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Sample records for adenines

  1. Quadracyclic adenine

    DEFF Research Database (Denmark)

    Dierckx, Anke; Miannay, Francois-Alexandre; Ben Gaied, Nouha

    2012-01-01

    Fluorescent-base analogues (FBAs) comprise a group of increasingly important molecules for the investigation of nucleic acid structure and dynamics as well as of interactions between nucleic acids and other molecules. Here, we report on the synthesis, detailed spectroscopic characterisation...... fluorescent adenine analogues for future detailed studies of nucleic acid-containing systems....... and base-pairing properties of a new environment-sensitive fluorescent adenine analogue, quadracyclic adenine (qA). After developing an efficient route of synthesis for the phosphoramidite of qA it was incorporated into DNA in high yield by using standard solid-phase synthesis procedures. In DNA qA serves...

  2. Adenine N6-methylation in diverse fungi.

    Science.gov (United States)

    Seidl, Michael F

    2017-05-26

    A DNA modification-methylation of cytosines and adenines-has important roles in diverse processes such as regulation of gene expression and genome stability, yet until recently adenine methylation had been considered to be only a hallmark of prokaryotes. A new study identifies abundant adenine methylation of transcriptionally active genes in early-diverging fungi that, together with recent other work, emphasizes the importance of adenine methylation in eukaryotes.

  3. Adenine N6-methylation in diverse fungi

    NARCIS (Netherlands)

    Seidl, Michael F.

    2017-01-01

    A DNA modification - methylation of cytosines and adenines - has important roles in diverse processes such as regulation of gene expression and genome stability, yet until recently adenine methylation had been considered to be only a hallmark of prokaryotes. A new study identifies abundant

  4. Novel non-specific DNA adenine methyltransferases

    Science.gov (United States)

    Drozdz, Marek; Piekarowicz, Andrzej; Bujnicki, Janusz M.; Radlinska, Monika

    2012-01-01

    The mom gene of bacteriophage Mu encodes an enzyme that converts adenine to N6-(1-acetamido)-adenine in the phage DNA and thereby protects the viral genome from cleavage by a wide variety of restriction endonucleases. Mu-like prophage sequences present in Haemophilus influenzae Rd (FluMu), Neisseria meningitidis type A strain Z2491 (Pnme1) and H. influenzae biotype aegyptius ATCC 11116 do not possess a Mom-encoding gene. Instead, at the position occupied by mom in Mu they carry an unrelated gene that encodes a protein with homology to DNA adenine N6-methyltransferases (hin1523, nma1821, hia5, respectively). Products of the hin1523, hia5 and nma1821 genes modify adenine residues to N6-methyladenine, both in vitro and in vivo. All of these enzymes catalyzed extensive DNA methylation; most notably the Hia5 protein caused the methylation of 61% of the adenines in λ DNA. Kinetic analysis of oligonucleotide methylation suggests that all adenine residues in DNA, with the possible exception of poly(A)-tracts, constitute substrates for the Hia5 and Hin1523 enzymes. Their potential ‘sequence specificity’ could be summarized as AB or BA (where B = C, G or T). Plasmid DNA isolated from Escherichia coli cells overexpressing these novel DNA methyltransferases was resistant to cleavage by many restriction enzymes sensitive to adenine methylation. PMID:22102579

  5. Bound anionic states of adenine

    Energy Technology Data Exchange (ETDEWEB)

    Haranczyk, Maciej; Gutowski, Maciej S; Li, Xiang; Bowen, Kit H

    2007-03-20

    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, which result from enamine-imine transformations, support valence anionic states with electron vertical detachment energies as large as 2.2 eV, and at least one of these anionic tautomers is adiabatically bound. Moreover, we predict that the new anionic tautomers should also dominate in solutions and should be characterized by larger values of electron vertical detachment energy than the canonical valence anion. All of the new-found anionic tautomers might be formed in the course of dissociative electron attachment followed by a hydrogen atom attachment to a carbon atom, and they might affect the structure and properties of DNA and RNA exposed to low-energy electrons. The discovery of these valence anionic states of adenine was facilitated by the development of: (i) a new experimental method for preparing parent anions of nucleic acid bases for photoelectron experiments, and (ii) a new combinatorial/ quantum chemical approach for identification of the most stable tautomers of organic molecules. The computational portion of this work was supported by the: (i) Polish State Committee for Scientific Research (KBN) Grants: DS/8000-4-0140-7 (M.G.) and N204 127 31/2963 (M.H.), (ii) European Social Funds (EFS) ZPORR/2.22/II/2.6/ARP/U/2/05 (M.H.), and (iii) US DOE Office of Biological and Environmental Research, Low Dose Radiation Research Program (M.G.). M.H. holds the Foundation for Polish Science (FNP) award for young scientists. The calculations were performed at the Academic

  6. Role of adenine in thymine-dimer repair by reduced flavin-adenine dinucleotide.

    Science.gov (United States)

    Li, Guifeng; Sichula, Vincent; Glusac, Ksenija D

    2008-08-28

    We present a study of excited-state behavior of reduced flavin cofactors using femtosecond optical transient absorption spectroscopy. The reduced flavin cofactors studied were in two protonation states: flavin-adenine dinucleotide (FADH2 and FADH-) and flavin-mononucleotide (FMNH2 and FMNH-). We find that FMNH- exhibits multiexponential decay dynamics due to the presence of two bent conformers of the isoalloxazine ring. FMNH2 exhibits an additional fast deactivation component that is assigned to an iminol tautomer. Reduced flavin cofactors also exhibit a long-lived component that is attributed to the semiquinone and the hydrated electron that are produced in photoinduced electron transfer to the solvent. The presence of adenine in FADH2 and FADH- further changes the excited-state dynamics due to intramolecular electron transfer from the isoalloxazine to the adenine moiety of cofactors. This electron transfer is more pronounced in FADH2 due to pi-stacking interactions between two moieties. We further studied cyclobutane thymine dimer (TT-dimer) repair via FADH- and FMNH- and found that the repair is much more efficient in the case of FADH-. These results suggest that the adenine moiety plays a significant role in the TT-dimer repair dynamics. Two possible explanations for the adenine mediation are presented: (i) a two-step electron transfer process, with the initial electron transfer occurring from flavin to adenine moiety of FADH-, followed by a second electron transfer from adenine to TT-dimer; (ii) the preconcentration of TT-dimer molecules around the flavin cofactor due to the hydrophobic nature of the adenine moiety.

  7. The catalase activity of diiron adenine deaminase

    Energy Technology Data Exchange (ETDEWEB)

    Kamat S. S.; Swaminathan S.; Holmes-Hampton, G. P.; Bagaria, A.; Kumaran, D.; Tichy, S. E.; Gheyi, T.; Zheng, X.; Bain, K.; Groshong, C.; Emtage, S.; Sauder, J. M.; Burley, S. K.; Lindahl, P. A.; Raushel, F. M.

    2011-12-01

    Adenine deaminase (ADE) from the amidohydrolase superfamily (AHS) of enzymes catalyzes the conversion of adenine to hypoxanthine and ammonia. Enzyme isolated from Escherichia coli was largely inactive toward the deamination of adenine. Molecular weight determinations by mass spectrometry provided evidence that multiple histidine and methionine residues were oxygenated. When iron was sequestered with a metal chelator and the growth medium supplemented with Mn{sup 2+} before induction, the post-translational modifications disappeared. Enzyme expressed and purified under these conditions was substantially more active for adenine deamination. Apo-enzyme was prepared and reconstituted with two equivalents of FeSO{sub 4}. Inductively coupled plasma mass spectrometry and Moessbauer spectroscopy demonstrated that this protein contained two high-spin ferrous ions per monomer of ADE. In addition to the adenine deaminase activity, [Fe{sup II}/Fe{sup II}]-ADE catalyzed the conversion of H{sub 2}O{sub 2} to O{sub 2} and H{sub 2}O. The values of k{sub cat} and k{sub cat}/K{sub m} for the catalase activity are 200 s{sup -1} and 2.4 x 10{sup 4} M{sup -1} s{sup -1}, respectively. [Fe{sup II}/Fe{sup II}]-ADE underwent more than 100 turnovers with H{sub 2}O{sub 2} before the enzyme was inactivated due to oxygenation of histidine residues critical for metal binding. The iron in the inactive enzyme was high-spin ferric with g{sub ave} = 4.3 EPR signal and no evidence of anti-ferromagnetic spin-coupling. A model is proposed for the disproportionation of H{sub 2}O{sub 2} by [Fe{sup II}/Fe{sup II}]-ADE that involves the cycling of the binuclear metal center between the di-ferric and di-ferrous oxidation states. Oxygenation of active site residues occurs via release of hydroxyl radicals. These findings represent the first report of redox reaction catalysis by any member of the AHS.

  8. Influence of Magnetic Microparticles Isolation on Adenine Homonucleotides Structure

    Directory of Open Access Journals (Sweden)

    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.

  9. Radiation and thermal stabilities of adenine nucleotides.

    Science.gov (United States)

    Demidov, V V; Potaman, V N; Solyanina, I P; Trofimov, V I

    1995-03-01

    We have investigated in detail radiation and thermal stabilities and transformations of adenosine mono- and triphosphates in liquid and frozen solid aqueous solutions within a wide range of absorbed radiation dose (up to 75 kGy) and temperature (up to 160 degrees C). Dephosphorylation is the main pathway of high temperature hydrolysis of adenine nucleotides. Basic thermodynamic and kinetic parameters of this process have been determined. Radiolysis of investigated compounds at room temperature results in scission of N-glycosidic bond with a radiation yield about of 1 mol/100 eV. Solution freezing significantly enhances radiation stability of nucleotides as well as other biomolecules. This circumstance is essential in the discussion of panspermia concepts.

  10. What is adenine doing in photolyase?

    Science.gov (United States)

    Acocella, Angela; Jones, Garth A; Zerbetto, Francesco

    2010-03-25

    The short answer to the title question is that it acts as an electrostatic bouncer that shoves the charge flow from flavin toward the DNA lesion that photolyase repairs. This explanation is provided by an explicit time-dependent quantum mechanical approach, which is used to investigate the electron transfer process that triggers the repair mechanism. The transfer occurs from the flavin photolyase cofactor to the cyclobutane ring of DNA, previously formed by light-induced cycloaddition of adjacent pyrimidine bases. The electron wave function dynamics accurately accounts for the previously proposed mechanism of transfer via the terminal methyl group of the flavin moiety present in the catalytic electron-donor cofactor, FADH(-), which also contains adenine. This latter moiety, which has often been assumed to be present mainly for structural reasons, instantaneously modifies the interaction between acceptor and donor by a variation of the electrostatic interactions so that the presence of its local atomic charges is necessary to trigger the transfer. In principle, knowledge of the details of the electron transfer dynamics and of the important role of polarization effects can be exploited to improve the efficiency of the repair mechanism in artificial systems.

  11. Nicotinamide adenine dinucleotide biosynthesis promotes liver regeneration.

    Science.gov (United States)

    Mukherjee, Sarmistha; Chellappa, Karthikeyani; Moffitt, Andrea; Ndungu, Joan; Dellinger, Ryan W; Davis, James G; Agarwal, Beamon; Baur, Joseph A

    2017-02-01

    The regenerative capacity of the liver is essential for recovery from surgical resection or injuries induced by trauma or toxins. During liver regeneration, the concentration of nicotinamide adenine dinucleotide (NAD) falls, at least in part due to metabolic competition for precursors. To test whether NAD availability restricts the rate of liver regeneration, we supplied nicotinamide riboside (NR), an NAD precursor, in the drinking water of mice subjected to partial hepatectomy. NR increased DNA synthesis, mitotic index, and mass restoration in the regenerating livers. Intriguingly, NR also ameliorated the steatosis that normally accompanies liver regeneration. To distinguish the role of hepatocyte NAD levels from any systemic effects of NR, we generated mice overexpressing nicotinamide phosphoribosyltransferase, a rate-limiting enzyme for NAD synthesis, specifically in the liver. Nicotinamide phosphoribosyltransferase overexpressing mice were mildly hyperglycemic at baseline and, similar to mice treated with NR, exhibited enhanced liver regeneration and reduced steatosis following partial hepatectomy. Conversely, mice lacking nicotinamide phosphoribosyltransferase in hepatocytes exhibited impaired regenerative capacity that was completely rescued by administering NR.

  12. Adenine nucleotides of the stria vascularis.

    Science.gov (United States)

    Thalmann, I; Marcus, N Y; Thalmann, R

    1979-01-01

    The levels of the adenine nucleotides ATP, ADP, and AMP in the stria vascularis were measured under normal conditions, and following various durations of ischemia. The concentrations of these compounds were used for the calculation of the adenylate energy charge, the energy status and the phosphorylation state of the stria. Following 10 min of ischemia the adenylate energy charge had decreased three fold, the energy status seven fold and the phosphorylation state 14 fold. To study the potential for recovery of strial function following various brief and prolonged ischemic intervals, a method for the perfusion of the ear via the anterior inferior cerebellar artery was developed. For various reasons it was found advantageous to use "artifical blood" as perfusate, relying upon fluorocarbons as oxygen carriers. The endolymphatic potential was used as electrical indicator of strial function. Recovery of the endolymphatic potential following brief periods of ischemia was paralleled by a corresponding increase of the ATP levels and a drastic decrease of the AMP levels of the stria vascularis. Preliminary results on the effects of substrate-free perfusion are presented.

  13. Characterization of cytokinin and adenine transport in Arabidopsis cell cultures.

    Science.gov (United States)

    Cedzich, Anna; Stransky, Harald; Schulz, Burkhard; Frommer, Wolf B

    2008-12-01

    Cytokinins are distributed through the vascular system and trigger responses of target cells via receptor-mediated signal transduction. Perception and transduction of the signal can occur at the plasma membrane or in the cytosol. The signal is terminated by the action of extra- or intracellular cytokinin oxidases. While radiotracer studies have been used to study transport and metabolism of cytokinins in plants, little is known about the kinetic properties of cytokinin transport. To provide a reference dataset, radiolabeled trans-zeatin (tZ) was used for uptake studies in Arabidopsis (Arabidopsis thaliana) cell culture. Uptake kinetics of tZ are multiphasic, indicating the presence of both low- and high-affinity transport systems. The protonophore carbonyl cyanide m-chlorophenylhydrazone is an effective inhibitor of cytokinin uptake, consistent with H(+)-mediated uptake. Other physiological cytokinins, such as isopentenyl adenine and benzylaminopurine, are effective competitors of tZ uptake, whereas allantoin has no inhibitory effect. Adenine competes for zeatin uptake, indicating that the degradation product of cytokinin oxidases is transported by the same systems. Comparison of adenine and tZ uptake in Arabidopsis seedlings reveals similar uptake kinetics. Kinetic properties, as well as substrate specificity determined in cell cultures, are compatible with the hypothesis that members of the plant-specific purine permease family play a role in adenine transport for scavenging extracellular adenine and may, in addition, be involved in low-affinity cytokinin uptake.

  14. DIETARY ADENINE ALLEVIATES FATTY LIVER INDUCED BY OROTIC ACID

    Directory of Open Access Journals (Sweden)

    Yohanes Buang

    2010-12-01

    Full Text Available The effects of dietary adenine in fatty liver induced by orotic acid (OA were studied. Rats were paired-fed 1% OA-supplemented diets with/or without 0.25% adenine or a diet without OA for 10 days. Serum lipid profiles were measured using enzyme assay kits. Lipids of liver tissues were extracted and liver lipid contents were determined. A peach of liver was prepared to determine the activities of fatty acid synthase (FAS and fatty acid β-oxidation. The results showed that liver TG content of OA-fed rats increased markedly in comparison to basal group.  However, the addition of adenine to the diet reversed promotion of liver TG content to basal level. It was also found that FAS activities decreased. Furthermore, these diets reversed the inhibition of fatty acid β-oxidation to basal level and induced the serum lipid levels secretion. Therefore, the alleviation of fatty liver in OA-treated rats given dietary adenine is associated with the inhibition of FAS activities accompanied with the promotion of mitochondrial fatty acid β-oxidation and the promotion of serum lipid secretion from the hepatic tissue into the bloodstream.

  15. Catalytic Mechanism and Three-Dimensional Structure of Adenine Deaminase

    Energy Technology Data Exchange (ETDEWEB)

    Kamat, S.S.; Swaminathan, S.; Bagaria, A.; Kumaran, D.; Holmes-Hampton, G. P.; Fan, H.; Sali, A.; Sauder, J. M.; Burley, S. K.; Lindahl, P. A.; Raushel, F. M.

    2011-03-22

    Adenine deaminase (ADE) catalyzes the conversion of adenine to hypoxanthine and ammonia. The enzyme isolated from Escherichia coli using standard expression conditions was low for the deamination of adenine (k{sub cat} = 2.0 s{sup -1}; k{sub cat}/K{sub m} = 2.5 x 10{sup 3} M{sup -1} s{sup -1}). However, when iron was sequestered with a metal chelator and the growth medium was supplemented with Mn{sup 2+} prior to induction, the purified enzyme was substantially more active for the deamination of adenine with kcat and kcat/Km values of 200 s{sup -1} and 5 x 10{sup 5} M{sup -1} s{sup -1}, respectively. The apoenzyme was prepared and reconstituted with Fe{sup 2+}, Zn{sup 2+}, or Mn{sup 2+}. In each case, two enzyme equivalents of metal were necessary for reconstitution of the deaminase activity. This work provides the first example of any member of the deaminase subfamily of the amidohydrolase superfamily to utilize a binuclear metal center for the catalysis of a deamination reaction. [Fe{sup II}/Fe{sup II}]-ADE was oxidized to [Fe{sup III}/Fe{sup III}]-ADE with ferricyanide with inactivation of the deaminase activity. Reducing [Fe{sup III}/Fe{sup III}]-ADE with dithionite restored the deaminase activity, and thus, the diferrous form of the enzyme is essential for catalytic activity. No evidence of spin coupling between metal ions was evident by electron paramagnetic resonance or Moessbauer spectroscopy. The three-dimensional structure of adenine deaminase from Agrobacterium tumefaciens (Atu4426) was determined by X-ray crystallography at 2.2 {angstrom} resolution, and adenine was modeled into the active site on the basis of homology to other members of the amidohydrolase superfamily. On the basis of the model of the adenine-ADE complex and subsequent mutagenesis experiments, the roles for each of the highly conserved residues were proposed. Solvent isotope effects, pH-rate profiles, and solvent viscosity were utilized to propose a chemical reaction mechanism and the

  16. Catalytic Mechanism and Three-Dimensional Structure of Adenine Deaminase

    Energy Technology Data Exchange (ETDEWEB)

    S Kamat; A Bagaria; D Kumaran; G Holmes-Hampton; H Fan; A Sali; J Sauder; S Burley; P Lindahl; et. al.

    2011-12-31

    Adenine deaminase (ADE) catalyzes the conversion of adenine to hypoxanthine and ammonia. The enzyme isolated from Escherichia coli using standard expression conditions was low for the deamination of adenine (k{sub cat} = 2.0 s{sup -1}; k{sub cat}/K{sub m} = 2.5 x 10{sup 3} M{sup -1} s{sup -1}). However, when iron was sequestered with a metal chelator and the growth medium was supplemented with Mn{sup 2+} prior to induction, the purified enzyme was substantially more active for the deamination of adenine with k{sub cat} and k{sub cat}/K{sub m} values of 200 s{sup -1} and 5 x 10{sup 5} M{sup -1} s{sup -1}, respectively. The apoenzyme was prepared and reconstituted with Fe{sup 2+}, Zn{sup 2+}, or Mn{sup 2+}. In each case, two enzyme equivalents of metal were necessary for reconstitution of the deaminase activity. This work provides the first example of any member of the deaminase subfamily of the amidohydrolase superfamily to utilize a binuclear metal center for the catalysis of a deamination reaction. [Fe{sup II}/Fe{sup II}]-ADE was oxidized to [Fe{sup III}/Fe{sup III}]-ADE with ferricyanide with inactivation of the deaminase activity. Reducing [Fe{sup III}/Fe{sup III}]-ADE with dithionite restored the deaminase activity, and thus, the diferrous form of the enzyme is essential for catalytic activity. No evidence of spin coupling between metal ions was evident by electron paramagnetic resonance or Moessbauer spectroscopy. The three-dimensional structure of adenine deaminase from Agrobacterium tumefaciens (Atu4426) was determined by X-ray crystallography at 2.2 {angstrom} resolution, and adenine was modeled into the active site on the basis of homology to other members of the amidohydrolase superfamily. On the basis of the model of the adenine-ADE complex and subsequent mutagenesis experiments, the roles for each of the highly conserved residues were proposed. Solvent isotope effects, pH-rate profiles, and solvent viscosity were utilized to propose a chemical reaction

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

    Science.gov (United States)

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

    2016-05-04

    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. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Study on the oxidation form of adenine in phosphate buffer solution.

    Science.gov (United States)

    Song, Yuan-Zhi; Zhou, Jian-Feng; Zhu, Feng-Xia; Ye, Yong; Xie, Ji-Min

    2010-07-01

    The oxidation of adenine in phosphate buffer solution is investigated using square-wave voltammetry and in situ UV spectroelectrochemistry. The geometry of adenine and the derivatives optimized at DFTB3LYP-6-31G (d, p)-PCM level is in agreement with the crystal structure, and the imitated UV spectra of adenine and the product at electrode are consistent with the in situ UV spectra. The relationship between the electrochemical property and the molecular structure is also discussed. The experimental and theoretical results show that the adenine oxidation origins from the neutral adenine.

  19. Excited State Pathways Leading to Formation of Adenine Dimers.

    Science.gov (United States)

    Banyasz, Akos; Martinez-Fernandez, Lara; Ketola, Tiia-Maaria; Muñoz-Losa, Aurora; Esposito, Luciana; Markovitsi, Dimitra; Improta, Roberto

    2016-06-02

    The reaction intermediate in the path leading to UV-induced formation of adenine dimers A═A and AA* is identified for the first time quantum mechanically, using PCM/TD-DFT calculations on (dA)2 (dA: 2'deoxyadenosine). In parallel, its fingerprint is detected in the absorption spectra recorded on the millisecond time-scale for the single strand (dA)20 (dA: 2'deoxyadenosine).

  20. Adenine nucleotide concentrations in patients with erythrocyte autoantibodies.

    OpenAIRE

    Strong, V F; Sokol, R J; Rodgers, S A; Hewitt, S.

    1985-01-01

    Erythrocyte adenine nucleotide concentrations were measured in 154 patients with erythrocyte autoantibodies and 811 normal subjects using a luciferin-luciferase bioluminescent assay. The patients were initially divided into haemolysing and non-haemolysing groups. Red cell adenosine triphosphate (ATP) concentrations were significantly raised in the 96 patients with active haemolysis compared with the normal subjects and with the 58 patients in the non-haemolysing group. Although the patients c...

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

    Indian Academy of Sciences (India)

    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.

  2. Examination of tyrosine/adenine stacking interactions in protein complexes.

    Science.gov (United States)

    Copeland, Kari L; Pellock, Samuel J; Cox, James R; Cafiero, Mauricio L; Tschumper, Gregory S

    2013-11-14

    The π-stacking interactions between tyrosine amino acid side chains and adenine-bearing ligands are examined. Crystalline protein structures from the protein data bank (PDB) exhibiting face-to-face tyrosine/adenine arrangements were used to construct 20 unique 4-methylphenol/N9-methyladenine (p-cresol/9MeA) model systems. Full geometry optimization of the 20 crystal structures with the M06-2X density functional theory method identified 11 unique low-energy conformations. CCSD(T) complete basis set (CBS) limit interaction energies were estimated for all of the structures to determine the magnitude of the interaction between the two ring systems. CCSD(T) computations with double-ζ basis sets (e.g., 6-31G*(0.25) and aug-cc-pVDZ) indicate that the MP2 method overbinds by as much as 3.07 kcal mol(-1) for the crystal structures and 3.90 kcal mol(-1) for the optimized structures. In the 20 crystal structures, the estimated CCSD(T) CBS limit interaction energy ranges from -4.00 to -6.83 kcal mol(-1), with an average interaction energy of -5.47 kcal mol(-1), values remarkably similar to the corresponding data for phenylalanine/adenine stacking interactions. Geometry optimization significantly increases the interaction energies of the p-cresol/9MeA model systems. The average estimated CCSD(T) CBS limit interaction energy of the 11 optimized structures is 3.23 kcal mol(-1) larger than that for the 20 crystal structures.

  3. Sensitive and selective detection of adenine using fluorescent ZnS nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Meerabai Devi, L; Negi, Devendra P S, E-mail: dpsnegi@nehu.ac.in [Department of Chemistry, North-Eastern Hill University, Permanent Campus, Shillong 793022 (India)

    2011-06-17

    We have used fluorescent ZnS nanoparticles as a probe for the determination of adenine. A typical 2 x 10{sup -7} M concentration of adenine quenches 39.3% of the ZnS fluorescence. The decrease in ZnS fluorescence as a function of adenine concentration was found to be linear in the concentration range 5 x 10{sup -9}-2 x 10{sup -7} M. The limit of detection (LOD) of adenine by this method is 3 nM. Among the DNA bases, only adenine quenched the fluorescence of ZnS nanoparticles in the submicromolar concentration range, thus adding selectivity to the method. The amino group of adenine was important in determining the quenching efficiency. Steady-state fluorescence experiments suggest that one molecule of adenine is sufficient to quench the emission arising from a cluster of ZnS consisting of about 20 molecules. Time-resolved fluorescence measurements indicate that the adenine molecules block the sites on the surface of ZnS responsible for emission with the longest lifetime component. This method may be applied for the determination of adenine in biological samples since the measurements have been carried out at pH 7.

  4. PA0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine

    Energy Technology Data Exchange (ETDEWEB)

    Goble, A.M.; Swaminathan, S.; Zhang, Z.; Sauder, J. M.; Burley, S. K.; Raushel, F. M.

    2011-08-02

    Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k{sub cat}/K{sub m} values that exceed 10{sup 5} M{sup -1} s{sup -1}. These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted ({beta}/{alpha}){sub 8} barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the residues responsible for coordinating the substrate and product.

  5. Pa0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine

    Energy Technology Data Exchange (ETDEWEB)

    A Goble; Z Zhang; J Sauder; S Burley; S Swaminathan; F Raushel

    2011-12-31

    Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k{sub cat}/K{sub m} values that exceed 10{sup 5} M{sup -1} s{sup -1}. These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted ({beta}/{alpha}){sub 8} barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the residues responsible for coordinating the substrate and product.

  6. Absorption spectroscopy of adenine, 9-methyladenine, and 2-aminopurine in helium nanodroplets

    NARCIS (Netherlands)

    S. Smolarek; A.M. Rijs; W.J. Buma; M. Drabbels

    2010-01-01

    High-resolution absorption spectra of adenine, 9-methyladenine and 2-aminopurine in helium nanodroplets have been recorded. In contrast to molecular beam experiments, large variations in linewidths are observed for adenine and 9-methyladenine. At the same time, the spectrum of 2-aminopurine remains

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...

  8. Suppression of feline immunodeficiency virus infection in vivo by 9-(2-phosphonomethoxyethyl)adenine

    NARCIS (Netherlands)

    Horzinek, M.C.; Egberink, H.F.; Borst, M.; Niphuis, H.; Balzarini, J.; Neu, H.; Schellekens, H.; Clercq, H. de; Koolen, M.J.M.

    1990-01-01

    The acyclic purine nucleoside analogue 9-(2-phosphonomethoxyethyl)adenine [PMEA; formerly referred to as 9-(2-phosphonylmethoxyethyl)adenine] is a potent and selective inhibitor of human immunodeficiency virus replication in vitro and of Moloney murine sarcoma virus-induced tumor formation in mice.

  9. Fluorescence spectroscopic study of the interaction of adenine and nucleotide with trichosanthin.

    Science.gov (United States)

    Hao, Q; Zhang, Y; Yang, H; Liu, G; Huang, Z; Liu, B; Yao, Q; Li, Q

    1995-07-01

    Trichosanthin (TCS) is an N-glycosidase that can attack the 28s rRNA of the ribosome at a highly conserved adenine residue. The interactions of adenine and its derivative nucleotides with TCS are reported. The fluorescence of Trp 192 of TCS is sensitive to the proximity of adenine, and produces a marked red shift indicative of trytophan in a more hydrophilic environment. By contrast AMP and ATP quench the maximal emission at 328nm. The binding of the adenine and ATP with TCS result in lower tryptophan accessibility to the quencher acrylamide, but higher tryptophan accessibility to the quencher iodide, while AMP caused higher tryptophan accessibility to acrylamide, and lower tryptophan accessibility to iodide. Also, the binding of nucleotides induces tryptophan heterogeneity in the protein. These findings lead us to propose that binding of nucleotides and adenine base cause different microenvironmental changes of the tryptophan residue, and Trp 192 may be involved in the active site of TCS.

  10. Interaction of sulfanilamide and sulfamethoxazole with bovine serum albumin and adenine: spectroscopic and molecular docking investigations.

    Science.gov (United States)

    Rajendiran, N; Thulasidhasan, J

    2015-06-05

    Interaction between sulfanilamide (SAM) and sulfamethoxazole (SMO) with BSA and DNA base (adenine) was investigated by UV-visible, fluorescence, cyclic voltammetry and molecular docking studies. Stern-Volmer fluorescence quenching constant (Ka) suggests SMO is more quenched with BSA/adenine than that of SAM. The distance r between donor (BSA/adenine) and acceptor (SAM and SMO) was obtained according to fluorescence resonance energy transfer (FRET). The results showed that hydrophobic forces, electrostatic interactions, and hydrogen bonds played vital roles in the SAM and SMO with BSA/adenine binding interaction. During the interaction, sulfa drugs could insert into the hydrophobic pocket, where the non-radioactive energy transfer from BSA/adenine to sulfa drugs occurred with high possibility. Cyclic voltammetry results suggested that when the drug concentration is increased, the anodic electrode potential deceased. The docking method indicates aniline group is interacted with the BSA molecules. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Gender differences in adenine-induced chronic kidney disease and cardiovascular complications in rats.

    Science.gov (United States)

    Diwan, Vishal; Small, David; Kauter, Kate; Gobe, Glenda C; Brown, Lindsay

    2014-12-01

    Gender contributes to differences in incidence and progression of chronic kidney disease (CKD) and associated cardiovascular disease. To induce kidney damage in male and female Wistar rats (n = 12/group), a 0.25% adenine diet for 16 wk was used. Kidney function (blood urea nitrogen, plasma creatinine, proteinuria) and structure (glomerular damage, tubulointerstitial atrophy, fibrosis, inflammation); cardiovascular function (blood pressure, ventricular stiffness, vascular responses, echocardiography) and structure (cardiac fibrosis); plasma testosterone and estrogen concentrations; and protein expression for oxidative stress [heme oxygenase-1, inflammation (TNF-α), fibrosis (transforming growth factor-β), ERK1/2, and estrogen receptor-α (ER-α)] were compared in males and females. Adenine-fed females had less decline in kidney function than adenine-fed males, although kidney atrophy, inflammation, and fibrosis were similar. Plasma estrogen concentrations increased and plasma testosterone concentrations decreased in adenine-fed males, with smaller changes in females. CKD-associated molecular changes in kidneys were more pronounced in males than females except for expression of ER-α in the kidney, which was completely suppressed in adenine-fed males but unchanged in adenine-fed females. Both genders showed increased blood pressure, ventricular stiffness, and cardiac fibrosis with the adenine diet. Cardiovascular changes with adenine were similar in males and females, except males developed concentric, and females eccentric cardiac hypertrophy. In hearts from adenine-fed male and female rats, expression of ER-α and activation of the ERK1/2 pathway were increased, in part explaining changes in cardiac hypertrophy. In summary, adenine-induced kidney damage may be increased in males due to the suppression of ER-α.

  12. File list: Oth.Lar.50.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. File list: Oth.Emb.20.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  15. File list: Oth.Emb.05.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: Oth.ALL.50.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  17. File list: Oth.Unc.05.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. File list: Oth.Adl.05.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  19. File list: Oth.Adl.10.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  1. File list: Oth.Emb.50.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  4. File list: Oth.Unc.10.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

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  6. File list: Oth.Lar.05.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. File list: Oth.ALL.20.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

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  8. File list: Oth.Adl.20.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

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  9. File list: Oth.Lar.10.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  10. File list: Oth.ALL.10.Adenine_N6-methylation.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

    Science.gov (United States)

    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.

  12. Design of laser pulses for selective vibrational excitation of the N6-H bond of adenine and adenine-thymine base pair using optimal control theory.

    Science.gov (United States)

    Sharma, Sitansh; Sharma, Purshotam; Singh, Harjinder; Balint-Kurti, Gabriel G

    2009-06-01

    Time dependent quantum dynamics and optimal control theory are used for selective vibrational excitation of the N6-H (amino N-H) bond in free adenine and in the adenine-thymine (A-T) base pair. For the N6-H bond in free adenine we have used a one dimensional model while for the hydrogen bond, N6-H(A)...O4(T), present in the A-T base pair, a two mathematical dimensional model is employed. The conjugate gradient method is used for the optimization of the field dependent cost functional. Optimal laser fields are obtained for selective population transfer in both the model systems, which give virtually 100% excitation probability to preselected vibrational levels. The effect of the optimized laser field on the other hydrogen bond, N1(A)...H-N3(T), present in A-T base pair is also investigated.

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

    Institute of Scientific and Technical Information of China (English)

    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

  14. Suppression of feline immunodeficiency virus infection in vivo by 9-(2-phosphonomethoxyethyl)adenine

    OpenAIRE

    Horzinek, M.C.; Egberink, H F; Borst, M.; Niphuis, H; Balzarini, J; Neu, H.; Schellekens, H.; De Clercq, H; Koolen, M.J.M.

    1990-01-01

    The acyclic purine nucleoside analogue 9-(2-phosphonomethoxyethyl)adenine [PMEA; formerly referred to as 9-(2-phosphonylmethoxyethyl)adenine] is a potent and selective inhibitor of human immunodeficiency virus replication in vitro and of Moloney murine sarcoma virus-induced tumor formation in mice. In the latter system PMEA has stronger antiretroviral potency and selectivity than 3'-azido-3'-thymidine (AZT). We have now investigated the effect of the drug in cats infected with the feline immu...

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

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Determination of the base composition of deoxyribonucleic acid by measurement of the adenine/guanine ratio

    Science.gov (United States)

    Kirk, J. T. O.

    1967-01-01

    A method is described for determination of the base composition (as guanine+cytosine or adenine+thymine content) of DNA by accurate measurement of the adenine/guanine ratio. The DNA is hydrolysed with 0·03n-hydrochloric acid for 40min. to release the purines. The hydrolysate is subjected to ion-exchange chromatography on Zeo-Karb 225. Apurinic acids are eluted with 0·03n-hydrochloric acid and then guanine and adenine are eluted separately with 2n-hydrochloric acid. Guanine and adenine are each collected as a single fraction, and the amount of base in each case is determined by measuring the volume and the extinction at suitable wavelengths. For use in the calculations, millimolar extinction coefficients in 2n-hydrochloric acid of 12·09 for adenine at 262mμ, and 10·77 for guanine at 248mμ, were determined with authentic samples of bases. The method gives extremely reproducible results: from 12 determinations with calf thymus DNA the adenine/guanine molar ratio had a standard deviation of 0·011; this corresponds to a standard deviation in guanine+cytosine content of 0·2% guanine+cytosine. PMID:5626094

  17. Determination of the base composition of deoxyribonucleic acid by measurement of the adenine-granine ratio.

    Science.gov (United States)

    Kirk, J T

    1967-11-01

    A method is described for determination of the base composition (as guanine+cytosine or adenine+thymine content) of DNA by accurate measurement of the adenine/guanine ratio. The DNA is hydrolysed with 0.03n-hydrochloric acid for 40min. to release the purines. The hydrolysate is subjected to ion-exchange chromatography on Zeo-Karb 225. Apurinic acids are eluted with 0.03n-hydrochloric acid and then guanine and adenine are eluted separately with 2n-hydrochloric acid. Guanine and adenine are each collected as a single fraction, and the amount of base in each case is determined by measuring the volume and the extinction at suitable wavelengths. For use in the calculations, millimolar extinction coefficients in 2n-hydrochloric acid of 12.09 for adenine at 262mmu, and 10.77 for guanine at 248mmu, were determined with authentic samples of bases. The method gives extremely reproducible results: from 12 determinations with calf thymus DNA the adenine/guanine molar ratio had a standard deviation of 0.011; this corresponds to a standard deviation in guanine+cytosine content of 0.2% guanine+cytosine.

  18. Benchmark Thermochemistry for Biologically Relevant Adenine and Cytosine. A Combined Experimental and Theoretical Study.

    Science.gov (United States)

    Emel'yanenko, Vladimir N; Zaitsau, Dzmitry H; Shoifet, Evgeni; Meurer, Florian; Verevkin, Sergey P; Schick, Christoph; Held, Christoph

    2015-09-17

    The thermochemical properties available in the literature for adenine and cytosine are in disarray. A new condensed phase standard (p° = 0.1 MPa) molar enthalpy of formation at T = 298.15 K was measured by using combustion calorimetry. New molar enthalpies of sublimation were derived from the temperature dependence of vapor pressure measured by transpiration and by the quarz-crystal microbalance technique. The heat capacities of crystalline adenine and cytosine were measured by temperature-modulated DSC. Thermodynamic data on adenine and cytosine available in the literature were collected, evaluated, and combined with our experimental results. Thus, the evaluated collection of data together with the new experimental results reported here has helped to resolve contradictions in the available enthalpies of formation. A set of reliable thermochemical data is recommended for adenine and cytosine for further thermochemical calculations. Quantum-chemical calculations of the gas phase molar enthalpies of formation of adenine and cytosine have been performed by using the G4 method and results were in excellent agreement with the recommended experimental data. The standard molar entropies of formation and the standard molar Gibbs functions of formation in crystal and gas state have been calculated. Experimental vapor-pressure data measured in this work were used to estimate pure-component PC-SAFT parameters. This allowed modeling solubility of adenine and cytosine in water over the temperature interval 278-310 K.

  19. Sequence-dependent folding landscapes of adenine riboswitch aptamers

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Binding of adenine to Stx2, the protein toxin from Escherichia coli O157:H7

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, Marie E., E-mail: frasm@ucalgary.ca [Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary AB T2N 1N4 (Canada); Cherney, Maia M. [Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, Edmonton AB T6G 2H7 (Canada); Marcato, Paola [Department of Medical Microbiology and Immunology, University of Alberta, Edmonton AB T6G 2H7 (Canada); Mulvey, George L.; Armstrong, Glen D. [Department of Microbiology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary AB T2N 4N1 (Canada); James, Michael N. G. [Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, Edmonton AB T6G 2H7 (Canada); Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary AB T2N 1N4 (Canada)

    2006-07-01

    Crystals of Stx2 were grown in the presence of adenosine and adenine. In both cases, the resulting electron density showed only adenine bound at the active site of the A subunit, proving that the holotoxin is an active N-glycosidase. Stx2 is a protein toxin whose catalytic subunit acts as an N-glycosidase to depurinate a specific adenine base from 28S rRNA. In the holotoxin, the catalytic portion, A1, is linked to the rest of the A subunit, A2, and A2 interacts with the pentameric ring formed by the five B subunits. In order to test whether the holotoxin is active as an N-glycosidase, Stx2 was crystallized in the presence of adenosine and adenine. The crystals diffracted to ∼1.8 Å and showed clear electron density for adenine in the active site. Adenosine had been cleaved, proving that Stx2 is an active N-glycosidase. While the holotoxin is active against small substrates, it would be expected that the B subunits would interfere with the binding of the 28S rRNA.

  2. Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

    Directory of Open Access Journals (Sweden)

    Xue-ying Chang

    2017-01-01

    Full Text Available Background. This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d, 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS/p38 mitogen activated protein kinase (p38MAPK pathway was determined to explore the potential mechanism. Results. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA and creatinine levels, malonaldehyde (MDA content, and superoxide dismutase (SOD activity in serum and the increases of calcium and alkaline phosphatase (ALP activity in the aorta (P<0.05 and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation. Conclusions. Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

  3. Electrochemical studies on the oxidation of guanine and adenine at cyclodextrin modified electrodes.

    Science.gov (United States)

    Abbaspour, Abdolkarim; Noori, Abolhassan

    2008-12-01

    An electrochemical sensor for guanine and adenine using cyclodextrin-modified poly(N-acetylaniline) (PNAANI) on a carbon paste electrode has been developed. The oxidation mechanism of guanine and adenine on the surface of the electrode was investigated by cyclic voltammetry. It was found that the electrode processes are irreversible, pH dependent, and involve several reaction products. The electron transfer process occurs in consecutive steps with the formation of a strongly adsorbed intermediate on the electrode surface. Also, a new method for estimating the apparent formation constants of guanine and adenine with the immobilized cyclodextrins, through the change of surface coverage of studied analytes has been reported. Both guanine and adenine showed linear concentrations in the range of 0.1-10 microM by using differential pulse voltammetry, with an experimental limit of detection down to 0.05 microM. Linear concentration ranges of 2-150 microM for guanine and 6-104 microM for adenine have been found when cyclic voltammetry was used for determination of both analytes.

  4. The essential role of stacking adenines in a two-base-pair RNA kissing complex.

    Science.gov (United States)

    Stephenson, William; Asare-Okai, Papa Nii; Chen, Alan A; Keller, Sean; Santiago, Rachel; Tenenbaum, Scott A; Garcia, Angel E; Fabris, Daniele; Li, Pan T X

    2013-04-17

    In minimal RNA kissing complexes formed between hairpins with cognate GACG tetraloops, the two tertiary GC pairs are likely stabilized by the stacking of 5'-unpaired adenines at each end of the short helix. To test this hypothesis, we mutated the flanking adenines to various nucleosides and examined their effects on the kissing interaction. Electrospray ionization mass spectrometry was used to detect kissing dimers in a multiequilibria mixture, whereas optical tweezers were applied to monitor the (un)folding trajectories of single RNA molecules. The experimental findings were rationalized by molecular dynamics simulations. Together, the results showed that the stacked adenines are indispensable for the tertiary interaction. By shielding the tertiary base pairs from solvent and reducing their fraying, the stacked adenines made terminal pairs act more like interior base pairs. The purine double-ring of adenine was essential for effective stacking, whereas additional functional groups modulated the stabilizing effects through varying hydrophobic and electrostatic forces. Furthermore, formation of the kissing complex was dominated by base pairing, whereas its dissociation was significantly influenced by the flanking bases. Together, these findings indicate that unpaired flanking nucleotides play essential roles in the formation of otherwise unstable two-base-pair RNA tertiary interactions.

  5. Excited-state lifetime of adenine near the first electronic band origin.

    Science.gov (United States)

    Kang, Hyuk; Chang, Jinyoung; Lee, Sang Hak; Ahn, Tae Kyu; Kim, Nam Joon; Kim, Seong Keun

    2010-10-21

    The excited-state lifetime of supersonically cooled adenine was measured in the gas phase by femtosecond pump-probe transient ionization as a function of excitation energy between 36 100 and 37 500cm(-1). The excited-state lifetime of adenine is ∼2ps around the 0-0 band of the (1)L(b) ππ(∗) state (36 105cm(-1)). The lifetime drops to ∼1ps when adenine is excited to the (1)L(a) ππ(∗) state with the pump energy at 36 800cm(-1) and above. The excited-state lifetimes of (1)L(a) and (1)L(b) ππ(∗) states are differentiated in accordance with previous frequency-resolved and computational studies.

  6. QSAR analysis for ADA upon interaction with a series of adenine derivatives as inhibitors.

    Science.gov (United States)

    Moosavi-Movahedi, A A; Safarian, S; Hakimelahi, G H; Ataei, G; Ajloo, D; Panjehpour, S; Riahi, S; Mousavi, M F; Mardanyan, S; Soltani, N; Khalafi-Nezhad, A; Sharghi, H; Moghadamnia, H; Saboury, A A

    2004-01-01

    The kinetic parameters of adenosine deaminase such as Km and Ki were determined in the absence and presence of adenine derivatives (R1-R24) in sodium phosphate buffer (50 mM; pH 7.5) solution at 27 degrees C. These kinetic parameters were used for QSAR analysis. As such, we found some theoretical descriptors to which the binding affinity of adenosine deaminase (ADA) towards several adenine nucleosides as inhibitors is correlated. QSAR analysis has revealed that binding affinity of the adenine nucleosides upon interaction with ADA depends on the molecular volume, dipole moment of the molecule, electric charge around the N1 atom, and the highest of positive charge for the related molecules.

  7. Efficacy of the acyclic nucleoside phosphonates (S)-9-(3-fluoro-2-phosphonylmethoxypropyl)adenine (FPMPA) and 9-(2-phosphonylmethoxyethyl)adenine (PMEA) against feline immunodeficiency virus.

    Science.gov (United States)

    Hartmann, K; Kuffer, M; Balzarini, J; Naesens, L; Goldberg, M; Erfle, V; Goebel, F D; De Clercq, E; Jindrich, J; Holy, A; Bischofberger, N; Kraft, W

    1998-02-01

    The acyclic nucleoside phosphonates (S)-9-(3-fluoro-2-phosphonylmethoxypropyl)adenine (FPMPA) and 9-(2-phosphonylmethoxyethyl)adenine (PMEA) were evaluated for their efficacy and side effects in a double-blind placebo-controlled trial using naturally occurring feline immunodeficiency virus (FIV)-infected cats. This natural retrovirus animal model is considered highly relevant for the pathogenesis and chemotherapy of HIV in humans. Both PMEA and FPMPA proved effective in ameliorating the clinical symptoms of FIV-infected cats, as measured by several clinical parameters including the incidence and severity of stomatitis, Karnofsky's score, immunologic parameters such as relative and absolute CD4+ lymphocyte counts, and virologic parameters including proviral DNA levels in peripheral blood mononuclear cells (PBMC) of drug-treated animals. In contrast with PMEA, FPMPA showed no hematologic side effects at a dose that was 2.5-fold higher than PMEA.

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

    DEFF Research Database (Denmark)

    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 ad...

  9. Synthesis of 9-[1-(1 -hydroxyethyl)-3-(phosphonomethoxy)propyl]adenine and prodrug as possible antiviral agents.

    Science.gov (United States)

    Ghosh, Ajit; El-Kattan, Yahya; Wu, Minwan; Lin, Tsu-Hsing; Vadlakonda, Satish; Kotian, Pravin L; Babu, Yarlagadda S; Chand, Pooran

    2005-01-01

    The appropriately protected C-1'-hydroxyethyl-3-hydroxypropyl-N9-adenine nucleoside was prepared from 1-pivaloyloxy-5-tert-butyldiphenylsilyloxy-3-pentanol and adenine through the Mitsunobu reaction. One of the terminal hydroxyls was converted to the phosphonomethoxy derivative and the prodrug.

  10. Structural Analysis of a Stereochemical Modification of Flavin Adenine Dinucleotide in Alcohol Oxidase from Methylotrophic Yeasts

    NARCIS (Netherlands)

    Kellogg, Richard M.; Kruizinga, Wim; Bystrykh, Leonid V.; Dijkhuizen, Lubbert; Harder, Wim

    1992-01-01

    Alcohol oxidase (MOX), a major peroxisomal protein of methanol-utilizing yeasts, contains two different forms of flavin adenine dinucleotide, one of which is identical with natural FAD whereas the other (mFAD) is a stereochemical modification of the natural coenzyme. This modification occurs spontan

  11. Modification of flavin adenine dinucleotide in alcohol oxidase of the yeast Hansenula polymorpha

    NARCIS (Netherlands)

    Bystrykh, Leonid V.; Dijkhuizen, Lubbert; Harder, Willem

    1991-01-01

    Alcohol oxidase, a major peroxisomal protein of methanol-utilizing yeasts, may possess two different forms of flavin adenine dinucleotide, classical FAD and so-called modified FAD (mFAD). Conversion of FAD into mFAD was observed both in purified preparations of the enzyme and in cells grown in batch

  12. The effect of activated charcoal on adenine-induced chronic renal failure in rats.

    Science.gov (United States)

    Ali, Badreldin H; Alza'abi, Mohamed; Ramkumar, Aishwarya; Al-Lawati, Intisar; Waly, Mostafa I; Beegam, Sumaya; Nemmar, Abderrahim; Brand, Susanne; Schupp, Nicole

    2014-03-01

    Activated charcoal (AC) is a sorbent that has been shown to remove urinary toxins like urea and indoxyl sulfate. Here, the influence of AC on kidney function of rats with experimental chronic renal failure (CRF) is investigated. CRF was induced in rats by feeding adenine (0.75%) for four weeks. As an intervention, AC was added to the feed at concentrations of 10%, 15% or 20%. Adenine treatment impaired kidney function: it lowered creatinine clearance and increased plasma concentrations of creatinine, urea, neutrophil gelatinase-associated lipocalin and vanin-1. Furthermore, it raised plasma concentrations of the uremic toxins indoxyl sulfate, phosphate and uric acid. Renal morphology was severely damaged and histopathological markers of inflammation and fibrosis were especially increased. In renal homogenates, antioxidant indices, including superoxide dismutase and catalase activity, total antioxidant capacity and reduced glutathione were adversely affected. Most of these changes were significantly ameliorated by dietary administration of AC at a concentration of 20%, while effects induced by lower doses of dietary AC on adenine nephrotoxicity were not statistically significant. The results suggest that charcoal is a useful sorbent agent in dietary adenine-induced CRF in rats and that its usability as a nephroprotective agent in human kidney disease should be studied.

  13. Effect of atracylodes rhizome polysaccharide in rats with adenine-induced chronic renal failure.

    Science.gov (United States)

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

    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 Atracylodes rhizome polysaccharide high group and the Atracylodes rhizome polysaccharide low group. All the rats, except those in the normal control group were fed adenine-enriched diets, containing 10 g adenine per kg food for 3 weeks. After being fed with adenine, the dexamethasone treatment group, Atracylodes rhizome polysaccharide high group and Atracylodes rhizome polysaccharide low group rats were administered the drug orally for 2 weeks. On day 35, the kidney coefficient of the rats and the serum levels of creatinine, blood urea nitrogen, total protein and hemalbumin were determined. Subsequent to experimentation on a model of chronic renal failure in rats, the preparation was proven to be able to reduce serum levels of creatinine, blood urea nitrogen and hemalbumin levels (Prenal function. Atracylodes rhizome polysaccharide had reversed the majority of the indices of chronic renal failure in rats.

  14. Kinetic analysis of Yersinia pestis DNA adenine methyltransferase activity using a hemimethylated molecular break light oligonucleotide.

    Directory of Open Access Journals (Sweden)

    Robert J Wood

    Full Text Available BACKGROUND: DNA adenine methylation plays an important role in several critical bacterial processes including mismatch repair, the timing of DNA replication and the transcriptional control of gene expression. The dependence of bacterial virulence on DNA adenine methyltransferase (Dam has led to the proposal that selective Dam inhibitors might function as broad spectrum antibiotics. METHODOLOGY/PRINCIPAL FINDINGS: Herein we report the expression and purification of Yersinia pestis Dam and the development of a continuous fluorescence based assay for DNA adenine methyltransferase activity that is suitable for determining the kinetic parameters of the enzyme and for high throughput screening against potential Dam inhibitors. The assay utilised a hemimethylated break light oligonucleotide substrate containing a GATC methylation site. When this substrate was fully methylated by Dam, it became a substrate for the restriction enzyme DpnI, resulting in separation of fluorophore (fluorescein and quencher (dabcyl and therefore an increase in fluorescence. The assays were monitored in real time using a fluorescence microplate reader in 96 well format and were used for the kinetic characterisation of Yersinia pestis Dam, its substrates and the known Dam inhibitor, S-adenosylhomocysteine. The assay has been validated for high throughput screening, giving a Z-factor of 0.71+/-0.07 indicating that it is a sensitive assay for the identification of inhibitors. CONCLUSIONS/SIGNIFICANCE: The assay is therefore suitable for high throughput screening for inhibitors of DNA adenine methyltransferases and the kinetic characterisation of the inhibition.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Dietary phosphate restriction ameliorates endothelial dysfunction in adenine-induced kidney disease rats

    Science.gov (United States)

    Van, Tan Vu; Watari, Eriko; Taketani, Yutaka; Kitamura, Tomoyo; Shiota, Asuka; Tanaka, Terumi; Tanimura, Ayako; Harada, Nagakatsu; Nakaya, Yutaka; Yamamoto, Hironori; Miyamoto, Ken-ichi; Takeda, Eiji

    2012-01-01

    Hyperphosphatemia causes endothelial dysfunction as well as vascular calcification. Management of serum phosphate level by dietary phosphate restriction or phosphate binders is considered to be beneficial to prevent chronic kidney disease patients from cardiovascular disease, but it has been unclear whether keeping lower serum phosphate level can ameliorate endothelial dysfunction. In this study we investigated whether low-phosphate diet can ameliorate endothelial dysfunction in adenine-induced kidney disease rats, one of useful animal model of chronic kidney disease. Administration of 0.75% adenine-containing diet for 21 days induced renal failure with hyperphosphatemia, and impaired acetylcholine-dependent vasodilation of thoracic aortic ring in rats. Then adenine-induced kidney disease rats were treated with either control diet (1% phosphate) or low-phosphate diet (0.2% phosphate) for 16 days. Low-phosphate diet ameliorated not only hyperphosphatemia but also the impaired vasodilation of aorta. In addition, the activatory phosphorylation of endothelial nitric oxide synthase at serine 1177 and Akt at serine 473 in the aorta were inhibited by in adenine-induced kidney disease rats. The inhibited phosphorylations were improved by the low-phosphate diet treatment. Thus, dietary phosphate restriction can improve aortic endothelial dysfunction in chronic kidney disease with hyperphosphatemia by increase in the activatory phosphorylations of endothelial nitric oxide synthase and Akt. PMID:22798709

  17. SERS, XPS, and DFT Study of Adenine Adsorption on Silver and Gold Surfaces.

    Science.gov (United States)

    Pagliai, Marco; Caporali, Stefano; Muniz-Miranda, Maurizio; Pratesi, Giovanni; Schettino, Vincenzo

    2012-01-19

    The adsorption of adenine on silver and gold surfaces has been investigated combining density functional theory calculations with surface-enhanced Raman scattering and angle-resolved X-ray photoelectron spectroscopy measurements, obtaining useful insight into the orientation and interaction of the nucleobase with the metal surfaces.

  18. Probing electronic coupling between adenine bases in RNA strands from synchrotron radiation circular dichroism experiments

    DEFF Research Database (Denmark)

    Nielsen, Lisbeth Munksgård; Hoffmann, Søren Vrønning; Nielsen, Steen Brøndsted

    2012-01-01

    Circular dichroism spectra (176–330 nm) of RNA adenine oligomers, (rA)n (n = 1–10, 12, 15, and 20), reveal electronic coupling between two bases in short strands. The number of interacting bases in long strands is more and larger than that reported previously for the corresponding DNA strands....

  19. The effect of solvation on the radiation damage rate constants for adenine

    DEFF Research Database (Denmark)

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

    2016-01-01

    in calculations of Gibbs free energies and reaction rates for the reaction between the OH radical and the DNA nucleobase adenine using Density Functional Theory at the ωB97X-D/6-311++G(2df,2pd) level with the Eckart tunneling correction. The solvent, water, has been included through either the implicit...

  20. Structural Analysis of a Stereochemical Modification of Flavin Adenine Dinucleotide in Alcohol Oxidase from Methylotrophic Yeasts

    NARCIS (Netherlands)

    Kellogg, Richard M.; Kruizinga, Wim; Bystrykh, Leonid V.; Dijkhuizen, Lubbert; Harder, Wim

    1992-01-01

    Alcohol oxidase (MOX), a major peroxisomal protein of methanol-utilizing yeasts, contains two different forms of flavin adenine dinucleotide, one of which is identical with natural FAD whereas the other (mFAD) is a stereochemical modification of the natural coenzyme. This modification occurs spontan

  1. Arxula adeninivorans recombinant adenine deaminase and its application in the production of food with low purine content.

    Science.gov (United States)

    Jankowska, D A; Faulwasser, K; Trautwein-Schult, A; Cordes, A; Hoferichter, P; Klein, C; Bode, R; Baronian, K; Kunze, G

    2013-11-01

    Construction of a transgenic Arxula adeninivorans strain that produces a high concentration of adenine deaminase and investigation into the application of the enzyme in the production of food with low purine content. The A. adeninivorans AADA gene, encoding adenine deaminase, was expressed in this yeast under the control of the strong inducible nitrite reductase promoter using the Xplor(®) 2 transformation/expression platform. The recombinant enzyme was biochemically characterized and was found to have a pH range of 5.5-7.5 and temperature range of 34-46 °C with medium thermostability. A beef broth was treated with the purified enzyme resulting in the concentration of adenine decreasing from 70.4 to 0.4 mg l(-1). It was shown that the production of adenine deaminase by A. adeninivorans can be increased and that the recombinant adenine deaminase can be used to lower the adenine content in the food. Adenine deaminase is one component of an enzymatic system that can reduce the production of uric acid from food constituents. This study gives details on the expression, characterization and application of the enzyme and thus provides evidence that supports the further development of the system. © 2013 The Society for Applied Microbiology.

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

    KAUST Repository

    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.

  3. Differences in Electrostatic Potential Around DNA Fragments Containing Adenine and 8-oxo-Adenine. An Analysis Based on Regular Cylindrical Projection

    Energy Technology Data Exchange (ETDEWEB)

    Haranczyk, Maciej; Miller, John H; Gutowski, Maciej S

    2007-07-01

    Changes of electrostatic potential (EP) around the DNA molecule resulting from chemical modifications of nucleotides may play a role in enzymatic recognition of damaged sites. Effects of chemical modifications of nucleotides on the structure of DNA have been characterized through large scale density functional theory computations. Quantum mechanical structural optimizations of DNA fragments with three pairs of nucleotides and accompanying counteractions were performed with a B3LYP exchange-correlation functional and 6-31G** basis sets. The “intact” DNA fragment contained adenine in the middle layer, while the “damaged” fragment had the adenine replaced with 8-oxo-adenine. The electrostatic potential around these DNA fragments was projected on a cylindrical surface around the double helix. The two-dimensional maps of EP of the intact and damaged DNA fragments were analyzed to identify these modifications of EP that result from the occurrence of 8-oxo-adenine (8oA). It was found that distortions of a phosphate group neighboring 8oA and displacements of the accompanying countercation are clearly reflected in the EP maps. Helpful discussions Michel Dupuis are gratefully acknowledged. Authors wish to thank Marcel Swart for directing us to a compilation of van der Waals radii. This work was supported by the: (i) US DOE Office of Biological and Environmental Research, Low Dose Radiation Research Program (M.G. and M.H.), (ii) the Office of Science (BER), U. S. Department of Energy, Grant No. DE-FG03-02ER63470 (JHM), (iii) Polish State Committee for Scientific Research (KBN) Grant DS/8221-4-0140-6 (MG), (iv) European Social Funds (EFS) ZPORR/2.22/II/2.6/ARP/U/2/05 (M.H.). M.H. holds the Foundation for Polish Science (FNP) award for young scientists. The calculations were performed at the Academic Computer Center in Gdansk (TASK) and at the Molecular Science Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences Laboratory, a national

  4. The influence of pH on the structure of adenine monolayers adsorbed at Au(110)/electrolyte interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bowfield, A.; Smith, C.I.; Mansley, C.P.; Weightman, P. [Department of Physics, Oliver Lodge Laboratory, University of Liverpool, L69 7ZE (United Kingdom)

    2010-08-15

    The pH of the solution is shown to significantly effect the reflection anisotropy spectroscopy (RAS) profiles of adenine adsorbed at Au(110)/electrolyte interfaces. At pH 12.8 the net adsorption is very weak due the formation of negative adenine ions in solution. The sensitivity of the RAS profiles to the pH of the solution is probably due to a change in the geometry of the adsorbed molecules caused by a disruption of the base stacking configuration that is adopted when adenine is adsorbed from solutions at pH 7.1. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  5. Induction of nucleoside phosphorylase in Enterobacter aerogenes and enzymatic synthesis of adenine arabinoside.

    Science.gov (United States)

    Wei, Xiao-Kun; Ding, Qing-Bao; Zhang, Lu; Guo, Yong-Li; Ou, Lin; Wang, Chang-Lu

    2008-07-01

    Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5'-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.

  6. Induction of nucleoside phosphorylase in Enterobacter aerogenes and enzymatic synthesis of adenine arabinoside

    Institute of Scientific and Technical Information of China (English)

    Xiao-kun WEI; Qing-bao DING; Lu ZHANG; Yong-li GUO; Lin OU; Chang-lu WANG

    2008-01-01

    Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5'-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells ofEnterobacter aerogenes DCJO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.

