroscopic and calorimetric techniques (Fourier-transform infrared, 1H-NMR and differential scanning calorimetry) and the solution behaviours have been characterized by solubility phase studies. The hydroxypropyl-beta-cyclodextrin complex was found to be the most suitable for biotransformation, and the reaction of prenylation resulted in a 6-fold higher yield of the final product when compared with the use of the free substrate. The reaction provided as the sole product the 3'-dimethylallyl derivative isocordoin, a biologically active plant compound. The results obtained allow the development of systems based on the use of biofermentors or the use of immobilized cells in order to enhance the biotransformation yields.

Familial chondrocalcinosis in the Spanish population.

PubMed

Fernandez Dapica, M P; Gómez-Reino, J J

1986-06-01

We have found in our clinic a 28.1% prevalence of familial chondrocalcinosis among 149 family members of 32 patients with calcium pyrophosphate dihydrate deposition disease. The clinical and radiological characteristics of these familial chondrocalcinosis patients were similar to those of the Chiloes with familial chondrocalcinosis previously reported. No significant clinical or radiological differences were detected between our sporadic and familial chondrocalcinosis patients. Our findings support the hypothesis that the Chiloes familial chondrocalcinosis was carried to Chile by Spanish immigrants.

Nontronite Particle Aggregation Induced by Microbial Fe(III) Reduction and Exopolysaccharide Production

DTIC Science & Technology

2007-01-01

polymers to achieve desired properties (such Chenu el al., 1979; Kimn el al., 2005). Among these as aggregation. dispersion ) without any structural...performed with and without Na pyrophosphate as a term ’aggregation’ broadly to include all processes that dispersant (25 mM) with shaking in a water...coagulation, at 25 mM was found to be optimal to disperse individual flocculation, agglutination, etc.). The results of this clay particles without

Sub-Equimolar Hydrolysis and Condensation of Organophosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alam, Todd M.; Kinnan, Mark K.; Wilson, Brendan W.

We characterized the in-situ hydrolysis and subsequent condensation reaction of the chemical agent simulant diethyl chlorophosphate (DECP) by high-resolution 31P NMR spectroscopy following the addition of water in sub-equimolar concentrations. Moreover, the identification and quantification of the multiple pyrophosphate and larger polyphosphate chemical species formed through a series of self-condensation reactions are reported. Finally, the DECP hydrolysis kinetics and distribution of breakdown species was strongly influenced by the water concentration and reaction temperature.

Isotopic Studies on Structure-function Relationships of Nucleic Acids and Enzymes. Three Year Progress Report, May 1972 -- October 1975

DOE R&D Accomplishments Database

Boyer, P. D.

1975-01-01

The most important accomplishments and major contributions are tabulated with citations to published work. The more important unpublished contributions deal with the early events in ATP formation by chloroplasts, energy linkage in reaction steps of oxidative phosphorylation, molecular integrity of parental DNA, bound pyrophosphate and {sup 18}O-exchanges by inorganic pyrophosphatase, and glutamine synthetase exchanges and mechanisms. These are being prepared for publication. (JSR)

Sub-Equimolar Hydrolysis and Condensation of Organophosphates

DOE PAGES

Alam, Todd M.; Kinnan, Mark K.; Wilson, Brendan W.; ...

2016-07-16

We characterized the in-situ hydrolysis and subsequent condensation reaction of the chemical agent simulant diethyl chlorophosphate (DECP) by high-resolution 31P NMR spectroscopy following the addition of water in sub-equimolar concentrations. Moreover, the identification and quantification of the multiple pyrophosphate and larger polyphosphate chemical species formed through a series of self-condensation reactions are reported. Finally, the DECP hydrolysis kinetics and distribution of breakdown species was strongly influenced by the water concentration and reaction temperature.

Ferrous ammonium phosphate (FeNH₄PO₄) as a new food fortificant: iron bioavailability compared to ferrous sulfate and ferric pyrophosphate from an instant milk drink.

PubMed

Walczyk, Thomas; Kastenmayer, Peter; Storcksdieck Genannt Bonsmann, Stefan; Zeder, Christophe; Grathwohl, Dominik; Hurrell, Richard F

2013-06-01

The main purpose of this study was to establish bioavailability data in humans for the new (Fe) fortification compound ferrous ammonium phosphate (FAP), which was specially developed for fortification of difficult-to-fortify foods where soluble Fe compounds cannot be used due to their negative impact on product stability. A double-blind, randomized clinical trial with cross-over design was conducted to obtain bioavailability data for FAP in humans. In this trial, Fe absorption from FAP-fortified full-cream milk powder was compared to that from ferric pyrophosphate (FPP) and ferrous sulfate. Fe absorption was determined in 38 young women using the erythrocyte incorporation dual stable isotope technique (⁵⁷Fe, ⁵⁸Fe). Geometric mean Fe absorption from ferrous sulfate, FAP and FPP was 10.4, 7.4 and 3.3 %, respectively. Fe from FAP was significantly better absorbed from milk than Fe from FPP (p < 0.0001). Fe absorption from FAP was significantly lower than Fe absorption from ferrous sulfate, which was used as water-soluble reference compound (p = 0.0002). Absorption ratios of FAP and FPP relative to ferrous sulfate as a measure of relative bioavailability were 0.71 and 0.32, respectively. The results of the present studies show that replacing FPP with FAP in full-cream milk could significantly improve iron bioavailability.

Evolutionary analysis of the TPP-dependent enzyme family.

PubMed

Costelloe, Seán J; Ward, John M; Dalby, Paul A

2008-01-01

The evolutionary relationships of the thiamine pyrophosphate (TPP)-dependent family of enzymes was investigated by generation of a neighbor joining phylogenetic tree using sequences from the conserved pyrophosphate (PP) and pyrimidine (Pyr) binding domains of 17 TPP-dependent enzymes. This represents the most comprehensive analysis of TPP-dependent enzyme evolution to date. The phylogeny was shown to be robust by comparison with maximum likelihood trees generated for each individual enzyme and also broadly confirms the evolutionary history proposed recently from structural comparisons alone (Duggleby 2006). The phylogeny is most parsimonious with the TPP enzymes having arisen from a homotetramer which subsequently diverged into an alpha(2)beta(2) heterotetramer. The relationship between the PP- and Pyr-domains and the recruitment of additional protein domains was examined using the transketolase C-terminal (TKC)-domain as an example. This domain has been recruited by several members of the family and yet forms no part of the active site and has unknown function. Removal of the TKC-domain was found to increase activity toward beta-hydroxypyruvate and glycolaldehyde. Further truncations of the Pyr-domain yielded several variants with retained activity. This suggests that the influence of TKC-domain recruitment on the evolution of the mechanism and specificity of transketolase (TK) has been minor, and that the smallest functioning unit of TK comprises the PP- and Pyr-domains, whose evolutionary histories extend to all TPP-dependent enzymes.

Molecular characterization of two isoforms of a farnesyl pyrophosphate synthase gene in wheat and their roles in sesquiterpene synthesis and inducible defence against aphid infestation.

PubMed

Zhang, Yan; Li, Zhi-Xia; Yu, Xiu-Dao; Fan, Jia; Pickett, John A; Jones, Huw D; Zhou, Jing-Jiang; Birkett, Michael A; Caulfield, John; Napier, Johnathan A; Zhao, Guang-Yao; Cheng, Xian-Guo; Shi, Yi; Bruce, Toby J A; Xia, Lan-Qin

2015-05-01

Aphids are important pests of wheat (Triticum aestivum) that affect crop production globally. Herbivore-induced emission of sesquiterpenes can repel pests, and farnesyl pyrophosphate synthase (FPS) is a key enzyme involved in sesquiterpene biosynthesis. However, fps orthologues in wheat and their functional roles in sesquiterpene synthesis and defence against aphid infestation are unknown. Here, two fps isoforms, Tafps1 and Tafps2, were identified in wheat. Quantitative real-time polymerase chain reaction (qRT-PCR) and in vitro catalytic activity analyses were conducted to investigate expression patterns and activity. Heterologous expression of these isoforms in Arabidopsis thaliana, virus-induced gene silencing (VIGS) in wheat and aphid behavioural assays were performed to understand the functional roles of these two isoforms. We demonstrated that Tafps1 and Tafps2 played different roles in induced responses to aphid infestation and in sesquiterpene synthesis. Heterologous expression in A. thaliana resulted in repulsion of the peach aphid (Myzus persicae). Wheat plants with these two isoforms transiently silenced were significantly attractive to grain aphid (Sitobion avenae). Our results provide new insights into induced defence against aphid herbivory in wheat, in particular, the different roles of the two Tafps isoforms in both sesquiterpene biosynthesis and defence against aphid infestation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site.

PubMed

Xu, Jinkun; Ai, Ying; Wang, Jianhui; Xu, Jingwei; Zhang, Yongkang; Yang, Dong

2017-05-01

S-limonene synthase is a model monoterpene synthase that cyclizes geranyl pyrophosphate (GPP) to form S-limonene. It is a relatively specific enzyme as the majority of its products are composed of limonene. In this study, we converted it to pinene or phellandrene synthases after introducing N345A/L423A/S454A or N345I mutations. Further studies on N345 suggest the polarity of this residue plays a critical role in limonene production by stabilizing the terpinyl cation intermediate. If it is mutated to a non-polar residue, further cyclization or hydride shifts occurs so the carbocation migrates towards the pyrophosphate, leading to the production of pinene or phellandrene. On the other hand, mutant enzymes that still possess a polar residue at this position produce limonene as the major product. N345 is not the only polar residue that may stabilize the terpinyl cation because it is not strictly conserved among limonene synthases across species and there are also several other polar residues in this area. These residues could form a "polar pocket" that may collectively play this stabilizing role. Our study provides important insights into the catalytic mechanism of limonene synthases. Furthermore, it also has wider implications on the evolution of terpene synthases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Precipitation of impurities in 9-32-0 grade fluid fertilizers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dillard, E.F.; Scheib, R.M.; Greenwell, B.E.

1986-01-01

For several years TVA has been studying production of 9-32-0 ammonium polyphosphate suspension produced from ammoniated merchant-grade wet-process orthophosphoric acid. Suspensions containing polyphosphate have an advantage over those that contain only orthophosphate in that they can be stored satisfactorily at much lower temperature. However, the introduction of polyphosphate (pyrophosphate anion) complicates the precipitation of impurities and has yielded inconsistent storage characteristics in 9-32-0 fluid fertilizers. Fluorine also has been shown to affect suspension fertilizer properties. The viscosity of 13-38-0 orthophosphate suspension fertilizers is affected by the atomic ratios F:(Al + Fe + Mg). Addition of fluorine prevents sludges and precipitatesmore » in ammonium polyphosphate fertilizer solutions - the proper amount of fluorine is related to the amount of each of the metallic impurities present and also to the fraction of the phosphate present as pyrophosphate. Incorporation of polyphosphate or fluorine or both has been shown to have positive effects on ammoniated wet-process phosphoric acid (WPPA), but they do not report the solubility relationships of the cation impurities (Fe, Al, Mg, and Ca) with respect to the anion constituents (PO/sub 4/, P/sub 2/O/sub 7/, and F). Therefore, a factorial study was developed to determine the solubility relationships of the precipitated metal impurities encountered in 9-32-0 fluid fertilizers. 10 refs., 1 fig., 20 tabs.« less

Partition coefficient of cadmium between organic soils and bean and oat plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddqui, M.F.R.; Courchesne, F.; Kennedy, G.

Environmental fate models require the partition coefficient data of contaminants among two or more environmental compartments. The bioaccumulation of cadmium (Cd) by bean and oat plants grown on organic soils in a controlled growth chamber was investigated to validate the plant/soil partition coefficient. Total Cd was measured in the soils and in the different parts of the plants. The mean total Cd concentrations for soil cultivated with beans and oats were 0.86 and 0.69 {micro}g/g, respectively. Selective extractants (BaCl{sub 2}, Na-pyrophosphate and HNO{sub 3}-hydroxy) were used to evaluate solid phase Cd species in the soil. In the soil cultivated withmore » bean, BaCl{sub 2} exchangeable, Na-pyrophosphate extractable and HNO{sub 3}-NH{sub 2}OH extractable Cd represented 1.2, 1.6 and 50.9% of total soil Cd, respectively. For the soil cultivated with oats, the same extractants gave values of 1.1, 1.8 and 61.9%. Cd concentration levels in bean plants followed the sequence roots > fruits = stems > leaves (p < 0.01) while the following sequence was observed for oat plants: roots > fruits > stems > leaves (p < 0.05). The partition coefficient for total Cd (Cd{sub Plant tissue}/Cd{sub Soil}) was in the range of 0.28--0.55 for bean plants and 1.03--1.86 for oat plants.« less

Lovastatin inhibits amyloid precursor protein (APP) beta-cleavage through reduction of APP distribution in Lubrol WX extractable low density lipid rafts.

PubMed

Won, Je-Seong; Im, Yeong-Bin; Khan, Mushfiquddin; Contreras, Miguel; Singh, Avtar K; Singh, Inderjit

2008-05-01

Previous studies have described that statins (inhibitors of cholesterol and isoprenoid biosynthesis) inhibit the output of amyloid-beta (Abeta) in the animal model and thus decrease risk of Alzheimer's disease. However, their action mechanism(s) in Abeta precursor protein (APP) processing and Abeta generation is not fully understood. In this study, we report that lovastatin treatment reduced Abeta output in cultured hippocampal neurons as a result of reduced APP levels and beta-secretase activities in low density Lubrol WX (non-ionic detergent) extractable lipid rafts (LDLR). Rather than altering cholesterol levels in lipid raft fractions and thus disrupting lipid raft structure, lovastatin decreased Abeta generation through down-regulating geranylgeranyl-pyrophosphate dependent endocytosis pathway. The inhibition of APP endocytosis by treatment with lovastatin and reduction of APP levels in LDLR fractions by treatment with phenylarsine oxide (a general endocytosis inhibitor) support the involvement of APP endocytosis in APP distribution in LDLR fractions and subsequent APP beta-cleavage. Moreover, lovastatin-mediated down-regulation of endocytosis regulators, such as early endosomal antigen 1, dynamin-1, and phosphatidylinositol 3-kinase activity, indicates that lovastatin modulates APP endocytosis possibly through its pleiotropic effects on endocytic regulators. Collectively, these data report that lovastatin mediates inhibition of LDLR distribution and beta-cleavage of APP in a geranylgeranyl-pyrophosphate and endocytosis-dependent manner.

Autophagy contributes to apoptosis in A20 and EL4 lymphoma cells treated with fluvastatin.

PubMed

Qi, Xu-Feng; Kim, Dong-Heui; Lee, Kyu-Jae; Kim, Cheol-Su; Song, Soon-Bong; Cai, Dong-Qing; Kim, Soo-Ki

2013-11-08

Convincing evidence indicates that statins stimulate apoptotic cell death in several types of proliferating tumor cells in a cholesterol-lowering-independent manner. However, the relationship between apoptosis and autophagy in lymphoma cells exposed to statins remains unclear. The objective of this study was to elucidate the potential involvement of autophagy in fluvastatin-induced cell death of lymphoma cells. We found that fluvastatin treatment enhanced the activation of pro-apoptotic members such as caspase-3 and Bax, but suppressed the activation of anti-apoptotic molecule Bcl-2 in lymphoma cells including A20 and EL4 cells. The process was accompanied by increases in numbers of annexin V alone or annexin V/PI double positive cells. Furthermore, both autophagosomes and increases in levels of LC3-II were also observed in fluvastatin-treated lymphoma cells. However, apoptosis in fluvastatin-treated lymphoma cells could be blocked by the addition of 3-methyladenine (3-MA), the specific inhibitor of autophagy. Fluvastatin-induced activation of caspase-3, DNA fragmentation, and activation of LC3-II were blocked by metabolic products of the HMG-CoA reductase reaction, such as mevalonate, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). These results suggest that autophagy contributes to fluvastatin-induced apoptosis in lymphoma cells, and that these regulating processes require inhibition of metabolic products of the HMG-CoA reductase reaction including mevalonate, FPP and GGPP.

Autophagy contributes to apoptosis in A20 and EL4 lymphoma cells treated with fluvastatin

PubMed Central

2013-01-01

Convincing evidence indicates that statins stimulate apoptotic cell death in several types of proliferating tumor cells in a cholesterol-lowering-independent manner. However, the relationship between apoptosis and autophagy in lymphoma cells exposed to statins remains unclear. The objective of this study was to elucidate the potential involvement of autophagy in fluvastatin-induced cell death of lymphoma cells. We found that fluvastatin treatment enhanced the activation of pro-apoptotic members such as caspase-3 and Bax, but suppressed the activation of anti-apoptotic molecule Bcl-2 in lymphoma cells including A20 and EL4 cells. The process was accompanied by increases in numbers of annexin V alone or annexin V/PI double positive cells. Furthermore, both autophagosomes and increases in levels of LC3-II were also observed in fluvastatin-treated lymphoma cells. However, apoptosis in fluvastatin-treated lymphoma cells could be blocked by the addition of 3-methyladenine (3-MA), the specific inhibitor of autophagy. Fluvastatin-induced activation of caspase-3, DNA fragmentation, and activation of LC3-II were blocked by metabolic products of the HMG-CoA reductase reaction, such as mevalonate, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). These results suggest that autophagy contributes to fluvastatin-induced apoptosis in lymphoma cells, and that these regulating processes require inhibition of metabolic products of the HMG-CoA reductase reaction including mevalonate, FPP and GGPP. PMID:24209962

Synthesis and Antimicrobial Evaluation of Amixicile-Based Inhibitors of the Pyruvate-Ferredoxin Oxidoreductases of Anaerobic Bacteria and Epsilonproteobacteria

PubMed Central

Kennedy, Andrew J.; Bruce, Alexandra M.; Gineste, Catherine; Ballard, T. Eric; Olekhnovich, Igor N.; Macdonald, Timothy L.

2016-01-01

Amixicile is a promising derivative of nitazoxanide (an antiparasitic therapeutic) developed to treat systemic infections caused by anaerobic bacteria, anaerobic parasites, and members of the Epsilonproteobacteria (Campylobacter and Helicobacter). Amixicile selectively inhibits pyruvate-ferredoxin oxidoreductase (PFOR) and related enzymes by inhibiting the function of the vitamin B1 cofactor (thiamine pyrophosphate) by a novel mechanism. Here, we interrogate the amixicile scaffold, guided by docking simulations, direct PFOR inhibition assays, and MIC tests against Clostridium difficile, Campylobacter jejuni, and Helicobacter pylori. Docking simulations revealed that the nitro group present in nitazoxanide interacts with the protonated N4′-aminopyrimidine of thiamine pyrophosphate (TPP). The ortho-propylamine on the benzene ring formed an electrostatic interaction with an aspartic acid moiety (B456) of PFOR that correlated with improved PFOR-inhibitory activity and potency by MIC tests. Aryl substitution with electron-withdrawing groups and substitutions of the propylamine with other alkyl amines or nitrogen-containing heterocycles both improved PFOR inhibition and, in many cases, biological activity against C. difficile. Docking simulation results correlate well with mechanistic enzymology and nuclear magnetic resonance (NMR) studies that show members of this class of antimicrobials to be specific inhibitors of vitamin B1 function by proton abstraction, which is both novel and likely to limit mutation-based drug resistance. PMID:27090174

Synthesis and Antimicrobial Evaluation of Amixicile-Based Inhibitors of the Pyruvate-Ferredoxin Oxidoreductases of Anaerobic Bacteria and Epsilonproteobacteria.

