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Sample records for adenine dinucleotide detection

  1. Ligation-triggered fluorescent silver nanoclusters system for the detection of nicotinamide adenine dinucleotide.

    Cao, Zhijuan; Wang, Pei; Qiu, Xue; Lau, Choiwan; Lu, Jianzhong

    2014-03-01

    Herein, we demonstrate a novel silver nanocluster-based fluorescent system for the detection of nicotinamide adenine dinucleotide (NAD(+)), an important biological small molecule involved in a wide range of biological processes. A single-stranded dumbbell DNA probe was designed and used for the assay, which contained a nick in the stem, a poly-cytosine nucleotide loop close to 5' end as the template for the formation of highly fluorescent silver nanoclusters (Ag NCs) and another loop close to 3' end. Only in the presence of NAD(+), the probe was linked at 5' and 3' ends by Escherichia coli DNA ligase, which blocked the DNA polymerase-based extension reaction, ensuring the formation of fluorescent Ag NCs. This technique provided a logarithmic linear relationship in the range of 1 pM-500 nM with a detection limit of as low as 1 pM NAD(+), and exhibited high selectivity against its analogues, and was then successfully used for the detection of NAD(+) level in four kinds of cell homogenates. In addition, this new approach was conducted in an isothermal and homogeneous condition without the need of any thermal cycling, washing, and separation steps, making it very simple. Overall, this label-free protocol offers a promising alternative for the detection of NAD(+), taking advantage of specificity, sensitivity, cost-efficiency, and simplicity. PMID:24442015

  2. Nicotinamide Adenine Dinucleotide Phosphate-Diaphorase (NADPH-d) Histochemistry Detecting NOS in Healthy and Chronically Inflamed Pulp

    Jukić, S.; Talan-Hranilović, J.; Buković, D.; Miletić, I.; Neziri, E.

    2002-01-01

    The aim of this study was to examine the expression of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity in human dental pulps and determine whether there are changes of the activity in chronically inflamed pulp tissue. Nineteen pulps with clinical diagnosis of chronic pulpitis were collected during endodontic treatment. The healthy controls were obtained from teeth extracted for orthodontic therapy. The clinical diagnosis was confirmed by histological a...

  3. OTOTOXIC MODEL OF OXALIPLATIN AND PROTECTION FROM NICOTINAMIDE ADENINE DINUCLEOTIDE

    DING Dalian; JIANG Haiyan; FU Yong; LI Yongqi; Richard Salvi; Shinichi Someya; Masaru Tanokura

    2013-01-01

    Oxaliplatin, an anticancer drug commonly used to treat colorectal cancer and other tumors, has a number of serious side effects, most notably neuropathy and ototoxicity. To gain insights into its ototoxic profile, oxaliplatin was applied to rat cochlear organ cultures. Consistent with it neurotoxic propensity, oxaliplatin selectively damaged nerve fibers at a very low dose 1 µM. In contrast, the dose required to damage hair cells and spiral ganglion neurons was 50 fold higher (50 µM). Oxailiplatin-induced cochlear lesions initial-ly increased with dose, but unexpectedly decreased at very high doses. This non-linear dose response could be related to depressed oxaliplatin uptake via active transport mechanisms. Previous studies have demon-strated that axonal degeneration involves biologically active processes which can be greatly attenuated by nicotinamide adenine dinucleotide (NAD+). To determine if NAD+would protect spiral ganglion axons and the hair cells from oxaliplatin damage, cochlear cultures were treated with oxaliplatin alone at doses of 10 µM or 50 µM respectively as controls or combined with 20 mM NAD+. Treatment with 10 µM oxaliplatin for 48 hours resulted in minor damage to auditory nerve fibers, but spared cochlear hair cells. However, when cochlear cultures were treated with 10 µM oxaliplatin plus 20 mM NAD+, most auditory nerve fibers were intact. 50 µM oxaliplatin destroyed most of spiral ganglion neurons and cochlear hair cells with apop-totic characteristics of cell fragmentations. However, 50 µM oxaliplatin plus 20 mM NAD+treatment great-ly reduced neuronal degenerations and hair cell missing. The results suggested that NAD+provides signifi-cant protection against oxaliplatin-induced neurotoxicity and ototoxicity, which may be due to its actions of antioxidant, antiapoptosis, and energy supply.

  4. Conducting polymer and its composite materials based electrochemical sensor for Nicotinamide Adenine Dinucleotide (NADH).

    Omar, Fatin Saiha; Duraisamy, Navaneethan; Ramesh, K; Ramesh, S

    2016-05-15

    Nicotinamide Adenine Dinucleotide (NADH) is an important coenzyme in the human body that participates in many metabolic reactions. The impact of abnormal concentrations of NADH significantly causes different diseases in human body. Electrochemical detection of NADH using bare electrode is a challenging task especially in the presence of main electroactive interferences such as ascorbic acid (AA), uric acid (UA) and dopamine (DA). Modified electrodes have been widely explored to overcome the problems of poor sensitivity and selectivity occurred from bare electrodes. This review gives an overview on the progress of using conducting polymers, polyelectrolyte and its composites (co-polymer, carbonaceous, metal, metal oxide and clay) based modified electrodes for the sensing of NADH. In addition, developments on the fabrication of numerous conducting polymer composites based modified electrodes are clearly described. PMID:26774092

  5. Insulin resistance and dysregulation of tryptophan – kynurenine and kynurenine – nicotinamide adenine dinucleotide metabolic pathways

    Oxenkrug, Gregory

    2013-01-01

    Insulin resistance (IR) underlines aging and aging-associated medical (diabetes, obesity, dyslipidemia, hypertension) and psychiatric (depression, cognitive decline) disorders (AAMPD). Molecular mechanisms of IR in genetically or metabolically predisposed individuals remain uncertain. Current review of literature and our data presents the evidences that dysregulation of tryptophan (TRP) – kynurenine (KYN) and KYN – nicotinamide adenine dinucleotide (NAD) metabolic pathways is one of the mecha...

  6. Deviant Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP)-mediated Ca2+ Signaling upon Lysosome Proliferation*

    Dickinson, G. D.; Churchill, G. C.; Brailoiu, E; Patel, S.

    2010-01-01

    Accumulating evidence suggests that the endolysosomal system is a novel intracellular Ca2+ pool mobilized by the second messenger, nicotinic acid adenine dinucleotide phosphate (NAADP). Although lysosomes in neurons are known to proliferate in numerous neurodegenerative diseases and during the normal course of aging, little is known concerning the effect of lysosomal proliferation on Ca2+ homeostasis. Here, we induce proliferation of lysosomes in primary cultures of rat hippocampal neurons an...

  7. Nicotinamide adenine dinucleotide assisted direct electrodeposition of gold nanodendrites and its electrochemical applications

    The shape tailoring in gold (Au) nanostructures is vital for tuning their optical and catalytic properties. Herein, we describe nicotinamide adenine dinucleotide (NAD+) assisted direct electrochemical growth of surface-confined Au nanodendrites as well as the application of these nanodendrites in the non-enzymatic detection of glucose in neutral pH and the oxidation of methanol in alkaline pH. NAD+ plays an important role in the growth of Au nanodendrites. The specific adsorption of NAD+ onto the Au (011) facet aids in the growth of Au nanodendrites. In the absence of NAD+, interconnected wall-like morphology is obtained. The Au nanodendrites are characterized by UV–visible spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical methods. FESEM and TEM analysis confirm that the Au nanostructures are dendritic, consisting of a trunk from which several branches evolve; the presence of NAD+ in the supporting electrolyte solution plays a vital role in the evolution of this morphology. The electrode based on Au dendrites has an electrochemically accessible surface area of 0.281 cm2 and shows excellent electrocatalytic activity for both glucose and methanol. In alkaline pH, the Au nanodendrite-based electrode oxidized methanol at 0.3 V with a highly-stable response. This electrode oxidizes glucose at 0.4 V in neutral pH without the use of enzymes. The sensitivity and limit of detection of the electrode are calculated to be 0.037 ± 0.02 μA mM−1 cm−2 and 7.29 μM (S/N = 3), respectively. The surface morphology of the Au nanostructure plays an important role in the electrocatalytic performance

  8. Electrochemical oxidation of dihydronicotinamide adenine dinucleotide at nitrogen-doped carbon nanotube electrodes.

    Goran, Jacob M; Favela, Carlos A; Stevenson, Keith J

    2013-10-01

    Nitrogen-doped carbon nanotubes (N-CNTs) substantially lower the overpotential necessary for dihydronicotinamide adenine dinucleotide (NADH) oxidation compared to nondoped CNTs or traditional carbon electrodes such as glassy carbon (GC). We observe a 370 mV shift in the peak potential (Ep) from GC to CNTs and another 170 mV shift from CNTs to 7.4 atom % N-CNTs in a sodium phosphate buffer solution (pH 7.0) with 2.0 mM NADH (scan rate 10 mV/s). The sensitivity of 7.4 atom % N-CNTs to NADH was measured at 0.30 ± 0.04 A M(-1) cm(-2), with a limit of detection at 1.1 ± 0.3 μM and a linear range of 70 ± 10 μM poised at a low potential of -0.32 V (vs Hg/Hg2SO4). NADH fouling, known to occur to the electrode surface during NADH oxidation, was investigated by measuring both the change in Ep and the resulting loss of electrode sensitivity. NADH degradation, known to occur in phosphate buffer, was characterized by absorbance at 340 nm and correlated with the loss of NADH electroactivity. N-CNTs are further demonstrated to be an effective platform for dehydrogenase-based biosensing by allowing glucose dehydrogenase to spontaneously adsorb onto the N-CNT surface and measuring the resulting electrode's sensitivity to glucose. The glucose biosensor had a sensitivity of 0.032 ± 0.003 A M(-1) cm(-2), a limit of detection at 6 ± 1 μM, and a linear range of 440 ± 50 μM. PMID:23991631

  9. Kinetic and thermodynamic study of the reaction catalyzed by glucose-6-phosphate dehydrogenase with nicotinamide adenine dinucleotide

    Martin del Campo, Julia S. [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico); Patino, Rodrigo, E-mail: rtarkus@mda.cinvestav.mx [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico)

    2011-04-20

    Research highlights: {yields} The reaction catalyzed by one enzyme of the pentose phosphate pathway was studied. {yields} A spectrophotometric method is proposed for kinetic and thermodynamic analysis. {yields} The pH and the temperature influences are reported on physical chemical properties. {yields} Relative concentrations of substrates are also important in the catalytic process. - Abstract: The enzyme glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from Leuconostoc mesenteroides has a dual coenzyme specificity with oxidized nicotinamide adenine dinucleotide (NAD{sub ox}) and oxidized nicotinamide adenine dinucleotide phosphate as electron acceptors. The G6PD coenzyme selection is determined by the metabolic cellular prevailing conditions. In this study a kinetic and thermodynamic analysis is presented for the reaction catalyzed by G6PD from L. mesenteroides with NAD{sub ox} as coenzyme in phosphate buffer. For this work, an in situ spectrophotometric technique was employed based on the detection of one product of the reaction. Substrate and coenzyme concentrations as well as temperature and pH effects were evaluated. The apparent equilibrium constant, the Michaelis constant, and the turnover number were determined as a function of each experimental condition. The standard transformed Gibbs energy of reaction was determined from equilibrium constants at different initial conditions. For the product 6-phospho-D-glucono-1,5-lactone, a value of the standard Gibbs energy of formation is proposed, {Delta}{sub f}G{sup o} = -1784 {+-} 5 kJ mol{sup -1}.

  10. Ultraviolet hypersensitivity of Cockayne syndrome lymphoblastoid lines - the effects of exogenous β-nicotinamide adenine dinucleotide

    Four Cockayne Syndrome (CS) lymphoblastoid lines were tested for the lethal effects of UV radiation (254 nm) with or without addition of exogenous β-nicotinamide adenine dinucleotide (β-NAD+) to their culture medium. Two of them exhibited a small but significantly increased resistance to UV radiation when β-NAD+ was added to the culture. However, their UV sensitivity after β-NAD+ addition was still much greater than that of normal control lines. Normal control lymphoblastoid lines and those from complementation group A and group C of xeroderma pigmentosum (XP) did not reveal any differences in post-UV sensitivity after the addition of exogenous β-NAD+. Thus the abnormal response to the lethal effects of UV radiation of CS lymphoblastoid lines could not be rectified by β-NAD+ addition. However, β-NAD+ does appear to play some partial role in reducing the high UV sensitivity of some CS lymphoblastoid lines. (author)

  11. Nicotinamide adenine dinucleotide assisted shape-controlled synthesis of catalytically active raspberry-like gold nanostructures

    Graphical abstract: A facile method was developed for the synthesis of raspberry-like Au nanostructure and it was used as an electrocatalyst for the oxidation of methanol and reduction of oxygen. - Highlights: • Raspberry-like gold nanostructures have been synthesized. • Nicotinamide adenine dinucleotide plays an important role in the synthesis. • Raspberry-like Au nanostructure has an excellent electrocatalytic activity in methanol oxidation and oxygen reduction. - Abstract: We describe the shape-controlled growth of raspberry-like gold (Au) nanostructures and their application in the electrochemical oxidation of methanol and reduction of oxygen. Nicotinamide adenine dinucleotide (NAD+) plays a vital role in the growth of raspberry-like Au nanostructures. The preferential adsorption of NAD+ onto the (011) facets of Au favors the growth of raspberry-like morphology. In the absence of NAD+, icosahedral Au nanostructures were obtained. The raspberry-like Au nanostructures have been characterized by UV-visible spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and electrochemical measurements. The FESEM image shows that the raspberry-like morphology has an average size of 170 nm. The spectral profile shows a broad band between 650 and 795 nm. Compared to Au nanoseeds and icosahedral Au nanostructures that were grown in the absence of NAD+, the raspberry-like morphology has excellent catalytic activity towards the electrochemical oxidation of methanol and reduction of oxygen. On the raspberry-like nanoparticle-based electrode, the oxidation of methanol was observed at 0.35 V in alkaline pH, and the reduction of oxygen was observed at -0.06 and -0.4 V in 0.1 M PBS. The electrochemical reduction of oxygen occurs in two steps: (i) reduction of oxygen to H2O2 and (ii) further reduction of electrogenerated H2O2 to water. The electrochemical performance of the raspberry-like nanostructure-based electrode is highly stable

  12. Magnitude of malate-aspartate reduced nicotinamide adenine dinucleotide shuttle activity in intact respiring tumor cells.

    Greenhouse, W V; Lehninger, A L

    1977-11-01

    Measurements of respiration, CO2 and lactate production, and changes in the levels of various key metabolites of the glycolytic sequence and tricarboxylic acid cycle were made on five lines of rodent ascites tumor cells (two strains of Ehrlich ascites tumor cells, Krebs II carcinoma, AS-30D carcinoma, and L1210 cells) incubated aerobically in the presence of uniformly labeled D-[14C]glucose. From these data, as well as earlier evidence demonstrating that the reduced nicotinamide adenine dinucleotide (NADH) shuttle in these cells requires a transaminase step and is thus identified as the malate-aspartate shuttle (W.V.V. Greenhouse and A.L. Lehninger, Cancer Res., 36: 1392-1396, 1976), metabolic flux diagrams were constructed for the five cell lines. These diagrams show the relative rates of glycolysis, the tricarboxylic acid cycle, electron transport, and the malate-aspartate shuttle in these tumors. Large amounts of cytosolic NADH were oxidized by the mitochondrial respiratory chain via the NADH shuttle, comprising anywhere from about 20 to 80% of the total flow of reducing equivalents to oxygen in these tumors. Calculations of the sources of energy for adenosine triphosphate synthesis indicated that on the average about one-third of the respiratory adenosine triphosphate is generated by electron flow originating from cytosolic NADH via the malate-aspartate shuttle. PMID:198130

  13. A novel twist on molecular interactions between thioredoxin and nicotinamide adenine dinucleotide phosphate-dependent thioredoxin reductase

    Kirkensgaard, Kristine Groth; Hägglund, Per; Shahpiri, Azar;

    2013-01-01

    The ubiquitous disulfide reductase thioredoxin (Trx) regulates several important biological processes such as seed germination in plants. Oxidized cytosolic Trx is regenerated by nicotinamide adenine dinucleotide phosphate (NADPH)-dependent thioredoxin reductase (NTR) in a multistep transfer of r....... Overall, the findings suggest that NTR:Trx interactions in different biological systems are fine-tuned by multiple intermolecular contacts. Proteins 2014; 82:607-619. (c) 2013 Wiley Periodicals, Inc....

  14. Role of Nicotinamide Adenine Dinucleotide Phosphate–Reduced Oxidase Proteins in Pseudomonas aeruginosa–Induced Lung Inflammation and Permeability

    Fu, Panfeng; Mohan, Vijay; Mansoor, Syed; Tiruppathi, Chinnaswamy; Sadikot, Ruxana T.; Natarajan, Viswanathan

    2013-01-01

    Earlier studies indicated a role for reactive oxygen species (ROS) in host defense against Pseudomonas aeruginosa infection. However, the role of nicotinamide adenine dinucleotide phosphate–reduced (NADPH) oxidase (NOX) proteins and the mechanism of activation for NADPH oxidase in P. aeruginosa infection are not well-defined. Here, we investigated the role of NOX2 and NOX4 proteins in P. aeruginosa infection, ROS generation, and endothelial barrier function in murine lungs and in human lung m...

  15. Purification and characterization of the enzymes involved in nicotinamide adenine dinucleotide degradation by Penicillium brevicompactum NRC 829

    Ali, Thanaa Hamed; El-Ghonemy, Dina Helmy

    2016-01-01

    The present study was conducted to investigate a new pathway for the degradation of nicotinamide adenine dinucleotide (NAD) by Penicillium brevicompactum NRC 829 extracts. Enzymes involved in the hydrolysis of NAD, i.e. alkaline phosphatase, aminohydrolase and glycohydrolase were determined. Alkaline phosphatase was found to catalyse the sequential hydrolysis of two phosphate moieties of NAD molecule to nicotinamide riboside plus adenosine. Adenosine was then deaminated by aminohydrolase to i...

  16. Induction of ischemic tolerance in rat liver via reduced nicotinamide adenine dinucleotide phosphate oxidase in Kupffer cells

    2007-01-01

    AIM: To elucidate the mechanisms of hepatocyte preconditioning by H2O2 to better understand the pathophysiology of ischemic preconditioning.METHODS: The in vitro effect of H2O2 pretreatment was investigated in rat isolated hepatocytes subjected to anoxia/reoxygenation. Cell viability was assessed with propidium iodide fluorometry. In other experiments, rat livers were excised and subjected to warm ischemia/reperfusion in an isolated perfused liver system to determine leakage of liver enzymes. Preconditioning was performed by H2O2 perfusion, or by stopping the perfusion for 10 min followed by 10 min of reperfusion.To inhibit Kupffer cell function or reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase,gadolinium chloride was injected prior to liver excision, or diphenyleneiodonium, an inhibitor of NADPH oxidase, was added to the perfusate, respectively. Histological detection of o~gen radical formation in Kupffer cells was performed by perfusion with nitro blue tetrazolium.RESULTS: Anoxia/reoxygenation decreased hepatocyte viability compared to the controls. Pretreatment with H2O2 did not improve such hepatocyte injury. In liver perfusion experiments, however, H2O2 preconditioning reduced warm ischemia/reperfusion injury, which was reversed by inhibition of Kupffer cell function or NADPH oxidase. Histological examination revealed that H2O2 preconditioning induced oxygen radical formation in Kupffer cells. NADPH oxidase inhibition also reversed hepatoprotection by ischemic preconditioning.CONCLUSION: H2O2 preconditioning protects hepatocytes against warm ischemia/reperfusion injury via NADPH oxidase in Kupffer cells, and not directly. NADPH oxidase also mediates hepatoprotection by ischemic preconditioning.

  17. Cleavage of nicotinamide adenine dinucleotide by the ribosome-inactivating protein from Momordica charantia.

    Vinkovic, M; Dunn, G; Wood, G E; Husain, J; Wood, S P; Gill, R

    2015-09-01

    The interaction of momordin, a type 1 ribosome-inactivating protein from Momordica charantia, with NADP(+) and NADPH has been investigated by X-ray diffraction analysis of complexes generated by co-crystallization and crystal soaking. It is known that the proteins of this family readily cleave the adenine-ribose bond of adenosine and related nucleotides in the crystal, leaving the product, adenine, bound to the enzyme active site. Surprisingly, the nicotinamide-ribose bond of oxidized NADP(+) is cleaved, leaving nicotinamide bound in the active site in the same position but in a slightly different orientation to that of the five-membered ring of adenine. No binding or cleavage of NADPH was observed at pH 7.4 in these experiments. These observations are in accord with current views of the enzyme mechanism and may contribute to ongoing searches for effective inhibitors. PMID:26323301

  18. Catalytic activity of iron hexacyanoosmate(II) towards hydrogen peroxide and nicotinamide adenine dinucleotide and its use in amperometric biosensors

    Kotzian, Petr; Janku, Tereza [Department of Analytical Chemistry, University of Pardubice, Nam. Cs. Legii 565, CZ-532 10 Pardubice (Czech Republic); Kalcher, Kurt [Institute of Chemistry - Analytical Chemistry, Karl-Franzens University, Universitaetsplatz 1, A-8010 Graz (Austria); Vytras, Karel [Department of Analytical Chemistry, University of Pardubice, Nam. Cs. Legii 565, CZ-532 10 Pardubice (Czech Republic)], E-mail: karel.vytras@upce.cz

    2007-09-19

    Hydrogen peroxide and nicotinamide adenine dinucleotide (NADH) may be determined amperometrically using screen-printed electrodes chemically modified with iron(III) hexacyanoosmate(II) (Osmium purple) in flow injection analysis (FIA). The determination is based on the exploitation of catalytic currents resulting from the oxidation/reduction of the modifier. The performance of the sensor was characterized and optimized by controlling several operational parameters (applied potential, pH and flow rate of the phosphate buffer). Comparison has been made with analogous complexes of ruthenium (Ruthenium purple) and iron (Prussian blue). Taking into account the sensitivity and stability of corresponding sensors, the best results were obtained with the use of Osmium purple. The sensor exhibited a linear increase of the amperometric signal with the concentration of hydrogen peroxide in the range of 0.1-100 mg L{sup -1} with a detection limit (evaluated as 3{sigma}) of 0.024 mg L{sup -1} with a R.S.D. 1.5% for 10 mg L{sup -1} H{sub 2}O{sub 2} under optimized flow rate of 0.4 mL min{sup -1} in 0.1 M phosphate buffer carrier (pH 6) and a working potential of +0.15 V versus Ag/AgCl. Afterwards, a biological recognition element - either glucose oxidase or ethanol dehydrogenase - was incorporated to achieve a sensor facilitating the determination of glucose or ethanol, respectively. The glucose sensor gave linearity between current and concentration in the range from 1 to 250 mg L{sup -1} with a R.S.D. 2.4% for 100 mg L{sup -1} glucose, detection limit 0.02 mg L{sup -1} (3{sigma}) and retained its original activity after 3 weeks when stored at 6 deg. C. Optimal parameters in the determination of ethanol were selected as: applied potential +0.45 V versus Ag/AgCl, flow rate 0.2 mL min{sup -1} in 0.1 M phosphate buffer carrier (pH 7). Different structural designs of the ethanol sensor were tested and linearity obtained was up to 1000 mg L{sup -1} with a maximum R.S.D. of 5

  19. Biocomposite based on reduced graphene oxide film modified with phenothiazone and flavin adenine dinucleotide-dependent glucose dehydrogenase for glucose sensing and biofuel cell applications.

    Ravenna, Yehonatan; Xia, Lin; Gun, Jenny; Mikhaylov, Alexey A; Medvedev, Alexander G; Lev, Ovadia; Alfonta, Lital

    2015-10-01

    A novel composite material for the encapsulation of redox enzymes was prepared. Reduced graphene oxide film with adsorbed phenothiazone was used as a highly efficient composite for electron transfer between flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase and electrodes. Measured redox potential for glucose oxidation was lower than 0 V vs Ag/AgCl electrode. The fabricated biosensor showed high sensitivity of 42 mA M(-1) cm(-2), a linear range of glucose detection of 0.5-12 mM, and good reproducibility and stability as well as high selectivity for different interfering compounds. In a semibiofuel cell configuration, the hybrid film generated high power output of 345 μW cm(-2). These results demonstrate a promising potential for this composition in various bioelectronic applications. PMID:26334692

  20. The conserved baculovirus protein p33 (Ac92) is a flavin adenine dinucleotide-linked sulfhydryl oxidase

    Open reading frame 92 of the Autographa californica baculovirus (Ac92) is one of about 30 core genes present in all sequenced baculovirus genomes. Computer analyses predicted that the Ac92 encoded protein (called p33) and several of its baculovirus orthologs were related to a family of flavin adenine dinucleotide (FAD)-linked sulfhydryl oxidases. Alignment of these proteins indicated that, although they were highly diverse, a number of amino acids in common with the Erv1p/Alrp family of sulfhydryl oxidases are present. Some of these conserved amino acids are predicted to stack against the isoalloxazine and adenine components of FAD, whereas others are involved in electron transfer. To investigate this relationship, Ac92 was expressed in bacteria as a His-tagged fusion protein, purified, and characterized both spectrophotometrically and for its enzymatic activity. The purified protein was found to have the color (yellow) and absorption spectrum consistent with it being a FAD-containing protein. Furthermore, it was demonstrated to have sulfhydryl oxidase activity using dithiothreitol and thioredoxin as substrates.

  1. Surface enhanced Raman scattering investigation of protein-bound flavin adenine dinucleotide structure

    Maskevich, S. A.; Strekal, N. D.; Artsukevich, I. M.; Kivach, L. N.; Chernikevich, I. P.

    1995-04-01

    The SERS spectra of alcohol oxidase from Pichia pastoris adsorbed on a silver electrode were obtained. The similarities and differences of these spectra with the SERS spectrum of free flavin adenine dinucleiotide were considered. The dependence of relative intensity of 1258 cm -1 band from the electrode potential in the protein SERS spectra differed from that of free flavin. From the data on this band being sensitive to the protein-flavin interaction a suggestion was made about incomplete dissociation of flavin from the protein. This conclusion is confirmed both by the fluorescence data and the SERS data on alcohol oxidase purified from Candida boidinii. The results of the SERS investigation of the interaction between the substrate, ethanol and the cofactor, FAD, as well as between protein-bound cofactor with the substrate are presented. The problem of retaining the protein enzyme activity is discussed.

  2. Synthesis of a Novel Benzoyl Adenosine Analog Containing a 1, 4-Dioxane Sugar Analog and the Synthesis of a Corresponding Uracil Adenine Dinucleotide

    Per Carlsen

    2011-05-01

    Full Text Available Adenosine analogs in which the sugar unit was replaced by a 1,4-dioxane sugar equivalent, were prepared by coupling the 1,4-dioxane sugar analog as its anomeric acetates, with N6-benzoyl protected adenine. The 1,4-dioxane system was obtained in an enantioselective synthesis from (R,R-dimethyl tartrate. Using standard phosphorimidite methodology, the adenine analog was further reacted with a 1,4-dioxane uridine analog to give the corresponding, protected dinucleotide, set-up for further condensation into larger oligonucleotides.

  3. Drought-Stimulated Activity of Plasma Membrane Nicotinamide Adenine Dinucleotide Phosphate Oxidase and Its Catalytic Properties in Rice

    Zhuang-Qin Duan; Lei Bai; Zhi-Guang Zhao; Guo-Ping Zhang; Fang-Min Cheng; Li-Xi Jiang; Kun-Ming Chen

    2009-01-01

    The activity of plasma membrane (PM) nicoUnamide adenine dinucleotide phosphate (NADPH) oxidase and Its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreased leaf relative water content (RWC) and, as a result of drought-induced oxidative stress, the activities of antioxidant enzymes increased significantly. More interestingly, the intensity of applied water stress was correlated with increased production of H_2O_2and O_2~- and elevated activity of PM NADPH oxidase, a key enzyme of reactive oxygen species generation in plants.Histochemlcal analyses also revealed increased H_2O_2 and O_2~- production in drought-stressed leaves. Application of dlphenylene iodonium (DPI), an Inhibitor of PM NADPH oxidasa, did not alleviate drought-induced production of H_2O_2 and O_2~-. Catalysis experiments indicated that the dce PM NADPH oxidass was partially fiavin-dependent. The pH and temperature optima for this enzyme were 9.8 and 40 ℃, respectively. In addition, drought stress enhanced the activity under alkaline pH and high temperature conditions. These results suggest that a complex regulatory mechanism, associated with the NADPH oxidase-H_2O_2 system, is involved in the response of rice to drought stress.

  4. Deficiency of the iron-sulfur clusters of mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone oxidoreductase (complex I) in an infant with congenital lactic acidosis.

    Moreadith, R W; Batshaw, M L; Ohnishi, T.; Kerr, D.; Knox, B; Jackson, D; Hruban, R; Olson, J; Reynafarje, B; Lehninger, A L

    1984-01-01

    We report the case of an infant with hypoglycemia, progressive lactic acidosis, an increased serum lactate/pyruvate ratio, and elevated plasma alanine, who had a moderate to profound decrease in the ability of mitochondria from four organs to oxidize pyruvate, malate plus glutamate, citrate, and other NAD+-linked respiratory substrates. The capacity to oxidize the flavin adenine dinucleotide-linked substrate, succinate, was normal. The most pronounced deficiency was in skeletal muscle, the le...

  5. Exceptionally high glucose current on a hierarchically structured porous carbon electrode with "wired" flavin adenine dinucleotide-dependent glucose dehydrogenase.

    Tsujimura, Seiya; Murata, Kazuki; Akatsuka, Wataru

    2014-10-15

    This article introduces a carbon electrode designed to achieve efficient enzymatic electrolysis by exploiting a hierarchical pore structure based on macropores for efficient mass transfer and mesopores for high enzyme loading. Magnesium oxide-templated mesoporous carbon (MgOC, mean pore diameter 38 nm) was used to increase the effective specific surface area for enzyme immobilization. MgOC particles were deposited on a current collector by an electrophoretic deposition method to generate micrometer-scale macropores to improve the mass transfer of glucose and electrolyte (buffer) ions. To create a glucose bioanode, the porous-carbon-modified electrode was further coated with a biocatalytic hydrogel composed of a conductive redox polymer, deglycosylated flavin adenine dinucleotide-dependent glucose dehydrogenase (d-FAD-GDH), and a cross-linker. Carbohydrate chains on the peripheral surfaces of the FAD-GDH molecules were removed by periodate oxidation before cross-linking. The current density for the oxidation of glucose was 100 mA cm(-2) at 25 °C and pH 7, with a hydrogel loading of 1.0 mg cm(-2). For the same hydrogel composition and loading, the current density on the MgOC-modified electrode was more than 30 times higher than that on a flat carbon electrode. On increasing the solution temperature to 45 °C, the catalytic current increased to 300 mA cm(-2), with a hydrogel loading of 1.6 mg cm(-2). Furthermore, the stability of the hydrogel electrode was improved by using the mesoporous carbon materials; more than 95% of the initial catalytic current remained after a 220-day storage test in 4 °C phosphate buffer, and 80% was observed after 7 days of continuous operation at 25 °C. PMID:25244161

  6. A comparative cluster analysis of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry in the brains of amphibians.

    Pinelli, Claudia; Rastogi, Rakesh K; Scandurra, Anna; Jadhao, Arun G; Aria, Massimo; D'Aniello, Biagio

    2014-09-01

    Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) is a key enzyme in the synthesis of the gaseous neurotransmitter nitric oxide. We compare the distribution of NADPH-d in the brain of four species of hylid frogs. NADPH-d-positive fibers are present throughout much of the brain, whereas stained cell groups are distributed in well-defined regions. Whereas most brain areas consistently show positive neurons in all species, in some areas species-specific differences occur. We analyzed our data and those available for other amphibian species to build a matrix on NADPH-d brain distribution for a multivariate analysis. Brain dissimilarities were quantified by using the Jaccard index in a hierarchical clustering procedure. The whole brain dendrogram was compared with that of its main subdivisions by applying the Fowlkes-Mallows index for dendrogram similarity, followed by bootstrap replications and a permutation test. Despite the differences in the distribution map of the NADPH-d system among species, cluster analysis of data from the whole brain and hindbrain faithfully reflected the evolutionary history (framework) of amphibians. Dendrograms from the secondary prosencephalon, diencephalon, mesencephalon, and isthmus showed some deviation from the main scheme. Thus, the present analysis supports the major evolutionary stability of the hindbrain. We provide evidence that the NADPH-d system in main brain subdivisions should be cautiously approached for comparative purposes because specific adaptations of a single species could occur and may affect the NADPH-d distribution pattern in a brain subdivision. The minor differences in staining pattern of particular subdivisions apparently do not affect the general patterns of staining across species. PMID:24549578

  7. Changes in phosphorylation of adenosine phosphate and redox state of nicotinamide-adenine dinucleotide (phosphate) in Geobacter sulfurreducens in response to electron acceptor and anode potential variation

    Rose, Nicholas D.

    2015-12-01

    © 2015 Elsevier B.V. Geobacter sulfurreducens is one of the dominant bacterial species found in biofilms growing on anodes in bioelectrochemical systems. The intracellular concentrations of reduced and oxidized forms of nicotinamide-adenine dinucleotide (NADH and NAD+, respectively) and nicotinamide-adenine dinucleotide phosphate (NADPH and NADP+, respectively) as well as adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) were measured in G. sulfurreducens using fumarate, Fe(III)-citrate, or anodes poised at different potentials (110, 10, -90, and -190mV (vs. SHE)) as the electron acceptor. The ratios of CNADH/CNAD+ (0.088±0.022) and CNADPH/CNADP+ (0.268±0.098) were similar under all anode potentials tested and with Fe(III)-citrate (reduced extracellularly). Both ratios significantly increased with fumarate as the electron acceptor (0.331±0.094 for NAD and 1.96±0.37 for NADP). The adenylate energy charge (the fraction of phosphorylation in intracellular adenosine phosphates) was maintained near 0.47 under almost all conditions. Anode-growing biofilms demonstrated a significantly higher molar ratio of ATP/ADP relative to suspended cultures grown on fumarate or Fe(III)-citrate. These results provide evidence that the cellular location of reduction and not the redox potential of the electron acceptor controls the intracellular redox potential in G. sulfurreducens and that biofilm growth alters adenylate phosphorylation.

  8. Diabetic complications within the context of aging: Nicotinamide adenine dinucleotide redox, insulin C-peptide, sirtuin 1-liver kinase B1-adenosine monophosphate-activated protein kinase positive feedback and forkhead box O3.

    Ido, Yasuo

    2016-07-01

    Recent research in nutritional control of aging suggests that cytosolic increases in the reduced form of nicotinamide adenine dinucleotide and decreasing nicotinamide adenine dinucleotide metabolism plays a central role in controlling the longevity gene products sirtuin 1 (SIRT1), adenosine monophosphate-activated protein kinase (AMPK) and forkhead box O3 (FOXO3). High nutrition conditions, such as the diabetic milieu, increase the ratio of reduced to oxidized forms of cytosolic nicotinamide adenine dinucleotide through cascades including the polyol pathway. This redox change is associated with insulin resistance and the development of diabetic complications, and might be counteracted by insulin C-peptide. My research and others' suggest that the SIRT1-liver kinase B1-AMPK cascade creates positive feedback through nicotinamide adenine dinucleotide synthesis to help cells cope with metabolic stress. SIRT1 and AMPK can upregulate liver kinase B1 and FOXO3, key factors that help residential stem cells cope with oxidative stress. FOXO3 directly changes epigenetics around transcription start sites, maintaining the health of stem cells. 'Diabetic memory' is likely a result of epigenetic changes caused by high nutritional conditions, which disturb the quiescent state of residential stem cells and impair tissue repair. This could be prevented by restoring SIRT1-AMPK positive feedback through activating FOXO3. PMID:27181414

  9. Protonation mechanism and location of rate-determining steps for the Ascaris suum nicotinamide adenine dinucleotide-malic enzyme reaction from isotope effects and pH studies

    Kiick, D.M.; Harris, B.G.; Cook, P.F.

    1986-01-14

    The pH dependence of the kinetic parameters and the primary deuterium isotope effects with nicotinamide adenine dinucleotide (NAD) and also thionicotinamide adenine dinucleotide (thio-NAD) as the nucleotide substrates were determined in order to obtain information about the chemical mechanism and location of rate-determining steps for the Ascaris suum NAD-malic enzyme reaction. The maximum velocity with thio-NAD as the nucleotide is pH-independent from pH 4.2 to 9.6, while with NAD, V decreases below a pK of 4.8. V/K for both nucleotides decreases below a pK of 5.6 and above a pK of 8.9. Both the tartronate pKi and V/Kmalate decrease below a pK of 4.8 and above a pK of 8.9. Oxalate is competitive vs. malate above pH 7 and noncompetitive below pH 7 with NAD as the nucleotide. The oxalate Kis increases from a constant value above a pK of 4.9 to another constant value above a pK of 6.7. The oxalate Kii also increases above a pK of 4.9, and this inhibition is enhanced by NADH. In the presence of thio-NAD the inhibition by oxalate is competitive vs. malate below pH 7. For thio-NAD, both DV and D(V/K) are pH-independent and equal to 1.7. With NAD as the nucleotide, DV decreases to 1.0 below a pK of 4.9, while D(V/KNAD) and D(V/Kmalate) are pH-independent. Above pH 7 the isotope effects on V and the V/K values for NAD and malate are equal to 1.45, the pH-independent value of DV above pH 7. Results indicate that substrates bind to only the correctly protonated form of the enzyme. Two enzyme groups are necessary for binding of substrates and catalysis. Both NAD and malate are released from the Michaelis complex at equal rates which are equal to the rate of NADH release from E-NADH above pH 7. Below pH 7 NADH release becomes more rate-determining as the pH decreases until at pH 4.0 it completely limits the overall rate of the reaction.

  10. Protonation mechanism and location of rate-determining steps for the Ascaris suum nicotinamide adenine dinucleotide-malic enzyme reaction from isotope effects and pH studies

    The pH dependence of the kinetic parameters and the primary deuterium isotope effects with nicotinamide adenine dinucleotide (NAD) and also thionicotinamide adenine dinucleotide (thio-NAD) as the nucleotide substrates were determined in order to obtain information about the chemical mechanism and location of rate-determining steps for the Ascaris suum NAD-malic enzyme reaction. The maximum velocity with thio-NAD as the nucleotide is pH-independent from pH 4.2 to 9.6, while with NAD, V decreases below a pK of 4.8. V/K for both nucleotides decreases below a pK of 5.6 and above a pK of 8.9. Both the tartronate pKi and V/Kmalate decrease below a pK of 4.8 and above a pK of 8.9. Oxalate is competitive vs. malate above pH 7 and noncompetitive below pH 7 with NAD as the nucleotide. The oxalate Kis increases from a constant value above a pK of 4.9 to another constant value above a pK of 6.7. The oxalate Kii also increases above a pK of 4.9, and this inhibition is enhanced by NADH. In the presence of thio-NAD the inhibition by oxalate is competitive vs. malate below pH 7. For thio-NAD, both DV and D(V/K) are pH-independent and equal to 1.7. With NAD as the nucleotide, DV decreases to 1.0 below a pK of 4.9, while D(V/KNAD) and D(V/Kmalate) are pH-independent. Above pH 7 the isotope effects on V and the V/K values for NAD and malate are equal to 1.45, the pH-independent value of DV above pH 7. Results indicate that substrates bind to only the correctly protonated form of the enzyme. Two enzyme groups are necessary for binding of substrates and catalysis. Both NAD and malate are released from the Michaelis complex at equal rates which are equal to the rate of NADH release from E-NADH above pH 7. Below pH 7 NADH release becomes more rate-determining as the pH decreases until at pH 4.0 it completely limits the overall rate of the reaction

  11. Detection of electronically equivalent tautomers of adenine base: DFT study

    Graphical abstract: - Highlights: • DFT calculations have been performed on adenine and its rare tautomer Cu2+ complexes. • Interaction of A-Cu2+ and rA-Cu2+ complexes with AlN modified fullerene (C60) have been studied briefly. • It is found that AlN modified C60 could be used as a nanoscale sensor to detect these two A-Cu2+ and rA-Cu2+ complexes. - Abstract: In the present study, quantum chemical calculations were carried out to investigate the electronic structures and stabilities of adenine and its rare tautomer along with their Cu2+ complexes. Density Functional Theory (B3LYP method) was used in all calculations. The two Cu2+ complexes of adenine have almost similar energies and electronic structures; hence, their chemical differentiation is very difficult. For this purpose, interactions of these complexes with AlN modified fullerene (C60) have been studied. Theoretical investigations reveal that AlN-doped C60 may serve as a potentially viable nanoscale sensor for detection of the two Cu2+ complexes of adenine

  12. Deficiency of the iron-sulfur clusters of mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone oxidoreductase (complex I) in an infant with congenital lactic acidosis.

    Moreadith, R W; Batshaw, M L; Ohnishi, T; Kerr, D; Knox, B; Jackson, D; Hruban, R; Olson, J; Reynafarje, B; Lehninger, A L

    1984-09-01

    We report the case of an infant with hypoglycemia, progressive lactic acidosis, an increased serum lactate/pyruvate ratio, and elevated plasma alanine, who had a moderate to profound decrease in the ability of mitochondria from four organs to oxidize pyruvate, malate plus glutamate, citrate, and other NAD+-linked respiratory substrates. The capacity to oxidize the flavin adenine dinucleotide-linked substrate, succinate, was normal. The most pronounced deficiency was in skeletal muscle, the least in kidney mitochondria. Enzymatic assays on isolated mitochondria ruled out defects in complexes II, III, and IV of the respiratory chain. Further studies showed that the defect was localized in the inner membrane mitochondrial NADH-ubiquinone oxidoreductase (complex I). When ferricyanide was used as an artificial electron acceptor, complex I activity was normal, indicating that electrons from NADH could reduce the flavin mononucleotide cofactor. However, electron paramagnetic resonance spectroscopy performed on liver submitochondrial particles showed an almost total loss of the iron-sulfur clusters characteristic of complex I, whereas normal signals were noted for other mitochondrial iron-sulfur clusters. This infant is presented as the first reported case of congenital lactic acidosis caused by a deficiency of the iron-sulfur clusters of complex I of the mitochondrial electron transport chain. PMID:6432847

  13. Wear Particles Promote Reactive Oxygen Species-Mediated Inflammation via the Nicotinamide Adenine Dinucleotide Phosphate Oxidase Pathway in Macrophages Surrounding Loosened Implants

    Weishen Chen

    2015-03-01

    Full Text Available Background/Aims: Prosthesis loosening is closely associated with chronic inflammatory cytokine secretion by macrophages, which are activated by wear particles or inflammatory stimulants such as lipopolysaccharide (LPS. Reactive oxygen species (ROS are critical regulators of inflammation, but their enzymatic sources in response to wear particles and their effects on peri-implant LPS-tolerance remain unclear. Methods: Three ROS-related enzymes—nicotinamide adenine dinucleotide phosphate oxidase (NOX-1 and -2 and catalase—were investigated in interface membrane tissues and in titanium (Ti particle-stimulated macrophages in vitro. The generation of ROS and downstream inflammatory effects were measured with or without pre-incubation with apocynin, an NOX inhibitor. Results: Pre-exposure to Ti particles attenuated NF-κB activation in LPS-stimulated macrophages, indicating that wear particles suppress immune response, which may lead to chronic inflammation. NOX-1 and -2 were highly expressed in aseptically loosened interface membranes and in macrophages stimulated with Ti particles; the particles induced a moderate amount of ROS generation, NF-κB activation, and TNF-a secretion in macrophages, and these effects were suppressed by apocynin. Conclusion: Wear particles induce ROS generation through the NOX signaling pathway, resulting in persistent inflammation and delayed loosening. Thus, the suppression of NOX activity may be a useful strategy for preventing prosthesis loosening.

  14. Excessive Copper Induces the Production of Reactive Oxygen Species, which is Mediated by Phospholipase D, Nicotinamide Adenine Dinucleotide Phosphate Oxidase and Antioxidant Systems

    Zhong-Lian Yu; Jin-Guang Zhang; Xue-Chen Wang; Jia Chen

    2008-01-01

    Tobacco BY-2 suspension cells were used to study the chemical damage and its associated mechanisms caused by Cu2+. Treatment with 100 μmol/L Cu2+ generated a large amount of H2O2 and thiobarbituric acid-reactive substances (TBARS) in cells. Using phospholipase D (PLD) specific inhibitor (1-butanol) or phosphatidic acid (PA), we demonstrated that PLD plays an important role in the generation of H2O2 and TBARS. Semi-quantitative reverse-transcriptase polymerase chain reaction and enzyme activity assays with wild type and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase- overexpressing BY-2 cells revealed that PLD and PA are the key factors leading to NADPH oxidase activation, which is responsible for H2O2 and TBARS production induced by Cu2+. Moreover, the content of ascorbic acid (AsA), an effective antioxidant, was sharply reduced in BY-2 cells exposed to excessive Cu2+. Furthermore, a significant downregulation of the enzymes of AsA biosynthesis and the antioxidant system was found. This evidencesuggests that excessive Cu2+-elevated reactive oxygen species (ROS) production is caused by upregulated PLD that elevates the activity of NADPH oxidase and its collapsed antioxidant systems that scavenges ROS.

  15. β-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum.

    Wang, Guo-Du; Wang, Xi-Yu; Liu, Sumei; Xia, Yun; Zou, Fei; Qu, Meihua; Needleman, Bradley J; Mikami, Dean J; Wood, Jackie D

    2015-06-01

    Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to β-nicotinamide adenine dinucleotide (β-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, β-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. β-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of β-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of β-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for β-NAD at intestinal neuromuscular junctions. The data suggest that β-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of β-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions. PMID:25813057

  16. Effect of telmisartan on the expression of adiponectin receptors and nicotinamide adenine dinucleotide phosphate oxidase in the heart and aorta in type 2 diabetic rats

    Guo Zhixin

    2012-08-01

    Full Text Available Abstract Background Diabetic cardiovascular disease is associated with decreased adiponectin and increased oxidative stress. This study investigated the effect of telmisartan on the expression of adiponectin receptor 2 (adipoR2 and nicotinamide adenine dinucleotide phosphate (NADPH oxidase subunits in the heart and the expression of adiponectin receptor 1 (adipoR1 in aorta in type 2 diabetic rats. Methods Type 2 diabetes was induced by high-fat and high-sugar diet and intraperitoneal injection of a low dose of streptozotocin (STZ. Heart function, adipoR2, p22phox, NOX4, glucose transporter 4(GLUT4, monocyte chemoattractant protein-1(MCP-1 and connective tissue growth factor (CTGFin the heart, and adipoR1, MCP-1 and nuclear factor kappa B (NF-κB in aorta were analyzed in controls and diabetic rats treated with or without telmisartan (5mg/kg/d by gavage for 12 weeks. Results Heart function, plasma and myocardial adiponectin levels, the expression of myocardial adipoR2 and GLUT4 were significantly decreased in diabetic rats (P Conclusions Our results suggest that telmisartan upregulates the expression of myocardial adiponectin, its receptor 2 and GLUT4. Simultaneously, it downregulates the expression of myocardial p22phox, NOX4, MCP-1, and CTGF, contributing so to the improvement of heart function in diabetic rats. Telmisartan also induces a protective role on the vascular system by upregulating the expression of adipoR1 and downregulating the expression of MCP-1 and NF-κB in the abdominal aorta in diabetic rats.

  17. Nicotinamide Adenine Dinucleotide Phosphate Oxidase-Mediated Redox Signaling and Vascular Remodeling by 16α-Hydroxyestrone in Human Pulmonary Artery Cells: Implications in Pulmonary Arterial Hypertension.

    Hood, Katie Y; Montezano, Augusto C; Harvey, Adam P; Nilsen, Margaret; MacLean, Margaret R; Touyz, Rhian M

    2016-09-01

    Estrogen and oxidative stress have been implicated in pulmonary arterial hypertension (PAH). Mechanisms linking these systems are elusive. We hypothesized that estrogen metabolite, 16α-hydroxyestrone (16αOHE1), stimulates nicotinamide adenine dinucleotide phosphate oxidase (Nox)-induced reactive oxygen species (ROS) generation and proliferative responses in human pulmonary artery smooth muscle cells (hPASMCs) and that in PAH aberrant growth signaling promotes vascular remodeling. The pathophysiological significance of estrogen-Nox-dependent processes was studied in female Nox1(-/-) and Nox4(-/-) mice with PAH. PASMCs from control subjects (control hPASMCs) and PAH patients (PAH-hPASMCs) were exposed to estrogen and 16αOHE1 in the presence/absence of inhibitors of Nox, cytochrome P450 1B1, and estrogen receptors. Estrogen, through estrogen receptor-α, increased Nox-derived ROS and redox-sensitive growth in hPASMCs, with greater effects in PAH-hPASMCs versus control hPASMCs. Estrogen effects were inhibited by cytochrome P450 1B1 blockade. 16αOHE1 stimulated transient ROS production in hPASMCs, with sustained responses in PAH-hPASMCs. Basal expression of Nox1/Nox4 was potentiated in PAH-hPASMCs. In hPASMCs, 16αOHE1 increased Nox1 expression, stimulated irreversible oxidation of protein tyrosine phosphatases, decreased nuclear factor erythroid-related factor 2 activity and expression of nuclear factor erythroid-related factor 2-regulated antioxidant genes, and promoted proliferation. This was further amplified in PAH-hPASMCs. Nox1(-/-) but not Nox4(-/-) mice were protected against PAH and vascular remodeling. Our findings demonstrate that in PAH-hPASMCs, 16αOHE1 stimulates redox-sensitive cell growth primarily through Nox1. Supporting this, in vivo studies exhibited protection against pulmonary hypertension and remodeling in Nox1(-/-) mice. This study provides new insights through Nox1/ROS and nuclear factor erythroid-related factor 2 whereby 16αOHE1 influences

  18. Role of Key Residues at the Flavin Mononucleotide (FMN:Adenylyltransferase Catalytic Site of the Bifunctional Riboflavin Kinase/Flavin Adenine Dinucleotide (FAD  Synthetase from Corynebacterium ammoniagenes

    Susana Frago

    2012-11-01

    Full Text Available In mammals and in yeast the conversion of Riboflavin (RF into flavin mononucleotide (FMN and flavin adenine dinucleotide (FAD is catalysed by the sequential action of two enzymes: an ATP:riboflavin kinase (RFK and an ATP:FMN adenylyltransferase (FMNAT. However, most prokaryotes depend on a single bifunctional enzyme, FAD synthetase (FADS, which folds into two modules: the C-terminal associated with RFK activity and the N-terminal associated with FMNAT activity. Sequence and structural analysis suggest that the 28-HxGH-31, 123-Gx(D/N-125 and 161-xxSSTxxR-168 motifs from FADS must be involved in ATP stabilisation for the adenylylation of FMN, as well as in FAD stabilisation for FAD phyrophosphorolysis. Mutants were produced at these motifs in the Corynebacterium ammoniagenes FADS (CaFADS. Their effects on the kinetic parameters of CaFADS activities (RFK, FMNAT and FAD pyrophosphorilase, and on substrates and product binding properties indicate that H28, H31, N125 and S164 contribute to the geometry of the catalytically competent complexes at the FMNAT-module of CaFADS.

  19. Effects of aqueous extract of Ruta graveolens and its ingredients on cytochrome P450, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH-quinone oxidoreductase in mice

    Yune-Fang Ueng

    2015-09-01

    Full Text Available Ruta graveolens (the common rue has been used for various therapeutic purposes, including relief of rheumatism and treatment of circulatory disorder. To elucidate the effects of rue on main drug-metabolizing enzymes, effects of an aqueous extract of the aerial part of rue and its ingredients on cytochrome P450 (P450/CYP, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH:quinone oxidoreductase were studied in C57BL/6JNarl mice. Oral administration of rue extract to males increased hepatic Cyp1a and Cyp2b activities in a dose-dependent manner. Under a 7-day treatment regimen, rue extract (0.5 g/kg induced hepatic Cyp1a and Cyp2b activities and protein levels in males and females. This treatment increased hepatic UDP-glucuronosyltransferase activity only in males. However, NAD(PH:quinone oxidoreductase activity remained unchanged. Based on the contents of rutin and furanocoumarins of mouse dose of rue extract, rutin increased hepatic Cyp1a activity and the mixture of furanocoumarins (Fmix increased Cyp2b activities in males. The mixture of rutin and Fmix increased Cyp1a and Cyp2b activities. These results revealed that rutin and Fmix contributed at least in part to the P450 induction by rue.

  20. Utilization of FIA-UV/ED for detection of adenine derivates

    Ondrej Zitka; Libuse Trnkova; Frantisek Jelen; Vojtech Adam; Rene Kizek

    2010-01-01

    A purine derivative adenine poses many biological functions.Besides the fact that this molecule is one of the building blocks forRNA and DNA, there are many derivates with their specificsattributes. 2-aminopurine is well known as mutagen. 2,6-diaminopurine is able to replace purine basis in nucleic acids.Benzylaminopurine belongs to phytohormones.

  1. A flow injection analysis coupled dual electrochemical detector for selective and simultaneous detection of guanine and adenine

    Graphical abstract: - Highlights: • First study for simultaneous determination of guanine (G) and adenine (A) using a dual electrode. • Separation-less flow-injection analysis technique was introduced for G and A. • This method is selective and no interference by the presence of other DNA bases (T and C). • DNA hybridization process and meat real sample analysis were demonstrated. - Abstract: Adenine (A) and guanine (G), important bases of nucleic acids, are often analyzed by separation coupled spectroscopic detection methods. Herein, we are demonstrated a new flow-injection analysis (FIA) coupled dual electrochemical detector (DECD), where a chitosan-carbon nanofiber (Chit-CNF) modified glassy carbon electrode prepared by a simple technique and pH 7 phosphate buffer solution as a carrier system, for separation-less quantification of G and A. This method is highly selective and no interference by the presence of the other DNA bases (Thymine and Cytosine). The FIA-DECD was operated at two different operating potentials, E1 = 0.80 V and E2 = 0.95 V vs Ag/AgCl, where G and {G + A} get oxidized, respectively. Amount of A was calculated from the difference between the FIA current signals, measured at E20.95V and E10.80V. The GCE/Chit-CNF was characterized by cyclic voltammetry with potassium ferricyanide system and Raman spectroscopy. The modified electrode showed unique electron-transfer feature with metal like conductivity. Under an optimal condition, FIA-DECD showed linear calibration plots for G and A in a concentration range, 200 nM—50 μM with current sensitivity values 13.83 ± 0.48 and 4.84 ± 0.11 nA μM−1 respectively. Calculated detection limit (signal-to-noise ratio = 3) values were 46.8 nM and 73.8 nM for G and A respectively. Applicability of the present technique was further demonstrated by detecting G and A in beef kidney sample and DNA hybridization process

  2. Synthesis and Biological Evaluation of Nicotinamide Adenine Dinucleotides Analogues as Inhibitors of CD38%烟酰胺腺嘌呤二核苷酸类CD38抑制剂的合成及生物活性评价

    陈哲; KWONGAnnaKa-Yee; 杨振军; 张亮仁; LEEHonCheung; 张礼和

    2012-01-01

    CD38 is the main mammalian ADP-ribosyl cyclase and a signaling enzyme responsible for catalyzing the synthesis of Ca2+-messengers and plays a critical role in a wide range of physiological functions. It is of great interest to develop specific and generally applicable inhibitors of CD38. Fluoro-substituted nicotina-mide adenine dinucleotides( NAD) , such as ara-F NMN and ara-F NAD, are catalysis-dependent inhibitors of CD38 and are often used as probes for investigating the function of CD38. For understanding the effect of fluo-ro-substitution on activity in more detail and discovery of active inhibitors of CD38, compounds 2a-2c were synthesized and their inhibition against the hydrolysis activities of CD38 were evaluated. The syntheses were performed by starting from the corresponding fluoro-substituted sugar, then followed by coupling with nicoti-namide, regio-seleclive 5 '-phosphorylation and condensation with adenosine monophosphate, successively. All target compounds were purified by HPLC and characterized by NMR and HRMS. Two compounds showed strong inhibitions, especially 2'-deoxy-2'-fluororibonofuranosyl which gave activity with IC50 of 0. 056μmol/L and was two orders of magnitude higher than positive control ara-F NAD. The results also showed that the activity was greatly affected by the number and the position of fluorine atom on the sugar ring, as well as the configuration of the inhibitors. The detailed biological investigation and structure-activity relationship are underway.%分别以1,3,5-三苯甲酰基-α-D-核糖、3,5-二苯甲酰基-2-脱氧-2,2-氟戊呋喃糖-1-酮和D-木糖为原料,经由烟酰胺核苷及烟酰胺核苷酸中间体,合成了系列糖环经氟原子取代的烟酰胺腺嘌呤二核苷酸(NAD)类CD38抑制剂.基于对CD38的水解抑制能力的考察,评价了所合成氟代NAD类似物的活性.结果表明,糖环上氟原子取代的数目和位置对抑制剂活性的影响十分明显,烟酰胺核苷的端

  3. Preparation of a sol-gel-derived carbon nanotube ceramic electrode by microwave irradiation and its application for the determination of adenine and guanine

    Abbaspour, Abdolkarim, E-mail: abbaspour@chem.susc.ac.i [Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Fars 71456-85464 (Iran, Islamic Republic of); Ghaffarinejad, Ali [Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Fars 71456-85464 (Iran, Islamic Republic of)

    2010-01-01

    In this study, microwave irradiation was used for the fast preparation (min) of a sol-gel-derived carbon nanotube ceramic electrode (MW-CNCE). For confirmation of the preparation of the ceramic by MW irradiation, Fourier transform infrared, X-ray diffraction spectra and scanning electron microscopy images of the produced ceramic were compared with those of conventional ceramic (which is produced by drying the ceramic in air for 48 h). The electrochemical behavior of MW-CNCE in nicotinamide adenine dinucleotide, L-cysteine, adenine and guanine was compared with that of a conventional sol-gel-derived carbon nanotube ceramic electrode (CNCE). In all systems, similar peak potentials and lower background currents were obtained with respect to CNCE. Finally, the MW-CNCE was used for the simultaneous determination of adenine and guanine using differential pulse voltammetry. The linear ranges of 0.1-10 and 0.1-20 muM were obtained for adenine and guanine, respectively. These results are comparable with some modified electrodes that have recently been reported for the determination of adenine and guanine, with the advantage that the proposed electrode did not contain modifier. In addition, the proposed electrode was successfully used for the oxidation of adenine and guanine in DNA, and the detection limit for this measurement was 0.05 mug mL{sup -1} DNA.

  4. Graphene-Enhanced Raman Scattering from the Adenine Molecules.

    Dolgov, Leonid; Pidhirnyi, Denys; Dovbeshko, Galyna; Lebedieva, Tetiana; Kiisk, Valter; Heinsalu, Siim; Lange, Sven; Jaaniso, Raivo; Sildos, Ilmo

    2016-12-01

    An enhanced Raman scattering from a thin layer of adenine molecules deposited on graphene substrate was detected. The value of enhancement depends on the photon energy of the exciting light. The benzene ring in the structure of adenine molecule suggests π-stacking of adenine molecule on top of graphene. So, it is proposed that the enhancement in the adenine Raman signal is explained by the resonance electron transfer from the Fermi level of graphene to the lowest unoccupied molecular orbital (LUMO) level of adenine. PMID:27075339

  5. Graphene-Enhanced Raman Scattering from the Adenine Molecules

    Dolgov, Leonid; Pidhirnyi, Denys; Dovbeshko, Galyna; Lebedieva, Tetiana; Kiisk, Valter; Heinsalu, Siim; Lange, Sven; Jaaniso, Raivo; Sildos, Ilmo

    2016-04-01

    An enhanced Raman scattering from a thin layer of adenine molecules deposited on graphene substrate was detected. The value of enhancement depends on the photon energy of the exciting light. The benzene ring in the structure of adenine molecule suggests π-stacking of adenine molecule on top of graphene. So, it is proposed that the enhancement in the adenine Raman signal is explained by the resonance electron transfer from the Fermi level of graphene to the lowest unoccupied molecular orbital (LUMO) level of adenine.

  6. Fate of prebiotic adenine.

    Cohn, C A; Hansson, T K; Larsson, H S; Sowerby, S J; Holm, N G

    2001-01-01

    Equilibrium adsorption isotherm data for the purine base adenine has been obtained on several prebiotically relevant minerals by frontal analysis using water as a mobile phase. Adenine is far displaced toward adsorption on pyrite (FeS2), quartz (SiO2), and pyrrhotite (FeS), but somewhat less for magnetite (Fe3O4) and forsterite (Mg2SiO4). The prebiotic prevalence of these minerals would have allowed them to act as a sink for adenine; removal from the aqueous phase would confer protection from hydrolysis as well, establishing a nonequilibrium thermodynamic framework for increased adenine synthesis. Our results provide evidence that adsorption phenomena may have been critical for the primordial genetic architecture. PMID:12448980

  7. Enhanced-oxidation and highly-sensitive detection of acetaminophen, guanine and adenine using NMP-exfoliated graphene nanosheets-modified electrode

    Graphical abstract: Display Omitted - Highlights: • Compared with RGO, NMP-exfoliated GS possessed lower electron transfer resistance. • Oxidation activity of AC, G and A on NMP-exfoliated GS surface increased greatly. • A highly-sensitive electrochemical sensing platform was constructed for AC, G and A. - Abstract: Graphene nanosheets (GS) were easily prepared by one-step ultrasonic exfoliation of graphite powder in N-methyl-2-pyrrolidone (NMP). Compared with the widely-used reduced graphene oxides that prepared via chemical methods, the NMP-exfoliated GS exhibited higher electron transfer ability. Moreover, the resulting GS displayed higher electrochemical reactivity toward the oxidation of acetaminophen (AC), guanine (G) and adenine (A). In pH 6.5 phosphate buffer, three well-defined oxidation waves at 0.41 V, 0.69 V and 0.96 V were observed, and the oxidation peak currents were greatly enhanced on the surface of GS. As a result, a highly-sensitive electrochemical sensing platform was developed for the simultaneous detection of AC, G and A. The detection limits of AC, G and A on GS-modified electrode were evaluated to be 2.5 nM, 10 nM and 10 nM, respectively. Besides, the proposed method was successfully applied in the detection of tablet and DNA samples

  8. The relationship between periodic dinucleotides and the nucleosomal DNA deformation revealed by normal mode analysis

    Nucleosomes, which contain DNA and proteins, are the basic unit of eukaryotic chromatins. Polymers such as DNA and proteins are dynamic, and their conformational changes can lead to functional changes. Periodic dinucleotide patterns exist in nucleosomal DNA chains and play an important role in the nucleosome structure. In this paper, we use normal mode analysis to detect significant structural deformations of nucleosomal DNA and investigate the relationship between periodic dinucleotides and DNA motions. We have found that periodic dinucleotides are usually located at the peaks or valleys of DNA and protein motions, revealing that they dominate the nucleosome dynamics. Also, a specific dinucleotide pattern CA/TG appears most frequently

  9. 不同糖耐量人群血清吞噬细胞样还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶水平与胰岛β细胞功能的关系%Relationship between serum level of phagocyte-like nicotinamide adenine dinucleotide phosphate oxidase and pancreaticβ-cell function among different groups of glucose tolerance

    陈鹤文; 吴垣辕; 田晶; 贾方; 刘东方

    2015-01-01

    Objective To evaluate the oxidative status under different blood glucose levels, and study the relationship between body phagocyte-like nicotinamide adenine dinucleotide phosphate oxidase (Nox) with oxidative stress and pancreaticβ-cell function. Methods According to the fasting blood-glucose and oral glucose tolerance test,84 individuals who participated physical exam were divided into 3 groups:normal glucose tolerance group(NGT,n=26, FPG<6.1 mmol/L and OGTT 2 hPG<7.8 mmol/L), impaired glucose regulation group (IGR, n=27, FPG between 6.1-7.0 mmol/L and OGTT 2 hPG<7.8 mmol/L)or FPG<6.1 mmol/L and OGTT 2 h PG between 7.8-11.1 mmol/L,or FPG between 6.1-7.0 mmol/L and OGTT 2 h PG between 7.8-11.1 mmol/L, and diabetes mellitus group(n=31, FPG≥7.0 mmol/L ,and/or OGTT 2 hPG≥11.1 mmol/L).Nox, 8-hydroxy-2′-deoxyguanosine (8-OHdG), superoxide dismutase(SOD), malondialdehyde( MDA) was measured. The islet beta cell function index(HBCI)was calculated by each recognized formula. Variance analysis was used to analysis between multiple groups,and independent samples t testto comparetwo groups. Pearson′s correlation Multivariate regression analysis were performed between HBCI which was corrected by insulin resistance and other variable. Results With the increase of blood glucose, the level of Nox in DMgroup was higher than IGR group.HBCI was decreased((143.3±22.1)vs(118.0±21.8)U/L, (12.4 ± 2.3)vs(31.1 ± 7.7), t=2.156,5.621, respectively,all P<0.05). Nox in DM group was significantly higher than NGT,group. HBCI was significantly decreased((143.3 ± 22.1)vs (97.2 ± 19.9)U/L,12.4 ± 2.3 vs 105.2±21.3, t=4.460,4.111, respectively,all P<0.05). The further multiple regression analysis indicated that only Nox was independent factor on HBCI(r=-0.572,β=-1.088, R2=0.455,P<0.001). Conclusions Nox maybe an ideal index in reflecting the oxidative status in the body. Oxidative stress derived from Nox is closely tied to pancreaticβ-cell function.%目的:研究不同血糖水

  10. Characterization of Two Mitochondrial Flavin Adenine Dinucleotide-Dependent Glycerol-3-Phosphate Dehydrogenases in Trypanosoma brucei

    Škodová, Ingrid; Verner, Zdeněk; Bringaud, F.; Fabian, P.; Lukeš, Julius; Horváth, A.

    2013-01-01

    Roč. 12, č. 12 (2013), s. 1664-1673. ISSN 1535-9778 R&D Projects: GA ČR(CZ) GAP305/11/2179; GA ČR GD206/09/H026; GA MŠk LH12104 Institutional support: RVO:60077344 Keywords : alternative NADH dehydrogenase * inducible expression system * blood-stream forms * complex-I * procyclic trypanosomes * sleeping sickness * oxidase * localization * metabolism * cycle Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.179, year: 2013

  11. [Synthesis of nicotinamide adenine dinucleotide in the nuclei of pigeon erythrocytes].