  7. DNA Bases Thymine and Adenine in Bio-Organic Light Emitting Diodes

    Science.gov (United States)

    2014-11-24

    DNA Bases Thymine and Adenine in Bio-Organic Light Emitting Diodes Eliot F. Gomez1, Vishak Venkatraman1, James G. Grote2 & Andrew J. Steckl1...45433-7707 USA. We report on the use of nucleic acid bases (NBs) in organic light emitting diodes (OLEDs). NBs are small molecules that are the basic...polymer has been a frequent natural material integrated in electronic devices. DNA has been used in organic light - emitting diodes (OLEDs)4,5,7–14

  8. Coulombic amino group-metal bonding: adsorption of adenine on Cu110.

    Science.gov (United States)

    Preuss, M; Schmidt, W G; Bechstedt, F

    2005-06-17

    The interaction between molecular amino groups and metal surfaces is analyzed from first-principles calculations using the adsorption of adenine on Cu110 as a model case. The amino group nitrogens are found to adsorb on top of the surface copper atoms. However, the bonding clearly cannot be explained in terms of covalent interactions. Instead, we find it to be largely determined by mutual polarization and Coulomb interaction between substrate and adsorbate.

  9. Two Adenine Nucleotide Translocase Paralogues Involved in Cell Proliferation and Spermatogenesis in the Silkworm Bombyx mori

    OpenAIRE

    Ryohei Sugahara; Akiya Jouraku; Takayo Nakakura; Takahiro Kusakabe; Takenori Yamamoto; Yasuo Shinohara; Hideto Miyoshi; Takahiro Shiotsuki

    2015-01-01

    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 m...

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

    Energy Technology Data Exchange (ETDEWEB)

    Baei, Mohammad T. [Department of Chemistry, Islamic Azad University, Azadshahr Branch, Azadshahr, Golestan (Iran, Islamic Republic of); Taghartapeh, Mohammad Ramezani [Young Researchers and Elite Club, Islamic Azad University, Gorgan Branch, Gorgan (Iran, Islamic Republic of); Lemeski, E. Tazikeh [Department of Chemistry, Islamic Azad University, Gorgan Branch, Gorgan (Iran, Islamic Republic of); Soltani, Alireza, E-mail: alireza.soltani46@yahoo.com [Young Researchers and Elite Club, Islamic Azad University, Gorgan Branch, Gorgan (Iran, Islamic Republic of)

    2014-07-01

    Density-functional theory calculations are used to investigate the interaction of Al{sub 12}N{sub 12} and B{sub 12}N{sub 12} 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 Al{sub 12}N{sub 12} and B{sub 12}N{sub 12}. It is observed that B{sub 12}N{sub 12} is highly sensitive to adenine, uracil, and cytosine compared with Al{sub 12}N{sub 12} to serve as a biochemical sensor.

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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26643504

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. White spot syndrome virus VP12 interacts with adenine nucleotide translocase of Litopenaeus vannamei.

    Science.gov (United States)

    Ma, Fang-fang; Chou, Zhi-guang; Liu, Qing-hui; Guan, Guangkuo; Li, Chen; Huang, Jie

    2014-05-01

    White spot syndrome virus VP12 contains cell attachment motif RGD which is considered to be critical for host cell binding. Until now, the function of this protein remains undefined. In this study, we explored the interaction of VP12 with host cells. A new shrimp protein (adenine nucleotide translocase of Litopenaeus vannamei, LvANT) is selected by far-western overlay assay. Tissue distribution of adenine nucleotide translocase mRNA showed that it was commonly spread in all the tissues detected. Cellular localization of LvANT in shrimp hemocytes showed that it was primarily located in the cytoplasm of hemocytes and colocalized with mitochondria. ELISA and far-western blot assay confirmed that VP12 interacted with LvANT. In vivo neutralization assay showed that anti-LvANT antibody can significantly reduce the mortality of shrimp challenged by WSSV at 48h post-treatment. Our results collectively showed that VP12 is involved in host cell binding via interaction with adenine nucleotide translocase.

  15. Design and synthesis of novel adenine fluorescence probe based on Eu(III) complexes with dtpa-bis(guanine) ligand.

    Science.gov (United States)

    Tian, Fengyun; Jiang, Xiaoqing; Dou, Xuekai; Wu, Qiong; Wang, Jun; Song, Youtao

    2017-02-24

    A novel adenine (Ad) fluorescence probe (Eu(III)-dtpa-bis(guanine)) was designed and synthesized by improving experimental method based on the Eu(III) complex and dtpa-bis(guanine) ligand. The dtpa-bis(guanine) ligand was first synthesized by the acylation action between dtpaa and guanine (Gu), and the corresponding Eu(III) complex was successfully prepared through heat-refluxing method with dtpa-bis(guanine) ligand. As a novel fluorescence probe, the Eu(III)-dtpa-bis(guanine) complex can detect adenine (Ad) with characteristics of strong targeting, high specificity and high recognition ability. The detection mechanism of the adenine (Ad) using this probe in buffer solution was studied by ultraviolet-visible (UV-vis) and fluorescence spectroscopy. When the Eu(III)-dtpa-bis(guanine) was introduced to the adenine (Ad) solution, the fluorescence emission intensity was significantly enhanced. However, adding other bases such as guanine (Gu), xanthine (Xa), hypoxanthine (Hy) and uric acid (Ur) with similar composition and structure to that of adenine (Ad) to the Eu(III)-dtpa-bis(guanine) solution, the fluorescence emission intensities are nearly invariable. Meanwhile, the interference of guanine (Gu), xanthine (Xa), hypoxanthine (Hy) and uric acid (Ur) on the detection of the adenine using Eu(III)-dtpa-bis(guanine) probe was also studied. It was found that presence of these bases does not affect the detection of adenine (Ad). A linear response of fluorescence emission intensities of Eu(III)-dtpa-bis(guanine) at 570nm as a function of adenine (Ad) concentration in the range of 0.00-5.00×10(-5)molL(-1) was observed. The detection limit is about 4.70×10(-7)molL(-1).

  16. Medium optimization for leaf numbers and shoot multiplication of lidah buaya (Aloe vera by BAP and adenine supplement

    Directory of Open Access Journals (Sweden)

    LAELA SARI

    2005-07-01

    Full Text Available Aloe vera of the Aloeaceae is originated from Canary Island (West Africa. This plant is commonly know in Indonesia and cultivated in large fields or in the house yard for many purposes, such as ornamental and medicine plant. The industries using it as the principle raw material has became more important due to the significant benefits of this plant. This study is purposed to obtain the medium optimization for leaf numbers and shoot multiplication of Aloe vera by BAP and adenine supplement. The shoot of Aloe vera was taken from green house of Biotechnology-LIPI. Shoots sterilized by clorox (sodium hypochlorite solution 35% and 20% for 30 and 15 min. until get aseptic shoot (in vitro plants. The shoot isolated from in vitro plant into MS (Murashige and Skoog medium in different concentration of BAP and adenine. The research used factorial Completely Randomized Design with two factors (BAP concentration: 0; 0.5; 1; 1.5; 2 mg/L and adenine concentration 0; 10; 20 mg/L with 5 replicates. The results obtained have showed that addition 20 mg/L adenine to MS raise the numbers of leaf. The shoot multiplication has been augmented by addition of BAP 1 mg/L and adenine 20 mg/L. The results showed that BAP has a positive role in increasing shoot multiplication rate and that adenine has a synergic effect when added together with BAP.

  17. Characterization of new G protein-coupled adenine receptors in mouse and hamster.

    Science.gov (United States)

    Thimm, Dominik; Knospe, Melanie; Abdelrahman, Aliaa; Moutinho, Miguel; Alsdorf, Bernt B A; von Kügelgen, Ivar; Schiedel, Anke C; Müller, Christa E

    2013-09-01

    The nucleobase adenine has previously been reported to activate G protein-coupled receptors in rat and mouse. Adenine receptors (AdeR) thus constitute a new family of purine receptors, for which the designation "P0-receptors" has been suggested. We now describe the cloning and characterization of two new members of the AdeR family from mouse (MrgA10, termed mAde1R) and hamster (cAdeR). Both receptors were expressed in Sf9 insect cells, and radioligand binding studies were performed using [(3)H]adenine. Specific binding of the radioligand was detected in transfected, but not in untransfected cells, and K D values of 286 nM (mAde1R, B max 1.18 pmol/mg protein) and 301 nM (cAdeR, B max 17.7 pmol/mg protein), respectively, were determined. A series of adenine derivatives was investigated in competition binding assays. Minor structural modifications generally led to a reduction or loss of affinity, with one exception: 2-fluoroadenine was at least as potent as adenine itself at the cAdeR. Structure-activity relationships at all AdeR orthologs and subtypes investigated so far were similar, but not identical. For functional analyses, the cAdeR was homologously expressed in Chinese hamster ovary (CHO) cells, while the mAde1R was heterologously expressed in 1321N1 astrocytoma cells. Like the previously described AdeRs from rat (rAdeR) and mouse (mAde2R), the mAde1R (EC50 9.77 nM) and the cAdeR (EC50 51.6 nM) were coupled to inhibition of adenylate cyclase. In addition, the cAdeR from hamster expressed in CHO cells produced an increase in intracellular calcium concentrations (EC50 6.24 nM) and was found to be additionally coupled to Gq proteins.

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

    Directory of Open Access Journals (Sweden)

    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

  19. Dynamic simulation and metabolome analysis of long-term erythrocyte storage in adenine-guanosine solution.

    Directory of Open Access Journals (Sweden)

    Taiko Nishino

    Full Text Available Although intraerythrocytic ATP and 2,3-bisphophoglycerate (2,3-BPG are known as direct indicators of the viability of preserved red blood cells and the efficiency of post-transfusion oxygen delivery, no current blood storage method in practical use has succeeded in maintaining both these metabolites at high levels for long periods. In this study, we constructed a mathematical kinetic model of comprehensive metabolism in red blood cells stored in a recently developed blood storage solution containing adenine and guanosine, which can maintain both ATP and 2,3-BPG. The predicted dynamics of metabolic intermediates in glycolysis, the pentose phosphate pathway, and purine salvage pathway were consistent with time-series metabolome data measured with capillary electrophoresis time-of-flight mass spectrometry over 5 weeks of storage. From the analysis of the simulation model, the metabolic roles and fates of the 2 major additives were illustrated: (1 adenine could enlarge the adenylate pool, which maintains constant ATP levels throughout the storage period and leads to production of metabolic waste, including hypoxanthine; (2 adenine also induces the consumption of ribose phosphates, which results in 2,3-BPG reduction, while (3 guanosine is converted to ribose phosphates, which can boost the activity of upper glycolysis and result in the efficient production of ATP and 2,3-BPG. This is the first attempt to clarify the underlying metabolic mechanism for maintaining levels of both ATP and 2,3-BPG in stored red blood cells with in silico analysis, as well as to analyze the trade-off and the interlock phenomena between the benefits and possible side effects of the storage-solution additives.

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

    Energy Technology Data Exchange (ETDEWEB)

    Minaev, B. F., E-mail: bfmin@rambler.ru, E-mail: boris@theochem.kth.se [Bohdan Khmelnitsky National University, 18031 Cherkasy (Ukraine); Tomsk State University, 634050 Tomsk (Russian Federation); Shafranyosh, M. I.; Svida, Yu. Yu; Sukhoviya, M. I.; Shafranyosh, I. I. [Uzhgorod National University, 88000 Uzhgorod (Ukraine); Baryshnikov, G. V.; Minaeva, V. A. [Bohdan Khmelnitsky National University, 18031 Cherkasy (Ukraine)

    2014-05-07

    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{sup −15} and 3.2 × 10{sup −15} cm{sup 2}, respectively. The total cross section for formation of the negative ions is 6.1 × 10{sup −18} and 7.6 × 10{sup −18} cm{sup 2} 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.

  1. In vitro propagation of Calla lily: adenine sulphate and 6-benzilaminopurine

    Directory of Open Access Journals (Sweden)

    Márcia De Nazaré Oliveira Ribeiro

    2014-09-01

    Full Text Available Calla lily [Zantedeschia aethiopica (L. Spreng.] belonging to the Araceae family is appreciated as cut flower and in com­position of gardens. However, the conventional propagation of this plants shows a poor productive. Thus, tissue culture besides allowing fast clonal propagation also provides healthy and uniforms plants. The aim was study the influence of the differents concentrations of 6-benzilaminopurine (BAP and adenine sulphate (AS on in vitro multiplication of Calla lily. The explants were maintained in MS medium added with BAP (0.0, 8.9, 17.8 and 26.7 μM and adenine sulphate (0, 54, 108 and 162 μM. The plants were transferred to growth room and maintained at 25±1ºC and photoperiod of 16 hours for 60 days, under luminous intensity of 35 μmol m-2 s-1, for a period of 60 days. The experimental design was entirely randomized with four repetitions of three seedlings each, resulting in twelve plants per treatment, each tube with one plant. The statistics analysis showed interactive effects for quantify of BAP and AS for leaves number and fresh mass of the aerial parts. The highest number of leaves (4.8 and fresh mass of aerial parts (0.73 g was obtained with 26.7 μM of BAP combined with 108 μM of AS, highest number of shoots (2.6 was obtained with 22,19 μM of BAP and highest lengh of sprouts (5.0 cm was observed in the absence of BAP. The addition of BAP increased the number of shoots per explant. The use of adenine sulphate in combination with BAP had a positive effect for the accumulation of fresh weight and number of leaves in vitro culture.

  2. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    DEFF Research Database (Denmark)

    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 2'-amino-α-l-LNA adenine monomers W-Z. The synthesis of the target phosphoramidites 1-4 is initiated from pentafuranose 5, which upon Vorbrüggen glycosylation, O2'-deacylation, O2'-activation and C2'-azide introduction yields nucleoside 8. A one-pot tandem Staudinger...

  4. A novel missense adenine nucleotide translocator-1 gene mutation in a Greek adPEO family.

    Science.gov (United States)

    Napoli, L; Bordoni, A; Zeviani, M; Hadjigeorgiou, G M; Sciacco, M; Tiranti, V; Terentiou, A; Moggio, M; Papadimitriou, A; Scarlato, G; Comi, G P

    2001-12-26

    Autosomal dominant progressive external ophthalmoplegia (adPEO) is caused by mutations in at least three different genes: ANT1 (chromosome 4q34-35), TWINKLE, and POLG. The ANT1 gene encodes the adenine nucleotide translocator-1 (ANT1). We identified a heterozygous T293C mutation of the ANT1 gene in a Greek family with adPEO. The resulting leucine to proline substitution likely modifies the secondary structure of the ANT1 protein. ANT1 gene mutations may account for adPEO in families with different ethnic backgrounds.

  5. Adenine arabinoside inhibition of adenovirus replication enhanced by an adenosine deaminase inhibitor.

    Science.gov (United States)

    Wigand, R

    1979-01-01

    The inhibition of adenovirus multiplication by adenine arabinoside was determined by yield reduction in one-step multiplication cycle. Inhibition was greatly enhanced by an adenosine deaminase inhibitor (2-deoxycoformycin) in concentrations down to 10 ng/ml. Adenovirus types from four subgroups showed similar results. However, the enhancing effect of adenosine deaminase inhibitor was great in HeLa cells, moderate in human fibroblasts, and negligible in Vero cells. This difference could be explained by different concentrations of adenosine deaminase found in cell homogenates.

  6. Gas-phase spectroscopy of protonated adenine, adenosine 5′-monophosphate and monohydrated ions

    DEFF Research Database (Denmark)

    Pedersen, S.O.; Støchkel, K.; Byskov, C.S.

    2013-01-01

    Microsolvation of chromophore ions commonly has large effects on their electronic structure and as a result on their optical absorption spectra. Here spectroscopy of protonated adenine (AdeH+) and its complex with one water molecule isolated in vacuo was done using a home-built mass spectrometer...... in combination with a tuneable pulsed laser system. Experiments also included the protonated adenosine 5′-monophosphate nucleotide (AMPH+). In the case of bare AdeH+ ions, one-photon absorption leads to four dominant fragment ions corresponding to ammonium and ions formed after loss of either NH3, HCN, or NH2CN...

  7. Association of flavin adenine dinucleotide with the Arabidopsis blue light receptor CRY1

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C.; Robertson, D.E.; Ahmad, M. [Univ. of Pennsylvania, Philadelphia, PA (United States)] [and others

    1995-08-18

    The Arabidopsis thaliana HY4 gene encodes CRY1, a 75-kilodalton flavoprotein mediating blue light-dependent regulation of seedling development. CRY1 is demonstrated here to noncovalently bind stoichiometric amounts of flavin adenine dinucleotide (FAD). The redox properties of FAD bound by CRY1 include an unexpected stability of the neutral radical flavosemiquinone (FADH{center_dot}). The absorption properties of this flavosemiquinone provide a likely explanation for the additional sensitivity exhibited by CRY1-mediated responses in the green region of the visible spectrum. Despite the sequence homology to microbial DNA photolyases, CRY1 was found to have no detectable photolyase activity. 27 refs., 4 figs.

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

    Science.gov (United States)

    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.

  9. Comparative study between transcriptionally- and translationally-acting adenine riboswitches reveals key differences in riboswitch regulatory mechanisms.

    Directory of Open Access Journals (Sweden)

    Jean-François Lemay

    2011-01-01

    Full Text Available Many bacterial mRNAs are regulated at the transcriptional or translational level by ligand-binding elements called riboswitches. Although they both bind adenine, the adenine riboswitches of Bacillus subtilis and Vibrio vulnificus differ by controlling transcription and translation, respectively. Here, we demonstrate that, beyond the obvious difference in transcriptional and translational modulation, both adenine riboswitches exhibit different ligand binding properties and appear to operate under different regulation regimes (kinetic versus thermodynamic. While the B. subtilis pbuE riboswitch fully depends on co-transcriptional binding of adenine to function, the V. vulnificus add riboswitch can bind to adenine after transcription is completed and still perform translation regulation. Further investigation demonstrates that the rate of transcription is critical for the B. subtilis pbuE riboswitch to perform efficiently, which is in agreement with a co-transcriptional regulation. Our results suggest that the nature of gene regulation control, that is transcription or translation, may have a high importance in riboswitch regulatory mechanisms.

  10. Simultaneous Determination of Adenine and Guanine Using Cadmium Selenide Quantum Dots-Graphene Oxide Nanocomposite Modified Electrode.

    Science.gov (United States)

    Kalaivani, Arumugam; Narayanan, Sangilimuthu Sriman

    2015-06-01

    A novel electrochemical sensor was fabricated by immobilizing Cadmium Selenide Quantum Dots (CdSe QDs)-Graphene Oxide (GO) nanocomposite on a paraffin wax impregnated graphite electrode (PIGE) and was used for the simultaneous determination of adenine and guanine. The CdSe QDs-GO nanocomposite was prepared by ultrasonication and was characterized with spectroscopic and microscopic techniques. The nanocomposite modified electrode was characterized by cyclic voltammetry (CV). The modified electrode showed excellent electrocatalytic activity towards the oxidative determination of adenine and guanine with a good peak separation of 0.31 V. This may be due to the high surface area and fast electron transfer kinetics of the nanocomposite. The modified electrode exhibited wide linear ranges from 0.167 μM to 245 μM for Guanine and 0.083 μM to 291 μM for Adenine with detection limits of 0.055 μM Guanine and 0.028 μM of Adenine (S/N = 3) respectively. Further, the modified electrode was used for the quantitative determination of adenine and guanine in herring sperm DNA with satisfactory results. The modified electrode showed acceptable selectivity, reproducibility and stability under optimal conditions.

  11. CeO{sub 2} nanoparticles decorated multi-walled carbon nanotubes for electrochemical determination of guanine and adenine

    Energy Technology Data Exchange (ETDEWEB)

    Wei Yan [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China); Department of Chemistry, Wannan Medical College, Wuhu 241002 (China); Huang Qinan [Department of Chemistry, Wannan Medical College, Wuhu 241002 (China); Li Maoguo [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China); Huang Xingjiu [Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Fang Bin, E-mail: binfang_47@yahoo.com.cn [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China); Wang Lun, E-mail: wanglun@mail.ahnu.edu.cn [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China)

    2011-10-01

    Sub-10 nm CeO{sub 2} nanoparticles decorated multi-walled carbon nanotubes has been constructed for electrochemial determination of guanine and adenine. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to characterize the nanoparticles CeO{sub 2}/MWCNTs. Electrochemical impedance spectroscopy (EIS) was used to characterize the electrode modifying process. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the electrocatalytic activity toward the electrochemical oxidation of guanine and adenine. The detection limit (S/N = 3) for adenine and guanine was found to be 20 and 10 nM, respectively. The obtained sensitivity toward guanine and adenine was 1.26 and 1.13 {mu}A/{mu}M in the linear concentration range 5-50 {mu}M and 5-35 {mu}M, respectively. These results demonstrate that the carbon nanotubes could provide huge locations and facilitate the adsorptive accumulation of the guanine and adenine, and the CeO{sub 2} nanoparticles are promising substrates for the development of high-performance electrocatalysts for biosensing.

  12. Adenine-functionalized Spongy Graphene for Green and High-Performance Supercapacitors

    Science.gov (United States)

    El-Gendy, Dalia M.; Ghany, Nabil A. Abdel; El Sherbini, E. E. Foad; Allam, Nageh K.

    2017-02-01

    A simple method is demonstrated to prepare spongy adenine-functionalized graphene (SFG) as interconnected, porous 3-dimensional (3D) network crinkly sheets. Such 3D network structure provides better contact at the electrode/electrolyte interface and facilitates the charge transfer kinetics. The fabricated SFG was characterized by X-ray diffraction (XRD), FTIR, scanning electron microscopy (FESEM), Raman spectroscopy, thermogravimetric analysis (TGA), UV‑vis absorption spectroscopy, and transmission electron microscopy (TEM). The synthesized materials have been evaluated as supercapacitor materials in 0.5 M H2SO4 using cyclic voltammetry (CV) at different potential scan rates, and galvanostatic charge/discharge tests at different current densities. The SFG electrodes showed a maximum specific capacitance of 333 F/g at scan rate of 1 mV/s and exhibited excellent cycling retention of 102% after 1000 cycles at 200 mV/s. The energy density was 64.42 Wh/kg with a power density of 599.8 W/kg at 1.0 A/g. Those figures of merit are much higher than those reported for graphene-based materials tested under similar conditions. The observed high performance can be related to the synergistic effects of the spongy structure and the adenine functionalization.

  13. DNA adenine methylation of sams1 gene in symbiont-bearing Amoeba proteus.

    Science.gov (United States)

    Jeon, Taeck J

    2008-10-01

    The expression of amoeba sams genes is switched from sams1 to sams2 when amoebae are infected with Legionella jeonii. To elucidate the mechanism for the inactivation of host sams1 gene by endosymbiotic bacteria, methylation states of the sams1 gene of D and xD amoebae was compared in this study. The sams1 gene of amoebae was methylated at an internal adenine residue of GATC site in symbiont-bearing xD amoebae but not in symbiont-free D amoebae, suggesting that the modification might have caused the inactivation of sams1 in xD amoebae. The sams1 gene of xD amoebae was inactivated at the transcriptional level. Analysis of DNA showed that adenine residues in L. jeonii sams were also methylated, implying that L. jeonii bacteria belong to a Dam methylase-positive strain. In addition, both SAM and Met appeared to act as negative regulators for the expression of sams1 whereas the expression of sams2 was not affected in amoebae.

  14. Flavin adenine dinucleotide content of quinone reductase 2: analysis and optimization for structure-function studies.

    Science.gov (United States)

    Leung, Kevin Ka Ki; Litchfield, David W; Shilton, Brian H

    2012-01-01

    Quinone reductase 2 (NQO2) is a broadly expressed enzyme implicated in responses to a number of compounds, including protein kinase inhibitors, resveratrol, and antimalarial drugs. NQO2 includes a flavin adenine dinucleotide (FAD) cofactor, but X-ray crystallographic analysis of human NQO2 expressed in Escherichia coli showed that electron density for the isoalloxazine ring of FAD was weak and there was no electron density for the adenine mononucleotide moiety. Reversed-phase high-performance liquid chromatography (HPLC) of the NQO2 preparation indicated that FAD was not present and only 38% of the protomers contained flavin mononucleotide (FMN), explaining the weak electron density for FAD in the crystallographic analysis. A method for purifying NQO2 and reconstituting with FAD such that the final content approaches 100% occupancy with FAD is presented here. The enzyme prepared in this manner has a high specific activity, and there is strong electron density for the FAD cofactor in the crystal structure. Analysis of NQO2 crystal structures present in the Protein Data Bank indicates that many may have sub-stoichiometric cofactor content and/or contain FMN rather than FAD. This method of purification and reconstitution will help to optimize structural and functional studies of NQO2 and possibly other flavoproteins.

  15. Role of Hydrogen Bonding in the Formation of Adenine Chains on Cu(110 Surfaces

    Directory of Open Access Journals (Sweden)

    Lanxia Cheng

    2016-12-01

    Full Text Available Understanding the adsorption properties of DNA bases on metal surfaces is fundamental for the rational control of surface functionalization leading to the realisation of biocompatible devices for biosensing applications, such as monitoring of particular parameters within bio-organic environments and drug delivery. In this study, the effects of deposition rate and substrate temperature on the adsorption behavior of adenine on Cu(110 surfaces have been investigated using scanning tunneling microscopy (STM and density functional theory (DFT modeling, with a focus on the characterization of the morphology of the adsorbed layers. STM results revealed the formation of one-dimensional linear chains and ladder-like chains parallel to the [110] direction, when dosing at a low deposition rate at room temperature, followed by annealing to 490 K. Two mirror related, well-ordered chiral domains oriented at ±55° with respect to the [110] direction are formed upon deposition on a substrate kept at 490 K. The molecular structures observed via STM are rationalized and qualitatively described on the basis of the DFT modeling. The observation of a variety of ad-layer structures influenced by deposition rate and substrate temperature indicates that dynamic processes and hydrogen bonding play an important role in the self-assembly of adenine on the Cu(110 surface.

  16. The chemistry of nicotinamide adenine dinucleotide (NAD) analogues containing C-nucleosides related to nicotinamide riboside.

    Science.gov (United States)

    Pankiewicz, Krzysztof W; Watanabe, Kyoichi A; Lesiak-Watanabe, Krystyna; Goldstein, Barry M; Jayaram, Hiremagalur N

    2002-04-01

    Oncolytic C-nucleosides, tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide) and benzamide riboside (3-beta-D-ribofuranosylbenzamide) are converted in cell into active metabolites thiazole-4-carboxamide- and benzamide adenine dinucleotide, TAD and BAD, respectively. TAD and BAD as NAD analogues were found to bind at the nicotinamide adenine dinucleotide (cofactor NAD) site of inosine monophosphate dehydrogenase (IMPDH), an important target in cancer treatment. The synthesis and evaluation of anticancer activity of a number of C-nucleosides related to tiazofurin and nicotinamide riboside then followed and are reviewed herein. Interestingly, pyridine C-nucleosides (such as C-nicotinamide riboside) are not metabolized into the corresponding NAD analogues in cell. Their conversion by chemical methods is described. As dinucleotides these compounds show inhibition of IMPDH in low micromolar level. Also, the synthesis of BAD in metabolically stable bis(phosphonate) form is discussed indicating the usefulness of such preformed inhibitors in drug development. Among tiazofurin analogues, Franchetti and Grifantini found, that the replacement of the sulfur by oxygen (as in oxazafurin) but not the removal of nitrogen (tiophenfurin) of the thiazole ring resulted in inactive compounds. The anti cancer activity of their synthetic dinucleotide analogues indicate that inactive compounds are not only poorly metabolized in cell but also are weak inhibitors of IMPDH as dinucleotides.

  17. Biofabrication of chitosan-silver composite SERS substrates enabling quantification of adenine by a spectroscopic shift

    Energy Technology Data Exchange (ETDEWEB)

    Luo, X L; Bentley, W E [Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, College Park, MD 20742 (United States); Buckhout-White, S; Rubloff, G W, E-mail: rubloff@umd.edu [Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742 (United States)

    2011-09-15

    Surface-enhanced Raman scattering (SERS) has grown dramatically as an analytical tool for the sensitive and selective detection of molecules adsorbed on nano-roughened noble metal structures. Quantification with SERS based on signal intensity remains challenging due to the complicated fabrication process to obtain well-dispersed nanoparticles and well-ordered substrates. We report a new biofabrication strategy of SERS substrates that enable quantification through a newly discovered spectroscopic shift resulting from the chitosan-analyte interactions in solution. We demonstrate this phenomenon by the quantification of adenine, which is an essential part of the nucleic acid structure and a key component in pathways which generate signal molecules for bacterial communications. The SERS substrates were fabricated simply by sequential electrodeposition of chitosan on patterned gold electrodes and electroplating of a silver nitrate solution through the chitosan scaffold to form a chitosan-silver nanoparticle composite. Active SERS signals of adenine solutions were obtained in real time from the chitosan-silver composite substrates with a significant concentration-dependent spectroscopic shift. The Lorentzian curve fitting of the dominant peaks suggests the presence of two separate peaks with a concentration-dependent area percentage of the separated peaks. The chitosan-mediated composite SERS substrates can be easily biofabricated on predefined electrodes within microfluidic channels for real-time detection in microsystems.

  18. Development of bright fluorescent quadracyclic adenine analogues: TDDFT-calculation supported rational design

    Science.gov (United States)

    Foller Larsen, Anders; Dumat, Blaise; Wranne, Moa S.; Lawson, Christopher P.; Preus, Søren; Bood, Mattias; Gradén, Henrik; Marcus Wilhelmsson, L.; Grøtli, Morten

    2015-07-01

    Fluorescent base analogues (FBAs) comprise a family of increasingly important molecules for the investigation of nucleic acid structure and dynamics. We recently reported the quantum chemical calculation supported development of four microenvironment sensitive analogues of the quadracyclic adenine (qA) scaffold, the qANs, with highly promising absorptive and fluorescence properties that were very well predicted by TDDFT calculations. Herein, we report on the efficient synthesis, experimental and theoretical characterization of nine novel quadracyclic adenine derivatives. The brightest derivative, 2-CNqA, displays a 13-fold increased brightness (ɛΦF = 4500) compared with the parent compound qA and has the additional benefit of being a virtually microenvironment-insensitive fluorophore, making it a suitable candidate for nucleic acid incorporation and use in quantitative FRET and anisotropy experiments. TDDFT calculations, conducted on the nine novel qAs a posteriori, successfully describe the relative fluorescence quantum yield and brightness of all qA derivatives. This observation suggests that the TDDFT-based rational design strategy may be employed for the development of bright fluorophores built up from a common scaffold to reduce the otherwise costly and time-consuming screening process usually required to obtain useful and bright FBAs.

  19. Adenine-functionalized Spongy Graphene for Green and High-Performance Supercapacitors

    Science.gov (United States)

    El-Gendy, Dalia M.; Ghany, Nabil A. Abdel; El Sherbini, E. E. Foad; Allam, Nageh K.

    2017-01-01

    A simple method is demonstrated to prepare spongy adenine-functionalized graphene (SFG) as interconnected, porous 3-dimensional (3D) network crinkly sheets. Such 3D network structure provides better contact at the electrode/electrolyte interface and facilitates the charge transfer kinetics. The fabricated SFG was characterized by X-ray diffraction (XRD), FTIR, scanning electron microscopy (FESEM), Raman spectroscopy, thermogravimetric analysis (TGA), UV−vis absorption spectroscopy, and transmission electron microscopy (TEM). The synthesized materials have been evaluated as supercapacitor materials in 0.5 M H2SO4 using cyclic voltammetry (CV) at different potential scan rates, and galvanostatic charge/discharge tests at different current densities. The SFG electrodes showed a maximum specific capacitance of 333 F/g at scan rate of 1 mV/s and exhibited excellent cycling retention of 102% after 1000 cycles at 200 mV/s. The energy density was 64.42 Wh/kg with a power density of 599.8 W/kg at 1.0 A/g. Those figures of merit are much higher than those reported for graphene-based materials tested under similar conditions. The observed high performance can be related to the synergistic effects of the spongy structure and the adenine functionalization. PMID:28216668

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

    Directory of Open Access Journals (Sweden)

    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. Microwave-assisted stereospecific synthesis of novel tetrahydropyran adenine isonucleosides and crystal structures determination

    Science.gov (United States)

    Silva, Fábio P. L.; Cirqueira, Marilia L.; Martins, Felipe T.; Vasconcellos, Mário L. A. A.

    2013-11-01

    We describe in this article stereospecific syntheses for new isonucleosides analogs of adenine 5-7 from tosyl derivatives 2-4 accessing by microwave irradiations (50-80%). The adenine reacts entirely at the N(9) position. Compounds 2-4 were prepared in two steps from the corresponding alcohols 1, 8 and 9 (81-92%). These tetrahydropyrans alcohols 1, 8 and 9 are achiral (Meso compounds) and were prepared in two steps with complete control of 2,4,6-cis relative configuration by Prins cyclization reaction (60-63%) preceded by the Barbier reaction between allyl bromide with benzaldehyde, 4-fluorobenzaldehyde and 2-naphthaldehyde respectively under Lewis acid conditions (96-98%). The configurations and preferential conformations of 5-7 were determined by crystal structure of 6. These novel isonucleosides 5-7 present in silico potentiality to act as GPCR ligand, kinase inhibitor and enzyme inhibitor, evaluated by Molinspiration program, consistent with the expected antiviral and anticancer bioactivities.

  2. 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.

    Science.gov (United States)

    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.

  3. Progesterone-adenine hybrids as bivalent inhibitors of P-glycoprotein-mediated multidrug efflux: design, synthesis, characterization and biological evaluation.

    Science.gov (United States)

    Zeinyeh, Waël; Mahiout, Zahia; Radix, Sylvie; Lomberget, Thierry; Dumoulin, Axel; Barret, Roland; Grenot, Catherine; Rocheblave, Luc; Matera, Eva-Laure; Dumontet, Charles; Walchshofer, Nadia

    2012-10-01

    Bivalent ligands were designed on the basis of the described close proximity of the ATP-site and the putative steroid-binding site of P-glycoprotein (ABCB1). The syntheses of 19 progesterone-adenine hybrids are described. Their abilities to inhibit P-glycoprotein-mediated daunorubicin efflux in K562/R7 human leukemic cells overexpressing P-glycoprotein were evaluated versus progesterone. The hybrid with a hexamethylene linker chain showed the best inhibitory potency. The efficiency of these progesterone-adenine hybrids depends on two main factors: (i) the nature of the linker and (ii) its attachment point on the steroid skeleton.

  4. Nicotinic acid adenine dinucleotide phosphate-mediated calcium signalling in effector T cells regulates autoimmunity of the central nervous system

    Science.gov (United States)

    Cordiglieri, Chiara; Odoardi, Francesca; Zhang, Bo; Nebel, Merle; Kawakami, Naoto; Klinkert, Wolfgang E. F.; Lodygin, Dimtri; Lühder, Fred; Breunig, Esther; Schild, Detlev; Ulaganathan, Vijay Kumar; Dornmair, Klaus; Dammermann, Werner; Potter, Barry V. L.; Guse, Andreas H.

    2010-01-01

    Nicotinic acid adenine dinucleotide phosphate represents a newly identified second messenger in T cells involved in antigen receptor-mediated calcium signalling. Its function in vivo is, however, unknown due to the lack of biocompatible inhibitors. Using a recently developed inhibitor, we explored the role of nicotinic acid adenine dinucleotide phosphate in autoreactive effector T cells during experimental autoimmune encephalomyelitis, the animal model for multiple sclerosis. We provide in vitro and in vivo evidence that calcium signalling controlled by nicotinic acid adenine dinucleotide phosphate is relevant for the pathogenic potential of autoimmune effector T cells. Live two photon imaging and molecular analyses revealed that nicotinic acid adenine dinucleotide phosphate signalling regulates T cell motility and re-activation upon arrival in the nervous tissues. Treatment with the nicotinic acid adenine dinucleotide phosphate inhibitor significantly reduced both the number of stable arrests of effector T cells and their invasive capacity. The levels of pro-inflammatory cytokines interferon-gamma and interleukin-17 were strongly diminished. Consecutively, the clinical symptoms of experimental autoimmune encephalomyelitis were ameliorated. In vitro, antigen-triggered T cell proliferation and cytokine production were evenly suppressed. These inhibitory effects were reversible: after wash-out of the nicotinic acid adenine dinucleotide phosphate antagonist, the effector T cells fully regained their functions. The nicotinic acid derivative BZ194 induced this transient state of non-responsiveness specifically in post-activated effector T cells. Naïve and long-lived memory T cells, which express lower levels of the putative nicotinic acid adenine dinucleotide phosphate receptor, type 1 ryanodine receptor, were not targeted. T cell priming and recall responses in vivo were not reduced. These data indicate that the nicotinic acid adenine dinucleotide phosphate

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

    DEFF Research Database (Denmark)

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  7. Chronic kidney disease induced by adenine: a suitable model of growth retardation in uremia.

    Science.gov (United States)

    Claramunt, Débora; Gil-Peña, Helena; Fuente, Rocío; García-López, Enrique; Loredo, Vanessa; Hernández-Frías, Olaya; Ordoñez, Flor A; Rodríguez-Suárez, Julián; Santos, Fernando

    2015-07-01

    Growth retardation is a major manifestation of chronic kidney disease (CKD) in pediatric patients. The involvement of the various pathogenic factors is difficult to evaluate in clinical studies. Here, we present an experimental model of adenine-induced CKD for the study of growth failure. Three groups (n = 10) of weaning female rats were studied: normal diet (control), 0.5% adenine diet (AD), and normal diet pair fed with AD (PF). After 21 days, serum urea nitrogen, creatinine, parathyroid hormone (PTH), weight and length gains, femur osseous front advance as an index of longitudinal growth rate, growth plate histomorphometry, chondrocyte proliferative activity, bone structure, aorta calcifications, and kidney histology were analyzed. Results are means ± SE. AD rats developed renal failure (serum urea nitrogen: 70 ± 6 mg/dl and creatinine: 0.6 ± 0.1 mg/dl) and secondary hyperparathyroidism (PTH: 480 ± 31 pg/ml). Growth retardation of AD rats was demonstrated by lower weight (AD rats: 63.3 ± 4.8 g, control rats: 112.6 ± 4.7 g, and PF rats: 60.0 ± 3.8 g) and length (AD rats: 7.2 ± 0.2 cm, control rats: 11.1 ± 0.3 cm, and PF rats: 8.1 ± 0.3 cm) gains as well as lower osseous front advances (AD rats: 141 ± 13 μm/day, control rats: 293 ± 16 μm/day, and PF rats: 251 ± 10 μm/day). The processes of chondrocyte maturation and proliferation were impaired in AD rats, as shown by lower growth plate terminal chondrocyte height (21.7 ± 2.3 vs. 26.2 ± 1.9 and 23.9 ± 1.3 μm in control and PF rats) and proliferative activity index (AD rats: 30 ± 2%, control rats: 38 ± 2%, and PF rats: 42 ± 3%). The bone primary spongiosa structure of AD rats was markedly disorganized. In conclusion, adenine-induced CKD in young rats is associated with growth retardation and disturbed endochondral ossification. This animal protocol may be a useful new experimental model to study growth in CKD.

  8. Hydroxyl radical reactions with adenine: reactant complexes, transition states, and product complexes.

    Science.gov (United States)

    Cheng, Qianyi; Gu, Jiande; Compaan, Katherine R; Schaefer, Henry F

    2010-10-18

    In order to address problems such as aging, cell death, and cancer, it is important to understand the mechanisms behind reactions causing DNA damage. One specific reaction implicated in DNA oxidative damage is hydroxyl free-radical attack on adenine (A) and other nucleic acid bases. The adenine reaction has been studied experimentally, but there are few theoretical results. In the present study, adenine dehydrogenation at various sites, and the potential-energy surfaces for these reactions, are investigated theoretically. Four reactant complexes [A···OH]* have been found, with binding energies relative to A+OH* of 32.8, 11.4, 10.7, and 10.1 kcal mol(-1). These four reactant complexes lead to six transition states, which in turn lie +4.3, -5.4, (-3.7 and +0.8), and (-2.3 and +0.8) kcal mol(-1) below A+OH*, respectively. Thus the lowest lying [A···OH]* complex faces the highest local barrier to formation of the product (A-H)*+H(2)O. Between the transition states and the products lie six product complexes. Adopting the same order as the reactant complexes, the product complexes [(A-H)···H(2)O]* lie at -10.9, -22.4, (-24.2 and -18.7), and (-20.5 and -17.5) kcal mol(-1), respectively, again relative to separated A+OH*. All six A+OH* → (A-H)*+H(2)O pathways are exothermic, by -0.3, -14.7, (-17.4 and -7.8), and (-13.7 and -7.8) kcal mol(-1), respectively. The transition state for dehydrogenation at N(6) lies at the lowest energy (-5.4 kcal mol(-1) relative to A+OH*), and thus reaction is likely to occur at this site. This theoretical prediction dovetails with the observed high reactivity of OH radicals with the NH(2) group of aromatic amines. However, the high barrier (37.1 kcal mol(-1)) for reaction at the C(8) site makes C(8) dehydrogenation unlikely. This last result is consistent with experimental observation of the imidazole ring opening upon OH radical addition to C(8). In addition, TD-DFT computed electronic transitions of the N(6) product around 420 nm

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

    Directory of Open Access Journals (Sweden)

    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

  10. A distinct sequence in the adenine nucleotide translocase from Artemia franciscana embryos is associated with insensitivity to bongkrekate and atypical effects of adenine nucleotides on Ca2+ uptake and sequestration.

    Science.gov (United States)

    Konràd, Csaba; Kiss, Gergely; Töröcsik, Beata; Lábár, János L; Gerencser, Akos A; Mándi, Miklós; Adam-Vizi, Vera; Chinopoulos, Christos

    2011-03-01

    Mitochondria isolated from embryos of the crustacean Artemia franciscana lack the Ca(2+)-induced permeability transition pore. Although the composition of the pore described in mammalian mitochondria is unknown, the impacts of several effectors of the adenine nucleotide translocase (ANT) on pore opening are firmly established. Notably, ADP, ATP and bongkrekate delay, whereas carboxyatractyloside hastens, Ca(2+)-induced pore opening. Here, we report that adenine nucleotides decreased, whereas carboxyatractyloside increased, Ca(2+) uptake capacity in mitochondria isolated from Artemia embryos. Bongkrekate had no effect on either Ca(2+) uptake or ADP-ATP exchange rate. Transmission electron microscopy imaging of Ca(2+)-loaded Artemia mitochondria showed needle-like formations of electron-dense material in the absence of adenine nucleotides, and dot-like formations in the presence of adenine nucleotides or Mg(2+). Energy-filtered transmission electron microscopy showed the material to be rich in calcium and phosphorus. Sequencing of the Artemia mRNA coding for ANT revealed that it transcribes a protein with a stretch of amino acids in the 198-225 region with 48-56% similarity to those from other species, including the deletion of three amino acids in positions 211, 212 and 219. Mitochondria isolated from the liver of Xenopus laevis, in which the ANT shows similarity to that in Artemia except for the 198-225 amino acid region, demonstrated a Ca(2+)-induced bongkrekate-sensitive permeability transition pore, allowing the suggestion that this region of ANT may contain the binding site for bongkrekate.

  11. Role of adenine nucleotide translocator 1 in mtDNA maintenance.

    Science.gov (United States)

    Kaukonen, J; Juselius, J K; Tiranti, V; Kyttälä, A; Zeviani, M; Comi, G P; Keränen, S; Peltonen, L; Suomalainen, A

    2000-08-04

    Autosomal dominant progressive external ophthalmoplegia is a rare human disease that shows a Mendelian inheritance pattern, but is characterized by large-scale mitochondrial DNA (mtDNA) deletions. We have identified two heterozygous missense mutations in the nuclear gene encoding the heart/skeletal muscle isoform of the adenine nucleotide translocator (ANT1) in five families and one sporadic patient. The familial mutation substitutes a proline for a highly conserved alanine at position 114 in the ANT1 protein. The analogous mutation in yeast caused a respiratory defect. These results indicate that ANT has a role in mtDNA maintenance and that a mitochondrial disease can be caused by a dominant mechanism.

  12. Dynamics of Excess-Electron Transfer through Alternating Adenine:Thymine Sequences in DNA.

    Science.gov (United States)

    Lin, Shih-Hsun; Fujitsuka, Mamoru; Majima, Tetsuro

    2015-11-02

    This paper presents the results of an investigation into the sequence-dependent excess-electron transfer (EET) dynamics in DNA, which plays an important role in DNA damage/repair. There are many published studies on EET in consecutive adenine:thymine (A:T) sequences (Tn), but those in alternating A:T sequences (ATn) remain limited. Here, two series of functionalized DNA oligomers, Tn and ATn, were synthesized with a strongly electron-donating photosensitizer, a trimer of ethylenedioxythiophene (3 E), and an electron acceptor, diphenylacetylene (DPA). Laser flash photolysis experiments showed that the EET rate constant of AT3 is two times lower than that of T3 due to the lack of π-stacking of Ts in AT3. Thus, it was indicated that excess-electron hopping is affected by the interaction between LUMOs of nucleotides. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Adenine phosphoribosyltransferase deficiency: an underdiagnosed cause of lithiasis and renal failure.

    Science.gov (United States)

    Marra, Giuseppina; Vercelloni, Paolo Gilles; Edefonti, Alberto; Manzoni, Gianantonio; Pavesi, Maria Angela; Fogazzi, Giovanni Battista; Garigali, Giuseppe; Mockel, Lionel; Picot, Irene Ceballos

    2012-01-01

    We describe an infant affected by adenine phosphoribosyltransferase (APRT) deficiency diagnosed at 18 months of age with a de novo mutation that has not been previously reported. APRT deficiency is a rare defect of uric acid catabolism that leads to the accumulation of 2,8 dihydroxyadenine (2,8-DHA), a highly insoluble substance excreted by the kidneys that may precipitate in urine and form stones. The child suffered from renal colic due to a stone found in the peno-scrotal junction of the bulbar urethra. Stone spectrophotometric analysis allowed us to diagnose the disease and start kidney-saving therapy in order to avoid irreversible chronic kidney damage. APRT deficiency should always be considered in the differential diagnosis of pediatric urolithiasis.

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

    Science.gov (United States)

    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.

  15. Simultaneous determination of adenine and guanine in ruminant bacterial pellets by ion-pair HPLC.

    Science.gov (United States)

    García del Moral, Pilar; Arín, María Jesús; Resines, José Antonio; Díez, María Teresa

    2005-11-05

    An ion-pair reversed-phase high-performance liquid chromatography with gradient elution and UV detection was used to measure adenine (A) and guanine (G) in lyophilized bacterial pellets from ruminants using allopurinol as internal standard. The separation was performed on a Symmetry C18 column and the detection was monitored at 280 nm. Calibration curves were found to be linear in the concentration range from 5 to 50 mg/l with correlation coefficients (r2)>0.999. Mean recoveries of A and G standards added to bacterial samples were 102.2 and 98.2, respectively. The method proposed yielded sharp, well-resolved peaks within 25 min and was successfully applied for the determination of A and G in bacterial pellets.

  16. Animal models of pediatric chronic kidney disease. Is adenine intake an appropriate model?

    Directory of Open Access Journals (Sweden)

    Débora Claramunt

    2015-11-01

    Full Text Available Pediatric chronic kidney disease (CKD has peculiar features. In particular, growth impairment is a major clinical manifestation of CKD that debuts in pediatric age because it presents in a large proportion of infants and children with CKD and has a profound impact on the self-esteem and social integration of the stunted patients. Several factors associated with CKD may lead to growth retardation by interfering with the normal physiology of growth plate, the organ where longitudinal growth rate takes place. The study of growth plate is hardly possible in humans and justifies the use of animal models. Young rats made uremic by 5/6 nephrectomy have been widely used as a model to investigate growth retardation in CKD. This article examines the characteristics of this model and analyzes the utilization of CKD induced by high adenine diet as an alternative research protocol.

  17. Substrate specificity and stereospecificity of nicotinamide adenine dinucleotide-linked alcohol dehydrogenases from methanol-grown yeasts.

    OpenAIRE

    Hou, C T; Patel, R; Laskin, A I; Barnabe, N; Marczak, I

    1981-01-01

    Nicotine adenine dinucleotide-linked primary alcohol dehydrogenase and a newly discovered secondary alcohol dehydrogenase coexist in most strains of methanol-grown yeasts. Alcohol dehydrogenases from methanol-grown yeasts oxidize (--)-2-butanol preferentially over its (+) enantiomorph. This is substantially different from alcohol dehydrogenases from bakers' yeast and horse liver.

  18. Simultaneous determination of adenine,uridine and adenosine in cordyceps sinensis and its substitutes by LC/ESI-MS

    Institute of Scientific and Technical Information of China (English)

    黄兰芳; 吴名剑; 孙贤军; 郭方遒; 梁逸曾; 李晓如

    2004-01-01

    A simple, sensitive and reproducible high performance liquid chromatography-mass spectrometry coupled with electrospray ionization method for simultaneous separation and determination of adenine, adenosine and uridine was developed. The analytical column is a 2.0 mm× 150 mm Shimadzu VP-ODS column and volume fraction of the mobile phase is 86.5 %water, 12.0%methanol and 1.5%formic acid. 2-chloroadenosine was used as internal standard. Selective ion monitoring mode and selective ion monitoring ions at ratio of mass to electric charge of 136 for adenine, 268 for adenosine and 267 for uridine were chosen for quantitative analysis of the three active components. The results show that the regression equations and linear range are Y=0. 062X+0. 005 and 2.0 - 140.0μg · mL 1for adenine, Y=0. 049X+0. 004 and 4. 0 - 115.0 μg · mL-1 for uridine, Y=0. 154X+0. 014 and 1.0 - 125.0 μg · mL 1 for adenosine. The limits of detection are 0.6 μg · mL 1 for adenine, 1.0μg · mL-1 for uri dine and 0.2 μg · mL 1 for adenosine.The recoveries of the three constituents are from 96.6% to 103.2%.

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

    Energy Technology Data Exchange (ETDEWEB)

    Prado, Cesar [Department of Physical Chemistry, University of Sevilla, c/ Prof. Garcia Gonzalez n 2, Sevilla 41012 (Spain); Prieto, Francisco [Department of Physical Chemistry, University of Sevilla, c/ Prof. Garcia Gonzalez n 2, Sevilla 41012 (Spain); Rueda, Manuela [Department of Physical Chemistry, University of Sevilla, c/ Prof. Garcia Gonzalez n 2, Sevilla 41012 (Spain)]. E-mail: marueda@us.es; Feliu, Juan [Department of Physical Chemistry, University of Alicante, Apart 99, Alicante E-03080 (Spain); Aldaz, Antonio [Department of Physical Chemistry, University of Alicante, Apart 99, Alicante E-03080 (Spain)

    2007-02-15

    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 KClO{sub 4} 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 {sub 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.

  20. Reduced Graphene Oxide/α-Cyclodextrin-Based Electrochemical Sensor: Characterization and Simultaneous Detection of Adenine, Guanine and Thymine

    Directory of Open Access Journals (Sweden)

    Erhan ZOR

    2016-12-01

    Full Text Available Graphene, the rising star of carbon nanomaterials, is a single layer of sp2-bonded carbon atoms patterned in a 2D honeycomb network. Thanks to its unique features, graphene has attracted enormous attention and it has arisen various applications in the fields of optical and electrochemical sensors. In the present work, reduced graphene oxide/alpha cyclodextrin (rGO/α-CD is proposed as a nanocomposite for individual and simultaneous detection of adenine, guanine and thymine. rGO/α-CD has been characterized by FT-IR, Raman spectroscopy, AFM, HR-TEM and SEM techniques. Cyclic voltammetry, differential pulse voltammetry and chronoamperometry techniques were utilized for detection of adenine, guanine and thymine. The limit of detection (LOD values for adenine, guanine and thymine were calculated to be 145.5, 38.9 and 52.9 nmol L-1, respectively. The results show that the developed sensor can be utilized for the determination of adenine, guanine and thymine in human serum, indicating its promising application in the analysis of real samples.

  1. 3-Methyl-2-butenal: an enzymatic degradation product of the cytokinin, N-6-(delta-2 isopentenyl)adenine.

    Science.gov (United States)

    Brownlee, B G; Hall, R H; Whitty, C D

    1975-01-01

    An enzyme preparation from immature corn kernels catalyzed cleavage of N-6-(delta-2-isopentenyl)adenine to give the aldehyde, 3-methyl-2-butenal, as the major side-chain derived product. This product, in the form of the semicarbazone, was identical with an authentic product by several criteria: chromatographic behavior, mass and ultraviolet spectra.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. Surface-enhanced Raman spectroscopy (SERS) for identifying traces of adenine in different mineral and rock samples

    Science.gov (United States)

    Lafuente, B.; Navarro, R.; Sansano, A.; Rull, F.

    2012-09-01

    The aim of this study is to analyze the potentials of SERS as a technique for in-situ identification of life traces in Mars surface explorations using the Raman instrument (RLS), payload of the ESA Mars mission Exomars. This preliminary study focused on detection of adenine on a variety of rocks soils samples using macro-SERS detection.

  4. Flavin adenine dinucleotide binding is the crucial step in alcohol oxidase assembly in the yeast Hansenula polymorpha

    NARCIS (Netherlands)

    Evers, Melchior E.; Titorenko, Vladimir; Harder, Wim; Klei, Ida van der; Veenhuis, Marten

    1996-01-01

    We have studied the role of flavin adenine dinucleotide (FAD) in the in vivo assembly of peroxisomal alcohol oxidase (AO) in the yeast Hansenula polymorpha. In previous studies, using a riboflavin (Rf) autotrophic mutant, an unequivocal judgement could not be made, since Rf-limitation led to a parti

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

    DEFF Research Database (Denmark)

    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 comp......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 computational method is validated by considering the hydrogen abstraction from the heterocyclic N9 nitrogen in adenine as a test system. Geometries for all molecules in the reaction are optimised with four different DFT exchange-correlation functionals (B3LYP, BHandHLYP, M06-2X and wB97X-D), in combination...... 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 between adenine...

  6. Expanding antitumor therapeutic windows by targeting cancer-specific nicotinamide adenine dinucleotide phosphate-biogenesis pathways

    Directory of Open Access Journals (Sweden)

    Chakrabarti G

    2015-03-01

    Full Text Available Gaurab Chakrabarti,1,2,4 David E Gerber,3,4 David A Boothman1,2,4 1Department of Pharmacology, 2Department of Radiation Oncology, 3Division of Hematology and Oncology, 4Harold C Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX, USA Abstract: Nicotinamide adenine dinucleotide phosphate (NADPH biogenesis is an essential mechanism by which both normal and cancer cells maintain redox balance. While antitumor approaches to treat cancers through elevated reactive oxygen species (ROS are not new ideas, depleting specific NADPH-biogenesis pathways that control recovery and repair pathways are novel, viable approaches to enhance cancer therapy. However, to elicit efficacious therapies exploiting NADPH-biogenic pathways, it is crucial to understand and specifically define the roles of NADPH-biogenesis pathways used by cancer cells for survival or recovery from cell stress. It is equally important to select NADPH-biogenic pathways that are expendable or not utilized in normal tissue to avoid unwanted toxicity. Here, we address recent literature that demonstrates specific tumor-selective NADPH-biogenesis pathways that can be exploited using agents that target specific cancer cell pathways normally not utilized in normal cells. Defining NADPH-biogenesis profiles of specific cancer-types should enable novel strategies to exploit these therapeutic windows for increased efficacy against recalcitrant neoplastic disease, such as pancreatic cancers. Accomplishing the goal of using ROS as a weapon against cancer cells will also require agents, such as NQO1 bioactivatable drugs, that selectively induce elevated ROS levels in cancer cells, while normal cells are protected. Keywords: reactive oxygen species (ROS, NQO1-bioactivatable drugs, nicotinamide adenine dinucleotide phosphate (NADPH, glutathione (GSH, biogenic pathways, antioxidant

  7. Regulation of Salmonella enterica pathogenicity island 1 by DNA adenine methylation.

    Science.gov (United States)

    López-Garrido, Javier; Casadesús, Josep

    2010-03-01

    DNA adenine methylase (Dam(-)) mutants of Salmonella enterica are attenuated in the mouse model and present multiple virulence-related defects. Impaired interaction of Salmonella Dam(-) mutants with the intestinal epithelium has been tentatively correlated with reduced secretion of pathogenicity island 1 (SPI-1) effectors. In this study, we show that S. enterica Dam(-) mutants contain lowered levels of the SPI-1 transcriptional regulators HilA, HilC, HilD, and InvF. Epistasis analysis indicates that Dam-dependent regulation of SPI-1 requires HilD, while HilA, HilC, and InvF are dispensable. A transcriptional hilDlac fusion is expressed at similar levels in Dam(+) and Dam(-) hosts. However, lower levels of hilD mRNA are found in a Dam(-) background, thus providing unsuspected evidence that Dam methylation might exert post-transcriptional regulation of hilD expression. This hypothesis is supported by the following lines of evidence: (i) lowered levels of hilD mRNA are found in Salmonella Dam(-) mutants when hilD is transcribed from a heterologous promoter; (ii) increased hilD mRNA turnover is observed in Dam(-) mutants; (iii) lack of the Hfq RNA chaperone enhances hilD mRNA instability in Dam(-) mutants; and (iv) lack of the RNA degradosome components polynucleotide phosphorylase and ribonuclease E suppresses hilD mRNA instability in a Dam(-) background. Our report of Dam-dependent control of hilD mRNA stability suggests that DNA adenine methylation plays hitherto unknown roles in post-transcriptional control of gene expression.

  8. Excretory Function of Intestinal Tract Enhanced in Kidney Impaired Rats Caused by Adenine

    Science.gov (United States)

    Yun, Yu; Gao, Tao; Li, Yue; Gao, Zhiyi; Duan, Jinlian; Yin, Hua

    2016-01-01

    The main aim of the study was to prove the compensative effect of intestine for renal function. Rat kidney was impaired by intragastrically administrating adenine (400 mg per day for 5 days). Intestinal tract was harvested and equally divided into 20 segments except cecum. Kidneys were harvested and histologically examined with hematoxylin-eosin staining kits. Uric acid, urea (BUN), and creatinine in serum were determined with assay kits, and BUN and creatinine in every intestinal segment were also determined. The results showed that adenine was able to increase uric acid level in serum from 20.98 ± 6.98 μg/mL to 40.77 ± 7.52 μg/mL and cause renal function damage with BUN (from 3.87 ± 0.62 mM to 12.33 ± 3.27 mM) and creatinine (from 51.48 ± 6.98 μM to 118.25 ± 28.63 μM) increasing in serum and with abnormally micromorphological changes in kidney. The amount of BUN and creatinine distributed in intestinal tract was positively correlated with those in blood. In impaired renal function rats, the amount of BUN (from 4.26 ± 0.21 μMole to 10.72 ± 0.55 μMole) and creatinine (from 681.4 ± 23.3 nMole to 928.7 ± 21.3 nMole) distributed in intestinal tract significantly increased. All the results proved that intestinal tract had excretory function compensative for renal function. PMID:27975080

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

    Science.gov (United States)

    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 K(I). 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.

  10. Lack of hepcidin ameliorates anemia and improves growth in an adenine-induced mouse model of chronic kidney disease.

    Science.gov (United States)

    Akchurin, Oleh; Sureshbabu, Angara; Doty, Steve B; Zhu, Yuan-Shan; Patino, Edwin; Cunningham-Rundles, Susanna; Choi, Mary E; Boskey, Adele; Rivella, Stefano

    2016-11-01

    Growth delay is common in children with chronic kidney disease (CKD), often associated with poor quality of life. The role of anemia in uremic growth delay is poorly understood. Here we describe an induction of uremic growth retardation by a 0.2% adenine diet in wild-type (WT) and hepcidin gene (Hamp) knockout (KO) mice, compared with their respective littermates fed a regular diet. Experiments were started at weaning (3 wk). After 8 wk, blood was collected and mice were euthanized. Adenine-fed WT mice developed CKD (blood urea nitrogen 82.8 ± 11.6 mg/dl and creatinine 0.57 ± 0.07 mg/dl) and were 2.1 cm shorter compared with WT controls. WT adenine-fed mice were anemic and had low serum iron, elevated Hamp, and elevated IL6 and TNF-α. WT adenine-fed mice had advanced mineral bone disease (serum phosphorus 16.9 ± 3.1 mg/dl and FGF23 204.0 ± 115.0 ng/ml) with loss of cortical and trabecular bone volume seen on microcomputed tomography. Hamp disruption rescued the anemia phenotype resulting in improved growth rate in mice with CKD, thus providing direct experimental evidence of the relationship between Hamp pathway and growth impairment in CKD. Hamp disruption ameliorated CKD-induced growth hormone-insulin-like growth factor 1 axis derangements and growth plate alterations. Disruption of Hamp did not mitigate the development of uremia, inflammation, and mineral and bone disease in this model. Taken together, these results indicate that an adenine diet can be successfully used to study growth in mice with CKD. Hepcidin appears to be related to pathways of growth retardation in CKD suggesting that investigation of hepcidin-lowering therapies in juvenile CKD is warranted.