PubMed

Kennedy, Andrew J; Bruce, Alexandra M; Gineste, Catherine; Ballard, T Eric; Olekhnovich, Igor N; Macdonald, Timothy L; Hoffman, Paul S

2016-07-01

Amixicile is a promising derivative of nitazoxanide (an antiparasitic therapeutic) developed to treat systemic infections caused by anaerobic bacteria, anaerobic parasites, and members of the Epsilonproteobacteria (Campylobacter and Helicobacter). Amixicile selectively inhibits pyruvate-ferredoxin oxidoreductase (PFOR) and related enzymes by inhibiting the function of the vitamin B1 cofactor (thiamine pyrophosphate) by a novel mechanism. Here, we interrogate the amixicile scaffold, guided by docking simulations, direct PFOR inhibition assays, and MIC tests against Clostridium difficile, Campylobacter jejuni, and Helicobacter pylori Docking simulations revealed that the nitro group present in nitazoxanide interacts with the protonated N4'-aminopyrimidine of thiamine pyrophosphate (TPP). The ortho-propylamine on the benzene ring formed an electrostatic interaction with an aspartic acid moiety (B456) of PFOR that correlated with improved PFOR-inhibitory activity and potency by MIC tests. Aryl substitution with electron-withdrawing groups and substitutions of the propylamine with other alkyl amines or nitrogen-containing heterocycles both improved PFOR inhibition and, in many cases, biological activity against C. difficile Docking simulation results correlate well with mechanistic enzymology and nuclear magnetic resonance (NMR) studies that show members of this class of antimicrobials to be specific inhibitors of vitamin B1 function by proton abstraction, which is both novel and likely to limit mutation-based drug resistance. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Hydrolysis of aspartic acid phosphoramidate nucleotides: a comparative quantum chemical study.

PubMed

Michielssens, Servaas; Tien Trung, Nguyen; Froeyen, Matheus; Herdewijn, Piet; Tho Nguyen, Minh; Ceulemans, Arnout

2009-09-07

L-Aspartic acid has recently been found to be a good leaving group during HIV reverse transcriptase catalyzed incorporation of deoxyadenosine monophosphate (dAMP) in DNA. This showed that L-Asp is a good mimic for the pyrophosphate moiety of deoxyadenosine triphosphate. The present work explores the thermochemistry and mechanism for hydrolysis of several models for L-aspartic-dAMP using B3LYP/DGDZVP, MP2/6-311++G** and G3MP2 level of theory. The effect of the new compound is gradually investigated: starting from a simple methyl amine leaving group up to the aspartic acid leaving group. The enzymatic environment was mimicked by involving two Mg(2+) ions and some important active site residues in the reaction. All reactions are compared to the corresponding O-coupled leaving group, which is methanol for methyl amine and malic acid for aspartic acid. With methyl amine as a leaving group a tautomeric associative or tautomeric dissociative mechanism is preferred and the barrier is lower than the comparable mechanism with methanol as a leaving group. The calculations on the aspartic acid in the enzymatic environment show that qualitatively the mechanism is the same as for triphosphate but the barrier for hydrolysis by the associative mechanism is higher for L-aspartic-dAMP than for L-malic-dAMP and pyrophosphate.

Human mitochondrial pyrophosphatase: cDNA cloning and analysis of the gene in patients with mtDNA depletion syndromes.

PubMed

Curbo, Sophie; Lagier-Tourenne, Clotilde; Carrozzo, Rosalba; Palenzuela, Lluis; Lucioli, Simona; Hirano, Michio; Santorelli, Filippo; Arenas, Joaquin; Karlsson, Anna; Johansson, Magnus

2006-03-01

Pyrophosphatases (PPases) catalyze the hydrolysis of inorganic pyrophosphate generated in several cellular enzymatic reactions. A novel human pyrophosphatase cDNA encoding a 334-amino-acid protein approximately 60% identical to the previously identified human cytosolic PPase was cloned and characterized. The novel enzyme, named PPase-2, was enzymatically active and catalyzed hydrolysis of pyrophosphate at a rate similar to that of the previously identified PPase-1. A functional mitochondrial import signal sequence was identified in the N-terminus of PPase-2, which targeted the enzyme to the mitochondrial matrix. The human pyrophosphatase 2 gene (PPase-2) was mapped to chromosome 4q25 and the 1.4-kb mRNA was ubiquitously expressed in human tissues, with highest levels in muscle, liver, and kidney. The yeast homologue of the mitochondrial PPase-2 is required for mitochondrial DNA maintenance and yeast cells lacking the enzyme exhibit mitochondrial DNA depletion. We sequenced the PPA2 gene in 13 patients with mitochondrial DNA depletion syndromes (MDS) of unknown cause to determine if mutations in the PPA2 gene of these patients were associated with this disease. No pathogenic mutations were identified in the PPA2 gene of these patients and we found no evidence that PPA2 gene mutations are a common cause of MDS in humans.

Evaluation of salt, polyphosphates and their blends at different levels on physicochemical properties of buffalo meat and patties.

PubMed

Anjaneyulu, A S; Sharma, N; Kondaiah, N

1989-01-01

The effects of sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP), sodium hexametaphosphate (SHMP), sodium acid pyrophosphate (SAPP) and their blends at different levels (0·3, 0·5 and 0·7%), along with 2% sodium chloride on certain quality parameters of buffalo meat and patties were evaluated. The SPP, STPP and phosphate blends significantly increased pH, water-holding capacity (WHC), emulsifying capacity (EC), extractability of salt soluble proteins (SSP), colour of ground meat, decreased cooking loss (CL), improved emulsion stability (ES) and enhanced yield, texture and moisture retention of cooked patties. Compared to these phosphates, SAPP and SHMP had significantly poorer effects on improving the quality of meat and patties. The order of effectiveness of phosphates was SPP > STPP > SHMP. In general, pH, WHC, SSP, ES, yield and moisture content of patties increased progressively with increasing level of phosphate while CL decreased. Among blends containing two polyphosphates, those of 90% SPP + 10% SHMP and 75% SPP + 25% STPP were relatively more effective. A phosphate blend consisting of 65% SPP, 17·5% STPP and 17·5% SAPP was equally effective as that of SPP in improving the functionality of hot and chilled meat and had the advantage of reducing the amount of sodium by 3%. Copyright © 1989. Published by Elsevier Ltd.

Isoprenoids and tau pathology in sporadic Alzheimer's disease.

PubMed

Pelleieux, Sandra; Picard, Cynthia; Lamarre-Théroux, Louise; Dea, Doris; Leduc, Valérie; Tsantrizos, Youla S; Poirier, Judes

2018-05-01

The mevalonate pathway has been described to play a key role in Alzheimer's disease (AD) physiopathology. Farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) are nonsterol isoprenoids derived from mevalonate, which serve as precursors to numerous human metabolites. They facilitate protein prenylation; hFPP and hGGPP synthases act as gateway enzymes to the prenylation of the small guanosine triphosphate (GTP)ase proteins such as RhoA and cdc42 that have been shown to facilitate phospho-tau (p-Tau, i.e., protein tau phosphorylated) production in the brain. In this study, a significant positive correlation was observed between the synthases mRNA prevalence and disease status (FPPS, p < 0.001, n = 123; GGPPS, p < 0.001, n = 122). The levels of mRNA for hFPPS and hGGPPS were found to significantly correlate with the amount of p-Tau protein levels (p < 0.05, n = 34) and neurofibrillary tangle density (p < 0.05, n = 39) in the frontal cortex. Interestingly, high levels of hFPPS and hGGPPS mRNA prevalence are associated with earlier age of onset in AD (p < 0.05, n = 58). Together, these results suggest that accumulation of p-Tau in the AD brain is related, at least in part, to increased levels of neuronal isoprenoids. Copyright © 2018 Elsevier Inc. All rights reserved.

Chronic administration of thiamine pyrophosphate decreases age-related histological atrophic testicular changes and improves sexual behavior in male Wistar rats.

PubMed

Hernández-Montiel, H L; Vásquez López, C M; González-Loyola, J G; Vega-Anaya, G C; Villagrán-Herrera, M E; Gallegos-Corona, M A; Saldaña, C; Ramos Gómez, M; García Horshman, P; García Solís, P; Solís-S, J C; Robles-Osorio, M L; Ávila Morales, J; Varela-Echavarría, A; Paredes Guerrero, R

2014-06-01

Aging is a multifactorial universal process and constitutes the most important risk factor for chronic-degenerative diseases. Although it is a natural process, pathological aging arises when these changes occur quickly and the body is not able to adapt. This is often associated with the generation of reactive oxygen species (ROS), inflammation, and a decrease in the endogenous antioxidant systems, constituting a physiopathological state commonly found in chronic-degenerative diseases. At the testicular level, aging is associated with tissue atrophy, decreased steroidogenesis and spermatogenesis, and sexual behavior disorders. This situation, in addition to the elevated generation of ROS in the testicular steroidogenesis, provides a critical cellular environment causing oxidative damage at diverse cellular levels. To assess the effects of a reduction in the levels of ROS, thiamine pyrophosphate (TPP) was chronically administered in senile Wistar rats. TPP causes an activation of intermediate metabolism routes, enhancing cellular respiration and decreasing the generation of ROS. Our results show an overall decrease of atrophic histological changes linked to aging, with higher levels of serum testosterone, sexual activity, and an increase in the levels of endogenous antioxidant enzymes in TPP-treated animals. These results suggest that TPP chronic administration decreases the progression of age-related atrophic changes by improving the intermediate metabolism, and by increasing the levels of antioxidant enzymes.

Effect of elicitors and precursors on azadirachtin production in hairy root culture of Azadirachta indica.

PubMed

Srivastava, Smita; Srivastava, A K

2014-02-01

The present study involved strategies for enhancement in in vitro azadirachtin (commercially used biopesticide) production by hairy root cultivation of Azadirachta indica. Improvement in the azadirachtin production via triggering its biosynthetic pathway in plant cells was carried out by the exogenous addition of precursors and elicitors in the growth medium. Among the different abiotic stress inducers (Ag(+), Hg(+2), Co(+2), Cu(+2)) and signal molecules (methyl jasmonate and salicylic acid) tested, salicylic acid at 15 mg l(-1) of concentration was found to enhance the azadirachtin yield in the hairy roots to the maximum (up to 4.95 mg g(-1)). Similarly, among the different biotic elicitors tested (filter-sterilized fungal culture filtrates of Phoma herbarium, Alternaria alternata, Myrothecium sp., Fusarium solani, Curvularia lunata, and Sclerotium rolfsii; yeast extract; and yeast extract carbohydrate fraction), addition of filter-sterilized fungal culture filtrate of C. lunata (1 % v/v) resulted in maximum azadirachtin yield enhancement in hairy root biomass (up to 7.1 mg g(-1)) with respect to the control (3.3 mg g(-1)). Among all the biosynthetic precursors studied (sodium acetate, cholesterol, squalene, isopentynyl pyrophosphate, mavalonic acid lactone, and geranyl pyrophosphate), the overall azadirachtin production (70.42 mg l(-1) in 25 days) was found to be the highest with cholesterol (50 mg l(-1)) addition as an indirect precursor in the medium.

Comparison of LDPI to SPECT perfusion imaging using (99m)Tc-sestamibi and (99m)Tc-pyrophosphate in a murine ischemic hind limb model of neovascularization.

PubMed

Hendrikx, Geert; Vries, Mark H; Bauwens, Matthias; De Saint-Hubert, Marijke; Wagenaar, Allard; Guillaume, Joël; Boonen, Levinia; Post, Mark J; Mottaghy, Felix M

2016-12-01

We aimed to determine the accuracy of laser Doppler perfusion imaging (LDPI) in an animal model for hind limb ischemia. We used a murine (C57Bl/6 mice) ischemic hind limb model in which we compared LDPI with the clinically used (99m)Tc-sestamibi SPECT perfusion imaging (n = 7). In addition, we used the SPECT tracer (99m)Tc-pyrophosphate ((99m)Tc-PyP) to image muscular damage (n = 6). LDPI indicated a quick and prominent decrease in perfusion immediately after ligation, subsequently recovering to 21.9 and 25.2 % 14 days later in the (99m)Tc-sestamibi and (99m)Tc-PyP group, respectively. (99m)Tc-sestamibi SPECT scans also showed a quick decrease in perfusion. However, nearly full recovery was reached 7 days post ligation. Muscular damage, indicated by the uptake of (99m)Tc-PyP, was highest at day 3 and recovered to baseline levels at day 14 post ligation. Postmortem histology supported these findings, as a significantly increased collateral diameter was found 7 and 14 days after ligation and peak macrophage infiltration and TUNEL positivity was found on day 3 after ligation. Here, we indicate that LDPI strongly underestimates perfusion recovery in a hind limb model for profound ischemia.

Isoprenoids and related pharmacological interventions: potential application in Alzheimer's disease.

PubMed

Li, Ling; Zhang, Wei; Cheng, Shaowu; Cao, Dongfeng; Parent, Marc

2012-08-01

Two major isoprenoids, farnesyl pyrophosphate and geranylgeranyl pyrophosphate, serve as lipid donors for the posttranslational modification (known as prenylation) of proteins that possess a characteristic C-terminal motif. The prenylation reaction is catalyzed by prenyltransferases. The lipid prenyl group facilitates to anchor the proteins in cell membranes and mediates protein-protein interactions. A variety of important intracellular proteins undergo prenylation, including almost all members of small GTPase superfamilies as well as heterotrimeric G protein subunits and nuclear lamins. These prenylated proteins are involved in regulating a wide range of cellular processes and functions, such as cell growth, differentiation, cytoskeletal organization, and vesicle trafficking. Prenylated proteins are also implicated in the pathogenesis of different types of diseases. Consequently, isoprenoids and/or prenyltransferases have emerged as attractive therapeutic targets for combating various disorders. This review attempts to summarize the pharmacological agents currently available or under development that control isoprenoid availability and/or the process of prenylation, mainly focusing on statins, bisphosphonates, and prenyltransferase inhibitors. Whereas statins and bisphosphonates deplete the production of isoprenoids by inhibiting the activity of upstream enzymes, prenyltransferase inhibitors directly block the prenylation of proteins. As the importance of isoprenoids and prenylated proteins in health and disease continues to emerge, the therapeutic potential of these pharmacological agents has expanded across multiple disciplines. This review mainly discusses their potential application in Alzheimer's disease.

Prediction of renal crystalline size distributions in space using a PBE analytic model. 2. Effect of dietary countermeasures.

PubMed

Kassemi, Mohammad; Thompson, David

2016-09-01

An analytic Population Balance Equation model is used to assess the efficacy of citrate, pyrophosphate, and augmented fluid intake as dietary countermeasures aimed at reducing the risk of renal stone formation for astronauts. The model uses the measured biochemical profile of the astronauts as input and predicts the steady-state size distribution of the nucleating, growing, and agglomerating renal calculi subject to biochemical changes brought about by administration of these dietary countermeasures. Numerical predictions indicate that an increase in citrate levels beyond its average normal ground-based urinary values is beneficial but only to a limited extent. Unfortunately, results also indicate that any decline in the citrate levels during space travel below its normal urinary values on Earth can easily move the astronaut into the stone-forming risk category. Pyrophosphate is found to be an effective inhibitor since numerical predictions indicate that even at quite small urinary concentrations, it has the potential of shifting the maximum crystal aggregate size to a much smaller and plausibly safer range. Finally, our numerical results predict a decline in urinary volume below 1.5 liters/day can act as a dangerous promoter of renal stone development in microgravity while urinary volume levels of 2.5-3 liters/day can serve as effective space countermeasures. Copyright © 2016 the American Physiological Society.

A comparative study on the effects of glucose monohydrate, hot water, and sodium pyrophosphate on quality parameters and microbial flora of deboned and matured brisket.

PubMed

Gögüs, U; Bozoglu, F; Alpas, H

2007-09-01

Organic acids, hot water (HW), and chlorine have been commonly used in carcass decontamination for years. However, it has been observed that organic acids have adverse effects on color and are corrosive, while HW is discoloring. On the other hand, glucose fermentation by lactic acid bacteria in meat during the rigor period might be effective in microbial inhibition, without producing an adverse effect on the organoleptic quality of meat. Therefore, this study has aimed at finding an alternative meat decontamination procedure without any adverse effects. In this study, briskets were treated with 6 different applications: D (+) glucose monohydrate (GM) (16.51 g/100 mL, 15%) dip, HW dip, sodium pyrophosphate (SPP) and HW dip, GM + SPP + HW, and GM + HW combined dip. Then, the results of these applications were compared. First, GM + HW and GM + SPP + HW applications indicated more inhibition on Pseudomonas spp., Coliform and total Mesophile Aerob Bacteria growth, resulting in lower acidity loss (P < 0.01). Second, additional use of SPP with GM and HW did not enhance microbial inhibition (P < 0.01). Finally and most importantly, GM, 15%, improved a and b Hunter values significantly (P < 0.01), producing a very intense red meat color that can be very attractive for meat producers and consumers.

Recyclable Cu(II)-Coordination Crosslinked Poly(benzimidazolyl pyridine)s as High-Performance Polymers.

PubMed

Wang, Cheng; Yang, Li; Chang, Guanjun

2018-03-01

Crosslinked high-performance polymers have many industrial applications, but are difficult to recycle or rework. A novel class of recyclable crosslinking Cu(II)-metallo-supramolecular coordination polymers are successfully prepared, which possess outstanding thermal stability and mechanical property. More importantly, the Cu 2+ coordination interactions can be further removed via external pyrophosphate to recover the linear polymers, which endow the crosslinking polymers with recyclability. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanocomposite scintillator, detector, and method

DOEpatents

Cooke, D Wayne [Santa Fe, NM; McKigney, Edward A [Los Alamos, NM; Muenchausen, Ross E [Los Alamos, NM; Bennett, Bryan L [Los Alamos, NM

2009-04-28

A compact includes a mixture of a solid binder and at least one nanopowder phosphor chosen from yttrium oxide, yttrium tantalate, barium fluoride, cesium fluoride, bismuth germanate, zinc gallate, calcium magnesium pyrosilicate, calcium molybdate, calcium chlorovanadate, barium titanium pyrophosphate, a metal tungstate, a cerium doped nanophosphor, a bismuth doped nanophosphor, a lead doped nanophosphor, a thallium doped sodium iodide, a doped cesium iodide, a rare earth doped pyrosilicate, or a lanthanide halide. The compact can be used in a radiation detector for detecting ionizing radiation.

Evaluation of meniscus tears of the knee by radionuclide imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marymont, J.V.; Lynch, M.A.; Henning, C.E.

We compare the accuracy of radionuclide imaging of the knee with Tc99m-pyrophosphate with arthrography for the evaluation of meniscus tears in young athletes with clinically suspected knee injury. All patients had arthroscopy which was used as the standard against which the other two diagnostic procedures were compared. Radionuclide scintigraphy and arthrography were comparable in their ability to detect tears of the medial meniscus. Scintigraphy was superior for the detection of tears of the lateral meniscus and of both menisci.

Genetic control of enzyme formation. Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mills, S. E.

1978-07-26

Research progress is reported on work on tryptophan biosynthesis in Euglena gracilis and higher plants. The experimental data provide an outline of the general evolution of the pathway. Structural analyses of the pathway proteins by quantitative immunochemical methods have been completed; this was done with the anthranilate synthase-1 phosphoribosyl transferase complex in Escherichia coli. An examination of the evolution, in the Enterobacteriaceae, of the enzyme activities anthranilate synthase and anthranilate-5-1 phosphoribosyl-1-pyrophosphate phosphoribosyltransferase has been begun. (ACR)

Abnormal scintigraphic evolution in AA hepatic amyloidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lomena, F.; Rosello, R.; Pons, F.

1988-03-01

A patient with AA amyloidosis secondary to ankylosing spondylitis showed intense liver uptake of Tc-99m MDP on bone imaging. The biopsy showed hepatic amyloid deposition. A repeat bone scan with Tc-99m MDP 1 year later was negative, although the clinical signs and liver function tests of the patient had not changed. A mechanism might exist, other than the affinity of amyloid to calcium, which would explain the extraosseous uptake of pyrophosphates and diphosphonates in organs and soft tissues affected by systemic amyloidosis.

Potentially Prebiotic Syntheses of Condensed Phosphates

NASA Technical Reports Server (NTRS)

Keefe, Anthony D.; Miller, Stanley L.

1996-01-01

In view of the importance of a prebiotic source of high energy phosphates, we have investigated a number of potentially prebiotic processes to produce condensed phosphates from orthophosphate and cyclic trimetaphosphate from tripolyphosphate. The reagents investigated include polymerizing nitriles, acid anhydrides, lactones, hexamethylene tetramine and carbon suboxide. A number of these processes give substantial yields of pyrophosphate from orthophosphate and trimetaphosphate from tripolyphosphate. Although these reactions may have been applicable in local areas, they are not sufficiently robust to have been of importance in the prebiotic open ocean.