    Nemchinskaia, V L; Makarova, T G; Mozhenok, T P; Braun, A D

    1975-08-01

    The nuclei of pigeon erythrocytes are capable of synthesizing NAD from nicotinamid-mononucleotides and ATP. Some data on the kinetics of NAD-pyrophosphorylase have been obtained: the optimal concentration of nuclei and the effect of various incubation time. The pretreatment of nuclei by Triton X-100, or by ultrasonics enhances NAD synthesis. The results suggest that cyclic 3',5'-AMP (Fluka) may have no effect on NAD synthesis. The control of the cell metabolism by NAD formation is considered. PMID:181878

  12. Bound anionic states of adenine

    Harańczyk, Maciej; Gutowski, Maciej; Li, Xiang; Bowen, Kit H.

    2007-01-01

    Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases are thought to be adiabatically unbound. Contrary to this expectation, we have demonstrated that some thus far ignored tautomers of adenine...

  13. Formation of the imidazolides of dinucleotides under potentially prebiotic conditions

    Sleeper, H. L.; Lohrmann, R.; Orgel, L. E.

    1978-01-01

    Imidazolides of dinucleotides such as ImpApA can be formed from the corresponding dinucleotides in a two-stage process, which gives up to 15% yields under potentially prebiotic conditions. First a solution of the dinucleotide and sodium trimetaphosphate is dried out at constant temperature and humidity. This produces polyphosphates such as p(n)ApA in excellent yield (greater than or equal to 80%). The products are dissolved in water, imidazole is added, and the solution is dried out again. This yields the 5'-phosphorimidazolides.

  14. Analysis of dinucleotide signatures in HIV-1 subtype B genomes

    Aridaman Pandit; Jyothirmayi Vadlamudi; Somdatta Sinha

    2013-12-01

    Dinucleotide usage is known to vary in the genomes of organisms. The dinucleotide usage profiles or genome signatures are similar for sequence samples taken from the same genome, but are different for taxonomically distant species. This concept of genome signatures has been used to study several organisms including viruses, to elucidate the signatures of evolutionary processes at the genome level. Genome signatures assume greater importance in the case of host–pathogen interactions, where molecular interactions between the two species take place continuously, and can influence their genomic composition. In this study, analyses of whole genome sequences of the HIV-1 subtype B, a retrovirus that caused global pandemic of AIDS, have been carried out to analyse the variation in genome signatures of the virus from 1983 to 2007.We show statistically significant temporal variations in some dinucleotide patterns highlighting the selective evolution of the dinucleotide profiles of HIV-1 subtype B, possibly a consequence of host specific selection.

  15. Responses of corn root protoplasts to exogenous reduced nicotinamide adenine dinucleotide: Oxygen consumption, ion uptake, and membrane potential

    Lin, Willy

    1982-01-01

    Addition of 1.5 mM NADH tripled the O2 consumption in corn root protoplasts. The stimulation was temperature and pH dependent, specific to NADH, and accompanied by a 2- to 3-fold increase in K+ and Pi uptake into protoplasts. The increase in ion uptake was not due to the accumulation of NADH into protoplasts. The effect of exogenous NADH on O2 consumption and ion uptake was also evident in corn root segments but to a lesser extent. A 20-mV hyperpolarization of protoplast membrane potential oc...

  16. Electrocatalytic oxidation of dihydronicotineamide adenine dinucleotide on gold electrode modified with catechol-terminated alkanethiol self-assembly

    Synthesis of a mercaptoundecaneamide derivative having a terminus of catechol is described. FT-IR spectroscopic characterization showed that the new molecular entry simply undergoes molecular self-assembly on Au substrate surfaces promoting intra- and intermolecular hydrogen bonds to form well-packed monolayers. Cyclic voltammetric (CV) measurements on the monolayer-modified Au electrode revealed that the surface adlayer possesses specific electrochemical activity due to the reversible catechol/o-quinone redox reaction having characteristics of a surface process and also pH-dependence in its formal potential (59 mV per pH). Detailed analysis of CVs gave fundamental electrochemical parameters including the electroactive surface coverage (0.20-0.24 nmol cm-2), the transfer coefficients (0.24 in oxidation and 0.81 in reduction), and also the electron transfer rate constant (1.10-2.76 s-1). These data were almost consistent to those seen in literature. We have also found that the catechol monolayer modified electrode exhibits an electrocatalytic function in NADH oxidation. That is, the faradaic current appeared reinforcingly at around the same potential where catechol function is oxidized in the monolayer and increased with an increase in the NADH concentration from 1 to 5 mM, and then reached to a plateau indicating a catalyzed reaction pathway. Detailed analyses revealed that the present system could be characterized by its weak stability of the intermediate compound formed and prompt reaction rate compared with the previously reported chemically modified electrode (CME) systems. We think this type of achievement should be important for the basics of biosensors that rely on dehydrogenase enzymes

  17. Catalytic properties of nickel ferrites for oxidation of glucose, β-nicotiamide adenine dinucleotide (NADH) and methanol

    Highlights: ► NiFe2O4 nanoparticles obtained by electrochemical method are effective catalyst. ► A partially inverse spinel was obtained with 57% Fe3+ in tetrahedral position. ► A non-enzymatic electrode using NiFe2O4 nanoparticles has been manufactured. -- Abstract: Nickel ferrite nanoparticles (NiFe2O4) were synthesized by electrochemical method and used as catalyst for direct oxidation of glucose, NADH and methanol. Characterization of these nanoparticles was carried out by X-ray diffraction, Mössbauer spectroscopy, and colloidal properties such as hydrodynamic radius and Zeta potential. To evaluate the catalytic properties of these nanoparticles against the oxidation process, paste graphite electrodes mixing nickel ferrites and different conductive materials (graphite, carbon nanotubes) and binders agents (mineral oil, 1-octylpyridinium hexafluorophosphate (nOPPF6)) were used. The results prove good catalytic properties of these materials, with an oxidation potential around 0.75, 0.5 and 0.8 V for glucose, NADH, and methanol, respectively

  18. The Nicotinamide Adenine Dinucleotide Phosphate Oxidase Homologues NOX1 and NOX2/gp91phox Mediate Hepatic Fibrosis in Mice

    Paik, Yong-Han; Iwaisako, Keiko; Seki, Ekihiro; Inokuchi, Sayaka; Schnabl, Bernd; Österreicher, Christoph H.; Kisseleva, Tatiana; Brenner, David A

    2011-01-01

    NADPH oxidase (NOX) is a multicomponent enzyme that mediates electron transfer from NADPH to molecular oxygen, which leads to the production of superoxide. NOX2/gp91phox is a catalytic subunit of NOX expressed in phagocytic cells. Several homologues of NOX2, including NOX1, have been identified in non-phagocytic cells. We investigated the contributory role of NOX1 and NOX2 in hepatic fibrosis. Hepatic fibrosis was induced in wild-type (WT) mice, NOX1-knockout (NOX1KO) mice, and NOX2-knockout ...

  19. Alternative Splicing and Differential Expression of Two Transcripts of Nicotine Adenine Dinucleotide Phosphate Oxidase B Gene from Zea mays

    Fan Lin; Yun Zhang; Ming-Yi Jiang

    2009-01-01

    With the exception of rice, little is known about the existence of respiratory burst oxidase homolog (rboh) gene in cereals. The present study reports the cloning and analysis of a novel rboh gene, termed ZmrbohB, from maize (Zea mays L.). The full-length cDNA of ZmrbohB encodes a 942 amino acid protein containing all of the respiratory burst oxidase homolog catalytically critical motifs.Altemative splicing of ZmrbohB has generated two transcript isoforms, ZmrbohB-α and -β. Spliced transcript ZmrbohB-β retains an unspliced intron 11 that carries a premature termination codon and probably leads to nonsense-mediated mRNA decay. Expression analysis showed that two splice isoforms were differentially expressed in various tissues and at different developmental stages, and the major product was ZmrbohB-α. The transcripts of ZmrbohB-α accumulated markedly when the maize seedlings were subjected to various abiotic stimuli, such as wounding, cold (4℃), heat (40℃), UV and salinity stress. In addition, several abiotic stimuli also affected the alternative splicing pattern of ZmrbohB except wounding. These results provide new insight into roles in the expression regulation of plant rboh genes and suggest that ZmrbohB gene may play a role in response to environmental stresses.

  20. Evidence for the existence of a tyrosyl residue in the nicotinamide adenine dinucleotide binding site of chicken liver xanthine dehydrogenase

    Xanthine-NAD and NADH-methylene blue oxidoreductase activities of chicken liver xanthine dehydrogenase were inactivated by incubation with 5'-[p-(fluorosulfonyl)benzoyl]adenosine (5'-FSBA), an active site directed reagent for nucleotide binding sites. The inactivation reaction displayed pseudo-first-order kinetics. A double-reciprocal plot of inactivation velocity vs. 5'-FSBA concentration showed that 5'-FSBA and enzyme formed a complex prior to inactivation. NAD protected the enzyme from inactivation by 5'-FSBA in a competitive fashion. The modified enzyme had the same xanthine-dichlorophenolindophenol and xanthine-O2 oxidoreductase activities as the native enzyme, and on addition of xanthine to the modified enzyme, bleaching of the spectrum occurred in the visible region. The amount of radioactivity incorporated into the enzyme by incubation with [14C]-5'-FSBA was parallel to the loss of xanthine-NAD oxidoreductase activity, and the stoichiometry was 1 mol/mol of enzyme-bound FAD for complete inactivation. These results indicated that 5'-FSBA modified specifically the binding site for NAD of chicken liver xanthine dehydrogenase. The incorporated radioactivity was released slowly from 14C-labeled enzyme by incubation with dithiothreitol with concomitant restoration of catalytic activity. The modified residue responsible for inactivation was identified as a tyrosine

  1. Determination of adenine based on the fluorescence recovery of the L-Tryptophan-Cu2+ complex

    Duan, Ruilin; Li, Chunyan; Liu, Shaopu; Liu, Zhongfang; Li, Yuanfang; Yuan, Yusheng; Hu, Xiaoli

    2016-01-01

    A simple and sensitive method for determination of adenine was developed based on fluorescence quenching and recovery of L-Tryptophan (L-Trp). The fluorescence of L-Trp could efficiently quenched by copper ion compared with other common metal ions. Upon addition of adenine (Ade) in L-Trp-Cu(II) system, the fluorescence was reoccurred. Under the optimum conditions, the recovery fluorescence intensity was linearly correlated with the concentration of adenine in the range from 0.34 to 25.0 μmol L-1, with a correlation coefficient (R2) of 0.9994. The detection limit (3σ/k) was 0.046 μmol L-1, indicating that this method could applied to detect trace adenine. In this study, amino acids including L-Trp, D-Trp, L-Tyr, D-Tyr, L-Phe, D-Phe were investigated and only L-Trp could well chelated copper ion. Additionally, the mechanism of quench and recovery also were discussed and the method was successfully applied to detect the adenine in DNA with satisfactory results.

  2. Molecularly imprinted polymer (MIP) based piezoelectric microgravimetry chemosensor for selective determination of adenine.

    Pietrzyk, Agnieszka; Suriyanarayanan, Subramanian; Kutner, Wlodzimierz; Chitta, Raghu; Zandler, Melvin E; D'Souza, Francis

    2010-07-15

    An adenine-templated molecularly imprinted polymer (MIP) film, deposited on a poly(bithiophene) barrier film, served as the recognition element of a piezomicrogravimetric (acoustic) chemosensor. A 10MHz AT-cut shear-thickness-mode bulk-acoustic-wave quartz crystal resonator with Pt film electrodes was used as the signal transducer. Adenine electrooxidation was prevented by the barrier film. The MIP film was deposited by electrochemical co-polymerization of two functional monomers of bis(bithiophene) derivatives, bearing either the 18-crown-6 or dioxaborinane substituent, in the presence of the adenine template. A strong base solution was then used to extract the template. Completeness of the template removal was substantiated by the UV-vis, XPS, DPV, and EIS measurements. The chemosensor performance was evaluated with the piezoelectric microgravimetry detection at QCM under FIA conditions using a carrier acetonitrile-water (1:1, v:v) mixed solvent solution. The linear dynamic concentration range extended from at least 0.1 to 1mM for the 35 microL/min flow rate, and 100 microL volume of the injected adenine solution. The chemosensor selectivity allowed for discrimination of the adenine analyte from structurally and functionally related interferants, such as 2-aminopurine, guanine, and ascorbic acid. The determined from the FIA kinetic studies stability constant of the MIP-adenine complex, (18+/-2.4)x10(4)M(-1), was much higher than that of the MIP-(2-aminopurine), (650+/-90)M(-1), MIP-guanine, (122+/-11)M(-1), and MIP-(ascorbic acid), (92+/-10)M(-1), complexes. The concentration limit of detection was as low as 5 nM adenine for the 35 microL/min flow rate, and 1 mL volume of the injected sample solution. PMID:20483586

  3. Second-Generation Fluorescent Quadracyclic Adenine Analogues

    Dumat, Blaise; Bood, Mattias; Wranne, Moa S.;

    2015-01-01

    quadracyclic adenine analogues. The compounds were efficiently synthesized from a common intermediate through a two-step pathway with the Suzuki-Miyaura coupling as the key step. Two of the compounds, qAN1 and qAN4, display brightnesses (epsilon Phi(F)) of 1700 and 2300, respectively, in water and behave as...

  4. A DNA-templated silver nanocluster probe for label-free, turn-on fluorescence-based screening of homo-adenine binding molecules.

    Park, Ki Soo; Park, Hyun Gyu

    2015-02-15

    A novel, label-free, turn-on fluorescence strategy to detect molecules that bind to adenine-rich DNA sequences has been developed. The probe employs DNA-templated silver nanoclusters (DNA-AgNCs) as the key detection component. The new strategy relies on the formation of non-Watson-Crick homo-adenine DNA duplex, triggered by strong interactions with homo-adenine binding molecules, which brings a guanine-rich sequence in one strand close to DNA-AgNCs located on the opposite strand. This phenomenon transforms weakly fluorescent AgNCs into highly emissive species that display bright red fluorescence. Finally, we have shown that the new fluorescence turn-on strategy can be employed to detect coralyne, the most representative homo-adenine binding molecule that triggers formation of a non-Watson-Crick homo-adenine DNA duplex. PMID:25441410

  5. A structurally conserved water molecule in Rossmann dinucleotide-binding domains

    Bottoms, Christopher A; Smith, Paul E.; Tanner, John J.

    2002-01-01

    A computational comparison of 102 high-resolution (≤1.90 Å) enzyme-dinucleotide (NAD, NADP, FAD) complexes was performed to investigate the role of solvent in dinucleotide recognition by Rossmann fold domains. The typical binding site contains about 9–12 water molecules, and about 30% of the hydrogen bonds between the protein and the dinucleotide are water mediated. Detailed inspection of the structures reveals a structurally conserved water molecule bridging dinucleotides with the well-known...

  6. Optical biopsy - a new armamentarium to detect disease using light

    Pu, Yang; Alfano, Robert R.

    2015-03-01

    Optical spectroscopy has been considered a promising method for cancer detection for past thirty years because of its advantages over the conventional diagnostic methods of no tissue removal, minimal invasiveness, rapid diagnoses, less time consumption and reproducibility since the first use in 1984. It offers a new armamentarium. Human tissue is mainly composed of extracellular matrix of collagen fiber, proteins, fat, water, and epithelial cells with key molecules in different structures. Tissues contain a number of key fingerprint native endogenous fluorophore molecules, such as tryptophan, collagen, elastin, reduced nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FAD) and porphyrins. It is well known that abnormalities in metabolic activity precede the onset of a lot of main diseases: carcinoma, diabetes mellitus, atherosclerosis, Alzheimer, and Parkinson's disease, etc. Optical spectroscopy may help in detecting various disorders. Conceivably the biochemical or morphologic changes that cause the spectra variations would appear earlier than the histological aberration. Therefore, "optical biopsy" holds a great promise as clinical tool for diagnosing early stage of carcinomas and other deceases by combining with available photonic technology (e.g. optical fibers, photon detectors, spectrographs spectroscopic ratiometer, fiber-optic endomicroscope and nasopharyngoscope) for in vivo use. This paper focuses on various methods available to detect spectroscopic changes in tissues, for example to distinguish cancerous prostate tissues and/or cells from normal prostate tissues and/or cells. The methods to be described are fluorescence, stokes shift, scattering, Raman, and time-resolved spectroscopy will be reviewed. The underlying physical and biological basis for these optical approaches will be discussed with examples. The idea is to present some of the salient works to show the usefulness and methods of Optical Biopsy for cancer detection and

  7. Mitochondrial Adenine Nucleotide Transport and Cardioprotection

    Das, Samarjit; Steenbergen, Charles

    2011-01-01

    Mitochondria are highly metabolically active cell organelles that not only act as the powerhouse of the cell by supplying energy through ATP production, but also play a destructive role by initiating cell death pathways. Growing evidence recognizes that mitochondrial dysfunction is one of the major causes of cardiovascular disease. Under de-energized conditions, slowing of adenine nucleotide transport in and out of the mitochondria significantly attenuates myocardial ischemia-reperfusion inju...

  8. The Nature's Clever Trick for Making Cyclic Dinucleotide.

    Fang, Pengfei; Guo, Min

    2015-05-01

    Ever since their initial discovery few years ago, cyclic dinucleotides (cDNs), their biosynthesis, and their biological function have been in focus of intense research efforts. In this issue, Kato et al. (2015) present strong evidence that the key enzyme in cDN biosynthesis, DncV, is poised on a tipping point such that, given a nudge, the enzyme, can link the nucleotides into a distinct cyclic loop, leading to a specific innate immune response. PMID:25955098

  9. Effect of gum arabic on oxidative stress and inflammation in adenine-induced chronic renal failure in rats.

    Badreldin H Ali

    Full Text Available Inflammation and oxidative stress are known to be involved in the pathogenesis of chronic kidney disease in humans, and in chronic renal failure (CRF in rats. The aim of this work was to study the role of inflammation and oxidative stress in adenine-induced CRF and the effect thereon of the purported nephroprotective agent gum arabic (GA. Rats were divided into four groups and treated for 4 weeks as follows: control, adenine in feed (0.75%, w/w, GA in drinking water (15%, w/v and adenine+GA, as before. Urine, blood and kidneys were collected from the rats at the end of the treatment for analysis of conventional renal function tests (plasma creatinine and urea concentration. In addition, the concentrations of the pro-inflammatory cytokine TNF-α and the oxidative stress markers glutathione and superoxide dismutase, renal apoptosis, superoxide formation and DNA double strand break frequency, detected by immunohistochemistry for γ-H2AX, were measured. Adenine significantly increased the concentrations of urea and creatinine in plasma, significantly decreased the creatinine clearance and induced significant increases in the concentration of the measured inflammatory mediators. Further, it caused oxidative stress and DNA damage. Treatment with GA significantly ameliorated these actions. The mechanism of the reported salutary effect of GA in adenine-induced CRF is associated with mitigation of the adenine-induced inflammation and generation of free radicals.

  10. Influence of Magnetic Microparticles Isolation on Adenine Homonucleotides Structure

    Monika Kremplova

    2014-02-01

    Full Text Available The electroactivity of purine and pyrimidine bases is the most important property of nucleic acids that is very useful for determining oligonucleotides using square wave voltammetry. This study was focused on the electrochemical behavior of adenine-containing oligonucleotides before and after their isolation using paramagnetic particles. Two peaks were detected—peak A related to the reduction of adenine base and another peak B involved in the interactions between individual adenine strands and contributes to the formation of various spatial structures. The influence of the number of adenine bases in the strand in the isolation process using paramagnetic particles was investigated too.

  11. Dual emission fluorescent silver nanoclusters for sensitive detection of the biological coenzyme NAD+/NADH.

    Yuan, Yufeng; Huang, Kehan; Chang, Mengfang; Qin, Cuifang; Zhang, Sanjun; Pan, Haifeng; Chen, Yan; Xu, Jianhua

    2016-02-01

    Fluorescent silver nanoclusters (Ag NCs) displaying dual-excitation and dual-emission properties have been developed for the specific detection of NAD(+) (nicotinamide adenine dinucleotide, oxidized form). With the increase of NAD(+) concentrations, the longer wavelength emission (with the peak at 550 nm) was gradually quenched due to the strong interactions between the NAD(+) and Ag NCs, whereas the shorter wavelength emission (peaking at 395 nm) was linearly enhanced. More important, the dual-emission intensity ratio (I395/I550), fitting by a single-exponential decay function, can efficiently detect various NAD(+) levels from 100 to 4000 μM, as well as label NAD(+)/NADH (reduced form of NAD) ratios in the range of 1-50. PMID:26452612

  12. Detection of ATP and NADH: A Bioluminescent Experience.

    Selig, Ted C.; And Others

    1984-01-01

    Described is a bioluminescent assay for adenosine triphosphate (ATP) and reduced nicotineamide-adenine dinucleotide (NADH) that meets the requirements of an undergraduate biochemistry laboratory course. The 3-hour experiment provides students with experience in bioluminescence and analytical biochemistry yet requires limited instrumentation,…

  13. Comparative anatomy of the human APRT gene and enzyme: nucleotide sequence divergence and conservation of a nonrandom CpG dinucleotide arrangement

    The functional human adenine phosphoribosyltransferase (APRT) gene is <2.6 kilobases in length and contains five exons. The amino acid sequences of APRTs have been highly conserved throughout evolution. The human enzyme is 82%, 90%, and 40% identical to the mouse, hamster, and Escherichia coli enzymes, respectively. The promoter region of the human APRT gene, like that of several other housekeeping genes, lacks TATA and CCAAT boxes but contains five GC boxes that are potential binding sites for the Sp1 transcription factor. The distal three, however, are dispensable for gene expression. Comparison between human and mouse APRT gene nucleotide sequences reveals a high degree of homology within protein coding regions but an absence of significant homology in 5' flanking, 3' untranslated, and intron sequences, except for similarly positioned GC boxes in the promoter region and a 26-base-pair region in intron 3. This 26-base-pair sequence is 92% identical with a similarly positioned sequence in the mouse gene and is also found in intron 3 of the hamster gene, suggesting that its retention may be a consequence of stringent selection. The positions of all introns have been precisely retained in the human and both rodent genes. Retention of an elevated CpG dinucleotide content, despite loss of sequence homology, suggests that there may be selection for CpG dinucleotides in these regions and that their maintenance may be important for APRT gene function

  14. Differences in dinucleotide frequencies of thermophilic genes encoding water soluble and membrane proteins

    Nakashima, Hiroshi; Kuroda, Yuka

    2011-01-01

    The occurrence frequencies of the dinucleotides of genes of three thermophilic and three mesophilic species from both archaea and eubacteria were investigated in this study. The genes encoding water soluble proteins were rich in the dinucleotides of purine dimers, whereas the genes encoding membrane proteins were rich in pyrimidine dimers. The dinucleotides of purine dimers are the counterparts of pyrimidine dimers in a double-stranded DNA. The purine/pyrimidine dimers were favored in the the...

  15. Adenine adlayers on Cu(111): XPS and NEXAFS study

    Tsud, Nataliya; Bercha, Sofiia; Ševčíková, Klára; Matolín, Vladimír [Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 18000 Prague 8 (Czech Republic); Acres, Robert G. [Elettra-Sincrotrone Trieste S.C.p.A., Area Science Park, Strada Statale 14, km 163.5, 34149 Basovizza, Trieste (Italy); Prince, Kevin C. [Elettra-Sincrotrone Trieste S.C.p.A., Area Science Park, Strada Statale 14, km 163.5, 34149 Basovizza, Trieste (Italy); Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche, 34149 Basovizza, Trieste (Italy)

    2015-11-07

    The adsorption of adenine on Cu(111) was studied by photoelectron and near edge x-ray absorption fine structure spectroscopy. Disordered molecular films were deposited by means of physical vapor deposition on the substrate at room temperature. Adenine chemisorbs on the Cu(111) surface with strong rehybridization of the molecular orbitals and the Cu 3d states. Annealing at 150 °C caused the desorption of weakly bonded molecules accompanied by formation of a short-range ordered molecular adlayer. The interface is characterized by the formation of new states in the valence band at 1.5, 7, and 9 eV. The present work complements and refines existing knowledge of adenine interaction with this surface. The coverage is not the main parameter that defines the adenine geometry and adsorption properties on Cu(111). Excess thermal energy can further rearrange the molecular adlayer and, independent of the initial coverage, the flat lying stable molecular adlayer is formed.

  16. The sonolysis and radiolysis of adenine and related biomolecules

    The sonolysis of adenine, its nucleoside adenosine and the carbohydrates glucose, fructose and ribose were investigated at 459 Hz. The insonation of air-saturated aqueous adenine solutions degrades adenine at a rate that is linear with time and independent of the initial concentration. The radiolytic decomposition of air-saturated aqueous adenine solutions were also investigated and the degradation products found to be essentially identical to those obtained by sonolysis. since the products derived from sonolysis and radiolysis were similar, a degradation mechanism can be proposed that accounts for all the observed products. The major feature of this mechanism is that the principal loci of attack are the C(8) position and the central C(4)-C(5) double bond. The sonolysis of air-saturated aqueous solutions of the carbohydrates results in the formation of products analogous to those produced by ionizing radiation. While two types of products are formed in the radiolysis of carbohydrate solutions, depending on the initial presence or absence of oxygen, the sonolysis of air-saturated carbohydrate solutions leads to the formation of both types of products. This is due to the depletion of oxygen from the solution during insonation. Existing mechanisms for the radiolytic decomposition of carbohydrates in the presence and absence of oxygen can be modified to rationalize the sonolysis products. Insonation of an aqueous solution of adenosine resulted in the production of adenine and ribose. The other products are consistent with those obtained in the ultrasonic degradation of adenine and ribose

  17. Wiring of Glucose Oxidizing Flavin Adenine Dinucleotide-Dependent Enzymes by Methylene Blue-Modified Third Generation Poly(amidoamine) Dendrimers Attached to Spectroscopic Graphite Electrodes

    Castaing, Victor; Álvarez-Martos, Isabel; Ferapontova, Elena

    2016-01-01

    ordered multiple redox centers, represent an advanced alternative to the existing approaches. Here we show that methylene blue (MB)-labeled G3 PAMAM dendrimers covalently attached to the high-surface area spectroscopic graphite (Gr) electrodes form stable and spatially resolved electronic wires......, characterized by the heterogeneous ET rate constant of 7.1 0.1 s1; they can be used for electronic wiring of glucose-oxidizing FAD-containing enzymes, such as hexose oxidase (HOX), and further bioelectrocatalysis of glucose oxidation, starting, at pH 7, from -100 mV vs. Ag/AgCl. Thus, dendrimer......-templated electronic wires, comprising MB molecules conjugated to the periphery of the PAMAM and anchored to the surface of cost-effective Gr electrodes represent an efficient and robust tool for protein wiring to electrodes for their perspective bioelectronic applications in biosensors and biofuel cells....

  18. Sjögren-Larsson syndrome. Impaired fatty alcohol oxidation in cultured fibroblasts due to deficient fatty alcohol:nicotinamide adenine dinucleotide oxidoreductase activity.

    Rizzo, W B; Dammann, A L; Craft, D A

    1988-01-01

    Lipid metabolism was studied in cultured skin fibroblasts from patients with the inherited disorder, Sjögren-Larsson syndrome (SLS). Intact SLS fibroblasts incubated in the presence of [1-14C]palmitate accumulated more radioactive hexadecanol than did normal cells, whereas incorporation of radioactivity into other cellular lipids was unaltered. The hexadecanol content of SLS fibroblasts was abnormally elevated. Hexadecanol accumulation was not due to increased fatty alcohol synthesis nor its ...

  19. Enhancement of photophysical and photosensitizing properties of flavin adenine dinucleotide by mutagenesis of the C-terminal extension of a bacterial flavodoxin reductase.

    Valle, Lorena; Abatedaga, Inés; Vieyra, Faustino E Morán; Bortolotti, Ana; Cortez, Néstor; Borsarelli, Claudio D

    2015-03-16

    The role of the mobile C-terminal extension present in Rhodobacter capsulatus ferredoxin-NADP(H) reductase (RcFPR) was evaluated using steady-state and dynamic spectroscopies for both intrinsic Trp and FAD in a series of mutants in the absence of NADP(H). Deletion of the six C-terminal amino acids beyond Ala266 was combined with the replacement A266Y to emulate the structure of plastidic reductases. Our results show that these modifications of the wild-type RcFPR produce subtle global conformational changes, but strongly reduce the local rigidity of the FAD-binding pocket, exposing the isoalloxazine ring to the solvent. Thus, the ultrafast charge-transfer quenching of (1) FAD* by the conserved Tyr66 residue was absent in the mutant series, producing enhancement of the excited singlet- and triplet-state properties of FAD. This work highlights the delicate balance of the specific interactions between FAD and the surrounding amino acids, and how the functionality and/or photostability of redox flavoproteins can be modified. PMID:25641205

  20. Wiring of Glucose Oxidizing Flavin Adenine Dinucleotide-Dependent Enzymes by Methylene Blue-Modified Third Generation Poly(amidoamine) Dendrimers Attached to Spectroscopic Graphite Electrodes

    Castaing, Victor; Álvarez-Martos, Isabel; Ferapontova, Elena

    2016-01-01

    , characterized by the heterogeneous ET rate constant of 7.1 0.1 s1; they can be used for electronic wiring of glucose-oxidizing FAD-containing enzymes, such as hexose oxidase (HOX), and further bioelectrocatalysis of glucose oxidation, starting, at pH 7, from -100 mV vs. Ag/AgCl. Thus, dendrimer......-templated electronic wires, comprising MB molecules conjugated to the periphery of the PAMAM and anchored to the surface of cost-effective Gr electrodes represent an efficient and robust tool for protein wiring to electrodes for their perspective bioelectronic applications in biosensors and biofuel cells....

  1. Flavin Adenine Dinucleotide Status and the Effects of High-Dose Riboflavin Treatment in Short-Chain Acyl-CoA Dehydrogenase Deficiency

    B.T. Maldegem; M. Duran; R.J.A. Wanders; H.R. Waterham; F.A. Wijburg

    2010-01-01

    Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an inborn error, biochemically characterized by increased plasma butyrylcarnitine (C4-C) concentration and increased ethylmalonic acid (EMA) excretion and caused by rare mutations and/or common gene variants in the SCAD encoding gene. Although

  2. Low potential biofuel cell anodes based on redox polymers with covalently bound phenothiazine derivatives for wiring flavin adenine dinucleotide-dependent enzymes

    The design of biofuel cell anodes with substantially decreased potential is a prerequisite for the development of biofuel cells with large open-circuit voltage and power density. Redox polymers with covalently attached phenothiazine derivatives such of thionine acetate, toluidine blue, azure B simultaneously providing epoxide functions for covalent binding to suitably modified electrode surfaces and crosslinking were synthesized and evaluated for their ability to transfer electrons from the FAD cofactor of the flavodehydrogenase domain of cellobiose dehydrogenase from Myriococcum thermophilum (FAD-MtCDH), the flavodehydrogenase domain of cellobiose dehydrogenase from Corynascus thermophilus (FAD-CtCDH), or glucose oxidase from Aspergillus niger (GOx). Polymer/enzyme films were covalently bound via polymer bound epoxy groups to terminal amino functions introduced to graphite electrode surfaces by electrochemically induced grafting of diaminoheptane or Boc-protected ethylene diamine (EDA). The electrodes were optimized for biocatalytic glucose oxidation with respect to the hydrophilicity of the polymer backbone, the nature of the phenothiazine derivative, the pH value, as well as the relative amount of enzyme, polymer and crosslinker. Biofuel cells based on toluidine blue-modified redox polymers with integrated FAD-MtCDH, FAD-CtCDH, or GOx in combination with a bilirubin oxidase based biocathode exhibited open-circuit voltages of more than 0.7 V and maximum power densities in the range of 4 to 6 μW cm−2 at a pH value of 7.8

  3. Solution structure of the 3'-5' cyclic dinucleotide d. A combined NMR, UV melting, and molecular mechanics study

    The 3'-5' cyclic dinucleotide d1H and 13C NMR experiments, UV-melting experiments, and molecular mechanics calculations. The 1H and 13C NMR spectra were analyzed by means of 2-dimensional NMR experiments. J-Coupling analysis of the 1D and 2D 1H and 13C spectra was used to determine the conformation of the ring systems in the molecule. It appeared that at low temperature (283 K) the deoxyribose sugars adopt a N-type conformation. The geometry is best described by an intermediate between the 32T and 3E forms. In addition, the authors were able to derive all other torsion angles in the phosphate backbone ring system, i.e., α+, β/sup t/, γ+, δ (=89/degrees/), ε/sup t/ and /zeta/+. When the molecule is subjected to an energy minimization procedure (using the program AMBER), the sugar ring system retains, practically speaking, the torsion angles found from the NMR experiments, while the torsion angles around the glycosidic bond adopt a value of 175/degrees/ in the minimum energy conformation. UV-melting experiments indicate that two molecules can form a dimer in which the adenine bases are intercalated. The feasibility of this structure is indicated by molecular mechanics calculations. At higher temperatures the dimer is converted into separate monomers. In the monomer form the sugars exhibit S-pucker 20% of the time. Concomitantly with the conversion of the N- to the S-conformation, the torsion angles α and γ change

  4. A new microplatform based on titanium dioxide nanofibers/graphene oxide nanosheets nanocomposite modified screen printed carbon electrode for electrochemical determination of adenine in the presence of guanine.

    Arvand, Majid; Ghodsi, Navid; Zanjanchi, Mohammad Ali

    2016-03-15

    The current techniques for determining adenine have several shortcomings such as high cost, high time consumption, tedious pretreatment steps and the requirements for highly skilled personnel often restrict their use in routine analytical practice. This paper describes the development and utilization of a new nanocomposite consisting of titanium dioxide nanofibers (TNFs) and graphene oxide nanosheets (GONs) for screen printed carbon electrode (SPCE) modification. The synthesized GONs and TNFs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The modified electrode (TNFs/GONs/SPCE) was used for electrochemical characterization of adenine. The TNFs/GONs/SPCE exhibited an increase in peak current and the electron transfer kinetics and decrease in the overpotential for the oxidation reaction of adenine. Using differential pulse voltammetry (DPV), the prepared sensor showed good sensitivity for determining adenine in two ranges from 0.1-1 and 1-10 μM, with a detection limit (DL) of 1.71 nM. Electrochemical studies suggested that the TNFs/GONs/SPCE provided a synergistic augmentation on the voltammetric behavior of electrochemical oxidation of adenine, which was indicated by the improvement of anodic peak current and a decrease in anodic peak potential. The amount of adenine in pBudCE4.1 plasmid was determined via the proposed sensor and the result was in good compatibility with the sequence data of pBudCE4.1 plasmid. PMID:26556182

  5. Electroactive Properties of 1-propyl-3-methylimidazolium Ionic Liquid Covalently Bonded on Mesoporous Silica Surface: Development of an Electrochemical Sensor Probed for NADH, Dopamine and Uric Acid Detection

    Graphical abstract: - Abstract: A hybrid organic-inorganic porous material was successfully prepared through chemical modification of a non-ordered mesoporous silica, obtained by the sol-gel process, with 1-propyl-3-methylimidazolium groups. The porous material was evaluated as a platform for the development of electrochemical sensors, here probed toward the electrooxidation of NADH (β-nicotinamide adenine dinucleotide), uric acid (UA) and dopamine (DA). The presence of cationic imidazolium groups on the surface of the hybrid silica-based material allowed the electrochemical detection of these biomolecules without any other electron mediator or biomolecular recognition component. Such behavior highlights the potentiality of this material to be applied in the development of new electrochemical sensing devices. Theoretical calculations based on density functional theory emphasizes that the cationic character of imidazolium group provides better oxidation conditions if the solvent effect is minimized

  6. Role of p73 Dinucleotide Polymorphism in Prostate Cancer and p73 Protein Isoform Balance

    L. Michael Carastro

    2014-01-01

    Full Text Available Background. Molecular markers for prostate cancer (PCa risks are currently lacking. Here we address the potential association of a dinucleotide polymorphism (DNP in exon 2 of the p73 gene with PCa risk/progression and discern any disruption of p73 protein isoforms levels in cells harboring a p73 DNP allele. Methods. We investigated the association between p73 DNP genotype and PCa risk/aggressiveness and survival by fitting logistic regression models in 1,292 incident cases and 682 controls. Results. Although we detected no association between p73 DNP and PCa risk, a significant inverse relationship between p73 DNP and PCa aggressiveness (AT/AT + GC/AT versus GC/GC, OR = 0.55, 95%Cl = 0.31–0.99 was detected. Also, p73 DNP is marginally associated with overall death (dominant model, HR = 0.76, 95%Cl = 0.57–1.00, P=0.053 as well as PCa specific death (HR = 0.69, 95%Cl = 0.45–1.06, P=0.09. Western blot analyses for p73 protein isoforms indicate that cells heterozygous for the p73 DNP have lower levels of ∆Np73 relative to TAp73 (P<0.001. Conclusions. Our findings are consistent with an association between p73 DNP and low risk for PCa aggressiveness by increasing the expressed TAp73/∆Np73 protein isoform ratio.

  7. Effects of Low-Molecular-Weight-Chitosan on the Adenine- Induced Chronic Renal Failure Ratsin vitro andin vivo

    ZHI Xuan; HAN Baoqin; SUI Xianxian; HU Rui; LIU Wanshun

    2015-01-01

    Theeffects of low-molecular-weight-chitosan (LMWC) on chronic renal failure (CRF) rats induced by adenine were investigatedin vivoand in vitro. Chitosan were hydrolyzed using chitosanase at pH 6–7 and 37℃ for 24h to obtain LMWC.In vitro, the effect of LMWC on the proliferation of renal tubular epithelial cells (RTEC) showed that it had no cytotoxic effect and could promote cell growth. For theinvivo experiment, chronic renal failure rats induced by adenine were randomly divided into control group, Niaoduqing group, and high-, medium- and low-dose LMWC groups. For each group, we detected serum creatinine (SCR), blood urea nitrogen (BUN), and total superoxide dismutase (T-SOD), glutathione oxidase (GSH-Px) activities of renal tissue, and obtained the ratio of kidney weight/body weight, pathological changes of kidney. The levels of serum SCR, BUN were higher in the adenine-induced rats than those in the controlgroup, indicating that the rat chronic renal failure model worked successfully. The re-sults after treatment showed that LMWC could reduce the SCR and BUN levels and enhance the activities/levels of T-SOD and GSH-PX in kidney compared to control group. Histopathological examination revealed that adenine-induced renal alterations were restored by LMWC at three tested dosages, especially at the low dosage of 100mgkg−1d−1.

  8. Human nucleosomes: special role of CG dinucleotides and Alu-nucleosomes

    Trifonov Edward N

    2011-05-01

    Full Text Available Abstract Background The periodical occurrence of dinucleotides with a period of 10.4 bases now is undeniably a hallmark of nucleosome positioning. Whereas many eukaryotic genomes contain visible and even strong signals for periodic distribution of dinucleotides, the human genome is rather featureless in this respect. The exact sequence features in the human genome that govern the nucleosome positioning remain largely unknown. Results When analyzing the human genome sequence with the positional autocorrelation method, we found that only the dinucleotide CG shows the 10.4 base periodicity, which is indicative of the presence of nucleosomes. There is a high occurrence of CG dinucleotides that are either 31 (10.4 × 3 or 62 (10.4 × 6 base pairs apart from one another - a sequence bias known to be characteristic of Alu-sequences. In a similar analysis with repetitive sequences removed, peaks of repeating CG motifs can be seen at positions 10, 21 and 31, the nearest integers of multiples of 10.4. Conclusions Although the CG dinucleotides are dominant, other elements of the standard nucleosome positioning pattern are present in the human genome as well. The positional autocorrelation analysis of the human genome demonstrates that the CG dinucleotide is, indeed, one visible element of the human nucleosome positioning pattern, which appears both in Alu sequences and in sequences without repeats. The dominant role that CG dinucleotides play in organizing human chromatin is to indicate the involvement of human nucleosomes in tuning the regulation of gene expression and chromatin structure, which is very likely due to cytosine-methylation/-demethylation in CG dinucleotides contained in the human nucleosomes. This is further confirmed by the positions of CG-periodical nucleosomes on Alu sequences. Alu repeats appear as monomers, dimers and trimers, harboring two to six nucleosomes in a run. Considering the exceptional role CG dinucleotides play in the

  9. Purine salvage in Methanocaldococcus jannaschii: Elucidating the role of a conserved cysteine in adenine deaminase.

    Miller, Danielle V; Brown, Anne M; Xu, Huimin; Bevan, David R; White, Robert H

    2016-06-01

    Adenine deaminases (Ade) and hypoxanthine/guanine phosphoribosyltransferases (Hpt) are widely distributed enzymes involved in purine salvage. Characterization of the previously uncharacterized Ade (MJ1459 gene product) and Hpt (MJ1655 gene product) are discussed here and provide insight into purine salvage in Methanocaldococcus jannaschii. Ade was demonstrated to use either Fe(II) and/or Mn(II) as the catalytic metal. Hpt demonstrated no detectable activity with adenine, but was equally specific for hypoxanthine and guanine with a kcat /KM of 3.2 × 10(7) and 3.0 × 10(7) s(- 1) M(- 1) , respectively. These results demonstrate that hypoxanthine and IMP are the central metabolites in purine salvage in M. jannaschii for AMP and GMP production. A conserved cysteine (C127, M. jannaschii numbering) was examined due to its high conservation in bacterial and archaeal homologues. To assess the role of this highly conserved cysteine in M. jannaschii Ade, site-directed mutagenesis was performed. It was determined that mutation to serine (C127S) completely abolished Ade activity and mutation to alanine (C127A) exhibited 10-fold decrease in kcat over the wild type Ade. To further investigate the role of C127, detailed molecular docking and dynamics studies were performed and revealed adenine was unable to properly orient in the active site in the C127A and C127S Ade model structures due to distinct differences in active site conformation and rotation of D261. Together this work illuminates purine salvage in M. jannaschii and the critical role of a cysteine residue in maintaining active site conformation of Ade. Proteins 2016; 84:828-840. © 2016 Wiley Periodicals, Inc. PMID:26990095

  10. Excited-State Deactivation of Adenine by Electron-Driven Proton-Transfer Reactions in Adenine-Water Clusters: A Computational Study.

    Wu, Xiuxiu; Karsili, Tolga N V; Domcke, Wolfgang

    2016-05-01

    The reactivity of photoexcited 9H-adenine with hydrogen-bonded water molecules in the 9H-adenine-(H2 O)5 cluster is investigated by using ab initio electronic structure methods, focusing on the photoreactivity of the three basic sites of 9H-adenine. The energy profiles of excited-state reaction paths for electron/proton transfer from water to adenine are computed. For two of the three sites, a barrierless or nearly barrierless reaction path towards a low-lying S1 -S0 conical intersection is found. This reaction mechanism, which is specific for adenine in an aqueous environment, can explain the substantially shortened excited-state lifetime of 9H-adenine in water. Depending on the branching ratio of the nonadiabatic dynamics at the S1 -S0 conical intersection, the electron/proton transfer process can enhance the photostability of 9H-adenine in water or can lead to the generation of adenine-H(⋅) and OH(⋅) free radicals. Although the branching ratio is yet unknown, these findings indicate that adenine might have served as a catalyst for energy harvesting by water splitting in the early stages of the evolution of life. PMID:26833826

  11. Cyclic dinucleotides modulate human T-cell response through monocyte cell death.

    Tosolini, Marie; Pont, Frédéric; Verhoeyen, Els; Fournié, Jean-Jacques

    2015-12-01

    Cyclic dinucleotides, a class of microbial messengers, have been recently identified in bacteria, but their activity in humans remains largely unknown. Here, we have studied the function of cyclic dinucleotides in humans. We found that c-di-AMP and cGAMP, two adenosine-based cyclic dinucleotides, activated T lymphocytes in an unusual manner through monocyte cell death. c-di-AMP and cGAMP induced the selective apoptosis of human monocytes, and T lymphocytes were activated by the direct contact with these dying monocytes. The ensuing T-cell response comprised cell-cycle exit, phenotypic maturation into effector memory cells and proliferation arrest, but not cell death. This quiescence was transient since T cells remained fully responsive to further restimulation. Together, our results depict a novel activation pattern for human T lymphocytes: a transient quiescence induced by c-di-AMP- or cGAMP-primed apoptotic monocytes. PMID:26460927

  12. An electrochemical aptasensor electrocatalyst for detection of thrombin.

    Tian, Rong; Chen, Xiaojun; Li, Qingwen; Yao, Cheng

    2016-05-01

    This work reports a novel signal amplification strategy based on three-dimensional ordered macroporous C60-poly(3,4-ethylenedioxythiophene)-1-butyl-3-methylimidazolium hexafluorophosphate (3DOM C60-PEDOT-[BMIm][BF6]) for ultrasensitive detection of thrombin by cascade catalysis of Au-PEDOT@SiO2 microspheres and alcohol dehydrogenase (ADH). Au-PEDOT@SiO2 microspheres were constructed not only as nanocarriers to anchor the large amounts of secondary thrombin aptamers but also as nanocatalysts to catalyze the oxidation of ethanol efficiently. Significantly, the electrochemical signal was greatly enhanced based on cascade catalysis: First, ADH catalyzed the oxidation of ethanol to acetaldehyde with the concomitant generation of NADH in the presence of β-nicotinamide adenine dinucleotide hydrate (NAD(+)). Then, gold nanoparticles (AuNPs) as nanocatalysts could effectively catalyze NADH to produce NAD(+) with the help of PEDOT as redox probe. Under the optimal conditions, the proposed aptasensor exhibits a linear range of 2 × 10(-13) to 2 × 10(-8) M with a low detection limit of 2 × 10(-14) M for thrombin detection and shows high sensitivity and good specificity. PMID:26869084

  13. Probing ultrafast dynamics in adenine with mid-UV four-wave mixing spectroscopies.

    West, Brantley A; Womick, Jordan M; Moran, Andrew M

    2011-08-11

    Heterodyne-detected transient grating (TG) and two-dimensional photon echo (2DPE) spectroscopies are extended to the mid-UV spectral range in this investigation of photoinduced relaxation processes of adenine in aqueous solution. These experiments are the first to combine a new method for generating 25 fs laser pulses (at 263 nm) with the passive phase stability afforded by diffractive optics-based interferometry. We establish a set of conditions (e.g., laser power density, solute concentration) appropriate for the study of dynamics involving the neutral solute. Undesired solute photoionization is shown to take hold at higher peak powers of the laser pulses. Signatures of internal conversion and vibrational cooling dynamics are examined using TG measurements with signal-to-noise ratios as high as 350 at short delay times. In addition, 2DPE line shapes reveal correlations between excitation and emission frequencies in adenine, which reflect electronic and nuclear relaxation processes associated with particular tautomers. Overall, this study demonstrates the feasibility of techniques that will hold many advantages for the study of biomolecules whose lowest-energy electronic resonances are found in the mid-UV (e.g., DNA bases, amino acids). PMID:21756005

  14. The family of N9-adenine: New entry for adenine-benzamide conjugates linked via versatile spacers

    Prabhpreet Singh

    2014-01-01

    We have prepared 4-nitrobenzamide-adenine conjugates (8, 13 and 14) linked with versatile spacer such as triethylene glycol (TEG), aminocaproic acid and ethyl chains which were eventually reduced to obtain the corresponding 4-aminobenzamide-adenine conjugates (1-3) in good yields. These conjugates bear a nucleobase for DNA recognition or self-assembly through base-pair complementarity, a biocompatible linker for interfacing with biological system, and a p-aminobenzamide moiety for pharmacological applications. The use of hydrophilic or lipophilic linkers may tune the dispersibility of these conjugates in different solvents, as well as impart different properties. In the preliminary experiments the versatility and application of these linkers has been tested for functionalization of SWCNTs.

  15. Dinucleotide microsatellite DNA loci from the ant Myrmica scabrinodis

    Zeisset, Inga; Ebsen, Jon R.; Boomsma, Jacobus Jan

    2005-01-01

    We describe the isolation and characterization of five dinucleotide microsatellite loci in the ant Myrmica scabrinodis, which were obtained using a magnetic bead hybridization selection protocol. The PCR primers were tested on nine to 11 individuals. The number of alleles ranged from two to 13, and...

  16. Influence of hydrogen bonding on the geometry of the adenine fragment

    Słowikowska, Joanna Maria; Woźniak, Krzysztof

    1996-01-01

    The crystal structures of two adenine derivatives, N(6),9-dimethyl-8-butyladenine (I) and its hydrate (1 : 1) (II), have been determined by single-crystal X-ray diffraction. The geometrical features of both structures are discussed. The influence of protonation, substitution and hydrogen bond formation on the geometry of the adenine fragment was studied, based on data retrieved from the Cambridge Structural Database. Total correlation analysis showed mutual correlation between the structural parameters in the adenine ring system; partial correlation calculations for the adenine nucleoside fragments suggest intercorrelation between the parameters of the hydrogen bonding involved in base pairing and the N(adenine)-C(sugar) bond through the adenine fragment; few such correlations were found for fragments without the sugar substituent.

  17. Carbon Nanomaterials Based Electrochemical Sensors/Biosensors for the Sensitive Detection of Pharmaceutical and Biological Compounds.

    Adhikari, Bal-Ram; Govindhan, Maduraiveeran; Chen, Aicheng

    2015-01-01

    Electrochemical sensors and biosensors have attracted considerable attention for the sensitive detection of a variety of biological and pharmaceutical compounds. Since the discovery of carbon-based nanomaterials, including carbon nanotubes, C60 and graphene, they have garnered tremendous interest for their potential in the design of high-performance electrochemical sensor platforms due to their exceptional thermal, mechanical, electronic, and catalytic properties. Carbon nanomaterial-based electrochemical sensors have been employed for the detection of various analytes with rapid electron transfer kinetics. This feature article focuses on the recent design and use of carbon nanomaterials, primarily single-walled carbon nanotubes (SWCNTs), reduced graphene oxide (rGO), SWCNTs-rGO, Au nanoparticle-rGO nanocomposites, and buckypaper as sensing materials for the electrochemical detection of some representative biological and pharmaceutical compounds such as methylglyoxal, acetaminophen, valacyclovir, β-nicotinamide adenine dinucleotide hydrate (NADH), and glucose. Furthermore, the electrochemical performance of SWCNTs, rGO, and SWCNT-rGO for the detection of acetaminophen and valacyclovir was comparatively studied, revealing that SWCNT-rGO nanocomposites possess excellent electrocatalytic activity in comparison to individual SWCNT and rGO platforms. The sensitive, reliable and rapid analysis of critical disease biomarkers and globally emerging pharmaceutical compounds at carbon nanomaterials based electrochemical sensor platforms may enable an extensive range of applications in preemptive medical diagnostics. PMID:26404304

  18. Quantification of ethanol in plasma by electrochemical detection with an unmodified screen printed carbon electrode.

    Tian, Gang; Zhang, Xiao-Qing; Zhu, Ming-Song; Zhang, Zhong; Shi, Zheng-Hu; Ding, Min

    2016-01-01

    Simple, rapid and accurate detection of ethanol concentration in blood is very crucial in the diagnosis and management of potential acute ethanol intoxication patients. A novel electrochemical detection method was developed for the quantification of ethanol in human plasma with disposable unmodified screen-printed carbon electrode (SPCE) without sample preparation procedure. Ethanol was detected indirectly by the reaction product of ethanol dehydrogenase (ADH) and cofactor nicotinamide adenine dinucleotide (NAD(+)). Method validation indicated good quantitation precisions with intra-day and inter-day relative standard deviations of ≤9.4% and 8.0%, respectively. Ethanol concentration in plasma is linear ranging from 0.10 to 3.20 mg/mL, and the detection limit is 40.0 μg/mL (S/N > 3). The method shows satisfactory correlation with the reference method of headspace gas chromatography in twenty human plasma samples (correlation coefficient 0.9311). The proposed method could be applied to diagnose acute ethanol toxicity or ethanol-related death. PMID:27006081

  19. Carbon Nanomaterials Based Electrochemical Sensors/Biosensors for the Sensitive Detection of Pharmaceutical and Biological Compounds

    Bal-Ram Adhikari

    2015-09-01

    Full Text Available Electrochemical sensors and biosensors have attracted considerable attention for the sensitive detection of a variety of biological and pharmaceutical compounds. Since the discovery of carbon-based nanomaterials, including carbon nanotubes, C60 and graphene, they have garnered tremendous interest for their potential in the design of high-performance electrochemical sensor platforms due to their exceptional thermal, mechanical, electronic, and catalytic properties. Carbon nanomaterial-based electrochemical sensors have been employed for the detection of various analytes with rapid electron transfer kinetics. This feature article focuses on the recent design and use of carbon nanomaterials, primarily single-walled carbon nanotubes (SWCNTs, reduced graphene oxide (rGO, SWCNTs-rGO, Au nanoparticle-rGO nanocomposites, and buckypaper as sensing materials for the electrochemical detection of some representative biological and pharmaceutical compounds such as methylglyoxal, acetaminophen, valacyclovir, β-nicotinamide adenine dinucleotide hydrate (NADH, and glucose. Furthermore, the electrochemical performance of SWCNTs, rGO, and SWCNT-rGO for the detection of acetaminophen and valacyclovir was comparatively studied, revealing that SWCNT-rGO nanocomposites possess excellent electrocatalytic activity in comparison to individual SWCNT and rGO platforms. The sensitive, reliable and rapid analysis of critical disease biomarkers and globally emerging pharmaceutical compounds at carbon nanomaterials based electrochemical sensor platforms may enable an extensive range of applications in preemptive medical diagnostics.

  20. Malic enzyme: Tritium isotope effects with alternative dinucleotide substrates and divalent metal ions

    The NAD-malic enzyme from Ascaris suum catalyzes the divalent metal ion dependent oxidative decarboxylation of L-malate to yield pyruvate, carbon dioxide and NADH. Multiple isotope effect studies suggest a stepwise chemical mechanism with hydride transfer from L-malate to NAD occurring first to form oxalacetate, followed by decarboxylation. Utilizing L-malate-2-T, tritium V/K isotope effects have been determined for the hydride transfer step using a variety of alternative dinucleotide substrates and divalent metal ions. Combination of these data with deuterium isotope effects data and previously determined 13C isotope effects has allowed the calculation of intrinsic isotope effects for the malic enzyme catalyzed reaction. The identity of both the dinucleotide substrate and divalent metal ion has an effect of the size of the intrinsic isotope effect for hydride transfer

  1. Malic enzyme: Tritium isotope effects with alternative dinucleotide substrates and divalent metal ions

    Karsten, W.E.; Harris, B.G.; Cook, P.F. (Texas College of Osteopathic Medicine, Fort Worth (United States))

    1992-01-01

    The NAD-malic enzyme from Ascaris suum catalyzes the divalent metal ion dependent oxidative decarboxylation of L-malate to yield pyruvate, carbon dioxide and NADH. Multiple isotope effect studies suggest a stepwise chemical mechanism with hydride transfer from L-malate to NAD occurring first to form oxalacetate, followed by decarboxylation. Utilizing L-malate-2-T, tritium V/K isotope effects have been determined for the hydride transfer step using a variety of alternative dinucleotide substrates and divalent metal ions. Combination of these data with deuterium isotope effects data and previously determined [sup 13]C isotope effects has allowed the calculation of intrinsic isotope effects for the malic enzyme catalyzed reaction. The identity of both the dinucleotide substrate and divalent metal ion has an effect of the size of the intrinsic isotope effect for hydride transfer.

  2. In Vivo Detection of Rat Colorectal Cancers by using a Dual-Wavelength Excitation Method

    Hypoxia is a characteristic feature of solid neoplasms, and insufficient oxygen supply increases cellular nicotinamide adenine dinucleotide (NADH) fluorescence, which is a main component of autofluorescence of the colorectal mucosa. We investigated whether a dual-wavelength excitation method which is optimized for sensing mucosal NADH fluorescence could be applicable to the detection of rat colorectal cancers in vivo. Rat colorectal adenocarcinomas were studied by using fluorescence stereomicroscopy. After autofluorescence images at 470 nm irradiated with dual-wavelength excitation at 365 nm (F365ex) and 405 nm (F405ex) were acquired, ratio images were produced by dividing F365ex by F405ex: The excitation-emission wavelength pairs in F365ex and F405ex were adjusted for acquisition of NADH fluorescence and reference fluorescence. Based on observations from the luminal surface in vivo, F365ex/F405ex ratio images indicated a 1.57-fold higher signal value in the cancers than in the surrounding normal mucosa. The signal values in F365ex/F405ex ratio images were less mutually related with the hemoglobin concentration index. Small adenocarcinomas (less than 4 mm) could be detected on F365ex/F405ex ratio images. The results showed that NADH fluorescence measurement with little interference from tissue hemoglobin is efficient for visualizing rat colorectal cancers in vivo, suggesting that the dual-wavelength excitation method has potential for label-free endoscopic detection of diminutive colorectal neoplasms

  3. Development of quantum dots-based biosensor towards on-farm detection of subclinical ketosis.

    Weng, Xuan; Chen, Longyan; Neethirajan, Suresh; Duffield, Todd

    2015-10-15

    Early detection of dairy animal health issues allows the producer or veterinarian to intervene before the animals' production levels, or even survival, is threatened. An increased concentration of β-hydroxybutyrate (βHBA) is a key biomarker for diagnosis of subclinical ketosis (SCK), and provides information on the health stress in cows well before any external symptoms are observable. In this study, quantum dots (QDs) modified with cofactor nicotinamide adenine dinucleotide (NAD(+)) were prepared for the sensing event, by which the βHBA concentration in the cow's blood and milk samples was determined via fluorescence analysis of the functionalized QDs. The detection was performed on a custom designed microfluidic platform combining with a low cost and miniaturized optical sensor. The sensing mechanism was first validated by a microplate reader method and then applied to the microfluidic platform. Standard βHBA solution, βHBA in blood and milk samples from cows were successfully measured by this novel technology with a detection limit at a level of 35 µM. Side by side comparison of the developed microfluidic biosensor with a commercial kit presented its good performance. PMID:25978442

  4. Few-layer graphene sheets with embedded gold nanoparticles for electrochemical analysis of adenine

    Biris AR

    2013-04-01

    Full Text Available Alexandru R Biris,1 Stela Pruneanu,1 Florina Pogacean,1 Mihaela D Lazar,1 Gheorghe Borodi,1 Stefania Ardelean,1 Enkeleda Dervishi,2 Fumiya Watanabe,2 Alexandru S Biris2 1National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj-Napoca, Romania; 2Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, Little Rock, AR, USA Abstract: This work describes the synthesis of few-layer graphene sheets embedded with various amounts of gold nanoparticles (Gr-Au-x over an Aux/MgO catalytic system (where x = 1, 2, or 3 wt%. The sheet-like morphology of the Gr-Au-x nanostructures was confirmed by transmission electron microscopy and high resolution transmission electron microscopy, which also demonstrated that the number of layers within the sheets varied from two to seven. The sample with the highest percentage of gold nanoparticles embedded within the graphitic layers (Gr-Au-3 showed the highest degree of crystallinity. This distinct feature, along with the large number of edge-planes seen in high resolution transmission electron microscopic images, has a crucial effect on the electrocatalytic properties of this material. The reaction yields (40%–50% and the final purity (96%–98% of the Gr-Au-x composites were obtained by thermogravimetric analysis. The Gr-Au-x composites were used to modify platinum substrates and subsequently to detect adenine, one of the DNA bases. For the bare electrode, no oxidation signal was recorded. In contrast, all of the modified electrodes showed a strong electrocatalytic effect, and a clear peak for adenine oxidation was recorded at approximately +1.05 V. The highest increase in the electrochemical signal was obtained using a platinum/Gr-Au-3-modified electrode. In addition, this modified electrode had an exchange current density (I0, obtained from the Tafel plot one order of magnitude higher than that of the bare platinum electrode, which also confirmed that

  5. Effects of low-molecular-weight-chitosan on the adenine-induced chronic renal failure rats in vitro and in vivo

    Zhi, Xuan; Han, Baoqin; Sui, Xianxian; Hu, Rui; Liu, Wanshun

    2015-02-01

    The effects of low-molecular-weight-chitosan (LMWC) on chronic renal failure (CRF) rats induced by adenine were investigated in vivo and in vitro. Chitosan were hydrolyzed using chitosanase at pH 6-7 and 37° for 24 h to obtain LMWC. In vitro, the effect of LMWC on the proliferation of renal tubular epithelial cells (RTEC) showed that it had no cytotoxic effect and could promote cell growth. For the in vivo experiment, chronic renal failure rats induced by adenine were randomly divided into control group, Niaoduqing group, and high-, medium- and low-dose LMWC groups. For each group, we detected serum creatinine (SCR), blood urea nitrogen (BUN), and total superoxide dismutase (T-SOD), glutathione oxidase (GSH-Px) activities of renal tissue, and obtained the ratio of kidney weight/body weight, pathological changes of kidney. The levels of serum SCR, BUN were higher in the adenine-induced rats than those in the control group, indicating that the rat chronic renal failure model worked successfully. The results after treatment showed that LMWC could reduce the SCR and BUN levels and enhance the activities/levels of T-SOD and GSH-PX in kidney compared to control group. Histopathological examination revealed that adenine-induced renal alterations were restored by LMWC at three tested dosages, especially at the low dosage of 100 mg kg-1 d-1.

  6. Dynamic changes in nicotinamide pyridine dinucleotide content in normal human epidermal keratinocytes and their effect on retinoic acid biosynthesis

    The function of many enzymes that regulate metabolism and transcription depends critically on the nicotinamide pyridine dinucleotides. To understand the role of NAD(P)(H) in physiology and pathophysiology, it is imperative to estimate both their amount and ratios in a given cell type. In human epidermis and in cultured epidermal keratinocytes, we found that the total dinucleotide content is in the low millimolar range. The dinucleotide pattern changes during proliferation and maturation of keratinocytes in culture. Differences in the concentrations of NAD(P)(H) of 1.5- to 12-fold were observed. This resulted in alteration of the NAD(P)H/NAD(P) ratio, which could impact the differential regulation of both transcriptional and metabolic processes. In support of this notion, we provide evidence that the two-step oxidation of retinol to retinoic acid, a nuclear hormone critical for epidermal homeostasis, can be regulated by the relative physiological amounts of the pyridine dinucleotides

  7. Sensitive NADH detection in a tumorigenic cell line using a nano-biosensor based on the organic complex formation.

    Akhtar, Mahmood H; Mir, Tanveer A; Gurudatt, N G; Chung, Saeromi; Shim, Yoon-Bo

    2016-11-15

    A robust amperometric sensor for β-nicotinamide adenine dinucleotide (NADH) detection was developed through the organic complex formation with ethylenediaminetetraacetic acid (EDTA) bonded on the polyethylenimine (PEI)/activated graphene oxide (AGO) layer. The EDTA immobilized sensor probe (GCE/AGO/PEI-EDTA) revealed a catalytic property towards NADH oxidation that allows for the highly sensitive electrochemical detection of NADH at a low oxidation potential. Surface characterization demonstrated that the negatively charged AGO acted as nanofillers in the positively charged PEI matrix through the charge interaction. The immobilization of EDTA on the polymer layer provided more surface area for NADH to interact with through the enhanced chemical interlocking between them. We observed the strong interaction between NADH and EDTA on the AGO/PEI layer using a quartz crystal microbalance (QCM), X-ray photoelectron spectroscopy (XPS), and the calculation of the minimized energy for complex formation. The dynamic range of NADH was determined to be between 0.05μM and 500μM with a detection limit (LD) of 20.0±1.1nM. The reliability of the developed sensor for biomedical applications was examined by detecting NADH in tumorigenic lung epithelial cells using the standard addition method. PMID:27209575

  8. Interaction of porphyrins with adenine and adenosine complexes. Effect of a metal nature

    Reactions of complex formation of 5,10,15,20-tetraphenylporphine (H2TPP) and tetra-tert-butylphthalocyanine (H2(t-Bu)4Pc) with adenine and adenosine complexes of d-metals (M=Cd, Co, Cu, Hg, Zn) in DMSO and ethanol are studied. It was found that H2TPP reacts with Cu(II) and Hg(II) adeninates and adenosinates in DMSO, but does not react with Zn(II), Co(II), and Cd(II) adeninates and adenosinates (with both bridging and monodentate type of the ligand coordination). H2(t-Bu)4Pc enters the complex formation reaction with adeninates and adenosinates of all studied metals in DMSO at almost equal rates. The states of adenine and adenosine complexes of different d-metals in DMSO and ethanol are proposed on the basis of kinetic data obtained

  9. {8-14C}-Adenine and {1-14C}-isopentenyl pyrophosphate - precursors for root-produced cytokinins in the tomato (Lycopersicon esculentum mill.)

    Following the detection of reasonable levels of biologically active cytokinin-like compounds in one-month-old tomato plants, the possible involvement of {8-14C}-adenine and {1-14C}-isopentenyl pyrophosphate in the biosynthetic pathway leading to an accumulation of free zeatin derivatives, was studied. Intact tomato plants were used for a time-course study involving the uptake of {8-14C}-adenine and the tentative identification of compounds into which the 14C became incorporated. Using high performance liquid chromatography, radioactive trans-zeatin was identified as being present in the Dowex 50 root extract. The 12-hour time interval was used and the roots of the tomato plants were immersed in a more heavily radiolabelled medium. Modified separation techniques were used to achieve enhanced radioactivity recovery rates. This experiment demonstrated the presence of relatively high levels of tentatively identified radioactive zeatin in the Dowex 50 root and stem extracts. Radioactivity in the aqueous extracts was found not to be contributed by cytokinin nucleotides. A final experiment was carried out using decapitated root systems to determine if the root tissue alone could be implicated in the synthesis of cytokinins. Decapitated tomato root systems were supplied with either {8-14C}-adenine or {1-14C}-isopentenyl pyrophosphate. The ratio of incorporation of {1-14C}-isopentenyl pyrophosphate into identified cytokinins was higher than for {8-14C}-adenine. It was concluded that both adenine and isopentenyl pyrophosphate are involved in the biosynthetic pathway leading to an accumulation of free zeatin derivatives in tomato roots

  10. Studies on the photosensitized reduction of resorufin and implications for the detection of oxidative stress with Amplex Red

    Zhao, Baozhong; Ranguelova, Kalina; Jiang, JinJie; Mason, Ronald P.

    2011-01-01

    The photosensitized reduction of resorufin (RSF), the fluorescent product of Amplex Red, was investigated using electron spin resonance (ESR), optical absorption/fluorescence, and oxygen consumption measurements. Anaerobic reaction of RSF in the presence of the electron donor reduced nicotinamide adenine dinucleotide (NADH) demonstrated that during visible light irradiation (λ > 300 nm), RSF underwent one-electron reduction to produce a semiquinoneimine-type anion radical (RSF•−) as demonstra...