  11. Efficacy of Adenine in the Treatment of Leukopenia and Neutropenia Associated with an Overdose of Antipsychotics or Discontinuation of Lithium Carbonate Administration: Three Case Studies

    Science.gov (United States)

    Tomita, Takashi; Goto, Hidekazu; Sumiya, Kenji; Yoshida, Tadashi; Tanaka, Katsuya; Kohda, Yukinao

    2016-01-01

    Because adenine is effective for managing cases of radiation-induced and drug-induced leukopenia, it may be effective in cases of antipsychotic-induced leukopenia and neutropenia. Here, we report our experience with patients with leukopenia and neutropenia caused by an antipsychotic overdose or discontinuation of lithium carbonate, in whom adenine administration ameliorated the white blood cell and neutrophil counts. The progress of patients suggests that adenine is effective in cases of leukopenia and neutropenia associated with lithium carbonate discontinuation and an antipsychotic overdose. PMID:27776394

  12. Adenine nucleotide effect on intraocular pressure: Involvement of the parasympathetic nervous system.

    Science.gov (United States)

    Peral, Assumpta; Gallar, Juana; Pintor, Jesús

    2009-06-15

    Nucleotides are present in the aqueous humor possibly exerting physiological effects on intraocular pressure (IOP). To determine the effect of nucleotides such as ATP and its related derivatives on IOP, New Zealand white rabbits were used. IOP was measured in rabbits treated topically either with saline (control) or with a single dose (10 microg/microL) of adenine nucleotides (ATP, 2-meS-ATP, ATP-gamma-S, alpha,beta-meADP, alpha,beta-meATP and beta,gamma-meATP). Those nucleotides reducing IOP (alpha,beta-meATP and beta,gamma-meATP) were then tested in concentrations ranging from 1 to 100 microg/microL to obtain the IC(50) value. Several antagonists for the P2 and adenosine A1 receptors (all at 10 microg/microL) were assayed 30 min before the application of the hypotensive nucleotide beta,gamma-meATP. To see whether the nucleotide was acting directly on the structures involved in aqueous humor dynamics or on the autonomic nerves controlling IOP, animal denervation and sympathetic (yohimbine and ICI-118,551 at 10 microg/microL) and parasympathetic (atropine and hexametonium at 10 microg/microL) receptors' antagonists were used 30 min before the instillation of beta,gamma-meATP. alpha,beta-meATP and beta,gamma-meATP decreased IOP to 60% of control value (basal IOP=23.2+/-1.3 mmHg), with IC(50) of 1.59+/-0.21 microg/microLand 0.56+/-0.62 microg/microL, which corresponds to 3mM and 1mM respectively. Denervation completely abolished the effect of beta,gamma-meATP. Sympathetic antagonists did not modify the hypotensive effect of beta,gamma-meATP, but parasympathetic antagonists were able to abolish it. Among the series of adenine nucleotide tested, alpha,beta-meATP and beta,gamma-meATP presented hypotensive actions on IOP. beta,gamma-meATP seems to stimulate cholinergic terminals being its final effect the IOP reduction. Therefore, these two nucleotides are interesting pharmacological tools for those pathologies related with high intraocular pressure.

  13. Detection of Guanine and Adenine Using an Aminated Reduced Graphene Oxide Functional Membrane-Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Di Li

    2017-07-01

    Full Text Available A new electrochemical sensor based on a Nafion, aminated reduced graphene oxide and chitosan functional membrane-modified glassy carbon electrode was proposed for the simultaneous detection of adenine and guanine. Fourier transform-infrared spectrometry (FTIR, transmission electron microscopy (TEM, and electrochemical methods were utilized for the additional characterization of the membrane materials. The prepared electrode was utilized for the detection of guanine (G and adenine (A. The anodic peak currents to G and A were linear in the concentrations ranging from 0.1 to 120 μM and 0.2 to 110 μM, respectively. The detection limits were found to be 0.1 μM and 0.2 μM, respectively. Moreover, the modified electrode could also be used to determine G and A in calf thymus DNA.

  14. Electrochemical study in both classical cell and microreactors of flavin adenine dinucleotide as a redox mediator for NADH regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Tzedakis, Theodore, E-mail: tzedakis@chimie.ups-tlse.f [Laboratoire de Genie Chimique, UMR 5503, Universite Paul Sabatier, 31062 Toulouse cedex 04 (France); Cheikhou, Kane [Ecole Superieure Polytechnique de Dakar BP: 16263 Dakar-Fann (Senegal); Jerome, Roche; Karine, Groenen Serrano; Olivier, Reynes [Laboratoire de Genie Chimique, UMR 5503, Universite Paul Sabatier, 31062 Toulouse cedex 04 (France)

    2010-02-28

    The electrochemical reduction of flavin adenine dinucleotide (FAD) is studied in a classical electrochemical cell as well as in two types of microreactors: the first one is a one-channel reactor and the other one, a multichannel filter-press reactor. The ultimate goal is to use the reduced form of flavin (FADH{sub 2}), in the presence of formate dehydrogenase (FDH), in order to continuously regenerate the reduced form of nicotinamide adenine dinucleotide (NADH) for chiral syntheses. Various voltammetric and adsorption measurements were carried out for a better understanding of the redox behavior of the FAD as well as its adsorption on gold. Diffusivity and kinetic electrochemical parameters of FAD were determined.

  15. Synthesis of adenine, guanine, cytosine, and other nitrogen organic compounds by a Fischer-Tropsch-like process.

    Science.gov (United States)

    Yang, C. C.; Oro, J.

    1971-01-01

    Study of the formation of purines, pyrimidines, and other bases from CO, H2, and NH3 under conditions similar to those used in the Fischer-Tropsch process. It is found that industrial nickel/iron alloy catalyzes the synthesis of adenine, guanine, cytosine, and other nitrogenous compounds from mixtures of CO, H2, and NH3 at temperatures of about 600 C. Sufficient sample was accumulated to isolate as solid products adenine, guanine, and cytosine, which were identified by infrared spectrophotometry. In the absence of nickel/iron catalyst, at 650 C, or in the presence of this catalyst, at 450 C, no purines or pyrimidines were synthesized. These results confirm and extend some of the work reported by Kayatsu et al. (1968).

  16. The contribution of adenines in the catalytic core of 10-23 DNAzyme improved by the 6-amino group modifications.

    Science.gov (United States)

    Zhu, Junfei; Li, Zhiwen; Wang, Qi; Liu, Yang; He, Junlin

    2016-09-15

    In the catalytic core of 10-23 DNAzyme, its five adenine residues are moderate conservative, but with highly conserved functional groups like 6-amino group and 7-nitrogen atom. It is this critical conservation that these two groups could be modified for better contribution. With 2'-deoxyadenosine analogues, several functional groups were introduced at the 6-amino group of the five adenine residues. 3-Aminopropyl substituent at 6-amino group of A15 resulted in a five-fold increase of kobs. More efficient DNAzymes are expected by delicate design of the linkage and the external functional groups for this 6-amino group of A15. With this modification approach, other functional groups or residues could be optimized for 10-23 DNAzyme.

  17. Temperate Myxococcus xanthus phage Mx8 encodes a DNA adenine methylase, Mox.

    Science.gov (United States)

    Magrini, V; Salmi, D; Thomas, D; Herbert, S K; Hartzell, P L; Youderian, P

    1997-07-01

    Temperate bacteriophage Mx8 of Myxococcus xanthus encapsidates terminally repetitious DNA, packaged as circular permutations of its 49-kbp genome. During both lytic and lysogenic development, Mx8 expresses a nonessential DNA methylase, Mox, which modifies adenine residues in occurrences of XhoI and PstI recognition sites, CTCGAG and CTGCAG, respectively, on both phage DNA and the host chromosome. The mox gene is necessary for methylase activity in vivo, because an amber mutation in the mox gene abolishes activity. The mox gene is the only phage gene required for methylase activity in vivo, because ectopic expression of mox as part of the M. xanthus mglBA operon results in partial methylation of the host chromosome. The predicted amino acid sequence of Mox is related most closely to that of the methylase involved in the cell cycle control of Caulobacter crescentus. We speculate that Mox acts to protect Mx8 phage DNA against restriction upon infection of a subset of natural M. xanthus hosts. One natural isolate of M. xanthus, the lysogenic source of related phage Mx81, produces a restriction endonuclease with the cleavage specificity of endonuclease BstBI.

  18. Alteration of the Intestinal Environment by Lubiprostone Is Associated with Amelioration of Adenine-Induced CKD.

    Science.gov (United States)

    Mishima, Eikan; Fukuda, Shinji; Shima, Hisato; Hirayama, Akiyoshi; Akiyama, Yasutoshi; Takeuchi, Yoichi; Fukuda, Noriko N; Suzuki, Takehiro; Suzuki, Chitose; Yuri, Akinori; Kikuchi, Koichi; Tomioka, Yoshihisa; Ito, Sadayoshi; Soga, Tomoyoshi; Abe, Takaaki

    2015-08-01

    The accumulation of uremic toxins is involved in the progression of CKD. Various uremic toxins are derived from gut microbiota, and an imbalance of gut microbiota or dysbiosis is related to renal failure. However, the pathophysiologic mechanisms underlying the relationship between the gut microbiota and renal failure are still obscure. Using an adenine-induced renal failure mouse model, we evaluated the effects of the ClC-2 chloride channel activator lubiprostone (commonly used for the treatment of constipation) on CKD. Oral administration of lubiprostone (500 µg/kg per day) changed the fecal and intestinal properties in mice with renal failure. Additionally, lubiprostone treatment reduced the elevated BUN and protected against tubulointerstitial damage, renal fibrosis, and inflammation. Gut microbiome analysis of 16S rRNA genes in the renal failure mice showed that lubiprostone treatment altered their microbial composition, especially the recovery of the levels of the Lactobacillaceae family and Prevotella genus, which were significantly reduced in the renal failure mice. Furthermore, capillary electrophoresis-mass spectrometry-based metabolome analysis showed that lubiprostone treatment decreased the plasma level of uremic toxins, such as indoxyl sulfate and hippurate, which are derived from gut microbiota, and a more recently discovered uremic toxin, trans-aconitate. These results suggest that lubiprostone ameliorates the progression of CKD and the accumulation of uremic toxins by improving the gut microbiota and intestinal environment.

  19. The experimental and theoretical gas phase acidities of adenine, guanine, cytosine, uracil, thymine and halouracils

    Science.gov (United States)

    Chen, Edward C. M.; Herder, Charles; Chen, Edward S.

    2006-10-01

    The gas phase acidities GPA (Δ H (298) for deprotonation) of the most stable tautomers of adenine, guanine, cytosine, uracil and thymine are evaluated. New GPA are obtained from electron impact spectra and acid dissociation constants measured in dimethylsulfoxide for A, U and 5-FU. The average experimental GPA are: [N1 sbnd H] C 340(2); T 333(2); U 333(2); 5-FU 329(4); [N9 sbnd H] A 333(1); G 332(4); all in kcal/mol. Only cytosine is a weaker acid than HCl in the gas phase. The most acidic hydrogens in the nucleotides are replaced by the sugar in DNA and RNA. The experimental N3 sbnd H GPA are G 334(4); U 347(2), T 347(4), while the predicted N3 sbnd H 5-FU GPA is 343 kcal/mol. The NH sbnd H GPA are: C 346(4); A 352(2); G 336(4) (all in kcal/mol). These are supported by semi-empirical multiconfiguration configuration interaction calculations. The predicted C8 sbnd H acidities of G and A and the C6 sbnd H of T are about the same, 360(2) kcal/mol. The remaining CH acidities are 370-380 kcal/mol. The 5-halouracils are predicted to be more acidic than HCl.

  20. Laser pulse trains for controlling excited state dynamics of adenine in water.

    Science.gov (United States)

    Petersen, Jens; Wohlgemuth, Matthias; Sellner, Bernhard; Bonačić-Koutecký, Vlasta; Lischka, Hans; Mitrić, Roland

    2012-04-14

    We investigate theoretically the control of the ultrafast excited state dynamics of adenine in water by laser pulse trains, with the aim to extend the excited state lifetime and to suppress nonradiative relaxation processes. For this purpose, we introduce the combination of our field-induced surface hopping method (FISH) with the quantum mechanical-molecular mechanical (QM/MM) technique for simulating the laser-driven dynamics in the condensed phase under explicit inclusion of the solvent environment. Moreover, we employ parametric pulse shaping in the frequency domain in order to design simplified laser pulse trains allowing to establish a direct link between the pulse parameters and the controlled dynamics. We construct pulse trains which achieve a high excitation efficiency and at the same time keep a high excited state population for a significantly extended time period compared to the uncontrolled dynamics. The control mechanism involves a sequential cycling of the population between the lowest and higher excited states, thereby utilizing the properties of the corresponding potential energy surfaces to avoid conical intersections and thus to suppress the nonradiative decay to the ground state. Our findings provide a means to increase the fluorescence yield of molecules with an intrinsically very short excited state lifetime, which can lead to novel applications of shaped laser fields in the context of biosensing.

  1. Decrease in nicotinamide adenine dinucleotide dehydrogenase is related to skin pigmentation.

    Science.gov (United States)

    Nakama, Mitsuo; Murakami, Yuhko; Tanaka, Hiroshi; Nakata, Satoru

    2012-03-01

    Skin pigmentation is caused by various physical and chemical factors. It might also be influenced by changes in the physiological function of skin with aging. Nicotinamide adenine dinucleotide (NADH) dehydrogenase is an enzyme related to the mitochondrial electron transport system and plays a key role in cellular energy production. It has been reported that the functional decrease in this system causes Parkinson's disease. Another study reports that the amount of NADH dehydrogenase in heart and skeletal muscle decreases with aging. A similar decrease in the skin would probably affect its physiological function. However, no reports have examined the age-related change in levels of NADH dehydrogenase in human skin. In this study, we investigated this change and its effect on skin pigmentation using cultured human epidermal keratinocytes. The mRNA expression of NDUFA1, NDUFB7, and NDUFS2, subunits of NADH dehydrogenase, and its activity were significantly decreased in late passage keratinocytes compared to early passage cells. Conversely, the mRNA expression of melanocyte-stimulating cytokines, interleukin-1 alpha and endothelin 1, was increased in late passage cells. On the other hand, the inhibition of NADH dehydrogenase upregulated the mRNA expression of melanocyte-stimulating cytokines. Moreover, the level of NDUFB7 mRNA was lower in pigmented than in nonpigmented regions of skin in vivo. These results suggest the decrease in NADH dehydrogenase with aging to be involved in skin pigmentation.

  2. Human Adenine Nucleotide Translocase (ANT) Modulators Identified by High-Throughput Screening of Transgenic Yeast.

    Science.gov (United States)

    Zhang, Yujian; Tian, Defeng; Matsuyama, Hironori; Hamazaki, Takashi; Shiratsuchi, Takayuki; Terada, Naohiro; Hook, Derek J; Walters, Michael A; Georg, Gunda I; Hawkinson, Jon E

    2016-04-01

    Transport of ADP and ATP across mitochondria is one of the primary points of regulation to maintain cellular energy homeostasis. This process is mainly mediated by adenine nucleotide translocase (ANT) located on the mitochondrial inner membrane. There are four human ANT isoforms, each having a unique tissue-specific expression pattern and biological function, highlighting their potential as drug targets for diverse clinical indications, including male contraception and cancer. In this study, we present a novel yeast-based high-throughput screening (HTS) strategy to identify compounds inhibiting the function of ANT. Yeast strains generated by deletion of endogenous proteins with ANT activity followed by insertion of individual human ANT isoforms are sensitive to cell-permeable ANT inhibitors, which reduce proliferation. Screening hits identified in the yeast proliferation assay were characterized in ADP/ATP exchange assays employing recombinant ANT isoforms expressed in isolated yeast mitochondria and Lactococcus lactis as well as by oxygen consumption rate in mammalian cells. Using this approach, closantel and CD437 were identified as broad-spectrum ANT inhibitors, whereas leelamine was found to be a modulator of ANT function. This yeast "knock-out/knock-in" screening strategy is applicable to a broad range of essential molecular targets that are required for yeast survival. © 2016 Society for Laboratory Automation and Screening.

  3. Nicotinamide adenine dinucleotide: An essential factor in preserving hearing in cisplatin-induced ototoxicity.

    Science.gov (United States)

    Kim, Hyung-Jin; Oh, Gi-Su; Shen, AiHua; Lee, Su-Bin; Khadka, Dipendra; Pandit, Arpana; Shim, Hyeok; Yang, Sei-Hoon; Cho, Eun-Young; Song, Jeho; Kwak, Tae Hwan; Choe, Seong-Kyu; Park, Raekil; So, Hong-Seob

    2015-08-01

    Ototoxicity is an important issue in patients receiving cisplatin chemotherapy. Numerous studies have demonstrated that several mechanisms, including oxidative stress, DNA damage, and inflammatory responses, are closely associated with cisplatin-induced ototoxicity. Although much attention has been directed at identifying ways to protect the inner ear from cisplatin-induced damage, the precise underlying mechanisms have not yet been elucidated. The cofactor nicotinamide adenine dinucleotide (NAD(+)) has emerged as an important regulator of cellular energy metabolism and homeostasis. NAD(+) acts as a cofactor for various enzymes including sirtuins (SIRTs) and poly(ADP-ribose) polymerases (PARPs), and therefore, maintaining adequate NAD(+) levels has therapeutic benefits because of its effect on NAD(+)-dependent enzymes. Recent studies demonstrated that disturbance in intracellular NAD(+) levels is critically involved in cisplatin-induced cochlear damage associated with oxidative stress, DNA damage, and inflammatory responses. In this review, we describe the importance of NAD(+) in cisplatin-induced ototoxicity and discuss potential strategies for the prevention or treatment of cisplatin-induced ototoxicity with a particular focus on NAD(+)-dependent cellular pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Studies of yeast cell oxygenation and energetics by laser fluorometry of reduced nicotinamide adenine dinucleotide

    Science.gov (United States)

    Pan, Fu-shih; Chen, Stephen; Mintzer, Robert A.; Chen, Chin-Tu; Schumacker, Paul

    1991-03-01

    It is of fundamental importance for biological scientists to assess cellular energetics. Under aerobic conditions, the tricarboxylic acid cycle (TCA cycle) is coupled with the mitochondrial electron cascade pathway to provide the cell with energy. The nicotinamide adenine dinucleotide-conjugated pair (NAD and NADH) is the coenzyme in numerous important biomedical reactions which include several important dehydrogenase reactions in the TCA cycle. Based on Le Chatelier's principle, NADH will accumulate when this energy production mechanism is impaired. The relative amounts of NAD and NADH in a cell are defined as the redox state of the cell (Williamson et.al. 1967) which provides a valuable index of cellular energetics. The sum of the amounts of NAD and NADH in a cell may be assumed to be constant during a finite time; therefore, a reliable means of measuring the NADH concentration would provide us with a useful indicator of tissue viability. Traditionally, the quantities of NADH and NAD may be measured by chemical assay methods. We can avoid these tediois analyses by exploiting the significant difference between the ultraviolet absorption spectra of this redox pair. However, because of the opacity of biological samples and the interference of other biochemicals that also absorb ultraviolet radiation, measurement of NADH and NAD+ concentrations in vivo by absorption spectroscopy is not feasible.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  7. Stimulation of nicotinamide adenine dinucleotide biosynthetic pathways delays axonal degeneration after axotomy.

    Science.gov (United States)

    Sasaki, Yo; Araki, Toshiyuki; Milbrandt, Jeffrey

    2006-08-16

    Axonal degeneration occurs in many neurodegenerative diseases and after traumatic injury and is a self-destructive program independent from programmed cell death. Previous studies demonstrated that overexpression of nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1) or exogenous application of nicotinamide adenine dinucleotide (NAD) can protect axons of cultured dorsal root ganglion (DRG) neurons from degeneration caused by mechanical or neurotoxic injury. In mammalian cells, NAD can be synthesized from multiple precursors, including tryptophan, nicotinic acid, nicotinamide, and nicotinamide riboside (NmR), via multiple enzymatic steps. To determine whether other components of these NAD biosynthetic pathways are capable of delaying axonal degeneration, we overexpressed each of the enzymes involved in each pathway and/or exogenously administered their respective substrates in DRG cultures and assessed their capacity to protect axons after axotomy. Among the enzymes tested, Nmnat1 had the strongest protective effects, whereas nicotinamide phosphoribosyl transferase and nicotinic acid phosphoribosyl transferase showed moderate protective activity in the presence of their substrates. Strong axonal protection was also provided by Nmnat3, which is predominantly located in mitochondria, and an Nmnat1 mutant localized to the cytoplasm, indicating that the subcellular location of NAD production is not crucial for protective activity. In addition, we showed that exogenous application of the NAD precursors that are the substrates of these enzymes, including nicotinic acid mononucleotide, nicotinamide mononucleotide, and NmR, can also delay axonal degeneration. These results indicate that stimulation of NAD biosynthetic pathways via a variety of interventions may be useful in preventing or delaying axonal degeneration.

  8. Eco-synthesis of graphene and its use in dihydronicotinamide adenine dinucleotide sensing.

    Science.gov (United States)

    Amouzadeh Tabrizi, Mahmoud; Jalilzadeh Azar, Somayeh; Nadali Varkani, Javad

    2014-09-01

    In this paper, we report a green and eco-friendly approach to synthesize reduced graphene oxide (rGO) via a mild hydrothermal process using malt as a reduced agent. The proposed method is based on the reduction of graphene oxide (GO) in malt solution by making use of the reducing capability of phenolic compounds contained in malt solution. The obtained rGO was characterized by atomic force microscopy (AFM), ultraviolet-visible (UV-vis) absorption spectroscopy, X-ray diffraction spectroscopy (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Electrochemical impedance spectroscopy analysis revealed that the charge transfer resistance of rGO modified glassy carbon (GC) electrode was much lower than that of the GC electrode. The electrochemical behavior of dihydronicotinamide adenine dinucleotide (NADH) on rGO modified GC electrode was investigated by cyclic voltammetry and amperometry. Electrochemical experiments indicated that rGO/GC electrode exhibited excellent electrocatalytic activity toward the NADH, which can be attributed to excellent electrical conductivity and high specific surface area of the rGO composite. The resulting biosensor showed highly sensitive amperometric response to NADH with a low detection limit (0.33μM). Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Cross sections for low-energy electron scattering from adenine in the condensed phase.

    Science.gov (United States)

    Panajotović, Radmila; Michaud, Marc; Sanche, Léon

    2007-01-07

    Measurements of the vibrational and electronic excitation of a sub-monolayer up to a monolayer film of adenine were performed with a high resolution electron energy-loss (HREEL) spectrometer. The integral cross sections (over the half-space angle) for excitation of the normal vibrational modes of the ground electronic state and electronically excited states are calculated from the measured reflectivity EEL spectra. Most cross sections for vibrational excitation are of the order of 10(-17) cm(2), the largest being the out-of-plane wagging of the amino-group and the six-member ring deformations. A wide resonance feature appears in the incident energy dependence of the vibrational cross sections at 3-5 eV, while a weak shoulder is present in this dependence for combined ring deformations and bending of hydrogen atoms. For the five excited electronic states, at 4.7, 5.0, 5.5, 6.1 and 6.6 eV, the cross sections are of the order of 10(-18) cm(2), except in the case of the state at the energy of 6.1 eV, for which it is two to three times higher.

  10. Interaction of flavin adenine dinucleotide (FAD) with a glassy carbon electrode surface.

    Science.gov (United States)

    Wei, Haizhen; Omanovic, Sasha

    2008-08-01

    The interaction of flavin adenine dinucleotide (FAD) with a glassy carbon electrode (GCE) surface was investigated in terms of the FAD adsorption thermodynamics and kinetics, the subsequent electroreduction mechanism, and the corresponding electron-transfer rate. The kinetics of FAD electroreduction at the GCE was found to be an adsorption-controlled process. A set of electroreduction kinetic parameters was calculated: the true number of electrons involved in the FAD reduction, n=1.76, the apparent transfer coefficient, alpha(app)=0.41, and the apparent heterogeneous electron-transfer rate constant, k(app)=1.4 s(-1). The deviation of the number of exchanged electrons from the theoretical value for the complete reduction of FAD to FADH(2) (n=2) indicates that a small portion of FAD goes to a semiquinone state during the redox process. The FAD adsorption was well described by the Langmuir adsorption isotherm. The large negative apparent Gibbs energy of adsorption (DeltaG(ads)=-39.7 +/-0.4 kJ mol(-1)) indicated a highly spontaneous and strong adsorption of FAD on the GCE. The energetics of the adsorption process was found to be independent of the electrode surface charge in the electrochemical double-layer region. The kinetics of FAD adsorption was modeled using a pseudo-first-order kinetic model.

  11. Thermal stabilization of formaldehyde dehydrogenase by encapsulation in liposomes with nicotinamide adenine dinucleotide.

    Science.gov (United States)

    Yoshimoto, Makoto; Yamashita, Takayuki; Kinoshita, Satoshi

    2011-07-10

    The thermal stability of formaldehyde dehydrogenase (FaDH) from Pseudomonas sp. was examined and controlled by encapsulation in liposomes with β-reduced nicotinamide adenine dinucleotide (NADH). The activity of 4.8 μg/mL free FaDH at pH 8.5 in catalyzing the oxidation of 50mM formaldehyde was highly dependent on temperature so that the activity at 60 °C was 27 times larger than that at 25 °C. Thermal stability of the FaDH activity was examined with and without liposomes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Rapid deactivation of free FaDH was observed at 60 °C because of its dissociation into two subunits. The rate of dissociative deactivation of POPC liposome-encapsulated FaDH was smaller than that of the free enzyme. The liposomal FaDH was however progressively deactivated for the incubation period of 60 min eventually leading to complete loss of its activity. The free FaDH and NADH molecules were revealed to form the thermostable binary complex. The thermal stability of POPC liposome-encapsulated FaDH and NADH system was significantly higher than the liposomal enzyme without cofactor. The above results clearly show that NADH is a key molecule that controls the activity and stability of FaDH in liposomes at high temperatures.

  12. Cellular localization of adenine receptors in the rat kidney and their functional significance in the inner medullary collecting duct.

    Science.gov (United States)

    Kishore, Bellamkonda K; Zhang, Yue; Gevorgyan, Haykanush; Kohan, Donald E; Schiedel, Anke C; Müller, Christa E; Peti-Peterdi, János

    2013-11-01

    The Gi-coupled adenine receptor (AdeR) binds adenine with high affinity and potentially reduces cellular cAMP levels. Since cAMP is an important second messenger in the renal transport of water and solutes, we localized AdeR in the rat kidney. Real-time RT-PCR showed higher relative expression of AdeR mRNA in the cortex and outer medulla compared with the inner medulla. Immunoblots using a peptide-derived and affinity-purified rabbit polyclonal antibody specific for an 18-amino acid COOH-terminal sequence of rat AdeR, which we generated, detected two bands between ∼30 and 40 kDa (molecular mass of native protein: 37 kDa) in the cortex, outer medulla, and inner medulla. These bands were ablated by preadsorption of the antibody with the immunizing peptide. Immunofluorescence labeling showed expression of AdeR protein in all regions of the kidney. Immunoperoxidase revealed strong labeling of AdeR protein in the cortical vasculature, including the glomerular arterioles, and less intense labeling in the cells of the collecting duct system. Confocal immunofluorescence imaging colocalized AdeR with aquaporin-2 protein to the apical plasma membrane in the collecting duct. Functionally, adenine (10 μM) significantly decreased (P < 0.01) 1-deamino-8-d-arginine vasopressin (10 nM)-induced cAMP production in ex vivo preparations of inner medullary collecting ducts, which was reversed by PSB-08162 (20 μM, P < 0.01), a selective antagonist of AdeR. Thus, we demonstrated the expression of AdeR in the renal vasculature and collecting ducts and its functional relevance. This study may open a new avenue for the exploration of autocrine/paracrine regulation of renal vascular and tubular functions by the nucleobase adenine in health and disease.

  13. Modulation of F0F1-ATP synthase activity by cyclophilin D regulates matrix adenine nucleotide levels.

    Science.gov (United States)

    Chinopoulos, Christos; Konràd, Csaba; Kiss, Gergely; Metelkin, Eugeniy; Töröcsik, Beata; Zhang, Steven F; Starkov, Anatoly A

    2011-04-01

    Cyclophilin D was recently shown to bind to and decrease the activity of F(0)F(1)-ATP synthase in submitochondrial particles and permeabilized mitochondria [Giorgio V et al. (2009) J Biol Chem, 284, 33982-33988]. Cyclophilin D binding decreased both ATP synthesis and hydrolysis rates. In the present study, we reaffirm these findings by demonstrating that, in intact mouse liver mitochondria energized by ATP, the absence of cyclophilin D or the presence of cyclosporin A led to a decrease in the extent of uncoupler-induced depolarization. Accordingly, in substrate-energized mitochondria, an increase in F(0)F(1)-ATP synthase activity mediated by a relief of inhibition by cyclophilin D was evident in the form of slightly increased respiration rates during arsenolysis. However, the modulation of F(0)F(1)-ATP synthase by cyclophilin D did not increase the adenine nucleotide translocase (ANT)-mediated ATP efflux rate in energized mitochondria or the ATP influx rate in de-energized mitochondria. The lack of an effect of cyclophilin D on the ANT-mediated adenine nucleotide exchange rate was attributed to the ∼ 2.2-fold lower flux control coefficient of the F(0)F(1)-ATP synthase than that of ANT, as deduced from measurements of adenine nucleotide flux rates in intact mitochondria. These findings were further supported by a recent kinetic model of the mitochondrial phosphorylation system, suggesting that an ∼ 30% change in F(0)F(1)-ATP synthase activity in fully energized or fully de-energized mitochondria affects the ADP-ATP exchange rate mediated by the ANT in the range 1.38-1.7%. We conclude that, in mitochondria exhibiting intact inner membranes, the absence of cyclophilin D or the inhibition of its binding to F(0)F(1)-ATP synthase by cyclosporin A will affect only matrix adenine nucleotides levels. © 2011 The Authors Journal compilation © 2011 FEBS.

  14. Ischemic preconditioning protects post-ischemic renal function in anesthetized dogs: role of adenosine and adenine nucleotides

    Institute of Scientific and Technical Information of China (English)

    Fan-zhu LI; Shoji KIMURA; Akira NISHIYAMA; Matlubur RAHMAN; Guo-xing ZHANG; Youichi ABE

    2005-01-01

    Aim: To investigate the effects of renal ischemic preconditioning (IPC) on both renal hemodynamics and the renal interstitial concentrations of adenosine and adenine nucleotides induced by ischemia-reperfusion injury.Methods: Renal hemodynamics responses to ischemia-reperfusion injury in mongrel dog models were determined with or without multiple brief renal ischemic preconditioning treatments, as well as the adenosine A1 receptor antagonist (KW-3902),respectively.The renal interstitial concentrations of adenosine and adenine nucleotides in response to ischemia-reperfusion injury, either following 1-3 cycles of IPC or not, were measured simultaneously using microdialysis sampling technology.Results: One 10-min IPC, adenosine A1 receptor antagonist (KW3902) also shortened the recovery time of renal blood flow (RBF) and urine flow (UF), as well as mean blood pressure (BP).Advanced renal IPC attenuated the increment of adenosine and adenine nucleotides, as well as recovery time during the 60-min reperfusion which followed the 60-min renal ischemia.All of these recovery times were dependent on the cycles of 10-min IPC.The renal interstitial concentrations of adenosine and adenine nucleotides increased and decreased during renal ischemia and reperfusion, respectively.Conclusion: A significant relativity in dog models exists between the cycles of 10-min renal IPC and the recovery time of BP, UF, and RBF during the 60-min renal reperfusion following 60-min renal ischemia, respectively.Renal IPC can protect against ischemiareperfusion injury and the predominant effect of endogenous adenosine induced by prolonged renal ischemia; renal adenosine A1 receptor activation during the renal ischemia-reperfusion injury is detrimental to renal function.

  15. IR Vibrational spectra of H-bonded complexes of adenine, 2-aminopurine and 2-aminopurine+ with cytosine and thymine: Quantum-chemical study

    Science.gov (United States)

    Brovarets', O. O.; Hovorun, D. M.

    2011-11-01

    Using theoretical study on the B3LYP/6-311++G(d,p) level of theory, we have compared vibrational spectra of 2-aminopurine (as neutral or protonated at N1 atom species) with adenine and H-bonded complexes of 2-aminopurine (as neutral or protoned at N1 atom species) · cytosine or 2-aminopurine · thymine with adenine · cytosine and adenine · thymine base pairs. The nature of the base pairing between adenine, 2-aminopurine, 2-aminopurine+ and cytosine or thymine have been investigated by means of quantum-mechanical calculations. We have investigated the effect of the hydrogen bond formation on the vibrational spectra of the investigated base pairs. The main differences in the vibrational spectra as for bases so for base pairs have been observed in the high-frequency region.

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

    Science.gov (United States)

    Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth; Nguy, Lisa; Mikkelsen, Minne Line Nedergaard; Marcussen, Niels; Guron, Gregor

    2014-03-15

    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 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 arterial pressure variability (SAPV), and heart rate variability were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in glomerular filtration rate and renal blood flow (RBF), whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous BRS was reduced by ∼50% in ACRF animals. High-NaCl diet significantly increased transfer function fractional gain values between arterial pressure and RBF in the frequency range of the myogenic response (0.06-0.09 Hz) only in ACRF animals (0.3 ± 4.0 vs. -4.4 ± 3.8 dB; P renal failure by facilitating pressure transmission to the microvasculature.

  17. Electrochemical biosensor based on silver nanoparticles-polydopamine-graphene nanocomposite for sensitive determination of adenine and guanine.

    Science.gov (United States)

    Huang, Ke-Jing; Wang, Lan; Wang, Hai-Bo; Gan, Tian; Wu, Ying-Ying; Li, Jing; Liu, Yan-Ming

    2013-09-30

    A multifunctional Ag nanoparticles (AgNPs)-polydopamine (Pdop)@graphene (Gr) composite was prepared by a simple and mild procedure. Gr was easily coated with Pdop at room temperature and then AgNPs was deposited by mildly stirring. The nanocomposite was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Guanine and adenine as model moleculars were employed to study their electrochemical responses at the Ag-Pdop@Gr composite modified electrode, which showed more favorable electron transfer kinetics than Gr modified glassy carbon and AgNPs modified glassy carbon electrodes. The Ag-Pdop@Gr modified electrode exhibited linear ranges of 0.04-50 μM and 0.02-40 μM with detection limits of 4.0 nM and 2.0 nM for guanine and adenine, respectively. The developed method was applied for simultaneous determination of trace-level adenine and guanine in fish sperm. The results demonstrated that the AgNPs-Pdop@Gr nanocomposite was a promising substrate for the development of high-performance electrocatalysts for biosensing. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. 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.

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Regenerative Neurogenesis After Ischemic Stroke Promoted by Nicotinamide Phosphoribosyltransferase-Nicotinamide Adenine Dinucleotide Cascade.

    Science.gov (United States)

    Zhao, Yan; Guan, Yun-Feng; Zhou, Xiao-Ming; Li, Guo-Qiang; Li, Zhi-Yong; Zhou, Can-Can; Wang, Pei; Miao, Chao-Yu

    2015-07-01

    Nicotinamide adenine dinucleotide (NAD) is a ubiquitous fundamental metabolite. Nicotinamide phosphoribosyltransferase (Nampt) is the rate-limiting enzyme for mammalian NAD salvage synthesis and has been shown to protect against acute ischemic stroke. In this study, we investigated the role of Nampt-NAD cascade in brain regeneration after ischemic stroke. Nampt transgenic (Nampt-Tg) mice and H247A mutant enzymatic-dead Nampt transgenic (ΔNampt-Tg) mice were subjected with experimental cerebral ischemia by middle cerebral artery occlusion. Activation of neural stem cells, neurogenesis, and neurological function recovery were measured. Besides, nicotinamide mononucleotide and NAD, two chemical enzymatic product of Nampt, were administrated in vivo and in vitro. Compared with wild-type mice, Nampt-Tg mice showed enhanced number of neural stem cells, improved neural functional recovery, increased survival rate, and accelerated body weight gain after middle cerebral artery occlusion, which were not observed in ΔNampt-Tg mice. A delayed nicotinamide mononucleotide administration for 7 days with the first dose at 12 hours post middle cerebral artery occlusion did not protect acute brain infarction and neuronal deficit; however, it still improved postischemic regenerative neurogenesis. Nicotinamide mononucleotide and NAD(+) promoted proliferation and differentiation of neural stem cells in vitro. Knockdown of NAD-dependent deacetylase sirtuin 1 (SIRT1) and SIRT2 inhibited the progrowth action of Nampt-NAD axis, whereas knockdown of SIRT1, SIRT2, and SIRT6 compromised the prodifferentiation effect of Nampt-NAD axis. Our data demonstrate that the Nampt-NAD cascade may act as a centralizing switch in postischemic regeneration through controlling different sirtuins and therefore represent a promising therapeutic target for long-term recovery of ischemic stroke. © 2015 American Heart Association, Inc.

  1. Loop-loop interaction in an adenine-sensing riboswitch: a molecular dynamics study.

    Science.gov (United States)

    Allnér, Olof; Nilsson, Lennart; Villa, Alessandra

    2013-07-01

    Riboswitches are mRNA-based molecules capable of controlling the expression of genes. They undergo conformational changes upon ligand binding, and as a result, they inhibit or promote the expression of the associated gene. The close connection between structural rearrangement and function makes a detailed knowledge of the molecular interactions an important step to understand the riboswitch mechanism and efficiency. We have performed all-atom molecular dynamics simulations of the adenine-sensing add A-riboswitch to study the breaking of the kissing loop, one key tertiary element in the aptamer structure. We investigated the aptamer domain of the add A-riboswitch in complex with its cognate ligand and in the absence of the ligand. The opening of the hairpins was simulated using umbrella sampling using the distance between two loops as the reaction coordinate. A two-step process was observed in all the simulated systems. First, a general loss of stacking and hydrogen bond interactions is seen. The last interactions that break are the two base pairs G37-C61 and G38-C60, but the break does not affect the energy profile, indicating their pivotal role in the tertiary structure formation but not in the structure stabilization. The junction area is partially organized before the kissing loop formation and residue A24 anchors together the loop helices. Moreover, when the distance between the loops is increased, one of the hairpins showed more flexibility by changing its orientation in the structure, while the other conserved its coaxial arrangement with the rest of the structure.

  2. Adenine Nucleotide Translocase 4 Is Expressed Within Embryonic Ovaries and Dispensable During Oogenesis

    Science.gov (United States)

    Lim, Chae Ho; Brower, Jeffrey V.; Resnick, James L.; Oh, S. Paul

    2015-01-01

    Adenine nucleotide translocase (Ant) facilitates the exchange of adenosine triphosphate across the mitochondrial inner membrane and plays a critical role for bioenergetics in eukaryotes. Mice have 3 Ant paralogs, Ant1 (Slc25a4), Ant2 (Slc25a5), and Ant4 (Slc25a31), which are expressed in a tissue-dependent manner. We previously identified that Ant4 was expressed exclusively in testicular germ cells in adult mice and essential for spermatogenesis and subsequently male fertility. Further investigation into the process of spermatogenesis revealed that Ant4 was particularly highly expressed during meiotic prophase I and indispensable for normal progression of leptotene spermatocytes to the stages thereafter. In contrast, the expression and roles of Ant4 in female germ cells have not previously been elucidated. Here, we demonstrate that the Ant4 gene is expressed during embryonic ovarian development during which meiotic prophase I occurs. We confirmed embryonic ovary-specific Ant4 expression using a bacterial artificial chromosome transgene. In contrast to male, however, Ant4 null female mice were fertile although the litter size was slightly decreased. They showed apparently normal ovarian development which was morphologically indistinguishable from the control animals. These data indicate that Ant4 is a meiosis-specific gene expressed during both male and female gametogenesis however indispensable only during spermatogenesis and not oogenesis. The differential effects of Ant4 depletion within the processes of male and female gametogenesis may be explained by meiosis-specific inactivation of the X-linked Ant2 gene in male, a somatic paralog of the Ant4 gene. PMID:25031318

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

    Science.gov (United States)

    Sugahara, Ryohei; Jouraku, Akiya; Nakakura, Takayo; Kusakabe, Takahiro; Yamamoto, Takenori; Shinohara, Yasuo; Miyoshi, Hideto; Shiotsuki, Takahiro

    2015-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-01-01

    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 molecular dynamics with explicit solvent in combination with enhanced sampling techniques and advanced analysis methods it could be possible to provide a more detailed perspective on the formation of these tertiary contacts. In this work, we used umbrella sampling simulations to study the thermodynamics of the kissing loop complex in the presence and in the absence of the cognate ligand. We enforced the breaking/formation of the loop-loop interaction restraining the distance between the two loops. We also assessed the convergence of the results by using two alternative initialization protocols. A structural analysis was performed using a novel approach to analyze base contacts. Contacts between the two loops were progressively lost when larger inter-loop distances were enforced. Inter-loop Watson-Crick contacts survived at larger separation when compared with non-canonical pairing and stacking interactions. Intra-loop stacking contacts remained formed upon loop undocking. Our simulations qualitatively indicated that the ligand could stabilize the kissing loop complex. We also compared with previously published simulation studies. Kissing complex stabilization given by the ligand was compatible with available experimental data. However, the dependence of its value on the initialization protocol of the umbrella sampling simulations posed some questions on the quantitative interpretation of the results and called for better converged enhanced sampling simulations.

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

    Science.gov (United States)

    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.

  8. Adsorption of adenine and thymine on zeolites: FT-IR and EPR spectroscopy and X-ray diffractometry and SEM studies.

    Science.gov (United States)

    Baú, João Paulo T; Carneiro, Cristine E A; de Souza Junior, Ivan G; de Souza, Cláudio M D; da Costa, Antonio C S; di Mauro, Eduardo; Zaia, Cássia T B V; Coronas, Joaquin; Casado, Clara; de Santana, Henrique; Zaia, Dimas A M

    2012-02-01

    The interactions of adenine and thymine with and adsorption on zeolites were studied using different techniques. There were two main findings. First, as shown by X-ray diffractometry, thymine increased the decomposition of the zeolites (Y, ZSM-5) while adenine prevented it. Second, zeolite Y adsorbed almost the same amount of adenine and thymine, thus both nucleic acid bases could be protected from hydrolysis and UV radiation and could be available for molecular evolution. The X-ray diffractometry and SEM showed that artificial seawater almost dissolved zeolite A. The adsorption of adenine on ZSM-5 zeolite was higher than that of thymine (Student-Newman-Keuls test-SNK pzeolite, when compared to other zeolites (SNK pzeolites was not statistically different (SNK p>0.05). The adsorption of adenine and thymine on zeolites did not depend on pore size or Si/Al ratio and it was not explained only by electrostatic forces; rather van der Waals interactions should also be considered.

  9. Control of dinucleoside polyphosphates by the FHIT-homologous HNT2 gene, adenine biosynthesis and heat shock in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Bieganowski Pawel

    2002-05-01

    Full Text Available Abstract Background The FHIT gene is lost early in the development of many tumors. Fhit possesses intrinsic ApppA hydrolase activity though ApppA cleavage is not required for tumor suppression. Because a mutant form of Fhit that is functional in tumor suppression and defective in catalysis binds ApppA well, it was hypothesized that Fhit-substrate complexes are the active, signaling form of Fhit. Which substrates are most important for Fhit signaling remain unknown. Results Here we demonstrate that dinucleoside polyphosphate levels increase 500-fold to hundreds of micromolar in strains devoid of the Saccharomyces cerevisiae homolog of Fhit, Hnt2. Accumulation of dinucleoside polyphosphates is reversed by re-expression of Hnt2 and is active site-dependent. Dinucleoside polyphosphate levels depend on an intact adenine biosynthetic pathway and time in liquid culture, and are induced by heat shock to greater than 0.1 millimolar even in Hnt2+ cells. Conclusions The data indicate that Hnt2 hydrolyzes both ApppN and AppppN in vivo and that, in heat-shocked, adenine prototrophic yeast strains, dinucleoside polyphosphates accumulate to levels in which they may saturate Hnt2.

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

    Energy Technology Data Exchange (ETDEWEB)

    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}.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    Allison E James

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  14. A Nicotinamide Adenine Dinucleotide Dispersed Multi-walled Carbon Nanotubes Electrode for Direct and Selective Electrochemical Detection of Uric Acid.

    Science.gov (United States)

    Chen, Yan; Li, Yiwei; Ma, Yaohong; Meng, Qingjun; Yan, Yan; Shi, Jianguo

    2015-01-01

    A nanocomposite platform built with multi-walled carbon nanotubes (MWCNTs) and nicotinamide adenine dinucleotide (NAD(+)) via a noncovalent interaction between the large π systems in NAD(+) molecules and MWCNTs on a glassy carbon substrate was successfully developed for the sensitive and selective detection of uric acid (UA) in the presence of ascorbic acid (AA), dopamine (DA). NAD(+) has an adenine subunit and a nicotinamide subunit, which enabled interaction with the purine subunit of UA through a strong π-π interaction to enhance the specificity of UA. Compared with a bare glassy carbon electrode (GCE) and MWCNTs/GCE, the MWCNTs-NAD(+)/GCE showed a low background current and a remarkable enhancement of the oxidation peak current of UA. Using differential pulse voltammetry (DPV), a high sensitivity for the determination of UA was explored for the MWCNTs-NAD(+) modified electrode. A linear relationship between the DPV peak current of UA and its concentration could be obtained in the range of 0.05 - 10 μM with the detection limit as low as 10 nM (S/N = 3). This present strategy provides a novel and promising platform for the detection of UA in human urine and serum samples.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Simultaneous quantitation of nicotinamide riboside, nicotinamide mononucleotide and nicotinamide adenine dinucleotide in milk by a novel enzyme-coupled assay.

    Science.gov (United States)

    Ummarino, Simone; Mozzon, Massimo; Zamporlini, Federica; Amici, Adolfo; Mazzola, Francesca; Orsomando, Giuseppe; Ruggieri, Silverio; Raffaelli, Nadia

    2017-04-15

    Nicotinamide riboside, the most recently discovered form of vitamin B3, and its phosphorylated form nicotinamide mononucleotide, have been shown to be potent supplements boosting intracellular nicotinamide adenine dinucleotide (NAD) levels, thus preventing or ameliorating metabolic and mitochondrial diseases in mouse models. Here we report for the first time on the simultaneous quantitation of nicotinamide riboside, nicotinamide mononucleotide and NAD in milk by means of a fluorometric, enzyme-coupled assay. Application of this assay to milk from different species revealed that the three vitamers were present in human and donkey milk, while being selectively distributed in the other milks. Human milk was the richest source of nicotinamide mononucleotide. Overall, the three vitamers accounted for a significant fraction of total vitamin B3 content. Pasteurization did not affect the bovine milk content of nicotinamide riboside, whereas UHT processing fully destroyed the vitamin. In human milk, NAD levels were significantly affected by the lactation time.

  17. Isolation, synthesis, and biological activity of aphrocallistin, an adenine-substituted bromotyramine metabolite from the Hexactinellida sponge Aphrocallistes beatrix.

    Science.gov (United States)

    Wright, Amy E; Roth, Gregory P; Hoffman, Jennifer K; Divlianska, Daniela B; Pechter, Diana; Sennett, Susan H; Guzmán, Esther A; Linley, Patricia; McCarthy, Peter J; Pitts, Tara P; Pomponi, Shirley A; Reed, John K

    2009-06-01

    A new adenine-substituted bromotyrosine-derived metabolite designated as aphrocallistin (1) has been isolated from the deep-water Hexactinellida sponge Aphrocallistes beatrix. Its structure was elucidated on the basis of spectral data and confirmed through a convergent, modular total synthetic route that is amenable toward future analogue preparation. Aphrocallistin inhibits the growth of a panel of human tumor cell lines with IC(50) values ranging from 7.5 to >100 microM and has been shown to induce G1 cell cycle arrest in the PANC-1 pancreatic carcinoma cell line. Aphrocallistin has been fully characterized in the NCI cancer cell line panel and has undergone in vitro ADME pharmacological profiling.

  18. ISOLATION, SYNTHESIS AND BIOLOGICAL ACTIVITY OF APHROCALLISTIN, AN ADENINE SUBSTITUTED BROMOTYRAMINE METABOLITE FROM THE HEXACTINELLIDA SPONGE APHROCALLISTES BEATRIX

    Science.gov (United States)

    Wright, Amy E.; Roth, Gregory P.; Hoffman, Jennifer K.; Divlianska, Daniela B.; Pechter, Diana; Sennett, Susan H.; Guzmán, Esther A.; Linley, Patricia; McCarthy, Peter J.; Pitts, Tara P.; Pomponi, Shirley A.; Reed, John K.

    2010-01-01

    A new adenine substituted bromotyrosine derived metabolite designated as aphrocallistin (1) has been isolated from the deep-water Hexactinellida sponge Aphrocallistes beatrix beatrix Gray, 1858 (Order Hexactinosida, Family Aphrocallistidae). Its structure was elucidated on the basis of spectral data and confirmed through a convergent, modular total synthetic route that is amenable towards future analog preparation. Aphrocallistin inhibits the growth of a panel of human tumor cell lines with IC50 values ranging from 7.5 to >100 μM and has been shown to induce G1 cell cycle arrest in the PANC-1 pancreatic carcinoma cell line. Aphrocallistin has been fully characterized in the NCI cancer cell line panel and has undergone in vitro ADME pharmacological profiling. PMID:19459694

  19. Immobilization of flavin adenine dinucleotide (FAD) onto carbon cloth and its application as working electrode in an electroenzymatic bioreactor.

    Science.gov (United States)

    Jayabalan, R; Sathishkumar, M; Jeong, E S; Mun, S P; Yun, S E

    2012-11-01

    A high porosity carbon cloth with immobilized FAD was employed as working electrode in electrochemical NADH-regeneration procedure. Carbon cloth was oxidized with hot acids to create surface carboxyl group and then coupled by adenine amino group of FAD with carbodiimide in the presence of N-hydroxysulfosuccinimide. The bioelectrocatalytic NADH-regeneration was coupled to the conversion of achiral substrate pyruvate into chiral product l-lactate by l-lactate dehydrogenase (l-LDH) within the same reactor. The conversion was completed at 96h in bioreactor with FAD-modified carbon cloth, resulting in about 6mM of l-lactate from 10mM of pyruvate. While with bare carbon cloth, the yield at 120h was around 5mM. Immobilized FAD on the surface of carbon cloth electrode facilitated it to carry electrons from electrode to electron transfer enzymes; thereby NADH-regeneration was accelerated to drive the enzymatic reaction efficiently.

  20. A label-free fluorescence DNA probe based on ligation reaction with quadruplex formation for highly sensitive and selective detection of nicotinamide adenine dinucleotide.

    Science.gov (United States)

    Zhao, Jingjin; Zhang, Liangliang; Jiang, Jianhui; Shen, Guoli; Yu, Ruqin

    2012-05-11

    A simple label-free fluorescent sensing scheme for sensitive and selective detection of nicotinamide adenine dinucleotide (NAD(+)) has been developed based on DNA ligation reaction with ligand-responsive quadruplex formation. This approach can detect 0.5 nM NAD(+) with high selectivity against other NAD(+) analogs.

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

    Science.gov (United States)

    Stephansen, Anne B; King, Sarah B; Yokoi, Yuki; Minoshima, Yusuke; Li, Wei-Li; Kunin, Alice; Takayanagi, Toshiyuki; Neumark, Daniel M

    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.

  2. Determination of Activity of the Enzymes Hypoxanthine Phosphoribosyl Transferase (HPRT) and Adenine Phosphoribosyl Transferase (APRT) in Blood Spots on Filter Paper.

    Science.gov (United States)

    Auler, Kasie; Broock, Robyn; Nyhan, William L

    2015-07-01

    Hypoxanthine-guanine phosphoribosyl-transferase (HPRT) deficiency is the cause of Lesch-Nyhan disease. Adenine phosphoribosyl-transferase (APRT) deficiency causes renal calculi. The activity of each enzyme is readily determined on spots of whole blood on filter paper. This unit describes a method for detecting deficiencies of HPRT and APRT. Copyright © 2015 John Wiley & Sons, Inc.

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

    Science.gov (United States)

    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.

  4. Real-time nucleic acid sequence-based amplification (NASBA) using an adenine-induced quenching probe and an intercalator dye.

    Science.gov (United States)

    Kouguchi, Y; Teramoto, M; Kuramoto, M

    2010-11-01

    We found that an adenine base caused fluorescence quenching of a fluorescein (FL)-labelled probe in DNA:RNA hybrid sequences, and applied this finding to a nucleic acid sequence-based amplification (NASBA) method. The present NASBA method employed a probe containing an FL-modified thymine at its 3' end and ethidium bromide (EtBr) on the basis of a combination of adenine-induced quenching and fluorescence resonance energy transfer (FRET) between the FL donor and EtBr acceptor. This NASBA was used to detect Shiga toxin (STX) stx-specific mRNA in STX-producing Escherichia coli, demonstrating rapid quantification of the target gene with high sensitivity. Although the inherent quenching effect of adenine was inferior to that of guanine, FRET between the FL and EtBr moieties enhanced the adenine-induced quenching, allowing rapid and sensitive real-time NASBA detection. This study gives a novel real-time diagnostic system based on NASBA for a sensitive mRNA (or viral RNA) detection. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  5. Persistent changes in the initial rate of pyruvate transport by isolated rat liver mitochondria after preincubation with adenine nucleotides and calcium ions

    NARCIS (Netherlands)

    Vaartjes, W.J.; Breejen, J.N. den; Geelen, M.J.H.; Bergh, S.G. van den

    1980-01-01

    1. Preincubation of isolated rat-liver mitochondria in the presence of adenine nucleotides or Ca2+ results in definite and persistent changes in the initial rate of pyruvate transport. 2. These changes in the rate of pyruvate transport are accompanied by equally persistent changes in the opposite d

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

    NARCIS (Netherlands)

    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

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

    Indian Academy of Sciences (India)

    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.

  8. Mismatch base pairing of the mutagen 8-oxoguanine and its derivatives with adenine: A theoretical search for possible antimutagenic agents

    Science.gov (United States)

    Singh, A. K.; Mishra, P. C.

    Molecular geometries of 8-oxoguanine (8OG), those of its substituted derivatives with the substitutions CH2, CF2, CO, CNH, O, and S in place of the N7H7 group, adenine (A), and the base pairs of 8OG and its substituted derivatives with adenine were optimized using the RHF/6-31+G* and B3LYP/6-31+G* methods in gas phase. All the molecules and their hydrogen-bonded complexes were solvated in aqueous media employing the polarized continuum model (PCM) of the self-consistent reaction field (SCRF) theory using the RHF/6-31+G* and B3LYP/6-31+G* methods. The optimized geometrical parameters of the 8OG-A base pair at the RHF/6-31+G* and B3LYP/6-31+G* levels of theory agree satisfactorily with those of an oligonucleotide containing the base pair found from X-ray crystallography. The pattern of hydrogen bonding in the CF2- and O-substituted 8OG-A base pair is of Watson-Crick type and that in the unsubstituted and CH2-, CNH-, and S-substituted base pairs is of Hoogsteen type. In the CO-substituted base pair, the hydrogen bonding pattern is of neither Watson-Crick nor Hoogsteen type. The CF2-substitution appears to introduce steric hindrance for stacking of DNA bases. On the basis of these results, it appears that among all the substituted 8OG molecules considered here, the O-substituted derivative may be useful as an antimutagenic drug. It is, however, subject to experimental verification. Content:text/plain; charset="UTF-8"

  9. Nitric oxide interacts with oxygen free radicals to evoke the release of adenosine and adenine nucleotides from rat hippocampal slices.

    Science.gov (United States)

    Broad, R M; Fallahi, N; Fredholm, B B

    2000-07-01

    The present study examined some possible mechanisms underlying the previously demonstrated release of adenosine by nitric oxide (NO) donors. Perfusion with the NO-donor S-nitroso-N-acetyl penicillamine (SNAP; 300 microM) led to a significant increase in the release of [3H]purines from both unstimulated and electrically stimulated hippocampal slices prelabeled with [3H]adenine. The NO-donor also evoked the release of endogenous ATP and ADP from unstimulated slices and, when combined with electrical stimulation, the release of ATP, AMP and adenosine. The SNAP-induced [3H]purine release was calcium-dependent, but not affected by the glutamate receptor antagonists MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a, d]-cyclohepten-5,10-imine;100 nM) and CNQX (6-cyano-7-nitroquinoxaline-2,3-dione; 10 microM). Zaprinast (5 microM), an inhibitor of the cyclic GMP-dependent phosphodiesterase and 8-Br-cyclic GMP (0.01-1 mM) failed to evoke the release of purines, whereas generation of oxygen free radicals by xanthine plus xanthine oxidase did evoke purine release. Coperfusion of SNAP with the free radical scavengers superoxide dismutase (SOD; 60 microg/ml) and catalase (50 microg/ml) reduced or eliminated the ability of the NO-donor to enhance [3H]purine release, but the poly (ADP-ribosyl) synthetase (PARS) inhibitor benzamide (500 microM) did not affect it. These data indicate that NO interacts with superoxide, likely forming peroxynitrite, which subsequently acts to release adenosine and adenine nucleotides from hippocampal tissue.

  10. Effect of base stacking on the acid-base properties of the adenine cation radical [A*+] in solution: ESR and DFT studies.

    Science.gov (United States)

    Adhikary, Amitava; Kumar, Anil; Khanduri, Deepti; Sevilla, Michael D

    2008-08-06

    In this study, the acid-base properties of the adenine cation radical are investigated by means of experiment and theory. Adenine cation radical (A*(+)) is produced by one-electron oxidation of dAdo and of the stacked DNA-oligomer (dA)6 by Cl2*(-) in aqueous glass (7.5 M LiCl in H2O and in D2O) and investigated by ESR spectroscopy. Theoretical calculations and deuterium substitution at C8-H and N6-H in dAdo aid in our assignments of structure. We find the pKa value of A*(+) in this system to be ca. 8 at 150 K in seeming contradiction to the accepted value of or = 160 K, complete deprotonation of A*(+) occurs in dAdo in these glassy systems even at pH ca. 3. A*(+) found in (dA)6 at 150 K also deprotonates on thermal annealing. The stability of A*(+) at 150 K in these systems is attributed to charge delocalization between stacked bases. Theoretical calculations at various levels (DFT B3LYP/6-31G*, MPWB95, and HF-MP2) predict binding energies for the adenine stacked dimer cation radical of 12 to 16 kcal/mol. Further DFT B3LYP/6-31G* calculations predict that, in aqueous solution, monomeric A*(+) should deprotonate spontaneously (a predicted pKa of ca. -0.3 for A*(+)). However, the charge resonance stabilized dimer AA*(+) is predicted to result in a significant barrier to deprotonation and a calculated pKa of ca. 7 for the AA*(+) dimer which is 7 pH units higher than the monomer. These theoretical and experimental results suggest that A*(+) isolated in solution and A*(+) in adenine stacks have highly differing acid-base properties resulting from the stabilization induced by hole delocalization within adenine stacks.

  11. The electrochemical reduction of the purines guanine and adenine at platinum electrodes in several room temperature ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Zanoni, Maria Valnice Boldrin, E-mail: boldrinv@iq.unesp.br [Department of Analytical Chemistry, Institute of Chemistry, University of Sao Paulo State, Araraquara, R. Prof. Francisco Degni, CP 355, 14801-970, SP (Brazil); Rogers, Emma I. [Department of Chemistry, Physical and Theoretical Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ (United Kingdom); Hardacre, Christopher, E-mail: c.hardacre@qub.ac.uk [School of Chemistry and Chemical Engineering/QUILL, Queen' s University Belfast, Belfast, Northern Ireland BT9 5AG (United Kingdom); Compton, Richard G., E-mail: richard.compton@chem.ox.ac.uk [Department of Chemistry, Physical and Theoretical Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ (United Kingdom)

    2010-02-05

    The reduction of guanine was studied by microelectrode voltammetry in the room temperature ionic liquids (RTILs) N-hexyltriethylammonium bis (trifluoromethanesulfonyl) imide [N{sub 6,2,2,2}][N(Tf){sub 2}], 1-butyl-3-methylimidazolium hexafluorosphosphate [C{sub 4}mim][PF{sub 6}], N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide [C{sub 4}mpyrr][N(Tf){sub 2}], 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C{sub 4}mim][N(Tf){sub 2}], N-butyl-N-methyl-pyrrolidinium dicyanamide [C{sub 4}mpyrr][N(NC){sub 2}] and tris(P-hexyl)-tetradecylphosphonium trifluorotris(pentafluoroethyl)phosphate [P{sub 14,6,6,6}][FAP] on a platinum microelectrode. In [N{sub 6,2,2,2}][NTf{sub 2}] and [P{sub 14,6,6,6}][FAP], but not in the other ionic liquids studied, guanine reduction involves a one-electron, diffusion-controlled process at very negative potential to produce an unstable radical anion, which is thought to undergo a dimerization reaction, probably after proton abstraction from the cation of the ionic liquid. The rate of this subsequent reaction depends on the nature of the ionic liquid, and it is faster in the ionic liquid [P{sub 14,6,6,6}][FAP], in which the formation of the resulting dimer can be voltammetrically monitored at less negative potentials than required for the reduction of the parent molecule. Adenine showed similar behaviour to guanine but the pyrimidines thymine and cytosine did not; thymine was not reduced at potentials less negative than required for solvent (RTIL) decomposition while only a poorly defined wave was seen for cytosine. The possibility for proton abstraction from the cation in [N{sub 6,2,2,2}][NTf{sub 2}] and [P{sub 14,6,6,6}][FAP] is noted and this is thought to aid the electrochemical dimerization process. The resulting rapid reaction is thought to shift the reduction potentials for guanine and adenine to lower values than observed in RTILs where the scope for proton abstraction is not present. Such shifts are

  12. Theoretical Investigation on the Substituent Effect of Halogen Atoms at the C8 Position of Adenine: Relative Stability, Vibrational Frequencies, and Raman Spectra of Tautomers.