The Organic Matter Molecular Characteristics of Pyrogenic Solids and Their Aqueous Leachable Fractions

NASA Astrophysics Data System (ADS)

Wozniak, A. S.; Hatcher, P.; Mitra, S.; Bostick, K. W.; Zimmerman, A. R.

2016-02-01

Pyrogenic organic matter (Py-OM), or black carbon (BC), derives from the incomplete combustion of fossil fuels and biomass and is recognized for its impacts on soil chemistry, pollutant transport, climate, and regional and global carbon cycling. In fact, Py-OM is commonly applied to agricultural plots, in the form of "biochars," with the intention of enhancing agricultural production and the expectation of a carbon sequestration side benefit due to Py-OM's refractory and immobile nature. However, several studies of riverine, estuarine, and oceanic waters have detected tracers of dissolved Py-OM in appreciable quantities suggesting that it is more mobile in the environment than previously expected. The quantities and impacts of Py-OM released to aqueous systems are likely dependent on Py-OM molecular characteristics which in turn likely depend on initial combustion conditions and environmental processing. Yet, very little is known about the detailed molecular composition of these materials, let alone their relationships with combustion and environmental processing. Here, pyrophosphate extractable and water leachable components of a range of Py-OM materials (natural charcoals aged in the environment for variable lengths of time, oak and grass combusted over a range of temperatures) are examined by Fourier transform ion cyclotron resonance mass spectrometry. The molecular characteristics of the dissolved and pyrophosphate extractable Py-OM is then compared in the context of production conditions. Results of this study will greatly improve our understanding of Py-OM cycling between watersheds and the oceans.

Aluminum extracts in Antarctic paleosols: Proxy data for organic compounds and bacteria and implications for Martian paleosols

NASA Astrophysics Data System (ADS)

Mahaney, William C.; Hart, Kris M.; Dohm, James M.; Hancock, Ronald G. V.; Costa, Pedro; O'Reilly, Shane S.; Kelleher, Brian P.; Schwartz, Stephane; Lanson, Bruno

2011-05-01

Pyrophosphate-extractable Al has been used to establish the presence of organically-complexed compounds in middle latitude and tropical soils and paleosols on Earth. As proxy data used to establish the presence of organic molecules and trace movement within profiles, it has proved an accurate indicator of downward translocation in Spodosols (podzols). Antarctic paleosols, dating from Middle to Early Miocene age (15-20 Ma), are mineralic weathering profiles lacking A and B horizons. These profiles exhibit pavement/Cox/Cz/Cu horizons, largely with sandy silt textures, little clay, and exceedingly low concentrations of organic matter. Recent chemical investigations of 33 soil samples from the New Mountain and Aztec Mountain areas near the Inland Ice, adjacent to the Taylor Glacier, show that pyrophosphate-extractable Al concentrations vary in phase with organic carbon as determined by loss-on-ignition. While Al-extract concentrations in selected samples are low (< 0.15%), increasing values above nil approximately correlate positively with increases in bacterial populations of several common phylum, the extreme high numbers with more advanced biota including fossil Coleoptera. Available data suggest Al p extracts may target samples which may have undergone minor chelation, and which over long periods of time might have a cumulative weathering effect resulting in the accumulation of small concentrations of organic matter. As such, Al p extracts may prove useful in targeting the presence of life once in situ investigations of paleosols begin on Mars.

A novel dual-functional biosensor for fluorometric detection of inorganic pyrophosphate and pyrophosphatase activity based on globulin stabilized gold nanoclusters.

PubMed

Xu, Shenghao; Feng, Xiuying; Gao, Teng; Wang, Ruizhi; Mao, Yaning; Lin, Jiehua; Yu, Xijuan; Luo, Xiliang

2017-03-15

A novel ultrasensitive dual-functional biosensor for highly sensitive detection of inorganic pyrophosphate (PPi) and pyrophosphatase (PPase) activity was developed based on the fluorescent variation of globulin protected gold nanoclusters (Glo@Au NCs) with the assistance of Cu 2+ . Glo@Au NCs and PPi were used as the fluorescent indicator and substrate for PPase activity evaluation, respectively. In the presence of Cu 2+ , the fluorescence of the Glo@Au NCs will be quenched owing to the formation of Cu 2+ -Glo@Au NCs complex, while PPi can restore the fluorescence of the Cu 2+ -Glo@Au NCs complex because of its higher binding affinity with Cu 2+ . As PPase can catalyze the hydrolysis of PPi, it will lead to the release of Cu 2+ and re-quench the fluorescence of the Glo@Au NCs. Based on this mechanism, quantitative evaluation of the PPi and PPase activity can be achieved ranging from 0.05 μM to 218.125 μM for PPi and from 0.1 to 8 mU for PPase, with detection limits of 0.02 μM and 0.04 mU, respectively, which is much lower than that of other PPi and PPase assay methods. More importantly, this ultrasensitive dual-functional biosensor can also be successfully applied to evaluate the PPase activity in human serum, showing great promise for practical diagnostic applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Protein hydrolysate of salted duck egg white as a substitute of phosphate and its effect on quality of Pacific white shrimp (Litopenaeus vannamei).

PubMed

Kaewmanee, Thammarat; Benjakul, Soottawat; Visessanguan, Wonnop

2009-10-01

Protein hydrolysate from salted egg white (PHSEW) with different degrees of hydrolysis (DH) (3%, 6%, and 9%) was produced using pepsin. Disappearance of proteins with molecular weight (MW) of 108 and 85 kDa with the concomitant formation of proteins with MW of 23, 20, 13, and 5 kDa was observed in PHSEW. The use of PHSEW for quality improvement of Pacific white shrimp (Litopenaeus vannamei) was investigated. Shrimp soaked in 4% NaCl containing 7% PHSEW and 2.5% mixed phosphates (0.625% sodium acid pyrophosphate [SAPP] and 1.875% tetrasodium pyrophosphate [TSPP]) had the highest cooking yield with the lowest cooking loss (P < 0.05), compared with shrimps with other treatments. Nevertheless, no difference in weight gain was obtained in comparison with those treated with 4% NaCl containing 3.5% mixed phosphate (P > 0.05). Cooked shrimp treated with 4% NaCl containing 7% PHSEW and 2.5% mixed phosphate or those treated with 4% NaCl containing 3.5% mixed phosphate had the higher score of appearance, texture, and overall likeness but less shear force, in comparison with the control (no treatment) (P < 0.05). Microstructure study revealed that muscle fibers of cooked shrimp from both treatments had the swollen fibrils and gaps, while the control had the swollen compact structure. Therefore, use of PHSEW could reduce phosphate residue in shrimps without an adverse effect on sensory properties.

cDNA cloning and expression of carotenogenic genes during flower development in Gentiana lutea.

PubMed

Zhu, Changfu; Yamamura, Saburo; Koiwa, Hiroyuki; Nishihara, Masashiro; Sandmann, Gerhard

2002-02-01

All cDNAs involved in carotenoid biosynthesis leading to lycopene in yellow petals of Gentiana lutea have been cloned from a cDNA library. They encode a geranylgeranyl pyrophosphate synthase, a phytoene synthase, a phytoene desaturase and a zeta-carotene desaturase. The indicated function of all cDNAs was established by heterologous complementation in Escherichia coli. The amino acid sequences deduced from the cDNAs were between 47.5% and 78.9% identical to those reported for the corresponding enzymes from other higher plants. Southern analysis suggested that the genes for each enzyme probably represent a small multi-gene family. Tissue-specific expression of the genes and expression during flower development was investigated. The expression of the phytoene synthase gene, psy, was enhanced in flowers but transcripts were not detected in stems and leaves by northern blotting. Transcripts of the genes for geranylgeranyl pyrophosphate (ggpps), phytoene desaturase (pds) and zeta-carotene desaturase (zds) were detected in flowers and leaves but not in stems. Analysis of the expression of psy and zds in petals revealed that levels of the transcripts were lowest in young buds and highest in fully open flowers, in parallel with the formation of carotenoids. Obviously, the transcription of these genes control the accumulation of carotenoids during flower development in G. lutea. For pds only a very slight increase of mRNA was found whereas the transcripts of ggpps decreased during flower development.

Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Mononucleotides

NASA Technical Reports Server (NTRS)

Kanavarioti, Anastassia

1997-01-01

Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2- methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2(+) in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MelmpU and 2-MelmpC produce about 65% of oligomers including 4% of the 3',5'-Iinked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of intemucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MelmpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

Construction of a Turn Off-On-Off Fluorescent System Based on Competitive Coordination of Cu2+ between 6,7-Dihydroxycoumarin and Pyrophosphate Ion for Sensitive Assay of Pyrophosphatase Activity

PubMed Central

Zhao, Liu; Miao, Yanqing; Liu, Chunye; Zhang, Chenxiao

2016-01-01

The detection of pyrophosphatase (PPase) activity is of great significance in diagnosing diseases and understanding the function of PPase-related biological events. This study constructed a turn off-on-off fluorescent system for PPase activity assay based on PPase-regulated competitive coordination of Cu2+ between a water-soluble fluorescent probe 6,7-dihydroxycoumarin (DHC) and pyrophosphate (PPi). The probe DHC can coordinate with Cu2+ and consequently display on-off type fluorescence response. Furthermore, the in situ formed nonfluorescent Cu2+-DHC complex can act as an effective off-on type fluorescent probe for sensing PPi due to the higher coordination reactivity between Cu2+ and PPi than that between Cu2+ and DHC. The subsequent addition of PPase to the mixture containing Cu2+, DHC, and PPi leads to the fluorescence requenching of the system again (an off state) because PPase catalyzes the hydrolysis of PPi into orthophosphate in the reaction system. Under the optimum conditions, the decrease of the fluorescence intensity of DHC-Cu2+-PPi system was linear with the increase of the PPase activity in the range from 0.1 to 0.3 U. The detection limit was down to 0.028 U PPase (S/N = 3). Moreover, the as-established system was also applied to evaluate PPase inhibitor. This study offers a simple yet effective method for the detection of PPase activity. PMID:27766179

Definition of APC presentation of phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate to Vgamma2Vdelta 2 TCR.

PubMed

Wei, Huiyong; Huang, Dan; Lai, Xiaomin; Chen, Meiling; Zhong, Weihua; Wang, Richard; Chen, Zheng W

2008-10-01

Although microbial (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) can activate primate Vgamma2Vdelta2 T cells, molecular mechanisms by which HMBPP interacts with Vgamma2Vdelta2 T cells remain poorly characterized. Here, we developed soluble, tetrameric Vgamma2Vdelta2 TCR of rhesus macaques to define HMBPP/APC interaction with Vgamma2Vdelta2 TCR. While exogenous HMBPP was associated with APC membrane in an appreciable affinity, the membrane-associated HMBPP readily bound to the Vgamma2Vdelta2 TCR tetramer. The Vgamma2Vdelta2 TCR tetramer was shown to bind stably to HMBPP presented on membrane by various APC cell lines from humans and nonhuman primates but not those from mouse, rat, or pig. The Vgamma2Vdelta2 TCR tetramer also bound to the membrane-associated HMBPP on primary monocytes, B cells and T cells. Consistently, endogenous phosphoantigen produced in Mycobacterium-infected dendritic cells was transported and presented on membrane, and bound stably to the Vgamma2Vdelta2 TCR tetramer. The capability of APC to present HMBPP for recognition by Vgamma2Vdelta2 TCR was diminished after protease treatment of APC. Thus, our studies elucidated an affinity HMBPP-APC association conferring stable binding to the Vgamma2Vdelta2 TCR tetramer and the protease-sensitive nature of phosphoantigen presentation. The findings defined APC presentation of phosphoantigen HMBPP to Vgamma2Vdelta2 TCR.

Clinical and ultrasound findings in patients with calcium pyrophosphate dihydrate deposition disease.

PubMed

Vele, Paulina; Simon, Siao-Pin; Damian, Laura; Felea, Ioana; Muntean, Laura; Filipescu, Ileana; Rednic, Simona

2018-05-02

To evaluate the presence and distribution of calcium pyrophosphate (CPP) deposits in joints commonly affected by CPP deposition (CPPD) disease (acromio-clavicular, gleno-humeral, wrists, hips, knees, ankles, and symphysis pubis joints) using ultrasound (US). Thirty consecutive patients fulfilling McCarty diagnostic criteria for CPPD were consecutively enrolled in the study. The data registered using the US included the affected joints, the calcification site, and the pattern of calcification (thin hyperechoic bands, parallel to the surface of the hyaline cartilage, hyperechoic spots, and hyperechoic nodular or oval deposits). The presence of CPP crystals in knees was confirmed by polarized light microscopy examination of the synovial fluid and radiographs of the knees were performed in all patients. In 30 patients, 390 joints were scanned, (13 joints in every patient). The mean±standard deviation number of joints with US CPPD evidence per patient was 2.93±1.8 (range 1-9). The knee was the most common joint involved both clinically and using US examination. The second US pattern (with hyperechoic spots) was the most frequent. Fibrocartilage calcifications were more common than hyaline calcification. Using radiography as reference method, the sensitivity and specificity of US for diagnosis CPPD in knees was 79.31%, 95CI(66.65%-88.83%), and 14.29%, 95CI(1.78%-42.81%), respectively. The knee is the most frequent joint affected by CPPD. The second ultrasound pattern is the most common. CPPD affects the fibrocartilage to a greater extent than the hyaline cartilage.

Structural Model for the Flip-Flop Action in Thiamin Pyrophosphate-Dependent Human Pyruvate Dehydrogenase

NASA Technical Reports Server (NTRS)

Ciszak, Ewa; Dominiak, Paulina

2003-01-01

The derivative of vitamin B1 thiamin pyrophosphate (TPP) is a cofactor of enzymes performing catalysis in pathways of energy production, including (i) decarboxylation of alpha-keto acids followed by (ii) transketolation. These enzymes have shown a common mechanism of TPP activation by imposing an active V-conformation of this coenzyme that brings the N4 atom of the aminopyrimidine ring to the distance required for the intramolecular C-H N hydrogen-bonding with the C2- atom of the thiazolium ring. The reactive C2 atom of TPP is the nucleophile that attacks the carbonyl carbon of different substrates used by the TPP-dependent enzymes. The structure of the heterotetrameric human pyruvate dehydrogenase (Elp) recently determined in our laboratory (1) revealed the association pattern of the subunits and the specifics of two chemically equivalent cofactor binding sites. Dynamic nonequivalence of these two cofactor sites directs the flip-flop action of this enzyme, depending upon which two active sites effect each other (2). The crystal structure derived from the holo-form of Elp provided the basis for the model of the flip-flop action of Elp in which different steps of the catalytic reaction are performed in each of the two cofactor sites at any given moment, where these steps are governed by the concerted shuttle-like motion of the subunits. It is further proposed that balancing a hydrogen-bond network and related cofactor geometry determine the continuity of catalytic events.

Water-insoluble material from apple pomace makes changes in intracellular NAD⁺/NADH ratio and pyrophosphate content and stimulates fermentative production of hydrogen.

PubMed

Sato, Osamu; Suzuki, Yuma; Sato, Yuki; Sasaki, Shinsuke; Sonoki, Tomonori

2015-05-01

Apple pomace is one of the major agricultural residues in Aomori prefecture, Japan, and it would be useful to develop effective applications for it. As apple pomace contains easily fermentable sugars such as glucose, fructose and sucrose, it can be used as a feedstock for the fermentation of fuels and chemicals. We previously isolated a new hydrogen-producing bacterium, Clostridium beijerinckii HU-1, which could produce H2 at a production rate of 14.5 mmol of H2/L/h in a fed-batch culture at 37 °C, pH 6.0. In this work we found that the HU-1 strain produces H2 at an approximately 20% greater rate when the fermentation medium contains the water-insoluble material from apple pomace. The water-insoluble material from apple pomace caused a metabolic shift that stimulated H2 production. HU-1 showed a decrease of lactate production, which consumes NADH, accompanied by an increase of the intracellular pyrophosphate content, which is an inhibitor of lactate dehydrogenase. The intracellular NAD(+)/NADH ratios of HU-1 during H2 fermentation were maintained in a more reductive state than those observed without the addition of the water insoluble material. To correct the abnormal intracellular redox balance, caused by the repression of lactate production, H2 production with NADH oxidation must be stimulated. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Novel selenium containing boro-phosphate glasses: preparation and structural study.

PubMed

Ciceo-Lucacel, R; Radu, T; Ponta, O; Simon, V

2014-06-01

We synthesized a new boro-phosphate glass system with different %mol SeO2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P2O7(4-) dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO3(-) middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ3 or BØ2O(-) units. A small contribution of BØ4(-) units was also detected from the FT-IR spectra of glasses. For SeO2 content higher than 5mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. Copyright © 2014 Elsevier B.V. All rights reserved.

Translocation by T7 RNA polymerase: a sensitively poised Brownian ratchet.

PubMed

Guo, Qing; Sousa, Rui

2006-04-21

Studies of halted T7 RNA polymerase (T7RNAP) elongation complexes (ECs) or of T7RNAP transcription against roadblocks due to DNA-bound proteins indicate that T7RNAP translocates via a passive Brownian ratchet mechanism. Crystal structures of T7RNAP ECs suggest that translocation involves an active power-stroke. However, neither solution studies of halted or slowed T7RNAP ECs, nor crystal structures of static complexes, are necessarily relevant to how T7RNAP translocates during rapid elongation. A recent single molecule study of actively elongating T7RNAPs provides support for the Brownian ratchet mechanism. Here, we obtain additional evidence for the existence of a Brownian ratchet during active T7RNAP elongation by showing that both rapidly elongating and halted complexes are equally sensitive to pyrophosphate. Using chemical nucleases tethered to the polymerase we achieve sub-ångström resolution in measuring the average position of halted T7RNAP ECs and find that the positional equilibrium of the EC is sensitively poised between pre-translocated and post-translocated states. This may be important in maximizing the sensitivity of the polymerase to sequences that cause pausing or termination. We also confirm that a crystallographically observed disorder to order transition in a loop formed by residues 589-612 also occurs in solution and is coupled to pyrophosphate or NTP release. This transition allows the loop to make interactions with the DNA that help stabilize the laterally mobile, ligand-free EC against dissociation.

Pyrophosphate Supplementation Prevents Chronic and Acute Calcification in ABCC6-Deficient Mice.

PubMed

Pomozi, Viola; Brampton, Christopher; van de Wetering, Koen; Zoll, Janna; Calio, Bianca; Pham, Kevin; Owens, Jesse B; Marh, Joel; Moisyadi, Stefan; Váradi, András; Martin, Ludovic; Bauer, Carolin; Erdmann, Jeanette; Aherrahrou, Zouhair; Le Saux, Olivier

2017-06-01

Soft tissue calcification occurs in several common acquired pathologies, such as diabetes and hypercholesterolemia, or can result from genetic disorders. ABCC6, a transmembrane transporter primarily expressed in liver and kidneys, initiates a molecular pathway inhibiting ectopic calcification. ABCC6 facilitates the cellular efflux of ATP, which is rapidly converted into pyrophosphate (PPi), a major calcification inhibitor. Heritable mutations in ABCC6 underlie the incurable calcification disorder pseudoxanthoma elasticum and some cases of generalized arterial calcification of infancy. Herein, we determined that the administration of PPi and the bisphosphonate etidronate to Abcc6 -/- mice fully inhibited the acute dystrophic cardiac calcification phenotype, whereas alendronate had no significant effect. We also found that daily injection of PPi to Abcc6 -/- mice over several months prevented the development of pseudoxanthoma elasticum-like spontaneous calcification, but failed to reverse already established lesions. Furthermore, we found that the expression of low amounts of the human ABCC6 in liver of transgenic Abcc6 -/- mice, resulting in only a 27% increase in plasma PPi levels, led to a major reduction in acute and chronic calcification phenotypes. This proof-of-concept study shows that the development of both acute and chronic calcification associated with ABCC6 deficiency can be prevented by compensating PPi deficits, even partially. Our work indicates that PPi substitution represents a promising strategy to treat ABCC6-dependent calcification disorders. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Overproduction of isoprenoids by Saccharomyces cerevisiae in a synthetic grape juice medium in the absence of plant genes.