  11. Detection of antibiotic resistant Avibacterium paragallinarum from broiler chickens in Bangladesh

    Mst. Mousumi Khatun

    2016-06-01

    Full Text Available Objective: An attempt was undertaken for the detection and characterization of Avibacterium paragallinarum from clinically sick broiler chickens during field outbreaks. Materials and methods: Nasal and ocular discharges (n=6, tracheal swab (n=6, tracheal washing (n=4 and infraorbital sinus exudates (n=4 were collected aseptically from broiler chickens (n=10. To isolate A. paragallinarum, the clinical samples were cultured onto blood agar and chocolate agar enriched with Nicotinamide Adenine Dinucleotide (NAD and feeder organism (Staphylococcus aureus. Identification of A. paragallinarum was performed by Gram staining reaction, sugar fermentation profiles using five basic sugars (Dextrose, Maltose, Sucrose, Lactose and Mannitol and biochemical tests (Indole, Voges Proskauer and Methyl red tests. Antibiogram of the bacterial isolates of infected chicken was performed against five antibiotics namely Ciprofloxacin, Azithromycin, Gentamicin, Ampicillin and Cefalexin using disk diffusion method. Results: Results of colonial morphology, Gram staining reaction, sugar fermentation and biochemical tests confirmed one isolate as A. paragallinarum. The overall prevalence of IC in broiler chicken was 10% (1 of 10. This isolate was found to be sensitive to Ciprofloxacin, Azithroycin and Gentamicin and resistant to Ampicillin and Cefalexin. Conclusion: This is the first report of detection of A. paragallinarum from broiler chicken in Bangladesh. [J Adv Vet Anim Res 2016; 3(2.000: 173-177

  12. Detection of Mercury - TpT Dinucleotide Binding by Raman Spectra: A Computional Study

    Benda, Ladislav; Straka, Michal; Sychrovský, Vladimír; Bouř, Petr; Tanaka, Y.

    2012-01-01

    Roč. 116, č. 32 (2012), s. 8313-8320. ISSN 1089-5639 R&D Projects: GA ČR GAP208/11/0105; GA ČR GAP205/10/0228; GA MŠk(CZ) LH11033 Grant ostatní: GA ČR(CZ) GAP206/12/0539 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleic acids * mercury complexes * density functional theory * Raman spectroscopy * vibrational analysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.771, year: 2012

  13. Comparative Study between topical applications liposomally entrapped DNA repair enzymes and thymidine dinucleotide as radioprotectors

    The delivery of active agents to the skin by liposome carriers received great interest during the last three decades. This is based on their potential to enclose various types of biological materials and to deliver them to diverse cell types. Recent work suggests that liposomes as vehicles for topical drug delivery may be superior to conventional preparations. Also, topical application of DNA repair enzymes to irradiated skin increases the rate of repair of DNA potentially damaged cells. Moreover, thymidine dinucleotide is a new skin photo-protective agent against non-ionizing radiation through induction of DNA repair. Gamma irradiation can produce DNA damage in human skin. DNA mutations have an important role in the development of skin cancer and precancerous skin lesions. Albino rats were irradiated with Cobalt-60 gamma radiation with different doses (0.5, 1.5, 3 Gy), and were treated by either thymidine dinucleotide or liposomally entrapped DNA repair enzymes topically 24 hours before irradiation. Evaluation was done histopathologically by H and E stain. Computerized image analyzer using Masson's trichrome stain was also done. Gamma radiation produced epidermal thinning and dermal inflammatory cells together with collagen fragmentation and clumping in a dose-dependent manner. Comparing between both thymidine dinucleotide and liposomally entrapped DNA repair enzymes pretreated and irradiated rats. Low dose irradiation (0.5 Gy) together with previous drugs showed preservation of epidermis with no inflammatory cells and also it maintained the normal architecture of collagen bundles. However, they were ineffective with higher doses. In conclusion our results may suggest that the effects of gamma radiation on the skin at low dose could be minimized by the use of these drugs before exposure

  14. Renoprotective effect of the xanthine oxidoreductase inhibitor topiroxostat on adenine-induced renal injury.

    Kamijo-Ikemori, Atsuko; Sugaya, Takeshi; Hibi, Chihiro; Nakamura, Takashi; Murase, Takayo; Oikawa, Tsuyoshi; Hoshino, Seiko; Hisamichi, Mikako; Hirata, Kazuaki; Kimura, Kenjiro; Shibagaki, Yugo

    2016-06-01

    The aim of the present study was to reveal the effect of a xanthine oxidoreductase (XOR) inhibitor, topiroxostat (Top), compared with another inhibitor, febuxostat (Feb), in an adenine-induced renal injury model. We used human liver-type fatty acid-binding protein (L-FABP) chromosomal transgenic mice, and urinary L-FABP, a biomarker of tubulointerstitial damage, was used to evaluate tubulointerstitial damage. Male transgenic mice (n = 24) were fed a 0.2% (wt/wt) adenine-containing diet. Two weeks after the start of this diet, renal dysfunction was confirmed, and the mice were divided into the following four groups: the adenine group was given only the diet containing adenine, and the Feb, high-dose Top (Top-H), and low-dose Top (Top-L) groups were given diets containing Feb (3 mg/kg), Top-H (3 mg/kg), and Top-L (1 mg/kg) in addition to adenine for another 2 wk. After withdrawal of the adenine diet, each medication was continued for 2 wk. Serum creatinine levels, the degree of macrophage infiltration, tubulointerstitial damage, renal fibrosis, urinary 15-F2t-isoprostane levels, and renal XOR activity were significantly attenuated in the kidneys of the Feb, Top-L, and Top-H groups compared with the adenine group. Serum creatinine levels in the Top-L and Top-H groups as well as renal XOR in the Top-H group were significantly lower than those in the Feb group. Urinary excretion of L-FABP in both the Top-H and Top-L groups was significantly lower than in the adenine and Feb groups. In conclusion, Top attenuated renal damage in an adenine-induced renal injury model. PMID:27029427

  15. Photochemical decoration of gold nanoparticles on polymer stabilized magnetic microspheres for determination of adenine by surface-enhanced Raman spectroscopy

    Magnetic microspheres decorated with gold nanoparticles (AuNPs) were prepared and used for the determination of adenine by surface-enhanced Raman scattering (SERS). Magnetic particles were first synthesized by coprecipitation of solutions containing iron(II) and iron(III) ions with ammonium hydroxide. Subsequently, the magnetic particles were suspended into a solution of poly(divinylbenzene-co-methyl methacrylate) to yield polymer-stabilized magnetic microspheres. These were further decorated with AuNPs via a new photochemical reduction method. The magnetic microspheres were characterized by XRD patterns and SEM images. They are shown to represent highly SERS-active substrates by giving an enhancement by almost 7 orders of magnitude compared to conventional Raman spectroscopy. Several factors that affect the photochemical reduction to form the AuNPs were examined. It is found that the concentration of gold ion, UV irradiation time, and citrate concentration have more impact on the reaction rate than on the morphologies of the AuNPs. The gold-decorated magnetic microspheres are highly stable in aqueous solution and capable of concentrating nucleobases. A linear response of the SERS signal to adenine in concentrations up to 10 μM is found, with a linear regression coefficient of 0.997. The detection limit is estimated to a few hundreds of nM (at an SNR of 3). Based on its specific Raman peak at 734 cm−1, adenine can be selectively determined without interference by other nucleobases, and a recovery higher than 95 % could be obtained. (author)

  16. Effects of hypobaric hypoxia on adenine nucleotide pools, adenine nucleotide transporter activity and protein expression in rat liver

    Cong-Yang Li; Jun-Ze Liu; Li-Ping Wu; Bing Li; Li-Fen Chen

    2006-01-01

    AIM: To explore the effect of hypobaric hypoxia on mitochondrial energy metabolism in rat liver.METHODS: Adult male Wistar rats were exposed to a hypobaric chamber simulating 5000 m high altitude for 23 h every day for 0 (HO), 1 (H1), 5 (HS), 15 (H15) and 30 d (H30) respectively. Rats were sacrificed by decapitation and liver was removed. Liver mitochondria were isolated by differential centrifugation program. The size of adenine nucleotide pool (ATP, ADP, and AMP) in tissue and mitochondria was separated and measured by high performance liquid chromatography (HPLC). The adenine nucleotide transporter (ANT) activity was determined by isotopic technique. The ANT total protein level was determined by Western blot. RESULTS: Compared with HO group, intra-mitochondrial ATP content decreased in all hypoxia groups. However,the H5 group reached the lowest point (70.6%) (P< 0.01)when compared to the control group. Intra-mitochondrial ADP and AMP level showed similar change in all hypoxia groups and were significantly lower than that in HO group. In addition, extra-mitochondrial ATP and ADP content decreased significantly in all hypoxia groups.Furthermore, extra-mitochondrial AMP in groups H5, H15and H30 was significantly lower than that in HO group,whereas H1 group had no marked change compared to the control situation. The activity of ANT in hypoxia groups decreased significantly, which was the lowest in H5 group (55.7%) (P<0.01) when compared to HO group. ANT activity in H30 group was higher than in H15 group, but still lower than that in HO group. ANT protein level in H5, H15, H30 groups, compared with HO group decreased significantly, which in H5 group was the lowest, being 27.1% of that in HO group (P<0.01). ANT protein level in H30 group was higher than in H15 group,but still lower than in HO group.CONCLUSION: Hypobaric hypoxia decreases the mitochondrial ATP content in rat liver, while mitochondrial ATP level recovers during long-term hypoxia exposure.The lower

  17. No evidence that mRNAs have lower folding free energies than random sequences with the same dinucleotide distribution

    Workman, Christopher; Krogh, Anders Stærmose

    1999-01-01

    This work investigates whether mRNA has a lower estimated folding free energy than random sequences. The free energy estimates are calculated by the mfold program for prediction of RNA secondary structures. For a set of 46 mRNAs it is shown that the predicted free energy is not significantly...... different from random sequences with the same dinucleotide distribution. For random sequences with the same mononucleotide distribution it has previously been shown that the native mRNA sequences have a lower predicted free energy, which indicates a more stable structure than random sequences. However......, dinucleotide content is important when assessing the significance of predicted free energy as the physical stability of RNA secondary structure is known to depend on dinucleotide base stacking energies. Even known RNA secondary structures, like tRNAs, can be shown to have predicted free energies...

  18. Heat-processed ginseng saponin ameliorates the adenine-induced renal failure in rats

    Kim, Eun Jin; Oh, Hyun-A; Choi, Hyuck Jai; Park, Jeong Hill; Kim, Dong-Hyun; Kim, Nam Jae

    2013-01-01

    To evaluate the effect of the saponin of heat-processed ginseng (Sun ginseng, SG), we investigated the protective effect of SG total saponin fraction against adenine-induced chronic renal failure in rats. SG saponin significantly decreased the levels of urea nitrogen and creatinine in the serum, but increased the urinary excretion of urea nitrogen and creatinine, indicating an improvement of renal function. SG saponin also inhibited adenine-induced kidney hypertrophy and edema. SG saponin red...

  19. Detection of NADH via electrocatalytic oxidation at single-walled carbon nanotubes modified with Variamine blue

    Radoi, A. [Dipartimento di Scienze e Tecnologie Chimiche, Universita ' Tor Vergata' , via della Ricerca Scientifica 1, 00133 Rome (Italy)], E-mail: radoiantonio@yahoo.com; Compagnone, D. [Dipartimento di Scienze degli Alimenti, Universita di Teramo, via C. Lerici 1, Mosciano S. Angelo, Teramo (Italy); Valcarcel, M.A. [Department of Chemistry, Universitat Autonoma de Barcelona, Edifici Cs./08193, Bellaterra, Barcelona (Spain); Placidi, P.; Materazzi, S. [Dipartimento di Chimica, Universita ' La Sapienza' , Piazzale A. Moro 5, 00185 Rome (Italy); Moscone, D.; Palleschi, G. [Dipartimento di Scienze e Tecnologie Chimiche, Universita ' Tor Vergata' , via della Ricerca Scientifica 1, 00133 Rome (Italy)

    2008-01-01

    Screen-printed electrodes (SPEs) modified with Variamine blue (VB), covalently attached to the oxidized single-walled carbon nanotubes (SWCNTs-COOH), were developed and used as chemical sensors for the detection of the reduced nicotinamide adenine dinucleotide (NADH). The Variamine blue redox mediator was covalently linked to the SWCNTs-COOH by the N,N'-dicyclohexylcarbodiimide (DCC) and N-hydroxysuccinimide (NHS) chemistry. Infrared Fourier transform (FT-IR) spectroscopy revealed the presence of the amide bands situated at 1623 cm{sup -1} (I band), 1577 cm{sup -1} (II band) and 1437 cm{sup -1} (III band) demonstrating the covalent linkage of Variamine blue to SWCNTs-COOH. The heterogeneous electron transfer rate, k{sub obs.}, was 13,850 M{sup -1} s{sup -1}, and the k{sub s} and {alpha} were 0.8 s{sup -1} and 0.56, respectively. The pH dependence was also investigated. SPEs modified with Variamine blue by using the DCC/NHS conjugation method, showed a variation of -36 mV per pH unit. A successful application was the development of a lactate biosensor obtained by the immobilization of the L-lactate dehydrogenase on the NADH sensor.

  20. Improved Growth and Stress Tolerance in the Arabidopsis oxt1 Mutant Triggered by Altered Adenine Metabolism

    Suchada Sukrong; Kil-Young Yun; Patrizia Stadler; Charan Kumar; Tony Facciuolo; Barbara A.Moffatt; Deane L.Falcone

    2012-01-01

    Plants perceive and respond to environmental stresses with complex mechanisms that are often associated with the activation of antioxidant defenses.A genetic screen aimed at isolating oxidative stress-tolerant lines of Arabidopsis thaliana has identified oxt1,a line that exhibits improved tolerance to oxidative stress and elevated temperature but displays no apparent deleterious growth effects under non-stress conditions.Oxt1 harbors a mutation that arises from the altered expression of a gene encoding adenine phosphoribosyltransferase (APT1),an enzyme that converts adenine to adenosine monophosphate (AMP),indicating a link between purine metabolism,whole-plant growth responses,and stress acclimation.The oxt1 mutation results in decreased APT1 expression that leads to reduced enzymatic activity.Correspondingly,oxt1 plants possess elevated levels of adenine.Decreased APT enzyme activity directly correlates with stress resistance in transgenic lines that ectopically express APT1.The metabolic alteration in oxt1 plants also alters the expression of several antioxidant defense genes and the response of these genes to oxidative challenge.Finally,it is shown that manipulation of adenine levels can induce stress tolerance to wild-type plants.Collectively,these results show that alterations in cellular adenine levels can trigger stress tolerance and improve growth,leading to increases in plant biomass.The results also suggest that adenine might play a part in the signals that modulate responses to abiotic stress and plant growth.

  1. Sequence-dependent folding landscapes of adenine riboswitch aptamers

    Lin, Jong-Chin; Hyeon, Changbong; Thirumalai, D.

    Prediction of the functions of riboswitches requires a quantitative description of the folding landscape so that the barriers and time scales for the conformational change in the switching region in the aptamer can be estimated. Using a combination of all atom molecular dynamics and coarse-grained model simulations we studied the response of adenine (A) binding add and pbuE A-riboswitches to mechanical force. The two riboswitches contain a structurally similar three-way junction formed by three paired helices, P1, P2, and P3, but carry out different functions. Using pulling simulations, with structures generated in MD simulations, we show that after P1 rips the dominant unfolding pathway in add A-riboswitch is the rupture of P2 followed by unraveling of P3. In the pbuE A-riboswitch, after P1 unfolds P3 ruptures ahead of P2. The order of unfolding of the helices, which is in accord with single molecule pulling experiments, is determined by the relative stabilities of the individual helices. Our results show that the stability of isolated helices determines the order of assembly and response to force in these non-coding regions. We use the simulated free energy profile for pbuE A-riboswitch to estimate the time scale for allosteric switching, which shows that this riboswitch is under kinetic control lending additional support to the conclusion based on single molecule pulling experiments. A consequence of the stability hypothesis is that a single point mutation (U28C) in the P2 helix of the add A-riboswitch, which increases the stability of P2, would make the folding landscapes of the two riboswitches similar. This prediction can be tested in single molecule pulling experiments.

  2. Co-immobilization of glucose oxidase and xylose dehydrogenase displayed whole cell on multiwalled carbon nanotube nanocomposite films modified electrode for simultaneous voltammetric detection of D-glucose and D-xylose.

    Li, Liang; Liang, Bo; Li, Feng; Shi, Jianguo; Mascini, Marco; Lang, Qiaolin; Liu, Aihua

    2013-04-15

    In this paper, we first report the construction of Nafion/glucose oxidase (GOD)/xylose dehydrogenase displayed bacteria (XDH-bacteria)/multiwalled carbon nanotubes (MWNTs) modified electrode for simultaneous voltammetric determination of D-glucose and D-xylose. The optimal conditions for the immobilized enzymes were established. Both enzymes retained their good stability and activities. In the mixture solution of D-glucose and D-xylose containing coenzyme NAD⁺ (the oxidized form of nicotinamide adenine dinucleotide), the Nafion/GOD/XDH-bacteria/MWNTs modified electrode exhibited quasi-reversible oxidation-reduction peak at -0.5 V (vs. saturated calomel electrode, SCE) originating from the catalytic oxidation of D-glucose, and oxidation peak at +0.55 V(vs. SCE) responding to the oxidation of NADH (the reduced form of nicotinamide adenine dinucleotide) by the carbon nanotubes, where NADH is the resultant product of coenzyme NAD⁺ involved in the catalysis of D-xylose by XDH-displayed bacteria. For the proposed biosensor, cathodic peak current at -0.5 V was linear with the concentration of D-glucose within the range of 0.25-6 mM with a low detection limit of 0.1 mM D-glucose (S/N=3), and the anodic peak current at +0.55 V was linear with the concentration of d-xylose in the range of 0.25∼4 mM with a low detection limit of 0.1 mM D-xylose (S/N=3). Further, D-xylose and D-glucose did not interfere with each other. 300-fold excess saccharides including D-maltose, D-galactose, D-mannose, D-sucrose, D-fructose, D-cellobiose, and 60-fold excess L-arabinose, and common interfering substances (100-fold excess ascorbic acid, dopamine, uric acid) as well as 300-fold excess D-xylitol did not affect the detection of D-glucose and D-xylose (both 1 mM). Therefore, the proposed biosensor is stable, specific, reproducible, simple, rapid and cost-effective, which holds great potential in real applications. PMID:23202346

  3. Autosomal recessive chronic granulomatous disease caused by deletion at a dinucleotide repeat

    Chronic granulomatous disease (CGD) is a rare inherited condition rendering neutrophils incapable of killing invading pathogens. This condition is due to the failure of a multicomponent microbicidal oxidase that normally yields a low-midpoint-potential b cytochrome (cytochrome b245). Although defects in the X chromosome-linked cytochrome account for the majority of CGD patients, as many as 30% of CGD cases are due to an autosomal recessive disease. Of these, >90% have been shown to be defective in the synthesis of a 47-kDa cytosolic component of the oxidase. The authors demonstrate here in three unrelated cases of autosomal recessive CGD that the identical underlying molecular lesion is a dinucleotide deletion at a GTGT tandem repeat, corresponding to the acceptor site of the first intron - exon junction. Slippage of the DNA duplex at this site may contribute to the high frequency of defects in this gene

  4. Interaction of Pd(II) and Pt(II) Amino Acid Complexes With Dinucleotides

    Vicens, Margarita; Caubet, Amparo; Moreno, Virtudes

    1997-01-01

    The interaction of the dinucleotides d(ApG) and d(ApA) with [Pd(aa)Cl2], where aa = L- or D-histidine or the methyl ester of L-histidine, and with [Pt(Met)Cl2], where Met = L-methionine was studied by H1 and C13 NMR and CD measurements. In the case of the L-histidine and L-histidineOMe, the reaction with d(ApG) appeared to give the bifunctional adducts Pd(L-Histidine)N1(1)N7(2) and Pd(L-HisOMe)N1(1)N7(2), but the behavior with D-histidine suggested the formation of the monofunctional adduct P...

  5. Estrogen receptor alpha dinucleotide repeat polymorphism in Japanese patients with autoimmune thyroid diseases

    Tozaki Teruaki

    2000-11-01

    Full Text Available Abstract Background The autoimmune thyroid diseases (AITDs, comprising Graves' disease (GD and Hashimoto's thyroiditis (HT, appear to develop as a result of complex interactions between predisposing genes and environmental triggers. Susceptibility to AITDs is conferred by genes in the human leukocyte antigen (HLA and genes unlinked to HLA, including the CTLA-4 gene. Recently, an association to some estrogen receptor (ERα genotypes with breast cancer, hypertension, osteoporosis, generalized osteoarthritis, and some autoimmune diseases such as rheumatoid arthritis has been reported. We have analyzed a dinucleotide (TAn repeat polymorphism lying upstream of the human ERα gene in patients with AITDs and in normal subjects. Results Seventeen different alleles were found in 130 patients with GD, 93 patients with HT, and 190 control subjects. There was no significant difference in the distributions of ERα alleles between patients and controls. Conclusions The present results do not support an association between the ERα gene and AITD in the Japanese population.

  6. Parvovirus b19 DNA CpG dinucleotide methylation and epigenetic regulation of viral expression.

    Francesca Bonvicini

    Full Text Available CpG DNA methylation is one of the main epigenetic modifications playing a role in the control of gene expression. For DNA viruses whose genome has the ability to integrate in the host genome or to maintain as a latent episome, a correlation has been found between the extent of DNA methylation and viral quiescence. No information is available for Parvovirus B19, a human pathogenic virus, which is capable of both lytic and persistent infections. Within Parvovirus B19 genome, the inverted terminal regions display all the characteristic signatures of a genomic CpG island; therefore we hypothesised a role of CpG dinucleotide methylation in the regulation of viral genome expression.The analysis of CpG dinucleotide methylation of Parvovirus B19 DNA was carried out by an aptly designed quantitative real-time PCR assay on bisulfite-modified DNA. The effects of CpG methylation on the regulation of viral genome expression were first investigated by transfection of either unmethylated or in vitro methylated viral DNA in a model cell line, showing that methylation of viral DNA was correlated to lower expression levels of the viral genome. Then, in the course of in vitro infections in different cellular environments, it was observed that absence of viral expression and genome replication were both correlated to increasing levels of CpG methylation of viral DNA. Finally, the presence of CpG methylation was documented in viral DNA present in bioptic samples, indicating the occurrence and a possible role of this epigenetic modification in the course of natural infections.The presence of an epigenetic level of regulation of viral genome expression, possibly correlated to the silencing of the viral genome and contributing to the maintenance of the virus in tissues, can be relevant to the balance and outcome of the different types of infection associated to Parvovirus B19.

  7. Drug: D04959 [KEGG MEDICUS

    Full Text Available D04959 Mixture, Drug Liver extract - flavin adenine dinucleotide; Liver extract - f...lavin adenine dinucleotide sodium; Adelavin (TN) Liver extract, (Flavin adenine dinucleotide [DR:D00005] | F...erapeutics 3262 Hepatic agents D04959 Liver extract - flavin adenine dinucleotide PubChem: 17398233 ...

  8. On-line wall-free cell for laser-induced fluorescence detection in capillary electrophoresis.

    Yu, Chang-Zhu; He, You-Zhao; Xie, Hai-Yang; Gao, Yong; Gan, Wu-Er; Li, Jun

    2009-05-15

    A wall-free detection method based on liquid junction in a capillary gap was proposed for laser-induced fluorescence (LIF) of capillary electrophoresis (CE). The capillary gap of the wall-free cell was fabricated by etching a 10-mm x 50-microm I.D. fused-silica capillary to obtain a polyimide coating sleeve, decoating about 6mm at one end of both 50 microm I.D. separation and liquid junction capillary, inserting the treated capillary ends into the coating sleeve oppositely, fixing the capillaries with a gap distance of 140 microm by epoxy glue and removing the coating sleeve by burning. The theoretical model, experimental results and wall-free cell images indicated that the gap distance and applied voltage were main influence factors on the wall-free detection. Since the wall-free cell increased the absorption light path and avoided the stray light from the capillary wall, it improved the ratio of signal to noise and limit of detection (LOD) of CE-LIF. Three flavin compounds of riboflavin (RF), flavin mononucleotide sodium (FMN) and flavin adenine dinucleotide disodium (FAD) were used to evaluate the wall-free detection method. Compared with on-column cell, the LODs of the wall-free cell were improved 15-, 6- and 9-fold for RF, FMN and FAD, respectively. The linear calibration concentrations of the flavins ranged from 0.005 to 5.0 micromol/L. The column efficiency was in the range from 1.0 x 10(5) to 2.5 x 10(5) plates. The wall-free detection of CE-LIF was applied to the analysis of the flavins in spinach and lettuce leaves. PMID:19329123

  9. A computational study of adenine, uracil, and cytosine adsorption upon AlN and BN nano-cages

    Density-functional theory calculations are used to investigate the interaction of Al12N12 and B12N12 clusters with the adenine (A), uracil (U), and cytosine (C) molecules. The current calculations demonstrate that these hybrid adsorbent materials are able to adsorb the adenine, uracil, and cytosine molecules through exothermic processes. Our theoretical results reveal improvement in the adsorption of adenine, uracil, and cytosine on Al12N12 and B12N12. It is observed that B12N12 is highly sensitive to adenine, uracil, and cytosine compared with Al12N12 to serve as a biochemical sensor.

  10. Deficiency of the reduced nicotinamide adenine dinucleotide dehydrogenase component of complex I of mitochondrial electron transport. Fatal infantile lactic acidosis and hypermetabolism with skeletal-cardiac myopathy and encephalopathy.

    Hoppel, C L; Kerr, D S; Dahms, B; Roessmann, U

    1987-01-01

    A mitochondrial defect was investigated in an infant with fatal congenital lactic acidosis (3-14 mM), high lactate-to-pyruvate ratio, hypotonia, and cardiomyopathy. His sister had died with a similar disorder. Resting oxygen consumption was 150% of controls. Pathological findings included increased numbers of skeletal muscle mitochondria (many with proliferated, concentric cristae), cardiomegaly, fatty infiltration of the viscera, and spongy encephalopathy. Mitochondria from liver and muscle ...

  11. Counterregulation of nuclear 3,5,3'-triiodo-L-thyronine (T3) binding by oxidized and reduced-nicotinamide adenine dinucleotide phosphates in the presence of cytosolic T3-binding protein in vitro

    The role of cytosolic T3-binding protein (CTBP) in the regulation of nuclear T3 binding was studied in vitro. Nuclear [125I]T3 binding was observed in the presence of 1.0 mM dithiothreitol (DTT). When the nuclei prepared from rat kidney were incubated with inactive form of CTBP which was also prepared from rat kidney, [125I]T3 binding to nuclei was not affected. When the nuclei were incubated with inactive form of CTBP in the presence of NADP, [125I]T3 binding to nuclei was increased, whereas binding was diminished when nuclei were incubated with CTBP in the presence of NADPH. The inactive form of CTBP was activated by NADPH. NADP also activated CTBP in the presence of DTT. Both active forms of CTBP were again inactivated by extraction with charcoal, and these inactive forms were reactivated by NADPH or by NADP and DTT, but not by NADP alone. Although the nuclei treated with 0.3 M NaCl lost the binding activity for [125I]T3 in the absence of NADP, the nuclei retained the binding activity for [125I]T3 in the presence of NADP and the inactive form of CTBP. Treatment of the nuclei with 0.5 M NaCl lost the binding activity for [125I]T3 not only in the absence but also in the presence of NADP and CTBP. These results suggested that NADP and NADPH play roles as counterregulatory factors for nuclear T3 binding in the presence of CTBP. Further, it was speculated that binding sites for the T3-CTBP complex, which is generated in the presence of NADP and DTT, are present in nuclei, and that binding sites for the complex are different from nuclear T3 receptors

  12. Alkaloid Cluster Gene ccsA of the Ergot Fungus Claviceps purpurea Encodes Chanoclavine I Synthase, a Flavin Adenine Dinucleotide-Containing Oxidoreductase Mediating the Transformation of N-Methyl-Dimethylallyltryptophan to Chanoclavine I

    Lorenz, N.; Olšovská, Jana; Šulc, Miroslav; Tudzynski, P.

    2010-01-01

    Roč. 76, č. 5 (2010), s. 1822-1830. ISSN 0099-2240 Institutional research plan: CEZ:AV0Z50200510 Keywords : BERBERINE BRIDGE ENZYME * BIOSYNTHESIS * IDENTIFICATION Subject RIV: EE - Microbiology, Virology Impact factor: 3.778, year: 2010

  13. Ultra-performance liquid chromatography tandem mass-spectrometry (uplc-ms/ms) for the rapid, simultaneous analysis of thiamin, riboflavin, flavin adenine dinucleotide, nicotinamide and pyridoxal in human milk

    A novel, rapid and sensitive Ultra Performance Liquid-Chromatography tandem Mass-Spectrometry (UPLC-MS/MS) method for the simultaneous determination of several B-vitamins in human milk was developed. Resolution by retention time or multiple reaction monitoring (MRM) for thiamin, riboflavin, flavin a...

  14. Biochemical Analysis of Recombinant AlkJ from Pseudomonas putida Reveals a Membrane-Associated, Flavin Adenine Dinucleotide-Dependent Dehydrogenase Suitable for the Biosynthetic Production of Aliphatic Aldehydes

    Kirmair, Ludwig; Skerra, Arne

    2014-01-01

    The noncanonical alcohol dehydrogenase AlkJ is encoded on the alkane-metabolizing alk operon of the mesophilic bacterium Pseudomonas putida GPo1. To gain insight into the enzymology of AlkJ, we have produced the recombinant protein in Escherichia coli and purified it to homogeneity using His6 tag affinity and size exclusion chromatography (SEC). Despite synthesis in the cytoplasm, AlkJ was associated with the bacterial cell membrane, and solubilization with n-dodecyl-β-d-maltoside was necessa...

  15. De novo synthesis of adenine nucleotides in different skeletal muscle fiber types

    Management of adenine nucleotide catabolism differs among skeletal muscle fiber types. This study evaluated whether there are corresponding differences in the rates of de novo synthesis of adenine nucleotide among fiber type sections of skeletal muscle using an isolated perfused rat hindquarter preparation. Label incorporation into adenine nucleotides from the [1-14C]glycine precursor was determined and used to calculate synthesis rates based on the intracellular glycine specific radioactivity. Results show that intracellular glycine is closely related to the direct precursor pool. Rates of de novo synthesis were highest in fast-twitch red muscle (57.0 +/- 4.0, 58.2 +/- 4.4 nmol.h-1.g-1; deep red gastrocnemius and vastus lateralis), relatively high in slow-twitch red muscle (47.0 +/- 3.1; soleus), and low in fast-twitch white muscle (26.1 +/- 2.0 and 21.6 +/- 2.3; superficial white gastrocnemius and vastus lateralis). Rates for four mixed muscles were intermediate, ranging between 32.3 and 37.3. Specific de novo synthesis rates exhibited a strong correlation (r = 0.986) with muscle section citrate synthase activity. Turnover rates (de novo synthesis rate/adenine nucleotide pool size) were highest in high oxidative muscle (0.82-1.06%/h), lowest in low oxidative muscle (0.30-0.35%/h), and intermediate in mixed muscle (0.44-0.55%/h). Our results demonstrate that differences in adenine nucleotide management among fiber types extends to the process of de novo adenine nucleotide synthesis

  16. Absorption by DNA single strands of adenine isolated in vacuo: The role of multiple chromophores

    Nielsen, L.M.; Pedersen, S.O.; Kirketerp, M.-B.S.;

    2012-01-01

    The degree of electronic coupling between DNA bases is a topic being up for much debate. Here we report on the intrinsic electronic properties of isolated DNA strands in vacuo free of solvent, which is a good starting point for high-level excited states calculations. Action spectra of DNA single...... strands of adenine reveal sign of exciton coupling between stacked bases from blueshifted absorption bands (~3 nm) relative to that of the dAMP mononucleotide (one adenine base). The bands are blueshifted by about 10 nm compared to those of solvated strands, which is a shift similar to that for the...

  17. Predicting DNA Methylation State of CpG Dinucleotide Using Genome Topological Features and Deep Networks

    Wang, Yiheng; Liu, Tong; Xu, Dong; Shi, Huidong; Zhang, Chaoyang; Mo, Yin-Yuan; Wang, Zheng

    2016-01-01

    The hypo- or hyper-methylation of the human genome is one of the epigenetic features of leukemia. However, experimental approaches have only determined the methylation state of a small portion of the human genome. We developed deep learning based (stacked denoising autoencoders, or SdAs) software named “DeepMethyl” to predict the methylation state of DNA CpG dinucleotides using features inferred from three-dimensional genome topology (based on Hi-C) and DNA sequence patterns. We used the experimental data from immortalised myelogenous leukemia (K562) and healthy lymphoblastoid (GM12878) cell lines to train the learning models and assess prediction performance. We have tested various SdA architectures with different configurations of hidden layer(s) and amount of pre-training data and compared the performance of deep networks relative to support vector machines (SVMs). Using the methylation states of sequentially neighboring regions as one of the learning features, an SdA achieved a blind test accuracy of 89.7% for GM12878 and 88.6% for K562. When the methylation states of sequentially neighboring regions are unknown, the accuracies are 84.82% for GM12878 and 72.01% for K562. We also analyzed the contribution of genome topological features inferred from Hi-C. DeepMethyl can be accessed at http://dna.cs.usm.edu/deepmethyl/.

  18. Predicting DNA Methylation State of CpG Dinucleotide Using Genome Topological Features and Deep Networks

    Wang, Yiheng; Liu, Tong; Xu, Dong; Shi, Huidong; Zhang, Chaoyang; Mo, Yin-Yuan; Wang, Zheng

    2016-01-01

    The hypo- or hyper-methylation of the human genome is one of the epigenetic features of leukemia. However, experimental approaches have only determined the methylation state of a small portion of the human genome. We developed deep learning based (stacked denoising autoencoders, or SdAs) software named “DeepMethyl” to predict the methylation state of DNA CpG dinucleotides using features inferred from three-dimensional genome topology (based on Hi-C) and DNA sequence patterns. We used the experimental data from immortalised myelogenous leukemia (K562) and healthy lymphoblastoid (GM12878) cell lines to train the learning models and assess prediction performance. We have tested various SdA architectures with different configurations of hidden layer(s) and amount of pre-training data and compared the performance of deep networks relative to support vector machines (SVMs). Using the methylation states of sequentially neighboring regions as one of the learning features, an SdA achieved a blind test accuracy of 89.7% for GM12878 and 88.6% for K562. When the methylation states of sequentially neighboring regions are unknown, the accuracies are 84.82% for GM12878 and 72.01% for K562. We also analyzed the contribution of genome topological features inferred from Hi-C. DeepMethyl can be accessed at http://dna.cs.usm.edu/deepmethyl/. PMID:26797014

  19. A dinucleotide motif in oligonucleotides shows potent immunomodulatory activity and overrides species-specific recognition observed with CpG motif

    Kandimalla, Ekambar R; Bhagat, Lakshmi; Zhu, Fu-Gang; Yu, Dong; Cong, Yan-Ping; Wang, Daqing; Tang, Jimmy X.; Tang, Jin-Yan; Knetter, Cathrine F.; Lien, Egil; Agrawal, Sudhir

    2003-01-01

    Bacterial and synthetic DNAs containing CpG dinucleotides in specific sequence contexts activate the vertebrate immune system through Toll-like receptor 9 (TLR9). In the present study, we used a synthetic nucleoside with a bicyclic heterobase [1-(2′-deoxy-β-d-ribofuranosyl)-2-oxo-7-deaza-8-methyl-purine; R] to replace the C in CpG, resulting in an RpG dinucleotide. The RpG dinucleotide was incorporated in mouse- and human-specific motifs in oligodeoxynucleotides (oligos) and 3′-3-linked oligo...

  20. Facile fabrication of FeN nanoparticles/nitrogen-doped graphene core-shell hybrid and its use as a platform for NADH detection in human blood serum.

    Balamurugan, Jayaraman; Thanh, Tran Duy; Kim, Nam Hoon; Lee, Joong Hee

    2016-09-15

    Herein, we present a novel strategy for the synthesis of an iron nitride nanoparticles-encapsulated nitrogen-doped graphene (FeN NPs/NG) core-shell hierarchical nanostructure to boost the electrochemical performance in a highly sensitive, selective, reproducible, and stable sensing platform for nicotinamide adenine dinucleotide (NADH). This core-shell hierarchical nanostructure provides an excellent conductive network for effective charge transfer and avoids the agglomeration and restacking of NG sheets, which provides better access to the electrode material for NADH oxidation. The FeN NPs/NG core-shell hierarchical nanostructure demonstrates direct and mediatorless responses to NADH oxidation at a low potential. This material displays a high sensitivity of 0.028μA/μMcm(2), a wide linear range from 0.4 to 718μM, and a detection limit of 25nM with a fast response time of less than 3s. The interferences from common interferents, such as glucose, uric acid, dopamine, and ascorbic acid, are negligible. The fabricated sensor was further tested for the determination of NADH in human blood serum. The resulting high sensitivity, excellent selectivity, outstanding stability, and good reproducibility make the proposed FeN NPs/NG core-shell hierarchical nanostructure as a promising candidate for biomedical applications. PMID:27104586

  1. Isolation and characterisation of a dinucleotide microsatellite set for a parentage and biodiversity study in domestic guinea pig (Cavia porcellus)

    Diana Aviles; Vincenzo Landi; Juan Vicente Delgado; José Luis Vega-Pla; Amparo Martinez

    2015-01-01

    The domestic guinea pig is a valuable genetic resource because it is part of local folklore and food tradition in many South American countries. The economic importance of the guinea pig is due to its high feed efficiency and the quality of animal protein produced. For these reasons, our study is aimed to design a complete dinucleotide microsatellite marker set following international recommendation to assess the genetic diversity and genealogy management of guinea pigs. We selected a total o...

  2. The Innate Immune DNA Sensor cGAS Produces a Noncanonical Cyclic Dinucleotide that Activates Human STING

    Elie J. Diner

    2013-05-01

    Full Text Available The presence of foreign DNA in the cytosol of mammalian cells elicits a potent antiviral interferon response. Recently, cytosolic DNA was proposed to induce the synthesis of cyclic GMP-AMP (cGAMP upon binding to an enzyme called cGAMP synthase (cGAS. cGAMP activates an interferon response by binding to a downstream receptor called STING. Here, we identify natural variants of human STING (hSTING that are poorly responsive to cGAMP yet, unexpectedly, are normally responsive to DNA and cGAS signaling. We explain this paradox by demonstrating that the cGAS product is actually a noncanonical cyclic dinucleotide, cyclic [G(2′-5′pA(3′-5′p], which contains a single 2′-5′ phosphodiester bond. Cyclic [G(2′-5′pA(3′-5′p] potently activates diverse hSTING receptors and, therefore, may be a useful adjuvant or immunotherapeutic. Our results indicate that hSTING variants have evolved to distinguish conventional (3′-5′ cyclic dinucleotides, known to be produced mainly by bacteria, from the noncanonical cyclic dinucleotide produced by mammalian cGAS.

  3. Wolbachia prophage DNA adenine methyltransferase genes in different Drosophila-Wolbachia associations

    Saridaki, Aggeliki; Sapountzis, Panagiotis; Harris, Harriet L;

    2011-01-01

    . The importance of DNA methylation in cell fate and biology calls for in depth studying of putative methylation-related genes. We present a molecular and phylogenetic analysis of a putative DNA adenine methyltransferase encoded by a prophage in the Wolbachia genome. Two slightly different copies of the gene, met1...

  4. Loss of Hoogsteen Pairing Ability upon N1 Adenine Platinum Binding

    Schmidt, K. S.; Reedijk, J.; Weisz, K.; Janke, E. M. B.; Šponer, Judit E.; Šponer, Jiří; Lippert, B.

    2002-01-01

    Roč. 41, č. 11 (2002), s. 2855-2863. ISSN 0020-1669 R&D Projects: GA MŠk LN00A016; GA AV ČR IAA4040903 Institutional research plan: CEZ:AV0Z4040901 Keywords : adenine * thymine * Hoogsteen pairing ability Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.950, year: 2002

  5. Assembly of an antiparallel homo-adenine DNA duplex by small-molecule binding.

    Persil, Ozgül; Santai, Catherine T; Jain, Swapan S; Hud, Nicholas V

    2004-07-21

    Molecules that reversibly bind DNA and trigger the formation of non-Watson-Crick secondary structures would be useful in the design of dynamic DNA nanostructures and as potential leads for new therapeutic agents. We demonstrate that coralyne, a small crescent-shaped molecule, promotes the formation of a duplex secondary structure from homo-adenine oligonucleotides. AFM studies reveal that the staggered alignment of homo-adenine oligonucleotides upon coralyne binding produces polymers of micrometers in length, but only 2 nm in height. A DNA duplex was also studied that contained eight A.A mismatches between two flanking 7-bp Watson-Crick helices. CD spectra confirm that the multiple A.A mismatches of this duplex bind coralyne in manner similar to that of homo-adenine oligonucleotides. Furthermore, the melting temperature of this hybrid duplex increases by 13 degrees C upon coralyne binding. These observations illustrate that the helical structure of the homo-adenine-coralyne duplex is compatible with the B-form DNA helix. PMID:15250704

  6. The effect of caffeine and adenine on radiation induced suppression of DNA synthesis, and cell survival

    Exposure of cultured mammalian cells to ionizing radiation or UV light results in a transient decrease in the rate of DNA synthesis. This depression in synthetic rate may be attenuated or deferred via a post-irradiation treatment with caffeine or adenine. It has been suggested that this attenuation may increase the fixation of damage and, therefore, increase radiation sensitivity. However, it has been previously reported that, for V79 cells treated with caffeine or adenine, no correlation exists between the extent of depression and cell survival. The present investigation expands upon these findings by examining the effect of caffeine or adenine post-irradiation treatment on two cell lines with normal UV sensitivity, mouse 3T3 and CHO AA8 cells, and one UV sensitive cell line, CHO UV5 cells. Both caffeine and adenine have been found to reduce, or delay, the suppression in DNA synthesis in all three cell lines. Surprisingly, caffeine appeared to induced even the UV5 cells to recover DNA synthetic ability. The amount of reduction in suppression of DNA synthesis, however, varies between the different cell lines and no consistent relationship with cell survival has emerged

  7. Effect of AST-120 on Endothelial Dysfunction in Adenine-Induced Uremic Rats

    Yuko Inami

    2014-01-01

    Full Text Available Aim. Chronic kidney disease (CKD represents endothelial dysfunction. Monocyte adhesion is recognized as the initial step of arteriosclerosis. Indoxyl sulfate (IS is considered to be a risk factor for arteriosclerosis in CKD. Oral adsorbent AST-120 retards deterioration of renal function, reducing accumulation of IS. In the present study, we determined the monocyte adhesion in the adenine-induced uremic rats in vivo and effects of AST-120 on the adhesion molecules. Methods. Twenty-four rats were divided into control, control+AST-120, adenine, and adenine+AST-120 groups. The number of monocytes adherent to the endothelium of thoracic aorta by imaging the entire endothelial surface and the mRNA expressions of adhesion and atherosclerosis-related molecules were examined on day 49. The mRNA expressions of ICAM-1 and VCAM-1 in human umbilical vein endothelial cells were also examined. Results. Adenine increased the number of adherent monocytes, and AST-120 suppressed the increase. The monocyte adhesion was related to serum creatinine and IS in sera. Overexpression of VCAM-1 and TGF-β1 mRNA in the arterial walls was observed in uremic rats. IS induced increase of the ICAM-1 and VCAM-1 mRNA expressions in vitro. Conclusion. It appears that uremic condition introduces the monocyte adhesion to arterial wall and AST-120 might inhibit increasing of the monocyte adherence with CKD progression.

  8. Detection and Quantification of ADP-Ribosylated RhoA/B by Monoclonal Antibody

    Rohrbeck, Astrid; Fühner, Viola; Schröder, Anke; Hagemann, Sandra; Vu, Xuan-Khang; Berndt, Sarah; Hust, Michael; Pich, Andreas; Just, Ingo

    2016-01-01

    Clostridium botulinum exoenzyme C3 is the prototype of C3-like ADP-ribosyltransferases that modify the GTPases RhoA, B, and C. C3 catalyzes the transfer of an ADP-ribose moiety from the co-substrate nicotinamide adenine dinucleotide (NAD) to asparagine-41 of Rho-GTPases. Although C3 does not possess cell-binding/-translocation domains, C3 is able to efficiently enter intact cells, including neuronal and macrophage-like cells. Conventionally, the detection of C3 uptake into cells is carried out via the gel-shift assay of modified RhoA. Since this gel-shift assay does not always provide clear, evaluable results an additional method to confirm the ADP-ribosylation of RhoA is necessary. Therefore, a new monoclonal antibody has been generated that specifically detects ADP-ribosylated RhoA/B, but not RhoC, in Western blot and immunohistochemical assay. The scFv antibody fragment was selected by phage display using the human naive antibody gene libraries HAL9/10. Subsequently, the antibody was produced as scFv-Fc and was found to be as sensitive as a commercially available RhoA antibody providing reproducible and specific results. We demonstrate that this specific antibody can be successfully applied for the analysis of ADP-ribosylated RhoA/B in C3-treated Chinese hamster ovary (CHO) and HT22 cells. Moreover, ADP-ribosylation of RhoA was detected within 10 min in C3-treated CHO wild-type cells, indicative of C3 cell entry. PMID:27043630

  9. ON THE INTERACTION OF ADENINE WITH IONIZING RADIATION: MECHANISTICAL STUDIES AND ASTROBIOLOGICAL IMPLICATIONS

    The molecular inventory available on the prebiotic Earth was likely derived from both terrestrial and extraterrestrial sources. A complete description of which extraterrestrial molecules may have seeded early Earth is therefore necessary to fully understand the prebiotic evolution which led to life. Galactic cosmic rays (GCRs) are expected to cause both the formation and destruction of important biomolecules-including nucleic acid bases such as adenine-in the interstellar medium within the ices condensed on interstellar grains. The interstellar ultraviolet (UV) component is expected to photochemically degrade gas-phase adenine on a short timescale of only several years. However, the destruction rate is expected to be significantly reduced when adenine is shielded in dense molecular clouds or even within the ices of interstellar grains. Here, biomolecule destruction by the energetic charged particle component of the GCR becomes important as it is not fully attenuated. Presented here are results on the destruction rate of the nucleobase adenine in the solid state at 10 K by energetic electrons, as generated in the track of cosmic ray particles as they penetrate ices. When both UV and energetic charged particle destructive processes are taken into account, the half-life of adenine within dense interstellar clouds is found to be ∼6 Myr, which is on the order of a star-forming molecular cloud. We also discuss chemical reaction pathways within the ices to explain the production of observed species, including the formation of nitriles (R-C≡N), epoxides (C-O-C), and carbonyl functions (R-C=O).

  10. Quantum chemical benchmark study on 46 RNA backbone families using a dinucleotide unit.

    Kruse, Holger; Mladek, Arnost; Gkionis, Konstantinos; Hansen, Andreas; Grimme, Stefan; Sponer, Jiri

    2015-10-13

    We have created a benchmark set of quantum chemical structure-energy data denoted as UpU46, which consists of 46 uracil dinucleotides (UpU), representing all known 46 RNA backbone conformational families. Penalty-function-based restrained optimizations with COSMO TPSS-D3/def2-TZVP ensure a balance between keeping the target conformation and geometry relaxation. The backbone geometries are close to the clustering-means of their respective RNA bioinformatics family classification. High-level wave function methods (DLPNO-CCSD(T) as reference) and a wide-range of dispersion-corrected or inclusive DFT methods (DFT-D3, VV10, LC-BOP-LRD, M06-2X, M11, and more) are used to evaluate the conformational energies. The results are compared to the Amber RNA bsc0χOL3 force field. Most dispersion-corrected DFT methods surpass the Amber force field significantly in accuracy and yield mean absolute deviations (MADs) for relative conformational energies of ∼0.4-0.6 kcal/mol. Double-hybrid density functionals represent the most accurate class of density functionals. Low-cost quantum chemical methods such as PM6-D3H+, HF-3c, DFTB3-D3, as well as small basis set calculations corrected for basis set superposition errors (BSSEs) by the gCP procedure are also tested. Unfortunately, the presently available low-cost methods are struggling to describe the UpU conformational energies with satisfactory accuracy. The UpU46 benchmark is an ideal test for benchmarking and development of fast methods to describe nucleic acids, including force fields. PMID:26574283

  11. A new sensitive 32P-postlabeling assay based on the specific enzymatic conversion of bulky DNA lesions to radiolabeled dinucleotides and nucleoside 5'-monophosphates

    A new sensitive 32P-postlabelling assay for DNA adducts has been developed. When DNA containing bulky adducts, X1, X2, .....Xn, is digested with nuclease P1 at pH 5, normal nucleotides are released as 5'-monophosphates, pN, while adducts are excised as 5'-phosphorylated dinucleotides, pXipN, because inter-nucleotide linkages on the 3' side of X resist attack by nuclease P1. Addition of prostatic acid phosphatase to such a digest results in 5'-dephosphorylation of the nucleotides to normal nucleosides, N, and adducted dinucleotides, XipN, carrying a 5'-terminal free hydroxyl group. The dinucleotides but not nucleosides are converted to 5'-32P-labeled dinucleotides,[32P]pXipN, by T4 polynucleotide kinase-catalyzed [32P]posphate transfer from [γ-32P]ATP. Upon mapping on polyethyleneimine-cellulose anion-exchange TLC, the labeled dinucleotide adducts produce characteristic autoradiographic fingerprints. Alternatively, they are further digested with snake venom phosphodiesterase to yield 5'-monophosphates, [32P]pXi and pN. TLC profiles of the monophosphate adducts are distinct from those of the dinucleotides. These reactions provide the basis of the new 32P-postlabeling scheme, which is compared in this paper with a previously reported protocol yielding adducts in the form of 5'-32P-labeled 3',5'-bisphosphates, [32P]pXip. (author)

  12. Watson-Crick Base Pairing, Electronic and Photophysical Properties of Triazole Modified Adenine Analogues: A Computational Study

    Das, Shubhajit

    2015-09-17

    We employ first-principles Density Functional Theory (DFT) and time-dependent DFT (TDDFT) to elucidate structural, electronic and optical properties of a few recently reported triazole adenine nucleobase analogues. The results are compared against the findings obtained for both natural adenine nucleobase and available experimental data. The optical absorption of these adenine analogues are calculated both in gas-phase and in solvent (methanol) using Polarized Continuum Model (PCM). We find that all the analogues show a red-shifted absorption profile as compared to adenine. Our simulated emission spectra in solvent compare fairly well with experimentally observed results. We investigate base paring ability of these adenine analogues with thymine. The calculations on the intrinsic stability of these base pairs ascertain that all the adenine analogues form the hydrogen bonded Watson-Crick base pair with similar H-bonding energy as obtained for natural adenine-thymine base pair. In our study, we provide a microscopic origin of the low-energy absorption and emission peaks, observed experimentally.

  13. Preparation of /sup 14/C-labelled AMP, ADP and ATP from adenine-8-/sup 14/C by using Brevibacterium ammoniagenes

    Pande, V.N. (Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.)

    1985-04-01

    High radiochemical yields of /sup 14/C-labelled adenine nucleotides (AMP, 4.6%, ADP, 15.5% and ATP 59.5%) could be obtained by growing the cells of Brevibacterium ammoniagenes in the presence of /sup 14/C-adenine. The specific radioactivity of the adenine nucleotides almost reached that of /sup 14/C-adenine indicating negligible dilution of the label. The procedure is convenient and especially suited for commercial preparation of the radiolabelled nucleotides directly from labelled adenine. Preliminary results indicate that the organism could also be used for the preparation of radiolabelled guanine nucleotides.

  14. Influence of gamma irradiation and benzyl adenine on keeping quality of custard apple fruits during storage

    The custard apple (Annona squamosa) fruits were procured from local market, irradiated with radiation doses 0, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 kGy and then treated with benzyl adenine (50 and 100 part per million) and stored at ambient temperature (25±5 °C, Relative Humidity 90±2%) for 12 days. The treated fruits were evaluated for sensory (viz; flavour, texture, internal and external colour) and chemical constituents (viz; Total Soluble Solids, titrable acidity, ascorbic acid, free soluble sugar, reducing sugar, non reducing sugar, carbohydrate) during storage. The study concluded that radiation dose of 1.5 kilo Gray along with 50 ppm benzyl adenine enhanced in shelf-life of custard apple fruits by 6 days at ambient temperature with good pulp texture, flavour, colour and nutritional quality as compared to control. (author)

  15. Sequence effects in structures of the dinucleotides d-pApT and d-pTpA

    The H1', H2' and H2 regions of the 270-MHz PMR spectra of two deoxydinucleotides, d-pTpA an d-pApT, have been analyzed. The coupling constants in the sugar ring indicate that both A and T sugars have a tendency to acquire 2E conformations. There is also a marginal difference in the 2E populations of the T sugar in the two dinucleotides. The trends in the chemical shifts of base protons indicate different stacking of the bases in d-pApT and d-pTpA. The sequence effects on base stacking and pentose conformation are discussed. (orig.)

  16. Downregulation of adenine nucleotide translocator 1 exacerbates tumor necrosis factor-α-mediated cardiac inflammatory responses

    Pan, Shi; Wang, Nadan; Bisetto, Sara; Yi, Bing; Sheu, Shey-Shing

    2014-01-01

    Inflammation contributes significantly to cardiac dysfunction. Although the initial phase of inflammation is essential for repair and healing, excessive proinflammatory cytokines are detrimental to the heart. We found that adenine nucleotide translocator isoform-1 (ANT1) protein levels were significantly decreased in the inflamed heart of C57BL/6 mice following cecal ligation and puncture. To understand the molecular mechanisms involved, we performed small-interfering RNA-mediated knockdown o...

  17. Synthesis of metal-adeninate frameworks with high separation capacity on C2/C1 hydrocarbons

    He, Yan-Ping; Zhou, Nan; Tan, Yan-Xi; Wang, Fei; Zhang, Jian

    2016-06-01

    By introducing isophthalic acid or 2,5-thiophenedicarboxylic acid to assemble with adenine and cadmium salt, two isostructural and anionic porous metal-organic frameworks (1 and 2) possessing the novel (4,8)-connected sqc topology are presented here. 1 shows permanent porosity with Langmuir surface area of 770.1 m2/g and exhibits high separation capacity on C2/C1 hydrocarbons.

  18. Effect of Atracylodes Rhizome Polysaccharide in Rats with Adenine-Induced Chronic Renal Failure

    Yang, C.; C. Liu; Zhou, Q.; Xie, Y. C.; Qiu, X. M.; X. Feng

    2015-01-01

    The aim of the study was to elucidate the therapeutic effects of Atracylodes rhizome polysaccharide on adenine-induced chronic renal failure in rats. Fifty male Sprague Dawley rats were selected and randomly divided in to 5 groups (n=10 rats per group): The normal control group, the chronic renal failure pathological control group, the dexamethasone treatment group and two Atracylodes rhizome polysaccharide treatment groups, treated with two different concentrations of the polysaccharide, the...

  19. Adenine ribbon stabilized by Watson–Crick and Hoogsteen hydrogen Bonds: WFT and DFT study

    Zierkiewicz, W.; Michalska, D.; Hobza, Pavel

    2010-01-01

    Roč. 12, č. 12 (2010), s. 2888-2894. ISSN 1463-9076 R&D Projects: GA MŠk LC512 Grant ostatní: Wroclaw University of Technology(PL) 343974/Z0304 Institutional research plan: CEZ:AV0Z40550506 Keywords : adenine ribbon * ab initio correlated calculations * self- organization Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.454, year: 2010

  20. Kissing loop interaction in adenine riboswitch: insights from umbrella sampling simulations

    Di Palma, Francesco; Bottaro, Sandro; Bussi, Giovanni

    2015-01-01

    Introduction Riboswitches are cis-acting regulatory RNA elements prevalently located in the leader sequences of bacterial mRNA. An adenine sensing riboswitch cis-regulates adeninosine deaminase gene (add) in Vibrio vulnificus. The structural mechanism regulating its conformational changes upon ligand binding mostly remains to be elucidated. In this open framework it has been suggested that the ligand stabilizes the interaction of the distal "kissing loop" complex. Using accurate full-atom mol...

  1. Long-Range Charge Transport in Adenine-Stacked RNA:DNA Hybrids.

    Li, Yuanhui; Artés, Juan M; Hihath, Joshua

    2016-01-27

    An extremely important biological component, RNA:DNA can also be used to design nanoscale structures such as molecular wires. The conductance of single adenine-stacked RNA:DNA hybrids is rapidly and reproducibly measured using the break junction approach. The conductance decreases slightly over a large range of molecular lengths, suggesting that RNA:DNA can be used as an oligonucleotide wire. PMID:26596516

  2. 5-azacytidine and purine nucleotide synthesis in guinea-pig cerebral cortex slices by salvage pathway from adenine

    The effect of the cytostatic, immunosuppressive and antiviral drug 5-azacytidine was studied on the synthesis of purine nucleotides and the total RNA fraction by the salvage pathway of adenine in in vitro experiments on slices from the brain cortex while the azapyrimidine nucleoside only decreased the specific radioactivity of nucleotide adenine and quanine in a relatively high resulting concentration (10-2M), no differences were found between the slices of the brain cortex incubated with and without 5-azacytidine. The comparison of the specific radioactivities of adenine of the total RNA fraction gave a similar picture. No substantial differences were observed between the levels of adenine nucleotides and the total RNA fraction in slices incubated with and without 5-azacytidine. (author)

  3. Thermodynamic Potential for the Abiotic Synthesis of Adenine, Cytosine, Guanine, Thymine, Uracil, Ribose, and Deoxyribose in Hydrothermal Systems

    LaRowe, D.E.; Regnier, P.

    2008-01-01

    The thermodynamic potential for the abiotic synthesis of the five common nucleobases (adenine, cytosine, guanine, thymine, and uracil) and two monosaccharides (ribose and deoxyribose) from formaldehyde and hydrogen cyanide has been quantified under temperature, pressure, and bulk composition conditi

  4. Selective self-assembly of adenine-silver nanoparticles forms rings resembling the size of cells

    Choi, Sungmoon; Park, Soonyoung; Yang, Seon-Ah; Jeong, Yujin; Yu, Junhua

    2015-12-01

    Self-assembly has played critical roles in the construction of functional nanomaterials. However, the structure of the macroscale multicomponent materials built by the self-assembly of nanoscale building blocks is hard to predict due to multiple intermolecular interactions of great complexity. Evaporation of solvents is usually an important approach to induce kinetically stable assemblies of building blocks with a large-scale specific arrangement. During such a deweting process, we tried to monitor the possible interactions between silver nanoparticles and nucleobases at a larger scale by epifluorescence microscopy, thanks to the doping of silver nanoparticles with luminescent silver nanodots. ssDNA oligomer-stabilized silver nanoparticles and adenine self-assemble to form ring-like compartments similar to the size of modern cells. However, the silver ions only dismantle the self-assembly of adenine. The rings are thermodynamically stable as the drying process only enrich the nanoparticles-nucleobase mixture to a concentration that activates the self-assembly. The permeable membrane-like edge of the ring is composed of adenine filaments glued together by silver nanoparticles. Interestingly, chemicals are partially confined and accumulated inside the ring, suggesting that this might be used as a microreactor to speed up chemical reactions during a dewetting process.

  5. L-Arginine Intake Effect on Adenine Nucleotide Metabolism in Rat Parenchymal and Reproductive Tissues

    G. Kocic

    2012-01-01

    Full Text Available L-arginine is conditionally essetcial amino acid, required for normal cell growth, protein synthesis, ammonia detoxification, tissue growth and general performance, proposed in the treatment of men sterility and prevention of male impotence. The aim of the present paper was to estimate the activity of the enzymes of adenine nucleotide metabolism: 5′-nucleotidase (5′-NU, adenosine deaminase (ADA, AMP deaminase, and xanthine oxidase (XO, during dietary intake of L-arginine for a period of four weeks of male Wistar rats. Adenosine concentration in tissues is maintained by the relative activities of the adenosine-producing enzyme, 5′-NU and the adenosine-degrading enzyme-ADA adenosine deaminase. Dietary L-arginine intake directed adenine nucleotide metabolism in liver, kidney, and testis tissue toward the activation of adenosine production, by increased 5′-NU activity and decreased ADA activity. Stimulation of adenosine accumulation could be of importance in mediating arginine antiatherosclerotic, vasoactive, immunomodulatory, and antioxidant effects. Assuming that the XO activity reflects the rate of purine catabolism in the cell, while the activity of AMP deaminase is of importance in ATP regeneration, reduced activity of XO, together with the increased AMP-deaminase activity, may suggest that adenine nucleotides are presumably directed to the ATP regenerating process during dietary L-arginine intake.

  6. Spectroscopic assessment of argon gas discharge induced radiolysis of aqueous adenine and thymine

    Su Xi [Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Shushanhu Road 350, Hefei 230031 (China); Huang Qing, E-mail: huangq@ipp.ac.cn [Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Shushanhu Road 350, Hefei 230031 (China); Dang Bingrong [Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Wang Xiangqin; Yu Zengliang [Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, P.O. Box 1138, Shushanhu Road 350, Hefei 230031 (China)

    2011-12-15

    Ionizing radiation influences life profoundly for it can modify genetic materials. It is a long-standing task to investigate the interaction between energetic particles and DNA together with its components such as nucleotides, nucleosides and bases so as to predict and assess the potential biological effects. In this study, argon gas discharge was employed to produce energetic ions and electrons. The gas discharge caused the radiolysis of aqueous bases and the involved reactions were analyzed by means of spectroscopic tools including UV-vis absorption, fluorescence and Fourier transformation infrared (FTIR) spectroscopy, also assisted by liquid chromatography/mass spectrometry (LC/MS). It was found that the discharge resulted in the adenine-derived lesions such as 4,6-diamino-5-formamidopyrimidine, 8-OH-Ade and 2-OH-Ade in the radiolysis of aqueous adenine, as well as the thymine-derived lesions such as thymine glycol, 5-hydroxy-6-hydrothymine and/or 6-hydroxy-5-hydrothymine, 5-hydroxymethyluracil and 5-formyluracil in the radiolysis of aqueous thymine. The study of radio-sensitivity showed that adenine was more resistant to the discharge. The mechanisms of the involved reactions were studied in detail, confirming that the hydroxyl radical played a dominant role. - Highlights: > Effective new way to study radiolysis of bases via a home-made argon discharge apparatus. > Quantitative analysis of base radiolysis employing spectroscopic tools combined with HPLC/MS. > Discovery of different radiolysis effect compared with other forms of ionizing radiations.

  7. Spectroscopic assessment of argon gas discharge induced radiolysis of aqueous adenine and thymine

    Ionizing radiation influences life profoundly for it can modify genetic materials. It is a long-standing task to investigate the interaction between energetic particles and DNA together with its components such as nucleotides, nucleosides and bases so as to predict and assess the potential biological effects. In this study, argon gas discharge was employed to produce energetic ions and electrons. The gas discharge caused the radiolysis of aqueous bases and the involved reactions were analyzed by means of spectroscopic tools including UV-vis absorption, fluorescence and Fourier transformation infrared (FTIR) spectroscopy, also assisted by liquid chromatography/mass spectrometry (LC/MS). It was found that the discharge resulted in the adenine-derived lesions such as 4,6-diamino-5-formamidopyrimidine, 8-OH-Ade and 2-OH-Ade in the radiolysis of aqueous adenine, as well as the thymine-derived lesions such as thymine glycol, 5-hydroxy-6-hydrothymine and/or 6-hydroxy-5-hydrothymine, 5-hydroxymethyluracil and 5-formyluracil in the radiolysis of aqueous thymine. The study of radio-sensitivity showed that adenine was more resistant to the discharge. The mechanisms of the involved reactions were studied in detail, confirming that the hydroxyl radical played a dominant role. - Highlights: → Effective new way to study radiolysis of bases via a home-made argon discharge apparatus. → Quantitative analysis of base radiolysis employing spectroscopic tools combined with HPLC/MS. Discovery of different radiolysis effect compared with other forms of ionizing radiations.

  8. Interaction of an adenine molecule with a Ag-terminated Si(111) surface

    The adsorption of an adenine molecule, one of four DNA bases, on a Ag/Si(111) √3 x √3 surface is investigated using a first-principles total-energy calculation. Extensive search of the adsorption structures reveals that two structures are energetically competing. One is a structure with a hexagonal ring of adenine on a large Ag triangle (LT) of the substrate. The molecular plane is inclined at a tilt angle of 10.2 .deg. with respect to the surface plane due to weak bonds between N and substrate Ag atoms. The other is a structure with N just above a Ag atom (T) with the molecular plane vertical to the surface. The N... Ag bond energy in the LT structure is of similar magnitude to the N...H hydrogen bonds of an adenine dimer. The local-density approximation (LDA) and the generalized-gradient approximation (GGA) produce different energy orders between the LT and the T structures. An incorrect treatment of the van der Waals interaction in the density-functional theory could be the origin of the difference.

  9. Prolonged Pulmonary Exposure to Diesel Exhaust Particles Exacerbates Renal Oxidative Stress, Inflammation and DNA Damage in Mice with Adenine-Induced Chronic Renal Failure

    Abderrahim Nemmar

    2016-05-01

    Full Text Available Background/Aims: Epidemiological evidence indicates that patients with chronic kidney diseases have increased susceptibility to adverse outcomes related to long-term exposure to particulate air pollution. However, mechanisms underlying these effects are not fully understood. Methods: Presently, we assessed the effect of prolonged exposure to diesel exhaust particles (DEP on chronic renal failure induced by adenine (0.25% w/w in feed for 4 weeks, which is known to involve inflammation and oxidative stress. DEP (0.5m/kg was intratracheally (i.t. instilled every 4th day for 4 weeks (7 i.t. instillation. Four days following the last exposure to either DEP or saline (control, various renal endpoints were measured. Results: While body weight was decreased, kidney weight increased in DEP+adenine versus saline+adenine or DEP. Water intake, urine volume, relative kidney weight were significantly increased in adenine+DEP versus DEP and adenine+saline versus saline. Plasma creatinine and urea increased and creatinine clearance decreased in adenine+DEP versus DEP and adenine+saline versus saline. Tumor necrosis factor α, lipid peroxidation and reactive oxygen species were significantly increased in adenine+DEP compared with either DEP or adenine+saline. The antioxidant calase was significantly decreased in adenine+DEP compared with either adenine+saline or DEP. Notably, renal DNA damage was significantly potentiated in adenine+DEP compared with either adenine+saline or DEP. Similarly, systolic blood pressure was increased in adenine+DEP versus adenine+saline or DEP, and in DEP versus saline. Histological evaluation revealed more collagen deposition, higher number of necrotic cell counts and dilated tubules, cast formation and collapsing glomeruli in adenine+DEP versus adenine+saline or DEP. Conclusion: Prolonged pulmonary exposure to diesel exhaust particles worsen renal oxidative stress, inflammation and DNA damage in mice with adenine-induced chronic

  10. A glassy carbon electrode modified with poly(eriochrome black T) for sensitive determination of adenine and guanine

    A thin film of poly(eriochrome black T) was deposited on the surface of glassy carbon electrode by cyclic voltammetry, and this system is shown to enable the sensitive determination of adenine (A) and guanine (G). Scanning electron microscopy, Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy were carried out to characterize the film which exhibits excellent electrocatalytic activity toward the oxidation of A and G in 0.1 M phosphate buffer solution (pH 4.0). Square wave voltammetry reveals an oxidation peak at 1084 mV whose current is linearly related to the concentration of A in the range from 0.05 to 1.00 μM. The oxidation peak for G occurs at 788 mV, and its current is linearly related to the concentration of G in the range from 0.025 to 1.00 μM. The detection limits are 0.017 μM for A and 0.008 μM for G (at S/N = 3), respectively. The modified electrode displays good reproducibility and selectivity for the determination of A and G. The sensor was applied to quantify A and G in fish sperm DNA with satisfactory results. (author)

  11. Kinetic and mechanistic analysis of dinucleotide and oligonucleotide formation from the 5'-phosphorimidazolide of adenosine on Na(+)-montmorillonite

    Kawamura, K.; Ferris, J. P.