    Science.gov (United States)

    Chen, Yan-Li; Wu, De-Yin; Tian, Zhong-Qun

    2016-06-16

    We have theoretically investigated the substituent effect of adenine at the C8 position with a substituent X = H, F, Cl, and Br by using the density functional theory (DFT) at the B3LYP/6-311+G(d, p) level. The aim is to study the substituent effect of halogen atoms on the relative stability, vibrational frequencies, and solvation effect of tautomers. Our calculated results show that for substituted adenine molecules the N9H8X tautomer to be the most stable structure in gas phase at the present theoretical level. Here N9H8X denotes the hydrogen atom binds to the N9 position of imidazole ring and X denotes H, F, Cl, and Br atoms. The influence of the induced attraction of the fluorine substituent is significantly larger than chlorine and bromine ones. The halogen substituent effect has a significant influence on changes of vibrational frequencies and Raman intensities.

  13. DNA damage induced by the environmental carcinogen butadiene: identification of a diepoxybutane-adenine adduct and its detection by 32P-postlabelling.

    Science.gov (United States)

    Leuratti, C; Jones, N J; Marafante, E; Kostiainen, R; Peltonen, K; Waters, R

    1994-09-01

    To date only a few studies have been undertaken on DNA adducts formed by epoxybutene (EB) and diepoxybutane (DEB), the two active metabolites of 1,3-butadiene. Our interests have focused on further investigating DNA alkylation by the two epoxides, especially in relation to the development of a method for human biomonitoring. Here, following the reaction of deoxyadenosine monophosphate and poly(dA-dT)(dA-dT) with DEB and subsequent HPLC, we have identified an adenine adduct. MS analyses indicate the structure of an adenine adducted by DEB at the N6 position. A HPLC/32P-postlabelling method was developed for its measurement in DNA samples and the adduct was detected in calf thymus DNA and DNA from Chinese hamster ovary cells exposed to DEB. The 100% labelling efficiency during postlabelling, the amount of the adduct and its elution before the normal nucleotides during HPLC suggest it could be a suitable indicator of BUT exposure.

  14. Photosensitized oxidation of nicotinamide adenine dinucleotide by diethoxyphosphorus(V)tetraphenylporphyrin and its fluorinated derivative: Possibility of chain reaction.

    Science.gov (United States)

    Hirakawa, Kazutaka; Murata, Atsushi

    2017-07-31

    Water-soluble porphyrins, diethoxyphosphorus(V)tetraphenylporphyrin (EtP(V)TPP) and its fluorinated analogue (FEtP(V)TPP), decreased the typical absorption around 340nm of nicotinamide adenine dinucleotide (NADH) under visible light irradiation, indicating oxidative decomposition. A singlet oxygen quencher, sodium azide, and a triplet quencher, potassium iodide, slightly inhibited photosensitized NADH oxidation. However, these inhibitory effects were very small. Furthermore, the fluorescence lifetime of these P(V)porphyrins was decreased by NADH, suggesting the contribution of electron transfer to the singlet excited (S1) state of P(V)porphyrin. The redox potential measurement supports the electron transfer-mediated oxidation of NADH. The quantum yields of NADH photodecomposition by P(V)porphyrins could be estimated from the kinetic data and the effect of these quenchers on NADH oxidation. The obtained values suggest that the electron accepting by the S1 states of P(V)porphyrins triggers a chain reaction of NADH oxidation. This photosensitized reaction may play an important role in the photocytotoxicity of P(V)porphyrins. The axial ligand fluorination of P(V)porphyrins improved electron accepting ability. However, fluorination slightly suppressed static interaction with NADH, resulting in decreased oxidation quantum yield. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. The tumour metabolism inhibitors GSAO and PENAO react with cysteines 57 and 257 of mitochondrial adenine nucleotide translocase

    Directory of Open Access Journals (Sweden)

    Park Danielle

    2012-03-01

    Full Text Available Abstract Background GSAO (4-(N-(S-glutathionylacetylamino phenylarsonous acid and PENAO (4-(N-(S-penicillaminylacetylamino phenylarsonous acid are tumour metabolism inhibitors that target adenine nucleotide translocase (ANT of the inner-mitochondrial membrane. Both compounds are currently being trialled in patients with solid tumours. The trivalent arsenical moiety of GSAO and PENAO reacts with two matrix facing cysteine residues of ANT, inactivating the transporter. This leads to proliferation arrest and death of tumour and tumour-supporting cells. Results The two reactive ANT cysteine residues have been identified in this study by expressing cysteine mutants of human ANT1 in Saccharomyces cerevisiae and measuring interaction with the arsenical moiety of GSAO and PENAO. The arsenic atom of both compounds cross-links cysteine residues 57 and 257 of human ANT1. Conclusions The sulphur atoms of these two cysteines are 20 Å apart in the crystal structures of ANT and the optimal spacing of cysteine thiolates for reaction with As (III is 3-4 Å. This implies that a significant conformational change in ANT is required for the organoarsenicals to react with cysteines 57 and 257. This conformational change may relate to the selectivity of the compounds for proliferating cells.

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

    CERN Document Server

    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. The product of the Herpes simplex virus 1 UL7 gene interacts with a mitochondrial protein, adenine nucleotide translocator 2

    Directory of Open Access Journals (Sweden)

    Kawaguchi Yasushi

    2008-10-01

    Full Text Available Abstract The herpes simplex virus 1 (HSV-1 UL7 gene is highly conserved among herpesviridae. Since the construction of recombinant HSV-1 with a mutation in the UL7 gene has not been reported, the involvement of HSV-1 UL7 in viral replication has been unclear. In this study, we succeeded in generating a UL7 null HSV-1 mutant virus, MT102, and characterized it. Our results were as follows. (i In Vero cells, MT102 was replication-competent, but formed smaller plaques and yielded 10- to 100-fold fewer progeny than the wild-type virus, depending on the multiplicity of infection. (ii Using mass spectrometry-based proteomics technology, we identified a cellular mitochondrial protein, adenine nucleotide translocator 2 (ANT2, as a UL7-interacting partner. (iii When ANT2 was transiently expressed in COS-7 cells infected with HSV-1, ANT2 was specifically co-precipitated with UL7. (iv Cell fractionation experiments with HSV-1-infected cells detected the UL7 protein in both the mitochondrial and cytosolic fractions, whereas ANT2 was detected only in the mitochondrial fraction. These results indicate the importance of HSV-1 UL7's involvement in viral replication and demonstrate that it interacts with ANT2 in infected cells. The potential biological significance of the interaction between UL7 and ANT2 is discussed.

  19. Yeast species utilizing uric acid, adenine, n-alkylamines or diamines as sole source of carbon and energy.

    Science.gov (United States)

    Middelhoven, W J; De Kievit, H; Biesbroek, A L

    1985-01-01

    Yeast strains utilizing uric acid, adenine, monoamines or diamines as sole source of carbon and energy were isolated from several soil samples by the enrichment culture method. The most common species was Trichosporon cutaneum. Strains of Candida catenulata, C. famata, C. parapsilosis, C. rugosa, Cryptococcus laurentii, Stephanoascus ciferrii and Tr. adeninovorans were also isolated. All strains utilizing uric acid as sole carbon source utilized some primary n-alkyl-l-amines, hydroxyamines or diamines as well. The ascomycetous yeast strains showing these characteristics all belonged to species known to assimilate hydrocarbons. Type strains of hydrocarbon-positive yeast species which were not found in the enrichment cultures generally assimilated putrescine, some type strains also butylamine or pentylamine, but none assimilated uric acid. Methanol-positive species were not isolated. Type strains of methanol-positive and of hydrocarbon-negative species did not assimilate uric acid, butylamine or putrescine. Assimilation of putrescine as sole source of carbon and energy may be a valuable diagnostic criterion in yeast taxonomy.

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

    Science.gov (United States)

    Ali, Thanaa Hamed; El-Ghonemy, Dina Helmy

    2016-06-01

    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 inosine and ammonia. While glycohydrolase catalyzed the hydrolysis of the nicotinamide-ribosidic bond of NAD+ to produce nicotinamide and ADP-ribose in equimolar amounts, enzyme purification through a 3-step purification procedure revealed the existence of two peaks of alkaline phosphatases, and one peak contained deaminase and glycohydrolase activities. NAD deaminase was purified to homogeneity as estimated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis with an apparent molecular mass of 91 kDa. Characterization and determination of some of NAD aminohydrolase kinetic properties were conducted due to its biological role in the regulation of cellular NAD level. The results also revealed that NAD did not exert its feedback control on nicotinamide amidase produced by P. brevicompactum.

  1. Synthesis, biological activity, and DNA-damage profile of platinum-threading intercalator conjugates designed to target adenine.

    Science.gov (United States)

    Guddneppanavar, Rajsekhar; Saluta, Gilda; Kucera, Gregory L; Bierbach, Ulrich

    2006-06-01

    PT-ACRAMTU {[PtCl(en)(ACRAMTU)](NO3)2, 2; ACRAMTU = 1-[2-(acridin-9-ylamino)ethyl]-1,3-dimethylthiourea, 1, en = ethane-1,2-diamine} is the prototype of a series of DNA-targeted adenine-affinic dual intercalating/platinating agents. Several novel 4,9-disubstituted acridines and the corresponding platinum-acridine conjugates were synthesized. The newly introduced 4-carboxamide side chains contain H-bond donor/acceptor functions designed to promote groove- and sequence-specific platinum binding. In HL-60 (leukemia) and H460 (lung) cancer cells, IC50 values in the micromolar to millimolar range were observed. Several of the intercalators show enhanced cytotoxicity compared to prototype 1, but conjugate 2 appears to be the most potent hybrid agent. Enzymatic digestion assays in conjunction with liquid chromatography-electrospray mass spectrometry analysis indicate that the new conjugates produce PT-ACRAMTU-type DNA damage. Platinum-modified 2'-deoxyguanosine, dG, and several dinucleotide fragments, d(NpN)*, were detected. One of the conjugates showed significantly higher levels of binding to A-containing sites than conjugate 2 (35 +/- 3% vs 24 +/- 3%). Possible structure-activity relationships are discussed.

  2. Structure of dimeric, recombinant Sulfolobus solfataricus phosphoribosyl diphosphate synthase: a bent dimer defining the adenine specificity of the substrate ATP.

    Science.gov (United States)

    Andersen, Rune W; Leggio, Leila Lo; Hove-Jensen, Bjarne; Kadziola, Anders

    2015-03-01

    The enzyme 5-phosphoribosyl-1-α-diphosphate (PRPP) synthase (EC 2.7.6.1) catalyses the Mg(2+)-dependent transfer of a diphosphoryl group from ATP to the C1 hydroxyl group of ribose 5-phosphate resulting in the production of PRPP and AMP. A nucleotide sequence specifying Sulfolobus solfataricus PRPP synthase was synthesised in vitro with optimised codon usage for expression in Escherichia coli. Following expression of the gene in E. coli PRPP synthase was purified by heat treatment and ammonium sulphate precipitation and the structure of S. solfataricus PRPP synthase was determined at 2.8 Å resolution. A bent dimer oligomerisation was revealed, which seems to be an abundant feature among PRPP synthases for defining the adenine specificity of the substrate ATP. Molecular replacement was used to determine the S. solfataricus PRPP synthase structure with a monomer subunit of Methanocaldococcus jannaschii PRPP synthase as a search model. The two amino acid sequences share 35 % identity. The resulting asymmetric unit consists of three separated dimers. The protein was co-crystallised in the presence of AMP and ribose 5-phosphate, but in the electron density map of the active site only AMP and a sulphate ion were observed. Sulphate ion, reminiscent of the ammonium sulphate precipitation step of the purification, seems to bind tightly and, therefore, presumably occupies and blocks the ribose 5-phosphate binding site. The activity of S. solfataricus PRPP synthase is independent of phosphate ion.

  3. Multi-pathway excited state relaxation of adenine oligomers in aqueous solution: a joint theoretical and experimental study.

    Science.gov (United States)

    Banyasz, Akos; Gustavsson, Thomas; Onidas, Delphine; Changenet-Barret, Pascale; Markovitsi, Dimitra; Improta, Roberto

    2013-03-11

    The singlet excited states of adenine oligomers, model systems widely used for the understanding of the interaction of ultraviolet radiation with DNA, are investigated by fluorescence spectroscopy and time-dependent (TD) DFT calculations. Fluorescence decays, fluorescence anisotropy decays, and time-resolved fluorescence spectra are recorded from the femtosecond to the nanosecond timescales for single strand (dA)20 in aqueous solution. These experimental observations and, in particular, the comparison of the fluorescence behavior upon UVC and UVA excitation allow the identification of various types of electronic transitions with different energy and polarization. Calculations performed for up to five stacked 9-methyladenines, taking into account the solvent, show that different excited states are responsible for the absorption in the UVC and UVA spectral domains. Independently of the number of bases, bright excitons may evolve toward two types of excited dimers having π-π* or charge-transfer character, each one distinguished by its own geometry and spectroscopic signature. According to the picture arising from the joint experimental and theoretical investigation, UVC-induced fluorescence contains contribution from 1) exciton states with a different degree of localization, decaying within a few ps, 2) "neutral" excited dimers decaying on the sub-nanosecond timescale, being the dominant species, and 3) charge-transfer states decaying on the nanosecond timescale. The majority of the photons emitted upon UVA excitation are related to charge-transfer states.

  4. Exercise effects on activities of Na(+),K(+)-ATPase, acetylcholinesterase and adenine nucleotides hydrolysis in ovariectomized rats.

    Science.gov (United States)

    Ben, Juliana; Soares, Flávia Mahatma Schneider; Cechetti, Fernanda; Vuaden, Fernanda Cenci; Bonan, Carla Denise; Netto, Carlos Alexandre; Wyse, Angela Terezinha de Souza

    2009-12-11

    Hormone deficiency following ovariectomy causes activation of Na(+),K(+)-ATPase and acetylcholinesterase (AChE) that has been related to cognitive deficits in experimental animals. Considering that physical exercise presents neuroprotector effects, we decide to investigate whether exercise training would affect enzyme activation in hippocampus and cerebral cortex, as well as adenosine nucleotide hydrolysis in synaptosomes from cerebral cortex of ovariectomized rats. Female adult Wistar rats were assigned to one of the following groups: sham (submitted to surgery without removal of the ovaries), exercise, ovariectomized (Ovx) and Ovx plus exercise. Thirty days after surgery, animals were submitted to one month of exercise training, three times per week. After, rats were euthanized, blood serum was collected and hippocampus and cerebral cortex were dissected. Data demonstrated that exercise reversed the activation of Na(+),K(+)-ATPase and AChE activities both in hippocampus and cerebral cortex of ovariectomized rats. Ovariectomy decreased AMP hydrolysis in cerebral cortex and did not alter adenine nucleotides hydrolysis in blood serum. Exercise per se decreased ADP and AMP hydrolysis in cerebral cortex. On the other hand, AMP hydrolysis in blood serum was increased by exercise in ovariectomized adult rats. Present data support that physical exercise might have beneficial effects and constitute a therapeutic alternative to hormone replacement therapy for estrogen deprivation.

  5. Amidate prodrugs of 9-[2-(phosphonomethoxy)ethyl]adenine as inhibitors of adenylate cyclase toxin from Bordetella pertussis.

    Science.gov (United States)

    Šmídková, Markéta; Dvoráková, Alexandra; Tloust'ová, Eva; Česnek, Michal; Janeba, Zlatko; Mertlíková-Kaiserová, Helena

    2014-01-01

    Adenylate cyclase toxin (ACT) is the key virulence factor of Bordetella pertussis that facilitates its invasion into the mammalian body. 9-[2-(Phosphonomethoxy)ethyl]adenine diphosphate (PMEApp), the active metabolite of the antiviral drug bis(POM)PMEA (adefovir dipivoxil), has been shown to inhibit ACT. The objective of this study was to evaluate six novel amidate prodrugs of PMEA, both phenyloxy phosphonamidates and phosphonodiamidates, for their ability to inhibit ACT activity in the J774A.1 macrophage cell line. The two phenyloxy phosphonamidate prodrugs exhibited greater inhibitory activity (50% inhibitory concentration [IC50] = 22 and 46 nM) than the phosphonodiamidates (IC50 = 84 to 3,960 nM). The inhibitory activity of the prodrugs correlated with their lipophilicity and the degree of their hydrolysis into free PMEA in J774A.1 cells. Although the prodrugs did not inhibit ACT as effectively as bis(POM)PMEA (IC50 = 6 nM), they were significantly less cytotoxic. Moreover, they all reduced apoptotic effects of ACT and prevented an ACT-induced elevation of intracellular [Ca(2+)]i. The amidate prodrugs were less susceptible to degradation in Caco-2 cells compared to bis(POM)PMEA, while they exerted good transepithelial permeability in this assay. As a consequence, a large amount of intact amidate prodrug is expected to be available to target macrophages in vivo. This feature makes nontoxic amidate prodrugs attractive candidates for further investigation as novel antimicrobial agents.

  6. Activation of protein kinase C and nicotinamide adenine dinucleotide phosphate oxidase in leukocytes of spontaneously hypertensive rats.

    Science.gov (United States)

    Maeda, Kensaku; Yasunari, Kenichi; Sato, Eisuke F; Yoshikawa, Junichi; Inoue, Masayasu

    2003-12-01

    The involvement of oxidative stress in polymorphonuclear leukocytes (PMN) in the pathogenesis of hypertension remains to be elucidated. We analyzed the generation of reactive oxygen species (ROS) by the circulating and peritoneally infiltrating PMN from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Flow cytometric analysis revealed that ROS generation by PMN from SHR was higher than that from WKY before (at 6 weeks of age) and after (at 16 weeks of age) the onset of hypertension. In vivo, ROS generation by PMN from SHR, but not that by PMN from WKY, was significantly suppressed by 10-week treatment with 50 mg/kg/day carvedilol, and this treatment did not affect blood pressure. Western blotting analysis revealed that protein kinase C alpha (PKCalpha), but not PKCbetaI or betaII, was activated more strongly in PMN from SHR than in PMN from WKY. Furthermore, expression of p47phox of nicotinamide adenine dinucleotide phosphate oxidase, but not of p67phox, in PMN from SHR was higher than that in PMN from WKY. These results suggest that ROS generation by PMN is principally enhanced in SHR through activation of PKCalpha and p47phox.

  7. An extended version of Boyd's force field method applicable to heteroatomic molecules. Part 1. Adenine and uracil

    Science.gov (United States)

    Espinosa-Müller, A. W.; Bravo, A. N.

    The force field method developed by Boyd is extended to include molecules containing atoms other than C and H (e.g., N, O, P, S, Cl, Br,…). A new set of force field parameters is determined in order to redefine the potential energy functions that govern the dynamics of the internal (valence coordinates) degrees of freedom of a molecule. It is shown that the minimum of the partial potential energy surface is significantly affected by electrostatic intramolecular interactions. In this regard the non-bonded interactions appears to be less important than the dipole-dipole type interactions for a given interatomic distance when heteroatoms are present in the molecular framework. The reliability of the extended method as regards minimized structure, vibrational spectra and thermodynamic properties has been checked for more than 20 polyatomic molecules. From the correlation between calculated and experimental properties it is concluded that the method has good potential for further applications on polyatomic molecules with increasing size and topological compexities such as adenine and uracil.

  8. Interaction between thymine dimer and flavin-adenine dinucleotide: a DFT and direct ab initio molecular dynamics study.

    Science.gov (United States)

    Tachikawa, Hiroto; Kawabata, Hiroshi

    2008-06-19

    The interaction between the fully reduced flavin-adenine dinucleotide (FADH (-)) and thymine dimer (T) 2 has been investigated by means of density functional theory (DFT) calculations. The charges of FADH (-) and (T) 2 were calculated to be -0.9 and -0.1, respectively, at the ground state. By photoirradiation, an electron transfer occurred from FADH (-) to (T) 2 at the first excited state. Next, the reaction dynamics of electron capture of (T) 2 have been investigated by means of the direct ab initio molecular dynamics (MD) method (HF/3-21G(d) and B3LYP/6-31G(d) levels) in order to elucidate the mechanism of the repair process of thymine dimer caused by the photoenzyme. The thymine dimer has two C-C single bonds between thymine rings (C 5-C 5' and C 6-C 6' bonds) at the neutral state, which is expressed by (T) 2. After the electron capture of (T) 2, the C 5-C 5' bond was gradually elongated and then it was preferentially broken. The time scale of the C-C bond breaking and formation of the intermediate with a single bond (T) 2 (-) was estimated to be 100-150 fs. The present calculations confirmed that the repair reaction of thymine dimer takes place efficiently via an electron-transfer process from the FADH (-) enzyme.

  9. Ozone therapy could attenuate tubulointerstitial injury in adenine-induced CKD rats by mediating Nrf2 and NF-κB

    Directory of Open Access Journals (Sweden)

    Gang Yu

    2016-10-01

    Full Text Available Objective(s: This study aims to determine the effects of ozone therapy on restoring impaired Nrf2 activation to ameliorate chronic tubulointerstitial injury in rats with adenine-induced CKD. Materials and Methods: Sprague–Dawley rats were fed with 0.75% adenine-containing diet to induce CKD and chronic tubulointerstitial injury. Ozone therapy was administered by rectal insufflation. After 4 weeks, serum and kidney samples were collected and analyzed. Renal function and systemic electrolyte level were detected. Pathological changes in kidney were assessed by hematoxylin–eosin staining and Masson trichrome staining. Nrf2 activation was detected by immunohistochemistry and Western blot analyses. The levels of SOD, CAT, GSH, PCO, and MDA were detected in the kidney. Immunohistochemistry, Western blot, and real-time PCR analyses were performed to evaluate the activation of the nuclear factor kappa B (NF-κB P65 pathway and inflammation infiltration in the tubulointerstitium of the rats. Results: Ozone therapy improved severe renal insufficiency and tubulointerstitial morphology injury as well as restored Nrf2 activation and inhibited the NF-κB pathway in rats with adenine-induced CKD. Ozone therapy also up-regulated anti-oxidation enzymes (SOD, CAT, and GSH and down-regulated oxidation products (PCO and MDA, as well as inflammatory cytokines (IL-1β, IL-6, TNF-α, and ICAM-1 in the kidney. Conclusion:These findings indicated that ozone therapy could attenuate tubulointerstitial injury in rats with adenine-induced CKD by mediating Nrf2 and NF-κB.

  10. Ozone therapy could attenuate tubulointerstitial injury in adenine-induced CKD rats by mediating Nrf2 and NF-κB

    Science.gov (United States)

    Yu, Gang; Liu, Xiuheng; Chen, Zhiyuan; Chen, Hui; Wang, Lei; Wang, Zhishun; Qiu, Tao; Weng, Xiaodong

    2016-01-01

    Objective(s): This study aims to determine the effects of ozone therapy on restoring impaired Nrf2 activation to ameliorate chronic tubulointerstitial injury in rats with adenine-induced CKD. Materials and Methods: Sprague–Dawley rats were fed with 0.75% adenine-containing diet to induce CKD and chronic tubulointerstitial injury. Ozone therapy was administered by rectal insufflation. After 4 weeks, serum and kidney samples were collected and analyzed. Renal function and systemic electrolyte level were detected. Pathological changes in kidney were assessed by hematoxylin–eosin staining and Masson trichrome staining. Nrf2 activation was detected by immunohistochemistry and Western blot analyses. The levels of SOD, CAT, GSH, PCO, and MDA were detected in the kidney. Immunohistochemistry, Western blot, and real-time PCR analyses were performed to evaluate the activation of the nuclear factor kappa B (NF-κB) P65 pathway and inflammation infiltration in the tubulointerstitium of the rats. Results: Ozone therapy improved severe renal insufficiency and tubulointerstitial morphology injury as well as restored Nrf2 activation and inhibited the NF-κB pathway in rats with adenine-induced CKD. Ozone therapy also up-regulated anti-oxidation enzymes (SOD, CAT, and GSH) and down-regulated oxidation products (PCO and MDA), as well as inflammatory cytokines (IL-1β, IL-6, TNF-α, and ICAM-1) in the kidney. Conclusion: These findings indicated that ozone therapy could attenuate tubulointerstitial injury in rats with adenine-induced CKD by mediating Nrf2 and NF-κB. PMID:27872711

  11. Can an excess electron localize on a purine moiety in the adenine-thymine Watson-Crick base pair? A computational study

    Science.gov (United States)

    Mazurkiewicz, Kamil; Harańczyk, Maciej; Gutowski, Maciej; Rak, Janusz

    The electron affinity and the propensity to electron-induced proton transfer (PT) of hydrogen-bonded complexes between the Watson-Crick adenine-thymine pair (AT) and simple organic acid (HX), attached to adenine in the Hoogsteen-type configuration, were studied at the B3LYP/6-31+G** level. Although the carboxyl group is deprotonated at physiological pH, its neutral form, COOH, resembles the peptide bond or the amide fragment in the side chain of asparagine (Asn) or glutamine (Gln). Thus, these complexes mimic the interaction between the DNA environment (e.g., proteins) and nucleobase pairs incorporated in the biopolymer. Electron attachment is thermodynamically feasible and adiabatic electron affinities range from 0.41 to 1.28 eV, while the vertical detachment energies of the resulting anions span the range of 0.39-2.88 eV. Low-energy activation barriers separate the anionic minima: aHX(AT) from the more stable single-PT anionic geometry, aHX(AT)-SPT, and aHX(AT)-SPT from the double-PT anionic geometry, aHX(AT)-DPT. Interaction between the adenine of the Watson-Crick AT base pair with an acidic proton donor probably counterbalances the larger EA of isolated thymine, as SOMO is almost evenly delocalized over both types of nucleic bases in the aHX(AT) anions. Moreover, as a result of PT the excess electron localizes entirely on adenine. Thus, in DNA interacting with its physiological environment, damage induced by low-energy electrons could begin, contrary to the current view, with the formation of purine anions, which are not formed in isolated DNA because of the greater stability of anionic pyrimidines.0

  12. The influence of calcium antagonists on the adenine nucleotide metabolism in the guinea-pig working heart during ischaemia and reperfusion.

    Science.gov (United States)

    Hugtenburg, J G; Mathy, M J; de Haan, N; Beckeringh, J J; van Zwieten, P A

    1991-05-01

    With the aim of gaining more insight into the metabolism of adenine nucleotides in working normoxic guinea-pigs and in hearts subjected to 45 min of global ischaemia and subsequent reperfusion for 25 min, we evaluated the effect of nifedipine, verapamil, diltiazem, bepridil, CERM 11956, lidoflazine, mioflazine and dipyridamole on the adenine nucleotide catabolite levels in these hearts. The drugs were applied at the concentrations that reduced the aortic dP/dt of normoxic working hearts by 10% (EC10) and 30% (EC30). In globally ischaemic hearts there was a large accumulation of adenine nucleotide catabolites. Inosine proved to be the major catabolite. The drugs, with the exception of bepridil, CERM 11956 and dipyridamole (3 mumol/l), decreased the accumulation of catabolites. In hearts treated with mioflazine and dipyridamole the amount of adenosine increased. A deficit in the balance between adenine nucleotides and catabolites indicated that in globally ischaemic hearts there was a large accumulation of inosine monophosphate. Indeed, a substantial amount of inosine monophosphate was determined in untreated hearts, and hearts treated with nifedipine (EC30) and mioflazine (EC10). During the first 5 min of reperfusion a large quantity of catabolites, mainly inosine, was washed out. During 20 min of subsequent reperfusion in untreated hearts and in nifedipine and mioflazine-treated hearts the efflux of catabolites returned to normoxic values. Similar to the effect in ischaemic hearts, in early perfusate from lidoflazine, mioflazine and dipyridamole-treated hearts the adenosine/inosine ratio was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

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

    OpenAIRE

    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...

  14. Approach to the unfolding and folding dynamics of add A-riboswitch upon adenine dissociation using a coarse-grained elastic network model

    Science.gov (United States)

    Li, Chunhua; Lv, Dashuai; Zhang, Lei; Yang, Feng; Wang, Cunxin; Su, Jiguo; Zhang, Yang

    2016-07-01

    Riboswitches are noncoding mRNA segments that can regulate the gene expression via altering their structures in response to specific metabolite binding. We proposed a coarse-grained Gaussian network model (GNM) to examine the unfolding and folding dynamics of adenosine deaminase (add) A-riboswitch upon the adenine dissociation, in which the RNA is modeled by a nucleotide chain with interaction networks formed by connecting adjoining atomic contacts. It was shown that the adenine binding is critical to the folding of the add A-riboswitch while the removal of the ligand can result in drastic increase of the thermodynamic fluctuations especially in the junction regions between helix domains. Under the assumption that the native contacts with the highest thermodynamic fluctuations break first, the iterative GNM simulations showed that the unfolding process of the adenine-free add A-riboswitch starts with the denature of the terminal helix stem, followed by the loops and junctions involving ligand binding pocket, and then the central helix domains. Despite the simplified coarse-grained modeling, the unfolding dynamics and pathways are shown in close agreement with the results from atomic-level MD simulations and the NMR and single-molecule force spectroscopy experiments. Overall, the study demonstrates a new avenue to investigate the binding and folding dynamics of add A-riboswitch molecule which can be readily extended for other RNA molecules.

  15. Urea induced unfolding dynamics of flavin adenine dinucleotide (FAD): spectroscopic and molecular dynamics simulation studies from femto-second to nanosecond regime.

    Science.gov (United States)

    Sengupta, Abhigyan; Singh, Reman K; Gavvala, Krishna; Koninti, Raj Kumar; Mukherjee, Arnab; Hazra, Partha

    2014-02-20

    Here, we investigate the effect of urea in the unfolding dynamics of flavin adenine dinucleotide (FAD), an important enzymatic cofactor, through steady state, time-resolved fluorescence spectroscopic and molecular dynamics (MD) simulation studies. Steady state results indicate the possibility of urea induced unfolding of FAD, inferred from increasing emission intensity of FAD with urea. The TCSPC and up-conversion results suggest that the stack-unstack dynamics of FAD severely gets affected in the presence of urea and leads to an increase in the unstack conformation population from 15% in pure water to 40% in 12 M urea. Molecular dynamics simulation was employed to understand the nature of the interaction between FAD and urea at the molecular level. Results depict that urea molecules replace many of the water molecules around adenine and isoalloxazine rings of FAD. However, the major driving force for the stability of this unstack conformations arises from the favorable stacking interaction of a significant fraction of the urea molecules with adenine and isoalloxazine rings of FAD, which overcomes the intramolecular stacking interaction between themselves observed in pure water.

  16. Apigenin Sensitizes Prostate Cancer Cells to Apo2L/TRAIL by Targeting Adenine Nucleotide Translocase-2

    Science.gov (United States)

    Taniguchi, Tomoyuki; Goi, Wakana; Miki, Tsuneharu; Sakai, Toshiyuki

    2013-01-01

    Apo2 ligand (Apo2L)/tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising cancer therapeutic agent. Recombinant human Apo2L/TRAIL has been under clinical trials, whereas various kinds of malignant tumors have resistance to Apo2L/TRAIL. We and others have shown that several anticancer agents and flavonoids overcome resistance to Apo2L/TRAIL by upregulating death receptor 5 (DR5) in malignant tumor cells. However, the mechanisms by which these compounds induce DR5 expression remain unknown. Here we show that the dietary flavonoid apigenin binds and inhibits adenine nucleotide translocase-2 (ANT2), resulting in enhancement of Apo2L/TRAIL-induced apoptosis by upregulation of DR5. Apigenin and genistein, which are major flavonoids, enhanced Apo2L/TRAIL-induced apoptosis in cancer cells. Apigenin induced DR5 expression, but genistein did not. Using our method identifying the direct targets of flavonoids, we compared the binding proteins of apigenin with those of genistein. We discovered that ANT2 was a target of apigenin, but not genistein. Similarly to apigenin, knockdown of ANT2 enhanced Apo2L/TRAIL-induced apoptosis by upregulating DR5 expression at the post-transcriptional level. Moreover, silencing of ANT2 attenuated the enhancement of Apo2L/TRAIL-induced apoptosis by apigenin. These results suggest that apigenin upregulates DR5 and enhances Apo2L/TRAIL-induced apoptosis by binding and inhibiting ANT2. We propose that ANT2 inhibitors may contribute to Apo2L/TRAIL therapy. PMID:23431365

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

    Science.gov (United States)

    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. © 2014 Wiley Periodicals, Inc.

  18. Adenine nucleotides and intracellular Ca2+ regulate a voltage-dependent and glucose-sensitive potassium channel in neurosecretory cells.

    Science.gov (United States)

    Onetti, C G; Lara, J; García, E

    1996-05-01

    Effects of membrane potential, intracellular Ca2+ and adenine nucleotides on glucose-sensitive channels from X organ (XO) neurons of the crayfish were studied in excised inside-out patches. Glucose- sensitive channels were selective to K+ ions; the unitary conductance was 112 pS in symmetrical K+, and the K+ permeability (PK) was 1.3 x 10(-13) cm x s(-1). An inward rectification was observed when intracellular K+ was reduced. Using a quasi-physiological K+ gradient, a non-linear K+ current/voltage relationship was found showing an outward rectification and a slope conductance of 51 pS. The open-state probability (Po) increased with membrane depolarization as a result of an enhancement of the mean open time and a shortening of the longer period of closures. In quasi-physio- logical K+ concentrations, the channel was activated from a threshold of about -60 mV, and the activation midpoint was -2 mV. Po decreased noticeably at 50 microM internal adenosine 5'-triphosphate (ATP), and single-channel activity was totally abolished at 1 mM ATP. Hill analysis shows that this inhibition was the result of simultaneous binding of two ATP molecules to the channel, and the half-blocking concentration of ATP was 174 microM. Internal application of 5'-adenylylimidodiphosphate (AMP-PNP) as well as glibenclamide also decreased Po. By contrast, the application of internal ADP (0.1 to 2 mM) activated this channel. An optimal range of internal free Ca2+ ions (0.1 to 10 microM) was required for the activation of this channel. The glucose--sensitive K+ channel of XO neurons could be considered as a subtype of ATP-sensitive K+ channel, contributing substantially to macroscopic outward current.

  19. A QM/QTAIM microstructural analysis of the tautomerisationviathe DPT of the hypoxanthine·adenine nucleobase pair

    Science.gov (United States)

    Brovarets', Ol'ha O.; Zhurakivsky, Roman O.; Hovorun, Dmytro M.

    2014-08-01

    We provide a pathway for the tautomerisation of the biologically important hypoxanthine.adenine (Hyp.Ade) nucleobase pair (Cs) formed by the keto tautomer of the Hyp and the amino tautomer of the Ade into the Hyp*.Ade* base pair (Cs) formed by the enol tautomer of the Hyp and the imino tautomer of the Ade by applying quantum-mechanical calculations and Bader's Quantum Theory of Atoms in Molecules analysis. It was found out that the dipole active Hyp.Ade↔Hyp*.Ade* tautomerisation occurs via the asynchronous concerted double proton transfer (DPT) through the TSHyp.Ade↔Hyp*.Ade* (Cs). Based on the sweeps of the energies of the intermolecular H-bonds along the intrinsic reaction coordinate, it was established that the N6H...O6 H-bond (5.40) is cooperative with the N1H...N1 H-bond (6.99) in the Hyp.Ade base pair, as well as the O6H...N6 H-bond (11.50) is cooperative with the N1H...N1 H-bond (7.28 kcal.mol-1) in the Hyp*.Ade* base pair, mutually strengthening each other. The Hyp*.Ade* base pair possesses an extremely short lifetime 2.68.10-14 s, which is predetermined by the negative value of the Gibbs free energy of the reverse barrier of its tautomerisation, and all of the six low-frequency intermolecular vibrations cannot develop during this period of time. Consequently, the Hyp.Ade→Hyp*.Ade* DPT tautomerisation cannot serve as a source of the rare tautomers of the bases.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Association of nicotinamide adenine dinucleotide phosphate oxidase p22phox gene 549C>T polymorphism with coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    LIU Tong-tao; WANG Li-li; FANG Sheng-xia; JIA Chong-qi

    2012-01-01

    Background The p22phox is a critical component of the superoxide-generating vascular nicotinamide adenine dinucleotide phosphate (NADPH) oxidase.Several polymorphisms in p22phox gene are studied for their association with cardiovascular diseases.However,no publication is available to assess the relation of 549C>T polymorphism in p22phox gene to coronary artery disease (CAD) risk.This study was to investigate the effect of the p22phox gene 549C>T polymorphism on CAD risk.Methods Hospital-based case-control study was conducted with 297 CAD patients and 343 healthy persons as the control group.Polymerase chain reaction and pyrosequencing using PSQ 96 MA Pyrosequencer (Biotage AB) were used to detect the polymorphisms.Multiple Logistic regression model was used to adjust the potential confounders and to estimate odds ratio (OR) with 95% confidence intervals (Cls).Results The observed genotype frequencies of this polymorphism obeyed the Hardy-Weinberg equilibrium in both cases (P=0.439) and controls (P=0.668).The frequency of mutant genotypes (TT+CT) in cases (41.08%) was higher than that in controls (36.73%) with an OR=-1.20 (95% CI=0.87-1.65).After the adjustment of the potential confounders,there was a significant association of the mutant genotypes with increased risk of CAD (OR=1.57,95% CI=1.01-2.46,P=0.047).Conclusions The mutant genotypes of the p22phox gene 549C>T polymorphism had a significant effect on the increased risk of CAD in this studied population.

  2. Hypothesis on skeletal muscle aging : mitochondrial adenine nucleotide translocator decreases reactive oxygen species production while preserving coupling efficiency

    Directory of Open Access Journals (Sweden)

    Philippe eDIOLEZ

    2015-12-01

    Full Text Available Mitochondrial membrane potential is the major regulator of mitochondrial functions, including coupling efficiency and production of reactive oxygen species (ROS. Both functions are crucial for cell bioenergetics. We previously presented evidences for a specific modulation of adenine nucleotide translocase (ANT appearing during aging that results in a decrease in membrane potential - and therefore ROS production – but surprisingly increases coupling efficiency under conditions of low ATP turnover. Careful study of the bioenergetic parameters (oxidation and phosphorylation rates, membrane potential of isolated mitochondria from skeletal muscles (gastrocnemius of aged and young rats revealed a remodeling at the level of the phosphorylation system, in the absence of alteration of the inner mitochondrial membrane (uncoupling or respiratory chain complexes regulation. We further observed a decrease in mitochondrial affinity for ADP in aged isolated mitochondria, and higher sensitivity of ANT to its specific inhibitor atractyloside. This age-induced modification of ANT results in an increase in the ADP concentration required to sustain the same ATP turnover as compared to young muscle, and therefore in a lower membrane potential under phosphorylating - in vivo - conditions. Thus, for equivalent ATP turnover (cellular ATP demand, coupling efficiency is even higher in aged muscle mitochondria, due to the down-regulation of inner membrane proton leak caused by the decrease in membrane potential. In the framework of the radical theory of aging, these modifications in ANT function may be the result of oxidative damage caused by intra mitochondrial ROS and may appear like a virtuous circle where ROS induce a mechanism that reduces their production, without causing uncoupling, and even leading in improved efficiency. Because of the importance of ROS as therapeutic targets, this new mechanism deserves further studies.

  3. Hydration properties of natural and synthetic DNA sequences with methylated adenine or cytosine bases in the R.DpnI target and BDNF promoter studied by molecular dynamics simulations

    Science.gov (United States)

    Shanak, Siba; Helms, Volkhard

    2014-12-01

    Adenine and cytosine methylation are two important epigenetic modifications of DNA sequences at the levels of the genome and transcriptome. To characterize the differential roles of methylating adenine or cytosine with respect to their hydration properties, we performed conventional MD simulations and free energy perturbation calculations for two particular DNA sequences, namely the brain-derived neurotrophic factor (BDNF) promoter and the R.DpnI-bound DNA that are known to undergo methylation of C5-methyl cytosine and N6-methyl adenine, respectively. We found that a single methylated cytosine has a clearly favorable hydration free energy over cytosine since the attached methyl group has a slightly polar character. In contrast, capping the strongly polar N6 of adenine with a methyl group gives a slightly unfavorable contribution to its free energy of solvation. Performing the same demethylation in the context of a DNA double-strand gave quite similar results for the more solvent-accessible cytosine but much more unfavorable results for the rather buried adenine. Interestingly, the same demethylation reactions are far more unfavorable when performed in the context of the opposite (BDNF or R.DpnI target) sequence. This suggests a natural preference for methylation in a specific sequence context. In addition, free energy calculations for demethylating adenine or cytosine in the context of B-DNA vs. Z-DNA suggest that the conformational B-Z transition of DNA transition is rather a property of cytosine methylated sequences but is not preferable for the adenine-methylated sequences investigated here.

  4. Can an Excess Electron Localise on a Purine Moiety in the Adenine-thymine Watson-Crick Base Pair? A Computational Study

    Energy Technology Data Exchange (ETDEWEB)

    Mazurkiewicz, Kamil; Haranczyk, Maciej; Gutowski, Maciej S.; Rak, Janusz

    2007-04-17

    The electron affinity and the propensity to electron-induced proton transfer (PT) of hydrogen-bonded complexes between the Watson–Crick adenine–thymine pair (AT) and simple organic acid (HX), attached to adenine in the Hoogsteen-type configuration, were studied at the B3LYP/6-31+G** level. Although the carboxyl group is deprotonated at physiological pH, its neutral form, COOH, resembles the peptide bond or the amide fragment in the side chain of asparagine (Asn) or glutamine (Gln). Thus, these complexes mimic the interaction between the DNA environment (e.g., proteins) and nucleobase pairs incorporated in the biopolymer. Electron attachment is thermodynamically feasible and adiabatic electron affinities range from 0.41 to 1.28 eV, while the vertical detachment energies of the resulting anions span the range of 0.39 –2.88 eV. Low-energy activation barriers separate the anionic minima: aHX(AT) from the more stable single-PT anionic geometry, aHX(AT)-SPT, and aHX(AT)-SPT from the double-PT anionic geometry, aHX(AT)-DPT. Interaction between the adenine of the Watson–Crick AT base pair with an acidic proton donor probably counterbalances the larger EA of isolated thymine, as SOMO is almost evenly delocalized over both types of nucleic bases in the aHX(AT) anions. Moreover, as a result of PT the excess electron localizes entirely on adenine. Thus, in DNA interacting with its physiological environment, damage induced by low-energy electrons could begin, contrary to the current view, with the formation of purine anions, which are not formed in isolated DNA because of the greater stability of anionic pyrimidines.

  5. New Dihydro OO'Bis(Salicylidene 2,2' Aminobenzothiazolyl Borate Complexes: Kinetic and Voltammetric Studies of Dimethyltin Copper Complex with Guanine, Adenine, and Calf Thymus DNA

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available The newly synthesized ligand, dihydro OO'bis(salicylidene 2,2' aminobenzothiazolyl borate (2, was derived from the reaction of Schiff base of 2-aminobenzothiazole and salicylaldehyde with KBH 4 . Cu II (3 and Zn II (4 complexes of (2 were synthesized and further metallated with dimethyltindichloride to yield heterobimetallic complexes (5 and (6. All complexes have been thoroughly characterized by elemental analysis, and IR, NMR, EPR, and UV-Vis spectroscopy and conductance measurements. The spectroscopic data support square planar environment around the Cu II atom, while the Sn IV atom acquires pentacoordinate geometry. The interaction of complex (5 with guanine, adenine, and calf thymus DNA was studied by spectrophotometric, electrochemical, and kinetic methods. The absorption spectra of complex (5 exhibit a remarkable "hyperchromic effect" in the presence of guanine and calf thymus DNA. Indicative of strong binding of the complex to calf thymus DNA preferentially binds through N 7 position of guanine base, while the adenine shows binding to a lesser extent. The kinetic data were obtained from the rate constants, k obs , values under pseudo-first-order conditions. Cyclic voltammetry was employed to study the interaction of complex (5 with guanine, adenine, and calf thymus DNA. The CV of complex (5 in the absence and in the presence of guanine and calf thymus DNA altered drastically, with a positive shift in formal peak potential E pa and E pc values and a significant increase in peak current. The positive shift in formal potentials with increase in peak current favours strong interaction of complex (5 with calf thymus DNA. The net shift in E 1/2 has been used to estimate the ratio of equilibrium constants for the binding of Cu(II and Cu(I complexes to calf thymus DNA.

  6. New Dihydro OO'Bis(Salicylidene) 2,2' Aminobenzothiazolyl Borate Complexes: Kinetic and Voltammetric Studies of Dimethyltin Copper Complex with Guanine, Adenine, and Calf Thymus DNA.

    Science.gov (United States)

    Arjmand, Farukh; Mohani, Bhawana; Parveen, Shamima

    2006-01-01

    The newly synthesized ligand, dihydro OO'bis(salicylidene) 2,2' aminobenzothiazolyl borate (2), was derived from the reaction of Schiff base of 2-aminobenzothiazole and salicylaldehyde with KBH(4). Cu(II) (3) and Zn(II) (4) complexes of (2) were synthesized and further metallated with dimethyltindichloride to yield heterobimetallic complexes (5) and (6). All complexes have been thoroughly characterized by elemental analysis, and IR, NMR, EPR, and UV-Vis spectroscopy and conductance measurements. The spectroscopic data support square planar environment around the Cu(II) atom, while the Sn(IV) atom acquires pentacoordinate geometry. The interaction of complex (5) with guanine, adenine, and calf thymus DNA was studied by spectrophotometric, electrochemical, and kinetic methods. The absorption spectra of complex (5) exhibit a remarkable "hyperchromic effect" in the presence of guanine and calf thymus DNA. Indicative of strong binding of the complex to calf thymus DNA preferentially binds through N(7) position of guanine base, while the adenine shows binding to a lesser extent. The kinetic data were obtained from the rate constants, k(obs), values under pseudo-first-order conditions. Cyclic voltammetry was employed to study the interaction of complex (5) with guanine, adenine, and calf thymus DNA. The CV of complex (5) in the absence and in the presence of guanine and calf thymus DNA altered drastically, with a positive shift in formal peak potential E(pa) and E(pc) values and a significant increase in peak current. The positive shift in formal potentials with increase in peak current favours strong interaction of complex (5) with calf thymus DNA. The net shift in E(1/2) has been used to estimate the ratio of equilibrium constants for the binding of Cu(II) and Cu(I) complexes to calf thymus DNA.

  7. Degradation of Adenine on the Martian Surface in the Presence of Perchlorates and Ionizing Radiation: A Reflectron Time-of-flight Mass Spectrometric Study

    Science.gov (United States)

    Góbi, Sándor; Bergantini, Alexandre; Kaiser, Ralf I.

    2017-04-01

    The aim of the present work is to unravel the radiolytic decomposition of adenine (C5H5N5) under conditions relevant to the Martian surface. Being the fundamental building block of (deoxy)ribonucleic acids, the possibility of survival of this biomolecule on the Martian surface is of primary importance to the astrobiology community. Here, neat adenine and adenine–magnesium perchlorate mixtures were prepared and irradiated with energetic electrons that simulate the secondary electrons originating from the interaction of the galactic cosmic rays with the Martian surface. Perchlorates were added to the samples since they are abundant—and therefore relevant oxidizers on the surface of Mars—and they have been previously shown to facilitate the radiolysis of organics such as glycine. The degradation of the samples were monitored in situ via Fourier transformation infrared spectroscopy and the electron ionization quadruple mass spectrometric method; temperature-programmed desorption profiles were then collected by means of the state-of-the-art single photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS), allowing for the detection of the species subliming from the sample. The results showed that perchlorates do increase the destruction rate of adenine by opening alternative reaction channels, including the concurrent radiolysis/oxidation of the sample. This new pathway provides a plethora of different radiolysis products that were identified for the first time. These are carbon dioxide (CO2), isocyanic acid (HNCO), isocyanate (OCN‑), carbon monoxide (CO), and nitrogen monoxide (NO); an oxidation product containing carbonyl groups (R1R2–C=O) with a constrained five-membered cyclic structure could also be observed. Cyanamide (H2N–C≡N) was detected in both irradiated samples as well.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  9. High negative ion production yield in 30 keV F{sup 2+} + adenine (C{sub 5}H{sub 5}N{sub 5}) collisions

    Energy Technology Data Exchange (ETDEWEB)

    Li, B; Ma, X; Zhu, X L; Zhang, S F; Liu, H P; Feng, W T; Qian, D B; Zhang, D C [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Chen, L; Bredy, R; Montagne, G; Bernard, J; Martin, S [Universite de Lyon, F-69622, Lyon (France) and Universite Lyon 1, Villeurbanne; CNRS, UMR5579, LASIM (France)], E-mail: chen@univ-lyon1.fr

    2009-04-14

    In collisions between slow F{sup 2+} ions (30 keV) and molecular targets, adenine, scattered particle production yields have been measured directly by simultaneous detection of neutrals, positive and negative ions. The relative cross-section for a negative ion formation channel was measured to be 1%. Despite a slight decrease compared to a larger target, the fullerene C{sub 60}, the measured negative ion formation cross section is still at least one order of magnitude larger than the yield in ion-atom interactions.

  10. Changes of collagen and nicotinamide adenine dinucleotide in human cancerous and normal prostate tissues studied using native fluorescence spectroscopy with selective excitation wavelength

    Science.gov (United States)

    Pu, Yang; Wang, Wubao; Tang, Guichen; Alfano, Robert R.

    2010-07-01

    The fluorescence spectra of human cancerous and normal prostate tissues obtained by the selective excitation wavelength of 340 nm were measured. The contributions of principle biochemical components to tissue fluorescence spectra were investigated using the method of multivariate curve resolution with alternating least squares. The results show that there is a reduced contribution from the emission of collagen and increased contribution from nicotinamide adenine dinucleotide (NADH) in cancerous tissues as compared with normal tissue. This difference is attributed to the changes of relative contents of NADH and collagen during cancer development. This research may present a potential native biomarker for prostate cancer detection.

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

    Indian Academy of Sciences (India)

    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.

  12. Characterization of 4-Hydroxyphenylacetate 3-Hydroxylase (HpaB) of Escherichia coli as a Reduced Flavin Adenine Dinucleotide-Utilizing Monooxygenase

    OpenAIRE

    2000-01-01

    4-Hydroxyphenylacetate 3-hydroxylase (HpaB and HpaC) of Escherichia coli W has been reported as a two-component flavin adenine dinucleotide (FAD)-dependent monooxygenase that attacks a broad spectrum of phenolic compounds. However, the function of each component in catalysis is unclear. The large component (HpaB) was demonstrated here to be a reduced FAD (FADH2)-utilizing monooxygenase. When an E. coli flavin reductase (Fre) having no apparent homology with HpaC was used to generate FADH2 in ...

  13. Mechanisms of the Formation of Adenine, Guanine, and Their Analogues in UV-Irradiated Mixed NH3:H2O Molecular Ices Containing Purine

    Science.gov (United States)

    Bera, Partha P.; Stein, Tamar; Head-Gordon, Martin; Lee, Timothy J.

    2017-08-01

    We investigated the formation mechanisms of the nucleobases adenine and guanine and the nucleobase analogues hypoxanthine, xanthine, isoguanine, and 2,6-diaminopurine in a UV-irradiated mixed 10:1 H2O:NH3 ice seeded with precursor purine by using ab initio and density functional theory computations. Our quantum chemical investigations suggest that a multistep reaction mechanism involving purine cation, hydroxyl and amino radicals, together with water and ammonia, explains the experimentally obtained products in an independent study. The relative abundances of these products appear to largely follow from relative thermodynamic stabilities. The key role of the purine cation is likely to be the reason why purine is not functionalized in pure ammonia ice, where cations are promptly neutralized by free electrons from NH3 ionization. Amine group addition to purine is slightly favored over hydroxyl group attachment based on energetics, but hydroxyl is much more abundant due to higher abundance of H2O. The amino group is preferentially attached to the 6 position, giving 6-aminopurine, that is, adenine, while the hydroxyl group is preferentially attached to the 2 position, leading to 2-hydroxypurine. A second substitution by hydroxyl or amino group occurs at either the 6 or the 2 position depending on the first substitution. Given that H2O is far more abundant than NH3 in the experimentally studied ices (as well as based on interstellar abundances), xanthine and isoguanine are expected to be the most abundant bi-substituted photoproducts.

  14. Post-synthetic modification of mesoporous zinc-adeninate framework with tris(2,2′-biprydine) ruthenium(II) complex and its electrochemiluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Eun; Shin, Ik Soo [Dept. of Chemistry, Soongsil University, Seoul (Korea, Republic of); Oh, Hye Jae; An, Ji Hyun [Dept. of Chemistry Education, Seoul National University, Seoul (Korea, Republic of)

    2017-04-15

    Herein we report a redox-active metal-organic framework (MOF) via post-synthetic cation exchange with tris(2,2′-biprydine) ruthenium(II) complex (Ru(bpy){sub 3}{sup 2+}). A porous anionic zinc-adeninate framework (bMOF-100) is spacious enough to easily entrap 2.43 of Ru(bpy){sub 3}{sup 2+} cations within the mesopore. The encapsulation supported the framework structure preventing any distortion from a rapid solvent evaporation under SEM observation. Ru(bpy){sub 3}{sup 2+}@bMOF-100 was then immobilized on the surface of glassy carbon electrode, and its electrocatalytic and electrochemiluminescent (ECL) properties were investigated in aqueous and organic solution. Especially, Ru(bpy){sub 3}{sup 2+}@bMOF-100 showed the excellent electrochemical properties of Ru(bpy){sub 3}{sup 2+}, but gradual decomposition of the MOF structure was observed under electrochemical measurements because of the sluggish oxidation of adeninate ligand.

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

    DEFF Research Database (Denmark)

    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...... suggest that the gene should be renamed gpT. Both enzymes exhibited unusual profiles of activity versus pH. The adenine PRTase showed the highest activity at pH 7.5-8.5, but had a distinct peak of activity also at pH 4.5. The 6-oxo PRTase showed maximal activity with hypoxanthine and guanine around pH 4...

  16. 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.

    Science.gov (United States)

    Rose, Nicholas D; Regan, John M

    2015-12-01

    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 -190 mV (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.

  17. Specific and nonspecific metal ion-nucleotide interactions at aqueous/solid interfaces functionalized with adenine, thymine, guanine, and cytosine oligomers.

    Science.gov (United States)

    Holland, Joseph G; Malin, Jessica N; Jordan, David S; Morales, Esmeralda; Geiger, Franz M

    2011-03-02

    This article reports nonlinear optical measurements that quantify, for the first time directly and without labels, how many Mg(2+) cations are bound to DNA 21-mers covalently linked to fused silica/water interfaces maintained at pH 7 and 10 mM NaCl, and what the thermodynamics are of these interactions. The overall interaction of Mg(2+) with adenine, thymine, guanine, and cytosine is found to involve -10.0 ± 0.3, -11.2 ± 0.3, -14.0 ± 0.4, and -14.9 ± 0.4 kJ/mol, and nonspecific interactions with the phosphate and sugar backbone are found to contribute -21.0 ± 0.6 kJ/mol for each Mg(2+) ion bound. The specific and nonspecific contributions to the interaction energy of Mg(2+) with oligonucleotide single strands is found to be additive, which suggests that within the uncertainty of these surface-specific experiments, the Mg(2+) ions are evenly distributed over the oligomers and not isolated to the most strongly binding nucleobase. The nucleobases adenine and thymine are found to bind only three Mg(2+) ions per 21-mer oligonucleotide, while the bases cytosine and guanine are found to bind eleven Mg(2+) ions per 21-mer oligonucleotide.

  18. Acidity and complex formation studies of 3-(adenine-9-yl)-propionic and 3-(thymine-1-yl)-propionic acids in ethanol-water media

    Science.gov (United States)

    Hammud, Hassan H.; El Shazly, Shawky; Sonji, Ghassan; Sonji, Nada; Bouhadir, Kamal H.

    2015-05-01

    The ligands 3-(adenine-9-yl)propionic acid (AA) and 3-(thymine-1-yl)propionic acid (TA) were prepared by N9-alkylation of adenine and N1-alkylation of thymine with ethylacrylate in presence of a base catalyst, followed by acid hydrolysis of the formed ethyl esters to give the corresponding propionic acid derivatives. The products were characterized by spectral methods (FTIR, 1H NMR and 13C NMR), which confirm their structures. The dissociation constants of ligands, were potentiometrically determined in 0.3 M KCl at 20-50 °C temperature range. The work was extended to study complexation behavior of AA and TA with various biologically important divalent metal ions (Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Mn2+ and Pb2+) in 50% v/v water-ethanol medium at four different temperatures, keeping ionic strength constant (0.3 M KCl). The order of the stability constants of the formed complexes decreases in the sequence Cu2+ > Pb2+ > Zn2+ > Ni2+ > Co2+ > Mn2+ > Cd2+ for both ligands. The effect of temperature was also studied and the corresponding thermodynamic functions (ΔG, ΔH, ΔS) were derived and discussed. The formation of metal complexes has been found to be spontaneous, and the stability constants were dependant markedly on the basicity of the ligands.

  19. 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

    KAUST Repository

    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.

  20. 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

    DEFF Research Database (Denmark)

    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......-phosphoribosyl-α-1-pyrophosphate (PRPP) and adenine or the product AMP or the inhibitor ADP in each active site. The individual subunit adopts an overall structure that resembles a 6-oxopurine phosphoribosyltransferase (PRTase) more than known APRTases implying that APRT functionality in Crenarchaeotae has its...... undergoes a conformational change upon binding of adenine and phosphate resulting in a slight contraction of the active site. The inhibitor, ADP binds like the product AMP with both the α- and β-phosphates occupying the 5’-phosphoribosyl binding site. The enzyme shows activity over a wide p...

  1. A preliminary study on adenine-limited control during the ribavirin fermentation%利巴韦林发酵过程中腺嘌呤限量供应的初步研究

    Institute of Scientific and Technical Information of China (English)

    刘莉; 王法松; 李燕军; 谢希贤; 陈宁

    2015-01-01

    Bacillus amyloliquefaciens TA208-LM is a guanosine producer with adenine auxotrophy.The adenine concentration in the fermentation broth is a critical factor because too little adenine will affect the growth of bacteria,while too much will restrain the synthesis of keyenzymes.Firstly the type of adenine donor and its appropriate concentration were optimized.The results indicated that Springer 2506 was the best adenine donor,and 15 g/L was optimal for ribavirin accumulation.However,the concentration of adenine released from this dose of Springer 2506 was too high at the end of fermentation.Therefore,the initial quantity of Springer 2506 was reduced and extra adenine was added.The results indicated that the activity of PRPP amidotransferase and the titer of ribavirin were both highest when the optimal initial adenine concentration was 47.95 mg/L and accordingly the adenine in the fermentation liquid was maintained at 40 ~ 50 mg/L.This data indicated that controlling the initial addition of yeast extract and further feeding appropriate quantity of yeast extract was likely a feasible way to control adenine concentration in the fermentation.Springer 2506 fed-batch fermentation in 7.5 L fermentation tank was studied.When 7.5 g/L Springer 2506 was used as substrate and another 7.5 g/L Springer 2506 was fed into the fermentation broth,the ribavirin production increased by 11.29% compared to one-time addition of 15 g/L Springer 2506.The study on limited control of adenine would provide some useful guidance for industrial production of ribavirin.%解淀粉芽孢杆菌(Bacillus amyloliquefaciens)TA208-LM是腺嘌呤缺陷型突变株,腺嘌呤浓度过低会影响菌体生长,过高又会反馈阻遏关键酶的合成.首先对腺嘌呤供体的种类和用量进行了研究,摇瓶发酵结果表明Springer 2506是最佳的腺嘌呤供体,用量在15 g/L时最有利于利巴韦林积累,但发酵后期腺嘌呤浓度过高.因此在降低Springer 2506的初始浓度的基

  2. Selective inhibitory effect of (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine and 2'-nor-cyclic GMP on adenovirus replication in vitro.

    Science.gov (United States)

    Baba, M; Mori, S; Shigeta, S; De Clercq, E

    1987-02-01

    The inhibitory effects of 20 selected antiviral compounds on the replication of adenoviruses (types 1 to 8) in vitro were investigated. While 18 compounds were ineffective, 2 compounds, namely (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA] and 9-[(2-hydroxy-1,3,2-dioxaphosphorinan-5-yl)oxymethyl]guanine P-oxide (2'-nor-cyclic GMP), were highly effective against all adenovirus types assayed in human embryonic fibroblast cultures. Their 50% inhibitory doses were 1.1 microgram/ml for (S)-HPMPA and 4.1 micrograms/ml for 2'-nor-cyclic GMP. They were nontoxic for the host cells at the effective antiviral doses.

  3. Regulation of Ca²⁺ release through inositol 1,4,5-trisphosphate receptors by adenine nucleotides in parotid acinar cells.