PubMed

Camesasca, L; Minteguiaga, M; Fariña, L; Salzman, V; Aguilar, P S; Gaggero, C; Carrau, F

2018-06-06

The objective of this work is to demonstrate if the hexaprenyl pyrophosphate synthetase Coq1p might be involved in monoterpenes synthesis in Saccharomyces cerevisiae, although its currently known function in yeast is to catalyze the first step in ubiquinone biosynthesis. However, in a BY4743 laboratory strain, the presence of an empty plasmid in a chemically defined grape juice medium results in a statistically significant increase of linalool, (E)-nerolidol and (E,E)-farnesol. When COQ1 is overexpressed from a plasmid, the levels of the volatile isoprenoids are further increased. Furthermore, overexpression of COQ1 in the same genetic context but with a mutated farnesyl pyrophosphate synthetase (erg20 mutation K197E), results in statistically significant higher levels of linalool (above 750 μg/L), geraniol, α-terpineol, and the sesquiterpenes, farnesol and nerolidol (total concentration of volatile isoprenoids surpasses 1300 μg/L). We show that the levels of monoterpenes and sesquiterpenes that S. cerevisiae can produce, in the absence of plant genes, depend on the composition of the medium and the genetic context. To the best of our knowledge, this is the highest level of linalool produced by S. cerevisiae up to now. Further research will be needed for understanding how COQ1 and the medium composition might interact to increase flavor complexity of fermented beverages. Copyright © 2018. Published by Elsevier B.V.

Radiation hardening of low condensation products containing amino group (in Japanese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okamura, S.; Hayashi, K.; Kaetsu, I.

1967-11-01

An initial condensation product is prepared by condensing a monomer selected from the group of urea, thiourea, melanine, aniline and acidamide with formalin. 0ne or more of the initial condensation product is then mixed with a substance which forms an acid or base by irradiation with an ionizing radiation in the presence or absence of the initial condensation product, except for halogenated hydrocarbon. The mixture is hardened by irradiation of the ionizing radiation to form a resinous substance. Formamide, acetamide, oxalic diamide, succinic diamide, acrylamide, etc. can be used as the acidamide monomer. Phosphonitrile chloride, cyanuric chloride, chloral hydrate, trichloroaceticmore » acid, monochloroacetic acid, ammonium chloride, aluminium chloride, gaseous chlorine, sullurous acid gas, sodium sulfite, aluminium sulfate, potassium hydrogensulfate, sodium pyrophosphate, potassium pyrophosphate, potassium phosphate, ammonia, bromine, bromal, bromal hydrate, dibromoacetic acid, sulfonated benzene, sulfonated toluene, etc. can be used as the acid- or base- forming substance. To the initial condensation product may be added 0.5-20%, in certain cases 20-50%, by weight of the said substances. The ionizing radiation can be electron beams. In an example, 2% chloral hydrate was homogeneously dissolved in the initial urea-formalin condensation product having a degree of condensation of 3--5. The solution was then irradiated by gamma rays at the dose rate of 4 x 10/sup 4/ r/hour from a /sup 60/Co source with a dose 5.0 x 10/sup 6/ roentgens. A white resinous composition was obtained. (JA)« less

The 3D protein of duck hepatitis A virus type 1 binds to a viral genomic 3' UTR and shows RNA-dependent RNA polymerase activity.

PubMed

Zhang, Yu; Cao, Qianda; Wang, Mingshu; Jia, Renyong; Chen, Shun; Zhu, Dekang; Liu, Mafeng; Sun, Kunfeng; Yang, Qiao; Wu, Ying; Zhao, Xinxin; Chen, Xiaoyue; Cheng, Anchun

2017-12-01

To explore the RNA-dependent RNA polymerase (RdRP) function of the 3D protein of duck hepatitis A virus type 1 (DHAV-1), the gene was cloned into the pET-32a(+) vector for prokaryotic expression. The 3' untranslated region (3' UTR) of DHAV-1 together with a T7 promoter was cloned into the pMD19-T vector for in vitro transcription of 3' UTR RNA, which was further used as a template in RNA-dependent RNA polymerization. In this study, three methods were applied to analyze the RdRP function of the 3D protein: (1) ammonium molybdate spectrophotometry to detect pyrophosphate produced during polymerization; (2) quantitative reverse transcription PCR (RT-qPCR) to investigate the changes in RNA quantity during polymerization; and (3) electrophoresis mobility shift assay to examine the interaction between the 3D protein and 3' UTR. The results showed the 3D protein was successfully expressed in bacteria culture supernatant in a soluble form, which could be purified by affinity chromatography. In 3D enzymatic activity assays, pyrophosphate and RNA were produced, the amounts of which increased based on approximative kinetics, and binding of the 3D protein to the 3' UTR was observed. These results indicate that prokaryotically expressed soluble DHAV-13D protein can bind to a viral genomic 3' UTR and exhibit RdRP activity.

Up-regulated expression of cartilage intermediate-layer protein and ANK in articular hyaline cartilage from patients with calcium pyrophosphate dihydrate crystal deposition disease.

PubMed

Hirose, Jun; Ryan, Lawrence M; Masuda, Ikuko

2002-12-01

Excess accumulation of extracellular inorganic pyrophosphate (ePPi) in aged human cartilage is crucial in calcium pyrophosphate dihydrate (CPPD) crystal formation in cartilage matrix. Two sources of ePPi are ePPi-generating ectoenzymes (NTPPPH) and extracellular transport of intracellular PPi by ANK. This study was undertaken to evaluate the role of NTPPPH and ANK in ePPi elaboration, by investigating expression of NTPPPH enzymes (cartilage intermediate-layer protein [CILP] and plasma cell membrane glycoprotein 1 [PC-1]) and ANK in human chondrocytes from osteoarthritic (OA) articular cartilage containing CPPD crystals and without crystals. Chondrocytes were harvested from knee cartilage at the time of arthroplasty (OA with CPPD crystals [CPPD], n = 8; OA without crystals [OA], n = 10). Normal adult human chondrocytes (n = 1) were used as a control. Chondrocytes were cultured with transforming growth factor beta1 (TGFbeta1), which stimulates ePPi elaboration, and/or insulin-like growth factor 1 (IGF-1), which inhibits ePPi elaboration. NTPPPH and ePPi were measured in the media at 48 hours. Media CILP, PC-1, and ANK were determined by dot-immunoblot analysis. Chondrocyte messenger RNA (mRNA) was extracted for reverse transcriptase-polymerase chain reaction to study expression of mRNA for CILP, PC-1, and ANK. NTPPPH and ANK mRNA and protein were also studied in fresh frozen cartilage. Basal ePPi elaboration and NTPPPH activity in conditioned media from CPPD chondrocytes were elevated compared with normal chondrocytes, and tended to be higher compared with OA chondrocytes. Basal expression of mRNA for CILP (chondrocytes) and ANK (cartilage) was higher in both CPPD chondrocytes and CPPD cartilage extract than in OA or normal samples. PC-1 mRNA was less abundant in CPPD chondrocytes and cartilage extract than in OA chondrocytes and extract, although the difference was not significant. CILP, PC-1, and ANK protein levels were similar in CPPD, OA, and normal chondrocytes or cartilage extracts. Both CILP and ANK mRNA expression and ePPi elaboration were stimulated by TGFbeta1 and inhibited by IGF-1 in chondrocytes from all sources. CILP and ANK mRNA expression correlates with chondrocyte ePPi accumulation around CPPD and OA chondrocytes, and all respond similarly to growth factor stimulation. These findings suggest that up-regulated CILP and ANK expression contributes to higher ePPi accumulation from CPPD crystal-forming cartilage.

Spondyloarthritis, diffuse idiopathic skeletal hyperostosis (DISH) and chondrocalcinosis.

PubMed

Armas, Jácome Brugues; Couto, Ana Rita; Bettencourt, Bruno Filipe

2009-01-01

The authors describe the main clinical and radiological findings of common enthesopathic disorders-spondylarthritis (SpA), chondrocalcinosis/calcium pyrophosphate dehydrate crystal deposition disease (CPPD CDD) and diffuse idiopathic skeletal hyperostosis (DISH), stressing similarities and differences which may help in the differential diagnosis. They emphasize the clinical presentation of the "pseudoankylosing spondylitis" forms of CPPD CDD. They also review the most relevant genes and molecular mechanisms associated with these conditions and with another enthesopathic disorder with high prevalence in the Japanese population-ossification of the posterior longitudinal ligament (OPLL).

Hepatocyte Growth Factor Inhibits Apoptosis by the Profibrotic Factor Angiotensin II via Extracellular Signal-regulated Kinase 1/2 in Endothelial Cells and Tissue Explants

DTIC Science & Technology

2010-12-01

were subjected to SDS- polyacryl - amide gel electrophoresis and electroblotted onto nitrocellulose membrane. Membranes were blocked with 5% bovine...1 mM sodium fluoride, 0.1 mM sodium orthovanadate, 1 mM tetrasodium pyrophosphate, 2 mM phenylmethylsulfonyl fluoride, 10 g/ml leupeptin, and 10 g...buffer [50 mM Tris-HCl, 1 mM EGTA, 1% (wt/vol) CHAPS, 10% glycerol, 50 mM sodium fluoride, 1 mM sodium orthovanadate, 2 mM phenylmethylsulfonyl fluoride

Structural and Mechanistic Analyses of TSC1/2 and Rheb 1/2-Mediated Regulation of the mTORC Pathway

DTIC Science & Technology

2010-07-01

endogenous mTORC1, the identification of buffer conditions that minimize mTORC1 disintegration and/or aggregation during purification, and the... disintegration of the already “weakened” mTORC1 and the complete abolishment of 4E-BP1 phosphorylation. Therefore, our work suggests that in vitro...mM EDTA or 5mM MgCl2, 10 mM pyrophosphate, 10 mM glycerophosphate, 0.3% CHAPS, or 1% Trition X-100 and one tablet of EDTA-free protease inhibitors

Nuclear cardiology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willerson, J.T.

1979-01-01

Nuclear Cardiology is a well-written, concise compendium of chapters that covers a wide range of topics in nuclear cardiology. Each chapter has been contributed by one or more recognized experts in the field, and the work is thoroughly referened. The physics and physiology of nuclear cardiology, myocardial imaging with /sup 201/Tl and /sup 99m/Tc pyrophosphate, left ventricular and right ventricular function, measurement of coronary blood flow with /sup 133/Xe, and microspheres are discussed, and there are chapters on metabolic imaging with positron emitters and on transmission computerized tomography of the heart.

Determination of phosphate phases in sewage sludge ash-based fertilizers by Raman microspectroscopy.

PubMed

Vogel, Christian; Adam, Christian; McNaughton, Don

2013-09-01

The chemical form of phosphate phases in sewage sludge ash (SSA)-based fertilizers was determined by Raman microspectroscopy. Raman mapping with a lateral resolution of 5 × 5 μm(2) easily detected different compounds present in the fertilizers with the help of recorded reference spectra of pure substances. Quartz and aluminosilicates showed Raman bands in the range of 450-520 cm(-1). Phosphates with apatite structure and magnesium triphosphate were determined at around 960 and 980 cm(-1), respectively. Furthermore, calcium/magnesium pyrophosphates were detected in some samples.

DNA sequencing with pyrophosphatase

DOEpatents

Tabor, S.; Richardson, C.C.

1996-03-12

A kit or solution is disclosed for use in extension of an oligonucleotide primer having a first single-stranded region on a template molecule and having a second single-stranded region homologous to the first single-stranded region. The first agent is able to cause extension of the first single-stranded region of the primer on the second single-stranded region of the template in a reaction mixture. The second agent is able to reduce the amount of pyrophosphate in the reaction mixture below the amount produced during the extension in the absence of the second agent.

Alterations in cholesterol and fatty acid biosynthesis in rat liver homogenates by aryloxy acids (Short Communication)

PubMed Central

Olson, Robert J.; Trumble, Thomas E.; Gamble, Wilbert

1974-01-01

2,4-Dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid inhibited the incorporation of [2-14C]mevalonate into cholesterol and non-saponifiable lipids. Both compounds inhibited the conversion of [1-14C]isopentenyl pyrophosphate into cholesterol and the synthesis of cholesterol and fatty acids from [2-14C]acetate. There was no inhibition of the conversion of [1-14C]mevalonate into CO2. At low concentrations (0.5mm) of the compounds there was a stimulation of acetate incorporation into fatty acids. PMID:4441387

DNA sequencing with pyrophosphatase

DOEpatents

Tabor, Stanley; Richardson, Charles C.

1996-03-12

A kit or solution for use in extension of an oligonucleotide primer having a first single-stranded region on a template molecule having a second single-stranded region homologous to the first single-stranded region, comprising a first agent able to cause extension of the first single-stranded region of the primer on the second single-stranded region of the template in a reaction mixture, and a second agent able to reduce the amount of pyrophosphate in the reaction mixture below the amount produced during the extension in the absence of the second agent.

Spectroscopic and Computational Investigations of Ligand Binding to IspH: Discovery of Non-diphosphate Inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Dowd, Bing; Williams, Sarah; Wang, Hongxin

Isoprenoid biosynthesis is an important area for anti-infective drug development. One isoprenoid target described is (E)-1-hydroxy-2-methyl-but-2-enyl 4-diphosphate (HMBPP) reductase (IspH), which forms isopentenyl diphosphate and dimethylallyl diphosphate from HMBPP in a 2H + /2e - reduction. IspH contains a 4 Fe-4 S cluster, and in this work, we first investigated how small molecules bound to the cluster by using HYSCORE and NRVS spectroscopies. The results of these, as well as other structural and spectroscopic investigations, led to the conclusion that, in most cases, ligands bound to IspH 4 Fe-4 S clusters by η 1 coordination, forming tetrahedral geometries at themore » unique fourth Fe, ligand side chains preventing further ligand (e.g., H 2 O, O 2 ) binding. Based on these ideas, we used in silico methods to find drug-like inhibitors that might occupy the HMBPP substrate binding pocket and bind to Fe, leading to the discovery of a barbituric acid analogue with a K i value of ≈500 nm against Pseudomonas aeruginosa IspH.« less

New Role of Flavin as a General Acid-Base Catalyst with No Redox Function in Type 2 Isopentenyl-diphosphate Isomerase*S⃞

PubMed Central

Unno, Hideaki; Yamashita, Satoshi; Ikeda, Yosuke; Sekiguchi, Shin-ya; Yoshida, Norie; Yoshimura, Tohru; Kusunoki, Masami; Nakayama, Toru; Nishino, Tokuzo; Hemmi, Hisashi

2009-01-01

Using FMN and a reducing agent such as NAD(P)H, type 2 isopentenyl-diphosphate isomerase catalyzes isomerization between isopentenyl diphosphate and dimethylallyl diphosphate, both of which are elemental units for the biosynthesis of highly diverse isoprenoid compounds. Although the flavin cofactor is expected to be integrally involved in catalysis, its exact role remains controversial. Here we report the crystal structures of the substrate-free and complex forms of type 2 isopentenyl-diphosphate isomerase from the thermoacidophilic archaeon Sulfolobus shibatae, not only in the oxidized state but also in the reduced state. Based on the active-site structures of the reduced FMN-substrate-enzyme ternary complexes, which are in the active state, and on the data from site-directed mutagenesis at highly conserved charged or polar amino acid residues around the active site, we demonstrate that only reduced FMN, not amino acid residues, can catalyze proton addition/elimination required for the isomerase reaction. This discovery is the first evidence for this long suspected, but previously unobserved, role of flavins just as a general acid-base catalyst without playing any redox roles, and thereby expands the known functions of these versatile coenzymes. PMID:19158086

New role of flavin as a general acid-base catalyst with no redox function in type 2 isopentenyl-diphosphate isomerase.

PubMed

Unno, Hideaki; Yamashita, Satoshi; Ikeda, Yosuke; Sekiguchi, Shin-Ya; Yoshida, Norie; Yoshimura, Tohru; Kusunoki, Masami; Nakayama, Toru; Nishino, Tokuzo; Hemmi, Hisashi

2009-04-03

Using FMN and a reducing agent such as NAD(P)H, type 2 isopentenyl-diphosphate isomerase catalyzes isomerization between isopentenyl diphosphate and dimethylallyl diphosphate, both of which are elemental units for the biosynthesis of highly diverse isoprenoid compounds. Although the flavin cofactor is expected to be integrally involved in catalysis, its exact role remains controversial. Here we report the crystal structures of the substrate-free and complex forms of type 2 isopentenyl-diphosphate isomerase from the thermoacidophilic archaeon Sulfolobus shibatae, not only in the oxidized state but also in the reduced state. Based on the active-site structures of the reduced FMN-substrate-enzyme ternary complexes, which are in the active state, and on the data from site-directed mutagenesis at highly conserved charged or polar amino acid residues around the active site, we demonstrate that only reduced FMN, not amino acid residues, can catalyze proton addition/elimination required for the isomerase reaction. This discovery is the first evidence for this long suspected, but previously unobserved, role of flavins just as a general acid-base catalyst without playing any redox roles, and thereby expands the known functions of these versatile coenzymes.

Anti-HIV and cytotoxic biphenyls, benzophenones and xanthones from stems, leaves and twigs of Garcinia speciosa.

PubMed

Pailee, Phanruethai; Kuhakarn, Chutima; Sangsuwan, Chanyapat; Hongthong, Sakchai; Piyachaturawat, Pawinee; Suksen, Kanoknetr; Jariyawat, Surawat; Akkarawongsapat, Radeekorn; Limthongkul, Jitra; Napaswad, Chanita; Kongsaeree, Palangpon; Prabpai, Samran; Jaipetch, Thaworn; Pohmakotr, Manat; Tuchinda, Patoomratana; Reutrakul, Vichai

2018-03-01

Eleven previously undescribed compounds, including four benzophenones (garciosones A-D), four xanthones (garciosones E-H) and three biphenyls (garciosines A-C), along with eighteen known compounds were isolated from the stems, leaves and twigs of Garcinia speciosa Wall. (Clusiaceae). Their structures were established by extensive spectroscopic analysis. For garciosines A-C, the structures were confirmed by single crystal X-ray diffraction analysis. Most of the isolated compounds were evaluated for their cytotoxic activity and anti-HIV-1 activity using the syncytium inhibition assay and HIV-1 reverse transcriptase (RT) assay. The known compounds, 4,6,3',4'-tetrahydroxy-2-methoxybenzophenone and macluraxanthone, displayed significant cytotoxic activity with the ED 50 in the range of 1.85-11.76 μM. 1,5-Dihydroxyxanthone exhibited the most potent anti-HIV activity against syncytium formation with EC 50  < 17.13 μM (SI > 25.28) and 2-(3,3-dimethylallyl)-1,3,7-trihydroxyxanthone was the most active compound in the HIV-1 reverse transcriptase assay with IC 50 value of 58.24 μM. Structure-activity relationship of some isolated compounds were also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deletion and Gene Expression Analyses Define the Paxilline Biosynthetic Gene Cluster in Penicillium paxilli

PubMed Central

Scott, Barry; Young, Carolyn A.; Saikia, Sanjay; McMillan, Lisa K.; Monahan, Brendon J.; Koulman, Albert; Astin, Jonathan; Eaton, Carla J.; Bryant, Andrea; Wrenn, Ruth E.; Finch, Sarah C.; Tapper, Brian A.; Parker, Emily J.; Jameson, Geoffrey B.

2013-01-01

The indole-diterpene paxilline is an abundant secondary metabolite synthesized by Penicillium paxilli. In total, 21 genes have been identified at the PAX locus of which six have been previously confirmed to have a functional role in paxilline biosynthesis. A combination of bioinformatics, gene expression and targeted gene replacement analyses were used to define the boundaries of the PAX gene cluster. Targeted gene replacement identified seven genes, paxG, paxA, paxM, paxB, paxC, paxP and paxQ that were all required for paxilline production, with one additional gene, paxD, required for regular prenylation of the indole ring post paxilline synthesis. The two putative transcription factors, PP104 and PP105, were not co-regulated with the pax genes and based on targeted gene replacement, including the double knockout, did not have a role in paxilline production. The relationship of indole dimethylallyl transferases involved in prenylation of indole-diterpenes such as paxilline or lolitrem B, can be found as two disparate clades, not supported by prenylation type (e.g., regular or reverse). This paper provides insight into the P. paxilli indole-diterpene locus and reviews the recent advances identified in paxilline biosynthesis. PMID:23949005

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems.