    1994-01-01

    The rate constants for the condensation reaction of the 5'-phosphorimidazolide of adenosine (ImpA) to form dinucleotides and oligonucleotides have been measured in the presence of Na(+)-volclay (a Na(+)-montmorillonite) in pH 8 aqueous solution at 25 degrees C. The rates of the reaction of ImpA with an excess of adenosine 5'-monophosphoramidate (NH2pA), P1,P2-diadenosine 5',5'-pyrophosphate (A5'ppA), or adenosine 5'-monophosphate (5'-AMP or pA) in the presence of the montmorillonite to form NH2pA3'pA, A5'ppA3'pA, and pA3'pA, respectively, were measured. Only 3',5'-linked products were observed. The magnitude of the rate constants decrease in the order NH2pA3'pA > A5'-ppA3'pA > pA3'pA. The binding of ImpA to montmorillonite was measured, and the adsorption isotherm was determined. The binding of ImpA to montmorillonite and the formation of higher oligonucleotides is not observed in the absence of salts. Mg2+ enhances binding and oligonucleotide formation more than Ca2+ and Na+. The rate constants for the oligonucleotide formation were determined from the reaction products formed from 10 to 40 mM ImpA in the presence of Na(+)-montmorillonite using the computer program SIMFIT. The magnitudes of the rate constants for the formation of oligonucleotides increased in the order 2-mer montmorillonite. The rate constants for the formation of dinucleotide, trinucleotide, and tetranucleotide are 41,2.6, and 3.7 times larger than those for the formation of oligo(G)s with a poly(C) template. The hydrolysis of ImpA was accelerated 35 times in the presence of the montmorillonite. The catalytic ability of montmorillonite to form dinucleotides and oligonucleotides is quantitatively evaluated and possible pathways for oligo(A) formation are proposed.

  12. Fragmentation of the adenine and guanine molecules induced by electron collisions

    Secondary electron emission is the most important stage in the mechanism of radiation damage to DNA biopolymers induced by primary ionizing radiation. These secondary electrons ejected by the primary electron impacts can produce further ionizations, initiating an avalanche effect, leading to genome damage through the energy transfer from the primary objects to sensitive biomolecular targets, such as nitrogenous bases, saccharides, and other DNA and peptide components. In this work, the formation of positive and negative ions of purine bases of nucleic acids (adenine and guanine molecules) under the impact of slow electrons (from 0.1 till 200 eV) is studied by the crossed electron and molecular beams technique. The method used makes it possible to measure the molecular beam intensity and determine the total cross-sections for the formation of positive and negative ions of the studied molecules, their energy dependences, and absolute values. It is found that the maximum cross section for formation of the adenine and guanine positive ions is reached at about 90 eV energy of the electron beam and their absolute values are equal to 2.8 × 10−15 and 3.2 × 10−15 cm2, respectively. The total cross section for formation of the negative ions is 6.1 × 10−18 and 7.6 × 10−18 cm2 at the energy of 1.1 eV for adenine and guanine, respectively. The absolute cross-section values for the molecular ions are measured and the cross-sections of dissociative ionization are determined. Quantum chemical calculations are performed for the studied molecules, ions and fragments for interpretation of the crossed beams experiments

  13. Fabrication of a Complex Two-Dimensional Adenine-Perylene-3,4,9, 10-tetracarboxylic Dianhydride Chiral Nanoarchitecture through Molecular Self-Assembly

    Sun, Xiaonan; Mura, Manuela; Jonkman, Harry T.; Kantorovich, Lev N.; Silly, Fabien

    2012-01-01

    The two-dimensional self-assembly of a nonsyrnmetric adenine DNA base mixed with symmetric perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules is investigated using scanning tunneling microscopy (STM). We experimentally observe that these two building blocks form a complex close-packed chiral supramolecular network on Au(111). The unit cell of the adenine PTCDA nanoarchitecture is composed of 14 molecules. The high stability of this structure relies on PTCDA-PTCDA and PTCDA-adenin...

  14. The effect of pi-stacking, h-bonding, and electrostatic interactions on the ionization energies of nucleic acid bases: adenine-adenine, thymine-thymine and adenine-thymine dimers

    Bravaya, Ksenia B.; Kostko, Oleg; Ahmed, Musahid; Krylov, Anna I.

    2009-09-02

    A combined theoretical and experimental study of the ionized dimers of thymine and adenine, TT, AA, and AT, is presented. Adiabatic and vertical ionization energies(IEs) for monomers and dimers as well as thresholds for the appearance of the protonated species are reported and analyzed. Non-covalent interactions stronglyaffect the observed IEs. The magnitude and the nature of the effect is different for different isomers of the dimers. The computations reveal that for TT, the largestchanges in vertical IEs (0.4 eV) occur in asymmetric h-bonded and symmetric pi- stacked isomers, whereas in the lowest-energy symmetric h-bonded dimer the shiftin IEs is much smaller (0.1 eV). The origin of the shift and the character of the ionized states is different in asymmetric h-bonded and symmetric stacked isomers. Inthe former, the initial hole is localized on one of the fragments, and the shift is due to the electrostatic stabilization of the positive charge of the ionized fragment by thedipole moment of the neutral fragment. In the latter, the hole is delocalized, and the change in IE is proportional to the overlap of the fragments' MOs. The shifts in AAare much smaller due to a less effcient overlap and a smaller dipole moment. The ionization of the h-bonded dimers results in barrierless (or nearly barrierless) protontransfer, whereas the pi-stacked dimers relax to structures with the hole stabilized by the delocalization or electrostatic interactions.

  15. Synthesis and Characterization of Oligodeoxyribonucleotides Modified with 2'-Amino-α-l-LNA Adenine Monomers

    Andersen, Nicolai K; Anderson, Brooke A; Wengel, Jesper;

    2013-01-01

    The development of conformationally restricted nucleotide building blocks continues to attract considerable interest because of their successful use within antisense, antigene, and other gene-targeting strategies. Locked nucleic acid (LNA) and its diastereomer α-l-LNA are two interesting examples....... ONs modified with pyrene-functionalized 2'-amino-α-l-LNA adenine monomers X-Z display greatly increased affinity toward DNA targets (ΔTm/modification up to +14 °C). Results from absorption and fluorescence spectroscopy suggest that the duplex stabilization is a result of pyrene intercalation. These...

  16. Severity of cardiomyopathy associated with adenine nucleotide translocator-1 deficiency correlates with mtDNA haplogroup

    Strauss, Kevin A.; DuBiner, Lauren; Simon, Mariella; Zaragoza, Michael; Sengupta, Partho P.; Li, Peng; Narula, Navneet; Dreike, Sandra; Platt, Julia; Procaccio, Vincent; Ortiz-Gonzalez, Xilma R.; Puffenberger, Erik G.; Kelley, Richard I.; Morton, D. Holmes; Narula, Jagat

    2013-01-01

    Mutations of both nuclear and mitochondrial DNA (mtDNA)–encoded mitochondrial proteins can cause cardiomyopathy associated with mitochondrial dysfunction. Hence, the cardiac phenotype of nuclear DNA mitochondrial mutations might be modulated by mtDNA variation. We studied a 13-generation Mennonite pedigree with autosomal recessive myopathy and cardiomyopathy due to an SLC25A4 frameshift null mutation (c.523delC, p.Q175RfsX38), which codes for the heart-muscle isoform of the adenine nucleotide...

  17. Isolation and characterisation of a dinucleotide microsatellite set for a parentage and biodiversity study in domestic guinea pig (Cavia porcellus

    Diana Aviles

    2015-10-01

    Full Text Available The domestic guinea pig is a valuable genetic resource because it is part of local folklore and food tradition in many South American countries. The economic importance of the guinea pig is due to its high feed efficiency and the quality of animal protein produced. For these reasons, our study is aimed to design a complete dinucleotide microsatellite marker set following international recommendation to assess the genetic diversity and genealogy management of guinea pigs. We selected a total of 20 microsatellites, looking for laboratory efficiency and good statistical parameters. The set was tested in 100 unrelated individuals of guinea pigs from Ecuador, Peru, Colombia, Bolivia and Spain. Our results show a high degree of polymorphisms with a total of 216 alleles and a mean number of 10.80±3.49 for markers with a combined exclusion probability of 0.99.

  18. Synthesis, spectroscopic, structural and thermal characterizations of vanadyl(IV) adenine complex prospective as antidiabetic drug agent

    El-Megharbel, Samy M.; Hamza, Reham Z.; Refat, Moamen S.

    2015-01-01

    The vanadyl(IV) adenine complex; [VO(Adn)2]ṡSO4; was synthesized and characterized. The molar conductivity of this complex was measured in DMSO solution that showed an electrolyte nature. Spectroscopic investigation of the green solid complex studied here indicate that the adenine acts as a bidentate ligand, coordinated to vanadyl(IV) ions through the nitrogen atoms N7 and nitrogen atom of amino group. Thus, from the results presented the vanadyl(IV) complex has square pyramid geometry. Further characterizations using thermal analyses and scanning electron techniques was useful. The aim of this paper was to introduce a new drug model for the diabetic complications by synthesized a novel mononuclear vanadyl(IV) adenine complex to mimic insulin action and reducing blood sugar level. The antidiabetic ability of this complex was investigated in STZ-induced diabetic mice. The results suggested that VO(IV)/adenine complex has antidiabetic activity, it improved the lipid profile, it improved liver and kidney functions, also it ameliorated insulin hormone and blood glucose levels. The vanadyl(IV) complex possesses an antioxidant activity and this was clear through studying SOD, CAT, MDA, GSH and methionine synthase. The current results support the therapeutic potentiality of vanadyl(IV)/adenine complex for the management and treatment of diabetes.

  19. A dose-response study on opening of imidazole ring of adenine in DNA by ionizing radiation

    A dose-response relationship between γ-irradiation and the cleavage of the imidazole ring of adenine in DNA to form formamidopyrimidine has been demonstrated. When the DNA aqueous solution was irradiated with 0.1 Gy under N2O there is little evidence of imidazole ring cleavage. A significant increase in cleavage begins to be noticed above 1 Gy reaching a plateau at 1000 Gy. No formamidopyrimidine was formed when 2'-deoxyadenosine was irradiated with up to 1000 Gy. A dose of 100 Gy converts 18 per cent of adenine in DNA to formamidopyrimidine. In irradiated DNA aqueous solution 1000 Gy convert 25 per cent of adenine to formamidopyrimidine under N2O. Some of the adenine was converted to 7,8-dihydro-8-oxoadenine but in amount that is 20 per cent of that converted to formamidopyrimidine under N2O. There was more adenine in DNA converted to formamidopyrimidine under N2O than under N2. (author)

  20. Thymine- and Adenine-Functionalized Polystyrene Form Self-Assembled Structures through Multiple Complementary Hydrogen Bonds

    Yu-Shian Wu

    2014-06-01

    Full Text Available In this study, we investigated the self-assembly of two homopolymers of the same molecular weight, but containing complementary nucleobases. After employing nitroxide-mediated radical polymerization to synthesize poly(vinylbenzyl chloride, we converted the polymer into poly(vinylbenzyl azide through a reaction with NaN3 and then performed click chemistry with propargyl thymine and propargyl adenine to yield the homopolymers, poly(vinylbenzyl triazolylmethyl methylthymine (PVBT and poly(vinylbenzyl triazolylmethyl methyladenine (PVBA, respectively. This PVBT/PVBA blend system exhibited a single glass transition temperature over the entire range of compositions, indicative of a miscible phase arising from the formation of multiple strong complementary hydrogen bonds between the thymine and adenine groups of PVBT and PVBA, respectively; Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy confirmed the presence of these noncovalent interactions. In addition, dynamic rheology, dynamic light scattering and transmission electron microscopy provided evidence for the formation of supramolecular network structures in these binary PVBT/PVBA blend systems.

  1. Bacteriophage adenine methyltransferase: a life cycle regulator? Modelled using Vibrio harveyi myovirus like.

    Bochow, S; Elliman, J; Owens, L

    2012-11-01

    The adenine methyltransferase (DAM) gene methylates GATC sequences that have been demonstrated in various bacteria to be a powerful gene regulator functioning as an epigenetic switch, particularly with virulence gene regulation. However, overproduction of DAM can lead to mutations, giving rise to variability that may be important for adaptation to environmental change. While most bacterial hosts carry a DAM gene, not all bacteriophage carry this gene. Currently, there is no literature regarding the role DAM plays in life cycle regulation of bacteriophage. Vibrio campbellii strain 642 carries the bacteriophage Vibrio harveyi myovirus like (VHML) that has been proven to increase virulence. The complete genome sequence of VHML bacteriophage revealed a putative adenine methyltransferase gene. Using VHML, a new model of phage life cycle regulation, where DAM plays a central role between the lysogenic and lytic states, will be hypothesized. In short, DAM methylates the rha antirepressor gene and once methylation is removed, homologous CI repressor protein becomes repressed and non-functional leading to the switching to the lytic cycle. Greater understanding of life cycle regulation at the genetic level can, in the future, lead to the genesis of chimeric bacteriophage with greater control over their life cycle for their safe use as probiotics within the aquaculture industry. PMID:22681538

  2. High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure

    Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth;

    2014-01-01

    This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without...... increase the susceptibility to hypertensive end-organ injury and progressive renal failure by facilitating pressure transmission to the microvasculature....... adenine (controls). After 10 wk, rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization, renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic...

  3. Cross sections of negative ion production in electron collisions with adenine molecules

    Full text: We report absolute cross sections for the formation negative ions resulting from electron interactions with adenine. Interest in experimental studies of the processes of electron impact ion production in the molecules of biological relevance is related, first of all, to the significance of the problem of intracellular irradiation of biological structures by secondary electrons produced in the substance in quite considerable amounts under the influence of different-type radiation. It has been shown in our preliminary experiments carried out with the heterocyclic components of the above molecules that under electron impact different physical processes occur: molecules excitation, ionization, dissociative excitation and dissociative ionization. Physical modeling of these processes and estimation of their radiobiological consequences require knowledge of their basic characteristics - absolute ionization cross sections. Reliable data on the ionization cross sections could be obtained only in a precise experiment, in which the role of environment is minimized. Such approach was applied in this work. Production of negative ions of adenine molecules (nucleic acid base) has been studied using a crossed electron and molecular beam technique. The method developed by the authors enabled the molecular beam intensity to be measured and the electron dependences and the absolute values of the total cross sections of production of negative adenine ions to be determined. A five-electrode electron gun with a thoriated tungsten cathode was used as an electron beam source. Electron gun temperature was about 400 K providing gun parameter stability during operation. Electrons having passed the interaction region were trapped by a Faraday cup kept at the positive potential. Measurements were carried out at the 10-7 - 10-6 AA electron beam current and the ΔE1/2 ∼ 0.3 eV (FWHM) energy spread. Electron gun was immersed into the longitudinal magnetic field (induction B = 1

  4. Development of a new model for the induction of chronic kidney disease via intraperitoneal adenine administration, and the effect of treatment with gum acacia thereon.

    Al Za'abi, Mohammed; Al Busaidi, Mahfouda; Yasin, Javid; Schupp, Nicole; Nemmar, Abderrahim; Ali, Badreldin H

    2015-01-01

    Oral adenine (0.75% w/w in feed), is an established model for human chronic kidney disease (CKD). Gum acacia (GA) has been shown to be a nephroprotective agent in this model. Here we aimed at developing a new adenine-induced CKD model in rats via a systemic route (intraperitoneal, i.p.) and to test it with GA to obviate the possibility of a physical interaction between GA and adenine in the gut. Adenine was injected i.p. (50 or 100 mg/Kg for four weeks), and GA was given concomitantly in drinking water at a concentration of 15%, w/v. Several plasma and urinary biomarkers of oxidative stress were measured and the renal damage was assessed histopathologically. Adenine, at the two given i.p. doses, significantly reduced body weight, and increased relative kidney weight, water intake and urine output. It dose-dependently increased plasma and urinary inflammatory and oxidative stress biomarkers, and caused morphological and histological damage resembling that which has been reported with oral adenine. Concomitant treatment with GA significantly mitigated almost all the above measured indices. Administration of adenine i.p. induced CKD signs very similar to those induced by oral adenine. Therefore, this new model is quicker, more practical and accurate than the original (oral) model. GA ameliorates the CKD effects caused by adenine given i.p. suggesting that the antioxidant and anti-inflammatory properties possessed by oral GA are the main mechanism for its salutary action in adenine-induced CKD, an action that is independent of its possible interaction with adenine in the gut. PMID:25755826

  5. Interfacial molecular recognition of adenine, adenosine and ATP by a C60-uracil adduct via complementary base pairing

    Marczak, Renata; Hoang, Vu T.; Noworyta, Krzysztof; Zandler, Melvin E.; Kutner, Wlodzimierz; D'Souza, Francis

    2002-10-01

    A new C60-uracil adduct was demonstrated to recognize adenine, adenosine, or adenosine 5'-triphosphate (ATP) via complementary base pairing which led to complex formation. The base-pairing mechanism was modeled by ab initio B3LYP/3-21G(*) calculations which revealed the Watson-Crick (A-T) interactions. Stable "expanded liquid" Langmuir films of the complexes were prepared with the limiting area per molecule increasing for different subphase composition in the order: water < adenine < adenosine < ATP solution. Comparison of experimental and calculated areas per molecule and dipole moments suggest both prevailing horizontal orientation of the complexes in films.

  6. On the existence of the H3 tautomer of adenine in aqueous solution. Rationalizations based on hybrid quantum mechanics/molecular mechanics predictions

    Aidas, Kestutis; Mikkelsen, Kurt V; Kongsted, Jacob

    2010-01-01

    The (15)N NMR spectrum of adenine in aqueous solution has been modeled using high-level combined density functional theory/molecular mechanics techniques coupled to a dynamical averaging scheme. The explicit consideration of the three lowest-energy tautomers of adenine-H9, H7 and H3-allows for a...

  7. Modeling the high-energy electronic state manifold of adenine: Calibration for nonlinear electronic spectroscopy

    Nenov, Artur, E-mail: Artur.Nenov@unibo.it; Giussani, Angelo; Segarra-Martí, Javier; Jaiswal, Vishal K. [Dipartimento di Chimica “G. Ciamician,” Università di Bologna, Via Selmi 2, IT-40126 Bologna (Italy); Rivalta, Ivan [Université de Lyon, CNRS, Institut de Chimie de Lyon, École Normale Supérieure de Lyon, 46 Allée d’Italie, F-69364 Lyon Cedex 07 (France); Cerullo, Giulio [Dipartimento di Fisica, Politecnico di Milano, IFN-CNR, Piazza Leonardo Da Vinci 32, IT-20133 Milano (Italy); Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States); Garavelli, Marco, E-mail: marco.garavelli@unibo.it, E-mail: marco.garavelli@ens-lyon.fr [Dipartimento di Chimica “G. Ciamician,” Università di Bologna, Via Selmi 2, IT-40126 Bologna (Italy); Université de Lyon, CNRS, Institut de Chimie de Lyon, École Normale Supérieure de Lyon, 46 Allée d’Italie, F-69364 Lyon Cedex 07 (France)

    2015-06-07

    Pump-probe electronic spectroscopy using femtosecond laser pulses has evolved into a standard tool for tracking ultrafast excited state dynamics. Its two-dimensional (2D) counterpart is becoming an increasingly available and promising technique for resolving many of the limitations of pump-probe caused by spectral congestion. The ability to simulate pump-probe and 2D spectra from ab initio computations would allow one to link mechanistic observables like molecular motions and the making/breaking of chemical bonds to experimental observables like excited state lifetimes and quantum yields. From a theoretical standpoint, the characterization of the electronic transitions in the visible (Vis)/ultraviolet (UV), which are excited via the interaction of a molecular system with the incoming pump/probe pulses, translates into the determination of a computationally challenging number of excited states (going over 100) even for small/medium sized systems. A protocol is therefore required to evaluate the fluctuations of spectral properties like transition energies and dipole moments as a function of the computational parameters and to estimate the effect of these fluctuations on the transient spectral appearance. In the present contribution such a protocol is presented within the framework of complete and restricted active space self-consistent field theory and its second-order perturbation theory extensions. The electronic excited states of adenine have been carefully characterized through a previously presented computational recipe [Nenov et al., Comput. Theor. Chem. 1040–1041, 295-303 (2014)]. A wise reduction of the level of theory has then been performed in order to obtain a computationally less demanding approach that is still able to reproduce the characteristic features of the reference data. Foreseeing the potentiality of 2D electronic spectroscopy to track polynucleotide ground and excited state dynamics, and in particular its expected ability to provide

  8. Modeling the high-energy electronic state manifold of adenine: Calibration for nonlinear electronic spectroscopy

    Pump-probe electronic spectroscopy using femtosecond laser pulses has evolved into a standard tool for tracking ultrafast excited state dynamics. Its two-dimensional (2D) counterpart is becoming an increasingly available and promising technique for resolving many of the limitations of pump-probe caused by spectral congestion. The ability to simulate pump-probe and 2D spectra from ab initio computations would allow one to link mechanistic observables like molecular motions and the making/breaking of chemical bonds to experimental observables like excited state lifetimes and quantum yields. From a theoretical standpoint, the characterization of the electronic transitions in the visible (Vis)/ultraviolet (UV), which are excited via the interaction of a molecular system with the incoming pump/probe pulses, translates into the determination of a computationally challenging number of excited states (going over 100) even for small/medium sized systems. A protocol is therefore required to evaluate the fluctuations of spectral properties like transition energies and dipole moments as a function of the computational parameters and to estimate the effect of these fluctuations on the transient spectral appearance. In the present contribution such a protocol is presented within the framework of complete and restricted active space self-consistent field theory and its second-order perturbation theory extensions. The electronic excited states of adenine have been carefully characterized through a previously presented computational recipe [Nenov et al., Comput. Theor. Chem. 1040–1041, 295-303 (2014)]. A wise reduction of the level of theory has then been performed in order to obtain a computationally less demanding approach that is still able to reproduce the characteristic features of the reference data. Foreseeing the potentiality of 2D electronic spectroscopy to track polynucleotide ground and excited state dynamics, and in particular its expected ability to provide

  9. [Absolute bioavailability of the adenine derivative VMA-99-82 possessing antiviral activity].

    Smirnova, L A; Suchkov, E A; Riabukha, A F; Kuznetsov, K A; Ozerov, A A

    2013-01-01

    Investigation of the main pharmacokinetic parameters of adenine derivative VMA-99-82 in rats showed large values of the half-life (T1/2 = 11.03 h) and the mean retention time of drug molecules in the organism (MRT = 9.53 h). A high rate of the drug concentration decrease in the plasma determines a small value of the area under the pharmacokinetic curve (AUC = 74.96 mg h/ml). The total distribution volume (V(d) = 10.61 l/kg) is 15.8 times greater than the volume of extracellular fluid in the body of rat, which is indicative of a high ability of VMA-99-82 to be distributed and accumulated in the organs and tissues. The absolute bioavailability of VMA-99-82 is 66%. PMID:24605425

  10. Prebiotic Synthesis of Adenine and Amino Acids Under Europa-like Conditions

    Levy, Matthew; Miller, Stanley L.; Brinton, Karen; Bada, Jeffrey L.

    2003-01-01

    In order to simulate prebiotic synthetic processes on Europa and other ice-covered planets and satellites. we have investigated the prebiotic synthesis of organic compounds from dilute solutions of NH4CN frozen for 25 year at -20 and -78 C. In addition the aqueous products of spark discharge reactions from a reducing atmosphere were frozen for 5 years at -20%. We find that both adenine and guanine, as well as a simple set of amino acids dominated by glycine, are produced in substantial yields under these conditions. These results indicate that some of the key components necessary for the origin of life may have been available on Europa throughout its history and suggest that the circumstellar zone where life might arise may be m der than previously thought.

  11. Effect of adenine on bacterial translocation using technetium-99m labeled E. coli in an intestinal obstruction model in rats

    This study aims to investigate effects of adenine on bacterial translocation (BT) using 99mTc-labeled E. coli in an intestinal obstruction rat model. In the study twenty-one rats were used. The rats were divided into three groups according to different feeding patterns. The control group (CG) was fed with a standard chow diet for 7 days. Group A1 and group A2 were fed with adenine supplemented chow diet for 7 days. At the end of the feeding period, after all groups was submitted intestinal obstruction. 99mTc-E. coli was injected into the rats' terminal ileum under anesthetic. The rats were sacrificed under aseptic conditions at 24th h after the surgery. The uptake of 99mTc-E. coli was determined in organs such as the liver, mesenteric lymph nodes, spleen and ileum. Group A1 and group A2 results show that the uptake of 99mTc-E. coli decreased in the blood and organs comparing to the CG. As a result, it was observed that adenine reduced the level of BT when compared with CG. The beneficial effect of adenine on BT in intestinal obstruction was observed. However, further studies are needed to more clearly assess how this benefit can be achieved. (author)

  12. The effects of tautomerization and protonation on the adenine-cytosine mismatches: a density functional theory study.

    Masoodi, Hamid Reza; Bagheri, Sotoodeh; Abareghi, Mahsa

    2016-06-01

    In the present work, we demonstrate the results of a theoretical study concerned with the question how tautomerization and protonation of adenine affect the various properties of adenine-cytosine mismatches. The calculations, in gas phase and in water, are performed at B3LYP/6-311++G(d,p) level. In gas phase, it is observed that any tautomeric form of investigated mismatches is more stabilized when adenine is protonated. As for the neutral mismatches, the mismatches containing amino form of cytosine and imino form of protonated adenine are more stable. The role of aromaticity on the stability of tautomeric forms of mismatches is investigated by NICS(1)ZZ index. The stability of mispairs decreases by going from gas phase to water. It can be explained using dipole moment parameter. The influence of hydrogen bonds on the stability of mismatches is examined by atoms in molecules and natural bond orbital analyses. In addition to geometrical parameters and binding energies, the study of the topological properties of electron charge density aids in better understanding of these mispairs. PMID:26198186

  13. Adenine adsorption on Au(1 1 1) and Au(1 0 0) electrodes: Characterisation, surface reconstruction effects and thermodynamic study

    Adsorption of adenine on Au(1 1 1) and Au(1 0 0) electrodes is studied by cyclic voltammetry, impedance and chronoamperometric measurements in 0.1 M and 0.01 M KClO4 and in 0.5 M NaF solutions. The experiments performed with flame-annealed electrodes at different contact potentials, scan potential limits and scan rates, suggest different adsorption behaviour on the unreconstructed and reconstructed surface domains. This is confirmed by comparing the results obtained with electrochemically annealed unreconstructed and with flame-annealed reconstructed surfaces. In both cases the initial electrode surface state is characterised by the E pzc values. The adsorption on reconstructed surfaces takes place at more positive potentials than on the unreconstructed surfaces and induces the lifting of the reconstruction. The thermodynamic analysis is performed on the chronoamperometric data for adenine desorption on well characterised unreconstructed Au(1 1 1) surfaces. To this end a new methodology of the chronoamperometric experiments is introduced. Quantitative thermodynamic adsorption parameters such as surface tension, Gibbs surface excess, Gibbs energy of adsorption, potential versus Gibbs excess slope and electrosorption valency are determined. Weak chemisorption of adenine is inferred with a molecular orientation independent on the coverage and on the electrode potential. It is proposed that adsorbed adenine molecules adopt a tilted orientation at the surface to facilitate the coordination to the gold atoms

  14. [Corrective effect of trimethylglycine on the nicotinamide coenzyme and adenine nucleotide content of the tissues in experimental atherosclerosis].

    Zapadniuk, V I; Chekman, I S; Panteleĭmonova, T N; Tumanov, V A

    1986-01-01

    Experiments on adult rabbits with experimental atherosclerosis induced by cholesterol (0.25 g/kg for 90 days) showed that chronic administration of trimethylglycine (1.5 g/kg for 30 days) prevented a decrease of the liver and myocardium content of nicotinamide coenzymes and adenine nucleotides. PMID:3758334

  15. Thermodynamic potential for the abiotic synthesis of Adenine, Cytosine, Guanine, Thymine, Uracil, Ribose, and Deoxyribose in hydrothermal systems

    Larowe, D. E.; Regnier, P.

    2008-01-01

    The thermodynamic potential for the abiotic synthesis of the five common nucleobases (adenine, cytosine, guanine, thymine, and uracil) and two monosaccharides (ribose and deoxyribose) from formaldehyde and hydrogen cyanide has been quantified under temperature, pressure, and bulk composition conditions that are representative of hydrothermal systems. The activities of the precursor molecules (formaldehyde and hydrogen cyanide) required to evaluate the thermodynamics of biomolecule synthesis w...

  16. The cyclic di-nucleotide c-di-AMP is an allosteric regulator of metabolic enzyme function

    Precit, Mimi; Delince, Matthieu; Pensinger, Daniel; Huynh, TuAnh Ngoc; Jurado, Ashley R.; Goo, Young Ah; Sadilek, Martin; Iavarone, Anthony T.; Sauer, John-Demian; Tong, Liang; Woodward, Joshua J.

    2014-01-01

    SUMMARY Cyclic di-adenosine monophosphate (c-di-AMP) is a broadly conserved second messenger required for bacterial growth and infection. However, the molecular mechanisms of c-di-AMP signaling are still poorly understood. Using a chemical proteomics screen for c-di-AMP interacting proteins in the pathogen Listeria monocytogenes, we identified several broadly conserved protein receptors, including the central metabolic enzyme pyruvate carboxylase (LmPC). Biochemical and crystallographic studies of the LmPC-c-di-AMP interaction revealed a previously unrecognized allosteric regulatory site 25 Å from the active site. Mutations in this site disrupted c-di-AMP binding and affected enzyme catalysis of LmPC as well as PC from pathogenic Enterococcus faecalis. C-di-AMP depletion resulted in altered metabolic activity in L. monocytogenes. Correction of this metabolic imbalance rescued bacterial growth, reduced bacterial lysis, and resulted in enhanced bacterial burdens during infection. These findings greatly expand the c-di-AMP signaling repertoire and reveal a central metabolic regulatory role for a cyclic di-nucleotide. PMID:25215494

  17. Chemical synthesis, crystal structure and enzymatic evaluation of a dinucleotide spore photoproduct analogue containing a formacetal linker.

    Lin, Gengjie; Chen, Chun-Hsing; Pink, Maren; Pu, Jingzhi; Li, Lei

    2011-08-22

    Spore photoproduct (SP) is the exclusive DNA photodamage product found in bacterial endospores. Its photoformation and repair by a metalloenzyme spore photoproduct lyase (SPL) composes the unique SP biochemistry. Despite the fact that the SP was discovered almost 50 years ago, its crystal structure is still unknown and the lack of structural information greatly hinders the study of SP biochemistry. Employing a formacetal linker and organic synthesis, we successfully prepared a dinucleotide SP isostere 5R-CH(2) SP, which contains a neutral CH(2) moiety between the two thymine residues instead of a phosphate. The neutral linker dramatically facilitates the crystallization process, allowing us to obtain the crystal structure for this intriguing thymine dimer half a century after its discovery. Further ROESY spectroscopic, DFT computational, and enzymatic studies of this 5R-CH(2) SP compound prove that it possesses similar properties with the 5R-SP species, suggesting that the revealed structure truly reflects that of SP generated in Nature. PMID:21780208

  18. Adenine nucleotide-dependent and redox-independent control of mitochondrial malate dehydrogenase activity in Arabidopsis thaliana.

    Yoshida, Keisuke; Hisabori, Toru

    2016-06-01

    Mitochondrial metabolism is important for sustaining cellular growth and maintenance; however, the regulatory mechanisms underlying individual processes in plant mitochondria remain largely uncharacterized. Previous redox-proteomics studies have suggested that mitochondrial malate dehydrogenase (mMDH), a key enzyme in the tricarboxylic acid (TCA) cycle and redox shuttling, is under thiol-based redox regulation as a target candidate of thioredoxin (Trx). In addition, the adenine nucleotide status may be another factor controlling mitochondrial metabolism, as respiratory ATP production in mitochondria is believed to be influenced by several environmental stimuli. Using biochemical and reverse-genetic approaches, we addressed the redox- and adenine nucleotide-dependent regulation of mMDH in Arabidopsis thaliana. Recombinant mMDH protein formed intramolecular disulfide bonds under oxidative conditions, but these bonds did not have a considerable effect on mMDH activity. Mitochondria-localized o-type Trx (Trx-o) did not facilitate re-reduction of oxidized mMDH. Determination of the in vivo redox state revealed that mMDH was stably present in the reduced form even in Trx-o-deficient plants. Accordingly, we concluded that mMDH is not in the class of redox-regulated enzymes. By contrast, mMDH activity was lowered by adenine nucleotides (AMP, ADP, and ATP). Each adenine nucleotide suppressed mMDH activity with different potencies and ATP exerted the largest inhibitory effect with a significantly lower Ki. Correspondingly, mMDH activity was inhibited by the increase in ATP/ADP ratio within the physiological range. These results suggest that mMDH activity is finely controlled in response to variations in mitochondrial adenine nucleotide balance. PMID:26946085

  19. Probing the reaction mechanism of spore photoproduct lyase (SPL) via diastereoselectively labeled dinucleotide SP TpT substrates.

    Yang, Linlin; Lin, Gengjie; Liu, Degang; Dria, Karl J; Telser, Joshua; Li, Lei

    2011-07-13

    5-Thyminyl-5,6-dihydrothymine (commonly called spore photoproduct or SP) is the exclusive DNA photodamage product in bacterial endospores. It is generated in the bacterial sporulation phase and repaired by a radical SAM enzyme, spore photoproduct lyase (SPL), at the early germination phase. SPL utilizes a special [4Fe-4S] cluster to reductively cleave S-adenosylmethionine (SAM) to generate a reactive 5'-dA radical. The 5'-dA radical is proposed to abstract one of the two H-atoms at the C6 carbon of SP to initiate the repair process. Via organic synthesis and DNA photochemistry, we selectively labeled the 6-H(proS) or 6-H(proR) position with a deuterium in a dinucleotide SP TpT substrate. Monitoring the deuterium migration in enzyme catalysis (employing Bacillus subtilis SPL) revealed that it is the 6-H(proR) atom of SP that is abstracted by the 5'-dA radical. Surprisingly, the abstracted deuterium was not returned to the resulting TpT after enzymatic catalysis; an H-atom from the aqueous buffer was incorporated into TpT instead. This result questions the currently hypothesized SPL mechanism which excludes the involvement of protein residue(s) in SPL reaction, suggesting that some protein residue(s), which is capable of exchanging a proton with the aqueous buffer, is involved in the enzyme catalysis. Moreover, evidence has been obtained for a possible SAM regeneration after each catalytic cycle; however, such a regeneration process is more complex than currently thought, with one or even more protein residues involved as well. These observations have enabled us to propose a modified reaction mechanism for this intriguing DNA repair enzyme. PMID:21671623

  20. Rigid Adenine Nucleoside Derivatives as Novel Modulators of the Human Sodium Symporters for Dopamine and Norepinephrine.

    Janowsky, Aaron; Tosh, Dilip K; Eshleman, Amy J; Jacobson, Kenneth A

    2016-04-01

    Thirty-two congeneric rigid adenine nucleoside derivatives containing a North (N)-methanocarba ribose substitution and a 2-arylethynyl group either enhanced (up to 760% of control) or inhibited [(125)I] methyl (1R,2S,3S)-3-(4-iodophenyl)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate (RTI-55) binding at the human dopamine (DA) transporter (DAT) and inhibited DA uptake. Several nucleosides also enhanced [(3)H]mazindol [(±)-5-(4-chlorophenyl)-3,5-dihydro-2H-imidazo[2,1-a]isoindol-5-ol] binding to the DAT. The combination of binding enhancement and functional inhibition suggests possible allosteric interaction with the tropanes. The structure-activity relationship of this novel class of DAT ligands was explored: small N(6)-substition (methyl or ethyl) was favored, while the N1 of the adenine ring was essential. Effective terminal aryl groups include thien-2-yl (compounds 9 and 16), with EC50 values of 35.1 and 9.1 nM, respectively, in [(125)I]RTI-55 binding enhancement, and 3,4-difluorophenyl as in the most potent DA uptake inhibitor (compound 6) with an IC50 value of 92 nM (3-fold more potent than cocaine), but not nitrogen heterocycles. Several compounds inhibited or enhanced binding at the norepinephrine transporter (NET) and serotonin transporter (SERT) and inhibited function in the micromolar range; truncation at the 4'-position in compound 23 allowed for weak inhibition of the SERT. We have not yet eliminated adenosine receptor affinity from this class of DAT modulators, but we identified modifications that remove DAT inhibition as an off-target effect of potent adenosine receptor agonists. Thus, we have identified a new class of allosteric DAT ligands, rigidified adenosine derivatives, and explored their initial structural requirements. They display a very atypical pharmacological profile, i.e., either enhancement by increasing affinity or inhibition of radioligand binding at the DAT, and in some cases the NET and SERT, and inhibition of neurotransmitter

  1. Rigid Adenine Nucleoside Derivatives as Novel Modulators of the Human Sodium Symporters for Dopamine and Norepinephrine

    Tosh, Dilip K.; Eshleman, Amy J.; Jacobson, Kenneth A.

    2016-01-01

    Thirty-two congeneric rigid adenine nucleoside derivatives containing a North (N)-methanocarba ribose substitution and a 2-arylethynyl group either enhanced (up to 760% of control) or inhibited [125I] methyl (1R,2S,3S)-3-(4-iodophenyl)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate (RTI-55) binding at the human dopamine (DA) transporter (DAT) and inhibited DA uptake. Several nucleosides also enhanced [3H]mazindol [(±)-5-(4-chlorophenyl)-3,5-dihydro-2H-imidazo[2,1-a]isoindol-5-ol] binding to the DAT. The combination of binding enhancement and functional inhibition suggests possible allosteric interaction with the tropanes. The structure-activity relationship of this novel class of DAT ligands was explored: small N6-substition (methyl or ethyl) was favored, while the N1 of the adenine ring was essential. Effective terminal aryl groups include thien-2-yl (compounds 9 and 16), with EC50 values of 35.1 and 9.1 nM, respectively, in [125I]RTI-55 binding enhancement, and 3,4-difluorophenyl as in the most potent DA uptake inhibitor (compound 6) with an IC50 value of 92 nM (3-fold more potent than cocaine), but not nitrogen heterocycles. Several compounds inhibited or enhanced binding at the norepinephrine transporter (NET) and serotonin transporter (SERT) and inhibited function in the micromolar range; truncation at the 4′-position in compound 23 allowed for weak inhibition of the SERT. We have not yet eliminated adenosine receptor affinity from this class of DAT modulators, but we identified modifications that remove DAT inhibition as an off-target effect of potent adenosine receptor agonists. Thus, we have identified a new class of allosteric DAT ligands, rigidified adenosine derivatives, and explored their initial structural requirements. They display a very atypical pharmacological profile, i.e., either enhancement by increasing affinity or inhibition of radioligand binding at the DAT, and in some cases the NET and SERT, and inhibition of neurotransmitter uptake

  2. Determination of guanine and adenine by high-performance liquid chromatography with a self-fabricated wall-jet/thin-layer electrochemical detector at a glassy carbon electrode.

    Zhou, Yaping; Yan, Hongling; Xie, Qingji; Yao, Shouzhuo

    2015-03-01

    A sensitive wall-jet/thin-layer amperometric electrochemical detector (ECD) coupled to high-performance liquid chromatography (HPLC) was developed for simultaneous determination of guanine (G) and adenine (A). The analytes were detected at a glassy carbon electrode (GCE) and the HPLC-ECD calibration curves showed good linearity (R(2)>0.997) under optimized conditions. Limits of detection for G and A are 0.6 nM and 1.4 nM (S/N=3), respectively, which are lower than those obtained with an UV-vis detector and a commercial electrochemical detector. We have successfully applied this HPLC-ECD to assess the contents of G and A in hydrochloric acid-digested calf thymus double-stranded DNA. In addition, we compared in detail the analysis of G and A by cyclic voltammetry (CV) and by the HPLC-ECD system on both bare GCE and electroreduced graphene oxide (ERGO) modified GCE. We found that the adsorption of G and A on the electrode surfaces can vary their anodic CV peaks and the competitive adsorption of G and A on the limited sites of the electrode surfaces can cause crosstalk effects on their anodic CV peak signals, but the HPLC-ECD system is insensitive to such electrode-adsorption and can give more reliable analytical results. PMID:25618679

  3. Conversion of adenine to 5-amino-4-pyrimidinylimidazole caused by acetyl capping during solid phase oligonucleotide synthesis.

    Rodriguez, Andrew A; Cedillo, Isaiah; McPherson, Andrew K

    2016-08-01

    The acetyl capping reaction used throughout solid phase oligonucleotide synthesis is meant to minimize n-1 deletionmer impurities by terminating sequences that fail to couple to a phosphoramidite. However, the reaction is also responsible for the formation of a number of impurities. One capping-related impurity has an additional mass of 98amu from the parent oligonucleotide. The n+98 amu impurity was found to result from modification of an adenine nucleobase. The structure of the impurity was determined by preparation of an oligonucleotide enriched in n+98 amu, enzymatic digestion to individual nucleosides, isolation of the pure nucleoside+98 amu species, crystallization, and X-ray crystallographic analysis. The n+98 amu impurity is an oligonucleotide in which one adenine residue has been converted to 5-amino-4-pyrimidinylimidazole. The mechanism of formation of the impurity was investigated, and a mechanism is proposed. PMID:27353533

  4. Adenine methylation in eukaryotes: Apprehending the complex evolutionary history and functional potential of an epigenetic modification.

    Iyer, Lakshminarayan M; Zhang, Dapeng; Aravind, L

    2016-01-01

    While N(6) -methyladenosine (m(6) A) is a well-known epigenetic modification in bacterial DNA, it remained largely unstudied in eukaryotes. Recent studies have brought to fore its potential epigenetic role across diverse eukaryotes with biological consequences, which are distinct and possibly even opposite to the well-studied 5-methylcytosine mark. Adenine methyltransferases appear to have been independently acquired by eukaryotes on at least 13 occasions from prokaryotic restriction-modification and counter-restriction systems. On at least four to five instances, these methyltransferases were recruited as RNA methylases. Thus, m(6) A marks in eukaryotic DNA and RNA might be more widespread and diversified than previously believed. Several m(6) A-binding protein domains from prokaryotes were also acquired by eukaryotes, facilitating prediction of potential readers for these marks. Further, multiple lineages of the AlkB family of dioxygenases have been recruited as m(6) A demethylases. Although members of the TET/JBP family of dioxygenases have also been suggested to be m(6) A demethylases, this proposal needs more careful evaluation. Also watch the Video Abstract. PMID:26660621

  5. Tools for DNA adenine methyltransferase identification analysis of nuclear organization during C. elegans development.

    Sharma, Rahul; Ritler, Dominic; Meister, Peter

    2016-04-01

    C. elegans has recently emerged as a valuable model to understand the link between nuclear organization and cell fate, by combining microscopy approaches, genome-wide mapping techniques with advanced genetics. Crucial to these analyses are techniques to determine the genome-wide interaction pattern of proteins with DNA. Chromatin immunoprecipitation has proven valuable but it requires considerable amounts of starting material. This is sometimes difficult to achieve, in particular for specific genotypes (balanced strains, different sexes, severe phenotypes…). As an alternative to ChIP, DNA adenine methyltransferase identification by sequencing (DamID-seq) was recently shown to be able to characterize binding sites in single mammalian cells. Additionally, DamID can be achieved for cell-type specific analysis by expressing Dam fusion proteins under tissue specific promoters in a controlled manner. In this report, we present a user-friendly pipeline to analyse DamID-seq data in C. elegans. Based upon this pipeline, we provide a comparative analysis of libraries generated with different starting material and discuss important library features. Moreover, we introduce an adaptation of an imaging based tool to visualize in vivo the cell-specific tridimensional binding pattern of any protein of interest. genesis 54:151-159, 2016. © 2016 Wiley Periodicals, Inc. PMID:26845390

  6. DNA adenine methylation is required to replicate both Vibrio cholerae chromosomes once per cell cycle.

    Gaëlle Demarre

    2010-05-01

    Full Text Available DNA adenine methylation is widely used to control many DNA transactions, including replication. In Escherichia coli, methylation serves to silence newly synthesized (hemimethylated sister origins. SeqA, a protein that binds to hemimethylated DNA, mediates the silencing, and this is necessary to restrict replication to once per cell cycle. The methylation, however, is not essential for replication initiation per se but appeared so when the origins (oriI and oriII of the two Vibrio cholerae chromosomes were used to drive plasmid replication in E. coli. Here we show that, as in the case of E. coli, methylation is not essential for oriI when it drives chromosomal replication and is needed for once-per-cell-cycle replication in a SeqA-dependent fashion. We found that oriII also needs SeqA for once-per-cell-cycle replication and, additionally, full methylation for efficient initiator binding. The requirement for initiator binding might suffice to make methylation an essential function in V. cholerae. The structure of oriII suggests that it originated from a plasmid, but unlike plasmids, oriII makes use of methylation for once-per-cell-cycle replication, the norm for chromosomal but not plasmid replication.

  7. Oral, subcutaneous, and intramuscular bioavailabilities of the antiviral nucleotide analog 9-(2-phosphonylmethoxyethyl) adenine in cynomolgus monkeys.

    Cundy, K C; Shaw, J P; Lee, W A

    1994-01-01

    Intravenous, subcutaneous, intramuscular, and oral pharmacokinetics of the antiretroviral nucleotide analog [9-(2-phosphonylmethoxyethyl)adenine] (PMEA) were examined in a crossover study with four cynomolgus monkeys using 14C-labelled drug at 10 mg/kg of body weight (20 microCi/kg). Plasma radioactivity declined biexponentially following intravenous administration. Radiochromatography of plasma revealed an absence of PMEA metabolites. Intramuscular and subcutaneous bioavailabilities of PMEA ...

  8. N-6-Adenine-Specific DNA Methyltransferase 1 (N6AMT1) Polymorphisms and Arsenic Methylation in Andean Women

    Harari, Florencia; Engström, Karin; Concha, Gabriela; Colque, Graciela; Vahter, Marie; Broberg, Karin

    2013-01-01

    BACKGROUND: In humans, inorganic arsenic is metabolized to methylated metabolites mainly by arsenic (+3 oxidation state) methyltransferase (AS3MT). AS3MT polymorphisms are associated with arsenic metabolism efficiency. Recently, a putative N-6-adenine-specific DNA methyltransferase 1 (N6AMT1) was found to methylate arsenic in vitro. OBJECTIVE: We evaluated the role of N6AMT1 polymorphisms in arsenic methylation efficiency in humans. METHODS: We assessed arsenic methylation efficiency in 188 w...

  9. N6-benzyl and phenyl substituted adenines and their use as cosmetics, pharmaceutical preparations and plant growth regulators

    Doležal, K. (Karel); Popa, I.; Holub, J.; Lenobel, R.; Werbrouck, S.; M. Strnad; Zatloukal, M.

    2012-01-01

    New heterocyclic derivatives based on N6-substituted adenine, having anticancer, mitotic, imunosuppressive and antisenescent propoerties for plant, animal and human cells and methods of their preparation. Included are also pharmaceutical compositions, cosmetic preparations and growth regulators, which contain these derivatives as active compound and the use of these derivatives for the preparation of drugs, cosmetic preparations, in biotechnological processes, in cosmetics and in agricu...

  10. Dispensability of the [4Fe-4S] cluster in novel homologues of adenine glycosylase MutY.

    Trasviña-Arenas, Carlos H; Lopez-Castillo, Laura M; Sanchez-Sandoval, Eugenia; Brieba, Luis G

    2016-02-01

    7,8-Dihydro-8-deoxyguanine (8oG) is one of the most common oxidative lesions in DNA. DNA polymerases misincorporate an adenine across from this lesion. Thus, 8oG is a highly mutagenic lesion responsible for G:C→T:A transversions. MutY is an adenine glycosylase, part of the base excision repair pathway that removes adenines, when mispaired with 8oG or guanine. Its catalytic domain includes a [4Fe-4S] cluster motif coordinated by cysteinyl ligands. When this cluster is absent, MutY activity is depleted and several studies concluded that the [4Fe-4S] cluster motif is an indispensable component for DNA binding, substrate recognition and enzymatic activity. In the present study, we identified 46 MutY homologues that lack the canonical cysteinyl ligands, suggesting an absence of the [4Fe-4S] cluster. A phylogenetic analysis groups these novel MutYs into two different clades. One clade is exclusive of the order Lactobacillales and another clade has a mixed composition of anaerobic and microaerophilic bacteria and species from the protozoan genus Entamoeba. Structural modeling and sequence analysis suggests that the loss of the [4Fe-4S] cluster is compensated by a convergent solution in which bulky amino acids substitute the [4Fe-4S] cluster. We functionally characterized MutYs from Lactobacillus brevis and Entamoeba histolytica as representative members from each clade and found that both enzymes are active adenine glycosylases. Furthermore, chimeric glycosylases, in which the [4Fe-4S] cluster of Escherichia coli MutY is replaced by the corresponding amino acids of LbY and EhY, are also active. Our data indicates that the [4Fe-4S] cluster plays a structural role in MutYs and evidences the existence of alternative functional solutions in nature. PMID:26613369

  11. Long-term incorporation of tritiated adenine into deoxyribonucleic acid and ribonucleic acid by Treponema pallidum (Nichols strain).

    Norris, S J; Miller, J N; Sykes, J A

    1980-01-01

    Treponema pallidum (Nichols strain), extracted in medium containing Eagle minimal essential medium 50% fresh, heat-inactivated normal rabbit serum, and 1.0 mM dithiothreitol, was incubated under 3% oxygen in the presence of tritiated nucleic acid precursors. [8-3H]adenine was incorporated with high efficiency into trichloroacetic acid-insoluble material; 2'-deoxyadenosine and uridine were incorporated in lower quantities, and thymine and thymidine were not incorporated. Incorporation of [3H]a...

  12. Back Electron Transfer Suppresses the Periodic Length Dependence of DNA-mediated Charge Transport Across Adenine Tracts

    Genereux, Joseph C.; Augustyn, Katherine E.; Davis, Molly L.; Shao, Fangwei; Barton, Jacqueline K.

    2008-01-01

    DNA-mediated charge transport (CT) is exquisitely sensitive to the integrity of the bridging π-stack and is characterized by a shallow distance dependence. These properties are obscured by poor coupling between the donor/acceptor pair and the DNA bridge, or by convolution with other processes. Previously, we found a surprising periodic length dependence for the rate of DNA-mediated CT across adenine tracts monitored by 2-aminopurine fluorescence. Here we report a similar periodicity by monito...

  13. ADENYLATE ENERGY CHARGE AND ADENINE NUCLEOTIDE MEASUREMENTS AS INDICATORS OF STRESS IN THE MUSSEL, MYTILUS EDULIS, TREATED WITH DREDGED MATERIAL UNDER LABORATORY CONDITIONS

    Adenylate energy charge is an indication of the amount of energy available to an organism from the adenylate pool. t is calculated from measured concentrations of three adenine nucleotides, adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP...

  14. Investigations on the performance of poly(o-anisidine)/graphene nanocomposites for the electrochemical detection of NADH

    Sangamithirai, D. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India); Narayanan, V. [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600025 (India); Muthuraaman, B. [Department of Energy, University of Madras, Guindy Campus, Chennai 600025 (India); Stephen, A., E-mail: stephen_arum@hotmail.com [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600025 (India)

    2015-10-01

    The electrocatalytic oxidation of dihydronicotinamide adenine dinucleotide (NADH) based on poly(o-anisidine)/graphene (POA/GR) nanocomposites modified glassy carbon electrode (GCE) was explored for the first time. POA/GR nanocomposites were synthesized via chemical oxidative polymerization method. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and UV–Vis spectroscopy results demonstrate that nanocomposites are successfully synthesized. An intriguing composite structure was observed using different ratios of o-anisidine monomer and graphene. The electrical properties and electrochemical properties of these nanocomposites are investigated by impedance spectroscopy technique and cyclic voltammetric (CV) method, respectively. The synthesized nanocomposites were used to modify glassy carbon electrode (GCE), and the modified electrodes were found to exhibit electrocatalytic activity for oxidation of NADH at low potential range of + 0.045 V in a neutral environment. The fabricated sensor based on POA/GR31-modified GCE exhibited enhanced current response with very high sensitivity of 47.1 μA μM{sup −1} for the detection of NADH. The developed POA/GR-modified GCE exhibited excellent reproducibility, stability, and selectivity for the determination of NADH. The practical analytical utility of the proposed method was demonstrated by NADH spiked ascorbic acid (AA) and the results confirmed that the proposed method is suitable for the determination of NADH in the presence of AA. This can open up new opportunities for simple and selective detection of NADH and provide a promising platform for biosensor designs. - Highlights: • NADH sensor was prepared by poly(o-anisidine)/graphene nanocomposite modified GCE. • FESEM technique revealed the growth of POA nanofibers on the surface of graphene. • Good

  15. DNA synthesis and cell survival after X-irradiation of mammalian cells treated with caffeine or adenine

    The expression of the transient depression in the rate of DNA synthesis normally observed after exposure of randomly-dividing Chinese hamster V-79 or Chinese hamster CHO cells to ionizing radiation could be postponed by a post-irradiation treatment with 1.0 to 2.0 mM adenine or 1.5 mM caffeine. Caffeine may exert its effect by creating additional sites for replication in irradiated cells. Cells treated with caffeine or adenine for 2 or 4 hours after exposure to 3000 rad of 300 kVp X-rays exhibited depressed synthesis only after the removal of caffeine or adenine. These alterations in the timing of the X-ray-induced depression of the rate of DNA synthesis had no effect on X-ray-induced cell killing. Although a 4 hour post-irradiation treatment of randomly-dividing Chinese hamster V-79 cells with 1.0 or 2.0 mM caffeine potentiated X-ray-induced cell killing, this reduction in survival was due primarily to effects on cells not in S-phase. (author)

  16. Engineered tryptophan in the adenine-binding pocket of catalytic subunit A of A-ATP synthase demonstrates the importance of aromatic residues in adenine binding, forming a tool for steady-state and time-resolved fluorescence spectroscopy

    The crystallographic structures of the subunit B mutants F427W and F508W of the Pyrococcus horikoshii OT3 of the A1AO ATP synthase reveal that the exact volume of the adenine ribose binding pocket is essential for ATP-/ADP-binding. A reporter tryptophan residue was individually introduced by site-directed mutagenesis into the adenine-binding pocket of the catalytic subunit A (F427W and F508W mutants) of the motor protein A1AO ATP synthase from Pyrococcus horikoshii OT3. The crystal structures of the F427W and F508W mutant proteins were determined to 2.5 and 2.6 Å resolution, respectively. The tryptophan substitution caused the fluorescence signal to increase by 28% (F427W) and 33% (F508W), with a shift from 333 nm in the wild-type protein to 339 nm in the mutant proteins. Tryptophan emission spectra showed binding of Mg-ATP to the F427W mutant with a Kd of 8.5 µM. In contrast, no significant binding of nucleotide could be observed for the F508W mutant. A closer inspection of the crystal structure of the F427W mutant showed that the adenine-binding pocket had widened by 0.7 Å (to 8.70 Å) in comparison to the wild-type subunit A (8.07 Å) owing to tryptophan substitution, as a result of which it was able to bind ATP. In contrast, the adenine-binding pocket had narrowed in the F508W mutant. The two mutants presented demonstrate that the exact volume of the adenine ribose binding pocket is essential for nucleotide binding and even minor narrowing makes it unfit for nucleotide binding. In addition, structural and fluorescence data confirmed the viability of the fluorescently active mutant F427W, which had ideal tryptophan spectra for future structure-based time-resolved dynamic measurements of the catalytic subunit A of the ATP-synthesizing enzyme A-ATP synthase

  17. Determination of the major tautomeric form of the covalently modified adenine in the (+)-CC-1065-DNA adduct by 1H and 15N NMR studies

    (+)-CC-1065 is an extremely potent antitumor antibiotic produced by Streptomyces zelensis. The potent cytotoxic effects of the drug are thought to be due to the formation of a covalent adduct with DNA through N3 of adenine. Although the covalent linkage sites between (+)-CC-1065 and DNA have been determined, the tautomeric form of the covalently modified adenine in the (+)-CC-1065-DNA duplex adduct was not defined. The [6-15N]deoxyadenosine-labeled 12-mer duplex adduct was then studied by 1H and 15N NMR. One-dimensional NOE difference and two-dimensional NOESY 1H NMR experiments on the nonisotopically labeled 12-mer duplex adduct demonstrate that the 6-amino protons of the covalently modified adenine exhibit two signals at 9.19 and 9.08 ppm. Proton NMR experiments on the [6-15N]deoxyadenosine-labeled 12-mer duplex adduct show that the two resonance signals for adenine H6 observed on the nonisotopically labeled duplex adduct were split into doublets by the 15N nucleus with coupling constants of 91.3 Hz for non-hydrogen-bonded and 86.8 Hz for hydrogen-bonded amino protons. The authors conclude that the covalently modified adenine N6 of the (+)-CC-1065-12-mer duplex adduct is predominantly in the doubly protonated form, in which calculations predict that the C6-N6 bond is shortened and the positive charge is delocalized over the entire adenine molecule

  18. 腺嘌呤致不同性别大鼠骨质疏松的差异%Sex Difference in Osteopenia Induced by Adenine in Rats

    小切间猛史; 田野香; 金原正幸; 高明; 王晓明; 郭义; 张艳军; 郭利平; 石田寅夫

    2005-01-01

    Adenine, which is common and essential to creatures, is widely used in clinical field. However,abundance of adenine is harmful to the living body. So far the male animals have been used for the research on adenine influence. In male rats, feeding of adenine-rich diet induces renal failure. Because of very few studies of adenine influence to female animals, we investigated the influence of adenine treatment between male and female rats and discussed the sex difference on adenine treatment. Young male and female rats were administrated each adjusted adenine (6, 50 and 100 mg/mL) for 8 weeks (3 times/week). In male rats, the renal failure was induced by 100 mg/mL adenine treatment and renal dysfunction was induced by 50 mg/mL adenine treatment. In female rats, however renal dysfunction was induced by 100 mg/mL group only, and that was somewhat different compared to that in male rats.Serum testosterone level and BMD in male rats were decreased by adenine treatment with or without renal dysfunction. On the contrary, serum 17-beta estradiol level and BMD in female rats were not affected by adenine treatment at all regardless of renal dysfunction. As abovementioned, this study could shed light on adenine effect on bone metabolism through sex hormone synthesis. Adenine is commonly contained in clinical medicines and general food. Abundant ingestion of nucleic acid including adenine may affect the internal secretion function.%肌酸尿时多见而又为主要病因的腺嘌呤广泛地应用于临床,但是腺嘌呤过多对人体是有害的.到目前为止,只有应用雄性动物研究腺嘌呤影响的报告.在雄鼠发现喂饲富含腺嘌呤的饲料会引起肾衰竭.由于腺嘌呤对雌性动物的影响的报告还甚少,本实验研究了腺嘌呤处理对不同性别大鼠的影响,并进行了讨论.年轻雄性和雌性大鼠分别给与一种预定浓度的腺嘌呤(6、60及100mg/mL)共8周(3次/周).结果100mg/mL腺嘌呤处理能引起雄鼠肾衰,50mg/m

  19. Detecting ricin: sensitive luminescent assay for ricin A-chain ribosome depurination kinetics.

    Sturm, Matthew B; Schramm, Vern L

    2009-04-15

    Ricin is a family member of the lethal ribosome-inactivating proteins (RIP) found in plants. Ricin toxin A-chain (RTA) from castor beans catalyzes the hydrolytic depurination of a single base from a GAGA tetraloop of eukaryotic rRNA to release a single adenine from the sarcin-ricin loop (SRL). Protein synthesis is inhibited by loss of the elongation factor binding site resulting in cell death. We report a sensitive coupled assay for the measurement of adenine released from ribosomes or small stem-loop RNAs by RTA catalysis. Adenine phosphoribosyl transferase (APRTase) and pyruvate orthophosphate dikinase (PPDK) convert adenine to ATP for quantitation by firefly luciferase. The resulting AMP is cycled to ATP to give sustained luminescence proportional to adenine concentration. Subpicomole adenine quantitation permits the action of RTA on eukaryotic ribosomes to be followed in continuous, high-throughput assays. Facile analysis of RIP catalytic activity will have applications in plant toxin detection, inhibitor screens, mechanistic analysis of depurinating agents on oligonucleotides and intact ribosomes, and in cancer immunochemotherapy. Kinetic analysis of the catalytic action of RTA on rabbit reticulocyte 80S ribosomes establishes a catalytic efficiency of 2.6 x 10(8) M(-1) s(-1), a diffusion limited reaction indicating catalytic perfection even with large reactants. PMID:19364139

  20. An alternative membrane transport pathway for phosphate and adenine nucleotides in mitochondria and its possible function.

    Reynafarje, B; Lehninger, A L

    1978-10-01

    This paper describes the properties and a possible biological role of a transport process across the inner membrane of rat liver mitochondria resulting in the exchange of ATP(4-) (out) for ADP(3-) (in) + 0.5 phosphate(2-) (in). This transmembrane exchange reaction, designated as the ATP-ADP-phosphate exchange, is specific for the ligands shown, electroneutral, insensitive to N-ethylmaleimide or mersalyl, inhibited by atractyloside, and appears to occur only in the direction as written. It is thus distinct from the well-known phosphate-hydroxide and phosphate-dicarboxylate exchange systems, which are inhibited by mersalyl, and from the ATP-ADP exchanger, which does not transport phosphate. During ATP hydrolysis by mitochondria, half of the phosphate formed from ATP passes from the matrix to the medium by the mersalyl-insensitive ATP-ADP-phosphate exchange and the other half by the well-known mersalyl-sensitive phosphate-hydroxide exchange. These and other considerations have led to a hypothesis for the pathway and stoichiometry of ATP-dependent reverse electron transport, characterized by a requirement of 1.33 molecules of ATP per pair of electrons reversed and by the utilization of a different membrane transport pathway for phosphate and adenine nucleotides than is taken in forward electron flow and oxidative phosphorylation. The possible occurrence of independent pathways for ATP-forming forward electron flow and ATP-consuming reverse electron flow is consonant with the fact that the opposing degradative and synthetic pathways in the central routes of cell metabolism generally have different pathways that are independently regulated. PMID:283393

  1. Two adenine nucleotide translocase paralogues involved in cell proliferation and spermatogenesis in the silkworm Bombyx mori.

    Ryohei Sugahara

    Full Text Available Mitochondrial adenine nucleotide translocase (ANT specifically acts in ADP/ATP exchange through the mitochondrial inner membrane. This transporter protein thereby plays a significant role in energy metabolism in eukaryotic cells. Most mammals have four paralogous ANT genes (ANT1-4 and utilize these paralogues in different types of cells. The fourth paralogue of ANT (ANT4 is present only in mammals and reptiles and is exclusively expressed in testicular germ cells where it is required for meiotic progression in the spermatocytes. Here, we report that silkworms harbor two ANT paralogues, the homeostatic paralogue (BmANTI1 and the testis-specific paralogue (BmANTI2. The BmANTI2 protein has an N-terminal extension in which the positions of lysine residues in the amino acid sequence are distributed as in human ANT4. An expression analysis showed that BmANTI2 transcripts were restricted to the testis, suggesting the protein has a role in the progression of spermatogenesis. By contrast, BmANTI1 was expressed in all tissues tested, suggesting it has an important role in homeostasis. We also observed that cultured silkworm cells required BmANTI1 for proliferation. The ANTI1 protein of the lepidopteran Plutella xylostella (PxANTI1, but not those of other insect species (or PxANTI2, restored cell proliferation in BmANTI1-knockdown cells suggesting that ANTI1 has similar energy metabolism functions across the Lepidoptera. Our results suggest that BmANTI2 is evolutionarily divergent from BmANTI1 and has developed a specific role in spermatogenesis similar to that of mammalian ANT4.

  2. Inhibition of the adenine nucleotide translocator by N-acetyl perfluorooctane sulfonamides in vitro.

    O'Brien, Timothy M; Oliveira, Paulo J; Wallace, Kendall B

    2008-03-01

    N-alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire retardants, and anti-corrosion agents, among many other commercial applications. The global distribution and environmental persistence of these compounds has generated considerable interest regarding potential toxic effects. We have previously reported that perfluorooctanesulfonamidoacetate (FOSAA) and N-ethylperfluorooctanesulfonamidoacetate (N-EtFOSAA) induce the mitochondrial permeability transition (MPT) in vitro. In this study we tested the hypothesis that FOSAA and N-EtFOSAA interact with the adenine nucleotide translocator (ANT) resulting in a functional inhibition of the translocator and induction of the MPT. Respiration and membrane potential of freshly isolated liver mitochondria from Sprague-Dawley rats were measured using an oxygen electrode and a tetraphenylphosphonium-selective (TPP(+)) electrode, respectively. Mitochondrial swelling was measured spectrophotometrically. The ANT ligands bongkregkic acid (BKA) and carboxyatractyloside (cATR) inhibited uncoupling of mitochondrial respiration caused by 10 microM N-EtFOSAA, 40 microM FOSAA, and the positive control 8 microM oleic acid. ADP-stimulated respiration and depolarization of mitochondrial membrane potential were inhibited by cATR, FOSAA, N-EtFOSAA, and oleic acid, but not by FCCP. BKA inhibited calcium-dependent mitochondrial swelling induced by FOSAA, N-EtFOSAA, and oleic acid. Seventy-five micromolar ADP also inhibited swelling induced by the test compounds, but cATR induced swelling was not inhibited by ADP. Results of this investigation indicate that N-acetyl perfluorooctane sulfonamides interact directly with the ANT to inhibit ADP translocation and induce the MPT, one or both of which may account for the metabolic dysfunction observed in vivo. PMID:18048072

  3. Deficiency in the mouse mitochondrial adenine nucleotide translocator isoform 2 gene is associated with cardiac noncompaction.