    Science.gov (United States)

    Park, Hyung Seo; Betzenhauser, Matthew J; Zhang, Yu; Yule, David I

    2012-01-01

    Secretagogue-stimulated intracellular Ca(2+) signals are fundamentally important for initiating the secretion of the fluid and ion component of saliva from parotid acinar cells. The Ca(2+) signals have characteristic spatial and temporal characteristics, which are defined by the specific properties of Ca(2+) release mediated by inositol 1,4,5-trisphosphate receptors (InsP(3)R). In this study we have investigated the role of adenine nucleotides in modulating Ca(2+) release in mouse parotid acinar cells. In permeabilized cells, the Ca(2+) release rate induced by submaximal [InsP(3)] was increased by 5 mM ATP. Enhanced Ca(2+) release was not observed at saturating [InsP(3)]. The EC(50) for the augmented Ca(2+) release was ∼8 μM ATP. The effect was mimicked by nonhydrolysable ATP analogs. ADP and AMP also potentiated Ca(2+) release but were less potent than ATP. In acini isolated from InsP(3)R-2-null transgenic animals, the rate of Ca(2+) release was decreased under all conditions but now enhanced by ATP at all [InsP(3)]. In addition the EC(50) for ATP potentiation increased to ∼500 μM. These characteristics are consistent with the properties of the InsP(3)R-2 dominating the overall features of InsP(3)R-induced Ca(2+) release despite the expression of all isoforms. Finally, Ca(2+) signals were measured in intact parotid lobules by multiphoton microscopy. Consistent with the release data, carbachol-stimulated Ca(2+) signals were reduced in lobules exposed to experimental hypoxia compared with control lobules only at submaximal concentrations. Adenine nucleotide modulation of InsP(3)R in parotid acinar cells likely contributes to the properties of Ca(2+) signals in physiological and pathological conditions.

  4. Data supporting the involvement of the adenine nucleotide translocase conformation in opening the Tl+-induced permeability transition pore in Ca2+-loaded rat liver mitochondria

    Directory of Open Access Journals (Sweden)

    Sergey M. Korotkov

    2016-06-01

    Full Text Available 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 Ca2+-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 Ca2+. The fixers and DIDS, in comparison to Ca2+ alone, greatly increased A540 decline and the rate of Ca2+-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 Ca2+-loaded rat liver mitochondria” (Korotkov et al., 2016 [1].

  5. Two novel mutations in the reduced nicotinamide adenine dinucleotide (NADH)-cytochrome b5 reductase gene of a patient with generalized type, hereditary methemoglobinemia.

    Science.gov (United States)

    Manabe, J; Arya, R; Sumimoto, H; Yubisui, T; Bellingham, A J; Layton, D M; Fukumaki, Y

    1996-10-15

    Hereditary methemoglobinemia due to reduced nicotinamide adenine dinucleotide (NADH) cytochrome b5 reductase (b5R) deficiency is classified into two types, an erythrocyte (type I) and a generalized (type II). We investigated the b5R gene of a patient with type II from a white United Kingdom (UK) family and found that the patient was a compound heterozygote for two novel mutations. The first mutation was a C-to-A transversion changing codon 42 (TAC: Tyr) to a stop codon in the one allele. From this mutant allele, the product without the catalytic portion of the enzyme is generated. The second one was a missense mutation at codon 95 (CCC-->CAC) in the other allele with the result that Pro changed to His within the flavin adenine dinucleotide (FAD)-binding domain of the enzyme. To characterize effects of this missense mutation on the enzyme function, we compared glutathione S-transferase (GST)-fused b5R with the GST-fused mutant enzyme with the codon 95 missense mutation (P95H) expressed in Escherichia coll. The mutant enzyme showed less catalytic activity, less thermostability, and a greater susceptibility to trypsin than did the normal counterpart. The absorption spectrum of the mutant enzyme in the visual region differed from that of the wild-type. These results suggest that this amino acid substitution influences both secondary structure and catalytic activity of the enzyme. The compound heterozygosity for the nonsense and the missense mutations apparently caused hereditary methemoglobinemia type II in this patient.

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

    Science.gov (United States)

    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

  7. An important role for adenine, cholera toxin, hydrocortisone and triiodothyronine in the proliferation, self-renewal and differentiation of limbal stem cells in vitro.

    Science.gov (United States)

    Yu, Min; Bojic, Sanja; Figueiredo, Gustavo S; Rooney, Paul; de Havilland, Julian; Dickinson, Anne; Figueiredo, Francisco C; Lako, Majlinda

    2016-11-01

    The cornea is a self-renewing tissue located at the front of the eye. Its transparency is essential for allowing light to focus onto the retina for visual perception. The continuous renewal of corneal epithelium is supported by limbal stem cells (LSCs) which are located in the border region between conjunctiva and cornea known as the limbus. Ex vivo expansion of LSCs has been successfully applied in the last two decades to treat patients with limbal stem cell deficiency (LSCD). Various methods have been used for their expansion, yet the most widely used culture media contains a number of ingredients derived from animal sources which may compromise the safety profile of human LSC transplantation. In this study we sought to understand the role of these components namely adenine, cholera toxin, hydrocortisone and triiodothyronine with the aim of re-defining a safe and GMP compatible minimal media for the ex vivo expansion of LSCs on human amniotic membrane. Our data suggest that all four components play a critical role in maintaining LSC proliferation and promoting LSC self-renewal. However removal of adenine and triiodothyronine had a more profound impact and led to LSC differentiation and loss of viability respectively, suggesting their essential role for ex vivo expansion of LSCs. Replacement of each of the components with GMP-grade reagents resulted in equal growth to non-GMP grade media, however an enhanced differentiation of LSCs was observed, suggesting that additional combinations of GMP grade reagents need to be tested to achieve similar or better level of LSC maintenance in the same manner as the traditional LSC media.

  8. A label-free fluorescence strategy for selective detection of nicotinamide adenine dinucleotide based on a dumbbell-like probe with low background noise.

    Science.gov (United States)

    Chen, Xuexu; Lin, Chunshui; Chen, Yiying; Wang, Yiru; Chen, Xi

    2016-03-15

    In this work we developed a novel label-free fluorescence sensing approach for the detection of nicotinamide adenine dinucleotide (NAD(+)) based on a dumbbell-like DNA probe designed for both ligation reaction and digestion reaction with low background noise. SYBR Green I (SG I), a double-helix dye, was chosen as the readout fluorescence signal. In the absence of NAD(+), the ligation reaction did not occur, but the probe was digested to mononucleotides after the addition of exonuclease I (Exo I) and exonuclease I (Exo III), resulting in a weak fluorescence intensity due to the weak interaction between SG I and mononucleotides. In the presence of NAD(+), the DNA probe was ligated by Escherichia coli DNA ligase, blocking the digestion by Exo I and Exo III. As a result, SG I was intercalated into the stem part of the DNA dumbbell probe and fluorescence enhancement was achieved. This method was simple in design, fast to operate, with good sensitivity and selectivity which could discriminate NAD(+) from its analogs.

  9. Discovery of Nicotinamide Adenine Dinucleotide Binding Proteins in the Escherichia coli Proteome Using a Combined Energetic- and Structural-Bioinformatics-Based Approach.

    Science.gov (United States)

    Zeng, Lingfei; Shin, Woong-Hee; Zhu, Xiaolei; Park, Sung Hoon; Park, Chiwook; Tao, W Andy; Kihara, Daisuke

    2017-02-03

    Protein-ligand interaction plays a critical role in regulating the biochemical functions of proteins. Discovering protein targets for ligands is vital to new drug development. Here, we present a strategy that combines experimental and computational approaches to identify ligand-binding proteins in a proteomic scale. For the experimental part, we coupled pulse proteolysis with filter-assisted sample preparation (FASP) and quantitative mass spectrometry. Under denaturing conditions, ligand binding affected protein stability, which resulted in altered protein abundance after pulse proteolysis. For the computational part, we used the software Patch-Surfer2.0. We applied the integrated approach to identify nicotinamide adenine dinucleotide (NAD)-binding proteins in the Escherichia coli proteome, which has over 4200 proteins. Pulse proteolysis and Patch-Surfer2.0 identified 78 and 36 potential NAD-binding proteins, respectively, including 12 proteins that were consistently detected by the two approaches. Interestingly, the 12 proteins included 8 that are not previously known as NAD binders. Further validation of these eight proteins showed that their binding affinities to NAD computed by AutoDock Vina are higher than their cognate ligands and also that their protein ratios in the pulse proteolysis are consistent with known NAD-binding proteins. These results strongly suggest that these eight proteins are indeed newly identified NAD binders.

  10. Identification of a compound heterozygote for adenine phosphoribosyltransferase deficiency (APRT*J/APART*Q0) leading to 2,8-dihydroxyadenine urolithiasis.

    Science.gov (United States)

    Kamatani, N; Kuroshima, S; Yamanaka, H; Nakashe, S; Take, H; Hakoda, M

    1990-10-01

    Homozygous deficiency of a purine salvage enzyme, adenine phosphoribosyltransferase (APRT), causes urolithiasis and renal failure. There are two known types of homozygous APRT deficiencies; type I patients completely lack APRT activity while type II patients only partially lack such activity. All type II patients possess at least one APRT*J allele with a substitution from ATG (Met) to ACG (Thr) at codon 136. Type I patients are considered to possess two alleles (APRT*Q0) both of which code for complete deficiencies. Thus, some patients with type II APRT deficiencies may have a genotype of APRT*J/APRT*Q0. As no individuals with such a genotype have previously been identified, we performed extensive analysis on four members of a family by (1) the T-cell method for the identification of a homozygote, (2) the B-cell method for the identification of heterozygotes, and (3) oligonucleotide hybridization after in vitro amplification of a part of genomic APRT sequence for the identification of APRT*J and non-APRT*J alleles. We report here the first evidence that 2,8-dihydroxyadenine urolithiasis developed in a boy aged 2 years with a genotype of APRT*J/APRT*Q0.

  11. Inhibition of lactate production in rat brain extracts and synaptosomes by 3-[4-(reduced 3-pyridine aldehyde-adenine dinucleotide)]-pyruvate.

    Science.gov (United States)

    Cooper, A J; Lai, J C; Coleman, A E; Pulsinelli, W A

    1987-06-01

    In basic solutions, pyruvate enolizes and reacts (through its 3-carbon) with the 4-carbon of the nicotinamide ring of NAD+, yielding an NAD-pyruvate adduct in which the nicotinamide ring is in the reduced form. This adduct is a strong inhibitor of lactate dehydrogenase, presumably because it binds simultaneously to the NADH and pyruvate sites. The potency of the inhibition, however, is muted by the adduct's tendency to cyclize to a lactam. We prepared solutions of the pyruvate adduct of NAD+ and of NAD+ analogues in which the -C(O)NH2 of NAD+ was replaced with -C(S)NH2, -C(O)CH3, and -C(O)H. Of the four, only the last analogue, 3-[4-(reduced 3-pyridine aldehyde-adenine dinucleotide)]-pyruvate (RAP) cannot cyclize and it was found to be the most potent inhibitor of beef heart and rat brain lactate dehydrogenases. The inhibitor binds very tightly to the NADH site (Ki approximately 1 nM for the A form). Even at high concentrations (20 microM), RAP had little or no effect on rat brain glyceraldehyde-3-phosphate, pyruvate, alpha-ketoglutarate, isocitrate, soluble and mitochondrial malate, and glutamate dehydrogenases. The glycolytic enzymes, hexokinase and phosphofructokinase, were similarly unaffected. RAP strongly inhibited lactate production from glucose in rat brain extracts but was less effective in inhibiting lactate production from glucose in synaptosomes.

  12. Protective effect of nicotinamide adenine dinucleotide (NAD(+)) against spinal cord ischemia-reperfusion injury via reducing oxidative stress-induced neuronal apoptosis.

    Science.gov (United States)

    Xie, Lei; Wang, Zhenfei; Li, Changwei; Yang, Kai; Liang, Yu

    2017-02-01

    As previous studies demonstrate that oxidative stress and apoptosis play crucial roles in ischemic pathogenesis and nicotinamide adenine dinucleotide (NAD(+)) treatment attenuates oxidative stress-induced cell death among primary neurons and astrocytes as well as significantly reduce cerebral ischemic injury in rats. We used a spinal cord ischemia injury (SCII) model in rats to verify our hypothesis that NAD(+) could ameliorate oxidative stress-induced neuronal apoptosis. Adult male rats were subjected to transient spinal cord ischemia for 60min, and different doses of NAD(+) were administered intraperitoneally immediately after the start of reperfusion. Neurological function was determined by Basso, Beattie, Bresnahan (BBB) scores. The oxidative stress level was assessed by superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The degree of apoptosis was analyzed by deoxyuridinetriphosphate nick-end labeling (TUNEL) staining and protein levels of cleaved caspase-3 and AIF (apoptosis inducing factor). The results showed that NAD(+) at 50 or 100mg/kg significantly decreased the oxidative stress level and neuronal apoptosis in the spinal cord of ischemia-reperfusion rats compared with saline, as accompanied with the decreased oxidative stress, NAD(+) administration significantly restrained the neuronal apoptosis after ischemia injury while improved the neurological and motor function. These findings suggested that NAD(+) might protect against spinal cord ischemia-reperfusion via reducing oxidative stress-induced neuronal apoptosis.

  13. Quantum-classical effective-modes dynamics of the pipi* --> npi* decay in 9H-adenine. A quadratic vibronic coupling model.

    Science.gov (United States)

    Picconi, David; Ferrer, Francisco José Avila; Improta, Roberto; Lami, Alessandro; Santoro, Fabrizio

    2013-01-01

    We present mixed quantum-classical simulation of the internal conversion between the lowest energy pipi* (S(La)) and npi* (S(n)) excited electronic states in adenine in the gas phase, adopting a quadratic vibronic model (QVC), parametrized with the help of PBE0 density functional calculations. Our approach is based on a hierarchical representation of the QVC Hamiltonian and a subsequent treatment of the most relevant coordinates at accurate time-dependent quantum level and of the other 'bath' modes at classical level. We predict an ultrafast transfer (-30 fs) of approximately 75% of the initial population excited on S(La) to S(n). Within an adiabatic picture, on the same timescale the wave packet concentrates almost completely on the lowest S1 state, where however it shows a very broad distribution with different characteristics (due to the different 'diabatic' character). It is shown that the proposed methodology offers a practicable route to describe the quantum dynamics of internal conversion processes in large semi-rigid systems.

  14. 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.

    Science.gov (United States)

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Changes in serum and urinary uric acid levels in normal human subjects fed purine-rich foods containing different amounts of adenine and hypoxanthine.

    Science.gov (United States)

    Brulé, D; Sarwar, G; Savoie, L

    1992-06-01

    The effect of ingesting some purine-rich foods (beef liver, haddock fillets and soybeans) on uric acid metabolism was investigated in 18 male subjects with no history of gout or kidney disorder. In a crossover design, three isoenergetic and isonitrogenous meals were fed to volunteers during a 3-week period. Only the content of uricogenic bases (adenine and hypoxanthine) varied among the test meals. Ingestion of all experimental meals caused an increase in serum uric acid levels at 120 minutes and this increase was more marked (about twofold) with haddock and soybean ingestion. In all groups, the postprandial serum uric acid levels at 240 minutes were lower than those obtained at 120 minutes, but still remained elevated in comparison to the fasting level. The test foods had little or no effect on serum and urinary creatinine values. As expected, 24-hour urinary uric acid excretion was similar for the three test meals due to the isonitrogenous load of proteins and purines. Assessment of each purine base content rather than the total purine content of foods should be considered in future recommendations for hyperuricemic individuals.

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

    Science.gov (United States)

    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.

  17. Enzyme-Mediated Conversion of Flavin Adenine Dinucleotide (FAD) to 8-Formyl FAD in Formate Oxidase Results in a Modified Cofactor with Enhanced Catalytic Properties.

    Science.gov (United States)

    Robbins, John M; Souffrant, Michael G; Hamelberg, Donald; Gadda, Giovanni; Bommarius, Andreas S

    2017-07-25

    Flavins, including flavin adenine dinucleotide (FAD), are fundamental catalytic cofactors that are responsible for the redox functionality of a diverse set of proteins. Alternatively, modified flavin analogues are rarely found in nature as their incorporation typically results in inactivation of flavoproteins, thus leading to the disruption of important cellular pathways. Here, we report that the fungal flavoenzyme formate oxidase (FOX) catalyzes the slow conversion of noncovalently bound FAD to 8-formyl FAD and that this conversion results in a nearly 10-fold increase in formate oxidase activity. Although the presence of an enzyme-bound 8-formyl FMN has been reported previously as a result of site-directed mutagenesis studies of lactate oxidase, FOX is the first reported case of 8-formyl FAD in a wild-type enzyme. Therefore, the formation of the 8-formyl FAD cofactor in formate oxidase was investigated using steady-state kinetics, site-directed mutagenesis, ultraviolet-visible, circular dichroism, and fluorescence spectroscopy, liquid chromatography with mass spectrometry, and computational analysis. Surprisingly, the results from these studies indicate not only that 8-formyl FAD forms spontaneously and results in the active form of FOX but also that its autocatalytic formation is dependent on a nearby arginine residue, R87. Thus, this work describes a new enzyme cofactor and provides insight into the little-understood mechanism of enzyme-mediated 8α-flavin modifications.

  18. Tissue-specific regulation of sirtuin and nicotinamide adenine dinucleotide biosynthetic pathways identified in C57Bl/6 mice in response to high-fat feeding.

    Science.gov (United States)

    Drew, Janice E; Farquharson, Andrew J; Horgan, Graham W; Williams, Lynda M

    2016-11-01

    The sirtuin (SIRT)/nicotinamide adenine dinucleotide (NAD) system is implicated in development of type 2 diabetes (T2D) and diet-induced obesity, a major risk factor for T2D. Mechanistic links have not yet been defined. SIRT/NAD system gene expression and NAD/NADH levels were measured in liver, white adipose tissue (WAT) and skeletal muscle from mice fed either a low-fat diet or high-fat diet (HFD) for 3 days up to 16 weeks. An in-house custom-designed multiplex gene expression assay assessed all 7 mouse SIRTs (SIRT1-7) and 16 enzymes involved in conversion of tryptophan, niacin, nicotinamide riboside and metabolic precursors to NAD. Significantly altered transcription was correlated with body weight, fat mass, plasma lipids and hormones. Regulation of the SIRT/NAD system was associated with early (SIRT4, SIRT7, NAPRT1 and NMNAT2) and late phases (NMNAT3, NMRK2, ABCA1 and CD38) of glucose intolerance. TDO2 and NNMT were identified as markers of HFD consumption. Altered regulation of the SIRT/NAD system in response to HFD was prominent in liver compared with WAT or muscle. Multiple components of the SIRTs and NAD biosynthetic enzymes network respond to consumption of dietary fat. Novel molecular targets identified above could direct strategies for dietary/therapeutic interventions to limit metabolic dysfunction and development of T2D.

  19. Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP)-mediated Calcium Signaling and Arrhythmias in the Heart Evoked by β-Adrenergic Stimulation*♦

    Science.gov (United States)

    Nebel, Merle; Schwoerer, Alexander P.; Warszta, Dominik; Siebrands, Cornelia C.; Limbrock, Ann-Christin; Swarbrick, Joanna M.; Fliegert, Ralf; Weber, Karin; Bruhn, Sören; Hohenegger, Martin; Geisler, Anne; Herich, Lena; Schlegel, Susan; Carrier, Lucie; Eschenhagen, Thomas; Potter, Barry V. L.; Ehmke, Heimo; Guse, Andreas H.

    2013-01-01

    Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent Ca2+-releasing second messenger known to date. Here, we report a new role for NAADP in arrhythmogenic Ca2+ release in cardiac myocytes evoked by β-adrenergic stimulation. Infusion of NAADP into intact cardiac myocytes induced global Ca2+ signals sensitive to inhibitors of both acidic Ca2+ stores and ryanodine receptors and to NAADP antagonist BZ194. Furthermore, in electrically paced cardiac myocytes BZ194 blocked spontaneous diastolic Ca2+ transients caused by high concentrations of the β-adrenergic agonist isoproterenol. Ca2+ transients were recorded both as increases of the free cytosolic Ca2+ concentration and as decreases of the sarcoplasmic luminal Ca2+ concentration. Importantly, NAADP antagonist BZ194 largely ameliorated isoproterenol-induced arrhythmias in awake mice. We provide strong evidence that NAADP-mediated modulation of couplon activity plays a role for triggering spontaneous diastolic Ca2+ transients in isolated cardiac myocytes and arrhythmias in the intact animal. Thus, NAADP signaling appears an attractive novel target for antiarrhythmic therapy. PMID:23564460

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

    CERN Document Server

    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 ...

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

    Science.gov (United States)

    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.

  2. Bisamidate Prodrugs of 2-Substituted 9-[2-(Phosphonomethoxy)ethyl]adenine (PMEA, adefovir) as Selective Inhibitors of Adenylate Cyclase Toxin from Bordetella pertussis.

    Science.gov (United States)

    Česnek, Michal; Jansa, Petr; Šmídková, Markéta; Mertlíková-Kaiserová, Helena; Dračínský, Martin; Brust, Tarsis F; Pávek, Petr; Trejtnar, František; Watts, Val J; Janeba, Zlatko

    2015-08-01

    Novel small-molecule agents to treat Bordetella pertussis infections are highly desirable, as pertussis (whooping cough) remains a serious health threat worldwide. In this study, a series of 2-substituted derivatives of 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA, adefovir), in their isopropyl ester bis(L-phenylalanine) prodrug form, were designed and synthesized as potent inhibitors of adenylate cyclase toxin (ACT) isolated from B. pertussis. The series consists of PMEA analogues bearing either a linear or branched aliphatic chain or a heteroatom at the C2 position of the purine moiety. Compounds with a small C2 substituent showed high potency against ACT without cytotoxic effects as well as good selectivity over human adenylate cyclase isoforms AC1, AC2, and AC5. The most potent ACT inhibitor was found to be the bisamidate prodrug of the 2-fluoro PMEA derivative (IC50 =0.145 μM). Although the bisamidate prodrugs reported herein exhibit overall lower activity than the bis(pivaloyloxymethyl) prodrug (adefovir dipivoxil), their toxicity and plasma stability profiles are superior. Furthermore, the bisamidate prodrug was shown to be more stable in plasma than in macrophage homogenate, indicating that the free phosphonate can be effectively distributed to target tissues, such as the lungs. Thus, ACT inhibitors based on acyclic nucleoside phosphonates may represent a new strategy to treat whooping cough.

  3. Enhancement of anaerobic degradation of azo dye with riboflavin and nicotinamide adenine dinucleotide harvested by osmotic lysis of wasted fermentation yeasts.

    Science.gov (United States)

    Victral, Davi M; Dias, Heitor R A; Silva, Silvana Q; Baeta, Bruno E L; Aquino, Sérgio F

    2017-02-01

    The study presented here aims at identifying the source of redox mediators (riboflavin), electron carriers nicotinamide adenine dinucleotide (NAD) and carbon to perform decolorization of azo dye under anaerobic conditions after osmotic shock pretreatment of residual yeast from industrial fermentation. Pretreatment conditions were optimized by Doehlert experiment, varying NaCl concentration, temperature, yeast density and time. After the optimization, the riboflavin concentration in the residual yeast lysate (RYL) was 46% higher than the one present in commercial yeast extract. Moreover, similar NAD concentration was observed in both extracts. Subsequently, two decolorization experiments were performed, that is, a batch experiment (48 h) and a kinetic experiment (102 h). The results of the batch experiment showed that the use of the RYL produced by the optimized method increased decolorization rates and led to color removal efficiencies similar to those found when using the commercial extract (∼80%) and from 23% to 50% higher when compared to the control (without redox mediators). Kinetics analysis showed that methane production was also higher in the presence of yeast extract and RYL, and biogas was mostly generated after stabilization of color removal. In all kinetics experiments the azo dye degradation followed the pseudo-second-order model, which suggested that there was a concomitant adsorption/degradation of the dye on the biomass cell surface. Therefore, results showed the possibility of applying the pretreated residual yeast to improve color removal under anaerobic conditions, which is a sustainable process.

  4. 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.

    Science.gov (United States)

    Serrano, Ana; Frago, Susana; Velázquez-Campoy, Adrián; Medina, Milagros

    2012-11-08

    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.

  5. Spectroscopy and Speciation Studies on the Interactions of Aluminum (III with Ciprofloxacin and β-Nicotinamide Adenine Dinucleotide Phosphate in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Xiaodi Yang

    2012-08-01

    Full Text Available In this study, both experimental and theoretical approaches, including absorption spectra, fluorescence emission spectra, 1H- and 31P-NMR, electrospray ionization mass spectrometry (ESI-MS, pH-potentiometry and theoretical approaches using the BEST & SPE computer programs were applied to study the competitive complexation between ciprofloxacin (CIP and b-nicotinamide adenine dinucleotide phosphate (NADP with aluminum (III in aqueous solutions. Rank annihilation factor analysis (RAFA was used to analyze the absorption and fluorescence emission spectra of the ligands, the binary complexes and the ternary complexes. It is found, at the mM total concentration level and pH = 7.0, the bidentate mononuclear species [Al(CIP]2+ and [Al(NADP] predominate in the aqueous solutions of the Al(III-CIP and Al(III-NADP systems, and the two complexes have similar conditional stability constants. However, the pH-potentiometry results show at the mM total concentration level and pH = 7.0, the ternary species [Al(CIP(HNADP] predominates in the ternary complex system. Comparing predicted NMR spectra with the experimental NMR results, it can be concluded that for the ternary complex, CIP binds to aluminum ion between the 3-carboxylic and 4-carbonyl groups, while the binding site of oxidized coenzyme II is through the oxygen of phosphate, which is linked to adenosine ribose, instead of pyrophosphate. The results also suggested CIP has the potential to be a probe molecular for the detection of NADP and the Al(III-NADP complexes under physiological condition.

  6. The distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) in the medulla oblongata, spinal cord, cranial and spinal nerves of frog, Microhyla ornata.

    Science.gov (United States)

    Jadhao, Arun G; Biswas, Saikat P; Bhoyar, Rahul C; Pinelli, Claudia

    2017-04-01

    Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) enzymatic activity has been reported in few amphibian species. In this study, we report its unusual localization in the medulla oblongata, spinal cord, cranial nerves, spinal nerves, and ganglions of the frog, Microhyla ornata. In the rhombencephalon, at the level of facial and vagus nerves, the NADPH-d labeling was noted in the nucleus of the abducent and facial nerves, dorsal nucleus of the vestibulocochlear nerve, the nucleus of hypoglossus nerve, dorsal and lateral column nucleus, the nucleus of the solitary tract, the dorsal field of spinal grey, the lateral and medial motor fields of spinal grey and radix ventralis and dorsalis (2-10). Many ependymal cells around the lining of the fourth ventricle, both facial and vagus nerves and dorsal root ganglion, were intensely labeled with NADPH-d. Most strikingly the NADPH-d activity was seen in small and large sized motoneurons in both medial and lateral motor neuron columns on the right and left sides of the brain. This is the largest stained group observed from the caudal rhombencephalon up to the level of radix dorsalis 10 in the spinal cord. The neurons were either oval or elongated in shape with long processes and showed significant variation in the nuclear and cellular diameter. A massive NADPH-d activity in the medulla oblongata, spinal cord, and spinal nerves implied an important role of this enzyme in the neuronal signaling as well as in the modulation of motor functions in the peripheral nervous systems of the amphibians.

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

    Science.gov (United States)

    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.

  8. 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

    Science.gov (United States)

    2012-01-01

    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 (CTGF)in 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 Telmisartan treatment significantly attenuated these changes in diabetic rats (P 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. PMID:22873349

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Electrochemical synthesis and characterization of TiO(2) nanoparticles and their use as a platform for flavin adenine dinucleotide immobilization and efficient electrocatalysis.

    Science.gov (United States)

    Ashok Kumar, S; Lo, Po-Hsun; Chen, Shen-Ming

    2008-06-25

    Here, we report the electrochemical synthesis of TiO(2) nanoparticles (NPs) using the potentiostat method. Synthesized particles have been characterized by using x-ray diffraction (XRD) studies, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results revealed that the TiO(2) film produced was mainly composed of rutile and that the particles are of a size in the range of 100 ± 50 nm. TiO(2) NPs were used for the modification of a screen printed carbon electrode (SPE). The resulting TiO(2) film coated SPE was used to immobilize flavin adenine dinucleotide (FAD). The flavin enzyme firmly attached onto the metal oxide surface and this modified electrode showed promising electrocatalytic activities towards the reduction of hydrogen peroxide (H(2)O(2)) in physiological conditions. The electrochemistry of FAD confined in the oxide film was investigated. The immobilized FAD displayed a pair of redox peaks with a formal potential of -0.42 V in pH 7.0 oxygen-free phosphate buffers at a scan rate of 50 mV s(-1). The FAD in the nanostructured TiO(2) film retained its bioactivity and exhibited excellent electrocatalytic response to the reduction of H(2)O(2), based on which a mediated biosensor for H(2)O(2) was achieved. The linear range for the determination of H(2)O(2) was from 0.15 × 10(-6) to 3.0 × 10(-3) M with the detection limit of 0.1 × 10(-6) M at a signal-to-noise ratio of 3. The stability and repeatability of the biosensor is also discussed.

  11. Structure-guided mutational analysis of gene regulation by the Bacillus subtilis pbuE adenine-responsive riboswitch in a cellular context.

    Science.gov (United States)

    Marcano-Velázquez, Joan G; Batey, Robert T

    2015-02-13

    Riboswitches are a broadly distributed form of RNA-based gene regulation in Bacteria and, more rarely, Archaea and Eukarya. Most often found in the 5'-leader sequence of bacterial mRNAs, they are generally composed of two functional domains: a receptor (aptamer) domain that binds an effector molecule and a regulatory domain (or expression platform) that instructs the expression machinery. One of the most studied riboswitches is the Bacillus subtilis adenine-responsive pbuE riboswitch, which regulates gene expression at the transcriptional level, up-regulating expression in response to increased intracellular effector concentrations. In this work, we analyzed sequence and structural elements that contribute to efficient ligand-dependent regulatory activity in a co-transcriptional and cellular context. Unexpectedly, we found that the P1 helix, which acts as the antitermination element of the switch in this RNA, supported ligand-dependent activation of a reporter gene over a broad spectrum of lengths from 3 to 10 bp. This same trend was also observed using a minimal in vitro single-turnover transcription assay, revealing that this behavior is intrinsic to the RNA sequence. We also found that the sequences at the distal tip of the terminator not directly involved in alternative secondary structure formation are highly important for efficient regulation. These data strongly support a model in which the switch is highly localized to the P1 helix adjacent to the ligand-binding pocket that likely presents a local kinetic block to invasion of the aptamer by the terminator.

  12. A Novel Nicotinamide Adenine Dinucleotide Correction Method for Mitochondrial Ca(2+) Measurement with FURA-2-FF in Single Permeabilized Ventricular Myocytes of Rat.

    Science.gov (United States)

    Lee, Jeong Hoon; Ha, Jeong Mi; Leem, Chae Hun

    2015-07-01

    Fura-2 analogs are ratiometric fluoroprobes that are widely used for the quantitative measurement of [Ca(2+)]. However, the dye usage is intrinsically limited, as the dyes require ultraviolet (UV) excitation, which can also generate great interference, mainly from nicotinamide adenine dinucleotide (NADH) autofluorescence. Specifically, this limitation causes serious problems for the quantitative measurement of mitochondrial [Ca(2+)], as no available ratiometric dyes are excited in the visible range. Thus, NADH interference cannot be avoided during quantitative measurement of [Ca(2+)] because the majority of NADH is located in the mitochondria. The emission intensity ratio of two different excitation wavelengths must be constant when the fluorescent dye concentration is the same. In accordance with this principle, we developed a novel online method that corrected NADH and Fura-2-FF interference. We simultaneously measured multiple parameters, including NADH, [Ca(2+)], and pH/mitochondrial membrane potential; Fura-2-FF for mitochondrial [Ca(2+)] and TMRE for Ψm or carboxy-SNARF-1 for pH were used. With this novel method, we found that the resting mitochondrial [Ca(2+)] concentration was 1.03 µM. This 1 µM cytosolic Ca(2+) could theoretically increase to more than 100 mM in mitochondria. However, the mitochondrial [Ca(2+)] increase was limited to ~30 µM in the presence of 1 µM cytosolic Ca(2+). Our method solved the problem of NADH signal contamination during the use of Fura-2 analogs, and therefore the method may be useful when NADH interference is expected.

  13. 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

    Directory of Open Access Journals (Sweden)

    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.

  14. Ryanodine receptor type I and nicotinic acid adenine dinucleotide phosphate receptors mediate Ca2+ release from insulin-containing vesicles in living pancreatic beta-cells (MIN6).

    Science.gov (United States)

    Mitchell, Kathryn J; Lai, F Anthony; Rutter, Guy A

    2003-03-28

    We have demonstrated recently (Mitchell, K. J., Pinton, P., Varadi, A., Tacchetti, C., Ainscow, E. K., Pozzan, T., Rizzuto, R., and Rutter, G. A. (2001) J. Cell Biol. 155, 41-51) that ryanodine receptors (RyR) are present on insulin-containing secretory vesicles. Here we show that pancreatic islets and derived beta-cell lines express type I and II, but not type III, RyRs. Purified by subcellular fractionation and membrane immuno-isolation, dense core secretory vesicles were found to possess a similar level of type I RyR immunoreactivity as Golgi/endoplasmic reticulum (ER) membranes but substantially less RyR II than the latter. Monitored in cells expressing appropriately targeted aequorins, dantrolene, an inhibitor of RyR I channels, elevated free Ca(2+) concentrations in the secretory vesicle compartment from 40.1 +/- 6.7 to 90.4 +/- 14.8 microm (n = 4, p < 0.01), while having no effect on ER Ca(2+) concentrations. Furthermore, nicotinic acid adenine dinucleotide phosphate (NAADP), a novel Ca(2+)-mobilizing agent, decreased dense core secretory vesicle but not ER free Ca(2+) concentrations in permeabilized MIN6 beta-cells, and flash photolysis of caged NAADP released Ca(2+) from a thapsigargin-insensitive Ca(2+) store in single MIN6 cells. Because dantrolene strongly inhibited glucose-stimulated insulin secretion (from 3.07 +/- 0.51-fold stimulation to no significant glucose effect; n = 3, p < 0.01), we conclude that RyR I-mediated Ca(2+)-induced Ca(2+) release from secretory vesicles, possibly potentiated by NAADP, is essential for the activation of insulin secretion.

  15. Characterization of 4-hydroxyphenylacetate 3-hydroxylase (HpaB) of Escherichia coli as a reduced flavin adenine dinucleotide-utilizing monooxygenase.

    Science.gov (United States)

    Xun, L; Sandvik, E R

    2000-02-01

    4-Hydroxyphenylacetate 3-hydroxylase (HpaB and HpaC) of Escherichia coli W has been reported as a two-component flavin adenine dinucleotide (FAD)-dependent monooxygenase that attacks a broad spectrum of phenolic compounds. However, the function of each component in catalysis is unclear. The large component (HpaB) was demonstrated here to be a reduced FAD (FADH(2))-utilizing monooxygenase. When an E. coli flavin reductase (Fre) having no apparent homology with HpaC was used to generate FADH(2) in vitro, HpaB was able to use FADH(2) and O(2) for the oxidation of 4-hydroxyphenylacetate. HpaB also used chemically produced FADH(2) for 4-hydroxyphenylacetate oxidation, further demonstrating that HpaB is an FADH(2)-utilizing monooxygenase. FADH(2) generated by Fre was rapidly oxidized by O(2) to form H(2)O(2) in the absence of HpaB. When HpaB was included in the reaction mixture without 4-hydroxyphenylacetate, HpaB bound FADH(2) and transitorily protected it from rapid autoxidation by O(2). When 4-hydroxyphenylacetate was also present, HpaB effectively competed with O(2) for FADH(2) utilization, leading to 4-hydroxyphenylacetate oxidation. With sufficient amounts of HpaB in the reaction mixture, FADH(2) produced by Fre was mainly used by HpaB for the oxidation of 4-hydroxyphenylacetate. At low HpaB concentrations, most FADH(2) was autoxidized by O(2), causing uncoupling. However, the coupling of the two enzymes' activities was increased by lowering FAD concentrations in the reaction mixture. A database search revealed that HpaB had sequence similarities to several proteins and gene products involved in biosynthesis and biodegradation in both bacteria and archaea. This is the first report of an FADH(2)-utilizing monooxygenase that uses FADH(2) as a substrate rather than as a cofactor.

  16. Characterization of chlorophenol 4-monooxygenase (TftD) and NADH:flavin adenine dinucleotide oxidoreductase (TftC) of Burkholderia cepacia AC1100.

    Science.gov (United States)

    Gisi, Michelle R; Xun, Luying

    2003-05-01

    Burkholderia cepacia AC1100 uses 2,4,5-trichlorophenoxyacetic acid, an environmental pollutant, as a sole carbon and energy source. Chlorophenol 4-monooxygenase is a key enzyme in the degradation of 2,4,5-trichlorophenoxyacetic acid, and it was originally characterized as a two-component enzyme (TftC and TftD). Sequence analysis suggests that they are separate enzymes. The two proteins were separately produced in Escherichia coli, purified, and characterized. TftC was an NADH:flavin adenine dinucleotide (FAD) oxidoreductase. A C-terminally His-tagged fusion TftC used NADH to reduce either FAD or flavin mononucleotide (FMN) but did not use NADPH or riboflavin as a substrate. Kinetic and binding property analysis showed that FAD was a better substrate than FMN. TftD was a reduced FAD (FADH(2))-utilizing monooxygenase, and FADH(2) was supplied by TftC. It converted 2,4,5-trichlorophenol to 2,5-dichloro-p-quinol and then to 5-chlorohydroxyquinol but converted 2,4,6-trichlorophenol only to 2,6-dichloro-p-quinol as the final product. TftD interacted with FADH(2) and retarded its rapid oxidation by O(2). A spectrum of possible TftD-bound FAD-peroxide was identified, indicating that the peroxide is likely the active oxygen species attacking the aromatic substrates. The reclassification of the two enzymes further supports the new discovery of FADH(2)-utilizing enzymes, which have homologues in the domains Bacteria and Archaea.

  17. G-tensors of the flavin adenine dinucleotide radicals in glucose oxidase: a comparative multifrequency electron paramagnetic resonance and electron-nuclear double resonance study.

    Science.gov (United States)

    Okafuji, Asako; Schnegg, Alexander; Schleicher, Erik; Möbius, Klaus; Weber, Stefan

    2008-03-20

    The flavin adenine dinucleotide (FAD) cofactor of Aspergillus niger glucose oxidase (GO) in its anionic (FAD*-) and neutral (FADH*) radical form was investigated by electron paramagnetic resonance (EPR) at high microwave frequencies (93.9 and 360 GHz) and correspondingly high magnetic fields and by pulsed electron-nuclear double resonance (ENDOR) spectroscopy at 9.7 GHz. Because of the high spectral resolution of the frozen-solution continuous-wave EPR spectrum recorded at 360 GHz, the anisotropy of the g-tensor of FAD*- could be fully resolved. By least-squares fittings of spectral simulations to experimental data, the principal values of g have been established with high precision: gX=2.00429(3), gY=2.00389(3), gZ=2.00216(3) (X, Y, and Z are the principal axes of g) yielding giso=2.00345(3). The gY-component of FAD*- from GO is moderately shifted upon deprotonation of FADH*, rendering the g-tensor of FAD*- slightly more axially symmetric as compared to that of FADH*. In contrast, significantly altered proton hyperfine couplings were observed by ENDOR upon transforming the neutral FADH* radical into the anionic FAD*- radical by pH titration of GO. That the g-principal values of both protonation forms remain largely identical demonstrates the robustness of g against local changes in the electron-spin density distribution of flavins. Thus, in flavins, the g-tensor reflects more global changes in the electronic structure and, therefore, appears to be ideally suited to identify chemically different flavin radicals.

  18. Fabrication and characterization of Meldola's blue/zinc oxide hybrid electrodes for efficient detection of the reduced form of nicotinamide adenine dinucleotide at low potential

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. Ashok [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan (China)]. E-mail: sakumar80@gmail.com; Chen Shenming [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan (China)]. E-mail: smchen78@ms15.hinet.net

    2007-05-29

    We report the synthesis and the electrochemical properties of hybrid films made of zinc oxide (ZnO) and Meldola's blue dye (MB) using cyclic voltammetry (CV). MB/ZnO hybrid films were electrochemically deposited onto glassy carbon, gold and indium tin oxide-coated glass (ITO) electrodes at room temperature (25 {+-} 2 deg. C) from the bath solution containing 0.1 M Zn(NO{sub 3}){sub 2}, 0.1 M KNO{sub 3} and 1 x 10{sup -4} M MB. The surface morphology and deposition kinetics of MB/ZnO hybrid films were studied by means of scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemical quartz crystal microbalance (EQCM) techniques, respectively. SEM and AFM images of MB/ZnO hybrid films have revealed that the surfaces are well crystallized, porous and micro structured. MB molecules were immobilized and strongly fixed in a transparent inorganic matrix. MB/ZnO hybrid films modified glassy carbon electrode (MB/ZnO/GC) showed one reversible redox couple centered at formal potential (E {sup 0}') -0.12 V (pH 6.9). The surface coverage ({gamma}) of the MB immobilized on ZnO/GC was about 9.86 x 10{sup -12} mol cm{sup -2} and the electron transfer rate constant (ks) was determined to be 38.9 s{sup -1}. The MB/ZnO/GC electrode acted as a sensor and displayed an excellent specific electrocatalytic response to the oxidation of nicotinamide adenine dinucleotide (NADH). The linear response range between 50 and 300 {mu}M NADH concentration at pH 6.9 was observed with a detection limit of 10 {mu}M (S/N = 3). The electrode was stable during the time it was used for the full study (about 1 month) without a notable decrease in current. Indeed, dopamine (DA), ascorbic acid (AA), acetaminophen (AP) and uric acid (UA) did not show any interference during the detection of NADH at this modified electrode.

  19. Relationship between reduced nicotinamide adenine dinucleotide phosphate oxidase subunit p22phox gene polymorphism and obstructive sleep apnea-hypopnea syndrome in the Chinese Han population

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-guo; LIU Kui; ZHOU Yan-ning; XU Yong-jian

    2009-01-01

    Background Increased production of reactive oxygen species (ROS) is thought to play a major role in the pathogenesis of obstructive sleep apnea-hypopnea syndrome (OSAHS). The reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex is an important source of ROS. The p22phox subunit is polymorphic with a C242T variant that changes histidine-72 for a tyrosine in the potential heme binding site. This study aimed to investigate the relationship between NADPH oxidase subunit p22phox gene polymorphism and OSAHS. Methods The genotypes of p22phox polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) assay in 176 unrelated subjects of the Han population in southern region of China (including 107 OSAHS subjects and 69 non-OSAHS subjects), while the plasma concentration of superoxide dismutase (SOD) was detected in the two groups, and p22phox mRNA expression in peripheral blood mononuclear cell (PBMC) was determined with reverse transcription polymerase chain reaction (RT-PCR).Results The phagocyte NADPH oxidase subunit p22phox mRNA expression was significantly increased in the OSAHS group than that in the non-OSAHS group (P<0.01). Compared with the non-OSAHS control group ((85.31±9.23) U/ml), the levels of SOD were lower in patients with OSAHS ((59.65±11.61) U/ml (P<0.01). There were significant differences in genotypes distribution in p22phox polymorphism between the two groups (P=0.02). Compared with the non-OSAHS control group, the OSAHS group had a significantly higher T allele frequency in p22phox polymorphism (P=0.03). There were independent effects of p22phox polymorphism on body mass index (BMI), neck circumference (NC), waist-to-hip ratio (WHR) in the OSAHS group, and the carriers of the T allele of p22phox polymorphism had greater NC, WHR, systolic blood pressure (SBP), diastolic blood pressure (DBP) and apnea-hypopnea index (AHI) (P <0.05), but the carriers of the T allele had lower SOD

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

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    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. DPT tautomerization of the long A∙A Watson-Crick base pair formed by the amino and imino tautomers of adenine: combined QM and QTAIM investigation.

    Science.gov (United States)

    Brovarets', Ol'ha O; Zhurakivsky, Roman O; Hovorun, Dmytro M

    2013-10-01

    Combining quantum-mechanical (QM) calculations with quantum theory of atoms in molecules (QTAIM) and using the methodology of sweeps of the energetic, electron-topological, geometric and polar parameters, which describe the course of the tautomerization along the intrinsic reaction coordinate (IRC), we showed for the first time that the biologically important A∙A base pair (Cs symmetry) formed by the amino and imino tautomers of adenine (A) tautomerizes via asynchronous concerted double proton transfer (DPT) through a transition state (TS), which is the A(+)∙A(-) zwitterion with the separated charge, with Cs symmetry. The nine key points, which can be considered as electron-topological "fingerprints" of the asynchronous concerted A∙A ↔A ∙A tautomerization process via the DPT, were detected and completely investigated along the IRC of the A∙A*↔A*∙A tautomerization. Based on the sweeps of the H-bond energies, it was found that intermolecular antiparallel N6Н⋯N6 (7.01 kcal mol(-1)) and N1H⋯N1 (6.88 kcal mol(-1)) H-bonds are significantly cooperative and mutually reinforce each other. It was shown for the first time that the A∙A ↔A ∙A tautomerization is assisted by the third C2H⋯HC2 dihydrogen bond (DHB), which, in contrast to the two others N6H⋯N6 and N1H⋯N1 H-bonds, exists within the IRC range from -2.92 to 2.92 Å. The DHB cooperatively strengthens, reaching its maximum energy 0.42 kcal mol(-1) at IRC = -0.52 Å and minimum energy 0.25 kcal mol(-1) at IRC = -2.92 Å, and is accompanied by strengthening of the two other aforementioned classical H-bonds. We established that the C2H⋯HC2 DHB completely satisfies the electron-topological criteria for H-bonding, in particular Bader's and all eight "two-molecule" Koch and Popelier's criteria. The positive value of the Grunenberg's compliance constant (5.203 Å/mdyn) at the TSA∙A ↔A ∙A proves that the C2H⋯HC2 DHB is a stabilizing interaction. NBO analysis predicts transfer

  2. Studies of Hepatic Lesion on Hyperuricemia Rat-model Induced by Adenine and Guanine%腺嘌呤、鸟嘌呤致高尿酸血症大鼠肝脏损害的研究

    Institute of Scientific and Technical Information of China (English)

    宋燕郡; 于维森; 殷凡; 宋扬

    2016-01-01

    Objective:To observe adenine and guanine effect liver function of hyperuricemia-model rat, and the changes under ultra microstructure.Method:The 36 male Wistar rats were randomly divided into 6 groups (A-control group,B-model group,C-adenine group,D-adenine starch paste group,E-adenine and guanine group,F-guanine group),each group of 6 cases.Groups B, C, D, E, F continuously given Yeast Extract Solution 15 g/(kg·d) to fill the stomach,7 days induced hyperuricemia-model rats.After the success of the building, group B for starch paste to fill the stomach.Group C:20 mg/(kg·d) adenine starch paste mixture.Group D:10 mg/(kg·d) adenine starch paste mixture.Group E:10 mg/(kg·d) adenine mixed 10 mg/(kg·d) guanine starch suspension.Group F:20 mg/(kg·d) guanine starch paste mixture to fill the stomach.For 14 days,the determination serum ALT,AST,UA and liver tissue electron microscope observation of liver injury of each group rats.Result:(1)Ultra microstructure observation the lysosome of group C increased obviously,scattered around the nucleus,and had dark grain material.Group D lysosome amount increased slightly,increased lipid drops, enter the lysosome.Group E the amount of lysosome increasing, increased lipid droplets, appear dark granular material.Group F bile duct in a small dark granular material.(2)ALT,AST of C-F groups were compared with group B,the differences were statistically significant(P cause ALT and AST levels significantly in hyperuricemia-model rats, the effect is higher than the same dose of guanine.Adenine has obvious effect to rat blood uric acid levels.%目的:观察腺嘌呤、鸟嘌呤作用高尿酸血症大鼠肝脏时,肝脏功能变化情况及透射电镜下肝脏超微结构的变化。方法:选用实验用雄性Wistar大鼠36只,随机分为A组(对照组)、B组(造模对照组)、C组(腺嘌呤组)、D组(腺嘌呤淀粉糊组)、E组(腺嘌呤、鸟嘌呤组)、F组(鸟嘌呤组),每组6只。B、C

  3. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  4. Netropsin . dG-dG-dA-dA-dT-dT-dC-dC complex. Antibiotic binding at adenine . thymine base pairs in the minor groove of the self-complementary octanucleotide duplex.

    Science.gov (United States)

    Patel, D J

    1979-09-01

    The structure of the netropsin . dG-dG-dA-dA-dT-dT-dC-dC complex (one antibiotic molecule/self-complementary octanucleodide duplex) and its dynamics as a function of temperature have been monitored by the nuclear magnetic resonances of the Watson-Crick protons, the nonexchangeable base and sugar protons and the backbone phosphates. The antibiotic forms a complex with the nucleic acid duplex at the dA . dT-containing tetranucleotide segment dA-dA-dT-dT, with slow migration amongst potential binding sites at low temperature. The downfield shifts in the exchangeable protons of netropsin on complex formation demonstrate the contributions of hydrogen-bonding interactions between the antibiotic and the nucleic acid to the stability of the complex. Complex formation results in changes in the glycosidic torsion angles of both thymidine residues and one deoxyadenosine residue as monitored by chemical shift changes in the thymine C-6 and adenine C-8 protons. The close proximity of the pyrrole rings of the antibiotic and the base-pair edges in the minor groove is manifested in the downfield shifts (0.3--0.5 ppm) of the pyrrole C-3 protons of netropsin and one adenine C-2 proton and one thymine N-3 base-pair proton on complex formation. The internucleotide phosphates of the octanucleotide undergo 31P chemical shift changes on addition of netropsin and these may reflect, in part, contributions from electrostatic interactions between the charged ends of the antibiotic and the backbone phosphates of the nucleic acid.

  5. Toxicity associated with high dosage 9-[(2R,5R-2,5-dihydro-5-phosphonomethoxy)-2-furanyl]adenine therapy off attempts to abort early FIV infection.

    Science.gov (United States)

    Hartmann, K; Ferk, G; North, T W; Pedersen, N C

    1997-09-01

    9-[(2R,5R-2,5-dihydro-5-phosphonomethoxy)-2-furanyl]adenine, or D4API, was tested in the feline immunodeficiency virus (FIV) infection model and found to be significantly more inhibitory in vitro than its parent compound 9-phosphonylmethoxethyl adenine (PMEA). Cytotoxicity was less than for PMEA or azidothymidine (AZT) for culture periods of 7 days, but more toxic after 10 days. D4API was rapidly absorbed by cats following subcutaneous inoculation, with a plasma half-life of less than 1 h after intravenous inoculation and between 2 and 3 h after subcutaneous injection. Peripheral blood mononuclear cells collected from cats given a single dose of D4API were refractory, however, to FIV infection in vitro for up to 24 h. Given its prolonged intracellular phase and high selectivity index, high dose D4API therapy was tested for its ability to abort an acute (i.e. 2 week) FIV infection. A divided daily dose of D4API, which was one-fourth the toxic dose and 125 times the concentration that would totally inhibit virus replication in vitro, completely abrogated the anticipated viremia and antibody responses. Unfortunately, a majority of treated/uninfected and treated/infected test cats died acutely of drug toxicity after 47 days of treatment. Toxicity in vivo mirrored what was observed in vitro, being precipitous and cumulative in nature. Toxic signs included widespread hepatic and lymphoid necrosis. A surviving treated/FIV infected cat remained healthy to day 175 when the study was terminated; antibodies appeared 2 months later than in untreated/infected cats and virus was only detectable at low levels on day 175. In contrast, untreated/infected cats were viremic and antibody positive from 3 to 4 weeks post-infection onwards. Therefore, it was possible to alter, but not abort, an early FIV infection with prolonged, high-dose D4API treatment.

  6. 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

    Directory of Open Access Journals (Sweden)

    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.

  7. Molecular characterization of Fasciola hepatica and phylogenetic analysis based on mitochondrial (nicotiamide adenine dinucleotide dehydrogenase subunit I and cytochrome oxidase subunit I) genes from the North-East of Iran

    Science.gov (United States)

    Reaghi, Saber; Haghighi, Ali; Harandi, Majid Fasihi; Spotin, Adel; Arzamani, Kourosh; Rouhani, Soheila

    2016-01-01

    Aim: Fascioliasis is one of the most zoonotic diseases with global extension. As the epidemiological distribution of Fasciola may lead to various genetic patterns of the parasite, the aim of this study is to identify Fasciola hepatica based on spermatogenesis, and phylogenetic analysis using mitochondrial (nicotiamide adenine dinucleotide dehydrogenase subunit I [ND1] and cytochrome oxidase subunit I) gene marker. Materials and Methods: In this study, 90 F. hepatica collected from 30 cattle at slaughterhouse located in three different geographical locations in the North-East of Iran were evaluated based on spermatogenetic ability and internal transcribed spacer 1 gene restriction fragment length polymorphism pattern. Genetic diversity and phylogenetic relationship using mtDNA gene marker for the isolates from the North-East of Iran, and other countries were then analyzed. Results: Partial sequences of mtDNA showed eight haplotypes in both genes. The phylogenic analysis using neighbor joining as well as maximum likelihood methods showed similar topologies of trees. Pairwise fixation index between different F. hepatica populations calculated from the nucleotide data set of ND1 gene are statistically significant and show the genetic difference. Conclusion: F. hepatica found in this region of Iran has different genetic structures through the other Fasciola populations in the world. PMID:27733809

  8. 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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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

    Directory of Open Access Journals (Sweden)

    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.

  10. A bridged nucleic acid, 2',4'-BNA COC: synthesis of fully modified oligonucleotides bearing thymine, 5-methylcytosine, adenine and guanine 2',4'-BNA COC monomers and RNA-selective nucleic-acid recognition.

    Science.gov (United States)

    Mitsuoka, Yasunori; Kodama, Tetsuya; Ohnishi, Ryo; Hari, Yoshiyuki; Imanishi, Takeshi; Obika, Satoshi

    2009-03-01

    Recently, we synthesized pyrimidine derivatives of the 2'-O,4'-C-methylenoxymethylene-bridged nucleic-acid (2',4'-BNA(COC)) monomer, the sugar conformation of which is restricted in N-type conformation by a seven-membered bridged structure. Oligonucleotides (BNA(COC)) containing this monomer show high affinity with complementary single-stranded RNA and significant resistance to nuclease degradation. Here, BNA(COC) consisting of 2',4'-BNA(COC) monomers bearing all four bases, namely thymine, 5-methylcytosine, adenine and guanine was efficiently synthesized and properties of duplexes containing the 2',4'-BNA(COC) monomers were investigated by UV melting experiments and circular dichroism (CD) spectroscopy. The UV melting curve analyses showed that the BNA(COC)/BNA(COC) duplex possessed excellent thermal stability and that the BNA(COC) increased thermal stability with a complementary RNA strand. On the other hand, BNA(COC)/DNA heteroduplexes showed almost the same thermal stability as RNA/DNA heteroduplexes. Furthermore, mismatched sequence studies showed that BNA(COC) generally improved the sequence selectivity with Watson-Crick base-pairing compared to the corresponding natural DNA and RNA. A CD spectroscopic analysis indicated that the BNA(COC) formed duplexes with complementary DNA and RNA in a manner similar to natural RNA.

  11. Role of Electron-Driven Proton-Transfer Processes in the Ultrafast Deactivation of Photoexcited Anionic 8-oxoGuanine-Adenine and 8-oxoGuanine-Cytosine Base Pairs.

    Science.gov (United States)

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

    2017-01-14

    It has been reported that 8-oxo-7,8-dihydro-guanosine (8-oxo-G), which is the main product of oxidative damage of DNA, can repair cyclobutane pyrimidine dimer (CPD) lesions when incorporated into DNA or RNA strands in proximity to such lesions. It has therefore been suggested that the 8-oxo-G nucleoside may have been a primordial precursor of present-day flavins in DNA or RNA repair. Because the electron transfer leading to the splitting of a thymine-thymine pair in a CPD lesion occurs in the photoexcited state, a reasonably long excited-state lifetime of 8-oxo-G is required. The neutral (protonated) form of 8-oxo-G exhibits a very short (sub-picosecond) intrinsic excited-state lifetime which is unfavorable for repair. It has therefore been argued that the anionic (deprotonated) form of 8-oxo-G, which exhibits a much longer excited-state lifetime, is more likely to be a suitable cofactor for DNA repair. Herein, we have investigated the exited-state quenching mechanisms in the hydrogen-bonded complexes of deprotonated 8-oxo-G(-) with adenine (A) and cytosine (C) using ab initio wave-function-based electronic-structure calculations. The calculated reaction paths and potential-energy profiles reveal the existence of barrierless electron-driven inter-base proton-transfer reactions which lead to low-lying S₁/S₀ conical intersections. The latter can promote ultrafast excited-state deactivation of the anionic base pairs. While the isolated deprotonated 8-oxo-G(-) nucleoside may have been an efficient primordial repair cofactor, the excited states of the 8-oxo-G(-)-A and 8-oxo-G(-)-C base pairs are likely too short-lived to be efficient electron-transfer repair agents.

  12. Does the tautomeric status of the adenine bases change upon the dissociation of the A*·A(syn) Topal-Fresco DNA mismatch? A combined QM and QTAIM atomistic insight.

    Science.gov (United States)

    Brovarets', Ol'ha O; Zhurakivsky, Roman O; Hovorun, Dmytro M

    2014-02-28

    We have scrupulously explored the tautomerisation mechanism via the double proton transfer of the A*·A(syn) Topal-Fresco base mispair (C(s) symmetry), formed by the imino and amino tautomers of the adenine DNA base in the anti- and syn-conformations, respectively, bridging quantum-mechanical calculations with Bader's quantum theory of atoms in molecules. It was found that the A*·A(syn) ↔ A·A*(syn) tautomerisation is the asynchronous concerted process. It was established that the A*·A(syn) DNA mismatch is stabilized by the N6H···N6 (6.35) and N1H···N7 (6.17) hydrogen (H) bonds, whereas the A·A*(syn) base mispair (Cs) by the N6H···N6 (8.82) and N7H···N1 (9.78) H-bonds and the C8H···HC2 HH-bond (0.30 kcal mol(-1)). Using the sweeps of the energies of the intermolecular H-bonds, it was observed that the N6H···N6 and N1H···N7/N7H···N1 H-bonds are anti-cooperative and mutually weaken each other in the A*·A(syn) and A·A*(syn) mispairs. It was revealed that the A·A*(syn) DNA mismatch is a dynamically unstable structure with a short lifetime of 1.12 × 10(-13) s and any of its 6 low-frequency intermolecular vibrations can develop during this period of time. This observation makes it impossible to change the tautomeric status of the A bases upon the dissociation of the A*·A(syn) base mispair into the monomers during DNA replication.

  13. Carboxyatractyloside effects on brown-fat mitochondria imply that the adenine nucleotide translocator isoforms ANT1 and ANT2 may be responsible for basal and fatty-acid-induced uncoupling respectively.

    Science.gov (United States)

    Shabalina, Irina G; Kramarova, Tatiana V; Nedergaard, Jan; Cannon, Barbara

    2006-11-01

    In brown-fat mitochondria, fatty acids induce thermogenic uncoupling through activation of UCP1 (uncoupling protein 1). However, even in brown-fat mitochondria from UCP1-/- mice, fatty-acid-induced uncoupling exists. In the present investigation, we used the inhibitor CAtr (carboxyatractyloside) to examine the involvement of the ANT (adenine nucleotide translocator) in the mediation of this UCP1-independent fatty-acid-induced uncoupling in brown-fat mitochondria. We found that the contribution of ANT to fatty-acid-induced uncoupling in UCP1-/- brown-fat mitochondria was minimal (whereas it was responsible for nearly half the fatty-acid-induced uncoupling in liver mitochondria). As compared with liver mitochondria, brown-fat mitochondria exhibit a relatively high (UCP1-independent) basal respiration ('proton leak'). Unexpectedly, a large fraction of this high basal respiration was sensitive to CAtr, whereas in liver mitochondria, basal respiration was CAtr-insensitive. Total ANT protein levels were similar in brown-fat mitochondria from wild-type mice and in liver mitochondria, but the level was increased in brown-fat mitochondria from UCP1-/- mice. However, in liver, only Ant2 mRNA was found, whereas in brown adipose tissue, Ant1 and Ant2 mRNA levels were equal. The data are therefore compatible with a tentative model in which the ANT2 isoform mediates fatty-acid-induced uncoupling, whereas the ANT1 isoform may mediate a significant part of the high basal proton leak in brown-fat mitochondria.

  14. Second-Generation Fluorescent Quadracyclic Adenine Analogues

    DEFF Research Database (Denmark)

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

    2015-01-01

    Fluorescent base analogues comprise a group of increasingly important molecules for the investigation of nucleic acid structure, dynamics, and interactions with other molecules. Herein, we report on the quantum chemical calculation aided design, synthesis, and characterization of four new putativ...