PubMed

Kemper, Katarina; Hirte, Max; Reinbold, Markus; Fuchs, Monika; Brück, Thomas

2017-01-01

With over 50.000 identified compounds terpenes are the largest and most structurally diverse group of natural products. They are ubiquitous in bacteria, plants, animals and fungi, conducting several biological functions such as cell wall components or defense mechanisms. Industrial applications entail among others pharmaceuticals, food additives, vitamins, fragrances, fuels and fuel additives. Central building blocks of all terpenes are the isoprenoid compounds isopentenyl diphosphate and dimethylallyl diphosphate. Bacteria like Escherichia coli harbor a native metabolic pathway for these isoprenoids that is quite amenable for genetic engineering. Together with recombinant terpene biosynthesis modules, they are very suitable hosts for heterologous production of high value terpenes. Yet, in contrast to the number of extracted and characterized terpenes, little is known about the specific biosynthetic enzymes that are involved especially in the formation of highly functionalized compounds. Novel approaches discussed in this review include metabolic engineering as well as site-directed mutagenesis to expand the natural terpene landscape. Focusing mainly on the validation of successful integration of engineered biosynthetic pathways into optimized terpene producing Escherichia coli , this review shall give an insight in recent progresses regarding manipulation of mostly diterpene synthases.

A novel flavonoid isolated from Sophora flavescens exhibited anti-angiogenesis activity, decreased VEGF expression and caused G0/G1 cell cycle arrest in vitro.

PubMed

Zhang, Xiu-Li; Cao, Mei-Ai; Pu, Li-Ping; Huang, Shuang-Sheng; Gao, Qing-Xiang; Yuan, Cheng-Shan; Wang, Chun-Ming

2013-05-01

Kushen, the dried root of Sophora flavescens Ait, is a traditional Chinese herbal medicine. Kushen alkaloids have been developed in China as anticancer drugs, and more potent antitumor activities have been identified in kushen flavonoids than in kushen alkaloids. In this study, the anti-angiogenic properties of (2S)-7,2',4'-triihydroxy-5-methoxy-8-dimethylallyl flavanone (Compound 1, a novel flavonoid isolated from Kushen), were examined using the human umbilical vein endothelial cell line (ECV304) in vitro. The results indicated that compound 1 shows anti-angiogenesis activity via inhibitory effects on cell proliferation, cell migration, cell adhesion, and tube formation. Further studies indicated that compound 1 blocks cell cycles in the G0/G1 phase without inducing apoptosis, and down regulates vascular endothelial growth factor (VEGF) expression. The free radical scavenging activity of compound 1 was found through 2',7'-dichlorofluorescin diacetate (DCFH-DA) incubation assay in cells. The anti-angiogenic properties of compound 1 and its antiproliferative effect on endothelial cells without causing apoptosis make it a good candidate for development as a agent against development of tumors.

Does ascorbic acid supplementation affect iron bioavailability in rats fed micronized dispersible ferric pyrophosphate fortified fruit juice?

PubMed

Haro-Vicente, Juan Francisco; Pérez-Conesa, Darío; Rincón, Francisco; Ros, Gaspar; Martínez-Graciá, Carmen; Vidal, Maria Luisa

2008-12-01

Food iron (Fe) fortification is an adequate approach for preventing Fe-deficiency anemia. Poorly water-soluble Fe compounds have good sensory attributes but low bioavailability. The reduction of the particle size of Fe fortificants and the addition of ascorbic acid might increase the bioavailability of low-soluble compounds. The present work aims to compare the Fe absorption and bioavailability of micronized dispersible ferric pyrophosphate (MDFP) (poorly soluble) to ferrous sufate (FS) (highly soluble) added to a fruit juice in presence or absence of ascorbic acid (AA) by using the hemoglobin repletion assay in rats. After a hemoglobin depletion period, four fruit juices comprised of (1) FS, (2) MDFP, (3) FS + AA, (4) MDFP + AA were produced and administered to a different group of rats (n = 18) over 21 days. During the repletion period, Fe balance, hemoglobin regeneration efficiency (HRE), relative bioavailability (RBV) and Fe tissue content were determined in the short, medium and long term. Fe absorption and bioavailability showed no significant differences between fortifying the fruit juice with FS or MDFP. The addition of AA to the juice enhanced Fe absorption during the long-term balance study within the same Fe source. HRE and Fe utilization increased after AA addition in both FS and MDFP groups in every period. Fe absorption and bioavailability from MDFP were comparable to FS added to a fruit juice in rats. Further, the addition of AA enhanced Fe absorption in the long term, as well as Fe bioavailability throughout the repletion period regardless of the Fe source employed.

Comparison of early myocardial technetium-99m pyrophosphate uptake to early peaking of creatine kinase and creatine kinase-MB as indicators of early reperfusion in acute myocardial infarction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondo, M.; Yuzuki, Y.; Arai, H.

1987-10-01

The value of technetium-99m pyrophosphate (Tc-99m-PYP) scintigraphy as an indicator of reperfusion 2.8 to 8 hours after the onset of symptoms of acute myocardial infarction was compared with the value of early peak creatine kinase (CK) and CK-MB release within 16 hours after the onset of symptoms. In 29 patients who received thrombolytic therapy, recanalization was seen (group 1) and in 7 it was not (group 2). In 23 patients (79%) in group 1 scintigraphic findings were positive and in all 7 in group 2 they were negative. In 15 patients (52%) in group 1 and 1 patient (14%) inmore » group 2, CK reached its peak level within 16 hours. In 20 patients (69%) in group 1 and 3 (43%) in group 2 the CK-MB level reached a peak within 16 hours. The sensitivity, specificity and predictive accuracy of positive results of early Tc-99m-PYP scintigraphy in predicting the reperfusion were 79%, 100% and 83%. These values are significantly higher than or similar to those of early peaking of CK and CK-MB release. In contrast to measurements of enzyme release, reperfusion data for Tc-99m-PYP scintigraphy are available immediately after thrombolytic therapy. Therefore, early Tc-99m-PYP scintigraphy (3 to 8 hours after onset of symptoms) is valuable as a noninvasive technique for early diagnosis of reperfusion.« less

Quantification of myocardial infarction: a comparison of single photon-emission computed tomography with pyrophosphate to serial plasma MB-creatine kinase measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, D.E.; Corbett, J.R.; Wolfe, C.L.

1985-08-01

Single photon-emission computed tomography (SPECT) with /sup 99m/Tc-pyrophosphate (PPi) has been shown to estimate size of myocardial infarction accurately in animals. The authors tested the hypothesis that SPECT with /sup /sup 99m//Tc-PPi and blood pool subtraction can provide prompt and accurate estimates of size of myocardial infarction in patients. SPECT estimates are potentially available early after the onset of infarction and should correlate with estimates of infarct size calculated from serial measurements of plasma MB-creatine kinase (CK) activity. Thirty-three patients with acute myocardial infarction and 16 control patients without acute myocardial infarction were studied. Eleven of the patients had transmuralmore » anterior myocardial infarction, 16 had transmural inferior myocardial infarction, and six had nontransmural myocardial infarction. SPECT was performed with a commercially available rotating gamma camera. Identical projection images of the distribution of 99mTc-PPi and the ungated cardiac blood pool were acquired sequentially over 180 degrees. Reconstructed sections were color coded and superimposed for purposes of localization of infarct. Areas of increased PPi uptake within myocardial infarcts were thresholded at 65% of peak activity. The blood pool was thresholded at 50% and subtracted to determine the endocardial border for the left ventricle. Myocardial infarcts ranged in size from 1 to 126 gram equivalents (geq) MB-CK. The correlation of MB-CK estimates of size of infarct with size determined by SPECT (both in geq) was good (r = .89 with a regression line of y = 13.1 + 1.5x).« less

Ultrasound detection of cartilage calcification at knee level in calcium pyrophosphate deposition disease.

PubMed

Gutierrez, Marwin; Di Geso, Luca; Salaffi, Fausto; Carotti, Marina; Girolimetti, Rita; De Angelis, Rossella; Filippucci, Emilio; Grassi, Walter

2014-01-01

To determine the sensitivity, specificity, and accuracy of ultrasound (US) in the detection of cartilage calcification at knee level in patients with calcium pyrophosphate deposition disease (CPDD) and to assess the interobserver reliability. Seventy-four CPDD patients and 83 controls with other chronic arthritis were included. All patients underwent a clinical examination, synovial fluid analysis, and radiographic assessment of the knee. US examinations were performed in order to detect hyperechoic spots within the hyaline cartilage layer and hyperechoic areas within the meniscal fibrocartilage. Twenty patients were assessed by 2 operators in order to calculate the interobserver reliability. A total of 314 knees in 157 patients (74 with CPDD, 19 with rheumatoid arthritis, 17 with spondyloarthritis, 32 with osteoarthritis, and 15 with gout) were assessed. In the 74 patients with CPDD, hyaline cartilage spots were detected by US in at least 1 knee in 44 patients (59.5%), whereas radiography detected hyaline cartilage spots in 34 patients (45.9%) (P < 0.001). Meniscal fibrocartilage calcifications were detected by US in 67 of the 74 CPDD patients (90.5%), whereas conventional radiography detected calcifications in 62 patients (83.7%) (P = 0.011). The criterion validity expressed as percentage of sensitivity, specificity, and accuracy of US in the detection of articular cartilage calcification was high. Both kappa values and overall agreement percentages showed moderate to excellent agreement. US is an accurate and reliable imaging technique in the detection of articular cartilage calcification at knee level in patients with CPDD. Copyright © 2014 by the American College of Rheumatology.

Investigation of reductive dechlorination supported by natural organic carbon

USGS Publications Warehouse

Rectanus, H.V.; Widdowson, M.A.; Chapelle, F.H.; Kelly, C.A.; Novak, J.T.

2007-01-01

Because remediation timeframes using monitored natural attenuation may span decades or even centuries at chlorinated solvent sites, new approaches are needed to assess the long-term sustainability of reductive dechlorination in ground water systems. In this study, extraction procedures were used to investigate the mass of indigenous organic carbon in aquifer sediment, and experiments were conducted to determine if the extracted carbon could support reductive dechlorination of chloroethenes. Aquifer sediment cores were collected from a site without an anthropogenic source of organic carbon where organic carbon varied from 0.02% to 0.12%. Single extraction results showed that 1% to 28% of sediment-associated organic carbon and 2% to 36% of the soft carbon were removed depending on nature and concentration of the extracting solution (Nanopure water; 0.1%, 0.5%, and 1.0% sodium pyrophosphate; and 0.5 N sodium hydroxide). Soft carbon is defined as organic carbon oxidized with potassium persulfate and is assumed to serve as a source of biodegradable carbon within the aquifer. Biodegradability studies demonstrated that 20% to 40% of extracted organic carbon was biodegraded aerobically and anaerobically by soil microorganisms in relatively brief tests (45 d). A five-step extraction procedure consisting of 0.1% pyrophosphate and base solutions was investigated to quantify bioavailable organic carbon. Using the extracted carbon as the sole electron donor source, tetrachloroethene was transformed to cis-1,2- dichloroethene and vinyl chloride in anaerobic enrichment culture experiments. Hydrogen gas was produced at levels necessary to sustain reductive dechlorination (>1 nM). ?? 2007 National Ground Water Association.

Adenine phosphoribosyltransferase from Sulfolobus solfataricus is an enzyme with unusual kinetic properties and a crystal structure that suggests it evolved from a 6-oxopurine phosphoribosyltransferase.

PubMed

Jensen, Kaj Frank; Hansen, Michael Riis; Jensen, Kristine Steen; Christoffersen, Stig; Poulsen, Jens-Christian Navarro; Mølgaard, Anne; Kadziola, Anders

2015-04-14

The adenine phosphoribosyltransferase (APRTase) encoded by the open reading frame SSO2342 of Sulfolobus solfataricus P2 was subjected to crystallographic, kinetic, and ligand binding analyses. The enzyme forms dimers in solution and in the crystals, and binds one molecule of the reactants 5-phosphoribosyl-α-1-pyrophosphate (PRPP) and adenine or the product adenosine monophosphate (AMP) or the inhibitor adenosine diphosphate (ADP) in each active site. The individual subunit adopts an overall structure that resembles a 6-oxopurine phosphoribosyltransferase (PRTase) more than known APRTases implying that APRT functionality in Crenarchaeotae has its evolutionary origin in this family of PRTases. Only the N-terminal two-thirds of the polypeptide chain folds as a traditional type I PRTase with a five-stranded β-sheet surrounded by helices. The C-terminal third adopts an unusual three-helix bundle structure that together with the nucleobase-binding loop undergoes a conformational change upon binding of adenine and phosphate resulting in a slight contraction of the active site. The inhibitor ADP binds like the product AMP with both the α- and β-phosphates occupying the 5'-phosphoribosyl binding site. The enzyme shows activity over a wide pH range, and the kinetic and ligand binding properties depend on both pH and the presence/absence of phosphate in the buffers. A slow hydrolysis of PRPP to ribose 5-phosphate and pyrophosphate, catalyzed by the enzyme, may be facilitated by elements in the C-terminal three-helix bundle part of the protein.

Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Monomucleotides

NASA Astrophysics Data System (ADS)

Kanavarioti, Anastassia

1997-08-01

Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2-methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2+ in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MeImpU and 2-MeImpC produce about 65% of oligomers including 4% of the 3',5'-linked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of internucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MeImpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

Conservation of Fold and Topology of Functional Elements in Thiamin Pyrophosphate Enzymes

NASA Technical Reports Server (NTRS)

Dominiak, P.; Ciszak, E. M.

2005-01-01

Thiamin pyrophosphate (TPP)-dependent enzymes are a highly divergent family of proteins binding both TPP and metal ions. They perform decarboxylation-hydroxyaldehydes. Prior -ketoacids and of a common - (O=)C-C(OH)- fragment of to knowledge of three-dimensional structures of these enzmes, the GDGY25-30NN sequence was used to identify these enzymes. Subsequently, a number of structural studies on those enzymes revealed multi-subunit organization and the features of the two duplicate cofactor binding sites. Analyzing the structures of 44 structurally known enzymes, we found that the common structure of these enzymes is reduced to 180-220 amino acid long fragments of two PP and two PYR domains that form the [PP:PYR]2 binding center of two cofactor molecules. The structures of PP and PYR are arranged in a similar fold-sheet with triplets of helices on both sides.Dconsisting of a six-stranded Residues surrounding the cofactors are not strictly conserved, but they provide the same interatomic contacts required for the catalytic functions that these enzymes perform while maintaining interactive structural integrity. These structural and functional amino acids are topological counterparts located in the same positions of the conserved fold of sets of PP and PYR domains. Additional parallels include short fragments of sequences that link these amino acids to the fold and function. This report on the structural commonalities amongst TPP dependent enzymes is thought to contribute new approaches to annotation that may assist in advancing the functional proteomics of TPP dependent enzymes, and trace their complexity within evolutionary context.

(99m)Tc-pyrophosphate scintigraphy for differentiating light-chain cardiac amyloidosis from the transthyretin-related familial and senile cardiac amyloidoses.

PubMed

Bokhari, Sabahat; Castaño, Adam; Pozniakoff, Ted; Deslisle, Susan; Latif, Farhana; Maurer, Mathew S

2013-03-01

Differentiating immunoglobulin light-chain (AL) from transthyretin-related cardiac amyloidoses (ATTR) is imperative given implications for prognosis, therapy, and genetic counseling. We validated the discriminatory ability of (99m)Tc-pyrophosphate ((99m)Tc-PYP) scintigraphy in AL versus ATTR. Forty-five subjects (12 AL, 16 ATTR wild type, and 17 ATTR mutants) underwent (99m)Tc-PYP planar and single-photon positive emission computed tomography cardiac imaging. Scans were performed by experienced nuclear cardiologists blinded to the subjects' cohort assignment. Cardiac retention was assessed with both a semiquantitative visual score (range, 0; no uptake to 3, diffuse uptake) and by quantitative analysis by drawing a region of interest over the heart corrected for contralateral counts and calculating a heart-to-contralateral ratio. Subjects with ATTR cardiac amyloid had a significantly higher semiquantitative cardiac visual score than the AL cohort (2.9±0.06 versus 0.8±0.27; P<0.0001) as well as a higher quantitative score (1.80±0.04 versus 1.21±0.04; P<0.0001). Using a heart-to-contralateral ratio >1.5 consistent with intensely diffuse myocardial tracer retention had a 97% sensitivity and 100% specificity with area under the curve 0.992, P<0.0001 for identifying ATTR cardiac amyloidosis. (99m)Tc-PYP cardiac imaging distinguishes AL from ATTR cardiac amyloidosis and may be a simple, widely available method for identifying subjects with ATTR cardiac amyloidosis, which should be studied in a larger prospective manner.

A profilometry-based dentifrice abrasion Method for V8 brushing machines. Part I: Introduction to RDA-PE.

PubMed

White, Donald J; Schneiderman, Eva; Colón, Ellen; St John, Samuel

2015-01-01

This paper describes the development and standardization of a profilometry-based method for assessment of dentifrice abrasivity called Radioactive Dentin Abrasivity - Profilometry Equivalent (RDA-PE). Human dentine substrates are mounted in acrylic blocks of precise standardized dimensions, permitting mounting and brushing in V8 brushing machines. Dentin blocks are masked to create an area of "contact brushing." Brushing is carried out in V8 brushing machines and dentifrices are tested as slurries. An abrasive standard is prepared by diluting the ISO 11609 abrasivity reference calcium pyrophosphate abrasive into carboxymethyl cellulose/glycerin, just as in the RDA method. Following brushing, masked areas are removed and profilometric analysis is carried out on treated specimens. Assessments of average abrasion depth (contact or optical profilometry) are made. Inclusion of standard calcium pyrophosphate abrasive permits a direct RDA equivalent assessment of abrasion, which is characterized with profilometry as Depth test/Depth control x 100. Within the test, the maximum abrasivity standard of 250 can be created in situ simply by including a treatment group of standard abrasive with 2.5x number of brushing strokes. RDA-PE is enabled in large part by the availability of easy-to-use and well-standardized modern profilometers, but its use in V8 brushing machines is enabled by the unique specific conditions described herein. RDA-PE permits the evaluation of dentifrice abrasivity to dentin without the requirement of irradiated teeth and infrastructure for handling them. In direct comparisons, the RDA-PE method provides dentifrice abrasivity assessments comparable to the gold industry standard RDA technique.

A surface physicochemical rationale for calculus formation in the oral cavity

NASA Astrophysics Data System (ADS)

Busscher, Henk J.; White, Don J.; Kamminga-Rasker, Hannetta J.; van der Mei, Henny C.

2004-01-01

Surface free energies of dental hard tissues, including salivary conditioning films on enamel, play a crucial role in mineralization, dissolution and adhesion processes at the tooth surface. These mineralization reactions at oral surfaces control the development and progression of various diseases. In this paper, we compare the surface free energies, as derived from measured contact angles with liquids, of salivary conditioning films on enamel after exposure to dentifrices with and without anti-calculus additives, such as hexametaphosphate, pyrophosphate or zinc citrate trihydrate. Measured contact angles were converted to surface free energies using the concept of Lifshitz-Van der Waals and Lewis acid-base components. Nearly all dentifrices yield film properties with a negative interfacial tension against an aqueous phase, which thermodynamically opposes mineralization. Concurrent with negative interfacial tensions, are positive values of the interfacial free energy of adhesion for octacalcium-phosphate (OCP) to the film surfaces, indicating that adhesion of newly mineralized, calcium-phosphate rich phases is thermodynamically unfavorable. Interestingly, two out of the three dentifrices with anti-calculus additives containing hexametaphosphate and pyrophosphate cause most positive interfacial free energies for OCP adhesion of 5.8 and 2.6 mJ/m 2, respectively. In summary, surface thermodynamical analyses indicate that anti-calculus effects of commercial dentifrice formulations are consistent with more negative interfacial tensions of salivary conditioning films on enamel surfaces and thus with more positive values for the interfacial free energy of adhesion toward newly formed mineral phases. A dentifrice containing hexametaphosphate yielded thermodynamic properties of salivary conditioning films most unfavorable for calculus formation.

Vitamin B1 diversity and characterization of biosynthesis genes in cassava.