    Kokoszka, Jason E; Waymire, Katrina G; Flierl, Adrian; Sweeney, Katelyn M; Angelin, Alessia; MacGregor, Grant R; Wallace, Douglas C

    2016-08-01

    The mouse fetal and adult hearts express two adenine nucleotide translocator (ANT) isoform genes. The predominant isoform is the heart-muscle-brain ANT-isoform gene 1 (Ant1) while the other is the systemic Ant2 gene. Genetic inactivation of the Ant1 gene does not impair fetal development but results in hypertrophic cardiomyopathy in postnatal mice. Using a knockin X-linked Ant2 allele in which exons 3 and 4 are flanked by loxP sites combined in males with a protamine 1 promoter driven Cre recombinase we created females heterozygous for a null Ant2 allele. Crossing the heterozygous females with the Ant2(fl), PrmCre(+) males resulted in male and female ANT2-null embryos. These fetuses proved to be embryonic lethal by day E14.5 in association with cardiac developmental failure, immature cardiomyocytes having swollen mitochondria, cardiomyocyte hyperproliferation, and cardiac failure due to hypertrabeculation/noncompaction. ANTs have two main functions, mitochondrial-cytosol ATP/ADP exchange and modulation of the mitochondrial permeability transition pore (mtPTP). Previous studies imply that ANT2 biases the mtPTP toward closed while ANT1 biases the mtPTP toward open. It has been reported that immature cardiomyocytes have a constitutively opened mtPTP, the closure of which signals the maturation of cardiomyocytes. Therefore, we hypothesize that the developmental toxicity of the Ant2 null mutation may be the result of biasing the cardiomyocyte mtPTP to remain open thus impairing cardiomyocyte maturation and resulting in cardiomyocyte hyperproliferation and failure of trabecular maturation. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:27048932

  4. Human ciliary neurotrophic factor: Localization to the proximal region of the long arm of chromosome 11 and association with CA/GT dinucleotide repeat

    Lev, A.A.; Rosen, D.R.; Kos, C.; Brown, R.H. Jr.; Clifford, E.; Landes, G.; Hauser, S.L.

    1993-05-01

    Ciliary neurotrophic factor (CNTF) promotes survival and differentiation of several types of sensory, motor, sympathetic, and parasympathetic neurons. The authors have used the polymerase chain reaction to amplify, clone, and partially sequence CNTF cDNA from human muscle. Using a rodent-human mapping panel and fluorescence in situ hybridization, they have localized a single copy of the gene for human CNTF to the proximal long arm of chromosome 11. They have also identified a polymorphic tandem CA/GT dinucleotide repeat associated with the human CNTF gene. 14 refs., 1 fig.

  5. Modification of glassy carbon electrode with a polymer/mediator composite and its application for the electrochemical detection of iodate

    Highlights: ► FAD and PEDOT are combined to modify the glassy carbon electrode for IO3− sensing. ► The doping of FAD into PEDOT matrix can almost be viewed as an irreversible process. ► The optimal cycle number for preparing the GCE/PEDOT/FAD electrode is found to be 9. ► The detection limit of the GCE/PEDOT/FAD electrode for IO3− is found to be 0.16 μM. ► The GCE/PEDOT/FAD electrode possesses enough selectivity toward IO3−. - Abstract: A modified glassy carbon electrode was prepared by depositing a composite of polymer and mediator on a glassy carbon electrode (GCE). The mediator, flavin adenine dinucleotide (FAD) and the polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) were electrochemically deposited as a composite on the GCE by applying cyclic voltammetry (CV). This modified electrode is hereafter designated as GCE/PEDOT/FAD. FAD was found to significantly enhance the growth of PEDOT. Electrochemical quartz crystal microbalance (EQCM) analysis was performed to study the mass changes in the electrode during the electrodeposition of PEDOT, with and without the addition of FAD. The optimal cycle number for preparing the modified electrode was determined to be 9, and the corresponding surface coverage of FAD (ΓFAD) was ca. 5.11 × 10−10 mol cm−2. The amperometric detection of iodate was performed in a 100 mM buffer solution (pH 1.5). The GCE/PEDOT/FAD showed a sensitivity of 0.78 μA μM−1 cm−2, a linear range of 4–140 μM, and a limit of detection of 0.16 μM for iodate. The interference effects of 250-fold Na+, Mg2+, Ca2+, Zn2+, Fe2+, Cl−, NO3−, I−, SO42− and SO32−, with reference to the concentration of iodate were negligible. The long-term stability of GCE/PEDOT/FAD was also investigated. The GCE/PEDOT/FAD electrode retained 82% of its initial amperometric response to iodate after 7 days. The GCE/PEDOT/FAD was also applied to determine iodate in a commercial salt.

  6. Actinomyces and Nocardia Infections in Chronic Granulomatous Disease

    Shahindokht Bassiri-Jahromi; Aida Doostkam

    2011-01-01

    Objective : Chronic granulomatous disease (CGD) is an inherited disorder of the Nicotinamide adenine dinucleotide phosphate reduced oxidase complex characterized by recurrent bacterial and fungal infections. Disseminated infection by combination of opportunistic agents is being increasingly reported in CGD patients. We presented in the retrospective review of medical records, the etiology, presentation, clinical characteristics the infections detected, predisposing condition and outcome of no...

  7. Autoradiographic study on the incorporation of carbon-14 labeled formate and adenine into nucleic acid in blood-forming cells

    The incorporation of [14C]formate and [8-14C]adenine into nucleic acid in blood-forming cells was studied by the autoradiographic technique. The isotopic markers were injected subcutaneously into young rats weighting from 100 to 150 g three times every 24 hours and the animals were examined 3 hours after the last injection. In the case of [14C]formate injection, erythroblasts exhibited extremely strong labeling in contrast to weaker labeling of other blood-forming cells. In the case of [14C]adenine administration, on the other hand, immature cells of the granuclocytic series as well as immature reticulum cells (proliferating cells of reticular tissue) were much more heavily labeled than were other blood-forming cells, particularly the erythroblasts which revealed weak or no labeling. By digestion or extraction of DNA, RNA or both from cells with DNase, RNase or hot 10% perchloric acid treatment, respectively, it was confirmed that the observed heavy labeling of any type of cells with either [14C]formate or [14C]adenine was due chiefly to incorporation of the radioactive materials into nuclear DNA. The present results are discussed together with the findings of earlier studies on lymphoid cells which indicate that, in certain cell types, the patterns of [3H]deoxycytidine labeling differ considerably from the corresponding patterns of [3H]deoxycytidine labeling. The present and earlier findings provide evidence to substantiate that, among blood-forming cells, there are considerable variations in the labeling patterns of nuclear DNA depending on differences in the radioactive DNA precursors used as well as in the cell types. (author)

  8. Multiple Decay Mechanisms and 2D-UV Spectroscopic Fingerprints of Singlet Excited Solvated Adenine-Uracil Monophosphate.

    Li, Quansong; Giussani, Angelo; Segarra-Martí, Javier; Nenov, Artur; Rivalta, Ivan; Voityuk, Alexander A; Mukamel, Shaul; Roca-Sanjuán, Daniel; Garavelli, Marco; Blancafort, Lluís

    2016-05-23

    The decay channels of singlet excited adenine uracil monophosphate (ApU) in water are studied with CASPT2//CASSCF:MM potential energy calculations and simulation of the 2D-UV spectroscopic fingerprints with the aim of elucidating the role of the different electronic states of the stacked conformer in the excited state dynamics. The adenine (1) La state can decay without a barrier to a conical intersection with the ground state. In contrast, the adenine (1) Lb and uracil S(U) states have minima that are separated from the intersections by sizeable barriers. Depending on the backbone conformation, the CT state can undergo inter-base hydrogen transfer and decay to the ground state through a conical intersection, or it can yield a long-lived minimum stabilized by a hydrogen bond between the two ribose rings. This suggests that the (1) Lb , S(U) and CT states of the stacked conformer may all contribute to the experimental lifetimes of 18 and 240 ps. We have also simulated the time evolution of the 2D-UV spectra and provide the specific fingerprint of each species in a recommended probe window between 25 000 and 38 000 cm(-1) in which decongested, clearly distinguishable spectra can be obtained. This is expected to allow the mechanistic scenarios to be discerned in the near future with the help of the corresponding experiments. Our results reveal the complexity of the photophysics of the relatively small ApU system, and the potential of 2D-UV spectroscopy to disentangle the photophysics of multichromophoric systems. PMID:27113273

  9. Reactivity of nitrogen atoms in adenine and (Ade)2Cu complexes towards ribose and 2-furanmethanol: Formation of adenosine and kinetin.

    Nashalian, Ossanna; Yaylayan, Varoujan A

    2017-01-15

    To explore the interaction of nucleosides and nucleobases in the context of the Maillard reaction and to identify the selectivity of purine nitrogen atoms towards various electrophiles, model systems composed of adenine or adenosine, glycine, ribose and/or 2-furanmethanol (with and without copper) were studied in aqueous solutions heated at 110°C for 2h and subsequently analyzed by ESI/qTOF/MS/MS in addition to isotope labelling techniques. The results indicated that ribose selectively formed mono-ribosylated N(6) adenine, but in the presence of (Ade)2Cu complex the reaction mixture generated mono-, di- and tri-substituted sugar complexes and their hydrolysis products of mono-ribosylated N(6) and N(9) adenine adducts and di-ribosylated N(6,9) adenine. Furthermore, the reaction of 2-furanmethanol with adenine in the presence of ribose generated kinetin and its isomer, while its reaction with adenosine generated kinetin riboside, as confirmed by comparing the MS/MS profiles of these adducts to those of commercial standards. PMID:27542499

  10. Evaluation of Porin Interaction with Adenine Nucleotide Translocase and Cyclophilin-D Proteins after Brain Ischemia and Reperfusion

    Mohammad Ali Atlasi

    2011-01-01

    Full Text Available Objective (s Porin is a mitochondrial outer membrane channel, which usually functions as the pathway for the movement of various substances in and out of the mitochondria and is considered to be a component of the permeability transition (PT pore complex that plays a role in the PT. We addressed the hypothesis that porin interacts with other mitochondrial proteins after ischemic injury.Materials and MethodsFor this purpose, we used in vivo 4-vessel occlusion model of rat brain and porin purification method by hydroxyapatite column. After SDS gel electrophoresis and silver nitrate staining, Western blotting was done for porin, adenine nucleotide translocase and cyclophilin-D proteins.Results Porin was purified from mitochondrial mixture in ischemic brain and control groups. Investigation of interaction of adenine nucleotide transposes (ANT and cyclophilin-D with porin by Western blotting showed no proteins co-purified with porin from injured tissues.Conclusion The present study implies that there may not be interaction between porin, and ANT or cyclophilin-D, and if there is any, it is not maintained during the purification procedure.

  11. A weak pulsed magnetic field affects adenine nucleotide oscillations, and related parameters in aggregating Dictyostelium discoideum amoebae.

    Davies, E; Olliff, C; Wright, I; Woodward, A; Kell, D

    1999-02-01

    A model eukaryotic cell system was used to explore the effect of a weak pulsed magnetic field (PMF) on time-varying physiological parameters. Dictyostelium discoideum cells (V12 strain) were exposed to a pulsed magnetic field (PMF) of flux density 0.4 mT, generated via air-cored coils in trains of 2 ms pulses gated at 20 ms. This signal is similar to those used to treat non-uniting fractures. Samples were taken over periods of 20 min from harvested suspensions of amoebae during early aggregation phase, extracted and derivatised for HPLC fluorescent assay of adenine nucleotides. Analysis of variance showed a significant athermal damping effect (P < 0.002, n = 22) of the PMF on natural adenine nucleotide oscillations and some consistent changes in phase relationships. The technique of nonlinear dielectric spectroscopy (NLDS) revealed a distinctive effect of PMF, caffeine and EGTA in modulating the cellular harmonic response to an applied weak signal. Light scattering studies also showed altered frequency response of cells to PMF, EGTA and caffeine. PMF caused a significant reduction of caffeine induced cell contraction (P < 0.0006, n = 19 by paired t-test) as shown by Malvern particle size analyser, suggesting that intracellular calcium may be involved in mediating the effect of the PMF. PMID:10228582

  12. Characterization of a DNA Adenine Methyltransferase Gene of Borrelia hermsii and Its Dispensability for Murine Infection and Persistence

    James, Allison E.; Rogovskyy, Artem S.; Crowley, Michael A.; Bankhead, Troy

    2016-01-01

    DNA methyltransferases have been implicated in the regulation of virulence genes in a number of pathogens. Relapsing fever Borrelia species harbor a conserved, putative DNA methyltransferase gene on their chromosome, while no such ortholog can be found in the annotated genome of the Lyme disease agent, Borrelia burgdorferi. In the relapsing fever species Borrelia hermsii, the locus bh0463A encodes this putative DNA adenine methyltransferase (dam). To verify the function of the BH0463A protein product as a Dam, the gene was cloned into a Dam-deficient strain of Escherichia coli. Restriction fragment analysis subsequently demonstrated that complementation of this E. coli mutant with bh0463A restored adenine methylation, verifying bh0463A as a Dam. The requirement of bh0463A for B. hermsii viability, infectivity, and persistence was then investigated by genetically disrupting the gene. The dam- mutant was capable of infecting immunocompetent mice, and the mean level of spirochetemia in immunocompetent mice was not significantly different from wild type B. hermsii. Collectively, the data indicate that dam is dispensable for B. hermsii viability, infectivity, and persistence. PMID:27195796

  13. Targeted disruption of the mouse adenine phosphoribosyltransferase (aprt) gene and the production of APRT-deficient mice

    Engle, S.J.; Chen, J.; Tischfield, J.A. [Indiana Univ., School of Medicine, Indianapolis, IN (United States)] [and others

    1994-09-01

    Adenine phosphoribosyltransferase (APRT: EC 2.4.2.7), a ubiquitously expressed purine salvage enzyme, catalyzes the synthesis of AMP and inorganic pyrophosphate from existing adenine and 5-phosphoribosyl-1-pyrophosphate. Deficiency of this enzyme in humans results in the accumulation of 2,8-dihydroxyadenine leading to crystalluria and nephrolithiasis. In order to facilitate our study of this rare, autosomal recessive disorder, we applied the advances in gene targeting technology and mouse embryonic stem (ES) cell culture to the production of APRT-deficient mice. A positive-negative targeting strategy was used. The tageting vector contain 5.6 kb of the mouse APRT gene, a neomycin resistance gene in exon 3 as a positive selection marker, and a HSV thymidine kinase gene at the 3{prime} end of the homology as a negative selection marker. The vector was introduced into D3 ES cells by electroporation and the cells were selected for G418 and ganciclovir (GANC) resistance. G418-GANC resistant clones were screened by Southern blot. One of several correctly targeted clones was expanded and used for blastocyst microinjection to produce chimeric mice. Chimeric animals were bred and agouti progeny heterozygous for the targeted allele were obtained. Heterozygous animals have been bred to produce APRT-deficient animals. Matings are currently underway to determine the phenotype of APRT/HPRT-deficient animals.

  14. Molecular cloning and characterization of the gene encoding the adenine methyltransferase M.CviRI from Chlorella virus XZ-6E.

    Stefan, C; Xia, Y N; Van Etten, J L

    1991-01-01

    The gene encoding the DNA methyltransferase M.CviRI from Chlorella virus XZ-6E was cloned and expressed in Escherichia coli. M.CviRI methylates adenine in TGCA sequences. DNA containing the M.CviRI gene was sequenced and a single open reading frame of 1137 bp was identified which could code for a polypeptide of 379 amino acids with a predicted molecular weight of 42,814. Comparison of the M.CviRI predicted amino acid sequence with another Chlorella virus and 14 bacterial adenine methyltransfe...

  15. NMR study of stacking interactions and conformational adjustment in the dinucleotide-carcinogen adduct 2'-deoxycytidylyl-(3 → 5)-2'deoxy-8-(N-flouren-2-ylacetamido)guanosine

    The conformation and dynamics of the dinucleotide d-CpG modified at the C(8) position of the guanine ring by the carcinogen 2-(acetylamino)fluorene has been investigated by high-field 1H NMR spectroscopy. A two-state analysis of chemical shift data has enabled estimation of the extent of intramolecular stacking in aqueous solution as a function of temperature. The stacking, which is mostly fluorene-cytosine, is virtually complete in the low-temperature range. The 500-MHz 1H NMR spectrum consists of two subspectra near ambient temperatures due to a 14.3 +/- 0.3 kcal/mol barrier to internal rotation about the amide bond in the stacked form. Problems of self-association and chemical exchange were identified and overcome to enable analysis of the sugar-phosphate backbone conformation utilizing coupling constants. For the exocyclic C(4')-C(5') bond of the deoxyguanosine moiety, there is a high gauche+ conformer population, which is uncommon for a purine nucleotide with a syn orientation about the glycosyl bond. The gauche- conformation, which is normally present in syn purine nucleotides in solution, was not detected. The exocyclic C(5')-O(5') torsion of the deoxyguanosine moiety remains near the classical energy minimum in the major stacked conformations. The sugar ring of the deoxycytidine moiety is predominantly in the C2'-endo conformation, while the deoxyguanosine ring is a mixture of conformations, one of which appears to be unusually puckered. The results support intercalation models of modified DNA and suggest a looped-out structure, with the modified guanine being the first base in the loop. Such structures could explain the relatively rapid rate of repair and the frame-shift mutations of this type of adduct

  16. Preliminary evidence for an association of a dinucleotide repeat polymorphism at the MAOA gene with early onset alcoholism/substance abuse

    Vanyukov, M.M.; Moss, H.B.; Tarter, R.E. [Univ. of Pittsburg, PA (United States)] [and others

    1995-04-24

    An association between the liability to early onset alcoholism/substance abuse and a recently discovered dinucleotide repeat length polymorphism at the MAOA gene (MAOCA-1) was examined using polymerase chain reaction (PCR). A significant correlation between the presence/absence of the disorder and the length of the MAOCA-1 repeat was found in males, but not females, with {open_quotes}long{close_quotes} alleles (repeat length above 115 bp) associated with both increased risk for the disorder and lower age of onset of substance abuse. These preliminary data suggest that further exploration of the relationship between the MAOA gene and behavioral traits in an expanded sample is warranted. 22 refs., 1 fig., 3 tabs.

  17. Heterocyclic compounds based on N6-substituted adenine, methods of their preparation, their use for preparation of drugs, cosmetic preparations and growth regulators, pharmaceutical preparations, cosmetic preparations and growth regulators containing these compounds

    Zatloukal, M.; Lenobel, R.; Holub, J.; Doležal, K. (Karel); Werbrouck, S.; Popa, I.; M. Strnad

    2011-01-01

    Heterocyclic compounds based on N6 -substituted adenine, methods of their preparation, their use for preparation of drugs, cosmetic preparations and growth regulators, pharmaceutical preparations, cosmetic preparations and growth regulators containing these compounds New heterocyclic derivatives based on N6-substituted adenine, having anticancer, mitotic, imunosuppressive and antisenescent properties for plant, animal and human cells and methods of their preparation. Included are also pharmac...

  18. Demographic changes and marker properties affect detection of human population differentiation

    Sanichwankul Kittipong

    2007-05-01

    Full Text Available Abstract Background Differentiating genetically between populations is valuable for admixture and population stratification detection and in understanding population history. This is easy to achieve for major continental populations, but not for closely related populations. It has been claimed that a large marker panel is necessary to reliably distinguish populations within a continent. We investigated whether empirical genetic differentiation could be accomplished efficiently among three Asian populations (Hmong, Thai, and Chinese using a small set of highly variable markers (15 tetranucleotide and 17 dinucleotide repeats. Results Hmong could be differentiated from Thai and Chinese based on multi-locus genotypes, but Thai and Chinese were indistinguishable from each other. We found significant evidence for a recent population bottleneck followed by expansion in the Hmong that was not present in the Thai or Chinese. Tetranucleotide repeats were less useful than dinucleotide repeat markers in distinguishing between major continental populations (Asian, European, and African while both successfully distinguished Hmong from Thai and Chinese. Conclusion Demographic history contributes significantly to robust detection of intracontinental population structure. Populations having experienced a rapid size reduction may be reliably distinguished as a result of a genetic drift -driven redistribution of population allele frequencies. Tetranucleotide markers, which differ from dinucleotide markers in mutation mechanism and rate, are similar in information content to dinucleotide markers in this situation. These factors should be considered when identifying populations suitable for gene mapping studies and when interpreting interpopulation relationships based on microsatellite markers.

  19. Kinetics and thermodynamics of the reaction between the •OH radical and adenine – a theoretical investigation

    Milhøj, Birgitte Olai; Sauer, Stephan P. A.

    2015-01-01

    The accessibility of all possible reaction paths for the reaction between the nucleobase adenine and the •OH radical is investigated through quantum chemical calculations of barrier heights and rate constants at the wB97X-D/6-311++G(2df,2pd) level with Eckart tunneling corrections. First the...... Pople and Dunning basis sets, all of which have been employed in similar investigations in the literature. Improved energies are obtained through single point calculations with CCSD(T) and the same basis sets, and reaction rate constants are calculated for all methods both without tunneling corrections...... and with the Wigner, Bell and Eckart corrections. Compared to CCSD(T)//BHandHLYP/aug-cc-pVTZ reference results, the wB97XD/6-311++G(2df,2pd) method combined with Eckart tunneling corrections provides a sensible compromise between accuracy and time. Using this method all sub-reactions of the reaction...

  20. Hydrogen peroxide formation photoinduced by near-UV radiation in aqueous solutions of adenine derivatives at 77 K

    Lozinova, T. A.; Lobanov, A. V.; Lander, A. V.

    2015-08-01

    An estimate of the content of free radicals in aqueous solutions of adenosine (Ado), adenosine-5'-diphosphate (ADP) and guanosine-5'-monophosphate (GMP) irradiated with near-UV radiation at 77 K is obtained by interpreting EPR spectra. It is established that in the presence of NaCl (0.1 M), the total number of peroxyl radicals O{2/-·} and HO{2/·} in samples of the studied compounds was 15-45% of the total quantity of produced free radicals and was affected by the conditions of exposure. The estimates are compared with the results from hydrogen peroxide (H2O2) determination in the same samples after thawing. Although the number of peroxyl radicals in the samples of adenine derivatives (A) and GMP are comparable, the formation of H2O2 is observed only in the case of A derivatives, but not in GMP. Possible reasons for these differences are discussed.

  1. Dynamics of dipole- and valence bound anions in iodide-adenine binary complexes: A time-resolved photoelectron imaging and quantum mechanical investigation

    Dipole bound (DB) and valence bound (VB) anions of binary iodide-adenine complexes have been studied using one-color and time-resolved photoelectron imaging at excitation energies near the vertical detachment energy. The experiments are complemented by quantum chemical calculations. One-color spectra show evidence for two adenine tautomers, the canonical, biologically relevant A9 tautomer and the A3 tautomer. In the UV-pump/IR-probe time-resolved experiments, transient adenine anions can be formed by electron transfer from the iodide. These experiments show signals from both DB and VB states of adenine anions formed on femto- and picosecond time scales, respectively. Analysis of the spectra and comparison with calculations suggest that while both the A9 and A3 tautomers contribute to the DB signal, only the DB state of the A3 tautomer undergoes a transition to the VB anion. The VB anion of A9 is higher in energy than both the DB anion and the neutral, and the VB anion is therefore not accessible through the DB state. Experimental evidence of the metastable A9 VB anion is instead observed as a shape resonance in the one-color photoelectron spectra, as a result of UV absorption by A9 and subsequent electron transfer from iodide into the empty π-orbital. In contrast, the iodide-A3 complex constitutes an excellent example of how DB states can act as doorway state for VB anion formation when the VB state is energetically available

  2. Dynamics of dipole- and valence bound anions in iodide-adenine binary complexes: A time-resolved photoelectron imaging and quantum mechanical investigation

    Stephansen, Anne B. [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 København Ø (Denmark); King, Sarah B.; Li, Wei-Li; Kunin, Alice [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Yokoi, Yuki; Minoshima, Yusuke; Takayanagi, Toshiyuki [Department of Chemistry, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan); Neumark, Daniel M., E-mail: dneumark@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2015-09-14

    Dipole bound (DB) and valence bound (VB) anions of binary iodide-adenine complexes have been studied using one-color and time-resolved photoelectron imaging at excitation energies near the vertical detachment energy. The experiments are complemented by quantum chemical calculations. One-color spectra show evidence for two adenine tautomers, the canonical, biologically relevant A9 tautomer and the A3 tautomer. In the UV-pump/IR-probe time-resolved experiments, transient adenine anions can be formed by electron transfer from the iodide. These experiments show signals from both DB and VB states of adenine anions formed on femto- and picosecond time scales, respectively. Analysis of the spectra and comparison with calculations suggest that while both the A9 and A3 tautomers contribute to the DB signal, only the DB state of the A3 tautomer undergoes a transition to the VB anion. The VB anion of A9 is higher in energy than both the DB anion and the neutral, and the VB anion is therefore not accessible through the DB state. Experimental evidence of the metastable A9 VB anion is instead observed as a shape resonance in the one-color photoelectron spectra, as a result of UV absorption by A9 and subsequent electron transfer from iodide into the empty π-orbital. In contrast, the iodide-A3 complex constitutes an excellent example of how DB states can act as doorway state for VB anion formation when the VB state is energetically available.

  3. Stacked base-pair structures of adenine nucleosides stabilized by the formation of hydrogen-bonding network involving the two sugar groups

    Highlights: ► A combination of laser desorption and supersonic jet-cooling is used to produce base pairs of adenine nucleosides. ► Stacked base-pair structure of N6,N6-dimethyladnosine is identified by IR vibrational spectroscopy. ► Anharmonic vibrational calculation is employed to analyze the vibrational mode coupling in the stacked base pair. - Abstract: We have employed a laser desorption technique combined with supersonic-jet cooling for producing base pairs of adenine nucleosides, adenosine (Ado) and N6,N6-dimethyladenosine (DMAdo) under low-temperature conditions. The resulting base pairs are then ionized through resonant two-photon ionization (R2PI) and analyzed by time-of-flight mass spectrometry. It is found that dimers of these adenine nucleosides are stable, especially in the case of DMAdo, with respect to those of the corresponding bases, i.e., adenine and N6,N6-dimethyladenine. Structural analysis of the DMAdo dimer is performed based on the IR–UV double resonance measurements and theoretical calculations. The result demonstrates that the dimer possesses a stacked structure being stabilized by the formation of hydrogen-bonding network involving the two sugar groups. The occurrence of the frequency shift and broadening is explained satisfactorily based on the anharmonic coupling of the OH stretching modes with specific bending modes and low-frequency modes of base and sugar moieties

  4. Modular kinetic analysis of the adenine nucleotide translocator-mediated effects of palmitoyl-CoA on the oxidative phosphorylation in isolated rat liver mitochondria

    Ciapaite, J; Van Eikenhorst, G; Bakker, SJL; Diamant, M; Heine, RJ; Wagner, MJ; Westerhoff, HV; Krab, K

    2005-01-01

    To test whether long-chain fatty acyl-CoA esters link obesity with type 2 diabetes through inhibition of the mitochondrial adenine nucleotide translocator, we applied a system-biology approach, dual modular kinetic analysis, with mitochondrial membrane potential (Delta psi) and the fraction of matri

  5. Metabolic control of mitochondrial properties by adenine nucleotide translocator determines palmitoyl-CoA effects - Implications for a mechanism linking obesity and type 2 diabetes

    Ciapaite, Jolita; Bakker, Stephan J. L.; Diamant, Michaela; van Eikenhorst, Gerco; Heine, Robert J.; Westerhoff, Hans V.; Krab, Klaas

    2006-01-01

    Inhibition of the mitochondrial adenine nucleotide translocator (ANT) by long-chain acyl-CoA esters has been proposed to contribute to cellular dysfunction in obesity and type 2 diabetes by increasing formation of reactive oxygen species and adenosine via effects on the coenzyme Q redox state, mitoc

  6. A concise and simple synthesis of 1-hydroxy-phenethylamine derivatives: Formal synthesis of naturally occurring norephedrine, virolin and 3-hydroxy-2-phosphonylmethoxypropyl adenine

    S Saha; P Chakraborty; S C Roy

    2014-05-01

    A concise and simple synthesis of 1-hydroxy-phenethylamine derivatives has been achieved following classical organic transformations using commercially available chiral pools. The said derivatives were explored for the synthesis of naturally occurring bio-active small molecules. Formal synthesis of norephedrine, virolin and 3-hydroxy-2-phosphonylmethoxypropyl adenine has been demonstrated.

  7. Tryptophan as key biomarker to detect gastrointestinal tract cancer using non-negative biochemical analysis of native fluorescence and Stokes Shift spectroscopy

    Wang, Leana; Zhou, Yan; Liu, Cheng-hui; Zhou, Lixin; He, Yong; Pu, Yang; Nguyen, Thien An; Alfano, Robert R.

    2015-03-01

    The objective of this study was to find out the emission spectral fingerprints for discrimination of human colorectal and gastric cancer from normal tissue in vitro by applying native fluorescence. The native fluorescence (NFL) and Stokes shift spectra of seventy-two human cancerous and normal colorectal (colon, rectum) and gastric tissues were analyzed using three selected excitation wavelengths (e.g. 300 nm, 320 nm and 340 nm). Three distinct biomarkers, tryptophan, collagen and reduced nicotinamide adenine dinucleotide hydrate (NADH), were found in the samples of cancerous and normal tissues from eighteen subjects. The spectral profiles of tryptophan exhibited a sharp peak in cancerous colon tissues under a 300 nm excitation when compared with normal tissues. The changes in compositions of tryptophan, collagen, and NADH were found between colon cancer and normal tissues under an excitation of 300 nm by the non-negative basic biochemical component analysis (BBCA) model.

  8. Topical delivery of DNA oligonucleotide to induce p53 generation in the skin via thymidine dinucleotide (pTT-encapsulated liposomal carrier

    Fang YP

    2011-12-01

    Full Text Available Yi-Ping FangDepartment of Biotechnology, Yuanpei University, Hsinchu, TaiwanIntroduction: Transcription factor p53 has a powerful tumor suppressing function that is associated with many cancers. Since the molecular weight of p53 is 53 kDa, it is difficult to transport across cell membranes. Thymidine dinucleotide (pTT is an oligonucleotide that can activate the p53 transcription factor and trigger the signal transduction cascade. However, the negative charge and high water solubility of pTT limit its transport through cellular membranes, thereby preventing it from reaching its target in the nucleus. A suitable delivery carrier for pTT is currently not available.Objective: The purpose of this study was to employ a nanoscale liposomal carrier to resolve the delivery problem, and increase the bioavailability and efficiency of pTT.Methodology: The approach was to employ liposomes to deliver pTT and then evaluate the particle size and zeta potential by laser light scattering (LLS, and permeation properties of pTT in vitro in a Franz diffusion assembly, and in vivo in a murine model using confocal laser scanning microscopy (CLSM.Results: We found that dioleoylphosphatidylethanolamine (DOPE combined with cholesterol 3 sulfate (C3S were the best ingredients to achieve an average desired vehicle size of 133.6 ± 2.8 nm, a polydispersity index (PDI, representing the distribution of particle sizes of 0.437, and a zeta potential of −93.3 ± 1.88. An in vitro penetration study showed that the liposomal carrier was superior to the free form of pTT at 2–24 hours. CLSM study observed that the penetration depth of pTT reached the upper epidermis and potential of penetration maintained up to 24 hours.Conclusion: These preliminary data demonstrate that nanosized DOPE/C3S liposomes can be exploited as a potential carrier of drugs for topical use in treating skin diseases.Keywords: thymidine dinucleotide, p53, liposome, permeation ability, confocal laser

  9. The rates of G:C[yields]T:A and G:C[yields]C:G transversions at CpG dinucleotides in the human factor IX gene

    Ketterling, R.P.; Vielhaber, E.; Sommer, S.S. (Mayo Clinic/Foundation, Rochester, MN (United States))

    1994-05-01

    The authors have identified eight independent transversions at CpG in 290 consecutive families with hemophilia B. These eight transversions account for 16.3% of all independent transversions in the sample, yet the expected frequency of CpG transversions at random in the factor IX gene is only 2.6% (P<0.1). The aggregate data suggest that the two types of CpG transversions (G:C[yields]T:A and G:C[yields]C:G) possess similar mutation rates (24.8 [times] 10[sup [minus]10] and 20.6 [times] 10[sup [minus]10], respectively), which are about fivefold greater than the comparable rates for transversions at non-CpG dinucleotides. The enhancement of transversions at CpG suggest that the model by which mutations occur at CpG may need to be reevaluated. The relationship, if any, between deamination of 5-methyl cytosine and enhancement of transversions at CpG remains to be defined. 28 refs., 2 tabs.

  10. Recognition and repair of the CC-1065-(N3-Adenine)-DNA adduct by the UVRABC nuclease

    Tang, M.; Lee, C.S.; Doisy, R.; Ross, L.; Needham-VanDevanter, D.R.; Hurley, L.H.

    1988-02-09

    The recognition and repair of the helix-stabilizing and relatively nondistortive CC-1065-(N3-adenine)-DNA adduct by UVRABC nuclease has been investigated both in vivo with phi X174RFI DNA by a transfection assay and in vitro by a site-directed adduct in a 117 base pair fragment from M13mp1. CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis which binds within the minor groove of DNA through N3 of adenine. In contrast to the helix-destabilizing and distortive modifications of DNA caused by ultraviolet light or N-acetoxy-2-(acetylamino)fluorene, CC-1065 increases the melting point of DNA and decreases the S1 nuclease activity. Using a viral DNA-Escherichia coli transfection system, the authors have found that the uvrA, uvrB, and uvrC genes, which code for the major excision repair proteins for UV- and NAAAF-induced DNA damage, are also involved in the repair of CC-1065-DNA adducts. In contrast, the uvrD gene product, which has been found to be involved in the repair of UV damage, has no effect in repairing CC-1065-DNA adducts. Purified UVRA, UVRB, and UVRC proteins must work in concert to incise the drug-modified phi X174RFI DNA. Using a site-directed and multiple CC-1065 modified (MspI-BstNI) 117 base pair fragment from M13mp1, they have found that UVRABC nuclease incises at the eight phosphodiester bond on the 5' side of the CC-1065-DNA adduct on the drug-modified strand. The enzymes do not cut the noncovalently modified strand. The DNA sequence and/or helix-stabilizing effect of multiple adducts may determine the recognition and/or incision of the drug-DNA adduct by UVRABC nuclease. These results are discussed in relation to the structure of the CC-1065-DNA adduct and the effect of drug binding on local DNA structure.

  11. Recognition and repair of the CC-1065-(N3-Adenine)-DNA adduct by the UVRABC nuclease

    The recognition and repair of the helix-stabilizing and relatively nondistortive CC-1065-(N3-adenine)-DNA adduct by UVRABC nuclease has been investigated both in vivo with phi X174RFI DNA by a transfection assay and in vitro by a site-directed adduct in a 117 base pair fragment from M13mp1. CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis which binds within the minor groove of DNA through N3 of adenine. In contrast to the helix-destabilizing and distortive modifications of DNA caused by ultraviolet light or N-acetoxy-2-(acetylamino)fluorene, CC-1065 increases the melting point of DNA and decreases the S1 nuclease activity. Using a viral DNA-Escherichia coli transfection system, the authors have found that the uvrA, uvrB, and uvrC genes, which code for the major excision repair proteins for UV- and NAAAF-induced DNA damage, are also involved in the repair of CC-1065-DNA adducts. In contrast, the uvrD gene product, which has been found to be involved in the repair of UV damage, has no effect in repairing CC-1065-DNA adducts. Purified UVRA, UVRB, and UVRC proteins must work in concert to incise the drug-modified phi X174RFI DNA. Using a site-directed and multiple CC-1065 modified (MspI-BstNI) 117 base pair fragment from M13mp1, they have found that UVRABC nuclease incises at the eight phosphodiester bond on the 5' side of the CC-1065-DNA adduct on the drug-modified strand. The enzymes do not cut the noncovalently modified strand. The DNA sequence and/or helix-stabilizing effect of multiple adducts may determine the recognition and/or incision of the drug-DNA adduct by UVRABC nuclease. These results are discussed in relation to the structure of the CC-1065-DNA adduct and the effect of drug binding on local DNA structure

  12. Drug: D04902 [KEGG MEDICUS

    Full Text Available apeutic category: 3179 Therapeutic category of drugs in Japan [BR:br08301] 3 Agents affecting metabolism 31 Vitamins 317 Multivitamin...D04902 Mixture, Drug Flavin adenine dinucleotide sodium - pyridoxal phosphate mixt; Ribomin S (TN) Flavin... preparations 3179 Others D04902 Flavin adenine dinucleotide sodium - pyridoxal phosphate mixt PubChem: 17398212 ... ... adenine dinucleotide sodium [DR:D02011], Pyridoxal phosphate hydrate [DR:D00006] Ther

  13. [Dependence of creatine kinase and glycogen synthetase activities of skeletal muscles on state of adenine nucleotide phosphorylation and cAMP metabolism].

    Iakovlev, N N; Chagovets, N R; Maksimova, L V

    1980-01-01

    Changes in the contents of adenine nucleotides, creatine phosphate, inorganic phosphate, creatine, glucose-6-phosphate and glycogen and the activity of adenylate cyclase, creatine kinase, glycogen phosphorylase 31:51-AMP-phosphodiesterase and glycogen synthetase in muscles and of blood catecholamines were studied in adult rats before loading, immediately after the cessation of the muscular activity, and at rest. Adenine nucleotides are established to play a regulatory role in catabolic and anabolic processes nucleotides are established to play a regulatory role in catabolic and anabolic processes related to the muscular activity. It is established that compensation and supercompensation of the working losses of muscular creatine phosphate and glycogen are due to activation of anabolic processes under conditions of higher phosphorylation of the adenylic system. PMID:6247797

  14. Effect of UV-irradiation in vitro on adenin nucleotides metabolism, Na+ and K+ concentration, osmotic properties and submicroscopic structure of pigeon red blood cells

    Effect of UV-irradiation in vitro on metabolism of adenine nucleotides: ADP, ATP and AXP, osmotic properties and submicroscopic structure of nucleated pigeon red blood cell was investigated. Irradiation was carried out for 60, 120, 180, 240 and 300 minutes. Hanau S-500 lamp with efficiency 4.34 x 108 erg/sec was used. A decrease of ATP content with a simultaneous increase of ADP and AXP contents and a rather constant level of the sum of adenine compounds was observed. UV-irradiation caused a decrease of reversal of hemolysis and osmotic resistance to hypotonic NaCl solutions. An equivalent exchange of Na+ and K+ ions and an increase of hematocrit value, following UV-irradiation was observed. Electron microscope studies demonstrated changes of ultrastructure concerning both cell nucleus and thickness and granulation of cell membrane. (orig.)

  15. Genetic mapping of human heart-skeletal muscle adenine nucleotide translocator and its relationship to the facioscapulohumeral muscular dystrophy locus

    Haraguchi, Y.; Chung, A.B.; Torroni, A.; Stepien, G.; Shoffner, J.M.; Costigan, D.A.; Polak, M. [Emory Univ. School of Medicine, Atlanta, GA (United States); Wasmuth, J.J.; Altherr, M.R.; Winokur, S.T. [Univ. of California, Irvine, CA (United States)] [and others

    1993-05-01

    The mitochondrial heart-skeletal muscle adenine nucleotide translocator (ANT1) was regionally mapped to 4q35-qter using somatic cell hybrids containing deleted chromosome 4. The regional location was further refined through family studies using ANT1 intron and promoter nucleotide polymorphisms recognized by the restriction endonucleases MboII, NdeI, and HaeIII. Two alleles were found, each at a frequency of 0.5. The ANT1 locus was found to be closely linked to D4S139, D4S171, and the dominant skeletal muscle disease locus facioscapulohumeral muscular dystrophy (FSHD). A crossover that separated D4S171 and ANT1 from D4S139 was found. Since previous studies have established the chromosome 4 map order as centromere-D4S171-D4S139-FSHD, it was concluded that ANT1 is located on the side of D4S139, that is opposite from FSHD. This conclusion was confirmed by sequencing the exons and analyzing the transcripts of ANT1 from several FSHD patients and finding no evidence of aberration. 35 refs., 5 figs., 1 tab.

  16. Mapping the Ultrafast Dynamics of Adenine onto Its Nucleotide and Oligonucleotides by Time-Resolved Photoelectron Imaging.

    Chatterley, Adam S; West, Christopher W; Roberts, Gareth M; Stavros, Vasilios G; Verlet, Jan R R

    2014-03-01

    The intrinsic photophysics of nucleobases and nucleotides following UV absorption presents a key reductionist step toward understanding the complex photodamage mechanisms occurring in DNA. The decay mechanism of adenine in particular has been the focus of intense investigation, as has how these correlate to those of its more biologically relevant nucleotide and oligonucleotides in aqueous solution. Here, we report on time-resolved photoelectron imaging of the deprotonated 3'-deoxy-adenosine-5'-monophosphate nucleotide and the adenosine di- and trinucleotides. Through a comparison of gas- and solution-phase experiments and available theoretical studies, the dynamics of the base are shown to be relatively insensitive to the surrounding environment. The decay mechanism primarily involves internal conversion from the initially populated (1)ππ* states to the ground state. The relaxation dynamics of the adenosine oligonucleotides are similar to those of the nucleobase, in contrast to the aqueous oligonucleotides, where a fraction of the ensemble forms long-lived excimer states. PMID:26274076

  17. Study of the chemical evolution and spectral signatures of some interstellar precursor molecules of adenine, glycine alanine

    Majumdar, Liton; Chakrabarti, Sandip K; Chakrabarti, Sonali; 10.1016/j.newast.2012.09.002

    2012-01-01

    We carry out a quantum chemical calculation to obtain the infrared and electronic absorption spectra of several complex molecules of the interstellar medium (ISM). These molecules are the precursors of adenine, glycine & alanine. They could be produced in the gas phase as well as in the ice phase. We carried out a hydro-chemical simulation to predict the abundances of these species in the gas as well as in the ice phase. Gas and grains are assumed to be interacting through the accretion of various species from the gas phase on to the grain surface and desorption (thermal evaporation and photo-evaporation) from the grain surface to the gas phase. Depending on the physical properties of the cloud, the calculated abundances varies. The influence of ice on vibrational frequencies of different pre-biotic molecules was obtained using Polarizable Continuum Model (PCM) model with the integral equation formalism variant (IEFPCM) as default SCRF method with a dielectric constant of 78.5. Time dependent density func...

  18. Over-expression of Adenine Nucleotide Translocase 1 (ANT1) Induces Apoptosis and Tumor Regression in vivo

    Adenine nucleotide translocase (ANT) is located in the inner mitochondrial membrane and catalyzes the exchange of mitochondrial ATP for cytosolic ADP. ANT has been known to be a major component of the permeability transition pore complex of mitochondria and contributes to mitochondria-mediated apoptosis. Human ANT has four isoforms (ANT1, ANT2, ANT3, and ANT4), and the expression of the ANT isoforms is variable depending on the tissue and cell type, developmental stage, and proliferation status. Among the isoforms, ANT1 is highly expressed in terminally-differentiated tissues, but expressed in low levels in proliferating cells, such as cancer cells. In particular, over-expression of ANT1 induces apoptosis in cultured tumor cells. We applied an ANT1 gene transfer approach to induce apoptosis and to evaluate the anti-tumor effect of ANT1 in a nude mouse model. We demonstrated that ANT1 transfection induced apoptosis of MDA-MB-231 cells, inactivated NF-κB activity, and increased Bax expression. ANT1-inducing apoptosis was accompanied by the disruption of mitochondrial membrane potential, cytochrome c release and the activation of caspases-9 and -3. Moreover, ANT1 transfection significantly suppressed tumor growth in vivo. Our results suggest that ANT1 transfection may be a useful therapeutic modality for the treatment of cancer

  19. Silver nanoparticles coated with adenine: preparation, self-assembly and application in surface-enhanced Raman scattering

    We describe herein the preparation of silver nanoparticles (AgNPs) using nucleobase adenine as protecting agent through the in situ chemical reduction of AgNO3 with NaBH4 in an aqueous medium at room temperature. As-prepared AgNPs were characterized by UV-visible spectra, transmission electron microscopy and x-ray photoelectron spectroscopy. All these data confirmed the formation of AgNPs. On the basis of electrostatic interactions between as-prepared AgNPs and anionic polyelectrolyte poly(sodium 4-styrenesulfonate) (PSS), we successfully fabricated (PSS/AgNP)n (n = 0-9) multilayers on a 3-mercaptopropyltrimethoxysilane/AgNP functionalized indium tin oxide (ITO) substrate via the layer-by-layer self-assembly technique and characterized as-formed multilayers with UV-visible spectra. Furthermore, these ITO substrates coated with multilayers of different thickness were investigated as surface-enhanced Raman scattering (SERS)-active substrates using p-aminothiophenol as a probe molecule, implying that these multilayers substrates may be promising for a new type of SERS-active substrate

  20. Continuing Exposure to Low-Dose Nonylphenol Aggravates Adenine-Induced Chronic Renal Dysfunction and Role of Rosuvastatin Therapy

    Yen Chia-Hung

    2012-07-01

    Full Text Available Abstract Background Nonylphenol (NP, an environmental organic compound, has been demonstrated to enhance reactive-oxygen species (ROS synthesis. Chronic exposure to low-dose adenine (AD has been reported to induce chronic kidney disease (CKD. Methods In this study, we tested the hypothesis that chronic exposure to NP will aggravate AD-induced CKD through increasing generations of inflammation, ROS, and apoptosis that could be attenuated by rosuvastatin. Fifty male Wistar rats were equally divided into group 1 (control, group 2 (AD in fodder at a concentration of 0.25%, group 3 (NP: 2 mg/kg/day, group 4 (combined AD & NP, and group 5 (AD-NP + rosuvastatin: 20 mg/kg/day. Treatment was continued for 24 weeks for all animals before being sacrificed. Results By the end of 24 weeks, serum blood urea nitrogen (BUN and creatinine levels were increased in group 4 than in groups 1–3, but significantly reduced in group 5 as compared with group 4 (all p  Conclusion NP worsened AD-induced CKD that could be reversed by rosuvastatin therapy.

  1. Over-expression of Adenine Nucleotide Translocase 1 (ANT1 Induces Apoptosis and Tumor Regression in vivo

    Kim Chul-Woo

    2008-06-01

    Full Text Available Abstract Background Adenine nucleotide translocase (ANT is located in the inner mitochondrial membrane and catalyzes the exchange of mitochondrial ATP for cytosolic ADP. ANT has been known to be a major component of the permeability transition pore complex of mitochondria and contributes to mitochondria-mediated apoptosis. Human ANT has four isoforms (ANT1, ANT2, ANT3, and ANT4, and the expression of the ANT isoforms is variable depending on the tissue and cell type, developmental stage, and proliferation status. Among the isoforms, ANT1 is highly expressed in terminally-differentiated tissues, but expressed in low levels in proliferating cells, such as cancer cells. In particular, over-expression of ANT1 induces apoptosis in cultured tumor cells. Methods We applied an ANT1 gene transfer approach to induce apoptosis and to evaluate the anti-tumor effect of ANT1 in a nude mouse model. Results We demonstrated that ANT1 transfection induced apoptosis of MDA-MB-231 cells, inactivated NF-κB activity, and increased Bax expression. ANT1-inducing apoptosis was accompanied by the disruption of mitochondrial membrane potential, cytochrome c release and the activation of caspases-9 and -3. Moreover, ANT1 transfection significantly suppressed tumor growth in vivo. Conclusion Our results suggest that ANT1 transfection may be a useful therapeutic modality for the treatment of cancer.

  2. Kinetics and mechanism of electron transfer between purines and pyrimidines, their dinucleotides and polynucleotides after reaction with hydrated electrons; a pulse radiolysis study

    The radical spectra of mixtures of thymidine 5'-monophosphate (TMP) or uridine 5'-monophosphate (UMP) with adenine 5'-monophosphate (AMP) after hydrated electron attack, measured from 5 to 3000 μs after pulse radiolysis, can only be described in terms of the radical spectra of the nucleotides if an electron transfer is taken into account from the purine radical anion to the pyrimidine, resulting in the formation of a pyrimidine radical anion. From analysis of the spectra of the dinucleoside phosphates ApU, dApT and dCpdA after eaq- attack it follows that the electron-donating species is the purine radical anion (A-radical) rather than the protonated purine radical. The electron transfer competes with the fast protonation of the purine radical anion: A-radical+py→A+py radical- and A-radical + H2O↔AH radical respectively. The electron transfer is found to have a diffusion-controlled reaction rate constant of approximately 1.2 x 1010 for TMP and 3.5 x 109 dm3 mol-1 s-1 for UMP. (author)

  3. Combining pseudo dinucleotide composition with the Z curve method to improve the accuracy of predicting DNA elements: a case study in recombination spots.

    Dong, Chuan; Yuan, Ya-Zhou; Zhang, Fa-Zhan; Hua, Hong-Li; Ye, Yuan-Nong; Labena, Abraham Alemayehu; Lin, Hao; Chen, Wei; Guo, Feng-Biao

    2016-08-16

    Pseudo dinucleotide composition (PseDNC) and Z curve showed excellent performance in the classification issues of nucleotide sequences in bioinformatics. Inspired by the principle of Z curve theory, we improved PseDNC to give the phase-specific PseDNC (psPseDNC). In this study, we used the prediction of recombination spots as a case to illustrate the capability of psPseDNC and also PseDNC fused with Z curve theory based on a novel machine learning method named large margin distribution machine (LDM). We verified that combining the two widely used approaches could generate better performance compared to only using PseDNC with a support vector machine based (SVM-based) model. The best Mathew's correlation coefficient (MCC) achieved by our LDM-based model was 0.7037 through the rigorous jackknife test and improved by ∼6.6%, ∼3.2%, and ∼2.4% compared with three previous studies. Similarly, the accuracy was improved by 3.2% compared with our previous iRSpot-PseDNC web server through an independent data test. These results demonstrate that the joint use of PseDNC and Z curve enhances performance and can extract more information from a biological sequence. To facilitate research in this area, we constructed a user-friendly web server for predicting hot/cold spots, HcsPredictor, which can be freely accessed from . In summary, we provided a united algorithm by integrating Z curve with PseDNC. We hope this united algorithm could be extended to other classification issues in DNA elements. PMID:27410247

  4. A reagentless enzymatic amperometric biosensor using vertically aligned carbon nanofibers (VACNF)

    Weeks, Martha L [University of Tennessee, Knoxville (UTK); Rahman, Touhidur [ORNL; Frymier, Paul Dexter [ORNL; Islam, Syed K [University of Tennessee, Knoxville (UTK); McKnight, Timothy E [ORNL

    2008-01-01

    A reagentless amperometric enzymatic biosensor is constructed on a carbon substrate for detection of ethanol. Yeast alcohol dehydrogenase (YADH), an oxidoreductase, and its cofactor nicotinamide adenine dinucleotide (NAD+) are immobilized by adsorption and covalent attachment to the carbon substrate. Carbon nanofibers grown by plasma enhanced chemical vapor deposition (PECVD) are chosen as the electrode material due to their excellent structural and electrical properties. Electrochemical techniques are employed to test the functionality and performance of the biosensor using reduced form of nicotinamide adenine dinucleotide (NADH) which also determines the oxidation peak potential of NADH. Subsequently, amperometric measurements are conducted for detection of ethanol to determine the electrical current response due to the increase in analyte concentration. The detection range, storage stability, reusability, and response time of the biosensor are also examined.

  5. Quantification of carnosine- related peptides by microchip electrophoresis with chemiluminescence detection

    Zhao, Shulin; Huang, Yong; Shi, Ming; Huang, Junming; Liu, Yi-Ming

    2009-01-01

    A microchip electrophoresis (MCE) method with chemiluminescence (CL) detection was developed for the determination of carnosine-related peptides including carnosine, homocarnosine and anserine in biological samples. A simple integrated MCE-CL system was built to perform the assays. The highly sensitive CL detection was achieved by means of the CL reaction between hydrogen peroxide and N-(4-aminobutyl)- N-ethylisoluminol-tagged peptides in the presence of adenine as a CL enhancer and Co2+ as a...

  6. A high-resolution map of genes, microsatellite markers, and new dinucleotide repeats from UBE1 to the GATA locus in the region Xp11.23

    Kwan, Sau-Ping; Hagemann, T.L. [Rush Medical School, Chicago, IL (United States); Rosen, F.S. [Harvard Medical School, Boston, MA (United States)] [and others

    1995-09-01

    Several new genes and markers have recently been identified on the proximal short arm of the human X chromosome in the area of Xp11.23. We had previously generated at YAC contig in this region extending from UBE1 to the OATL1 locus. In this report two polymorphic dinucleotide repeats, DXS6949 and DXS6950, were isolated and characterized from the OATL1 locus. A panel of YAC deletion derivatives from the distal portion of the contig was used in conjunction with the rest of the YAC map to position the new microsatellites and order other markers localizing to this interval. The marker order was determined to be DXS1367-ZNF81-DXS6849-ZNF21-DXS6616-DXS6950-DXS6949. In the proximal region below OATL1, we have isolated a pair of YACs from the GATA locus, B1026 and C01160. Mapping within these YACs indicates the orientation of DXS1126 and DXS1240, while a cosmid near the OATL1 region reveals the overlap between the YAC contigs from the two loci. This cosmid contains the gene responsible for Wiskott-Aldrich syndrome (WAS) and localizes the disease gene between OATL1 and GATA. These data enable the expansion of the present physical map of the X chromosome from UBE1 to the GATA locus, covering a large portion of the Xp11.23 region. Genetic crossovers in Xp11.23 support the marker orientation and the position of WAS, contrary to previous reports. With the integration of both physical and genetic maps we have predicted the following marker order: Xpter-UBE1-SYN1/ARAF1/TIMP1/DXS1367-ZNF81-DXS-6849-ZNF21-DXSy6616-(OATL1, DXS6950-DXS6949)-WAS-(GATA,DXS1126)-DXS12410-Xcen. This orientation identifies DXS6949 and DXS1126 as the nearest flanking polymorphic markers for WAS and provides useful anchor positions for the analysis of other disease genes that have been localized to this area including three different retinal defects and X-linked nephrolithiasis. 39 refs., 3 figs., 1 tab.

  7. Pleiotropic effects of the yeast Sal1 and Aac2 carriers on mitochondrial function via an activity distinct from adenine nucleotide transport

    Kucejova, Blanka; Li, Li; Wang, Xiaowen; Giannattasio, Sergio; Chen, Xin Jie

    2009-01-01

    In Saccharomyces cerevisiae, SAL1 encodes a Ca2+-binding mitochondrial carrier. Disruption of SAL1 is synthetically lethal with the loss of a specific function associated with the Aac2 isoform of the ATP/ADP translocase. This novel activity of Aac2 is defined as the V function (for Viability of aac2 sal1 double mutant), which is independent of the ATP/ADP exchange activity required for respiratory growth (the R function). We found that co-inactivation of SAL1 and AAC2 leads to defects in mitochondrial translation and mitochondrial DNA (mtDNA) maintenance. Additionally, sal1Δ exacerbates the respiratory deficiency and mtDNA instability of ggc1Δ, shy1Δ and mtg1Δ mutants, which are known to reduce mitochondrial protein synthesis or protein complex assembly. The V function is complemented by the human Short Ca2+-binding Mitochondrial Carrier (SCaMC) protein, SCaMC-2, a putative ATP-Mg/Pi exchangers on the inner membrane. However, mitochondria lacking both Sal1p and Aac2p are not depleted of adenine nucleotides. The Aac2R252I and Aac2R253I variants mutated at the R252-254 triplet critical for nucleotide transport retain the V function. Likewise, Sal1p remains functionally active when the R479I and R481I mutations were introduced into the structurally equivalent R479-T480-R481 motif. Finally, we found that the naturally occurring V-R+ Aac1 isoform of adenine nucleotide translocase partially gains the V function at the expense of the R function by introducing the mutations P89L and A96V. Thus, our data support the view that the V function is independent of adenine nucleotide transport associated with Sal1p and Aac2p and this evolutionarily conserved activity affects multiple processes in mitochondria. PMID:18431598

  8. P2Y13 receptors mediate presynaptic inhibition of acetylcholine release induced by adenine nucleotides at the mouse neuromuscular junction.

    Guarracino, Juan F; Cinalli, Alejandro R; Fernández, Verónica; Roquel, Liliana I; Losavio, Adriana S

    2016-06-21

    It is known that adenosine 5'-triphosphate (ATP) is released along with the neurotransmitter acetylcholine (ACh) from motor nerve terminals. At mammalian neuromuscular junctions (NMJs), we have previously demonstrated that ATP is able to decrease ACh secretion by activation of P2Y receptors coupled to pertussis toxin-sensitive Gi/o protein. In this group, the receptor subtypes activated by adenine nucleotides are P2Y12 and P2Y13. Here, we investigated, by means of pharmacological and immunohistochemical assays, the P2Y receptor subtype that mediates the modulation of spontaneous and evoked ACh release in mouse phrenic nerve-diaphragm preparations. First, we confirmed that the preferential agonist for P2Y12-13 receptors, 2-methylthioadenosine 5'-diphosphate trisodium salt hydrate (2-MeSADP), reduced MEPP frequency without affecting MEPP amplitude as well as the amplitude and quantal content of end-plate potentials (EPPs). The effect on spontaneous secretion disappeared after the application of the selective P2Y12-13 antagonists AR-C69931MX or 2-methylthioadenosine 5'-monophosphate triethylammonium salt hydrate (2-MeSAMP). 2-MeSADP was more potent than ADP and ATP in reducing MEPP frequency. Then we demonstrated that the selective P2Y13 antagonist MRS-2211 completely prevented the inhibitory effect of 2-MeSADP on MEPP frequency and EPP amplitude, whereas the P2Y12 antagonist MRS-2395 failed to do this. The preferential agonist for P2Y13 receptors inosine 5'-diphosphate sodium salt (IDP) reduced spontaneous and evoked ACh secretion and MRS-2211 abolished IDP-mediated modulation. Immunohistochemical studies confirmed the presence of P2Y13 but not P2Y12 receptors at the end-plate region. Disappearance of P2Y13 receptors after denervation suggests the presynaptic localization of the receptors. We conclude that, at motor nerve terminals, the Gi/o protein-coupled P2Y receptors implicated in presynaptic inhibition of spontaneous and evoked ACh release are of the subtype P2Y

  9. Experimental study on the fragmentation of Adenine and Porphyrin molecules induced by low energy multicharged ion impact

    Since the dissociation of small molecules might play key roles in the understanding of radiation induced damages of living tissues at the primary steps and at the molecular levels, fragmentation dynamics of small biomolecules have drawn much attention. The knowledge of the internal energy is of fundamental importance for understanding its fragmentation dynamics following external excitation. For a long time however, it was difficult to measure this parameter in coincidence with the fragmentation patterns until the development of CIDEC (Collision Induced Dissociation under Energy Control) method in 2007. In this work, the CIDEC method was extended to study the fragmentation of gas-phase biomolecules adenine (Ade: H5C5N5) and porphyrin chloride FeTPPCl (C44H28N4FeCl). The population distribution for each dissociation channel as a function of the excitation energy of the parent molecular ions at a well-determined initial charge state has been experimentally determined, which could shed some light on the fragmentation dynamics of these molecules. In collisions between Cl+ and Ade at 3 keV, the fragmentation pattern of Ade2+ is dominated by the loss of H2CN+ and the successive emission of HCN. The energy distribution of the parent dication confirms the successive emission dynamics. A specific decay channel is observed, i.e. the emission of a charged H2CN+ followed by the emission of HC2N2. The measured mean excitation energies of this channel and other competitive channels are compared. In Kr8+ - FeTPPCl collisions at 80 keV, parent ions FeTPPCL1+,2+,3+ are observed, along with the corresponding decay patterns. It is found that, in the first step the dominant low-energy-cost decay channel is the emission of Cl0 independent of the initial charge state of FeTPPClr+. For the resulted dication FeTPP2+, the dominant fragmentation channel is the neutral evaporation; for the tri-cation however, the dominant fragmentation channel is the asymmetrical fission by emission of a

  10. Sequence-specific interaction of Hoechst 33258 with the minor groove of an adenine-tract DNA duplex studied in solution by 1H NMR spectroscopy.

    Searle, M S; Embrey, K J

    1990-01-01

    The interaction of Hoechst 33258 with the minor groove of the adenine-tract DNA duplex d(CTTTTGCAAAAG)2 has been studied in both D2O and H2O solutions by 1D and 2D 1H NMR spectroscopy. Thirty-one nuclear Overhauser effects between drug and nucleotide protons within the minor groove of the duplex, together with ring-current induced perturbations to the chemical shifts of basepair and deoxyribose protons, define the position and orientation of the bound dye molecules. Two drug molecules bind co...

  11. 腺嘌呤-5-溴尿嘧啶复合物中的卤键%Halogen Bonds in Adenine-5-Bromouracil Complexes

    王艳花; 李立; 卢运祥; 邹建卫

    2007-01-01

    Ab initio and density functional calculations were employed to investigate the bonding patterns in the adenine-5-bromouracil(AT+)complexes.It is shown that the Br atom in 5-bromouracil(T+)is involved in bonding both with the hydrogen atom of the amino group of adenine(A)and with N7(A)(or N1(A)).With this motif,the Br atom interacts with a nucleophile(H)in a"head-on"fashion and an electrophile(N)in a"side-on"fashion,forming both hydrogen and halogen bonds.Electrostatic attraction between the Br atom in T+and N7(or N1)of adenine was found via the electrostatic potential analysis.The existence of A bond critical point is identified for the halogen bonds and the topological parameters at the bond critical point indicate the typical closed-shellinteractions in the pairs.Natural bond orbital analysis suggests that the charge transfer from the lone pair of the nitrogen atom of adenine is mainly directed to the C-Br antibonding orbital.Finally,halogen bonds in the T+AT+A tetrads were also explored.%利用从头算和密度泛函理论研究了腺嘌呤(A)-5-溴尿嘧啶复合物中(T+)中的键合模式.研究结果表明,T+中的Br原子同时与A分子中的氨基氢和氮原子存在弱的相互作用,在这种结合模式中,Br原子与亲核基团H正面结合,同时与来电基团N侧面结合,分别形成氢键和卤键.静电势分析发现:T+中的Br原子与A中的N7(或N1)是通过静电相互吸引的.Br与N原子之间的相互作用通过分了中的原子理论得以证实.关键点的拓扑参数显示卤键是闭壳层相互作用.自然键轨道分析说明,A中N原子上孤对电子的电荷主要转移到C-Br的反键轨道.另外在T+AT+A四面体结构中也发现了卤键.

  12. XRD and optical microscopic studies of Co(III) complexes containing 5-cyano-6-(4-pyridyl)-2-thiouracil, thymine and adenine bases

    Lallan Mishra; Brajesh Pathak; R K Mandal

    2001-06-01

    Multifunctional ligand 5-cyano-6-(-4-pyridyl)-2-thiouracil (L) was prepared and allowed to react with trans [Co(en)2Cl2]+Cl– resulting into [Co(en)2LCl]2+.2Cl– which upon further reaction with equimolar ratio of ligand [L] gave the complex [Co(en)2L2]3+.3Cl–. These metal complexes were then separately reacted with thymine and adenine bases. Complexes thus prepared after characterization by their elemental analysis, FAB mass and spectral (IR, 1HNMR, UV-visible) data were studied for their powder X-ray diffraction and optical microscopic characteristics.

  13. Physicochemical studies of the reaction of (99m)Tc with 5,5'-diethyl barbituric acid, adenine, d-glucose and thiobarbituric acid at different temperatures.

    Masoud, M S; El-Shahat, M F; Elkholany, A S

    2014-06-01

    The reaction of (99m)Tc pertechnetate with 5,5'-diethyl barbituric acid, adenine, d-glucose and thiobarbituric acid at different temperatures was studied. The solvent effect on the electronic absorption spectra of the reactions was recorded. The reaction mixtures have been analyzed at different times using TLC and a radiodetctor to show the peaks at the plates. (99m)Tc pertechnetate is obtained from the Mo generators. It is difficult to separate the complexes in the solid state. The percentage of (99m)Tc involved in the complexes can be determined. Characterization of the (99m)Tc complexes as well as the determination of the extent of radiolabeling was done by thin layer chromatography using 0.9% NaCl solution as a solvent. The Rf value of (99m)TcO4(-) is (≈1). The solvatochromism for the reaction of (99m)Tc with d-glucose was mainly affected by solute permanent dipole-solvent permanent dipole interaction, the dipolar interaction for the reaction of (99m)Tc with of 5,5'-diethyl barbituric acid and for the reaction of (99m)Tc with adenine and thiobarbituric was solute-solvent hydrogen bonding. PMID:24632174

  14. Determination of the recognition site for adenine-specific methylase of Shigella sonnei 47 by hydazinolysis of DNA, followed by separation of the purine oligonucleotides by thin-layer chromatography on DEAE-cellulose

    A method has been developed for the separation of oligopurine units according to length and composition by two-dimensional thin-layer chromatography on plates with DEAE-cellulose, permitting a comparative analysis of the content of various purine isopliths in DNA of different origin. In the case of the analysis of methylated DNA, the method permits a comparison of the substrate specificity of various enzymes of methylation of the adenine residues in DNA. In conjunction with enzymatic treatment of labeled methylated isopliths, the method permits determination of the methylatable sequence and in a number of cases an ascertainment of the recognition site for adenine-specific methylase as a whole. The proposed method was used to establish the fact that the methylase Ssol recognizes the sequence 5'...G-A-A-T-T-C...3' and methylates the adenine residue closest to its 5'-end

  15. Molecular dynamics simulations and coupled nucleotide substitution experiments indicate the nature of A·A base pairing and a putative structure of the coralyne-induced homo-adenine duplex

    Joung, In Suk; Persil Çetinkol, Özgül; Hud, Nicholas V.; Cheatham, Thomas E.

    2009-01-01

    Coralyne is an alkaloid drug that binds homo-adenine DNA (and RNA) oligonucleotides more tightly than it does Watson–Crick DNA. Hud’s laboratory has shown that poly(dA) in the presence of coralyne forms an anti-parallel duplex, however attempts to determine the structure by NMR spectroscopy and X-ray crystallography have been unsuccessful. Assuming adenine–adenine hydrogen bonding between the two poly(dA) strands, we constructed 40 hypothetical homo-(dA) anti-parallel duplexes and docked cora...

  16. Lack of Maternal Glutamate Cysteine Ligase Modifier Subunit (Gclm) Decreases Oocyte Glutathione Concentrations and Disrupts Preimplantation Development in Mice

    Nakamura, Brooke N.; Fielder, Thomas J.; Hoang, Yvonne D.; Lim, Jinhwan; McConnachie, Lisa A.; Kavanagh, Terrance J.; Luderer, Ulrike

    2011-01-01

    Glutathione (GSH) is the most abundant intracellular thiol and an important regulator of cellular redox status. Mice that lack the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in GSH synthesis, have decreased GSH synthesis. Nicotinamide nucleotide transhydrogenase, an inner mitochondrial membrane protein, catalyzes the interconversion of reduced nicotinamide adenine dinucleotide and reduced nicotinamide adenine dinucleotide phosphate; reduced nicotinamide ade...