  15. 益生菌发酵驼乳对慢性肾功能衰竭的治疗作用%The rapeutic Action of Probiotic Fermented Camel Milk on Chronic Renal Failure Rats Caused by Adenine

    Institute of Scientific and Technical Information of China (English)

    李建美; 潘蕾; 张敏; 王娟; 刘薇; 郭春燕; 李擎; 吉日木图

    2011-01-01

    Purpose: To compare the different therapeutic Failure(CRF) of rats. Method: CRF rat models induced by fermentation camel milk. And then evaluated the therapeutic action of probiotics felTnented camel milk on Chronic Renal adenine were received intragastric administration with probiotic effect of three kinds of fermented camel milk by measure the diet and water intake, weight, kidney index, serum creatinine(Scr), Urea Nitrogen(BUN), nitric oxide(NO), superoxide dismutase(SOD), serum total protein(STP), calcium(Ca), phosphorus(P), urine volume in 24 hours, urine protein(UP) and the Renal Biopsy. Result: The result showed that fermentation camel milk can reduce the serum level of Set and BUN, slow down UP, ameliorate the balance of calcium and phosphorus, enhanced the level of SOD and STP and alleviated pathological changes of the kidney tissue. Conclusion: Different kinds of probiotic fermented camel milk are effective in treating CRF of rats and the effect of camel milk fermented by L.casei Zhang is superior to camel milk fermented by other probiotics.%目的:比较不同菌种发酵的驼乳制品对腺嘌呤所致大鼠慢性。肾功能衰竭(CRF)的缓解作用。方法:采用腺嘌呤复制CRF大鼠模型,以不同发酵剂发酵的驼乳作为受试物进行灌胃干预。通过检测大鼠的饮食饮水情况、排尿量、尿液和血清常规指标及肾脏病理组织学变化,评估各发酵驼乳对CRF大鼠的治疗效果。结果:发酵驼乳均可改善肾功能衰竭大鼠的一般生理状况,可降低大鼠血肌酐(Scr)、尿素氦(BUN)水平,减缓尿蛋白(UP),调节Ca、P的含量,提高过氧化物歧化酶(SOD)、血清总蛋白(STP)水平,具有保护肾功能的作用,其中LIcaseiZhang发酵的驼乳对CRF大鼠的改善效果最佳。

  16. 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

    Directory of Open Access Journals (Sweden)

    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

  17. DNA adenine methyltransferase (Dam) controls the expression of the cytotoxic enterotoxin (act) gene of Aeromonas hydrophila via tRNA modifying enzyme-glucose-inhibited division protein (GidA).

    Science.gov (United States)

    Erova, Tatiana E; Kosykh, Valeri G; Sha, Jian; Chopra, Ashok K

    2012-05-01

    Aeromonas hydrophila is both a human and animal pathogen, and the cytotoxic enterotoxin (Act) is a crucial virulence factor of this bacterium because of its associated hemolytic, cytotoxic, and enterotoxic activities. Previously, to define the role of some regulatory genes in modulating Act production, we showed that deletion of a glucose-inhibited division gene (gidA) encoding tRNA methylase reduced Act levels, while overproduction of DNA adenine methyltransferase (Dam) led to a concomitant increase in Act-associated biological activities of a diarrheal isolate SSU of A. hydrophila. Importantly, there are multiple GATC binding sites for Dam within an upstream sequence of the gidA gene and one such target site in the act gene upstream region. We showed the dam gene to be essential for the viability of A. hydrophila SSU, and, therefore, to better understand the interaction of the encoding genes, Dam and GidA, in act gene regulation, we constructed a gidA in-frame deletion mutant of Escherichia coli GM28 (dam(+)) and GM33 (∆dam) strains. We then tested the expressional activity of the act and gidA genes by using a promoterless pGlow-TOPO vector containing a reporter green fluorescent protein (GFP). Our data indicated that in GidA(+) strains of E. coli, constitutive methylation of the GATC site(s) by Dam negatively regulated act and gidA gene expression as measured by GFP production. However, in the ∆gidA strains, irrespective of the presence or absence of constitutively active Dam, we did not observe any alteration in the expression of the act gene signifying the role of GidA in positively regulating Act production. To determine the exact mechanism of how Dam and GidA influence Act, a real-time quantitative PCR (RT-qPCR) assay was performed. The analysis indicated an increase in gidA and act gene expression in the A. hydrophila Dam-overproducing strain, and these data matched with Act production in the E. coli GM28 strain. Thus, the extent of DNA methylation

  18. Associations between arsenic (+3 oxidation state) methyltransferase (AS3MT) and N-6 adenine-specific DNA methyltransferase 1 (N6AMT1) polymorphisms, arsenic metabolism, and cancer risk in a chilean population.

    Science.gov (United States)

    de la Rosa, Rosemarie; Steinmaus, Craig; Akers, Nicholas K; Conde, Lucia; Ferreccio, Catterina; Kalman, David; Zhang, Kevin R; Skibola, Christine F; Smith, Allan H; Zhang, Luoping; Smith, Martyn T

    2017-07-01

    Inter-individual differences in arsenic metabolism have been linked to arsenic-related disease risks. Arsenic (+3) methyltransferase (AS3MT) is the primary enzyme involved in arsenic metabolism, and we previously demonstrated in vitro that N-6 adenine-specific DNA methyltransferase 1 (N6AMT1) also methylates the toxic inorganic arsenic (iAs) metabolite, monomethylarsonous acid (MMA), to the less toxic dimethylarsonic acid (DMA). Here, we evaluated whether AS3MT and N6AMT1 gene polymorphisms alter arsenic methylation and impact iAs-related cancer risks. We assessed AS3MT and N6AMT1 polymorphisms and urinary arsenic metabolites (%iAs, %MMA, %DMA) in 722 subjects from an arsenic-cancer case-control study in a uniquely exposed area in northern Chile. Polymorphisms were genotyped using a custom designed multiplex, ligation-dependent probe amplification (MLPA) assay for 6 AS3MT SNPs and 14 tag SNPs in the N6AMT1 gene. We found several AS3MT polymorphisms associated with both urinary arsenic metabolite profiles and cancer risk. For example, compared to wildtypes, individuals carrying minor alleles in AS3MT rs3740393 had lower %MMA (mean difference = -1.9%, 95% CI: -3.3, -0.4), higher %DMA (mean difference = 4.0%, 95% CI: 1.5, 6.5), and lower odds ratios for bladder (OR = 0.3; 95% CI: 0.1-0.6) and lung cancer (OR = 0.6; 95% CI: 0.2-1.1). Evidence of interaction was also observed for both lung and bladder cancer between these polymorphisms and elevated historical arsenic exposures. Clear associations were not seen for N6AMT1. These results are the first to demonstrate a direct association between AS3MT polymorphisms and arsenic-related internal cancer risk. This research could help identify subpopulations that are particularly vulnerable to arsenic-related disease. Environ. Mol. Mutagen. 58:411-422, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. Unprecedented head-to-head right-handed cross-links between the antitumor bis(mu-N,N'-di-p-tolylformamidinate) dirhodium(II,II) core and the dinucleotide d(ApA) with the adenine bases in the rare imino form.

    Science.gov (United States)

    Chifotides, Helen T; Dunbar, Kim R

    2007-10-17

    Reactions of the anticancer active compound cis-[Rh2(DTolF)2(CH3CN)6](BF4)2 with 9-ethyladenine (9-EtAdeH) or the dinucleotide d(ApA) proceed with bridging adenine bases in the rare imino form (A*), spanning the Rh-Rh bond at equatorial positions via N7/N6. The inflection points for the pH-dependent H2 and H8 NMR resonance curves of cis-[Rh2(DTolF)2(9-EtAdeH)2](BF4)2 correspond to N1H deprotonation of the metal-stabilized rare imino tautomer, which takes place at pKa approximately 7.5 in CD3CN-d3, a considerably reduced value as compared to that of the imino form of 9-EtAdeH. Similarly, coordination of the metal atoms to the N7/N6 adenine sites in Rh2(DTolF)2{d(ApA)} induces formation of the rare imino tautomer of the bases with a concomitant substantial decrease in the basicity of the N1H sites (pKa approximately 7.0 in CD3CN-d3), as compared to the imino form of the free dinucleotide. The presence of the adenine bases in the rare imino form, due to bidentate metalation of the N6/N7 sites, is further corroborated by DQF-COSY H2/N1H and ROE N1H/N6H cross-peaks in the 2D NMR spectra of Rh2(DTolF)2{d(ApA)} in CD3CN-d3 at -38 degrees C. Due to the N7/N6 bridging mode of the adenine bases in Rh2(DTolF)2{d(ApA)}, only the anti orientation of the imino tautomer is possible. The imino form A* of adenine in DNA may result in AT-->CG transversions or AT-->GC transitions, which can eventually lead to lethal mutations. The HH arrangement of the bases in Rh2(DTolF)2{d(ApA)} is indicated by the H8/H8 NOE cross-peaks in the 2D ROESY NMR spectrum, whereas the formamidinate bridging groups dictate the presence of one right-handed conformer HH1R in solution. Complete characterization of Rh2(DTolF)2{d(ApA)} by 2D NMR spectroscopy and molecular modeling supports the presence of the HH1R conformer, anti orientation of both sugar residues about the glycosyl bonds, and N-type conformation for the 5'-A base.

  20. Is the DPT tautomerization of the long A·G Watson-Crick DNA base mispair a source of the adenine and guanine mutagenic tautomers? A QM and QTAIM response to the biologically important question.

    Science.gov (United States)

    Brovarets', Ol'ha O; Zhurakivsky, Roman O; Hovorun, Dmytro M

    2014-03-05

    Herein, we first address the question posed in the title by establishing the tautomerization trajectory via the double proton transfer of the adenine·guanine (A·G) DNA base mispair formed by the canonical tautomers of the A and G bases into the A*·G* DNA base mispair, involving mutagenic tautomers, with the use of the quantum-mechanical calculations and quantum theory of atoms in molecules (QTAIM). It was detected that the A·G ↔ A*·G* tautomerization proceeds through the asynchronous concerted mechanism. It was revealed that the A·G base mispair is stabilized by the N6H···O6 (5.68) and N1H···N1 (6.51) hydrogen bonds (H-bonds) and the N2H···HC2 dihydrogen bond (DH-bond) (0.68 kcal·mol(-1) ), whereas the A*·G* base mispair-by the O6H···N6 (10.88), N1H···N1 (7.01) and C2H···N2 H-bonds (0.42 kcal·mol(-1) ). The N2H···HC2 DH-bond smoothly and without bifurcation transforms into the C2H···N2 H-bond at the IRC = -10.07 Bohr in the course of the A·G ↔ A*·G* tautomerization. Using the sweeps of the energies of the intermolecular H-bonds, it was observed that the N6H···O6 H-bond is anticooperative to the two others-N1H···N1 and N2H···HC2 in the A·G base mispair, while the latters are significantly cooperative, mutually strengthening each other. In opposite, all three O6H···N6, N1H···N1, and C2H···N2 H-bonds are cooperative in the A*·G* base mispair. All in all, we established the dynamical instability of the А*·G* base mispair with a short lifetime (4.83·10(-14) s), enabling it not to be deemed feasible source of the A* and G* mutagenic tautomers of the DNA bases. The small lifetime of the А*·G* base mispair is predetermined by the negative value of the Gibbs free energy for the A*·G* → A·G transition. Moreover, all of the six low-frequency intermolecular vibrations cannot develop during this lifetime that additionally confirms the aforementioned results. Thus, the A*·G* base mispair cannot be

  1. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  2. Reference MP2/CBS and CCSD(T) quantum-chemical calculations on stacked adenine dimers. Comparison with DFT-D, MP2.5, SCS(MI)-MP2, M06-2X, CBS(SCS-D) and force field descriptions.

    Science.gov (United States)

    Morgado, Claudio A; Jurecka, Petr; Svozil, Daniel; Hobza, Pavel; Sponer, Jirí

    2010-04-14

    We have performed reference quantum-chemical calculations for about 130 structures of adenine dimers in stacked conformations, with special attention given to dimers that are either vertically compressed (parallel structures) or contain close interatomic contacts (non-parallel structures). Such geometries are sampled during thermal fluctuations of nucleic acids and contribute to the local conformational variability of these systems. Their theoretical characterization requires a good description of interaction energies in the short-range repulsion region. The reference calculations have been performed with the CBS(T) method, i.e., MP2/CBS computations corrected for higher-order electron-correlation effects using the CCSD(T) method. These benchmark data have been used to examine the performance of the DFT-D, SCS(MI)-MP2, MP2.5, M06-2X and CBS(SCS-D) quantum-mechanical methods, and of the AMBER Cornell et al. force field. The present results, as well as those of our previous study on stacked uracil dimers, confirm that the force field severely exaggerates the repulsion at short intermolecular distances. This behavior complicates the use of the force field in scans of the stacking-energy dependence on local conformational parameters in nucleic acids. Compared against the previous results obtained in the uracil dimer study, the performance of DFT-D to describe stacking at short intermolecular distances has worsened, showing for the adenine dimers a larger exaggeration of the repulsion, especially for structures where the monomers are parallel to each other. Despite these deviations, the performance of DFT-D is still reasonably good and this method provides, for example, a relatively inexpensive way to monitor stacking energies along molecular dynamics trajectories. The best performers are the MP2.5, SCS(MI)-MP2, and CBS(SCS-D) methods. In addition, the energy profiles given by the SCS(MI)-MP2 and CBS(SCS-D) methods are the ones that most closely resemble the CBS(T) data

  3. Synthesis of salicylaldehyde-adenine schiff base and its application for the spectrophotometric determination of copper(Ⅱ)%水杨醛缩腺嘌呤席夫碱的合成及其光度法测定铜(Ⅱ)的研究

    Institute of Scientific and Technical Information of China (English)

    洪涛; 龙巍然; 陶晋飞; 刘鹏; 曹秋娥

    2012-01-01

    以水杨醛和腺嘌呤为原料,合成了一个新的席夫碱(水杨醛缩腺嘌呤席夫碱,SASB),并对其结构进行了鉴定.以该席夫碱为显色剂,在优化了反应条件后,建立了一个测定痕量Cu2+的新光度分析方法.方法在400 nm处的表现摩尔吸光系数为7.68×104 L-mol-1·cm-1,线性范围为0.05~0.60μg/mL.常见离子都不干扰测定,加入2 mL 10.0 g/L NH4F溶液作为掩蔽剂时,Al3+和Fe3+的允许量可分别提高到75倍和25倍.将方法用于铝合金中铜的测定,结果同原子吸收光谱法的测定值一致,相对标准偏差在2.5%以内.%A new schiff base (salicylaldehyde-adenine schiff base. SASB) has been synthesized by the condensation reaction between salicylaldehyde and adenine. And its structure has been identified. With schiff base as color reagents, a new spectrophotometric method for the determination of trace Cu2+ has been established after the conditions of the reaction between SASB and Cu2+ was optimized. The linear range and apparent molar absorptivity at 400nm was 0. 05-0. 60 μg/mL and 7. 68 ×104 L · mol-1 · cm-1, respectively. The method, which was free from the interference of much common ions, could be used for the determination of copper in the presence of 75 times of Al3+ and 25 times of Fe3+ after 2 mL of 10. 0 g/L NH4F was added as screening agent. The results for the determination of trace copper in aluminium alloys obtained by this method with the standard deviation of less than 2. 5% was in agreement with that obtained by AAS.

  4. Alteration of marker enzymes in adenine-induced impaired testis and the interference of total flavonoids of herba epimedii in rats%腺嘌呤致大鼠睾丸损伤中标志酶的变化及淫羊藿总黄酮的干预作用

    Institute of Scientific and Technical Information of China (English)

    张作涛; 谢高宇; 陈凯; 齐敏友; 刘浩然

    2012-01-01

    目的 研究淫羊藿总黄酮(TFE)对腺嘌呤致大鼠睾丸损伤中标志酶的干预作用.方法 将70只Sprague Dawley雄性大鼠随机分为5组:正常对照组(蒸馏水灌胃)、模型组(蒸馏水灌胃)、TFE组(TFE 100 mg/kg灌胃)、维生素E组(维生素E 10 mg/kg灌胃)和甲基睾酮组(甲基睾酮5 mg/kg灌胃),每组14只.除正常对照组外,其余每组大鼠均予腺嘌呤150 mg/kg灌胃14 d建立大鼠睾丸病变模型,第15天开始各组大鼠分别给予相应处理.30 d后处死大鼠,称量睾丸、附睾、精囊腺及大鼠质量,计算脏器指数;检测血清睾酮、卵泡刺激素(FSH)、黄体生成素(LH);睾丸中乳酸脱氢酶(LDH)、酸性磷酸酶(ACP)、谷氨酰转肽酶(γ-GT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力及丙二醛(MDA)含量.结果 与正常对照组比较,模型组各性腺脏器指数下降,血清睾酮下降,睾丸中LDH、ACP及γ-GT活力降低,MDA含量升高,差异有统计学意义(P<0.05).与模型组比较,TFE组大鼠脏器指数、血清睾酮水平及特异性酶类活力提高(P<0.05).结论 TFE可能通过促进睾酮释放及抗氧化作用而显著提高腺嘌呤致大鼠睾丸损伤中标志酶活力.%Objective To study the interference effect of total flavonoids of herba epimedii(TFE) on marker enzymes in adenine-induced impaired testis in rats. Methods 70 Sprague Dawley male rats were randomly divided into 5 groups of 14 rats each; normal control group(intravenous infusion of distilled water) ,model groupCgastric perfusion of distilled water) ,TFE groupCgastric perfu-sion of TFE 100 mg/kg) , Vitamin E groupCgastric perfusion of vitamin E 10 mg/kg) and methyl testosterone group (gastric perfusion of methyl-testosterone 5 mg/kg) ,Except rats in normal group,those in the rest groups were subjected to gastric perfusion of adenine 150 mg/kg for 14 days to establish the rat models of testicular lesion. Rats in each group were accepted corresponding

  5. RNA aptamers for an essential prebiotic molecule: adenine

    Science.gov (United States)

    Meli, M.; Vergne, J.; Josse, T.; Décout, J.-L.; Maurel, M.-C.

    2001-08-01

    Among all known bio-organic molecules within the living cells, RNA molecules are the only ones storing genetic information and performing catalysis. The RNA world hypthesis assumes that livings on earth are derived from an RNA molecular ancestor where RNA both stored the genetic information and catalyzed the first metabolic reactions. Among diverse RNA worlds proposed, it is thought that the invention of translation and encoded peptide synthesis took place with a "breakthrough organism", then giving rise to a ribonucleoprotein (RNP) world. Finally, modern biochemistry arose with the invention of DNA and the birth of modern molecular biology where the information flows from DNA to RNA which directs protein synthesis. Considering modern metabolism, it is possible to assign biochemical traits to the last common ancestor by simple parsimony rules, and assumptions about earlier metabolisms are possible using chemical criteria. According to this point of view, modern metabolism is considered as a palimpsest that has to be read and deciphered in ordered to understand its origin and evolution.

  6. 吗替麦考酚酯对大鼠肾小管上皮-间充质转化的作用及其机制探讨%The effects of mycophenolate mofetil on renal interstitial fibrosis and epithelial-myofibroblast transiation in adenine-induced renal failure rats

    Institute of Scientific and Technical Information of China (English)

    何春梅; 郑法雷; 刘燕萍

    2008-01-01

    (EMT) in adenine-induced chronic renal failure (CRF) rat model and the role of vascular endothelial growth factor(VEGF) and inhibitor of differentiation (Id2 and Id3) in EMT in the rat kidney. Methods Sixty-four male Wistar rats were randomly assigned to the following groups: normal control (n=16), CRF (n=24) and MMF(n=24). CRF was induced by gastric gavage of adenine (125 mg·kg-1·d-1) to rats for eight weeks. CRF rats were treated with MMF (15 mg·kg-1·d-1) as "MMF" group. The rats were sacrificed at week 2, 4, 6 and 8, respectively.Urinary protein and serum ereatinine levels were measured, and the histopathologic degrees of interstitial fibrosis were evaluated in Massen-stained sections. Expressions of a-smooth muscle actin (α-SMA),transforming growth factor β1 (TGFβ1), VEGF and Id (Id2 and Id3) in the kidney tissue were assessed by immunohistochemistry, RT-PCR and/or Western blot methods. Results The urinary protein level in MMF group was evidently lower than that in CRF group (P<0.01), whereas no statistically significant difference was observed in serum creatinine level between the two groups. Renal interstitial fibrosis was reduced significantly with MMF treatment (P<0.01). Expression of α-SMA in MMF group was lower than that in CRF rats at week 6, 8 (P<0.01), while expression of TGFβ1 was decreased markedly at week 2, 4,6 (P<0.01). The expressions of VEGF in MMF rats were increased significantly at week 6,8 (P<0.01),and Id2,Id3 in MMF rats were increased significantly at week 4,6 (P<0.05). Conclusions MMF may ameliorate chronic renal fibrosis and EMT in adenine-induced CRF rats. This effect of MMF on EMT is probably related to upregulation of VEGF, Id2 and Id3 expressions and suppressing overexpression of TGFβ1 in renal tissue. The exact mechanism needs to be studied further.

  7. 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

    Institute of Scientific and Technical Information of China (English)

    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

  8. Study on the Inclusion Interactions of Cucurbit[7]uril with 6-Mercaptopurine and Adenine by Fluorescence Spectrometric Method%荧光光谱法研究葫芦[7]脲与6-巯嘌呤和腺嘌呤的包结作用

    Institute of Scientific and Technical Information of China (English)

    何小英; 李来生; 方奕珊; 陈红

    2012-01-01

    The inclusion interactions of cucurbit [7] uril (CB[7]) with 6-mercaptopurine (6-MP) and adenine(ADP) were studied by fluorescence spectrometric method. Several effect factors such as time, the pH value and temperature on the fluorescence intensity and the stability of the complex were investigated. The complex constants of CB[7] with 6-MP and ADP were determined according to the Benesi-Hildebrand equation,respectively. The results indicated that the pH value had a significant effect on the inclusion interactions. 6-MP and ADP had the optimal and stable excitation and emission wavelength as the pH value were 8. 0 for 6-MP and 2. 0 for ADP within 5 min. With the increasing of the concentrations of CB[7],the fluorescence of the two complexes increased obviously. The inclusion constants were 3. 6797× 102 L·mol-1 for 6-MP-CB[7] and 2. 2033 × 102 L·mol-1 for ADP-CB[7] at 298 K with the same inclusive ratio of It 1. The main interaction forces between CB[7] and the above purines were discussed based on the thermodynamic parameters. CB[7] is only well water-soluble superamolecules among cucurbituril family members, and has great potential as drug carriers with safety and low toxicity.%采用荧光光谱法分别研究了葫芦[7]脲(CB[7])对6-巯嘌呤(6-MP)和腺嘌呤(ADP)的包结作用.实验考察了时间、pH值以及温度对荧光强度和包结作用的影响,利用Benesi-Hildebrand方程分别计算出6-MP和ADP与CB[7]的包结常数.结果表明:酸度对体系的包结有明显的影响.在pH值为8.0和2.0左右时,6-MP和ADP分别具有稳定和最佳激发和发射波长,随着CB[7]浓度的增大,体系的荧光强度都有明显增强,包结作用迅速(小于5 min).实验得出CB[7]与6-MP和ADP的包结比均为1∶1,在298 K时的包结常数分别为3.6797×102 L·mol-1和2.2033×102 L·mo1-1.通过热力学参数的变化,探讨了维系包结物稳定性的主要作用力.CB[7]是葫芦脲家族中水溶性最强的主体分子,作为一种

  9. 金匮肾气丸对腺嘌呤致不育大鼠精子质量与肾脏功能的影响%Effect of Jinkui Shenqi Pill on Sperm Quality and Renal Function in Rats Adenine-induced Infertility

    Institute of Scientific and Technical Information of China (English)

    马亮; 刘华剑; 南亚昀; 刘镘利; 王南丁; 陈艳秋; 王宗仁; 马静

    2011-01-01

    Objective:To observe the influence of Jinkui Shenqi Pill on sperm quality and renal function in rats with adenine-induced infertility. Method: Thirty adult male SD rats were randomly divided into Jinkui Shenqi Pill group, model group and control group. Sperm qualities of experimental rats were detected by automatic sperm quality analyzer, and contents of testosterone(T), estradiol( E2 ), luteinizing hormone(LH) and follicle-stimulating hormone (FSH) were measured by radioimmunoassay. Contents of BUN and Scr were ested by automatic biochemical analyzer. Renal tissue was observed by optical microscope. Testis was observed by transmission electron microscopy. Result: Jinkui Shenqi Pill could significantly improve symptoms of Shen-yang deficiency in adenineinduced infertility rats, and it could improve the sperm quality, including sperm density, sperm motility and sperm activity. It could increase content of T obviously, lower contents of E2, LH and FSH, lower contents of BUN and Scr. And it can better the damaged kidney tissue in model rats. Conclusion: Jinkui Shenqi pill can improve sperm quality significantly and improve function of kidney. And the mechanism of improving sperm quality may be related to the increase in content of T by stimulating the interstitial cells and lowering level of E2.%目的:观察金匮肾气丸对腺嘌呤致雄性不育大鼠精子质量及肾功能的影响.方法:30只成年雄性SD大鼠随机分为空白组、模型组、金匮肾气丸组.应用自动精子质量分析仪检测实验大鼠的精子质量(精子密度、活率及活动度);应用放射免疫法测定血清睾酮(T)、雌二醇(E2)、促黄体激素(LH)和促卵泡激素(FSH)含量;自动生化分析仪分析血清尿素氮(BUN)、肌酐(Scr)含量;HE染色、光镜观察肾脏组织变化,透射电镜观察实验大鼠睾丸中精子鞭毛密度.结果:金匮肾气丸能明显增加大鼠精子密度、活率及活动度,提高大鼠血清T含量,降低E2,LH,FSH含

  10. 脊髓烟酰胺腺嘌呤二核苷酸磷酸氧化酶在大鼠糖尿病神经痛维持中的作用%Role of nicotinamide adenine dinucleotide phosphate oxidase in spinal cord in maintenance of diabetic neuropathic pain in rats

    Institute of Scientific and Technical Information of China (English)

    黄晓雷; 李晓芸; 吴铭广; 文亚杰; 齐晓非; 胡薇; 李元涛

    2014-01-01

    目的 评价脊髓烟酰胺腺嘌呤二核苷酸磷酸氧化酶(NADPH氧化酶)在大鼠糖尿病神经痛维持中的作用.方法 清洁级雄性SD大鼠,2月龄,体重180 ~ 220 g,采用腹腔注射1%链脲佐菌素(STZ)的方法制备糖尿病模型,注射STZ后72 h血糖>16.7 mmol/L的大鼠作为糖尿病大鼠.采用随机数字表法,将20只糖尿病大鼠分为2组(n=10):糖尿病神经痛组(DN组)和NADPH氧化酶特异性抑制剂香荚兰乙酮组(A组),另取10只大鼠为正常对照组(C组).A组于注射STZ后28 d腹腔注射香荚兰乙酮5 mg/kg,1次/d,连续7d.分别于注射STZ前(T1)、注射STZ后7、14、21、28、35 d(T2-6)时测定机械缩足反应阈(PWT).于T6时PWT测定结束后,处死大鼠,取L4,5节段脊髓组织,检测NADPH氧化酶亚基gp91phox和p47phox的表达、MDA含量及SOD活性.结果 与C组比较,DN组和A组T3-5时PWT降低,脊髓gp91phpx和p47phox的表达上调,MDA含量升高,SOD活性降低(P<0.05);与DN组比较,A组T6时PWT升高,脊髓gp91phox和p47phox的表达下调,MDA含量降低,SOD活性升高(P<0.05).结论 脊髓NADPH氧化酶参与了大鼠糖尿病神经痛的维持.%Objective To evaluate the role of nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) in the spinal cord in the maintenance of diabetic neuropathic pain in rats.Methods Pathogenfree male Sprague-Dawley rats,aged 2 months,weighing 180-220 g,were used in the study.Diabetes mellitus was induced by intraperitoneal streptozotocin (STZ) 60mg/kg and confirmed by blood glucose > 16.7 mmol/L at 72 h after STZ injection.Twenty diabetic rats were randomly allocated to diabetic neuropathic pain group (DN group,n =10) and apocynin (specific NADPH oxidase inhibitor) group (A group,n =10).Another 10 agematched normal rats served as control group (C group,n =10).Twenty-eight days after STZ injection,apyconin 5 mg/kg was injected intraperitoneally once a day for 7 consecutive days in A group.Paw withdrawal threshold to yon

  11. 尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4源性活性氧过量产生抑制胚胎干细胞向心肌细胞的分化%Excessive production of nicotinamide adenine dinucleotide phosphate oxidase 4-dependent reactive oxygen species suppresses cardiomyocyte differentiation from embrvonic stem cells

    Institute of Scientific and Technical Information of China (English)

    张小勇; 国汉邦; 黎健

    2007-01-01

    二核苷酸磷酸氧化酶4过表达诱导的细胞凋亡.结果:①不同水平的活性氧对心肌细胞分化具有不同的效应.在分化后4 d用较低浓度(1~100 nmol/L)的过氧化氢处理胚小体2 h可明显促进心肌细胞分化(P<0.01),而较高浓度(> 1 μmol/L)的过氧化氢则显示出抑制作用(P<0.01).②尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4程小鼠胚胎干细胞中的表达水平最高,尼克酰胺腺嘌呤二核苷酸磷酸氧化酶3虽然也在胚胎干细胞中表达,但表达水平低,丽尼克酰胺腺嘌呤二核苷酸磷酸氧化酶1、2在胚胎干细胞中不表达.RT-PCR检测结果显示,与单纯转染pcDNA3.1细胞相比,转染pcDNA3.1-NOX4质粒的CGR8细胞中尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4过表达.③四唑氮蓝实验检测结果显示,高水平表达的尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4引起过量活性氧产生(P<0.05).与未转染质粒的细胞相比,尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4过表达抑制了心肌细胞的分化(P<0.01). Western Blot结果显示高水平尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4导致胚小体内MLC2v蛋白水平降低.④p21和p53可能参与了NADPH氧化酶4诱导的凋亡过程.转染尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4的p53-/-ES细胞R72D27并未发生凋亡,高水平的Bcl-2可以抑制尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4过表达诱导的细胞凋亡.结论:尼克酰胺腺嘌呤二核苷酸磷酸氧化酶4在心肌细胞分化中起关键作用,p53和p21以及Bcl-2可能参与了凋亡信号通路的调控.%BACKGROUND: Reactive oxygen species (ROS), including superoxide anion (O2) and hydrogen peroxide (H2O2), have been recognized as specific second messengers in signaling cascades involved in the growth and differentiation of cells.The generation of excessive ROS initiates cardiomyocyte apoptosis. This paper is aimed to corroborate the hypothesis that excessive amounts of nicotinamide adenine

  12. Effects of glucagon-like peptide-1 on the expression of nicotinamide adenine dinucleotide phosphate oxidase subunits in the heart of type 1 diabetic rats%胰高血糖素样肽1对1型糖尿病大鼠心肌烟酰胺腺嘌呤二核苷酸氧化酶亚单位表达的影响

    Institute of Scientific and Technical Information of China (English)

    俞媛贤; 郭志新; 齐伟; 杜时晶; 刘晋津; 吴杰萍

    2013-01-01

    Objective To explore the effect of glucagon-like peptide-1 on the expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits p22phox and Nox4 in the heart tissue of type 1 diabetic rats.Methods Forty-two male Sprague-Dawley(SD) rats were randomly divided into normal control group (group A,n=7) and diabetic model group (n =35) with the random number table.Type 1 diabetic model was established by intraperitoneal injection of streptozotocin.Twenty-nine successfully-induced diabetic rats were randomly divided into diabetic (group DM,n =10),diabetic treated with low-dose of GLP-1 (group DL,n =10) and diabetic treated with high-dose of GLP-1 (group DH,n =9) with the random number table method.The rats in group DL were given exenatide in dose of 1 μg/kg twice daily by subcutaneous injection.The rats in group DH were given exenatide in dose of 5 μg/kg twice daily by subcutaneous injection.All rats were sacrificed after exenatide treatment for eight weeks.The mRNA expression of myocardial p22phox and Nox4 in the rats of four groups was detected by real-time fluorescence quantitative polymerase chain reaction(PCR),and the protein expression of myocardial copper zinc-superoxide dismutase (Cu-Zn-SOD) was detected by immunohistochemical staining.Statistical analysis among groups was performed by using one way ANOVA.Results Compared with group NC,the mRNA expression of myocardial p22phox and Nox4 and the myocardial Cu-Zn-SOD protein expression increased significantly in group DM(t =5.77,5.36,59.91,all P <0.05).After exenatide treatment for 8 weeks,the mRNA expression of myocardial p22phox and Nox4 and the myocardial Cu-Zn-SOD protein expression decreased significantly in group DL and DH (t =16.86,7.66 and 16.11,7.59 and 56.00,47.05,and all P < 0.05).Compared with group DL,the mRNA expression of myocardial p22phox and Nox4 decreased significantly in group DH (t =10.14,8.67,both P < 0.05).There was no significant difference in the expression of

  13. Comparison of three typing assays for nicotinamide adenine dinucleotide-independent Actinobacillus pleuropneumoniae.

    Science.gov (United States)

    Maldonado, Jaime; Blanco, Mónica; Martínez, Eva; Navas, Jesús

    2011-07-01

    Three tests for typing clinical isolates of Actinobacillus pleuropneumoniae biovar 2 were compared: 1) standard coagglutination with type-specific antisera against serovars 1-12 of biovar 1 of A. pleuropneumoniae; 2) a previously described polymerase chain reaction system for detecting the apx genes encoding the ApxI, ApxII, and ApxIII toxins in A. pleuropneumoniae; and 3) a restriction fragment length polymorphism analysis of the transferrin-binding protein B gene. The panel of strains tested included 112 field isolates of biovar 2 recovered from pigs between 1979 and 2007 in Italy and Spain, and reference strains for all described serovars of both biovars. The values of Simpson index of diversity obtained for the 3 methods were 0.68, 0.20, and 0.60, respectively. Coagglutination assays identified the field isolates as belonging to serovars 2 (9 strains), 4 (13 strains), 7 (61 strains), 9 (17 strains), and 11 (1 strain). Eleven strains were not typeable, and cross-reactivity was observed between serovars 2 and 4, 4 and 7, and 9 and 11. Isolates of A. pleuropneumoniae biovar 2 displayed 2 apx patterns: ApxII(+) (94 strains) and ApxI(+)/ApxII(+) (18 strains). The restriction fragment length polymorphism analysis assigned the strains tested to 3 different patterns. This method distinguished between biovar 2 reference strains and field strains that could not be identified by other methods, thus constituting a useful complementary test for the typing of A. pleuropneumoniae biovar 2.

  14. Caffeic acid treatment alters the extracellular adenine nucleotide hydrolysis in platelets and lymphocytes of adult rats.

    Science.gov (United States)

    Anwar, Javed; Spanevello, Roselia Maria; Pimentel, Victor Camera; Gutierres, Jessié; Thomé, Gustavo; Cardoso, Andreia; Zanini, Daniela; Martins, Caroline; Palma, Heloisa Einloft; Bagatini, Margarete Dulce; Baldissarelli, Jucimara; Schmatz, Roberta; Leal, Cláudio Alberto Martins; da Costa, Pauline; Morsch, Vera Maria; Schetinger, Maria Rosa Chitolina

    2013-06-01

    This study evaluated the effects of caffeic acid on ectonucleotidase activities such as NTPDase (nucleoside triphosphate diphosphohydrolase), Ecto-NPP (nucleotide pyrophosphatase/phosphodiesterase), 5'-nucleotidase and adenosine deaminase (ADA) in platelets and lymphocytes of rats, as well as in the profile of platelet aggregation. Animals were divided into five groups: I (control); II (oil); III (caffeic acid 10 mg/kg); IV (caffeic acid 50 mg/kg); and V (caffeic acid 100 mg/kg). Animals were treated with caffeic acid diluted in oil for 30 days. In platelets, caffeic acid decreased the ATP hydrolysis and increased ADP hydrolysis in groups III, IV and V when compared to control (P<0.05). The 5'-nucleotidase activity was decreased, while E-NPP and ADA activities were increased in platelets of rats of groups III, IV and V (P<0.05). Caffeic acid reduced significantly the platelet aggregation in the animals of groups III, IV and V in relation to group I (P<0.05). In lymphocytes, the NTPDase and ADA activities were increased in all groups treated with caffeic acid when compared to control (P<0.05). These findings demonstrated that the enzymes were altered in tissues by caffeic acid and this compound decreased the platelet aggregation suggesting that caffeic acid should be considered a potentially therapeutic agent in disorders related to the purinergic system.

  15. X-ray crystal structure of N-6 adenine deoxyribose nucleic acid methyltransferase from Streptococcus pneumoniae

    Science.gov (United States)

    Tran, Phidung Hong

    X-ray diffraction by using resonant anomalous scattering has become a popular tool for solving crystal structures in the last ten years with the expanded availability of tunable synchrotron radiation for protein crystallography. Mercury atoms were used for phasing. The crystal structure of N-6 deoxyribose nucleic acid methyltransferase from Streptoccocus pneumoniae (DpnM) was solved by using the Multiple Anomalous Diffraction technique. The crystal structure reveals the formation of mercaptide between the mercury ion and the thiol group on the cysteine amino acid in a hydrophobic environment. The crystal structure contains the bound ligand, S- adenosyl-l-methionine on the surface of the concave opening. The direction of the β-strands on the beta sheets are identical to other solved methyltransferases. The highly conserved motifs, DPPY and the FxGxG, are found to be important in ligand binding and possibly in methyl group transfer. The structure has a concave cleft with an opening on the order of 30 Å that can accommodate a DNA duplex. By molecular modelling coupled to sequence alignment, two other highly conserved residues Arg21 and Gly19 are found to be important in catalysis.

  16. Nucleotide sequence of yeast GDH1 encoding nicotinamide adenine dinucleotide phosphate-dependent glutamate dehydrogenase.

    Science.gov (United States)

    Moye, W S; Amuro, N; Rao, J K; Zalkin, H

    1985-07-15

    The yeast GDH1 gene encodes NADP-dependent glutamate dehydrogenase. This gene was isolated by complementation of an Escherichia coli glutamate auxotroph. NADP-dependent glutamate dehydrogenase was overproduced 6-10-fold in Saccharomyces cerevisiae bearing GDH1 on a multicopy plasmid. The nucleotide sequence of the 1362-base pair coding region and 5' and 3' flanking sequences were determined. Transcription start sites were located by S1 nuclease mapping. Regulation of GDH1 was not maintained when the gene was present on a multicopy plasmid. Protein secondary structure predictions identified a region with potential to form the dinucleotide-binding domain. The amino acid sequences of the yeast and Neurospora crassa enzymes are 63% conserved. Unlike the N. crassa gene, yeast GDH1 has no introns.

  17. A CBS domain-containing pyrophosphatase of Moorella thermoacetica is regulated by adenine nucleotides

    Science.gov (United States)

    Jämsen, Joonas; Tuominen, Heidi; Salminen, Anu; Belogurov, Georgiy A.; Magretova, Natalia N.; Baykov, Alexander A.; Lahti, Reijo

    2007-01-01

    CBS (cystathionine β-synthase) domains are found in proteins from all kingdoms of life, and point mutations in these domains are responsible for a variety of hereditary diseases in humans; however, the functions of CBS domains are not well understood. In the present study, we cloned, expressed in Escherichia coli, and characterized a family II PPase (inorganic pyrophosphatase) from Moorella thermoacetica (mtCBS-PPase) that has a pair of tandem 60-amino-acid CBS domains within its N-terminal domain. Because mtCBS-PPase is a dimer and requires transition metal ions (Co2+ or Mn2+) for activity, it resembles common family II PPases, which lack CBS domains. The mtCBS-PPase, however, has lower activity than common family II PPases, is potently inhibited by ADP and AMP, and is activated up to 1.6-fold by ATP. Inhibition by AMP is competitive, whereas inhibition by ADP and activation by ATP are both of mixed types. The nucleotides are effective at nanomolar (ADP) or micromolar concentrations (AMP and ATP) and appear to compete for the same site on the enzyme. The nucleotide-binding affinities are thus 100–10000-fold higher than for other CBS-domain-containing proteins. Interestingly, genes encoding CBS-PPase occur most frequently in bacteria that have a membrane-bound H+-translocating PPase with a comparable PPi-hydrolysing activity. Our results suggest that soluble nucleotide-regulated PPases act as amplifiers of metabolism in bacteria by enhancing or suppressing ATP production and biosynthetic reactions at high and low [ATP]/([AMP]+[ADP]) ratios respectively. PMID:17714078

  18. Alterations of adenine nucleotide metabolism and function of blood platelets in patients with diabetes.

    Science.gov (United States)

    Michno, Anna; Bielarczyk, Hanna; Pawełczyk, Tadeusz; Jankowska-Kulawy, Agnieszka; Klimaszewska, Joanna; Szutowicz, Andrzej

    2007-02-01

    Increased activity of blood platelets contributes to vascular complications in patients with diabetes. The aim of this work was to investigate whether persisting hyperglycemia in diabetic patients generates excessive accumulation of ATP/ADP, which may underlie platelet hyperactivity. Platelet ATP and ADP levels, thiobarbituric acid-reactive species synthesis, and aggregation of platelets from patients with diabetes were 18-82% higher than in platelets from healthy participants. In patients with diabetes, platelet stimulation with thrombin caused about two times greater release of ATP and ADP than in the healthy group while decreasing intraplatelet nucleotide content to similar levels in both groups. This indicates that the increased content of adenylate nucleotides in the releasable pool in the platelets of diabetic patients does not affect their level in metabolic cytoplasmic/mitochondrial compartments. Significant correlations between platelet ATP levels and plasma fructosamine, as well as between platelet ATP/ADP and platelet activities, have been found in diabetic patients. In conclusion, chronic hyperglycemia-evoked elevations of ATP/ADP levels and release from blood platelets of patients with diabetes may be important factors underlying platelet hyperactivity in the course of the disease.

  19. Activities of adenine nucleotide and nucleoside degradation enzymes in platelets of rats infected by Trypanosoma evansi.

    Science.gov (United States)

    Oliveira, Camila B; Da Silva, Aleksandro S; Vargas, Lara B; Bitencourt, Paula E R; Souza, Viviane C G; Costa, Marcio M; Leal, Claudio A M; Moretto, Maria B; Leal, Daniela B R; Lopes, Sonia T A; Monteiro, Silvia G

    2011-05-31

    Nucleotide and nucleoside-degrading enzymes, such as nucleoside triphosphate diphosphohydrose (NTPDase), 5'-nucleotidase and adenosine deaminase (ADA) are present in the surface membranes of platelets, involved in clotting disturbances of Trypanosoma evansi-infected animals. Thus, this study was aimed at evaluating the activities of these enzymes in platelets of rats experimentally infected with T. evansi. Animals were divided into four groups, according to the level of parasitemia. Blood samples were collected on days 3 (group A: at the beginning of parasitemia), 5 (group B: high parasitemia) and 15 (group C: chronic infection), post-infection. Group D (control group) was composed of non-infected animals for platelet count, separation and enzymatic assays. Animals from groups A and B showed marked thrombocytopenia, but platelet count was not affected in chronically infected rats. NTPDase, 5'-nucleotidase and ADA activities decreased (pplatelets from rats of groups A and B, when compared to the control group. In group C, only NTPDase and 5'-nucleoside activities decreased (pplatelet count and nucleotide/nucleoside hydrolysis were positive and statistically significant (pPlatelet aggregation was decreased in all infected groups, in comparison to the control group (pplatelets of T. evansi-infected animals might be related to thrombocytopenia, that by reducing the number of platelets, there was less release of ATP and ADP. Another possibility being suggested is that changes have occurred in the membrane of these cells, decreasing the expression of these enzymes in the cell membrane.

  20. Flipping of the ribosomal A-site adenines provides a basis for tRNA selection

    Science.gov (United States)

    Zeng, Xiancheng; Chugh, Jeetender; Casiano-Negroni, Anette; Al-Hashimi, Hashim M.; Brooks, Charles L.

    2014-01-01

    Ribosomes control the missense error rate of ~10−4 during translation though quantitative contributions of individual mechanistic steps of the conformational changes yet to be fully determined. Biochemical and biophysical studies led to a qualitative tRNA selection model in which ribosomal A-site residues A1492 and A1493 (A1492/3) flip out in response to cognate tRNA binding, promoting the subsequent reactions, but not in the case of near cognate or non-cognate tRNA. However, this model was recently questioned by X-ray structures revealing conformations of extrahelical A1492/3 and domain closure of the decoding center in both cognate and near-cognate tRNA bound ribosome complexes, suggesting that the non-specific flipping of A1492/3 has no active role in tRNA selection. We explore this question by carrying out molecular dynamics (MD) simulations, aided with fluorescence and NMR experiments, to probe the free energy cost of extrahelical flipping of 1492/3 and the strain energy associated with domain conformational change. Our rigorous calculations demonstrate that the A1492/3 flipping is indeed a specific response to the binding of cognate tRNA, contributing 3 kcal/mol to the specificity of tRNA selection. Furthermore, the different A-minor interactions in cognate and near-cognate complexes propagate into the conformational strain and contribute another 4 kcal/mol in domain closure. The recent structure of ribosome with features of extrahelical A1492/3 and closed domain in near-cognate complex is reconciled by possible tautomerization of the wobble base pair in mRNA-tRNA. These results quantitatively rationalize other independent experimental observations and explain the ribosomal discrimination mechanism of selecting cognate versus near-cognate tRNA. PMID:24813122

  1. UV-Induced Adenine Radicals Induced in DNA A-Tracts: Spectral and Dynamical Characterization.

    Science.gov (United States)

    Banyasz, Akos; Ketola, Tiia-Maaria; Muñoz-Losa, Aurora; Rishi, Sunny; Adhikary, Amitava; Sevilla, Michael D; Martinez-Fernandez, Lara; Improta, Roberto; Markovitsi, Dimitra

    2016-10-06

    Adenyl radicals generated in DNA single and double strands, (dA)20 and (dA)20·(dT)20, by one- and two-photon ionization by 266 nm laser pulses decay at 600 nm with half-times of 1.0 ± 0.1 and 4 ± 1 ms, respectively. Though ionization initially forms the cation radical, the radicals detected for (dA)20 are quantitatively identified as N6-deprotonated adenyl radicals by their absorption spectrum, which is computed quantum mechanically employing TD-DFT. Theoretical calculations show that deprotonation of the cation radical induces only weak spectral changes, in line with the spectra of the adenyl radical cation and the deprotonated radical trapped in low temperature glasses.

  2. Prevention of injury by resveratrol in a rat model of adenine-induced ...

    African Journals Online (AJOL)

    development of end-stage renal disease [1]. CKD ... of inducible nitric oxide synthase by human epithelial cells [10]. In addition, it prevents cartilage degradation in animal models of arthritis. [11]. .... occurring in a rat model of CKD, in which the animals were administered ... unrestricted use, distribution, and reproduction.

  3. Effects of acute gamma-irradiation on extracellular adenine nucleotide hydrolysis in developing rat brain

    Science.gov (United States)

    Stanojević, I.; Drakulić, D.; Veličković, N.; Milošević, M.; Petrović, S.; Horvat, A.

    2009-09-01

    Cell membrane is highly sensitive to irradiation which, acting directly or indirectly, may disturb functions of constitutive proteins including membrane enzymes. Plasma membrane surface-located enzyme chain of ecto-nucleotide triphospho diphosphohydrolases (NTPDases) and 5'-nucleotidase are involved in termination of cell purinergic signalization by hydrolyzing extracellular, excitatory adenosine triphosphate (ATP), as well as nucleotide di-, and mono-phosphate (ADP and AMP) to neuroprotective adenosine. Extracellular ATP, ADP, and AMP hydrolyzes were examined in purified synaptic plasma membranes after whole-body acute irradiation. All measurements were done 24 h after irradiation of developing (15-, 30-day-old) and adult (90-day-old) rats with low (50 cGy) and high (2 Gy) dose of gamma-rays. Both, high and low doses inhibited nucleotide hydrolyses in 15-day-old rats; in 30-day-old rats low dose of radiation inhibited ADP and AMP hydrolyses while high dose inhibited only ATP hydrolyse. In adult rats high dose induced no effects, while low dose stimulated nucleotides hydrolyses. According to obtained results it was concluded that ecto-nucleotidases of young rats are more sensitive to irradiation, since even low dose induces inhibition of ecto-nucleotidases activities. Ionizing radiation, by decreasing brain nucleotide hydrolyses in developing rats, induces accumulation of ATP and decreases production of adenosine in synaptic cleft which could be neurocytotoxic. On the contrary, in adult rats low dose of radiation stimulates NTPDase and 5'-nucleotidase activity and protective adenosine production which indicates protective and adaptive mechanisms developed in adult brain neuronal cells.

  4. Drug Release Properties of a Series of Adenine-Based Metal-Organic Frameworks.

    Science.gov (United States)

    Oh, Hyojae; Li, Tao; An, Jihyun

    2015-11-16

    The drug uptake and release properties of a series of biomolecule-based metal-organic frameworks (bMOF-1, bMOF-4, bMOF-100, and bMOF-102) have been studied. The bMOFs were loaded with the small molecule etilefrine hydrochloride and release profiles were collected in both Nanopure water and simulated body fluid (SBF). Each bMOF exhibited an initial burst of drug release at the initial stages of the experiment followed by a gradual release of the remaining drug molecules over time. bMOF-1 released 50% of the drug after 15 days and complete release at 80 days in SBF. bMOF-4 released 50% of the drug within two days and complete release at 49 days in SBF. bMOF-100 and bMOF-102 released 50% of the drug after 4 h and complete release at 69 and 54 days in SBF, respectively.

  5. Folding dynamics of flavin adenine dinucleotide (FAD) inside non-aqueous and aqueous reverse micelles

    Science.gov (United States)

    Sengupta, Abhigyan; Gavvala, Krishna; Koninti, Raj Kumar; Chaudhuri, Haribandhu; Hazra, Partha

    2013-10-01

    Present Letter describes dynamics of FAD in non-aqueous and aqueous reverse micelles (RMs). FAD in non-aqueous reverse micelles (containing MeOH, glycerol, formamide or DMF) shows a prominent rise of quantum yield with increasing solvent loading, whereas in water RM FAD shows a rise in quantum yield only up to w0 = 10 and afterwards drops sharply up to bulk. A relative difference in polarity of dry AOT to solvent loaded RMs can be attributed to the opposite trend of changes in emission. This Letter of FAD in different RMs and its preferential orientation might be useful for understanding FAD dynamics inside flavoproteins.

  6. 小分子干扰RNA抑制高氧暴露下人肺腺癌A549细胞中的硫氧还蛋白-2对还原型烟酰胺腺嘌呤二核苷酸脱氢酶亚单位1、细胞色素C氧化酶工表达的影响%Suppressed expression of thioredoxin-2 by small interference RNA in A549 cells exposed to hyperoxia reduced expression of nicotinamide-adenine dinucleotide dehydrogenase subunit 1 and cytochrome C oxidase Ⅰ

    Institute of Scientific and Technical Information of China (English)

    蔡成; 常立文; 李文斌; 陈燕; 单瑞艳; 刘伟; 潘睿

    2010-01-01

    Objective To explore the effects of expression of thioredoxin-2(Trx-2) suppressed by small interference RNA(SiRNA) in A549 cells exposed to hyperoxia on expression of nicotinamide adenine dinucleotide(NADH) dehydrogenase subunit 1(ND1)and cytochrome C oxidase Ⅰ(COX Ⅰ). Methods A549 cells were gained by serial subcultivation in vitro and transfered with synthetic Trx-2 sequence-specific SiRNA and then were randomly divided into air group without interference,hyperoxia group without interference,air group after interference,and hyperoxia group after interference.After exposure to oxygen or room air for 12,24 and 48 h,expressions of Trx-2,ND1 and COX Ⅰ mRNA of these cells were detected by reverse transcription-polymerase chain reaction (RT-PCR),and Trx-2 protein was detected by Western blot. Results (1)Sequence-specific SiRNA targeting Trx-2 could significantly down-regulate its expression in A549 cells.(2)Trx-2 mRNA levds in hyperoxia group without interference at 24 h was higher than those in air group without interference(0.7799±0.1249 VS 0.4424±Ⅰ.1140,P<0.05).Th-2 mRNA levels in hyperoxia group after ireedcrence at 24 h and 48 h were 0.2774±0.0174 and 0.2587±0.0069,lower than those in air group after interference and hyperoxia group without interference (P<0.05).(3)ND1 mRNA levels in hyperoxia group without interference at 24 h was 0.6609±0.0368,lower than those in air group without interference(0.8898±0.1049)(P<0.05).ND1 mRNA levels in hyperoxia group after interference at 12 h was 0.8848±0.0135,higher than those in air group after imederence(P<0.05).ND1 mRNA levels in hypemxia group after interference at 48 h was 0.3808±0.0937,lower than those in air group after imerference and hyperoxia group without interference(P<0.05).(4)COXI mRNA levels in hypemxia group without inteference at 12,24 and 48 h were 1.7313±0.4331,2.1929±0.6722 and 2.0754±0.2584,higher than those in air group witheUt interference,respectively (P<0.05). Conclusions ND1 and

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Resistant starch alters gut microbiota and reduces uremic retention solutes in rats with adenine-induced chronic kidney disease

    Science.gov (United States)

    Chronic kidney disease (CKD) is characterized by the reduced ability to void urine, leading to accumulation of waste products in the body. Recently, it has been observed that patients with CKD have an altered gut microbiome. This may in part be due to reduced fiber intake. Patients with CKD are ofte...

  9. Inhibiting pollen reduced nicotinamide adenine dinucleotide phosphate oxidase–induced signal by intrapulmonary administration of antioxidants blocks allergic airway inflammation

    Science.gov (United States)

    Dharajiya, Nilesh; Choudhury, Barun K.; Bacsi, Attila; Boldogh, Istvan; Alam, Rafeul; Sur, Sanjiv

    2011-01-01

    Background Ragweed extract (RWE) contains NADPH oxidases that induce oxidative stress in the airways independent of adaptive immunity (signal 1) and augment antigen (signal 2)–induced allergic airway inflammation. Objective To test whether inhibiting signal 1 by administering antioxidants inhibits allergic airway inflammation in mice. Methods The ability of ascorbic acid (AA), N-acetyl cystenine (NAC), and tocopherol to scavenge pollen NADPH oxidase–generated reactive oxygen species (ROS) was measured. These antioxidants were administered locally to inhibit signal 1 in the airways of RWE-sensitized mice. Recruitment of inflammatory cells, mucin production, calcium-activated chloride channel 3, IL-4, and IL-13 mRNA expression was quantified in the lungs. Results Antioxidants inhibited ROS generation by pollen NADPH oxidases and intracellular ROS generation in cultured epithelial cells. AA in combination with NAC or Tocopherol decreased RWE-induced ROS levels in cultured bronchial epithelial cells. Coadministration of antioxidants with RWE challenge inhibited 4-hydroxynonenal adduct formation, upregulation of Clca3 and IL-4 in lungs, mucin production, recruitment of eosinophils, and total inflammatory cells into the airways. Administration of antioxidants with a second RWE challenge also inhibited airway inflammation. However, administration of AA+NAC 4 or 24 hours after RWE challenge failed to inhibit allergic inflammation. Conclusion Signal 1 plays a proinflammatory role during repeated exposure to pollen extract. We propose that inhibiting signal 1 by increasing antioxidant potential in the airways may be a novel therapeutic strategy to attenuate pollen-induced allergic airway inflammation. Clinical implications Administration of antioxidants in the airways may constitute a novel therapeutic strategy to prevent pollen induced allergic airway inflammation. PMID:17336614

  10. Chloroethyinitrosourea-derived ethano cytosine and adenine adducts are substrates for escherichia coli glycosylases excising analogous etheno adducts

    Energy Technology Data Exchange (ETDEWEB)

    Guliaev, Anton B.; Singer, B.; Hang, Bo

    2004-05-05

    Exocyclic ethano DNA adducts are saturated etheno ring derivatives formed mainly by therapeutic chloroethylnitrosoureas (CNUs), which are also mutagenic and carcinogenic. In this work, we report that two of the ethano adducts, 3,N{sup 4}-ethanocytosine (EC) and 1,N{sup 6}-ethanoadenine (EA), are novel substrates for the Escherichia coli mismatch-specific uracil-DNA glycosylase (Mug) and 3-methyladenine DNA glycosylase II (AlkA), respectively. It has been shown previously that Mug excises 3,N{sup 4}-ethenocytosine ({var_epsilon}C) and AlkA releases 1,N{sup 6}-ethenoadenine ({var_epsilon}A). Using synthetic oligonucleotides containing a single ethano or etheno adduct, we found that both glycosylases had a {approx}20-fold lower excision activity toward EC or EA than that toward their structurally analogous {var_epsilon}C or {var_epsilon}A adduct. Both enzymes were capable of excising the ethano base paired with any of the four natural bases, but with varying efficiencies. The Mug activity toward EC could be stimulated by E. coli endonuclease IV and, more efficiently, by exonuclease III. Molecular dynamics (MD) simulations showed similar structural features of the etheno and ethano derivatives when present in DNA duplexes. However, also as shown by MD, the stacking interaction between the EC base and Phe 30 in the Mug active site is reduced as compared to the {var_epsilon}C base, which could account for the lower EC activity observed in this study.

  11. Syntheses of nicotinamide riboside and derivatives: effective agents for increasing nicotinamide adenine dinucleotide concentrations in mammalian cells.

    Science.gov (United States)

    Yang, Tianle; Chan, Noel Yan-Ki; Sauve, Anthony A

    2007-12-27

    A new two-step methodology achieves stereoselective synthesis of beta-nicotinamide riboside and a series of related amide, ester, and acid nucleosides. Compounds were prepared through a triacetylated-nicotinate ester nucleoside, via coupling of either ethylnicotinate or phenylnicotinate with 1,2,3,5-tetra-O-acetyl-beta-D-ribofuranose. Nicotinamide riboside, nicotinic acid riboside, O-ethylnicotinate riboside, O-methylnicotinate riboside, and several N-alkyl derivatives increased NAD+ concentrations from 1.2-2.7-fold in several mammalian cell lines. These findings establish bioavailability and potent effects of these nucleosides in stimulating the increase of NAD+ concentrations in mammalian cells.

  12. Degradation Products of Adenine Nucleotide in Rainbow Trout (Oncorhynchus mykiss) Stored in Ice and in Modified Atmosphere Packaging

    OpenAIRE

    ÖZOĞUL, Yeşim; Özoğul, Fatih

    2002-01-01

    The breakdown products of adenosine triphosphate (ATP) were separated using a rapid HPLC method. The K-value, Ki-value and H-value were also determined as a means of evaluating the quality of rainbow trout held in ice and modified atmosphere packaging comparing with sensory and microbiological analysis in terms of fresh fish quality. Results from the present research indicated that modified atmosphere did not extend the shelf life of trout but inhibited microbial growth compared to ice storag...

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

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Koji [Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)], E-mail: kojitcm@mbox.nc.kyushu-u.ac.jp; Ohkubo, Kimihiko; Taira, Hiroaki [Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Takagi, Makoto [Fukuoka Women' s University, 1-1-1, Kasumigaoka, Higashi-ku, Fukuoka 813-8529 (Japan); Imato, Toshihiko [Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

    2008-06-30

    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{sup -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{sup -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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  15. The role of calcium and nicotinic acid adenine dinucleotide phosphate (NAADP) in human osteoclast formation and resorption.

    Science.gov (United States)

    Cheng, X; Hookway, E S; Kashima, T; Oppermann, U; Galione, A; Athanasou, N A

    2015-01-01

    Osteoclasts are specialised bone resorbing cells which form by fusion of circulating mononuclear phagocyte precursors. Bone resorption results in the release of large amounts of calcium into the extracellular fluid (ECF), but it is not certain whether changes in extracellular calcium concentration [Ca(2+)]e influence osteoclast formation and resorption. In this study, we sought to determine the effect of [Ca(2+)]e and NAADP, a potent calcium mobilising messenger that induces calcium uptake, on human osteoclast formation and resorption. CD14+ human monocytes were cultured with M-CSF and RANKL in the presence of different concentrations of calcium and NAADP and the effect on osteoclast formation and resorption evaluated. We found that the number of TRAP+ multinucleated cells and the extent of lacunar resorption were reduced when there was an increase in extracellular calcium and NAADP. This was associated with a decrease in RANK mRNA expression by CD14+ cells. At high concentrations (20 mM) of [Ca(2+)]e mature osteoclast resorption activity remained unaltered relative to control cultures. Our findings indicate that osteoclast formation is inhibited by a rise in [Ca(2+)]e and that RANK expression by mononuclear phagocyte osteoclast precursors is also [Ca(2+)]e dependent. Changes in NAADP also influence osteoclast formation, suggesting a role for this molecule in calcium handling. Osteoclasts remained capable of lacunar resorption, even at high ECF [Ca(2+)]e, in keeping with their role in physiological and pathological bone resorption.