PubMed

Mangel, Nathalie; Fudge, Jared B; Fitzpatrick, Teresa B; Gruissem, Wilhelm; Vanderschuren, Hervé

2017-06-15

Vitamin B1, which consists of the vitamers thiamin and its phosphorylated derivatives, is an essential micronutrient for all living organisms because it is required as a metabolic cofactor in several enzymatic reactions. Genetic diversity of vitamin B1 biosynthesis and accumulation has not been investigated in major crop species other than rice and potato. We analyzed cassava germplasm for accumulation of B1 vitamers. Vitamin B1 content in leaves and roots of 41 cassava accessions showed significant variation between accessions. HPLC analyses of B1 vitamers revealed distinct profiles in cassava leaves and storage roots, with nearly equal relative levels of thiamin pyrophosphate and thiamin monophosphate in leaves, but mostly thiamin pyrophosphate in storage roots. Unusually, the cassava genome has two genes encoding the 4-amino-2-methyl-5-hydroxymethylpyrimidine phosphate synthase, THIC (MeTHIC1 and MeTHIC2), both of which carry a riboswitch in the 3'-UTR, as well as the adenylated thiazole synthase, THI1 (MeTHI1a and MeTHI1b). The THIC and THI1 genes are expressed at very low levels in storage roots compared with the accumulation of vitamin B1, indicating only limited biosynthesis de novo therein. In leaves, vitamin B1 content is negatively correlated with THIC and THI1 expression levels, suggesting post-transcriptional regulation of THIC by the riboswitch present in the 3'-UTR of the THIC mRNA and regulation of THI1 by promoter activity or alternative post-transcriptional mechanisms. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Isoprenoid Pyrophosphate-Dependent Transcriptional Regulation of Carotenogenesis in Corynebacterium glutamicum

PubMed Central

Henke, Nadja A.; Heider, Sabine A. E.; Hannibal, Silvin; Wendisch, Volker F.; Peters-Wendisch, Petra

2017-01-01

Corynebacterium glutamicum is a natural producer of the C50 carotenoid decaprenoxanthin. The crtEcg0722crtBIYEb operon comprises most of its genes for terpenoid biosynthesis. The MarR-type regulator encoded upstream and in divergent orientation of the carotenoid biosynthesis operon has not yet been characterized. This regulator, named CrtR in this study, is encoded in many actinobacterial genomes co-occurring with terpenoid biosynthesis genes. CrtR was shown to repress the crt operon of C. glutamicum since DNA microarray experiments revealed that transcript levels of crt operon genes were increased 10 to 70-fold in its absence. Transcriptional fusions of a promoter-less gfp gene with the crt operon and crtR promoters confirmed that CrtR represses its own gene and the crt operon. Gel mobility shift assays with purified His-tagged CrtR showed that CrtR binds to a region overlapping with the −10 and −35 promoter sequences of the crt operon. Isoprenoid pyrophosphates interfered with binding of CrtR to its target DNA, a so far unknown mechanism for regulation of carotenogenesis. The molecular details of protein-ligand interactions remain to be studied. Decaprenoxanthin synthesis by C. glutamicum wild type was enhanced 10 to 30-fold upon deletion of crtR and was decreased 5 to 6-fold as result of crtR overexpression. Moreover, deletion of crtR was shown as metabolic engineering strategy to improve production of native and non-native carotenoids including lycopene, β-carotene, C.p. 450 and sarcinaxanthin. PMID:28484430

Properties and substrate specificities of the phenylalanyl-transfer-ribonucleic acid synthetases of Aesculus species

PubMed Central

Anderson, J. W.; Fowden, L.

1970-01-01

1. Phenylalanyl-tRNA synthetases have been partially purified from cotyledons of seeds of Aesculus californica, which contains 2-amino-4-methylhex-4-enoic acid, and from four other species of Aesculus that do not contain this amino acid. The A. californica preparation was free from other aminoacyl-tRNA synthetases, and the contaminating synthetase activity in preparations from A. hippocastanum was decreased to acceptable limits by conducting assays of pyrophosphate exchange activity in 0.5m-potassium chloride. 2. The phenylalanyl-tRNA synthetase from each species activated 2-amino-4-methylhex-4-enoic acid with Km 30–40 times that for phenylalanine. The maximum velocity for 2-amino-4-methylhex-4-enoic acid was only 30% of that for phenylalanine with the A. californica enzyme, but the maximum velocities for the two substrates were identical for the other four species. 3. 2-Amino-4-methylhex-4-enoic acid was not found in the protein of A. californica, so discrimination against this amino acid probably occurs in the step of transfer to tRNA, though subcellular localization, or subsequent steps of protein synthesis could be involved. 4. Crotylglycine, methallylglycine, ethallylglycine, 2-aminohex-4,5-dienoic acid, 2-amino-5-methylhex-4-enoic acid, 2-amino-4-methylhex-4-enoic acid, β-(thien-2-yl)alanine, β-(pyrazol-1-yl)alanine, phenylserine and m-fluorophenylalanine were substrates for pyrophosphate exchange catalysed by the phenylalanyl-tRNA synthetases of A. californica or A. hippocastanum. Allylglycine, phenylglycine and 2-amino-4-phenylbutyric acid were inactive. PMID:5493504

Computational Insights into Binding of Bisphosphates to Farnesyl Pyrophosphate Synthase

PubMed Central

Ohno, K; Mori, K; Orita, M; Takeuchi, M

2011-01-01

Bisphosphonates (BPs) are the most widely used and effective treatment for osteoporosis and Paget's disease. Non-nitrogen containing BPs (non-N-BPs), namely etidronate, clodronate, tiludronate, as well as nitrogen-containing BPs (N-BPs), namely pamidronate, alendronate, ibandronate, risedronate, zoledronate and minodronate have been launched on the market to date. N-BPs act by inhibiting the enzyme farnesyl pyrophosphate synthase (FPPS), and several crystal structures of complexes between FPPS and N-BPs have been revealed. Understanding the physical basis of the binding between protein and small molecules is an important goal in both medicinal chemistry and structural biology. In this review, we analyze in detail the energetic basis of molecular recognition between FPPS and N-BPs. First, we summarize the interactions between ligands and proteins observed in N-BPs-FPPS complexes in the Protein Data Bank (PDB). Second, we present an interaction energy analysis on the basis of full quantum mechanical calculation of FPPS and N-BP complexes using the fragment molecular orbital (FMO) method. The FMO result revealed that not only hydrogen bond and electrostatic interaction but also CH-O and π-π interaction with FPPS are important for N-BP’s potency. Third, we describe a binding site analysis of FPPS on the basis of the inhomogeneous solvation theory which, by clustering the results from an explicit solvent molecular dynamics simulation (MD), is capable of describing the entropic and enthalpic contributions to the free energies of individual hydration sites. Finally, we also discuss the structure-activity relationship (SAR) of the series of minodronate derivatives. PMID:21110804

Adenosine 5'-tetraphosphate phosphohydrolase from yellow lupin seeds: purification to homogeneity and some properties.

PubMed Central

Guranowski, A; Starzyńska, E; Brown, P; Blackburn, G M

1997-01-01

Adenosine 5'-tetraphosphate phosphohydrolase (EC 3.6.1.14) has been purified to homogeneity from the meal of yellow lupin (Lupinus luteus) seeds. The enzyme is a single polypeptide chain of 25+/-1 kDa. It catalyses the hydrolysis of a nucleoside 5'-tetraphosphate to a nucleoside triphosphate and orthophosphate, and hydrolysis of tripolyphosphate but neither pyrophosphate nor tetraphosphate. A divalent cation, Mg2+, Co2+, Ni2+ or Mn2+, is required for these reactions. The pH optimum for hydrolysis of adenosine 5'-tetraphosphate (p4A) is 8.2, Vmax is 21+/-1.7 micromol/min per mg of protein and the Km for p4A is 3+/-0.6 microM. At saturating p4A concentrations, the rate constant for the reaction is 8.5+/-0.7 s-1 [at 30 degrees C, in 50 mM Hepes/KOH (pH8.2)/5 mM MgCl2/0.1 mM dithiothreitol]. p4A and guanosine 5'-tetraphosphate are hydrolysed at the same rate. Adenosine 5'-pentaphosphate (p5A) is degraded 1/200 as fast and is converted into ATP and two molecules of orthophosphate, which are liberated sequentially. This contrasts with the cleavage of p5A by the lupin diadenosine tetraphosphate hydrolase (EC 3.6.1.17), which gives ATP and pyrophosphate. Zn2+, F- and Ca2+ ions inhibit the hydrolysis of p4A with I50 values of 0.1, 0.12 and 0.2 mM respectively. PMID:9359862

Using solid 13C NMR coupled with solution 31P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China.

PubMed

Liu, Shasha; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Wang, Hao; He, Zhongqi; Guo, Wenjing; Song, Fanhao; Giesy, John P

2017-01-01

Forms and labilities of plant-derived organic matters (OMs) including carbon (C) and phosphorus (P) were fundamental for understanding their release, degradation and environmental behaviour in lake ecosystems. Thus, solid 13 C and solution 31 P nuclear magnetic resonance (NMR) spectroscopy were used to characterize biomass of six aquatic plants in Tai Lake, China. The results showed that carbohydrates (61.2% of the total C) were predominant C functional group in the solid 13 C NMR spectra of plant biomass, which may indicate high lability and bioavailability of aquatic plants-derived organic matter in lakes. There was 72.6-103.7% of the total P in aquatic plant biomass extracted by NaOH-EDTA extracts. Solution 31 P NMR analysis of these NaOH-EDTA extracts further identified several molecular species of P including orthophosphate (50.1%), orthophosphate monoesters (46.8%), DNA (1.6%) and pyrophosphate (1.4%). Orthophosphate monoesters included β-glycerophosphate (17.7%), hydrolysis products of RNA (11.7%), α-glycerophosphate (9.2%) and other unknown monoesters (2.1%). Additionally, phytate, the major form of organic P in many lake sediments, was detected in floating plant water poppy. These inorganic P (e.g. orthophosphate and pyrophosphate) and organic P (e.g. diester and its degradation products) identified in plant biomass were all labile and bioavailable P, which would play an important role in recycling of P in lakes. These results increased knowledge of chemical composition and bioavailability of OMs derived from aquatic plants in lakes.

Identification of the Inorganic Pyrophosphate Metabolizing, ATP Substituting Pathway in Mammalian Spermatozoa

PubMed Central

Yi, Young-Joo; Sutovsky, Miriam; Kennedy, Chelsey; Sutovsky, Peter

2012-01-01

Inorganic pyrophosphate (PPi) is generated by ATP hydrolysis in the cells and also present in extracellular matrix, cartilage and bodily fluids. Fueling an alternative pathway for energy production in cells, PPi is hydrolyzed by inorganic pyrophosphatase (PPA1) in a highly exergonic reaction that can under certain conditions substitute for ATP-derived energy. Recombinant PPA1 is used for energy-regeneration in the cell-free systems used to study the zymology of ATP-dependent ubiquitin-proteasome system, including the role of sperm-borne proteasomes in mammalian fertilization. Inspired by an observation of reduced in vitro fertilization (IVF) rates in the presence of external, recombinant PPA1, this study reveals, for the first time, the presence of PPi, PPA1 and PPi transporter, progressive ankylosis protein ANKH in mammalian spermatozoa. Addition of PPi during porcine IVF increased fertilization rates significantly and in a dose-dependent manner. Fluorometric assay detected high levels of PPi in porcine seminal plasma, oviductal fluid and spermatozoa. Immunofluorescence detected PPA1 in the postacrosomal sheath (PAS) and connecting piece of boar spermatozoa; ANKH was present in the sperm head PAS and equatorial segment. Both ANKH and PPA1 were also detected in human and mouse spermatozoa, and in porcine spermatids. Higher proteasomal-proteolytic activity, indispensable for fertilization, was measured in spermatozoa preserved with PPi. The identification of an alternative, PPi dependent pathway for ATP production in spermatozoa elevates our understanding of sperm physiology and sets the stage for the improvement of semen extenders, storage media and IVF media for animal biotechnology and human assisted reproductive therapies. PMID:22485177

Relative bioavailability of micronized, dispersible ferric pyrophosphate added to an apple juice drink.

PubMed

Roe, Mark A; Collings, Rachel; Hoogewerff, Jurian; Fairweather-Tait, Susan J

2009-03-01

Food iron fortification is a sustainable and relatively simple strategy to reduce/prevent iron deficiency but is a challenge for the food industry because of possible adverse organoleptic changes caused by the added iron. A micronized dispersible ferric pyrophosphate, trademarked as SunActive Fe, has recently been developed. SunActive Fe has a small particle size, is water soluble and may be suitable for fortifying liquid products. To determine the relative bioavailability of SunActive Fe and its suitability for addition to pure apple juice. Iron absorption from SunActive Fe added to pure apple juice (Minute Maid) was compared with absorption from ferrous sulphate, a highly bioavailable form of iron, in 15 women with relatively low iron stores. Both forms of iron were enriched with an iron stable isotope and iron absorption from the apple juice drinks was calculated from the isotopic enrichment of red blood cells 14 days after the last test meal. Although mean absorption of iron from SunActive Fe was significantly lower than from ferrous sulphate (5.5% compared with 9.1%), the mean bioavailability of SunActive Fe iron relative to ferrous sulphate was 0.6, indicating that it is a good source of bioavailable iron. Iron Absorption from SunActive Fe was positively correlated (r = 0.97, P = 0.01) with absorption from ferrous sulphate, and negatively correlated with serum ferritin concentration (ferrous sulphate r = -0.81, P < 0.001; SunActive Fe r = -0.76, P = 0.01). SunActive Fe was well absorbed from apple juice and is a potentially useful fortificant for liquid food products.

Peritoneal delivery of sodium pyrophosphate blocks the progression of pre-existing vascular calcification in uremic apolipoprotein-E knockout mice.

PubMed

de Oliveira, Rodrigo B; Louvet, Loïc; Riser, Bruce L; Barreto, Fellype C; Benchitrit, Joyce; Rezg, Raja; Poirot, Sabrina; Jorgetti, Vanda; Drüeke, Tilman B; Massy, Ziad A

2015-08-01

Chronic kidney disease (CKD) is generally associated with disturbances of mineral and bone metabolism. They contribute to the development of vascular calcification (VC), a strong, independent predictor of cardiovascular risk. Pyrophosphate (PPi), an endogenous inhibitor of hydroxyapatite formation, has been shown to slow the progression of VC in uremic animals. Since in patients with CKD treatment is usually initiated for already existing calcifications, we aimed to compare the efficacy of PPi therapy with that of the phosphate binder sevelamer, using a uremic apolipoprotein-E knockout mouse model with advanced VCs. After CKD creation or sham surgery, 12-week-old female mice were randomized to one sham group and four CKD groups (n = 18-19/group). Treatment was initiated 8 weeks after left nephrectomy allowing prior VC development. Uremic groups received either intraperitoneal PPi (high dose, 1.65 mg/kg or low dose, 0.33 mg/kg per day), oral sevelamer (3 % in diet), or placebo treatment for 8 weeks. Both intima and media calcifications worsened with time in placebo-treated CKD mice, based on both quantitative image analysis and biochemical measurements. Progression of calcification between 8 and 16 weeks was entirely halted by PPi treatment, as it was by sevelamer treatment. PPi did not induce consistent bone histomorphometry changes. Finally, the beneficial vascular action of PPi probably involved mechanisms different from that of sevelamer. Further studies are needed to gain more precise insight into underlying mechanisms and to see whether PPi administration may also be useful in patients with CKD and VC.

A novel amido-pyrophosphate Mn(II) chelate complex with the synthetic ligand O{P(O)[NHC(CH3)3]2}2 (L): [Mn(L)2{OC(H)N(CH3)2}2]Cl2·2H2O.

PubMed

Tarahhomi, Atekeh; Pourayoubi, Mehrdad; Fejfarová, Karla; Dušek, Michal

2013-03-01

The title complex, trans-bis(dimethylformamide-κO)bis{N,N'-N'',N'''-tetra-tert-butyl[oxybis(phosphonic diamide-κO)]}manganese(II) dichloride dihydrate, [Mn(C16H40N4O3P2)2(C3H7NO)2]Cl2·2H2O, is the first example of a bis-chelate amido-pyrophosphate (pyrophosphoramide) complex containing an O[P(O)(NH)2]2 fragment. Its asymmetric unit contains half of the complex dication, one chloride anion and one water molecule. The Mn(II) atom, located on an inversion centre, is octahedrally coordinated, with a slight elongation towards the monodentate dimethylformamide ligand. Structural features of the title complex, such as the P=O bond lengths and the planarity of the chelate ring, are compared with those of previously reported complexes with six-membered chelates involving the fragments C(O)NHP(O), (X)NP(O) [X = C(O), C(S), S(O)2 and P(O)] and O[P(O)(N)2]2. This analysis shows that the six-membered chelate rings are less puckered in pyrophosphoramide complexes containing a P(O)OP(O) skeleton, such as the title compound. The extended structure of the title complex involves a linear aggregate mediated by N-H...O and N-H...Cl hydrogen bonds, in which the chloride anion is an acceptor in two additional O-H...Cl hydrogen bonds.

Identification of the inorganic pyrophosphate metabolizing, ATP substituting pathway in mammalian spermatozoa.

PubMed

Yi, Young-Joo; Sutovsky, Miriam; Kennedy, Chelsey; Sutovsky, Peter

2012-01-01

Inorganic pyrophosphate (PPi) is generated by ATP hydrolysis in the cells and also present in extracellular matrix, cartilage and bodily fluids. Fueling an alternative pathway for energy production in cells, PPi is hydrolyzed by inorganic pyrophosphatase (PPA1) in a highly exergonic reaction that can under certain conditions substitute for ATP-derived energy. Recombinant PPA1 is used for energy-regeneration in the cell-free systems used to study the zymology of ATP-dependent ubiquitin-proteasome system, including the role of sperm-borne proteasomes in mammalian fertilization. Inspired by an observation of reduced in vitro fertilization (IVF) rates in the presence of external, recombinant PPA1, this study reveals, for the first time, the presence of PPi, PPA1 and PPi transporter, progressive ankylosis protein ANKH in mammalian spermatozoa. Addition of PPi during porcine IVF increased fertilization rates significantly and in a dose-dependent manner. Fluorometric assay detected high levels of PPi in porcine seminal plasma, oviductal fluid and spermatozoa. Immunofluorescence detected PPA1 in the postacrosomal sheath (PAS) and connecting piece of boar spermatozoa; ANKH was present in the sperm head PAS and equatorial segment. Both ANKH and PPA1 were also detected in human and mouse spermatozoa, and in porcine spermatids. Higher proteasomal-proteolytic activity, indispensable for fertilization, was measured in spermatozoa preserved with PPi. The identification of an alternative, PPi dependent pathway for ATP production in spermatozoa elevates our understanding of sperm physiology and sets the stage for the improvement of semen extenders, storage media and IVF media for animal biotechnology and human assisted reproductive therapies.

Identification and analysis of proton-translocating pyrophosphatases in the methanogenic archaeon Methanosarcina mazei

PubMed Central

Bäumer, Sebastian; Lentes, Sabine; Gottschalk, Gerhard; Deppenmeier, Uwe

2002-01-01

Analysis of genome sequence data from the methanogenic archaeon Methanosarcina mazei Gö1 revealed the existence of two open reading frames encoding proton-translocating pyrophosphatases (PPases). These open reading frames are linked by a 750-bp intergenic region containing TC-rich stretches and are transcribed in opposite directions. The corresponding polypeptides are referred to as Mvp1 and Mvp2 and consist of 671 and 676 amino acids, respectively. Both enzymes represent extremely hydrophobic, integral membrane proteins with 15 predicted transmembrane segments and an overall amino acid sequence similarity of 50.1%. Multiple sequence alignments revealed that Mvp1 is closely related to eukaryotic PPases, whereas Mvp2 shows highest homologies to bacterial PPases. Northern blot experiments with RNA from methanol-grown cells harvested in the mid-log growth phase indicated that only Mvp2 was produced under these conditions. Analysis of washed membranes showed that Mvp2 had a specific activity of 0.34 U mg (protein)–1. Proton translocation experiments with inverted membrane vesicles prepared from methanol-grown cells showed that hydrolysis of 1 mol of pyrophosphate was coupled to the translocation of about 1 mol of protons across the cytoplasmic membrane. Appropriate conditions for mvp1 expression could not be determined yet. The pyrophosphatases of M. mazei Gö1 represent the first examples of this enzyme class in methanogenic archaea and may be part of their energy-conserving system. Abbreviations: DCCD, N,N′-dicyclohexylcarbodiimide; PPase, inorganic pyrophosphatase; PPi, inorganic pyrophosphate; Δp, proton motive force. PMID:15803653

Positive selection and functional divergence of farnesyl pyrophosphate synthase genes in plants.