  17. Sensing cell metabolism by time-resolved autofluorescence

    Wu, Yicong; Zheng, Wei; Qu, Jianan Y.

    2006-11-01

    We built a time-resolved confocal fluorescence spectroscopy system equipped with the multichannel time-correlated single-photon-counting technique. The instrument provides a unique approach to study the fluorescence sensing of cell metabolism via analysis of the wavelength- and time-resolved intracellular autofluorescence. The experiments on monolayered cell cultures show that with UV excitation at 365 nm the time-resolved autofluorescence decays, dominated by free-bound reduced nicotinamide adenine dinucleotide signals, are sensitive indicators for cell metabolism. However, the sensitivity decreases with the increase of excitation wavelength possibly due to the interference from free-bound flavin adenine dinucleotide fluorescence. The results demonstrate that time-resolved autofluorescence can be potentially used as an important contrast mechanism to detect epithelial precancer.

  18. Liquid Chromatography-Mass Spectrometry Interface for Detection of Extraterrestrial Organics

    Southard, Adrian E.; Getty, Stephanie A.; Balvin, Manuel; Cook, Jamie E.; Espiritu, Ana Mellina; Kotecki, Carl; Towner, Deborah W.; Dworkin, J. P.; Glavin, Daniel P.; Mahaffy, Paul R.; Ferrance, J.

    2014-01-01

    The OASIS (Organics Analyzer for Sampling Icy surfaces) microchip enables electrospray or thermospray of analyte for subsequent analysis by the OASIS time-of-flight mass spectrometer. Electrospray of buffer solution containing the nucleobase adenine was performed using the microchip and detected by a commercial time-of-flight mass spectrometer. Future testing of thermospray and electrospray capability will be performed using a test fixture and vacuum chamber developed especially for optimization of ion spray at atmosphere and in low pressure environments.

  19. Mechanisms and energetics for N-glycosidic bond cleavage of protonated adenine nucleosides: N3 protonation induces base rotation and enhances N-glycosidic bond stability.

    Wu, R R; Rodgers, M T

    2016-06-21

    Our previous gas-phase infrared multiple photon dissociation action spectroscopy study of protonated 2'-deoxyadenosine and adenosine, [dAdo+H](+) and [Ado+H](+), found that both N3 and N1 protonated conformers are populated with the N3 protonated ground-state conformers predominant in the experiments. Therefore, N-glycosidic bond dissociation mechanisms of N3 and N1 protonated [dAdo+H](+) and [Ado+H](+) and the associated quantitative thermochemical values are investigated here using both experimental and theoretical approaches. Threshold collision-induced dissociation (TCID) of [dAdo+H](+) and [Ado+H](+) with Xe is studied using guided ion beam tandem mass spectrometry techniques. For both systems, N-glycosidic bond cleavage reactions are observed as the major dissociation pathways resulting in production of protonated adenine or elimination of neutral adenine. Electronic structure calculations are performed at the B3LYP/6-311+G(d,p) level of theory to probe the potential energy surfaces (PESs) for N-glycosidic bond cleavage of [dAdo+H](+) and [Ado+H](+). Relative energetics of the reactants, transition states, intermediates and products along the PESs for N-glycosidic bond cleavage are determined at the B3LYP/6-311+G(2d,2p), B3LYP-GD3BJ/6-311+G(2d,2p), and MP2(full)/6-311+G(2d,2p) levels of theory. The predicted N-glycosidic bond dissociation mechanisms for the N3 and N1 protonated species differ. Base rotation of the adenine residue enables formation of a strong N3H(+)O5' hydrogen-bonding interaction that stabilizes the N3 protonated species and its glycosidic bond. Comparison between experiment and theory indicates that the N3 protonated species determine the threshold energies, as excellent agreement between the measured and B3LYP computed activation energies (AEs) and reaction enthalpies (ΔHrxns) for N-glycosidic bond cleavage of the N3 protonated species is found. PMID:27240654

  20. A possible prebiotic synthesis of purine, adenine, cytosine, and 4(3H)-pyrimidinone from formamide: implications for the origin of life.

    Saladino, R; Crestini, C; Costanzo, G; Negri, R; Di Mauro, E

    2001-05-01

    The synthesis of prebiotic molecules is a major problem in chemical evolution as well as in any origin-of-life theory. We report here a plausible new prebiotic synthesis of naturally occurring purine and pyrimidine derivatives from formamide under catalytic conditions. In the presence of CaCO(3) and different inorganic oxides, namely silica, alumine, kaolin, and zeolite (Y type), neat formamide undergoes the formation of purine, adenine, cytosine, and 4(3H)-pyrimidinone, from acceptable to good yields. The role of catalysts showed to be not limited to the improvement of the yield but it is also relevant in providing a high selectivity in the products distribution. PMID:11377183

  1. Studies on the energy metabolism of opossum (Didelphis virginiana) erythrocytes: V. Utilization of hypoxanthine for the synthesis of adenine and guanine nucleotides in vitro

    Bethlenfalvay, N.C.; White, J.C.; Chadwick, E.; Lima, J.E. (Fitzsimons Army Medical Center, Aurora, CO (USA))

    1990-06-01

    High pressure liquid radiochromatography was used to test the ability of opossum erythrocytes to incorporate tracer amounts of (G-{sup 3}H) hypoxanthine (Hy) into ({sup 3}H) labelled triphosphates of adenine and guanine. In the presence of supraphysiologic (30 mM) phosphate which is optimal for PRPP synthesis, both ATP and GTP are extensively labelled. When physiologic (1 mM) medium phosphate is used, red cells incubated under an atmosphere of nitrogen accumulate ({sup 3}H) ATP in a linear fashion suggesting ongoing PRPP synthesis in red cells whose hemoglobin is deoxygenated. In contrast, a lesser increase of labelled ATP is observed in cells incubated under oxygen, suggesting that conditions for purine nucleotide formation from ambient Hy are more favorable in the venous circulation.

  2. Studies on the energy metabolism of opossum (Didelphis virginiana) erythrocytes: V. Utilization of hypoxanthine for the synthesis of adenine and guanine nucleotides in vitro

    High pressure liquid radiochromatography was used to test the ability of opossum erythrocytes to incorporate tracer amounts of [G-3H] hypoxanthine (Hy) into [3H] labelled triphosphates of adenine and guanine. In the presence of supraphysiologic (30 mM) phosphate which is optimal for PRPP synthesis, both ATP and GTP are extensively labelled. When physiologic (1 mM) medium phosphate is used, red cells incubated under an atmosphere of nitrogen accumulate [3H] ATP in a linear fashion suggesting ongoing PRPP synthesis in red cells whose hemoglobin is deoxygenated. In contrast, a lesser increase of labelled ATP is observed in cells incubated under oxygen, suggesting that conditions for purine nucleotide formation from ambient Hy are more favorable in the venous circulation

  3. Reactivities of radicals of adenine and guanine towards reactive oxygen species and reactive nitrogen oxide species: OH rad and NO 2rad

    Agnihotri, Neha; Mishra, P. C.

    2011-02-01

    Reactions of radicals of the DNA bases with reactive oxygen species and reactive nitrogen oxide species produce mutagenic products. We have studied reactivities of all the carbon sites of radicals of adenine A(-H) rad and guanine G(-H) rad obtained by removal of H-atoms from their nitrogen sites towards OH rad and NO 2rad . We studied stabilities of A(-H) rad and G(-H) rad and binding energies of their adducts with each of OH rad and NO 2rad using density functional theoretic and MP2 calculations employing the AUG-cc-pVDZ basis set. Solvation in aqueous media was treated using the polarization continuum model. The results obtained explain experimental observations.

  4. 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

    Jensen, Kaj Frank; Hansen, Michael Riis; Jensen, Kristine Steen;

    2015-01-01

    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...

  5. Specificity of the ModA11, ModA12 and ModD1 epigenetic regulator N6-adenine DNA methyltransferases of Neisseria meningitidis

    Seib, Kate L.; Jen, Freda E.-C.; Tan, Aimee; Scott, Adeana L.; Kumar, Ritesh; Power, Peter M.; Chen, Li-Tzu; Wu, Hsing-Ju; Wang, Andrew H.-J.; Hill, Dorothea M. C.; Luyten, Yvette A.; Morgan, Richard D.; Roberts, Richard J.; Maiden, Martin C. J.; Boitano, Matthew; Clark, Tyson A.; Korlach, Jonas; Rao, Desirazu N.; Jennings, Michael P.

    2015-01-01

    Phase variation (random ON/OFF switching) of gene expression is a common feature of host-adapted pathogenic bacteria. Phase variably expressed N6-adenine DNA methyltransferases (Mod) alter global methylation patterns resulting in changes in gene expression. These systems constitute phase variable regulons called phasevarions. Neisseria meningitidis phasevarions regulate genes including virulence factors and vaccine candidates, and alter phenotypes including antibiotic resistance. The target site recognized by these Type III N6-adenine DNA methyltransferases is not known. Single molecule, real-time (SMRT) methylome analysis was used to identify the recognition site for three key N. meningitidis methyltransferases: ModA11 (exemplified by M.NmeMC58I) (5′-CGYm6AG-3′), ModA12 (exemplified by M.Nme77I, M.Nme18I and M.Nme579II) (5′-ACm6ACC-3′) and ModD1 (exemplified by M.Nme579I) (5′-CCm6AGC-3′). Restriction inhibition assays and mutagenesis confirmed the SMRT methylome analysis. The ModA11 site is complex and atypical and is dependent on the type of pyrimidine at the central position, in combination with the bases flanking the core recognition sequence 5′-CGYm6AG-3′. The observed efficiency of methylation in the modA11 strain (MC58) genome ranged from 4.6% at 5′-GCGCm6AGG-3′ sites, to 100% at 5′-ACGTm6AGG-3′ sites. Analysis of the distribution of modified sites in the respective genomes shows many cases of association with intergenic regions of genes with altered expression due to phasevarion switching. PMID:25845594

  6. Data supporting the involvement of the adenine nucleotide translocase conformation in opening the Tl(+)-induced permeability transition pore in Ca(2+)-loaded rat liver mitochondria.

    Korotkov, Sergey M

    2016-06-01

    There we made available information about the effects of the adenine nucleotide translocase (ANT) 'c' conformation fixers (phenylarsine oxide (PAO), tert-butylhydroperoxide (tBHP), and carboxyatractyloside) as well as thiol reagent (4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS)) on isolated rat liver mitochondria. We observed a decrease in A540 (mitochondrial swelling) and respiratory control rates (RCRADP [state 3/state 4] and RCRDNP [2,4-dinitrophenol-uncoupled state/basal state or state 4]), as well as an increase in Ca(2+)-induced safranin fluorescence (F485/590, arbitrary units), showed a dissipation in the inner membrane potential (ΔΨmito), in experiments with energized rat liver mitochondria, injected into the buffer containing 25-75 mM TlNO3, 125 mM KNO3, and 100 µM Ca(2+). The fixers and DIDS, in comparison to Ca(2+) alone, greatly increased A540 decline and the rate of Ca(2+)-induced ΔΨmito dissipation. These reagents also markedly decreased RCRADP and RCRDNP. The MPTP inhibitors (ADP, cyclosporin A, bongkrekic acid, and N-ethylmaleimide) fixing the ANT in 'm' conformation significantly hindered the above-mentioned effects of the fixers and DIDS. A more complete scientific analysis of these findings may be obtained from the manuscript "To involvement the conformation of the adenine nucleotide translocase in opening the Tl(+)-induced permeability transition pore in Ca(2+)-loaded rat liver mitochondria" (Korotkov et al., 2016 [1]). PMID:27054168

  7. To involvement the conformation of the adenine nucleotide translocase in opening the Tl(+)-induced permeability transition pore in Ca(2+)-loaded rat liver mitochondria.

    Korotkov, Sergey M; Konovalova, Svetlana A; Brailovskaya, Irina V; Saris, Nils-Erik L

    2016-04-01

    The conformation of adenine nucleotide translocase (ANT) has a profound impact in opening the mitochondrial permeability transition pore (MPTP) in the inner membrane. Fixing the ANT in 'c' conformation by phenylarsine oxide (PAO), tert-butylhydroperoxide (tBHP), and carboxyatractyloside as well as the interaction of 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) with mitochondrial thiols markedly attenuated the ability of ADP to inhibit the MPTP opening. We earlier found (Korotkov and Saris, 2011) that calcium load of rat liver mitochondria in medium containing TlNO3 and KNO3 stimulated the Tl(+)-induced MPTP opening in the inner mitochondrial membrane. The MPTP opening as well as followed increase in swelling, a drop in membrane potential (ΔΨmito), and a decrease in state 3, state 4, and 2,4-dinitrophenol-uncoupled respiration were visibly enhanced in the presence of PAO, tBHP, DIDS, and carboxyatractyloside. However, these effects were markedly inhibited by ADP and membrane-penetrant hydrophobic thiol reagent, N-ethylmaleimide (NEM) which fix the ANT in 'm' conformation. Cyclosporine A additionally potentiated these effects of ADP and NEM. Our data suggest that conformational changes of the ANT may be directly involved in the opening of the Tl(+)-induced MPTP in the inner membrane of Ca(2+)-loaded rat liver mitochondria. Using the Tl(+)-induced MPTP model is discussed in terms finding new transition pore inhibitors and inducers among different chemical and natural compounds. PMID:26835787

  8. An adenine nucleotide translocase (ANT) gene from Apostichopus japonicus; molecular cloning and expression analysis in response to lipopolysaccharide (LPS) challenge and thermal stress.

    Liu, Qiu-Ning; Chai, Xin-Yue; Tu, Jie; Xin, Zhao-Zhe; Li, Chao-Feng; Jiang, Sen-Hao; Zhou, Chun-Lin; Tang, Bo-Ping

    2016-02-01

    The adenine nucleotide translocases (ANTs) play a vital role in energy metabolism via ADP/ATP exchange in eukaryotic cells. Apostichopus japonicus (Echinodermata: Holothuroidea) is an important economic species in China. Here, a cDNA representing an ANT gene of A. japonicus was isolated and characterized from respiratory tree and named AjANT. The full-length AjANT cDNA is 1924 bp, including a 5'-untranslated region (UTR) of 38 bp, 3'-UTR of 980 bp and an open reading frame (ORF) of 906 bp encoding a polypeptide of 301 amino acids. The protein contains three homologous repeat Mito_carr domains (Pfam00153). The deduced AjANT protein sequence has 49-81% in comparison to ANT proteins from other individuals. The predicted tertiary structure of AjANT protein is highly similar to animal ANT proteins. Phylogenetic analysis showed that the AjANT is closely related to Holothuroidea ANT genes. Real-time quantitative reverse transcription-PCR (qPCR) analysis showed that AjANT expression is higher in the respiratory tree than in other examined tissues. After thermal stress or LPS challenge, expression of AjANT was significantly fluctuant compared to the control. These results suggested that changes in the expression of ANT gene might be involved in immune defense and in protecting A. japonicus against thermal stress. PMID:26706223

  9. Specificities and pH profiles of adenine and hypoxanthine-guanine-xanthine phosphoribosyltransferases (nucleotide synthases) of the thermoacidophile archaeon Sulfolobus solfataricus

    Hansen, Michael Riis; Jensen, Kristine Steen; Rasmussen, Mads Skytte;

    2014-01-01

    Two open reading frames in the genome of Sulfolobus solfataricus (SSO2341 and SSO2424) were cloned and expressed in E. coli. The protein products were purified and their enzymatic activity characterized. Although SSO2341 was annotated as a gene (gpT-1) encoding a 6-oxopurine phosphoribosyltransfe......Two open reading frames in the genome of Sulfolobus solfataricus (SSO2341 and SSO2424) were cloned and expressed in E. coli. The protein products were purified and their enzymatic activity characterized. Although SSO2341 was annotated as a gene (gpT-1) encoding a 6-oxopurine...... phosphoribosyltransferase (PRTase), the protein product turned out to be a PRTase highly specific for adenine and we suggest that the reading frame should be renamed apT. The other reading frame SSO2424 (gpT-2) proved to be a true 6-oxopurine PRTase active with hypoxanthine, xanthine and guanine as substrates, and we.......5, while maximal activity with xanthine was observed at pH 7.5. We discuss likely reasons why SSO2341 in S. solfataricus and similar open reading frames in other Crenarchaeota could not be identified as genes encoding APRTase....

  10. Nitrogen Substituted Polycyclic Aromatic Hydrocarbon As Capable Interstellar Infrared Spectrum Source Considering Astronomical Chemical Evolution Step To Biological Organic Purine And Adenine

    Ota, Norio

    2016-01-01

    In order to find out capable chemical evolution step from astronomically created organic in interstellar space to biological organic on the earth, infrared spectrum of nitrogen substituted carbon pentagon-hexagon coupled polycyclic aromatic hydrocarbon was analyzed by the density functional theory. Ionization was modeled from neutral to tri-cation. Among one nitrogen and two nitrogen substituted NPAH, we could find good examples showing similar IR behavior with astronomically well observed one as like C8H6N1, C7H5N2, and C7H5N2. We can imagine that such ionized NPAH may be created in interstellar space by attacks of high energy nitrogen and photon. Whereas, in case of three and four nitrogen substituted cases as like C6H4N3 and C5H3N4, there were no candidate showing similar behavior with observed one. Also, IR of typical biological organic with four and five nitrogen substituted one as like purine and adenine resulted no good similarity with observed one. By such theoretical comparison, one capable story of ...

  11. Gender and chronological age affect erythrocyte membrane oxidative indices in citrate phosphate dextrose adenine-formula 1 (CPDA-1) blood bank storage condition.

    Erman, Hayriye; Aksu, Uğur; Belce, Ahmet; Atukeren, Pınar; Uzun, Duygu; Cebe, Tamer; Kansu, Ahmet D; Gelişgen, Remisa; Uslu, Ezel; Aydın, Seval; Çakatay, Ufuk

    2016-07-01

    It is well known that in vitro storage lesions lead to membrane dysfunction and decreased number of functional erythrocytes. As erythrocytes get older, in storage media as well as in peripheral circulation, they undergo a variety of biochemical changes. In our study, the erythrocytes with different age groups in citrate phosphate dextrose adenine-formula 1 (CPDA-1) storage solution were used in order to investigate the possible effect of gender factor on oxidative damage. Oxidative damage biomarkers in erythrocyte membranes such as ferric reducing antioxidant power, pro-oxidant-antioxidant balance, protein-bound advance glycation end products, and sialic acid were analyzed. Current study reveals that change in membrane redox status during blood-bank storage condition also depends on both gender depended homeostatic factors and the presence of CPDA-1. During the storage period in CPDA-1, erythrocytes from the male donors are mostly affected by free radical-mediated oxidative stress but erythrocytes obtained from females are severely affected by glyoxidative stress. PMID:27045670

  12. A study of fast and metastable dissociations of adenine-thymine binary-base oligonucleotides by using positive-ion MALDI-TOF mass spectrometry.

    Chan, T W Dominic; Fung, Y M Eva; Li, Y C Leo

    2002-09-01

    In the present study, fast and metastable dissociations of a number of adenine-thymine binary-base oligonucleotides under the conditions of UV matrix-assisted laser desorption/ionization mass spectrometry were investigated. 2-Aminobenzoic acid/ammonium fluoride (ABA/NH4F) matrix system was used. The spectra obtained under metastable and fast dissociation conditions exhibit distinctive dissociation products. From the post-source-decay analysis, all oligonucleotides underwent predominantly metastable dissociations at the 3' C-O linkages to form [a(n)-B]+ and w(n)+ complimentary ion series. Based on the present results, the so-called "[wn+80]+" ions were postulated to be the complimentary [Z(8-n)AH]+ ions rather than the expected phosphate rearrangement products. In addition, these oligonucleotides were found to generate fast dissociation products of b(n)+, d(N)+, w(N)+ and y(N)+ ions through backbone cleavages at 5' C-O, 5' O-P, 3' C-O and 3' P-O linkages, respectively. Product ion series formed under PSD conditions were not observed. The implications of this mutually exclusive occurrence of the two sets of fragment ions under fast and metastable conditions using ABA/NH4F matrix would be discussed. A model of ion activation under UV-MALDI conditions was also proposed. PMID:12322953

  13. An adenine-to-guanine nucleotide change in the IRES SL-IV domain of picornavirus/hepatitis C chimeric viruses leads to a nonviable phenotype

    The inability for the internal ribosomal entry site (IRES) of hepatitis C virus (HCV) to be readily studied in the context of viral replication has been circumvented by constructing chimeras such as with poliovirus (PV), in which translation of the genome polyprotein is under control of the HCV IRES. During our attempts to configure the PV/HCV chimera for our drug discovery efforts, we discovered that an adenine- (A) to-guanine (G) change at nt 350 in domain IV of the HCV IRES resulted in a nonviable phenotype. Similarly, a mengovirus (MV)/HCV chimera using the same configuration with a G at nt 350 (G-350) was found to be nonviable. In contrast, a bovine viral diarrhea virus (BVDV)/HCV chimera remained viable with G-350 in the HCV IRES insert. Second-site, resuscitating mutations were identified from the G-350 PV/HCV and MV/HCV viruses after blind passaging. For both viruses, the resuscitating mutations involved destabilization of domain IV in the HCV IRES. The nonviability of G-350 in the picornavirus/HCV chimeric background might be linked to translation efficiency as indicated by analyses with dual reporter and PV/HCV replicon constructs

  14. Heterocyclic compounds based on N6-substituted adenine, methods of their preparation, their use for preparation of drugs, cosmetic preparations and growth regulators, pharmaceutical preparations, cosmetic preparations and growth regulators containing these compounds

    Popa, I.; Holub, J.; Lenobel, R.; Werbrouck, S.; Doležal, K. (Karel); M. Strnad; Zatloukal, M.; Massino, F. J.

    2013-01-01

    Novel heterocyclic derivatives based on N6-substituted adenine, having anticancer, mitotic, immunosuppressive and antisenescent properties for plant, animal and human cells and methods of their preparation. Included are also pharmaceutical compositions, cosmetic preparations and growth regulators, which contain these derivatives as active compound and the use of these derivatives for the preparation of drugs, cosmetic preparations, in biotechnological processes, in cosmetics and in agriculture.

  15. Detection of non-ΔGT NCF-1 mutations in chronic granulomatous disease

    Jakobsen, Marianne Antonius; Pedersen, Svend Stenvang; Barington, Torben

    2009-01-01

    AIMS: Chronic granulomatous disease (CGD) is a rare inherited disorder caused by mutations in the subunits of the NADPH oxidase complex, leaving phagocytes unable to produce superoxide and thereby unable to kill invading microorganisms. A subgroup of CGD patients (approximately 20%) is reported to...... dinucleotide repeat was set up and used to identify a novel mutation in exon 7 of NCF-1 in a patient with autosomal recessive CGD, explaining the disease by changing a UGG codon to a premature UGA STOP codon. CONCLUSION: The method is generally applicable for the detection of NCF-1 mutations in patients with...... suspected CGD....

  16. Chemical and structural characterization of interstrand cross-links formed between abasic sites and adenine residues in duplex DNA

    Price, Nathan E.; Catalano, Michael J.; Liu, Shuo; Wang, Yinsheng; Gates, Kent S.

    2015-01-01

    A new type of interstrand DNA–DNA cross-link between abasic (Ap) sites and 2′-deoxyadenosine (dA) residues was recently reported, but the chemical structure and properties of this lesion were not rigorously established. Here we characterized the nucleoside cross-link remnant released by enzymatic digestion of duplex DNA containing the dA-Ap cross-link. A synthetic standard was prepared for the putative nucleoside cross-link remnant 6 in which the anomeric carbon of the 2-deoxyribose residue was connected to the exocyclic N6-amino group of dA. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that the synthetic material 6 matched the authentic cross-link remnant released by enzymatic digestion of cross-linked DNA. These findings establish the chemical structure of the dA-Ap cross-link released from duplex DNA and may provide methods for the detection of this lesion in cellular DNA. Both the nucleoside cross-link remnant 6 and the cross-link in duplex DNA were quite stable at pH 7 and 37°C, suggesting that the dA-Ap cross-link could be a persistent lesion with the potential to block the action of various DNA processing enzymes. PMID:25779045

  17. Isolation of methylcarbamoyl-adducts of adenine and cytosine following in vitro reaction of methyl isocyanate with calf thymus DNA.

    Segal, A; Solomon, J J; Li, F J

    1989-01-01

    Methylisocyanate (MIC) is the direct-acting acylating compound involved in the Bhopal, India disaster which occurred on December 3rd, 1984. The accidental release of MIC resulted in at least 2000 deaths, thousands of injuries and exposure of at least 200,000 people to varying amounts of MIC. We have studied how MIC reacts with 2'-deoxyribonucleosides at pH 7.0 and 37 degrees C for 1 h. MIC acylates exocyclic amino groups resulting in the following methylcarbamoyl (MC) adducts: N6-MC-Ade (0.5% yield) and N4-MC-dCyd (6%). No adducts were detected with dThd and dGuo. UV, NMR and mass spectrometry were employed to spectroscopically characterize these adducts. MIC was reacted with calf thymus DNA (pH 7.0, 37 degrees C, 1 h) and yielded N6-MC-Ade (0.3 nmol/mg DNA) and N4-MC-dCyd (2.0 nmol/mg DNA). The inability of others to observe genetic mutations by MIC in Salmonella and Drosophila is consistent with the exocyclic adducts at N4 of Cyt and N6 of Ade where normal hydrogen bonding can occur after rotation of the methylcarbamoyl group anti to the Watson-Crick side of the molecule assuming that MIC binds to DNA within the intact cell. PMID:2731306

  18. Transgene sequences free of CG dinucleotides lead to high level, long-term expression in the lung independent of plasmid backbone design.

    Bazzani, Reto P; Pringle, Ian A; Connolly, Mary M; Davies, Lee A; Sumner-Jones, Stephanie G; Schleef, Martin; Hyde, Stephen C; Gill, Deborah R

    2016-07-01

    Non-viral aerosol gene therapy offers great potential for treating chronic lung diseases of the airways such as cystic fibrosis (CF). Early clinical trials showed that transgene expression in the airways was transient whereas maximal duration of transgene expression is essential in order to minimise the frequency of aerosol treatments. Improved vector design, such as careful selection of the promoter/enhancer, can lead to more persistent levels of transgene expression, but multiple factors affect expression in vivo. Following aerosol delivery to the lungs of mice, we measured reporter gene expression from a CpG-free luciferase transgene cassette in the context of both a plasmid and minicircle vector configuration and showed that the vector backbone had no effect on expression. Transgene activity was affected by the vector backbone however, when a similar, but sub-optimal CpG-containing transgene was used, suggesting that aspects of the plasmid backbone had a negative impact on transgene expression. Similar studies were performed in Toll-like receptor-9 (TLR9) knockout mice to investigate a potential role for the TLR9 signalling pathway in detecting CpGs in the vector sequence. Even in the absence of TLR9, persistent expression could only be achieved with a CpG-free transgene. Together, these data indicate that in order to achieve high levels of persistent expression in vivo, a CpG-free transgene cassette is required. PMID:27061267

  19. {sup 19}F-labeling of the adenine H2-site to study large RNAs by NMR spectroscopy

    Sochor, F. [Johann Wolfgang Goethe-University Frankfurt, Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ) (Germany); Silvers, R. [Massachusetts Institute of Technology, Department of Chemistry, Francis Bitter Magnet Laboratory (United States); Müller, D.; Richter, C.; Fürtig, B., E-mail: fuertig@nmr.uni-frankfurt.de; Schwalbe, H., E-mail: schwalbe@nmr.uni-frankfurt.de [Johann Wolfgang Goethe-University Frankfurt, Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ) (Germany)

    2016-01-15

    In comparison to proteins and protein complexes, the size of RNA amenable to NMR studies is limited despite the development of new isotopic labeling strategies including deuteration and ligation of differentially labeled RNAs. Due to the restricted chemical shift dispersion in only four different nucleotides spectral resolution remains limited in larger RNAs. Labeling RNAs with the NMR-active nucleus {sup 19}F has previously been introduced for small RNAs up to 40 nucleotides (nt). In the presented work, we study the natural occurring RNA aptamer domain of the guanine-sensing riboswitch comprising 73 nucleotides from Bacillus subtilis. The work includes protocols for improved in vitro transcription of 2-fluoroadenosine-5′-triphosphat (2F-ATP) using the mutant P266L of the T7 RNA polymerase. Our NMR analysis shows that the secondary and tertiary structure of the riboswitch is fully maintained and that the specific binding of the cognate ligand hypoxanthine is not impaired by the introduction of the {sup 19}F isotope. The thermal stability of the {sup 19}F-labeled riboswitch is not altered compared to the unmodified sequence, but local base pair stabilities, as measured by hydrogen exchange experiments, are modulated. The characteristic change in the chemical shift of the imino resonances detected in a {sup 1}H,{sup 15}N-HSQC allow the identification of Watson–Crick base paired uridine signals and the {sup 19}F resonances can be used as reporters for tertiary and secondary structure transitions, confirming the potential of {sup 19}F-labeling even for sizeable RNAs in the range of 70 nucleotides.

  20. TGF-β1 induction of the adenine nucleotide translocator 1 in astrocytes occurs through Smads and Sp1 transcription factors

    Wallace Douglas C

    2004-01-01

    Full Text Available Abstract Background The adenine nucleotide translocator 1 (Ant1 is an inner mitochondrial membrane protein involved with energy mobilization during oxidative phosphorylation. We recently showed that rodent Ant1 is upregulated by transforming growth factor-beta (TGF-β in reactive astrocytes following CNS injury. In the present study, we describe the molecular mechanisms by which TGF-β1 regulates Ant1 gene expression in cultured primary rodent astrocytes. Results Transcription reporter analysis verified that TGF-β1 regulates transcription of the mouse Ant1 gene, but not the gene encoding the closely related Ant2 isoform. A 69 basepair TGF-β1 responsive element of the Ant1 promoter was also identified. Electrophoretic mobility shift assays demonstrated that astrocyte nuclear proteins bind to this response element and TGF-β1 treatment recruits additional nuclear protein binding to this element. Antibody supershift and promoter deletion analyses demonstrated that Sp1 consensus binding sites in the RE are important for TGF-β1 regulation of Ant1 in astrocytes. Additionally, we demonstrate that Smad 2, 3 and 4 transcription factors are expressed in injured cerebral cortex and in primary astrocyte cultures. TGF-β1 activated Smad transcription factors also contribute to Ant1 regulation since transcription reporter assays in the presence of dominant negative (DN-Smads 3 and 4 significantly reduced induction of Ant1 by TGF-β1. Conclusion The specific regulation of Ant1 by TGF-β1 in astrocytes involves a cooperative interaction of both Smad and Sp1 binding elements located immediately upstream of the transcriptional start site. The first report of expression of Smads 2, 3 and 4 in astrocytes provided here is consistent with a regulation of Ant1 gene expression by these transcription factors in reactive astrocytes. Given the similarity in TGF-β1 regulation of Ant1 with other genes that are thought to promote neuronal survival, this interaction may

  1. Fabrication of Gold Nanoparticles/Graphene-PDDA Nanohybrids for Bio-detection by SERS Nanotechnology

    Mevold, Andreas H. H.; Hsu, Wei-Wu; Hardiansyah, Andri; Huang, Li-Ying; Yang, Ming-Chien; Liu, Ting-Yu; Chan, Tzu-Yi; Wang, Kuan-Syun; Su, Yu-An; Jeng, Ru-Jong; Wang, Juen-Kai; Wang, Yuh-Lin

    2015-10-01

    In this research, graphene nanosheets were functionalized with cationic poly (diallyldimethylammonium chloride) (PDDA) and citrate-capped gold nanoparticles (AuNPs) for surface-enhanced Raman scattering (SERS) bio-detection application. AuNPs were synthesized by the traditional citrate thermal reduction method and then adsorbed onto graphene-PDDA nanohybrid sheets with electrostatic interaction. The nanohybrids were subject to characterization including X-ray diffraction (XRD), transmission electron microscopy (TEM), zeta potential, and X-ray photoelectron spectroscopy (XPS). The results showed that the diameter of AuNPs is about 15-20 nm immobilized on the graphene-PDDA sheets, and the zeta potential of various AuNPs/graphene-PDDA ratio is 7.7-38.4 mV. Furthermore, the resulting nanohybrids of AuNPs/graphene-PDDA were used for SERS detection of small molecules (adenine) and microorganisms ( Staphylococcus aureus), by varying the ratios between AuNPs and graphene-PDDA. AuNPs/graphene-PDDA in the ratio of AuNPs/graphene-PDDA = 4:1 exhibited the strongest SERS signal in SERS detection of adenine and S. aureus. Thus, it is promising in the application of rapid and label-free bio-detection of bacteria or tumor cells.

  2. Molecular analysis of the Duchenne muscular dystrophy gene in Spanish individuals: Deletion detection and familial diagnosis

    Patino, A.; Garcia-Delgado, M.; Narbona, J. [Univ. of Navarra, Pamplona (Spain)

    1995-11-06

    Deletion studies were performed in 26 Duchenne muscular dystrophy (DMD) patients through amplification of nine different exons by multiplex polymerase chain reaction (PCR). DNA from paraffin-embedded muscle biopsies was analyzed in 12 of the 26 patients studied. Optimization of this technique is of great utility because it enables analysis of material stored in pathology archives. PCR deletion detection, useful in DMD-affected boys, is problematic in determining the carrier state in female relatives. For this reason, to perform familial linkage diagnosis, we made use of a dinucleotide repeat polymorphism (STRP, or short tandem repeat polymorphism) located in intron 49 of the gene. We designed a new pair of primers that enabled the detection of 22 different alleles in relatives in the 14 DMD families studied. The use of this marker allowed familial diagnosis in 11 of the 14 DMD families and detection of de novo deletions in 3 of the probands. 8 refs., 5 figs., 2 tabs.

  3. DMXAA Causes Tumor Site-Specific Vascular Disruption in Murine Non-Small Cell Lung Cancer, and like the Endogenous Non-Canonical Cyclic Dinucleotide STING Agonist, 2′3′-cGAMP, Induces M2 Macrophage Repolarization

    Downey, Charlene M.; Aghaei, Mehrnoosh; Schwendener, Reto A.; Jirik, Frank R.

    2014-01-01

    The vascular disrupting agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA), a murine agonist of the stimulator of interferon genes (STING), appears to target the tumor vasculature primarily as a result of stimulating pro-inflammatory cytokine production from tumor-associated macrophages (TAMs). Since there were relatively few reports of DMXAA effects in genetically-engineered mutant mice (GEMM), and models of non-small cell lung cancer (NSCLC) in particular, we examined both the effectiveness and macrophage dependence of DMXAA in various NSCLC models. The DMXAA responses of primary adenocarcinomas in K-rasLA1/+ transgenic mice, as well as syngeneic subcutaneous and metastatic tumors, generated by a p53R172HΔg/+; K-rasLA1/+ NSCLC line (344SQ-ELuc), were assessed both by in vivo bioluminescence imaging as well as by histopathology. Macrophage-dependence of DMXAA effects was explored by clodronate liposome-mediated TAM depletion. Furthermore, a comparison of the vascular structure between subcutaneous tumors and metastases was carried out using micro-computed tomography (micro-CT). Interestingly, in contrast to the characteristic hemorrhagic necrosis produced by DMXAA in 344SQ-ELuc subcutaneous tumors, this agent failed to cause hemorrhagic necrosis of either 344SQ-ELuc-derived metastases or autochthonous K-rasLA1/+ NSCLCs. In addition, we found that clodronate liposome-mediated depletion of TAMs in 344SQ-ELuc subcutaneous tumors led to non-hemorrhagic necrosis due to tumor feeding-vessel occlusion. Since NSCLC were comprised exclusively of TAMs with anti-inflammatory M2-like phenotype, the ability of DMXAA to re-educate M2-polarized macrophages was examined. Using various macrophage phenotypic markers, we found that the STING agonists, DMXAA and the non-canonical endogenous cyclic dinucleotide, 2′3′-cGAMP, were both capable of re-educating M2 cells towards an M1 phenotype. Our findings demonstrate that the choice of preclinical model and the anatomical site of a

  4. DMXAA causes tumor site-specific vascular disruption in murine non-small cell lung cancer, and like the endogenous non-canonical cyclic dinucleotide STING agonist, 2'3'-cGAMP, induces M2 macrophage repolarization.

    Downey, Charlene M; Aghaei, Mehrnoosh; Schwendener, Reto A; Jirik, Frank R

    2014-01-01

    The vascular disrupting agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA), a murine agonist of the stimulator of interferon genes (STING), appears to target the tumor vasculature primarily as a result of stimulating pro-inflammatory cytokine production from tumor-associated macrophages (TAMs). Since there were relatively few reports of DMXAA effects in genetically-engineered mutant mice (GEMM), and models of non-small cell lung cancer (NSCLC) in particular, we examined both the effectiveness and macrophage dependence of DMXAA in various NSCLC models. The DMXAA responses of primary adenocarcinomas in K-rasLA1/+ transgenic mice, as well as syngeneic subcutaneous and metastatic tumors, generated by a p53R172HΔg/+; K-rasLA1/+ NSCLC line (344SQ-ELuc), were assessed both by in vivo bioluminescence imaging as well as by histopathology. Macrophage-dependence of DMXAA effects was explored by clodronate liposome-mediated TAM depletion. Furthermore, a comparison of the vascular structure between subcutaneous tumors and metastases was carried out using micro-computed tomography (micro-CT). Interestingly, in contrast to the characteristic hemorrhagic necrosis produced by DMXAA in 344SQ-ELuc subcutaneous tumors, this agent failed to cause hemorrhagic necrosis of either 344SQ-ELuc-derived metastases or autochthonous K-rasLA1/+ NSCLCs. In addition, we found that clodronate liposome-mediated depletion of TAMs in 344SQ-ELuc subcutaneous tumors led to non-hemorrhagic necrosis due to tumor feeding-vessel occlusion. Since NSCLC were comprised exclusively of TAMs with anti-inflammatory M2-like phenotype, the ability of DMXAA to re-educate M2-polarized macrophages was examined. Using various macrophage phenotypic markers, we found that the STING agonists, DMXAA and the non-canonical endogenous cyclic dinucleotide, 2'3'-cGAMP, were both capable of re-educating M2 cells towards an M1 phenotype. Our findings demonstrate that the choice of preclinical model and the anatomical site of a

  5. The role of sirtuins in cellular homeostasis.

    Kupis, Wioleta; Pałyga, Jan; Tomal, Ewa; Niewiadomska, Ewa

    2016-09-01

    Sirtuins are evolutionarily conserved nicotinamide adenine dinucleotide (NAD(+))-dependent lysine deacylases or ADP-ribosyltransferases. These cellular enzymes are metabolic sensors sensitive to NAD(+) levels that maintain physiological homeostasis in the animal and plant cells. PMID:27154583

  6. Decreased visfatin after exercise training correlates with improved glucose tolerance

    Haus, Jacob M; Solomon, Thomas; Marchetti, Christine M; O'Leary, Valerie B; Brooks, Latina M; Gonzalez, Frank; Kirwan, John P

    2009-01-01

    Nampt/pre-B-cell colony-enhancing factor/visfatin (visfatin) release from adipocytes has recently been suggested to be nutrient responsive and linked to systemic nicotinamide adenine dinucleotide biosynthesis and regulation of pancreatic beta-cell function....

  7. Anticancer agent CHS-828 inhibits cellular synthesis of NAD

    Olesen, U.H.; Christensen, M.K.; Bjorkling, F.;

    2008-01-01

    Malignant cells display increased demands for energy production and DNA repair. Nicotinamide adenine dinucleotide (NAD) is required for both processes and is also continuously degraded by cellular enzymes. Nicotinamide phosphoribosyltransferase (Nampt) is a crucial factor in the resynthesis of NA...

  8. 3bzu - Proteopedia, life in 3D [Proteopedia

    Full Text Available 3bzu From Proteopedia Jump to: navigation, search Crystal structure of human 11-beta-hydroxyster ... amide adenine dinucleotide phosphate (reduced). In lean ... C57BL/6 mice, the compound inhibited both the in v ...

  9. Primaquine

    ... carry oxygen to the tissues in the body),nicotinamide adenine dinucleotide (NADH) deficiency (a genetic condition), glucose- ... these symptoms, call your doctor immediately: tiredness pale skin shortness of breath fast heartbeat yellowing of the ...

  10. Sequence Classification: 890397 [

    Full Text Available TMB Non-TMH TMB TMB TMB TMB >gi|6322057|ref|NP_012132.1| Protein required for transport of flavi ... n adenine dinucleotide (FAD) from mit ochondria, where it ... is synthesized from riboflavin, ...

  11. Physicochemical studies of the reaction of 99mTc with 5,5‧-diethyl barbituric acid, adenine, D-glucose and thiobarbituric acid at different temperatures

    Masoud, M. S.; El-Shahat, M. F.; Elkholany, A. S.

    2014-06-01

    The reaction of 99mTc pertechnetate with 5,5‧-diethyl barbituric acid, adenine, D-glucose and thiobarbituric acid at different temperatures was studied. The solvent effect on the electronic absorption spectra of the reactions was recorded. The reaction mixtures have been analyzed at different times using TLC and a radiodetctor to show the peaks at the plates. 99mTc pertechnetate is obtained from the Mo generators. It is difficult to separate the complexes in the solid state. The percentage of 99mTc involved in the complexes can be determined. Characterization of the 99mTc complexes as well as the determination of the extent of radiolabeling was done by thin layer chromatography using 0.9% NaCl solution as a solvent. The Rf value of 99TcO4- is (≈1). The solvatochromism for the reaction of 99mTc with D-glucose was mainly affected by solute permanent dipole-solvent permanent dipole interaction, the dipolar interaction for the reaction of 99mTc with of 5,5‧-diethyl barbituric acid and for the reaction of 99mTc with adenine and thiobarbituric was solute-solvent hydrogen bonding.

  12. HepG2 cells develop signs of riboflavin deficiency within four days of culture in riboflavin-deficient medium*

    Werner, Ricarda; MANTHEY, KAROLINE C.; Griffin, Jacob B.; Zempleni, Janos

    2005-01-01

    Flavin mononucleotide and flavin adenine dinucleotide are essential coenzymes in redox reactions. For example, flavin adenine dinucleotide is a coenzyme for both glutathione reductase and enzymes that mediate the oxidative folding of secretory proteins. Here we investigated short-term effects of moderately riboflavin-deficient culture medium on flavin-related responses in HepG2 hepatocarcinoma cells. Cells were cultured in riboflavin-deficient (3.1 nmol/L) medium for up to six days; controls ...

  13. Involvement of the NADPH Oxidase NOX2-Derived Brain Oxidative Stress in an Unusual Fatal Case of Cocaine-Related Neurotoxicity Associated With Excited Delirium Syndrome.

    Schiavone, Stefania; Riezzo, Irene; Turillazzi, Emanuela; Trabace, Luigia

    2016-10-01

    Here, we investigated the possible role of the Nicotinamide Adenine Dinucleotide Phosphate oxidase NOX2-derived brain oxidative stress in a fatal case of cocaine-related neurotoxicity, associated to excited delirium syndrome. We detected a strong NOX2 immunoreactivity, mainly in cortical GABAergic neurons and astrocytes, with a minor presence in microglia, glutamatergic and dopaminergic neurons as well as a significant immunostaining for other markers of oxidative stress (8OhDG, HSP70, HSP90, and NF-κB) and apoptotic phenomena. These results support a crucial role of NOX2-derived brain oxidative stress in cocaine-induced brain dysfunctions and neurotoxicity. PMID:27533346

  14. Genotypic and phenotypic spectrum of pyridoxine-dependent epilepsy (ALDH7A1 deficiency)

    Mills, Philippa B; Footitt, Emma J; Mills, Kevin A;

    2010-01-01

    Pyridoxine-dependent epilepsy was recently shown to be due to mutations in the ALDH7A1 gene, which encodes antiquitin, an enzyme that catalyses the nicotinamide adenine dinucleotide-dependent dehydrogenation of l-alpha-aminoadipic semialdehyde/L-Delta1-piperideine 6-carboxylate. However, whilst...... normal range, DNA sequencing of the ALDH7A1 gene was performed. Clinicians were asked to complete questionnaires on clinical, biochemical, magnetic resonance imaging and electroencephalography features of patients. The clinical spectrum of antiquitin deficiency extended from ventriculomegaly detected on...

  15. 基于SERS光谱的银溶胶溶液中腺嘌呤的定量分析%Quantitative Analysis with Adenine in Silver Colloidal Sol by Surface-enhanced Raman Scattering Spectroscopic Technique

    冯小平; 曹晓卫; 汪佳俐; 李玲; 张志学

    2012-01-01

    Surface-enhanced Raman scattering (SERS) spectroscopic technique was used to perform quantitative analyses with adenine, an important basic group from nucleic acid, by using silver colloidal sol as the SERS substrate. Sodium polyacrylate was added into the silver colloidal sol in order to improve its stability. In addition, during different SERS measurements, pyridine was used an internal standard to eliminate the impact of the variations in laser power, optical alignment and focusing on the SERS signal intensity of the an-alyte. It reveals that a good linear relationship is presented between the concentration of adenine and the characteristic SERS signal intensity ratio of the analyte adenine (733 cm-1) to the internal standard pyridine (1003 cm-1) in the range of 1× 10-4~1× 10-3mol ·L-1.%碱基是构成核酸的物质基础.碱基的含量分析对于生物体的生理活动及新陈代谢过程研究具有重要意义.本文利用表面增强拉曼散射(SERS)光谱技术研究了腺嘌呤在相对稳定的银溶胶溶液中的SERS光谱信号强度与浓度的定量关系.研究表明添加聚合物作为稳定剂的银溶胶具有良好的稳定性.进一步研究表明,在1×10-4~1×10-2mol·L-1的浓度范围内,以吡啶作为内标,分析物腺嘌呤与内标物特征谱峰强度之比与腺嘌呤的浓度之间呈现良好的线性关系.

  16. Detection of neuroinflammation through the retina by means of Raman spectroscopy and multivariate analysis

    Marro, Monica; Taubes, Alice; Villoslada, Pablo; Petrov, Dmitri

    2012-06-01

    Retinal nervous tissue sustains a substantial damage during the autoimmune inflammatory processes characteristic for Multiple Sclerosis (MS). The damage can be characterized non-surgically by Raman Spectroscopy, a non-invasive optical imaging technology. We used non-resonant near-infrared Raman spectrosocopy to create a spectral library of eight pivotal biomolecules known to be involved in neuroinflammation: Nicotinamide Adenine Dinucliotide (NADH), Flavin Adenine Nucleotide (FAD), Lactate, Cytochrome C, Glutamate, N-Acetyl- Aspartate (NAA), Phosphotidylcholine, with Advanced Glycolization End Products (AGEs) analyzed as a reference. Principal Component Analysis (PCA) of 50 spectra taken of murine retinal tissue culture undergoing an inflammatory response and healthy controls was used in order to characterize the molecular makeup of the inflammation. The loading plots revealed a heavy influence of peaks related to Glutamate, NADH, and Phosphotidylcholine to inflammation-related spectral changes. Partial Least Squares - Discriminant analysis (PLS-DA) was performed to create a multivariate classifier for the spectral diagnosis of neuroinflammed tissue and yielded a diagnostic sensitivity of 100% and specificity of 100%. We demonstrate then the effectiveness of combining Raman spectroscopy with PCA and PLS-DA statistical techniques to detect and monitor neuroinflamation in retina. With this technique Glutamate, NAA and NADH are detected in retina tissue as signs for neuroinflammation.

  17. X-ray crystallographic characterization of an adenine-cadmium (II) complex, di-. mu. -adeninium-di-. mu. -aquo-tetrakis(nitrato-0,0')dicadmium(II) dinitrate, containing a cationic nuclei acid base as a bidentate ligand

    Wei, C.H.; Jacobson, K.B.

    1981-02-01

    The reaction of the monosodium salt of adenosine-5'-monophosphoric acid with cadmium nitrate in the presence of nitric acid has resulted in the formation of a binuclear cadmium complex of adenine, ((C/sub 5/H/sub 6/N/sub 5/)Cd(NO/sub 3/)/sub 2/.H/sub 2/O)/sub 2/(NO/sub 3/)/sub 2/. The crystal structure of this complex has been characterized by single-crystal x-ray analysis based on counter data collected with an automated diffractometer. The crystals contain one centrosymmetric dimer in a reduced triclinic cell of symmetry P anti 1 and of dimensions a = 7.595 (2) A, b = 9.539 (5) A, c = 10.527 (5) A, ..cap alpha.. = 101.37 (3)/sup 0/, ..beta.. = 108.69 (3)/sup 0/, and ..gamma.. = 107.42 (3)/sup 0/.

  18. Molecular cloning and functional characterization of the dual oxidase (BmDuox gene from the silkworm Bombyx mori.

    Xiaolong Hu

    Full Text Available Reactive oxygen species (ROS from nicotinamide adenine dinucleotide phosphate (NADPH oxidases and their related dual oxidases are known to have significant roles in innate immunity and cell proliferation. In this study, the 5,545 bp cDNA of the silkworm Bombyx mori dual oxidase (BmDuox gene containing a full-length open reading frame was cloned. It was shown to include an N-terminal signal peptide consisting of 28 amino acid residues, a 240 bp 5'-terminal untranslated region (5'-UTR, an 802 bp 3'-terminal region (3'-UTR, which contains nine ATTTA motifs, and a 4,503 bp open reading frame encoding a polypeptide of 1,500 amino acid residues. Structural analysis indicated that BmDuox contains a typical peroxidase domain at the N-terminus followed by a calcium-binding domain, a ferric-reducing domain, six transmembrane regions and binding domains for flavin adenine dinucleotide (FAD and nicotinamide adenine dinucleotide (NAD. Transcriptional analysis revealed that BmDuox mRNA was expressed more highly in the head, testis and trachea compared to the midgut, hemocyte, Malpighian tube, ovary, fat bodies and silk glands. BmDuox mRNA was expressed during all the developmental stages of the silkworm. Subcellular localization revealed that BmDoux was present mainly in the periphery of the cells. Some cytoplasmic staining was detected, with rare signals in the nucleus. Expression of BmDuox was induced significantly in the larval midgut upon challenge by Escherichia coli and Bombyx mori nucleopolyhedrovirus (BmNPV. BmDuox-deleted larvae showed a marked increase in microbial proliferation in the midgut after ingestion of fluorescence-labeled bacteria compared to the control. We conclude that reducing BmDuox expression greatly increased the bacterial load, suggesting BmDuox has an important role in inhibiting microbial proliferation and the maintenance of homeostasis in the silkworm midgut.

  19. NADH supplementation decreases pinacidil-primed IK(ATP) in ventricular cardiomyocytes by increasing intracellular ATP

    Pelzmann, Brigitte; Hallström, Seth; Schaffer, Peter; Lang, Petra; Nadlinger, Karl; Birkmayer, George D; Vrecko, Karoline; Reibnegger, Gilbert; Koidl, Bernd

    2003-01-01

    The aim of this study was to investigate the effect of nicotinamide-adenine dinucleotide (NADH) supplementation on the metabolic condition of isolated guinea-pig ventricular cardiomyocytes. The pinacidil-primed ATP-dependent potassium current IK(ATP) was used as an indicator of subsarcolemmal ATP concentration and intracellular adenine nucleotide contents were measured.Membrane currents were studied using the patch-clamp technique in the whole-cell recording mode at 36–37°C. Adenine nucleotid...

  20. The N-Ethyl-N-Nitrosourea-Induced Goldenticket Mouse Mutant Reveals an Essential Function of Sting in the In Vivo Interferon Response to Listeria monocytogenes and Cyclic Dinucleotides

    Sauer, John-Demian; Sotelo-Troha, Katia; von Moltke, Jakob; Monroe, Kathryn M.; Rae, Chris S.; Brubaker, Sky W.; Hyodo, Mamoru; Hayakawa, Yoshihiro; Woodward, Joshua J.; Portnoy, Daniel A.; Vance, Russell E.

    2010-01-01

    Type I interferons (IFNs) are central regulators of the innate and adaptive immune responses to viral and bacterial infections. Type I IFNs are induced upon cytosolic detection of microbial nucleic acids, including DNA, RNA, and the bacterial second messenger cyclic-di-GMP (c-di-GMP). In addition, a recent study demonstrated that the intracellular bacterial pathogen Listeria monocytogenes stimulates a type I IFN response due to cytosolic detection of bacterially secreted c-di-AMP. The transme...

  1. Efeito da sacarose, cinetina, isopentenil adenina e zeatina no desenvolvimento de embriões de Heliconia rostrata in vitro Effect of sucrose, kinetin, isopentenyl adenine and zeatin on the development of embryos of Heliconia rostrata in vitro

    Antonio Carlos Torres

    2005-07-01

    Full Text Available Embriões provenientes de frutos maturos de Heliconia rostrata Ruiz & Pavon foram excisados e inoculados em meio de cultura contendo os sais básicos MS, vitaminas e sacarose. A adição de sacarose foi essencial para o desenvolvimento dos embriões. Em meio desprovido de sacarose os embriões morreram em cultura. Concentrações de 1%, 2% e 3% (p/v de sacarose favoreceram o desenvolvimento dos embriões. Concentrações de 6%, 9% e 12% (p/v de sacarose inibiram o crescimento dos embriões. A adição de cinetina, isopentenil adenina e zeatina não favoreceram o crescimento e o desenvolvimento dos embriões.Embryos from mature fruits of Heliconia rostrata were excised and cultured in basal medium containing MS salts, vitamins and sucrose. Sucrose was essential for embryo development. In meclium without sucrose the embryos died in culture. Sucrose concentrations of 1%, 2% and 3% (w/v were beneficial for embryo development. Sucrose concentrations of 6%, 9% and 12% (w/v inhibited embryo growth. The addition of kinetin, isopentenyl adenine and zeatin did not improve embryo growth and development.

  2. Detection and Monitoring of Neurotransmitters - a Spectroscopic Analysis

    Manciu, Felicia; Lee, Kendall; Durrer, William; Bennet, Kevin

    2012-10-01

    In this work we demonstrate the capability of confocal Raman mapping spectroscopy for simultaneously and locally detecting important compounds in neuroscience such as dopamine, serotonin, and adenosine. The Raman results show shifting of the characteristic vibrations of the compounds, observations consistent with previous spectroscopic studies. Although some vibrations are common in these neurotransmitters, Raman mapping was achieved by detecting non-overlapping characteristic spectral signatures of the compounds, as follows: for dopamine the vibration attributed to C-O stretching, for serotonin the indole ring stretching vibration, and for adenosine the adenine ring vibrations. Without damage, dyeing, or preferential sample preparation, confocal Raman mapping provided positive detection of each neurotransmitter, allowing association of the high-resolution spectra with specific micro-scale image regions. Such information is particularly important for complex, heterogeneous samples, where modification of the chemical or physical composition can influence the neurotransmission processes. We also report an estimated dopamine diffusion coefficient two orders of magnitude smaller than that calculated by the flow-injection method.

  3. New Surface-Enhanced Raman Sensing Chip Designed for On-Site Detection of Active Ricin in Complex Matrices Based on Specific Depurination.

    Tang, Ji-Jun; Sun, Jie-Fang; Lui, Rui; Zhang, Zong-Mian; Liu, Jing-Fu; Xie, Jian-Wei

    2016-01-27

    Quick and accurate on-site detection of active ricin has very important realistic significance in view of national security and defense. In this paper, optimized single-stranded oligodeoxynucleotides named poly(21dA), which function as a depurination substrate of active ricin, were screened and chemically attached on gold nanoparticles (AuNPs, ∼100 nm) via the Au-S bond [poly(21dA)-AuNPs]. Subsequently, poly(21dA)-AuNPs were assembled on a dihydrogen lipoic-acid-modified Si wafer (SH-Si), thus forming the specific surface-enhanced Raman spectroscopy (SERS) chip [poly(21dA)-AuNPs@SH-Si] for depurination of active ricin. Under optimized conditions, active ricin could specifically hydrolyze multiple adenines from poly(21dA) on the chip. This depurination-induced composition change could be conveniently monitored by measuring the distinct attenuation of the SERS signature corresponding to adenine. To improve sensitivity of this method, a silver nanoshell was deposited on post-reacted poly(21dA)-AuNPs, which lowered the limit of detection to 8.9 ng mL(-1). The utility of this well-controlled SERS chip was successfully demonstrated in food and biological matrices spiked with different concentrations of active ricin, thus showing to be very promising assay for reliable and rapid on-site detection of active ricin. PMID:26719952

  4. Multiphoton fluorescence lifetime imaging of metabolic status in mesenchymal stem cell during adipogenic differentiation

    Meleshina, A. V.; Dudenkova, V. V.; Shirmanova, M. V.; Bystrova, A. S.; Zagaynova, E. V.

    2016-03-01

    Non-invasive imaging of cell metabolism is a valuable approach to assess the efficacy of stem cell therapy and understand the tissue development. In this study we analyzed metabolic trajectory of the mesenchymal stem cells (MCSs) during differentiation into adipocytes by measuring fluorescence lifetimes of free and bound forms of the reduced nicotinamide adenine dinucleotide (NAD(P)H) and flavine adenine dinucleotide (FAD). Undifferentiated MSCs and MSCs on the 5, 12, 19, 26 days of differentiation were imaged on a Zeiss 710 microscope with fluorescence lifetime imaging (FLIM) system B&H (Germany). Fluorescence of NAD(P)H and FAD was excited at 750 nm and 900 nm, respectively, by a femtosecond Ti:sapphire laser and detected in a range 455-500 nm and 500-550 nm, correspondingly. We observed the changes in the NAD(P)H and FAD fluorescence lifetimes and their relative contributions in the differentiated adipocytes compare to undifferentiated MSCs. Increase of fluorescence lifetimes of the free and bound forms of NAD(P)H and the contribution of protein-bound NAD(P)H was registered, that can be associated with a metabolic switch from glycolysis to oxidative phosphorylation and/or synthesis of lipids in adipogenically differentiated MSCs. We also found that the contribution of protein-bound FAD decreased during differentiation. After carrying out appropriate biochemical measurements, the observed changes in cellular metabolism can potentially serve to monitor stem cell differentiation by FLIM.

  5. Imaging corneal pathology in a transgenic mouse model using nonlinear microscopy

    Lyubovitsky, Julia G.; Spencer, Joel A.; Krasieva, Tatiana B.; Andersen, Bogi; Tromberg, Bruce J.

    2006-01-01

    A transgenic mouse model with a Clim [co-factor of LIM (a combination of first letters of Lin-11 (C. elegans), ISL1 (rat), and Mec-3 (C. elegans) gene names) domain proteins] gene partially blocked in the epithelial compartment of its tissues is used to establish the sensitivity of intrinsic reflectance nonlinear optical microscopy (NLOM) to stromal and cellular perturbations in the cornea. Our results indicate dysplasia in the squamous epithelium, irregular collagen arrays in the stroma, and a compromised posterior endothelium in the corneas of these mice. As suggested by biochemical data, the collagen alterations are likely due to collagen III synthesis and deposition during healing and remodeling of transgenic mice corneal stromas. All of the topographic features seen in NLOM images of normal and aberrant corneas are confirmed by coregistration with histological sections. In this work, we also use ratiometric redox fluorometry based on two-photon excited cellular fluorescence from reduced nicotinamide adenine dinucleotide (NAD)(P)H and oxidized flavin adenine dinucleotide (FAD) to study mitocondrial energy metabolism. Employing this method, we detect higher metabolic activity in the endothelial layer of cornea compared to an epithelial layer located further away from the metabolites. The combination of two-photon excited fluorescence (TPF) with second harmonic generation (SHG) signals allows imaging to aid in understanding the relationship between alternation of specific genes and structural changes in cells and extracellular matrix.

  6. Fluorescence lifetime imaging ophthalmoscopy in type 2 diabetic patients who have no signs of diabetic retinopathy

    Schweitzer, Dietrich; Deutsch, Lydia; Klemm, Matthias; Jentsch, Susanne; Hammer, Martin; Peters, Sven; Haueisen, Jens; Müller, Ulrich A.; Dawczynski, Jens

    2015-06-01

    The time-resolved autofluorescence of the eye is used for the detection of metabolic alteration in diabetic patients who have no signs of diabetic retinopathy. One eye from 37 phakic and 11 pseudophakic patients with type 2 diabetes, and one eye from 25 phakic and 23 pseudophakic healthy subjects were included in the study. After a three-exponential fit of the decay of autofluorescence, histograms of lifetimes τi, amplitudes αi, and relative contributions Qi were statistically compared between corresponding groups in two spectral channels (490diabetic patients and age-matched controls (p450 ps, and the shift of τ3 from ˜3000 to 3700 ps in ch1 of diabetic patients when compared with healthy subjects indicate an increased production of free flavin adenine dinucleotide, accumulation of advanced glycation end products (AGE), and, probably, a change from free to protein-bound reduced nicotinamide adenine dinucleotide at the fundus. AGE also accumulated in the crystalline lens.

  7. 2-Aminopurine hairpin probes for the detection of ultraviolet-induced DNA damage

    Highlights: ► Molecular beacon with 2AP bases detects DNA damage in a simple mix-and-read assay. ► Molecular beacons with 2AP bases detect damage at a 17.2 nM limit of detection. ► The 2AP molecular beacon is linear over a 0–3.5 μM concentration range for damage. - Abstract: Nucleic acid exposure to radiation and chemical insults leads to damage and disease. Thus, detection and understanding DNA damage is important for elucidating molecular mechanisms of disease. However, current methods of DNA damage detection are either time-consuming, destroy the sample, or are too specific to be used for generic detection of damage. In this paper, we develop a fluorescence sensor of 2-aminopurine (2AP), a fluorescent analogue of adenine, incorporated in the loop of a hairpin probe for the quantification of ultraviolet (UV) C-induced nucleic acid damage. Our results show that the selectivity of the 2AP hairpin probe to UV-induced nucleic acid damage is comparable to molecular beacon (MB) probes of DNA damage. The calibration curve for the 2AP hairpin probe shows good linearity (R2 = 0.98) with a limit of detection of 17.2 nM. This probe is a simple, fast and economic fluorescence sensor for the quantification of UV-induced damage in DNA.

  8. Statistical methods for detecting periodic fragments in DNA sequence data

    Ying Hua

    2011-04-01

    period detection in the presence of eroded periodicity. The autocorrelation method was identified as poorly suited for use with the blockwise bootstrap. Application of our methods to the genomes of two model organisms revealed a striking proportion of the yeast and mouse genomes are spanned by NPS. Despite their markedly different sizes, roughly equivalent proportions (19-21% of the genomes lie within period-10 spans of the NPS dinucleotides {AA, TT, TA}. The biological significance of these regions remains to be demonstrated. To facilitate this, the genomic coordinates are available as Additional files 1, 2, and 3 in a format suitable for visualisation as tracks on popular genome browsers. Reviewers This article was reviewed by Prof Tomas Radivoyevitch, Dr Vsevolod Makeev (nominated by Dr Mikhail Gelfand, and Dr Rob D Knight.

  9. Change Detection

    Rensink, Ronald A.

    2002-01-01

    Five aspects of visual change detection are reviewed. The first concerns the concept of change itself, in particular the ways it differs from the related notions of motion and difference. The second involves the various methodological approaches that have been developed to study change detection; it is shown that under a variety of conditions observers are often unable to see large changes directly in front of them. Next, it is argued that this "change blindness" indicates that focused att...

  10. Biochemical evidence of the interactions of membrane type-1 matrix metalloproteinase (MT1-MMP) with adenine nucleotide translocator (ANT): potential implications linking proteolysis with energy metabolism in cancer cells.

    Radichev, Ilian A; Remacle, Albert G; Sounni, Nor Eddine; Shiryaev, Sergey A; Rozanov, Dmitri V; Zhu, Wenhong; Golubkova, Natalya V; Postnova, Tatiana I; Golubkov, Vladislav S; Strongin, Alex Y

    2009-05-15

    Invasion-promoting MT1-MMP (membrane type-1 matrix metalloproteinase) is a key element in cell migration processes. To identify the proteins that interact and therefore co-precipitate with this proteinase from cancer cells, we used the proteolytically active WT (wild-type), the catalytically inert E240A and the C-end truncated (tailless; DeltaCT) MT1-MMP-FLAG constructs as baits. The identity of the pulled-down proteins was determined by LC-MS/MS (liquid chromatography tandem MS) and then confirmed by Western blotting using specific antibodies. We determined that, in breast carcinoma MCF cells (MCF-7 cells), ANT (adenine nucleotide translocator) efficiently interacted with the WT, E240A and DeltaCT constructs. The WT and E240A constructs also interacted with alpha-tubulin, an essential component of clathrin-mediated endocytosis. In turn, tubulin did not co-precipitate with the DeltaCT construct because of the inefficient endocytosis of the latter, thus suggesting a high level of selectivity of our test system. To corroborate these results, we then successfully used the ANT2-FLAG construct as a bait to pull-down MT1-MMP, which was naturally produced by fibrosarcoma HT1080 cells. We determined that the presence of the functionally inert catalytic domain alone was sufficient to cause the proteinase to interact with ANT2, thus indicating that there is a non-proteolytic mode of these interactions. Overall, it is tempting to hypothesize that by interacting with pro-invasive MT1-MMP, ANT plays a yet to be identified role in a coupling mechanism between energy metabolism and pericellular proteolysis in migrating cancer cells. PMID:19232058

  11. Comparison of lipid oxidation, messenger ribonucleic acid levels of avian uncoupling protein, avian adenine nucleotide translocator, and avian peroxisome proliferator-activated receptor-γ coactivator-1α in skeletal muscles from electrical- and gas-stunned broilers.