  16. A case of hyperkalemia after transfusion of irradiated red cell concentrate in mannitol-adenine-phosphate (RC-MAP)

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Akira; Yokota, Kimio; Aoki, Masanori; Sari, Atsuo [Kawasaki Medical School, Kurashiki, Okayama (Japan)

    1998-11-01

    A 72-year-old male, 45 kg in weight, underwent anterior and posterior fixations of the lumbar vertebra. Preanesthetic blood chemistry was within normal range. Following transfusion of 400 ml of RC-MAP in two hours (11 days after blood collection and 2 days after irradiation at a dose of 20 Gy), and then another 100 ml of 400 ml RC-MAP (12 days after blood collection and 2 days after irradiation at a dose of 20 Gy), the patient`s serum kalium value increased from 4.8 to 5.5 mEq/l. Even though the transfusion was immediately discontinued, the level continued to rise to 6.0 mEq/l. It subsequently fell to the normal level with glucose-insulin therapy. The hyperkalemia in this case could have been attributable to the period of storage after irradiation, the transfusion of salvaged autologous blood, and the storage state of RC-MAP. However, since the kalium values of RC-MAP and the salvaged autologous blood were not measured in this case, the exact cause was unknown. In conclusion, hyperkalemia can occur in patients during transfusion of irradiated blood. Therefore, kalium levels should be monitored carefully. (author)

  17. "Your funeral... my trial": a review of the mechanisms leading to cancer cells death when targeting nicotinamide adenine dinucleotide

    OpenAIRE

    MORISOD, L.

    2014-01-01

    Le nicotinamide adénine dinucléotide (NAD) est un métabolite jouant un rôle crucial dans la vie cellulaire. Dans la mitochondrie, il est surtout utilisé comme co-enzyme d'oxydo-réduction afin de produire de l'énergie sous forme d'ATP (respiration cellulaire). Dans le noyau, il est utilisé en tant que co-substrat par plusieurs enzymes (sirtuines, PARP,...) impliquées dans diverses fonctions d'expression génique, de réparation cellulaire ou d'apoptose. Le NAD tend dès lors à deveni...

  18. Transient overexpression of DNA adenine methylase enables efficient and mobile genome engineering with reduced off-target effects

    DEFF Research Database (Denmark)

    Lennen, Rebecca; Nilsson Wallin, Annika; Pedersen, Margit;

    2016-01-01

    result in reduced efficiencies of replacement. Therefore a new system was developed, Transient Mutator Multiplex Automated Genome Engineering (TM-MAGE), that solves problems encountered in other methods for oligonucleotide-mediated recombination. TM-MAGE enables nearly equivalent efficiencies of allelic......Homologous recombination of single-stranded oligonucleotides is a highly efficient process for introducing precise mutations into the genome of E. coli and other organisms when mismatch repair (MMR) is disabled. This can result in the rapid accumulation of off-target mutations that can mask desired...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    dinucleotide (FAD)-binding domain of HvNTR2 to strongly affect the interaction with Trx. In particular, Trp42 and Met43 play key roles for recognition of the endogenous HvTrxh2. Trx from Arabidopsis thaliana is also efficiently recycled by HvNTR2 but turnover in this case appears to be less dependent...... on these two residues, suggesting a distinct mode for NTR:Trx recognition. Comparison between the HvNTR2:HvTrxh2 model and the crystal structure of the Escherichia coli NTR:Trx complex reveals major differences in interactions involving the FAD- and NADPH-binding domains as supported by our experiments...

  20. Mutations in PurBox1 of the Bacillus subtilis pur operon control site affect adenine-regulated expression in vivo

    Institute of Scientific and Technical Information of China (English)

    XUAN; Jinsong; Howard; Zalkin; WENG; Manli

    2005-01-01

    Transcription of the Bacillus subtilis pur operon is regulated by a purine repressor (PurR)-DNA control site interaction. The pur operon control site has two PurBoxes that are required for high-affinity PurR binding. An upstream, strong-binding PurBox1 is at position -81 to -68 relative to the transcription start site and a downstream weak-binding PurBox2 is at position -49 to -36. We constructed three PurBox1 mutations and the effects on binding of PurR to the control region in vitro and on regulation of pur operon expression in vivo were investigated. The mutations significantly reduced the binding of PurR to control region DNA. In strains with G-75A, G-75T and a five bp deletion (△5) pur operon repression was defective in vivo. In addition in vivo PurR titration was used to confirm that sequences flanking PurBox1 and PurBox2 are required for PurR binding to the pur operon control site.

  1. ESTRUCTURA TRIDIMENSIONAL DE LA CITOQUININA N-BENZIL 9 (2 TETRAHIDROPIRANYL ADENINE UTILIZANDO EL MÉTODO DE RESONANCIA MAGNÉTICA NUCLEAR

    Directory of Open Access Journals (Sweden)

    Carlos Rojas

    2004-06-01

    Full Text Available Para comprender la función biológica de las moléculas que conforman los seres vivos es necesario conocer la estructura tridimensional de ellas, pues está comprobado que la función depende más de la distribución espacial que de los mismos componentes. El objetivo del presente trabajo es determinar la estructura de una fitohormona. Uno de los métodos que existen para determinar estas estructuras es la resonancia magnética nuclear pulsada el cual se escogió para este trabajo. Este método se diferencia de la resonancia de onda continua en el hecho de que el campo magnético variable es aplicado en forma de pulsos y su amplitud no puede ser considerada como una perturbación al sistema. La determinación de la estructura exigió la toma de los espectros unidimensionales de H1, C13 y los Distortionless Enhacement by Polarization Transfer (DEPT; este último es una secuencia de pulsos que permite diferenciar entre carbonos unidos a tres, a dos y a un hidrógeno. Con la ayuda del espectro C13 también se pueden distinguir los carbonos que no están enlazados con ningún hidrógeno. Además de éstos, fueron necesarios los siguientes espectros bidimensionales: 1 Heteronuclear Multiple Quantum Correlation (HMQC el cual correlaciona hidrógenos con carbonos que se encuentren enlazados; 2 Heteronuclear Multiple Bond Correlation (HMBC que correlaciona carbonos con hidrógenos que se encuentren a dos o tres enlaces; 3 Correlation Spectroscopy (COSY el cual muestra la correlación entre hidrógenos que se encuentren a dos o tres enlaces; y 4 Nuclear Overhauser Effect Spectroscopy (NOESY el cual correlaciona hidrógenos que distan entre sí menos de 5 Å. A partir de la información obtenida del análisis de estos espectros se dedujo el modelo de la fitohormona que se presenta como resultado del trabajo.

  2. Determination of the B2 vitamer flavin-adenine dinucleotide in whole blood by high-performance liquid chromatography with fluorometric detection

    NARCIS (Netherlands)

    Speek, A.J.; Schaik, F. van; Schrijver, J.; Schreurs, W.H.P.

    1982-01-01

    A reliable high-performance liquid chromatographic (HPLC) method is developed for the analysis of FAD in whole blood of humans. The method is able to separate FAD, FMN and Rb from each other and from interfering compounds. A reliable and sensitive detection of FAD has been obtained by selecting the

  3. Enhanced Reduced Nicotinamide Adenine Dinucleotide electrocatalysis onto multi-walled carbon nanotubes-decorated gold nanoparticles and their use in hybrid biofuel cell

    Science.gov (United States)

    Aquino Neto, S.; Almeida, T. S.; Belnap, D. M.; Minteer, S. D.; De Andrade, A. R.

    2015-01-01

    We report the preparation of Au nanoparticles synthetized by different protocols and supported on the surface of multi-walled carbon nanotubes containing different functional groups, focusing on their electrochemical performance towards NADH oxidation, ethanol bioelectrocatalysis, and ethanol/O2 biofuel cell. We describe four different synthesis protocols: microwave-assisted heating, water-in-oil, and dendrimer-encapsulated nanoparticles using acid or thiol species in the extraction step. The physical characterization of the metallic nanoparticles indicated that both the synthetic protocol as well as the type of functional groups on the carbon nanotubes affect the final particle size (varying from 13.4 to 2.4 nm) and their distribution onto the carbon surface. Moreover, the electrochemical data indicated that these two factors also influence their performance toward the electrooxidation of NADH. We observed that the samples containing Au nanoparticles with smaller size leads to higher catalytic currents and also shifts the oxidation potential of the targeted reaction, which varied from 0.13 to -0.06 V vs Ag/AgCl. Ethanol/O2 biofuel cell tests indicated that the hybrid bioelectrodes containing smaller and better distributed Au nanoparticles on the surface of carbon nanotubes generates higher power output, confirming that the electrochemical regeneration of NAD+ plays an important role in the overall biofuel cell performance.

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

    DEFF Research Database (Denmark)

    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...

  5. Novel concept of enzyme selective nicotinamide adenine dinucleotide (NAD)-modified inhibitors based on enzyme taxonomy from the diphosphate conformation of NAD.

    Science.gov (United States)

    Fujii, Mikio; Kitagawa, Yasuyuki; Iida, Shui; Kato, Keisuke; Ono, Machiko

    2015-11-15

    The dihedral angle θ of the diphosphate part of NAD(P) were investigated to distinguish the differences in the binding-conformation of NAD(P) to enzymes and to create an enzyme taxonomy. Furthermore, new inhibitors with fixed dihedral angles showed that enzymes could recognize the differences in the dihedral angle θ. We suggest the taxonomy and the dihedral angle θ are important values for chemists to consider when designing inhibitors and drugs that target enzymes.

  6. Structure of Stacked Dimers of N-Methylated Watson–Crick Adenine–Thymine Base Pairs

    Directory of Open Access Journals (Sweden)

    Sándor Suhai

    2003-09-01

    Full Text Available Abstract: The structure of two isomeric stacked dimers of Watson-Crick 9-methyladenine-1-methylthymine pairs was fully optimized using an approximate density functional theory (DFT method augmented with an empirical dispersion interaction. The results of the calculations reveal that head-to-tail (AT-TA and head-to-head (AT-AT dimers possess a significantly different geometry. The structure of both complexes is stabilized by vertical CH…O and C-H…N hydrogen bonds with the participation of the hydrogen atoms of the methyl groups. The energy of hydrogen bonding and stacking interactions was additionally calculated using the MP2/6-31G*(0.25 method. Differences in the mutual arrangement of the base pairs in two isomeric dimers lead to significant changes of intra and interstrand stacking interaction energies.

  7. Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) and Cyclic ADP-Ribose (cADPR) Mediate Ca2+ Signaling in Cardiac Hypertrophy Induced by β-Adrenergic Stimulation

    Science.gov (United States)

    Shawl, Asif Iqbal; Im, Soo-Yeul; Nam, Tae-Sik; Lee, Sun-Hwa; Ko, Jae-Ki; Jang, Kyu Yoon; Kim, Donghee; Kim, Uh-Hyun

    2016-01-01

    Ca2+ signaling plays a fundamental role in cardiac hypertrophic remodeling, but the underlying mechanisms remain poorly understood. We investigated the role of Ca2+-mobilizing second messengers, NAADP and cADPR, in the cardiac hypertrophy induced by β-adrenergic stimulation by isoproterenol. Isoproterenol induced an initial Ca2+ transients followed by sustained Ca2+ rises. Inhibition of the cADPR pathway with 8-Br-cADPR abolished only the sustained Ca2+ increase, whereas inhibition of the NAADP pathway with bafilomycin-A1 abolished both rapid and sustained phases of the isoproterenol-mediated signal, indicating that the Ca2+ signal is mediated by a sequential action of NAADP and cADPR. The sequential production of NAADP and cADPR was confirmed biochemically. The isoproterenol-mediated Ca2+ increase and cADPR production, but not NAADP production, were markedly reduced in cardiomyocytes obtained from CD38 knockout mice. CD38 knockout mice were rescued from chronic isoproterenol infusion-induced myocardial hypertrophy, interstitial fibrosis, and decrease in fractional shortening and ejection fraction. Thus, our findings indicate that β-adrenergic stimulation contributes to the development of maladaptive cardiac hypertrophy via Ca2+ signaling mediated by NAADP-synthesizing enzyme and CD38 that produce NAADP and cADPR, respectively. PMID:26959359

  8. High-NaCl Diet Aggravates Cardiac Injury in Rats with Adenine-Induced Chronic Renal Failure and Increases Serum Troponin T Levels

    DEFF Research Database (Denmark)

    Kashioulis, Pavlos; Hammarsten, Ola; Marcussen, Niels

    2016-01-01

    correlation between the degree of LV fibrosis and serum cTnT levels in ACRF rats (r = 0.81, p hypertension-induced small artery lesions leading...... to myocardial ischemia. This model may be suitable for studying pathophysiological mechanisms in chronic renicardiac syndromes....

  9. AB154. Testosterone improves erectile function through regulation of nicotinamide adenine dinucleotide phosphate-oxidase and cyclooxygenase-2 expression in castrated rats

    Science.gov (United States)

    Li, Rui; Wang, Tao; Yang, Jun; Zhang, Yan; Niu, Yonghua; Wang, Shaogang; Ye, Zhangqun; Rao, Ke; Liu, Jihong

    2015-01-01

    Objective Testosterone significantly improves hypogonadal-related erectile dysfunction (ED). However, the molecular mechanisms are poorly understood. The purpose of this study was to explore the effect and mechanism of testosterone in castrated rats. Methods Forty male Sprague-Dawley rats were randomized to 4 groups (control, sham-operated, castration and castration-with-testosterone-replacement). After 2 months, reactive oxygen species (ROS) production was measured by dihydroethidium (DHE) staining. Erectile function was tested by recording intracavernosal pressure (ICP) and mean arterial blood pressure (MAP). Protein expression levels were examined by Western blot. Results Castration reduced erectile function, and testosterone restored it. The concentrations of testosterone, cyclic guanosine mono-phosphate (cGMP) and cyclic adenosine monophosphate (cAMP) were lower in castrated rats than in controls, and testosterone restored these decreases (each P<0.05). The expression levels of cyclooxygenase-2 (COX-2), prostacyclin synthase (PTGIS or PGIS), endothelial nitric oxide synthase (eNOS) and phospho-eNOS were reduced in castrated rats compared with controls. The expression levels were significantly elevated in rats treated with testosterone (each P<0.05). The expression levels of p40phox and p67phox were increased in castrated rats, and testosterone significantly reduced these increases (each P<0.05). ROS production was markedly enhanced in castrated rats, and testosterone administration reversed this effect (P<0.05). Conclusions Testosterone can ameliorate ED after castration by reducing ROS production and increasing activity of the eNOS/cGMP and COX-2/PTGIS/cAMP signaling pathways.

  10. Pioglitazone inhibits the expression of nicotinamide adenine dinucleotide phosphate oxidase and p38 mitogen-activated protein kinase in rat mesangial cells

    Institute of Scientific and Technical Information of China (English)

    WANG Shan; YE Shan-dong; SUN Wen-jia; HU Yuan-yuan

    2013-01-01

    Background Oxidative Stress and p38 mitogen-activated protein kinase (p38MAPK) play a vital role in renal fibrosis.Pioglitazone can protect kidney but the underlying mechanisms are less clear.The purpose of this study was to investigate the effect of pioglitazone on oxidative stress and whether the severity of oxidative stress was associated with the phosphorylation level of p38MAPK.Methods Rat mesangial cells were cultured and randomly assigned to control group,high glucose group and pioglitazone group.After 48-hour exposure,the supernatants and ceils were collected.The protein levels of p22phox,p47phox,phosphorylated p38MAPK,total p38MAPK were measured by Western blotting.The gene expressions of p22phox,p47phox were detected by RT-PCR.The levels of intracellular reactive oxygen species (ROS) were determined by flow cytometry.The levels of superoxide dismutase (SOD) and maleic dialdehyde (MDA) in the supernatant were determined respectively.Results Compared with the control group,the expression levels of p22phox,p47phox,phospho-p38 and ROS significantly increased,activity of SOD decreased in high glucose group,while the level of MDA greatly increased (P <0.01).Pioglitazone significantly suppressed p22phox,p47phox expressions and oxidative stress induced by high glucose.The expressions of p22phox,p47phox,phospho-p38MAPK and ROS generation were markedly reduced after pioglitazone treatment (P <0.05).The activity of SOD in the the supernatant increased (P <0.05),while the level of MDA decreased greatly by pioglitazone (P <0.05).The level of oxidative stress was associated with the phosphorylation level of p38MAPK (P <0.01).Conclusion Pioglitazone can inhibit oxidative stress through suppressing NADPH oxidase expression and p38MAPK phosphorylation.

  11. Renal reduced nicotinamide adenine dinucleotide phosphate:cytochrome c reductase-mediated metabolism of the carcinogen N-(4-(5-nitro-2-furyl)-2-thiazolyl)acetamide

    Energy Technology Data Exchange (ETDEWEB)

    Mattammal, M.B.; Zenser, T.V.; Palmier, M.O.; Davis, B.B.

    1985-01-01

    N-(4-(5-Nitro-2-furyl)-2-thiazolyl)acetamide (NFTA) metabolism was examined in vitro using microsomes prepared from rat liver and renal cortex and from rabbit liver and renal cortex and outer and inner medulla. NFTA nitroreduction was observed with each tissue. Three mol of NADPH were used per mol of NFTA reduced. Substrate and inhibitor specificity suggested that the microsomal nitroreduction was due to NADPH:cytochrome c reductase. Metabolite(s) formed bound to protein, RNA, DNA, and synthetic polyribonucleotides. Maximum covalent binding was seen with polyguanylic acid. A guanosine-NFTA adduct was isolated. Binding was inhibited by sulfhydryl compounds and vitamin E. The (/sup 14/C)NFTA:glutathione or (/sup 3/H)glutathione:NFTA conjugates obtained from microsomal incubations showed identical chromatographic properties as the product obtained by the reaction of synthetic N-hydroxy-NFTA with (/sup 3/H)glutathione. Structures of synthetic N-hydroxy-NFTA and the microsomal reduction product 1-(4-(2-acetylaminothiazolyl))-3-cyano-1-propanone were established by mass spectrometry. The latter reduction product did not bind macromolecules. These results suggest that renal NADPH:cytochrome c reductase reduces NFTA to an N-hydroxy-NFTA intermediate that binds nucleophilic sites on macromolecules.

  12. SYNTHESIS, METABOLIC STABILITY AND ANTIVIRAL EVALUATION OF VARIOUS ALKOXYALKYL ESTERS OF CIDOFOVIR AND (S)-[3-HYDROXY-2-(PHOSPHONOMETHOXY)PROPYL]ADENINE

    Science.gov (United States)

    Ruiz, Jacqueline; Beadle, James R.; Buller, R. Mark; Schreiwer, Jill; Prichard, Mark N.; Keith, Kathy A.; Lewis, Kenneth C.; Hostetler, Karl Y.

    2011-01-01

    Alkoxyalkyl esters of cidofovir (CDV) are orally active agents which inhibit the replication of a variety of double stranded DNA (dsDNA) viruses including variola, vaccinia, ectromelia, herpes simplex virus, cytomegalovirus, adenovirus and others. One of these compounds, hexadecyloxypropyl-CDV (HDP-CDV, CMX001) is in clinical development for prevention and treatment of poxvirus infection, vaccination complications, and for infections caused by cytomegalovirus, adenovirus, herpesviruses and other dsDNA viruses. This class of lipid analogs is potentially prone to undergo omega oxidation of the alkyl moiety which can lead to a short chain carboxylic acid lacking antiviral activity. To address this issue, we synthesized a series of alkoxyalkyl or alkyl glycerol esters of CDV and (S)-HPMPA having modifications in the structure of the alkyl residue. Antiviral activity was assessed in cells infected with vaccinia, cowpox or ectromelia viruses. Metabolic stability was determined in S9 membrane fractions from rat, guinea pig, monkey and human liver. All compounds had substantial antiviral activity in cells infected with vaccinia, cowpox or ectromelia. Metabolic stability was lowest in monkey liver S9 incubations where rapid disappearance of HDP-CDV and HDP-(S)-HPMPA was noted. Metabolic stability in monkey preparations increased substantially when a ω-1 methyl group (15-methyl-HDP-CDV) or a terminal cyclopropyl residue (14-cyclopropyl-tetradecyloxypropyl-CDV) was present in the alkyl chain. The most stable compound was 1-O-octadecyl-2-O-benzyl-sn-glycero-3-CDV (ODBG-CDV) which was not metabolized extensively by monkey liver S9. In rat, guinea pig or human liver S9 incubations, most of the modified antiviral compounds were considerably more stable. PMID:21493074

  13. The activity of uridine diphosphate-D-glucose: Nicotinamide-adenine dinucleotide oxidoreductase in cambial tissue and differentiating xylem isolated from sycamore trees.

    Science.gov (United States)

    Rubery, P H

    1972-06-01

    The activity of UDPGlc: NAD oxidoreductase is measured in enzyme preparations obtained from sycamore cambium and xylem tissue. The activity of this enzyme is greater in xylem than in cambium whether expressed on a specific activity basis or on a per-cell basis. It is suggested that, in developing xylem, direct oxidation of UDPGlc may contribute significantly to the biosynthesis of polysaccharide precursors.

  14. Inhibitory effects of acyclic nucleoside phosphonates on human hepatitis B virus and duck hepatitis B virus infections in tissue culture

    NARCIS (Netherlands)

    R.A. Heijtink; J. Kruining; G.A. de Wilde; J. Balzarini; E. de Clercq; S.W. Schalm (Solko)

    1994-01-01

    textabstractThe inhibitory effects of the 9-(2-phosphonylmethoxyethyl)adenine-related compounds (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)-adenine, (S)-9-(3-fluoro-2-phosphonylmethoxypropyl)adenine, (R)-9-(2-phosphonylmethoxypropyl)adenine, (R)-9-(2-phosphony

  15. Drug: D04959 [KEGG MEDICUS

    Lifescience Database Archive (English)

    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 ...

  16. Inhibitory effects of acyclic nucleoside phosphonates on human hepatitis B virus and duck hepatitis B virus infections in tissue culture

    NARCIS (Netherlands)

    R.A. Heijtink; J. Kruining; G.A. de Wilde; J. Balzarini; E. de Clercq; S.W. Schalm (Solko)

    1994-01-01

    textabstractThe inhibitory effects of the 9-(2-phosphonylmethoxyethyl)adenine-related compounds (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)-adenine, (S)-9-(3-fluoro-2-phosphonylmethoxypropyl)adenine, (R)-9-(2-phosphonylmethoxypropyl)adenine, (R)-9-(2-phosphony

  17. Uncaria tomentosa extract alters the catabolism of adenine nucleotides and expression of ecto-5'-nucleotidase/CD73 and P2X7 and A1 receptors in the MDA-MB-231 cell line.

    Science.gov (United States)

    Santos, Karen Freitas; Gutierres, Jessié Martins; Pillat, Micheli Mainardi; Rissi, Vitor Braga; Santos Araújo, Maria do Carmo Dos; Bertol, Gustavo; Gonçalves, Paulo Bayard Dias; Schetinger, Maria Rosa Chitolina; Morsch, Vera Maria

    2016-12-24

    Uncaria tomentosa (Willd.) DC. (Rubiaceae) (Ut), also known as cat's claw, is a woody liana widely spread throughout the Amazon rainforest of Central and South America, containing many chemical constituents such as oxindole alkaloids, which are responsible for various biological activities. Since ancient times, the indigenous people of Peru have used it as a bark infusion for the treatment of a wide range of health problems gastric ulcers, arthritis and rheumatism. Recently, Ut is distributed worldwide and used as an immunomodulatory and anti-inflammatory herbal remedy. Additionally, U. tomentosa also has antitumural activity. However, little is known about the action of U. tomentosa on the purinergic system mechanisms, which is involved in tumor progression. Considering the pharmacological properties of U. tomentosa, we sought to evaluate the hydroalcoholic extract U tomentosa is able to influence the purinergic system in breast cancer cells, MDA-MB-231. Through the activity and expression of ectonucleotidases (NTPDase - CD39; Ecto-5'-nucleotidase - CD73) and purinergic repceptores (P2X7 and A1). A hydroalcoholic extract was prepared in two concentrations, 250 and 500μg/mL. (Ut250; Ut500). The effect of these concentrations on the activity and expression of ectonucleotidases, as well as on the density of purinergic receptors were investigated in MDA-MB-231 breast cancer cells. Cells were treated with the hydroalcoholic extract of Uncaria tomentosa and/or doxorubicin (Doxo 1μM; Ut250+Doxo; Ut500+Doxo) for 24h. Although the results were not significant for the hydrolysis of the ATP, they presented an increase in the ADP hydrolysis in the Ut500+Doxo group when compared to the control group. Additionally, the activity of 5'-nucleotidase was inhibited in all groups when compared with the untreated group of cells. Inhibition of the enzyme was more evident in groups with U. tomentosa per se. The expression of CD39 was increased in the Ut250 and Ut250+Doxo groups when compared to the control group. No changes were found in the CD73 expression. Furthermore, a reduction in the density of the P2X7 receptor in all treated groups was detected. On the other hand, the density of the A1 receptor increased in all groups compared to the control group, with the exception of the Ut500+Doxo group. Therefore, we conclude that hydroalcoholic extract of U. tomentosa may be responsible for the reduction of adenosine levels in the extracellular medium, which accelerates tumor progression. Interestingly, the dysregulation of A1 and P2X7 receptors in the MDA-MB-231 cells exacerbate the proliferation of this cells and U. tomentosa treatment may be stimulate the antitumor activity of adenosine A1 receptor and control the P2X7 effects. Our study demonstrates the significant participation of purinergic pathway in the regulation of MDA-MB-231 progression; additionally, U. tomentosa treatment alone or combined with chemotherapy may favor the action of doxorubicin. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Adenine nucleotides inhibit proliferation of the human lung adenocarcinoma cell line LXF-289 by activation of nuclear factor kappaB1 and mitogen-activated protein kinase pathways.

    Science.gov (United States)

    Schäfer, Rainer; Hartig, Roland; Sedehizade, Fariba; Welte, Tobias; Reiser, Georg

    2006-08-01

    Extracellular nucleotides have a profound role in the regulation of the proliferation of diseased tissue. We studied how extracellular nucleotides regulate the proliferation of LXF-289 cells, the adenocarcinoma-derived cell line from human lung bronchial tumor. ATP and ADP strongly inhibited LXF-289 cell proliferation. The nucleotide potency profile was ATP = ADP = ATPgammaS > > UTP, UDP, whereas alpha,beta-methylene-ATP, beta,gamma-methylene-ATP, 2',3'-O-(4-benzoylbenzoyl)-ATP, AMP and UMP were inactive. The nucleotide potency profile and the total blockade of the ATP-mediated inhibitory effect by the phospholipase C inhibitor U-73122 clearly show that P2Y receptors, but not P2X receptors, control LXF-289 cell proliferation. Treatment of proliferating LXF-289 cells with 100 microm ATP or ADP induced significant reduction of cell number and massive accumulation of cells in the S phase. Arrest in S phase is also indicated by the enhancement of the antiproliferative effect of ATP by coapplication of the cytostatic drugs cisplatin, paclitaxel and etoposide. Inhibition of LXF-289 cell proliferation by ATP was completely reversed by inhibitors of extracellular signal related kinase-activating kinase/extracellular signal related kinase 1/2 (PD98059, U0126), p38 mitogen-activated protein kinase (SB203508), phosphatidylinositol-3-kinase (wortmannin), and nuclear factor kappaB1 (SN50). Western blot analysis revealed transient activation of p38 mitogen-activated protein kinase, extracellular signal-related kinase 1/2, and nuclear factor kappaB1 and possibly new formation of p50 from its precursor p105. ATP-induced attenuation of LXF-289 cell proliferation was accompanied by transient translocation of p50 nuclear factor kappaB1 and extracellular signal-related kinase 1/2 to the nucleus in a similar time period. In summary, inhibition of LXF-289 cell proliferation is mediated via P2Y receptors by activation of multiple mitogen-activated protein kinase pathways and nuclear factor kappaB1, arresting the cells in the S phase.

  19. The yfiC gene of E. coli encodes an adenine-N6 methyltransferase that specifically modifies A37 of tRNA1Val(cmo5UAC).

    Science.gov (United States)

    Golovina, Anna Y; Sergiev, Petr V; Golovin, Andrey V; Serebryakova, Marina V; Demina, Irina; Govorun, Vadim M; Dontsova, Olga A

    2009-06-01

    Transfer RNA is highly modified. Nucleotide 37 of the anticodon loop is represented by various modified nucleotides. In Escherichia coli, the valine-specific tRNA (cmo(5)UAC) contains a unique modification, N(6)-methyladenosine, at position 37; however, the enzyme responsible for this modification is unknown. Here we demonstrate that the yfiC gene of E. coli encodes an enzyme responsible for the methylation of A37 in tRNA(1)(Val). Inactivation of yfiC gene abolishes m(6)A formation in tRNA(1)(Val), while expression of the yfiC gene from a plasmid restores the modification. Additionally, unmodified tRNA(1)(Val) can be methylated by recombinant YfiC protein in vitro. Although the methylation of m(6)A in tRNA(1)(Val) by YfiC has little influence on the cell growth under standard conditions, the yfiC gene confers a growth advantage under conditions of osmotic and oxidative stress.

  20. 聚硫堇/石墨烯复合材料修饰电极对NADH的电催化氧化研究%Grapheme functionalized with poly thionine for electrochemical determination of nicotinamide adenine dinucleotide

    Institute of Scientific and Technical Information of China (English)

    张天祎; 赵曼竹; 魏倾鹤; 齐斌

    2016-01-01

    采用循环伏安法将硫堇在石墨烯修饰的玻碳电极表面聚合,得到了一种新的聚硫堇/石墨烯修饰电极,此电极兼备了石墨烯和聚硫堇的特性.实验表明:该修饰电极能有效降低NADH的过电位;对NADH的检测范围为2.4×10-6~4.89×10-3 mol·L-1;检出限为6.826×10-7 mol·L-1;对尿酸和抗坏血酸的干扰有很好的消除作用;此电极稳定性、重现性较好,有很高的实际应用价值.

  1. The 2.5 Å Crystal Structure of the SIRT1 Catalytic Domain Bound to Nicotinamide Adenine Dinucleotide (NAD + ) and an Indole (EX527 Analogue) Reveals a Novel Mechanism of Histone Deacetylase Inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xun; Allison, Dagart; Condon, Bradley; Zhang, Feiyu; Gheyi, Tarun; Zhang, Aiping; Ashok, Sheela; Russell, Marijane; MacEwan, Iain; Qian, Yuewei; Jamison, James A.; Luz, John Gately

    2013-02-14

    The sirtuin SIRT1 is a NAD+-dependent histone deacetylase, a Sir2 family member, and one of seven human sirtuins. Sirtuins are conserved from archaea to mammals and regulate transcription, genome stability, longevity, and metabolism. SIRT1 regulates transcription via deacetylation of transcription factors such as PPARγ, NFκB, and the tumor suppressor protein p53. EX527 (27) is a nanomolar SIRT1 inhibitor and a micromolar SIRT2 inhibitor. To elucidate the mechanism of SIRT inhibition by 27, we determined the 2.5 Å crystal structure of the SIRT1 catalytic domain (residues 241–516) bound to NAD+ and the 27 analogue compound 35. 35 binds deep in the catalytic cleft, displacing the NAD+ nicotinamide and forcing the cofactor into an extended conformation. The extended NAD+ conformation sterically prevents substrate binding. The SIRT1/NAD+/35 crystal structure defines a novel mechanism of histone deacetylase inhibition and provides a basis for understanding, and rationally improving, inhibition of this therapeutically important target by drug-like molecules.

  2. Simultaneous Determination of Four Tanshinones by UPLC-TQ/MS and Their Pharmacokinetic Application after Administration of Single Ethanol Extract of Danshen Combined with Water Extract in Normal and Adenine-Induced Chronic Renal Failure Rats

    Directory of Open Access Journals (Sweden)

    Hong-Die Cai

    2016-11-01

    Full Text Available Salvia miltiorrhiza, one of the major traditional Chinese medicines, is commonly used and the main active ingredients—tanshinones—possess the ability to improve renal function. In this paper, the UPLC-TQ/MS method of simultaneously determining four tanshinones—tanshinone IIA, dihydrotanshinone I, tanshinone I, and cryptotanshinone—was established and applied to assess the pharmacokinetics in normal and chronic renal failure (CRF rat plasma. The pharmacokinetics of tanshinones in rats were studied after separately intragastric administration of Salvia miltiorrhiza ethanol extract (SMEE (0.65 g/kg, SMEE (0.65 g/kg combined with Salvia miltiorrhiza water extract (SMWE (1.55 g/kg. The results showed Cmax and AUC0–t of tanshinone IIA, tanshinone I, cryptotanshinone reduced by 50%~80% and CLz/F increased by 2~4 times (p < 0.05 in model group after administrated with SMEE. Nevertheless, after intragastric administration of a combination of SMWE and SMEE, the Cmax and AUC0–t of four tanshinones were upregulated and CLz/F was downregulated, which undulated similarity from the model group to the normal group with compatibility of SMEE and SMWE. These results hinted that SMWE could improve the bioavailability of tanshinones in CRF rats, which provides scientific information for further exploration the mechanism of the combination of SMWE and SMEE and offers a reference for clinical administration of Salvia miltiorrhiza.

  3. Replacement of Tyr50 stacked on the si-face of the isoalloxazine ring of the flavin adenine dinucleotide prosthetic group modulates Bacillus subtilis ferredoxin-NADP(+) oxidoreductase activity toward NADPH.

    Science.gov (United States)

    Seo, Daisuke; Naito, Hiroshi; Nishimura, Erika; Sakurai, Takeshi

    2015-08-01

    Ferredoxin-NAD(P)(+) oxidoreductases ([EC 1.18.1.2], [EC 1.18.1.3], FNRs) from green sulfur bacteria, purple non-sulfur bacteria and most of Firmicutes, such as Bacillus subtilis (BsFNR) are homo-dimeric flavoproteins homologous to bacterial NADPH-thioredoxin reductase. These FNRs contain two unique aromatic residues stacked on the si- and re-face of the isoalloxazine ring moiety of the FAD prosthetic group whose configurations are often found among other types of flavoproteins including plant-type FNR and flavodoxin, but not in bacterial NADPH-thioredoxin reductase. To investigate the role of the si-face Tyr50 residue in BsFNR, we replaced Tyr50 with Gly, Ser, and Trp and examined its spectroscopic properties and enzymatic activities in the presence of NADPH and ferredoxin (Fd) from B. subtilis (BsFd). The replacement of Tyr50 to Gly (Y50G), Ser (Y50S), and Trp (Y50W) in BsFNR resulted in a blue shift of the FAD transition bands. The Y50G and Y50S mutations enhanced the FAD fluorescence emission, whereas those of the wild type and Y50W mutant were quenched. All three mutants decreased thermal stabilities compared to wild type. Using a diaphorase assay, the k cat values for the Y50G and Y50S mutants in the presence of NADPH and ferricyanide were decreased to less than 5 % of the wild type activity. The Y50W mutant retained approximately 20 % reactivity in the diaphorase assay and BsFd-dependent cytochrome c reduction assay relative to wild type. The present results suggest that Tyr50 modulates the electronic properties and positioning of the prosthetic group.

  4. Molecular and crystal structures of dialkylated adenines ( N6, N9-Me 2Ade, N3, N6-MeBnAde) and cytosines ( N1, N4-Me 2Cyt)

    Science.gov (United States)

    Krüger, Thomas; Wagner, Christoph; Bruhn, Clemens; Lis, Tadeusz; Steinborn, Dirk

    2008-11-01

    N6, N9-Dimethyladenine ( N6, N9-Me 2Ade, 1) and N1, N4-dimethylcytosine ( N1, N4-Me 2Cyt, 3) were obtained by conventional methods, whereas the reaction of N6-benzyladenine with MeI/NaOH resulted in the formation of N3, N6-MeBnAde ( 2a) and N6, N9-BnMeAde ( 2b). All compounds were fully characterized by microanalysis, NMR spectroscopy ( 1H, 13C) and 1, 2a·2MeOH and 3 also by single-crystal X-ray diffraction analyses. In single-crystals of 1, obtained from THF solutions, twofold N6-H···N7' hydrogen-bonded dimeric units ( N6, N9-Me 2Ade) 2 (AA1 2 type according to Jeffrey and Saenger, 1991) were found. This proved to be another modification than that obtained by crystallization N6, N9-Me 2Ade from MeOH/PhCl (Sternglanz, 1978). Crystals of 2a·2MeOH exhibited an analogous hydrogen bond pattern as found in 1. The shorter N6···N7' distance in 2a·2MeOH (2.932(2) Å) indicates slightly stronger hydrogen bonds than in 1 (3.078(3) Å). Crystals of 3 are built up from centrosymmetric dimers ( N1, N4-Me 2Cyt) 2 having a twofold N4-H···N3' hydrogen bond, thus exhibiting the CC3 2 hydrogen bond pattern. The hydrogen bonding patterns in the dialkylated nucleobase derivatives are discussed in terms of those found in crystals of the less substituted nucleobases N9-MeAde and Cyt/ N1-MeCyt, respectively.

  5. 心肌线粒体腺苷酸配体门控钙离子释放通道%A pathway for adenine nucleotide ligand gating Ca2+ efflux of myocadial mitochondria

    Institute of Scientific and Technical Information of China (English)

    康少平; 李旭光; 董嘉良; 张艳君; 康英姿; 于公元

    2008-01-01

    目的:探讨心肌线粒体腺苷酸配体门控钙离子释放通道.方法:32只Wistar大鼠随机分成4组:ATP组、ADP组、NaCl组和咖啡因(Caffeine)组,每组8只.利用差速离心的方法提取心肌细胞线粒体.分别用ATP、ADP、NaCl和Caffeine启动线粒体Ca2+释放反应.紫外分光光度计监测线粒体的Ca2+释放.结果:ATP、ADP组线粒体Ca2+释放速度及最大释放量显著高于NaCl、Caffeine组(P<0.01),差异有统计学意义.结论:ATP、ADP能够触发心肌线粒体Ca2+释放,而NaCl、Caffeine则不可以.该实验数据提示心肌线粒体存在一种腺苷酸配体门控钙离子释放通道.

  6. Discovery and Synthesis of GS-5734, a Phosphoramidate Prodrug of a Pyrrolo[2,1 f][triazin-4-amino] Adenine C-Nucleoside for the Treatment of Ebola and Emerging Viruses

    Science.gov (United States)

    2017-01-26

    and other Federal statutes and regulations relating to animals and experiments involving animals . The facility where this research was conducted...outbreak in West Africa was the largest recorded in history with over 28,000 cases confirmed in Guinea, Liberia, and Sierra Leone resulting in...on viremia and mortality resulting in 100% survival of infected treated animals [Nature 2016, 531, 381-385]. Phase 1 studies with 4b in normal human

  7. 参附强心丸对腺嘌呤致肾阳虚大鼠温阳利水作用及机制研究%Research of Effects and Mechanism of Shenfuqiangxin Pills on the Warming Yang for Diuresis of Kidney-yang Deficiency Rats Caused by AdenineΔ

    Institute of Scientific and Technical Information of China (English)

    王梓; 张浩; 郝迪; 李旭; 袁玲; 王蕾

    2015-01-01

    OBJECTIVE:To probe into the effects and mechanism of Shenfuqiangxin pills on the warming yang for diuresis of chronic renal failure rats via the link of signs, renal function, neuroendocrine hormone, serum electrolytes and renal tissue morphology, etc.METHODS:The CRF model of rat was established by“unilateral nephrectomy combined with gavageing adenine”, the rats were divided into the model control, dexamethasone group and the dosage group with Shenfuqiangxin pills of 2.14 g/kg, 1.07 g/kg, 0.54 g/kg in crude drug via the random number table.The indexes of neuroendocrine hormone, renal function, blood electrolytes, body temperature, ratio of the kidney weight versus kidney volume and the form of organization of kidney in rates were observed.RESULTS: Some asthenia signs like sparse fur, sedentary lying and emaciation were observed in rats in mode group.The general conditions in three dosage groups of Shenfuqiangxin pills had been significantly improved.Level of UREA and CREA contents increased significantly in mode group,which in three dosage groups of Shenfuqiangxin pills were significantly lower than that in mode group.In mode group and three dosage groups of Shenfuqiangxin pills, angiotensinⅡ( AngⅡ) were significantly lower than that of sham-operation group, but aldosterone (ALD) were significantly higher than that of sham-operation group.Compared with the mode group, ALD in dosage group with 2.14 g/kg Shenfuqiangxin pills and dexamethasone group were obviously decreased, the differences were statistically significant ( P <0.05 ).Hyperkalemia, low calcium and hyperphosphatemia of rats were observed in the mode group, dosage group with 2.14 g/kg Shenfuqiangxin pills could correct hypocalcemia, and three dosage groups of Shenfuqiangxin pills all could correct hyperphosphatemia; the dexamethasone group could correct hyperkalemia, low calcium and hyperphosphatemia of rats,the differences were statistically significant(P<0.05).The body temperature of rats in mode group were significantly decreased,but hypothermia were observed in dexamethasone group.The kidney weight in mode group were significantly higher than that in sham-operation group;compared with the mode group, kidney weight in dosage group with 2.14 g/kg Shenfuqiangxin pills decreased, and the kidney volume was smaller, the difference was statistically significant ( P<0.05).From the visual inspection and renal pathology, it indicated that the kidney size and lesions both had various degrees of relief in three dosage groups of Shenfuqiangxin pills and dexamethasone group.CONCLUSIONS:Shenfuqiangxin pills can improve the function of kidney-yang deficiency rats, protect the renal function, improve water and sodium retention, correct the electrolyte imbalance, and repair the renal lesions.%目的:通过体征、肾功能、神经内分泌激素、血清电解质、肾脏组织形态等环节,探讨参附强心丸对慢性肾衰竭大鼠温阳利水的作用与机制。方法:采用“单肾切除合并腺嘌呤灌胃法”制备大鼠CRF模型,按随机数字表法分为模型对照组、地塞米松对照组、参附强心丸2.14、1.07、0.54 g生药/kg剂量组,观察各组大鼠神经内分泌激素、肾功能、血电解质、体温、肾脏质量与肾体比、肾脏的组织形态等指标。结果:模型对照组大鼠出现皮毛稀疏,蜷卧少动,消瘦等衰弱体征,参附强心丸3个剂量组大鼠一般状况较模型对照组明显好转;模型对照组大鼠尿素氮( UREA)、肌酐( CREA)含量明显升高,参附强心丸3个剂量组和地塞米松对照组UREA、CREA水平均明显低于模型对照组;模型对照组和参附强心组大鼠的血管紧张素Ⅱ( AngII)显著低于假手术对照组,醛固酮( ALD)明显高于假手术对照组,参附强心丸2.14 g/kg和地塞米松对照组大鼠的ALD较模型对照组明显降低,差异均有统计学意义( P<0.05)。模型对照组大鼠呈高钾、低钙、高磷血症,参附强心丸2.14 g/kg组大鼠可纠正低血钙

  8. 人参养荣汤对腺嘌呤致CRF营养不良模型大鼠下丘脑信号传导蛋白STAT3、PIAS3的影响%Effect of Ginsengyangrong Soup on STAT3 ,PIAS3 in hypothalamus in malnutrition rats with chronic renal failure by adenine

    Institute of Scientific and Technical Information of China (English)

    王明; 王艳靖; 许璇; 魏连波

    2011-01-01

    目的:探讨细胞因子信号传导蛋白STAT3及其抑制因子PIAS3在慢性肾衰竭营养不良大鼠中的表达情况,以及人参养荣汤对其的调节作用.方法:予0.5%腺嘌呤和4%酪蛋白混合饲料喂养制作CRF营养不良大鼠模型,将符合条件的随机分为模型组、人参养荣汤组和开同组,同时设正常组.各组分别予蒸馏水、人参养荣汤(含生药11.43 g/kg·d)、开同(1 g/kg·d)灌胃.治疗4周后检测白蛋白、血红蛋白的变化,Western免疫印迹法检测信号转导蛋白STAT3、PIAS3在下丘脑的表达.结果:人参养荣汤可增加白蛋白、血红蛋白水平,减低血浆瘦素水平,与正常组比较,模型组及人参养荣汤组STAT3表达均增强(P<0.001),人参养荣汤组STAT3表达显著低于模型组(P<0.001);模型组下丘脑PIAS3表达较正常组显著增强(P<0.001);人参养荣汤组PIAS3蛋白表达比模型组有显著增强(P<0.05).结论:人参养荣汤通过上调CRF营养大鼠下丘脑PIAS3蛋白的表达水平,下调STAT3蛋白表达,从而进一步阻止瘦素受体JAK2/STAT3的信号传导,从而改善CRF营养不良状态.

  9. 腺嘌呤用于制作雄性大鼠不育症模型理想剂量和时效关系的研究%Optimal dosage and duration in establishment of adenine-induced male infertility rat model

    Institute of Scientific and Technical Information of China (English)

    俞铮铮; 冯磊

    2008-01-01

    目的 研究腺嘌呤用于制作雄性大鼠不育症模型的理想剂量和时效关系.方法 将30只SD雄性大鼠分成3组(n=10),低剂量组每日予腺嘌呤300mg/kg灌胃给药,连续30d;高剂量组予腺嘌呤500mg/kg灌胃给药,连续15d;空白对照组予等量0 9%氯化钠溶液灌胃,连续30d.观察大鼠体征变化、睾丸系数、血清性激素水平及睾丸组织形态学改变.结果 低剂量与高剂量腺嘌呤均能造成大鼠生殖功能损害,服用低剂量30 d或高剂量15d均造模成功.结论 腺嘌呤对雄性大鼠生殖系统有明显毒性作用,应用高剂量可缩短造模时间.

  10. Diurnal Changes in the Contents of Adenine Nucleotides and Inorganic Pyrophosphate in the Chlorenchyma and the Water Storage Parenchyma of Ananas comosus Leaves%菠萝叶片绿色组织与贮水组织的腺苷酸及焦磷酸水平的昼夜变化

    Institute of Scientific and Technical Information of China (English)

    陈立松; 齐一萍; 等

    2001-01-01

    研究了景天酸代谢(CAM)植物菠萝(Ananas comosus)叶片绿色组织与贮水组织的苹果酸、腺苷酸及焦磷酸含量的昼夜变化。夜间苹果酸的积累仅发生在绿色组织中,而且,其含量也远高于贮水组织。绿色组织中能荷和无机磷含量夜间增高,白天下降。绿色组织中焦磷酸含量夜间增加,在白天的头几个小时迅速下降到低的水平,然后保持稳定。与绿色组织相比,贮水组织中ATP、ADP、无机磷和焦磷酸的含量低得多,且不表现昼夜变化,在贮水组织中没有测到AMP。

  11. 脊髓小脑共济失调1型中等重复动态突变患者临床表型分析%Clinical analysis on the cases with intermediate Cytosine-Adenine-Guanine repeat alleles of spinocerebellar ataxia type 1

    Institute of Scientific and Technical Information of China (English)

    顾卫红; 郝莹; 王晓工; 王康; 杜皓萍; 杨斯柳; 王国相

    2008-01-01

    目的:探讨脊髓小脑共济失调1型(SCA1)中等重复动态突变患者临床表型特征.方法:采用基于CEQ8000核酸分析仪的片段分析方法对2个表型为常染色体显性遗传脊髓小脑共济失调家系进行SCA1基因CAG重复序列突变检测,并分析其临床特征.结果:所研究家系的先证者为SCA1基因CAG中等重复序列等位基因携带者,其临床表型存在共性和一定的差异.结论:本研究证实了SCA1基因CAG中等重复序列的致病性,且在不同的家系患者存在临床变异.

  12. Mechanisms of Mitochondrial Defects in Gulf War Syndrome

    Science.gov (United States)

    2012-08-01

    FADH2: flavin adenine dinucleotide, reduced; O2: oxygen; NADH: Nicotinamide Adenine Dinucleotide, reduced; NAD: Nicotinamide Adenine Dinucleotide...criteria, an appointment is made for clinical examination by the P.I., blood draw, and skin biopsy. Modified criteria for chronic fatigue syndrome and...muscle and we have now established reference ranges in uncultured skin cells, fibroblasts, and EBV transformed cell lines. Sample testing is

  13. Disease: H00195 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00195 Adenine phosphoribosyltransferase deficiency; 2,8-Dihydroxyadenine urolithiasis... Adenine phosphoribosyltransferase deficiency is an autosomal recessive disorder of purine metabolism and causes urolithiasis...transferase gene in patients with 2,8-dihydroxyadenine urolithiasis. Nucleosides Nucleotides Nucleic Acids 2...denine phosphoribosyltransferase and its relation to DHA-urolithiasis. Biochemist...,8-Dihydroxyadenine urolithiasis in a patient with considerable residual adenine phosphoribosyltransferase a

  14. Gene : CBRC-PMAR-01-0528 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PMAR-01-0528 Novel UN A Adenosine and adenine nucleotide receptors P2RY1_RAT 7...GLPGNVTAIWLYARSVRTWSSSAVFLFNLAVADLLYLLTLPMQIVYQANDSIWVFGSITCKLMRFLTYAQMYISILFLVYICLDRYVAIVHPLKWHRSPRHRVSLWMC...LRNVKMYFTLYPPHPCDNQVIRVAYIITKDLCSLNSALNPMFYFVAGDNFRLRLTVAVKSCCTGGGNQVHPEQISSSIS ...

  15. Gene : CBRC-PMAR-01-0805 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PMAR-01-0805 Novel UN A Adenosine and adenine nucleotide receptors P2RY1_BOVIN...YQTALGVRVARARRRAARLVVLVQLIVAICFTPLHVVRPLLTATSMLTPTKCGLLRDLAKGFFISMSLSGLNSCLDPLLFYHSGGKFRKEAKAVVMTLLCRGCVCPAGPMARSEMQASVINVEPSLNSNRT ...

  16. Plastic Antibodies: Molecular Recognition with Imprinted Polymers

    Science.gov (United States)

    Rushton, Gregory T.; Furmanski, Brian; Shimizu, Ken D.

    2005-01-01

    Synthetic polymers are prepared and tested in a study for their molecular recognition properties of an adenine derivative, ethyl adenine-9-acetate (EA9A), within two laboratory periods. The procedure introduces undergraduate chemistry students to noncovalent molecular imprinting as well as the analytical techniques for assessing their recognition…

  17. Boron Nitride sheet as a novel surface for medical adsorption and drug synthesis

    OpenAIRE

    M. Zawari

    2015-01-01

    In this study we investigate Adenine, Guanine, Cytosine and Thymine moleculesadsorption on Boron Nitride by Density-functional theory (DFT). For this purpose we calculate adsorption energy (∆Ead), HOMO- LUMO energy gap(∆Eg), voltage difference (∆V) and (∆q) of Adenine, Guanine, Cytosine and Thymine molecules on different adsorption distances on Boron Nitride layer and compare them.

  18. Advanced Imaging Approaches to Characterize Stromal and Metabolic Changes in In Vivo Mammary Tumor Models

    Science.gov (United States)

    2013-03-01

    have been using Fluorescence Lifetime Imaging Microscopy (FLIM) (7) to examine Nicotinamide adenine dinucleotide (NADH) and Flavin adenine...an optical imaging window into the skin of these mice above the tumor. We will then collect SHG from collagen and FLIM data for NADH using an MPM

  19. Efficient N-Arylation and N-Alkenylation of the Five DNA/RNANucleobases

    DEFF Research Database (Denmark)

    Jacobsen, Mikkel Fog; Knudsen, Martin M.; Gothelf, Kurt Vesterager

    2006-01-01

    -substituted pyrimidin-2(1H)-one served as both a cytosine and a uracil precursor and was N-arylated and N-alkenylated in high yields. Adenine was efficiently and selectively N-arylated and N-alkenylated at the N9 position by employing a bis-Boc-protected adenine derivative, while a bis-Boc-protected 2-amino-6...

  20. A quick look at biochemistry : Carbohydrate metabolism

    NARCIS (Netherlands)

    Dashty, Monireh

    2013-01-01

    In mammals, there are different metabolic pathways in cells that break down fuel molecules to transfer their energy into high energy compounds such as adenosine-5'-triphosphate (ATP), guanosine-5'-triphosphate (GTP), reduced nicotinamide adenine dinucleotide (NADH2), reduced flavin adenine dinucleot

  1. A quick look at biochemistry : Carbohydrate metabolism

    NARCIS (Netherlands)

    Dashty, Monireh

    2013-01-01

    In mammals, there are different metabolic pathways in cells that break down fuel molecules to transfer their energy into high energy compounds such as adenosine-5'-triphosphate (ATP), guanosine-5'-triphosphate (GTP), reduced nicotinamide adenine dinucleotide (NADH2), reduced flavin adenine

  2. Drug: D07633 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D07633 Mixture, Drug Chondroitin sulfate sodium - flavin adenine dinucleotide sodium mixt; Chondroit...in sulfate sodium - FAD sodium mixt; Mucofadin (TN); Mucotear (TN) Chondroitin sulfate sodi...rgans 13 Agents affecting sensory organs 131 Ophthalmic agents 1319 Others D07633 Chondroitin sulfate sodium - flavin adenine dinucleotide sodium mixt PubChem: 96024455 ...

  3. H-bonding-directed self-assembly of synthetic copolymers containing nucleobases: organization and colloidal fusion in a noncompetitive solvent.

    Science.gov (United States)

    Lutz, Jean-François; Pfeifer, Sebastian; Chanana, Munish; Thünemann, Andreas F; Bienert, Ralf

    2006-08-15

    The self-organization of random copolymers composed of a nucleobase monomer (either 1-(4-vinylbenzyl)thymine or 9-(4-vinylbenzyl)adenine) and dodecyl methacrylate (DMA) was studied in dilute chloroform solutions. The balance between the molar fractions of the nucleobase monomer (leading to intermolecular H-bonding) and DMA (soluble moiety in chloroform) in the polymer chains was found to be the parameter that principally influences the self-organization. DMA-rich copolymers are molecularly soluble in chloroform, whereas nucleobase-rich copolymers are insoluble in this solvent. Copolymers possessing an equimolar comonomer composition self-assemble into micrometer-sized particles physically cross-linked by intermolecular H-bonds (either thymine-thymine or adenine-adenine interactions, depending on the studied copolymer). Nevertheless, when mixed together, thymine- and adenine-based colloids fuse into thermodynamically stable microspheres cross linked by adenine-thymine interactions.

  4. Synthesis of carbasugars from aldonolactones, part III - A study on the allylic substitution of (1R,5R,8R)- and (1R,5R,8S)-8-hydroxy-2-oxabicyclo[3.3.0]oct-6-en-3-one derivatives - Preparation of (1S,2R,3R)-9-[2-hydroxy-3-(2-hydroxyethyl)cyclopent-4-en-1-yl]-9H-adenine

    DEFF Research Database (Denmark)

    Johansen, Steen Karsk; Lundt, Inge

    2001-01-01

    The palladium-catalyzed substitution of acylated (1R,5R,8R)- and (1R,SR,8S)-8-hydroxy-2-oxabicyclo[3.3.0] ones has been studied using a number of C- and N-nucleophiles, In all cases, the exo derivatives (8R) were found to be more reactive than the corresponding endo derivatives (8S). The reaction...

  5. Raman Spectroscopy of the Interferon-Induced 2’,5’-Oligoadenylates

    Science.gov (United States)

    1987-06-25

    generation of the Raman spectrum of triethyl ammonium ion ••••••••••••••••••••••••••••••• 41 12. structures of purine, adenine, purine riboside , adenosine...ribose 5 1-phosphate, AMP, and ATP........ 48 13. Raman spectra of adenine and purine •••••••.••••••••• 49 14. Raman spectra of purine riboside and... nicotinamide adenine dinucleotide; TFAB, triethyl anunonium bicarbonate; TFA, triethyl amm::mium. ion; CD circular _dichroism; NMR, nuclear magnetic

  6. Drug: D08741 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D08741 Mixture, Drug Adenine - sodium citrate hydrate - citric acid hydrate - gluco...se - potassium phosphate, monobasic mixt; CPDA solution; Karmi CA (TN) Adenine [DR:D00034], Sodium citrate hydr...ate [DR:D01781], Citric acid hydrate [DR:D01222], Glucose [DR:D00009], Sodium phosphate, monobasic Therap...eutic category: 3339 Therapeutic category of drugs in Japan [BR:br08301] 3 Agents... affecting metabolism 33 Blood and body fluid agents 333 Anticoagulants 3339 Others D08741 Adenine - sodium citrate hydr

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

    DEFF Research Database (Denmark)

    Haus, Jacob M; Solomon, Thomas; Marchetti, Christine M

    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....

  8. Effect of the acquisition enhancing drug piracetam on rat cerebral energy metabolism. Comparison with naftidrofuryl and methamphetamine

    NARCIS (Netherlands)

    Nickolson, V.J.; Wolthuis, O.L.

    1976-01-01

    The effects of Piracetam, Naftidrofuryl and methamphetamine on several parameters of cerebral energy metabolism have been studied. At variance with some reports in the literature neither Piracetam nor Naftidrofuryl affected the cerebral contents of adenine nucleotides and, accordingly, both

  9. Primaquine

    Science.gov (United States)

    ... 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. Detoxification and color removal of Congo red by a novel Dietzia sp. (DTS26) – A microcosm approach

    Digital Repository Service at National Institute of Oceanography (India)

    SatheeshBabu, S.; Mohandass, C.; VijayRaj, A.S.; Dhale, M.A.

    of desired concentration were obtained by successive dilution. Chemicals related to enzymatic analysis i.e., Tartaric acid, n-Propanol and Catechol were purchased from Merck-Germany. Nicotinamide adenine dinucleotide (NADH), mono sodium phosphate, di...

  11. Identification of a new restriction endonuclease R.NciII, from Neisseria cinerea.

    Science.gov (United States)

    Piekarowicz, A

    1994-01-01

    Site-specific restriction endonuclease R. Nci II has been purified from Neisseria cinerea strain 32615. The enzyme recognizes the sequence 5' GATC 3' and its activity is inhibited by the presence of methylated adenine residue within the recognition sequence.

  12. Insight into Nek2A activity regulation and its pharmacological ...

    African Journals Online (AJOL)

    Ambuj Kumar

    2012-11-28

    Nov 28, 2012 ... 3. Nek2A activity regulation and associated pathological outcomes . .... vide a detailed insight into how they coordinate the cell cycle .... the adenine subpocket creating steric hindrance in the plane of ... Three dimensional.

  13. The structures of pyruvate oxidase from Aerococcus viridans with cofactors and with a reaction intermediate reveal the flexibility of the active-site tunnel for catalysis

    OpenAIRE

    Juan, Ella Czarina Magat; Hoque, Md Mominul; Hossain, Md Tofazzal; Yamamoto, Tamotsu; Imamura, Shigeyuki; Suzuki, Kaoru; Sekiguchi, Takeshi; Takénaka, Akio

    2007-01-01

    The crystal structures of pyruvate oxidase from A. viridans in complex with flavin adenine dinucleotide, thiamine diphosphate and the reaction intermediate 2-acetyl-thiamine diphosphate reveal details of substrate recognition and catalysis.

  14. Evidence for a Direct Effect of the NAD+ Precursor Acipimox on Muscle Mitochondrial Function in Humans

    NARCIS (Netherlands)

    van de Weijer, T.; Phielix, E.; Bilet, L.; Williams, E.G.; Ropelle, E.R.; Bierwagen, A.; Livingstone, R.; Nowotny, P.; Sparks, L.M.; Paglialunga, S.A.; Szendroedi, J.; Havekes, B.; Moullan, N.; Pirinen, E.; Hwang, J.H.; Schrauwen-Hinderling, V.B.; Hesselink, M.K.; Auwerx, J.; Roden, M.; Schrauwen, P.

    2015-01-01

    Recent preclinical studies showed the potential of nicotinamide adenine dinucleotide : NAD+ : precursors to increase oxidative phosphorylation and improve metabolic health, but human data is lacking. Here, we hypothesized that the nicotinic acid derivative Acipimox, a NAD+ precursor, would directly

  15. Spermidine and resveratrol induce autophagy by distinct pathways converging on the acetylproteome

    DEFF Research Database (Denmark)

    Morselli, Eugenia; Mariño, Guillermo; Bennetzen, Martin V

    2011-01-01

    Autophagy protects organelles, cells, and organisms against several stress conditions. Induction of autophagy by resveratrol requires the nicotinamide adenine dinucleotide-dependent deacetylase sirtuin 1 (SIRT1). In this paper, we show that the acetylase inhibitor spermidine stimulates autophagy ...

  16. Sequence Classification: 892139 [

    Lifescience Database Archive (English)

    Full Text Available se and inosine monophosphate cyclohydrolase activities, isozyme of Ade16p; ade16 ade17 mutants require adenine and histidine; Ade17p || http://www.ncbi.nlm.nih.gov/protein/6323768 ...

  17. 黄精核糖体灭活蛋白双元表达载体的构建与鉴定%Construction of Binary Vector pGV4945 of Ribosome-Inactivating Protein Gene from Polygonatum multiflorum

    Institute of Scientific and Technical Information of China (English)

    常维山; Henry De Greve; 翟静; Nele Buys; Jan Pierre Hernal Steens

    2004-01-01

    Ribosome-inactivating proteins (RIPs)have been known to have cytotoxic activity by cleaving a specific adenine residue of 28S rRNA. RIPs can be divided into, type 1 and type 2. Type 2 is a toxic protein that was consisted of two Gal/GalNAc-binding chains, A and B Chains that connected through a disulfide linkage. The A chain of RIP has RNA N-glycosidase activity to cleave a specific adenine base from ribosomal RNA,

  18. Boron Nitride sheet as a novel surface for medical adsorption and drug synthesis

    Directory of Open Access Journals (Sweden)

    M. Zawari

    2015-03-01

    Full Text Available In this study we investigate Adenine, Guanine, Cytosine and Thymine moleculesadsorption on Boron Nitride by Density-functional theory (DFT. For this purpose we calculate adsorption energy (∆Ead, HOMO- LUMO energy gap(∆Eg, voltage difference (∆V and (∆q of Adenine, Guanine, Cytosine and Thymine molecules on different adsorption distances on Boron Nitride layer and compare them.