PubMed

Qian, Jieying; Liu, Yong; Chao, Naixia; Ma, Chengtong; Chen, Qicong; Sun, Jian; Wu, Yaosheng

2017-02-04

Farnesyl pyrophosphate synthase (FPS) belongs to the short-chain prenyltransferase family, and it performs a conserved and essential role in the terpenoid biosynthesis pathway. However, its classification, evolutionary history, and the forces driving the evolution of FPS genes in plants remain poorly understood. Phylogeny and positive selection analysis was used to identify the evolutionary forces that led to the functional divergence of FPS in plants, and recombinant detection was undertaken using the Genetic Algorithm for Recombination Detection (GARD) method. The dataset included 68 FPS variation pattern sequences (2 gymnosperms, 10 monocotyledons, 54 dicotyledons, and 2 outgroups). This study revealed that the FPS gene was under positive selection in plants. No recombinant within the FPS gene was found. Therefore, it was inferred that the positive selection of FPS had not been influenced by a recombinant episode. The positively selected sites were mainly located in the catalytic center and functional areas, which indicated that the 98S and 234D were important positively selected sites for plant FPS in the terpenoid biosynthesis pathway. They were located in the FPS conserved domain of the catalytic site. We inferred that the diversification of FPS genes was associated with functional divergence and could be driven by positive selection. It was clear that protein sequence evolution via positive selection was able to drive adaptive diversification in plant FPS proteins. This study provides information on the classification and positive selection of plant FPS genes, and the results could be useful for further research on the regulation of triterpenoid biosynthesis.

Farnesyl Pyrophosphate Inhibits Epithelialization and Wound Healing through the Glucocorticoid Receptor*

PubMed Central

Vukelic, Sasa; Stojadinovic, Olivera; Pastar, Irena; Vouthounis, Constantinos; Krzyzanowska, Agata; Das, Sharmistha; Samuels, Herbert H.; Tomic-Canic, Marjana

2010-01-01

Farnesyl pyrophosphate (FPP), a key intermediate in the mevalonate pathway and protein farnesylation, can act as an agonist for several nuclear hormone receptors. Here we show a novel mechanism by which FPP inhibits wound healing acting as an agonist for glucocorticoid receptor (GR). Elevation of endogenous FPP by the squalene synthetase inhibitor zaragozic acid A (ZGA) or addition of FPP to the cell culture medium results in activation and nuclear translocation of the GR, a known wound healing inhibitor. We used functional studies to evaluate the effects of FPP on wound healing. Both FPP and ZGA inhibited keratinocyte migration and epithelialization in vitro and ex vivo. These effects were independent of farnesylation and indicate that modulation of FPP levels in skin may be beneficial for wound healing. FPP inhibition of keratinocyte migration and wound healing proceeds, in part, by repression of the keratin 6 gene. Furthermore, we show that the 3-hydroxy-3-methylglutaryl-CoA-reductase inhibitor mevastatin, which blocks FPP formation, not only promotes epithelialization in acute wounds but also reverses the effect of ZGA on activation of the GR and inhibition of epithelialization. We conclude that FPP inhibits wound healing by acting as a GR agonist. Of special interest is that FPP is naturally present in cells prior to glucocorticoid synthesis and that FPP levels can be further altered by the statins. Therefore, our findings may provide a better understanding of the pleiotropic effects of statins as well as molecular mechanisms by which they may accelerate wound healing. PMID:19903814

In Vitro Selection for Small-Molecule-Triggered Strand Displacement and Riboswitch Activity.

PubMed

Martini, Laura; Meyer, Adam J; Ellefson, Jared W; Milligan, John N; Forlin, Michele; Ellington, Andrew D; Mansy, Sheref S

2015-10-16

An in vitro selection method for ligand-responsive RNA sensors was developed that exploited strand displacement reactions. The RNA library was based on the thiamine pyrophosphate (TPP) riboswitch, and RNA sequences capable of hybridizing to a target duplex DNA in a TPP regulated manner were identified. After three rounds of selection, RNA molecules that mediated a strand exchange reaction upon TPP binding were enriched. The enriched sequences also showed riboswitch activity. Our results demonstrated that small-molecule-responsive nucleic acid sensors can be selected to control the activity of target nucleic acid circuitry.

Oligomerization of deoxynucleoside-biphosphate dimers - Template and linkage specificity

NASA Technical Reports Server (NTRS)

Visscher, J.; Van Der Woerd, R.; Bakker, C. G.; Schwartz, Alan W.

1989-01-01

The oligomerization of the activated 3-prime-5-prime pyrophosphate-linked dimer, pdAppdAp, is presently noted to be selectively favored by a poly(U) template over the 3-prime-3-prime and 5-prime-5-prime linked dimers. Both overall yields and the production of the longest oligomers were markedly stimulated by poly(U)'s presence; in its absence, the 5-prime-5-prime linked dimer became the most reactive, yielding chains of the order of 60 monomer-unit lengths. Remarkable self-organization properties are noted for the 5-prime-5-prime dimer of pdAp.

Oligomerization of mononucleotides on montmorillonite: A potential approach to the prebiotic synthesis of RNA. [Abstract only

NASA Technical Reports Server (NTRS)

Ferris, James P.; Ertem, Goezen; Ding, Zi Ping; Prabahar, Joseph

1994-01-01

The condensation of the 5'-phosphorimidazolide of adenosine (ImpA) on montmorillonite in a pH 8 aqueous solution yields oligomers containing up to 10 monomer units. The regiospecificity of 3',5'-phosphodiester bond formation is enhanced by addition of 10% diadenosine pyrophosphate (AppA) to the reaction mixture. A series of activated derivatives of 5'-AMP was prepared to investigate the effect of the leaving group on oligomer formation. The benzimidazole and p-dimethylamino-pyridine derivatives gave the best yields of oligomers. Factors important for oligomer formation is discussed.

Bacteria transport through porous media. Annual report, December 31, 1984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yen, T.F.

1986-09-01

The following five chapters in this report have been processed separately for inclusion in the Energy Data Base: (1) theoretical model of convective diffusion of motile and non-motile bacteria toward solid surfaces; (2) interfacial electrochemistry of oxide surfaces in oil-bearing sands and sandstones; (3) effects of sodium pyrophosphate additive on the ''huff and puff''/nutrient flooding MEOR process; (4) interaction of Escherichia coli B, B/4, and bacteriophage T4D with Berea sandstone rock in relation to enhanced oil recovery; and (5) transport of bacteria in porous media and its significance in microbial enhanced oil recovery.

Possible pseudogout in two dogs.

PubMed

Forsyth, S F; Thompson, K G; Donald, J J

2007-03-01

Pseudogout, the acute form of calcium pyrophosphate deposition disease, is a common condition in elderly human beings and is characterised by the sudden onset of intense joint pain and synovitis. It is rarely identified in animals but was diagnosed in two dogs that presented with acute lameness and pyrexia. Cytology of the synovial fluid showed a mildly elevated cell count with both non-degenerate neutrophils and mononuclear cells present. Many of the mononuclear cells and occasional neutrophils contained square or rhomboid-shaped crystals that were variable in shape and size and weakly birefringent on examination under polarised light. Clinical signs resolved following treatment with prednisolone.

Polynucleotides. XXXII. Further studies on the synthesis of oligonucleotides containing 8,2'-S-cycloadenosine.

PubMed Central

Ikehara, M; Tezuka, T

1975-01-01

A dinucleoside monophosphate, 8,2'-anhydro-8-mercapto-9-beta-D-arabinofuranosyladenine phosphoryl-(3'-5')-inosine (AspI) was synthesized by the condensation of protected 8-mercapto-adenosine 2',3'-cyclic phosphate and 2',3'-isopropylideneinosine with diphenylphosphorochloridate. 8-Mercaptoadenosine 2',3'-cyclic phosphate was polymerized by using tetraphenyl pyrophosphate as the condensing reagent. As oligonucleotides, thus obtained, contained some uncyclized 8-mercaptoadenosine residues and were cleaved at these sites with 0.3N KOH. As 5'-phosphate was synthesized and polymerized with DCC to give oligonucleotides with chain lengths 2 to 9. PMID:170595

Universal nature of spondyloarthropathy as a reactive disease, reflecting differential sensitivities.

PubMed

Rothschild, Bruce M

2013-01-01

Tendency to afflict one part of the skeleton, rather than another, could be referred to as the osseotropism of the disease. That term would also include which part of the particular bone was affected. That, in addition to characteristics of erosions, facilitates distinguishing spondyloarthropathy from rheumatoid arthritis, calcium pyrophosphate deposition disease and gout. Spondyloarthropathy, however, is not limited to humans. Initially recognized in 20% of gorillas and rhesus macaques, it was subsequently identified in 25% of bears and 35% of rhinoceros. It is truly a pan-mammalian phenomenon, extending from marsupials and rodents to whales and as ancient as dinosaurs.

Superoxide Dismutase and Transcription Factor sox9 as Mediators of Tumor Suppression by mac25 (IGFBP-rp1) in Prostate Cancer Cells

DTIC Science & Technology

2006-10-01

6 SSC, 5 Denhardt’s solution, 0.1M NaPO4 (pH 7.2), 10mM sodium pyrophosphate, and 50mg/ml sonicated herring sperm DNA (Ulrich et al., 1984). 32P... retention of SOX9 expression. Apoptosis assay Apoptosis was assessed by demonstrating cleavage of PARP by Western blotting (Drivdahl et al., 2001...is the second leading cause of cancer deaths in men and the seventh cause of all cancer deaths (30,000 per year) [1]. From a treatment perspective

The effects of the mineral phase on C stabilization mechanisms and the microbial community along an eroding slope transect

NASA Astrophysics Data System (ADS)

Doetterl, S.; Opfergelt, S.; Cornelis, J.; Boeckx, P. F.; van oost, K.; Six, J.

2013-12-01

An increasing number of studies show the importance of including soil redistribution processes in understanding carbon (C) dynamics in eroding landscapes. The quality and quantity of soil organic carbon in sloping cropland differs with topographic position. These differences are commonly more visible in the subsoil, while the size and composition of topsoil C pools are similar along the hillslope. The type (plant- or microbial-derived) and quality (level of degradation) of C found in a specific soil fraction depends on the interplay between the temporal dynamic of the specific mechanism and it's strength to protect C from decomposition. Here, we present an analysis that aims to clarify the bio/geo-chemical and mineralogical components involved in stabilizing C at various depths and slope positions and how they affect the microbial community and the degradation of C. For this we analyzed soil samples from different soil depths along a slope transect applying (i) a sequential extraction of the reactive soil phase using pyrophosphate, oxalate and dithionite-citrate-bicarbonate, (ii) a semi-quantitative and qualitative analysis of the clay mineralogy, (iii) an analysis of the microbial community using amino sugars and (iv) an analysis of the level of degradation of C in different soil fractions focusing on the soil Lignin signature. The results show that the pattern of minerals and their relative importance in stabilizing C varies greatly along the transect. In the investigated soils, pyrophosphate extractable Manganese, and not Iron or Aluminum as often observed, is strongly correlated to C in the bulk soil and in the non-aggregated silt and clay fractions. This suggests a certain role of Manganese for C stabilization where physical protection is absent. In contrast, pyrophosphate extractable Iron and Aluminum components are largely abundant in water-stable soil aggregates but not correlated to C, suggesting importance of these extracts to stabilize aggregates and, hence, providing physical protection of C. Oxalate extractable amorphous and poorly crystalline minerals are correlated to C, especially for the more recalcitrant C fractions, but only at the depositional site. However, decreasing contents of oxalate extractable elements with depth indicate a temporal limitation of this stabilization mechanism and this is also supported by the results of our lignin extraction. Non-expandable clay minerals experience a relative enrichment at the depositional site while expandable clay minerals experience the same at the eroding site. These changes in clay mineralogy along the slope are partly responsible for the abundance of silt and clay associated C. The changes in soil mineralogy and micro-scale environmental conditions led to an adaptation of the microbial community in comparison to sites not affected by soil redistribution.

Metabolic Profile and Root Development of Hypericum perforatum L. In vitro Roots under Stress Conditions Due to Chitosan Treatment and Culture Time.

PubMed

Brasili, Elisa; Miccheli, Alfredo; Marini, Federico; Praticò, Giulia; Sciubba, Fabio; Di Cocco, Maria E; Cechinel, Valdir Filho; Tocci, Noemi; Valletta, Alessio; Pasqua, Gabriella

2016-01-01

The responses of Hypericum perforatum root cultures to chitosan elicitation had been investigated through (1)H-NMR-based metabolomics associated with morpho-anatomical analyses. The root metabolome was influenced by two factors, i.e., time of culture (associated with biomass growth and related "overcrowding stress") and chitosan elicitation. ANOVA simultaneous component analysis (ASCA) modeling showed that these factors act independently. In response to the increase of biomass density over time, a decrease in the synthesis of isoleucine, valine, pyruvate, methylamine, etanolamine, trigonelline, glutamine and fatty acids, and an increase in the synthesis of phenolic compounds, such as xanthones, epicatechin, gallic, and shikimic acid were observed. Among the xanthones, brasilixanthone B has been identified for the first time in chitosan-elicited root cultures of H. perforatum. Chitosan treatment associated to a slowdown of root biomass growth caused an increase in DMAPP and a decrease in stigmasterol, shikimic acid, and tryptophan levels. The histological analysis of chitosan-treated roots revealed a marked swelling of the root apex, mainly due to the hypertrophy of the first two sub-epidermal cell layers. In addition, periclinal divisions in hypertrophic cortical cells, resulting in an increase of cortical layers, were frequently observed. Most of the metabolic variations as well as the morpho-anatomical alterations occurred within 72 h from the elicitation, suggesting an early response of H. perforatum roots to chitosan elicitation. The obtained results improve the knowledge of the root responses to biotic stress and provide useful information to optimize the biotechnological production of plant compounds of industrial interest.

Metabolic Profile and Root Development of Hypericum perforatum L. In vitro Roots under Stress Conditions Due to Chitosan Treatment and Culture Time

PubMed Central

Brasili, Elisa; Miccheli, Alfredo; Marini, Federico; Praticò, Giulia; Sciubba, Fabio; Di Cocco, Maria E.; Cechinel, Valdir Filho; Tocci, Noemi; Valletta, Alessio; Pasqua, Gabriella

2016-01-01

The responses of Hypericum perforatum root cultures to chitosan elicitation had been investigated through 1H-NMR-based metabolomics associated with morpho-anatomical analyses. The root metabolome was influenced by two factors, i.e., time of culture (associated with biomass growth and related “overcrowding stress”) and chitosan elicitation. ANOVA simultaneous component analysis (ASCA) modeling showed that these factors act independently. In response to the increase of biomass density over time, a decrease in the synthesis of isoleucine, valine, pyruvate, methylamine, etanolamine, trigonelline, glutamine and fatty acids, and an increase in the synthesis of phenolic compounds, such as xanthones, epicatechin, gallic, and shikimic acid were observed. Among the xanthones, brasilixanthone B has been identified for the first time in chitosan-elicited root cultures of H. perforatum. Chitosan treatment associated to a slowdown of root biomass growth caused an increase in DMAPP and a decrease in stigmasterol, shikimic acid, and tryptophan levels. The histological analysis of chitosan-treated roots revealed a marked swelling of the root apex, mainly due to the hypertrophy of the first two sub-epidermal cell layers. In addition, periclinal divisions in hypertrophic cortical cells, resulting in an increase of cortical layers, were frequently observed. Most of the metabolic variations as well as the morpho-anatomical alterations occurred within 72 h from the elicitation, suggesting an early response of H. perforatum roots to chitosan elicitation. The obtained results improve the knowledge of the root responses to biotic stress and provide useful information to optimize the biotechnological production of plant compounds of industrial interest. PMID:27148330

Comparison of methods for the removal of organic carbon and extraction of chromium, iron and manganese from an estuarine sediment standard and sediment from the Calcasieu River estuary, Louisiana, U.S.A.

USGS Publications Warehouse

Simon, N.S.; Hatcher, S.A.; Demas, C.

1992-01-01

U.S. National Bureau of Standards (NBS) estuarine sediment 1646 from the Chesapeake Bay, Maryland, and surface sediment collected at two sites in the Calcasieu River estuary, Louisiana, were used to evaluate the dilute hydrochloric acid extraction of Cr, Fe and Mn from air-dried and freeze-dried samples that had been treated by one of three methods to remove organic carbon. The three methods for the oxidation and removal of organic carbon were: (1) 30% hydrogen peroxide; (2) 30% hydrogen peroxide plus 0.25 mM pyrophosphate; and (3) plasma oxidation (low-temperature ashing). There was no statistically significant difference at the 95% confidence level between air- and freeze-dried samples with respect to the percent of organic carbon removed by the three methods. Generally, there was no statistically significant difference at the 95% confidence level between air- and freeze-dried samples with respect to the concentration of Cr, Fe and Mn that was extracted, regardless of the extraction technique that was used. Hydrogen peroxide plus pyrophosphate removed the most organic carbon from sediment collected at the site in the Calcasieu River that was upstream from industrial outfalls. Plasma oxidation removed the most organic carbon from the sediment collected at a site in the Calcasieu River close to industrial outfalls and from the NBS estuarine sediment sample. Plasma oxidation merits further study as a treatment for removal of organic carbon. Operational parameters can be chosen to limit the plasma oxidation of pyrite which, unlike other Fe species, will not be dissolved by dilute hydrochloric acid. Preservation of pyrite allows the positive identification of Fe present as pyrite in sediments. ?? 1992.

Increased technetium uptake is not equivalent to muscle necrosis: scintigraphic, morphological and intramuscular pressure analyses of sore muscles after exercise

NASA Technical Reports Server (NTRS)

Crenshaw, A. G.; Friden, J.; Hargens, A. R.; Lang, G. H.; Thornell, L. E.

1993-01-01

A scintigraphic technique employing technetium pyrophosphate uptake was used to identify the area of skeletal muscle damage in the lower leg of four runners 24 h after an ultramarathon footrace (160 km). Most of the race had been run downhill which incorporated an extensive amount of eccentric work. Soreness was diffuse throughout the posterior region of the lower leg. In order to interpret what increased technetium uptake reflects and to express extreme endurance related damages, a biopsy was taken from the 3-D position of abnormal uptake. In addition, intramuscular pressures were determined in the deep posterior compartment. Scintigraphs revealed increased technetium pyrophosphate uptake in the medial portion of the gastrocnemius muscle. For 3698 fibres analysed, 33 fibres (1%) were necrotic, while a few other fibres were either atrophic or irregular shaped. A cluster of necrotic fibres occurred at the fascicular periphery for one subject and fibre type grouping occurred for another. Ultrastructural analysis revealed Z-line streaming near many capillaries and variously altered subsarcolemmal mitochondria including some with paracrystalline inclusions. The majority of the capillaries included thickened and irregular shaped endothelial cells. Intramuscular pressures of the deep posterior compartment were slightly elevated (12-15 mmHg) for three of the four subjects. Increased technetium uptake following extreme endurance running does not just reflect muscle necrosis but also subtle fibre abnormalities. Collectively, these pathological findings are attributed to relative ischaemia occurring during the race and during pre-race training, whereas, intramuscular pressure elevations associated with muscle soreness are attributed to mechanical stress caused by extensive eccentric work during the race.

Effect of calcium pyrophosphate on microstructural evolution and in vitro biocompatibility of Ti-35Nb-7Zr composite by spark plasma sintering.