    Xu, L; Wu, S G; Zhang, H J; Zhang, L; Yue, H Y; Ji, F; Qi, G H

    2011-09-01

    The aim of this study was to compare the effects of stunning methods [electrical stunning (ES) vs. gas stunning (GS)] on lipid oxidation in broiler meat and to investigate possible mechanisms of lipid oxidation by measuring plasma variables, muscle reactive oxygen species (ROS), and TBA reactive substance (TBARS) concentrations, muscle fiber ratios, and mRNA levels of avian uncoupling protein (avUCP), avian adenine nucleotide translocator, and avian peroxisome proliferator-activated receptor-γ coactivator-1α (avPGC-1α). Arbor Acres broilers (n = 36) were not stunned (control) or were exposed to the following stunning treatments: 40% CO(2) + 21% O(2) + N(2); 60% CO(2) + 21% O(2) + N(2); 35 V, 47 mA, 400 Hz; 50 V, 67 mA, 160 Hz; and 65 V, 86 mA, 1,000 Hz. The ROS level in tibialis anterior (TA; P < 0.05) and the TBARS concentration in pectoralis major (PM; P < 0.01) were decreased in the GS groups compared with the ES groups at 45 min postmortem. However, the TBARS concentrations at 24 h postmortem in the PM and TA groups were not affected by stunning method (ES or GS). Compared with ES, GS caused greater expression of avUCP mRNA (1.47-fold in PM, and 2.41-fold in TA) and avPGC-1α mRNA (1.42-fold in PM, and 2.08-fold in TA). In conclusion, the upregulation of avUCP and avPGC-1α reduced ROS accumulation and lipid oxidation at 45 min postmortem in the skeletal muscles of broilers stunned with hypercapnic moderate oxygenation GS. However, these changes were not sufficient to cause a difference in meat lipid oxidation at 24 h postmortem between broilers stunned with hypercapnic moderate oxygenation GS and those stunned with low-current, high-frequency ES. PMID:21844275

  12. Fingerprint detection

    Saunders, George C. (Rt. 1, Box 428B, Espanola, NM 87532)

    1992-01-01

    A method for detection and visualization of latent fingerprints is provided and includes contacting a substrate containing a latent print thereon with a colloidal metal composition for time sufficient to allow reaction of said colloidal metal composition with said latent print, and preserving or recording the observable print. Further, the method for detection and visualization of latent fingerprints can include contacting the metal composition-latent print reaction product with a secondary metal-containing solution for time sufficient to allow precipitation of said secondary metal thereby enhancing the visibility of the latent print, and preserving or recording the observable print.

  13. Synthesis and physicochemical properties of novel lophine derivatives as chemiluminescent in vitro activators for detection of free radicals.

    Pavlova, Elitsa; Kaloyanova, Stefka; Deligeorgiev, Todor; Lesev, Nedyalko

    2015-12-01

    The overproduction of free radicals and reactive oxygen species (ROS) has been proved as a basic damage mechanism and cause for oxidative stress. Their measurement is often hindered by the low signal. This could be resolved with the application of luminescent probes (lophines, luminol, lucigenin, etc.). The focus of this study is to synthesize and describe the spectral properties and physicochemical characteristics of lophine and its derivatives as new chemiluminescent in vitro activators. The prepared luminophores are analogues of lophine. Their absorption maxima are in the range 329-340 nm, with good-to-high extinction coefficients. Their spectral properties are measured in methanol and buffer solutions with pH 3.5, 7.4 and 8.5. Same conditions were applied in the systems for chemiluminescent assay in vitro: (1) Fenton's (Fe(2+)+H2O2) for the generation of ·OH and -OH species, (2) Hydrogen peroxide (H2O2), (3) Iron (II) sulfate (FeSO4), (4) Glutathione-peroxidase, monitoring the deactivation of H2O2, (5) Ascorbic acid-Fenton's reagent: Vit.C appears a strong oxidant, generating free-radical products when applied in higher than physiological concentrations, (6) Reduced α-nicotinamide adenine dinucleotide (NADH)-phenazine methosulfate-for the generation of superoxide radicals (O2 (·-)). Lophine and all novel compounds do not alter the kinetics, except of the dimethyl amino substituted derivative (4-(3a,11b-dihydro-1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-N,N-dimethylaniline) in the glutathione-peroxidase system, at pH 8.5. Same derivative showed a comparable or higher activity than Lucigenin and Rhodamine 6G. In neutral and acidic medium, in the Fenton's system, Rhodamine 6G was the most appropriate probe. In alkaline pH and oxidant H2O2, Lucigenin induced a signal twice as strong as the signal compared to all other activators. PMID:26224302

  14. Detection of transposable elements by their compositional bias

    Anxolabéhère Dominique

    2004-07-01

    Full Text Available Abstract Background Transposable elements (TE are mobile genetic entities present in nearly all genomes. Previous work has shown that TEs tend to have a different nucleotide composition than the host genes, either considering codon usage bias or dinucleotide frequencies. We show here how these compositional differences can be used as a tool for detection and analysis of TE sequences. Results We compared the composition of TE sequences and host gene sequences using probabilistic models of nucleotide sequences. We used hidden Markov models (HMM, which take into account the base composition of the sequences (occurrences of words n nucleotides long, with n ranging here from 1 to 4 and the heterogeneity between coding and non-coding parts of sequences. We analyzed three sets of sequences containing class I TEs, class II TEs and genes respectively in three species: Drosophila melanogaster, Cænorhabditis elegans and Arabidopsis thaliana. Each of these sets had a distinct, homogeneous composition, enabling us to distinguish between the two classes of TE and the genes. However the particular base composition of the TEs differed in the three species studied. Conclusions This approach can be used to detect and annotate TEs in genomic sequences and complements the current homology-based TE detection methods. Furthermore, the HMM method is able to identify the parts of a sequence in which the nucleotide composition resembles that of a coding region of a TE. This is useful for the detailed annotation of TE sequences, which may contain an ancient, highly diverged coding region that is no longer fully functional.

  15. Fingerprint detection

    Saunders, G.C.

    1992-01-07

    This patent describes a method for detection and visualization of latent fingerprints. It comprises contacting a substrate containing a latent print thereon the a colloidal metal composition at a pH from about 2.5 to about 4.0 for time sufficient to allow reaction of the colloidal metal composition with the latent print; and, preserving or recording the observable print.

  16. Applications of adenine nucleotide measurements in oceanography

    Holm-Hansen, O.; Hodson, R.; Azam, F.

    1975-01-01

    The methodology involved in nucleotide measurements is outlined, along with data to support the premise that ATP concentrations in microbial cells can be extrapolated to biomass parameters. ATP concentrations in microorganisms and nucleotide analyses are studied.

  17. Short-hairpin RNA-induced suppression of adenine nucleotide translocase-2 in breast cancer cells restores their susceptibility to TRAIL-induced apoptosis by activating JNK and modulating TRAIL receptor expression

    Kim Chul-Woo

    2010-09-01

    Full Text Available Abstract Background Tumor necrosis factor (TNF-related apoptosis-inducing ligand (TRAIL; apo2 ligand induces apoptosis in cancer cells but has little effect on normal cells. However, many cancer cell types are resistant to TRAIL-induced apoptosis, limiting the clinical utility of TRAIL as an anti-cancer agent. We previously reported that the suppression of adenine nucleotide translocase-2 (ANT2 by short-hairpin RNA (shRNA induces apoptosis of breast cancer cells, which frequently express high levels of ANT2. In the present study, we examined the effect of RNA shRNA-induced suppression of ANT2 on the resistance of breast cancer cells to TRAIL-induced apoptosis in vitro and in vivo. Results ANT2 shRNA treatment sensitized MCF7, T47 D, and BT474 cells to TRAIL-induced apoptosis by up-regulating the expression of TRAIL death receptors 4 and 5 (DR4 and DR5 and down-regulating the TRAIL decoy receptor 2 (DcR2. In MCF7 cells, ANT2 knockdown activated the stress kinase c-Jun N-terminal kinase (JNK, subsequently stabilizing and increasing the transcriptional activity of p53 by phosphorylating it at Thr81; it also enhanced the expression and activity of DNA methyltransferase 1 (DNMT1. ANT2 shRNA-induced overexpression of DR4/DR5 and TRAIL sensitization were blocked by a p53 inhibitor, suggesting that p53 activation plays an important role in the transcriptional up-regulation of DR4/DR5. However, ANT2 knockdown also up-regulated DR4/DR5 in the p53-mutant cell lines BT474 and T47 D. In MCF7 cells, ANT2 shRNA treatment led to DcR2 promoter methylation and concomitant down-regulation of DcR2 expression, consistent with the observed activation of DNMT1. Treatment of the cells with a demethylating agent or JNK inhibitor prevented the ANT2 shRNA-induced down-regulation of DcR2 and activation of both p53 and DNMT1. In in vivo experiments using nude mice, ANT2 shRNA caused TRAIL-resistant MCF7 xenografts to undergo TRAIL-induced cell death, up-regulated DR4/DR5

  18. Electron Detachment as a Probe of Intrinsic Nucleobase Dynamics in Dianion-Nucleobase Clusters: Photoelectron Spectroscopy of the Platinum II Cyanide Dianion Bound to Uracil, Thymine, Cytosine and Adenine

    Sen, Ananya; Hou, Gao-Lei; Wang, Xue B.; Dessent, Caroline

    2015-08-05

    We report the first low-temperature photodetachment photoelectron spectra of isolated gas-phase complexes of the platinum II cyanide dianion bound to nucleobases. These systems are model systems for understanding platinum-complex photodynamic therapies, and knowledge of the intrinsic photodetachment properties is crucial for understanding their broader photophysical properties. Well-resolved, distinct peaks are observed in the spectra consistent with the complexes where the Pt(CN)42- moiety is largely intact. The adiabatic electron detachment energies for the dianion-nucleobase complexes are measured to be between 2.39-2.46 eV. The magnitudes of the repulsive Coulomb barriers of the complexes are estimated to be between 1.9 and 2.1 eV, values that are lower than for the bare Pt(CN)42- dianion as a result of charge solvation by the nucleobases. In addition to the resolved spectral features, broad featureless bands indicative of delayed electron detachment are observed in the 193 nm photodetachment spectra of the four nucleobase-dianion complexes, and also in the 266 nm spectra of the Pt(CN)42-∙thymine and Pt(CN)42-∙adenine complexes. The selective excitation of these features in the 266 nm spectra is attributed to one-photon excitation of [Pt(CN)42-∙T]* and [Pt(CN)42-∙A]* long-lived excited states that can effectively couple to the electron detachment continuum, producing strong electron detachment signals. We attribute the resonant electron detachment bands observed here for Pt(CN)42-∙T and Pt(CN)42-∙A but not for Pt(CN)42-∙U and Pt(CN)42-∙C to fundamental differences in the individual nucleobase photophysics following 266 nm excitation. This indicates that the Pt(CN)42- dianion in the Pt(CN)42-∙M clusters can be viewed as a “dynamic tag” which has the propensity to emit electrons when the attached nucleobase disaplys a long-lived excited state.

  19. Utilizing Gold Nanoparticle Probes to Visually Detect DNA Methylation.

    Chen, Kui; Zhang, Mingyi; Chang, Ya-Nan; Xia, Lin; Gu, Weihong; Qin, Yanxia; Li, Juan; Cui, Suxia; Xing, Gengmei

    2016-12-01

    The surface plasmon resonance (SPR) effect endows gold nanoparticles (GNPs) with the ability to visualize biomolecules. In the present study, we designed and constructed a GNP probe to allow the semi-quantitative analysis of methylated tumor suppressor genes in cultured cells. To construct the probe, the GNP surfaces were coated with single-stranded DNA (ssDNA) by forming Au-S bonds. The ssDNA contains a thiolated 5'-end, a regulatory domain of 12 adenine nucleotides, and a functional domain with absolute pairing with methylated p16 sequence (Met-p16). The probe, paired with Met-p16, clearly changed the color of aggregating GNPs probe in 5 mol/L NaCl solution. Utilizing the probe, p16 gene methylation in HCT116 cells was semi-quantified. Further, the methylation of E-cadherin, p15, and p16 gene in Caco2, HepG2, and HCT116 cell lines were detected by the corresponding probes, constructed with three domains. This simple and cost-effective method was useful for the diagnosis of DNA methylation-related diseases. PMID:27325520

  20. Utilizing Gold Nanoparticle Probes to Visually Detect DNA Methylation

    Chen, Kui; Zhang, Mingyi; Chang, Ya-Nan; Xia, Lin; Gu, Weihong; Qin, Yanxia; Li, Juan; Cui, Suxia; Xing, Gengmei

    2016-06-01

    The surface plasmon resonance (SPR) effect endows gold nanoparticles (GNPs) with the ability to visualize biomolecules. In the present study, we designed and constructed a GNP probe to allow the semi-quantitative analysis of methylated tumor suppressor genes in cultured cells. To construct the probe, the GNP surfaces were coated with single-stranded DNA (ssDNA) by forming Au-S bonds. The ssDNA contains a thiolated 5'-end, a regulatory domain of 12 adenine nucleotides, and a functional domain with absolute pairing with methylated p16 sequence (Met- p16). The probe, paired with Met- p16, clearly changed the color of aggregating GNPs probe in 5 mol/L NaCl solution. Utilizing the probe, p16 gene methylation in HCT116 cells was semi-quantified. Further, the methylation of E-cadherin, p15, and p16 gene in Caco2, HepG2, and HCT116 cell lines were detected by the corresponding probes, constructed with three domains. This simple and cost-effective method was useful for the diagnosis of DNA methylation-related diseases.

  1. Detection of E-cyanomethanimine towards Sagittarius B2(N) in the Green Bank Telescope PRIMOS Survey

    Zaleski, Daniel P; Steber, Amanda L; Muckle, Matt T; Loomis, Ryan A; Corby, Joanna F; Martinez,, Oscar; Crabtree, Kyle N; Jewell, Philip R; Hollis, Jan M; Lovas, Frank J; Vasquez, David; Nyiramahirwe, Jolie; Sciortino, Nicole; Johnson, Kennedy; McCarthy, Michael C; Remijan, Anthony J; Pate, Brooks H

    2013-01-01

    The detection E-cyanomethanimine (E-HNCHCN) towards Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra (Hollis et al.) to laboratory rotational spectra from a reaction product screening experiment. The experiment uses broadband molecular rotational spectroscopy to monitor the reaction products produced in an electric discharge source using a gas mixture of NH3 and CH3CN. Several transition frequency coincidences between the reaction product screening spectra and previously unassigned interstellar rotational transitions in the PRIMOS survey have been assigned to E cyanomethanimine. A total of 8 molecular rotational transitions of this molecule between 9 and 50 GHz are observed with the GBT. E-cyanomethanimine, often called the HCN dimer, is an important molecule in prebiotic chemistry because it is a chemical intermediate in proposed synthetic routes of adenine, one of the two purine nucleobases found in DNA and RNA. New analyses of the rotational spe...

  2. Smoke detection

    Warmack, Robert J. Bruce; Wolf, Dennis A.; Frank, Steven Shane

    2016-09-06

    Various apparatus and methods for smoke detection are disclosed. In one embodiment, a method of training a classifier for a smoke detector comprises inputting sensor data from a plurality of tests into a processor. The sensor data is processed to generate derived signal data corresponding to the test data for respective tests. The derived signal data is assigned into categories comprising at least one fire group and at least one non-fire group. Linear discriminant analysis (LDA) training is performed by the processor. The derived signal data and the assigned categories for the derived signal data are inputs to the LDA training. The output of the LDA training is stored in a computer readable medium, such as in a smoke detector that uses LDA to determine, based on the training, whether present conditions indicate the existence of a fire.

  3. Smoke detection

    Warmack, Robert J. Bruce; Wolf, Dennis A.; Frank, Steven Shane

    2015-10-27

    Various apparatus and methods for smoke detection are disclosed. In one embodiment, a method of training a classifier for a smoke detector comprises inputting sensor data from a plurality of tests into a processor. The sensor data is processed to generate derived signal data corresponding to the test data for respective tests. The derived signal data is assigned into categories comprising at least one fire group and at least one non-fire group. Linear discriminant analysis (LDA) training is performed by the processor. The derived signal data and the assigned categories for the derived signal data are inputs to the LDA training. The output of the LDA training is stored in a computer readable medium, such as in a smoke detector that uses LDA to determine, based on the training, whether present conditions indicate the existence of a fire.

  4. Nicotinamide mononucleotide synthetase is the key enzyme for an alternative route of NAD biosynthesis in Francisella tularensis

    Sorci, Leonardo; Martynowski, Dariusz; Rodionov, Dmitry A; Eyobo, Yvonne; Zogaj, Xhavit; Klose, Karl E.; Nikolaev, Evgeni V.; Magni, Giulio; Zhang, Hong; Osterman, Andrei L.

    2009-01-01

    Enzymes involved in the last 2 steps of nicotinamide adenine dinucleotide (NAD) cofactor biosynthesis, which catalyze the adenylylation of the nicotinic acid mononucleotide (NaMN) precursor to nicotinic acid dinucleotide (NaAD) followed by its amidation to NAD, constitute promising drug targets for the development of new antibiotics. These enzymes, NaMN adenylyltransferase (gene nadD) and NAD synthetase (gene nadE), respectively, are indispensable and conserved in nearly all bacterial pathoge...

  5. Nonlinear spectral imaging microscopy of rabbit aortic wall

    Quangang Liu; Jianxin Chen; Shuangmu Zhuo; Xingshan Jiang; Kecheng Lu

    2009-01-01

    Employing nonlinear spectral imaging technique based on two-photon-excited fluorescence and second-harmonic generation (SHG) of biological tissue, we combine the image-guided spectral analysis method and multi-channel subsequent detection imaging to map and visualize the intrinsic species in a native rabbit aortic wall. A series of recorded nonlinear spectral images excited by a broad range of laser wavelengths (730-910 nm) are used to identify five components in the native rabbit aortic wall, including nicotinamide adenine dinucleotide (NADH), elastic fiber, flavin, porphyrin derivatives, and collagen. Integrating multi-channel subsequent detection imaging technique, the high-resolution, high contrast images of collagen and elastic fiber in the aortic wall are obtained. Our results demonstrate that this method can yield complementary biochemical and morphological information about aortic tissues, which have the potential to determine the tissue pathology associated with mechanical properties of aortic wall and to evaluate the pharmacodynamical studies of vessels.

  6. A Novel Conductive Poly(3,4-ethylenedioxythiophene-BSA Film for the Construction of a Durable HRP Biosensor Modified with NanoAu Particles

    Fangcheng Xu

    2016-03-01

    Full Text Available In this study, we have investigated the contribution of bovine serum albumin (BSA to the durability of the electrochemically synthesized poly(3,4-ethylenedioxythiophene (PEDOT film on a platinum (Pt electrode. The electrode was capable to effectively adsorb the nano Au particles (AuNPs to form a uniform layout, which was then able to immobilize the horseradish peroxidase (HRP to construct a functional HRP/AuNPs/PEDOT(BSA/Pt biosensor. Cyclic voltammetry was employed to evaluate the performance of the biosensor through the measurement of hydrogen peroxide. Our results revealed a satisfied linear correlation between the cathodic current and the concentration of H2O2. Furthermore, the addition of oxidized form of nicotinamide adenine dinucleotide, or NAD+, as the electron transfer mediator in the detection solution could dramatically enhance the sensitivity of detection by about 35.5%. The main advantages of the current biosensor are its durability, sensitivity, reliability, and biocompatibility.

  7. A hyperspectral fluorescence lifetime probe for skin cancer diagnosis

    De Beule, P. A. A.; Dunsby, C.; Galletly, N. P.; Stamp, G. W.; Chu, A. C.; Anand, U.; Anand, P.; Benham, C. D.; Naylor, A.; French, P. M. W.

    2007-12-01

    The autofluorescence of biological tissue can be exploited for the detection and diagnosis of disease but, to date, its complex nature and relatively weak signal levels have impeded its widespread application in biology and medicine. We present here a portable instrument designed for the in situ simultaneous measurement of autofluorescence emission spectra and temporal decay profiles, permitting the analysis of complex fluorescence signals. This hyperspectral fluorescence lifetime probe utilizes two ultrafast lasers operating at 355 and 440nm that can excite autofluorescence from many different biomolecules present in skin tissue including keratin, collagen, nicotinamide adenine dinucleotide (phosphate), and flavins. The instrument incorporates an optical fiber probe to provide sample illumination and fluorescence collection over a millimeter-sized area. We present a description of the system, including spectral and temporal characterizations, and report the preliminary application of this instrument to a study of recently resected (skin lesions, illustrating its potential for skin cancer detection and diagnosis.

  8. Resolution of overlapping skin auto-fluorescence for development of non-invasive applications

    Su, Yu-Zheng; Lin, Li-Wu; Chen, Chuen-Yau; Hung, Min-Wei; Huang, Kuo-Cheng

    2010-08-01

    Skin auto-fluorescence spectra can provide useful biological information, but the obtained spectrum is overlapped and is difficult to distinguish each contributed component. We applied the genetic algorithm to decompose the overlapping spectrum. First, we simulate the overlapping spectral to confirm our feasible algorithm. The skin auto-fluorescence spectra were obtained from the normal human skin with 337 nm excitation light source. The nicotinamide adenine dinucleotid (NADH) and flavin adenine dinucleotide (FAD) are accurately decomposed and demonstrated. The developed algorithm can be widely applied to achieve qualitative and quantitative analysis for overlapping spectra.

  9. Development of an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) aptasensor for direct detection of DNA hybridization.

    Karaballi, R A; Nel, A; Krishnan, S; Blackburn, J; Brosseau, C L

    2015-09-01

    Rapid detection of disease biomarkers at the patient point-of-care is essential to timely and effective treatment. The research described herein focuses on the development of an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) DNA aptasensor capable of direct detection of tuberculosis (TB) DNA. Specifically, a plausible DNA biomarker present in TB patient urine was chosen as the model target for detection. Cost-effective screen printed electrodes (SPEs) modified with silver nanoparticles (AgNP) were used as the aptasensor platform, onto which the aptamer specific for the target DNA was immobilized. Direct detection of the target DNA was demonstrated through the appearance of SERS peaks characteristic for adenine, present only in the target strand. Modulation of the applied potential allowed for a sizeable increase in the observed SERS response and the use of thiol back-filling prevented non-specific adsorption of non-target DNA. To our knowledge, this work represents the first EC-SERS study of an aptasensor for the direct, label-free detection of DNA hybridization. Such a technology paves the way for rapid detection of disease biomarkers at the patient point-of-care. PMID:25780805

  10. Numerical Characterization of DNA Sequence Based on Dinucleotides

    Xingqin Qi; Edgar Fuller; Qin Wu; Cun-Quan Zhang

    2012-01-01

    Sequence comparison is a primary technique for the analysis of DNA sequences. In order to make quantitative comparisons, one devises mathematical descriptors that capture the essence of the base composition and distribution of the sequence. Alignment methods and graphical techniques (where each sequence is represented by a curve in high-dimension Euclidean space) have been used popularly for a long time. In this contribution we will introduce a new nongraphical and nonalignment approach based...

  11. Point mutation in a family with hyperproinsulinemia detected by single stranded conformational polymorphism

    Nakashima, Naoki; Sakamoto, Norihiro; Umeda, Fumio; Hashimoto, Toshihiko; Hisatomi, Akitaka; Umemura, Tsukuru; Sakaki, Yoshiyuki; Nawata, Hajime (Kyushu Univ., Fukuoka (Japan)); Aso, Nobunori (Kaho Hospital, Fukuoka (Japan))

    1993-03-01

    The authors previously described a case of familial hyperproinsulinemia, the fifth to be reported. In the present study they characterized the genetic defect carried by this family and demonstrated that it could be detected by polymerase chain reaction-single stranded conformational polymorphism. Since the serum proinsulin molecule from the propositus, a 63-yr-old Japanese man, was eluted on the same fraction of human proinsulin intermediate cleaved only at the B-C junction, the authors sequenced exon 3 of his insulin gene, including the C-A junction. A point mutation was discovered that changed codon 65 from arginine (CGT) to histidine (CAT) in one allele. This was the same point mutation as that described previously in three unrelated kindreds representing two races, consistent with the hypothesis that the dinucleotide sequence CpG may be a hot spot for mutations. Recently, developed polymerase chain reaction-single stranded conformational polymorphism proved useful in detecting this mutation in the family members. The daughter of the propositus and one of his two grandsons were also demonstrated to be heterozygous for this point mutation by this method. 25 refs., 2 figs.

  12. 石榴皮鞣质对腺嘌呤性慢性肾衰大鼠保护作用的研究%Protective Effect of Tannin in Punica granatum L.on Chronic Renal Failure in Rats Induced by Adenine

    周本宏; 郭志磊; 王慧媛; 冯琪

    2009-01-01

    目的 观察石榴皮鞣质对腺嘌呤性慢性肾功能衰竭(CRF)大鼠的影响.方法 用250 mg·kg~(-1)腺嘌呤溶液连续灌胃21 d使Wistar大鼠产生类似慢性肾袁的症状.21d后,治疗组大鼠每天用石榴皮鞣质(40,20,10mg·kg~(-1).d~(-1))灌胃,阳性组用20%尿毒清混悬液按2.1 g·kg~(-1)·灌胃.60 d后收集尿液,处死大鼠,取血、留取肾组织,测定血Ca~(2+)、P~(3+)及血肌酐(Scr)、尿素氮(BUN),血脂和24h尿蛋白定量、尿Ca~(2+)、P~(3+),进行统计学处理,并进行形态学观察.结果 石榴皮鞣质对慢性肾衰竭大鼠的血Ca~(2+)、P~(3+)及Scr、BUN和24 h尿蛋白定量、尿Ca~(2+)、P~(3+)有不同程度的改善.结论 石榴皮鞣质对腺嘌呤导致的大鼠慢性肾衰竭有一定的保护作用.%OBJECTIVE To observe the effeets of tannin in Punica granatum L.on chronic renal failure(CRF)in rats induced by adenine.METHODS The Wistar rats were administered intragastrically with adenine(200 mg·kg~(-1)·d~(-1))for 21 d to induce the symptoms similar to chronic renal failure.Then,the rats were administered intragastrically with tannin(40,20 and 10 blood urea nitrogen(BUN),calcium ion(Ca~(2+)),phosphorus ion(P~(3+)),blood lipids and urine protein of 24 h were determined and analyzed.Meanwhile morphology was observed.RESULTS Serum levels of Scr,BUN and P~(3+) were decreased but Ca~(2+) level was increased by tannin in Punica granatum L.CONCLUSION Tannin in Punica granatum L can improve the renal function injuried by metabolic products in adenine-modeled CRF rats.

  13. Multi-fractal property of perchlorate reductase gene sequences and DNA photonics application to UV fluorescence detection on Mars-like surfaces

    Tremberger, George, Jr.; Cheung, Eric; Gadura, N.; Holden, Todd; Subramaniam, Raji; Sullivan, Regina; Schneider, Pat; Flamholz, Alex; Lieberman, David H.; Cheung, Tak D.

    2009-08-01

    The discovery of perchlorate on Mars raises the possibility of the existence of perchlorate reduction microbes on that planet. The perchlorate reductase gene sequence fractal dimensions of two Dechloromonas species were compared with five other sequences in the microbial dimethyl sulfoxide (DMSO) reductase family. A nucleotide sequence can be expressed as a numerical sequence where each nucleotide is assigned its proton number. The resulting numerical sequence can be investigated for its fractal dimension in terms of evolution and chemical properties for comparative studies. Analysis of the fractal dimensions for the DMSO reductase family supports phylogenetic analyses that show that the perchlorate reductase gene sequences are members of the same family. A sub-family with roughly the same nucleotide length emerges having the property that the gene fractal dimension is negatively correlated with the Shannon di-nucleotide entropy (R2 ~ 0.95, N =5). The gene sequence fractal dimension is found to be positively correlated with the neighbor joining distances reported in a published protein phylogeny tree (R2~ 0.92, N = 5). The multi-fractal property associated with these genes shows that perchlorate reductase has lower dimensionality as compared to the relatively higher dimensionality DNA-break repair genes Rec-A and Rad-A observed in the Dechloromonas aromatica and Deinococcus radiodurans genomes. The studied perchlorate gene sequences show a higher Shannon di-nucleotide entropy (~3.97 bits) relative to Dechloromonas aromatica DNA repair sequences (~3.87 bits Rec-A, ~3.92 bits Rad-A), suggesting that there are fewer constraints on nucleotide variety in the perchorlate sequences . These observations thus allow for the existence of perchlorate reducing microbes on Mars now or in the past. Timeresolved UV fluorescence study near the emission bands of nucleotide sequences could be used for bio-detection on Mars-like surfaces and the results may further constrain the

  14. Elaborately designed diblock nanoprobes for simultaneous multicolor detection of microRNAs

    Wang, Chenguang; Zhang, Huan; Zeng, Dongdong; Sun, Wenliang; Zhang, Honglu; Aldalbahi, Ali; Wang, Yunsheng; San, Lili; Fan, Chunhai; Zuo, Xiaolei; Mi, Xianqiang

    2015-09-01

    Simultaneous detection of multiple biomarkers has important prospects in the biomedical field. In this work, we demonstrated a novel strategy for the detection of multiple microRNAs (miRNAs) based on gold nanoparticles (Au NPs) and polyadenine (polyA) mediated nanoscale molecular beacon (MB) probes (denoted p-nanoMBs). Novel fluorescent labeled p-nanoMBs bearing consecutive adenines were designed, of which polyA served as an effective anchoring block binding to the surface of Au NPs, and the appended hairpin block formed an upright conformation that favored the hybridization with targets. Using the co-assembling method and the improved hybridization conformation of the hairpin probes, we achieved high selectivity for specifically distinguishing DNA targets from single-base mismatched DNA targets. We also realized multicolor detection of three different synthetic miRNAs in a wide dynamic range from 0.01 nM to 200 nM with a detection limit of 10 pM. What's more, we even detected miRNAs in a simulated serum environment, which indicated that our method could be used in complex media. Compared with the traditional method, our strategy provides a promising alternative method for the qualitative and quantitative detection of miRNAs.Simultaneous detection of multiple biomarkers has important prospects in the biomedical field. In this work, we demonstrated a novel strategy for the detection of multiple microRNAs (miRNAs) based on gold nanoparticles (Au NPs) and polyadenine (polyA) mediated nanoscale molecular beacon (MB) probes (denoted p-nanoMBs). Novel fluorescent labeled p-nanoMBs bearing consecutive adenines were designed, of which polyA served as an effective anchoring block binding to the surface of Au NPs, and the appended hairpin block formed an upright conformation that favored the hybridization with targets. Using the co-assembling method and the improved hybridization conformation of the hairpin probes, we achieved high selectivity for specifically distinguishing

  15. 斑节对虾腺苷酸转移酶(PmANT)基因的cDNA克隆与表达分析%Molecular cloning and expression analysis of adenine nucleotide translocase (PmANT) in Penaeus monodon

    孙文文; 周发林; 黄建华; 邱丽华; 杨其彬; 江世贵

    2013-01-01

    利用RACE技术获得了斑节对虾(Penaeus monodon)ANT基因(PmANT)的cDNA序列.该序列全长1 388 bp,开放阅读框(ORF)为930 bp,3’非编码区(UTR)为393 bp,5 '非编码区(UTR)为65 bp.ORF可编码309个氨基酸,分子量大约为33.622 ku.与所有ANT家族成员一样,PmANT蛋白具有3个重复同源的线粒体跨膜结构域,但不含信号肽和糖基化位点.相似性、同源性及系统进化树分析显示,斑节对虾的ANT基因与凡纳滨对虾的同源性和相似性最高,并与其聚为一支.采用荧光定量的方法研究了ANT基因在雌雄个体不同组织、卵巢不同发育阶段及未成熟和成熟精巢的差异表达情况.结果表明:PmANT的mRNA在各组织中都有表达,其中,在雄性个体的肌肉中表达量最高,其次为雌性肌肉,在精巢的表达量最低,且未成熟精巢低于成熟精巢.PmANT的mRNA在卵巢的表达量高于精巢,且在Ⅲ期卵巢表达量最高,Ⅳ期最低.为今后进一步研究该基因在斑节对虾性腺发育中的作用提供基础材料.%The adenine nucleotide translocase (ANT) is the most abundant mitochondrial inner membrane protein, which catalyzes the exchange of ADP and ATP between cytosol and mitochondria and participates in many models of mitochondrial apoptosis. In the present study, the full sequence of P. Monodon ANT gene was cloned and named PmANT. The full length cDNA of PmANT contained a 5' untranslated region (UTR) of 65 bp, a 3' UTR of 393 bp and an ORF of 930 bp encoding a polypeptide of 309 amino acids with an estimated molecular mass of 33. 622 ku. Like other animal ANTs, the structure of the PmANT protein consists of three homologous repeated domains. But there are no signal peptide and glycosylation sites in PmANT protein. Sequence alignment analysis showed that the PmANT with the ANT of Litopenaeus vannamei shared a similarity of 98. 7% and the homology of 97. 4%. Analysis of the tissue expression pattern of the PmANT showed that the PmANT m

  16. Electrocatalytic oxidation behavior of NADH at Pt/Fe3O4/reduced-graphene oxide nanohybrids modified glassy carbon electrode and its determination.

    Roushani, Mahmoud; Hoseini, S Jafar; Azadpour, Mitra; Heidari, Vahid; Bahrami, Mehrangiz; Maddahfar, Mahnaz

    2016-10-01

    We have developed Pt/Fe3O4/reduced-graphene oxide nanohybrids modified glassy carbon (Pt/Fe3O4/RGO/GC) electrode as a novel system for the preparation of electrochemical sensing platform. Characterization of as-made composite was determined using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM) and energy-dispersive analysis of X-ray (EDAX) where the Pt, Fe, Si, O and C elements were observed. The Pt/Fe3O4/RGO/GC electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Due to the synergistic effect between Pt, Fe3O4 and RGO, the nanohybrid exhibited excellent performance toward dihydronicotinamide adenine dinucleotide (NADH) oxidation in 0.1M phosphate buffer solution, pH7.0, with a low detection limit of 5nM. PMID:27287119

  17. Silver nanoparticles embedded in amine-functionalized silicate sol-gel network assembly for sensing cysteine, adenosine and NADH

    Maduraiveeran, Govindhan; Ramaraj, Ramasamy, E-mail: ramarajr@yahoo.com [Madurai Kamaraj University, Centre for Photoelectrochemistry, School of Chemistry (India)

    2011-09-15

    Silver nanoparticles embedded in amine-functionalized silicate sol-gel network were synthesized and used for sensing biomolecules such as cysteine, adenosine, and {beta}-nicotinamide adenine dinucleotide (NADH). The sensing of these biomolecules by the assembly of silver nanoparticles was triggered by the optical response of the surface plasmon resonance (SPR) of the silver nanoparticles. The optical sensor exhibited the lowest detection limit (LOD) of 5, 20, and 5 {mu}M for cysteine, adenosine, and NADH, respectively. The sensing of biomolecules in the micromolar range by using the amine-functionalized silicate sol-gel embedded silver nanoparticles was studied in the presence of interference molecules like uridine, glycine, guanine, and guanosine. Thus, the present approach might open up a new avenue for the development of silver nanoparticles-based optical sensor devices for biomolecules.

  18. Carbon nanotubes (CNTs) for the development of electrochemical biosensors.

    Lin, Yuehe; Yantasee, Wassana; Wang, Joseph

    2005-01-01

    Carbon nanotube (CNT) is a very attractive material for the development of biosensors because of its capability to provide strong electrocatalytic activity and minimize surface fouling of the sensors. This article reviews our recent developments of oxidase- and dehydrogenase-amperometric biosensors based on the immobilization of CNTs, the co-immobilization of enzymes on the CNTs/Nafion or the CNT/Teflon composite materials, or the attachment of enzymes on the controlled-density aligned CNT-nanoelectrode arrays. The excellent electrocatalytic activities of the CNTs on the redox reactions of hydrogen peroxide, nicotinamide adenine dinucleotide (NADH), and homocysteine have been demonstrated. Successful applications of the CNT-based biosensors reviewed herein include the low-potential detections of glucose, organophosphorus compounds, and alcohol. PMID:15574386

  19. Carbon Nanotubes (CNTs) for the Development of Electrochemical Biosensors

    Lin, Yuehe; Yantasee, Wassana; Wang, Joseph

    2005-01-01

    Carbon nanotube (CNT) is a very attractive material for the development of biosensors because of its capability to provide strong electrocatalytic activity and minimize surface fouling of the sensors. This article reviews our recent developments of oxidase- and dehydrogenase-amperometric biosensors based on the immobilization of CNTs, the co-immobilization of enzymes on the CNTs/Nafion or the CNT/Teflon composite materials, or the attachment of enzymes on the controlled-density aligned CNT-nanoelectrode arrays. The excellent electrocatalytic activities of the CNTs on the redox reactions of hydrogen peroxide, nicotinamide adenine dinucleotide (NADH), and homocysteine have been demonstrated. Successful applications of the CNT-based biosensors reviewed herein include the low-potential detections of glucose, organophosphorus compounds, and alcohol.

  20. Interfacial electron transfer of glucose oxidase on poly(glutamic acid)-modified glassy carbon electrode and glucose sensing.

    Zhou, Xuechou; Tan, Bingcan; Zheng, Xinyu; Kong, Dexian; Li, Qinglu

    2015-11-15

    The interfacial electron transfer of glucose oxidase (GOx) on a poly(glutamic acid)-modified glassy carbon electrode (PGA/GCE) was investigated. The redox peaks measured for GOx and flavin adenine dinucleotide (FAD) are similar, and the anodic peak of GOx does not increase in the presence of glucose in a mediator-free solution. These indicate that the electroactivity of GOx is not the direct electron transfer (DET) between GOx and PGA/GCE and that the observed electroactivity of GOx is ascribed to free FAD that is released from GOx. However, efficient electron transfer occurred if an appropriate mediator was placed in solution, suggesting that GOx is active. The PGA/GCE-based biosensor showed wide linear response in the range of 0.5-5.5 mM with a low detection limit of 0.12 mM and high sensitivity and selectivity for measuring glucose. PMID:26278169

  1. Detection of neuronal tissue in meat using tissue specific DNA modifications

    Harris N.

    2004-01-01

    Full Text Available A method has been developed to differentiate between non-muscle tissues such as liver, kidney and heart and that of muscle in meat samples using tissue specific DNA detection. Only muscle tissue is considered meat from the point of view of labelling (Food Labelling [Amendment] (England Regulations 2003 and Quantitative Ingredient Declaration (QUID, and also certain parts of the carcass are prohibited to be used in raw meat products (Meat Products [England] Regulations 2003. Included in the prohibited offal are brain and spinal cord. The described methodology has therefore been developed primarily to enforce labelling rules but also to contribute to the enforcement of BSE legislation on the detection of Central Nervous System (CNS tissue. The latter requires the removal of Specified Risk Material (SRM, such as bovine and ovine brain and spinal cord, from the food chain. Current methodologies for detection of CNS tissue include histological examination, analysis of cholesterol content and immunodetection. These can potentially be time consuming, less applicable to processed samples and may not be readily adapted to high throughput sample analysis. The objective of this work was therefore to develop a DNAbased detection assay that exploits the sensitivity and specificity of PCR and is potentially applicable to more highly processed food samples. For neuronal tissue, the DNA target selected was the promoter for Glial Fibrillary Acidic Protein (GFAP, a gene whose expression is restricted to astroglial cells within CNS tissue. The promoter fragments from both cattle and sheep have been isolated and key differences in the methylation patterns of certain CpG dinucleotides in the sequences from bovine and sheep brain and spinal cord and the corresponding skeletal muscle identified. These have been used to design a PCR assay exploiting Methylation Specific PCR (MSP to specifically amplify the neuronal tissue derived sequence and therefore identify the

  2. A first attempt of identifying irradiated foods via the detection of DNA damages with GC-MS

    For the identification of irradiated foods it is of greatest importance to find a unique radiolytic product that is detectable with normal analysis equipment. This requirement is met by DNA, located in nearly all cells of meat, fish, vegetables, fruits, etc. Of disadvantage is the low DNA content in the cells (about 0.2 to 1%). The present paper considers the question whether damages in the base molety are suitable for identifying irradiated foods by use of GC/MS. To examine the practical applicability of identifying irradiated food via the detection of DNA damages standards (uracil, thymine, cytosine, adenine, guanine) poultry meat and herring sperm, were irradiated with a dose of 7 KGy. The detection of radiation-induced based lesions in nucleic acid is a promising method for the identification of irradiated food in the future. This first attempt shows some differences between irradiated and control samples. But up to now, it is necessary to have a control sample for identification of the irradiated sample. The method is currently tested only on meat, but there are many possibilities for optimization to extend the detection to other radiation-induced base derivatives or other foods to gain a broader applicability of this method. (8 figs, 2 tabs, 21 refs)

  3. Detection of Factor XI Deficiency (FXID and Complex Vertebral Malformation (CVM in Bali Cattle

    S. W. Siswanti

    2014-12-01

    Full Text Available Factor XI Deficiency (FXID is caused by imperfect insertion of poly adenine which is resulted in introduction of premature stop codon in FXI gene. Substitution of guanine into thymine in SLC35A3 gene caused Complex Vertebral Malformation (CVM. The research was aimed to detect the presence or absence of a genetic defect mainly CVM using SLC35A3 gene and FXID using FXI gene in Indonesian Bali cattle. The presence of this genetic defect may have a significant economic impact on the breeding program. The research of genetic defect was done mostly in dairy cattle, but there was no report for screening of genetic defect in Bali cattle. In this study, 303 fresh blood samples and 22 semen samples which were collected from Indonesian Bali cattle breeding center (BPTU HMT Denpasar, BPT HMT Serading West Nusa Tenggara and district Barru South Sulawesi and artificial insemination centre (BBIB Singosari and BIBD Baturiti were used for screening of FXID and CVM. The amplicons of FXI gene were obtained by using PCR and that for SLC35A3 gene were obtained by using PCR-RFLP method with PstI restriction enzyme. These PCR products were analyzed by using 2% agarose gels electrophoresis. All genotypes were confirmed by DNA sequencing to determine an allele mutant. The allele mutant was not found in all of the samples. The result of this study showed that CVM and FXID were not detected in Bali cattle from Indonesian Bali cattle breeding and artificial insemination centres.

  4. Chitosan-coated anisotropic silver nanoparticles as a SERS substrate for single-molecule detection

    Surface-enhanced Raman spectroscopy (SERS) is a technique that has become widely used for identifying and providing structural information about molecular species in low concentration. There is an ongoing interest in finding optimum particle size, shape and spatial distribution for optimizing the SERS substrates and pushing the sensitivity toward the single-molecule detection limit. This work reports the design of a novel, biocompatible SERS substrate based on small clusters of anisotropic silver nanoparticles embedded in a film of chitosan biopolymer. The SERS efficiency of the biocompatible film is assessed by employing Raman imaging and spectroscopy of adenine, a significant biological molecule. By combining atomic force microscopy with SERS imaging we find that the chitosan matrix enables the formation of small clusters of silver nanoparticles, with junctions and gaps that greatly enhance the Raman intensities of the adsorbed molecules. The study demonstrates that chitosan-coated anisotropic silver nanoparticle clusters are sensitive enough to be implemented as effective plasmonic substrates for SERS detection of nonresonant analytes at the single-molecule level. (paper)

  5. PPARγ activation normalizes resolution of acute sterile inflammation in murine chronic granulomatous disease

    Fernandez-Boyanapalli, Ruby; Frasch, S. Courtney; Riches, David W.H.; Vandivier, R. William; Henson, Peter M.; Bratton, Donna L.

    2010-01-01

    Absence of a functional nicotinamide adenine dinucleotide phosphate (NADPH) oxidase predisposes chronic granulomatous disease (CGD) patients to infection, and also to unexplained, exaggerated inflammation. The impaired recognition and removal (efferocytosis) of apoptotic neutrophils by CGD macrophages may contribute to this effect. We hypothesized that peroxisome proliferator-activated receptor γ (PPARγ) activation during CGD inflammation is deficient, leading to altered macrophage programmin...

  6. Pleiotropic effects of the sirtuin inhibitor sirtinol involves concentration-dependent modulation of multiple nuclear receptor-mediated pathways in the androgen-responsive prostate cancer cell LNCaP

    Sirtinol, a purported specific inhibitor of the nicotinamide adenine dinucleotide (NAD)-dependent type III histone deacetylase (also known as sirtuin), has been used extensively to identify chemopreventive/chemotherapeutic agents that modulate the activity of this group of enzymes. However, the mole...

  7. First-pass metabolism of ethanol in human beings: effect of intravenous infusion of fructose

    Parlesak, Alexandr; Billinger, MH; Schäfer, C.;

    2004-01-01

    Intravenous infusion of fructose has been shown to enhance reduced form of nicotinamide adenine dinucleotide reoxidation and, thereby, to enhance the metabolism of ethanol. In the current study, the effect of fructose infusion on first-pass metabolism of ethanol was studied in human volunteers...

  8. Thiamin and riboflavin vitamers in human milk: effects of lipid-based nutrient supplementation and stage of lactation on vitamer secretion and contributions to total vitamin content

    While thiamin and riboflavin in breast milk have been analyzed for over 50 years, less attention has been given to the different forms of each vitamin. Thiamin-monophosphate (TMP) and free thiamin contribute to total thiamin content; flavin adenine-dinucleotide (FAD) and free riboflavin are the main...

  9. Protein Modification: Bacterial Effectors Rewrite the Rules of Ubiquitylation.

    Berk, Jason M; Hochstrasser, Mark

    2016-07-11

    A family of virulence factors from the bacterial pathogen Legionella pneumophila has been discovered to modify human Rab GTPases with ubiquitin. Surprisingly, this modification occurs via a non-canonical mechanism that uses nicotinamide adenine dinucleotide as a cofactor. PMID:27404243

  10. On-line measurements of oscillating mitochondrial membrane potential in glucose-fermenting Saccharomyces cerevisiae

    Andersen, Ann Zahle; Poulsen, Allan K; Olsen, Lars Folke;

    2007-01-01

    We employed the fluorescent cyanine dye DiOC(2)(3) to measure membrane potential in semi-anaerobic yeast cells under conditions where glycolysis was oscillating. Oscillations in glycolysis were studied by means of the naturally abundant nicotinamide adenine dinucleotide (NADH). We found that the...

  11. P-hydroxybenzoate hydroxylase. Determination of the amino acid sequence and its integration with the crystal structure.

    Hofsteenge, Jan

    1981-01-01

    Het enzym p-hydroxybenzoaat hydroxylase katalyseert een belangrijke reaktie in de metabolische weg voor de afbraak van aromatische verbindingen (B-ketoadipaat route). […] Het enzym bevat flavine adenine dinucleotide (FAD). De flavine wordt tijdens de reaktie gereduceerd door NADPH, waarna het een co

  12. Efficacy of oral curcuminoid fraction from curcuma xanthorrhiza and curcuminoid cider in high-cholesterol fed rats

    Flavia Maria Mauren

    2016-01-01

    Abbreviations Used: ROS: Reactive oxygen species, NO: Nitric oxide, NOS: NO synthase, NADPH: Nicotinamide adenine dinucleotide phosphate, CD44: Cluster of differentiation 44, ICAM-1: Intercellular adhesion molecule 1, iNOS: inducible NOS, LOX-1: lectin-like oxidized LDL receptor-1, HMG-CoA: 3-hydroxy-3-methylglutaryl-coenzyme A, 5-HMF: 5-hydroxymethylfurfural, HCD: High-cholesterol diet

  13. The mechanism of the antagonism by naloxone of acute alcohol intoxication.

    Badawy, A. A.; Evans, M

    1981-01-01

    Naloxone lowers blood-ethanol concentration and causes a simultaneous reversal of the disturbances in the redox states of the hepatic nicotinamide-adenine dinucleotide (phosphate) couples in acutely-ethanol-intoxicated rats. It is suggested that these effects of naloxone form the basis of its antagonism of acute alcohol intoxication.

  14. DNA apophotolyase from Anacystis nidulans: 1.8 A structure, 8-HDF reconstitution and X-ray-induced FAD reduction.

    R. Kort; H. Komori; S. Adachi; K. Miki; A. Eker

    2004-01-01

    DNA photolyase is a unique flavoenzyme that repairs UV-induced DNA lesions using the energy of visible light. Anacystis nidulans photolyase contains a light-harvesting chromophore, 8-hydroxy-5-deazaflavin (8-HDF), and flavin adenine dinucleotide (FAD) which, in contrast to the 8-HDF chromophore, is

  15. CONTINUOUS MONITORING OF EXTRACELLULAR LACTATE CONCENTRATION BY MICRODIALYSIS LACTOGRAPHY FOR THE STUDY OF RAT MUSCLE METABOLISM INVIVO

    DEBOER, J; POSTEMA, F; PLIJTERGROENDIJK, H; KORF, J

    1991-01-01

    A method is described for the measurement and on-line monitoring of muscular extracellular lactate concentration in both anaesthetized and freely moving rats. This method is based on microdialysis sampling and lactic dehydrogenase-catalysed nicotinamide adenine dinucleotide, reduced (NADH)-fluoresce

  16. Efficient regeneration of NADPH in a 3-enzyme cascade reaction by in situ generation of glucose 6-phosphate from glucose and pyrophosphate

    A.F. Hartog; T. van Herk; R. Wever

    2011-01-01

    We report here a promising method to regenerate NADPH (nicotinamide adenine dinucleotide phosphate) using the intermediate formation of glucose 6-phosphate (G6P) from glucose and pyrophosphate (PPi) catalyzed by the acid phosphatase from Shigella flexneri (PhoN-Sf). The G6P formed is used in turn by

  17. Detecting Ricin: A Sensitive Luminescent Assay for Ricin A-chain Ribosome Depurination Kinetics+

    Sturm, Matthew B.; Schramm, Vern L.

    2009-01-01

    Ricin is a family member of the lethal ribosome-inactivating proteins (RIP) found in plants. Ricin toxin A-chain (RTA) from castor beans catalyzes the hydrolytic depurination of a single base from a GAGA tetraloop of eukaryotic ribosomal RNA to release a single adenine from the sarcin-ricin loop (SRL). Protein synthesis is inhibited by loss of elongation factor binding resulting in cell death. We report a sensitive coupled assay for the measurement of adenine released from ribosomes or small ...

  18. Portable modular detection system

    Brennan, James S.; Singh, Anup; Throckmorton, Daniel J.; Stamps, James F.

    2009-10-13

    Disclosed herein are portable and modular detection devices and systems for detecting electromagnetic radiation, such as fluorescence, from an analyte which comprises at least one optical element removably attached to at least one alignment rail. Also disclosed are modular detection devices and systems having an integrated lock-in amplifier and spatial filter and assay methods using the portable and modular detection devices.

  19. Detection of Terahertz Radiation

    2015-01-01

    The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation.......The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation....

  20. Bicycle Detection System

    Yu, James; Arellano , Secundino; Carrillo , Alma; Cruz , Melinda; Kunitskiy, Dmitriy; Maynigo , Marlo; Sell , Monica

    2013-01-01

    Project Description:  Bicycle detection has become a popular feature of high demand in cities and agencies across the United States. California has recently mandated that all new limit line detector installations as well as modifications to existing limit line detection must provide bicycle detection. This has created the need to develop detection methodologies which are able to detect bicycles as well as differentiate them from vehicles. The objective of this project is to utilize Econolite ...

  1. Outlier detection using autoencoders

    Lyudchik, Olga

    2016-01-01

    Outlier detection is a crucial part of any data analysis applications. The goal of outlier detection is to separate a core of regular observations from some polluting ones, called “outliers”. We propose an outlier detection method using deep autoencoder. In our research the invented method was applied to detect outlier points in the MNIST dataset of handwriting digits. The experimental results show that the proposed method has a potential to be used for anomaly detection.

  2. p210 Bcr-Abl confers overexpression of inosine monophosphate dehydrogenase : an intrinsic pathway to drug resistance mediated by oncogene.

    Gharehbaghi, K.; Burgess, G. S.; Collart, F. R.; Litz-Jackson, S.; Huberman, E.; Jayaram, H. N.; Boswell, H. S.; Center for Mechanistic Biology and Biotechnology; Lab. for Experimental Oncology; Indiana Univ. School of Medicine

    1994-01-01

    The p210 bcr-abl fusion protein tyrosine kinase oncogene has been implicated in the pathogenesis of chronic granulocytic leukemia (CGL). Specific intracellular functions performed by p210 bcr-abl have recently been delineated. We considered the possibility that p210 bcr-abl may also regulate the abundance of inosine 5'-monophosphate dehydrogenase (IMPDH) which is a rate-limiting enzyme for de novo guanylate synthesis. We performed studies of the inhibition of IMPDH by tiazofurin, which acts as a competitive inhibitor through its active species that mimics nicotinamide adenine dinucleotide (NAD), i.e. thiazole-4-carboxamide adenine dinucleotide (TAD). The mean inhibitory concentration (IC50) of tiazofurin for cellular proliferation inhibition was 2.3-2.8-fold greater in cells expressing p210 bcr-abl than in their corresponding parent cells proliferating under the influence of growth factors or in growth factor-independent derivative cells not expressing detectable p210 bcr-abl. IMPDH activity was 1.5-2.3-fold greater within cells expressing p210 bcr-abl than in their parent cells. This increase in enzyme activity was a result of 2-fold increased IMPDH protein as determined by immunoblotting. In addition, an increase in the Km value for NAD utilization by IMPDH was observed in p210 bcr-abl transformed cells, but this increase was within the range of resident NAD concentrations observed in the cells. Increased IMPDH protein in p210 bcr-abl transformed cells was traced to an increased level of IMP dehydrogenase II messenger RNA. Thus, regulation of IMPDH gene expression is mediated at least in part by the bcr-abl gene product and may therefore be indicative of a specific mechanism of intrinsic resistance to tiazofurin.

  3. p210 bcr-abl confers overexpression of inosine monophosphate dehydrogenase: an intrinsic pathway to drug resistance mediated by oncogene.

    Gharehbaghi, K; Burgess, G S; Collart, F R; Litz-Jackson, S; Huberman, E; Jayaram, H N; Boswell, H S

    1994-08-01

    The p210 bcr-abl fusion protein tyrosine kinase oncogene has been implicated in the pathogenesis of chronic granulocytic leukemia (CGL). Specific intracellular functions performed by p210 bcr-abl have recently been delineated. We considered the possibility that p210 bcr-abl may also regulate the abundance of inosine 5'-monophosphate dehydrogenase (IMPDH) which is a rate-limiting enzyme for de novo guanylate synthesis. We performed studies of the inhibition of IMPDH by tiazofurin, which acts as a competitive inhibitor through its active species that mimics nicotinamide adenine dinucleotide (NAD), i.e. thiazole-4-carboxamide adenine dinucleotide (TAD). The mean inhibitory concentration (IC50) of tiazofurin for cellular proliferation inhibition was 2.3-2.8-fold greater in cells expressing p210 bcr-abl than in their corresponding parent cells proliferating under the influence of growth factors or in growth factor-independent derivative cells not expressing detectable p210 bcr-abl. IMPDH activity was 1.5-2.3-fold greater within cells expressing p210 bcr-abl than in their parent cells. This increase in enzyme activity was a result of 2-fold increased IMPDH protein as determined by immunoblotting. In addition, an increase in the Km value for NAD utilization by IMPDH was observed in p210 bcr-abl transformed cells, but this increase was within the range of resident NAD concentrations observed in the cells. Increased IMPDH protein in p210 bcr-abl transformed cells was traced to an increased level of IMP dehydrogenase II messenger RNA. Thus, regulation of IMPDH gene expression is mediated at least in part by the bcr-abl gene product and may therefore be indicative of a specific mechanism of intrinsic resistance to tiazofurin. PMID:7520100

  4. In vivo diagnosis of colonic precancer and cancer using near-infrared autofluorescence spectroscopy and biochemical modeling

    Shao, Xiaozhuo; Zheng, Wei; Huang, Zhiwei

    2011-06-01

    The aim of this study is to evaluate the biochemical foundation and clinical capability of an image-guided near-infrared (NIR) autofluorescence (AF) spectroscopy technique for in vivo diagnosis of colonic malignancies during clinical colonoscopy. A novel endoscopic fiber-optic AF system was utilized for in vivo NIR AF measurements at 785 nm excitation. A total of 263 in vivo NIR AF spectra of colonic tissues were measured from 100 patients, in which 164 spectra were from benign tissue (116 normal and 48 hyperplastic polyps), 34 spectra were from precancer (adenomatous polyps), and 65 spectra were from cancer. The non-negativity constrained least squares minimization biochemical modeling was explored to estimate the biochemical compositions of colonic tissue using nine basis reference spectra from the representative biochemicals (i.e., collagen I, elastin, β-nicotinamide adenine dinucleotide, flavin adenine dinucleotide, L-tryptophan, hematoporphyrin, 4-pyridoxic acid, pyridoxal 5'-phosphate, and water) associated with structural or cellular metabolic progression in colonic precancer and cancer. High-quality in vivo NIR AF spectra in the spectral range of 810 to 1000 nm were acquired from colonic benign, precancerous, and cancerous mucosa under white-light reflectance endoscopic imaging guidance. Partial least squares discriminant analysis, together with the leave-one tissue site-out, cross validation on in vivo NIR AF spectra yields diagnostic sensitivities of 85.4%, 76.5%, and 84.6%, and specificities of 89.9%, 93.4%, and 91.4%, respectively, for classification of benign, precancer, and cancer in the colon. This work demonstrates that image-guided NIR AF spectroscopy in conjunction with biochemical modeling has promising potential for improving in vivo detection and diagnosis of colonic precancer and cancer during clinical colonoscopic screening.

  5. Generation of reactive oxygen radicals through bioactivation of mitomycin antibiotics.

    Pritsos, C A; Sartorelli, A C

    1986-07-01

    Mitomycin C (MC) is a naturally occurring anticancer agent which has been shown to be more cytotoxic to hypoxic tumor cells than to their aerobic counterparts. The mechanism of action of this agent is thought to involve biological reductive activation, to a species that alkylates DNA. A comparison of the cytotoxicity of MC to EMT6 tumor cells with that of the structural analogues porfiromycin (PM), N-(N',N'-dimethylaminomethylene)amine analogue of mitomycin C (BMY-25282), and N-(N',N'-dimethylaminomethylene)amine analogue of porfiromycin (BL-6783) has demonstrated that PM is considerably less cytotoxic to aerobic EMT6 cells than MC, whereas BMY-25282 and BL-6783 are significantly more toxic. The relative abilities of each of these compounds to generate oxygen free radicals following biological activation were measured. Tumor cell sonicates, reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase, xanthine oxidase, and mitochondria were used as the biological reducing systems. All four mitomycin antibiotics produced oxygen radicals following biological reduction, a process that may account for the aerobic cytotoxicity of agents of this class. The generation of relative amounts of superoxide and hydroxyl radical were also measured in EMT6 cell sonicates. BMY-25282 and BL-6783 produced significantly greater quantities of oxygen free radicals with the EMT6 cell sonicate, reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase, and mitochondria than did MC and PM. In contrast, BMY-25282 and BL-6783 did not generate detectable levels of free radicals in the presence of xanthine oxidase, whereas this enzyme was capable of generating free radicals with MC and PM as substrates. MC consistently produced greater amounts of free radicals than PM with all of the reducing systems. BMY-25282, BL-6783, and MC all generated hydroxyl radicals, while PM did not appear to form these radicals. The findings indicate that a correlation exists between

  6. Time-gated FLIM microscope for corneal metabolic imaging

    Silva, Susana F.; Batista, Ana; Domingues, José Paulo; Quadrado, Maria João.; Morgado, António Miguel

    2016-03-01

    Detecting corneal cells metabolic alterations may prove a valuable tool in the early diagnosis of corneal diseases. Nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are autofluorescent metabolic co-factors that allow the assessment of metabolic changes through non-invasive optical methods. These co-factors exhibit double-exponential fluorescence decays, with well-separated short and lifetime components, which are related to their protein-bound and free-states. Corneal metabolism can be assessed by measuring the relative contributions of these two components. For that purpose, we have developed a wide-field time-gated fluorescence lifetime microscope based on structured illumination and one-photon excitation to record FAD lifetime images from corneas. NADH imaging was not considered as its UV excitation peak is regarded as not safe for in vivo measurements. The microscope relies on a pulsed blue diode laser (λ=443 nm) as excitation source, an ultra-high speed gated image intensifier coupled to a CCD camera to acquire fluorescence signals and a Digital Micromirror Device (DMD) to implement the Structured Illumination technique. The system has a lateral resolution better than 2.4 μm, a field of view of 160 per 120 μm and an optical sectioning of 6.91 +/- 0.45 μm when used with a 40x, 0.75 NA, Water Immersion Objective. With this setup we were able to measure FAD contributions from ex-vivo chicken corneas collected from a local slaughterhouse..

  7. Metabolomics analysis of metabolic effects of nicotinamide phosphoribosyltransferase (NAMPT inhibition on human cancer cells.

    Vladimir Tolstikov

    Full Text Available Nicotinamide phosphoribosyltransferase (NAMPT plays an important role in cellular bioenergetics. It is responsible for converting nicotinamide to nicotinamide adenine dinucleotide, an essential molecule in cellular metabolism. NAMPT has been extensively studied over the past decade due to its role as a key regulator of nicotinamide adenine dinucleotide-consuming enzymes. NAMPT is also known as a potential target for therapeutic intervention due to its involvement in disease. In the current study, we used a global mass spectrometry-based metabolomic approach to investigate the effects of FK866, a small molecule inhibitor of NAMPT currently in clinical trials, on metabolic perturbations in human cancer cells. We treated A2780 (ovarian cancer and HCT-116 (colorectal cancer cell lines with FK866 in the presence and absence of nicotinic acid. Significant changes were observed in the amino acids metabolism and the purine and pyrimidine metabolism. We also observed metabolic alterations in glycolysis, the citric acid cycle (TCA, and the pentose phosphate pathway. To expand the range of the detected polar metabolites and improve data confidence, we applied a global metabolomics profiling platform by using both non-targeted and targeted hydrophilic (HILIC-LC-MS and GC-MS analysis. We used Ingenuity Knowledge Base to facilitate the projection of metabolomics data onto metabolic pathways. Several metabolic pathways showed differential responses to FK866 based on several matches to the list of annotated metabolites. This study suggests that global metabolomics can be a useful tool in pharmacological studies of the mechanism of action of drugs at a cellular level.

  8. Design, Synthesis and SAR Studies of NAD Analogues as Potent Inhibitors towards CD38 NADase

    Shengjun Wang

    2014-09-01

    Full Text Available Nicotinamide adenine dinucleotide (NAD, one of the most important coenzymes in the cells, is a substrate of the signaling enzyme CD38, by which NAD is converted to a second messenger, cyclic ADP-ribose, which releases calcium from intracellular calcium stores. Starting with 2′-deoxy-2′-fluoroarabinosyl-β-nicotinamide adenine dinucleotide (ara-F NAD, a series of NAD analogues were synthesized and their activities to inhibit CD38 NAD glycohydrolase (NADase were evaluated. The adenosine-modified analogues showed potent inhibitory activities, among which 2′-deoxy-2′-fluoroarabinosyl-β-nicotinamide guanine dinucleotide (ara-F NGD was the most effective one. The structure-activity relationship of NAD analogues was also discussed.

  9. Mined area detection overview

    Burch, Ian A.; Deas, Robert M.; Port, Daniel M.

    2002-08-01

    An overview of the progress on the UK MOD Applied Research Program for Land Mine Detection. The Defense Science and Technology Laboratory (Dstl) carries out and manages the whole of the UK MOD's Mined Area Detection Applied Research Program both within its own laboratories and in partnership with industrial and academic research organizations. This paper will address two specific areas of Applied Research: hand held mine detection and vehicle mounted mine detection in support of the Mine Detection Neutralization and Route Marking System which started in April 1997. Both are multi-sensor systems, incorporating between them metal detection, ground penetrating radar, nuclear quadrupole resonance, ultra-wideband radar, and polarized thermal imaging.

  10. Revolution in Detection Affairs

    Stern W.

    2013-11-02

    The detection of nuclear or radioactive materials for homeland or national security purposes is inherently difficult. This is one reason detection efforts must be seen as just one part of an overall nuclear defense strategy which includes, inter alia, material security, detection, interdiction, consequence management and recovery. Nevertheless, one could argue that there has been a revolution in detection affairs in the past several decades as the innovative application of new technology has changed the character and conduct of detection operations. This revolution will likely be most effectively reinforced in the coming decades with the networking of detectors and innovative application of anomaly detection algorithms.

  11. Colorimetric DNA detection of transgenic plants using gold nanoparticles functionalized with L-shaped DNA probes

    Nourisaeid, Elham; Mousavi, Amir; Arpanaei, Ayyoob

    2016-01-01

    In this study, a DNA colorimetric detection system based on gold nanoparticles functionalized with L-shaped DNA probes was prepared and evaluated. We investigated the hybridization efficiency of the L-shaped probes and studied the effect of nanoparticle size and the L-shaped DNA probe length on the performance of the as-prepared system. Probes were attached to the surface of gold nanoparticles using an adenine sequence. An optimal sequence of 35S rRNA gene promoter from the cauliflower mosaic virus, which is frequently used in the development of transgenic plants, and the two complementary ends of this gene were employed as model target strands and probe molecules, respectively. The spectrophotometric properties of the as-prepared systems indicated that the large NPs show better changes in the absorption spectrum and consequently present a better performance. The results of this study revealed that the probe/Au-NPs prepared using a vertical spacer containing 5 thymine oligonucleotides exhibited a stronger spectrophotometric response in comparison to that of larger probes. These results in general indicate the suitable performance of the L-shaped DNA probe-functionalized Au-NPs, and in particular emphasize the important role of the gold nanoparticle size and length of the DNA probes in enhancing the performance of such a system.

  12. Lighting detectives forum

    Bülow, Katja; Skindbjerg Kristensen, Lisbeth

    2003-01-01

    Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003.......Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003....

  13. Interior intrusion detection systems

    Rodriguez, J.R.; Matter, J.C. (Sandia National Labs., Albuquerque, NM (United States)); Dry, B. (BE, Inc., Barnwell, SC (United States))

    1991-10-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs.

  14. Interior intrusion detection systems

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs

  15. Enzyme detection by microfluidics

    2013-01-01

    Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted by that...... enzyme...

  16. Fluorescence lifetime imaging ophthalmoscopy in type 2 diabetic patients who have no signs of diabetic retinopathy.

    Schweitzer, Dietrich; Deutsch, Lydia; Klemm, Matthias; Jentsch, Susanne; Hammer, Martin; Peters, Sven; Haueisen, Jens; Müller, Ulrich A; Dawczynski, Jens

    2015-06-01

    The time-resolved autofluorescence of the eye is used for the detection of metabolic alteration in diabetic patients who have no signs of diabetic retinopathy. One eye from 37 phakic and 11 pseudophakic patients with type 2 diabetes, and one eye from 25 phakic and 23 pseudophakic healthy subjects were included n the study. After a three-exponential fit of the decay of autofluorescence, histograms of lifetimes τ(i), amplitudes α(i), and relative contributions Q(i) were statistically compared between corresponding groups in two spectral channels (490 diabetic patients and age-matched controls (p 450 ps, and the shift of τ(3) from ∼3000 to 3700 ps in ch1 of diabetic patients when compared with healthy subjects indicate an increased production of free flavin adenine dinucleotide, accumulation of advanced glycation end products (AGE), and, probably, a change from free to protein-bound reduced nicotinamide adenine inucleotide at the fundus. AGE also accumulated in the crystalline lens. PMID:25769278

  17. Multifunctional Dumbbell-Shaped DNA-Templated Selective Formation of Fluorescent Silver Nanoclusters or Copper Nanoparticles for Sensitive Detection of Biomolecules.