  19. Investigation of Rho Signaling Pathways in 3-D Collagen Matrices with Multidimensional Microscopy and Visualization Techniques

    Science.gov (United States)

    2008-03-01

    Rueden (lead software developer at LOCI) using Image J, VisBio, and SlimPlotter. The goal is to create an efficient and accurate method to translate...MPLSM imaging of en- dogenous signals from collagen and fluorophores such as nicotinamide adenine dinucleotide NADH or flavin ad- enine ...phores imaged with MPLSM are tryptophan, nicotinamide ad- enine dinucleotide NADH and flavin adenine dinucleotide FAD, as well as endogenous SHG

  20. In vitro Toxicity and Inflammatory Response Induced by Copper Nanoparticles in Rat Alveolar Macrophages

    Science.gov (United States)

    2008-03-01

    ingestion (via the gastrointestinal tract) or skin absorption routes of exposure (Tsuji, et al., 2006:43). More research is needed to determine if...nanoparticles can penetrate the skin (Tsuji, et al., 2006:44), because little information exists as to whether nanoparticles can be absorbed through...below). The conversion in viable cells is done by nicotinamide adenine dinucleotide phosphate (NADPH) or nicotinamide adenine dinucleotide (reduced

  1. The Postconditioning Effects Of Diazoxide in the Brain Following Hemorrhagic Shock and Cerebral Hypoperfusion

    Science.gov (United States)

    2009-10-13

    mmHg millimeter of mercury mPTP mitochondrial permeability transition pore Na sodium NAD+ nicotinamide adenine dinucleotide ion NADH... nicotinamide adenine dinucleotide NaHCO3 sodium bicarbonate NBD nucleotide binding domain nm nanometer xix     NS normal saline O2 oxygen PBS...saline-locked and secured to the tail using 3-0 silk thread. Three 18 gauge needles were then placed through small folds of skin on the right upper

  2. Targeting the Adipocyte-Tumor Cell Interaction in Prostate Cancer Treatment

    Science.gov (United States)

    2014-10-01

    is required for IL-6 overproduction in p62-deficient fibroblasts. We observed a striking decrease in the reduced nicotinamide adenine dinucleotide...phosphate (NADPH)/ nicotinamide adenine dinucleotide phosphate (NADP) ratio in p62-deficient fibroblasts(F) Immunoblot analysis of KEAP1 in cell lysates...liquid organotypic culture cultures have been used extensively in skin (Gaggioli et al., 2007), esophageal (Okawa et al., 2007), pancreas (Coleman et

  3. Botanical Extracts as Medical Countermeasures for Radiation Induced DNA Damage

    Science.gov (United States)

    2012-03-01

    date June 2013 Listed medicinal ingredients - Grape seed extract standardized to 85 % polyphenols - Grape skin extract standardized to 15...Control wells contained dH2O or ethanol (concentration dependent on test substance solvent), NADPH (beta- nicotinamide adenine dinucleotide phosphate...statistical number of repeats NaCl sodium chloride NADPH beta- nicotinamide adenine dinucleotide phosphate nm nanometer (10-9) PBS phosphate buffered

  4. Biomarkers of petroleum contamination in the digestive gland of Perna viridis (L.)

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Jena, K.B.; Desai, S.R.; Das, P.B.; Chainy, G.B.N.

    ,5-dithiobis (2-nitrobenzoic acid) (DTNB), horseradish peroxidase (HRP), and streptomycin sulfate were procured from Sigma Chemical Co. (USA). Reduced nicotinamide adenine dinucleotide phosphate (NADPH), oxidized glutathione (GSSG), GSH, 1-chloro-2... by the method of Paoletti et al. by monitoring the rate of oxidation of reduced nicotinamide adenine dinucleotide (NADH) (32). One unit of SOD activity was defi ned as a 50% inhibition of NADH oxidation in the reaction. Th e absorbance was recorded at 340...

  5. Direct Base-to-Base Transitions in ssDNA Revealed by Tip-Enhanced Raman Scattering

    CERN Document Server

    Lin, Xiu-Mei; Singh, Prabha; Siegmann, Michael; Kupfer, Stephan; Zhang, Zhenglong; Gräfe, Stefanie; Deckert, Volker

    2016-01-01

    In the present contribution, specifically designed single-stranded DNA (ssDNA) sequences composed of adenine and cytosine were used as nanometric rulers to target the maximum achievable spatial resolution of tip-enhanced Raman spectroscopy (TERS) under ambient conditions. By stepping along a strand with a TERS tip, the obtained spectra allowed for a clear spectral discrimination including conformational information of the nucleobases, and even sharp adenine-cytosine transitions were detected repeatedly with a spatial resolution below 1 nm.

  6. [Mass spectrometry of triterpene glycosides molecular complexation with purine bases of nucleic acids].

    Science.gov (United States)

    Lekar', A V; Vetrova, E V; Borisenko, N I; Iakovishin, L A; Grishkovets, V I

    2011-01-01

    The molecular complexation of adenine and guanine with hederagenin 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-alpha-L-arabinopyranoside (alpha-hederin) and its 28-O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl ester (hederasaponin C) was investigated for the first time using the method of electrospray ionization mass spectrometry. Guanine forms complexes more diverse in composition than adenine.

  7. The Role Of Salivary Glands In Phosphate Homeostasis

    Directory of Open Access Journals (Sweden)

    Tomo Mukai

    2012-06-01

    In Npt2b+/- mice, the salivary Pi concentrations were significantly increased compared with those in Npt2b+/+ mice. Npt2b+/- mice with adenine-induced renal failure had low plasma and salivary Pi levels, and plasma creatinine and BUN levels compared with Npt2b+/+ mice treated with adenine. In conclusion, Npt2b is involved in Pi secretion by salivary glands.

  8. A Prebiotic Chemistry Experiment on the Adsorption of Nucleic Acids Bases onto a Natural Zeolite

    Science.gov (United States)

    Anizelli, Pedro R.; Baú, João Paulo T.; Gomes, Frederico P.; da Costa, Antonio Carlos S.; Carneiro, Cristine E. A.; Zaia, Cássia Thaïs B. V.; Zaia, Dimas A. M.

    2015-09-01

    There are currently few mechanisms that can explain how nucleic acid bases were synthesized, concentrated from dilute solutions, and/or protected against degradation by UV radiation or hydrolysis on the prebiotic Earth. A natural zeolite exhibited the potential to adsorb adenine, cytosine, thymine, and uracil over a range of pH, with greater adsorption of adenine and cytosine at acidic pH. Adsorption of all nucleic acid bases was decreased in artificial seawater compared to water, likely due to cation complexation. Furthermore, adsorption of adenine appeared to protect natural zeolite from thermal degradation. The C=O groups from thymine, cytosine and uracil appeared to assist the dissolution of the mineral while the NH2 group from adenine had no effect. As shown by FT-IR spectroscopy, adenine interacted with a natural zeolite through the NH2 group, and cytosine through the C=O group. A pseudo-second-order model best described the kinetics of adenine adsorption, which occurred faster in artificial seawaters.

  9. Mammalian adaptation to extrauterine environment: mitochondrial functional impairment caused by prematurity.

    Science.gov (United States)

    Valcarce, C; Izquierdo, J M; Chamorro, M; Cuezva, J M

    1994-01-01

    In this paper we report that, compared with term rat neonates, both mitochondrial content and function are diminished in liver of preterm neonates (delivered 24 h before full term) compromising cellular energy provision in the postnatal period. In addition, there is a parallel reduction in the content of mRNAs encoding mitochondrial proteins in preterm rats. Also, efficient oxidative phosphorylation is not attained in these pups until 3 h after birth. Although isolated liver mitochondria from preterm neonates show a two-fold increase in F1-ATPase beta-subunit and cytochrome c oxidase activity 1 h after birth, the abnormal coupling efficiency between respiration and oxidative phosphorylation (ADP/O ratio) is due to maintenance of high H(+)-leakage values in the inner mitochondrial membrane. Postnatal reduction of the H+ leak occurs concomitantly with an increase in intra-mitochondrial adenine nucleotide concentration. Accumulation of adenine nucleotides in preterm and term liver mitochondria parallels the postnatal increase in total liver adenine nucleotides. Delayed postnatal induction of adenine biosynthesis most likely accounts for the lower adenine nucleotide pool in the liver of preterm neonates. The delayed postnatal accumulation of adenine nucleotides in mitochondria is thus responsible for the impairment in oxidative phosphorylation displayed by organelles of the preterm liver. Images Figure 1 PMID:7980455

  10. A Prebiotic Chemistry Experiment on the Adsorption of Nucleic Acids Bases onto a Natural Zeolite.

    Science.gov (United States)

    Anizelli, Pedro R; Baú, João Paulo T; Gomes, Frederico P; da Costa, Antonio Carlos S; Carneiro, Cristine E A; Zaia, Cássia Thaïs B V; Zaia, Dimas A M

    2015-09-01

    There are currently few mechanisms that can explain how nucleic acid bases were synthesized, concentrated from dilute solutions, and/or protected against degradation by UV radiation or hydrolysis on the prebiotic Earth. A natural zeolite exhibited the potential to adsorb adenine, cytosine, thymine, and uracil over a range of pH, with greater adsorption of adenine and cytosine at acidic pH. Adsorption of all nucleic acid bases was decreased in artificial seawater compared to water, likely due to cation complexation. Furthermore, adsorption of adenine appeared to protect natural zeolite from thermal degradation. The C=O groups from thymine, cytosine and uracil appeared to assist the dissolution of the mineral while the NH2 group from adenine had no effect. As shown by FT-IR spectroscopy, adenine interacted with a natural zeolite through the NH2 group, and cytosine through the C=O group. A pseudo-second-order model best described the kinetics of adenine adsorption, which occurred faster in artificial seawaters.

  11. Brain purine metabolism and xanthine dehydrogenase/oxidase conversion in hyperammonemia are under control of NMDA receptors and nitric oxide.

    Science.gov (United States)

    Kaminsky, Yury; Kosenko, Elena

    2009-10-19

    In hyperammonemia, a decrease in brain ATP can be a result of adenine nucleotide catabolism. Xanthine dehydrogenase (XD) and xanthine oxidase (XO) are the end steps in the purine catabolic pathway and directly involved in depletion of the adenylate pool in the cell. Besides, XD can easily be converted to XO to produce reactive oxygen species in the cell. In this study, the effects of acute ammonia intoxication in vivo on brain adenine nucleotide pool and xanthine and hypoxanthine, the end degradation products of adenine nucleotides, during the conversion of XD to XO were studied. Injection of rats with ammonium acetate was shown to lead to the dramatic decrease in the ATP level, adenine nucleotide pool size and adenylate energy charge and to the great increase in hypoxanthine and xanthine 11 min after the lethal dose indicating rapid degradation of adenylates. Conversion of XD to XO in hyperammonemic rat brain was evidenced by elevated XO/XD activity ratio. Injection of MK-801, a NMDA receptor blocker, prevented ammonia-induced catabolism of adenine nucleotides and conversion of XD to XO suggesting that in vivo these processes are mediated by activation of NMDA receptors. The in vitro dose-dependent effects of sodium nitroprusside, a NO donor, on XD and XO activities are indicative of the direct modification of the enzymes by nitric oxide. This is the first report evidencing the increase in brain xanthine and hypoxanthine levels and adenine nucleotide breakdown in acute ammonia intoxication and NMDA receptor-mediated prevention of these alterations.

  12. Absence of Ca2+-induced mitochondrial permeability transition but presence of bongkrekate-sensitive nucleotide exchange in C. crangon and P. serratus.

    Directory of Open Access Journals (Sweden)

    Csaba Konrad

    Full Text Available Mitochondria from the embryos of brine shrimp (Artemia franciscana do not undergo Ca(2+-induced permeability transition in the presence of a profound Ca(2+ uptake capacity. Furthermore, this crustacean is the only organism known to exhibit bongkrekate-insensitive mitochondrial adenine nucleotide exchange, prompting the conjecture that refractoriness to bongkrekate and absence of Ca(2+-induced permeability transition are somehow related phenomena. Here we report that mitochondria isolated from two other crustaceans, brown shrimp (Crangon crangon and common prawn (Palaemon serratus exhibited bongkrekate-sensitive mitochondrial adenine nucleotide transport, but lacked a Ca(2+-induced permeability transition. Ca(2+ uptake capacity was robust in the absence of adenine nucleotides in both crustaceans, unaffected by either bongkrekate or cyclosporin A. Transmission electron microscopy images of Ca(2+-loaded mitochondria showed needle-like formations of electron-dense material strikingly similar to those observed in mitochondria from the hepatopancreas of blue crab (Callinectes sapidus and the embryos of Artemia franciscana. Alignment analysis of the partial coding sequences of the adenine nucleotide translocase (ANT expressed in Crangon crangon and Palaemon serratus versus the complete sequence expressed in Artemia franciscana reappraised the possibility of the 208-214 amino acid region for conferring sensitivity to bongkrekate. However, our findings suggest that the ability to undergo Ca(2+-induced mitochondrial permeability transition and the sensitivity of adenine nucleotide translocase to bongkrekate are not necessarily related phenomena.

  13. Suppression of Cu Oxidation Using Environmentally Friendly Inhibitors under Conditions of High Temperature and High Humidity for Cu/Low-k

    Science.gov (United States)

    Hara, Makoto; Watanabe, Daisuke; Kimura, Chiharu; Aoki, Hidemitsu; Sugino, Takashi

    2009-04-01

    The Cu surface at a via bottom is exposed to conditions of high temperature and high humidity during annealing after the via hole for Cu/low-k interconnection is cleaned. The Cu surface is oxidized by the water desorbed from the low-k film. The suppression of Cu corrosion is a necessary process. Benzotriazole (BTA) has been used as a conventional Cu corrosion inhibitor, but it has a large environmental impact. An environmentally friendly inhibitor to replace BTA is required. In this study, adenine and hypoxanthine are used as environmentally friendly Cu corrosion inhibitors. We have succeeded in effectively suppressing Cu corrosion under conditions of high temperature and high humidity using adenine and hypoxanthine. We have also investigated the desorption temperature of Cu corrosion inhibitor films by thermal desorption spectroscopy (TDS). We have found that adenine and hypoxanthine are stable inhibitors during annealing. Moreover, it is clear from impedance measurements that adenine and hypoxanthine inhibitor films are thinner than BTA films. Adenine and hypoxanthine can readily be applied to next-generation LSI devices.

  14. Purine metabolism in Toxoplasma gondii

    Energy Technology Data Exchange (ETDEWEB)

    Krug, E.C.; Marr, J.J.; Berens, R.L.

    1989-06-25

    We have studied the incorporation and interconversion of purines into nucleotides by freshly isolated Toxoplasma gondii. They did not synthesize nucleotides from formate, glycine, or serine. The purine bases hypoxanthine, xanthine, guanine, and adenine were incorporated at 9.2, 6.2, 5.1, and 4.3 pmol/10(7) cells/h, respectively. The purine nucleosides adenosine, inosine, guanosine, and xanthosine were incorporated at 110, 9.0, 2.7, and 0.3 pmol/10(7) cells/h, respectively. Guanine, xanthine, and their respective nucleosides labeled only guanine nucleotides. Inosine, hypoxanthine, and adenine labeled both adenine and guanine nucleotide pools at nearly equal ratios. Adenosine kinase was greater than 10-fold more active than the next most active enzyme in vitro. This is consistent with the metabolic data in vivo. No other nucleoside kinase or phosphotransferase activities were found. Phosphorylase activities were detected for guanosine and inosine; no other cleavage activities were detected. Deaminases were found for adenine and guanine. Phosphoribosyltransferase activities were detected for all four purine nucleobases. Interconversion occurs only in the direction of adenine to guanine nucleotides.

  15. Cytokinins and urea derivatives stimulate seed germination in Lotus corniculatus L.

    Directory of Open Access Journals (Sweden)

    Nikolić Radomirka

    2007-01-01

    Full Text Available We studied the effects of various cytokinins and urea derivatives on germination of aged seeds of in Lotus corniculatus L. The following substances were applied: N6-isoprenoid cytokinins (isopentenyl adenine and zeatin, adenine sulfate, N6-aromatic cytokinins (kinetin, benzyladenine and their N9-ribosides, N-benzyl-9-(2- tetrahydropyranyladenine, and urea derivatives (diphenylurea, thidiazuron, and chloro-pyridyl phenylurea. With the exception of adenine sulfate, all cytokinins increased the percentage of seed germination up to twofold, depending on their kind and concentration. It is concluded that cytokinins may be among the missing factors in aged seeds of L. corniculatus contributing to the implementation of their full germination potential. They could be used to improve germination of both freshly harvested and aged seed samples, if necessary. .

  16. The prebiotic synthesis of modified purines and their potential role in the RNA world

    Science.gov (United States)

    Levy, M.; Miller, S. L.; Bada, J. L. (Principal Investigator)

    1999-01-01

    Modified purines are found in all organisms in the tRNA, rRNA, and even DNA, raising the possibility of an early role for these compounds in the evolution of life. These include N6-methyladenine, 1-methyladenine, N6,N6-dimethyladenine, 1-methylhypoxanthine, 1-methylguanine, and N2-methylguanine. We find that these bases as well as a number of nonbiological modified purines can be synthesized from adenine and guanine by the simple reaction of an amine or an amino group with adenine and guanine under the concentrated conditions of the drying-lagoon or drying-beach model of prebiotic synthesis with yields as high as 50%. These compounds are therefore as prebiotic as adenine and guanine and could have played an important role in the RNA world by providing additional functional groups in ribozymes, especially for the construction of hydrophobic binding pockets.

  17. New method for estimating bacterial cell abundances in natural samples by use of sublimation

    Science.gov (United States)

    Glavin, Daniel P.; Cleaves, H. James; Schubert, Michael; Aubrey, Andrew; Bada, Jeffrey L.

    2004-01-01

    We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples, including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert, were heated to a temperature of 500 degrees C for several seconds under reduced pressure. The sublimate was collected on a cold finger, and the amount of adenine released from the samples was then determined by high-performance liquid chromatography with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from approximately 10(5) to 10(9) E. coli cell equivalents per gram. For most of these samples, the sublimation-based cell counts were in agreement with total bacterial counts obtained by traditional DAPI (4,6-diamidino-2-phenylindole) staining.

  18. Optoelectronic studies on heterocyclic bases of deoxyribonucleic acid for DNA photonics.

    Science.gov (United States)

    El-Diasty, Fouad; Abdel-Wahab, Fathy

    2015-10-01

    The optoelectronics study of large molecules, particularly π-stacking molecules, such as DNA is really an extremely difficult task. We perform first electronic structure calculations on the heterocyclic bases of 2'-deoxyribonucleic acid based on Lorentz-Fresnel dispersion theory. In the UV-VIS range of spectrum, many of the optoelectronic parameters for DNA four bases namely adenine, guanine, cytosine and thymine are calculated and discussed. The results demonstrate that adenine has the highest hyperpolarizability, whereas thymine has the lowest hyperpolarizability. Cytosine has the lower average oscillator energy and the higher lattice energy. Thymine infers the most stable nucleic base with the lower phonon energy. Thymine also has the highest average oscillator energy and the lower lattice energy. Moreover, the four nucleic acid bases have large band gap energies less than 5 eV with a semiconducting behavior. Guanine shows the smallest band gap and the highest Fermi level energy, whereas adenine elucidates the highest band gap energy.

  19. Determination of nucleosides in Cordyceps sinensis and Ganoderma lucidum by high performance liquid chromatography method

    Science.gov (United States)

    Khan, Masood Shah; Parveen, Rabea; Mishra, Kshipra; Tulsawani, Rajkumar; Ahmad, Sayeed

    2015-01-01

    Background: Nucleosides are supportive in the regulation and modulation of various physiological processes in body, they acts as precursors in nucleic acid synthesis, enhance immune response, help in absorption of iron and influence the metabolism of fatty acids. Cordyceps sinensis and Ganoderma lucidum are well-known for its use in traditional medicine of China, Nepal and India. They are rich in nucleosides such as adenine, adenosine, cordycepin, etc. Hence, a simple, economic and accurate high-performance liquid chromatography (HPLC) analytical method was proposed for determination of adenine and adenosine for the quality control of plants. Materials and Methods: Chromatographic experiments were conducted on YL9100 HPLC system (South Korea). Reversed-phase chromatography was performed on a C18 column with methanol and dihydrogen phosphate as the mobile phase in isocratic elution method at a flow rate of 1.0 mL/min. Detection was carried out at 254 nm, which gives a sharp peak of adenine and adenosine at a retention time of 6.53 ± 0.02 min and 12.41 ± 0.02, respectively. Results and Discussion: Linear regression analysis data for the calibration plot showed a good linear relationship between response and concentration in the range of 25–200 µg/mL for adenosine and 100–800 µg/mL for adenine with regression coefficient of 0.999 and 0.996, respectively. The adenine was found 0.16% and 0.71% w/w in G. lucidum and in C. sinensis, respectively, and adenosine was found to be 0.14% w/w in G. lucidum whereas absent in C. sinensis. Conclusion: The developed HPLC method for the quantification of adenosine and adenine can be used for the quality control and standardization of crude drug and for the different herbal formulations, in which adenine and adenosine are present as major constituents. The wide linearity range, sensitivity, accuracy, and simple mobile phase imply the method is suitable for routine quantification of adenosine and adenine with high precision and

  20. Studies on the Factors Affecting on Somatic Embryogenesis in Soybean

    Institute of Scientific and Technical Information of China (English)

    WANG Ping; WANG Gang; LU Wen-he; JI Jing; YANG Qing-kai

    2002-01-01

    The effects of the concentration of MS micro salts, 2,4-dichlorophenoxyacetic acid (2,4-D), 3-naphthalene acetic acid (NAA), proline and adenine on callus formation and somatic embryogenesis were investigated using orthogonal design with immature cotyledons of soybean. The results showed that the role of concentration of micro salts on frequency of callus formation and somatic embryogenesis were significant. MS medium supplemented with 2,4-D, NAA, proline and adenine could stimulate callus formation. The concentration of MS micro salts possessed obvious effects on somatic embryogenesis of soybean. The category and concentration of the hormone needed were different among genotypes when embryogenesis were induced.

  1. Selective killing of tumors deficient in methylthioadenosine phosphorylase: a novel strategy.

    Directory of Open Access Journals (Sweden)

    Martin Lubin

    Full Text Available BACKGROUND: The gene for methylthioadenosine phosphorylase (MTAP lies on 9p21, close to the gene CDKN2A that encodes the tumor suppressor proteins p16 and p14ARF. MTAP and CDKN2A are homozygously co-deleted, with a frequency of 35 to 70%, in lung and pancreatic cancer, glioblastoma, osteosarcoma, soft-tissue sarcoma, mesothelioma, and T-cell acute lymphoblastic leukemia. In normal cells, but not in tumor cells lacking MTAP, MTAP cleaves the natural substrate, 5'-deoxy-5'-methylthioadenosine (MTA, to adenine and 5-methylthioribose-1-phosphate (MTR-1-P, which are then converted to adenine nucleotides and methionine. This distinct difference between normal MTAP-positive cells and tumor MTAP-negative cells led to several proposals for therapy. We offer a novel strategy in which both MTA and a toxic adenine analog, such as 2,6-diaminopurine (DAP, 6-methylpurine (MeP, or 2-fluoroadenine (F-Ade, are administered. In MTAP-positive cells, abundant adenine, generated from supplied MTA, competitively blocks the conversion of an analog, by adenine phosphoribosyltransferase (APRT, to its active nucleotide form. In MTAP-negative tumor cells, the supplied MTA cannot generate adenine; hence conversion of the analog is not blocked. PRINCIPAL FINDINGS: We show that this combination treatment--adenine analog plus MTA--kills MTAP-negative A549 lung tumor cells, while MTAP-positive human fibroblasts (HF are protected. In co-cultures of the breast tumor cell line, MCF-7, and HF cells, MCF-7 is inhibited or killed, while HF cells proliferate robustly. 5-Fluorouracil (5-FU and 6-thioguanine (6-TG may also be used with our strategy. Though neither analog is activated by APRT, in MTAP-positive cells, adenine produced from supplied MTA blocks conversion of 5-FU and 6-TG to their toxic nucleotide forms by competing for 5-phosphoribosyl-1-pyrophosphate (PRPP. The combination of MTA with 5-FU or 6-TG, in the treatment of MTAP-negative tumors, may produce a significantly

  2. Biosynthesis of cytokinins.

    Science.gov (United States)

    Kakimoto, Tatsuo

    2003-06-01

    Cytokinins are adenine derivatives with an isoprenoid side chain and play an essential role in plant development. Plant isopentenyltransferases that catalyze the first and rate-limiting steps of cytokinin biosynthesis have recently been identified. Unlike bacterial enzymes, which catalyze the transfer of the isopentenyl moiety from dimethylallyldiphosphate (DMAPP) to the N(6) position of adenosine 5'-monophosphate (AMP), plant enzymes catalyze the transfer of the isopentenyl moiety from DMAPP preferentially to ATP and to ADP. The isopentenylated side chain is hydroxylated to form zeatin-type cytokinins. An alternative pathway, in which a hydroxylated side chain is directly added to the N(6) position of the adenine moiety, has also been suggested.

  3. Resolution of overlapping skin auto-fluorescence for development of non-invasive applications

    Science.gov (United States)

    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.

  4. Procedure for studying population genetic aspects of marine organisms using biochemical techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    .1.1.44); and general protein (PROT). Staining procedures ofenzymes and proteins (Menezes and Taniguchi, 1988) 1. NADP+ dependent Each mixture ofsubstrate staining solution is added with: Nicotinamide-adenine dinucleotide phosphate (NADP) 6mg Phenazine methosulphate... is added with: Nicotinamide-adenine dinucleotide (NAD) 6mg Phenazine methosulphate (PMS) 1mg 189 NBDBlDBTSponsored TraJnbrion T/UU)nOlrlJ, Genet/cs IUld Gene BanJdni ofCoastaJ and Marine BlorDO,m:es, elF£, MwnbaI --Nitro blue tetrazolium (NBT) of 1...

  5. Determination of nucleosides in Cordyceps sinensis and Ganoderma lucidum by high performance liquid chromatography method

    Directory of Open Access Journals (Sweden)

    Masood Shah Khan

    2015-01-01

    Full Text Available Background: Nucleosides are supportive in the regulation and modulation of various physiological processes in body, they acts as precursors in nucleic acid synthesis, enhance immune response, help in absorption of iron and influence the metabolism of fatty acids. Cordyceps sinensis and Ganoderma lucidum are well-known for its use in traditional medicine of China, Nepal and India. They are rich in nucleosides such as adenine, adenosine, cordycepin, etc. Hence, a simple, economic and accurate high-performance liquid chromatography (HPLC analytical method was proposed for determination of adenine and adenosine for the quality control of plants. Materials and Methods: Chromatographic experiments were conducted on YL9100 HPLC system (South Korea. Reversed-phase chromatography was performed on a C18 column with methanol and dihydrogen phosphate as the mobile phase in isocratic elution method at a flow rate of 1.0 mL/min. Detection was carried out at 254 nm, which gives a sharp peak of adenine and adenosine at a retention time of 6.53 ± 0.02 min and 12.41 ± 0.02, respectively. Results and Discussion: Linear regression analysis data for the calibration plot showed a good linear relationship between response and concentration in the range of 25–200 µg/mL for adenosine and 100–800 µg/mL for adenine with regression coefficient of 0.999 and 0.996, respectively. The adenine was found 0.16% and 0.71% w/w in G. lucidum and in C. sinensis, respectively, and adenosine was found to be 0.14% w/w in G. lucidum whereas absent in C. sinensis. Conclusion: The developed HPLC method for the quantification of adenosine and adenine can be used for the quality control and standardization of crude drug and for the different herbal formulations, in which adenine and adenosine are present as major constituents. The wide linearity range, sensitivity, accuracy, and simple mobile phase imply the method is suitable for routine quantification of adenosine and adenine with

  6. Characterization of Two-pore Channel 2 (TPCN2)-mediated Ca2+ Currents in Isolated Lysosomes*

    OpenAIRE

    Schieder, Michael; Rötzer, Katrin; Brüggemann, Andrea; Biel, Martin; Wahl-Schott, Christian A.

    2010-01-01

    Two-pore channels (TPCNs) have been proposed to form lysosomal Ca2+ release channels that are activated by nicotinic acid adenine dinucleotide phosphate. Here, we employ a glass chip-based method to record for the first time nicotinic acid adenine dinucleotide phosphate -dependent currents through a two-pore channel (TPCN2) from intact lysosomes. We show that TPCN2 is a highly selective Ca2+ channel that is regulated by intralysosomal pH. Using site-directed mutagenesis, we identify an amino ...

  7. Fluorescent Oligonucleotides Containing a 2-Ethynylfluorene-or 2-Ethynylfluorenone-labeled 2'-Deoxyguanosine Unit: Fluorescence Changes upon Duplex Formation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Ji; Hwang, Gil Tae [Kyungpook National University, Daegu (Korea, Republic of)

    2016-08-15

    Two new DNA probes bearing a fluorescent deoxyguanosine unit labeled with 2-ethynylfluorene (G{sup FL} )or 2-ethynylfluorenone (G{sup FO}) were synthesized and examined for their efficiency as quencher-free linear beacon probes. Oligodeoxynucleotides (ODNs) containing a G{sup FL} or G{sup FO} unit exhibit low thermal selectivity and few distinctive fluorescence changes upon duplex formation due to the syn conformation about the glycosidic bond. An exciplex emission was observed when the G{sup FL} unit of ODNs bearing adenine flanking bases was positioned opposite to the adenine nucleobases.

  8. Synthesis of 3-O-methyI-D-chiro-inositol adenosine analogues

    Institute of Scientific and Technical Information of China (English)

    Tianrong ZHAN; Huijuan YANG

    2008-01-01

    Using 3-O-methyl-D-chiro-inositol as starting material, the title compound 5 was synthesized by con-densation of adenine and methanesulfonate 3. Additionally, compounds 8 and 9 were prepared through the opening of the epoxide ring in 7 by adenine. The key intermediate 7 was obtained in good yield via an epoxida-tion from mono-mesylate 6. The process of opening of epoxide ring appeared to be regioselective in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

  9. Antioxidant effect of naturally occurring xanthines on the oxidative damage of DNA bases; Effet antioxydant de xanthines naturelles sur le dommage oxydant des bases de l`ADN

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, A.J.S.C.; Telo, J.P.; Pereira, H.F.; Patrocinio, P.F. [Instituto Superior Tecnico, Lisbon (Portugal); Dias, R.M.B. [Instituto Tecnologico e Nuclear, Sacavem codex (Portugal). Dept. de Quimica

    1999-01-01

    The repair of the oxidised radicals of adenine and guanosine by several naturally occurring xanthines was studied. Each pair of DNA purine/xanthine was made to react with the sulphate radical and the decrease of the concentration of both compounds was measured by HPLC as a function of irradiation time. The results show that xanthine efficiently prevents the oxidation of the two DNA purines. Theophylline and para-xanthine repair the oxidizes radical of adenine but not the one from guanosine. Theobromine and caffeine to do not show any protecting effect. An order of the oxidation potentials of all the purines studied is proposed. (authors) 10 refs.

  10. Hypothesis: intracellular acidification contributes to infertility in varicocele.

    Science.gov (United States)

    Ghabili, Kamyar; Shoja, Mohammadali M; Agutter, Paul S; Agarwal, Ashok

    2009-07-01

    We suggest that varicocele leads to male factor infertility by a mechanism involving underperfusion of the testis, a shortfall in glucose supply to the tissue, decreased flux through the pentose phosphate pathway, lowering of the reduced nicotinamide-adenine dinucleotide phosphate/oxidized nicotinamide-adenine dinucleotide phosphate ratio and the supply of glutathione to the antioxidant systems, increased levels of reactive oxygen species, peroxidation of spermatozoon membrane lipids, and the consequent generation of acidic degradation products and sequestering of spermine. Acidification of the seminal plasma impairs sperm motility and also inhibits most antioxidant enzymes, exacerbating the accumulation of reactive oxygen species and the resultant lowering of pH.

  11. Characterization of ricin toxin family members from Ricinus communis.

    Science.gov (United States)

    Leshin, Jonathan; Danielsen, Mark; Credle, Joel J; Weeks, Andrea; O'Connell, Kevin P; Dretchen, Kenneth

    2010-01-01

    Ricin inhibits translation by removal of a specific adenine from 28S RNA. The Ricinus communis genome encodes seven full-length ricin family members. All encoded proteins have the ability of hydrolyzing adenine in 28S rRNA. As expected, these proteins also inhibited an in vitro transcription/translation system. These data show that the ricin gene family contains at least seven members that have the ability to inhibit translation and that may contribute to the toxicity of R. communis. Copyright 2009 Elsevier Ltd. All rights reserved.

  12. The self assembly of thymine at Au(110)/liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Molina Contreras, J.R. [Departamento de Ingenieria Electrica y Electronica, Instituto Tecnologico de Aguascalientes, Mexico (Mexico); Smith, C.I.; Bowfield, A.; Weightman, P. [Physics Department, University of Liverpool (United Kingdom); Tillner, F. [Fachbereich Physik, Universitaet Konstanz (Germany)

    2012-06-15

    We show that thymine self-assembles into an ordered structure when adsorbed at a Au(110)/liquid interface. Reflection anisotropy spectroscopy (RAS) shows that as found for cytosine and adenine the adsorbed thymine molecules are oriented essentially vertically on the Au(110) surface with the molecule aligned along one of the principal axes of the Au(110) surface. Simulations of the RA spectra to an empirical model indicates that as found for adsorbed cytosine and adenine, thymine is aligned along the [1 anti 10] direction on the Au(110) surface. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Reversible electrochemistry of DNA on multi-walled carbon nanotube modified electrode

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Calf thymus DNA was electrochemically oxidized at a multi-walled carbon nanotube modified electrode. The potentials for DNA oxidation at pH 7.0 were 0.71 and 0.81 V versus SCE, corresponding to the oxidation of guanine and adenine residues,respectively. The initial 6e-oxidation of adenine, observed in the first scan, resulted a quasi-reversible 2e-redox process of the oxidation product in the following scans.(C) 2007 Hong Xia Luo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  14. Deciphering the four-letter code : The genetic basis of complex traits and common disease

    NARCIS (Netherlands)

    Pulit, S.L.

    2016-01-01

    Deoxyribonucleic acid (DNA) is made up of four bases: adenine (A), cytosine (C), guanine (G), and thymine (T). Assembled in a strategic fashion, these bases code for the unique genomes of all walks of life, from viruses, to rodents, to primates. The human genome, mapped completely for the first time

  15. Metal-ion catalyzed polymerization in the eutectic phase in water-ice

    DEFF Research Database (Denmark)

    Monnard, Pierre-Alain; Szostak, Jack W.

    2008-01-01

    The emergence of an RNA world requires among other processes the non-enzymatic, template-directed replication of genetic polymers such as RNA or related nucleic acids, possibly catalyzed by metal ions. The absence of uridilate derivative polymerization on adenine containing templates has been the...

  16. Metabolic footprint of Lactobacillus acidophilus NCFM at different pH

    DEFF Research Database (Denmark)

    Sulek, Karolina; Frandsen, Henrik Lauritz; Smedsgaard, Jørn

    2012-01-01

    increased the concentration of lactic acid, succinic acid, adenine and arginine in the medium. The metabolism of NCFM did not change significantly between pH 5 and 7, suggesting that other environmental factors than pH might have bigger impact on its colonization throughout the gastrointestinal tract....

  17. Ethylmalonic aciduria is associated with an amino acid variant of short chain acyl-coenzyme A dehydrogenase

    DEFF Research Database (Denmark)

    Corydon, M J; Gregersen, N; Lehnert, W

    1996-01-01

    metabolized by propionyl-CoA carboxylase to EMA. We have recently detected a guanine to adenine polymorphism in the SCAD gene at position 625 in the SCAD cDNA, which changes glycine 209 to serine (G209S). The variant allele (A625) is present in homozygous and in heterozygous form in 7 and 34.8% of the general...

  18. Purine Bases in Blood Plasma of Patients with Chronic Pulmonary Diseases

    Directory of Open Access Journals (Sweden)

    Larissa E. Muravluyova

    2012-09-01

    Full Text Available The article is focused on the study of purine bases and intermediates of purine catabolism in plasma of patients with chronic obstructive bronchitis and idiopathic interstitial pneumonia. Decrease of adenine and hypoxantine in plasma of patients with idiopathic interstitial pneumonia was registered. Increase of guanine in plasma of patients with chronic obstructive pulmonary disease was established.

  19. Role of BRCA2 in the Expressions of IRF9-regulated Genes in Human Breast Cells

    Science.gov (United States)

    2010-07-01

    interacting proteins . Yeast cells were also plated onto synthetic dropout medium lacking leucine, tryptophan, histidine, and adenine in the presence of 5...bromo-4-chloro-3-indolyl-ft-D-galactopyranoside (X-α-Gal; Clontech) to select for yeast containing stronger interacting proteins . The positive control

  20. An efficient protocol for regeneration and transformation of Symphyotrichum novi-belgii

    DEFF Research Database (Denmark)

    Mørk, Eline Kirk; Henriksen, Karin; Brinch-Pedersen, Henrik

    2012-01-01

    on Murashige and Skoog medium supplemented with 13.3 μM 6-benzylaminopurine, 4.5 μM thidiazuron, 50 mg l−1 adenine sulfate, and 10% coconut water. GUS- and polymerase chain reaction (PCR)-positive shoots from the cut ends of hypocotyls were produced via an intermediate callus stage. Presence of the GUS and npt...

  1. Optimization of Micropropagation Protocol for Goji Berry (Lycium barbarum L.

    Directory of Open Access Journals (Sweden)

    Alexandru Fira

    2016-11-01

    Full Text Available Micropropagation of Lycium barbarum cv. 'Ningxia N1' was achieved. The cultures were by initiated by axenical seed germination. The highest shoot proliferation was obtained on the MS media with 1.33 or 2.22 µM benzyl adenine, gelled with wheat starch as an agar alternative. The treatments with 2.22 µM benzyl adenine ensured proliferation rates superior to the ones with 1.33 μM benzyl adenine, but the latter provided longer and more robust shoots. Use of large microcuttings as an explant onto the multiplication media ensured higher in vitro explant survival, higher number of shoots regeneration and more vigorous plantlets. The microcuttings inserted vertically into the media yielded superior growth and multiplication as compared to the microcuttings placed horizontally. The non-rooted, elongated shoots from the treatment 1.33 μM benzyl adenine were either rooted in vitro on a hormone-free MS medium with starch or used for direct ex vitro rooting and acclimatization. The optimal number of microcuttings/vessel for in vitro rooting was 40 and the rooted plantlets were efficiently acclimatized ex vitro by three methods: float hydroculture in floating cell trays, floating perlite, and in Jiffy7 pellets.

  2. On-line measurements of oscillating mitochondrial membrane potential in glucose-fermenting Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    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 ...

  3. AcEST: DK947175 [AcEST

    Lifescience Database Archive (English)

    Full Text Available T_ECO24 Adenine phosphoribosyltransferase OS=Escheri... 31 3.1 sp|O95076|ALX3_HUMAN Homeobox protein aristales...s-like 3 OS=Homo ... 31 3.1 sp|O70137|ALX3_MOUSE Homeobox protein aristaless-like 3 OS=Mus m... 31 4.0 sp|

  4. Saccharomyces cerevisiae engineered for xylose metabolism requires gluconeogenesis and the oxidative branch of the pentose phosphate pathway for aerobic xylose assimilation

    Science.gov (United States)

    Saccharomyces strains engineered to ferment xylose using Scheffersomyces stipitis xylose reductase (XR) and xylitol dehydrogenase (XDH) genes appear to be limited by metabolic imbalances due to differing cofactor specificities of XR and XDH. The S. stipitis XR, which uses nicotinamide adenine dinucl...

  5. Sequence Classification: 894643 [

    Lifescience Database Archive (English)

    Full Text Available t position 58 in tRNAs, especially tRNAi-Met; first identified as a negative regulator of GCN4 expression; Gcd14p || http://www.ncbi.nlm.nih.gov/protein/6322336 ... ...t of tRNA (1-methyladenosine) methyltransferase, with Gcd10p, required for the modification of the adenine a

  6. Supramolecular hydrogen-bonding patterns in the N(9—H protonated and N(7—H tautomeric form of an N6-benzoyladenine salt: N6-benzoyladeninium nitrate

    Directory of Open Access Journals (Sweden)

    Ammasai Karthikeyan

    2016-02-01

    Full Text Available In the title molecular salt, C12H10N5O+·NO3−, the adenine unit has an N9-protonated N(7—H tautomeric form with non-protonated N1 and N3 atoms. The dihedral angle between the adenine ring system and the phenyl ring is 51.10 (10°. The typical intramolecular N7—H...O hydrogen bond with an S(7 graph-set motif is also present. The benzoyladeninium cations also form base pairs through N—H...O and C—H...N hydrogen bonds involving the Watson–Crick face of the adenine ring and the C and O atoms of the benzoyl ring of an adjacent cation, forming a supramolecular ribbon with R22(9 rings. Benzoyladeninum cations are also bridged by one of the oxygen atoms of the nitrate anion, which acts as a double acceptor, forming a pair of N—H...O hydrogen bonds to generate a second ribbon motif. These ribbons together with π–π stacking interactions between the phenyl ring and the five- and six-membered adenine rings of adjacent molecules generate a three-dimensional supramolecular architecture.

  7. Functioning of oxidative phosphorylation in liver mitochondria of high-fat diet fed rats

    NARCIS (Netherlands)

    Ciapaite, Jolita; Bakker, Stephan J. L.; Van Eikenhorst, Gerco; Wagner, Marijke J.; Teerlink, Tom; Schalkwijk, Casper G.; Fodor, Mariann; Ouwens, D. Margriet; Diamant, Michaela; Heine, Robert J.; Westerhoff, Hans V.; Krab, Klaas

    We proposed that inhibition of mitochondrial adenine nucleotide translocator (ANT) by long chain acyl-CoA (LCAC) underlies the mechanism associating obesity and type 2 diabetes. Here we test that after long-term exposure to a higb-fat diet (HFD): (i) there is no adaptation of the mitochondrial

  8. Mutant tristetraprolin: a potent inhibitor of malignant glioma cell growth

    Science.gov (United States)

    Malignant gliomas rely on the production of certain critical growth factors including VEGF, interleukin (IL)-6 and IL-8, to fuel rapid tumor growth, angiogenesis, and treatment resistance. Post-transcriptional regulation through adenine and uridine-rich elements of the 3' untranslated region is one ...

  9. Continuation of the Ecological Risk Assessment of Explosive Residues in Rodents, Reptiles, Amphibians, Fish and Invertebrates: An Integrated Laboratory and Field Investigation Related to Live-Fire Ranges in the Department of Defense

    Science.gov (United States)

    2008-08-01

    Both compounds elicited similar symptoms of toxicity including changes of skin color, body weight, development of seizures, liver and kidney necrosis...adult bullfrogs. Both compounds elicited similar symptoms of toxicity including changes of skin color, body weight, development of seizures, liver...substrate and substrate inhibition (Smith, 2000). Nicotinamide adenine dinucleotide phosphate (NADPH, reduced form) concentration was kept constant at

  10. Role of SIRT6 in Metabolic Reprogramming During Colorectal Carcinoma

    Science.gov (United States)

    2014-09-01

    pathway (PPP), which will support nucleotide biosynthesis and generate NADPH ( nicotinamide adenine dinucleotide phosphate) for reductive biosynthetic...tissue can account for the different cancer subtypes arising from that particular tissue. This is the case for skin tumors, medulloblastomas, breast...Sistonen P, Paetau A, Salovaara R, Herva R, Launonen V, Aaltonen LA. Germline mutations in FH predispose to dominantly inherited uterine fibroids, skin

  11. The Development of Therapeutic and Diagnostic Countermeasures to WMD by the Advanced Medical Countermeasures Consortium

    Science.gov (United States)

    2008-09-01

    Papirmeister, B., Brinkley, F.B., Johnson, J.B., 1985. Sulfurmus- tard lowers nicotinamide adenine dinucleotide concentrations in human skin grafted to nude...07pm Compositor Name: BMani 247 B. Skin ...274 1. Role of Skin Mast Cells in Vesicant Toxicity...................................................... 274 C. Eyes

  12. Niacin, poly(ADP-ribose) polymerase-1 and genomic stability

    NARCIS (Netherlands)

    Hageman, G.J.; Stierum, R.H.

    2001-01-01

    Nicotinic acid (NA) and nicotinamide (NAM), commonly called niacin, are the dietary precursors for NAD+ (nicotinamide adenine dinucleotide), which is required for DNA synthesis, as well as for the activity of the enzyme poly(ADP-ribose) polymerase-1 (PARP-1; EC 2.4.2.30) for which NAD+ is the sole s

  13. Innate Immunity Dysregulation in Myelodysplastic Syndromes

    Science.gov (United States)

    2013-10-01

    IL, interleukin; ITAM, immunoreceptor tyrosine-based activating motif; MDS, myelodysplastic syndromes; NADPH, nicotinamide adenine dinucleotide...differentiation, including macrophage, skin cells and neurons.19,2on In this study, we have shown that knock down of JMJ03 in BM C034 + cells of lower

  14. Summary Review of the Aquatic Toxicology of Munitions Constituents

    Science.gov (United States)

    2013-06-01

    phase II enzymes as well as the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome C reductase in TNT metabolism in eels...which also accounted for a small fraction of the total biomass (Table 6.8). The remaining tissues (muscles, skin , and subdermal fat) contained a

  15. Structural Characterisation of Proteins from the Peroxiredoxin Family

    Science.gov (United States)

    2014-01-01

    Bloch, W. and Werner, S. (2007) Peroxiredoxin 6 is require for blood vessel integrity in wounded skin . Journal of Cell Biology 179, 747-760. 72 P a g...Reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent formation and breakdown of hydrogen peroxide during mixed function oxidation

  16. Hawaii Energy and Environmental Technologies (HEET) Initiative

    Science.gov (United States)

    2007-11-01

    electrochemical oxidization of NADH (the reduced form of nicotinamide adenine dinucleotide), high-resolution surface imaging, porosity measurements, and...hollow-fiber support layer were assumed to be the same, i.e., kin, which is true for an integrally skinned membrane [19]. Addendum B-5 The convective heat

  17. Niacin-mediated Gene Expression and Role of NiaR as a Transcriptional Repressor of niaX, nadC, and pnuC in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Afzal, Muhammad; Kuipers, Oscar P; Shafeeq, Sulman

    2017-01-01

    NAD (Nicotinamide Adenine Dinucleotide) biosynthesis is vital for bacterial physiology and plays an important role in cellular metabolism. A naturally occurring vitamin B complex, niacin (nicotinic acid), is a precursor of coenzymes NAD and NADP. Here, we study the impact of niacin on global gene ex

  18. Design and synthesis of ATP-based nucleotide analogues and profiling of nucleotide-binding proteins

    NARCIS (Netherlands)

    Wolters, Justina. C.; Roelfes, Gerard; Poolman, Bert

    2011-01-01

    Two nucleotide-based probes were designed and synthesized in order to enrich samples for specific classes of proteins by affinity-based protein profiling. We focused on the profiling of adenine nucleotide-binding proteins. Two properties were considered in the design of the probes: the bait needs to

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

    Science.gov (United States)

    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,…

  20. Design and synthesis of ATP-based nucleotide analogues and profiling of nucleotide-binding proteins

    NARCIS (Netherlands)

    Wolters, Justina. C.; Roelfes, Gerard; Poolman, Bert

    Two nucleotide-based probes were designed and synthesized in order to enrich samples for specific classes of proteins by affinity-based protein profiling. We focused on the profiling of adenine nucleotide-binding proteins. Two properties were considered in the design of the probes: the bait needs to

  1. Sequence Classification: 893114 [

    Lifescience Database Archive (English)

    Full Text Available tRNA (1-methyladenosine) methyltransferase with Gcd14p, required for the modification of the adenine at position 58 in tRNAs, especi...ally tRNAi-Met; first identified as a negative regulator of GCN4 expression; Gcd10p || http://www.ncbi.nlm.nih.gov/protein/6324267 ...

  2. Dependence of surface-enhanced Raman scattering from Calf thymus DNA on anions

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Dependence of surface-enhanced Raman scattering (SERS) from Calf thymus DNA on anions is investigated.With the silver colloid,the bands at 732,960 and 1333 cm-1 for adenine (A),1466 cm-1 for deoxyribose,and 1652 cm-1 for the C=O group of thymine (T) are observably enhanced.With the presence of the Cl- or SO42- anions,the bands at 732 and 1326/1329 cm-1 for the symmetric stretching and skeletal vibrational modes of adenine (A) are dramatically enhanced,and the enhancement effect with the SO24- ion is more than that with the Cl- ion.The experimental results show that the DNA molecule can be adsorbed on the silver colloid particles through the C6N and N7 of adenine (A),the C=O of thymine (T) and deoxyribose.Moreover,the formed hydrogen bonding of the Cl- or S2O4- ions to the C6NH2 group of adenine (A) can induce larger C6N electronegativity,which is favor for the C6N/N7 cooperative adsorption on the (Ag)+n colloid particles.

  3. An improved red blood cell additive solution maintains 2,3-diphosphoglycerate and adenosine triphosphate levels by an enhancing effect on phosphofructokinase activity during cold storage

    NARCIS (Netherlands)

    P. Burger; H. Korsten; D. de Korte; E. Rombout; R. van Bruggen; A.J. Verhoeven

    2010-01-01

    BACKGROUND: Current additive solutions (ASs) for red blood cells (RBCs) do not maintain constant 2,3-diphosphoglycerate (DPG) and adenosine triphosphate (ATP) levels during cold storage We have previously shown that with a new AS called phosphate-adenine-glucose-guanosine-gluconate-mannitol (PAGGGM)

  4. Reduction Kinetics of 3-Hydroxybenzoate 6-Hydroxylase from Rhodococcus jostii RHA1

    NARCIS (Netherlands)

    Sucharitakul, J.; Wongnate, T.; Montersino, S.; Berkel, van W.J.H.; Chaiyen, P.

    2012-01-01

    3-Hydroxybenzoate 6-hydroxylase (3HB6H) from Rhodococcus jostii RHA1 is a nicotinamide adenine dinucleotide (NADH)-specific flavoprotein monooxygenase involved in microbial aromatic degradation. The enzyme catalyzes the para hydroxylation of 3-hydroxybenzoate (3-HB) to 2,5-dihydroxybenzoate (2,5-DHB

  5. Congenital hypertrophic cardiomyopathy, cataract, mitochondrial myopathy and defective oxidative phosphorylation in two siblings with Sengers-like syndrome.

    NARCIS (Netherlands)

    Morava, E.; Sengers, R.C.A.; Laak, H.J. ter; Heuvel, L.P.W.J. van den; Janssen, A.; Trijbels, J.M.F.; Cruysberg, H.; Boelen, C.; Smeitink, J.A.M.

    2004-01-01

    We describe two siblings with a Sengers-like syndrome, who presented with congenital hypertrophic cardiomyopathy, infantile cataract, mitochondrial myopathy, lactic acidosis and normal mental development. A mitochondrial adenine nucleotide translocator 1 (ANT1) defect was detected since the ANT1 pro

  6. Drug: D06767 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D:C01595], Adenine [CPD:C00147], Trigonelline [CPD:C01004], Linolenic acid [CPD:C06426 C06427] Benincasa cer...ifera [TAX:102210] Same as: E00137 Therapeutic category: 5100 Cucurbitaceae (cucumber family) Benincasa seed Major component: Trigo

  7. Mutations in the gene for methylenetetrahydrofolate reductase, homocysteine levels, and vitamin status in women with a history of preeclampsia

    NARCIS (Netherlands)

    Lachmeijer, AMA; Arngrimsson, R; Bastiaans, EJ; Pals, G; ten Kate, LP; de Vries, JIP; Kostense, PJ; Aarnoudse, JG; Dekker, GA

    OBJECTIVE: This study was undertaken to assess frequencies of the methylenetetrahydrofolate reductase gene mutations cytosine-to-thymine substitution at base 677 (C677T) and adenine-to-cytosine substitution at base 1298 (A1298C) and their interactions with homocysteine and vitamin levels among Dutch

  8. Ketogenesis in rat-liver mitochondria: Stimulation by palmityl-coenzyme A

    NARCIS (Netherlands)

    Vaartjes, W.J.; Lopes-Cardozo, M.; Bergh, S.G. van den

    1972-01-01

    It is well-known that the movement of adenine nucleotides (AdN) across the inner mitochondrial membrane is markedly decreased both by unsaturated and by saturated long-chain fatty acids. A similar effect is displayed by palmityl-CoA as demonstrated recently with isolated mitochondria of rat heart an

  9. Ketogenesis in rat-liver mitochondria: Stimulation by palmityl-coenzyme A

    NARCIS (Netherlands)

    Vaartjes, W.J.; Lopes-Cardozo, M.; Bergh, S.G. van den

    1972-01-01

    It is well-known that the movement of adenine nucleotides (AdN) across the inner mitochondrial membrane is markedly decreased both by unsaturated and by saturated long-chain fatty acids. A similar effect is displayed by palmityl-CoA as demonstrated recently with isolated mitochondria of rat heart an

  10. SIRT2 deacetylates FOXO3a in response to oxidative stress and caloric restriction

    Science.gov (United States)

    The sirtuin family of nicotinamide adenine dinucleotide-dependent (NAD) deacetylases plays an important role in aging and metabolic regulation. In yeast, the Sir2 gene and its homolog Hst2 independently mediate the action of caloric restriction on lifespan extension. The mammalian Sir2 ortholog, SIR...

  11. A click chemistry approach to pleuromutilin derivatives. Part 3

    DEFF Research Database (Denmark)

    Dreier, Ida; Hansen, Lykke H; Nielsen, Poul

    2014-01-01

    Five promising pleuromutilin derivatives from our former studies, all containing adenine on various linkers, were supplemented with two new compounds. The binding to Escherichia coli ribosomes was verified by extensive chemical footprinting analysis. The ability to inhibit bacterial growth was in...

  12. Biochemical characterization of putative adenylate dimethylallyltransferase and cytokinin dehydrogenase from Nostoc sp. PCC 7120

    NARCIS (Netherlands)

    Frébortová, Jitka; Greplová, Marta; Seidl, Michael F.; Heyl, Alexander; Frébort, Ivo

    2015-01-01

    Cytokinins, a class of phytohormones, are adenine derivatives common to many different organisms. In plants, these play a crucial role as regulators of plant development and the reaction to abiotic and biotic stress. Key enzymes in the cytokinin synthesis and degradation in modern land plants are

  13. Structure and stereochemistry of the base excision repair glycosylase MutY reveal a mechanism similar to retaining glycosidases.

    Science.gov (United States)

    Woods, Ryan D; O'Shea, Valerie L; Chu, Aurea; Cao, Sheng; Richards, Jody L; Horvath, Martin P; David, Sheila S

    2016-01-29

    MutY adenine glycosylases prevent DNA mutations by excising adenine from promutagenic 8-oxo-7,8-dihydroguanine (OG):A mismatches. Here, we describe structural features of the MutY active site bound to an azaribose transition state analog which indicate a catalytic role for Tyr126 and approach of the water nucleophile on the same side as the departing adenine base. The idea that Tyr126 participates in catalysis, recently predicted by modeling calculations, is strongly supported by mutagenesis and by seeing close contact between the hydroxyl group of this residue and the azaribose moiety of the transition state analog. NMR analysis of MutY methanolysis products corroborates a mechanism for adenine removal with retention of stereochemistry. Based on these results, we propose a revised mechanism for MutY that involves two nucleophilic displacement steps akin to the mechanisms accepted for 'retaining' O-glycosidases. This new-for-MutY yet familiar mechanism may also be operative in related base excision repair glycosylases and provides a critical framework for analysis of human MutY (MUTYH) variants associated with inherited colorectal cancer.

  14. [Hopping and superexchange mechanisms of charge transport to DNA].

    Science.gov (United States)

    Lakhno, V D; Sultanov, V B

    2003-01-01

    A theory for charge transport in nucleobase sequences was constructed in which the hole migration proceeds via hopping between guanines. Each hop over the adenine-thymine (A-T) bridge connecting neighboring guanines occurs by means of the superexchange mechanism. The experimental data and theoretical results for various types of nucleobase sequences are compared.

  15. Temperature dependence of electronic heat capacity in Holstein model

    CERN Document Server

    Fialko, N S; Lakhno, V D

    2015-01-01

    The dynamics of charge migration was modeled to calculate temperature dependencies of its thermodynamic equilibrium values such as energy and electronic heat capacity in homogeneous adenine fragments. The energy varies from nearly polaron one at T~0 to midpoint of the conductivity band at high temperatures. The peak on the graph of electronic heat capacity is observed at the polaron decay temperature.

  16. Huntington's Disease

    Science.gov (United States)

    ... seizures. More than 30,000 Americans have HD. Huntington’s disease is caused by a mutation in the gene for a protein called huntingtin. The defect causes the cytosine, adenine, and guanine (CAG) building blocks of DNA to repeat many more ...

  17. Day-night variations of adenosine and its metabolizing enzymes in the brain cortex of the rat--possible physiological significance for the energetic homeostasis and the sleep-wake cycle.

    Science.gov (United States)

    Chagoya de Sánchez, V; Hernández Múñoz, R; Suárez, J; Vidrio, S; Yáñez, L; Díaz Múñoz, M

    1993-05-28

    The role of adenosine as a metabolic regulator of physiological processes in the brain was studied by measuring its concentrations and the activity of adenosine-metabolizing enzymes: 5'-nucleotidase, S-adenosylhomocysteine hydrolase, adenosine deaminase and adenosine kinase in the cerebral cortex of the rat. Other purine compounds, such as, inosine, hypoxanthine and adenine nucleotides were also studied. The purines' pattern was bimodal with high levels of adenosine, inosine and hypoxanthine during the light period reaching their peak at 12.00 h, 08.00 h and 16.00 h, respectively, and small increments during the night between 02.00 h and 04.00 h. The enzymatic activities showed, in general, an unimodal profile with low activity during the day and high activities at night. The adenine nucleotide profile showed a significant diminution between 12.00 h and 24.00 h. The high adenosine level during the day might be due to a diminution of adenine nucleotide and to the low activity of adenosine-metabolizing enzymes, suggesting an accumulation of the nucleoside. The night increase, although of less magnitude, is simultaneous to high activity of adenosine-metabolizing enzymes and could be due to an increased formation of the nucleoside. The present data and the findings from other authors strongly suggest that adenosine in the brain cortex of the rat can participate at least in two physiological processes: regulation of the sleep-wake cycle and replenishment of the adenine nucleotide pool.

  18. Laboratory Evaluation of Adenylate Energy Charge as a Test for Stress in Mytilus edulis and Nephtys incisa Treated with Dredged Material.

    Science.gov (United States)

    1985-02-01

    concentrations of three adenine nucleotides, adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP), which are...that all trace metals but iron were eliminated and the concentration of the vitamins thiamin and B12 were doubled. Adenylate Extraction 13. The adductor

  19. KIDNEY AND URINARY TRACT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Objective: To study the relationship between insulin-like growth factor-1 (IGF-1), basic fibroblast growth factor (bFGF) and the pathological changes in uric acid nephropathy. Methods: In the pathological progress of 30 uric acid nephropathy rats induced by adenine, the expression of IGF-lmRNA,

  20. Direct measurement of interaction forces between a platinum dichloride complex and DNA molecules.

    Science.gov (United States)

    Muramatsu, Hiroshi; Shimada, Shogo; Okada, Tomoko

    2017-06-29

    The interaction forces between a platinum dichloride complex and DNA molecules have been studied using atomic force microscopy (AFM). The platinum dichloride complex, di-dimethylsulfoxide-dichloroplatinum (II) (Pt(DMSO)2Cl2), was immobilized on an AFM probe by coordinating the platinum to two amino groups to form a complex similar to Pt(en)Cl2, which is structurally similar to cisplatin. The retraction forces were measured between the platinum complex and DNA molecules immobilized on mica plates using force curve measurements. The histogram of the retraction force for λ-DNA showed several peaks; the unit retraction force was estimated to be 130 pN for a pulling rate of 60 nm/s. The retraction forces were also measured separately for four single-base DNA oligomers (adenine, guanine, thymine, and cytosine). Retraction forces were frequently observed in the force curves for the DNA oligomers of guanine and adenine. For the guanine DNA oligomer, the most frequent retraction force was slightly lower than but very similar to the retraction force for λ-DNA. A higher retraction force was obtained for the adenine DNA oligomer than for the guanine oligomer. This result is consistent with a higher retraction activation energy of adenine with the Pt complex being than that of guanine because the kinetic rate constant for retraction correlates to exp(FΔx - ΔE) where ΔE is an activation energy, F is an applied force, and Δx is a displacement of distance.