PubMed

Zhang, L; Tan, J; He, Z Y; Jiang, Y H

2018-09-01

β-type Ti-35Nb-7Zr alloy has attracted considerable attentions as a bone implant material. The alloy, however, has poor bioactivity, which difficult to form a strong osseointegration between the bone tissues. Combining Ti alloy with a bioactive and biodegradable ceramic has been of interest to researchers. But the large difference in physicochemical property of high-melting metal and ceramic elements would bring the manufacturing restriction. In this work, Ti-35Nb-7Zr-CPP composites were fabricated with mechanical alloy of Ti, Nb, Zr and Nano calcium pyrophosphate (CPP) powders mixture followed by spark plasma sintering (SPS) routes. The effect of CPP ceramic on microstructural evolution and in vitro biocompatibility were investigated. As the addition of CPP (10-30 wt%), ceramic elements spreading towards the matrix, the generated metal-ceramic bioactive phases CaTiO 3 are observed well consolidated with β-Ti matrix. With the CPP increasing, Ca and P atoms rapidly migrated to the β-Ti matrix to form granulated Ti 5 P 3 , which leads to the increasing porosity (10%-18%) in the composites. The results demonstrated that the favorable cell viability (the cell proliferation rates were higher than 100%) and growth inside the pores of the composites arise from the rough micro-porous surface and the release of bioactive metal-ceramic phase ions into the biological environment. The enhanced bioactivity and microstructural evolution behaviors of the Ti-35Nb-7Zr-CPP composites may provide a strategy for designing and fabricating multifunctional implants. Copyright © 2018 Elsevier B.V. All rights reserved.

Estimating cancer risk from 99mTc pyrophosphate imaging for transthyretin cardiac amyloidosis.

PubMed

Einstein, Andrew J; Shuryak, Igor; Castaño, Adam; Mintz, Akiva; Maurer, Mathew S; Bokhari, Sabahat

2018-05-30

Increasing recognition that transthyretin cardiac amyloidosis (ATTR-CA) is much more common than previously appreciated and the emergence of novel disease-modifying therapeutic agents have led to a paradigm shift in which ATTR-CA screening is considered in high-risk populations, such as patients with heart failure with preserved ejection fraction (HFpEF) or aortic stenosis. Radiation risk from 99m Tc-pyrophosphate ( 99m Tc-PYP) scintigraphy, a test with very high sensitivity and specificity for ATTR-CA, has not been previously determined. Radiation doses to individual organs from 99m Tc-PYP were estimated using models developed by the Medical Internal Radiation Dose Committee and the International Commission on Radiological Protection. Excess future cancer risks were estimated from organ doses, using risk projection models developed by the National Academies and extended by the National Cancer Institute. Excess future risks were estimated for men and women aged 40-80 and compared to total (excess plus baseline) future risks. All-organ excess cancer risks (90% uncertainty intervals) ranged from 5.88 (2.45,11.4) to 12.2 (4.11,26.0) cases per 100,000 patients undergoing 99m Tc-PYP testing, were similar for men and women, and decreased with increasing age at testing. Cancer risks were highest to the urinary bladder, and bladder risk varied nearly twofold depending on which model was used. Excess 99m Tc-PYP-related cancers constituted < 1% of total future cancers to the critical organs. Very low cancer risks associated with 99m Tc-PYP testing suggest a favorable benefit-risk profile for 99m Tc-PYP as a screening test for ATTR-CA in high-risk populations, such as such as patients with HFpEF or aortic stenosis.

In vitro evaluation of iron solubility and dialyzability of various iron fortificants and of iron-fortified milk products targeted for infants and toddlers.

PubMed

Kapsokefalou, Maria; Alexandropoulou, Isidora; Komaitis, Michail; Politis, Ioannis

2005-06-01

The objectives of the present study were: to compare the solubility and dialyzability of various iron fortificants (iron pyrophosphate, ferrous bis-glycinate, ferrous gluconate, ferrous lactate, ferrous sulfate) added, in the presence of ascorbic acid, to pasteurized milk samples produced under laboratory conditions; and to compare the solubility and dialyzability of iron in commercial pasteurized, UHT and condensed milk products available in the Greek market fortified with various vitamins and minerals including iron and targeted towards infants (6-12 months old) and toddlers. Iron solubility and dialyzability were determined using a simulated gastrointestinal digestive system. Ferrous dialyzable iron (molecular weight lower than 8000) was used as an index for prediction of iron bioavailability. Ferrous dialyzable iron in pasteurized milk samples fortified with iron pyrophosphate, ferrous lactate and ferrous bis-glycinate was higher (P < 0.05) than that in milk samples fortified with ferrous sulfate and ferrous gluconate. In commercial liquid pasteurized or UHT milk products, formation of ferrous dialyzable iron in products fortified with ferrous lactate was not different (P > 0.05) from those fortified with ferrous sulfate. Ferrous dialyzable iron in four condensed commercial milk products was higher (P < 0.05) than the corresponding values of the liquid UHT milk samples fortified with the same fortificant (ferrous sulfate). Ferrous dialyzable iron was higher (P < 0.05) in products targeted for infants compared with those targeted for toddlers. In conclusion, the type of iron source, milk processing and the overall product composition affect formation of ferrous dialyzable iron and may determine the success and effectiveness of iron fortification of milk.

Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals.

PubMed

Zimmermann, Michael B; Biebinger, Ralf; Egli, Ines; Zeder, Christophe; Hurrell, Richard F

2011-04-01

Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric pyrophosphate (FPP) and (2) to compare the efficacy of FS with FPP in a fortification trial to increase body Fe stores in Fe-deficient children v. Fe-sufficient children. Using stable isotopes in test meals in young women (n 49) selected for low and high Fe status, we compared the absorption of FPP with FS. We analysed data from previous efficacy trials in children (n 258) to determine whether Fe status at baseline predicted response to FS v. FPP as salt fortificants. Plasma ferritin was a strong negative predictor of Fe bioavailability from FS (P < 0·0001) but not from FPP. In the efficacy trials, body Fe at baseline was a negative predictor of the change in body Fe for both FPP and FS, but the effect was significantly greater with FS (P < 0·01). Because Fe deficiency up-regulates Fe absorption from FS but not from FPP, food fortification with FS may have relatively greater impact in Fe-deficient children. Thus, more soluble Fe compounds not only demonstrate better overall absorption and can be used at lower fortification levels, but they also have the added advantage that, because their absorption is up-regulated in Fe deficiency, they innately 'target' Fe-deficient individuals in a population.

Effects of pH on the Production of Phosphate and Pyrophosphate by Matrix Vesicles' Biomimetics

PubMed Central

Simão, Ana Maria S.; Bolean, Maytê; Hoylaerts, Marc F.; Millán, José Luis; Ciancaglini, Pietro

2013-01-01

During endochondral bone formation, chondrocytes and osteoblasts synthesize and mineralize the extracellular matrix through a process that initiates within matrix vesicles (MVs) and ends with bone mineral propagation onto the collagenous scaffold. pH gradients have been identified in the growth plate of long bones, but how pH changes affect the initiation of skeletal mineralization is not known. Tissue-nonspecific alkaline phosphatase (TNAP) degrades extracellular inorganic pyrophosphate (ePPi), a mineralization inhibitor produced by ectonucleotide pyrophosphatase/ phosphodiesterase-1 (NPP1), while contributing Pi from ATP to initiate mineralization. TNAP and NPP1, alone or combined, were reconstituted in dipalmitoylphosphatidylcholine (DPPC) liposomes to mimic the microenvironment of MVs. The hydrolysis of ATP, ADP, AMP and PPi was studied at pH 8 and 9 and compared to the data determined at pH 7.4. While catalytic efficiencies in general were higher at alkaline pH, PPi hydrolysis was maximal at pH 8 and indicated a preferential utilization of PPi over ATP, at pH 8 versus 9. In addition, all proteoliposomes induced mineral formation when incubated in a synthetic cartilage lymph (SCL) containing 1 mM ATP as substrate and amorphous calcium phosphate (ACP) or calciumphosphate- phosphatidylserine complexes (PS-CPLX) as nucleators. Propagation of mineralization was significantly more efficient at pHs 7.5 and 8 than at pH 9. Since a slight pH elevation from 7.4 to 8 promotes considerably more hydrolysis of ATP, ADP and AMP primarily by TNAP, this small pH change facilitates mineralization, especially via upregulated PPi hydrolysis by both NPP1 and TNAP, further elevating the Pi/PPi ratio, thus enhancing bone mineralization. PMID:23942722

Effects of pH on the production of phosphate and pyrophosphate by matrix vesicles' biomimetics.

PubMed

Simão, Ana Maria S; Bolean, Maytê; Hoylaerts, Marc F; Millán, José Luis; Ciancaglini, Pietro

2013-09-01

During endochondral bone formation, chondrocytes and osteoblasts synthesize and mineralize the extracellular matrix through a process that initiates within matrix vesicles (MVs) and ends with bone mineral propagation onto the collagenous scaffold. pH gradients have been identified in the growth plate of long bones, but how pH changes affect the initiation of skeletal mineralization is not known. Tissue-nonspecific alkaline phosphatase (TNAP) degrades extracellular inorganic pyrophosphate (PPi), a mineralization inhibitor produced by ectonucleotide pyrophosphatase/phosphodiesterase-1 (NPP1), while contributing Pi from ATP to initiate mineralization. TNAP and NPP1, alone or combined, were reconstituted in dipalmitoylphosphatidylcholine liposomes to mimic the microenvironment of MVs. The hydrolysis of ATP, ADP, AMP, and PPi was studied at pH 8 and 9 and compared to the data determined at pH 7.4. While catalytic efficiencies in general were higher at alkaline pH, PPi hydrolysis was maximal at pH 8 and indicated a preferential utilization of PPi over ATP at pH 8 versus 9. In addition, all proteoliposomes induced mineral formation when incubated in a synthetic cartilage lymph containing 1 mM ATP as substrate and amorphous calcium phosphate or calcium-phosphate-phosphatidylserine complexes as nucleators. Propagation of mineralization was significantly more efficient at pH 7.5 and 8 than at pH 9. Since a slight pH elevation from 7.4 to 8 promotes considerably more hydrolysis of ATP, ADP, and AMP primarily by TNAP, this small pH change facilitates mineralization, especially via upregulated PPi hydrolysis by both NPP1 and TNAP, further elevating the Pi/PPi ratio, thus enhancing bone mineralization.

Characterization of phosphorus forms in lake macrophytes and algae by solution (31)P nuclear magnetic resonance spectroscopy.

PubMed

Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Giesy, John P; He, Zhongqi; Song, Lirong; Fan, Mingle

2016-04-01

Debris from aquatic macrophytes and algae are important recycling sources of phosphorus (P), which can result in continuing blooms of algae by recycling bioavailable P in the eutrophic lakes. However, knowledge of forms of P in aquatic macrophytes and algae and their contribution to internal loads of P in lakes is limited. Without such knowledge, it is difficult to develop appropriate strategies to remediate and or restore aquatic ecosystems that have become eutrophic. Therefore, in this work, P was extracted from six types of aquatic macrophytes and algae collected from Tai Lake of China and characterized by use of solution (31)P-nuclear magnetic resonance (NMR) spectroscopy. When extracted by 0.5 M NaOH-25 mM EDTA, extraction recovery of total P(TP) and organic P(Po) exceeded 90 %. Concentrations of Po in algae and aquatic macrophytes were 5552 mg kg(-1) and 1005 mg kg(-1) and accounted for 56.0 and 47.2 % of TP, respectively. When Po, including condensed P, was characterized by solution (31)P-NMR Po in algae included orthophosphate monoesters (79.8 %), pyrophosphate (18.2 %), and orthophosphate diester (2.0 %), and Po in aquatic macrophytes included orthophosphate monoesters (90.3 %), pyrophosphate (4.2 %), and orthophosphate diester (5.5 %). Additionally, orthophosphate monoesters in algal debris mainly included β-glycerophosphate (44.1 %), α-glycerophosphate (13.5 %), and glucose 6-phosphate (13.5 %). Orthophosphate monoesters in aquatic macrophytes mainly included β-glycerophosphate (27.9 %), α-glycerophosphate (24.6 %), and adenosine 5' monophosphate (8.2 %). Results derived from this study will be useful in better understanding nutrient cycling, relevant eutrophication processes, and pollution control for freshwater lakes.

Independent modulation of the activity of alpha-ketoglutarate dehydrogenase complex by Ca2+ and Mg2+.

PubMed

Panov, A; Scarpa, A

1996-01-16

The activity of alpha-ketoglutarate dehydrogenase complex (KGDHC), an important enzyme regulating several metabolic pathways, could be regulated by changes in the environment within the mitochondrial matrix. It has been postulated that the activity of this and other dehydrogenases in vivo could be modulated by changes in the intramitochondrial concentrations of Ca2+ or Mg2+. Using a purified alpha-ketoglutarate dehydrogenase from pig hearts, the effect of Ca2+ and/or Mg2+ on the enzyme activity was investigated. Either Ca2+ or Mg2+ increased enzyme activity, and the effects were additive if the concentrations of free divalent cations were below 0.1 and 1 mM for Ca2+ and Mg2+, respectively. In the presence of 1 mM alpha-ketoglutarate and other cofactors, the KM for Mg2+ was 25 microM and less than 1 microM for Ca2+. The KM for alpha-ketoglutarate was a function of the divalent cation(s) present: 4 +/- 1.1 mM in the absence of Ca2+, with or without Mg2+; 2.2 mM in the presence of 1.8 microM Ca2+ alone; and 0.3 mM in the presence of both Ca2+ and Mg2+. Mg2+ increased KGDHC activity only in the presence of thiamine pyrophosphate (TPP) indicating that KGDHC requires both TPP and Mg2+ for enzyme's maximal activity. The affinity of KGDHC for NAD+ is significantly changed by either Mg2+ or Ca2+. The conclusions are that changes in both Ca2+ and Mg2+, in concentrations possibly occurring within mitochondria, could control KGDHC activity and that thiamine pyrophosphate is required for maximal enzyme activity.

Identification of natural rubber and characterization of rubber biosynthetic activity in fig tree.

PubMed

Kang, H; Kang, M Y; Han, K H

2000-07-01

Natural rubber was extracted from the fig tree (Ficus carica) cultivated in Korea as part of a survey of rubber producing plants. Fourier transform infrared and (13)C nuclear magnetic resonance analysis of samples prepared by successive extraction with acetone and benzene confirmed that the benzene-soluble residues are natural rubber, cis-1,4-polyisoprene. The rubber content in the latex of fig tree was about 4%, whereas the rubber content in the bark, leaf, and fruit was 0.3%, 0.1%, and 0.1%, respectively. Gel-permeation chromatography revealed that the molecular size of the natural rubber from fig tree is about 190 kD. Similar to rubber tree (Hevea brasiliensis) and guayule (Parthenium argentatum Gray), rubber biosynthesis in fig tree is tightly associated with rubber particles. The rubber transferase in rubber particles exhibited a higher affinity for farnesyl pyrophosphate than for isopentenyl pyrophosphate, with apparent K(m) values of 2.8 and 228 microM, respectively. Examination of latex serum from fig tree by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed major proteins of 25 and 48 kD in size, and several proteins with molecular mass below 20 and above 100 kD. Partial N-terminal amino acid sequencing and immunochemical analyses revealed that the 25- and 48-kD proteins were novel and not related to any other suggested rubber transferases. The effect of EDTA and Mg(2+) ion on in vitro rubber biosynthesis in fig tree and rubber tree suggested that divalent metal ion present in the latex serum is an important factor in determining the different rubber biosynthetic activities in fig tree and rubber tree.

Identification of Natural Rubber and Characterization of Rubber Biosynthetic Activity in Fig Tree1

PubMed Central

Kang, Hunseung; Kang, Min Young; Han, Kyung-Hwan

2000-01-01

Natural rubber was extracted from the fig tree (Ficus carica) cultivated in Korea as part of a survey of rubber producing plants. Fourier transform infrared and 13C nuclear magnetic resonance analysis of samples prepared by successive extraction with acetone and benzene confirmed that the benzene-soluble residues are natural rubber, cis-1,4-polyisoprene. The rubber content in the latex of fig tree was about 4%, whereas the rubber content in the bark, leaf, and fruit was 0.3%, 0.1%, and 0.1%, respectively. Gel-permeation chromatography revealed that the molecular size of the natural rubber from fig tree is about 190 kD. Similar to rubber tree (Hevea brasiliensis) and guayule (Parthenium argentatum Gray), rubber biosynthesis in fig tree is tightly associated with rubber particles. The rubber transferase in rubber particles exhibited a higher affinity for farnesyl pyrophosphate than for isopentenyl pyrophosphate, with apparent Km values of 2.8 and 228 μm, respectively. Examination of latex serum from fig tree by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed major proteins of 25 and 48 kD in size, and several proteins with molecular mass below 20 and above 100 kD. Partial N-terminal amino acid sequencing and immunochemical analyses revealed that the 25- and 48-kD proteins were novel and not related to any other suggested rubber transferases. The effect of EDTA and Mg2+ ion on in vitro rubber biosynthesis in fig tree and rubber tree suggested that divalent metal ion present in the latex serum is an important factor in determining the different rubber biosynthetic activities in fig tree and rubber tree. PMID:10889262

X-ray Crystal Structure of Aristolochene Synthase from Aspergillus terreus and Evolution of Templates for the Cyclization of Farnesyl Diphosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shishova,E.; Di Costanzo, L.; Cane, D.

2007-01-01

Aristolochene synthase from Aspergillus terreus catalyzes the cyclization of the universal sesquiterpene precursor, farnesyl diphosphate, to form the bicyclic hydrocarbon aristolochene. The 2.2 {angstrom} resolution X-ray crystal structure of aristolochene synthase reveals a tetrameric quaternary structure in which each subunit adopts the {alpha}-helical class I terpene synthase fold with the active site in the 'open', solvent-exposed conformation. Intriguingly, the 2.15 {angstrom} resolution crystal structure of the complex with Mg{sup 2+}{sub 3}-pyrophosphate reveals ligand binding only to tetramer subunit D, which is stabilized in the 'closed' conformation required for catalysis. Tetramer assembly may hinder conformational changes required for the transition frommore » the inactive open conformation to the active closed conformation, thereby accounting for the attenuation of catalytic activity with an increase in enzyme concentration. In both conformations, but especially in the closed conformation, the active site contour is highly complementary in shape to that of aristolochene, and a catalytic function is proposed for the pyrophosphate anion based on its orientation with regard to the presumed binding mode of aristolochene. A similar active site contour is conserved in aristolochene synthase from Penicillium roqueforti despite the substantial divergent evolution of these two enzymes, while strikingly different active site contours are found in the sesquiterpene cyclases 5-epi-aristolochene synthase and trichodiene synthase. Thus, the terpenoid cyclase active site plays a critical role as a template in binding the flexible polyisoprenoid substrate in the proper conformation for catalysis. Across the greater family of terpenoid cyclases, this template is highly evolvable within a conserved {alpha}-helical fold for the synthesis of terpene natural products of diverse structure and stereochemistry.« less

Revisiting sesquiterpene biosynthetic pathways leading to santalene and its analogues: a comprehensive mechanistic study.

PubMed

Jindal, Garima; Sunoj, Raghavan B

2012-10-21

Santalene and bergamotene are the major olefinic sesquiterpenes responsible for the fragrance of sandalwood oil. Herein we report the details of density functional theory investigations on the biosynthetic pathway of this important class of terpenes. The mechanistic study has been found to be effective toward gaining significant new insight into different possibilities for the formation of the key intermediates involved in santalene and bergamotene biosynthesis. The stereoelectronic features of the transition states and intermediates for (i) ring closure of the initial bisabolyl cation, and (ii) skeletal rearrangements in the ensuing bicyclic carbocationic intermediates leading to (-)-epi-β-santalene, (-)-β-santalene, (-)-α-santalene, (+)-epi-β-santalene, exo-β-bergamotene, endo-β-bergamotene, exo-α-bergamotene, and endo-α-bergamotene are presented. Interesting structural features pertaining to certain new carbocationic intermediates (such as b) resulting from the ring closure of bisabolyl cation are discussed. Extensive conformational sampling of all key intermediates along the biosynthetic pathway offered new insight into the role of the isoprenyl side chain conformation in the formation of santalene and its analogues. Although the major bicyclic products in Santalum album appear to arise from the right or left handed helical form of farnesyl pyrophosphate (FPP), different alternatives for their formation are found to be energetically feasible. The interconversion of the exo and endo isomers of bisabolyl cation and a likely epimerization, both with interesting mechanistic implications, are presented. The exo to endo conversion is identified to be energetically more favorable than another pathway emanating from the left handed helical FPP. The role of pyrophosphate (OPP(-)) in the penultimate deprotonation step leading to olefinic sesquiterpenes is also examined.