    Chen, Jinyang; Ji, Xinghu; Tinnefeld, Philip; He, Zhike

    2016-01-27

    In this work, a multifunctional template for selective formation of fluorescent silver nanoclusters (AgNCs) or copper nanoparticles (CuNPs) is put forward. This dumbbell-shaped (DS) DNA template is made up of two cytosine hairpin loops and an adenine-thymine-rich double-helical stem which is closed by the loops. The cytosine loops act as specific regions for the growth of AgNCs, and the double-helical stem serves as template for the CuNPs formation. By carefully investigating the sequence and length of DS DNA, we present the optimal design of the template. Benefiting from the smart design and facile synthesis, a simple, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection is proposed. Through the systematic comparison, it is found that the strategy based on CuNPs formation is more sensitive for ATP assay than that based on AgNCs synthesis, and the detection limitation was found to be 81 pM. What's more, the CuNPs formation-based method is successfully applied in the detection of ATP in human serum as well as the determination of cellular ATP. In addition to small target molecule, the sensing strategy was also extended to the detection of biomacromolecule (DNA), which illustrates the generality of this biosensor. PMID:26719979

  18. Aerial Radiation Detection

    An airborne system designed for the detection of radioactive sources on the soil surface from an aircraft normally senses gamma rays emitted by the source. Gamma rays have the longest path length (least attenuation) through the air of any of the common radioactive emissions and will thus permit source detection at large distances. A secondary benefit from gamma rays detection if that nearly all radioactive isotopes can be identified by the spectrum of gammas emitted. Major gaseous emissions from fuel processing plants emit gammas that may be detected and identified. Some types of special nuclear material also emit neutrons which are also useful for detection at a distance

  19. Statistical methods for detecting periodic fragments in DNA sequence data

    Ying Hua; Epps Julien; Huttley Gavin A

    2011-01-01

    Abstract Background Period 10 dinucleotides are structurally and functionally validated factors that influence the ability of DNA to form nucleosomes, histone core octamers. Robust identification of periodic signals in DNA sequences is therefore required to understand nucleosome organisation in genomes. While various techniques for identifying periodic components in genomic sequences have been proposed or adopted, the requirements for such techniques have not been considered in detail and con...

  20. GPU accelerated face detection

    Mäkelä, J.

    2013-01-01

    Graphics processing units have massive parallel processing capabilities, and there is a growing interest in utilizing them for generic computing. One area of interest is computationally heavy computer vision algorithms, such as face detection and recognition. Face detection is used in a variety of applications, for example the autofocus on cameras, face and emotion recognition, and access control. In this thesis, the face detection algorithm was accelerated with GPU using OpenCL. The goal was...

  1. Detection in Random Fields

    Hupkens, Erik Peter

    1997-01-01

    In general, a detection problem arises when changes may appear in a certain process. These changes may be errors in a dynamic process, objects in images, scratches on surfaces, or anything that is not supposed to be present. This thesis is concerned with a generalization from one-parameter detection theory to multi-parameter detection theory. The difference between these problems is not just an increase in dimension of the independent parameter. Consider for example a process that is defined ...

  2. Network Traffic Anomaly Detection

    Huang, Hong; Al-Azzawi, Hussein; Brani, Hajar

    2014-01-01

    This paper presents a tutorial for network anomaly detection, focusing on non-signature-based approaches. Network traffic anomalies are unusual and significant changes in the traffic of a network. Networks play an important role in today's social and economic infrastructures. The security of the network becomes crucial, and network traffic anomaly detection constitutes an important part of network security. In this paper, we present three major approaches to non-signature-based network detect...

  3. Multiview Face Detection

    Sauquet, Tiffany; Rodriguez, Yann; Marcel, Sébastien

    2005-01-01

    In this document, we address the problem of multiview face detection. This work extends the frontal face detection system developed at the IDIAP Research Institute to multiview face detection. The main state-of-the art techniques are reviewed and a novel architecture is presented, based on a pyramid of detectors that are trained for different views of faces. The proposed approach robustly detects faces rotated up to -67.5 degree in the image plane and up to -90 degree out of the image plane. ...

  4. DROWSY DRIVER DETECTION SYSTEM

    Mrs. Smita Jawale; Ms. Pragati Malvadia; Ms. Ashwini Meena

    2016-01-01

    A Drowsy Driver Detection System is an Image processing based system. This system is developed using a non-intrusive machine vision based concepts. In this system, there is a camera that will be continuously monitoring the driver’s face to detect fatigue. In case the driver is detected as fatigue, the system issues an alarm. This system detects drowsiness by checking the amount of time the eyes are closed. The first five consecutive frames of the camera is checked, if the eyes are found...

  5. Explicit Content Image Detection

    Jorge Alberto Marcial Basilio

    2010-12-01

    Full Text Available This paper proposes a system gives for explicit content image detection based on Computer Vision Algorithms, pattern recognition and FTK software Explicit Image Detection. In the first stage, HSV color model is used for the input images for the purpose of discriminating elements that are not human skin images. Then the image is filtered using skin detection. The output image only contains the areas of which it is composed. The results show a comparison between the proposed system and the company software Access Data called Forensic Toolkit 3.1 Explicit Image Detection isperformed.

  6. Lean blowoff detection sensor

    Thornton, Jimmy; Straub, Douglas L.; Chorpening, Benjamin T.; Huckaby, David

    2007-04-03

    Apparatus and method for detecting incipient lean blowoff conditions in a lean premixed combustion nozzle of a gas turbine. A sensor near the flame detects the concentration of hydrocarbon ions and/or electrons produced by combustion and the concentration monitored as a function of time are used to indicate incipient lean blowoff conditions.

  7. Introduction to detection systems

    Larsen, Jan

    Presentation of the information processing pipleline for detection including discussing of various issues and the use of mathematical modeling. A simple example of detection a signal in noise illustrated that simple modeling outperforms human visual and auditory perception. Particiants are going to...

  8. Semiconductor radiation detection systems

    2010-01-01

    Covers research in semiconductor detector and integrated circuit design in the context of medical imaging using ionizing radiation. This book explores other applications of semiconductor radiation detection systems in security applications such as luggage scanning, dirty bomb detection and border control.

  9. Radar target detection simulation

    Tarig Ibrahim Osman

    2014-12-01

    Full Text Available Standard radar detection process requires that the sensor output is compared to a predetermined threshold. The threshold is selected based on a-priori knowledge available and/or certain assumptions. However, any knowledge and/or assumptions become in adequate due to the presence of multiple targets with varying signal return and usually non stationary background. Thus, any predetermined threshold may result in either increased false alarm rate or increased track loss. Even approaches where the threshold is adaptively varied will not perform well in situations when the signal return from the target of interest is too low compared to the average level of the background .Track-before-detect techniques eliminate the need for a detection threshold and provide detecting and tracking targets with lower signal-to-noise ratios than standard methods. However, although trackbefore-detect techniques eliminate the need for detection threshold at sensor's signal processing stage, they often use tuning thresholds at the output of the filtering stage .This paper presents a computerized simulation model for target detection process. Moreover, the proposed model method is based on the target motion models, the output of the detection process can easily be employed for maneuvering target tracking.

  10. Bayesian community detection

    Mørup, Morten; Schmidt, Mikkel N

    2012-01-01

    community detection consistent with an intuitive definition of communities and present a Markov chain Monte Carlo procedure for inferring the community structure. A Matlab toolbox with the proposed inference procedure is available for download. On synthetic and real networks, our model detects communities...

  11. Biometric Fingerprint Liveness Detection

    Váňa, T.

    2015-01-01

    This paper deals with biometric fingerprint liveness detection. A software-based liveness detection approach using neural network is proposed. To distinguish between live and fake samples, three image quality features extracted from one image are used. The algorithm is tested on LivDet database comprising real and fake images acquired with three sensors.

  12. Detection in Random Fields

    Hupkens, Erik Peter

    1997-01-01

    In general, a detection problem arises when changes may appear in a certain process. These changes may be errors in a dynamic process, objects in images, scratches on surfaces, or anything that is not supposed to be present. This thesis is concerned with a generalization from one-parameter detection

  13. Array for detecting microbes

    Andersen, Gary L.; DeSantis, Todd D.

    2014-07-08

    The present embodiments relate to an array system for detecting and identifying biomolecules and organisms. More specifically, the present embodiments relate to an array system comprising a microarray configured to simultaneously detect a plurality of organisms in a sample at a high confidence level.

  14. Amplified leak detection

    Mahony, James

    2011-12-15

    Leaks are one of the major concerns for oil and gas producers. But recently, a Calgary-based company developed a tool that can find natural gas leaks in wellbores. This has relieved the oil and gas producers because the optics of finding downhole leaks just got a little brighter. Since then, there have been continuous efforts to broaden and refine fiber optics based methods. This paper presents amplified leak detection using fiber optics to identify even the smallest liquid leaks downhole. At high volumes, detection of downhole leaks in liquids is not a problem but at lower flow rates, the leaks become harder to detect, and at very low flow rates, they might not be detected at all. Hifi Engineering Inc. has developed the LeakSonar fiber optic acoustic sensor array that is specifically designed to detect and locate fluid migration in wellbores, even through multiple strings of casing.

  15. WLAN Intrusion Detection System

    Ms. Sushama Shirke

    2011-08-01

    Full Text Available This is an implementation of the Wireless LAN Intrusion Detection System (WIDS using clock-skews as a fingerprinting property as suggested by Jana-Kasera [1]. Our objective is to detect the presence of a fake access point (AP in a Wireless LAN (WLAN. Use of clock -skew enables us to effectively detect Medium Access Control (MAC Address spoofing. The principle used in this project is that clock s k e w s remain consistent over time for the same AP but vary significantly across AP’s. We have also tried to exploreprobable points of failure and implemented algorithms to overcome these problems. Advantage of this implementation is that fake AP can be detected very quickly as WLAN Intrusion Detection System needs only 100 -200 packets in most cases.

  16. Soybean allergen detection methods

    Pedersen, Mona H; Holzhauser, Thomas; Bisson, Caroline;

    2008-01-01

    ) using basophils passively sensitized with patient serum and a PCR method detecting soy DNA. Eight food products were selected as model foods to test the performance of the methods. There was an overall good agreement between the methods in terms of ranks of soy content but not the quantity. The sandwich......Soybean containing products are widely consumed, thus reliable methods for detection of soy in foods are needed in order to make appropriate risk assessment studies to adequately protect soy allergic patients. Six methods were compared using eight food products with a declared content of soy...... ELISA aimed at native soy proteins had the lowest detection limit of 0.05 ppm, but only identified soy in 5/8 products, and generally in lower amounts compared to other methods. The competitive ELISA had a higher detection limit of 21 ppm, but seemed more successful in detecting processed soy. Only HR...

  17. Breast Cancer Detection

    2000-01-01

    The BioScan System was developed by OmniCorder Technologies, Inc. at the Jet Propulsion Laboratory. The system is able to locate cancerous lesions by detecting the cancer's ability to recruit a new blood supply. A digital sensor detects infrared energy emitted from the body and identifies the minute differences accompanying the blood flow changes associated with cancerous cells. It also has potential use as a monitoring device during cancer treatment. This technology will reduce the time taken to detect cancerous cells and allow for earlier intervention, therefore increasing the overall survival rates of breast cancer patients.

  18. Analogue MIMO Detection

    McNamara Darren

    2006-01-01

    Full Text Available In this contribution we propose an analogue receiver that can perform turbo detection in MIMO systems. We present the case for a receiver that is built from nonlinear analogue devices, which perform detection in a "free-flow" network (no notion of iterations. This contribution can be viewed as an extension of analogue turbo decoder concepts to include MIMO detection. These first analogue implementations report reductions of few orders of magnitude in the number of required transistors and in consumed energy, and the same order of improvement in processing speed. It is anticipated that such analogue MIMO decoder could bring about the same advantages, when compared to traditional digital implementations.

  19. WLAN Intrusion Detection System

    Ms. Sushama Shirke; Mr. S.B.Vanjale

    2011-01-01

    This is an implementation of the Wireless LAN Intrusion Detection System (WIDS ) using clock-skews as a fingerprinting property as suggested by Jana-Kasera [1]. Our objective is to detect the presence of a fake access point (AP) in a Wireless LAN (WLAN). Use of clock -skew enables us to effectively detect Medium Access Control (MAC) Address spoofing. The principle used in this project is that clock s k e w s remain consistent over time for the same AP but vary significantly across AP’s. We ha...

  20. DETECTION OF E-CYANOMETHANIMINE TOWARD SAGITTARIUS B2(N) IN THE GREEN BANK TELESCOPE PRIMOS SURVEY

    The detection of E-cyanomethanimine (E-HNCHCN) toward Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra to laboratory rotational spectra from a reaction product screening experiment. The experiment uses broadband molecular rotational spectroscopy to monitor the reaction products produced in an electric discharge source using a gas mixture of NH3 and CH3CN. Several transition frequency coincidences between the reaction product screening spectra and previously unassigned interstellar rotational transitions in the PRIMOS survey have been assigned to E-cyanomethanimine. A total of eight molecular rotational transitions of this molecule between 9 and 50 GHz are observed with the GBT. E-cyanomethanimine, often called the HCN dimer, is an important molecule in prebiotic chemistry because it is a chemical intermediate in proposed synthetic routes of adenine, one of the two purine nucleobases found in DNA and RNA. New analyses of the rotational spectra of both E-cyanomethanimine and Z-cyanomethanimine that incorporate previous millimeter-wave measurements are also reported.

  1. DNA-templated silver nanoclusters based label-free fluorescent molecular beacon for the detection of adenosine deaminase.

    Zhang, Kai; Wang, Ke; Xie, Minhao; Zhu, Xue; Xu, Lan; Yang, Runlin; Huang, Biao; Zhu, Xiaoli

    2014-02-15

    A general and reliable fluorescent molecular beacon is proposed in this work utilizing DNA-templated silver nanoclusters (AgNCs). The fluorescent molecular beacon has been employed for sensitive determination of the concentration of adenosine deaminase (ADA) and its inhibition. A well-designed oligonucleotide containing three functional regions (an aptamer region for adenosine assembly, a sequence complementary to the region of the adenosine aptamer, and an inserted six bases cytosine-loop) is adopted as the core element in the strategy. The enzymatic reaction of adenosine catalyzed by ADA plays a key role as well in the regulation of the synthesis of the DNA-templated AgNCs, i.e. the signal indicator. The intensity of the fluorescence signal may thereby determine the concentration of the enzyme and its inhibitor. The detection limit of the ADA can be lowered to 0.05 UL(-1). Also, 100 fM of a known inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride (EHNA) is enough to present distinguishable fluorescence emission. Moreover, since the fluorescent signal indicator is not required to be bound with the oligonucleotide, this fluorescent molecular beacon may integrate the advantages of both the label-free and signal-on strategies. PMID:24035856

  2. DETECTION OF E-CYANOMETHANIMINE TOWARD SAGITTARIUS B2(N) IN THE GREEN BANK TELESCOPE PRIMOS SURVEY

    Zaleski, Daniel P.; Seifert, Nathan A.; Steber, Amanda L.; Muckle, Matt T.; Loomis, Ryan A.; Vasquez, David; Nyiramahirwe, Jolie; Sciortino, Nicole; Johnson, Kennedy; Pate, Brooks H. [Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22904 (United States); Corby, Joanna F. [Department of Astronomy, University of Virginia, McCormick Road, Charlottesville, VA 22904 (United States); Martinez, Oscar Jr.; Crabtree, Kyle N.; McCarthy, Michael C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jewell, Philip R.; Remijan, Anthony J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Hollis, Jan M. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lovas, Frank J., E-mail: bp2k@virginia.edu, E-mail: mccarthy@cfa.harvard.edu, E-mail: aremijan@nrao.edu [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2013-03-01

    The detection of E-cyanomethanimine (E-HNCHCN) toward Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra to laboratory rotational spectra from a reaction product screening experiment. The experiment uses broadband molecular rotational spectroscopy to monitor the reaction products produced in an electric discharge source using a gas mixture of NH{sub 3} and CH{sub 3}CN. Several transition frequency coincidences between the reaction product screening spectra and previously unassigned interstellar rotational transitions in the PRIMOS survey have been assigned to E-cyanomethanimine. A total of eight molecular rotational transitions of this molecule between 9 and 50 GHz are observed with the GBT. E-cyanomethanimine, often called the HCN dimer, is an important molecule in prebiotic chemistry because it is a chemical intermediate in proposed synthetic routes of adenine, one of the two purine nucleobases found in DNA and RNA. New analyses of the rotational spectra of both E-cyanomethanimine and Z-cyanomethanimine that incorporate previous millimeter-wave measurements are also reported.

  3. Core-shell of FePt@SiO2-Au magnetic nanoparticles for rapid SERS detection.

    Hardiansyah, Andri; Chen, An-Yu; Liao, Hung-Liang; Yang, Ming-Chien; Liu, Ting-Yu; Chan, Tzu-Yi; Tsou, Hui-Ming; Kuo, Chih-Yu; Wang, Juen-Kai; Wang, Yuh-Lin

    2015-12-01

    In this study, multifunctional hybrid nanoparticles composed of iron platinum (FePt), silica (SiO2), and gold nanoparticles (AuNPs) had been developed for surface-enhanced Raman scattering (SERS) application. Core-shell structure of SiO2 and FePt nanoparticles (FePt@SiO2) was fabricated through sol-gel process and then immobilized gold nanoparticles onto the surface of FePt@SiO2, which displays huge Raman enhancement effect and magnetic separation capability. The resulting core-shell nanoparticles were subject to evaluation by transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX), zeta potential measurement, and X-ray photoelectron spectroscopy (XPS). TEM observation revealed that the particle size of resultant nanoparticles displayed spherical structure with the size ~30 nm and further proved the successful immobilization of Au onto the surface of FePt@SiO2. Zeta potential measurement exhibited the successful reaction between FePt@SiO2 and AuNPs. The rapid SERS detection and identification of small biomolecules (adenine) and microorganisms (gram-positive bacteria, Staphylococcus aureus) was conducted through Raman spectroscopy. In summary, the novel core-shell magnetic nanoparticles could be anticipated to apply in the rapid magnetic separation under the external magnetic field due to the core of the FePt superparamagnetic nanoparticles and label-free SERS bio-sensing of biomolecules and bacteria. PMID:26489855

  4. Detection of counterfeit currency

    Burns, Donald A.

    1998-01-01

    A method of detecting counterfeit currency by contacting the currency to be tested with near infrared beams in the spectrum below 1250 namometers, measuring reflectance of the near infrared beams and comparing the reflectance values with those from genuine currency.

  5. Anomaly Detection in Sequences

    National Aeronautics and Space Administration — We present a set of novel algorithms which we call sequenceMiner, that detect and characterize anomalies in large sets of high-dimensional symbol sequences that...

  6. Light Detection And Ranging

    U.S. Geological Survey, Department of the Interior — LiDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  7. Towards Corrosion Detection System

    B.B.Zaidan

    2010-05-01

    Full Text Available Corrosion is a natural process that seeks to reduce the binding energy in metals. The end result of corrosion involves a metal atom being oxidized. Surface corrosion on aluminum aircraft skins, near joints and around fasteners, is often an indicator of buried structural corrosion and cracking In this paper we proposed a new method on which we are moving towards designing a method to detect the corrosion within the metals, the new method has defined texture analysis as the main method for this approach, the proposed enhancement shows less false positive and less false negative. The main functions used in this approach beside texture analysis are Edge detection, structure element and image dilation. The new approach has designed to detect a part of the image that has been affected by the corrosion, the tested images has showed a good result lying on detecting the corrosion part from the image.

  8. Detecting Prostate Cancer

    Full Text Available ... M.D.: PSA stands for Prostate Specific Antigen. It is a test that men have by having ... detection is the digital rectal exam. Barry Trevithick: It doesn't make sense to be afraid of ...

  9. Kick detection during drilling

    This patent describes a borehole drilling system including a drill string in a borehole with the drill string defining an annulus between the outer diameter of the string and the borehole. It comprises: pressure detecting means near the surface of the system for detecting the modulated pressure pulse train in the annulus which is transmitted to the surface from the transmitter and for generating an annulus pressure signal corresponding thereto; pressure detecting means near the surface of the system for detecting the modulated pressure pulse train in the standpipe which is transmitted to the surface from the transmitter via the drill pipe and for generating a standpipe pressure signal corresponding thereto; surface instrumentation means responsive to the annulus pressure signal and to the standpipe pressure signal; and means for comparing the difference in arrival time signal DTmeas with a predetermined difference in arrival time signal DTalarm to generate a signal if DTmeas > DTalarm

  10. Detecting Prostate Cancer

    Full Text Available ... necessary test for detection is the digital rectal exam. Barry Trevithick: It doesn't make sense to ... your open mouth. Narrator: When a digital rectal exam or PSA test indicates an abnormality, an ultrasound ...

  11. Lead Poison Detection

    1976-01-01

    With NASA contracts, Whittaker Corporations Space Science division has developed an electro-optical instrument to mass screen for lead poisoning. Device is portable and detects protoporphyrin in whole blood. Free corpuscular porphyrins occur as an early effect of lead ingestion. Also detects lead in urine used to confirm blood tests. Test is inexpensive and can be applied by relatively unskilled personnel. Similar Whittaker fluorometry device called "drug screen" can measure morphine and quinine in urine much faster and cheaper than other methods.

  12. Face Detection using Ferns

    Marcel, Sébastien; Subburaman, Venkatesh Bala

    2011-01-01

    This paper discusses the use of ferns (a set of binary features) for face detection. The binary feature used here is the sign of pixel intensity difference. Ferns were first introduced for keypoint recognition and showed good performance, and improving the speed of recognition. Keypoint recognition deals with classification of few hundred different classes, while face detection is a two-class problem with an unbalanced data. For keypoint recognition random pixel pairs proved to be good enoug...

  13. Scaling up Copy Detection

    Li, Xian; Dong, Xin Luna; Lyons, Kenneth B.; Meng, Weiyi; Srivastava, Divesh

    2015-01-01

    Recent research shows that copying is prevalent for Deep-Web data and considering copying can significantly improve truth finding from conflicting values. However, existing copy detection techniques do not scale for large sizes and numbers of data sources, so truth finding can be slowed down by one to two orders of magnitude compared with the corresponding techniques that do not consider copying. In this paper, we study {\\em how to improve scalability of copy detection on structured data}. Ou...

  14. Sensor for metal detection

    Kodzius, Rimantas

    2014-06-26

    NOVELTY - The sensor has a microfluidic flow channel that is provided with an inlet port, an outlet port, and a detection chamber. The detection chamber is provided with a group of sensing electrodes (4) having a working electrode (8), a counter electrode (9), and a reference electrode (10). A flow sensor is configured to measure flow in the channel. A temperature sensor (6) is configured to measure temperature in the channel (3). An electrical connection is configured to connect the sensor to a sensing device. USE - Sensor for detecting metal such as toxic metal in sample such as clinical sample such as stool, saliva, sputum, bronchial lavage, urine, vaginal swab, nasal swab, biopsy, tissue, tears, breath, blood, serum, plasma, cerebrospinal fluid, peritoneal fluid, pleural fluid, pericardial fluid, joint fluid, and amniotic fluid, water sample, food sample, air sample, and soil sample (all claimed). ADVANTAGE - The sensor for use with the portable analytical instrument is configured for detection of metalsin samples. The sensor can provide the excellent solution for on-site metal detection, including heavy metal detection. The sensors can provide significant advantages in higher throughput, lower cost, at the same time being less labor intensive and less dependent on individual skills. The disposable design of the sensor, the enhanced reliability and repeatability of measurements can be obtained. The sensors can be widely applied in various industries. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a system for detecting metal in sample; and (2) a method for using sensor for detecting metal in sample. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the sensor prototype. Channel (3) Sensing electrodes (4) Temperature sensor (6) Working electrode (8) Counter electrode (9) Reference electrode (10)

  15. EMOTION DETECTION FROM TEXT

    Shiv Naresh Shivhare

    2012-05-01

    Full Text Available Emotion can be expressed in many ways that can be seen such as facial expression and gestures, speech and by written text. Emotion Detection in text documents is essentially a content – based classification problem involving concepts from the domains of Natural Language Processing as well as Machine Learning. In this paper emotion recognition based on textual data and the techniques used in emotion detection are discussed.

  16. EMOTION DETECTION FROM TEXT

    Shiv Naresh Shivhare; Saritha Khethawat

    2012-01-01

    Emotion can be expressed in many ways that can be seen such as facial expression and gestures, speech and by written text. Emotion Detection in text documents is essentially a content – based classification problem involving concepts from the domains of Natural Language Processing as well as Machine Learning. In this paper emotion recognition based on textual data and the techniques used in emotion detection are discussed.

  17. Emotion Detection from Text

    Shivhare, Shiv Naresh

    2012-01-01

    Emotion can be expressed in many ways that can be seen such as facial expression and gestures, speech and by written text. Emotion Detection in text documents is essentially a content - based classification problem involving concepts from the domains of Natural Language Processing as well as Machine Learning. In this paper emotion recognition based on textual data and the techniques used in emotion detection are discussed.

  18. Detecting Illegal Arms Trade

    DellaVigna, Stefano; Ferrara, Eliana La

    2010-01-01

    Illegal arms are responsible for thousands of deaths in civil wars every year. Yet, their trade is very hard to detect. We propose a method to statistically detect illegal arms trade based on the investor knowledge embedded in financial markets. We focus on eight countries under UN arms embargo in the period 1990-2005, and analyze eighteen events during the embargo that suddenly increase or decrease conflict intensity. If the weapon-making companies are not trading or are trading legally, an ...

  19. Methods of Endotoxin Detection.

    Su, Wenqiong; Ding, Xianting

    2015-08-01

    Endotoxin, present in the outer membrane of all gram-negative bacteria, can pose serious risks to human health, from irreversible shock to death. Therefore, it is essential to develop sensitive, accurate, and rapid methods for its detection. The rabbit pyrogen test is the first standard technique for endotoxin detection and, nowadays, has been replaced by the Limulus Amoebocyte Lysate test, which is the most popular detection technique for endotoxin. With in-depth understanding of endotoxin, biosensors based on endotoxin-sensing components are promising alternatives to pursue in developing low-cost, easy-operation, and fast-response endotoxin detection techniques. This article summarizes the recent advances of endotoxin detection methods with a particular emphasis on optical and electrochemical biosensors based on various sensing elements ranging from nature biomolecules to artificial materials. As the research and technological revolution continues, the highly integrated and miniaturized commercial devices for sensitively and reliably detecting endotoxin will provide a wide range of applications in people's daily life. PMID:25720597

  20. A reagentless DNA-based electrochemical silver(I) sensor for real time detection of Ag(I) - the effect of probe sequence and orientation on sensor response.

    Wu, Yao; Lai, Rebecca Y

    2016-06-01

    Ag(I) is known to interact with cytosine (C) via the formation C-Ag(I)-C complexes. The authors have utilized this concept to design six electrochemical Ag(I) sensors using C-rich DNA probes. Alternating current voltammetry and cyclic voltammetry were used to analyze the sensors. The results show that the dual-probe sensors that require the use of both 5'- and 3'-thiolated DNA probes are not suitable for this application, the differences in probe orientation impedes formation of C-Ag(I)-C complexes. Sensors fabricated with DNA probes containing both thymine (T) and C, independent of the location of the alkanethiol linker, do not response to Ag(I) either; T-T mismatches destabilize the duplex even in the presence of Ag(I). However, sensors fabricated with DNA probes containing both adenine (A) and C are ideal for this application, owing to the formation of C-Ag(I)-C complexes, as well as other lesser known interactions between A and Ag(I). Both sensors are sensitive, specific and selective enough to be used in 50% human saliva. They can also be used to detect silver sulfadiazine, a commonly prescribed antimicrobial drug. With further optimization, this sensing strategy may offer a promising approach for detection of Ag(I) in environmental and clinical samples. PMID:26901685

  1. DNA methyltransferase activity detection based on fluorescent silver nanocluster hairpin-shaped DNA probe with 5'-C-rich/G-rich-3' tails.

    Liu, Wenting; Lai, Han; Huang, Rong; Zhao, Chuntao; Wang, Yimo; Weng, Xiaocheng; Zhou, Xiang

    2015-06-15

    DNA methylation has received a large amount of attention due to its close relationship to a wide range of biological phenomena, such as gene activation, gene imprinting, and chromatin stability. Herein, we have designed a hairpin-shaped DNA probe with 5'-C-rich/G-rich-3' tails and developed a simple and reliable fluorescence turn-off assay for DNA adenine methylation (Dam) methyltransferase (MTase) detection combining site recognition and the fluorescence enhancement of DNA-templated silver nanoclusters (DNA-AgNCs) by guanine-rich DNA sequences. A designed hairpin probe with 5' CCCTTACCCC and 3' GGGTGGGGTGGGGTGGGG displays a bright red emission after reacting with AgNO3 and NaBH4. In the presence of Dam MTase, the methylation-sensitive restriction endonuclease Dpn I which has the same recognition site with the Dam MTase can split the probe, freeing the G-rich sequence from the C-rich sequence, thus quenching the fluorescence of DNA-AgNCs. Compared to traditional fluorescent-based methods, this strategy is simple and inexpensive. A linear response to concentrations of Dam MTase which range from 1 U/mL to 100 U/mL and a detection limit of 1 U/mL are obtained without any amplification steps. In addition, we also demonstrate the method can be used for evaluation and screening of inhibitors for Dam MTase. PMID:25682501

  2. Proactive malware detection

    Gloster, Jonathan; Diep, Michael; Dredden, David; Mix, Matthew; Olsen, Mark; Price, Brian; Steil, Betty

    2014-06-01

    Small-to-medium sized businesses lack resources to deploy and manage high-end advanced solutions to deter sophisticated threats from well-funded adversaries, but evidence shows that these types of businesses are becoming key targets. As malicious code and network attacks become more sophisticated, classic signature-based virus and malware detection methods are less effective. To augment the current malware methods of detection, we developed a proactive approach to detect emerging malware threats using open source tools and intelligence to discover patterns and behaviors of malicious attacks and adversaries. Technical and analytical skills are combined to track adversarial behavior, methods and techniques. We established a controlled (separated domain) network to identify, monitor, and track malware behavior to increase understanding of the methods and techniques used by cyber adversaries. We created a suite of tools that observe the network and system performance looking for anomalies that may be caused by malware. The toolset collects information from open-source tools and provides meaningful indicators that the system was under or has been attacked. When malware is discovered, we analyzed and reverse engineered it to determine how it could be detected and prevented. Results have shown that with minimum resources, cost effective capabilities can be developed to detect abnormal behavior that may indicate malicious software.

  3. The adsorption and reaction of adenine nucleotides on montmorillonite

    Ferris, James P.; Hagan, William J., Jr.

    1986-01-01

    The binding of AMP to Zn(2+)-montmorillonite is investigated in the presence of salts and Good's zwitterion buffers, PIPES and MES. The initial concentrations of nucleotide and the percent adsorbtion are used to calculate the adsorption isotherms, and the Langmuir adsorption equation is used for the analysis of data. The adsorption coefficient was found to be three times greater in the presence of 0.2 M PIPES than in its absence. In addition, basal spacings measured by X-ray diffraction were increased by the buffer. These results are interpreted in terms of a model in which the adsorption of AMP is mediated by a Zn(2+) complex of PIPES in different orientations in the interlamellar region of the montmorillonite. Mixed ligand complexes of this type are reminiscent of the complexes observed between metal ions and biological molecules in living systems.

  4. Synthesis of N6-Substituted-2-Triazolyl-Adenine Derivatives

    Novosjolova, I; Bizdēna, Ē; Beļakovs, S; Turks, M

    2013-01-01

    A novel class of 2,6-bis-triazolylpurine nucleosides were obtained from 2,6-diazido precursors via copper (I) catalyzed azide-alkyne 1,3-dipolar cycloaddition reaction. These intermediates appeared to be very reactive towards N-nucleophiles and thus selectively gave C(6)-substituted analogs with triazolyl moiety at C(2)-position. Thereby, 1,2,3-triazoles act as good leaving groups in regioselective nucleophilic aromatic substitution reactions.

  5. Synthesis and biological evaluation of conformationally restricted adenine bicycloribonucleosides

    Hřebabecký, Hubert; Procházková, Eliška; Šála, Michal; Plačková, Pavla; Tloušťová, Eva; Barauskas, O.; Lee, Y. J.; Tian, Y.; Mackman, R.; Nencka, Radim

    2015-01-01

    Roč. 13, č. 35 (2015), s. 9300-9313. ISSN 1477-0520 R&D Projects: GA ČR GPP207/12/P625; GA ČR GA15-09310S; GA ČR GA13-24880S; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : nucleic acid analogs * nucleoside triphosphates * sugar ring Subject RIV: CC - Organic Chemistry Impact factor: 3.562, year: 2014 http://pubs.rsc.org/en/content/articlepdf/2015/ob/c5ob00987a

  6. Forensic audio watermark detection

    Steinebach, Martin; Zmudzinski, Sascha; Petrautzki, Dirk

    2012-03-01

    Digital audio watermarking detection is often computational complex and requires at least as much audio information as required to embed a complete watermark. In some applications, especially real-time monitoring, this is an important drawback. The reason for this is the usage of sync sequences at the beginning of the watermark, allowing a decision about the presence only if at least the sync has been found and retrieved. We propose an alternative method for detecting the presence of a watermark. Based on the knowledge of the secret key used for embedding, we create a mark for all potential marking stages and then use a sliding window to test a given audio file on the presence of statistical characteristics caused by embedding. In this way we can detect a watermark in less than 1 second of audio.

  7. Nucleic acid detection kits

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  8. Traffic Light Detection

    Philipsen, Mark Philip; Jensen, Morten Bornø; Møgelmose, Andreas; Moeslund, Thomas B.; Trivedi, Mohan M.

    Traffic light recognition (TLR) is an integral part of any intelligent vehicle, which must function in the existing infrastructure. Pedestrian and sign detection have recently seen great improvements due to the introduction of learning based detectors using integral channel features. A similar push...... database is collected based on footage from US roads. The database consists of both test and training data, totaling 46,418 frames and 112,971 annotated traffic lights, captured in continuous sequences under a varying light and weather conditions. The learning based detector achieves an AUC of 0.4 and 0...... have not yet been seen for the detection sub-problem of TLR, where detection is dominated by methods based on heuristic models. Evaluation of existing systems is currently limited primarily to small local datasets. In order to provide a common basis for comparing future TLR research an extensive public...

  9. Neurology and detective writing.

    Kempster, Peter A; Lees, Andrew J

    2013-12-01

    When searching for clues to reach a diagnosis, neurologists often empathise with the detective who is trying to solve a case. The premise of this article is that detective stories have been part of the fabric of neurology ever since the time that it evolved into a discrete medical speciality. We will examine how this form of narrative has found expression in detective mystery fiction and popular science publications created by 20th century neurologist physician-writers. We will also investigate the power of the neurologist's alter ego, Sherlock Holmes: his relationship to founders of clinical neuroscience such as Jean-Martin Charcot, William Gowers and Sigmund Freud, and his influences on neurological practice and its literary traditions. PMID:24006370

  10. Dark matter direct detection

    There are now enough pieces of (gravitational or cosmological) evidence for the existence of dark matter in the universe. The dark matter is an unknown matter that do not emit any electromagnetic radiation and perhaps have very feeble interaction with other particles. It is now established from the study of anisotropies in apparently smooth cosmic microwave background radiation that about 26.5% of the content of the universe is made up of dark matter as compared to only a paltry amount of about 4.5% of known matter. Although the evidence of dark matter is so far gravitational by and large, there are now worldwide endeavours to detect the dark matter directly in the laboratories. The direct detection of dark matter is based on measuring the recoil energy of the nucleus that scatters off a possible dark matter particle that may happen to interact with a nucleus of the detecting material

  11. Methods for Doping Detection.

    Ponzetto, Federico; Giraud, Sylvain; Leuenberger, Nicolas; Boccard, Julien; Nicoli, Raul; Baume, Norbert; Rudaz, Serge; Saugy, Martial

    2016-01-01

    Over the past few years, the World Anti-Doping Agency (WADA) has focused its efforts on detecting not only small prohibited molecules, but also larger endogenous molecules such as hormones, in the view of implementing an endocrinological module in the Athlete Biological Passport (ABP). In this chapter, the detection of two major types of hormones used for doping, growth hormone (GH) and endogenous anabolic androgenic steroids (EAASs), will be discussed: a brief historical background followed by a description of state-of-the-art methods applied by accredited anti-doping laboratories will be provided and then current research trends outlined. In addition, microRNAs (miRNAs) will also be presented as a new class of biomarkers for doping detection. PMID:27348309

  12. Diagnostics - Crack Detection '87

    The Proceedings of the International Symposium Diagnostics -Crack Detection '87 which was held from June 23 to 26 1987 in Sala (CSSR) contains 5 papers falling under the INIS Subject Scope. The said papers mainly deal with the problems of in-service diagnostics of pumps and steam turbines of nuclear power plants with WWER reactors, as well as crack detection of materials and welded joints of equipment and the control of the water regimen of the primary circuit of such power plants. (Z.M.)

  13. Detection of neutrinos

    Fischbach, Ephraim; Jenkins, Jere

    2016-05-10

    A flux detection apparatus can include a radioactive sample having a decay rate capable of changing in response to interaction with a first particle or a field, and a detector associated with the radioactive sample. The detector is responsive to a second particle or radiation formed by decay of the radioactive sample. The rate of decay of the radioactive sample can be correlated to flux of the first particle or the field. Detection of the first particle or the field can provide an early warning for an impending solar event.

  14. Intrusion Detection Systems

    Pietro, Roberto Di

    2008-01-01

    In our world of ever-increasing Internet connectivity, there is an on-going threat of intrusion, denial of service attacks, or countless other abuses of computer and network resources. In particular, these threats continue to persist due to the flaws of current commercial intrusion detection systems (IDSs). Intrusion Detection Systems is an edited volume by world class leaders in this field. This edited volume sheds new light on defense alert systems against computer and network intrusions. It also covers integrating intrusion alerts within security policy framework for intrusion response, rel

  15. Readers as research detectives

    Gøtzsche, Peter C

    2009-01-01

    Flaws in research papers are common but it may require arduous detective work to unravel them. Checklists are helpful, but many inconsistencies will only be revealed through repeated cross-checks of every little detail, just like in a crime case. As a major deterrent for dishonesty, raw data from...... all trials should be posted on a public website. This would also make it much easier to detect errors and flaws in publications, and it would allow many research projects to be performed without collecting new data. The prevailing culture of secrecy and ownership to data is not in the best interests...

  16. On lie detection "wizards".

    Bond, Charles F; Uysal, Ahmet

    2007-02-01

    M. O'Sullivan and P. Ekman (2004) claim to have discovered 29 wizards of deception detection. The present commentary offers a statistical critique of the evidence for this claim. Analyses reveal that chance can explain results that the authors attribute to wizardry. Thus, by the usual statistical logic of psychological research, O'Sullivan and Ekman's claims about wizardry are gratuitous. Even so, there may be individuals whose wizardry remains to be uncovered. Thus, the commentary outlines forms of evidence that are (and are not) capable of diagnosing lie detection wizardry. PMID:17221309

  17. Detecting Android Malware Using Clone Detection

    陈健; Manar H. Alalfi; Member; ACM; IEEE; Thomas R. Dean; 邹颖

    2015-01-01

    Android is currently one of the most popular smartphone operating systems. However, Android has the largest share of global mobile malware and significant public attention has been brought to the security issues of Android. In this paper, we investigate the use of a clone detector to identify known Android malware. We collect a set of Android applications known to contain malware and a set of benign applications. We extract the Java source code from the binary code of the applications and use NiCad, a near-miss clone detector, to find the classes of clones in a small subset of the malicious applications. We then use these clone classes as a signature to find similar source files in the rest of the malicious applications. The benign collection is used as a control group. In our evaluation, we successfully decompile more than 1 000 malicious apps in 19 malware families. Our results show that using a small portion of malicious applications as a training set can detect 95% of previously known malware with very low false positives and high accuracy at 96.88%. Our method can effectively and reliably pinpoint malicious applications that belong to certain malware families.

  18. Evolutionary Theories of Detection

    Fitch, J P

    2005-04-29

    Current, mid-term and long range technologies for detection of pathogens and toxins are briefly described in the context of performance metrics and operational scenarios. Predictive (evolutionary) and speculative (revolutionary) assessments are given with trade-offs identified, where possible, among competing performance goals.

  19. Global Disease Detectives

    2010-09-21

    This podcast documents U.S. efforts to prevent, detect, and control emerging infectious diseases, such as SARS and pandemic influenza.  Created: 9/21/2010 by CDC Center for Global Health.   Date Released: 9/21/2010.

  20. Supernova neutrino detection

    World-wide, several detectors currently running or nearing completion are sensitive to a core collapse supernova neutrino signal in the Galaxy. I will briefly describe the nature of the neutrino signal and then survey current and future detection techniques. I will also explore what physics and astrophysics we can learn from the next Galactic core collapse

  1. Optical Detection of Formaldehyde

    Patty, Kira D.; Gregory, Don A.

    2008-01-01

    The potential for buildup .of formaldehyde in closed space environments poses a direct health hazard to personnel. The National Aeronautic Space Agency (NASA) has established a maximum permitted concentration of 0.04 ppm for 7 to 180 days for all space craft. Early detection is critical to ensure that formaldehyde levels do not accumulate. above these limits. New sensor technologies are needed to enable real time,in situ detection in a compact and reusable form factor. Addressing this need,research into the use of reactive fluorescent dyes which reversibly bind to formaldehyde (liquid or gas) has been conducted to support the development of a formaldehyde.sensor. In the presence of formaldehyde the dyes' characteristic fluorescence peaks shift providing the basis for an optical detection. Dye responses to formaldehyde exposure were characterized; demonstrating the optical detection of formaldehyde in under 10 seconds and down to concentrations of 0.5 ppm. To .incorporate the dye .in.an optical sensor device requires. a means of containing and manipulating the dye. Multiple form factors using two dissimilar sbstrates were considered to determine a suitable configuration. A prototype sensor was demonstrated and considerations for a field able sensor were presented. This research provides a necessary first step toward the development of a compact, reusable; real time optical formaldehyde sensor suitable for use in the U.S. space program,

  2. Network Power Fault Detection

    Siviero, Claudio

    2013-01-01

    Network power fault detection. At least one first network device is instructed to temporarily disconnect from a power supply path of a network, and at least one characteristic of the power supply path of the network is measured at a second network device connected to the network while the at least one first network device is temporarily disconnected from the network

  3. Detecting plastics in seedcotton

    To increase global market share and value the US cotton industry needs to supply cotton lint that is free of contamination. Removing plastic contamination first requires developing a means to detect plastics in seedcotton. This study was conducted to validate a custom Ion Mobility Spectrometer (IM...

  4. Crack detection '86

    The participants of the conference heard 36 papers of which 13 were incorporated in INIS. The incorporated papers deal with the quality control of the equipment of nuclear power plants, with technical specifications and possibilities of diverse crack detection devices, as well as with personnel training for nondestructive materials testing. (E.S.)

  5. Portable raman explosives detection

    Moore, David Steven [Los Alamos National Laboratory; Scharff, Robert J [Los Alamos National Laboratory

    2008-01-01

    Recent advances in portable Raman instruments have dramatically increased their application to emergency response and forensics, as well as homeland defense. This paper reviews the relevant attributes and disadvantages of portable Raman spectroscopy, both essentially and instrumentally, to the task of explosives detection in the field.

  6. Electrical load detection aparatus

    2010-01-01

    A load detection technique for a load comprising multiple frequency-dependant sub-loads comprises measuring a representation of the impedance characteristic of the load; providing stored representations of a multiplicity of impedance characteristics of the load; each one of the stored representat...

  7. Coherent detection spectroscopy

    Bueren, H.G. van

    1969-01-01

    Various methods of optical spectroscopy are compared, with special emphasis on resolution and acceptance of the systems. It is shown that coherent detection with a laser as a local oscillator has important advantages for specific applications in astronomical spectroscopy and interferometry, especial

  8. Detecting Quantum Entanglement

    Terhal, Barbara M.

    2001-01-01

    We review the criteria for separability and quantum entanglement, both in a bipartite as well as a multipartite setting. We discuss Bell inequalities, entanglement witnesses, entropic inequalities, bound entanglement and several features of multipartite entanglement. We indicate how these criteria bear on the experimental detection of quantum entanglement.

  9. Antigen detection systems

    Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissues or other specimens, using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular m...

  10. Electrically detected ferromagnetic resonance

    Goennenwein, S.T.B.; Schink, S.W.; Brandlmaier, A.; Boger, A.; Opel, M.; Gross, R.; Keizer, R.S.; Klapwijk, T.M.; Gupta, A.; Huebl, H.; Bihler, C.; Brandt, M.S.

    2007-01-01

    We study the magnetoresistance properties of thin ferromagnetic CrO2 and Fe3O4 films under microwave irradiation. Both the sheet resistance ρ and the Hall voltage VHall characteristically change when a ferromagnetic resonance (FMR) occurs in the film. The electrically detected ferromagnetic resonanc

  11. Fast fight detection.

    Serrano Gracia, Ismael; Deniz Suarez, Oscar; Bueno Garcia, Gloria; Kim, Tae-Kyun

    2015-01-01

    Action recognition has become a hot topic within computer vision. However, the action recognition community has focused mainly on relatively simple actions like clapping, walking, jogging, etc. The detection of specific events with direct practical use such as fights or in general aggressive behavior has been comparatively less studied. Such capability may be extremely useful in some video surveillance scenarios like prisons, psychiatric centers or even embedded in camera phones. As a consequence, there is growing interest in developing violence detection algorithms. Recent work considered the well-known Bag-of-Words framework for the specific problem of fight detection. Under this framework, spatio-temporal features are extracted from the video sequences and used for classification. Despite encouraging results in which high accuracy rates were achieved, the computational cost of extracting such features is prohibitive for practical applications. This work proposes a novel method to detect violence sequences. Features extracted from motion blobs are used to discriminate fight and non-fight sequences. Although the method is outperformed in accuracy by state of the art, it has a significantly faster computation time thus making it amenable for real-time applications. PMID:25860667

  12. 升清降浊胶囊对腺嘌呤所致大鼠肾性贫血肾组织TNF-α表达的影响%Influence of Shengqing Jiangzhuo Capsule on Expression of TNF-α in Rat Renal Tissue with Adenine-induced Anemia

    宋丽; 桑志强; 张慧; 金礼; 刘禹; 聂子牧; 姬赐祥; 刘韬; 童安荣

    2012-01-01

    Objective To explore the influence of Shengqing Jiangzhuo capsule on expression of TNF - α in rat renal tissue with adenine - indeced anemia. Methods The chronic anemia model was established by adenine intragastrically in SD rats. According to the weight rats were divided into six groups: normal control group, model control group , high Shengqingjiangzhuo capsule group, middle concentration group, low concentration group and Shenshuaining Capsule control group. After four and six weeks with treatment, blood red blood cells ( RBC ) , the hemoglobin ( HGB ) , aspartate transaminase ( AST ) , alanine aminotransferase (ALT) , creatinine (Scr) , blood urea nitrogen (BUN) were determined and observed. The renal pathology change were observed using HE dyeing. TNF alpha expression was monitored with immunohistochemistry methods in kidney tissues. Results After 4 weeks and six weeks of treatment, RBC, HGB were reduced significantly and Scr, BUN were elevated significantly (P <0. 05 ) . TNF alpha positive expression rate increased significantly in model control group compared with normal control group (P <0.05). RBC, HGB in Shenshuaining group and Shengqingjiangzhuo capsule groups were significantly higher , than those in model group (P<0.05 ). Scr, BUN in Shenshuaining group and Shengqingjiangzhuo capsule groups were significantly lower than those in model group ( P < 0. 05 ) . The TNF alpha positive expression rate in Shenshuaining group and Shengqingjiangzhuo capsule groups was significantly lower than that in model group (P <0. 05) . Conclusion Shengqing Jiangzhuo capsule may increase generation of the red blood cells by clearing urine toxins, reducing the inflammatory cells infiltration and restraining TNF alpha in the expression of the kidney tissues. It plays an active role in the treatment of renal anemia.%目的 观察升清降浊胶囊对腺嘌呤所致慢性贫血大鼠TNF-α表达的影响,探讨升清降浊胶囊治疗贫血的作用机制.方法 采用腺嘌

  13. How People Really Detect Lies.

    Park, Hee Sun; Levine, Timothy R.; McCornack, Steven A.; Morrison, Kelly; Ferrara, Merissa

    2002-01-01

    Considers that participants in previous deception detection experiments may not have had access to the types of information people most often use to detect real-life lies. Suggests that people most often rely on information from third parties and physical evidence when detecting lies, and that the detection of a lie is a process that takes days,…

  14. Pre-impact fall detection.

    Hu, Xinyao; Qu, Xingda

    2016-01-01

    Pre-impact fall detection has been proposed to be an effective fall prevention strategy. In particular, it can help activate on-demand fall injury prevention systems (e.g. inflatable hip protectors) prior to fall impacts, and thus directly prevent the fall-related physical injuries. This paper gave a systematical review on pre-impact fall detection, and focused on the following aspects of the existing pre-impact fall detection research: fall detection apparatus, fall detection indicators, fall detection algorithms, and types of falls for fall detection evaluation. In addition, the performance of the existing pre-impact fall detection solutions were also reviewed and reported in terms of their sensitivity, specificity, and detection/lead time. This review also summarized the limitations in the existing pre-impact fall detection research, and proposed future research directions in this field. PMID:27251528

  15. An Amperometric Biosensor Based on Alanine Dehydrogenase for the Determination of Low Level of Ammonium Ion in Water

    Tan Ling Ling

    2011-01-01

    Full Text Available An amperometric electrochemical biosensor has been developed for ammonium (NH4+ ion detection by immobilising alanine dehydrogenase (AlaDH enzyme in a photocurable methacrylic membrane made up of poly(2-hydroxyethyl methacrylate (pHEMA on a screen-printed carbon paste electrode (SPE. The current detected was based on the electrocatalytic oxidation of nicotinamide adenine dinucleotide reduced (NADH that is proportional to the consumption of NH4+ ion whilst enzymatic amination of AlaDH and pyruvate is taking place. The biosensor was operated amperometrically at a potential of +0.6 V and optimum pH 7. The NH4+ biosensor demonstrated linear response to NH4+ ion concentration in the range of 0.03–1.02 mg/L with a limit of detection (LOD of 8.52 μg/L. The proposed method has been successfully applied to the determination of NH4+ ion in river water samples without any pretreatment. The levels of possible interferents in the waters were negligible to cause any interference on the proposed method. The analytical performance of the biosensor was comparable to the colorimetric method using Nesslerisation but with much lower detection limit and linear response range at ppb level.

  16. Solar neutrino detection

    Miramonti, Lino

    2009-01-01

    More than 40 years ago, neutrinos where conceived as a way to test the validity of the solar models which tell us that stars are powered by nuclear fusion reactions. The first measurement of the neutrino flux, in 1968 in the Homestake mine in South Dakota, detected only one third of the expected value, originating what has been known as the Solar Neutrino Problem. Different experiments were built in order to understand the origin of this discrepancy. Now we know that neutrinos undergo oscillation phenomenon changing their nature traveling from the core of the Sun to our detectors. In the work the 40 year long saga of the neutrino detection is presented; from the first proposals to test the solar models to last real time measurements of the low energy part of the neutrino spectrum.

  17. Sherlock Holmes: scientific detective.

    Snyder, Laura J

    2004-09-01

    Sherlock Holmes was intended by his creator, Arthur Conan Doyle, to be a 'scientific detective'. Conan Doyle criticized his predecessor Edgar Allan Poe for giving his creation - Inspector Dupin - only the 'illusion' of scientific method. Conan Doyle believed that he had succeeded where Poe had failed; thus, he has Watson remark that Holmes has 'brought detection as near an exact science as it will ever be brought into the world.' By examining Holmes' methods, it becomes clear that Conan Doyle modelled them on certain images of science that were popular in mid- to late-19th century Britain. Contrary to a common view, it is also evident that rather than being responsible for the invention of forensic science, the creation of Holmes was influenced by the early development of it. PMID:15350761

  18. Acoustic detection of pneumothorax

    Mansy, Hansen A.; Royston, Thomas J.; Balk, Robert A.; Sandler, Richard H.

    2003-04-01

    This study aims at investigating the feasibility of using low-frequency (pneumothorax detection were tested in dogs. In the first approach, broadband acoustic signals were introduced into the trachea during end-expiration and transmitted waves were measured at the chest surface. Pneumothorax was found to consistently decrease pulmonary acoustic transmission in the 200-1200-Hz frequency band, while less change was observed at lower frequencies (ppneumothorax states (pPneumothorax was found to be associated with a preferential reduction of sound amplitude in the 200- to 700-Hz range, and a decrease of sound amplitude variation (in the 300 to 600-Hz band) during the respiration cycle (pPneumothorax changed the frequency and decay rate of percussive sounds. These results imply that certain medical conditions may be reliably detected using appropriate acoustic measurements and analysis. [Work supported by NIH/NHLBI #R44HL61108.

  19. Chaos detection and predictability

    Gottwald, Georg; Laskar, Jacques

    2016-01-01

    Distinguishing chaoticity from regularity in deterministic dynamical systems and specifying the subspace of the phase space in which instabilities are expected to occur is of utmost importance in as disparate areas as astronomy, particle physics and climate dynamics.   To address these issues there exists a plethora of methods for chaos detection and predictability. The most commonly employed technique for investigating chaotic dynamics, i.e. the computation of Lyapunov exponents, however, may suffer a number of problems and drawbacks, for example when applied to noisy experimental data.   In the last two decades, several novel methods have been developed for the fast and reliable determination of the regular or chaotic nature of orbits, aimed at overcoming the shortcomings of more traditional techniques. This set of lecture notes and tutorial reviews serves as an introduction to and overview of modern chaos detection and predictability techniques for graduate students and non-specialists.   The book cover...

  20. Seismic detection of tornadoes

    Tatom, F. B.

    1993-01-01

    Tornadoes represent the most violent of all forms of atmospheric storms, each year resulting in hundreds of millions of dollars in property damage and approximately one hundred fatalities. In recent years, considerable success has been achieved in detecting tornadic storms by means of Doppler radar. However, radar systems cannot determine when a tornado is actually in contact with the ground, expect possibly at extremely close range. At the present time, human observation is the only truly reliable way of knowing that a tornado is actually on the ground. However, considerable evidence exists indicating that a tornado in contact with the ground produces a significant seismic signal. If such signals are generated, the seismic detection and warning of an imminent tornado can become a distinct possibility. 

  1. Handbook for Language Detectives

    Bryanne, Ulla; Bruntt, Karen Scheel Lassen

    Handbook for Language Detectives gives a thorough presentation of English grammar and discusses how to teach grammar. The book unveils to the readers, who will be working as grammar detectives, the fascinating world of language. It does not only deal with "traditional grammar" but also discusses...... what different grammatical structures mean (semantics) and how they influence the level of style (pragmatics). Grammar should not be taught as a separate discipline; it can and should be integrated in communicative language teaching. The book gives you innovative and valuable ideas of how this can be...... done. The book serves a double purpose: - English grammar and language usage at bachelor level from a functional linguistic point of view. - How to teach English grammar within a communicative approach. The book is mainly intended for Danish student teachers of English, but anyone else interested in...

  2. Cell Phone Detection Techniques

    Pratt, Richard M.; Bunch, Kyle J.; Puzycki, David J.; Slaugh, Ryan W.; Good, Morris S.; McMakin, Douglas L.

    2007-10-01

    A team composed of Rick Pratt, Dave Puczyki, Kyle Bunch, Ryan Slaugh, Morris Good, and Doug McMakin teamed together to attempt to exploit cellular telephone features and detect if a person was carrying a cellular telephone into a Limited Area. The cell phone’s electromagnetic properties were measured, analyzed, and tested in over 10 different ways to determine if an exploitable signature exists. The method that appears to have the most potential for success without adding an external tag is to measure the RF spectrum, not in the cell phone band, but between 240 and 400MHz. Figures 1- 7 show the detected signal levels from cell phones from three different manufacturers.

  3. Particles: glueballs detected

    For about twenty years, the glueballs, hypothetical particles predicted by the quantum chromodynamics (QCD) theory, have never been detected with certainty. Thanks to extraordinary complex computer calculations, Donald Weingarten's team from the IBM research center of Yorktown Heights new New York (USA), have claimed that they are now able to define glueballs. According to their calculations, glueballs have been detected several times in the debris from the collision experiments carried out at the SLAC, the CERN or the Pekin Institute for High Energy Physics. A critical commentary of these affirmations is given by Pierre Fayet from the ENS (Ecole Normale Superieure of Paris, France). This short paper gives also a short recall of the gluon model and of glueballs properties according to QCD theory. (J.S.). 1 fig., 1 photo

  4. May Gravity detect Tsunami ?

    Fargion, D

    2004-01-01

    The present gravitational wave detectors are reaching lowest metric deviation fields able to detect galactic and extra-galactic gravitational waves, related to Supernova explosions up to Virgo cluster. The same gravitational wave detector are nevertheless almost able to reveal near field gravitational perturbations due to fast huge mass displacements as the ones occurring during largest Earth-Quake or Tsunami as the last on 26th December 2004 in Asiatic area. The prompt gravitational near field deformation by the Tsunami may reach the LIGO threshold sensitivity within 3000-10000 km distances. Their eventual discover (in LIGO data or in future on-line detector arrays) may offer the most rapid warning alarm system on earth. Nevertheless the later continental mass rearrangement and their gravitational field assessment on Earth must induce, for Richter Magnitude 9 Tsunami, a different terrestrial inertia momentum and a different rotation axis, as well as a detectable shrinking of the Earth radius of nearly R =1.7...

  5. CDC Disease Detective Camp

    2010-08-02

    The CDC Disease Detective Camp gives rising high school juniors and seniors exposure to key aspects of the CDC, including basic epidemiology, infectious and chronic disease tracking, public health law, and outbreak investigations. The camp also helps students explore careers in public health.  Created: 8/2/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 8/2/2010.

  6. Detecting ''secret'' quantum numbers

    For a general quantum mechanical system undergoing a process, it is shown that one can tell from measurements on this system whether or not the system is characterized by quantum numbers the existence of which is unknown to the observer, even though the detection equipment used by the observer is unable to distinguish among the various possible values of the ''secret'' quantum number and hence always averages over them

  7. Aspects of leak detection

    Chivers, T.C. [Berkeley Technology Centre, Glos (United Kingdom)

    1997-04-01

    A requirement of a Leak before Break safety case is that the leakage from the through wall crack be detected prior to any growth leading to unacceptable failure. This paper sets out to review some recent developments in this field. It does not set out to be a comprehensive guide to all of the methods available. The discussion concentrates on acoustic emission and how the techniques can be qualified and deployed on operational plant.

  8. Operational Network Intrusion Detection

    Dreger, Holger

    2008-01-01

    The goal of this thesis is to examine dependencies and tradeoffs between the resource usage (CPU and memory) and the analysis capabilities of Network Intrusion Detection Systems (NIDS). We base our work on the experience of running NIDS in large network environments (among them the Münchener Wissenschaftsnetz (MWN)). These show that resource management is vital for running NIDS in high volume networks. To reduce the resource consumption of NIDS is often only possible by reducing the NIDS' ana...

  9. Community Detection in Hypergraphs

    Neubauer, Nicolas

    2012-01-01

    Viele Datensätze können als Graphen aufgefasst werden, d.h. als Elemente (Knoten) und binäre Verbindungen zwischen ihnen (Kanten). Unter dem Begriff der "Complex Network Analysis" sammeln sich eine ganze Reihe von Verfahren, die die Untersuchung von Datensätzen allein aufgrund solcher struktureller Eigenschaften erlauben. "Community Detection" als Untergebiet beschäftigt sich mit der Identifikation besonders stark vernetzter Teilgraphen. Über den Nutzen hinaus, den eine Gruppierung verwandter...

  10. Fraud Detection in Healthcare

    Chandola, Varun [ORNL; Schryver, Jack C [ORNL; Sukumar, Sreenivas R [ORNL

    2015-01-01

    We discuss the problem of fraud detection in healthcare in this chapter. Given the recent scrutiny of the ineciencies in the US healthcare system, identifying fraud has been on the forefront of the eorts towards reducing the healthcare costs. In this chapter we will focus on understanding the issue of healthcare fraud in detail, and review methods that have been proposed in the literature to combat this issue using data driven approach.

  11. Detecting microdamage in bone.

    Lee, T Clive; Mohsin, Sahar; Taylor, David; Parkesh, Raman; Gunnlaugsson, TThorfinnur; O'Brien, Fergal J.; Giehl, Michael; Gowin, Wolfgang

    2003-01-01

    Fatigue-induced microdamage in bone contributes to stress and fragility fractures and acts as a stimulus for bone remodelling. Detecting such microdamage is difficult as pre-existing microdamage sustained in vivo must be differentiated from artefactual damage incurred during specimen preparation. This was addressed by bulk staining specimens in alcohol-soluble basic fuchsin dye, but cutting and grinding them in an aqueous medium. Nonetheless, some artefactual cracks are partially stained and ...

  12. Multimoment Radio Transient Detection

    Spitler, Laura; Cordes, Jim; Chatterjee, Shami; Stone, Julia

    2011-01-01

    We present a multimoment technique for signal classification and apply it to the detection of fast radio transients in incoherently dedispersed data. Specifically, we define a spectral modulation index in terms of the fractional variation in intensity across a spectrum. A signal whose intensity is distributed evenly across the entire band has a much lower modulation index than a spectrum with the same intensity localized in a single channel. We are interested in broadband pulses and use the m...

  13. Detection of pump degradation

    Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  14. Detection of pump degradation

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented

  15. Innovations. DNA detectives.

    May, M

    1999-01-01

    To understand the many potential causes and resulting consequences of DNA damage, scientists first need methods to detect it. Canadian scientists X. Chris Le and Michael Weinfeld, with help from U.S. molecular biologist Steven Leadon, developed a selective, sensitive technique for measuring DNA damage. The scientists combined a thymine glycol antibody with thymine glycol to selectively tag a specific type of DNA damage. They then added a second antibody with fluorescing properties, and used l...

  16. Electronic spinal posture detection

    Thoné, Jef; Jourand, Philippe; Puers, Robert

    2009-01-01

    A wearable automatic monitoring system for back posture has been developed and tested. Making use of only five accelerometers placed on strategic locations on the back, a stand alone system enables detection, logging and feedback of the patient’s posture. The system enables alerting the patient of a bad posture, or long-term data logging to analyze the patient’s posture over a prolonged period.

  17. Progress in Nuclear Detection

    Vojtech, Richard

    2010-02-01

    The Transformational and Applied Research Directorate (TAR) was established within the Department of Homeland Security's Domestic Nuclear Detection Office (DNDO) to conduct, support, coordinate, and encourage near- and long-term Research and Development (R&D) programs for break-through technologies designed to dramatically improve capabilities to detect and report illicit trafficking of nuclear and radiological materials. These programs cover a wide range of technologies and high-level technical challenges associated with the DNDO mission and the Global Nuclear Detection Architecture (GNDA). They encompass a range of technology levels, ranging from feasibility and proof of concept studies to technology demonstrations of systems. Even though the focus is on high level challenges, the direction of some topic areas can change from year to year. This presentation will provide an overview of the TAR mission and discuss the current status of transformational R&D efforts in three major program areas: Advanced Technology Demonstrations (ATD), Exploratory Research (ER) and Academic Research Initiative (ARI). )

  18. Nonlinear Multiantenna Detection Methods

    Chen Sheng

    2004-01-01

    Full Text Available A nonlinear detection technique designed for multiple-antenna assisted receivers employed in space-division multiple-access systems is investigated. We derive the optimal solution of the nonlinear spatial-processing assisted receiver for binary phase shift keying signalling, which we refer to as the Bayesian detector. It is shown that this optimal Bayesian receiver significantly outperforms the standard linear beamforming assisted receiver in terms of a reduced bit error rate, at the expense of an increased complexity, while the achievable system capacity is substantially enhanced with the advent of employing nonlinear detection. Specifically, when the spatial separation expressed in terms of the angle of arrival between the desired and interfering signals is below a certain threshold, a linear beamformer would fail to separate them, while a nonlinear detection assisted receiver is still capable of performing adequately. The adaptive implementation of the optimal Bayesian detector can be realized using a radial basis function network. Two techniques are presented for constructing block-data-based adaptive nonlinear multiple-antenna assisted receivers. One of them is based on the relevance vector machine invoked for classification, while the other on the orthogonal forward selection procedure combined with the Fisher ratio class-separability measure. A recursive sample-by-sample adaptation procedure is also proposed for training nonlinear detectors based on an amalgam of enhanced -means clustering techniques and the recursive least squares algorithm.

  19. Neutrino Detection With CLEAN

    McKinsey, D N

    2005-01-01

    This article describes CLEAN, an approach to the detection of low-energy solar neutrinos and neutrinos released from supernovae. The CLEAN concept is based on the detection of elastic scattering events (neutrino-electron scattering and neutrino-nuclear scattering) in liquified noble gases such as liquid helium, liquid neon, and liquid xenon, all of which scintillate brightly in the ultraviolet. Key to the CLEAN technique is the use of a thin film of wavelength-shifting fluor to convert the ultraviolet scintillation light to the visible. This allows the same liquid to be used as both a passive shielding medium and an active self-shielding detector, allowing lower intrinsic radioactive backgrounds at low energies. Liquid neon is a particularly promising medium for CLEAN. Because liquid neon has a high scintillation yield, has no long-lived radioactive isotopes, and can be easily purified by use of cold traps, it is an ideal medium for the detection of rare nuclear events. In addition, neon is inexpensive, dense...

  20. Human kin detection.

    Bressan, Paola; Kramer, Peter

    2015-01-01

    Natural selection has favored the evolution of behaviors that benefit not only one's genes, but also their copies in genetically related individuals. These behaviors include optimal outbreeding (choosing a mate that is neither too closely related, nor too distant), nepotism (helping kin), and spite (hurting non-kin at a personal cost), and all require some form of kin detection or kin recognition. Yet, kinship cannot be assessed directly; human kin detection relies on heuristic cues that take into account individuals' context (whether they were reared by our mother, or grew up in our home, or were given birth by our spouse), appearance (whether they smell or look like us), and ability to arouse certain feelings (whether we feel emotionally close to them). The uncertainties of kin detection, along with its dependence on social information, create ample opportunities for the evolution of deception and self-deception. For example, babies carry no unequivocal stamp of their biological father, but across cultures they are passionately claimed to resemble their mother's spouse; to the same effect, 'neutral' observers are greatly influenced by belief in relatedness when judging resemblance between strangers. Still, paternity uncertainty profoundly shapes human relationships, reducing not only the investment contributed by paternal versus maternal kin, but also prosocial behavior between individuals who are related through one or more males rather than females alone. Because of its relevance to racial discrimination and political preferences, the evolutionary pressure to prefer kin to non-kin has a manifold influence on society at large. PMID:26263231